4 files changed, 143 insertions, 69 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index eff5e46f005..99dde874fbb 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -148,6 +148,7 @@ struct rdma_id_private {
 	u32			qp_num;
 	u8			srq;
 	u8			tos;
+	u8			reuseaddr;
 };
 
 struct cma_multicast {
@@ -1579,50 +1580,6 @@ static void cma_listen_on_all(struct rdma_id_private *id_priv)
 	mutex_unlock(&lock);
 }
 
-int rdma_listen(struct rdma_cm_id *id, int backlog)
-{
-	struct rdma_id_private *id_priv;
-	int ret;
-
-	id_priv = container_of(id, struct rdma_id_private, id);
-	if (id_priv->state == CMA_IDLE) {
-		((struct sockaddr *) &id->route.addr.src_addr)->sa_family = AF_INET;
-		ret = rdma_bind_addr(id, (struct sockaddr *) &id->route.addr.src_addr);
-		if (ret)
-			return ret;
-	}
-
-	if (!cma_comp_exch(id_priv, CMA_ADDR_BOUND, CMA_LISTEN))
-		return -EINVAL;
-
-	id_priv->backlog = backlog;
-	if (id->device) {
-		switch (rdma_node_get_transport(id->device->node_type)) {
-		case RDMA_TRANSPORT_IB:
-			ret = cma_ib_listen(id_priv);
-			if (ret)
-				goto err;
-			break;
-		case RDMA_TRANSPORT_IWARP:
-			ret = cma_iw_listen(id_priv, backlog);
-			if (ret)
-				goto err;
-			break;
-		default:
-			ret = -ENOSYS;
-			goto err;
-		}
-	} else
-		cma_listen_on_all(id_priv);
-
-	return 0;
-err:
-	id_priv->backlog = 0;
-	cma_comp_exch(id_priv, CMA_LISTEN, CMA_ADDR_BOUND);
-	return ret;
-}
-EXPORT_SYMBOL(rdma_listen);
-
 void rdma_set_service_type(struct rdma_cm_id *id, int tos)
 {
 	struct rdma_id_private *id_priv;
@@ -2105,6 +2062,25 @@ err:
 }
 EXPORT_SYMBOL(rdma_resolve_addr);
 
+int rdma_set_reuseaddr(struct rdma_cm_id *id, int reuse)
+{
+	struct rdma_id_private *id_priv;
+	unsigned long flags;
+	int ret;
+
+	id_priv = container_of(id, struct rdma_id_private, id);
+	spin_lock_irqsave(&id_priv->lock, flags);
+	if (id_priv->state == CMA_IDLE) {
+		id_priv->reuseaddr = reuse;
+		ret = 0;
+	} else {
+		ret = -EINVAL;
+	}
+	spin_unlock_irqrestore(&id_priv->lock, flags);
+	return ret;
+}
+EXPORT_SYMBOL(rdma_set_reuseaddr);
+
 static void cma_bind_port(struct rdma_bind_list *bind_list,
 			  struct rdma_id_private *id_priv)
 {
@@ -2180,43 +2156,73 @@ retry:
 	return -EADDRNOTAVAIL;
 }
 
-static int cma_use_port(struct idr *ps, struct rdma_id_private *id_priv)
+/*
+ * Check that the requested port is available.  This is called when trying to
+ * bind to a specific port, or when trying to listen on a bound port.  In
+ * the latter case, the provided id_priv may already be on the bind_list, but
+ * we still need to check that it's okay to start listening.
+ */
+static int cma_check_port(struct rdma_bind_list *bind_list,
+			  struct rdma_id_private *id_priv, uint8_t reuseaddr)
 {
 	struct rdma_id_private *cur_id;
 	struct sockaddr *addr, *cur_addr;
-	struct rdma_bind_list *bind_list;
 	struct hlist_node *node;
-	unsigned short snum;
 
 	addr = (struct sockaddr *) &id_priv->id.route.addr.src_addr;
-	snum = ntohs(cma_port(addr));
-	if (snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
-		return -EACCES;
-
-	bind_list = idr_find(ps, snum);
-	if (!bind_list)
-		return cma_alloc_port(ps, id_priv, snum);
-
-	/*
-	 * We don't support binding to any address if anyone is bound to
-	 * a specific address on the same port.
-	 */
-	if (cma_any_addr(addr))
+	if (cma_any_addr(addr) && !reuseaddr)
 		return -EADDRNOTAVAIL;
 
 	hlist_for_each_entry(cur_id, node, &bind_list->owners, node) {
-		cur_addr = (struct sockaddr *) &cur_id->id.route.addr.src_addr;
-		if (cma_any_addr(cur_addr))
-			return -EADDRNOTAVAIL;
+		if (id_priv == cur_id)
+			continue;
 
-		if (!cma_addr_cmp(addr, cur_addr))
-			return -EADDRINUSE;
-	}
+		if ((cur_id->state == CMA_LISTEN) ||
+		    !reuseaddr || !cur_id->reuseaddr) {
+			cur_addr = (struct sockaddr *) &cur_id->id.route.addr.src_addr;
+			if (cma_any_addr(cur_addr))
+				return -EADDRNOTAVAIL;
 
-	cma_bind_port(bind_list, id_priv);
+			if (!cma_addr_cmp(addr, cur_addr))
+				return -EADDRINUSE;
+		}
+	}
 	return 0;
 }
 
+static int cma_use_port(struct idr *ps, struct rdma_id_private *id_priv)
+{
+	struct rdma_bind_list *bind_list;
+	unsigned short snum;
+	int ret;
+
+	snum = ntohs(cma_port((struct sockaddr *) &id_priv->id.route.addr.src_addr));
+	if (snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
+		return -EACCES;
+
+	bind_list = idr_find(ps, snum);
+	if (!bind_list) {
+		ret = cma_alloc_port(ps, id_priv, snum);
+	} else {
+		ret = cma_check_port(bind_list, id_priv, id_priv->reuseaddr);
+		if (!ret)
+			cma_bind_port(bind_list, id_priv);
+	}
+	return ret;
+}
+
+static int cma_bind_listen(struct rdma_id_private *id_priv)
+{
+	struct rdma_bind_list *bind_list = id_priv->bind_list;
+	int ret = 0;
+
+	mutex_lock(&lock);
+	if (bind_list->owners.first->next)
+		ret = cma_check_port(bind_list, id_priv, 0);
+	mutex_unlock(&lock);
+	return ret;
+}
+
 static int cma_get_port(struct rdma_id_private *id_priv)
 {
 	struct idr *ps;
@@ -2268,6 +2274,56 @@ static int cma_check_linklocal(struct rdma_dev_addr *dev_addr,
 	return 0;
 }
 
+int rdma_listen(struct rdma_cm_id *id, int backlog)
+{
+	struct rdma_id_private *id_priv;
+	int ret;
+
+	id_priv = container_of(id, struct rdma_id_private, id);
+	if (id_priv->state == CMA_IDLE) {
+		((struct sockaddr *) &id->route.addr.src_addr)->sa_family = AF_INET;
+		ret = rdma_bind_addr(id, (struct sockaddr *) &id->route.addr.src_addr);
+		if (ret)
+			return ret;
+	}
+
+	if (!cma_comp_exch(id_priv, CMA_ADDR_BOUND, CMA_LISTEN))
+		return -EINVAL;
+
+	if (id_priv->reuseaddr) {
+		ret = cma_bind_listen(id_priv);
+		if (ret)
+			goto err;
+	}
+
+	id_priv->backlog = backlog;
+	if (id->device) {
+		switch (rdma_node_get_transport(id->device->node_type)) {
+		case RDMA_TRANSPORT_IB:
+			ret = cma_ib_listen(id_priv);
+			if (ret)
+				goto err;
+			break;
+		case RDMA_TRANSPORT_IWARP:
+			ret = cma_iw_listen(id_priv, backlog);
+			if (ret)
+				goto err;
+			break;
+		default:
+			ret = -ENOSYS;
+			goto err;
+		}
+	} else
+		cma_listen_on_all(id_priv);
+
+	return 0;
+err:
+	id_priv->backlog = 0;
+	cma_comp_exch(id_priv, CMA_LISTEN, CMA_ADDR_BOUND);
+	return ret;
+}
+EXPORT_SYMBOL(rdma_listen);
+
 int rdma_bind_addr(struct rdma_cm_id *id, struct sockaddr *addr)
 {
 	struct rdma_id_private *id_priv;
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index ec1e9da1488..b3fa798525b 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/drivers/infiniband/core/ucma.c
@@ -883,6 +883,13 @@ static int ucma_set_option_id(struct ucma_context *ctx, int optname,
 		}
 		rdma_set_service_type(ctx->cm_id, *((u8 *) optval));
 		break;
+	case RDMA_OPTION_ID_REUSEADDR:
+		if (optlen != sizeof(int)) {
+			ret = -EINVAL;
+			break;
+		}
+		ret = rdma_set_reuseaddr(ctx->cm_id, *((int *) optval) ? 1 : 0);
+		break;
 	default:
 		ret = -ENOSYS;
 	}
diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index 4fae9030464..169f7a53fb0 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -329,4 +329,14 @@ void rdma_leave_multicast(struct rdma_cm_id *id, struct sockaddr *addr);
  */
 void rdma_set_service_type(struct rdma_cm_id *id, int tos);
 
+/**
+ * rdma_set_reuseaddr - Allow the reuse of local addresses when binding
+ *    the rdma_cm_id.
+ * @id: Communication identifier to configure.
+ * @reuse: Value indicating if the bound address is reusable.
+ *
+ * Reuse must be set before an address is bound to the id.
+ */
+int rdma_set_reuseaddr(struct rdma_cm_id *id, int reuse);
+
 #endif /* RDMA_CM_H */
diff --git a/include/rdma/rdma_user_cm.h b/include/rdma/rdma_user_cm.h
index 1d165022c02..fc82c1896f7 100644
--- a/include/rdma/rdma_user_cm.h
+++ b/include/rdma/rdma_user_cm.h
@@ -221,8 +221,9 @@ enum {
 
 /* Option details */
 enum {
-	RDMA_OPTION_ID_TOS	= 0,
-	RDMA_OPTION_IB_PATH	= 1
+	RDMA_OPTION_ID_TOS	 = 0,
+	RDMA_OPTION_ID_REUSEADDR = 1,
+	RDMA_OPTION_IB_PATH	 = 1
 };
 
 struct rdma_ucm_set_option {