IPoIB: improve IPv4/IPv6 to IB mcast mapping functions

An IPoIB subnet on an IB fabric that spans multiple IB subnets can't
use link-local scope in multicast GIDs.  The existing routines that
map IP/IPv6 multicast addresses into IB link-level addresses hard-code
the scope to link-local, and they also leave the partition key field
uninitialised.  This patch adds a parameter (the link-level broadcast
address) to the mapping routines, allowing them to initialise both the
scope and the P_Key appropriately, and fixes up the call sites.

The next step will be to add a way to configure the scope for an IPoIB
interface.

Signed-off-by: Rolf Manderscheid <rvm@obsidianresearch.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 08174a2aa878..54a76b8b803a 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -211,7 +211,7 @@ int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
                 ip_tr_mc_map(addr, haddr);
                 return 0;
         case ARPHRD_INFINIBAND:
-                ip_ib_mc_map(addr, haddr);
+                ip_ib_mc_map(addr, dev->broadcast, haddr);
                 return 0;
         default:
                 if (dir) {
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 777ed733b2d7..85947eae5bf7 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -337,7 +337,7 @@ int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int d
                 ipv6_arcnet_mc_map(addr, buf);
                 return 0;
         case ARPHRD_INFINIBAND:
-                ipv6_ib_mc_map(addr, buf);
+                ipv6_ib_mc_map(addr, dev->broadcast, buf);
                 return 0;
         default:
                 if (dir) {