tipc: support binding to specific ip address when activating UDP bearer

INADDR_ANY is hard-coded when activating UDP bearer. So, we could not
bind to a specific IP address even with replicast mode using - given
remote ip address instead of using multicast ip address.

In this commit, we fixed it by checking and switch to use appropriate
local ip address.

before:
$netstat -plu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address
udp        0      0 **0.0.0.0:6118**            0.0.0.0:*

after:
$netstat -plu
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address
udp        0      0 **10.0.0.2:6118**           0.0.0.0:*

Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 15 insertions, 3 deletions

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 9783101bc4a9..10dc59ce9c82 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -650,6 +650,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
         struct udp_tunnel_sock_cfg tuncfg = {NULL};
         struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
         u8 node_id[NODE_ID_LEN] = {0,};
+        int rmcast = 0;
 
         ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
         if (!ub)
@@ -680,6 +681,9 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
         if (err)
                 goto err;
 
+        /* Checking remote ip address */
+        rmcast = tipc_udp_is_mcast_addr(&remote);
+
         /* Autoconfigure own node identity if needed */
         if (!tipc_own_id(net)) {
                 memcpy(node_id, local.ipv6.in6_u.u6_addr8, 16);
@@ -705,7 +709,12 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
                         goto err;
                 }
                 udp_conf.family = AF_INET;
-                udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
+
+                /* Switch to use ANY to receive packets from group */
+                if (rmcast)
+                        udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
+                else
+                        udp_conf.local_ip.s_addr = local.ipv4.s_addr;
                 udp_conf.use_udp_checksums = false;
                 ub->ifindex = dev->ifindex;
                 if (tipc_mtu_bad(dev, sizeof(struct iphdr) +
@@ -719,7 +728,10 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
                 udp_conf.family = AF_INET6;
                 udp_conf.use_udp6_tx_checksums = true;
                 udp_conf.use_udp6_rx_checksums = true;
-                udp_conf.local_ip6 = in6addr_any;
+                if (rmcast)
+                        udp_conf.local_ip6 = in6addr_any;
+                else
+                        udp_conf.local_ip6 = local.ipv6;
                 b->mtu = 1280;
 #endif
         } else {
@@ -741,7 +753,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
          * is used if it's a multicast address.
          */
         memcpy(&b->bcast_addr.value, &remote, sizeof(remote));
-        if (tipc_udp_is_mcast_addr(&remote))
+        if (rmcast)
                 err = enable_mcast(ub, &remote);
         else
                 err = tipc_udp_rcast_add(b, &remote);