[ovs-dev] [PATCH v4] netdev-vport: Use the dst_port in tunnel netdev name

[Chris Mi]

If tunnel device dst_port is not the default one, "ovs-dpctl dump-flows"
will fail. The error message for vxlan is:

netdev_linux|INFO|ioctl(SIOCGIFINDEX) on vxlan_sys_4789 device failed: No such device

That's because when calling netdev_vport_construct() for netdev
vxlan_sys_xxxx, the default dst_port is used. Actually, the dst_port
value is in the netdev name. Use it to avoid the error.

Signed-off-by: Chris Mi <chrism at mellanox.com>
Reviewed-by: Roi Dayan <roid at mellanox.com>
---

v1
==

Any comment about this patch? We are not sure if it is correct
to verify the port from the name. If it is correct, is it applicable
for other tunnels? Thanks!

v2
==

Apply the same fix to other tunnel types according to Flavio Leitner's
comment.

v3
==

Addressed Ben Pfaff's comment to deal with the string correctly.

v4
==

Fix errors reported by AddressSanitizer.

 lib/netdev-vport.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/lib/netdev-vport.c b/lib/netdev-vport.c
index 808a43f99..ab591667f 100644
--- a/lib/netdev-vport.c
+++ b/lib/netdev-vport.c
@@ -189,22 +189,34 @@ netdev_vport_alloc(void)
 int
 netdev_vport_construct(struct netdev *netdev_)
 {
+    const struct netdev_class *class = netdev_get_class(netdev_);
+    const char *dpif_port = netdev_vport_class_get_dpif_port(class);
     struct netdev_vport *dev = netdev_vport_cast(netdev_);
+    const char *p, *name = netdev_get_name(netdev_);
     const char *type = netdev_get_type(netdev_);
+    uint16_t port = 0;
 
     ovs_mutex_init(&dev->mutex);
     eth_addr_random(&dev->etheraddr);
 
-    /* Add a default destination port for tunnel ports if none specified. */
+    if (name && dpif_port && (strlen(name) > strlen(dpif_port) + 1) &&
+        (!strncmp(name, dpif_port, strlen(dpif_port)))) {
+        p = name + strlen(dpif_port) + 1;
+        port = atoi(p);
+    }
+
+    /* If a destination port for tunnel ports is specified in the netdev
+     * name, use it instead of the default one. Otherwise, use the default
+     * destination port */
     if (!strcmp(type, "geneve")) {
-        dev->tnl_cfg.dst_port = htons(GENEVE_DST_PORT);
+        dev->tnl_cfg.dst_port = port ? htons(port) : htons(GENEVE_DST_PORT);
     } else if (!strcmp(type, "vxlan")) {
-        dev->tnl_cfg.dst_port = htons(VXLAN_DST_PORT);
+        dev->tnl_cfg.dst_port = port ? htons(port) : htons(VXLAN_DST_PORT);
         update_vxlan_global_cfg(netdev_, NULL, &dev->tnl_cfg);
     } else if (!strcmp(type, "lisp")) {
-        dev->tnl_cfg.dst_port = htons(LISP_DST_PORT);
+        dev->tnl_cfg.dst_port = port ? htons(port) : htons(LISP_DST_PORT);
     } else if (!strcmp(type, "stt")) {
-        dev->tnl_cfg.dst_port = htons(STT_DST_PORT);
+        dev->tnl_cfg.dst_port = port ? htons(port) : htons(STT_DST_PORT);
     }
 
     dev->tnl_cfg.dont_fragment = true;
-- 
2.14.4