#! /usr/bin/python3
# @lint-avoid-python-3-compatibility-imports
#
# tcplife Trace the lifespan of TCP sessions and summarize.
# For Linux, uses BCC, BPF. Embedded C.
#
# USAGE: tcplife [-h] [-C] [-S] [-p PID] [-4 | -6] [interval [count]]
#
# This uses the sock:inet_sock_set_state tracepoint if it exists (added to
# Linux 4.16, and replacing the earlier tcp:tcp_set_state), else it uses
# kernel dynamic tracing of tcp_set_state().
#
# While throughput counters are emitted, they are fetched in a low-overhead
# manner: reading members of the tcp_info struct on TCP close. ie, we do not
# trace send/receive.
#
# Copyright 2016 Netflix, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# IDEA: Julia Evans
#
# 18-Oct-2016 Brendan Gregg Created this.
# 29-Dec-2017 " " Added tracepoint support.
from __future__ import print_function
from bcc import BPF
import argparse
from socket import inet_ntop, AF_INET, AF_INET6
from struct import pack
from time import strftime
# arguments
examples = """examples:
./tcplife # trace all TCP connect()s
./tcplife -T # include time column (HH:MM:SS)
./tcplife -w # wider columns (fit IPv6)
./tcplife -stT # csv output, with times & timestamps
./tcplife -p 181 # only trace PID 181
./tcplife -L 80 # only trace local port 80
./tcplife -L 80,81 # only trace local ports 80 and 81
./tcplife -D 80 # only trace remote port 80
./tcplife -4 # only trace IPv4 family
./tcplife -6 # only trace IPv6 family
"""
parser = argparse.ArgumentParser(
description="Trace the lifespan of TCP sessions and summarize",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-T", "--time", action="store_true",
help="include time column on output (HH:MM:SS)")
parser.add_argument("-t", "--timestamp", action="store_true",
help="include timestamp on output (seconds)")
parser.add_argument("-w", "--wide", action="store_true",
help="wide column output (fits IPv6 addresses)")
parser.add_argument("-s", "--csv", action="store_true",
help="comma separated values output")
parser.add_argument("-p", "--pid",
help="trace this PID only")
parser.add_argument("-L", "--localport",
help="comma-separated list of local ports to trace.")
parser.add_argument("-D", "--remoteport",
help="comma-separated list of remote ports to trace.")
group = parser.add_mutually_exclusive_group()
group.add_argument("-4", "--ipv4", action="store_true",
help="trace IPv4 family only")
group.add_argument("-6", "--ipv6", action="store_true",
help="trace IPv6 family only")
parser.add_argument("--ebpf", action="store_true",
help=argparse.SUPPRESS)
args = parser.parse_args()
debug = 0
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
#include <linux/tcp.h>
#include <net/sock.h>
#include <bcc/proto.h>
BPF_HASH(birth, struct sock *, u64);
// separate data structs for ipv4 and ipv6
struct ipv4_data_t {
u64 ts_us;
u32 pid;
u32 saddr;
u32 daddr;
u64 ports;
u64 rx_b;
u64 tx_b;
u64 span_us;
char task[TASK_COMM_LEN];
};
BPF_PERF_OUTPUT(ipv4_events);
struct ipv6_data_t {
u64 ts_us;
u32 pid;
unsigned __int128 saddr;
unsigned __int128 daddr;
u64 ports;
u64 rx_b;
u64 tx_b;
u64 span_us;
char task[TASK_COMM_LEN];
};
BPF_PERF_OUTPUT(ipv6_events);
struct id_t {
u32 pid;
char task[TASK_COMM_LEN];
};
BPF_HASH(whoami, struct sock *, struct id_t);
"""
#
# XXX: The following is temporary code for older kernels, Linux 4.14 and
# older. It uses kprobes to instrument tcp_set_state(). On Linux 4.16 and
# later, the sock:inet_sock_set_state tracepoint should be used instead, as
# is done by the code that follows this. In the distant future (2021?), this
# kprobe code can be removed. This is why there is so much code
# duplication: to make removal easier.
#
bpf_text_kprobe = """
int kprobe__tcp_set_state(struct pt_regs *ctx, struct sock *sk, int state)
{
u32 pid = bpf_get_current_pid_tgid() >> 32;
// lport is either used in a filter here, or later
u16 lport = sk->__sk_common.skc_num;
FILTER_LPORT
// dport is either used in a filter here, or later
u16 dport = sk->__sk_common.skc_dport;
dport = ntohs(dport);
FILTER_DPORT
/*
* This tool includes PID and comm context. It's best effort, and may
* be wrong in some situations. It currently works like this:
* - record timestamp on any state < TCP_FIN_WAIT1
* - cache task context on:
* TCP_SYN_SENT: tracing from client
* TCP_LAST_ACK: client-closed from server
* - do output on TCP_CLOSE:
* fetch task context if cached, or use current task
*/
// capture birth time
if (state < TCP_FIN_WAIT1) {
/*
* Matching just ESTABLISHED may be sufficient, provided no code-path
* sets ESTABLISHED without a tcp_set_state() call. Until we know
* that for sure, match all early states to increase chances a
* timestamp is set.
* Note that this needs to be set before the PID filter later on,
* since the PID isn't reliable for these early stages, so we must
* save all timestamps and do the PID filter later when we can.
*/
u64 ts = bpf_ktime_get_ns();
birth.update(&sk, &ts);
}
// record PID & comm on SYN_SENT
if (state == TCP_SYN_SENT || state == TCP_LAST_ACK) {
// now we can PID filter, both here and a little later on for CLOSE
FILTER_PID
struct id_t me = {.pid = pid};
bpf_get_current_comm(&me.task, sizeof(me.task));
whoami.update(&sk, &me);
}
if (state != TCP_CLOSE)
return 0;
// calculate lifespan
u64 *tsp, delta_us;
tsp = birth.lookup(&sk);
if (tsp == 0) {
whoami.delete(&sk); // may not exist
return 0; // missed create
}
delta_us = (bpf_ktime_get_ns() - *tsp) / 1000;
birth.delete(&sk);
// fetch possible cached data, and filter
struct id_t *mep;
mep = whoami.lookup(&sk);
if (mep != 0)
pid = mep->pid;
FILTER_PID
// get throughput stats. see tcp_get_info().
u64 rx_b = 0, tx_b = 0;
struct tcp_sock *tp = (struct tcp_sock *)sk;
rx_b = tp->bytes_received;
tx_b = tp->bytes_acked;
u16 family = sk->__sk_common.skc_family;
FILTER_FAMILY
if (family == AF_INET) {
struct ipv4_data_t data4 = {};
data4.span_us = delta_us;
data4.rx_b = rx_b;
data4.tx_b = tx_b;
data4.ts_us = bpf_ktime_get_ns() / 1000;
data4.saddr = sk->__sk_common.skc_rcv_saddr;
data4.daddr = sk->__sk_common.skc_daddr;
// a workaround until data4 compiles with separate lport/dport
data4.pid = pid;
data4.ports = dport + ((0ULL + lport) << 32);
if (mep == 0) {
bpf_get_current_comm(&data4.task, sizeof(data4.task));
} else {
bpf_probe_read_kernel(&data4.task, sizeof(data4.task), (void *)mep->task);
}
ipv4_events.perf_submit(ctx, &data4, sizeof(data4));
} else /* 6 */ {
struct ipv6_data_t data6 = {};
data6.span_us = delta_us;
data6.rx_b = rx_b;
data6.tx_b = tx_b;
data6.ts_us = bpf_ktime_get_ns() / 1000;
bpf_probe_read_kernel(&data6.saddr, sizeof(data6.saddr),
sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32);
bpf_probe_read_kernel(&data6.daddr, sizeof(data6.daddr),
sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32);
// a workaround until data6 compiles with separate lport/dport
data6.ports = dport + ((0ULL + lport) << 32);
data6.pid = pid;
if (mep == 0) {
bpf_get_current_comm(&data6.task, sizeof(data6.task));
} else {
bpf_probe_read_kernel(&data6.task, sizeof(data6.task), (void *)mep->task);
}
ipv6_events.perf_submit(ctx, &data6, sizeof(data6));
}
if (mep != 0)
whoami.delete(&sk);
return 0;
}
"""
bpf_text_tracepoint = """
TRACEPOINT_PROBE(sock, inet_sock_set_state)
{
if (args->protocol != IPPROTO_TCP)
return 0;
u32 pid = bpf_get_current_pid_tgid() >> 32;
// sk is mostly used as a UUID, and for two tcp stats:
struct sock *sk = (struct sock *)args->skaddr;
// lport is either used in a filter here, or later
u16 lport = args->sport;
FILTER_LPORT
// dport is either used in a filter here, or later
u16 dport = args->dport;
FILTER_DPORT
/*
* This tool includes PID and comm context. It's best effort, and may
* be wrong in some situations. It currently works like this:
* - record timestamp on any state < TCP_FIN_WAIT1
* - cache task context on:
* TCP_SYN_SENT: tracing from client
* TCP_LAST_ACK: client-closed from server
* - do output on TCP_CLOSE:
* fetch task context if cached, or use current task
*/
// capture birth time
if (args->newstate < TCP_FIN_WAIT1) {
/*
* Matching just ESTABLISHED may be sufficient, provided no code-path
* sets ESTABLISHED without a tcp_set_state() call. Until we know
* that for sure, match all early states to increase chances a
* timestamp is set.
* Note that this needs to be set before the PID filter later on,
* since the PID isn't reliable for these early stages, so we must
* save all timestamps and do the PID filter later when we can.
*/
u64 ts = bpf_ktime_get_ns();
birth.update(&sk, &ts);
}
// record PID & comm on SYN_SENT
if (args->newstate == TCP_SYN_SENT || args->newstate == TCP_LAST_ACK) {
// now we can PID filter, both here and a little later on for CLOSE
FILTER_PID
struct id_t me = {.pid = pid};
bpf_get_current_comm(&me.task, sizeof(me.task));
whoami.update(&sk, &me);
}
if (args->newstate != TCP_CLOSE)
return 0;
// calculate lifespan
u64 *tsp, delta_us;
tsp = birth.lookup(&sk);
if (tsp == 0) {
whoami.delete(&sk); // may not exist
return 0; // missed create
}
delta_us = (bpf_ktime_get_ns() - *tsp) / 1000;
birth.delete(&sk);
// fetch possible cached data, and filter
struct id_t *mep;
mep = whoami.lookup(&sk);
if (mep != 0)
pid = mep->pid;
FILTER_PID
u16 family = args->family;
FILTER_FAMILY
// get throughput stats. see tcp_get_info().
u64 rx_b = 0, tx_b = 0;
struct tcp_sock *tp = (struct tcp_sock *)sk;
rx_b = tp->bytes_received;
tx_b = tp->bytes_acked;
if (args->family == AF_INET) {
struct ipv4_data_t data4 = {};
data4.span_us = delta_us;
data4.rx_b = rx_b;
data4.tx_b = tx_b;
data4.ts_us = bpf_ktime_get_ns() / 1000;
__builtin_memcpy(&data4.saddr, args->saddr, sizeof(data4.saddr));
__builtin_memcpy(&data4.daddr, args->daddr, sizeof(data4.daddr));
// a workaround until data4 compiles with separate lport/dport
data4.ports = dport + ((0ULL + lport) << 32);
data4.pid = pid;
if (mep == 0) {
bpf_get_current_comm(&data4.task, sizeof(data4.task));
} else {
bpf_probe_read_kernel(&data4.task, sizeof(data4.task), (void *)mep->task);
}
ipv4_events.perf_submit(args, &data4, sizeof(data4));
} else /* 6 */ {
struct ipv6_data_t data6 = {};
data6.span_us = delta_us;
data6.rx_b = rx_b;
data6.tx_b = tx_b;
data6.ts_us = bpf_ktime_get_ns() / 1000;
__builtin_memcpy(&data6.saddr, args->saddr_v6, sizeof(data6.saddr));
__builtin_memcpy(&data6.daddr, args->daddr_v6, sizeof(data6.daddr));
// a workaround until data6 compiles with separate lport/dport
data6.ports = dport + ((0ULL + lport) << 32);
data6.pid = pid;
if (mep == 0) {
bpf_get_current_comm(&data6.task, sizeof(data6.task));
} else {
bpf_probe_read_kernel(&data6.task, sizeof(data6.task), (void *)mep->task);
}
ipv6_events.perf_submit(args, &data6, sizeof(data6));
}
if (mep != 0)
whoami.delete(&sk);
return 0;
}
"""
if (BPF.tracepoint_exists("sock", "inet_sock_set_state")):
bpf_text += bpf_text_tracepoint
else:
bpf_text += bpf_text_kprobe
# code substitutions
if args.pid:
bpf_text = bpf_text.replace('FILTER_PID',
'if (pid != %s) { return 0; }' % args.pid)
if args.remoteport:
dports = [int(dport) for dport in args.remoteport.split(',')]
dports_if = ' && '.join(['dport != %d' % dport for dport in dports])
bpf_text = bpf_text.replace('FILTER_DPORT',
'if (%s) { birth.delete(&sk); return 0; }' % dports_if)
if args.localport:
lports = [int(lport) for lport in args.localport.split(',')]
lports_if = ' && '.join(['lport != %d' % lport for lport in lports])
bpf_text = bpf_text.replace('FILTER_LPORT',
'if (%s) { birth.delete(&sk); return 0; }' % lports_if)
if args.ipv4:
bpf_text = bpf_text.replace('FILTER_FAMILY',
'if (family != AF_INET) { return 0; }')
elif args.ipv6:
bpf_text = bpf_text.replace('FILTER_FAMILY',
'if (family != AF_INET6) { return 0; }')
bpf_text = bpf_text.replace('FILTER_PID', '')
bpf_text = bpf_text.replace('FILTER_DPORT', '')
bpf_text = bpf_text.replace('FILTER_LPORT', '')
bpf_text = bpf_text.replace('FILTER_FAMILY', '')
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
#
# Setup output formats
#
# Don't change the default output (next 2 lines): this fits in 80 chars. I
# know it doesn't have NS or UIDs etc. I know. If you really, really, really
# need to add columns, columns that solve real actual problems, I'd start by
# adding an extended mode (-x) to included those columns.
#
header_string = "%-5s %-10.10s %s%-15s %-5s %-15s %-5s %5s %5s %s"
format_string = "%-5d %-10.10s %s%-15s %-5d %-15s %-5d %5d %5d %.2f"
if args.wide:
header_string = "%-5s %-16.16s %-2s %-39s %-5s %-39s %-5s %6s %6s %s"
format_string = "%-5d %-16.16s %-2s %-39s %-5s %-39s %-5d %6d %6d %.2f"
if args.csv:
header_string = "%s,%s,%s,%s,%s,%s,%s,%s,%s,%s"
format_string = "%d,%s,%s,%s,%s,%s,%d,%d,%d,%.2f"
# process event
def print_ipv4_event(cpu, data, size):
event = b["ipv4_events"].event(data)
global start_ts
if args.time:
if args.csv:
print("%s," % strftime("%H:%M:%S"), end="")
else:
print("%-8s " % strftime("%H:%M:%S"), end="")
if args.timestamp:
if start_ts == 0:
start_ts = event.ts_us
delta_s = (float(event.ts_us) - start_ts) / 1000000
if args.csv:
print("%.6f," % delta_s, end="")
else:
print("%-9.6f " % delta_s, end="")
print(format_string % (event.pid, event.task.decode('utf-8', 'replace'),
"4" if args.wide or args.csv else "",
inet_ntop(AF_INET, pack("I", event.saddr)), event.ports >> 32,
inet_ntop(AF_INET, pack("I", event.daddr)), event.ports & 0xffffffff,
event.tx_b / 1024, event.rx_b / 1024, float(event.span_us) / 1000))
def print_ipv6_event(cpu, data, size):
event = b["ipv6_events"].event(data)
global start_ts
if args.time:
if args.csv:
print("%s," % strftime("%H:%M:%S"), end="")
else:
print("%-8s " % strftime("%H:%M:%S"), end="")
if args.timestamp:
if start_ts == 0:
start_ts = event.ts_us
delta_s = (float(event.ts_us) - start_ts) / 1000000
if args.csv:
print("%.6f," % delta_s, end="")
else:
print("%-9.6f " % delta_s, end="")
print(format_string % (event.pid, event.task.decode('utf-8', 'replace'),
"6" if args.wide or args.csv else "",
inet_ntop(AF_INET6, event.saddr), event.ports >> 32,
inet_ntop(AF_INET6, event.daddr), event.ports & 0xffffffff,
event.tx_b / 1024, event.rx_b / 1024, float(event.span_us) / 1000))
# initialize BPF
b = BPF(text=bpf_text)
# header
if args.time:
if args.csv:
print("%s," % ("TIME"), end="")
else:
print("%-8s " % ("TIME"), end="")
if args.timestamp:
if args.csv:
print("%s," % ("TIME(s)"), end="")
else:
print("%-9s " % ("TIME(s)"), end="")
print(header_string % ("PID", "COMM",
"IP" if args.wide or args.csv else "", "LADDR",
"LPORT", "RADDR", "RPORT", "TX_KB", "RX_KB", "MS"))
start_ts = 0
# read events
b["ipv4_events"].open_perf_buffer(print_ipv4_event, page_cnt=64)
b["ipv6_events"].open_perf_buffer(print_ipv6_event, page_cnt=64)
while 1:
try:
b.perf_buffer_poll()
except KeyboardInterrupt:
exit()
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