The Tor Browser: ipc/chromium/src/third_party/libevent/evrpc.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/evrpc.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/evrpc.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /*
  * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. The name of the author may not be used to endorse or promote products
  *    derived from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include "event2/event-config.h"
 #ifdef WIN32
 #define WIN32_LEAN_AND_MEAN
 #include <winsock2.h>
 #include <windows.h>
 #undef WIN32_LEAN_AND_MEAN
 #endif
 #include <sys/types.h>
 #ifndef WIN32
 #include <sys/socket.h>
 #endif
 #ifdef _EVENT_HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 #include <sys/queue.h>
 #include <stdio.h>
 #include <stdlib.h>
 #ifndef WIN32
 #include <unistd.h>
 #endif
 #include <errno.h>
 #include <signal.h>
 #include <string.h>
 #include <sys/queue.h>
 #include "event2/event.h"
 #include "event2/event_struct.h"
 #include "event2/rpc.h"
 #include "event2/rpc_struct.h"
 #include "evrpc-internal.h"
 #include "event2/http.h"
 #include "event2/buffer.h"
 #include "event2/tag.h"
 #include "event2/http_struct.h"
 #include "event2/http_compat.h"
 #include "event2/util.h"
 #include "util-internal.h"
 #include "log-internal.h"
 #include "mm-internal.h"
 struct evrpc_base *
 evrpc_init(struct evhttp *http_server)
 {
 	struct evrpc_base* base = mm_calloc(1, sizeof(struct evrpc_base));
 	if (base == NULL)
 		return (NULL);
 	/* we rely on the tagging sub system */
 	evtag_init();
 	TAILQ_INIT(&base->registered_rpcs);
 	TAILQ_INIT(&base->input_hooks);
 	TAILQ_INIT(&base->output_hooks);
 	TAILQ_INIT(&base->paused_requests);
 	base->http_server = http_server;
 	return (base);
 }
 void
 evrpc_free(struct evrpc_base *base)
 {
 	struct evrpc *rpc;
 	struct evrpc_hook *hook;
 	struct evrpc_hook_ctx *pause;
 	int r;
 	while ((rpc = TAILQ_FIRST(&base->registered_rpcs)) != NULL) {
 		r = evrpc_unregister_rpc(base, rpc->uri);
 		EVUTIL_ASSERT(r == 0);
 	}
 	while ((pause = TAILQ_FIRST(&base->paused_requests)) != NULL) {
 		TAILQ_REMOVE(&base->paused_requests, pause, next);
 		mm_free(pause);
 	}
 	while ((hook = TAILQ_FIRST(&base->input_hooks)) != NULL) {
 		r = evrpc_remove_hook(base, EVRPC_INPUT, hook);
 		EVUTIL_ASSERT(r);
 	}
 	while ((hook = TAILQ_FIRST(&base->output_hooks)) != NULL) {
 		r = evrpc_remove_hook(base, EVRPC_OUTPUT, hook);
 		EVUTIL_ASSERT(r);
 	}
 	mm_free(base);
 }
 void *
 evrpc_add_hook(void *vbase,
     enum EVRPC_HOOK_TYPE hook_type,
     int (*cb)(void *, struct evhttp_request *, struct evbuffer *, void *),
     void *cb_arg)
 {
 	struct _evrpc_hooks *base = vbase;
 	struct evrpc_hook_list *head = NULL;
 	struct evrpc_hook *hook = NULL;
 	switch (hook_type) {
 	case EVRPC_INPUT:
 		head = &base->in_hooks;
 		break;
 	case EVRPC_OUTPUT:
 		head = &base->out_hooks;
 		break;
 	default:
 		EVUTIL_ASSERT(hook_type == EVRPC_INPUT || hook_type == EVRPC_OUTPUT);
 	}
 	hook = mm_calloc(1, sizeof(struct evrpc_hook));
 	EVUTIL_ASSERT(hook != NULL);
 	hook->process = cb;
 	hook->process_arg = cb_arg;
 	TAILQ_INSERT_TAIL(head, hook, next);
 	return (hook);
 }
 static int
 evrpc_remove_hook_internal(struct evrpc_hook_list *head, void *handle)
 {
 	struct evrpc_hook *hook = NULL;
 	TAILQ_FOREACH(hook, head, next) {
 		if (hook == handle) {
 			TAILQ_REMOVE(head, hook, next);
 			mm_free(hook);
 			return (1);
 		}
 	}
 	return (0);
 }
 /*
  * remove the hook specified by the handle
  */
 int
 evrpc_remove_hook(void *vbase, enum EVRPC_HOOK_TYPE hook_type, void *handle)
 {
 	struct _evrpc_hooks *base = vbase;
 	struct evrpc_hook_list *head = NULL;
 	switch (hook_type) {
 	case EVRPC_INPUT:
 		head = &base->in_hooks;
 		break;
 	case EVRPC_OUTPUT:
 		head = &base->out_hooks;
 		break;
 	default:
 		EVUTIL_ASSERT(hook_type == EVRPC_INPUT || hook_type == EVRPC_OUTPUT);
 	}
 	return (evrpc_remove_hook_internal(head, handle));
 }
 static int
 evrpc_process_hooks(struct evrpc_hook_list *head, void *ctx,
     struct evhttp_request *req, struct evbuffer *evbuf)
 {
 	struct evrpc_hook *hook;
 	TAILQ_FOREACH(hook, head, next) {
 		int res = hook->process(ctx, req, evbuf, hook->process_arg);
 		if (res != EVRPC_CONTINUE)
 			return (res);
 	}
 	return (EVRPC_CONTINUE);
 }
 static void evrpc_pool_schedule(struct evrpc_pool *pool);
 static void evrpc_request_cb(struct evhttp_request *, void *);
 /*
  * Registers a new RPC with the HTTP server.   The evrpc object is expected
  * to have been filled in via the EVRPC_REGISTER_OBJECT macro which in turn
  * calls this function.
  */
 static char *
 evrpc_construct_uri(const char *uri)
 {
 	char *constructed_uri;
 	size_t constructed_uri_len;
 	constructed_uri_len = strlen(EVRPC_URI_PREFIX) + strlen(uri) + 1;
 	if ((constructed_uri = mm_malloc(constructed_uri_len)) == NULL)
 		event_err(1, "%s: failed to register rpc at %s",
 		    __func__, uri);
 	memcpy(constructed_uri, EVRPC_URI_PREFIX, strlen(EVRPC_URI_PREFIX));
 	memcpy(constructed_uri + strlen(EVRPC_URI_PREFIX), uri, strlen(uri));
 	constructed_uri[constructed_uri_len - 1] = '\0';
 	return (constructed_uri);
 }
 int
 evrpc_register_rpc(struct evrpc_base *base, struct evrpc *rpc,
     void (*cb)(struct evrpc_req_generic *, void *), void *cb_arg)
 {
 	char *constructed_uri = evrpc_construct_uri(rpc->uri);
 	rpc->base = base;
 	rpc->cb = cb;
 	rpc->cb_arg = cb_arg;
 	TAILQ_INSERT_TAIL(&base->registered_rpcs, rpc, next);
 	evhttp_set_cb(base->http_server,
 	    constructed_uri,
 	    evrpc_request_cb,
 	    rpc);
 	mm_free(constructed_uri);
 	return (0);
 }
 int
 evrpc_unregister_rpc(struct evrpc_base *base, const char *name)
 {
 	char *registered_uri = NULL;
 	struct evrpc *rpc;
 	int r;
 	/* find the right rpc; linear search might be slow */
 	TAILQ_FOREACH(rpc, &base->registered_rpcs, next) {
 		if (strcmp(rpc->uri, name) == 0)
 			break;
 	}
 	if (rpc == NULL) {
 		/* We did not find an RPC with this name */
 		return (-1);
 	}
 	TAILQ_REMOVE(&base->registered_rpcs, rpc, next);
 	registered_uri = evrpc_construct_uri(name);
 	/* remove the http server callback */
 	r = evhttp_del_cb(base->http_server, registered_uri);
 	EVUTIL_ASSERT(r == 0);
 	mm_free(registered_uri);
 	mm_free((char *)rpc->uri);
 	mm_free(rpc);
 	return (0);
 }
 static int evrpc_pause_request(void *vbase, void *ctx,
     void (*cb)(void *, enum EVRPC_HOOK_RESULT));
 static void evrpc_request_cb_closure(void *, enum EVRPC_HOOK_RESULT);
 static void
 evrpc_request_cb(struct evhttp_request *req, void *arg)
 {
 	struct evrpc *rpc = arg;
 	struct evrpc_req_generic *rpc_state = NULL;
 	/* let's verify the outside parameters */
 	if (req->type != EVHTTP_REQ_POST ||
 	    evbuffer_get_length(req->input_buffer) <= 0)
 		goto error;
 	rpc_state = mm_calloc(1, sizeof(struct evrpc_req_generic));
 	if (rpc_state == NULL)
 		goto error;
 	rpc_state->rpc = rpc;
 	rpc_state->http_req = req;
 	rpc_state->rpc_data = NULL;
 	if (TAILQ_FIRST(&rpc->base->input_hooks) != NULL) {
 		int hook_res;
 		evrpc_hook_associate_meta(&rpc_state->hook_meta, req->evcon);
 		/*
 		 * allow hooks to modify the outgoing request
 		 */
 		hook_res = evrpc_process_hooks(&rpc->base->input_hooks,
 		    rpc_state, req, req->input_buffer);
 		switch (hook_res) {
 		case EVRPC_TERMINATE:
 			goto error;
 		case EVRPC_PAUSE:
 			evrpc_pause_request(rpc->base, rpc_state,
 			    evrpc_request_cb_closure);
 			return;
 		case EVRPC_CONTINUE:
 			break;
 		default:
 			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
 			    hook_res == EVRPC_CONTINUE ||
 			    hook_res == EVRPC_PAUSE);
 		}
 	}
 	evrpc_request_cb_closure(rpc_state, EVRPC_CONTINUE);
 	return;
 error:
 	if (rpc_state != NULL)
 		evrpc_reqstate_free(rpc_state);
 	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
 	return;
 }
 static void
 evrpc_request_cb_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
 {
 	struct evrpc_req_generic *rpc_state = arg;
 	struct evrpc *rpc;
 	struct evhttp_request *req;
 	EVUTIL_ASSERT(rpc_state);
 	rpc = rpc_state->rpc;
 	req = rpc_state->http_req;
 	if (hook_res == EVRPC_TERMINATE)
 		goto error;
 	/* let's check that we can parse the request */
 	rpc_state->request = rpc->request_new(rpc->request_new_arg);
 	if (rpc_state->request == NULL)
 		goto error;
 	if (rpc->request_unmarshal(
 		    rpc_state->request, req->input_buffer) == -1) {
 		/* we failed to parse the request; that's a bummer */
 		goto error;
 	}
 	/* at this point, we have a well formed request, prepare the reply */
 	rpc_state->reply = rpc->reply_new(rpc->reply_new_arg);
 	if (rpc_state->reply == NULL)
 		goto error;
 	/* give the rpc to the user; they can deal with it */
 	rpc->cb(rpc_state, rpc->cb_arg);
 	return;
 error:
 	if (rpc_state != NULL)
 		evrpc_reqstate_free(rpc_state);
 	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
 	return;
 }
 void
 evrpc_reqstate_free(struct evrpc_req_generic* rpc_state)
 {
 	struct evrpc *rpc;
 	EVUTIL_ASSERT(rpc_state != NULL);
 	rpc = rpc_state->rpc;
 	/* clean up all memory */
 	if (rpc_state->hook_meta != NULL)
 		evrpc_hook_context_free(rpc_state->hook_meta);
 	if (rpc_state->request != NULL)
 		rpc->request_free(rpc_state->request);
 	if (rpc_state->reply != NULL)
 		rpc->reply_free(rpc_state->reply);
 	if (rpc_state->rpc_data != NULL)
 		evbuffer_free(rpc_state->rpc_data);
 	mm_free(rpc_state);
 }
 static void
 evrpc_request_done_closure(void *, enum EVRPC_HOOK_RESULT);
 void
 evrpc_request_done(struct evrpc_req_generic *rpc_state)
 {
 	struct evhttp_request *req;
 	struct evrpc *rpc;
 	EVUTIL_ASSERT(rpc_state);
 	req = rpc_state->http_req;
 	rpc = rpc_state->rpc;
 	if (rpc->reply_complete(rpc_state->reply) == -1) {
 		/* the reply was not completely filled in.  error out */
 		goto error;
 	}
 	if ((rpc_state->rpc_data = evbuffer_new()) == NULL) {
 		/* out of memory */
 		goto error;
 	}
 	/* serialize the reply */
 	rpc->reply_marshal(rpc_state->rpc_data, rpc_state->reply);
 	if (TAILQ_FIRST(&rpc->base->output_hooks) != NULL) {
 		int hook_res;
 		evrpc_hook_associate_meta(&rpc_state->hook_meta, req->evcon);
 		/* do hook based tweaks to the request */
 		hook_res = evrpc_process_hooks(&rpc->base->output_hooks,
 		    rpc_state, req, rpc_state->rpc_data);
 		switch (hook_res) {
 		case EVRPC_TERMINATE:
 			goto error;
 		case EVRPC_PAUSE:
 			if (evrpc_pause_request(rpc->base, rpc_state,
 				evrpc_request_done_closure) == -1)
 				goto error;
 			return;
 		case EVRPC_CONTINUE:
 			break;
 		default:
 			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
 			    hook_res == EVRPC_CONTINUE ||
 			    hook_res == EVRPC_PAUSE);
 		}
 	}
 	evrpc_request_done_closure(rpc_state, EVRPC_CONTINUE);
 	return;
 error:
 	if (rpc_state != NULL)
 		evrpc_reqstate_free(rpc_state);
 	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
 	return;
 }
 void *
 evrpc_get_request(struct evrpc_req_generic *req)
 {
 	return req->request;
 }
 void *
 evrpc_get_reply(struct evrpc_req_generic *req)
 {
 	return req->reply;
 }
 static void
 evrpc_request_done_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
 {
 	struct evrpc_req_generic *rpc_state = arg;
 	struct evhttp_request *req;
 	EVUTIL_ASSERT(rpc_state);
 	req = rpc_state->http_req;
 	if (hook_res == EVRPC_TERMINATE)
 		goto error;
 	/* on success, we are going to transmit marshaled binary data */
 	if (evhttp_find_header(req->output_headers, "Content-Type") == NULL) {
 		evhttp_add_header(req->output_headers,
 		    "Content-Type", "application/octet-stream");
 	}
 	evhttp_send_reply(req, HTTP_OK, "OK", rpc_state->rpc_data);
 	evrpc_reqstate_free(rpc_state);
 	return;
 error:
 	if (rpc_state != NULL)
 		evrpc_reqstate_free(rpc_state);
 	evhttp_send_error(req, HTTP_SERVUNAVAIL, NULL);
 	return;
 }
 /* Client implementation of RPC site */
 static int evrpc_schedule_request(struct evhttp_connection *connection,
     struct evrpc_request_wrapper *ctx);
 struct evrpc_pool *
 evrpc_pool_new(struct event_base *base)
 {
 	struct evrpc_pool *pool = mm_calloc(1, sizeof(struct evrpc_pool));
 	if (pool == NULL)
 		return (NULL);
 	TAILQ_INIT(&pool->connections);
 	TAILQ_INIT(&pool->requests);
 	TAILQ_INIT(&pool->paused_requests);
 	TAILQ_INIT(&pool->input_hooks);
 	TAILQ_INIT(&pool->output_hooks);
 	pool->base = base;
 	pool->timeout = -1;
 	return (pool);
 }
 static void
 evrpc_request_wrapper_free(struct evrpc_request_wrapper *request)
 {
 	if (request->hook_meta != NULL)
 		evrpc_hook_context_free(request->hook_meta);
 	mm_free(request->name);
 	mm_free(request);
 }
 void
 evrpc_pool_free(struct evrpc_pool *pool)
 {
 	struct evhttp_connection *connection;
 	struct evrpc_request_wrapper *request;
 	struct evrpc_hook_ctx *pause;
 	struct evrpc_hook *hook;
 	int r;
 	while ((request = TAILQ_FIRST(&pool->requests)) != NULL) {
 		TAILQ_REMOVE(&pool->requests, request, next);
 		evrpc_request_wrapper_free(request);
 	}
 	while ((pause = TAILQ_FIRST(&pool->paused_requests)) != NULL) {
 		TAILQ_REMOVE(&pool->paused_requests, pause, next);
 		mm_free(pause);
 	}
 	while ((connection = TAILQ_FIRST(&pool->connections)) != NULL) {
 		TAILQ_REMOVE(&pool->connections, connection, next);
 		evhttp_connection_free(connection);
 	}
 	while ((hook = TAILQ_FIRST(&pool->input_hooks)) != NULL) {
 		r = evrpc_remove_hook(pool, EVRPC_INPUT, hook);
 		EVUTIL_ASSERT(r);
 	}
 	while ((hook = TAILQ_FIRST(&pool->output_hooks)) != NULL) {
 		r = evrpc_remove_hook(pool, EVRPC_OUTPUT, hook);
 		EVUTIL_ASSERT(r);
 	}
 	mm_free(pool);
 }
 /*
  * Add a connection to the RPC pool.   A request scheduled on the pool
  * may use any available connection.
  */
 void
 evrpc_pool_add_connection(struct evrpc_pool *pool,
     struct evhttp_connection *connection)
 {
 	EVUTIL_ASSERT(connection->http_server == NULL);
 	TAILQ_INSERT_TAIL(&pool->connections, connection, next);
 	/*
 	 * associate an event base with this connection
 	 */
 	if (pool->base != NULL)
 		evhttp_connection_set_base(connection, pool->base);
 	/*
 	 * unless a timeout was specifically set for a connection,
 	 * the connection inherits the timeout from the pool.
 	 */
 	if (connection->timeout == -1)
 		connection->timeout = pool->timeout;
 	/*
 	 * if we have any requests pending, schedule them with the new
 	 * connections.
 	 */
 	if (TAILQ_FIRST(&pool->requests) != NULL) {
 		struct evrpc_request_wrapper *request =
 		    TAILQ_FIRST(&pool->requests);
 		TAILQ_REMOVE(&pool->requests, request, next);
 		evrpc_schedule_request(connection, request);
 	}
 }
 void
 evrpc_pool_remove_connection(struct evrpc_pool *pool,
     struct evhttp_connection *connection)
 {
 	TAILQ_REMOVE(&pool->connections, connection, next);
 }
 void
 evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs)
 {
 	struct evhttp_connection *evcon;
 	TAILQ_FOREACH(evcon, &pool->connections, next) {
 		evcon->timeout = timeout_in_secs;
 	}
 	pool->timeout = timeout_in_secs;
 }
 static void evrpc_reply_done(struct evhttp_request *, void *);
 static void evrpc_request_timeout(evutil_socket_t, short, void *);
 /*
  * Finds a connection object associated with the pool that is currently
  * idle and can be used to make a request.
  */
 static struct evhttp_connection *
 evrpc_pool_find_connection(struct evrpc_pool *pool)
 {
 	struct evhttp_connection *connection;
 	TAILQ_FOREACH(connection, &pool->connections, next) {
 		if (TAILQ_FIRST(&connection->requests) == NULL)
 			return (connection);
 	}
 	return (NULL);
 }
 /*
  * Prototypes responsible for evrpc scheduling and hooking
  */
 static void evrpc_schedule_request_closure(void *ctx, enum EVRPC_HOOK_RESULT);
 /*
  * We assume that the ctx is no longer queued on the pool.
  */
 static int
 evrpc_schedule_request(struct evhttp_connection *connection,
     struct evrpc_request_wrapper *ctx)
 {
 	struct evhttp_request *req = NULL;
 	struct evrpc_pool *pool = ctx->pool;
 	struct evrpc_status status;
 	if ((req = evhttp_request_new(evrpc_reply_done, ctx)) == NULL)
 		goto error;
 	/* serialize the request data into the output buffer */
 	ctx->request_marshal(req->output_buffer, ctx->request);
 	/* we need to know the connection that we might have to abort */
 	ctx->evcon = connection;
 	/* if we get paused we also need to know the request */
 	ctx->req = req;
 	if (TAILQ_FIRST(&pool->output_hooks) != NULL) {
 		int hook_res;
 		evrpc_hook_associate_meta(&ctx->hook_meta, connection);
 		/* apply hooks to the outgoing request */
 		hook_res = evrpc_process_hooks(&pool->output_hooks,
 		    ctx, req, req->output_buffer);
 		switch (hook_res) {
 		case EVRPC_TERMINATE:
 			goto error;
 		case EVRPC_PAUSE:
 			/* we need to be explicitly resumed */
 			if (evrpc_pause_request(pool, ctx,
 				evrpc_schedule_request_closure) == -1)
 				goto error;
 			return (0);
 		case EVRPC_CONTINUE:
 			/* we can just continue */
 			break;
 		default:
 			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
 			    hook_res == EVRPC_CONTINUE ||
 			    hook_res == EVRPC_PAUSE);
 		}
 	}
 	evrpc_schedule_request_closure(ctx, EVRPC_CONTINUE);
 	return (0);
 error:
 	memset(&status, 0, sizeof(status));
 	status.error = EVRPC_STATUS_ERR_UNSTARTED;
 	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
 	evrpc_request_wrapper_free(ctx);
 	return (-1);
 }
 static void
 evrpc_schedule_request_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
 {
 	struct evrpc_request_wrapper *ctx = arg;
 	struct evhttp_connection *connection = ctx->evcon;
 	struct evhttp_request *req = ctx->req;
 	struct evrpc_pool *pool = ctx->pool;
 	struct evrpc_status status;
 	char *uri = NULL;
 	int res = 0;
 	if (hook_res == EVRPC_TERMINATE)
 		goto error;
 	uri = evrpc_construct_uri(ctx->name);
 	if (uri == NULL)
 		goto error;
 	if (pool->timeout > 0) {
 		/*
 		 * a timeout after which the whole rpc is going to be aborted.
 		 */
 		struct timeval tv;
 		evutil_timerclear(&tv);
 		tv.tv_sec = pool->timeout;
 		evtimer_add(&ctx->ev_timeout, &tv);
 	}
 	/* start the request over the connection */
 	res = evhttp_make_request(connection, req, EVHTTP_REQ_POST, uri);
 	mm_free(uri);
 	if (res == -1)
 		goto error;
 	return;
 error:
 	memset(&status, 0, sizeof(status));
 	status.error = EVRPC_STATUS_ERR_UNSTARTED;
 	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
 	evrpc_request_wrapper_free(ctx);
 }
 /* we just queue the paused request on the pool under the req object */
 static int
 evrpc_pause_request(void *vbase, void *ctx,
     void (*cb)(void *, enum EVRPC_HOOK_RESULT))
 {
 	struct _evrpc_hooks *base = vbase;
 	struct evrpc_hook_ctx *pause = mm_malloc(sizeof(*pause));
 	if (pause == NULL)
 		return (-1);
 	pause->ctx = ctx;
 	pause->cb = cb;
 	TAILQ_INSERT_TAIL(&base->pause_requests, pause, next);
 	return (0);
 }
 int
 evrpc_resume_request(void *vbase, void *ctx, enum EVRPC_HOOK_RESULT res)
 {
 	struct _evrpc_hooks *base = vbase;
 	struct evrpc_pause_list *head = &base->pause_requests;
 	struct evrpc_hook_ctx *pause;
 	TAILQ_FOREACH(pause, head, next) {
 		if (pause->ctx == ctx)
 			break;
 	}
 	if (pause == NULL)
 		return (-1);
 	(*pause->cb)(pause->ctx, res);
 	TAILQ_REMOVE(head, pause, next);
 	mm_free(pause);
 	return (0);
 }
 int
 evrpc_make_request(struct evrpc_request_wrapper *ctx)
 {
 	struct evrpc_pool *pool = ctx->pool;
 	/* initialize the event structure for this rpc */
 	evtimer_assign(&ctx->ev_timeout, pool->base, evrpc_request_timeout, ctx);
 	/* we better have some available connections on the pool */
 	EVUTIL_ASSERT(TAILQ_FIRST(&pool->connections) != NULL);
 	/*
 	 * if no connection is available, we queue the request on the pool,
 	 * the next time a connection is empty, the rpc will be send on that.
 	 */
 	TAILQ_INSERT_TAIL(&pool->requests, ctx, next);
 	evrpc_pool_schedule(pool);
 	return (0);
 }
 struct evrpc_request_wrapper *
 evrpc_make_request_ctx(
 	struct evrpc_pool *pool, void *request, void *reply,
 	const char *rpcname,
 	void (*req_marshal)(struct evbuffer*, void *),
 	void (*rpl_clear)(void *),
 	int (*rpl_unmarshal)(void *, struct evbuffer *),
 	void (*cb)(struct evrpc_status *, void *, void *, void *),
 	void *cbarg)
 {
 	struct evrpc_request_wrapper *ctx = (struct evrpc_request_wrapper *)
 	    mm_malloc(sizeof(struct evrpc_request_wrapper));
 	if (ctx == NULL)
 		return (NULL);
 	ctx->pool = pool;
 	ctx->hook_meta = NULL;
 	ctx->evcon = NULL;
 	ctx->name = mm_strdup(rpcname);
 	if (ctx->name == NULL) {
 		mm_free(ctx);
 		return (NULL);
 	}
 	ctx->cb = cb;
 	ctx->cb_arg = cbarg;
 	ctx->request = request;
 	ctx->reply = reply;
 	ctx->request_marshal = req_marshal;
 	ctx->reply_clear = rpl_clear;
 	ctx->reply_unmarshal = rpl_unmarshal;
 	return (ctx);
 }
 static void
 evrpc_reply_done_closure(void *, enum EVRPC_HOOK_RESULT);
 static void
 evrpc_reply_done(struct evhttp_request *req, void *arg)
 {
 	struct evrpc_request_wrapper *ctx = arg;
 	struct evrpc_pool *pool = ctx->pool;
 	int hook_res = EVRPC_CONTINUE;
 	/* cancel any timeout we might have scheduled */
 	event_del(&ctx->ev_timeout);
 	ctx->req = req;
 	/* we need to get the reply now */
 	if (req == NULL) {
 		evrpc_reply_done_closure(ctx, EVRPC_CONTINUE);
 		return;
 	}
 	if (TAILQ_FIRST(&pool->input_hooks) != NULL) {
 		evrpc_hook_associate_meta(&ctx->hook_meta, ctx->evcon);
 		/* apply hooks to the incoming request */
 		hook_res = evrpc_process_hooks(&pool->input_hooks,
 		    ctx, req, req->input_buffer);
 		switch (hook_res) {
 		case EVRPC_TERMINATE:
 		case EVRPC_CONTINUE:
 			break;
 		case EVRPC_PAUSE:
 			/*
 			 * if we get paused we also need to know the
 			 * request.  unfortunately, the underlying
 			 * layer is going to free it.  we need to
 			 * request ownership explicitly
 			 */
 			if (req != NULL)
 				evhttp_request_own(req);
 			evrpc_pause_request(pool, ctx,
 			    evrpc_reply_done_closure);
 			return;
 		default:
 			EVUTIL_ASSERT(hook_res == EVRPC_TERMINATE ||
 			    hook_res == EVRPC_CONTINUE ||
 			    hook_res == EVRPC_PAUSE);
 		}
 	}
 	evrpc_reply_done_closure(ctx, hook_res);
 	/* http request is being freed by underlying layer */
 }
 static void
 evrpc_reply_done_closure(void *arg, enum EVRPC_HOOK_RESULT hook_res)
 {
 	struct evrpc_request_wrapper *ctx = arg;
 	struct evhttp_request *req = ctx->req;
 	struct evrpc_pool *pool = ctx->pool;
 	struct evrpc_status status;
 	int res = -1;
 	memset(&status, 0, sizeof(status));
 	status.http_req = req;
 	/* we need to get the reply now */
 	if (req == NULL) {
 		status.error = EVRPC_STATUS_ERR_TIMEOUT;
 	} else if (hook_res == EVRPC_TERMINATE) {
 		status.error = EVRPC_STATUS_ERR_HOOKABORTED;
 	} else {
 		res = ctx->reply_unmarshal(ctx->reply, req->input_buffer);
 		if (res == -1)
 			status.error = EVRPC_STATUS_ERR_BADPAYLOAD;
 	}
 	if (res == -1) {
 		/* clear everything that we might have written previously */
 		ctx->reply_clear(ctx->reply);
 	}
 	(*ctx->cb)(&status, ctx->request, ctx->reply, ctx->cb_arg);
 	evrpc_request_wrapper_free(ctx);
 	/* the http layer owned the original request structure, but if we
 	 * got paused, we asked for ownership and need to free it here. */
 	if (req != NULL && evhttp_request_is_owned(req))
 		evhttp_request_free(req);
 	/* see if we can schedule another request */
 	evrpc_pool_schedule(pool);
 }
 static void
 evrpc_pool_schedule(struct evrpc_pool *pool)
 {
 	struct evrpc_request_wrapper *ctx = TAILQ_FIRST(&pool->requests);
 	struct evhttp_connection *evcon;
 	/* if no requests are pending, we have no work */
 	if (ctx == NULL)
 		return;
 	if ((evcon = evrpc_pool_find_connection(pool)) != NULL) {
 		TAILQ_REMOVE(&pool->requests, ctx, next);
 		evrpc_schedule_request(evcon, ctx);
 	}
 }
 static void
 evrpc_request_timeout(evutil_socket_t fd, short what, void *arg)
 {
 	struct evrpc_request_wrapper *ctx = arg;
 	struct evhttp_connection *evcon = ctx->evcon;
 	EVUTIL_ASSERT(evcon != NULL);
 	evhttp_connection_fail(evcon, EVCON_HTTP_TIMEOUT);
 }
 /*
  * frees potential meta data associated with a request.
  */
 static void
 evrpc_meta_data_free(struct evrpc_meta_list *meta_data)
 {
 	struct evrpc_meta *entry;
 	EVUTIL_ASSERT(meta_data != NULL);
 	while ((entry = TAILQ_FIRST(meta_data)) != NULL) {
 		TAILQ_REMOVE(meta_data, entry, next);
 		mm_free(entry->key);
 		mm_free(entry->data);
 		mm_free(entry);
 	}
 }
 static struct evrpc_hook_meta *
 evrpc_hook_meta_new(void)
 {
 	struct evrpc_hook_meta *ctx;
 	ctx = mm_malloc(sizeof(struct evrpc_hook_meta));
 	EVUTIL_ASSERT(ctx != NULL);
 	TAILQ_INIT(&ctx->meta_data);
 	ctx->evcon = NULL;
 	return (ctx);
 }
 static void
 evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,
     struct evhttp_connection *evcon)
 {
 	struct evrpc_hook_meta *ctx = *pctx;
 	if (ctx == NULL)
 		*pctx = ctx = evrpc_hook_meta_new();
 	ctx->evcon = evcon;
 }
 static void
 evrpc_hook_context_free(struct evrpc_hook_meta *ctx)
 {
 	evrpc_meta_data_free(&ctx->meta_data);
 	mm_free(ctx);
 }
 /* Adds meta data */
 void
 evrpc_hook_add_meta(void *ctx, const char *key,
     const void *data, size_t data_size)
 {
 	struct evrpc_request_wrapper *req = ctx;
 	struct evrpc_hook_meta *store = NULL;
 	struct evrpc_meta *meta = NULL;
 	if ((store = req->hook_meta) == NULL)
 		store = req->hook_meta = evrpc_hook_meta_new();
 	meta = mm_malloc(sizeof(struct evrpc_meta));
 	EVUTIL_ASSERT(meta != NULL);
 	meta->key = mm_strdup(key);
 	EVUTIL_ASSERT(meta->key != NULL);
 	meta->data_size = data_size;
 	meta->data = mm_malloc(data_size);
 	EVUTIL_ASSERT(meta->data != NULL);
 	memcpy(meta->data, data, data_size);
 	TAILQ_INSERT_TAIL(&store->meta_data, meta, next);
 }
 int
 evrpc_hook_find_meta(void *ctx, const char *key, void **data, size_t *data_size)
 {
 	struct evrpc_request_wrapper *req = ctx;
 	struct evrpc_meta *meta = NULL;
 	if (req->hook_meta == NULL)
 		return (-1);
 	TAILQ_FOREACH(meta, &req->hook_meta->meta_data, next) {
 		if (strcmp(meta->key, key) == 0) {
 			*data = meta->data;
 			*data_size = meta->data_size;
 			return (0);
 		}
 	}
 	return (-1);
 }
 struct evhttp_connection *
 evrpc_hook_get_connection(void *ctx)
 {
 	struct evrpc_request_wrapper *req = ctx;
 	return (req->hook_meta != NULL ? req->hook_meta->evcon : NULL);
 }
 int
 evrpc_send_request_generic(struct evrpc_pool *pool,
     void *request, void *reply,
     void (*cb)(struct evrpc_status *, void *, void *, void *),
     void *cb_arg,
     const char *rpcname,
     void (*req_marshal)(struct evbuffer *, void *),
     void (*rpl_clear)(void *),
     int (*rpl_unmarshal)(void *, struct evbuffer *))
 {
 	struct evrpc_status status;
 	struct evrpc_request_wrapper *ctx;
 	ctx = evrpc_make_request_ctx(pool, request, reply,
 	    rpcname, req_marshal, rpl_clear, rpl_unmarshal, cb, cb_arg);
 	if (ctx == NULL)
 		goto error;
 	return (evrpc_make_request(ctx));
 error:
 	memset(&status, 0, sizeof(status));
 	status.error = EVRPC_STATUS_ERR_UNSTARTED;
 	(*(cb))(&status, request, reply, cb_arg);
 	return (-1);
 }
 /** Takes a request object and fills it in with the right magic */
 static struct evrpc *
 evrpc_register_object(const char *name,
     void *(*req_new)(void*), void *req_new_arg, void (*req_free)(void *),
     int (*req_unmarshal)(void *, struct evbuffer *),
     void *(*rpl_new)(void*), void *rpl_new_arg, void (*rpl_free)(void *),
     int (*rpl_complete)(void *),
     void (*rpl_marshal)(struct evbuffer *, void *))
 {
 	struct evrpc* rpc = (struct evrpc *)mm_calloc(1, sizeof(struct evrpc));
 	if (rpc == NULL)
 		return (NULL);
 	rpc->uri = mm_strdup(name);
 	if (rpc->uri == NULL) {
 		mm_free(rpc);
 		return (NULL);
 	}
 	rpc->request_new = req_new;
 	rpc->request_new_arg = req_new_arg;
 	rpc->request_free = req_free;
 	rpc->request_unmarshal = req_unmarshal;
 	rpc->reply_new = rpl_new;
 	rpc->reply_new_arg = rpl_new_arg;
 	rpc->reply_free = rpl_free;
 	rpc->reply_complete = rpl_complete;
 	rpc->reply_marshal = rpl_marshal;
 	return (rpc);
 }
 int
 evrpc_register_generic(struct evrpc_base *base, const char *name,
     void (*callback)(struct evrpc_req_generic *, void *), void *cbarg,
     void *(*req_new)(void *), void *req_new_arg, void (*req_free)(void *),
     int (*req_unmarshal)(void *, struct evbuffer *),
     void *(*rpl_new)(void *), void *rpl_new_arg, void (*rpl_free)(void *),
     int (*rpl_complete)(void *),
     void (*rpl_marshal)(struct evbuffer *, void *))
 {
 	struct evrpc* rpc =
 	    evrpc_register_object(name, req_new, req_new_arg, req_free, req_unmarshal,
 		rpl_new, rpl_new_arg, rpl_free, rpl_complete, rpl_marshal);
 	if (rpc == NULL)
 		return (-1);
 	evrpc_register_rpc(base, rpc,
 	    (void (*)(struct evrpc_req_generic*, void *))callback, cbarg);
 	return (0);
 }
 /** accessors for obscure and undocumented functionality */
 struct evrpc_pool *
 evrpc_request_get_pool(struct evrpc_request_wrapper *ctx)
 {
 	return (ctx->pool);
 }
 void
 evrpc_request_set_pool(struct evrpc_request_wrapper *ctx,
     struct evrpc_pool *pool)
 {
 	ctx->pool = pool;
 }
 void
 evrpc_request_set_cb(struct evrpc_request_wrapper *ctx,
     void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg),
     void *cb_arg)
 {
 	ctx->cb = cb;
 	ctx->cb_arg = cb_arg;
 }

The Tor Browser / annotate

ipc/chromium/src/third_party/libevent/evrpc.c@6474c204b198 (annotated)

ipc/chromium/src/third_party/libevent/evrpc.c