Use binded port in local_addr

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

mud.c

@@ -151,6 +151,7 @@ struct mud {
     uint64_t send_timeout;
     uint64_t time_tolerance;
     uint64_t keyx_timeout;
+    struct sockaddr_storage addr;
     struct mud_path *paths;
     unsigned count;
     struct {
@@ -443,6 +444,30 @@ mud_get_paths(struct mud *mud, unsigned *ret_count)
     return paths;
 }
 
+static void
+mud_copy_port(struct sockaddr_storage *d, struct sockaddr_storage *s)
+{
+    uint16_t port = 0;
+
+    switch (s->ss_family) {
+    case AF_INET:
+        port = ((struct sockaddr_in *)s)->sin_port;
+        break;
+    case AF_INET6:
+        port = ((struct sockaddr_in6 *)s)->sin6_port;
+        break;
+    }
+
+    switch (d->ss_family) {
+    case AF_INET:
+        ((struct sockaddr_in *)d)->sin_port = port;
+        break;
+    case AF_INET6:
+        ((struct sockaddr_in6 *)d)->sin6_port = port;
+        break;
+    }
+}
+
 static struct mud_path *
 mud_get_path(struct mud *mud, struct sockaddr_storage *local_addr,
              struct sockaddr_storage *addr, int create)
@@ -452,6 +477,8 @@ mud_get_path(struct mud *mud, struct sockaddr_storage *local_addr,
         return NULL;
     }
 
+    mud_copy_port(local_addr, &mud->addr);
+
     for (unsigned i = 0; i < mud->count; i++) {
         struct mud_path *path = &mud->paths[i];
 
@@ -477,7 +504,7 @@ mud_get_path(struct mud *mud, struct sockaddr_storage *local_addr,
 
     if (!path) {
         struct mud_path *paths = realloc(mud->paths,
-                                         (mud->count + 1) * sizeof(struct mud_path));
+                (mud->count + 1) * sizeof(struct mud_path));
 
         if (!paths)
             return NULL;
@@ -650,7 +677,7 @@ mud_set_keyx_timeout(struct mud *mud, unsigned long msec)
 }
 
 int
-mud_set_state(struct mud *mud, struct sockaddr *peer, enum mud_state state)
+mud_set_state(struct mud *mud, struct sockaddr *addr, enum mud_state state)
 {
     if (!mud->peer.set ||
         (state < MUD_DOWN) || (state > MUD_UP)) {
@@ -658,12 +685,13 @@ mud_set_state(struct mud *mud, struct sockaddr *peer, enum mud_state state)
         return -1;
     }
 
-    struct sockaddr_storage addr;
+    struct sockaddr_storage local_addr;
 
-    if (mud_ss_from_sa(&addr, peer))
+    if (mud_ss_from_sa(&local_addr, addr))
         return -1;
 
-    struct mud_path *path = mud_get_path(mud, &addr, &mud->peer.addr, state > MUD_DOWN);
+    struct mud_path *path = mud_get_path(mud,
+            &local_addr, &mud->peer.addr, state > MUD_DOWN);
 
     if (!path)
         return -1;
@@ -862,6 +890,8 @@ mud_create(struct sockaddr *addr)
     mud->tc = MUD_PACKET_TC;
     mud->mtu = sizeof(struct mud_packet);
 
+    memcpy(&mud->addr, addr, addrlen);
+
     mud_keyx_init(mud);
     randombytes_buf(mud->local.kiss, sizeof(mud->local.kiss));
 
@@ -966,21 +996,16 @@ mud_decrypt(struct mud *mud,
 }
 
 static int
-mud_localaddr(struct sockaddr_storage *addr, struct msghdr *msg, int family)
+mud_localaddr(struct sockaddr_storage *addr, struct msghdr *msg)
 {
-    int cmsg_level = IPPROTO_IP;
-    int cmsg_type = MUD_PKTINFO;
-
-    if (family == AF_INET6) {
-        cmsg_level = IPPROTO_IPV6;
-        cmsg_type = IPV6_PKTINFO;
-    }
-
     struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
 
     for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
-        if ((cmsg->cmsg_level == cmsg_level) &&
+        if ((cmsg->cmsg_level == IPPROTO_IP) &&
-            (cmsg->cmsg_type == cmsg_type))
+            (cmsg->cmsg_type == MUD_PKTINFO))
+            break;
+        if ((cmsg->cmsg_level == IPPROTO_IPV6) &&
+            (cmsg->cmsg_type == IPV6_PKTINFO))
             break;
     }
 
@@ -988,18 +1013,21 @@ mud_localaddr(struct sockaddr_storage *addr, struct msghdr *msg, int family)
         return 1;
 
     memset(addr, 0, sizeof(struct sockaddr_storage));
-    addr->ss_family = family;
 
-    if (family == AF_INET) {
+    if (cmsg->cmsg_level == IPPROTO_IP) {
+        addr->ss_family = AF_INET;
         memcpy(&((struct sockaddr_in *)addr)->sin_addr,
                MUD_PKTINFO_SRC(CMSG_DATA(cmsg)),
                sizeof(struct in_addr));
     } else {
+        addr->ss_family = AF_INET6;
         memcpy(&((struct sockaddr_in6 *)addr)->sin6_addr,
                &((struct in6_pktinfo *)CMSG_DATA(cmsg))->ipi6_addr,
                sizeof(struct in6_addr));
     }
 
+    mud_unmapv4(addr);
+
     return 0;
 }
 
@@ -1237,7 +1265,7 @@ mud_recv(struct mud *mud, void *data, size_t size)
 
     struct sockaddr_storage local_addr;
 
-    if (mud_localaddr(&local_addr, &msg, addr.ss_family))
+    if (mud_localaddr(&local_addr, &msg))
         return 0;
 
     struct mud_path *path = mud_get_path(mud, &local_addr, &addr, 1);