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>

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 9783101bc4a9ad5fb80cc014490bfa3da5ed1c8b..10dc59ce9c8221abbe0edce624d59bd0cf758d69 100644 (file)
--- 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);