Export sockaddr comparison functionality.

svn:r1400

ChangeLog

@@ -8,6 +8,8 @@ Changes in 2.0.3-alpha:
  o Expose an ev_socklen_t type for consistent use across platforms.
  o Make bufferevenr_socket_connect() work when the original fd was -1.
  o Fix a bug in bufferevent_socket_connect() when the connection succeeds too quickly.
+ o Export an evutil_sockaddr_cmp() to compare to sockaddr objects for equality.
+
        
 Changes in 2.0.2-alpha:
  o Add a new flag to bufferevents to make all callbacks automatically deferred.

evdns.c

@@ -448,39 +448,6 @@ debug_ntop(const struct sockaddr *sa)
 	return "<unknown>";
 }
 
-static int
-sockaddr_eq(const struct sockaddr *sa1, const struct sockaddr *sa2,
-			int include_port)
-{
-	if (sa1->sa_family != sa2->sa_family)
-		return 0;
-	if (sa1->sa_family == AF_INET) {
-		const struct sockaddr_in *sin1, *sin2;
-		sin1 = (const struct sockaddr_in *)sa1;
-		sin2 = (const struct sockaddr_in *)sa2;
-		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
-			return 0;
-		else if (include_port && sin1->sin_port != sin2->sin_port)
-			return 0;
-		else
-			return 1;
-	}
-#ifdef AF_INET6
-	if (sa1->sa_family == AF_INET6) {
-		const struct sockaddr_in6 *sin1, *sin2;
-		sin1 = (const struct sockaddr_in6 *)sa1;
-		sin2 = (const struct sockaddr_in6 *)sa2;
-		if (memcmp(sin1->sin6_addr.s6_addr, sin2->sin6_addr.s6_addr, 16))
-			return 0;
-		else if (include_port && sin1->sin6_port != sin2->sin6_port)
-			return 0;
-		else
-			return 1;
-	}
-#endif
-	return 1;
-}
-
 static evdns_debug_log_fn_type evdns_log_fn = NULL;
 
 void
@@ -1349,7 +1316,7 @@ nameserver_read(struct nameserver *ns) {
 			    evutil_socket_error_to_string(err));
 			return;
 		}
-		if (!sockaddr_eq((struct sockaddr*)&ss,
+		if (evutil_sockaddr_cmp((struct sockaddr*)&ss,
 			(struct sockaddr*)&ns->address, 0)) {
 			log(EVDNS_LOG_WARN, "Address mismatch on received "
 			    "DNS packet.  Apparent source was %s",
@@ -2398,7 +2365,7 @@ _evdns_nameserver_add_impl(struct evdns_base *base, const struct sockaddr *addre
 	ASSERT_LOCKED(base);
 	if (server) {
 		do {
-			if (sockaddr_eq((struct sockaddr*)&server->address, address, 1)) return 3;
+			if (!evutil_sockaddr_cmp((struct sockaddr*)&server->address, address, 1)) return 3;
 			server = server->next;
 		} while (server != started_at);
 	}

evutil.c

@@ -716,6 +716,45 @@ evutil_parse_sockaddr_port(const char *ip_as_string, struct sockaddr *out, int *
 	}
 }
 
+int
+evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2,
+    int include_port)
+{
+	int r;
+	if (0 != (r = (sa1->sa_family - sa2->sa_family)))
+		return r;
+
+	if (sa1->sa_family == AF_INET) {
+		const struct sockaddr_in *sin1, *sin2;
+		sin1 = (const struct sockaddr_in *)sa1;
+		sin2 = (const struct sockaddr_in *)sa2;
+		if (sin1->sin_addr.s_addr < sin2->sin_addr.s_addr)
+			return -1;
+		else if (sin1->sin_addr.s_addr > sin2->sin_addr.s_addr)
+			return 1;
+		else if (include_port &&
+		    (r = ((int)sin1->sin_port - (int)sin2->sin_port)))
+			return r;
+		else
+			return 0;
+	}
+#ifdef AF_INET6
+	else if (sa1->sa_family == AF_INET6) {
+		const struct sockaddr_in6 *sin1, *sin2;
+		sin1 = (const struct sockaddr_in6 *)sa1;
+		sin2 = (const struct sockaddr_in6 *)sa2;
+		if ((r = memcmp(sin1->sin6_addr.s6_addr, sin2->sin6_addr.s6_addr, 16)))
+			return r;
+		else if (include_port &&
+		    (r = ((int)sin1->sin6_port - (int)sin2->sin6_port)))
+			return r;
+		else
+			return 0;
+	}
+#endif
+	return 1;
+}
+
 /* Tables to implement ctypes-replacement EVUTIL_IS*() functions.  Each table
  * has 256 bits to look up whether a character is in some set or not.  This
  * fails on non-ASCII platforms, but so does every other place where we

include/event2/util.h

@@ -303,6 +303,14 @@ struct sockaddr;
 */
 int evutil_parse_sockaddr_port(const char *str, struct sockaddr *out, int *outlen);
 
+/** Compare two sockaddrs; return 0 if they are equal, or less than 0 if sa1
+ * preceeds sa2, or greater than 0 if sa1 follows sa2.  If include_port is
+ * true, consider the port as well as the address.  Only implemented for
+ * AF_INET and AF_INET6 addresses. The ordering is not guaranteed to remain
+ * the same between Libevent versions. */
+int evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2,
+    int include_port);
+
 /** As strcasecmp, but always compares the characters in locale-independent
     ASCII.  That's useful if you're handling data in ASCII-based protocols.
  */