--- /dev/null
+#!/usr/bin/python
+#
+# tcpv4tracer Trace TCP connections.
+# For Linux, uses BCC, eBPF. Embedded C.
+#
+# USAGE: tcpv4tracer [-h] [-v] [-p PID] [-N NETNS]
+#
+# You should generally try to avoid writing long scripts that measure multiple
+# functions and walk multiple kernel structures, as they will be a burden to
+# maintain as the kernel changes.
+# The following code should be replaced, and simplified, when static TCP probes
+# exist.
+#
+# Copyright 2017 Kinvolk GmbH
+#
+# Licensed under the Apache License, Version 2.0 (the "License")
+from __future__ import print_function
+from bcc import BPF
+
+import argparse as ap
+import ctypes
+from socket import inet_ntop, AF_INET, AF_INET6
+from struct import pack
+
+parser = ap.ArgumentParser(description="Trace TCP connections",
+ formatter_class=ap.RawDescriptionHelpFormatter)
+parser.add_argument("-p", "--pid", default=0, type=int,
+ help="trace this PID only")
+parser.add_argument("-N", "--netns", default=0, type=int,
+ help="trace this Network Namespace only")
+parser.add_argument("-v", "--verbose", action="store_true",
+ help="include Network Namespace in the output")
+args = parser.parse_args()
+
+bpf_text = """
+#include <uapi/linux/ptrace.h>
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wtautological-compare"
+#include <net/sock.h>
+#pragma clang diagnostic pop
+#include <net/inet_sock.h>
+#include <net/net_namespace.h>
+#include <bcc/proto.h>
+
+#define TCP_EVENT_TYPE_CONNECT 1
+#define TCP_EVENT_TYPE_ACCEPT 2
+#define TCP_EVENT_TYPE_CLOSE 3
+
+struct tcp_ipv4_event_t {
+ u32 type;
+ u32 pid;
+ char comm[TASK_COMM_LEN];
+ u8 ip;
+ u32 saddr;
+ u32 daddr;
+ u16 sport;
+ u16 dport;
+ u32 netns;
+};
+BPF_PERF_OUTPUT(tcp_ipv4_event);
+
+struct tcp_ipv6_event_t {
+ u32 type;
+ u32 pid;
+ char comm[TASK_COMM_LEN];
+ u8 ip;
+ unsigned __int128 saddr;
+ unsigned __int128 daddr;
+ u16 sport;
+ u16 dport;
+ u32 netns;
+};
+BPF_PERF_OUTPUT(tcp_ipv6_event);
+
+// tcp_set_state doesn't run in the context of the process that initiated the
+// connection so we need to store a map TUPLE -> PID to send the right PID on
+// the event
+struct ipv4_tuple_t {
+ u32 saddr;
+ u32 daddr;
+ u16 sport;
+ u16 dport;
+ u32 netns;
+};
+
+struct ipv6_tuple_t {
+ unsigned __int128 saddr;
+ unsigned __int128 daddr;
+ u16 sport;
+ u16 dport;
+ u32 netns;
+};
+
+struct pid_comm_t {
+ u64 pid;
+ char comm[TASK_COMM_LEN];
+};
+
+BPF_HASH(tuplepid_ipv4, struct ipv4_tuple_t, struct pid_comm_t);
+BPF_HASH(tuplepid_ipv6, struct ipv6_tuple_t, struct pid_comm_t);
+
+BPF_HASH(connectsock, u64, struct sock *);
+
+static int read_ipv4_tuple(struct ipv4_tuple_t *tuple, struct sock *skp)
+{
+ u32 saddr = 0, daddr = 0, net_ns_inum = 0;
+ u16 sport = 0, dport = 0;
+ possible_net_t skc_net;
+
+ bpf_probe_read(&saddr, sizeof(saddr), &skp->__sk_common.skc_rcv_saddr);
+ bpf_probe_read(&daddr, sizeof(daddr), &skp->__sk_common.skc_daddr);
+ bpf_probe_read(&sport, sizeof(sport),
+ &((struct inet_sock *)skp)->inet_sport);
+ bpf_probe_read(&dport, sizeof(dport), &skp->__sk_common.skc_dport);
+#ifdef CONFIG_NET_NS
+ bpf_probe_read(&skc_net, sizeof(skc_net), &skp->__sk_common.skc_net);
+ bpf_probe_read(&net_ns_inum, sizeof(net_ns_inum), &skc_net.net->ns.inum);
+#else
+ net_ns_inum = 0;
+#endif
+
+ ##FILTER_NETNS##
+
+ tuple->saddr = saddr;
+ tuple->daddr = daddr;
+ tuple->sport = sport;
+ tuple->dport = dport;
+ tuple->netns = net_ns_inum;
+
+ // if addresses or ports are 0, ignore
+ if (saddr == 0 || daddr == 0 || sport == 0 || dport == 0) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static int read_ipv6_tuple(struct ipv6_tuple_t *tuple, struct sock *skp)
+{
+ u32 net_ns_inum = 0;
+ u16 sport = 0, dport = 0;
+ unsigned __int128 saddr = 0, daddr = 0;
+ possible_net_t skc_net;
+
+ bpf_probe_read(&sport, sizeof(sport),
+ &((struct inet_sock *)skp)->inet_sport);
+ bpf_probe_read(&dport, sizeof(dport), &skp->__sk_common.skc_dport);
+ bpf_probe_read(&saddr, sizeof(saddr),
+ &skp->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32);
+ bpf_probe_read(&daddr, sizeof(daddr),
+ &skp->__sk_common.skc_v6_daddr.in6_u.u6_addr32);
+#ifdef CONFIG_NET_NS
+ bpf_probe_read(&skc_net, sizeof(skc_net), &skp->__sk_common.skc_net);
+ bpf_probe_read(&net_ns_inum, sizeof(net_ns_inum), &skc_net.net->ns.inum);
+#else
+ net_ns_inum = 0;
+#endif
+
+ ##FILTER_NETNS##
+
+ tuple->saddr = saddr;
+ tuple->daddr = daddr;
+ tuple->sport = sport;
+ tuple->dport = dport;
+ tuple->netns = net_ns_inum;
+
+ // if addresses or ports are 0, ignore
+ if (saddr == 0 || daddr == 0 || sport == 0 || dport == 0) {
+ return 0;
+ }
+
+ return 1;
+}
+
+static bool check_family(struct sock *sk, u16 expected_family) {
+ u64 zero = 0;
+ u16 family = 0;
+
+ bpf_probe_read(&family, sizeof(family), &sk->__sk_common.skc_family);
+
+ return family == expected_family;
+}
+
+int trace_connect_v4_entry(struct pt_regs *ctx, struct sock *sk)
+{
+ u64 pid = bpf_get_current_pid_tgid();
+
+ ##FILTER_PID##
+
+ // stash the sock ptr for lookup on return
+ connectsock.update(&pid, &sk);
+
+ return 0;
+}
+
+int trace_connect_v4_return(struct pt_regs *ctx)
+{
+ int ret = PT_REGS_RC(ctx);
+ u64 pid = bpf_get_current_pid_tgid();
+
+ struct sock **skpp;
+ skpp = connectsock.lookup(&pid);
+ if (skpp == 0) {
+ return 0; // missed entry
+ }
+
+ connectsock.delete(&pid);
+
+ if (ret != 0) {
+ // failed to send SYNC packet, may not have populated
+ // socket __sk_common.{skc_rcv_saddr, ...}
+ return 0;
+ }
+
+ // pull in details
+ struct sock *skp = *skpp;
+ struct ipv4_tuple_t t = { };
+ if (!read_ipv4_tuple(&t, skp)) {
+ return 0;
+ }
+
+ struct pid_comm_t p = { };
+ p.pid = pid;
+ bpf_get_current_comm(&p.comm, sizeof(p.comm));
+
+ tuplepid_ipv4.update(&t, &p);
+
+ return 0;
+}
+
+int trace_connect_v6_entry(struct pt_regs *ctx, struct sock *sk)
+{
+ u64 pid = bpf_get_current_pid_tgid();
+
+ ##FILTER_PID##
+
+ // stash the sock ptr for lookup on return
+ connectsock.update(&pid, &sk);
+
+ return 0;
+}
+
+int trace_connect_v6_return(struct pt_regs *ctx)
+{
+ int ret = PT_REGS_RC(ctx);
+ u64 pid = bpf_get_current_pid_tgid();
+
+ struct sock **skpp;
+ skpp = connectsock.lookup(&pid);
+ if (skpp == 0) {
+ return 0; // missed entry
+ }
+
+ connectsock.delete(&pid);
+
+ if (ret != 0) {
+ // failed to send SYNC packet, may not have populated
+ // socket __sk_common.{skc_rcv_saddr, ...}
+ return 0;
+ }
+
+ // pull in details
+ struct sock *skp = *skpp;
+ struct ipv6_tuple_t t = { };
+ if (!read_ipv6_tuple(&t, skp)) {
+ return 0;
+ }
+
+ struct pid_comm_t p = { };
+ p.pid = pid;
+ bpf_get_current_comm(&p.comm, sizeof(p.comm));
+
+ tuplepid_ipv6.update(&t, &p);
+
+ return 0;
+}
+
+int trace_tcp_set_state_entry(struct pt_regs *ctx, struct sock *sk, int state)
+{
+ if (state != TCP_ESTABLISHED && state != TCP_CLOSE) {
+ return 0;
+ }
+
+ struct sock *skp;
+ bpf_probe_read(&skp, sizeof(struct sock *), &sk);
+
+ u8 ipver = 0;
+ if (check_family(skp, AF_INET)) {
+ ipver = 4;
+ struct ipv4_tuple_t t = { };
+ if (!read_ipv4_tuple(&t, skp)) {
+ return 0;
+ }
+
+ if (state == TCP_CLOSE) {
+ tuplepid_ipv4.delete(&t);
+ return 0;
+ }
+
+ struct pid_comm_t *p;
+ p = tuplepid_ipv4.lookup(&t);
+ if (p == 0) {
+ return 0; // missed entry
+ }
+
+ struct tcp_ipv4_event_t evt4 = { };
+ evt4.type = TCP_EVENT_TYPE_CONNECT;
+ evt4.pid = p->pid >> 32;
+ evt4.ip = ipver;
+ evt4.saddr = t.saddr;
+ evt4.daddr = t.daddr;
+ evt4.sport = ntohs(t.sport);
+ evt4.dport = ntohs(t.dport);
+ evt4.netns = t.netns;
+
+ int i;
+ for (i = 0; i < TASK_COMM_LEN; i++) {
+ evt4.comm[i] = p->comm[i];
+ }
+
+ tcp_ipv4_event.perf_submit(ctx, &evt4, sizeof(evt4));
+ tuplepid_ipv4.delete(&t);
+ } else if (check_family(skp, AF_INET6)) {
+ ipver = 6;
+ struct ipv6_tuple_t t = { };
+ if (!read_ipv6_tuple(&t, skp)) {
+ return 0;
+ }
+
+ if (state == TCP_CLOSE) {
+ tuplepid_ipv6.delete(&t);
+ return 0;
+ }
+
+ struct pid_comm_t *p;
+ p = tuplepid_ipv6.lookup(&t);
+ if (p == 0) {
+ return 0; // missed entry
+ }
+
+ struct tcp_ipv6_event_t evt6 = { };
+ evt6.type = TCP_EVENT_TYPE_CONNECT;
+ evt6.pid = p->pid >> 32;
+ evt6.ip = ipver;
+ evt6.saddr = t.saddr;
+ evt6.daddr = t.daddr;
+ evt6.sport = ntohs(t.sport);
+ evt6.dport = ntohs(t.dport);
+ evt6.netns = t.netns;
+
+ int i;
+ for (i = 0; i < TASK_COMM_LEN; i++) {
+ evt6.comm[i] = p->comm[i];
+ }
+
+ tcp_ipv6_event.perf_submit(ctx, &evt6, sizeof(evt6));
+ tuplepid_ipv6.delete(&t);
+ }
+ // else drop
+
+ return 0;
+}
+
+int trace_close_entry(struct pt_regs *ctx, struct sock *sk)
+{
+ u64 pid = bpf_get_current_pid_tgid();
+
+ ##FILTER_PID##
+
+ // pull in details
+ struct sock *skp;
+ bpf_probe_read(&skp, sizeof(struct sock *), &sk);
+
+ u8 oldstate = 0;
+ bpf_probe_read(&oldstate, sizeof(oldstate), (u8 *)&skp->sk_state);
+ // Don't generate close events for connections that were never
+ // established in the first place.
+ if (oldstate == TCP_SYN_SENT ||
+ oldstate == TCP_SYN_RECV ||
+ oldstate == TCP_NEW_SYN_RECV)
+ return 0;
+
+ u8 ipver = 0;
+ if (check_family(skp, AF_INET)) {
+ ipver = 4;
+ struct ipv4_tuple_t t = { };
+ if (!read_ipv4_tuple(&t, skp)) {
+ return 0;
+ }
+
+ struct tcp_ipv4_event_t evt4 = { };
+ evt4.type = TCP_EVENT_TYPE_CLOSE;
+ evt4.pid = pid >> 32;
+ evt4.ip = ipver;
+ evt4.saddr = t.saddr;
+ evt4.daddr = t.daddr;
+ evt4.sport = ntohs(t.sport);
+ evt4.dport = ntohs(t.dport);
+ evt4.netns = t.netns;
+ bpf_get_current_comm(&evt4.comm, sizeof(evt4.comm));
+
+ tcp_ipv4_event.perf_submit(ctx, &evt4, sizeof(evt4));
+ } else if (check_family(skp, AF_INET6)) {
+ ipver = 6;
+ struct ipv6_tuple_t t = { };
+ if (!read_ipv6_tuple(&t, skp)) {
+ return 0;
+ }
+
+ struct tcp_ipv6_event_t evt6 = { };
+ evt6.type = TCP_EVENT_TYPE_CLOSE;
+ evt6.pid = pid >> 32;
+ evt6.ip = ipver;
+ evt6.saddr = t.saddr;
+ evt6.daddr = t.daddr;
+ evt6.sport = ntohs(t.sport);
+ evt6.dport = ntohs(t.dport);
+ evt6.netns = t.netns;
+ bpf_get_current_comm(&evt6.comm, sizeof(evt6.comm));
+
+ tcp_ipv6_event.perf_submit(ctx, &evt6, sizeof(evt6));
+ }
+ // else drop
+
+ return 0;
+};
+
+int trace_accept_return(struct pt_regs *ctx)
+{
+ struct sock *newsk = (struct sock *)PT_REGS_RC(ctx);
+ u64 pid = bpf_get_current_pid_tgid();
+
+ ##FILTER_PID##
+
+ if (newsk == NULL) {
+ return 0;
+ }
+
+ // pull in details
+ u16 lport = 0, dport = 0;
+ u32 net_ns_inum = 0;
+ u8 ipver = 0;
+
+ bpf_probe_read(&dport, sizeof(dport), &newsk->__sk_common.skc_dport);
+ bpf_probe_read(&lport, sizeof(lport), &newsk->__sk_common.skc_num);
+
+ // Get network namespace id, if kernel supports it
+#ifdef CONFIG_NET_NS
+ possible_net_t skc_net;
+ bpf_probe_read(&skc_net, sizeof(skc_net), &newsk->__sk_common.skc_net);
+ bpf_probe_read(&net_ns_inum, sizeof(net_ns_inum), &skc_net.net->ns.inum);
+#else
+ net_ns_inum = 0;
+#endif
+
+ ##FILTER_NETNS##
+
+ if (check_family(newsk, AF_INET)) {
+ ipver = 4;
+
+ struct tcp_ipv4_event_t evt4 = { 0 };
+
+ evt4.type = TCP_EVENT_TYPE_ACCEPT;
+ evt4.netns = net_ns_inum;
+ evt4.pid = pid >> 32;
+ evt4.ip = ipver;
+
+ bpf_probe_read(&evt4.saddr, sizeof(evt4.saddr),
+ &newsk->__sk_common.skc_rcv_saddr);
+ bpf_probe_read(&evt4.daddr, sizeof(evt4.daddr),
+ &newsk->__sk_common.skc_daddr);
+
+ evt4.sport = lport;
+ evt4.dport = ntohs(dport);
+ bpf_get_current_comm(&evt4.comm, sizeof(evt4.comm));
+
+ // do not send event if IP address is 0.0.0.0 or port is 0
+ if (evt4.saddr != 0 && evt4.daddr != 0 &&
+ evt4.sport != 0 && evt4.dport != 0) {
+ tcp_ipv4_event.perf_submit(ctx, &evt4, sizeof(evt4));
+ }
+ } else if (check_family(newsk, AF_INET6)) {
+ ipver = 6;
+
+ struct tcp_ipv6_event_t evt6 = { 0 };
+
+ evt6.type = TCP_EVENT_TYPE_ACCEPT;
+ evt6.netns = net_ns_inum;
+ evt6.pid = pid >> 32;
+ evt6.ip = ipver;
+
+ bpf_probe_read(&evt6.saddr, sizeof(evt6.saddr),
+ &newsk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32);
+ bpf_probe_read(&evt6.daddr, sizeof(evt6.daddr),
+ &newsk->__sk_common.skc_v6_daddr.in6_u.u6_addr32);
+
+ evt6.sport = lport;
+ evt6.dport = ntohs(dport);
+ bpf_get_current_comm(&evt6.comm, sizeof(evt6.comm));
+
+ // do not send event if IP address is 0.0.0.0 or port is 0
+ if (evt6.saddr != 0 && evt6.daddr != 0 &&
+ evt6.sport != 0 && evt6.dport != 0) {
+ tcp_ipv6_event.perf_submit(ctx, &evt6, sizeof(evt6));
+ }
+ }
+ // else drop
+
+ return 0;
+}
+"""
+
+TASK_COMM_LEN = 16 # linux/sched.h
+
+
+class TCPIPV4Evt(ctypes.Structure):
+ _fields_ = [
+ ("type", ctypes.c_uint),
+ ("pid", ctypes.c_uint),
+ ("comm", ctypes.c_char * TASK_COMM_LEN),
+ ("ip", ctypes.c_ubyte),
+ ("saddr", ctypes.c_uint),
+ ("daddr", ctypes.c_uint),
+ ("sport", ctypes.c_ushort),
+ ("dport", ctypes.c_ushort),
+ ("netns", ctypes.c_uint)
+ ]
+
+
+class TCPIPV6Evt(ctypes.Structure):
+ _fields_ = [
+ ("type", ctypes.c_uint),
+ ("pid", ctypes.c_uint),
+ ("comm", ctypes.c_char * TASK_COMM_LEN),
+ ("ip", ctypes.c_ubyte),
+ ("saddr", (ctypes.c_ulong * 2)),
+ ("daddr", (ctypes.c_ulong * 2)),
+ ("sport", ctypes.c_ushort),
+ ("dport", ctypes.c_ushort),
+ ("netns", ctypes.c_uint)
+ ]
+
+
+verbose_types = {"C": "connect", "A": "accept",
+ "X": "close", "U": "unknown"}
+
+
+def print_ipv4_event(cpu, data, size):
+ event = ctypes.cast(data, ctypes.POINTER(TCPIPV4Evt)).contents
+ if event.type == 1:
+ type_str = "C"
+ elif event.type == 2:
+ type_str = "A"
+ elif event.type == 3:
+ type_str = "X"
+ else:
+ type_str = "U"
+
+ if args.verbose:
+ print("%-12s " % (verbose_types[type_str]), end="")
+ else:
+ print("%-2s " % (type_str), end="")
+
+ print("%-6d %-16s %-2d %-16s %-16s %-6d %-6d" %
+ (event.pid, event.comm.decode('utf-8'),
+ event.ip,
+ inet_ntop(AF_INET, pack("I", event.saddr)),
+ inet_ntop(AF_INET, pack("I", event.daddr)),
+ event.sport,
+ event.dport), end="")
+ if args.verbose and not args.netns:
+ print(" %-8d" % event.netns)
+ else:
+ print()
+
+
+def print_ipv6_event(cpu, data, size):
+ event = ctypes.cast(data, ctypes.POINTER(TCPIPV6Evt)).contents
+ if event.type == 1:
+ type_str = "C"
+ elif event.type == 2:
+ type_str = "A"
+ elif event.type == 3:
+ type_str = "X"
+ else:
+ type_str = "U"
+
+ if args.verbose:
+ print("%-12s " % (verbose_types[type_str]), end="")
+ else:
+ print("%-2s " % (type_str), end="")
+
+ print("%-6d %-16s %-2d %-16s %-16s %-6d %-6d" %
+ (event.pid, event.comm.decode('utf-8'),
+ event.ip,
+ "["+inet_ntop(AF_INET6, event.saddr)+"]",
+ "["+inet_ntop(AF_INET6, event.daddr)+"]",
+ event.sport,
+ event.dport), end="")
+ if args.verbose and not args.netns:
+ print(" %-8d" % event.netns)
+ else:
+ print()
+
+
+pid_filter = ""
+netns_filter = ""
+
+if args.pid:
+ pid_filter = 'if (pid >> 32 != %d) { return 0; }' % args.pid
+if args.netns:
+ netns_filter = 'if (net_ns_inum != %d) { return 0; }' % args.netns
+
+bpf_text = bpf_text.replace('##FILTER_PID##', pid_filter)
+bpf_text = bpf_text.replace('##FILTER_NETNS##', netns_filter)
+
+# initialize BPF
+b = BPF(text=bpf_text)
+b.attach_kprobe(event="tcp_v4_connect", fn_name="trace_connect_v4_entry")
+b.attach_kretprobe(event="tcp_v4_connect", fn_name="trace_connect_v4_return")
+b.attach_kprobe(event="tcp_v6_connect", fn_name="trace_connect_v6_entry")
+b.attach_kretprobe(event="tcp_v6_connect", fn_name="trace_connect_v6_return")
+b.attach_kprobe(event="tcp_set_state", fn_name="trace_tcp_set_state_entry")
+b.attach_kprobe(event="tcp_close", fn_name="trace_close_entry")
+b.attach_kretprobe(event="inet_csk_accept", fn_name="trace_accept_return")
+
+print("Tracing TCP established connections. Ctrl-C to end.")
+
+# header
+if args.verbose:
+ print("%-12s %-6s %-16s %-2s %-16s %-16s %-6s %-7s" % ("TYPE",
+ "PID", "COMM", "IP", "SADDR", "DADDR", "SPORT", "DPORT"), end="")
+ if not args.netns:
+ print("%-8s" % "NETNS", end="")
+ print()
+else:
+ print("%-2s %-6s %-16s %-2s %-16s %-16s %-6s %-6s" %
+ ("T", "PID", "COMM", "IP", "SADDR", "DADDR", "SPORT", "DPORT"))
+
+
+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
+
+
+b["tcp_ipv4_event"].open_perf_buffer(print_ipv4_event)
+b["tcp_ipv6_event"].open_perf_buffer(print_ipv6_event)
+while True:
+ b.kprobe_poll()
projects / platform / upstream / bcc.git / commitdiff