IB/cma: Fix broken AF_IB UD support

Support for using UD and AF_IB is currently broken.  The
IB_CM_SIDR_REQ_RECEIVED message is not handled properly in
cma_save_net_info() and we end up falling into code that will try and
process the request as ipv4/ipv6, which will end up failing.

The resolution is to add a check for the SIDR_REQ and call
cma_save_ib_info() with a NULL path record.  Change cma_save_ib_info()
to copy the src sib info from the listen_id when the path record is NULL.

Reported-by: Hari Shankar <Hari.Shankar@netapp.com>
Signed-off-by: Matt Finlay <matt@mellanox.com>
Acked-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/cma.c

@@ -845,18 +845,26 @@ static void cma_save_ib_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_id
 	listen_ib = (struct sockaddr_ib *) &listen_id->route.addr.src_addr;
 	ib = (struct sockaddr_ib *) &id->route.addr.src_addr;
 	ib->sib_family = listen_ib->sib_family;
-	ib->sib_pkey = path->pkey;
-	ib->sib_flowinfo = path->flow_label;
-	memcpy(&ib->sib_addr, &path->sgid, 16);
+	if (path) {
+		ib->sib_pkey = path->pkey;
+		ib->sib_flowinfo = path->flow_label;
+		memcpy(&ib->sib_addr, &path->sgid, 16);
+	} else {
+		ib->sib_pkey = listen_ib->sib_pkey;
+		ib->sib_flowinfo = listen_ib->sib_flowinfo;
+		ib->sib_addr = listen_ib->sib_addr;
+	}
 	ib->sib_sid = listen_ib->sib_sid;
 	ib->sib_sid_mask = cpu_to_be64(0xffffffffffffffffULL);
 	ib->sib_scope_id = listen_ib->sib_scope_id;
 
-	ib = (struct sockaddr_ib *) &id->route.addr.dst_addr;
-	ib->sib_family = listen_ib->sib_family;
-	ib->sib_pkey = path->pkey;
-	ib->sib_flowinfo = path->flow_label;
-	memcpy(&ib->sib_addr, &path->dgid, 16);
+	if (path) {
+		ib = (struct sockaddr_ib *) &id->route.addr.dst_addr;
+		ib->sib_family = listen_ib->sib_family;
+		ib->sib_pkey = path->pkey;
+		ib->sib_flowinfo = path->flow_label;
+		memcpy(&ib->sib_addr, &path->dgid, 16);
+	}
 }
 
 static __be16 ss_get_port(const struct sockaddr_storage *ss)
@@ -905,9 +913,11 @@ static int cma_save_net_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_id
 {
 	struct cma_hdr *hdr;
 
-	if ((listen_id->route.addr.src_addr.ss_family == AF_IB) &&
-	    (ib_event->event == IB_CM_REQ_RECEIVED)) {
-		cma_save_ib_info(id, listen_id, ib_event->param.req_rcvd.primary_path);
+	if (listen_id->route.addr.src_addr.ss_family == AF_IB) {
+		if (ib_event->event == IB_CM_REQ_RECEIVED)
+			cma_save_ib_info(id, listen_id, ib_event->param.req_rcvd.primary_path);
+		else if (ib_event->event == IB_CM_SIDR_REQ_RECEIVED)
+			cma_save_ib_info(id, listen_id, NULL);
 		return 0;
 	}