tools/tcpaccept.py - platform/external/bcc - Git at Google

 #!/usr/bin/env python
 # @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()
	#!/usr/bin/env python
	# @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()