michael@0: /*
michael@0:   This example code shows how to use the high-level, low-level, and
michael@0:   server-level interfaces of evdns.
michael@0: 
michael@0:   XXX It's pretty ugly and should probably be cleaned up.
michael@0:  */
michael@0: 
michael@0: #include <event2/event-config.h>
michael@0: 
michael@0: /* Compatibility for possible missing IPv6 declarations */
michael@0: #include "../ipv6-internal.h"
michael@0: 
michael@0: #include <sys/types.h>
michael@0: 
michael@0: #ifdef WIN32
michael@0: #include <winsock2.h>
michael@0: #include <ws2tcpip.h>
michael@0: #else
michael@0: #include <sys/socket.h>
michael@0: #include <netinet/in.h>
michael@0: #include <arpa/inet.h>
michael@0: #endif
michael@0: 
michael@0: #include <event2/event.h>
michael@0: #include <event2/dns.h>
michael@0: #include <event2/dns_struct.h>
michael@0: #include <event2/util.h>
michael@0: 
michael@0: #ifdef _EVENT_HAVE_NETINET_IN6_H
michael@0: #include <netinet/in6.h>
michael@0: #endif
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <stdlib.h>
michael@0: #include <string.h>
michael@0: 
michael@0: #define u32 ev_uint32_t
michael@0: #define u8 ev_uint8_t
michael@0: 
michael@0: static const char *
michael@0: debug_ntoa(u32 address)
michael@0: {
michael@0: 	static char buf[32];
michael@0: 	u32 a = ntohl(address);
michael@0: 	evutil_snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
michael@0: 					(int)(u8)((a>>24)&0xff),
michael@0: 					(int)(u8)((a>>16)&0xff),
michael@0: 					(int)(u8)((a>>8 )&0xff),
michael@0: 					(int)(u8)((a	)&0xff));
michael@0: 	return buf;
michael@0: }
michael@0: 
michael@0: static void
michael@0: main_callback(int result, char type, int count, int ttl,
michael@0: 			  void *addrs, void *orig) {
michael@0: 	char *n = (char*)orig;
michael@0: 	int i;
michael@0: 	for (i = 0; i < count; ++i) {
michael@0: 		if (type == DNS_IPv4_A) {
michael@0: 			printf("%s: %s\n", n, debug_ntoa(((u32*)addrs)[i]));
michael@0: 		} else if (type == DNS_PTR) {
michael@0: 			printf("%s: %s\n", n, ((char**)addrs)[i]);
michael@0: 		}
michael@0: 	}
michael@0: 	if (!count) {
michael@0: 		printf("%s: No answer (%d)\n", n, result);
michael@0: 	}
michael@0: 	fflush(stdout);
michael@0: }
michael@0: 
michael@0: static void
michael@0: gai_callback(int err, struct evutil_addrinfo *ai, void *arg)
michael@0: {
michael@0: 	const char *name = arg;
michael@0: 	int i;
michael@0: 	if (err) {
michael@0: 		printf("%s: %s\n", name, evutil_gai_strerror(err));
michael@0: 	}
michael@0: 	if (ai && ai->ai_canonname)
michael@0: 		printf("    %s ==> %s\n", name, ai->ai_canonname);
michael@0: 	for (i=0; ai; ai = ai->ai_next, ++i) {
michael@0: 		char buf[128];
michael@0: 		if (ai->ai_family == PF_INET) {
michael@0: 			struct sockaddr_in *sin =
michael@0: 			    (struct sockaddr_in*)ai->ai_addr;
michael@0: 			evutil_inet_ntop(AF_INET, &sin->sin_addr, buf,
michael@0: 			    sizeof(buf));
michael@0: 			printf("[%d] %s: %s\n",i,name,buf);
michael@0: 		} else {
michael@0: 			struct sockaddr_in6 *sin6 =
michael@0: 			    (struct sockaddr_in6*)ai->ai_addr;
michael@0: 			evutil_inet_ntop(AF_INET6, &sin6->sin6_addr, buf,
michael@0: 			    sizeof(buf));
michael@0: 			printf("[%d] %s: %s\n",i,name,buf);
michael@0: 		}
michael@0: 	}
michael@0: }
michael@0: 
michael@0: static void
michael@0: evdns_server_callback(struct evdns_server_request *req, void *data)
michael@0: {
michael@0: 	int i, r;
michael@0: 	(void)data;
michael@0: 	/* dummy; give 192.168.11.11 as an answer for all A questions,
michael@0: 	 *	give foo.bar.example.com as an answer for all PTR questions. */
michael@0: 	for (i = 0; i < req->nquestions; ++i) {
michael@0: 		u32 ans = htonl(0xc0a80b0bUL);
michael@0: 		if (req->questions[i]->type == EVDNS_TYPE_A &&
michael@0: 		    req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
michael@0: 			printf(" -- replying for %s (A)\n", req->questions[i]->name);
michael@0: 			r = evdns_server_request_add_a_reply(req, req->questions[i]->name,
michael@0: 										  1, &ans, 10);
michael@0: 			if (r<0)
michael@0: 				printf("eeep, didn't work.\n");
michael@0: 		} else if (req->questions[i]->type == EVDNS_TYPE_PTR &&
michael@0: 		    req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
michael@0: 			printf(" -- replying for %s (PTR)\n", req->questions[i]->name);
michael@0: 			r = evdns_server_request_add_ptr_reply(req, NULL, req->questions[i]->name,
michael@0: 											"foo.bar.example.com", 10);
michael@0: 			if (r<0)
michael@0: 				printf("ugh, no luck");
michael@0: 		} else {
michael@0: 			printf(" -- skipping %s [%d %d]\n", req->questions[i]->name,
michael@0: 				   req->questions[i]->type, req->questions[i]->dns_question_class);
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	r = evdns_server_request_respond(req, 0);
michael@0: 	if (r<0)
michael@0: 		printf("eeek, couldn't send reply.\n");
michael@0: }
michael@0: 
michael@0: static int verbose = 0;
michael@0: 
michael@0: static void
michael@0: logfn(int is_warn, const char *msg) {
michael@0: 	if (!is_warn && !verbose)
michael@0: 		return;
michael@0: 	fprintf(stderr, "%s: %s\n", is_warn?"WARN":"INFO", msg);
michael@0: }
michael@0: 
michael@0: int
michael@0: main(int c, char **v) {
michael@0: 	int idx;
michael@0: 	int reverse = 0, servertest = 0, use_getaddrinfo = 0;
michael@0: 	struct event_base *event_base = NULL;
michael@0: 	struct evdns_base *evdns_base = NULL;
michael@0: 	const char *resolv_conf = NULL;
michael@0: 	if (c<2) {
michael@0: 		fprintf(stderr, "syntax: %s [-x] [-v] [-c resolv.conf] hostname\n", v[0]);
michael@0: 		fprintf(stderr, "syntax: %s [-servertest]\n", v[0]);
michael@0: 		return 1;
michael@0: 	}
michael@0: 	idx = 1;
michael@0: 	while (idx < c && v[idx][0] == '-') {
michael@0: 		if (!strcmp(v[idx], "-x"))
michael@0: 			reverse = 1;
michael@0: 		else if (!strcmp(v[idx], "-v"))
michael@0: 			verbose = 1;
michael@0: 		else if (!strcmp(v[idx], "-g"))
michael@0: 			use_getaddrinfo = 1;
michael@0: 		else if (!strcmp(v[idx], "-servertest"))
michael@0: 			servertest = 1;
michael@0: 		else if (!strcmp(v[idx], "-c")) {
michael@0: 			if (idx + 1 < c)
michael@0: 				resolv_conf = v[++idx];
michael@0: 			else
michael@0: 				fprintf(stderr, "-c needs an argument\n");
michael@0: 		} else
michael@0: 			fprintf(stderr, "Unknown option %s\n", v[idx]);
michael@0: 		++idx;
michael@0: 	}
michael@0: 
michael@0: #ifdef WIN32
michael@0: 	{
michael@0: 		WSADATA WSAData;
michael@0: 		WSAStartup(0x101, &WSAData);
michael@0: 	}
michael@0: #endif
michael@0: 
michael@0: 	event_base = event_base_new();
michael@0: 	evdns_base = evdns_base_new(event_base, 0);
michael@0: 	evdns_set_log_fn(logfn);
michael@0: 
michael@0: 	if (servertest) {
michael@0: 		evutil_socket_t sock;
michael@0: 		struct sockaddr_in my_addr;
michael@0: 		sock = socket(PF_INET, SOCK_DGRAM, 0);
michael@0: 		if (sock == -1) {
michael@0: 			perror("socket");
michael@0: 			exit(1);
michael@0: 		}
michael@0: 		evutil_make_socket_nonblocking(sock);
michael@0: 		my_addr.sin_family = AF_INET;
michael@0: 		my_addr.sin_port = htons(10053);
michael@0: 		my_addr.sin_addr.s_addr = INADDR_ANY;
michael@0: 		if (bind(sock, (struct sockaddr*)&my_addr, sizeof(my_addr))<0) {
michael@0: 			perror("bind");
michael@0: 			exit(1);
michael@0: 		}
michael@0: 		evdns_add_server_port_with_base(event_base, sock, 0, evdns_server_callback, NULL);
michael@0: 	}
michael@0: 	if (idx < c) {
michael@0: 		int res;
michael@0: #ifdef WIN32
michael@0: 		if (resolv_conf == NULL)
michael@0: 			res = evdns_base_config_windows_nameservers(evdns_base);
michael@0: 		else
michael@0: #endif
michael@0: 			res = evdns_base_resolv_conf_parse(evdns_base,
michael@0: 			    DNS_OPTION_NAMESERVERS,
michael@0: 			    resolv_conf ? resolv_conf : "/etc/resolv.conf");
michael@0: 
michael@0: 		if (res < 0) {
michael@0: 			fprintf(stderr, "Couldn't configure nameservers");
michael@0: 			return 1;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	printf("EVUTIL_AI_CANONNAME in example = %d\n", EVUTIL_AI_CANONNAME);
michael@0: 	for (; idx < c; ++idx) {
michael@0: 		if (reverse) {
michael@0: 			struct in_addr addr;
michael@0: 			if (evutil_inet_pton(AF_INET, v[idx], &addr)!=1) {
michael@0: 				fprintf(stderr, "Skipping non-IP %s\n", v[idx]);
michael@0: 				continue;
michael@0: 			}
michael@0: 			fprintf(stderr, "resolving %s...\n",v[idx]);
michael@0: 			evdns_base_resolve_reverse(evdns_base, &addr, 0, main_callback, v[idx]);
michael@0: 		} else if (use_getaddrinfo) {
michael@0: 			struct evutil_addrinfo hints;
michael@0: 			memset(&hints, 0, sizeof(hints));
michael@0: 			hints.ai_family = PF_UNSPEC;
michael@0: 			hints.ai_protocol = IPPROTO_TCP;
michael@0: 			hints.ai_flags = EVUTIL_AI_CANONNAME;
michael@0: 			fprintf(stderr, "resolving (fwd) %s...\n",v[idx]);
michael@0: 			evdns_getaddrinfo(evdns_base, v[idx], NULL, &hints,
michael@0: 			    gai_callback, v[idx]);
michael@0: 		} else {
michael@0: 			fprintf(stderr, "resolving (fwd) %s...\n",v[idx]);
michael@0: 			evdns_base_resolve_ipv4(evdns_base, v[idx], 0, main_callback, v[idx]);
michael@0: 		}
michael@0: 	}
michael@0: 	fflush(stdout);
michael@0: 	event_base_dispatch(event_base);
michael@0: 	return 0;
michael@0: }
michael@0: