| Current File : //proc/960276/root/sbin/tcpaccept-bpfcc |
#! /usr/bin/python3
# @lint-avoid-python-3-compatibility-imports
#
# tcpaccept Trace TCP accept()s.
# For Linux, uses BCC, eBPF. Embedded C.
#
# USAGE: tcpaccept [-h] [-T] [-t] [-p PID] [-P PORTS] [-4 | -6]
#
# This uses dynamic tracing of the kernel inet_csk_accept() socket function
# (from tcp_prot.accept), and will need to be modified to match kernel changes.
#
# Copyright (c) 2015 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 13-Oct-2015 Brendan Gregg Created this.
# 14-Feb-2016 " " Switch to bpf_perf_output.
from __future__ import print_function
from bcc.containers import filter_by_containers
from bcc import BPF
from socket import inet_ntop, AF_INET, AF_INET6
from struct import pack
import argparse
from bcc.utils import printb
from time import strftime
# arguments
examples = """examples:
./tcpaccept # trace all TCP accept()s
./tcpaccept -t # include timestamps
./tcpaccept -P 80,81 # only trace port 80 and 81
./tcpaccept -p 181 # only trace PID 181
./tcpaccept --cgroupmap mappath # only trace cgroups in this BPF map
./tcpaccept --mntnsmap mappath # only trace mount namespaces in the map
./tcpaccept -4 # trace IPv4 family
./tcpaccept -6 # trace IPv6 family
"""
parser = argparse.ArgumentParser(
description="Trace TCP accepts",
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")
parser.add_argument("-p", "--pid",
help="trace this PID only")
parser.add_argument("-P", "--port",
help="comma-separated list of local 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("--cgroupmap",
help="trace cgroups in this BPF map only")
parser.add_argument("--mntnsmap",
help="trace mount namespaces in this BPF map 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 <net/sock.h>
#include <bcc/proto.h>
// separate data structs for ipv4 and ipv6
struct ipv4_data_t {
u64 ts_us;
u32 pid;
u32 saddr;
u32 daddr;
u64 ip;
u16 lport;
u16 dport;
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 ip;
u16 lport;
u16 dport;
char task[TASK_COMM_LEN];
};
BPF_PERF_OUTPUT(ipv6_events);
"""
#
# The following code uses kprobes to instrument inet_csk_accept().
# On Linux 4.16 and later, we could use sock:inet_sock_set_state
# tracepoint for efficiency, but it may output wrong PIDs. This is
# because sock:inet_sock_set_state may run outside of process context.
# Hence, we stick to kprobes until we find a proper solution.
#
bpf_text_kprobe = """
int kretprobe__inet_csk_accept(struct pt_regs *ctx)
{
if (container_should_be_filtered()) {
return 0;
}
struct sock *newsk = (struct sock *)PT_REGS_RC(ctx);
u32 pid = bpf_get_current_pid_tgid() >> 32;
##FILTER_PID##
if (newsk == NULL)
return 0;
// check this is TCP
u16 protocol = 0;
// workaround for reading the sk_protocol bitfield:
// Following comments add by Joe Yin:
// Unfortunately,it can not work since Linux 4.10,
// because the sk_wmem_queued is not following the bitfield of sk_protocol.
// And the following member is sk_gso_max_segs.
// So, we can use this:
// bpf_probe_read_kernel(&protocol, 1, (void *)((u64)&newsk->sk_gso_max_segs) - 3);
// In order to diff the pre-4.10 and 4.10+ ,introduce the variables gso_max_segs_offset,sk_lingertime,
// sk_lingertime is closed to the gso_max_segs_offset,and
// the offset between the two members is 4
int gso_max_segs_offset = offsetof(struct sock, sk_gso_max_segs);
int sk_lingertime_offset = offsetof(struct sock, sk_lingertime);
// Since kernel v5.6 sk_protocol is its own u16 field and gso_max_segs
// precedes sk_lingertime.
if (sk_lingertime_offset - gso_max_segs_offset == 2)
protocol = newsk->sk_protocol;
else if (sk_lingertime_offset - gso_max_segs_offset == 4)
// 4.10+ with little endian
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
protocol = *(u8 *)((u64)&newsk->sk_gso_max_segs - 3);
else
// pre-4.10 with little endian
protocol = *(u8 *)((u64)&newsk->sk_wmem_queued - 3);
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
// 4.10+ with big endian
protocol = *(u8 *)((u64)&newsk->sk_gso_max_segs - 1);
else
// pre-4.10 with big endian
protocol = *(u8 *)((u64)&newsk->sk_wmem_queued - 1);
#else
# error "Fix your compiler's __BYTE_ORDER__?!"
#endif
if (protocol != IPPROTO_TCP)
return 0;
// pull in details
u16 family = 0, lport = 0, dport;
family = newsk->__sk_common.skc_family;
lport = newsk->__sk_common.skc_num;
dport = newsk->__sk_common.skc_dport;
dport = ntohs(dport);
##FILTER_FAMILY##
##FILTER_PORT##
if (family == AF_INET) {
struct ipv4_data_t data4 = {.pid = pid, .ip = 4};
data4.ts_us = bpf_ktime_get_ns() / 1000;
data4.saddr = newsk->__sk_common.skc_rcv_saddr;
data4.daddr = newsk->__sk_common.skc_daddr;
data4.lport = lport;
data4.dport = dport;
bpf_get_current_comm(&data4.task, sizeof(data4.task));
ipv4_events.perf_submit(ctx, &data4, sizeof(data4));
} else if (family == AF_INET6) {
struct ipv6_data_t data6 = {.pid = pid, .ip = 6};
data6.ts_us = bpf_ktime_get_ns() / 1000;
bpf_probe_read_kernel(&data6.saddr, sizeof(data6.saddr),
&newsk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32);
bpf_probe_read_kernel(&data6.daddr, sizeof(data6.daddr),
&newsk->__sk_common.skc_v6_daddr.in6_u.u6_addr32);
data6.lport = lport;
data6.dport = dport;
bpf_get_current_comm(&data6.task, sizeof(data6.task));
ipv6_events.perf_submit(ctx, &data6, sizeof(data6));
}
// else drop
return 0;
}
"""
bpf_text += bpf_text_kprobe
# code substitutions
if args.pid:
bpf_text = bpf_text.replace('##FILTER_PID##',
'if (pid != %s) { return 0; }' % args.pid)
else:
bpf_text = bpf_text.replace('##FILTER_PID##', '')
if args.port:
lports = [int(lport) for lport in args.port.split(',')]
lports_if = ' && '.join(['lport != %d' % lport for lport in lports])
bpf_text = bpf_text.replace('##FILTER_PORT##',
'if (%s) { 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 = filter_by_containers(args) + bpf_text
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
bpf_text = bpf_text.replace('##FILTER_PORT##', '')
bpf_text = bpf_text.replace('##FILTER_FAMILY##', '')
# process event
def print_ipv4_event(cpu, data, size):
event = b["ipv4_events"].event(data)
global start_ts
if args.time:
printb(b"%-9s" % strftime("%H:%M:%S").encode('ascii'), nl="")
if args.timestamp:
if start_ts == 0:
start_ts = event.ts_us
printb(b"%-9.3f" % ((float(event.ts_us) - start_ts) / 1000000), nl="")
printb(b"%-7d %-12.12s %-2d %-16s %-5d %-16s %-5d" % (event.pid,
event.task, event.ip,
inet_ntop(AF_INET, pack("I", event.daddr)).encode(),
event.dport,
inet_ntop(AF_INET, pack("I", event.saddr)).encode(),
event.lport))
def print_ipv6_event(cpu, data, size):
event = b["ipv6_events"].event(data)
global start_ts
if args.time:
printb(b"%-9s" % strftime("%H:%M:%S").encode('ascii'), nl="")
if args.timestamp:
if start_ts == 0:
start_ts = event.ts_us
printb(b"%-9.3f" % ((float(event.ts_us) - start_ts) / 1000000), nl="")
printb(b"%-7d %-12.12s %-2d %-16s %-5d %-16s %-5d" % (event.pid,
event.task, event.ip,
inet_ntop(AF_INET6, event.daddr).encode(),
event.dport,
inet_ntop(AF_INET6, event.saddr).encode(),
event.lport))
# initialize BPF
b = BPF(text=bpf_text)
# header
if args.time:
print("%-9s" % ("TIME"), end="")
if args.timestamp:
print("%-9s" % ("TIME(s)"), end="")
print("%-7s %-12s %-2s %-16s %-5s %-16s %-5s" % ("PID", "COMM", "IP", "RADDR",
"RPORT", "LADDR", "LPORT"))
start_ts = 0
# read events
b["ipv4_events"].open_perf_buffer(print_ipv4_event)
b["ipv6_events"].open_perf_buffer(print_ipv6_event)
while 1:
try:
b.perf_buffer_poll()
except KeyboardInterrupt:
exit()