1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/third_party/libevent/evdns.c Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,4655 @@
1.4 +/* Copyright 2006-2007 Niels Provos
1.5 + * Copyright 2007-2012 Nick Mathewson and Niels Provos
1.6 + *
1.7 + * Redistribution and use in source and binary forms, with or without
1.8 + * modification, are permitted provided that the following conditions
1.9 + * are met:
1.10 + * 1. Redistributions of source code must retain the above copyright
1.11 + * notice, this list of conditions and the following disclaimer.
1.12 + * 2. Redistributions in binary form must reproduce the above copyright
1.13 + * notice, this list of conditions and the following disclaimer in the
1.14 + * documentation and/or other materials provided with the distribution.
1.15 + * 3. The name of the author may not be used to endorse or promote products
1.16 + * derived from this software without specific prior written permission.
1.17 + *
1.18 + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
1.19 + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1.20 + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
1.21 + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
1.22 + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
1.23 + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
1.24 + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
1.25 + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
1.26 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
1.27 + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.28 + */
1.29 +
1.30 +/* Based on software by Adam Langly. Adam's original message:
1.31 + *
1.32 + * Async DNS Library
1.33 + * Adam Langley <agl@imperialviolet.org>
1.34 + * http://www.imperialviolet.org/eventdns.html
1.35 + * Public Domain code
1.36 + *
1.37 + * This software is Public Domain. To view a copy of the public domain dedication,
1.38 + * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to
1.39 + * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
1.40 + *
1.41 + * I ask and expect, but do not require, that all derivative works contain an
1.42 + * attribution similar to:
1.43 + * Parts developed by Adam Langley <agl@imperialviolet.org>
1.44 + *
1.45 + * You may wish to replace the word "Parts" with something else depending on
1.46 + * the amount of original code.
1.47 + *
1.48 + * (Derivative works does not include programs which link against, run or include
1.49 + * the source verbatim in their source distributions)
1.50 + *
1.51 + * Version: 0.1b
1.52 + */
1.53 +
1.54 +#include <sys/types.h>
1.55 +#include "event2/event-config.h"
1.56 +
1.57 +#ifndef _FORTIFY_SOURCE
1.58 +#define _FORTIFY_SOURCE 3
1.59 +#endif
1.60 +
1.61 +#include <string.h>
1.62 +#include <fcntl.h>
1.63 +#ifdef _EVENT_HAVE_SYS_TIME_H
1.64 +#include <sys/time.h>
1.65 +#endif
1.66 +#ifdef _EVENT_HAVE_STDINT_H
1.67 +#include <stdint.h>
1.68 +#endif
1.69 +#include <stdlib.h>
1.70 +#include <string.h>
1.71 +#include <errno.h>
1.72 +#ifdef _EVENT_HAVE_UNISTD_H
1.73 +#include <unistd.h>
1.74 +#endif
1.75 +#include <limits.h>
1.76 +#include <sys/stat.h>
1.77 +#include <stdio.h>
1.78 +#include <stdarg.h>
1.79 +#ifdef WIN32
1.80 +#include <winsock2.h>
1.81 +#include <ws2tcpip.h>
1.82 +#ifndef _WIN32_IE
1.83 +#define _WIN32_IE 0x400
1.84 +#endif
1.85 +#include <shlobj.h>
1.86 +#endif
1.87 +
1.88 +#include "event2/dns.h"
1.89 +#include "event2/dns_struct.h"
1.90 +#include "event2/dns_compat.h"
1.91 +#include "event2/util.h"
1.92 +#include "event2/event.h"
1.93 +#include "event2/event_struct.h"
1.94 +#include "event2/thread.h"
1.95 +
1.96 +#include "event2/bufferevent.h"
1.97 +#include "event2/bufferevent_struct.h"
1.98 +#include "bufferevent-internal.h"
1.99 +
1.100 +#include "defer-internal.h"
1.101 +#include "log-internal.h"
1.102 +#include "mm-internal.h"
1.103 +#include "strlcpy-internal.h"
1.104 +#include "ipv6-internal.h"
1.105 +#include "util-internal.h"
1.106 +#include "evthread-internal.h"
1.107 +#ifdef WIN32
1.108 +#include <ctype.h>
1.109 +#include <winsock2.h>
1.110 +#include <windows.h>
1.111 +#include <iphlpapi.h>
1.112 +#include <io.h>
1.113 +#else
1.114 +#include <sys/socket.h>
1.115 +#include <netinet/in.h>
1.116 +#include <arpa/inet.h>
1.117 +#endif
1.118 +
1.119 +#ifdef _EVENT_HAVE_NETINET_IN6_H
1.120 +#include <netinet/in6.h>
1.121 +#endif
1.122 +
1.123 +#define EVDNS_LOG_DEBUG 0
1.124 +#define EVDNS_LOG_WARN 1
1.125 +#define EVDNS_LOG_MSG 2
1.126 +
1.127 +#ifndef HOST_NAME_MAX
1.128 +#define HOST_NAME_MAX 255
1.129 +#endif
1.130 +
1.131 +#include <stdio.h>
1.132 +
1.133 +#undef MIN
1.134 +#define MIN(a,b) ((a)<(b)?(a):(b))
1.135 +
1.136 +#define ASSERT_VALID_REQUEST(req) \
1.137 + EVUTIL_ASSERT((req)->handle && (req)->handle->current_req == (req))
1.138 +
1.139 +#define u64 ev_uint64_t
1.140 +#define u32 ev_uint32_t
1.141 +#define u16 ev_uint16_t
1.142 +#define u8 ev_uint8_t
1.143 +
1.144 +/* maximum number of addresses from a single packet */
1.145 +/* that we bother recording */
1.146 +#define MAX_V4_ADDRS 32
1.147 +#define MAX_V6_ADDRS 32
1.148 +
1.149 +
1.150 +#define TYPE_A EVDNS_TYPE_A
1.151 +#define TYPE_CNAME 5
1.152 +#define TYPE_PTR EVDNS_TYPE_PTR
1.153 +#define TYPE_SOA EVDNS_TYPE_SOA
1.154 +#define TYPE_AAAA EVDNS_TYPE_AAAA
1.155 +
1.156 +#define CLASS_INET EVDNS_CLASS_INET
1.157 +
1.158 +/* Persistent handle. We keep this separate from 'struct request' since we
1.159 + * need some object to last for as long as an evdns_request is outstanding so
1.160 + * that it can be canceled, whereas a search request can lead to multiple
1.161 + * 'struct request' instances being created over its lifetime. */
1.162 +struct evdns_request {
1.163 + struct request *current_req;
1.164 + struct evdns_base *base;
1.165 +
1.166 + int pending_cb; /* Waiting for its callback to be invoked; not
1.167 + * owned by event base any more. */
1.168 +
1.169 + /* elements used by the searching code */
1.170 + int search_index;
1.171 + struct search_state *search_state;
1.172 + char *search_origname; /* needs to be free()ed */
1.173 + int search_flags;
1.174 +};
1.175 +
1.176 +struct request {
1.177 + u8 *request; /* the dns packet data */
1.178 + u8 request_type; /* TYPE_PTR or TYPE_A or TYPE_AAAA */
1.179 + unsigned int request_len;
1.180 + int reissue_count;
1.181 + int tx_count; /* the number of times that this packet has been sent */
1.182 + void *user_pointer; /* the pointer given to us for this request */
1.183 + evdns_callback_type user_callback;
1.184 + struct nameserver *ns; /* the server which we last sent it */
1.185 +
1.186 + /* these objects are kept in a circular list */
1.187 + /* XXX We could turn this into a CIRCLEQ. */
1.188 + struct request *next, *prev;
1.189 +
1.190 + struct event timeout_event;
1.191 +
1.192 + u16 trans_id; /* the transaction id */
1.193 + unsigned request_appended :1; /* true if the request pointer is data which follows this struct */
1.194 + unsigned transmit_me :1; /* needs to be transmitted */
1.195 +
1.196 + /* XXXX This is a horrible hack. */
1.197 + char **put_cname_in_ptr; /* store the cname here if we get one. */
1.198 +
1.199 + struct evdns_base *base;
1.200 +
1.201 + struct evdns_request *handle;
1.202 +};
1.203 +
1.204 +struct reply {
1.205 + unsigned int type;
1.206 + unsigned int have_answer : 1;
1.207 + union {
1.208 + struct {
1.209 + u32 addrcount;
1.210 + u32 addresses[MAX_V4_ADDRS];
1.211 + } a;
1.212 + struct {
1.213 + u32 addrcount;
1.214 + struct in6_addr addresses[MAX_V6_ADDRS];
1.215 + } aaaa;
1.216 + struct {
1.217 + char name[HOST_NAME_MAX];
1.218 + } ptr;
1.219 + } data;
1.220 +};
1.221 +
1.222 +struct nameserver {
1.223 + evutil_socket_t socket; /* a connected UDP socket */
1.224 + struct sockaddr_storage address;
1.225 + ev_socklen_t addrlen;
1.226 + int failed_times; /* number of times which we have given this server a chance */
1.227 + int timedout; /* number of times in a row a request has timed out */
1.228 + struct event event;
1.229 + /* these objects are kept in a circular list */
1.230 + struct nameserver *next, *prev;
1.231 + struct event timeout_event; /* used to keep the timeout for */
1.232 + /* when we next probe this server. */
1.233 + /* Valid if state == 0 */
1.234 + /* Outstanding probe request for this nameserver, if any */
1.235 + struct evdns_request *probe_request;
1.236 + char state; /* zero if we think that this server is down */
1.237 + char choked; /* true if we have an EAGAIN from this server's socket */
1.238 + char write_waiting; /* true if we are waiting for EV_WRITE events */
1.239 + struct evdns_base *base;
1.240 +};
1.241 +
1.242 +
1.243 +/* Represents a local port where we're listening for DNS requests. Right now, */
1.244 +/* only UDP is supported. */
1.245 +struct evdns_server_port {
1.246 + evutil_socket_t socket; /* socket we use to read queries and write replies. */
1.247 + int refcnt; /* reference count. */
1.248 + char choked; /* Are we currently blocked from writing? */
1.249 + char closing; /* Are we trying to close this port, pending writes? */
1.250 + evdns_request_callback_fn_type user_callback; /* Fn to handle requests */
1.251 + void *user_data; /* Opaque pointer passed to user_callback */
1.252 + struct event event; /* Read/write event */
1.253 + /* circular list of replies that we want to write. */
1.254 + struct server_request *pending_replies;
1.255 + struct event_base *event_base;
1.256 +
1.257 +#ifndef _EVENT_DISABLE_THREAD_SUPPORT
1.258 + void *lock;
1.259 +#endif
1.260 +};
1.261 +
1.262 +/* Represents part of a reply being built. (That is, a single RR.) */
1.263 +struct server_reply_item {
1.264 + struct server_reply_item *next; /* next item in sequence. */
1.265 + char *name; /* name part of the RR */
1.266 + u16 type; /* The RR type */
1.267 + u16 class; /* The RR class (usually CLASS_INET) */
1.268 + u32 ttl; /* The RR TTL */
1.269 + char is_name; /* True iff data is a label */
1.270 + u16 datalen; /* Length of data; -1 if data is a label */
1.271 + void *data; /* The contents of the RR */
1.272 +};
1.273 +
1.274 +/* Represents a request that we've received as a DNS server, and holds */
1.275 +/* the components of the reply as we're constructing it. */
1.276 +struct server_request {
1.277 + /* Pointers to the next and previous entries on the list of replies */
1.278 + /* that we're waiting to write. Only set if we have tried to respond */
1.279 + /* and gotten EAGAIN. */
1.280 + struct server_request *next_pending;
1.281 + struct server_request *prev_pending;
1.282 +
1.283 + u16 trans_id; /* Transaction id. */
1.284 + struct evdns_server_port *port; /* Which port received this request on? */
1.285 + struct sockaddr_storage addr; /* Where to send the response */
1.286 + ev_socklen_t addrlen; /* length of addr */
1.287 +
1.288 + int n_answer; /* how many answer RRs have been set? */
1.289 + int n_authority; /* how many authority RRs have been set? */
1.290 + int n_additional; /* how many additional RRs have been set? */
1.291 +
1.292 + struct server_reply_item *answer; /* linked list of answer RRs */
1.293 + struct server_reply_item *authority; /* linked list of authority RRs */
1.294 + struct server_reply_item *additional; /* linked list of additional RRs */
1.295 +
1.296 + /* Constructed response. Only set once we're ready to send a reply. */
1.297 + /* Once this is set, the RR fields are cleared, and no more should be set. */
1.298 + char *response;
1.299 + size_t response_len;
1.300 +
1.301 + /* Caller-visible fields: flags, questions. */
1.302 + struct evdns_server_request base;
1.303 +};
1.304 +
1.305 +struct evdns_base {
1.306 + /* An array of n_req_heads circular lists for inflight requests.
1.307 + * Each inflight request req is in req_heads[req->trans_id % n_req_heads].
1.308 + */
1.309 + struct request **req_heads;
1.310 + /* A circular list of requests that we're waiting to send, but haven't
1.311 + * sent yet because there are too many requests inflight */
1.312 + struct request *req_waiting_head;
1.313 + /* A circular list of nameservers. */
1.314 + struct nameserver *server_head;
1.315 + int n_req_heads;
1.316 +
1.317 + struct event_base *event_base;
1.318 +
1.319 + /* The number of good nameservers that we have */
1.320 + int global_good_nameservers;
1.321 +
1.322 + /* inflight requests are contained in the req_head list */
1.323 + /* and are actually going out across the network */
1.324 + int global_requests_inflight;
1.325 + /* requests which aren't inflight are in the waiting list */
1.326 + /* and are counted here */
1.327 + int global_requests_waiting;
1.328 +
1.329 + int global_max_requests_inflight;
1.330 +
1.331 + struct timeval global_timeout; /* 5 seconds by default */
1.332 + int global_max_reissues; /* a reissue occurs when we get some errors from the server */
1.333 + int global_max_retransmits; /* number of times we'll retransmit a request which timed out */
1.334 + /* number of timeouts in a row before we consider this server to be down */
1.335 + int global_max_nameserver_timeout;
1.336 + /* true iff we will use the 0x20 hack to prevent poisoning attacks. */
1.337 + int global_randomize_case;
1.338 +
1.339 + /* The first time that a nameserver fails, how long do we wait before
1.340 + * probing to see if it has returned? */
1.341 + struct timeval global_nameserver_probe_initial_timeout;
1.342 +
1.343 + /** Port to bind to for outgoing DNS packets. */
1.344 + struct sockaddr_storage global_outgoing_address;
1.345 + /** ev_socklen_t for global_outgoing_address. 0 if it isn't set. */
1.346 + ev_socklen_t global_outgoing_addrlen;
1.347 +
1.348 + struct timeval global_getaddrinfo_allow_skew;
1.349 +
1.350 + int getaddrinfo_ipv4_timeouts;
1.351 + int getaddrinfo_ipv6_timeouts;
1.352 + int getaddrinfo_ipv4_answered;
1.353 + int getaddrinfo_ipv6_answered;
1.354 +
1.355 + struct search_state *global_search_state;
1.356 +
1.357 + TAILQ_HEAD(hosts_list, hosts_entry) hostsdb;
1.358 +
1.359 +#ifndef _EVENT_DISABLE_THREAD_SUPPORT
1.360 + void *lock;
1.361 +#endif
1.362 +};
1.363 +
1.364 +struct hosts_entry {
1.365 + TAILQ_ENTRY(hosts_entry) next;
1.366 + union {
1.367 + struct sockaddr sa;
1.368 + struct sockaddr_in sin;
1.369 + struct sockaddr_in6 sin6;
1.370 + } addr;
1.371 + int addrlen;
1.372 + char hostname[1];
1.373 +};
1.374 +
1.375 +static struct evdns_base *current_base = NULL;
1.376 +
1.377 +struct evdns_base *
1.378 +evdns_get_global_base(void)
1.379 +{
1.380 + return current_base;
1.381 +}
1.382 +
1.383 +/* Given a pointer to an evdns_server_request, get the corresponding */
1.384 +/* server_request. */
1.385 +#define TO_SERVER_REQUEST(base_ptr) \
1.386 + ((struct server_request*) \
1.387 + (((char*)(base_ptr) - evutil_offsetof(struct server_request, base))))
1.388 +
1.389 +#define REQ_HEAD(base, id) ((base)->req_heads[id % (base)->n_req_heads])
1.390 +
1.391 +static struct nameserver *nameserver_pick(struct evdns_base *base);
1.392 +static void evdns_request_insert(struct request *req, struct request **head);
1.393 +static void evdns_request_remove(struct request *req, struct request **head);
1.394 +static void nameserver_ready_callback(evutil_socket_t fd, short events, void *arg);
1.395 +static int evdns_transmit(struct evdns_base *base);
1.396 +static int evdns_request_transmit(struct request *req);
1.397 +static void nameserver_send_probe(struct nameserver *const ns);
1.398 +static void search_request_finished(struct evdns_request *const);
1.399 +static int search_try_next(struct evdns_request *const req);
1.400 +static struct request *search_request_new(struct evdns_base *base, struct evdns_request *handle, int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg);
1.401 +static void evdns_requests_pump_waiting_queue(struct evdns_base *base);
1.402 +static u16 transaction_id_pick(struct evdns_base *base);
1.403 +static struct request *request_new(struct evdns_base *base, struct evdns_request *handle, int type, const char *name, int flags, evdns_callback_type callback, void *ptr);
1.404 +static void request_submit(struct request *const req);
1.405 +
1.406 +static int server_request_free(struct server_request *req);
1.407 +static void server_request_free_answers(struct server_request *req);
1.408 +static void server_port_free(struct evdns_server_port *port);
1.409 +static void server_port_ready_callback(evutil_socket_t fd, short events, void *arg);
1.410 +static int evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename);
1.411 +static int evdns_base_set_option_impl(struct evdns_base *base,
1.412 + const char *option, const char *val, int flags);
1.413 +static void evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests);
1.414 +
1.415 +static int strtoint(const char *const str);
1.416 +
1.417 +#ifdef _EVENT_DISABLE_THREAD_SUPPORT
1.418 +#define EVDNS_LOCK(base) _EVUTIL_NIL_STMT
1.419 +#define EVDNS_UNLOCK(base) _EVUTIL_NIL_STMT
1.420 +#define ASSERT_LOCKED(base) _EVUTIL_NIL_STMT
1.421 +#else
1.422 +#define EVDNS_LOCK(base) \
1.423 + EVLOCK_LOCK((base)->lock, 0)
1.424 +#define EVDNS_UNLOCK(base) \
1.425 + EVLOCK_UNLOCK((base)->lock, 0)
1.426 +#define ASSERT_LOCKED(base) \
1.427 + EVLOCK_ASSERT_LOCKED((base)->lock)
1.428 +#endif
1.429 +
1.430 +static void
1.431 +default_evdns_log_fn(int warning, const char *buf)
1.432 +{
1.433 + if (warning == EVDNS_LOG_WARN)
1.434 + event_warnx("[evdns] %s", buf);
1.435 + else if (warning == EVDNS_LOG_MSG)
1.436 + event_msgx("[evdns] %s", buf);
1.437 + else
1.438 + event_debug(("[evdns] %s", buf));
1.439 +}
1.440 +
1.441 +static evdns_debug_log_fn_type evdns_log_fn = NULL;
1.442 +
1.443 +void
1.444 +evdns_set_log_fn(evdns_debug_log_fn_type fn)
1.445 +{
1.446 + evdns_log_fn = fn;
1.447 +}
1.448 +
1.449 +#ifdef __GNUC__
1.450 +#define EVDNS_LOG_CHECK __attribute__ ((format(printf, 2, 3)))
1.451 +#else
1.452 +#define EVDNS_LOG_CHECK
1.453 +#endif
1.454 +
1.455 +static void _evdns_log(int warn, const char *fmt, ...) EVDNS_LOG_CHECK;
1.456 +static void
1.457 +_evdns_log(int warn, const char *fmt, ...)
1.458 +{
1.459 + va_list args;
1.460 + char buf[512];
1.461 + if (!evdns_log_fn)
1.462 + return;
1.463 + va_start(args,fmt);
1.464 + evutil_vsnprintf(buf, sizeof(buf), fmt, args);
1.465 + va_end(args);
1.466 + if (evdns_log_fn) {
1.467 + if (warn == EVDNS_LOG_MSG)
1.468 + warn = EVDNS_LOG_WARN;
1.469 + evdns_log_fn(warn, buf);
1.470 + } else {
1.471 + default_evdns_log_fn(warn, buf);
1.472 + }
1.473 +
1.474 +}
1.475 +
1.476 +#define log _evdns_log
1.477 +
1.478 +/* This walks the list of inflight requests to find the */
1.479 +/* one with a matching transaction id. Returns NULL on */
1.480 +/* failure */
1.481 +static struct request *
1.482 +request_find_from_trans_id(struct evdns_base *base, u16 trans_id) {
1.483 + struct request *req = REQ_HEAD(base, trans_id);
1.484 + struct request *const started_at = req;
1.485 +
1.486 + ASSERT_LOCKED(base);
1.487 +
1.488 + if (req) {
1.489 + do {
1.490 + if (req->trans_id == trans_id) return req;
1.491 + req = req->next;
1.492 + } while (req != started_at);
1.493 + }
1.494 +
1.495 + return NULL;
1.496 +}
1.497 +
1.498 +/* a libevent callback function which is called when a nameserver */
1.499 +/* has gone down and we want to test if it has came back to life yet */
1.500 +static void
1.501 +nameserver_prod_callback(evutil_socket_t fd, short events, void *arg) {
1.502 + struct nameserver *const ns = (struct nameserver *) arg;
1.503 + (void)fd;
1.504 + (void)events;
1.505 +
1.506 + EVDNS_LOCK(ns->base);
1.507 + nameserver_send_probe(ns);
1.508 + EVDNS_UNLOCK(ns->base);
1.509 +}
1.510 +
1.511 +/* a libevent callback which is called when a nameserver probe (to see if */
1.512 +/* it has come back to life) times out. We increment the count of failed_times */
1.513 +/* and wait longer to send the next probe packet. */
1.514 +static void
1.515 +nameserver_probe_failed(struct nameserver *const ns) {
1.516 + struct timeval timeout;
1.517 + int i;
1.518 +
1.519 + ASSERT_LOCKED(ns->base);
1.520 + (void) evtimer_del(&ns->timeout_event);
1.521 + if (ns->state == 1) {
1.522 + /* This can happen if the nameserver acts in a way which makes us mark */
1.523 + /* it as bad and then starts sending good replies. */
1.524 + return;
1.525 + }
1.526 +
1.527 +#define MAX_PROBE_TIMEOUT 3600
1.528 +#define TIMEOUT_BACKOFF_FACTOR 3
1.529 +
1.530 + memcpy(&timeout, &ns->base->global_nameserver_probe_initial_timeout,
1.531 + sizeof(struct timeval));
1.532 + for (i=ns->failed_times; i > 0 && timeout.tv_sec < MAX_PROBE_TIMEOUT; --i) {
1.533 + timeout.tv_sec *= TIMEOUT_BACKOFF_FACTOR;
1.534 + timeout.tv_usec *= TIMEOUT_BACKOFF_FACTOR;
1.535 + if (timeout.tv_usec > 1000000) {
1.536 + timeout.tv_sec += timeout.tv_usec / 1000000;
1.537 + timeout.tv_usec %= 1000000;
1.538 + }
1.539 + }
1.540 + if (timeout.tv_sec > MAX_PROBE_TIMEOUT) {
1.541 + timeout.tv_sec = MAX_PROBE_TIMEOUT;
1.542 + timeout.tv_usec = 0;
1.543 + }
1.544 +
1.545 + ns->failed_times++;
1.546 +
1.547 + if (evtimer_add(&ns->timeout_event, &timeout) < 0) {
1.548 + char addrbuf[128];
1.549 + log(EVDNS_LOG_WARN,
1.550 + "Error from libevent when adding timer event for %s",
1.551 + evutil_format_sockaddr_port(
1.552 + (struct sockaddr *)&ns->address,
1.553 + addrbuf, sizeof(addrbuf)));
1.554 + }
1.555 +}
1.556 +
1.557 +/* called when a nameserver has been deemed to have failed. For example, too */
1.558 +/* many packets have timed out etc */
1.559 +static void
1.560 +nameserver_failed(struct nameserver *const ns, const char *msg) {
1.561 + struct request *req, *started_at;
1.562 + struct evdns_base *base = ns->base;
1.563 + int i;
1.564 + char addrbuf[128];
1.565 +
1.566 + ASSERT_LOCKED(base);
1.567 + /* if this nameserver has already been marked as failed */
1.568 + /* then don't do anything */
1.569 + if (!ns->state) return;
1.570 +
1.571 + log(EVDNS_LOG_MSG, "Nameserver %s has failed: %s",
1.572 + evutil_format_sockaddr_port(
1.573 + (struct sockaddr *)&ns->address,
1.574 + addrbuf, sizeof(addrbuf)),
1.575 + msg);
1.576 +
1.577 + base->global_good_nameservers--;
1.578 + EVUTIL_ASSERT(base->global_good_nameservers >= 0);
1.579 + if (base->global_good_nameservers == 0) {
1.580 + log(EVDNS_LOG_MSG, "All nameservers have failed");
1.581 + }
1.582 +
1.583 + ns->state = 0;
1.584 + ns->failed_times = 1;
1.585 +
1.586 + if (evtimer_add(&ns->timeout_event,
1.587 + &base->global_nameserver_probe_initial_timeout) < 0) {
1.588 + log(EVDNS_LOG_WARN,
1.589 + "Error from libevent when adding timer event for %s",
1.590 + evutil_format_sockaddr_port(
1.591 + (struct sockaddr *)&ns->address,
1.592 + addrbuf, sizeof(addrbuf)));
1.593 + /* ???? Do more? */
1.594 + }
1.595 +
1.596 + /* walk the list of inflight requests to see if any can be reassigned to */
1.597 + /* a different server. Requests in the waiting queue don't have a */
1.598 + /* nameserver assigned yet */
1.599 +
1.600 + /* if we don't have *any* good nameservers then there's no point */
1.601 + /* trying to reassign requests to one */
1.602 + if (!base->global_good_nameservers) return;
1.603 +
1.604 + for (i = 0; i < base->n_req_heads; ++i) {
1.605 + req = started_at = base->req_heads[i];
1.606 + if (req) {
1.607 + do {
1.608 + if (req->tx_count == 0 && req->ns == ns) {
1.609 + /* still waiting to go out, can be moved */
1.610 + /* to another server */
1.611 + req->ns = nameserver_pick(base);
1.612 + }
1.613 + req = req->next;
1.614 + } while (req != started_at);
1.615 + }
1.616 + }
1.617 +}
1.618 +
1.619 +static void
1.620 +nameserver_up(struct nameserver *const ns)
1.621 +{
1.622 + char addrbuf[128];
1.623 + ASSERT_LOCKED(ns->base);
1.624 + if (ns->state) return;
1.625 + log(EVDNS_LOG_MSG, "Nameserver %s is back up",
1.626 + evutil_format_sockaddr_port(
1.627 + (struct sockaddr *)&ns->address,
1.628 + addrbuf, sizeof(addrbuf)));
1.629 + evtimer_del(&ns->timeout_event);
1.630 + if (ns->probe_request) {
1.631 + evdns_cancel_request(ns->base, ns->probe_request);
1.632 + ns->probe_request = NULL;
1.633 + }
1.634 + ns->state = 1;
1.635 + ns->failed_times = 0;
1.636 + ns->timedout = 0;
1.637 + ns->base->global_good_nameservers++;
1.638 +}
1.639 +
1.640 +static void
1.641 +request_trans_id_set(struct request *const req, const u16 trans_id) {
1.642 + req->trans_id = trans_id;
1.643 + *((u16 *) req->request) = htons(trans_id);
1.644 +}
1.645 +
1.646 +/* Called to remove a request from a list and dealloc it. */
1.647 +/* head is a pointer to the head of the list it should be */
1.648 +/* removed from or NULL if the request isn't in a list. */
1.649 +/* when free_handle is one, free the handle as well. */
1.650 +static void
1.651 +request_finished(struct request *const req, struct request **head, int free_handle) {
1.652 + struct evdns_base *base = req->base;
1.653 + int was_inflight = (head != &base->req_waiting_head);
1.654 + EVDNS_LOCK(base);
1.655 + ASSERT_VALID_REQUEST(req);
1.656 +
1.657 + if (head)
1.658 + evdns_request_remove(req, head);
1.659 +
1.660 + log(EVDNS_LOG_DEBUG, "Removing timeout for request %p", req);
1.661 + if (was_inflight) {
1.662 + evtimer_del(&req->timeout_event);
1.663 + base->global_requests_inflight--;
1.664 + } else {
1.665 + base->global_requests_waiting--;
1.666 + }
1.667 + /* it was initialized during request_new / evtimer_assign */
1.668 + event_debug_unassign(&req->timeout_event);
1.669 +
1.670 + if (!req->request_appended) {
1.671 + /* need to free the request data on it's own */
1.672 + mm_free(req->request);
1.673 + } else {
1.674 + /* the request data is appended onto the header */
1.675 + /* so everything gets free()ed when we: */
1.676 + }
1.677 +
1.678 + if (req->handle) {
1.679 + EVUTIL_ASSERT(req->handle->current_req == req);
1.680 +
1.681 + if (free_handle) {
1.682 + search_request_finished(req->handle);
1.683 + req->handle->current_req = NULL;
1.684 + if (! req->handle->pending_cb) {
1.685 + /* If we're planning to run the callback,
1.686 + * don't free the handle until later. */
1.687 + mm_free(req->handle);
1.688 + }
1.689 + req->handle = NULL; /* If we have a bug, let's crash
1.690 + * early */
1.691 + } else {
1.692 + req->handle->current_req = NULL;
1.693 + }
1.694 + }
1.695 +
1.696 + mm_free(req);
1.697 +
1.698 + evdns_requests_pump_waiting_queue(base);
1.699 + EVDNS_UNLOCK(base);
1.700 +}
1.701 +
1.702 +/* This is called when a server returns a funny error code. */
1.703 +/* We try the request again with another server. */
1.704 +/* */
1.705 +/* return: */
1.706 +/* 0 ok */
1.707 +/* 1 failed/reissue is pointless */
1.708 +static int
1.709 +request_reissue(struct request *req) {
1.710 + const struct nameserver *const last_ns = req->ns;
1.711 + ASSERT_LOCKED(req->base);
1.712 + ASSERT_VALID_REQUEST(req);
1.713 + /* the last nameserver should have been marked as failing */
1.714 + /* by the caller of this function, therefore pick will try */
1.715 + /* not to return it */
1.716 + req->ns = nameserver_pick(req->base);
1.717 + if (req->ns == last_ns) {
1.718 + /* ... but pick did return it */
1.719 + /* not a lot of point in trying again with the */
1.720 + /* same server */
1.721 + return 1;
1.722 + }
1.723 +
1.724 + req->reissue_count++;
1.725 + req->tx_count = 0;
1.726 + req->transmit_me = 1;
1.727 +
1.728 + return 0;
1.729 +}
1.730 +
1.731 +/* this function looks for space on the inflight queue and promotes */
1.732 +/* requests from the waiting queue if it can. */
1.733 +static void
1.734 +evdns_requests_pump_waiting_queue(struct evdns_base *base) {
1.735 + ASSERT_LOCKED(base);
1.736 + while (base->global_requests_inflight < base->global_max_requests_inflight &&
1.737 + base->global_requests_waiting) {
1.738 + struct request *req;
1.739 + /* move a request from the waiting queue to the inflight queue */
1.740 + EVUTIL_ASSERT(base->req_waiting_head);
1.741 + req = base->req_waiting_head;
1.742 + evdns_request_remove(req, &base->req_waiting_head);
1.743 +
1.744 + base->global_requests_waiting--;
1.745 + base->global_requests_inflight++;
1.746 +
1.747 + req->ns = nameserver_pick(base);
1.748 + request_trans_id_set(req, transaction_id_pick(base));
1.749 +
1.750 + evdns_request_insert(req, &REQ_HEAD(base, req->trans_id));
1.751 + evdns_request_transmit(req);
1.752 + evdns_transmit(base);
1.753 + }
1.754 +}
1.755 +
1.756 +/* TODO(nickm) document */
1.757 +struct deferred_reply_callback {
1.758 + struct deferred_cb deferred;
1.759 + struct evdns_request *handle;
1.760 + u8 request_type;
1.761 + u8 have_reply;
1.762 + u32 ttl;
1.763 + u32 err;
1.764 + evdns_callback_type user_callback;
1.765 + struct reply reply;
1.766 +};
1.767 +
1.768 +static void
1.769 +reply_run_callback(struct deferred_cb *d, void *user_pointer)
1.770 +{
1.771 + struct deferred_reply_callback *cb =
1.772 + EVUTIL_UPCAST(d, struct deferred_reply_callback, deferred);
1.773 +
1.774 + switch (cb->request_type) {
1.775 + case TYPE_A:
1.776 + if (cb->have_reply)
1.777 + cb->user_callback(DNS_ERR_NONE, DNS_IPv4_A,
1.778 + cb->reply.data.a.addrcount, cb->ttl,
1.779 + cb->reply.data.a.addresses,
1.780 + user_pointer);
1.781 + else
1.782 + cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
1.783 + break;
1.784 + case TYPE_PTR:
1.785 + if (cb->have_reply) {
1.786 + char *name = cb->reply.data.ptr.name;
1.787 + cb->user_callback(DNS_ERR_NONE, DNS_PTR, 1, cb->ttl,
1.788 + &name, user_pointer);
1.789 + } else {
1.790 + cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
1.791 + }
1.792 + break;
1.793 + case TYPE_AAAA:
1.794 + if (cb->have_reply)
1.795 + cb->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA,
1.796 + cb->reply.data.aaaa.addrcount, cb->ttl,
1.797 + cb->reply.data.aaaa.addresses,
1.798 + user_pointer);
1.799 + else
1.800 + cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
1.801 + break;
1.802 + default:
1.803 + EVUTIL_ASSERT(0);
1.804 + }
1.805 +
1.806 + if (cb->handle && cb->handle->pending_cb) {
1.807 + mm_free(cb->handle);
1.808 + }
1.809 +
1.810 + mm_free(cb);
1.811 +}
1.812 +
1.813 +static void
1.814 +reply_schedule_callback(struct request *const req, u32 ttl, u32 err, struct reply *reply)
1.815 +{
1.816 + struct deferred_reply_callback *d = mm_calloc(1, sizeof(*d));
1.817 +
1.818 + if (!d) {
1.819 + event_warn("%s: Couldn't allocate space for deferred callback.",
1.820 + __func__);
1.821 + return;
1.822 + }
1.823 +
1.824 + ASSERT_LOCKED(req->base);
1.825 +
1.826 + d->request_type = req->request_type;
1.827 + d->user_callback = req->user_callback;
1.828 + d->ttl = ttl;
1.829 + d->err = err;
1.830 + if (reply) {
1.831 + d->have_reply = 1;
1.832 + memcpy(&d->reply, reply, sizeof(struct reply));
1.833 + }
1.834 +
1.835 + if (req->handle) {
1.836 + req->handle->pending_cb = 1;
1.837 + d->handle = req->handle;
1.838 + }
1.839 +
1.840 + event_deferred_cb_init(&d->deferred, reply_run_callback,
1.841 + req->user_pointer);
1.842 + event_deferred_cb_schedule(
1.843 + event_base_get_deferred_cb_queue(req->base->event_base),
1.844 + &d->deferred);
1.845 +}
1.846 +
1.847 +/* this processes a parsed reply packet */
1.848 +static void
1.849 +reply_handle(struct request *const req, u16 flags, u32 ttl, struct reply *reply) {
1.850 + int error;
1.851 + char addrbuf[128];
1.852 + static const int error_codes[] = {
1.853 + DNS_ERR_FORMAT, DNS_ERR_SERVERFAILED, DNS_ERR_NOTEXIST,
1.854 + DNS_ERR_NOTIMPL, DNS_ERR_REFUSED
1.855 + };
1.856 +
1.857 + ASSERT_LOCKED(req->base);
1.858 + ASSERT_VALID_REQUEST(req);
1.859 +
1.860 + if (flags & 0x020f || !reply || !reply->have_answer) {
1.861 + /* there was an error */
1.862 + if (flags & 0x0200) {
1.863 + error = DNS_ERR_TRUNCATED;
1.864 + } else if (flags & 0x000f) {
1.865 + u16 error_code = (flags & 0x000f) - 1;
1.866 + if (error_code > 4) {
1.867 + error = DNS_ERR_UNKNOWN;
1.868 + } else {
1.869 + error = error_codes[error_code];
1.870 + }
1.871 + } else if (reply && !reply->have_answer) {
1.872 + error = DNS_ERR_NODATA;
1.873 + } else {
1.874 + error = DNS_ERR_UNKNOWN;
1.875 + }
1.876 +
1.877 + switch (error) {
1.878 + case DNS_ERR_NOTIMPL:
1.879 + case DNS_ERR_REFUSED:
1.880 + /* we regard these errors as marking a bad nameserver */
1.881 + if (req->reissue_count < req->base->global_max_reissues) {
1.882 + char msg[64];
1.883 + evutil_snprintf(msg, sizeof(msg), "Bad response %d (%s)",
1.884 + error, evdns_err_to_string(error));
1.885 + nameserver_failed(req->ns, msg);
1.886 + if (!request_reissue(req)) return;
1.887 + }
1.888 + break;
1.889 + case DNS_ERR_SERVERFAILED:
1.890 + /* rcode 2 (servfailed) sometimes means "we
1.891 + * are broken" and sometimes (with some binds)
1.892 + * means "that request was very confusing."
1.893 + * Treat this as a timeout, not a failure.
1.894 + */
1.895 + log(EVDNS_LOG_DEBUG, "Got a SERVERFAILED from nameserver"
1.896 + "at %s; will allow the request to time out.",
1.897 + evutil_format_sockaddr_port(
1.898 + (struct sockaddr *)&req->ns->address,
1.899 + addrbuf, sizeof(addrbuf)));
1.900 + break;
1.901 + default:
1.902 + /* we got a good reply from the nameserver: it is up. */
1.903 + if (req->handle == req->ns->probe_request) {
1.904 + /* Avoid double-free */
1.905 + req->ns->probe_request = NULL;
1.906 + }
1.907 +
1.908 + nameserver_up(req->ns);
1.909 + }
1.910 +
1.911 + if (req->handle->search_state &&
1.912 + req->request_type != TYPE_PTR) {
1.913 + /* if we have a list of domains to search in,
1.914 + * try the next one */
1.915 + if (!search_try_next(req->handle)) {
1.916 + /* a new request was issued so this
1.917 + * request is finished and */
1.918 + /* the user callback will be made when
1.919 + * that request (or a */
1.920 + /* child of it) finishes. */
1.921 + return;
1.922 + }
1.923 + }
1.924 +
1.925 + /* all else failed. Pass the failure up */
1.926 + reply_schedule_callback(req, ttl, error, NULL);
1.927 + request_finished(req, &REQ_HEAD(req->base, req->trans_id), 1);
1.928 + } else {
1.929 + /* all ok, tell the user */
1.930 + reply_schedule_callback(req, ttl, 0, reply);
1.931 + if (req->handle == req->ns->probe_request)
1.932 + req->ns->probe_request = NULL; /* Avoid double-free */
1.933 + nameserver_up(req->ns);
1.934 + request_finished(req, &REQ_HEAD(req->base, req->trans_id), 1);
1.935 + }
1.936 +}
1.937 +
1.938 +static int
1.939 +name_parse(u8 *packet, int length, int *idx, char *name_out, int name_out_len) {
1.940 + int name_end = -1;
1.941 + int j = *idx;
1.942 + int ptr_count = 0;
1.943 +#define GET32(x) do { if (j + 4 > length) goto err; memcpy(&_t32, packet + j, 4); j += 4; x = ntohl(_t32); } while (0)
1.944 +#define GET16(x) do { if (j + 2 > length) goto err; memcpy(&_t, packet + j, 2); j += 2; x = ntohs(_t); } while (0)
1.945 +#define GET8(x) do { if (j >= length) goto err; x = packet[j++]; } while (0)
1.946 +
1.947 + char *cp = name_out;
1.948 + const char *const end = name_out + name_out_len;
1.949 +
1.950 + /* Normally, names are a series of length prefixed strings terminated */
1.951 + /* with a length of 0 (the lengths are u8's < 63). */
1.952 + /* However, the length can start with a pair of 1 bits and that */
1.953 + /* means that the next 14 bits are a pointer within the current */
1.954 + /* packet. */
1.955 +
1.956 + for (;;) {
1.957 + u8 label_len;
1.958 + if (j >= length) return -1;
1.959 + GET8(label_len);
1.960 + if (!label_len) break;
1.961 + if (label_len & 0xc0) {
1.962 + u8 ptr_low;
1.963 + GET8(ptr_low);
1.964 + if (name_end < 0) name_end = j;
1.965 + j = (((int)label_len & 0x3f) << 8) + ptr_low;
1.966 + /* Make sure that the target offset is in-bounds. */
1.967 + if (j < 0 || j >= length) return -1;
1.968 + /* If we've jumped more times than there are characters in the
1.969 + * message, we must have a loop. */
1.970 + if (++ptr_count > length) return -1;
1.971 + continue;
1.972 + }
1.973 + if (label_len > 63) return -1;
1.974 + if (cp != name_out) {
1.975 + if (cp + 1 >= end) return -1;
1.976 + *cp++ = '.';
1.977 + }
1.978 + if (cp + label_len >= end) return -1;
1.979 + memcpy(cp, packet + j, label_len);
1.980 + cp += label_len;
1.981 + j += label_len;
1.982 + }
1.983 + if (cp >= end) return -1;
1.984 + *cp = '\0';
1.985 + if (name_end < 0)
1.986 + *idx = j;
1.987 + else
1.988 + *idx = name_end;
1.989 + return 0;
1.990 + err:
1.991 + return -1;
1.992 +}
1.993 +
1.994 +/* parses a raw request from a nameserver */
1.995 +static int
1.996 +reply_parse(struct evdns_base *base, u8 *packet, int length) {
1.997 + int j = 0, k = 0; /* index into packet */
1.998 + u16 _t; /* used by the macros */
1.999 + u32 _t32; /* used by the macros */
1.1000 + char tmp_name[256], cmp_name[256]; /* used by the macros */
1.1001 + int name_matches = 0;
1.1002 +
1.1003 + u16 trans_id, questions, answers, authority, additional, datalength;
1.1004 + u16 flags = 0;
1.1005 + u32 ttl, ttl_r = 0xffffffff;
1.1006 + struct reply reply;
1.1007 + struct request *req = NULL;
1.1008 + unsigned int i;
1.1009 +
1.1010 + ASSERT_LOCKED(base);
1.1011 +
1.1012 + GET16(trans_id);
1.1013 + GET16(flags);
1.1014 + GET16(questions);
1.1015 + GET16(answers);
1.1016 + GET16(authority);
1.1017 + GET16(additional);
1.1018 + (void) authority; /* suppress "unused variable" warnings. */
1.1019 + (void) additional; /* suppress "unused variable" warnings. */
1.1020 +
1.1021 + req = request_find_from_trans_id(base, trans_id);
1.1022 + if (!req) return -1;
1.1023 + EVUTIL_ASSERT(req->base == base);
1.1024 +
1.1025 + memset(&reply, 0, sizeof(reply));
1.1026 +
1.1027 + /* If it's not an answer, it doesn't correspond to any request. */
1.1028 + if (!(flags & 0x8000)) return -1; /* must be an answer */
1.1029 + if ((flags & 0x020f) && (flags & 0x020f) != DNS_ERR_NOTEXIST) {
1.1030 + /* there was an error and it's not NXDOMAIN */
1.1031 + goto err;
1.1032 + }
1.1033 + /* if (!answers) return; */ /* must have an answer of some form */
1.1034 +
1.1035 + /* This macro skips a name in the DNS reply. */
1.1036 +#define SKIP_NAME \
1.1037 + do { tmp_name[0] = '\0'; \
1.1038 + if (name_parse(packet, length, &j, tmp_name, \
1.1039 + sizeof(tmp_name))<0) \
1.1040 + goto err; \
1.1041 + } while (0)
1.1042 +#define TEST_NAME \
1.1043 + do { tmp_name[0] = '\0'; \
1.1044 + cmp_name[0] = '\0'; \
1.1045 + k = j; \
1.1046 + if (name_parse(packet, length, &j, tmp_name, \
1.1047 + sizeof(tmp_name))<0) \
1.1048 + goto err; \
1.1049 + if (name_parse(req->request, req->request_len, &k, \
1.1050 + cmp_name, sizeof(cmp_name))<0) \
1.1051 + goto err; \
1.1052 + if (base->global_randomize_case) { \
1.1053 + if (strcmp(tmp_name, cmp_name) == 0) \
1.1054 + name_matches = 1; \
1.1055 + } else { \
1.1056 + if (evutil_ascii_strcasecmp(tmp_name, cmp_name) == 0) \
1.1057 + name_matches = 1; \
1.1058 + } \
1.1059 + } while (0)
1.1060 +
1.1061 + reply.type = req->request_type;
1.1062 +
1.1063 + /* skip over each question in the reply */
1.1064 + for (i = 0; i < questions; ++i) {
1.1065 + /* the question looks like
1.1066 + * <label:name><u16:type><u16:class>
1.1067 + */
1.1068 + TEST_NAME;
1.1069 + j += 4;
1.1070 + if (j > length) goto err;
1.1071 + }
1.1072 +
1.1073 + if (!name_matches)
1.1074 + goto err;
1.1075 +
1.1076 + /* now we have the answer section which looks like
1.1077 + * <label:name><u16:type><u16:class><u32:ttl><u16:len><data...>
1.1078 + */
1.1079 +
1.1080 + for (i = 0; i < answers; ++i) {
1.1081 + u16 type, class;
1.1082 +
1.1083 + SKIP_NAME;
1.1084 + GET16(type);
1.1085 + GET16(class);
1.1086 + GET32(ttl);
1.1087 + GET16(datalength);
1.1088 +
1.1089 + if (type == TYPE_A && class == CLASS_INET) {
1.1090 + int addrcount, addrtocopy;
1.1091 + if (req->request_type != TYPE_A) {
1.1092 + j += datalength; continue;
1.1093 + }
1.1094 + if ((datalength & 3) != 0) /* not an even number of As. */
1.1095 + goto err;
1.1096 + addrcount = datalength >> 2;
1.1097 + addrtocopy = MIN(MAX_V4_ADDRS - reply.data.a.addrcount, (unsigned)addrcount);
1.1098 +
1.1099 + ttl_r = MIN(ttl_r, ttl);
1.1100 + /* we only bother with the first four addresses. */
1.1101 + if (j + 4*addrtocopy > length) goto err;
1.1102 + memcpy(&reply.data.a.addresses[reply.data.a.addrcount],
1.1103 + packet + j, 4*addrtocopy);
1.1104 + j += 4*addrtocopy;
1.1105 + reply.data.a.addrcount += addrtocopy;
1.1106 + reply.have_answer = 1;
1.1107 + if (reply.data.a.addrcount == MAX_V4_ADDRS) break;
1.1108 + } else if (type == TYPE_PTR && class == CLASS_INET) {
1.1109 + if (req->request_type != TYPE_PTR) {
1.1110 + j += datalength; continue;
1.1111 + }
1.1112 + if (name_parse(packet, length, &j, reply.data.ptr.name,
1.1113 + sizeof(reply.data.ptr.name))<0)
1.1114 + goto err;
1.1115 + ttl_r = MIN(ttl_r, ttl);
1.1116 + reply.have_answer = 1;
1.1117 + break;
1.1118 + } else if (type == TYPE_CNAME) {
1.1119 + char cname[HOST_NAME_MAX];
1.1120 + if (!req->put_cname_in_ptr || *req->put_cname_in_ptr) {
1.1121 + j += datalength; continue;
1.1122 + }
1.1123 + if (name_parse(packet, length, &j, cname,
1.1124 + sizeof(cname))<0)
1.1125 + goto err;
1.1126 + *req->put_cname_in_ptr = mm_strdup(cname);
1.1127 + } else if (type == TYPE_AAAA && class == CLASS_INET) {
1.1128 + int addrcount, addrtocopy;
1.1129 + if (req->request_type != TYPE_AAAA) {
1.1130 + j += datalength; continue;
1.1131 + }
1.1132 + if ((datalength & 15) != 0) /* not an even number of AAAAs. */
1.1133 + goto err;
1.1134 + addrcount = datalength >> 4; /* each address is 16 bytes long */
1.1135 + addrtocopy = MIN(MAX_V6_ADDRS - reply.data.aaaa.addrcount, (unsigned)addrcount);
1.1136 + ttl_r = MIN(ttl_r, ttl);
1.1137 +
1.1138 + /* we only bother with the first four addresses. */
1.1139 + if (j + 16*addrtocopy > length) goto err;
1.1140 + memcpy(&reply.data.aaaa.addresses[reply.data.aaaa.addrcount],
1.1141 + packet + j, 16*addrtocopy);
1.1142 + reply.data.aaaa.addrcount += addrtocopy;
1.1143 + j += 16*addrtocopy;
1.1144 + reply.have_answer = 1;
1.1145 + if (reply.data.aaaa.addrcount == MAX_V6_ADDRS) break;
1.1146 + } else {
1.1147 + /* skip over any other type of resource */
1.1148 + j += datalength;
1.1149 + }
1.1150 + }
1.1151 +
1.1152 + if (!reply.have_answer) {
1.1153 + for (i = 0; i < authority; ++i) {
1.1154 + u16 type, class;
1.1155 + SKIP_NAME;
1.1156 + GET16(type);
1.1157 + GET16(class);
1.1158 + GET32(ttl);
1.1159 + GET16(datalength);
1.1160 + if (type == TYPE_SOA && class == CLASS_INET) {
1.1161 + u32 serial, refresh, retry, expire, minimum;
1.1162 + SKIP_NAME;
1.1163 + SKIP_NAME;
1.1164 + GET32(serial);
1.1165 + GET32(refresh);
1.1166 + GET32(retry);
1.1167 + GET32(expire);
1.1168 + GET32(minimum);
1.1169 + (void)expire;
1.1170 + (void)retry;
1.1171 + (void)refresh;
1.1172 + (void)serial;
1.1173 + ttl_r = MIN(ttl_r, ttl);
1.1174 + ttl_r = MIN(ttl_r, minimum);
1.1175 + } else {
1.1176 + /* skip over any other type of resource */
1.1177 + j += datalength;
1.1178 + }
1.1179 + }
1.1180 + }
1.1181 +
1.1182 + if (ttl_r == 0xffffffff)
1.1183 + ttl_r = 0;
1.1184 +
1.1185 + reply_handle(req, flags, ttl_r, &reply);
1.1186 + return 0;
1.1187 + err:
1.1188 + if (req)
1.1189 + reply_handle(req, flags, 0, NULL);
1.1190 + return -1;
1.1191 +}
1.1192 +
1.1193 +/* Parse a raw request (packet,length) sent to a nameserver port (port) from */
1.1194 +/* a DNS client (addr,addrlen), and if it's well-formed, call the corresponding */
1.1195 +/* callback. */
1.1196 +static int
1.1197 +request_parse(u8 *packet, int length, struct evdns_server_port *port, struct sockaddr *addr, ev_socklen_t addrlen)
1.1198 +{
1.1199 + int j = 0; /* index into packet */
1.1200 + u16 _t; /* used by the macros */
1.1201 + char tmp_name[256]; /* used by the macros */
1.1202 +
1.1203 + int i;
1.1204 + u16 trans_id, flags, questions, answers, authority, additional;
1.1205 + struct server_request *server_req = NULL;
1.1206 +
1.1207 + ASSERT_LOCKED(port);
1.1208 +
1.1209 + /* Get the header fields */
1.1210 + GET16(trans_id);
1.1211 + GET16(flags);
1.1212 + GET16(questions);
1.1213 + GET16(answers);
1.1214 + GET16(authority);
1.1215 + GET16(additional);
1.1216 + (void)answers;
1.1217 + (void)additional;
1.1218 + (void)authority;
1.1219 +
1.1220 + if (flags & 0x8000) return -1; /* Must not be an answer. */
1.1221 + flags &= 0x0110; /* Only RD and CD get preserved. */
1.1222 +
1.1223 + server_req = mm_malloc(sizeof(struct server_request));
1.1224 + if (server_req == NULL) return -1;
1.1225 + memset(server_req, 0, sizeof(struct server_request));
1.1226 +
1.1227 + server_req->trans_id = trans_id;
1.1228 + memcpy(&server_req->addr, addr, addrlen);
1.1229 + server_req->addrlen = addrlen;
1.1230 +
1.1231 + server_req->base.flags = flags;
1.1232 + server_req->base.nquestions = 0;
1.1233 + server_req->base.questions = mm_calloc(sizeof(struct evdns_server_question *), questions);
1.1234 + if (server_req->base.questions == NULL)
1.1235 + goto err;
1.1236 +
1.1237 + for (i = 0; i < questions; ++i) {
1.1238 + u16 type, class;
1.1239 + struct evdns_server_question *q;
1.1240 + int namelen;
1.1241 + if (name_parse(packet, length, &j, tmp_name, sizeof(tmp_name))<0)
1.1242 + goto err;
1.1243 + GET16(type);
1.1244 + GET16(class);
1.1245 + namelen = (int)strlen(tmp_name);
1.1246 + q = mm_malloc(sizeof(struct evdns_server_question) + namelen);
1.1247 + if (!q)
1.1248 + goto err;
1.1249 + q->type = type;
1.1250 + q->dns_question_class = class;
1.1251 + memcpy(q->name, tmp_name, namelen+1);
1.1252 + server_req->base.questions[server_req->base.nquestions++] = q;
1.1253 + }
1.1254 +
1.1255 + /* Ignore answers, authority, and additional. */
1.1256 +
1.1257 + server_req->port = port;
1.1258 + port->refcnt++;
1.1259 +
1.1260 + /* Only standard queries are supported. */
1.1261 + if (flags & 0x7800) {
1.1262 + evdns_server_request_respond(&(server_req->base), DNS_ERR_NOTIMPL);
1.1263 + return -1;
1.1264 + }
1.1265 +
1.1266 + port->user_callback(&(server_req->base), port->user_data);
1.1267 +
1.1268 + return 0;
1.1269 +err:
1.1270 + if (server_req) {
1.1271 + if (server_req->base.questions) {
1.1272 + for (i = 0; i < server_req->base.nquestions; ++i)
1.1273 + mm_free(server_req->base.questions[i]);
1.1274 + mm_free(server_req->base.questions);
1.1275 + }
1.1276 + mm_free(server_req);
1.1277 + }
1.1278 + return -1;
1.1279 +
1.1280 +#undef SKIP_NAME
1.1281 +#undef GET32
1.1282 +#undef GET16
1.1283 +#undef GET8
1.1284 +}
1.1285 +
1.1286 +
1.1287 +void
1.1288 +evdns_set_transaction_id_fn(ev_uint16_t (*fn)(void))
1.1289 +{
1.1290 +}
1.1291 +
1.1292 +void
1.1293 +evdns_set_random_bytes_fn(void (*fn)(char *, size_t))
1.1294 +{
1.1295 +}
1.1296 +
1.1297 +/* Try to choose a strong transaction id which isn't already in flight */
1.1298 +static u16
1.1299 +transaction_id_pick(struct evdns_base *base) {
1.1300 + ASSERT_LOCKED(base);
1.1301 + for (;;) {
1.1302 + u16 trans_id;
1.1303 + evutil_secure_rng_get_bytes(&trans_id, sizeof(trans_id));
1.1304 +
1.1305 + if (trans_id == 0xffff) continue;
1.1306 + /* now check to see if that id is already inflight */
1.1307 + if (request_find_from_trans_id(base, trans_id) == NULL)
1.1308 + return trans_id;
1.1309 + }
1.1310 +}
1.1311 +
1.1312 +/* choose a namesever to use. This function will try to ignore */
1.1313 +/* nameservers which we think are down and load balance across the rest */
1.1314 +/* by updating the server_head global each time. */
1.1315 +static struct nameserver *
1.1316 +nameserver_pick(struct evdns_base *base) {
1.1317 + struct nameserver *started_at = base->server_head, *picked;
1.1318 + ASSERT_LOCKED(base);
1.1319 + if (!base->server_head) return NULL;
1.1320 +
1.1321 + /* if we don't have any good nameservers then there's no */
1.1322 + /* point in trying to find one. */
1.1323 + if (!base->global_good_nameservers) {
1.1324 + base->server_head = base->server_head->next;
1.1325 + return base->server_head;
1.1326 + }
1.1327 +
1.1328 + /* remember that nameservers are in a circular list */
1.1329 + for (;;) {
1.1330 + if (base->server_head->state) {
1.1331 + /* we think this server is currently good */
1.1332 + picked = base->server_head;
1.1333 + base->server_head = base->server_head->next;
1.1334 + return picked;
1.1335 + }
1.1336 +
1.1337 + base->server_head = base->server_head->next;
1.1338 + if (base->server_head == started_at) {
1.1339 + /* all the nameservers seem to be down */
1.1340 + /* so we just return this one and hope for the */
1.1341 + /* best */
1.1342 + EVUTIL_ASSERT(base->global_good_nameservers == 0);
1.1343 + picked = base->server_head;
1.1344 + base->server_head = base->server_head->next;
1.1345 + return picked;
1.1346 + }
1.1347 + }
1.1348 +}
1.1349 +
1.1350 +/* this is called when a namesever socket is ready for reading */
1.1351 +static void
1.1352 +nameserver_read(struct nameserver *ns) {
1.1353 + struct sockaddr_storage ss;
1.1354 + ev_socklen_t addrlen = sizeof(ss);
1.1355 + u8 packet[1500];
1.1356 + char addrbuf[128];
1.1357 + ASSERT_LOCKED(ns->base);
1.1358 +
1.1359 + for (;;) {
1.1360 + const int r = recvfrom(ns->socket, (void*)packet,
1.1361 + sizeof(packet), 0,
1.1362 + (struct sockaddr*)&ss, &addrlen);
1.1363 + if (r < 0) {
1.1364 + int err = evutil_socket_geterror(ns->socket);
1.1365 + if (EVUTIL_ERR_RW_RETRIABLE(err))
1.1366 + return;
1.1367 + nameserver_failed(ns,
1.1368 + evutil_socket_error_to_string(err));
1.1369 + return;
1.1370 + }
1.1371 + if (evutil_sockaddr_cmp((struct sockaddr*)&ss,
1.1372 + (struct sockaddr*)&ns->address, 0)) {
1.1373 + log(EVDNS_LOG_WARN, "Address mismatch on received "
1.1374 + "DNS packet. Apparent source was %s",
1.1375 + evutil_format_sockaddr_port(
1.1376 + (struct sockaddr *)&ss,
1.1377 + addrbuf, sizeof(addrbuf)));
1.1378 + return;
1.1379 + }
1.1380 +
1.1381 + ns->timedout = 0;
1.1382 + reply_parse(ns->base, packet, r);
1.1383 + }
1.1384 +}
1.1385 +
1.1386 +/* Read a packet from a DNS client on a server port s, parse it, and */
1.1387 +/* act accordingly. */
1.1388 +static void
1.1389 +server_port_read(struct evdns_server_port *s) {
1.1390 + u8 packet[1500];
1.1391 + struct sockaddr_storage addr;
1.1392 + ev_socklen_t addrlen;
1.1393 + int r;
1.1394 + ASSERT_LOCKED(s);
1.1395 +
1.1396 + for (;;) {
1.1397 + addrlen = sizeof(struct sockaddr_storage);
1.1398 + r = recvfrom(s->socket, (void*)packet, sizeof(packet), 0,
1.1399 + (struct sockaddr*) &addr, &addrlen);
1.1400 + if (r < 0) {
1.1401 + int err = evutil_socket_geterror(s->socket);
1.1402 + if (EVUTIL_ERR_RW_RETRIABLE(err))
1.1403 + return;
1.1404 + log(EVDNS_LOG_WARN,
1.1405 + "Error %s (%d) while reading request.",
1.1406 + evutil_socket_error_to_string(err), err);
1.1407 + return;
1.1408 + }
1.1409 + request_parse(packet, r, s, (struct sockaddr*) &addr, addrlen);
1.1410 + }
1.1411 +}
1.1412 +
1.1413 +/* Try to write all pending replies on a given DNS server port. */
1.1414 +static void
1.1415 +server_port_flush(struct evdns_server_port *port)
1.1416 +{
1.1417 + struct server_request *req = port->pending_replies;
1.1418 + ASSERT_LOCKED(port);
1.1419 + while (req) {
1.1420 + int r = sendto(port->socket, req->response, (int)req->response_len, 0,
1.1421 + (struct sockaddr*) &req->addr, (ev_socklen_t)req->addrlen);
1.1422 + if (r < 0) {
1.1423 + int err = evutil_socket_geterror(port->socket);
1.1424 + if (EVUTIL_ERR_RW_RETRIABLE(err))
1.1425 + return;
1.1426 + log(EVDNS_LOG_WARN, "Error %s (%d) while writing response to port; dropping", evutil_socket_error_to_string(err), err);
1.1427 + }
1.1428 + if (server_request_free(req)) {
1.1429 + /* we released the last reference to req->port. */
1.1430 + return;
1.1431 + } else {
1.1432 + EVUTIL_ASSERT(req != port->pending_replies);
1.1433 + req = port->pending_replies;
1.1434 + }
1.1435 + }
1.1436 +
1.1437 + /* We have no more pending requests; stop listening for 'writeable' events. */
1.1438 + (void) event_del(&port->event);
1.1439 + event_assign(&port->event, port->event_base,
1.1440 + port->socket, EV_READ | EV_PERSIST,
1.1441 + server_port_ready_callback, port);
1.1442 +
1.1443 + if (event_add(&port->event, NULL) < 0) {
1.1444 + log(EVDNS_LOG_WARN, "Error from libevent when adding event for DNS server.");
1.1445 + /* ???? Do more? */
1.1446 + }
1.1447 +}
1.1448 +
1.1449 +/* set if we are waiting for the ability to write to this server. */
1.1450 +/* if waiting is true then we ask libevent for EV_WRITE events, otherwise */
1.1451 +/* we stop these events. */
1.1452 +static void
1.1453 +nameserver_write_waiting(struct nameserver *ns, char waiting) {
1.1454 + ASSERT_LOCKED(ns->base);
1.1455 + if (ns->write_waiting == waiting) return;
1.1456 +
1.1457 + ns->write_waiting = waiting;
1.1458 + (void) event_del(&ns->event);
1.1459 + event_assign(&ns->event, ns->base->event_base,
1.1460 + ns->socket, EV_READ | (waiting ? EV_WRITE : 0) | EV_PERSIST,
1.1461 + nameserver_ready_callback, ns);
1.1462 + if (event_add(&ns->event, NULL) < 0) {
1.1463 + char addrbuf[128];
1.1464 + log(EVDNS_LOG_WARN, "Error from libevent when adding event for %s",
1.1465 + evutil_format_sockaddr_port(
1.1466 + (struct sockaddr *)&ns->address,
1.1467 + addrbuf, sizeof(addrbuf)));
1.1468 + /* ???? Do more? */
1.1469 + }
1.1470 +}
1.1471 +
1.1472 +/* a callback function. Called by libevent when the kernel says that */
1.1473 +/* a nameserver socket is ready for writing or reading */
1.1474 +static void
1.1475 +nameserver_ready_callback(evutil_socket_t fd, short events, void *arg) {
1.1476 + struct nameserver *ns = (struct nameserver *) arg;
1.1477 + (void)fd;
1.1478 +
1.1479 + EVDNS_LOCK(ns->base);
1.1480 + if (events & EV_WRITE) {
1.1481 + ns->choked = 0;
1.1482 + if (!evdns_transmit(ns->base)) {
1.1483 + nameserver_write_waiting(ns, 0);
1.1484 + }
1.1485 + }
1.1486 + if (events & EV_READ) {
1.1487 + nameserver_read(ns);
1.1488 + }
1.1489 + EVDNS_UNLOCK(ns->base);
1.1490 +}
1.1491 +
1.1492 +/* a callback function. Called by libevent when the kernel says that */
1.1493 +/* a server socket is ready for writing or reading. */
1.1494 +static void
1.1495 +server_port_ready_callback(evutil_socket_t fd, short events, void *arg) {
1.1496 + struct evdns_server_port *port = (struct evdns_server_port *) arg;
1.1497 + (void) fd;
1.1498 +
1.1499 + EVDNS_LOCK(port);
1.1500 + if (events & EV_WRITE) {
1.1501 + port->choked = 0;
1.1502 + server_port_flush(port);
1.1503 + }
1.1504 + if (events & EV_READ) {
1.1505 + server_port_read(port);
1.1506 + }
1.1507 + EVDNS_UNLOCK(port);
1.1508 +}
1.1509 +
1.1510 +/* This is an inefficient representation; only use it via the dnslabel_table_*
1.1511 + * functions, so that is can be safely replaced with something smarter later. */
1.1512 +#define MAX_LABELS 128
1.1513 +/* Structures used to implement name compression */
1.1514 +struct dnslabel_entry { char *v; off_t pos; };
1.1515 +struct dnslabel_table {
1.1516 + int n_labels; /* number of current entries */
1.1517 + /* map from name to position in message */
1.1518 + struct dnslabel_entry labels[MAX_LABELS];
1.1519 +};
1.1520 +
1.1521 +/* Initialize dnslabel_table. */
1.1522 +static void
1.1523 +dnslabel_table_init(struct dnslabel_table *table)
1.1524 +{
1.1525 + table->n_labels = 0;
1.1526 +}
1.1527 +
1.1528 +/* Free all storage held by table, but not the table itself. */
1.1529 +static void
1.1530 +dnslabel_clear(struct dnslabel_table *table)
1.1531 +{
1.1532 + int i;
1.1533 + for (i = 0; i < table->n_labels; ++i)
1.1534 + mm_free(table->labels[i].v);
1.1535 + table->n_labels = 0;
1.1536 +}
1.1537 +
1.1538 +/* return the position of the label in the current message, or -1 if the label */
1.1539 +/* hasn't been used yet. */
1.1540 +static int
1.1541 +dnslabel_table_get_pos(const struct dnslabel_table *table, const char *label)
1.1542 +{
1.1543 + int i;
1.1544 + for (i = 0; i < table->n_labels; ++i) {
1.1545 + if (!strcmp(label, table->labels[i].v))
1.1546 + return table->labels[i].pos;
1.1547 + }
1.1548 + return -1;
1.1549 +}
1.1550 +
1.1551 +/* remember that we've used the label at position pos */
1.1552 +static int
1.1553 +dnslabel_table_add(struct dnslabel_table *table, const char *label, off_t pos)
1.1554 +{
1.1555 + char *v;
1.1556 + int p;
1.1557 + if (table->n_labels == MAX_LABELS)
1.1558 + return (-1);
1.1559 + v = mm_strdup(label);
1.1560 + if (v == NULL)
1.1561 + return (-1);
1.1562 + p = table->n_labels++;
1.1563 + table->labels[p].v = v;
1.1564 + table->labels[p].pos = pos;
1.1565 +
1.1566 + return (0);
1.1567 +}
1.1568 +
1.1569 +/* Converts a string to a length-prefixed set of DNS labels, starting */
1.1570 +/* at buf[j]. name and buf must not overlap. name_len should be the length */
1.1571 +/* of name. table is optional, and is used for compression. */
1.1572 +/* */
1.1573 +/* Input: abc.def */
1.1574 +/* Output: <3>abc<3>def<0> */
1.1575 +/* */
1.1576 +/* Returns the first index after the encoded name, or negative on error. */
1.1577 +/* -1 label was > 63 bytes */
1.1578 +/* -2 name too long to fit in buffer. */
1.1579 +/* */
1.1580 +static off_t
1.1581 +dnsname_to_labels(u8 *const buf, size_t buf_len, off_t j,
1.1582 + const char *name, const size_t name_len,
1.1583 + struct dnslabel_table *table) {
1.1584 + const char *end = name + name_len;
1.1585 + int ref = 0;
1.1586 + u16 _t;
1.1587 +
1.1588 +#define APPEND16(x) do { \
1.1589 + if (j + 2 > (off_t)buf_len) \
1.1590 + goto overflow; \
1.1591 + _t = htons(x); \
1.1592 + memcpy(buf + j, &_t, 2); \
1.1593 + j += 2; \
1.1594 + } while (0)
1.1595 +#define APPEND32(x) do { \
1.1596 + if (j + 4 > (off_t)buf_len) \
1.1597 + goto overflow; \
1.1598 + _t32 = htonl(x); \
1.1599 + memcpy(buf + j, &_t32, 4); \
1.1600 + j += 4; \
1.1601 + } while (0)
1.1602 +
1.1603 + if (name_len > 255) return -2;
1.1604 +
1.1605 + for (;;) {
1.1606 + const char *const start = name;
1.1607 + if (table && (ref = dnslabel_table_get_pos(table, name)) >= 0) {
1.1608 + APPEND16(ref | 0xc000);
1.1609 + return j;
1.1610 + }
1.1611 + name = strchr(name, '.');
1.1612 + if (!name) {
1.1613 + const size_t label_len = end - start;
1.1614 + if (label_len > 63) return -1;
1.1615 + if ((size_t)(j+label_len+1) > buf_len) return -2;
1.1616 + if (table) dnslabel_table_add(table, start, j);
1.1617 + buf[j++] = (ev_uint8_t)label_len;
1.1618 +
1.1619 + memcpy(buf + j, start, label_len);
1.1620 + j += (int) label_len;
1.1621 + break;
1.1622 + } else {
1.1623 + /* append length of the label. */
1.1624 + const size_t label_len = name - start;
1.1625 + if (label_len > 63) return -1;
1.1626 + if ((size_t)(j+label_len+1) > buf_len) return -2;
1.1627 + if (table) dnslabel_table_add(table, start, j);
1.1628 + buf[j++] = (ev_uint8_t)label_len;
1.1629 +
1.1630 + memcpy(buf + j, start, label_len);
1.1631 + j += (int) label_len;
1.1632 + /* hop over the '.' */
1.1633 + name++;
1.1634 + }
1.1635 + }
1.1636 +
1.1637 + /* the labels must be terminated by a 0. */
1.1638 + /* It's possible that the name ended in a . */
1.1639 + /* in which case the zero is already there */
1.1640 + if (!j || buf[j-1]) buf[j++] = 0;
1.1641 + return j;
1.1642 + overflow:
1.1643 + return (-2);
1.1644 +}
1.1645 +
1.1646 +/* Finds the length of a dns request for a DNS name of the given */
1.1647 +/* length. The actual request may be smaller than the value returned */
1.1648 +/* here */
1.1649 +static size_t
1.1650 +evdns_request_len(const size_t name_len) {
1.1651 + return 96 + /* length of the DNS standard header */
1.1652 + name_len + 2 +
1.1653 + 4; /* space for the resource type */
1.1654 +}
1.1655 +
1.1656 +/* build a dns request packet into buf. buf should be at least as long */
1.1657 +/* as evdns_request_len told you it should be. */
1.1658 +/* */
1.1659 +/* Returns the amount of space used. Negative on error. */
1.1660 +static int
1.1661 +evdns_request_data_build(const char *const name, const size_t name_len,
1.1662 + const u16 trans_id, const u16 type, const u16 class,
1.1663 + u8 *const buf, size_t buf_len) {
1.1664 + off_t j = 0; /* current offset into buf */
1.1665 + u16 _t; /* used by the macros */
1.1666 +
1.1667 + APPEND16(trans_id);
1.1668 + APPEND16(0x0100); /* standard query, recusion needed */
1.1669 + APPEND16(1); /* one question */
1.1670 + APPEND16(0); /* no answers */
1.1671 + APPEND16(0); /* no authority */
1.1672 + APPEND16(0); /* no additional */
1.1673 +
1.1674 + j = dnsname_to_labels(buf, buf_len, j, name, name_len, NULL);
1.1675 + if (j < 0) {
1.1676 + return (int)j;
1.1677 + }
1.1678 +
1.1679 + APPEND16(type);
1.1680 + APPEND16(class);
1.1681 +
1.1682 + return (int)j;
1.1683 + overflow:
1.1684 + return (-1);
1.1685 +}
1.1686 +
1.1687 +/* exported function */
1.1688 +struct evdns_server_port *
1.1689 +evdns_add_server_port_with_base(struct event_base *base, evutil_socket_t socket, int flags, evdns_request_callback_fn_type cb, void *user_data)
1.1690 +{
1.1691 + struct evdns_server_port *port;
1.1692 + if (flags)
1.1693 + return NULL; /* flags not yet implemented */
1.1694 + if (!(port = mm_malloc(sizeof(struct evdns_server_port))))
1.1695 + return NULL;
1.1696 + memset(port, 0, sizeof(struct evdns_server_port));
1.1697 +
1.1698 +
1.1699 + port->socket = socket;
1.1700 + port->refcnt = 1;
1.1701 + port->choked = 0;
1.1702 + port->closing = 0;
1.1703 + port->user_callback = cb;
1.1704 + port->user_data = user_data;
1.1705 + port->pending_replies = NULL;
1.1706 + port->event_base = base;
1.1707 +
1.1708 + event_assign(&port->event, port->event_base,
1.1709 + port->socket, EV_READ | EV_PERSIST,
1.1710 + server_port_ready_callback, port);
1.1711 + if (event_add(&port->event, NULL) < 0) {
1.1712 + mm_free(port);
1.1713 + return NULL;
1.1714 + }
1.1715 + EVTHREAD_ALLOC_LOCK(port->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
1.1716 + return port;
1.1717 +}
1.1718 +
1.1719 +struct evdns_server_port *
1.1720 +evdns_add_server_port(evutil_socket_t socket, int flags, evdns_request_callback_fn_type cb, void *user_data)
1.1721 +{
1.1722 + return evdns_add_server_port_with_base(NULL, socket, flags, cb, user_data);
1.1723 +}
1.1724 +
1.1725 +/* exported function */
1.1726 +void
1.1727 +evdns_close_server_port(struct evdns_server_port *port)
1.1728 +{
1.1729 + EVDNS_LOCK(port);
1.1730 + if (--port->refcnt == 0) {
1.1731 + EVDNS_UNLOCK(port);
1.1732 + server_port_free(port);
1.1733 + } else {
1.1734 + port->closing = 1;
1.1735 + }
1.1736 +}
1.1737 +
1.1738 +/* exported function */
1.1739 +int
1.1740 +evdns_server_request_add_reply(struct evdns_server_request *_req, int section, const char *name, int type, int class, int ttl, int datalen, int is_name, const char *data)
1.1741 +{
1.1742 + struct server_request *req = TO_SERVER_REQUEST(_req);
1.1743 + struct server_reply_item **itemp, *item;
1.1744 + int *countp;
1.1745 + int result = -1;
1.1746 +
1.1747 + EVDNS_LOCK(req->port);
1.1748 + if (req->response) /* have we already answered? */
1.1749 + goto done;
1.1750 +
1.1751 + switch (section) {
1.1752 + case EVDNS_ANSWER_SECTION:
1.1753 + itemp = &req->answer;
1.1754 + countp = &req->n_answer;
1.1755 + break;
1.1756 + case EVDNS_AUTHORITY_SECTION:
1.1757 + itemp = &req->authority;
1.1758 + countp = &req->n_authority;
1.1759 + break;
1.1760 + case EVDNS_ADDITIONAL_SECTION:
1.1761 + itemp = &req->additional;
1.1762 + countp = &req->n_additional;
1.1763 + break;
1.1764 + default:
1.1765 + goto done;
1.1766 + }
1.1767 + while (*itemp) {
1.1768 + itemp = &((*itemp)->next);
1.1769 + }
1.1770 + item = mm_malloc(sizeof(struct server_reply_item));
1.1771 + if (!item)
1.1772 + goto done;
1.1773 + item->next = NULL;
1.1774 + if (!(item->name = mm_strdup(name))) {
1.1775 + mm_free(item);
1.1776 + goto done;
1.1777 + }
1.1778 + item->type = type;
1.1779 + item->dns_question_class = class;
1.1780 + item->ttl = ttl;
1.1781 + item->is_name = is_name != 0;
1.1782 + item->datalen = 0;
1.1783 + item->data = NULL;
1.1784 + if (data) {
1.1785 + if (item->is_name) {
1.1786 + if (!(item->data = mm_strdup(data))) {
1.1787 + mm_free(item->name);
1.1788 + mm_free(item);
1.1789 + goto done;
1.1790 + }
1.1791 + item->datalen = (u16)-1;
1.1792 + } else {
1.1793 + if (!(item->data = mm_malloc(datalen))) {
1.1794 + mm_free(item->name);
1.1795 + mm_free(item);
1.1796 + goto done;
1.1797 + }
1.1798 + item->datalen = datalen;
1.1799 + memcpy(item->data, data, datalen);
1.1800 + }
1.1801 + }
1.1802 +
1.1803 + *itemp = item;
1.1804 + ++(*countp);
1.1805 + result = 0;
1.1806 +done:
1.1807 + EVDNS_UNLOCK(req->port);
1.1808 + return result;
1.1809 +}
1.1810 +
1.1811 +/* exported function */
1.1812 +int
1.1813 +evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl)
1.1814 +{
1.1815 + return evdns_server_request_add_reply(
1.1816 + req, EVDNS_ANSWER_SECTION, name, TYPE_A, CLASS_INET,
1.1817 + ttl, n*4, 0, addrs);
1.1818 +}
1.1819 +
1.1820 +/* exported function */
1.1821 +int
1.1822 +evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl)
1.1823 +{
1.1824 + return evdns_server_request_add_reply(
1.1825 + req, EVDNS_ANSWER_SECTION, name, TYPE_AAAA, CLASS_INET,
1.1826 + ttl, n*16, 0, addrs);
1.1827 +}
1.1828 +
1.1829 +/* exported function */
1.1830 +int
1.1831 +evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl)
1.1832 +{
1.1833 + u32 a;
1.1834 + char buf[32];
1.1835 + if (in && inaddr_name)
1.1836 + return -1;
1.1837 + else if (!in && !inaddr_name)
1.1838 + return -1;
1.1839 + if (in) {
1.1840 + a = ntohl(in->s_addr);
1.1841 + evutil_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
1.1842 + (int)(u8)((a )&0xff),
1.1843 + (int)(u8)((a>>8 )&0xff),
1.1844 + (int)(u8)((a>>16)&0xff),
1.1845 + (int)(u8)((a>>24)&0xff));
1.1846 + inaddr_name = buf;
1.1847 + }
1.1848 + return evdns_server_request_add_reply(
1.1849 + req, EVDNS_ANSWER_SECTION, inaddr_name, TYPE_PTR, CLASS_INET,
1.1850 + ttl, -1, 1, hostname);
1.1851 +}
1.1852 +
1.1853 +/* exported function */
1.1854 +int
1.1855 +evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl)
1.1856 +{
1.1857 + return evdns_server_request_add_reply(
1.1858 + req, EVDNS_ANSWER_SECTION, name, TYPE_CNAME, CLASS_INET,
1.1859 + ttl, -1, 1, cname);
1.1860 +}
1.1861 +
1.1862 +/* exported function */
1.1863 +void
1.1864 +evdns_server_request_set_flags(struct evdns_server_request *exreq, int flags)
1.1865 +{
1.1866 + struct server_request *req = TO_SERVER_REQUEST(exreq);
1.1867 + req->base.flags &= ~(EVDNS_FLAGS_AA|EVDNS_FLAGS_RD);
1.1868 + req->base.flags |= flags;
1.1869 +}
1.1870 +
1.1871 +static int
1.1872 +evdns_server_request_format_response(struct server_request *req, int err)
1.1873 +{
1.1874 + unsigned char buf[1500];
1.1875 + size_t buf_len = sizeof(buf);
1.1876 + off_t j = 0, r;
1.1877 + u16 _t;
1.1878 + u32 _t32;
1.1879 + int i;
1.1880 + u16 flags;
1.1881 + struct dnslabel_table table;
1.1882 +
1.1883 + if (err < 0 || err > 15) return -1;
1.1884 +
1.1885 + /* Set response bit and error code; copy OPCODE and RD fields from
1.1886 + * question; copy RA and AA if set by caller. */
1.1887 + flags = req->base.flags;
1.1888 + flags |= (0x8000 | err);
1.1889 +
1.1890 + dnslabel_table_init(&table);
1.1891 + APPEND16(req->trans_id);
1.1892 + APPEND16(flags);
1.1893 + APPEND16(req->base.nquestions);
1.1894 + APPEND16(req->n_answer);
1.1895 + APPEND16(req->n_authority);
1.1896 + APPEND16(req->n_additional);
1.1897 +
1.1898 + /* Add questions. */
1.1899 + for (i=0; i < req->base.nquestions; ++i) {
1.1900 + const char *s = req->base.questions[i]->name;
1.1901 + j = dnsname_to_labels(buf, buf_len, j, s, strlen(s), &table);
1.1902 + if (j < 0) {
1.1903 + dnslabel_clear(&table);
1.1904 + return (int) j;
1.1905 + }
1.1906 + APPEND16(req->base.questions[i]->type);
1.1907 + APPEND16(req->base.questions[i]->dns_question_class);
1.1908 + }
1.1909 +
1.1910 + /* Add answer, authority, and additional sections. */
1.1911 + for (i=0; i<3; ++i) {
1.1912 + struct server_reply_item *item;
1.1913 + if (i==0)
1.1914 + item = req->answer;
1.1915 + else if (i==1)
1.1916 + item = req->authority;
1.1917 + else
1.1918 + item = req->additional;
1.1919 + while (item) {
1.1920 + r = dnsname_to_labels(buf, buf_len, j, item->name, strlen(item->name), &table);
1.1921 + if (r < 0)
1.1922 + goto overflow;
1.1923 + j = r;
1.1924 +
1.1925 + APPEND16(item->type);
1.1926 + APPEND16(item->dns_question_class);
1.1927 + APPEND32(item->ttl);
1.1928 + if (item->is_name) {
1.1929 + off_t len_idx = j, name_start;
1.1930 + j += 2;
1.1931 + name_start = j;
1.1932 + r = dnsname_to_labels(buf, buf_len, j, item->data, strlen(item->data), &table);
1.1933 + if (r < 0)
1.1934 + goto overflow;
1.1935 + j = r;
1.1936 + _t = htons( (short) (j-name_start) );
1.1937 + memcpy(buf+len_idx, &_t, 2);
1.1938 + } else {
1.1939 + APPEND16(item->datalen);
1.1940 + if (j+item->datalen > (off_t)buf_len)
1.1941 + goto overflow;
1.1942 + memcpy(buf+j, item->data, item->datalen);
1.1943 + j += item->datalen;
1.1944 + }
1.1945 + item = item->next;
1.1946 + }
1.1947 + }
1.1948 +
1.1949 + if (j > 512) {
1.1950 +overflow:
1.1951 + j = 512;
1.1952 + buf[2] |= 0x02; /* set the truncated bit. */
1.1953 + }
1.1954 +
1.1955 + req->response_len = j;
1.1956 +
1.1957 + if (!(req->response = mm_malloc(req->response_len))) {
1.1958 + server_request_free_answers(req);
1.1959 + dnslabel_clear(&table);
1.1960 + return (-1);
1.1961 + }
1.1962 + memcpy(req->response, buf, req->response_len);
1.1963 + server_request_free_answers(req);
1.1964 + dnslabel_clear(&table);
1.1965 + return (0);
1.1966 +}
1.1967 +
1.1968 +/* exported function */
1.1969 +int
1.1970 +evdns_server_request_respond(struct evdns_server_request *_req, int err)
1.1971 +{
1.1972 + struct server_request *req = TO_SERVER_REQUEST(_req);
1.1973 + struct evdns_server_port *port = req->port;
1.1974 + int r = -1;
1.1975 +
1.1976 + EVDNS_LOCK(port);
1.1977 + if (!req->response) {
1.1978 + if ((r = evdns_server_request_format_response(req, err))<0)
1.1979 + goto done;
1.1980 + }
1.1981 +
1.1982 + r = sendto(port->socket, req->response, (int)req->response_len, 0,
1.1983 + (struct sockaddr*) &req->addr, (ev_socklen_t)req->addrlen);
1.1984 + if (r<0) {
1.1985 + int sock_err = evutil_socket_geterror(port->socket);
1.1986 + if (EVUTIL_ERR_RW_RETRIABLE(sock_err))
1.1987 + goto done;
1.1988 +
1.1989 + if (port->pending_replies) {
1.1990 + req->prev_pending = port->pending_replies->prev_pending;
1.1991 + req->next_pending = port->pending_replies;
1.1992 + req->prev_pending->next_pending =
1.1993 + req->next_pending->prev_pending = req;
1.1994 + } else {
1.1995 + req->prev_pending = req->next_pending = req;
1.1996 + port->pending_replies = req;
1.1997 + port->choked = 1;
1.1998 +
1.1999 + (void) event_del(&port->event);
1.2000 + event_assign(&port->event, port->event_base, port->socket, (port->closing?0:EV_READ) | EV_WRITE | EV_PERSIST, server_port_ready_callback, port);
1.2001 +
1.2002 + if (event_add(&port->event, NULL) < 0) {
1.2003 + log(EVDNS_LOG_WARN, "Error from libevent when adding event for DNS server");
1.2004 + }
1.2005 +
1.2006 + }
1.2007 +
1.2008 + r = 1;
1.2009 + goto done;
1.2010 + }
1.2011 + if (server_request_free(req)) {
1.2012 + r = 0;
1.2013 + goto done;
1.2014 + }
1.2015 +
1.2016 + if (port->pending_replies)
1.2017 + server_port_flush(port);
1.2018 +
1.2019 + r = 0;
1.2020 +done:
1.2021 + EVDNS_UNLOCK(port);
1.2022 + return r;
1.2023 +}
1.2024 +
1.2025 +/* Free all storage held by RRs in req. */
1.2026 +static void
1.2027 +server_request_free_answers(struct server_request *req)
1.2028 +{
1.2029 + struct server_reply_item *victim, *next, **list;
1.2030 + int i;
1.2031 + for (i = 0; i < 3; ++i) {
1.2032 + if (i==0)
1.2033 + list = &req->answer;
1.2034 + else if (i==1)
1.2035 + list = &req->authority;
1.2036 + else
1.2037 + list = &req->additional;
1.2038 +
1.2039 + victim = *list;
1.2040 + while (victim) {
1.2041 + next = victim->next;
1.2042 + mm_free(victim->name);
1.2043 + if (victim->data)
1.2044 + mm_free(victim->data);
1.2045 + mm_free(victim);
1.2046 + victim = next;
1.2047 + }
1.2048 + *list = NULL;
1.2049 + }
1.2050 +}
1.2051 +
1.2052 +/* Free all storage held by req, and remove links to it. */
1.2053 +/* return true iff we just wound up freeing the server_port. */
1.2054 +static int
1.2055 +server_request_free(struct server_request *req)
1.2056 +{
1.2057 + int i, rc=1, lock=0;
1.2058 + if (req->base.questions) {
1.2059 + for (i = 0; i < req->base.nquestions; ++i)
1.2060 + mm_free(req->base.questions[i]);
1.2061 + mm_free(req->base.questions);
1.2062 + }
1.2063 +
1.2064 + if (req->port) {
1.2065 + EVDNS_LOCK(req->port);
1.2066 + lock=1;
1.2067 + if (req->port->pending_replies == req) {
1.2068 + if (req->next_pending && req->next_pending != req)
1.2069 + req->port->pending_replies = req->next_pending;
1.2070 + else
1.2071 + req->port->pending_replies = NULL;
1.2072 + }
1.2073 + rc = --req->port->refcnt;
1.2074 + }
1.2075 +
1.2076 + if (req->response) {
1.2077 + mm_free(req->response);
1.2078 + }
1.2079 +
1.2080 + server_request_free_answers(req);
1.2081 +
1.2082 + if (req->next_pending && req->next_pending != req) {
1.2083 + req->next_pending->prev_pending = req->prev_pending;
1.2084 + req->prev_pending->next_pending = req->next_pending;
1.2085 + }
1.2086 +
1.2087 + if (rc == 0) {
1.2088 + EVDNS_UNLOCK(req->port); /* ????? nickm */
1.2089 + server_port_free(req->port);
1.2090 + mm_free(req);
1.2091 + return (1);
1.2092 + }
1.2093 + if (lock)
1.2094 + EVDNS_UNLOCK(req->port);
1.2095 + mm_free(req);
1.2096 + return (0);
1.2097 +}
1.2098 +
1.2099 +/* Free all storage held by an evdns_server_port. Only called when */
1.2100 +static void
1.2101 +server_port_free(struct evdns_server_port *port)
1.2102 +{
1.2103 + EVUTIL_ASSERT(port);
1.2104 + EVUTIL_ASSERT(!port->refcnt);
1.2105 + EVUTIL_ASSERT(!port->pending_replies);
1.2106 + if (port->socket > 0) {
1.2107 + evutil_closesocket(port->socket);
1.2108 + port->socket = -1;
1.2109 + }
1.2110 + (void) event_del(&port->event);
1.2111 + event_debug_unassign(&port->event);
1.2112 + EVTHREAD_FREE_LOCK(port->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
1.2113 + mm_free(port);
1.2114 +}
1.2115 +
1.2116 +/* exported function */
1.2117 +int
1.2118 +evdns_server_request_drop(struct evdns_server_request *_req)
1.2119 +{
1.2120 + struct server_request *req = TO_SERVER_REQUEST(_req);
1.2121 + server_request_free(req);
1.2122 + return 0;
1.2123 +}
1.2124 +
1.2125 +/* exported function */
1.2126 +int
1.2127 +evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len)
1.2128 +{
1.2129 + struct server_request *req = TO_SERVER_REQUEST(_req);
1.2130 + if (addr_len < (int)req->addrlen)
1.2131 + return -1;
1.2132 + memcpy(sa, &(req->addr), req->addrlen);
1.2133 + return req->addrlen;
1.2134 +}
1.2135 +
1.2136 +#undef APPEND16
1.2137 +#undef APPEND32
1.2138 +
1.2139 +/* this is a libevent callback function which is called when a request */
1.2140 +/* has timed out. */
1.2141 +static void
1.2142 +evdns_request_timeout_callback(evutil_socket_t fd, short events, void *arg) {
1.2143 + struct request *const req = (struct request *) arg;
1.2144 + struct evdns_base *base = req->base;
1.2145 +
1.2146 + (void) fd;
1.2147 + (void) events;
1.2148 +
1.2149 + log(EVDNS_LOG_DEBUG, "Request %p timed out", arg);
1.2150 + EVDNS_LOCK(base);
1.2151 +
1.2152 + req->ns->timedout++;
1.2153 + if (req->ns->timedout > req->base->global_max_nameserver_timeout) {
1.2154 + req->ns->timedout = 0;
1.2155 + nameserver_failed(req->ns, "request timed out.");
1.2156 + }
1.2157 +
1.2158 + if (req->tx_count >= req->base->global_max_retransmits) {
1.2159 + /* this request has failed */
1.2160 + log(EVDNS_LOG_DEBUG, "Giving up on request %p; tx_count==%d",
1.2161 + arg, req->tx_count);
1.2162 + reply_schedule_callback(req, 0, DNS_ERR_TIMEOUT, NULL);
1.2163 + request_finished(req, &REQ_HEAD(req->base, req->trans_id), 1);
1.2164 + } else {
1.2165 + /* retransmit it */
1.2166 + struct nameserver *new_ns;
1.2167 + log(EVDNS_LOG_DEBUG, "Retransmitting request %p; tx_count==%d",
1.2168 + arg, req->tx_count);
1.2169 + (void) evtimer_del(&req->timeout_event);
1.2170 + new_ns = nameserver_pick(base);
1.2171 + if (new_ns)
1.2172 + req->ns = new_ns;
1.2173 + evdns_request_transmit(req);
1.2174 + }
1.2175 + EVDNS_UNLOCK(base);
1.2176 +}
1.2177 +
1.2178 +/* try to send a request to a given server. */
1.2179 +/* */
1.2180 +/* return: */
1.2181 +/* 0 ok */
1.2182 +/* 1 temporary failure */
1.2183 +/* 2 other failure */
1.2184 +static int
1.2185 +evdns_request_transmit_to(struct request *req, struct nameserver *server) {
1.2186 + int r;
1.2187 + ASSERT_LOCKED(req->base);
1.2188 + ASSERT_VALID_REQUEST(req);
1.2189 + r = sendto(server->socket, (void*)req->request, req->request_len, 0,
1.2190 + (struct sockaddr *)&server->address, server->addrlen);
1.2191 + if (r < 0) {
1.2192 + int err = evutil_socket_geterror(server->socket);
1.2193 + if (EVUTIL_ERR_RW_RETRIABLE(err))
1.2194 + return 1;
1.2195 + nameserver_failed(req->ns, evutil_socket_error_to_string(err));
1.2196 + return 2;
1.2197 + } else if (r != (int)req->request_len) {
1.2198 + return 1; /* short write */
1.2199 + } else {
1.2200 + return 0;
1.2201 + }
1.2202 +}
1.2203 +
1.2204 +/* try to send a request, updating the fields of the request */
1.2205 +/* as needed */
1.2206 +/* */
1.2207 +/* return: */
1.2208 +/* 0 ok */
1.2209 +/* 1 failed */
1.2210 +static int
1.2211 +evdns_request_transmit(struct request *req) {
1.2212 + int retcode = 0, r;
1.2213 +
1.2214 + ASSERT_LOCKED(req->base);
1.2215 + ASSERT_VALID_REQUEST(req);
1.2216 + /* if we fail to send this packet then this flag marks it */
1.2217 + /* for evdns_transmit */
1.2218 + req->transmit_me = 1;
1.2219 + EVUTIL_ASSERT(req->trans_id != 0xffff);
1.2220 +
1.2221 + if (req->ns->choked) {
1.2222 + /* don't bother trying to write to a socket */
1.2223 + /* which we have had EAGAIN from */
1.2224 + return 1;
1.2225 + }
1.2226 +
1.2227 + r = evdns_request_transmit_to(req, req->ns);
1.2228 + switch (r) {
1.2229 + case 1:
1.2230 + /* temp failure */
1.2231 + req->ns->choked = 1;
1.2232 + nameserver_write_waiting(req->ns, 1);
1.2233 + return 1;
1.2234 + case 2:
1.2235 + /* failed to transmit the request entirely. */
1.2236 + retcode = 1;
1.2237 + /* fall through: we'll set a timeout, which will time out,
1.2238 + * and make us retransmit the request anyway. */
1.2239 + default:
1.2240 + /* all ok */
1.2241 + log(EVDNS_LOG_DEBUG,
1.2242 + "Setting timeout for request %p, sent to nameserver %p", req, req->ns);
1.2243 + if (evtimer_add(&req->timeout_event, &req->base->global_timeout) < 0) {
1.2244 + log(EVDNS_LOG_WARN,
1.2245 + "Error from libevent when adding timer for request %p",
1.2246 + req);
1.2247 + /* ???? Do more? */
1.2248 + }
1.2249 + req->tx_count++;
1.2250 + req->transmit_me = 0;
1.2251 + return retcode;
1.2252 + }
1.2253 +}
1.2254 +
1.2255 +static void
1.2256 +nameserver_probe_callback(int result, char type, int count, int ttl, void *addresses, void *arg) {
1.2257 + struct nameserver *const ns = (struct nameserver *) arg;
1.2258 + (void) type;
1.2259 + (void) count;
1.2260 + (void) ttl;
1.2261 + (void) addresses;
1.2262 +
1.2263 + if (result == DNS_ERR_CANCEL) {
1.2264 + /* We canceled this request because the nameserver came up
1.2265 + * for some other reason. Do not change our opinion about
1.2266 + * the nameserver. */
1.2267 + return;
1.2268 + }
1.2269 +
1.2270 + EVDNS_LOCK(ns->base);
1.2271 + ns->probe_request = NULL;
1.2272 + if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) {
1.2273 + /* this is a good reply */
1.2274 + nameserver_up(ns);
1.2275 + } else {
1.2276 + nameserver_probe_failed(ns);
1.2277 + }
1.2278 + EVDNS_UNLOCK(ns->base);
1.2279 +}
1.2280 +
1.2281 +static void
1.2282 +nameserver_send_probe(struct nameserver *const ns) {
1.2283 + struct evdns_request *handle;
1.2284 + struct request *req;
1.2285 + char addrbuf[128];
1.2286 + /* here we need to send a probe to a given nameserver */
1.2287 + /* in the hope that it is up now. */
1.2288 +
1.2289 + ASSERT_LOCKED(ns->base);
1.2290 + log(EVDNS_LOG_DEBUG, "Sending probe to %s",
1.2291 + evutil_format_sockaddr_port(
1.2292 + (struct sockaddr *)&ns->address,
1.2293 + addrbuf, sizeof(addrbuf)));
1.2294 + handle = mm_calloc(1, sizeof(*handle));
1.2295 + if (!handle) return;
1.2296 + req = request_new(ns->base, handle, TYPE_A, "google.com", DNS_QUERY_NO_SEARCH, nameserver_probe_callback, ns);
1.2297 + if (!req) {
1.2298 + mm_free(handle);
1.2299 + return;
1.2300 + }
1.2301 + ns->probe_request = handle;
1.2302 + /* we force this into the inflight queue no matter what */
1.2303 + request_trans_id_set(req, transaction_id_pick(ns->base));
1.2304 + req->ns = ns;
1.2305 + request_submit(req);
1.2306 +}
1.2307 +
1.2308 +/* returns: */
1.2309 +/* 0 didn't try to transmit anything */
1.2310 +/* 1 tried to transmit something */
1.2311 +static int
1.2312 +evdns_transmit(struct evdns_base *base) {
1.2313 + char did_try_to_transmit = 0;
1.2314 + int i;
1.2315 +
1.2316 + ASSERT_LOCKED(base);
1.2317 + for (i = 0; i < base->n_req_heads; ++i) {
1.2318 + if (base->req_heads[i]) {
1.2319 + struct request *const started_at = base->req_heads[i], *req = started_at;
1.2320 + /* first transmit all the requests which are currently waiting */
1.2321 + do {
1.2322 + if (req->transmit_me) {
1.2323 + did_try_to_transmit = 1;
1.2324 + evdns_request_transmit(req);
1.2325 + }
1.2326 +
1.2327 + req = req->next;
1.2328 + } while (req != started_at);
1.2329 + }
1.2330 + }
1.2331 +
1.2332 + return did_try_to_transmit;
1.2333 +}
1.2334 +
1.2335 +/* exported function */
1.2336 +int
1.2337 +evdns_base_count_nameservers(struct evdns_base *base)
1.2338 +{
1.2339 + const struct nameserver *server;
1.2340 + int n = 0;
1.2341 +
1.2342 + EVDNS_LOCK(base);
1.2343 + server = base->server_head;
1.2344 + if (!server)
1.2345 + goto done;
1.2346 + do {
1.2347 + ++n;
1.2348 + server = server->next;
1.2349 + } while (server != base->server_head);
1.2350 +done:
1.2351 + EVDNS_UNLOCK(base);
1.2352 + return n;
1.2353 +}
1.2354 +
1.2355 +int
1.2356 +evdns_count_nameservers(void)
1.2357 +{
1.2358 + return evdns_base_count_nameservers(current_base);
1.2359 +}
1.2360 +
1.2361 +/* exported function */
1.2362 +int
1.2363 +evdns_base_clear_nameservers_and_suspend(struct evdns_base *base)
1.2364 +{
1.2365 + struct nameserver *server, *started_at;
1.2366 + int i;
1.2367 +
1.2368 + EVDNS_LOCK(base);
1.2369 + server = base->server_head;
1.2370 + started_at = base->server_head;
1.2371 + if (!server) {
1.2372 + EVDNS_UNLOCK(base);
1.2373 + return 0;
1.2374 + }
1.2375 + while (1) {
1.2376 + struct nameserver *next = server->next;
1.2377 + (void) event_del(&server->event);
1.2378 + if (evtimer_initialized(&server->timeout_event))
1.2379 + (void) evtimer_del(&server->timeout_event);
1.2380 + if (server->probe_request) {
1.2381 + evdns_cancel_request(server->base, server->probe_request);
1.2382 + server->probe_request = NULL;
1.2383 + }
1.2384 + if (server->socket >= 0)
1.2385 + evutil_closesocket(server->socket);
1.2386 + mm_free(server);
1.2387 + if (next == started_at)
1.2388 + break;
1.2389 + server = next;
1.2390 + }
1.2391 + base->server_head = NULL;
1.2392 + base->global_good_nameservers = 0;
1.2393 +
1.2394 + for (i = 0; i < base->n_req_heads; ++i) {
1.2395 + struct request *req, *req_started_at;
1.2396 + req = req_started_at = base->req_heads[i];
1.2397 + while (req) {
1.2398 + struct request *next = req->next;
1.2399 + req->tx_count = req->reissue_count = 0;
1.2400 + req->ns = NULL;
1.2401 + /* ???? What to do about searches? */
1.2402 + (void) evtimer_del(&req->timeout_event);
1.2403 + req->trans_id = 0;
1.2404 + req->transmit_me = 0;
1.2405 +
1.2406 + base->global_requests_waiting++;
1.2407 + evdns_request_insert(req, &base->req_waiting_head);
1.2408 + /* We want to insert these suspended elements at the front of
1.2409 + * the waiting queue, since they were pending before any of
1.2410 + * the waiting entries were added. This is a circular list,
1.2411 + * so we can just shift the start back by one.*/
1.2412 + base->req_waiting_head = base->req_waiting_head->prev;
1.2413 +
1.2414 + if (next == req_started_at)
1.2415 + break;
1.2416 + req = next;
1.2417 + }
1.2418 + base->req_heads[i] = NULL;
1.2419 + }
1.2420 +
1.2421 + base->global_requests_inflight = 0;
1.2422 +
1.2423 + EVDNS_UNLOCK(base);
1.2424 + return 0;
1.2425 +}
1.2426 +
1.2427 +int
1.2428 +evdns_clear_nameservers_and_suspend(void)
1.2429 +{
1.2430 + return evdns_base_clear_nameservers_and_suspend(current_base);
1.2431 +}
1.2432 +
1.2433 +
1.2434 +/* exported function */
1.2435 +int
1.2436 +evdns_base_resume(struct evdns_base *base)
1.2437 +{
1.2438 + EVDNS_LOCK(base);
1.2439 + evdns_requests_pump_waiting_queue(base);
1.2440 + EVDNS_UNLOCK(base);
1.2441 + return 0;
1.2442 +}
1.2443 +
1.2444 +int
1.2445 +evdns_resume(void)
1.2446 +{
1.2447 + return evdns_base_resume(current_base);
1.2448 +}
1.2449 +
1.2450 +static int
1.2451 +_evdns_nameserver_add_impl(struct evdns_base *base, const struct sockaddr *address, int addrlen) {
1.2452 + /* first check to see if we already have this nameserver */
1.2453 +
1.2454 + const struct nameserver *server = base->server_head, *const started_at = base->server_head;
1.2455 + struct nameserver *ns;
1.2456 + int err = 0;
1.2457 + char addrbuf[128];
1.2458 +
1.2459 + ASSERT_LOCKED(base);
1.2460 + if (server) {
1.2461 + do {
1.2462 + if (!evutil_sockaddr_cmp((struct sockaddr*)&server->address, address, 1)) return 3;
1.2463 + server = server->next;
1.2464 + } while (server != started_at);
1.2465 + }
1.2466 + if (addrlen > (int)sizeof(ns->address)) {
1.2467 + log(EVDNS_LOG_DEBUG, "Addrlen %d too long.", (int)addrlen);
1.2468 + return 2;
1.2469 + }
1.2470 +
1.2471 + ns = (struct nameserver *) mm_malloc(sizeof(struct nameserver));
1.2472 + if (!ns) return -1;
1.2473 +
1.2474 + memset(ns, 0, sizeof(struct nameserver));
1.2475 + ns->base = base;
1.2476 +
1.2477 + evtimer_assign(&ns->timeout_event, ns->base->event_base, nameserver_prod_callback, ns);
1.2478 +
1.2479 + ns->socket = socket(address->sa_family, SOCK_DGRAM, 0);
1.2480 + if (ns->socket < 0) { err = 1; goto out1; }
1.2481 + evutil_make_socket_closeonexec(ns->socket);
1.2482 + evutil_make_socket_nonblocking(ns->socket);
1.2483 +
1.2484 + if (base->global_outgoing_addrlen &&
1.2485 + !evutil_sockaddr_is_loopback(address)) {
1.2486 + if (bind(ns->socket,
1.2487 + (struct sockaddr*)&base->global_outgoing_address,
1.2488 + base->global_outgoing_addrlen) < 0) {
1.2489 + log(EVDNS_LOG_WARN,"Couldn't bind to outgoing address");
1.2490 + err = 2;
1.2491 + goto out2;
1.2492 + }
1.2493 + }
1.2494 +
1.2495 + memcpy(&ns->address, address, addrlen);
1.2496 + ns->addrlen = addrlen;
1.2497 + ns->state = 1;
1.2498 + event_assign(&ns->event, ns->base->event_base, ns->socket, EV_READ | EV_PERSIST, nameserver_ready_callback, ns);
1.2499 + if (event_add(&ns->event, NULL) < 0) {
1.2500 + err = 2;
1.2501 + goto out2;
1.2502 + }
1.2503 +
1.2504 + log(EVDNS_LOG_DEBUG, "Added nameserver %s as %p",
1.2505 + evutil_format_sockaddr_port(address, addrbuf, sizeof(addrbuf)), ns);
1.2506 +
1.2507 + /* insert this nameserver into the list of them */
1.2508 + if (!base->server_head) {
1.2509 + ns->next = ns->prev = ns;
1.2510 + base->server_head = ns;
1.2511 + } else {
1.2512 + ns->next = base->server_head->next;
1.2513 + ns->prev = base->server_head;
1.2514 + base->server_head->next = ns;
1.2515 + ns->next->prev = ns;
1.2516 + }
1.2517 +
1.2518 + base->global_good_nameservers++;
1.2519 +
1.2520 + return 0;
1.2521 +
1.2522 +out2:
1.2523 + evutil_closesocket(ns->socket);
1.2524 +out1:
1.2525 + event_debug_unassign(&ns->event);
1.2526 + mm_free(ns);
1.2527 + log(EVDNS_LOG_WARN, "Unable to add nameserver %s: error %d",
1.2528 + evutil_format_sockaddr_port(address, addrbuf, sizeof(addrbuf)), err);
1.2529 + return err;
1.2530 +}
1.2531 +
1.2532 +/* exported function */
1.2533 +int
1.2534 +evdns_base_nameserver_add(struct evdns_base *base, unsigned long int address)
1.2535 +{
1.2536 + struct sockaddr_in sin;
1.2537 + int res;
1.2538 + memset(&sin, 0, sizeof(sin));
1.2539 + sin.sin_addr.s_addr = address;
1.2540 + sin.sin_port = htons(53);
1.2541 + sin.sin_family = AF_INET;
1.2542 + EVDNS_LOCK(base);
1.2543 + res = _evdns_nameserver_add_impl(base, (struct sockaddr*)&sin, sizeof(sin));
1.2544 + EVDNS_UNLOCK(base);
1.2545 + return res;
1.2546 +}
1.2547 +
1.2548 +int
1.2549 +evdns_nameserver_add(unsigned long int address) {
1.2550 + if (!current_base)
1.2551 + current_base = evdns_base_new(NULL, 0);
1.2552 + return evdns_base_nameserver_add(current_base, address);
1.2553 +}
1.2554 +
1.2555 +static void
1.2556 +sockaddr_setport(struct sockaddr *sa, ev_uint16_t port)
1.2557 +{
1.2558 + if (sa->sa_family == AF_INET) {
1.2559 + ((struct sockaddr_in *)sa)->sin_port = htons(port);
1.2560 + } else if (sa->sa_family == AF_INET6) {
1.2561 + ((struct sockaddr_in6 *)sa)->sin6_port = htons(port);
1.2562 + }
1.2563 +}
1.2564 +
1.2565 +static ev_uint16_t
1.2566 +sockaddr_getport(struct sockaddr *sa)
1.2567 +{
1.2568 + if (sa->sa_family == AF_INET) {
1.2569 + return ntohs(((struct sockaddr_in *)sa)->sin_port);
1.2570 + } else if (sa->sa_family == AF_INET6) {
1.2571 + return ntohs(((struct sockaddr_in6 *)sa)->sin6_port);
1.2572 + } else {
1.2573 + return 0;
1.2574 + }
1.2575 +}
1.2576 +
1.2577 +/* exported function */
1.2578 +int
1.2579 +evdns_base_nameserver_ip_add(struct evdns_base *base, const char *ip_as_string) {
1.2580 + struct sockaddr_storage ss;
1.2581 + struct sockaddr *sa;
1.2582 + int len = sizeof(ss);
1.2583 + int res;
1.2584 + if (evutil_parse_sockaddr_port(ip_as_string, (struct sockaddr *)&ss,
1.2585 + &len)) {
1.2586 + log(EVDNS_LOG_WARN, "Unable to parse nameserver address %s",
1.2587 + ip_as_string);
1.2588 + return 4;
1.2589 + }
1.2590 + sa = (struct sockaddr *) &ss;
1.2591 + if (sockaddr_getport(sa) == 0)
1.2592 + sockaddr_setport(sa, 53);
1.2593 +
1.2594 + EVDNS_LOCK(base);
1.2595 + res = _evdns_nameserver_add_impl(base, sa, len);
1.2596 + EVDNS_UNLOCK(base);
1.2597 + return res;
1.2598 +}
1.2599 +
1.2600 +int
1.2601 +evdns_nameserver_ip_add(const char *ip_as_string) {
1.2602 + if (!current_base)
1.2603 + current_base = evdns_base_new(NULL, 0);
1.2604 + return evdns_base_nameserver_ip_add(current_base, ip_as_string);
1.2605 +}
1.2606 +
1.2607 +int
1.2608 +evdns_base_nameserver_sockaddr_add(struct evdns_base *base,
1.2609 + const struct sockaddr *sa, ev_socklen_t len, unsigned flags)
1.2610 +{
1.2611 + int res;
1.2612 + EVUTIL_ASSERT(base);
1.2613 + EVDNS_LOCK(base);
1.2614 + res = _evdns_nameserver_add_impl(base, sa, len);
1.2615 + EVDNS_UNLOCK(base);
1.2616 + return res;
1.2617 +}
1.2618 +
1.2619 +/* remove from the queue */
1.2620 +static void
1.2621 +evdns_request_remove(struct request *req, struct request **head)
1.2622 +{
1.2623 + ASSERT_LOCKED(req->base);
1.2624 + ASSERT_VALID_REQUEST(req);
1.2625 +
1.2626 +#if 0
1.2627 + {
1.2628 + struct request *ptr;
1.2629 + int found = 0;
1.2630 + EVUTIL_ASSERT(*head != NULL);
1.2631 +
1.2632 + ptr = *head;
1.2633 + do {
1.2634 + if (ptr == req) {
1.2635 + found = 1;
1.2636 + break;
1.2637 + }
1.2638 + ptr = ptr->next;
1.2639 + } while (ptr != *head);
1.2640 + EVUTIL_ASSERT(found);
1.2641 +
1.2642 + EVUTIL_ASSERT(req->next);
1.2643 + }
1.2644 +#endif
1.2645 +
1.2646 + if (req->next == req) {
1.2647 + /* only item in the list */
1.2648 + *head = NULL;
1.2649 + } else {
1.2650 + req->next->prev = req->prev;
1.2651 + req->prev->next = req->next;
1.2652 + if (*head == req) *head = req->next;
1.2653 + }
1.2654 + req->next = req->prev = NULL;
1.2655 +}
1.2656 +
1.2657 +/* insert into the tail of the queue */
1.2658 +static void
1.2659 +evdns_request_insert(struct request *req, struct request **head) {
1.2660 + ASSERT_LOCKED(req->base);
1.2661 + ASSERT_VALID_REQUEST(req);
1.2662 + if (!*head) {
1.2663 + *head = req;
1.2664 + req->next = req->prev = req;
1.2665 + return;
1.2666 + }
1.2667 +
1.2668 + req->prev = (*head)->prev;
1.2669 + req->prev->next = req;
1.2670 + req->next = *head;
1.2671 + (*head)->prev = req;
1.2672 +}
1.2673 +
1.2674 +static int
1.2675 +string_num_dots(const char *s) {
1.2676 + int count = 0;
1.2677 + while ((s = strchr(s, '.'))) {
1.2678 + s++;
1.2679 + count++;
1.2680 + }
1.2681 + return count;
1.2682 +}
1.2683 +
1.2684 +static struct request *
1.2685 +request_new(struct evdns_base *base, struct evdns_request *handle, int type,
1.2686 + const char *name, int flags, evdns_callback_type callback,
1.2687 + void *user_ptr) {
1.2688 +
1.2689 + const char issuing_now =
1.2690 + (base->global_requests_inflight < base->global_max_requests_inflight) ? 1 : 0;
1.2691 +
1.2692 + const size_t name_len = strlen(name);
1.2693 + const size_t request_max_len = evdns_request_len(name_len);
1.2694 + const u16 trans_id = issuing_now ? transaction_id_pick(base) : 0xffff;
1.2695 + /* the request data is alloced in a single block with the header */
1.2696 + struct request *const req =
1.2697 + mm_malloc(sizeof(struct request) + request_max_len);
1.2698 + int rlen;
1.2699 + char namebuf[256];
1.2700 + (void) flags;
1.2701 +
1.2702 + ASSERT_LOCKED(base);
1.2703 +
1.2704 + if (!req) return NULL;
1.2705 +
1.2706 + if (name_len >= sizeof(namebuf)) {
1.2707 + mm_free(req);
1.2708 + return NULL;
1.2709 + }
1.2710 +
1.2711 + memset(req, 0, sizeof(struct request));
1.2712 + req->base = base;
1.2713 +
1.2714 + evtimer_assign(&req->timeout_event, req->base->event_base, evdns_request_timeout_callback, req);
1.2715 +
1.2716 + if (base->global_randomize_case) {
1.2717 + unsigned i;
1.2718 + char randbits[(sizeof(namebuf)+7)/8];
1.2719 + strlcpy(namebuf, name, sizeof(namebuf));
1.2720 + evutil_secure_rng_get_bytes(randbits, (name_len+7)/8);
1.2721 + for (i = 0; i < name_len; ++i) {
1.2722 + if (EVUTIL_ISALPHA(namebuf[i])) {
1.2723 + if ((randbits[i >> 3] & (1<<(i & 7))))
1.2724 + namebuf[i] |= 0x20;
1.2725 + else
1.2726 + namebuf[i] &= ~0x20;
1.2727 + }
1.2728 + }
1.2729 + name = namebuf;
1.2730 + }
1.2731 +
1.2732 + /* request data lives just after the header */
1.2733 + req->request = ((u8 *) req) + sizeof(struct request);
1.2734 + /* denotes that the request data shouldn't be free()ed */
1.2735 + req->request_appended = 1;
1.2736 + rlen = evdns_request_data_build(name, name_len, trans_id,
1.2737 + type, CLASS_INET, req->request, request_max_len);
1.2738 + if (rlen < 0)
1.2739 + goto err1;
1.2740 +
1.2741 + req->request_len = rlen;
1.2742 + req->trans_id = trans_id;
1.2743 + req->tx_count = 0;
1.2744 + req->request_type = type;
1.2745 + req->user_pointer = user_ptr;
1.2746 + req->user_callback = callback;
1.2747 + req->ns = issuing_now ? nameserver_pick(base) : NULL;
1.2748 + req->next = req->prev = NULL;
1.2749 + req->handle = handle;
1.2750 + if (handle) {
1.2751 + handle->current_req = req;
1.2752 + handle->base = base;
1.2753 + }
1.2754 +
1.2755 + return req;
1.2756 +err1:
1.2757 + mm_free(req);
1.2758 + return NULL;
1.2759 +}
1.2760 +
1.2761 +static void
1.2762 +request_submit(struct request *const req) {
1.2763 + struct evdns_base *base = req->base;
1.2764 + ASSERT_LOCKED(base);
1.2765 + ASSERT_VALID_REQUEST(req);
1.2766 + if (req->ns) {
1.2767 + /* if it has a nameserver assigned then this is going */
1.2768 + /* straight into the inflight queue */
1.2769 + evdns_request_insert(req, &REQ_HEAD(base, req->trans_id));
1.2770 + base->global_requests_inflight++;
1.2771 + evdns_request_transmit(req);
1.2772 + } else {
1.2773 + evdns_request_insert(req, &base->req_waiting_head);
1.2774 + base->global_requests_waiting++;
1.2775 + }
1.2776 +}
1.2777 +
1.2778 +/* exported function */
1.2779 +void
1.2780 +evdns_cancel_request(struct evdns_base *base, struct evdns_request *handle)
1.2781 +{
1.2782 + struct request *req;
1.2783 +
1.2784 + if (!handle->current_req)
1.2785 + return;
1.2786 +
1.2787 + if (!base) {
1.2788 + /* This redundancy is silly; can we fix it? (Not for 2.0) XXXX */
1.2789 + base = handle->base;
1.2790 + if (!base)
1.2791 + base = handle->current_req->base;
1.2792 + }
1.2793 +
1.2794 + EVDNS_LOCK(base);
1.2795 + if (handle->pending_cb) {
1.2796 + EVDNS_UNLOCK(base);
1.2797 + return;
1.2798 + }
1.2799 +
1.2800 + req = handle->current_req;
1.2801 + ASSERT_VALID_REQUEST(req);
1.2802 +
1.2803 + reply_schedule_callback(req, 0, DNS_ERR_CANCEL, NULL);
1.2804 + if (req->ns) {
1.2805 + /* remove from inflight queue */
1.2806 + request_finished(req, &REQ_HEAD(base, req->trans_id), 1);
1.2807 + } else {
1.2808 + /* remove from global_waiting head */
1.2809 + request_finished(req, &base->req_waiting_head, 1);
1.2810 + }
1.2811 + EVDNS_UNLOCK(base);
1.2812 +}
1.2813 +
1.2814 +/* exported function */
1.2815 +struct evdns_request *
1.2816 +evdns_base_resolve_ipv4(struct evdns_base *base, const char *name, int flags,
1.2817 + evdns_callback_type callback, void *ptr) {
1.2818 + struct evdns_request *handle;
1.2819 + struct request *req;
1.2820 + log(EVDNS_LOG_DEBUG, "Resolve requested for %s", name);
1.2821 + handle = mm_calloc(1, sizeof(*handle));
1.2822 + if (handle == NULL)
1.2823 + return NULL;
1.2824 + EVDNS_LOCK(base);
1.2825 + if (flags & DNS_QUERY_NO_SEARCH) {
1.2826 + req =
1.2827 + request_new(base, handle, TYPE_A, name, flags,
1.2828 + callback, ptr);
1.2829 + if (req)
1.2830 + request_submit(req);
1.2831 + } else {
1.2832 + search_request_new(base, handle, TYPE_A, name, flags,
1.2833 + callback, ptr);
1.2834 + }
1.2835 + if (handle->current_req == NULL) {
1.2836 + mm_free(handle);
1.2837 + handle = NULL;
1.2838 + }
1.2839 + EVDNS_UNLOCK(base);
1.2840 + return handle;
1.2841 +}
1.2842 +
1.2843 +int evdns_resolve_ipv4(const char *name, int flags,
1.2844 + evdns_callback_type callback, void *ptr)
1.2845 +{
1.2846 + return evdns_base_resolve_ipv4(current_base, name, flags, callback, ptr)
1.2847 + ? 0 : -1;
1.2848 +}
1.2849 +
1.2850 +
1.2851 +/* exported function */
1.2852 +struct evdns_request *
1.2853 +evdns_base_resolve_ipv6(struct evdns_base *base,
1.2854 + const char *name, int flags,
1.2855 + evdns_callback_type callback, void *ptr)
1.2856 +{
1.2857 + struct evdns_request *handle;
1.2858 + struct request *req;
1.2859 + log(EVDNS_LOG_DEBUG, "Resolve requested for %s", name);
1.2860 + handle = mm_calloc(1, sizeof(*handle));
1.2861 + if (handle == NULL)
1.2862 + return NULL;
1.2863 + EVDNS_LOCK(base);
1.2864 + if (flags & DNS_QUERY_NO_SEARCH) {
1.2865 + req = request_new(base, handle, TYPE_AAAA, name, flags,
1.2866 + callback, ptr);
1.2867 + if (req)
1.2868 + request_submit(req);
1.2869 + } else {
1.2870 + search_request_new(base, handle, TYPE_AAAA, name, flags,
1.2871 + callback, ptr);
1.2872 + }
1.2873 + if (handle->current_req == NULL) {
1.2874 + mm_free(handle);
1.2875 + handle = NULL;
1.2876 + }
1.2877 + EVDNS_UNLOCK(base);
1.2878 + return handle;
1.2879 +}
1.2880 +
1.2881 +int evdns_resolve_ipv6(const char *name, int flags,
1.2882 + evdns_callback_type callback, void *ptr) {
1.2883 + return evdns_base_resolve_ipv6(current_base, name, flags, callback, ptr)
1.2884 + ? 0 : -1;
1.2885 +}
1.2886 +
1.2887 +struct evdns_request *
1.2888 +evdns_base_resolve_reverse(struct evdns_base *base, const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) {
1.2889 + char buf[32];
1.2890 + struct evdns_request *handle;
1.2891 + struct request *req;
1.2892 + u32 a;
1.2893 + EVUTIL_ASSERT(in);
1.2894 + a = ntohl(in->s_addr);
1.2895 + evutil_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
1.2896 + (int)(u8)((a )&0xff),
1.2897 + (int)(u8)((a>>8 )&0xff),
1.2898 + (int)(u8)((a>>16)&0xff),
1.2899 + (int)(u8)((a>>24)&0xff));
1.2900 + handle = mm_calloc(1, sizeof(*handle));
1.2901 + if (handle == NULL)
1.2902 + return NULL;
1.2903 + log(EVDNS_LOG_DEBUG, "Resolve requested for %s (reverse)", buf);
1.2904 + EVDNS_LOCK(base);
1.2905 + req = request_new(base, handle, TYPE_PTR, buf, flags, callback, ptr);
1.2906 + if (req)
1.2907 + request_submit(req);
1.2908 + if (handle->current_req == NULL) {
1.2909 + mm_free(handle);
1.2910 + handle = NULL;
1.2911 + }
1.2912 + EVDNS_UNLOCK(base);
1.2913 + return (handle);
1.2914 +}
1.2915 +
1.2916 +int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) {
1.2917 + return evdns_base_resolve_reverse(current_base, in, flags, callback, ptr)
1.2918 + ? 0 : -1;
1.2919 +}
1.2920 +
1.2921 +struct evdns_request *
1.2922 +evdns_base_resolve_reverse_ipv6(struct evdns_base *base, const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) {
1.2923 + /* 32 nybbles, 32 periods, "ip6.arpa", NUL. */
1.2924 + char buf[73];
1.2925 + char *cp;
1.2926 + struct evdns_request *handle;
1.2927 + struct request *req;
1.2928 + int i;
1.2929 + EVUTIL_ASSERT(in);
1.2930 + cp = buf;
1.2931 + for (i=15; i >= 0; --i) {
1.2932 + u8 byte = in->s6_addr[i];
1.2933 + *cp++ = "0123456789abcdef"[byte & 0x0f];
1.2934 + *cp++ = '.';
1.2935 + *cp++ = "0123456789abcdef"[byte >> 4];
1.2936 + *cp++ = '.';
1.2937 + }
1.2938 + EVUTIL_ASSERT(cp + strlen("ip6.arpa") < buf+sizeof(buf));
1.2939 + memcpy(cp, "ip6.arpa", strlen("ip6.arpa")+1);
1.2940 + handle = mm_calloc(1, sizeof(*handle));
1.2941 + if (handle == NULL)
1.2942 + return NULL;
1.2943 + log(EVDNS_LOG_DEBUG, "Resolve requested for %s (reverse)", buf);
1.2944 + EVDNS_LOCK(base);
1.2945 + req = request_new(base, handle, TYPE_PTR, buf, flags, callback, ptr);
1.2946 + if (req)
1.2947 + request_submit(req);
1.2948 + if (handle->current_req == NULL) {
1.2949 + mm_free(handle);
1.2950 + handle = NULL;
1.2951 + }
1.2952 + EVDNS_UNLOCK(base);
1.2953 + return (handle);
1.2954 +}
1.2955 +
1.2956 +int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) {
1.2957 + return evdns_base_resolve_reverse_ipv6(current_base, in, flags, callback, ptr)
1.2958 + ? 0 : -1;
1.2959 +}
1.2960 +
1.2961 +/* ================================================================= */
1.2962 +/* Search support */
1.2963 +/* */
1.2964 +/* the libc resolver has support for searching a number of domains */
1.2965 +/* to find a name. If nothing else then it takes the single domain */
1.2966 +/* from the gethostname() call. */
1.2967 +/* */
1.2968 +/* It can also be configured via the domain and search options in a */
1.2969 +/* resolv.conf. */
1.2970 +/* */
1.2971 +/* The ndots option controls how many dots it takes for the resolver */
1.2972 +/* to decide that a name is non-local and so try a raw lookup first. */
1.2973 +
1.2974 +struct search_domain {
1.2975 + int len;
1.2976 + struct search_domain *next;
1.2977 + /* the text string is appended to this structure */
1.2978 +};
1.2979 +
1.2980 +struct search_state {
1.2981 + int refcount;
1.2982 + int ndots;
1.2983 + int num_domains;
1.2984 + struct search_domain *head;
1.2985 +};
1.2986 +
1.2987 +static void
1.2988 +search_state_decref(struct search_state *const state) {
1.2989 + if (!state) return;
1.2990 + state->refcount--;
1.2991 + if (!state->refcount) {
1.2992 + struct search_domain *next, *dom;
1.2993 + for (dom = state->head; dom; dom = next) {
1.2994 + next = dom->next;
1.2995 + mm_free(dom);
1.2996 + }
1.2997 + mm_free(state);
1.2998 + }
1.2999 +}
1.3000 +
1.3001 +static struct search_state *
1.3002 +search_state_new(void) {
1.3003 + struct search_state *state = (struct search_state *) mm_malloc(sizeof(struct search_state));
1.3004 + if (!state) return NULL;
1.3005 + memset(state, 0, sizeof(struct search_state));
1.3006 + state->refcount = 1;
1.3007 + state->ndots = 1;
1.3008 +
1.3009 + return state;
1.3010 +}
1.3011 +
1.3012 +static void
1.3013 +search_postfix_clear(struct evdns_base *base) {
1.3014 + search_state_decref(base->global_search_state);
1.3015 +
1.3016 + base->global_search_state = search_state_new();
1.3017 +}
1.3018 +
1.3019 +/* exported function */
1.3020 +void
1.3021 +evdns_base_search_clear(struct evdns_base *base)
1.3022 +{
1.3023 + EVDNS_LOCK(base);
1.3024 + search_postfix_clear(base);
1.3025 + EVDNS_UNLOCK(base);
1.3026 +}
1.3027 +
1.3028 +void
1.3029 +evdns_search_clear(void) {
1.3030 + evdns_base_search_clear(current_base);
1.3031 +}
1.3032 +
1.3033 +static void
1.3034 +search_postfix_add(struct evdns_base *base, const char *domain) {
1.3035 + size_t domain_len;
1.3036 + struct search_domain *sdomain;
1.3037 + while (domain[0] == '.') domain++;
1.3038 + domain_len = strlen(domain);
1.3039 +
1.3040 + ASSERT_LOCKED(base);
1.3041 + if (!base->global_search_state) base->global_search_state = search_state_new();
1.3042 + if (!base->global_search_state) return;
1.3043 + base->global_search_state->num_domains++;
1.3044 +
1.3045 + sdomain = (struct search_domain *) mm_malloc(sizeof(struct search_domain) + domain_len);
1.3046 + if (!sdomain) return;
1.3047 + memcpy( ((u8 *) sdomain) + sizeof(struct search_domain), domain, domain_len);
1.3048 + sdomain->next = base->global_search_state->head;
1.3049 + sdomain->len = (int) domain_len;
1.3050 +
1.3051 + base->global_search_state->head = sdomain;
1.3052 +}
1.3053 +
1.3054 +/* reverse the order of members in the postfix list. This is needed because, */
1.3055 +/* when parsing resolv.conf we push elements in the wrong order */
1.3056 +static void
1.3057 +search_reverse(struct evdns_base *base) {
1.3058 + struct search_domain *cur, *prev = NULL, *next;
1.3059 + ASSERT_LOCKED(base);
1.3060 + cur = base->global_search_state->head;
1.3061 + while (cur) {
1.3062 + next = cur->next;
1.3063 + cur->next = prev;
1.3064 + prev = cur;
1.3065 + cur = next;
1.3066 + }
1.3067 +
1.3068 + base->global_search_state->head = prev;
1.3069 +}
1.3070 +
1.3071 +/* exported function */
1.3072 +void
1.3073 +evdns_base_search_add(struct evdns_base *base, const char *domain) {
1.3074 + EVDNS_LOCK(base);
1.3075 + search_postfix_add(base, domain);
1.3076 + EVDNS_UNLOCK(base);
1.3077 +}
1.3078 +void
1.3079 +evdns_search_add(const char *domain) {
1.3080 + evdns_base_search_add(current_base, domain);
1.3081 +}
1.3082 +
1.3083 +/* exported function */
1.3084 +void
1.3085 +evdns_base_search_ndots_set(struct evdns_base *base, const int ndots) {
1.3086 + EVDNS_LOCK(base);
1.3087 + if (!base->global_search_state) base->global_search_state = search_state_new();
1.3088 + if (base->global_search_state)
1.3089 + base->global_search_state->ndots = ndots;
1.3090 + EVDNS_UNLOCK(base);
1.3091 +}
1.3092 +void
1.3093 +evdns_search_ndots_set(const int ndots) {
1.3094 + evdns_base_search_ndots_set(current_base, ndots);
1.3095 +}
1.3096 +
1.3097 +static void
1.3098 +search_set_from_hostname(struct evdns_base *base) {
1.3099 + char hostname[HOST_NAME_MAX + 1], *domainname;
1.3100 +
1.3101 + ASSERT_LOCKED(base);
1.3102 + search_postfix_clear(base);
1.3103 + if (gethostname(hostname, sizeof(hostname))) return;
1.3104 + domainname = strchr(hostname, '.');
1.3105 + if (!domainname) return;
1.3106 + search_postfix_add(base, domainname);
1.3107 +}
1.3108 +
1.3109 +/* warning: returns malloced string */
1.3110 +static char *
1.3111 +search_make_new(const struct search_state *const state, int n, const char *const base_name) {
1.3112 + const size_t base_len = strlen(base_name);
1.3113 + const char need_to_append_dot = base_name[base_len - 1] == '.' ? 0 : 1;
1.3114 + struct search_domain *dom;
1.3115 +
1.3116 + for (dom = state->head; dom; dom = dom->next) {
1.3117 + if (!n--) {
1.3118 + /* this is the postfix we want */
1.3119 + /* the actual postfix string is kept at the end of the structure */
1.3120 + const u8 *const postfix = ((u8 *) dom) + sizeof(struct search_domain);
1.3121 + const int postfix_len = dom->len;
1.3122 + char *const newname = (char *) mm_malloc(base_len + need_to_append_dot + postfix_len + 1);
1.3123 + if (!newname) return NULL;
1.3124 + memcpy(newname, base_name, base_len);
1.3125 + if (need_to_append_dot) newname[base_len] = '.';
1.3126 + memcpy(newname + base_len + need_to_append_dot, postfix, postfix_len);
1.3127 + newname[base_len + need_to_append_dot + postfix_len] = 0;
1.3128 + return newname;
1.3129 + }
1.3130 + }
1.3131 +
1.3132 + /* we ran off the end of the list and still didn't find the requested string */
1.3133 + EVUTIL_ASSERT(0);
1.3134 + return NULL; /* unreachable; stops warnings in some compilers. */
1.3135 +}
1.3136 +
1.3137 +static struct request *
1.3138 +search_request_new(struct evdns_base *base, struct evdns_request *handle,
1.3139 + int type, const char *const name, int flags,
1.3140 + evdns_callback_type user_callback, void *user_arg) {
1.3141 + ASSERT_LOCKED(base);
1.3142 + EVUTIL_ASSERT(type == TYPE_A || type == TYPE_AAAA);
1.3143 + EVUTIL_ASSERT(handle->current_req == NULL);
1.3144 + if ( ((flags & DNS_QUERY_NO_SEARCH) == 0) &&
1.3145 + base->global_search_state &&
1.3146 + base->global_search_state->num_domains) {
1.3147 + /* we have some domains to search */
1.3148 + struct request *req;
1.3149 + if (string_num_dots(name) >= base->global_search_state->ndots) {
1.3150 + req = request_new(base, handle, type, name, flags, user_callback, user_arg);
1.3151 + if (!req) return NULL;
1.3152 + handle->search_index = -1;
1.3153 + } else {
1.3154 + char *const new_name = search_make_new(base->global_search_state, 0, name);
1.3155 + if (!new_name) return NULL;
1.3156 + req = request_new(base, handle, type, new_name, flags, user_callback, user_arg);
1.3157 + mm_free(new_name);
1.3158 + if (!req) return NULL;
1.3159 + handle->search_index = 0;
1.3160 + }
1.3161 + EVUTIL_ASSERT(handle->search_origname == NULL);
1.3162 + handle->search_origname = mm_strdup(name);
1.3163 + if (handle->search_origname == NULL) {
1.3164 + /* XXX Should we dealloc req? If yes, how? */
1.3165 + if (req)
1.3166 + mm_free(req);
1.3167 + return NULL;
1.3168 + }
1.3169 + handle->search_state = base->global_search_state;
1.3170 + handle->search_flags = flags;
1.3171 + base->global_search_state->refcount++;
1.3172 + request_submit(req);
1.3173 + return req;
1.3174 + } else {
1.3175 + struct request *const req = request_new(base, handle, type, name, flags, user_callback, user_arg);
1.3176 + if (!req) return NULL;
1.3177 + request_submit(req);
1.3178 + return req;
1.3179 + }
1.3180 +}
1.3181 +
1.3182 +/* this is called when a request has failed to find a name. We need to check */
1.3183 +/* if it is part of a search and, if so, try the next name in the list */
1.3184 +/* returns: */
1.3185 +/* 0 another request has been submitted */
1.3186 +/* 1 no more requests needed */
1.3187 +static int
1.3188 +search_try_next(struct evdns_request *const handle) {
1.3189 + struct request *req = handle->current_req;
1.3190 + struct evdns_base *base = req->base;
1.3191 + struct request *newreq;
1.3192 + ASSERT_LOCKED(base);
1.3193 + if (handle->search_state) {
1.3194 + /* it is part of a search */
1.3195 + char *new_name;
1.3196 + handle->search_index++;
1.3197 + if (handle->search_index >= handle->search_state->num_domains) {
1.3198 + /* no more postfixes to try, however we may need to try */
1.3199 + /* this name without a postfix */
1.3200 + if (string_num_dots(handle->search_origname) < handle->search_state->ndots) {
1.3201 + /* yep, we need to try it raw */
1.3202 + newreq = request_new(base, NULL, req->request_type, handle->search_origname, handle->search_flags, req->user_callback, req->user_pointer);
1.3203 + log(EVDNS_LOG_DEBUG, "Search: trying raw query %s", handle->search_origname);
1.3204 + if (newreq) {
1.3205 + search_request_finished(handle);
1.3206 + goto submit_next;
1.3207 + }
1.3208 + }
1.3209 + return 1;
1.3210 + }
1.3211 +
1.3212 + new_name = search_make_new(handle->search_state, handle->search_index, handle->search_origname);
1.3213 + if (!new_name) return 1;
1.3214 + log(EVDNS_LOG_DEBUG, "Search: now trying %s (%d)", new_name, handle->search_index);
1.3215 + newreq = request_new(base, NULL, req->request_type, new_name, handle->search_flags, req->user_callback, req->user_pointer);
1.3216 + mm_free(new_name);
1.3217 + if (!newreq) return 1;
1.3218 + goto submit_next;
1.3219 + }
1.3220 + return 1;
1.3221 +
1.3222 +submit_next:
1.3223 + request_finished(req, &REQ_HEAD(req->base, req->trans_id), 0);
1.3224 + handle->current_req = newreq;
1.3225 + newreq->handle = handle;
1.3226 + request_submit(newreq);
1.3227 + return 0;
1.3228 +}
1.3229 +
1.3230 +static void
1.3231 +search_request_finished(struct evdns_request *const handle) {
1.3232 + ASSERT_LOCKED(handle->current_req->base);
1.3233 + if (handle->search_state) {
1.3234 + search_state_decref(handle->search_state);
1.3235 + handle->search_state = NULL;
1.3236 + }
1.3237 + if (handle->search_origname) {
1.3238 + mm_free(handle->search_origname);
1.3239 + handle->search_origname = NULL;
1.3240 + }
1.3241 +}
1.3242 +
1.3243 +/* ================================================================= */
1.3244 +/* Parsing resolv.conf files */
1.3245 +
1.3246 +static void
1.3247 +evdns_resolv_set_defaults(struct evdns_base *base, int flags) {
1.3248 + /* if the file isn't found then we assume a local resolver */
1.3249 + ASSERT_LOCKED(base);
1.3250 + if (flags & DNS_OPTION_SEARCH) search_set_from_hostname(base);
1.3251 + if (flags & DNS_OPTION_NAMESERVERS) evdns_base_nameserver_ip_add(base,"127.0.0.1");
1.3252 +}
1.3253 +
1.3254 +#ifndef _EVENT_HAVE_STRTOK_R
1.3255 +static char *
1.3256 +strtok_r(char *s, const char *delim, char **state) {
1.3257 + char *cp, *start;
1.3258 + start = cp = s ? s : *state;
1.3259 + if (!cp)
1.3260 + return NULL;
1.3261 + while (*cp && !strchr(delim, *cp))
1.3262 + ++cp;
1.3263 + if (!*cp) {
1.3264 + if (cp == start)
1.3265 + return NULL;
1.3266 + *state = NULL;
1.3267 + return start;
1.3268 + } else {
1.3269 + *cp++ = '\0';
1.3270 + *state = cp;
1.3271 + return start;
1.3272 + }
1.3273 +}
1.3274 +#endif
1.3275 +
1.3276 +/* helper version of atoi which returns -1 on error */
1.3277 +static int
1.3278 +strtoint(const char *const str)
1.3279 +{
1.3280 + char *endptr;
1.3281 + const int r = strtol(str, &endptr, 10);
1.3282 + if (*endptr) return -1;
1.3283 + return r;
1.3284 +}
1.3285 +
1.3286 +/* Parse a number of seconds into a timeval; return -1 on error. */
1.3287 +static int
1.3288 +strtotimeval(const char *const str, struct timeval *out)
1.3289 +{
1.3290 + double d;
1.3291 + char *endptr;
1.3292 + d = strtod(str, &endptr);
1.3293 + if (*endptr) return -1;
1.3294 + if (d < 0) return -1;
1.3295 + out->tv_sec = (int) d;
1.3296 + out->tv_usec = (int) ((d - (int) d)*1000000);
1.3297 + if (out->tv_sec == 0 && out->tv_usec < 1000) /* less than 1 msec */
1.3298 + return -1;
1.3299 + return 0;
1.3300 +}
1.3301 +
1.3302 +/* helper version of atoi that returns -1 on error and clips to bounds. */
1.3303 +static int
1.3304 +strtoint_clipped(const char *const str, int min, int max)
1.3305 +{
1.3306 + int r = strtoint(str);
1.3307 + if (r == -1)
1.3308 + return r;
1.3309 + else if (r<min)
1.3310 + return min;
1.3311 + else if (r>max)
1.3312 + return max;
1.3313 + else
1.3314 + return r;
1.3315 +}
1.3316 +
1.3317 +static int
1.3318 +evdns_base_set_max_requests_inflight(struct evdns_base *base, int maxinflight)
1.3319 +{
1.3320 + int old_n_heads = base->n_req_heads, n_heads;
1.3321 + struct request **old_heads = base->req_heads, **new_heads, *req;
1.3322 + int i;
1.3323 +
1.3324 + ASSERT_LOCKED(base);
1.3325 + if (maxinflight < 1)
1.3326 + maxinflight = 1;
1.3327 + n_heads = (maxinflight+4) / 5;
1.3328 + EVUTIL_ASSERT(n_heads > 0);
1.3329 + new_heads = mm_calloc(n_heads, sizeof(struct request*));
1.3330 + if (!new_heads)
1.3331 + return (-1);
1.3332 + if (old_heads) {
1.3333 + for (i = 0; i < old_n_heads; ++i) {
1.3334 + while (old_heads[i]) {
1.3335 + req = old_heads[i];
1.3336 + evdns_request_remove(req, &old_heads[i]);
1.3337 + evdns_request_insert(req, &new_heads[req->trans_id % n_heads]);
1.3338 + }
1.3339 + }
1.3340 + mm_free(old_heads);
1.3341 + }
1.3342 + base->req_heads = new_heads;
1.3343 + base->n_req_heads = n_heads;
1.3344 + base->global_max_requests_inflight = maxinflight;
1.3345 + return (0);
1.3346 +}
1.3347 +
1.3348 +/* exported function */
1.3349 +int
1.3350 +evdns_base_set_option(struct evdns_base *base,
1.3351 + const char *option, const char *val)
1.3352 +{
1.3353 + int res;
1.3354 + EVDNS_LOCK(base);
1.3355 + res = evdns_base_set_option_impl(base, option, val, DNS_OPTIONS_ALL);
1.3356 + EVDNS_UNLOCK(base);
1.3357 + return res;
1.3358 +}
1.3359 +
1.3360 +static inline int
1.3361 +str_matches_option(const char *s1, const char *optionname)
1.3362 +{
1.3363 + /* Option names are given as "option:" We accept either 'option' in
1.3364 + * s1, or 'option:randomjunk'. The latter form is to implement the
1.3365 + * resolv.conf parser. */
1.3366 + size_t optlen = strlen(optionname);
1.3367 + size_t slen = strlen(s1);
1.3368 + if (slen == optlen || slen == optlen - 1)
1.3369 + return !strncmp(s1, optionname, slen);
1.3370 + else if (slen > optlen)
1.3371 + return !strncmp(s1, optionname, optlen);
1.3372 + else
1.3373 + return 0;
1.3374 +}
1.3375 +
1.3376 +static int
1.3377 +evdns_base_set_option_impl(struct evdns_base *base,
1.3378 + const char *option, const char *val, int flags)
1.3379 +{
1.3380 + ASSERT_LOCKED(base);
1.3381 + if (str_matches_option(option, "ndots:")) {
1.3382 + const int ndots = strtoint(val);
1.3383 + if (ndots == -1) return -1;
1.3384 + if (!(flags & DNS_OPTION_SEARCH)) return 0;
1.3385 + log(EVDNS_LOG_DEBUG, "Setting ndots to %d", ndots);
1.3386 + if (!base->global_search_state) base->global_search_state = search_state_new();
1.3387 + if (!base->global_search_state) return -1;
1.3388 + base->global_search_state->ndots = ndots;
1.3389 + } else if (str_matches_option(option, "timeout:")) {
1.3390 + struct timeval tv;
1.3391 + if (strtotimeval(val, &tv) == -1) return -1;
1.3392 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3393 + log(EVDNS_LOG_DEBUG, "Setting timeout to %s", val);
1.3394 + memcpy(&base->global_timeout, &tv, sizeof(struct timeval));
1.3395 + } else if (str_matches_option(option, "getaddrinfo-allow-skew:")) {
1.3396 + struct timeval tv;
1.3397 + if (strtotimeval(val, &tv) == -1) return -1;
1.3398 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3399 + log(EVDNS_LOG_DEBUG, "Setting getaddrinfo-allow-skew to %s",
1.3400 + val);
1.3401 + memcpy(&base->global_getaddrinfo_allow_skew, &tv,
1.3402 + sizeof(struct timeval));
1.3403 + } else if (str_matches_option(option, "max-timeouts:")) {
1.3404 + const int maxtimeout = strtoint_clipped(val, 1, 255);
1.3405 + if (maxtimeout == -1) return -1;
1.3406 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3407 + log(EVDNS_LOG_DEBUG, "Setting maximum allowed timeouts to %d",
1.3408 + maxtimeout);
1.3409 + base->global_max_nameserver_timeout = maxtimeout;
1.3410 + } else if (str_matches_option(option, "max-inflight:")) {
1.3411 + const int maxinflight = strtoint_clipped(val, 1, 65000);
1.3412 + if (maxinflight == -1) return -1;
1.3413 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3414 + log(EVDNS_LOG_DEBUG, "Setting maximum inflight requests to %d",
1.3415 + maxinflight);
1.3416 + evdns_base_set_max_requests_inflight(base, maxinflight);
1.3417 + } else if (str_matches_option(option, "attempts:")) {
1.3418 + int retries = strtoint(val);
1.3419 + if (retries == -1) return -1;
1.3420 + if (retries > 255) retries = 255;
1.3421 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3422 + log(EVDNS_LOG_DEBUG, "Setting retries to %d", retries);
1.3423 + base->global_max_retransmits = retries;
1.3424 + } else if (str_matches_option(option, "randomize-case:")) {
1.3425 + int randcase = strtoint(val);
1.3426 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3427 + base->global_randomize_case = randcase;
1.3428 + } else if (str_matches_option(option, "bind-to:")) {
1.3429 + /* XXX This only applies to successive nameservers, not
1.3430 + * to already-configured ones. We might want to fix that. */
1.3431 + int len = sizeof(base->global_outgoing_address);
1.3432 + if (!(flags & DNS_OPTION_NAMESERVERS)) return 0;
1.3433 + if (evutil_parse_sockaddr_port(val,
1.3434 + (struct sockaddr*)&base->global_outgoing_address, &len))
1.3435 + return -1;
1.3436 + base->global_outgoing_addrlen = len;
1.3437 + } else if (str_matches_option(option, "initial-probe-timeout:")) {
1.3438 + struct timeval tv;
1.3439 + if (strtotimeval(val, &tv) == -1) return -1;
1.3440 + if (tv.tv_sec > 3600)
1.3441 + tv.tv_sec = 3600;
1.3442 + if (!(flags & DNS_OPTION_MISC)) return 0;
1.3443 + log(EVDNS_LOG_DEBUG, "Setting initial probe timeout to %s",
1.3444 + val);
1.3445 + memcpy(&base->global_nameserver_probe_initial_timeout, &tv,
1.3446 + sizeof(tv));
1.3447 + }
1.3448 + return 0;
1.3449 +}
1.3450 +
1.3451 +int
1.3452 +evdns_set_option(const char *option, const char *val, int flags)
1.3453 +{
1.3454 + if (!current_base)
1.3455 + current_base = evdns_base_new(NULL, 0);
1.3456 + return evdns_base_set_option(current_base, option, val);
1.3457 +}
1.3458 +
1.3459 +static void
1.3460 +resolv_conf_parse_line(struct evdns_base *base, char *const start, int flags) {
1.3461 + char *strtok_state;
1.3462 + static const char *const delims = " \t";
1.3463 +#define NEXT_TOKEN strtok_r(NULL, delims, &strtok_state)
1.3464 +
1.3465 +
1.3466 + char *const first_token = strtok_r(start, delims, &strtok_state);
1.3467 + ASSERT_LOCKED(base);
1.3468 + if (!first_token) return;
1.3469 +
1.3470 + if (!strcmp(first_token, "nameserver") && (flags & DNS_OPTION_NAMESERVERS)) {
1.3471 + const char *const nameserver = NEXT_TOKEN;
1.3472 +
1.3473 + if (nameserver)
1.3474 + evdns_base_nameserver_ip_add(base, nameserver);
1.3475 + } else if (!strcmp(first_token, "domain") && (flags & DNS_OPTION_SEARCH)) {
1.3476 + const char *const domain = NEXT_TOKEN;
1.3477 + if (domain) {
1.3478 + search_postfix_clear(base);
1.3479 + search_postfix_add(base, domain);
1.3480 + }
1.3481 + } else if (!strcmp(first_token, "search") && (flags & DNS_OPTION_SEARCH)) {
1.3482 + const char *domain;
1.3483 + search_postfix_clear(base);
1.3484 +
1.3485 + while ((domain = NEXT_TOKEN)) {
1.3486 + search_postfix_add(base, domain);
1.3487 + }
1.3488 + search_reverse(base);
1.3489 + } else if (!strcmp(first_token, "options")) {
1.3490 + const char *option;
1.3491 + while ((option = NEXT_TOKEN)) {
1.3492 + const char *val = strchr(option, ':');
1.3493 + evdns_base_set_option_impl(base, option, val ? val+1 : "", flags);
1.3494 + }
1.3495 + }
1.3496 +#undef NEXT_TOKEN
1.3497 +}
1.3498 +
1.3499 +/* exported function */
1.3500 +/* returns: */
1.3501 +/* 0 no errors */
1.3502 +/* 1 failed to open file */
1.3503 +/* 2 failed to stat file */
1.3504 +/* 3 file too large */
1.3505 +/* 4 out of memory */
1.3506 +/* 5 short read from file */
1.3507 +int
1.3508 +evdns_base_resolv_conf_parse(struct evdns_base *base, int flags, const char *const filename) {
1.3509 + int res;
1.3510 + EVDNS_LOCK(base);
1.3511 + res = evdns_base_resolv_conf_parse_impl(base, flags, filename);
1.3512 + EVDNS_UNLOCK(base);
1.3513 + return res;
1.3514 +}
1.3515 +
1.3516 +static char *
1.3517 +evdns_get_default_hosts_filename(void)
1.3518 +{
1.3519 +#ifdef WIN32
1.3520 + /* Windows is a little coy about where it puts its configuration
1.3521 + * files. Sure, they're _usually_ in C:\windows\system32, but
1.3522 + * there's no reason in principle they couldn't be in
1.3523 + * W:\hoboken chicken emergency\
1.3524 + */
1.3525 + char path[MAX_PATH+1];
1.3526 + static const char hostfile[] = "\\drivers\\etc\\hosts";
1.3527 + char *path_out;
1.3528 + size_t len_out;
1.3529 +
1.3530 + if (! SHGetSpecialFolderPathA(NULL, path, CSIDL_SYSTEM, 0))
1.3531 + return NULL;
1.3532 + len_out = strlen(path)+strlen(hostfile);
1.3533 + path_out = mm_malloc(len_out+1);
1.3534 + evutil_snprintf(path_out, len_out, "%s%s", path, hostfile);
1.3535 + return path_out;
1.3536 +#else
1.3537 + return mm_strdup("/etc/hosts");
1.3538 +#endif
1.3539 +}
1.3540 +
1.3541 +static int
1.3542 +evdns_base_resolv_conf_parse_impl(struct evdns_base *base, int flags, const char *const filename) {
1.3543 + size_t n;
1.3544 + char *resolv;
1.3545 + char *start;
1.3546 + int err = 0;
1.3547 +
1.3548 + log(EVDNS_LOG_DEBUG, "Parsing resolv.conf file %s", filename);
1.3549 +
1.3550 + if (flags & DNS_OPTION_HOSTSFILE) {
1.3551 + char *fname = evdns_get_default_hosts_filename();
1.3552 + evdns_base_load_hosts(base, fname);
1.3553 + if (fname)
1.3554 + mm_free(fname);
1.3555 + }
1.3556 +
1.3557 + if ((err = evutil_read_file(filename, &resolv, &n, 0)) < 0) {
1.3558 + if (err == -1) {
1.3559 + /* No file. */
1.3560 + evdns_resolv_set_defaults(base, flags);
1.3561 + return 1;
1.3562 + } else {
1.3563 + return 2;
1.3564 + }
1.3565 + }
1.3566 +
1.3567 + start = resolv;
1.3568 + for (;;) {
1.3569 + char *const newline = strchr(start, '\n');
1.3570 + if (!newline) {
1.3571 + resolv_conf_parse_line(base, start, flags);
1.3572 + break;
1.3573 + } else {
1.3574 + *newline = 0;
1.3575 + resolv_conf_parse_line(base, start, flags);
1.3576 + start = newline + 1;
1.3577 + }
1.3578 + }
1.3579 +
1.3580 + if (!base->server_head && (flags & DNS_OPTION_NAMESERVERS)) {
1.3581 + /* no nameservers were configured. */
1.3582 + evdns_base_nameserver_ip_add(base, "127.0.0.1");
1.3583 + err = 6;
1.3584 + }
1.3585 + if (flags & DNS_OPTION_SEARCH && (!base->global_search_state || base->global_search_state->num_domains == 0)) {
1.3586 + search_set_from_hostname(base);
1.3587 + }
1.3588 +
1.3589 + mm_free(resolv);
1.3590 + return err;
1.3591 +}
1.3592 +
1.3593 +int
1.3594 +evdns_resolv_conf_parse(int flags, const char *const filename) {
1.3595 + if (!current_base)
1.3596 + current_base = evdns_base_new(NULL, 0);
1.3597 + return evdns_base_resolv_conf_parse(current_base, flags, filename);
1.3598 +}
1.3599 +
1.3600 +
1.3601 +#ifdef WIN32
1.3602 +/* Add multiple nameservers from a space-or-comma-separated list. */
1.3603 +static int
1.3604 +evdns_nameserver_ip_add_line(struct evdns_base *base, const char *ips) {
1.3605 + const char *addr;
1.3606 + char *buf;
1.3607 + int r;
1.3608 + ASSERT_LOCKED(base);
1.3609 + while (*ips) {
1.3610 + while (isspace(*ips) || *ips == ',' || *ips == '\t')
1.3611 + ++ips;
1.3612 + addr = ips;
1.3613 + while (isdigit(*ips) || *ips == '.' || *ips == ':' ||
1.3614 + *ips=='[' || *ips==']')
1.3615 + ++ips;
1.3616 + buf = mm_malloc(ips-addr+1);
1.3617 + if (!buf) return 4;
1.3618 + memcpy(buf, addr, ips-addr);
1.3619 + buf[ips-addr] = '\0';
1.3620 + r = evdns_base_nameserver_ip_add(base, buf);
1.3621 + mm_free(buf);
1.3622 + if (r) return r;
1.3623 + }
1.3624 + return 0;
1.3625 +}
1.3626 +
1.3627 +typedef DWORD(WINAPI *GetNetworkParams_fn_t)(FIXED_INFO *, DWORD*);
1.3628 +
1.3629 +/* Use the windows GetNetworkParams interface in iphlpapi.dll to */
1.3630 +/* figure out what our nameservers are. */
1.3631 +static int
1.3632 +load_nameservers_with_getnetworkparams(struct evdns_base *base)
1.3633 +{
1.3634 + /* Based on MSDN examples and inspection of c-ares code. */
1.3635 + FIXED_INFO *fixed;
1.3636 + HMODULE handle = 0;
1.3637 + ULONG size = sizeof(FIXED_INFO);
1.3638 + void *buf = NULL;
1.3639 + int status = 0, r, added_any;
1.3640 + IP_ADDR_STRING *ns;
1.3641 + GetNetworkParams_fn_t fn;
1.3642 +
1.3643 + ASSERT_LOCKED(base);
1.3644 + if (!(handle = evutil_load_windows_system_library(
1.3645 + TEXT("iphlpapi.dll")))) {
1.3646 + log(EVDNS_LOG_WARN, "Could not open iphlpapi.dll");
1.3647 + status = -1;
1.3648 + goto done;
1.3649 + }
1.3650 + if (!(fn = (GetNetworkParams_fn_t) GetProcAddress(handle, "GetNetworkParams"))) {
1.3651 + log(EVDNS_LOG_WARN, "Could not get address of function.");
1.3652 + status = -1;
1.3653 + goto done;
1.3654 + }
1.3655 +
1.3656 + buf = mm_malloc(size);
1.3657 + if (!buf) { status = 4; goto done; }
1.3658 + fixed = buf;
1.3659 + r = fn(fixed, &size);
1.3660 + if (r != ERROR_SUCCESS && r != ERROR_BUFFER_OVERFLOW) {
1.3661 + status = -1;
1.3662 + goto done;
1.3663 + }
1.3664 + if (r != ERROR_SUCCESS) {
1.3665 + mm_free(buf);
1.3666 + buf = mm_malloc(size);
1.3667 + if (!buf) { status = 4; goto done; }
1.3668 + fixed = buf;
1.3669 + r = fn(fixed, &size);
1.3670 + if (r != ERROR_SUCCESS) {
1.3671 + log(EVDNS_LOG_DEBUG, "fn() failed.");
1.3672 + status = -1;
1.3673 + goto done;
1.3674 + }
1.3675 + }
1.3676 +
1.3677 + EVUTIL_ASSERT(fixed);
1.3678 + added_any = 0;
1.3679 + ns = &(fixed->DnsServerList);
1.3680 + while (ns) {
1.3681 + r = evdns_nameserver_ip_add_line(base, ns->IpAddress.String);
1.3682 + if (r) {
1.3683 + log(EVDNS_LOG_DEBUG,"Could not add nameserver %s to list,error: %d",
1.3684 + (ns->IpAddress.String),(int)GetLastError());
1.3685 + status = r;
1.3686 + } else {
1.3687 + ++added_any;
1.3688 + log(EVDNS_LOG_DEBUG,"Successfully added %s as nameserver",ns->IpAddress.String);
1.3689 + }
1.3690 +
1.3691 + ns = ns->Next;
1.3692 + }
1.3693 +
1.3694 + if (!added_any) {
1.3695 + log(EVDNS_LOG_DEBUG, "No nameservers added.");
1.3696 + if (status == 0)
1.3697 + status = -1;
1.3698 + } else {
1.3699 + status = 0;
1.3700 + }
1.3701 +
1.3702 + done:
1.3703 + if (buf)
1.3704 + mm_free(buf);
1.3705 + if (handle)
1.3706 + FreeLibrary(handle);
1.3707 + return status;
1.3708 +}
1.3709 +
1.3710 +static int
1.3711 +config_nameserver_from_reg_key(struct evdns_base *base, HKEY key, const TCHAR *subkey)
1.3712 +{
1.3713 + char *buf;
1.3714 + DWORD bufsz = 0, type = 0;
1.3715 + int status = 0;
1.3716 +
1.3717 + ASSERT_LOCKED(base);
1.3718 + if (RegQueryValueEx(key, subkey, 0, &type, NULL, &bufsz)
1.3719 + != ERROR_MORE_DATA)
1.3720 + return -1;
1.3721 + if (!(buf = mm_malloc(bufsz)))
1.3722 + return -1;
1.3723 +
1.3724 + if (RegQueryValueEx(key, subkey, 0, &type, (LPBYTE)buf, &bufsz)
1.3725 + == ERROR_SUCCESS && bufsz > 1) {
1.3726 + status = evdns_nameserver_ip_add_line(base,buf);
1.3727 + }
1.3728 +
1.3729 + mm_free(buf);
1.3730 + return status;
1.3731 +}
1.3732 +
1.3733 +#define SERVICES_KEY TEXT("System\\CurrentControlSet\\Services\\")
1.3734 +#define WIN_NS_9X_KEY SERVICES_KEY TEXT("VxD\\MSTCP")
1.3735 +#define WIN_NS_NT_KEY SERVICES_KEY TEXT("Tcpip\\Parameters")
1.3736 +
1.3737 +static int
1.3738 +load_nameservers_from_registry(struct evdns_base *base)
1.3739 +{
1.3740 + int found = 0;
1.3741 + int r;
1.3742 +#define TRY(k, name) \
1.3743 + if (!found && config_nameserver_from_reg_key(base,k,TEXT(name)) == 0) { \
1.3744 + log(EVDNS_LOG_DEBUG,"Found nameservers in %s/%s",#k,name); \
1.3745 + found = 1; \
1.3746 + } else if (!found) { \
1.3747 + log(EVDNS_LOG_DEBUG,"Didn't find nameservers in %s/%s", \
1.3748 + #k,#name); \
1.3749 + }
1.3750 +
1.3751 + ASSERT_LOCKED(base);
1.3752 +
1.3753 + if (((int)GetVersion()) > 0) { /* NT */
1.3754 + HKEY nt_key = 0, interfaces_key = 0;
1.3755 +
1.3756 + if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0,
1.3757 + KEY_READ, &nt_key) != ERROR_SUCCESS) {
1.3758 + log(EVDNS_LOG_DEBUG,"Couldn't open nt key, %d",(int)GetLastError());
1.3759 + return -1;
1.3760 + }
1.3761 + r = RegOpenKeyEx(nt_key, TEXT("Interfaces"), 0,
1.3762 + KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS,
1.3763 + &interfaces_key);
1.3764 + if (r != ERROR_SUCCESS) {
1.3765 + log(EVDNS_LOG_DEBUG,"Couldn't open interfaces key, %d",(int)GetLastError());
1.3766 + return -1;
1.3767 + }
1.3768 + TRY(nt_key, "NameServer");
1.3769 + TRY(nt_key, "DhcpNameServer");
1.3770 + TRY(interfaces_key, "NameServer");
1.3771 + TRY(interfaces_key, "DhcpNameServer");
1.3772 + RegCloseKey(interfaces_key);
1.3773 + RegCloseKey(nt_key);
1.3774 + } else {
1.3775 + HKEY win_key = 0;
1.3776 + if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_9X_KEY, 0,
1.3777 + KEY_READ, &win_key) != ERROR_SUCCESS) {
1.3778 + log(EVDNS_LOG_DEBUG, "Couldn't open registry key, %d", (int)GetLastError());
1.3779 + return -1;
1.3780 + }
1.3781 + TRY(win_key, "NameServer");
1.3782 + RegCloseKey(win_key);
1.3783 + }
1.3784 +
1.3785 + if (found == 0) {
1.3786 + log(EVDNS_LOG_WARN,"Didn't find any nameservers.");
1.3787 + }
1.3788 +
1.3789 + return found ? 0 : -1;
1.3790 +#undef TRY
1.3791 +}
1.3792 +
1.3793 +int
1.3794 +evdns_base_config_windows_nameservers(struct evdns_base *base)
1.3795 +{
1.3796 + int r;
1.3797 + char *fname;
1.3798 + if (base == NULL)
1.3799 + base = current_base;
1.3800 + if (base == NULL)
1.3801 + return -1;
1.3802 + EVDNS_LOCK(base);
1.3803 + if (load_nameservers_with_getnetworkparams(base) == 0) {
1.3804 + EVDNS_UNLOCK(base);
1.3805 + return 0;
1.3806 + }
1.3807 + r = load_nameservers_from_registry(base);
1.3808 +
1.3809 + fname = evdns_get_default_hosts_filename();
1.3810 + evdns_base_load_hosts(base, fname);
1.3811 + if (fname)
1.3812 + mm_free(fname);
1.3813 +
1.3814 + EVDNS_UNLOCK(base);
1.3815 + return r;
1.3816 +}
1.3817 +
1.3818 +int
1.3819 +evdns_config_windows_nameservers(void)
1.3820 +{
1.3821 + if (!current_base) {
1.3822 + current_base = evdns_base_new(NULL, 1);
1.3823 + return current_base == NULL ? -1 : 0;
1.3824 + } else {
1.3825 + return evdns_base_config_windows_nameservers(current_base);
1.3826 + }
1.3827 +}
1.3828 +#endif
1.3829 +
1.3830 +struct evdns_base *
1.3831 +evdns_base_new(struct event_base *event_base, int initialize_nameservers)
1.3832 +{
1.3833 + struct evdns_base *base;
1.3834 +
1.3835 + if (evutil_secure_rng_init() < 0) {
1.3836 + log(EVDNS_LOG_WARN, "Unable to seed random number generator; "
1.3837 + "DNS can't run.");
1.3838 + return NULL;
1.3839 + }
1.3840 +
1.3841 + /* Give the evutil library a hook into its evdns-enabled
1.3842 + * functionality. We can't just call evdns_getaddrinfo directly or
1.3843 + * else libevent-core will depend on libevent-extras. */
1.3844 + evutil_set_evdns_getaddrinfo_fn(evdns_getaddrinfo);
1.3845 +
1.3846 + base = mm_malloc(sizeof(struct evdns_base));
1.3847 + if (base == NULL)
1.3848 + return (NULL);
1.3849 + memset(base, 0, sizeof(struct evdns_base));
1.3850 + base->req_waiting_head = NULL;
1.3851 +
1.3852 + EVTHREAD_ALLOC_LOCK(base->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
1.3853 + EVDNS_LOCK(base);
1.3854 +
1.3855 + /* Set max requests inflight and allocate req_heads. */
1.3856 + base->req_heads = NULL;
1.3857 +
1.3858 + evdns_base_set_max_requests_inflight(base, 64);
1.3859 +
1.3860 + base->server_head = NULL;
1.3861 + base->event_base = event_base;
1.3862 + base->global_good_nameservers = base->global_requests_inflight =
1.3863 + base->global_requests_waiting = 0;
1.3864 +
1.3865 + base->global_timeout.tv_sec = 5;
1.3866 + base->global_timeout.tv_usec = 0;
1.3867 + base->global_max_reissues = 1;
1.3868 + base->global_max_retransmits = 3;
1.3869 + base->global_max_nameserver_timeout = 3;
1.3870 + base->global_search_state = NULL;
1.3871 + base->global_randomize_case = 1;
1.3872 + base->global_getaddrinfo_allow_skew.tv_sec = 3;
1.3873 + base->global_getaddrinfo_allow_skew.tv_usec = 0;
1.3874 + base->global_nameserver_probe_initial_timeout.tv_sec = 10;
1.3875 + base->global_nameserver_probe_initial_timeout.tv_usec = 0;
1.3876 +
1.3877 + TAILQ_INIT(&base->hostsdb);
1.3878 +
1.3879 + if (initialize_nameservers) {
1.3880 + int r;
1.3881 +#ifdef WIN32
1.3882 + r = evdns_base_config_windows_nameservers(base);
1.3883 +#else
1.3884 + r = evdns_base_resolv_conf_parse(base, DNS_OPTIONS_ALL, "/etc/resolv.conf");
1.3885 +#endif
1.3886 + if (r == -1) {
1.3887 + evdns_base_free_and_unlock(base, 0);
1.3888 + return NULL;
1.3889 + }
1.3890 + }
1.3891 + EVDNS_UNLOCK(base);
1.3892 + return base;
1.3893 +}
1.3894 +
1.3895 +int
1.3896 +evdns_init(void)
1.3897 +{
1.3898 + struct evdns_base *base = evdns_base_new(NULL, 1);
1.3899 + if (base) {
1.3900 + current_base = base;
1.3901 + return 0;
1.3902 + } else {
1.3903 + return -1;
1.3904 + }
1.3905 +}
1.3906 +
1.3907 +const char *
1.3908 +evdns_err_to_string(int err)
1.3909 +{
1.3910 + switch (err) {
1.3911 + case DNS_ERR_NONE: return "no error";
1.3912 + case DNS_ERR_FORMAT: return "misformatted query";
1.3913 + case DNS_ERR_SERVERFAILED: return "server failed";
1.3914 + case DNS_ERR_NOTEXIST: return "name does not exist";
1.3915 + case DNS_ERR_NOTIMPL: return "query not implemented";
1.3916 + case DNS_ERR_REFUSED: return "refused";
1.3917 +
1.3918 + case DNS_ERR_TRUNCATED: return "reply truncated or ill-formed";
1.3919 + case DNS_ERR_UNKNOWN: return "unknown";
1.3920 + case DNS_ERR_TIMEOUT: return "request timed out";
1.3921 + case DNS_ERR_SHUTDOWN: return "dns subsystem shut down";
1.3922 + case DNS_ERR_CANCEL: return "dns request canceled";
1.3923 + case DNS_ERR_NODATA: return "no records in the reply";
1.3924 + default: return "[Unknown error code]";
1.3925 + }
1.3926 +}
1.3927 +
1.3928 +static void
1.3929 +evdns_nameserver_free(struct nameserver *server)
1.3930 +{
1.3931 + if (server->socket >= 0)
1.3932 + evutil_closesocket(server->socket);
1.3933 + (void) event_del(&server->event);
1.3934 + event_debug_unassign(&server->event);
1.3935 + if (server->state == 0)
1.3936 + (void) event_del(&server->timeout_event);
1.3937 + event_debug_unassign(&server->timeout_event);
1.3938 + mm_free(server);
1.3939 +}
1.3940 +
1.3941 +static void
1.3942 +evdns_base_free_and_unlock(struct evdns_base *base, int fail_requests)
1.3943 +{
1.3944 + struct nameserver *server, *server_next;
1.3945 + struct search_domain *dom, *dom_next;
1.3946 + int i;
1.3947 +
1.3948 + /* Requires that we hold the lock. */
1.3949 +
1.3950 + /* TODO(nickm) we might need to refcount here. */
1.3951 +
1.3952 + for (i = 0; i < base->n_req_heads; ++i) {
1.3953 + while (base->req_heads[i]) {
1.3954 + if (fail_requests)
1.3955 + reply_schedule_callback(base->req_heads[i], 0, DNS_ERR_SHUTDOWN, NULL);
1.3956 + request_finished(base->req_heads[i], &REQ_HEAD(base, base->req_heads[i]->trans_id), 1);
1.3957 + }
1.3958 + }
1.3959 + while (base->req_waiting_head) {
1.3960 + if (fail_requests)
1.3961 + reply_schedule_callback(base->req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL);
1.3962 + request_finished(base->req_waiting_head, &base->req_waiting_head, 1);
1.3963 + }
1.3964 + base->global_requests_inflight = base->global_requests_waiting = 0;
1.3965 +
1.3966 + for (server = base->server_head; server; server = server_next) {
1.3967 + server_next = server->next;
1.3968 + evdns_nameserver_free(server);
1.3969 + if (server_next == base->server_head)
1.3970 + break;
1.3971 + }
1.3972 + base->server_head = NULL;
1.3973 + base->global_good_nameservers = 0;
1.3974 +
1.3975 + if (base->global_search_state) {
1.3976 + for (dom = base->global_search_state->head; dom; dom = dom_next) {
1.3977 + dom_next = dom->next;
1.3978 + mm_free(dom);
1.3979 + }
1.3980 + mm_free(base->global_search_state);
1.3981 + base->global_search_state = NULL;
1.3982 + }
1.3983 +
1.3984 + {
1.3985 + struct hosts_entry *victim;
1.3986 + while ((victim = TAILQ_FIRST(&base->hostsdb))) {
1.3987 + TAILQ_REMOVE(&base->hostsdb, victim, next);
1.3988 + mm_free(victim);
1.3989 + }
1.3990 + }
1.3991 +
1.3992 + mm_free(base->req_heads);
1.3993 +
1.3994 + EVDNS_UNLOCK(base);
1.3995 + EVTHREAD_FREE_LOCK(base->lock, EVTHREAD_LOCKTYPE_RECURSIVE);
1.3996 +
1.3997 + mm_free(base);
1.3998 +}
1.3999 +
1.4000 +void
1.4001 +evdns_base_free(struct evdns_base *base, int fail_requests)
1.4002 +{
1.4003 + EVDNS_LOCK(base);
1.4004 + evdns_base_free_and_unlock(base, fail_requests);
1.4005 +}
1.4006 +
1.4007 +void
1.4008 +evdns_shutdown(int fail_requests)
1.4009 +{
1.4010 + if (current_base) {
1.4011 + struct evdns_base *b = current_base;
1.4012 + current_base = NULL;
1.4013 + evdns_base_free(b, fail_requests);
1.4014 + }
1.4015 + evdns_log_fn = NULL;
1.4016 +}
1.4017 +
1.4018 +static int
1.4019 +evdns_base_parse_hosts_line(struct evdns_base *base, char *line)
1.4020 +{
1.4021 + char *strtok_state;
1.4022 + static const char *const delims = " \t";
1.4023 + char *const addr = strtok_r(line, delims, &strtok_state);
1.4024 + char *hostname, *hash;
1.4025 + struct sockaddr_storage ss;
1.4026 + int socklen = sizeof(ss);
1.4027 + ASSERT_LOCKED(base);
1.4028 +
1.4029 +#define NEXT_TOKEN strtok_r(NULL, delims, &strtok_state)
1.4030 +
1.4031 + if (!addr || *addr == '#')
1.4032 + return 0;
1.4033 +
1.4034 + memset(&ss, 0, sizeof(ss));
1.4035 + if (evutil_parse_sockaddr_port(addr, (struct sockaddr*)&ss, &socklen)<0)
1.4036 + return -1;
1.4037 + if (socklen > (int)sizeof(struct sockaddr_in6))
1.4038 + return -1;
1.4039 +
1.4040 + if (sockaddr_getport((struct sockaddr*)&ss))
1.4041 + return -1;
1.4042 +
1.4043 + while ((hostname = NEXT_TOKEN)) {
1.4044 + struct hosts_entry *he;
1.4045 + size_t namelen;
1.4046 + if ((hash = strchr(hostname, '#'))) {
1.4047 + if (hash == hostname)
1.4048 + return 0;
1.4049 + *hash = '\0';
1.4050 + }
1.4051 +
1.4052 + namelen = strlen(hostname);
1.4053 +
1.4054 + he = mm_calloc(1, sizeof(struct hosts_entry)+namelen);
1.4055 + if (!he)
1.4056 + return -1;
1.4057 + EVUTIL_ASSERT(socklen <= (int)sizeof(he->addr));
1.4058 + memcpy(&he->addr, &ss, socklen);
1.4059 + memcpy(he->hostname, hostname, namelen+1);
1.4060 + he->addrlen = socklen;
1.4061 +
1.4062 + TAILQ_INSERT_TAIL(&base->hostsdb, he, next);
1.4063 +
1.4064 + if (hash)
1.4065 + return 0;
1.4066 + }
1.4067 +
1.4068 + return 0;
1.4069 +#undef NEXT_TOKEN
1.4070 +}
1.4071 +
1.4072 +static int
1.4073 +evdns_base_load_hosts_impl(struct evdns_base *base, const char *hosts_fname)
1.4074 +{
1.4075 + char *str=NULL, *cp, *eol;
1.4076 + size_t len;
1.4077 + int err=0;
1.4078 +
1.4079 + ASSERT_LOCKED(base);
1.4080 +
1.4081 + if (hosts_fname == NULL ||
1.4082 + (err = evutil_read_file(hosts_fname, &str, &len, 0)) < 0) {
1.4083 + char tmp[64];
1.4084 + strlcpy(tmp, "127.0.0.1 localhost", sizeof(tmp));
1.4085 + evdns_base_parse_hosts_line(base, tmp);
1.4086 + strlcpy(tmp, "::1 localhost", sizeof(tmp));
1.4087 + evdns_base_parse_hosts_line(base, tmp);
1.4088 + return err ? -1 : 0;
1.4089 + }
1.4090 +
1.4091 + /* This will break early if there is a NUL in the hosts file.
1.4092 + * Probably not a problem.*/
1.4093 + cp = str;
1.4094 + for (;;) {
1.4095 + eol = strchr(cp, '\n');
1.4096 +
1.4097 + if (eol) {
1.4098 + *eol = '\0';
1.4099 + evdns_base_parse_hosts_line(base, cp);
1.4100 + cp = eol+1;
1.4101 + } else {
1.4102 + evdns_base_parse_hosts_line(base, cp);
1.4103 + break;
1.4104 + }
1.4105 + }
1.4106 +
1.4107 + mm_free(str);
1.4108 + return 0;
1.4109 +}
1.4110 +
1.4111 +int
1.4112 +evdns_base_load_hosts(struct evdns_base *base, const char *hosts_fname)
1.4113 +{
1.4114 + int res;
1.4115 + if (!base)
1.4116 + base = current_base;
1.4117 + EVDNS_LOCK(base);
1.4118 + res = evdns_base_load_hosts_impl(base, hosts_fname);
1.4119 + EVDNS_UNLOCK(base);
1.4120 + return res;
1.4121 +}
1.4122 +
1.4123 +/* A single request for a getaddrinfo, either v4 or v6. */
1.4124 +struct getaddrinfo_subrequest {
1.4125 + struct evdns_request *r;
1.4126 + ev_uint32_t type;
1.4127 +};
1.4128 +
1.4129 +/* State data used to implement an in-progress getaddrinfo. */
1.4130 +struct evdns_getaddrinfo_request {
1.4131 + struct evdns_base *evdns_base;
1.4132 + /* Copy of the modified 'hints' data that we'll use to build
1.4133 + * answers. */
1.4134 + struct evutil_addrinfo hints;
1.4135 + /* The callback to invoke when we're done */
1.4136 + evdns_getaddrinfo_cb user_cb;
1.4137 + /* User-supplied data to give to the callback. */
1.4138 + void *user_data;
1.4139 + /* The port to use when building sockaddrs. */
1.4140 + ev_uint16_t port;
1.4141 + /* The sub_request for an A record (if any) */
1.4142 + struct getaddrinfo_subrequest ipv4_request;
1.4143 + /* The sub_request for an AAAA record (if any) */
1.4144 + struct getaddrinfo_subrequest ipv6_request;
1.4145 +
1.4146 + /* The cname result that we were told (if any) */
1.4147 + char *cname_result;
1.4148 +
1.4149 + /* If we have one request answered and one request still inflight,
1.4150 + * then this field holds the answer from the first request... */
1.4151 + struct evutil_addrinfo *pending_result;
1.4152 + /* And this event is a timeout that will tell us to cancel the second
1.4153 + * request if it's taking a long time. */
1.4154 + struct event timeout;
1.4155 +
1.4156 + /* And this field holds the error code from the first request... */
1.4157 + int pending_error;
1.4158 + /* If this is set, the user canceled this request. */
1.4159 + unsigned user_canceled : 1;
1.4160 + /* If this is set, the user can no longer cancel this request; we're
1.4161 + * just waiting for the free. */
1.4162 + unsigned request_done : 1;
1.4163 +};
1.4164 +
1.4165 +/* Convert an evdns errors to the equivalent getaddrinfo error. */
1.4166 +static int
1.4167 +evdns_err_to_getaddrinfo_err(int e1)
1.4168 +{
1.4169 + /* XXX Do this better! */
1.4170 + if (e1 == DNS_ERR_NONE)
1.4171 + return 0;
1.4172 + else if (e1 == DNS_ERR_NOTEXIST)
1.4173 + return EVUTIL_EAI_NONAME;
1.4174 + else
1.4175 + return EVUTIL_EAI_FAIL;
1.4176 +}
1.4177 +
1.4178 +/* Return the more informative of two getaddrinfo errors. */
1.4179 +static int
1.4180 +getaddrinfo_merge_err(int e1, int e2)
1.4181 +{
1.4182 + /* XXXX be cleverer here. */
1.4183 + if (e1 == 0)
1.4184 + return e2;
1.4185 + else
1.4186 + return e1;
1.4187 +}
1.4188 +
1.4189 +static void
1.4190 +free_getaddrinfo_request(struct evdns_getaddrinfo_request *data)
1.4191 +{
1.4192 + /* DO NOT CALL this if either of the requests is pending. Only once
1.4193 + * both callbacks have been invoked is it safe to free the request */
1.4194 + if (data->pending_result)
1.4195 + evutil_freeaddrinfo(data->pending_result);
1.4196 + if (data->cname_result)
1.4197 + mm_free(data->cname_result);
1.4198 + event_del(&data->timeout);
1.4199 + mm_free(data);
1.4200 + return;
1.4201 +}
1.4202 +
1.4203 +static void
1.4204 +add_cname_to_reply(struct evdns_getaddrinfo_request *data,
1.4205 + struct evutil_addrinfo *ai)
1.4206 +{
1.4207 + if (data->cname_result && ai) {
1.4208 + ai->ai_canonname = data->cname_result;
1.4209 + data->cname_result = NULL;
1.4210 + }
1.4211 +}
1.4212 +
1.4213 +/* Callback: invoked when one request in a mixed-format A/AAAA getaddrinfo
1.4214 + * request has finished, but the other one took too long to answer. Pass
1.4215 + * along the answer we got, and cancel the other request.
1.4216 + */
1.4217 +static void
1.4218 +evdns_getaddrinfo_timeout_cb(evutil_socket_t fd, short what, void *ptr)
1.4219 +{
1.4220 + int v4_timedout = 0, v6_timedout = 0;
1.4221 + struct evdns_getaddrinfo_request *data = ptr;
1.4222 +
1.4223 + /* Cancel any pending requests, and note which one */
1.4224 + if (data->ipv4_request.r) {
1.4225 + /* XXXX This does nothing if the request's callback is already
1.4226 + * running (pending_cb is set). */
1.4227 + evdns_cancel_request(NULL, data->ipv4_request.r);
1.4228 + v4_timedout = 1;
1.4229 + EVDNS_LOCK(data->evdns_base);
1.4230 + ++data->evdns_base->getaddrinfo_ipv4_timeouts;
1.4231 + EVDNS_UNLOCK(data->evdns_base);
1.4232 + }
1.4233 + if (data->ipv6_request.r) {
1.4234 + /* XXXX This does nothing if the request's callback is already
1.4235 + * running (pending_cb is set). */
1.4236 + evdns_cancel_request(NULL, data->ipv6_request.r);
1.4237 + v6_timedout = 1;
1.4238 + EVDNS_LOCK(data->evdns_base);
1.4239 + ++data->evdns_base->getaddrinfo_ipv6_timeouts;
1.4240 + EVDNS_UNLOCK(data->evdns_base);
1.4241 + }
1.4242 +
1.4243 + /* We only use this timeout callback when we have an answer for
1.4244 + * one address. */
1.4245 + EVUTIL_ASSERT(!v4_timedout || !v6_timedout);
1.4246 +
1.4247 + /* Report the outcome of the other request that didn't time out. */
1.4248 + if (data->pending_result) {
1.4249 + add_cname_to_reply(data, data->pending_result);
1.4250 + data->user_cb(0, data->pending_result, data->user_data);
1.4251 + data->pending_result = NULL;
1.4252 + } else {
1.4253 + int e = data->pending_error;
1.4254 + if (!e)
1.4255 + e = EVUTIL_EAI_AGAIN;
1.4256 + data->user_cb(e, NULL, data->user_data);
1.4257 + }
1.4258 +
1.4259 + data->user_cb = NULL; /* prevent double-call if evdns callbacks are
1.4260 + * in-progress. XXXX It would be better if this
1.4261 + * weren't necessary. */
1.4262 +
1.4263 + if (!v4_timedout && !v6_timedout) {
1.4264 + /* should be impossible? XXXX */
1.4265 + free_getaddrinfo_request(data);
1.4266 + }
1.4267 +}
1.4268 +
1.4269 +static int
1.4270 +evdns_getaddrinfo_set_timeout(struct evdns_base *evdns_base,
1.4271 + struct evdns_getaddrinfo_request *data)
1.4272 +{
1.4273 + return event_add(&data->timeout, &evdns_base->global_getaddrinfo_allow_skew);
1.4274 +}
1.4275 +
1.4276 +static inline int
1.4277 +evdns_result_is_answer(int result)
1.4278 +{
1.4279 + return (result != DNS_ERR_NOTIMPL && result != DNS_ERR_REFUSED &&
1.4280 + result != DNS_ERR_SERVERFAILED && result != DNS_ERR_CANCEL);
1.4281 +}
1.4282 +
1.4283 +static void
1.4284 +evdns_getaddrinfo_gotresolve(int result, char type, int count,
1.4285 + int ttl, void *addresses, void *arg)
1.4286 +{
1.4287 + int i;
1.4288 + struct getaddrinfo_subrequest *req = arg;
1.4289 + struct getaddrinfo_subrequest *other_req;
1.4290 + struct evdns_getaddrinfo_request *data;
1.4291 +
1.4292 + struct evutil_addrinfo *res;
1.4293 +
1.4294 + struct sockaddr_in sin;
1.4295 + struct sockaddr_in6 sin6;
1.4296 + struct sockaddr *sa;
1.4297 + int socklen, addrlen;
1.4298 + void *addrp;
1.4299 + int err;
1.4300 + int user_canceled;
1.4301 +
1.4302 + EVUTIL_ASSERT(req->type == DNS_IPv4_A || req->type == DNS_IPv6_AAAA);
1.4303 + if (req->type == DNS_IPv4_A) {
1.4304 + data = EVUTIL_UPCAST(req, struct evdns_getaddrinfo_request, ipv4_request);
1.4305 + other_req = &data->ipv6_request;
1.4306 + } else {
1.4307 + data = EVUTIL_UPCAST(req, struct evdns_getaddrinfo_request, ipv6_request);
1.4308 + other_req = &data->ipv4_request;
1.4309 + }
1.4310 +
1.4311 + EVDNS_LOCK(data->evdns_base);
1.4312 + if (evdns_result_is_answer(result)) {
1.4313 + if (req->type == DNS_IPv4_A)
1.4314 + ++data->evdns_base->getaddrinfo_ipv4_answered;
1.4315 + else
1.4316 + ++data->evdns_base->getaddrinfo_ipv6_answered;
1.4317 + }
1.4318 + user_canceled = data->user_canceled;
1.4319 + if (other_req->r == NULL)
1.4320 + data->request_done = 1;
1.4321 + EVDNS_UNLOCK(data->evdns_base);
1.4322 +
1.4323 + req->r = NULL;
1.4324 +
1.4325 + if (result == DNS_ERR_CANCEL && ! user_canceled) {
1.4326 + /* Internal cancel request from timeout or internal error.
1.4327 + * we already answered the user. */
1.4328 + if (other_req->r == NULL)
1.4329 + free_getaddrinfo_request(data);
1.4330 + return;
1.4331 + }
1.4332 +
1.4333 + if (data->user_cb == NULL) {
1.4334 + /* We already answered. XXXX This shouldn't be needed; see
1.4335 + * comments in evdns_getaddrinfo_timeout_cb */
1.4336 + free_getaddrinfo_request(data);
1.4337 + return;
1.4338 + }
1.4339 +
1.4340 + if (result == DNS_ERR_NONE) {
1.4341 + if (count == 0)
1.4342 + err = EVUTIL_EAI_NODATA;
1.4343 + else
1.4344 + err = 0;
1.4345 + } else {
1.4346 + err = evdns_err_to_getaddrinfo_err(result);
1.4347 + }
1.4348 +
1.4349 + if (err) {
1.4350 + /* Looks like we got an error. */
1.4351 + if (other_req->r) {
1.4352 + /* The other request is still working; maybe it will
1.4353 + * succeed. */
1.4354 + /* XXXX handle failure from set_timeout */
1.4355 + evdns_getaddrinfo_set_timeout(data->evdns_base, data);
1.4356 + data->pending_error = err;
1.4357 + return;
1.4358 + }
1.4359 +
1.4360 + if (user_canceled) {
1.4361 + data->user_cb(EVUTIL_EAI_CANCEL, NULL, data->user_data);
1.4362 + } else if (data->pending_result) {
1.4363 + /* If we have an answer waiting, and we weren't
1.4364 + * canceled, ignore this error. */
1.4365 + add_cname_to_reply(data, data->pending_result);
1.4366 + data->user_cb(0, data->pending_result, data->user_data);
1.4367 + data->pending_result = NULL;
1.4368 + } else {
1.4369 + if (data->pending_error)
1.4370 + err = getaddrinfo_merge_err(err,
1.4371 + data->pending_error);
1.4372 + data->user_cb(err, NULL, data->user_data);
1.4373 + }
1.4374 + free_getaddrinfo_request(data);
1.4375 + return;
1.4376 + } else if (user_canceled) {
1.4377 + if (other_req->r) {
1.4378 + /* The other request is still working; let it hit this
1.4379 + * callback with EVUTIL_EAI_CANCEL callback and report
1.4380 + * the failure. */
1.4381 + return;
1.4382 + }
1.4383 + data->user_cb(EVUTIL_EAI_CANCEL, NULL, data->user_data);
1.4384 + free_getaddrinfo_request(data);
1.4385 + return;
1.4386 + }
1.4387 +
1.4388 + /* Looks like we got some answers. We should turn them into addrinfos
1.4389 + * and then either queue those or return them all. */
1.4390 + EVUTIL_ASSERT(type == DNS_IPv4_A || type == DNS_IPv6_AAAA);
1.4391 +
1.4392 + if (type == DNS_IPv4_A) {
1.4393 + memset(&sin, 0, sizeof(sin));
1.4394 + sin.sin_family = AF_INET;
1.4395 + sin.sin_port = htons(data->port);
1.4396 +
1.4397 + sa = (struct sockaddr *)&sin;
1.4398 + socklen = sizeof(sin);
1.4399 + addrlen = 4;
1.4400 + addrp = &sin.sin_addr.s_addr;
1.4401 + } else {
1.4402 + memset(&sin6, 0, sizeof(sin6));
1.4403 + sin6.sin6_family = AF_INET6;
1.4404 + sin6.sin6_port = htons(data->port);
1.4405 +
1.4406 + sa = (struct sockaddr *)&sin6;
1.4407 + socklen = sizeof(sin6);
1.4408 + addrlen = 16;
1.4409 + addrp = &sin6.sin6_addr.s6_addr;
1.4410 + }
1.4411 +
1.4412 + res = NULL;
1.4413 + for (i=0; i < count; ++i) {
1.4414 + struct evutil_addrinfo *ai;
1.4415 + memcpy(addrp, ((char*)addresses)+i*addrlen, addrlen);
1.4416 + ai = evutil_new_addrinfo(sa, socklen, &data->hints);
1.4417 + if (!ai) {
1.4418 + if (other_req->r) {
1.4419 + evdns_cancel_request(NULL, other_req->r);
1.4420 + }
1.4421 + data->user_cb(EVUTIL_EAI_MEMORY, NULL, data->user_data);
1.4422 + if (res)
1.4423 + evutil_freeaddrinfo(res);
1.4424 +
1.4425 + if (other_req->r == NULL)
1.4426 + free_getaddrinfo_request(data);
1.4427 + return;
1.4428 + }
1.4429 + res = evutil_addrinfo_append(res, ai);
1.4430 + }
1.4431 +
1.4432 + if (other_req->r) {
1.4433 + /* The other request is still in progress; wait for it */
1.4434 + /* XXXX handle failure from set_timeout */
1.4435 + evdns_getaddrinfo_set_timeout(data->evdns_base, data);
1.4436 + data->pending_result = res;
1.4437 + return;
1.4438 + } else {
1.4439 + /* The other request is done or never started; append its
1.4440 + * results (if any) and return them. */
1.4441 + if (data->pending_result) {
1.4442 + if (req->type == DNS_IPv4_A)
1.4443 + res = evutil_addrinfo_append(res,
1.4444 + data->pending_result);
1.4445 + else
1.4446 + res = evutil_addrinfo_append(
1.4447 + data->pending_result, res);
1.4448 + data->pending_result = NULL;
1.4449 + }
1.4450 +
1.4451 + /* Call the user callback. */
1.4452 + add_cname_to_reply(data, res);
1.4453 + data->user_cb(0, res, data->user_data);
1.4454 +
1.4455 + /* Free data. */
1.4456 + free_getaddrinfo_request(data);
1.4457 + }
1.4458 +}
1.4459 +
1.4460 +static struct hosts_entry *
1.4461 +find_hosts_entry(struct evdns_base *base, const char *hostname,
1.4462 + struct hosts_entry *find_after)
1.4463 +{
1.4464 + struct hosts_entry *e;
1.4465 +
1.4466 + if (find_after)
1.4467 + e = TAILQ_NEXT(find_after, next);
1.4468 + else
1.4469 + e = TAILQ_FIRST(&base->hostsdb);
1.4470 +
1.4471 + for (; e; e = TAILQ_NEXT(e, next)) {
1.4472 + if (!evutil_ascii_strcasecmp(e->hostname, hostname))
1.4473 + return e;
1.4474 + }
1.4475 + return NULL;
1.4476 +}
1.4477 +
1.4478 +static int
1.4479 +evdns_getaddrinfo_fromhosts(struct evdns_base *base,
1.4480 + const char *nodename, struct evutil_addrinfo *hints, ev_uint16_t port,
1.4481 + struct evutil_addrinfo **res)
1.4482 +{
1.4483 + int n_found = 0;
1.4484 + struct hosts_entry *e;
1.4485 + struct evutil_addrinfo *ai=NULL;
1.4486 + int f = hints->ai_family;
1.4487 +
1.4488 + EVDNS_LOCK(base);
1.4489 + for (e = find_hosts_entry(base, nodename, NULL); e;
1.4490 + e = find_hosts_entry(base, nodename, e)) {
1.4491 + struct evutil_addrinfo *ai_new;
1.4492 + ++n_found;
1.4493 + if ((e->addr.sa.sa_family == AF_INET && f == PF_INET6) ||
1.4494 + (e->addr.sa.sa_family == AF_INET6 && f == PF_INET))
1.4495 + continue;
1.4496 + ai_new = evutil_new_addrinfo(&e->addr.sa, e->addrlen, hints);
1.4497 + if (!ai_new) {
1.4498 + n_found = 0;
1.4499 + goto out;
1.4500 + }
1.4501 + sockaddr_setport(ai_new->ai_addr, port);
1.4502 + ai = evutil_addrinfo_append(ai, ai_new);
1.4503 + }
1.4504 + EVDNS_UNLOCK(base);
1.4505 +out:
1.4506 + if (n_found) {
1.4507 + /* Note that we return an empty answer if we found entries for
1.4508 + * this hostname but none were of the right address type. */
1.4509 + *res = ai;
1.4510 + return 0;
1.4511 + } else {
1.4512 + if (ai)
1.4513 + evutil_freeaddrinfo(ai);
1.4514 + return -1;
1.4515 + }
1.4516 +}
1.4517 +
1.4518 +struct evdns_getaddrinfo_request *
1.4519 +evdns_getaddrinfo(struct evdns_base *dns_base,
1.4520 + const char *nodename, const char *servname,
1.4521 + const struct evutil_addrinfo *hints_in,
1.4522 + evdns_getaddrinfo_cb cb, void *arg)
1.4523 +{
1.4524 + struct evdns_getaddrinfo_request *data;
1.4525 + struct evutil_addrinfo hints;
1.4526 + struct evutil_addrinfo *res = NULL;
1.4527 + int err;
1.4528 + int port = 0;
1.4529 + int want_cname = 0;
1.4530 +
1.4531 + if (!dns_base) {
1.4532 + dns_base = current_base;
1.4533 + if (!dns_base) {
1.4534 + log(EVDNS_LOG_WARN,
1.4535 + "Call to getaddrinfo_async with no "
1.4536 + "evdns_base configured.");
1.4537 + cb(EVUTIL_EAI_FAIL, NULL, arg); /* ??? better error? */
1.4538 + return NULL;
1.4539 + }
1.4540 + }
1.4541 +
1.4542 + /* If we _must_ answer this immediately, do so. */
1.4543 + if ((hints_in && (hints_in->ai_flags & EVUTIL_AI_NUMERICHOST))) {
1.4544 + res = NULL;
1.4545 + err = evutil_getaddrinfo(nodename, servname, hints_in, &res);
1.4546 + cb(err, res, arg);
1.4547 + return NULL;
1.4548 + }
1.4549 +
1.4550 + if (hints_in) {
1.4551 + memcpy(&hints, hints_in, sizeof(hints));
1.4552 + } else {
1.4553 + memset(&hints, 0, sizeof(hints));
1.4554 + hints.ai_family = PF_UNSPEC;
1.4555 + }
1.4556 +
1.4557 + evutil_adjust_hints_for_addrconfig(&hints);
1.4558 +
1.4559 + /* Now try to see if we _can_ answer immediately. */
1.4560 + /* (It would be nice to do this by calling getaddrinfo directly, with
1.4561 + * AI_NUMERICHOST, on plaforms that have it, but we can't: there isn't
1.4562 + * a reliable way to distinguish the "that wasn't a numeric host!" case
1.4563 + * from any other EAI_NONAME cases.) */
1.4564 + err = evutil_getaddrinfo_common(nodename, servname, &hints, &res, &port);
1.4565 + if (err != EVUTIL_EAI_NEED_RESOLVE) {
1.4566 + cb(err, res, arg);
1.4567 + return NULL;
1.4568 + }
1.4569 +
1.4570 + /* If there is an entry in the hosts file, we should give it now. */
1.4571 + if (!evdns_getaddrinfo_fromhosts(dns_base, nodename, &hints, port, &res)) {
1.4572 + cb(0, res, arg);
1.4573 + return NULL;
1.4574 + }
1.4575 +
1.4576 + /* Okay, things are serious now. We're going to need to actually
1.4577 + * launch a request.
1.4578 + */
1.4579 + data = mm_calloc(1,sizeof(struct evdns_getaddrinfo_request));
1.4580 + if (!data) {
1.4581 + cb(EVUTIL_EAI_MEMORY, NULL, arg);
1.4582 + return NULL;
1.4583 + }
1.4584 +
1.4585 + memcpy(&data->hints, &hints, sizeof(data->hints));
1.4586 + data->port = (ev_uint16_t)port;
1.4587 + data->ipv4_request.type = DNS_IPv4_A;
1.4588 + data->ipv6_request.type = DNS_IPv6_AAAA;
1.4589 + data->user_cb = cb;
1.4590 + data->user_data = arg;
1.4591 + data->evdns_base = dns_base;
1.4592 +
1.4593 + want_cname = (hints.ai_flags & EVUTIL_AI_CANONNAME);
1.4594 +
1.4595 + /* If we are asked for a PF_UNSPEC address, we launch two requests in
1.4596 + * parallel: one for an A address and one for an AAAA address. We
1.4597 + * can't send just one request, since many servers only answer one
1.4598 + * question per DNS request.
1.4599 + *
1.4600 + * Once we have the answer to one request, we allow for a short
1.4601 + * timeout before we report it, to see if the other one arrives. If
1.4602 + * they both show up in time, then we report both the answers.
1.4603 + *
1.4604 + * If too many addresses of one type time out or fail, we should stop
1.4605 + * launching those requests. (XXX we don't do that yet.)
1.4606 + */
1.4607 +
1.4608 + if (hints.ai_family != PF_INET6) {
1.4609 + log(EVDNS_LOG_DEBUG, "Sending request for %s on ipv4 as %p",
1.4610 + nodename, &data->ipv4_request);
1.4611 +
1.4612 + data->ipv4_request.r = evdns_base_resolve_ipv4(dns_base,
1.4613 + nodename, 0, evdns_getaddrinfo_gotresolve,
1.4614 + &data->ipv4_request);
1.4615 + if (want_cname)
1.4616 + data->ipv4_request.r->current_req->put_cname_in_ptr =
1.4617 + &data->cname_result;
1.4618 + }
1.4619 + if (hints.ai_family != PF_INET) {
1.4620 + log(EVDNS_LOG_DEBUG, "Sending request for %s on ipv6 as %p",
1.4621 + nodename, &data->ipv6_request);
1.4622 +
1.4623 + data->ipv6_request.r = evdns_base_resolve_ipv6(dns_base,
1.4624 + nodename, 0, evdns_getaddrinfo_gotresolve,
1.4625 + &data->ipv6_request);
1.4626 + if (want_cname)
1.4627 + data->ipv6_request.r->current_req->put_cname_in_ptr =
1.4628 + &data->cname_result;
1.4629 + }
1.4630 +
1.4631 + evtimer_assign(&data->timeout, dns_base->event_base,
1.4632 + evdns_getaddrinfo_timeout_cb, data);
1.4633 +
1.4634 + if (data->ipv4_request.r || data->ipv6_request.r) {
1.4635 + return data;
1.4636 + } else {
1.4637 + mm_free(data);
1.4638 + cb(EVUTIL_EAI_FAIL, NULL, arg);
1.4639 + return NULL;
1.4640 + }
1.4641 +}
1.4642 +
1.4643 +void
1.4644 +evdns_getaddrinfo_cancel(struct evdns_getaddrinfo_request *data)
1.4645 +{
1.4646 + EVDNS_LOCK(data->evdns_base);
1.4647 + if (data->request_done) {
1.4648 + EVDNS_UNLOCK(data->evdns_base);
1.4649 + return;
1.4650 + }
1.4651 + event_del(&data->timeout);
1.4652 + data->user_canceled = 1;
1.4653 + if (data->ipv4_request.r)
1.4654 + evdns_cancel_request(data->evdns_base, data->ipv4_request.r);
1.4655 + if (data->ipv6_request.r)
1.4656 + evdns_cancel_request(data->evdns_base, data->ipv6_request.r);
1.4657 + EVDNS_UNLOCK(data->evdns_base);
1.4658 +}
