Greetings! I was lucky enough to spend some time having fun with OVS recently and encountered a bug that may be worth sharing with you.
The code path in the error case when bridge's del-port is attempted for the parent (instead of the fake-bridge) segfaults. Here are some simple steps for reproducing this issue: ./boot.sh ; ./configure ; make -j4 ; make sandbox PARENT_BRIDGE=br0 ; FAKE_BRIDGE=br0c ; VLAN_TAG=666 ovs-vsctl add-br ${PARENT_BRIDGE} ovs-vsctl add-br $FAKE_BRIDGE $PARENT_BRIDGE $VLAN_TAG # Add a port to parent bridge, which happens to have same tag as the fake_bridge # Note: The port could be have been added directly to the fake bridge too, of course. # The end result of the add-port is the same. ovs-vsctl add-port $PARENT_BRIDGE p1 -- set port p1 tag=${VLAN_TAG} # ovs-vsctl add-port $FAKE_BRIDGE p1 # removing p1 will make a segfault ovs-vsctl del-port $PARENT_BRIDGE p1 ; # sad panda moment # Here are 3 ways of working around this segfault # workaround 1: remove tag before removing port from parent ovs-vsctl remove port p1 tag $VLAN_TAG && \ ovs-vsctl del-port $PARENT_BRIDGE p1 && echo ok # workaround 2: remove port as if it belongs to fake bridge ovs-vsctl del-port $FAKE_BRIDGE p1 && echo ok # workaround 3: remove port w/out specifying a bridge ovs-vsctl del-port p1 && echo ok This issue appears to exist since commit 7c79588e , which dates back to Feb/2010. I see it in OVS 2.3.2. -- flaviof More details about the segfault: |main: Ubuntu ~/ovs.git/_ffbuilddir/utilities/sandbox on devel $ sudo ovs-vsctl show fa096c6f-8f5f-49ae-92b4-e94ce58aceec Bridge "br0" Port "br0" Interface "br0" type: internal Port "p1" tag: 666 Interface "p1" Port "br0c" tag: 666 Interface "br0c" type: internal |main: Ubuntu ~/ovs.git/_ffbuilddir/utilities/sandbox on devel $ gdb /home/ff/ovs.git/_ffbuilddir/utilities/ovs-vsctl ... Reading symbols from /home/ff/ovs.git/_ffbuilddir/utilities/ovs-vsctl...done. (gdb) run del-port br0 p1 Starting program: /home/ff/ovs.git/_ffbuilddir/utilities/ovs-vsctl del-port br0 p1 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0x000000000040a945 in cmd_del_port (ctx=0x7fffffffc5d0) at ../utilities/ovs-vsctl.c:1750 1750 ctl_fatal("bridge %s does not have a port %s (although " (gdb) bt #0 0x000000000040a945 in cmd_del_port (ctx=0x7fffffffc5d0) at ../utilities/ovs-vsctl.c:1750 #1 0x00000000004075dd in do_vsctl (args=0xc8f7f0 "/home/ff/ovs.git/_ffbuilddir/utilities/ovs-vsctl del-port br0 p1", commands=0xc8fd50, n_commands=1, idl=0xc8fdb0) at ../utilities/ovs-vsctl.c:2623 #2 0x0000000000405e7e in main (argc=4, argv=0x7fffffffc868) at ../utilities/ovs-vsctl.c:184 (gdb) list 1745 struct vsctl_bridge *bridge; 1746 1747 bridge = find_bridge(vsctl_ctx, ctx->argv[1], true); 1748 if (port->bridge != bridge) { 1749 if (port->bridge->parent == bridge) { 1750 ctl_fatal("bridge %s does not have a port %s (although " 1751 "its parent bridge %s does)", 1752 ctx->argv[1], ctx->argv[2], 1753 bridge->parent->name); 1754 } else { (gdb) p ctx->argv[1] $1 = 0x7fffffffcba5 "br0" (gdb) p ctx->argv[2] $2 = 0x7fffffffcba9 "p1" (gdb) p port->bridge->name $3 = 0xc9a290 "br0c" (gdb) p bridge $4 = (struct vsctl_bridge *) 0xcc9d60 (gdb) p bridge->parent $5 = (struct vsctl_bridge *) 0x0 (gdb) p port->bridge $6 = (struct vsctl_bridge *) 0xccb440 (gdb) p bridge->name $7 = 0xcc8da0 "br0" (gdb) Flavio Fernandes (2): ovs-vsctl.at: deleting a port from fake bridge ovs-vsctl: Fix segfault when attempting to del-port from parent bridge. tests/ovs-vsctl.at | 17 +++++++++++++++++ utilities/ovs-vsctl.c | 4 ++-- 2 files changed, 19 insertions(+), 2 deletions(-) -- 1.9.1 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev