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:
# ./dpif_nl_exec_monitor.py --packet-decode decode
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
Signed-off-by: Eelco Chaudron <[email protected]>
---
v2: Added script to usdt_SCRIPTS
Documentation/topics/usdt-probes.rst | 1
utilities/automake.mk | 3
utilities/usdt-scripts/dpif_nl_exec_monitor.py | 662 ++++++++++++++++++++++++
3 files changed, 666 insertions(+)
create mode 100755 utilities/usdt-scripts/dpif_nl_exec_monitor.py
diff --git a/Documentation/topics/usdt-probes.rst
b/Documentation/topics/usdt-probes.rst
index 7ce19aaed..004817b1c 100644
--- a/Documentation/topics/usdt-probes.rst
+++ b/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``
diff --git a/utilities/automake.mk b/utilities/automake.mk
index 132a16942..b020511c6 100644
--- a/utilities/automake.mk
+++ b/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
diff --git a/utilities/usdt-scripts/dpif_nl_exec_monitor.py b/utilities/usdt-scripts/dpif_nl_exec_monitor.py
new file mode 100755
index 000000000..0a9ff8123
--- /dev/null
+++ b/utilities/usdt-scripts/dpif_nl_exec_monitor.py
@@ -0,0 +1,662 @@
+#!/usr/bin/env python3
+#
+# Copyright (c) 2022 Red Hat, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Script information:
+# -------------------
+# dpif_nl_exec_monitor.py uses the dpif_netlink_operate__:op_flow_execute USDT
+# probe to receive all DPIF_OP_EXECUTE operations that are queued for
+# transmission over the netlink socket. It will do some basic decoding, and if
+# requested a packet dump.
+#
+# Here is an example:
+#
+# # ./dpif_nl_exec_monitor.py --packet-decode decode
+# 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...
+# 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...
+# 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
+#
+# The example above dumps the full netlink and packet decode. However options
+# exist to disable this. Here is the full list of supported options:
+#
+# usage: dpif_nl_exec_monitor.py [-h] [--buffer-page-count NUMBER] [-D [DEBUG]]
+# [-d {none,hex,decode}] [-n {none,hex,nlraw}]
+# [-p VSWITCHD_PID] [-s [64-2048]]
+# [-w PCAP_FILE]
+#
+# optional arguments:
+# -h, --help show this help message and exit
+# --buffer-page-count NUMBER
+# Number of BPF ring buffer pages, default 1024
+# -D [DEBUG], --debug [DEBUG]
+# Enable eBPF debugging
+# -d {none,hex,decode}, --packet-decode {none,hex,decode}
+# Display packet content in selected mode, default none
+# -n {none,hex,nlraw}, --nlmsg-decode {none,hex,nlraw}
+# Display netlink message content in selected mode,
+# default nlraw
+# -p VSWITCHD_PID, --pid VSWITCHD_PID
+# ovs-vswitch's PID
+# -s [64-2048], --nlmsg-size [64-2048]
+# Set maximum netlink message size to capture, default
+# 512
+# -w PCAP_FILE, --pcap PCAP_FILE
+# Write upcall packets to specified pcap file
+
+from bcc import BPF, USDT, USDTException
+from os.path import exists
+from scapy.all import hexdump, wrpcap
+from scapy.layers.l2 import Ether
+
+import argparse
+import psutil
+import re
+import struct
+import sys
+import time
+
+#
+# Actual eBPF source code
+#
+ebpf_source = """
+#include <linux/sched.h>
+
+#define MAX_NLMSG <MAX_NLMSG_VAL>
+
+struct event_t {
+ u32 cpu;
+ u32 pid;
+ u64 ts;
+ u32 nl_size;
+ char comm[TASK_COMM_LEN];
+ u8 nl_msg[MAX_NLMSG];
+};
+
+struct ofpbuf {
+ void *base;
+ void *data;
+ uint32_t size;
+
+ /* The actual structure is longer, but we are only interested in the
+ * first couple of entries. */
+};
+
+BPF_RINGBUF_OUTPUT(events, <BUFFER_PAGE_CNT>);
+BPF_TABLE("percpu_array", uint32_t, uint64_t, dropcnt, 1);
+
+int trace__op_flow_execute(struct pt_regs *ctx) {
+ struct ofpbuf nlbuf;
+ uint32_t size;
+
+ bpf_usdt_readarg_p(5, ctx, &nlbuf, sizeof(nlbuf));
+
+ struct event_t *event = events.ringbuf_reserve(sizeof(struct event_t));
+ if (!event) {
+ uint32_t type = 0;
+ uint64_t *value = dropcnt.lookup(&type);
+ if (value)
+ __sync_fetch_and_add(value, 1);
+
+ return 1;
+ }
+
+ event->ts = bpf_ktime_get_ns();
+ event->cpu = bpf_get_smp_processor_id();
+ event->pid = bpf_get_current_pid_tgid();
+ bpf_get_current_comm(&event->comm, sizeof(event->comm));
+
+ event->nl_size = nlbuf.size;
+ if (event->nl_size > MAX_NLMSG)
+ size = MAX_NLMSG;
+ else
+ size = event->nl_size;
+
+ bpf_probe_read(&event->nl_msg, size, nlbuf.data);
+
+ events.ringbuf_submit(event, 0);
+ return 0;
+};
+"""
+
+
+#
+# print_event()
+#
+def print_event(ctx, data, size):
+ event = b["events"].event(data)
+ print("{:<18.9f} {:<4} {:<16} {:<10} {:<10}".
+ format(event.ts / 1000000000,
+ event.cpu,
+ event.comm.decode("utf-8"),
+ event.pid,
+ event.nl_size))
+
+ #
+ # Dumping the netlink message data if requested.
+ #
+ if event.nl_size < options.nlmsg_size:
+ nl_size = event.nl_size
+ else:
+ nl_size = options.nlmsg_size
+
+ if options.nlmsg_decode == "hex":
+ #
+ # Abuse scapy's hex dump to dump flow key
+ #
+ print(re.sub("^", " " * 4,
+ hexdump(Ether(bytes(event.nl_msg)[:nl_size]), dump=True),
+ flags=re.MULTILINE))
+
+ if options.nlmsg_decode == "nlraw":
+ decode_result = decode_nlm(bytes(event.nl_msg)[:nl_size], dump=True)
+ else:
+ decode_result = decode_nlm(bytes(event.nl_msg)[:nl_size], dump=False)
+
+ #
+ # Decode packet only if there is data
+ #
+ if "OVS_PACKET_ATTR_PACKET" not in decode_result:
+ return
+
+ pkt_data = decode_result["OVS_PACKET_ATTR_PACKET"]
+ indent = 4 if options.nlmsg_decode != "nlraw" else 6
+
+ if options.packet_decode != "none":
+ print("{}- Dumping OVS_PACKET_ATR_PACKET data:".format(" " * indent))
+
+ if options.packet_decode == "hex":
+ print(re.sub("^", " " * indent, hexdump(pkt_data, dump=True),
+ flags=re.MULTILINE))
+
+ packet = Ether(pkt_data)
+ if options.packet_decode == "decode":
+ print(re.sub("^", " " * indent, packet.show(dump=True),
+ flags=re.MULTILINE))
+
+ if options.pcap is not None:
+ wrpcap(options.pcap, packet, append=True)
+
+
+#
+# decode_nlm_tlvs()
+#
+def decode_nlm_tlvs(tlvs, header=None, indent=4, dump=True,
+ attr_to_str_func=None, decode_tree=None):
+ bytes_left = len(tlvs)
+ result = {}
+
+ if dump:
+ print("{}{}".format(" " * indent, header))
+
+ while bytes_left:
+ if bytes_left < 4:
+ if dump:
+ print("{}WARN: decode truncated; can't read header".format(
+ " " * indent))
+ break
+
+ nla_len, nla_type = struct.unpack("=HH", tlvs[:4])
+
+ if nla_len < 4:
+ if dump:
+ print("{}WARN: decode truncated; nla_len < 4".format(
+ " " * indent))
+ break
+
+ nla_data = tlvs[4:nla_len]
+ trunc = ""
+
+ if attr_to_str_func is None:
+ nla_type_name = "type_{}".format(nla_type)
+ else:
+ nla_type_name = attr_to_str_func(nla_type)
+
+ if nla_len > bytes_left:
+ trunc = "..."
+ nla_data = nla_data[:(bytes_left - 4)]
+ else:
+ result[nla_type_name] = nla_data
+
+ if dump:
+ print("{}nla_len {}, nla_type {}[{}], data: {}{}".format(
+ " " * indent, nla_len, nla_type_name, nla_type,
+ "".join("{:02x} ".format(b) for b in nla_data), trunc))
+
+ #
+ # If we have the full data, try to decode further
+ #
+ if trunc == "" and decode_tree is not None \
+ and nla_type_name in decode_tree:
+ node = decode_tree[nla_type_name]
+ decode_nlm_tlvs(nla_data,
+ header=node["header"],
+ indent=indent + node["indent"], dump=True,
+ attr_to_str_func=node["attr_str_func"],
+ decode_tree=node["decode_tree"])
+
+ if trunc != "":
+ if dump:
+ print("{}WARN: decode truncated; nla_len > msg_len[{}] ".
+ format(" " * indent, bytes_left))
+ break
+
+ # update next offset, but make sure it's aligned correctly
+ next_offset = (nla_len + 3) & ~(3)
+ tlvs = tlvs[next_offset:]
+ bytes_left -= next_offset
+
+ return result
+
+
+#
+# decode_nlm()
+#
+def decode_nlm(msg, indent=4, dump=True):
+ result = {}
+
+ #
+ # Decode 'struct nlmsghdr'
+ #
+ if dump:
+ print("{}nlmsghdr : len = {}, type = {}, flags = {}, seq = {}, "
+ "pid = {}".format(" " * indent,
+ *struct.unpack("=IHHII", msg[:16])))
+
+ msg = msg[16:]
+
+ #
+ # Decode 'struct genlmsghdr'
+ #
+ if dump:
+ print("{}genlmsghdr: cmd = {}, version = {}, reserver = {}".format(
+ " " * indent, *struct.unpack("=BBH", msg[:4])))
+
+ msg = msg[4:]
+
+ #
+ # Decode 'struct ovs_header'
+ #
+ if dump:
+ print("{}ovs_header: dp_ifindex = {}".format(
+ " " * indent, *struct.unpack("=I", msg[:4])))
+
+ msg = msg[4:]
+
+ #
+ # Decode TLVs
+ #
+ nl_attr_tree = {
+ "OVS_PACKET_ATTR_KEY": {
+ "header": "> Decode OVS_KEY_ATTR_* TLVs:",
+ "indent": 4,
+ "attr_str_func": get_ovs_key_attr_str,
+ "decode_tree": None,
+ },
+ "OVS_PACKET_ATTR_ACTIONS": {
+ "header": "> Decode OVS_ACTION_ATTR_* TLVs:",
+ "indent": 4,
+ "attr_str_func": get_ovs_action_attr_str,
+ "decode_tree": {
+ "OVS_ACTION_ATTR_SET": {
+ "header": "> Decode OVS_KEY_ATTR_* TLVs:",
+ "indent": 4,
+ "attr_str_func": get_ovs_key_attr_str,
+ "decode_tree": {
+ "OVS_KEY_ATTR_TUNNEL": {
+ "header": "> Decode OVS_TUNNEL_KEY_ATTR_* TLVs:",
+ "indent": 4,
+ "attr_str_func": get_ovs_tunnel_key_attr_str,
+ "decode_tree": None,
+ },
+ },
+ },
+ },
+ },
+ }
+
+ result = decode_nlm_tlvs(msg, indent=indent + 2, dump=dump,
+ header="> Decode OVS_PACKET_ATTR_* TLVs:",
+ attr_to_str_func=get_ovs_pkt_attr_str,
+ decode_tree=nl_attr_tree)
+ return result
+
+
+#
+# get_ovs_pkt_attr_str()
+#
+def get_ovs_pkt_attr_str(attr):
+ ovs_pkt_attr = ["OVS_PACKET_ATTR_UNSPEC",
+ "OVS_PACKET_ATTR_PACKET",
+ "OVS_PACKET_ATTR_KEY",
+ "OVS_PACKET_ATTR_ACTIONS",
+ "OVS_PACKET_ATTR_USERDATA",
+ "OVS_PACKET_ATTR_EGRESS_TUN_KEY",
+ "OVS_PACKET_ATTR_UNUSED1",
+ "OVS_PACKET_ATTR_UNUSED2",
+ "OVS_PACKET_ATTR_PROBE",
+ "OVS_PACKET_ATTR_MRU",
+ "OVS_PACKET_ATTR_LEN",
+ "OVS_PACKET_ATTR_HASH"]
+ if attr < 0 or attr >= len(ovs_pkt_attr):
+ return "<UNKNOWN:{}>".format(attr)
+
+ return ovs_pkt_attr[attr]
+
+
+#
+# get_ovs_key_attr_str()
+#
+def get_ovs_key_attr_str(attr):
+ ovs_key_attr = ["OVS_KEY_ATTR_UNSPEC",
+ "OVS_KEY_ATTR_ENCAP",
+ "OVS_KEY_ATTR_PRIORITY",
+ "OVS_KEY_ATTR_IN_PORT",
+ "OVS_KEY_ATTR_ETHERNET",
+ "OVS_KEY_ATTR_VLAN",
+ "OVS_KEY_ATTR_ETHERTYPE",
+ "OVS_KEY_ATTR_IPV4",
+ "OVS_KEY_ATTR_IPV6",
+ "OVS_KEY_ATTR_TCP",
+ "OVS_KEY_ATTR_UDP",
+ "OVS_KEY_ATTR_ICMP",
+ "OVS_KEY_ATTR_ICMPV6",
+ "OVS_KEY_ATTR_ARP",
+ "OVS_KEY_ATTR_ND",
+ "OVS_KEY_ATTR_SKB_MARK",
+ "OVS_KEY_ATTR_TUNNEL",
+ "OVS_KEY_ATTR_SCTP",
+ "OVS_KEY_ATTR_TCP_FLAGS",
+ "OVS_KEY_ATTR_DP_HASH",
+ "OVS_KEY_ATTR_RECIRC_ID",
+ "OVS_KEY_ATTR_MPLS",
+ "OVS_KEY_ATTR_CT_STATE",
+ "OVS_KEY_ATTR_CT_ZONE",
+ "OVS_KEY_ATTR_CT_MARK",
+ "OVS_KEY_ATTR_CT_LABELS",
+ "OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4",
+ "OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6",
+ "OVS_KEY_ATTR_NSH"]
+
+ if attr < 0 or attr >= len(ovs_key_attr):
+ return "<UNKNOWN:{}>".format(attr)
+
+ return ovs_key_attr[attr]
+
+
+#
+# get_ovs_action_attr_str()
+#
+def get_ovs_action_attr_str(attr):
+ ovs_action_attr = ["OVS_ACTION_ATTR_UNSPEC",
+ "OVS_ACTION_ATTR_OUTPUT",
+ "OVS_ACTION_ATTR_USERSPACE",
+ "OVS_ACTION_ATTR_SET",
+ "OVS_ACTION_ATTR_PUSH_VLAN",
+ "OVS_ACTION_ATTR_POP_VLAN",
+ "OVS_ACTION_ATTR_SAMPLE",
+ "OVS_ACTION_ATTR_RECIRC",
+ "OVS_ACTION_ATTR_HASH",
+ "OVS_ACTION_ATTR_PUSH_MPLS",
+ "OVS_ACTION_ATTR_POP_MPLS",
+ "OVS_ACTION_ATTR_SET_MASKED",
+ "OVS_ACTION_ATTR_CT",
+ "OVS_ACTION_ATTR_TRUNC",
+ "OVS_ACTION_ATTR_PUSH_ETH",
+ "OVS_ACTION_ATTR_POP_ETH",
+ "OVS_ACTION_ATTR_CT_CLEAR",
+ "OVS_ACTION_ATTR_PUSH_NSH",
+ "OVS_ACTION_ATTR_POP_NSH",
+ "OVS_ACTION_ATTR_METER",
+ "OVS_ACTION_ATTR_CLONE",
+ "OVS_ACTION_ATTR_CHECK_PKT_LEN",
+ "OVS_ACTION_ATTR_ADD_MPLS",
+ "OVS_ACTION_ATTR_TUNNEL_PUSH",
+ "OVS_ACTION_ATTR_TUNNEL_POP",
+ "OVS_ACTION_ATTR_DROP",
+ "OVS_ACTION_ATTR_LB_OUTPUT"]
+ if attr < 0 or attr >= len(ovs_action_attr):
+ return "<UNKNOWN:{}>".format(attr)
+
+ return ovs_action_attr[attr]
+
+
+#
+# get_ovs_tunnel_key_attr_str()
+#
+def get_ovs_tunnel_key_attr_str(attr):
+ ovs_tunnel_key_attr = ["OVS_TUNNEL_KEY_ATTR_ID",
+ "OVS_TUNNEL_KEY_ATTR_IPV4_SRC",
+ "OVS_TUNNEL_KEY_ATTR_IPV4_DST",
+ "OVS_TUNNEL_KEY_ATTR_TOS",
+ "OVS_TUNNEL_KEY_ATTR_TTL",
+ "OVS_TUNNEL_KEY_ATTR_DONT_FRAGMENT",
+ "OVS_TUNNEL_KEY_ATTR_CSUM",
+ "OVS_TUNNEL_KEY_ATTR_OAM",
+ "OVS_TUNNEL_KEY_ATTR_GENEVE_OPTS",
+ "OVS_TUNNEL_KEY_ATTR_TP_SRC",
+ "OVS_TUNNEL_KEY_ATTR_TP_DST",
+ "OVS_TUNNEL_KEY_ATTR_VXLAN_OPTS",
+ "OVS_TUNNEL_KEY_ATTR_IPV6_SRC",
+ "OVS_TUNNEL_KEY_ATTR_IPV6_DST",
+ "OVS_TUNNEL_KEY_ATTR_PAD",
+ "OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS",
+ "OVS_TUNNEL_KEY_ATTR_GTPU_OPTS"]
+ if attr < 0 or attr >= len(ovs_tunnel_key_attr):
+ return "<UNKNOWN:{}>".format(attr)
+
+ return ovs_tunnel_key_attr[attr]
+
+
+#
+# buffer_size_type()
+#
+def buffer_size_type(astr, min=64, max=2048):
+ value = int(astr)
+ if min <= value <= max:
+ return value
+ else:
+ raise argparse.ArgumentTypeError(
+ "value not in range {}-{}".format(min, max))
+
+
+#
+# next_power_of_two()
+#
+def next_power_of_two(val):
+ np = 1
+ while np < val:
+ np *= 2
+ return np
+
+
+#
+# main()
+#
+def main():
+ #
+ # Don't like these globals, but ctx passing does not seem to work with the
+ # existing open_ring_buffer() API :(
+ #
+ global b
+ global options
+
+ #
+ # Argument parsing
+ #
+ parser = argparse.ArgumentParser()
+
+ parser.add_argument("--buffer-page-count",
+ help="Number of BPF ring buffer pages, default 1024",
+ type=int, default=1024, metavar="NUMBER")
+ parser.add_argument("-D", "--debug",
+ help="Enable eBPF debugging",
+ type=int, const=0x3f, default=0, nargs="?")
+ parser.add_argument("-d", "--packet-decode",
+ help="Display packet content in selected mode, "
+ "default none",
+ choices=["none", "hex", "decode"], default="none")
+ parser.add_argument("-n", "--nlmsg-decode",
+ help="Display netlink message content in selected mode"
+ ", default nlraw",
+ choices=["none", "hex", "nlraw"], default="nlraw")
+ parser.add_argument("-p", "--pid", metavar="VSWITCHD_PID",
+ help="ovs-vswitch's PID",
+ type=int, default=None)
+ parser.add_argument("-s", "--nlmsg-size",
+ help="Set maximum netlink message size to capture, "
+ "default 512", type=buffer_size_type, default=512,
+ metavar="[64-2048]")
+ parser.add_argument("-w", "--pcap", metavar="PCAP_FILE",
+ help="Write upcall packets to specified pcap file",
+ type=str, default=None)
+
+ options = parser.parse_args()
+
+ #
+ # Find the PID of the ovs-vswitchd daemon if not specified.
+ #
+ if options.pid is None:
+ for proc in psutil.process_iter():
+ if "ovs-vswitchd" in proc.name():
+ if options.pid is not None:
+ print("ERROR: Multiple ovs-vswitchd daemons running, "
+ "use the -p option!")
+ sys.exit(-1)
+
+ options.pid = proc.pid
+
+ #
+ # Error checking on input parameters
+ #
+ if options.pid is None:
+ print("ERROR: Failed to find ovs-vswitchd's PID!")
+ sys.exit(-1)
+
+ if options.pcap is not None:
+ if exists(options.pcap):
+ print("ERROR: Destination capture file \"{}\" already exists!".
+ format(options.pcap))
+ sys.exit(-1)
+
+ options.buffer_page_count = next_power_of_two(options.buffer_page_count)
+
+ #
+ # Attach the usdt probe
+ #
+ u = USDT(pid=int(options.pid))
+ try:
+ u.enable_probe(probe="dpif_netlink_operate__:op_flow_execute",
+ fn_name="trace__op_flow_execute")
+ except USDTException as e:
+ print("ERROR: {}"
+ "ovs-vswitchd!".format(
+ (re.sub("^", " " * 7, str(e), flags=re.MULTILINE)).strip().
+ replace("--with-dtrace or --enable-dtrace",
+ "--enable-usdt-probes")))
+ sys.exit(-1)
+
+ #
+ # Uncomment to see how arguments are decoded.
+ # print(u.get_text())
+ #
+
+ #
+ # Attach probe to running process
+ #
+ source = ebpf_source.replace("<MAX_NLMSG_VAL>", str(options.nlmsg_size))
+ source = source.replace("<BUFFER_PAGE_CNT>",
+ str(options.buffer_page_count))
+
+ b = BPF(text=source, usdt_contexts=[u], debug=options.debug)
+
+ #
+ # Print header
+ #
+ print("Display DPIF_OP_EXECUTE operations being queued for transmission "
+ "onto the netlink socket.")
+ print("{:<18} {:<4} {:<16} {:<10} {:<10}".format(
+ "TIME", "CPU", "COMM", "PID", "NL_SIZE"))
+
+ #
+ # Dump out all events
+ #
+ b["events"].open_ring_buffer(print_event)
+ while 1:
+ try:
+ b.ring_buffer_poll()
+ time.sleep(0.5)
+ except KeyboardInterrupt:
+ break
+
+ dropcnt = b.get_table("dropcnt")
+ for k in dropcnt.keys():
+ count = dropcnt.sum(k).value
+ if k.value == 0 and count > 0:
+ print("\nWARNING: Not all upcalls were captured, {} were dropped!"
+ "\n Increase the BPF ring buffer size with the "
+ "--buffer-page-count option.".format(count))
+
+
+#
+# Start main() as the default entry point...
+#
+if __name__ == "__main__":
+ main()
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