utilities: Add some GDB macros for ovs-vswitchd

This commit adds basic GDB macro's for ovs-vswitchd:
  - ovs_dump_bridge [ports|wanted]
  - ovs_dump_bridge_ports <struct bridge *>
  - ovs_dump_dp_netdev [ports]
  - ovs_dump_dp_netdev_ports <struct dp_netdev *>
  - ovs_dump_netdev

These dump functions show limited info, but you can simply cut/paste
the address and get the full structure info. For example:

(gdb) ovs_dump_netdev
(struct netdev *) 0x555771ed89e0: name = ovs-netdev     , auto_classified = false, netdev_class = 0x5557714413c0 <netdev_tap_class>
(struct netdev *) 0x555771fc62a0: name = ovs_pvp_br0    , auto_classified = false, netdev_class = 0x5557714413c0 <netdev_tap_class>
(struct netdev *) 0x555771fc9660: name = vnet0          , auto_classified = true , netdev_class = 0x555771445e00 <netdev_linux_class>
(struct netdev *) 0x555771fc78d0: name = virbr0         , auto_classified = true , netdev_class = 0x555771445e00 <netdev_linux_class>
(struct netdev *) 0x7fbefffb5540: name = dpdk0          , auto_classified = false, netdev_class = 0x5557714419e0 <dpdk_class>
(struct netdev *) 0x555771fc98b0: name = em3            , auto_classified = true , netdev_class = 0x555771445e00 <netdev_linux_class>
(struct netdev *) 0x7fbea0a31c40: name = vhost0         , auto_classified = false, netdev_class = 0x555771442040 <dpdk_vhost_client_class>

(gdb) p *((struct netdev *) 0x7fbefffb5540)
$1 = {name = 0x555771ecef70 "dpdk0", netdev_class = 0x5557714419e0 <dpdk_class>, auto_classified = false, mtu_user_config = true, ref_cnt = 2, change_seq = 12,
  reconfigure_seq = 0x555771ecf2e0, last_reconfigure_seq = 110, n_txq = 2, n_rxq = 1, node = 0x555771efafe0, saved_flags_list = {prev = 0x7fbefffb5580, next = 0x7fbefffb5580}}

Signed-off-by: Eelco Chaudron <[email protected]>
Signed-off-by: Ben Pfaff <[email protected]>

Documentation/tutorials/ovs-advanced.rst

@@ -145,6 +145,10 @@ can be passed via the ``SANDBOXFLAGS`` environment variable.  ``make sandbox
 SANDBOXFLAGS=-g`` will start the sandbox with ovs-vswitchd running under GDB in
 its own xterm if X is available.
 
+In addition, a set of GDB macros are available in ``utilities/gdb/ovs_gdb.py``.
+Which are able to dump various internal data structures. See the header of the
+file itself for some more details and an example.
+
 Motivation
 ----------
 

utilities/automake.mk

@@ -38,6 +38,7 @@ noinst_SCRIPTS += utilities/ovs-sim
 utilities/ovs-lib: $(top_builddir)/config.status
 
 EXTRA_DIST += \
+	utilities/gdb/ovs_gdb.py \
 	utilities/ovs-appctl-bashcomp.bash \
 	utilities/ovs-check-dead-ifs.in \
 	utilities/ovs-ctl.in \