On Thu, Jan 25, 2024 at 12:55 PM Aaron Conole <[email protected]> wrote: > > From: Kevin Sprague <[email protected]> > > During normal operations, it is useful to understand when a particular flow > gets removed from the system. This can be useful when debugging performance > issues tied to ofproto flow changes, trying to determine deployed traffic > patterns, or while debugging dynamic systems where ports come and go. > > Prior to this change, there was a lack of visibility around flow expiration. > The existing debugging infrastructure could tell us when a flow was added to > the datapath, but not when it was removed or why. > > This change introduces a USDT probe at the point where the revalidator > determines that the flow should be removed. Additionally, we track the > reason for the flow eviction and provide that information as well. With > this change, we can track the complete flow lifecycle for the netlink > datapath by hooking the upcall tracepoint in kernel, the flow put USDT, and > the revaldiator USDT, letting us watch as flows are added and removed from > the kernel datapath. > > This change only enables this information via USDT probe, so it won't be > possible to access this information any other way (see: > Documentation/topics/usdt-probes.rst). > > Also included is a script (utilities/usdt-scripts/flow_reval_monitor.py) > which serves as a demonstration of how the new USDT probe might be used > going forward. > > Signed-off-by: Kevin Sprague <[email protected]> > Co-authored-by: Aaron Conole <[email protected]> > Signed-off-by: Aaron Conole <[email protected]>
Thanks Aaron for taking care of this patch. I saw you resolved most of my comments for the v6 of the original patch: https://mail.openvswitch.org/pipermail/ovs-dev/2023-January/401220.html Butit seems my last comment was missed: === I do notice a counter in my patch doesn't have a counterpart in this patch. In revalidator_sweep__(), I have: if (purge) { result = UKEY_DELETE; + COVERAGE_INC(upcall_flow_del_purge); Would it be good to add one (e.g. FDR_PURGE) here, too? === Could you check if this can be added? If this is merged I can rebase my patch on top of this. Thanks, Han > > --- > Documentation/topics/usdt-probes.rst | 1 + > ofproto/ofproto-dpif-upcall.c | 42 +- > utilities/automake.mk | 3 + > utilities/usdt-scripts/flow_reval_monitor.py | 653 +++++++++++++++++++ > 4 files changed, 693 insertions(+), 6 deletions(-) > create mode 100755 utilities/usdt-scripts/flow_reval_monitor.py > > diff --git a/Documentation/topics/usdt-probes.rst b/Documentation/topics/usdt-probes.rst > index e527f43bab..a8da9bb1f7 100644 > --- a/Documentation/topics/usdt-probes.rst > +++ b/Documentation/topics/usdt-probes.rst > @@ -214,6 +214,7 @@ Available probes in ``ovs_vswitchd``: > - dpif_recv:recv_upcall > - main:poll_block > - main:run_start > +- revalidate:flow_result > - revalidate_ukey\_\_:entry > - revalidate_ukey\_\_:exit > - udpif_revalidator:start_dump > diff --git a/ofproto/ofproto-dpif-upcall.c b/ofproto/ofproto-dpif-upcall.c > index b5cbeed878..97d75833f7 100644 > --- a/ofproto/ofproto-dpif-upcall.c > +++ b/ofproto/ofproto-dpif-upcall.c > @@ -269,6 +269,18 @@ enum ukey_state { > }; > #define N_UKEY_STATES (UKEY_DELETED + 1) > > +enum flow_del_reason { > + FDR_REVALIDATE = 0, /* The flow was revalidated. */ > + FDR_FLOW_IDLE, /* The flow went unused and was deleted. */ > + FDR_TOO_EXPENSIVE, /* The flow was too expensive to revalidate. */ > + FDR_FLOW_WILDCARDED, /* The flow needed a narrower wildcard mask. */ > + FDR_BAD_ODP_FIT, /* The flow had a bad ODP flow fit. */ > + FDR_NO_OFPROTO, /* The flow didn't have an associated ofproto. */ > + FDR_XLATION_ERROR, /* There was an error translating the flow. */ > + FDR_AVOID_CACHING, /* Flow deleted to avoid caching. */ > + FDR_FLOW_LIMIT, /* All flows being killed. */ > +}; > + > /* 'udpif_key's are responsible for tracking the little bit of state udpif > * needs to do flow expiration which can't be pulled directly from the > * datapath. They may be created by any handler or revalidator thread at any > @@ -2272,7 +2284,8 @@ populate_xcache(struct udpif *udpif, struct udpif_key *ukey, > static enum reval_result > revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey, > uint16_t tcp_flags, struct ofpbuf *odp_actions, > - struct recirc_refs *recircs, struct xlate_cache *xcache) > + struct recirc_refs *recircs, struct xlate_cache *xcache, > + enum flow_del_reason *reason) > { > struct xlate_out *xoutp; > struct netflow *netflow; > @@ -2293,11 +2306,13 @@ revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey, > netflow = NULL; > > if (xlate_ukey(udpif, ukey, tcp_flags, &ctx)) { > + *reason = FDR_XLATION_ERROR; > goto exit; > } > xoutp = &ctx.xout; > > if (xoutp->avoid_caching) { > + *reason = FDR_AVOID_CACHING; > goto exit; > } > > @@ -2311,6 +2326,7 @@ revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey, > ofpbuf_clear(odp_actions); > > if (!ofproto) { > + *reason = FDR_NO_OFPROTO; > goto exit; > } > > @@ -2322,6 +2338,7 @@ revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey, > if (odp_flow_key_to_mask(ukey->mask, ukey->mask_len, &dp_mask, &ctx.flow, > NULL) > == ODP_FIT_ERROR) { > + *reason = FDR_BAD_ODP_FIT; > goto exit; > } > > @@ -2331,6 +2348,7 @@ revalidate_ukey__(struct udpif *udpif, const struct udpif_key *ukey, > * down. Note that we do not know if the datapath has ignored any of the > * wildcarded bits, so we may be overly conservative here. */ > if (flow_wildcards_has_extra(&dp_mask, ctx.wc)) { > + *reason = FDR_FLOW_WILDCARDED; > goto exit; > } > > @@ -2400,7 +2418,7 @@ static enum reval_result > revalidate_ukey(struct udpif *udpif, struct udpif_key *ukey, > const struct dpif_flow_stats *stats, > struct ofpbuf *odp_actions, uint64_t reval_seq, > - struct recirc_refs *recircs) > + struct recirc_refs *recircs, enum flow_del_reason *reason) > OVS_REQUIRES(ukey->mutex) > { > bool need_revalidate = ukey->reval_seq != reval_seq; > @@ -2430,8 +2448,12 @@ revalidate_ukey(struct udpif *udpif, struct udpif_key *ukey, > xlate_cache_clear(ukey->xcache); > } > result = revalidate_ukey__(udpif, ukey, push.tcp_flags, > - odp_actions, recircs, ukey->xcache); > - } /* else delete; too expensive to revalidate */ > + odp_actions, recircs, ukey->xcache, > + reason); > + } else { > + /* delete; too expensive to revalidate */ > + *reason = FDR_TOO_EXPENSIVE; > + } > } else if (!push.n_packets || ukey->xcache > || !populate_xcache(udpif, ukey, push.tcp_flags)) { > result = UKEY_KEEP; > @@ -2831,6 +2853,7 @@ revalidate(struct revalidator *revalidator) > for (f = flows; f < &flows[n_dumped]; f++) { > long long int used = f->stats.used; > struct recirc_refs recircs = RECIRC_REFS_EMPTY_INITIALIZER; > + enum flow_del_reason reason = FDR_REVALIDATE; > struct dpif_flow_stats stats = f->stats; > enum reval_result result; > struct udpif_key *ukey; > @@ -2905,9 +2928,14 @@ revalidate(struct revalidator *revalidator) > } > if (kill_them_all || (used && used < now - max_idle)) { > result = UKEY_DELETE; > + if (kill_them_all) { > + reason = FDR_FLOW_LIMIT; > + } else { > + reason = FDR_FLOW_IDLE; > + } > } else { > result = revalidate_ukey(udpif, ukey, &stats, &odp_actions, > - reval_seq, &recircs); > + reval_seq, &recircs, &reason); > } > ukey->dump_seq = dump_seq; > > @@ -2916,6 +2944,7 @@ revalidate(struct revalidator *revalidator) > udpif_update_flow_pps(udpif, ukey, f); > } > > + OVS_USDT_PROBE(revalidate, flow_result, reason, udpif, ukey); > if (result != UKEY_KEEP) { > /* Takes ownership of 'recircs'. */ > reval_op_init(&ops[n_ops++], result, udpif, ukey, &recircs, > @@ -2962,6 +2991,7 @@ revalidator_sweep__(struct revalidator *revalidator, bool purge) > uint64_t odp_actions_stub[1024 / 8]; > struct ofpbuf odp_actions = OFPBUF_STUB_INITIALIZER(odp_actions_stub); > > + enum flow_del_reason reason = FDR_REVALIDATE; > struct ukey_op ops[REVALIDATE_MAX_BATCH]; > struct udpif_key *ukey; > struct umap *umap = &udpif->ukeys[i]; > @@ -2993,7 +3023,7 @@ revalidator_sweep__(struct revalidator *revalidator, bool purge) > COVERAGE_INC(revalidate_missed_dp_flow); > memcpy(&stats, &ukey->stats, sizeof stats); > result = revalidate_ukey(udpif, ukey, &stats, &odp_actions, > - reval_seq, &recircs); > + reval_seq, &recircs, &reason); > } > if (result != UKEY_KEEP) { > /* Clears 'recircs' if filled by revalidate_ukey(). */ > diff --git a/utilities/automake.mk b/utilities/automake.mk > index 9a2114df40..146b8c37fb 100644 > --- a/utilities/automake.mk > +++ b/utilities/automake.mk > @@ -23,6 +23,7 @@ scripts_DATA += utilities/ovs-lib > usdt_SCRIPTS += \ > utilities/usdt-scripts/bridge_loop.bt \ > utilities/usdt-scripts/dpif_nl_exec_monitor.py \ > + utilities/usdt-scripts/flow_reval_monitor.py \ > utilities/usdt-scripts/kernel_delay.py \ > utilities/usdt-scripts/kernel_delay.rst \ > utilities/usdt-scripts/reval_monitor.py \ > @@ -72,6 +73,7 @@ EXTRA_DIST += \ > utilities/docker/debian/build-kernel-modules.sh \ > utilities/usdt-scripts/bridge_loop.bt \ > utilities/usdt-scripts/dpif_nl_exec_monitor.py \ > + utilities/usdt-scripts/flow_reval_monitor.py \ > utilities/usdt-scripts/kernel_delay.py \ > utilities/usdt-scripts/kernel_delay.rst \ > utilities/usdt-scripts/reval_monitor.py \ > @@ -146,6 +148,7 @@ FLAKE8_PYFILES += utilities/ovs-pcap.in \ > utilities/ovs-tcpdump.in \ > utilities/ovs-pipegen.py \ > utilities/usdt-scripts/dpif_nl_exec_monitor.py \ > + utilities/usdt-scripts/flow_reval_monitor.py \ > utilities/usdt-scripts/upcall_monitor.py \ > utilities/usdt-scripts/upcall_cost.py > > diff --git a/utilities/usdt-scripts/flow_reval_monitor.py b/utilities/usdt-scripts/flow_reval_monitor.py > new file mode 100755 > index 0000000000..e808020bb5 > --- /dev/null > +++ b/utilities/usdt-scripts/flow_reval_monitor.py > @@ -0,0 +1,653 @@ > +#!/usr/bin/env python3 > +# > +# Copyright (c) 2022 Redhat, 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: > +# ------------------- > +# flow_reval_monitor.py uses the dpif_netlink_operate:flow_put and > +# revalidator:flow_result USDT probes to monitor flow lifetimes and > +# expiration events. By default, this will show all flow_put and flow > +# expiration events, along with their reasons. This will look like so: > +# > +# TIME UFID EVENT/REASON > +# 101536.226986736 ufid:f76fc899-376d-466b-bc74-0000b933eb97 flow_put > +# 101536.227196214 ufid:d08472b6-110e-46cb-a9e4-00008f46838e flow_put > +# 101541.516610178 ufid:fc5cc4a2-39e7-4a2d-bbce-000019665b32 flow_put > +# 101541.516967303 ufid:fddd6510-26dc-4c87-8f7a-0000fc0c2c3a flow_put > +# 101551.688050747 ufid:fddd6510-26dc-4c87-8f7a-0000fc0c2c3a flow timed out > +# 101551.688077175 ufid:fc5cc4a2-39e7-4a2d-bbce-000019665b32 flow timed out > +# 101557.695391371 ufid:f76fc899-376d-466b-bc74-0000b933eb97 flow timed out > +# 101557.695408909 ufid:d08472b6-110e-46cb-a9e4-00008f46838e flow timed out > +# > +# flow key data can be printed using the --flow-keys option. This will > +# print the equivalent datapath flow string. > +# > +# When filtering flows, the syntax is the same as used by > +# `ovs-appctl dpctl/add-flow`. > +# > +# The following options are available: > +# > +# usage: flow_reval_monitor.py [-h] [--buffer-page-count NUMBER] > +# [-k [FLOW_KEYS]] [-p VSWITCHD_PID] > +# [-D [DEBUG]] [-f [FLOW STRING ...]] > +# > +# optional arguments: > +# -h, --help show this help message and exit > +# --buffer-page-count NUMBER > +# Number of BPF ring buffer pages, default 1024 > +# -f <64..2048>, --flow-key-size=<64..2048> > +# Set the size of the flow key, default 64 > +# -k, --flow-keys Print flow keys as flow strings > +# -l [FLOW_STRING ...], --filter-flows [FLOW_STRING ...] > +# Filter flows that match the specified ODP-like flow > +# -p VSWITCHD_PID, --pid VSWITCHD_PID > +# ovs-vswitchd's PID > +# -D [DEBUG], --debug [DEBUG] > +# Enable eBPF debugging > +# > +# Examples: > +# > +# To use the script on a running ovs-vswitchd to see flow keys and expiration > +# events for flows with an ipv4 source of 192.168.10.10: > +# $ ./flow_reval_monitor.py --flow-keys --filter-flows \ > +# "ipv4(src=192.168.10.10)" > +# TIME UFID EVENT/REASON > +# 105082.457322742 ufid:f76fc899-376d-466b-bc74-0000b933eb97 flow_put > +# ufid:f76fc899-376d-466b-bc74-0000b933eb97 has the following flow information: > +# in_port(2), > +# eth(src=0e:04:47:fc:74:51, dst=da:dc:c5:69:05:d7), \ > +# eth_type(0x800), \ > +# ipv4(src=192.168.10.10, dst=192.168.10.30, proto=1, tos=0, ttl=64,[...]), > +# icmp(type=8, code=0) > +# 105092.635450202 ufid:f76fc899-376d-466b-bc74-0000b933eb97 Flow timed out > +# > +# Notes: > +# 1) No options are needed to attach when there is a single running instance > +# of ovs-vswitchd. > +# 2) If you're using the flow filtering option, it will only track flows that > +# have been upcalled since the script began running. > +# 3) When using the flow filtering option, the key size will likely need to > +# be expanded to match on all the fields in the message. The default is > +# kept small to keep the buffer copy sizes down when displaying > +# flows (-k), but is hardcoded to 2048 when an actual filter (-l) is > +# applied > + > +try: > + from bcc import BPF > + from bcc import USDT > + from bcc import USDTException > +except ModuleNotFoundError: > + print("ERROR: Can't find the BPF Compiler Collection Tools.") > + print("Please install them before running this script.") > + exit(1) > + > +import argparse > +from ipaddress import IPv4Address, IPv6Address > +import psutil > +import struct > +import sys > +import time > + > +# > +# eBPF source code > +# > +bpf_src = """ > +#include <linux/sched.h> > +#include <uapi/linux/ptrace.h> > + > +#define MAX_KEY <MAX_KEY_VAL> > +#define FLOW_FILTER <FILTER_BOOL> > + > +enum probe { OP_FLOW_PUT, FLOW_RESULT }; > + > +typedef union ovs_u128 { > + unsigned int ufid32[4]; > + unsigned long long ufid64[2]; > +} ovs_u128; > + > +struct dpif_flow_put { > + int flags; > + void *key_ptr; > + size_t key_len; > + void *mask_ptr; > + size_t mask_len; > + u64 action_ptr; > + size_t action_len; > + void *ufid_ptr; > +}; > + > +struct udpif_key { > + void *cmap_node; > + void *key_ptr; > + size_t key_len; > + void *mask_ptr; > + size_t mask_len; > + ovs_u128 ufid; > +}; > + > +struct event_t { > + u64 ts; > + u32 reason; > + u32 ufid[4]; /* Can't seem to make the ovs_u128 pass to python side. */ > + u64 key_size; > + u8 key[MAX_KEY]; > + enum probe probe; > +}; > + > +BPF_HASH(watchlist, ovs_u128); > +BPF_RINGBUF_OUTPUT(events, <BUFFER_PAGE_COUNT>); > + > +int usdt__flow_result(struct pt_regs *ctx) { > + u64 *ufid_present = NULL; > + struct udpif_key ukey; > + > + bpf_usdt_readarg_p(3, ctx, &ukey, sizeof ukey); > + ovs_u128 ufid = ukey.ufid; > + ufid_present = watchlist.lookup(&ufid); > + if(FLOW_FILTER && !ufid_present) { > + return 0; > + } > + > + struct event_t *event = events.ringbuf_reserve(sizeof(struct event_t)); > + if(!event) { > + /* If we can't reserve the space in the ring buffer, return 1. */ > + return 1; > + } > + > + event->probe = FLOW_RESULT; > + event->ts = bpf_ktime_get_ns(); > + bpf_probe_read(&event->ufid, sizeof ufid, &ufid); > + bpf_usdt_readarg(1, ctx, &event->reason); > + events.ringbuf_submit(event, 0); > + > + return 0; > +}; > + > + > +int usdt__op_flow_put(struct pt_regs *ctx) { > + struct dpif_flow_put put; > + ovs_u128 ufid; > + > + struct event_t *event = events.ringbuf_reserve(sizeof(struct event_t)); > + if(!event) { > + /* If we can't reserve the space in the ring buffer, return 1. */ > + return 1; > + } > + > + event->probe = OP_FLOW_PUT; > + event->ts = bpf_ktime_get_ns(); > + bpf_usdt_readarg_p(2, ctx, &put, sizeof put); > + bpf_probe_read(&event->ufid, sizeof event->ufid, put.ufid_ptr); > + bpf_probe_read(&ufid, sizeof ufid, &event->ufid); > + if (put.key_len > MAX_KEY) { > + put.key_len = MAX_KEY; > + } > + event->key_size = put.key_len; > + bpf_probe_read(&event->key, put.key_len, put.key_ptr); > + event->reason = 0; > + events.ringbuf_submit(event, 0); > + > + watchlist.increment(ufid); > + return 0; > +}; > +""" > + > + > +# > +# 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)) > + > + > +# > +# format_ufid() > +# > +def format_ufid(ufid): > + if ufid is None: > + return "ufid:none" > + > + return "ufid:{:08x}-{:04x}-{:04x}-{:04x}-{:04x}{:08x}".format( > + ufid[0], ufid[1] >> 16, ufid[1] & 0xffff, > + ufid[2] >> 16, ufid[2] & 0, ufid[3]) > + > + > +# > +# find_and_delete_from_watchlist() > +# > +def find_and_delete_from_watchlist(event): > + for k, _ in b["watchlist"].items(): > + key_ufid = struct.unpack("=IIII", k) > + if key_ufid == tuple(event.ufid): > + key = (b["watchlist"].Key * 1)(k) > + b["watchlist"].items_delete_batch(key) > + break > + > + > +# > +# handle_flow_put() > +# > +def handle_flow_put(event): > + if args.flow_keys or args.filter_flows is not None: > + key = decode_key(bytes(event.key)[:event.key_size]) > + flow_dict, flow_str = parse_flow_dict(key) > + # For each attribute that we're watching. > + if args.filter_flows is not None: > + if not compare_flow_to_target(args.filter_flows, flow_dict): > + find_and_delete_from_watchlist(event) > + return > + > + print("{:<18.9f} {:<45} {:<13}".format(event.ts / 1000000000, > + format_ufid(event.ufid), "Insert (put) flow to kernel.")) > + > + if args.flow_keys: > + if len(flow_str) > 80: > + flow_str = " " + "),\n ".join(flow_str.split("), ")) > + else: > + flow_str = " " + flow_str > + print(" - It holds the following flow information:") > + print(flow_str) > + > + > +# > +# compare_flow_to_target() > +# > +def compare_flow_to_target(target, flow): > + for key in target: > + if key not in flow: > + return False > + elif target[key] is True: > + continue > + elif target[key] == flow[key]: > + continue > + elif isinstance(target[key], dict) and isinstance(flow[key], dict): > + return compare_flow_to_target(target[key], flow[key]) > + else: > + return False > + return True > + > + > +# > +# parse_flow_str() > +# > +def parse_flow_str(flow_str): > + f_list = [i.strip(", ") for i in flow_str.split(")")] > + if f_list[-1] == "": > + f_list = f_list[:-1] > + flow_dict = {} > + for e in f_list: > + split_list = e.split("(") > + k = split_list[0] > + if len(split_list) == 1: > + flow_dict[k] = True > + elif split_list[1].count("=") == 0: > + flow_dict[k] = split_list[1] > + else: > + sub_dict = {} > + sublist = [i.strip() for i in split_list[1].split(",")] > + for subkey in sublist: > + brk = subkey.find("=") > + sub_dict[subkey[:brk]] = subkey[brk + 1:] > + flow_dict[k] = sub_dict > + return flow_dict > + > + > +# > +# print_expiration() > +# > +def print_expiration(event): > + reasons = ["Unknown flow expiration reason!", "Flow timed out", > + "Flow revalidation too expensive", > + "Flow needs narrower wildcard mask", > + "Bad ODP flow fit", "Flow with associated ofproto", > + "Flow translation error", "Flow cache avoidance", > + "Kill them all signal"] > + > + ufid_str = format_ufid(event.ufid) > + reason = event.reason > + > + if reason not in range(0, len(reasons) - 1): > + reason = 0 > + print("{:<18.9f} {:<45} {:<17}". > + format(event.ts / 1000000000, ufid_str, reasons[reason])) > + > + > +# > +# decode_key() > +# > +def decode_key(msg): > + bytes_left = len(msg) > + result = {} > + while bytes_left: > + if bytes_left < 4: > + break > + nla_len, nla_type = struct.unpack("=HH", msg[:4]) > + if nla_len < 4: > + break > + nla_data = msg[4:nla_len] > + trunc = False > + if nla_len > bytes_left: > + trunc = True > + nla_data = nla_data[:(bytes_left - 4)] > + else: > + result[get_ovs_key_attr_str(nla_type)] = nla_data > + if trunc: > + break > + next_offset = (nla_len + 3) & (~3) > + msg = msg[next_offset:] > + bytes_left -= next_offset > + return result > + > + > +# > +# get_ovs_key_attr_str() > +# > +def get_ovs_key_attr_str(attr): > + ovs_key_attr = ["OVS_KEY_ATTR_UNSPEC", > + "encap", > + "skb_priority", > + "in_port", > + "eth", > + "vlan", > + "eth_type", > + "ipv4", > + "ipv6", > + "tcp", > + "udp", > + "icmp", > + "icmpv6", > + "arp", > + "nd", > + "skb_mark", > + "tunnel", > + "sctp", > + "tcp_flags", > + "dp_hash", > + "recirc_id", > + "mpls", > + "ct_state", > + "ct_zone", > + "ct_mark", > + "ct_label", > + "ct_tuple4", > + "ct_tuple6", > + "nsh"] > + > + if attr < 0 or attr > len(ovs_key_attr): > + return "<UNKNOWN>: {}".format(attr) > + return ovs_key_attr[attr] > + > + > +# > +# is_nonzero() > +# > +def is_nonzero(val): > + if isinstance(val, int): > + return (val != 0) > + > + if isinstance(val, str): > + val = bytes(val, "utf-8") > + > + # If it's not a string or an int, it's bytes. > + return (val.count(0) < len(val)) > + > + > +# > +# parse_flow_dict() > +# > +def parse_flow_dict(key_dict, decode=True): > + ret_str = "" > + parseable = {} > + skip = ["nsh", "tunnel", "mpls", "vlan"] > + need_byte_swap = ["ct_label"] > + ipv4addrs = ["ct_tuple4", "tunnel", "ipv4", "arp"] > + ipv6addrs = ["ipv6", "nd", "ct_tuple6"] > + macs = {"eth": [0, 1], "arp": [3, 4], "nd": [1, 2]} > + fields = [("OVS_KEY_ATTR_UNSPEC"), > + ("encap", ), > + ("skb_priority", "<I"), > + ("in_port", "<I"), > + ("eth", "!6s6s", "src", "dst"), > + ("vlan", ), > + ("eth_type", "!H"), > + ("ipv4", "!4s4s4B", "src", "dst", "proto", "tos", "ttl", "frag"), > + ("ipv6", "!16s16s4s4B", "src", "dst", > + "label", "proto", "tclass", "hlimit", "frag"), > + ("tcp", "!2H", "src", "dst"), > + ("udp", "!2H", "src", "dst"), > + ("icmp", "!2B", "type", "code"), > + ("icmpv6", "!2B", "type", "code"), > + ("arp", "!4s4sH6s6s", "sip", "tip", "op", "sha", "tha"), > + ("nd", "!16s6s6s", "target", "sll", "tll"), > + ("skb_mark", "<I"), > + ("tunnel", ), > + ("sctp", "!2H", "src", "dst"), > + ("tcp_flags", "!H"), > + ("dp_hash", "<I"), > + ("recirc_id", "<I"), > + ("mpls", ), > + ("ct_state", "<I"), > + ("ct_zone", "<H"), > + ("ct_mark", "<I"), > + ("ct_label", "!16s"), > + ("ct_tuple4", > + "!4s4s2HB", "src", "dst", "tp_src", "tp_dst", "proto"), > + ("ct_tuple6", > + "!16s16sB2H", "src", "dst", "proto", "tp_src", "tp_dst"), > + ("nsh", )] > + for k, v in key_dict.items(): > + s = "" > + if k in skip: > + continue > + if decode and int.from_bytes(v, "big") == 0: > + parseable[k] = "0" > + continue > + if decode and k in need_byte_swap: > + v = int.from_bytes(v, "little").to_bytes(len(v), "big") > + attr = -1 > + found = False > + for f in fields: > + if k == f[0]: > + attr = fields.index(f) > + found = True > + break > + if not found: > + raise KeyError("Invalid flow field '%s'" % k) > + if decode and len(fields[attr]) > 1: > + data = list(struct.unpack(fields[attr][1], > + v[:struct.calcsize(fields[attr][1])])) > + if k in ipv4addrs: > + if data[0].count(0) < 4: > + data[0] = str(IPv4Address(data[0])) > + else: > + data[0] = b"\x00" > + if data[1].count(0) < 4: > + data[1] = str(IPv4Address(data[1])) > + else: > + data[1] = b"\x00" > + if k in ipv6addrs: > + if data[0].count(0) < 16: > + data[0] = str(IPv6Address(data[0])) > + else: > + data[0] = b"\x00" > + if data[1].count(0) < len(data[1]): > + data[1] = str(IPv6Address(data[1])) > + else: > + data[1] = b"\x00" > + if k in macs.keys(): > + for e in macs[k]: > + if data[e].count(0) == 6: > + mac_str = b"\x00" > + else: > + mac_str = ":".join(["%02x" % i for i in data[e]]) > + data[e] = mac_str > + if decode and len(fields[attr]) > 2: > + field_dict = {field: d for field, d in zip(fields[attr][2:], data)} > + s = ", ".join(k + "=" + str(v) for k, v in field_dict.items()) > + elif decode and k != "eth_type": > + s = str(data[0]) > + field_dict = s > + else: > + if decode: > + s = hex(data[0]) > + field_dict = s > + ret_str += k + "(" + s + "), " > + parseable[k] = field_dict > + ret_str = ret_str[:-2] > + return (parseable, ret_str) > + > + > +# > +# handle_event() > +# > +def handle_event(ctx, data, size): > + # Once we grab the event, we have three cases. > + # 1. It's a revalidator probe and the reason is nonzero: A flow is expiring > + # 2. It's a revalidator probe and the reason is zero: flow revalidated > + # 3. It's a flow_put probe. > + # > + # We will ignore case 2, and report all others. > + # > + event = b["events"].event(data) > + if event.probe == 0: # OP_FLOW_PUT > + handle_flow_put(event) > + elif event.probe == 1 and event.reason > 0: # FLOW_RESULT > + print_expiration(event) > + > + > +def main(): > + # > + # Don't like these globals, but ctx passing does not work with the existing > + # open_ring_buffer() API :( > + # > + global b > + global args > + > + # > + # 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("-f", "--flow-key-size", > + help="Set maximum flow key size to capture, " > + "default 64 - see notes", type=buffer_size_type, > + default=64, metavar="[64-2048]") > + parser.add_argument("-k", "--flow-keys", > + help="Print flow keys as flow strings", > + action="store_true") > + parser.add_argument("-l", "--filter-flows", metavar="FLOW_STRING", > + help="Filter flows that match the specified " > + "ODP-like flow", > + type=str, default=None, nargs="*") > + parser.add_argument("-p", "--pid", metavar="VSWITCHD_PID", > + help="ovs-vswitchd's PID", type=int, default=None) > + parser.add_argument("-D", "--debug", help="Enable eBPF debugging", > + type=int, const=0x3f, default=0, nargs="?") > + args = parser.parse_args() > + > + # > + # Find the PID of the ovs-vswitchd daemon if not specified. > + # > + if args.pid is None: > + for proc in psutil.process_iter(): > + if "ovs-vswitchd" in proc.name(): > + if args.pid is not None: > + print("Error: Multiple ovs-vswitchd daemons running, " > + "use the -p option!") > + sys.exit(-1) > + > + args.pid = proc.pid > + # > + # Error checking on input parameters > + # > + if args.pid is None: > + print("ERROR: Failed to find ovs-vswitchd's PID!") > + sys.exit(-1) > + > + # > + # Attach the USDT probes > + # > + u = USDT(pid=int(args.pid)) > + try: > + u.enable_probe(probe="op_flow_put", fn_name="usdt__op_flow_put") > + except USDTException as e: > + print("Error attaching the dpif_netlink_operate__:op_flow_put probe.") > + print(str(e)) > + sys.exit(-1) > + > + try: > + u.enable_probe(probe="flow_result", fn_name="usdt__flow_result") > + except USDTException as e: > + print("Error attaching the revalidate:flow_result probe.") > + print(str(e)) > + sys.exit(-1) > + > + # > + # Attach the probes to the running process > + # > + source = bpf_src.replace("<BUFFER_PAGE_COUNT>", > + str(args.buffer_page_count)) > + > + if args.filter_flows is None: > + filter_bool = 0 > + > + # Set the key size based on what the user wanted > + source = source.replace("<MAX_KEY_VAL>", str(args.flow_key_size)) > + else: > + filter_bool = 1 > + args.filter_flows = parse_flow_str(args.filter_flows[0]) > + > + # Run through the parser to make sure we only filter on fields we > + # understand > + parse_flow_dict(args.filter_flows, False) > + > + # This is hardcoded here because it doesn't make sense to shrink the > + # size, since the flow key might be missing fields that are matched in > + # the flow filter. > + source = source.replace("<MAX_KEY_VAL>", "2048") > + > + source = source.replace("<FILTER_BOOL>", str(filter_bool)) > + > + b = BPF(text=source, usdt_contexts=[u], debug=args.debug) > + > + # > + # Print header > + # > + print("{:<18} {:<45} {:<17}".format("TIME", "UFID", "EVENT/REASON")) > + > + # > + # Dump out all events. > + # > + b["events"].open_ring_buffer(handle_event) > + while 1: > + try: > + b.ring_buffer_poll() > + time.sleep(0.5) > + except KeyboardInterrupt: > + break > + > + > +# > +# Start main() as the default entry point > +# > +if __name__ == "__main__": > + main() > -- > 2.41.0 > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
