utilities: Add USDT script to monitor dpif netlink execute message qu…

…euing.

This patch adds the dpif_nl_exec_monitor.py script that will used the
existing dpif_netlink_operate__:op_flow_execute USDT probe to show
all DPIF_OP_EXECUTE operations being queued for transmission over
the netlink interface.

Here is an example, truncated output:

Display DPIF_OP_EXECUTE operations being queued for transmission...
TIME               CPU  COMM             PID        NL_SIZE
3124.516679897     1    ovs-vswitchd     8219       180
    nlmsghdr  : len = 0, type = 36, flags = 1, seq = 0, pid = 0
    genlmsghdr: cmd = 3, version = 1, reserver = 0
    ovs_header: dp_ifindex = 21
      > Decode OVS_PACKET_ATTR_* TLVs:
      nla_len 46, nla_type OVS_PACKET_ATTR_PACKET[1], data: 00 00 00...
      nla_len 20, nla_type OVS_PACKET_ATTR_KEY[2], data: 08 00 02 00...
          > Decode OVS_KEY_ATTR_* TLVs:
          nla_len 8, nla_type OVS_KEY_ATTR_PRIORITY[2], data: 00 00...
          nla_len 8, nla_type OVS_KEY_ATTR_SKB_MARK[15], data: 00 00...
      nla_len 88, nla_type OVS_PACKET_ATTR_ACTIONS[3], data: 4c 00 03...
          > Decode OVS_ACTION_ATTR_* TLVs:
          nla_len 76, nla_type OVS_ACTION_ATTR_SET[3], data: 48 00...
                  > Decode OVS_TUNNEL_KEY_ATTR_* TLVs:
                  nla_len 12, nla_type OVS_TUNNEL_KEY_ATTR_ID[0], data:...
                  nla_len 20, nla_type OVS_TUNNEL_KEY_ATTR_IPV6_DST[13], ...
                  nla_len 5, nla_type OVS_TUNNEL_KEY_ATTR_TTL[4], data: 40
                  nla_len 4, nla_type OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT[5]...
                  nla_len 4, nla_type OVS_TUNNEL_KEY_ATTR_CSUM[6], data:
                  nla_len 6, nla_type OVS_TUNNEL_KEY_ATTR_TP_DST[10],...
                  nla_len 12, nla_type OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS[8],...
          nla_len 8, nla_type OVS_ACTION_ATTR_OUTPUT[1], data: 02 00 00 00
      - Dumping OVS_PACKET_ATR_PACKET data:
      ###[ Ethernet ]###
        dst       = 00:00:00:00:ec:01
        src       = 04:f4:bc:28:57:00
        type      = IPv4
      ###[ IP ]###
           version   = 4
           ihl       = 5
           tos       = 0x0
           len       = 50
           id        = 0
           flags     =
           frag      = 0
           ttl       = 127
           proto     = icmp
           chksum    = 0x2767
           src       = 10.0.0.1
           dst       = 10.0.0.100
           \options   \
      ###[ ICMP ]###
              type      = echo-request
              code      = 0
              chksum    = 0xf7f3
              id        = 0x0
              seq       = 0xc

Acked-by: Adrian Moreno <[email protected]>
Signed-off-by: Eelco Chaudron <[email protected]>
Signed-off-by: Ilya Maximets <[email protected]>

Documentation/topics/usdt-probes.rst

@@ -254,6 +254,7 @@ DPIF_OP_FLOW_EXECUTE operation as part of the dpif ``operate()`` callback.
 
 **Script references**:
 
+- ``utilities/usdt-scripts/dpif_nl_exec_monitor.py``
 - ``utilities/usdt-scripts/upcall_cost.py``
 
 

utilities/automake.mk

@@ -22,6 +22,7 @@ scripts_SCRIPTS += \
 scripts_DATA += utilities/ovs-lib
 usdt_SCRIPTS += \
 	utilities/usdt-scripts/bridge_loop.bt \
+	utilities/usdt-scripts/dpif_nl_exec_monitor.py \
 	utilities/usdt-scripts/upcall_cost.py \
 	utilities/usdt-scripts/upcall_monitor.py
 
@@ -67,6 +68,7 @@ EXTRA_DIST += \
 	utilities/docker/debian/Dockerfile \
 	utilities/docker/debian/build-kernel-modules.sh \
 	utilities/usdt-scripts/bridge_loop.bt \
+	utilities/usdt-scripts/dpif_nl_exec_monitor.py \
 	utilities/usdt-scripts/upcall_cost.py \
 	utilities/usdt-scripts/upcall_monitor.py
 MAN_ROOTS += \
@@ -137,6 +139,7 @@ FLAKE8_PYFILES += utilities/ovs-pcap.in \
 	utilities/ovs-check-dead-ifs.in \
 	utilities/ovs-tcpdump.in \
 	utilities/ovs-pipegen.py \
+	utilities/usdt-scripts/dpif_nl_exec_monitor.py \
 	utilities/usdt-scripts/upcall_monitor.py \
 	utilities/usdt-scripts/upcall_cost.py