Add the LocalDiscoveryAddress option.

When LocalDiscovery is enabled, tinc normally sends broadcast packets during
PMTU discovery to the broadcast address (255.255.255.255 or ff02::1). This
option lets tinc use a different address.

At the moment only one LocalDiscoveryAddress can be specified.

diff --git a/doc/tinc.conf.5.in b/doc/tinc.conf.5.in
index 89ef739708a4a2829003efad34f5ade4cbec5ee5..0376328f07714e7791943c40fa84f6264dc09714 100644 (file)
--- a/doc/tinc.conf.5.in
+++ b/doc/tinc.conf.5.in
@@ -326,6 +326,9 @@ which normally would prevent the peers from learning each other's LAN address.
 .Pp
 Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
 This feature may not work in all possible situations.
+.It Va LocalDiscoveryAddress Li = Ar address
+If this variable is specified, local discovery packets are sent to the given
+.Ar address .
 .It Va MACExpire Li = Ar seconds Pq 600
 This option controls the amount of time MAC addresses are kept before they are removed.
 This only has effect when

diff --git a/doc/tinc.texi b/doc/tinc.texi
index 5e8df2b7e82ed9a2a7f351a32c16882bb1931a31..08021f9ad4051d0b38675b230d4c2a3aa3392e4d 100644 (file)
--- a/doc/tinc.texi
+++ b/doc/tinc.texi
@@ -1056,6 +1056,10 @@ which normally would prevent the peers from learning each other's LAN address.
 Currently, local discovery is implemented by sending broadcast packets to the LAN during path MTU discovery.
 This feature may not work in all possible situations.
 
+@cindex LocalDiscoveryAddress
+@item LocalDiscoveryAddress <@var{address}>
+If this variable is specified, local discovery packets are sent to the given @var{address}.
+
 @cindex Mode
 @item Mode = <router|switch|hub> (router)
 This option selects the way packets are routed to other daemons.

diff --git a/src/net.h b/src/net.h
index 879dfffbeae0e9346f61d95c611e33ac79ccb96a..5f6224e2ccc31a083d189e1c82405d649fd55360 100644 (file)
--- a/src/net.h
+++ b/src/net.h
@@ -125,6 +125,7 @@ extern int seconds_till_retry;
 extern int addressfamily;
 extern unsigned replaywin;
 extern bool localdiscovery;
+extern sockaddr_t localdiscovery_address;
 
 extern listen_socket_t listen_socket[MAXSOCKETS];
 extern int listen_sockets;

diff --git a/src/net_packet.c b/src/net_packet.c
index 26e4907140556c49025c24750cfd0113a71b1e9f..4bbb2d6f16e560bd5911addf946b8ca379d713fc 100644 (file)
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -56,6 +56,7 @@ static void send_udppacket(node_t *, vpn_packet_t *);
 
 unsigned replaywin = 16;
 bool localdiscovery = false;
+sockaddr_t localdiscovery_address;
 
 #define MAX_SEQNO 1073741824
 
@@ -580,12 +581,22 @@ static void choose_broadcast_address(const node_t *n, const sockaddr_t **sa, int
        *sock = rand() % listen_sockets;
 
        if(listen_socket[*sock].sa.sa.sa_family == AF_INET6) {
-               broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
-               broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
-               *sa = &broadcast_ipv6;
+               if(localdiscovery_address.sa.sa_family == AF_INET6) {
+                       localdiscovery_address.in6.sin6_port = n->prevedge->address.in.sin_port;
+                       *sa = &localdiscovery_address;
+               } else {
+                       broadcast_ipv6.in6.sin6_port = n->prevedge->address.in.sin_port;
+                       broadcast_ipv6.in6.sin6_scope_id = listen_socket[*sock].sa.in6.sin6_scope_id;
+                       *sa = &broadcast_ipv6;
+               }
        } else {
-               broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
-               *sa = &broadcast_ipv4;
+               if(localdiscovery_address.sa.sa_family == AF_INET) {
+                       localdiscovery_address.in.sin_port = n->prevedge->address.in.sin_port;
+                       *sa = &localdiscovery_address;
+               } else {
+                       broadcast_ipv4.in.sin_port = n->prevedge->address.in.sin_port;
+                       *sa = &broadcast_ipv4;
+               }
        }
 }
 

diff --git a/src/net_setup.c b/src/net_setup.c
index c61a90122810719d924be949f5f46ea459859a2e..ee8296cd5b49fff47892b64770ffab8ec871c320 100644 (file)
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -444,6 +444,7 @@ bool setup_myself_reloadable(void) {
        char *fmode = NULL;
        char *bmode = NULL;
        char *afname = NULL;
+       char *address = NULL;
        char *space;
        bool choice;
 
@@ -534,6 +535,16 @@ bool setup_myself_reloadable(void) {
        get_config_bool(lookup_config(config_tree, "DirectOnly"), &directonly);
        get_config_bool(lookup_config(config_tree, "LocalDiscovery"), &localdiscovery);
 
+       memset(&localdiscovery_address, 0, sizeof localdiscovery_address);
+       if(get_config_string(lookup_config(config_tree, "LocalDiscoveryAddress"), &address)) {
+               struct addrinfo *ai = str2addrinfo(address, myport, SOCK_DGRAM);
+               free(address);
+               if(!ai)
+                       return false;
+               memcpy(&localdiscovery_address, ai->ai_addr, ai->ai_addrlen);
+       }
+
+
        if(get_config_string(lookup_config(config_tree, "Mode"), &rmode)) {
                if(!strcasecmp(rmode, "router"))
                        routing_mode = RMODE_ROUTER;