- tools/[opensnoop](tools/opensnoop): Trace open() syscalls. [Examples](tools/opensnoop_example.txt).
- tools/[pidpersec](tools/pidpersec): Count new processes (via fork). [Examples](tools/pidpersec_example.txt).
- tools/[syncsnoop](tools/syncsnoop): Trace sync() syscall. [Examples](tools/syncsnoop_example.txt).
-- tools/[tcpv4connect](tools/tcpv4connect): Trace TCP IPv4 active connections. [Examples](tools/tcpv4connect_example.txt).
+- tools/[tcpaccept](tools/tcpaccept): Trace TCP passive connections (accept()). [Examples](tools/tcpaccept_example.txt).
+- tools/[tcpv4connect](tools/tcpv4connect): Trace TCP IPv4 active connections (connect()). [Examples](tools/tcpv4connect_example.txt).
- tools/[vfscount](tools/vfscount) tools/[vfscount.c](tools/vfscount.c): Count VFS calls. [Examples](tools/vfscount_example.txt).
- tools/[vfsstat](tools/vfsstat) tools/[vfsstat.c](tools/vfsstat.c): Count some VFS calls, with column output. [Examples](tools/vfsstat_example.txt).
--- /dev/null
+.TH tcpaccept 8 "2015-08-25" "USER COMMANDS"
+.SH NAME
+tcpaccept \- Trace TCP passive connections (accept()). Uses Linux eBPF/bcc.
+.SH SYNOPSIS
+.B tcpaccept [\-h] [\-t] [\-x] [\-p PID]
+.SH DESCRIPTION
+This tool traces passive TCP connections (eg, via an accept() syscall;
+connect() are active connections). This can be useful for general
+troubleshooting to see what new connections the local server is accepting.
+
+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.
+This also traces DCCP traffic; check for future versions where this should
+be filtered.
+
+This tool only traces successful TCP accept()s. Connection attempts to closed
+ports will not be shown (those can be traced via other functions).
+
+Since this uses BPF, only the root user can use this tool.
+.SH REQUIREMENTS
+CONFIG_BPF and bcc.
+.SH OPTIONS
+.TP
+\-h
+Print usage message.
+.TP
+\-t
+Include a timestamp column.
+.TP
+\-p PID
+Trace this process ID only (filtered in-kernel).
+.SH EXAMPLES
+.TP
+Trace all passive TCP connections (accept()s):
+#
+.B tcpaccept
+.TP
+Trace all TCP accepts, and include timestamps:
+#
+.B tcpconnect \-t
+.TP
+Trace PID 181 only:
+#
+.B tcpconnect \-p 181
+.SH FIELDS
+.TP
+TIME(s)
+Time of the event, in seconds.
+.TP
+PID
+Process ID
+.TP
+COMM
+Process name
+.TP
+IP
+IP address family (4 or 6)
+.TP
+RADDR
+Remote IP address. IPv4 as a dotted quad, IPv6 shows "..." then the last 4
+bytes (check for newer versions of this tool for the full address).
+.TP
+LADDR
+Local IP address. IPv4 as a dotted quad, IPv6 shows "..." then the last 4
+bytes (check for newer versions of this tool for the full address).
+.TP
+LPORT
+Local port
+.SH OVERHEAD
+This traces the kernel inet_csk_accept function and prints output for each event.
+The rate of this depends on your server application. If it is a web or proxy server
+accepting many tens of thousands of connections per second, then the overhead
+of this tool may be measurable (although, still a lot better than tracing
+every packet). If it is less than a thousand a second, then the overhead is
+expected to be negligible. Test and understand this overhead before use.
+.SH SOURCE
+This is from bcc.
+.IP
+https://github.com/iovisor/bcc
+.PP
+Also look in the bcc distribution for a companion _examples.txt file containing
+example usage, output, and commentary for this tool.
+.SH OS
+Linux
+.SH STABILITY
+Unstable - in development.
+.SH AUTHOR
+Brendan Gregg
+.SH SEE ALSO
+tcpv4connect(8), funccount(8), tcpdump(8)
.TH tcpv4connect 8 "2015-08-25" "USER COMMANDS"
.SH NAME
-tcpv4connect \- Trace TCP IPv4 active connections. Uses Linux eBPF/bcc.
+tcpv4connect \- Trace TCP IPv4 active connections (connect()). Uses Linux eBPF/bcc.
.SH SYNOPSIS
.B tcpv4connect [\-h] [\-t] [\-x] [\-p PID]
.SH DESCRIPTION
.SH AUTHOR
Brendan Gregg
.SH SEE ALSO
-funccount(8), tcpdump(8)
+tcpaccept(8), funccount(8), tcpdump(8)
--- /dev/null
+#!/usr/bin/python
+#
+# tcpaccept Trace TCP accept()s.
+# For Linux, uses BCC, eBPF. Embedded C.
+#
+# USAGE: tcpaccept [-h] [-t] [-p PID]
+#
+# 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.
+# This also traces DCCP traffic; check for future versions where this should
+# be filtered (should be done via "sk_protocol != IPPROTO_TCP").
+#
+# IPv4 addresses are printed as dotted quads. For IPv6 addresses, the last four
+# bytes are printed after "..."; check for future versions with better IPv6
+# support.
+#
+# Copyright (c) 2015 Brendan Gregg.
+# Licensed under the Apache License, Version 2.0 (the "License")
+#
+# 13-Oct-2015 Brendan Gregg Created this.
+
+from __future__ import print_function
+from bcc import BPF
+import argparse
+
+# arguments
+examples = """examples:
+ ./tcpaccept # trace all open() syscalls
+ ./tcpaccept -t # include timestamps
+ ./tcpaccept -p 181 # only trace PID 181
+"""
+parser = argparse.ArgumentParser(
+ description="Trace TCP accepts",
+ formatter_class=argparse.RawDescriptionHelpFormatter,
+ epilog=examples)
+parser.add_argument("-t", "--timestamp", action="store_true",
+ help="include timestamp on output")
+parser.add_argument("-p", "--pid",
+ help="trace this PID only")
+args = parser.parse_args()
+debug = 0
+
+# define BPF program
+bpf_text = """
+#include <uapi/linux/ptrace.h>
+#include <net/sock.h>
+#include <bcc/proto.h>
+
+int kretprobe__inet_csk_accept(struct pt_regs *ctx)
+{
+ struct sock *newsk = (struct sock *)ctx->ax;
+ u32 pid = bpf_get_current_pid_tgid();
+
+ if (newsk == NULL)
+ return 0;
+
+ // pull in details
+ u16 family = 0, lport = 0;
+ u32 saddr = 0, daddr = 0;
+ bpf_probe_read(&family, sizeof(family), &newsk->__sk_common.skc_family);
+ bpf_probe_read(&lport, sizeof(lport), &newsk->__sk_common.skc_num);
+ if (family == AF_INET) {
+ bpf_probe_read(&saddr, sizeof(saddr),
+ &newsk->__sk_common.skc_rcv_saddr);
+ bpf_probe_read(&daddr, sizeof(daddr),
+ &newsk->__sk_common.skc_daddr);
+
+ // output
+ bpf_trace_printk("4 %x %x %d\\n", daddr, saddr, lport);
+ } else if (family == AF_INET6) {
+ // just grab the last 4 bytes for now
+ bpf_probe_read(&saddr, sizeof(saddr),
+ &newsk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32[3]);
+ bpf_probe_read(&daddr, sizeof(daddr),
+ &newsk->__sk_common.skc_v6_daddr.in6_u.u6_addr32[3]);
+
+ // output and flip byte order of addresses
+ bpf_trace_printk("6 %x %x %d\\n", bpf_ntohl(daddr),
+ bpf_ntohl(saddr), lport);
+ }
+ // else drop
+
+ return 0;
+}
+"""
+
+# code substitutions
+if args.pid:
+ bpf_text = bpf_text.replace('FILTER',
+ 'if (pid != %s) { return 0; }' % args.pid)
+else:
+ bpf_text = bpf_text.replace('FILTER', '')
+if debug:
+ print(bpf_text)
+
+# initialize BPF
+b = BPF(text=bpf_text)
+
+# header
+if args.timestamp:
+ print("%-9s" % ("TIME(s)"), end="")
+print("%-6s %-12s %-2s %-16s %-16s %-4s" % ("PID", "COMM", "IP", "RADDR",
+ "LADDR", "LPORT"))
+
+start_ts = 0
+
+def inet_ntoa(addr):
+ dq = ''
+ for i in range(0, 4):
+ dq = dq + str(addr & 0xff)
+ if (i != 3):
+ dq = dq + '.'
+ addr = addr >> 8
+ return dq
+
+# format output
+while 1:
+ (task, pid, cpu, flags, ts, msg) = b.trace_fields()
+ (ip_s, raddr_hs, laddr_hs, lport_s) = msg.split(" ")
+
+ if args.timestamp:
+ if start_ts == 0:
+ start_ts = ts
+ print("%-9.3f" % (ts - start_ts), end="")
+ print("%-6d %-12.12s %-2s %-16s %-16s %-4s" % (pid, task, ip_s,
+ inet_ntoa(int(raddr_hs, 16)) if ip_s == "4" else "..." + raddr_hs,
+ inet_ntoa(int(laddr_hs, 16)) if ip_s == "4" else "..." + laddr_hs,
+ lport_s))
--- /dev/null
+Demonstrations of tcpaccept, the Linux eBPF/bcc version.
+
+
+This tool traces the kernel function accepting TCP socket connections (eg, a
+passive connection via accept(); not connect()). Some example output (IP
+addresses changed to protect the innocent):
+
+# ./tcpaccept
+PID COMM IP RADDR LADDR LPORT
+907 sshd 4 192.168.56.1 192.168.56.102 22
+907 sshd 4 127.0.0.1 127.0.0.1 22
+5389 perl 6 ...fec0ae21 ...fec0ae21 7001
+
+This output shows three connections, two to PID 907, an "sshd" process listening
+on port 22, and one to a "perl" process listening on port 7001.
+
+The sshd connections were IPv4, and the addresses are printed as dotted quads.
+The perl connection was IPv6, and the last 4 bytes of each address is printed
+(for now; check for updated versions).
+
+The overhead of this tool should be negligible, since it is only tracing the
+kernel function performing accept. It is not tracing every packet and then
+filtering.
+
+This tool only traces successful TCP accept()s. Connection attempts to closed
+ports will not be shown (those can be traced via other functions).
+
+
+The -t option prints a timestamp column:
+
+# ./tcpaccept -t
+TIME(s) PID COMM IP RADDR LADDR LPORT
+0.000 907 sshd 4 127.0.0.1 127.0.0.1 22
+0.992 907 sshd 4 127.0.0.1 127.0.0.1 22
+1.984 907 sshd 4 127.0.0.1 127.0.0.1 22
+
+
+USAGE message:
+
+# ./tcpaccept -h
+usage: tcpaccept [-h] [-t] [-p PID]
+
+Trace TCP accepts
+
+optional arguments:
+ -h, --help show this help message and exit
+ -t, --timestamp include timestamp on output
+ -p PID, --pid PID trace this PID only
+
+examples:
+ ./tcpaccept # trace all open() syscalls
+ ./tcpaccept -t # include timestamps
+ ./tcpaccept -p 181 # only trace PID 181
projects / platform / upstream / bcc.git / commitdiff