RDMA/cma: Bind to a specific address family

The RDMA CM uses a single port space for all associated (tcp, udp,
etc.) port bindings, regardless of the address family that the user
binds to.  The result is that if a user binds to AF_INET, but does not
specify an IP address, the bind will occur for AF_INET6.  This causes
an attempt to bind to the same port using AF_INET6 to fail, and
connection requests to AF_INET6 will match with the AF_INET listener.
Align the behavior with sockets and restrict the bind to AF_INET only.

If a user binds to AF_INET6, we bind the port to AF_INET6 and
AF_INET depending on the value of bindv6only.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 21 insertions, 11 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 2e826f9702c6..c10c45a07162 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -140,6 +140,7 @@ struct rdma_id_private {
         u8                      srq;
         u8                      tos;
         u8                      reuseaddr;
+        u8                      afonly;
 };
 
 struct cma_multicast {
@@ -1573,6 +1574,7 @@ static void cma_listen_on_dev(struct rdma_id_private *id_priv,
         list_add_tail(&dev_id_priv->listen_list, &id_priv->listen_list);
         atomic_inc(&id_priv->refcount);
         dev_id_priv->internal_id = 1;
+        dev_id_priv->afonly = id_priv->afonly;
 
         ret = rdma_listen(id, id_priv->backlog);
         if (ret)
@@ -2187,22 +2189,24 @@ static int cma_check_port(struct rdma_bind_list *bind_list,
         struct hlist_node *node;
 
         addr = (struct sockaddr *) &id_priv->id.route.addr.src_addr;
-        if (cma_any_addr(addr) && !reuseaddr)
-                return -EADDRNOTAVAIL;
-
         hlist_for_each_entry(cur_id, node, &bind_list->owners, node) {
                 if (id_priv == cur_id)
                         continue;
 
-                if ((cur_id->state == RDMA_CM_LISTEN) ||
-                    !reuseaddr || !cur_id->reuseaddr) {
-                        cur_addr = (struct sockaddr *) &cur_id->id.route.addr.src_addr;
-                        if (cma_any_addr(cur_addr))
-                                return -EADDRNOTAVAIL;
+                if ((cur_id->state != RDMA_CM_LISTEN) && reuseaddr &&
+                    cur_id->reuseaddr)
+                        continue;
 
-                        if (!cma_addr_cmp(addr, cur_addr))
-                                return -EADDRINUSE;
-                }
+                cur_addr = (struct sockaddr *) &cur_id->id.route.addr.src_addr;
+                if (id_priv->afonly && cur_id->afonly &&
+                    (addr->sa_family != cur_addr->sa_family))
+                        continue;
+
+                if (cma_any_addr(addr) || cma_any_addr(cur_addr))
+                        return -EADDRNOTAVAIL;
+
+                if (!cma_addr_cmp(addr, cur_addr))
+                        return -EADDRINUSE;
         }
         return 0;
 }
@@ -2371,6 +2375,12 @@ int rdma_bind_addr(struct rdma_cm_id *id, struct sockaddr *addr)
         }
 
         memcpy(&id->route.addr.src_addr, addr, ip_addr_size(addr));
+        if (addr->sa_family == AF_INET)
+                id_priv->afonly = 1;
+#if IS_ENABLED(CONFIG_IPV6)
+        else if (addr->sa_family == AF_INET6)
+                id_priv->afonly = init_net.ipv6.sysctl.bindv6only;
+#endif
         ret = cma_get_port(id_priv);
         if (ret)
                 goto err2;