From: Pavel Šimerda <pavlix@pavlix.net>
Date: Tue, 14 Jan 2014 14:34:52 +0000 (+0100)
Subject: core: sort IPv6 paths before IPv4 paths
X-Git-Url: https://www.sourceware.org/git/?a=commitdiff_plain;h=1ae3bf4088befa936a371343d56f1a80c7cd3e71;p=netresolve.git

core: sort IPv6 paths before IPv4 paths
---

diff --git a/TODO b/TODO
index afd9ae7..f369c09 100644
--- a/TODO
+++ b/TODO
@@ -2,10 +2,11 @@
 
 ## Core library
 
- * Return items in the right order
-    - http://tools.ietf.org/html/rfc6724
+ * Improve path ordering
     - use priority from DNS SRV
-    - randomize order using weight from DNS SRV
+    - use weight from DNS SRV for randomized ordering
+    - use rules from http://tools.ietf.org/html/rfc6724
+    - use /etc/gai.conf
  * Support multiple concurrent queries per channel
  * Support reverse lookup
  * Improve socket API and happy eyeballs
diff --git a/lib/backend.c b/lib/backend.c
index 8df323c..a827361 100644
--- a/lib/backend.c
+++ b/lib/backend.c
@@ -106,6 +106,17 @@ path_callback(int socktype, int protocol, int port, void *user_data)
 			0, 0);
 }
 
+static int
+path_cmp(struct netresolve_path *p1, struct netresolve_path *p2)
+{
+	if (p1->node.family == AF_INET6 && p2->node.family == AF_INET)
+		return -1;
+	if (p1->node.family == AF_INET && p2->node.family == AF_INET6)
+		return 1;
+
+	return 0;
+}
+
 void
 netresolve_backend_add_path(netresolve_query_t channel,
 		int family, const void *address, int ifindex,
@@ -114,6 +125,7 @@ netresolve_backend_add_path(netresolve_query_t channel,
 {
 	struct netresolve_response *response = &channel->response;
 	struct netresolve_path path;
+	int i;
 
 	if (family == AF_UNIX && socktype == -1) {
 		netresolve_backend_add_path(channel, family, address, 0, SOCK_STREAM, 0, 0, 0, 0);
@@ -152,8 +164,14 @@ netresolve_backend_add_path(netresolve_query_t channel,
 	path.priority = priority;
 	path.weight = weight;
 
+	for (i = 0; i < response->pathcount; i++)
+		if (path_cmp(&path, &response->paths[i]) < 0)
+			break;
+
 	response->paths = realloc(response->paths, (response->pathcount + 1) * sizeof path);
-	memcpy(&response->paths[response->pathcount++], &path, sizeof path);
+	memmove(&response->paths[i+1], &response->paths[i],
+			(response->pathcount++ - i) * sizeof *response->paths);
+	memcpy(&response->paths[i], &path, sizeof path);
 
 	debug("added path: %s", netresolve_get_path_string(channel, response->pathcount - 1));
 
diff --git a/tests/data/any b/tests/data/any
index bf2a55f..cfe61bd 100644
--- a/tests/data/any
+++ b/tests/data/any
@@ -1,4 +1,4 @@
 response netresolve 0.0.1
-path 0.0.0.0 any any 0 0 0
 path :: any any 0 0 0
+path 0.0.0.0 any any 0 0 0
 
diff --git a/tests/data/localhost b/tests/data/localhost
index c5119a2..4271fa1 100644
--- a/tests/data/localhost
+++ b/tests/data/localhost
@@ -1,4 +1,4 @@
 response netresolve 0.0.1
-path 127.0.0.1 any any 0 0 0
 path ::1 any any 0 0 0
+path 127.0.0.1 any any 0 0 0
 
diff --git a/tests/data/services b/tests/data/services
index e4c1969..4d13e72 100644
--- a/tests/data/services
+++ b/tests/data/services
@@ -1,6 +1,6 @@
 response netresolve 0.0.1
-path 0.0.0.0 stream tcp 1021 0 0
-path 0.0.0.0 dgram udp 1021 0 0
 path :: stream tcp 1021 0 0
 path :: dgram udp 1021 0 0
+path 0.0.0.0 stream tcp 1021 0 0
+path 0.0.0.0 dgram udp 1021 0 0