RDMA/addr: Fix build breakage when IPv6 is disabled

Commit 38617c64 ("RDMA/addr: Add support for translating IPv6
addresses") broke the build when CONFIG_IPV6=n, because the ib_addr
module unconditionally attempted to call ipv6_chk_addr() and other
IPv6 functions that are not defined when IPv6 is disabled.  Fix this
by only building IPv6 support if CONFIG_IPV6 is turned on, and
add a Kconfig dependency to prevent the ib_addr code from being built
in when IPv6 is built modular.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 41 insertions, 7 deletions

diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index a5dc78ae62d4..dd0db67bf8d7 100644
--- a/drivers/infiniband/Kconfig
+++ b/drivers/infiniband/Kconfig
@@ -37,6 +37,7 @@ config INFINIBAND_USER_MEM
 config INFINIBAND_ADDR_TRANS
         bool
         depends on INET
+        depends on !(INFINIBAND = y && IPV6 = m)
         default y
 
 source "drivers/infiniband/hw/mthca/Kconfig"
diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index d98b05b28262..ce511d8748ce 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -128,6 +128,8 @@ int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
                 ret = rdma_copy_addr(dev_addr, dev, NULL);
                 dev_put(dev);
                 break;
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
         case AF_INET6:
                 for_each_netdev(&init_net, dev) {
                         if (ipv6_chk_addr(&init_net,
@@ -138,8 +140,7 @@ int rdma_translate_ip(struct sockaddr *addr, struct rdma_dev_addr *dev_addr)
                         }
                 }
                 break;
-        default:
-                break;
+#endif
         }
         return ret;
 }
@@ -179,10 +180,11 @@ static void addr_send_arp(struct sockaddr *dst_in)
 {
         struct rtable *rt;
         struct flowi fl;
-        struct dst_entry *dst;
 
         memset(&fl, 0, sizeof fl);
-        if (dst_in->sa_family == AF_INET)  {
+
+        switch (dst_in->sa_family) {
+        case AF_INET:
                 fl.nl_u.ip4_u.daddr =
                         ((struct sockaddr_in *) dst_in)->sin_addr.s_addr;
 
@@ -191,8 +193,13 @@ static void addr_send_arp(struct sockaddr *dst_in)
 
                 neigh_event_send(rt->u.dst.neighbour, NULL);
                 ip_rt_put(rt);
+                break;
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case AF_INET6:
+        {
+                struct dst_entry *dst;
 
-        } else {
                 fl.nl_u.ip6_u.daddr =
                         ((struct sockaddr_in6 *) dst_in)->sin6_addr;
 
@@ -202,6 +209,9 @@ static void addr_send_arp(struct sockaddr *dst_in)
 
                 neigh_event_send(dst->neighbour, NULL);
                 dst_release(dst);
+                break;
+        }
+#endif
         }
 }
 
@@ -254,6 +264,7 @@ out:
         return ret;
 }
 
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static int addr6_resolve_remote(struct sockaddr_in6 *src_in,
                                struct sockaddr_in6 *dst_in,
                                struct rdma_dev_addr *addr)
@@ -282,6 +293,14 @@ static int addr6_resolve_remote(struct sockaddr_in6 *src_in,
         dst_release(dst);
         return ret;
 }
+#else
+static int addr6_resolve_remote(struct sockaddr_in6 *src_in,
+                               struct sockaddr_in6 *dst_in,
+                               struct rdma_dev_addr *addr)
+{
+        return -EADDRNOTAVAIL;
+}
+#endif
 
 static int addr_resolve_remote(struct sockaddr *src_in,
                                 struct sockaddr *dst_in,
@@ -340,7 +359,9 @@ static int addr_resolve_local(struct sockaddr *src_in,
         struct net_device *dev;
         int ret;
 
-        if (dst_in->sa_family == AF_INET) {
+        switch (dst_in->sa_family) {
+        case AF_INET:
+        {
                 __be32 src_ip = ((struct sockaddr_in *) src_in)->sin_addr.s_addr;
                 __be32 dst_ip = ((struct sockaddr_in *) dst_in)->sin_addr.s_addr;
 
@@ -362,7 +383,12 @@ static int addr_resolve_local(struct sockaddr *src_in,
                                 memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
                 }
                 dev_put(dev);
-        } else {
+                break;
+        }
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+        case AF_INET6:
+        {
                 struct in6_addr *a;
 
                 for_each_netdev(&init_net, dev)
@@ -390,6 +416,13 @@ static int addr_resolve_local(struct sockaddr *src_in,
                         if (!ret)
                                 memcpy(addr->dst_dev_addr, dev->dev_addr, MAX_ADDR_LEN);
                 }
+                break;
+        }
+#endif
+
+        default:
+                ret = -EADDRNOTAVAIL;
+                break;
         }
 
         return ret;