Oops; add missing bufferevent_evdns.c file

svn:r1497

bufferevent_evdns.c

@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2009 Niels Provos, 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.
+ */
+
+/** @file bufferevent_evdns.c
+ *
+ * This module contains code to implement the asynchronous
+ * resolve-then-connect behavior of bufferevent_socket_connect_hostname.
+ *
+ * It isn't part of bufferevent_socket because evdns is in libevent_extras,
+ * and bufferevent is in libevent_core.
+ */
+
+#ifdef WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#endif
+
+#include "event-config.h"
+
+#include <sys/types.h>
+#ifdef _EVENT_HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef _EVENT_HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef _EVENT_HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef _EVENT_HAVE_NETINET_IN6_H
+#include <netinet/in6.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+
+#include <event2/event.h>
+#include <event2/bufferevent.h>
+#include <event2/bufferevent_struct.h>
+#include <event2/dns.h>
+#include "bufferevent-internal.h"
+#include "mm-internal.h"
+
+/* Holds info passed to the dns callback  */
+struct resolveinfo {
+	ev_uint8_t family; /* address family that we tried to resolve. */
+	ev_uint16_t port; /* port to connect to, in network order. */
+	struct bufferevent *bev; /* bufferevent to inform of the resolve. */
+};
+
+/* Callback: Invoked when we are done resolving (or failing to resolve) the
+ * hostname */
+static void
+dns_reply_callback(int result, char type, int count, int ttl, void *addresses,
+    void *arg)
+{
+	struct resolveinfo *info = arg;
+	struct sockaddr_in sin;
+	struct sockaddr_in6 sin6;
+	struct sockaddr *sa = NULL;
+	int socklen;
+
+	EVUTIL_ASSERT(info->bev);
+	BEV_LOCK(info->bev);
+
+	if (result != DNS_ERR_NONE || count == 0) {
+		_bufferevent_run_eventcb(info->bev, BEV_EVENT_ERROR);
+		_bufferevent_decref_and_unlock(info->bev);
+		memset(info, 0, sizeof(*info));
+		mm_free(info);
+		return;
+	}
+
+	if (type == DNS_IPv4_A) {
+		EVUTIL_ASSERT(info->family == AF_INET);
+		memset(&sin, 0, sizeof(sin));
+		sin.sin_family = AF_INET;
+		sin.sin_port = info->port;
+		/* XXX handle multiple addresses better */
+		sin.sin_addr.s_addr = *(ev_uint32_t*)addresses;
+		sa = (struct sockaddr*)&sin;
+		socklen = sizeof(sin);
+	} else if (type == DNS_IPv6_AAAA) {
+		EVUTIL_ASSERT(info->family == AF_INET6);
+		memset(&sin6, 0, sizeof(sin6));
+		sin6.sin6_family = AF_INET;
+		sin6.sin6_port = info->port;
+		/* XXX handle multiple addresses better */
+		memcpy(sin6.sin6_addr.s6_addr, addresses, 16);
+		sa = (struct sockaddr*)&sin6;
+		socklen = sizeof(sin6);
+	} else {
+		EVUTIL_ASSERT(info->family == AF_INET ||
+		    info->family == AF_INET6);
+		return; /* unreachable */
+	}
+
+	bufferevent_socket_connect(info->bev, sa, socklen);
+	_bufferevent_decref_and_unlock(info->bev);
+	memset(info, 0, sizeof(*info));
+	mm_free(info);
+}
+
+/* Implements the asynchronous-resolve side of
+ * bufferevent_socket_connect_hostname(). */
+int
+_bufferevent_socket_connect_hostname_evdns(
+	struct bufferevent *bufev,
+	struct evdns_base *evdns_base,
+	int family,
+	const char *hostname,
+	int port)
+{
+	struct evdns_request *r;
+	struct resolveinfo *resolveinfo;
+
+	if (family == AF_UNSPEC)
+		family = AF_INET; /* XXXX handle "unspec" correctly */
+	if (family != AF_INET && family != AF_INET6)
+		return -1;
+	if (!bufev || !evdns_base || !hostname)
+		return -1;
+	if (port < 1 || port > 65535)
+		return -1;
+
+	resolveinfo = mm_calloc(1, sizeof(resolveinfo));
+	if (!resolveinfo)
+		return -1;
+	resolveinfo->family = family;
+	resolveinfo->port = htons(port);
+	resolveinfo->bev = bufev;
+
+	if (family == AF_INET) {
+		r = evdns_base_resolve_ipv4(evdns_base, hostname, 0,
+		    dns_reply_callback, resolveinfo);
+	} else {
+		r = evdns_base_resolve_ipv6(evdns_base, hostname, 0,
+		    dns_reply_callback, resolveinfo);
+	}
+
+	if (!r) {
+		mm_free(resolveinfo);
+		return -1;
+	}
+
+	/* We either need to incref the bufferevent here, or have some code to
+	 * cancel the resolve if the bufferevent gets freed.  Let's take the
+	 * first approach. */
+	bufferevent_incref(bufev);
+	return 0;
+}
+