Preserve IPv6 scope_id in edges.

When creating an edge after authenticating a peer, we copy the address
used for the TCP connection, but change the port to that used for UDP.
But the way we did it discarded the scope_id for IPv6 addresses. This
prevented UDP communication from working correctly when connecting to a
peer on the same LAN using an IPv6 link-local address.

Thanks to Rafał Leśniak for pointing out this issue.

diff --git a/src/netutl.c b/src/netutl.c
index 2abbe86..37887be 100644 (file)
--- a/src/netutl.c
+++ b/src/netutl.c
@@ -231,6 +231,25 @@ void sockaddrunmap(sockaddr_t *sa) {
        }
 }
 
+void sockaddr_setport(sockaddr_t *sa, const char *port) {
+       uint16_t portnum = htons(atoi(port));
+       if(!portnum)
+               return;
+       switch(sa->sa.sa_family) {
+               case AF_INET:
+                       sa->in.sin_port = portnum;
+                       break;
+               case AF_INET6:
+                       sa->in6.sin6_port = portnum;
+                       break;
+               case AF_UNKNOWN:
+                       free(sa->unknown.port);
+                       sa->unknown.port = xstrdup(port);
+               default:
+                       return;
+       }
+}
+
 /* Subnet mask handling */
 
 int maskcmp(const void *va, const void *vb, int masklen) {

diff --git a/src/netutl.h b/src/netutl.h
index 7fc41e8..7c31f2b 100644 (file)
--- a/src/netutl.h
+++ b/src/netutl.h
@@ -34,6 +34,7 @@ extern int sockaddrcmp_noport(const sockaddr_t *, const sockaddr_t *);
 extern void sockaddrunmap(sockaddr_t *);
 extern void sockaddrfree(sockaddr_t *);
 extern void sockaddrcpy(sockaddr_t *, const sockaddr_t *);
+extern void sockaddr_setport(sockaddr_t *, const char *);
 extern int maskcmp(const void *, const void *, int);
 extern void maskcpy(void *, const void *, int, int);
 extern void mask(void *, int, int);

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 8fa9b93..091629a 100644 (file)
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -516,7 +516,6 @@ static void send_everything(connection_t *c) {
 
 bool ack_h(connection_t *c) {
        char hisport[MAX_STRING_SIZE];
-       char *hisaddress;
        int weight, mtu;
        uint32_t options;
        node_t *n;
@@ -585,9 +584,8 @@ bool ack_h(connection_t *c) {
        c->edge = new_edge();
        c->edge->from = myself;
        c->edge->to = n;
-       sockaddr2str(&c->address, &hisaddress, NULL);
-       c->edge->address = str2sockaddr(hisaddress, hisport);
-       free(hisaddress);
+       sockaddrcpy(&c->edge->address, &c->address);
+       sockaddr_setport(&c->edge->address, hisport);
        c->edge->weight = (weight + c->estimated_weight) / 2;
        c->edge->connection = c;
        c->edge->options = c->options;