Use free_known_addresses() to free memory allocated by get_known_addresses().

We know what struct addrinfo looks like, but the standard says nothing about
how it is allocated. So we cannot trust freeaddrinfo() to work correctly on
the struct addrinfo list we allocated ourselves in get_known_addresses().
To make a distinction by allocations from the latter and from str2addrinfo(),
we keep two pointers (*ai and *aip) in struct outgoing, and use the freeing
function that is appropriate for each.

diff --git a/src/net.h b/src/net.h
index 6a361a05d18722af781262d6ad96b35fc281ac0a..6c5a0a6fd3779c635fed0368fc370fa773f67faf 100644 (file)
--- a/src/net.h
+++ b/src/net.h
@@ -63,8 +63,9 @@ typedef struct outgoing_t {
        int timeout;
        struct splay_tree_t *config_tree;
        struct config_t *cfg;
-       struct addrinfo *ai;
+       struct addrinfo *ai; // addresses from config files
        struct addrinfo *aip;
+       struct addrinfo *nai; // addresses known via other online nodes (use free_known_addresses())
        timeout_t ev;
        struct meshlink_handle *mesh;
 } outgoing_t;

diff --git a/src/net_socket.c b/src/net_socket.c
index 0639478102df0d6cbe8ff47d69fac7809a611230..b147bfdf8870c197102407b36b91594931ce5aa5 100644 (file)
--- a/src/net_socket.c
+++ b/src/net_socket.c
@@ -355,13 +355,55 @@ static void handle_meta_io(event_loop_t *loop, void *data, int flags) {
                handle_meta_connection_data(mesh, c);
 }
 
+// Find edges pointing to this node, and use them to build a list of unique, known addresses.
+static struct addrinfo *get_known_addresses(node_t *n) {
+       struct addrinfo *ai = NULL;
+
+       for splay_each(edge_t, e, n->edge_tree) {
+               if(!e->reverse)
+                       continue;
+
+               bool found = false;
+               for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
+                       if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
+                               found = true;
+                               break;
+                       }
+               }
+               if(found)
+                       continue;
+
+               // Create a new struct addrinfo, and put it at the head of the list.
+               struct addrinfo *nai = xzalloc(sizeof *nai + SALEN(e->reverse->address.sa));
+               nai->ai_next = ai;
+               ai = nai;
+
+               ai->ai_family = e->reverse->address.sa.sa_family;
+               ai->ai_socktype = SOCK_STREAM;
+               ai->ai_protocol = IPPROTO_TCP;
+               ai->ai_addrlen = SALEN(e->reverse->address.sa);
+               ai->ai_addr = (struct sockaddr *)(nai + 1);
+               memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
+       }
+
+       return ai;
+}
+
+// Free struct addrinfo list from get_known_addresses().
+static void free_known_addresses(struct addrinfo *ai) {
+       for(struct addrinfo *aip = ai, *next; aip; aip = next) {
+               next = aip->ai_next;
+               free(aip);
+       }
+}
+
 bool do_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
        char *address, *port, *space;
        struct addrinfo *proxyai = NULL;
        int result;
 
 begin:
-       if(!outgoing->ai) {
+       if(!outgoing->ai && !outgoing->nai) {
                if(!outgoing->cfg) {
                        logger(mesh, MESHLINK_ERROR, "Could not set up a meta connection to %s", outgoing->name);
                        retry_outgoing(mesh, outgoing);
@@ -395,6 +437,11 @@ begin:
                if(outgoing->ai)
                        freeaddrinfo(outgoing->ai);
                outgoing->ai = NULL;
+
+               if(outgoing->nai)
+                       free_known_addresses(outgoing->nai);
+               outgoing->nai = NULL;
+
                goto begin;
        }
 
@@ -476,39 +523,6 @@ begin:
        return true;
 }
 
-// Find edges pointing to this node, and use them to build a list of unique, known addresses.
-static struct addrinfo *get_known_addresses(node_t *n) {
-       struct addrinfo *ai = NULL;
-
-       for splay_each(edge_t, e, n->edge_tree) {
-               if(!e->reverse)
-                       continue;
-
-               bool found = false;
-               for(struct addrinfo *aip = ai; aip; aip = aip->ai_next) {
-                       if(!sockaddrcmp(&e->reverse->address, (sockaddr_t *)aip->ai_addr)) {
-                               found = true;
-                               break;
-                       }
-               }
-               if(found)
-                       continue;
-
-               struct addrinfo *nai = xzalloc(sizeof *nai);
-               if(ai)
-                       ai->ai_next = nai;
-               ai = nai;
-               ai->ai_family = e->reverse->address.sa.sa_family;
-               ai->ai_socktype = SOCK_STREAM;
-               ai->ai_protocol = IPPROTO_TCP;
-               ai->ai_addrlen = SALEN(e->reverse->address.sa);
-               ai->ai_addr = xmalloc(ai->ai_addrlen);
-               memcpy(ai->ai_addr, &e->reverse->address, ai->ai_addrlen);
-       }
-
-       return ai;
-}
-
 void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
        bool blacklisted = false;
        timeout_del(&mesh->loop, &outgoing->ev);
@@ -532,8 +546,8 @@ void setup_outgoing_connection(meshlink_handle_t *mesh, outgoing_t *outgoing) {
 
        if(!outgoing->cfg) {
                if(n)
-                       outgoing->aip = outgoing->ai = get_known_addresses(n);
-               if(!outgoing->ai) {
+                       outgoing->aip = outgoing->nai = get_known_addresses(n);
+               if(!outgoing->nai) {
                        logger(mesh, MESHLINK_ERROR, "No address known for %s", outgoing->name);
                        return;
                }
@@ -648,6 +662,9 @@ static void free_outgoing(outgoing_t *outgoing) {
        if(outgoing->ai)
                freeaddrinfo(outgoing->ai);
 
+       if(outgoing->nai)
+               free_known_addresses(outgoing->nai);
+
        if(outgoing->config_tree)
                exit_configuration(&outgoing->config_tree);