#!/usr/bin/python # @lint-avoid-python-3-compatibility-imports # # tcpconnect Trace TCP connect()s. # For Linux, uses BCC, eBPF. Embedded C. # # USAGE: tcpconnect [-h] [-c] [-t] [-p PID] [-P PORT [PORT ...]] # # All connection attempts are traced, even if they ultimately fail. # # This uses dynamic tracing of kernel functions, and will need to be updated # to match kernel changes. # # Copyright (c) 2015 Brendan Gregg. # Licensed under the Apache License, Version 2.0 (the "License") # # 25-Sep-2015 Brendan Gregg Created this. # 14-Feb-2016 " " Switch to bpf_perf_output. # 09-Jan-2019 Takuma Kume Support filtering by UID # 30-Jul-2019 Xiaozhou Liu Count connects. from __future__ import print_function from bcc import BPF from bcc.containers import filter_by_containers from bcc.utils import printb import argparse from socket import inet_ntop, ntohs, AF_INET, AF_INET6 from struct import pack from time import sleep # arguments examples = """examples: ./tcpconnect # trace all TCP connect()s ./tcpconnect -t # include timestamps ./tcpconnect -p 181 # only trace PID 181 ./tcpconnect -P 80 # only trace port 80 ./tcpconnect -P 80,81 # only trace port 80 and 81 ./tcpconnect -U # include UID ./tcpconnect -u 1000 # only trace UID 1000 ./tcpconnect -c # count connects per src ip and dest ip/port ./tcpconnect --cgroupmap mappath # only trace cgroups in this BPF map ./tcpconnect --mntnsmap mappath # only trace mount namespaces in the map """ parser = argparse.ArgumentParser( description="Trace TCP connects", 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") parser.add_argument("-P", "--port", help="comma-separated list of destination ports to trace.") parser.add_argument("-U", "--print-uid", action="store_true", help="include UID on output") parser.add_argument("-u", "--uid", help="trace this UID only") parser.add_argument("-c", "--count", action="store_true", help="count connects per src ip and dest ip/port") 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 #include #include BPF_HASH(currsock, u32, struct sock *); // separate data structs for ipv4 and ipv6 struct ipv4_data_t { u64 ts_us; u32 pid; u32 uid; u32 saddr; u32 daddr; u64 ip; u16 dport; char task[TASK_COMM_LEN]; }; BPF_PERF_OUTPUT(ipv4_events); struct ipv6_data_t { u64 ts_us; u32 pid; u32 uid; unsigned __int128 saddr; unsigned __int128 daddr; u64 ip; u16 dport; char task[TASK_COMM_LEN]; }; BPF_PERF_OUTPUT(ipv6_events); // separate flow keys per address family struct ipv4_flow_key_t { u32 saddr; u32 daddr; u16 dport; }; BPF_HASH(ipv4_count, struct ipv4_flow_key_t); struct ipv6_flow_key_t { unsigned __int128 saddr; unsigned __int128 daddr; u16 dport; }; BPF_HASH(ipv6_count, struct ipv6_flow_key_t); int trace_connect_entry(struct pt_regs *ctx, struct sock *sk) { if (container_should_be_filtered()) { return 0; } u64 pid_tgid = bpf_get_current_pid_tgid(); u32 pid = pid_tgid >> 32; u32 tid = pid_tgid; FILTER_PID u32 uid = bpf_get_current_uid_gid(); FILTER_UID // stash the sock ptr for lookup on return currsock.update(&tid, &sk); return 0; }; static int trace_connect_return(struct pt_regs *ctx, short ipver) { int ret = PT_REGS_RC(ctx); u64 pid_tgid = bpf_get_current_pid_tgid(); u32 pid = pid_tgid >> 32; u32 tid = pid_tgid; struct sock **skpp; skpp = currsock.lookup(&tid); if (skpp == 0) { return 0; // missed entry } if (ret != 0) { // failed to send SYNC packet, may not have populated // socket __sk_common.{skc_rcv_saddr, ...} currsock.delete(&tid); return 0; } // pull in details struct sock *skp = *skpp; u16 dport = skp->__sk_common.skc_dport; FILTER_PORT if (ipver == 4) { IPV4_CODE } else /* 6 */ { IPV6_CODE } currsock.delete(&tid); return 0; } int trace_connect_v4_return(struct pt_regs *ctx) { return trace_connect_return(ctx, 4); } int trace_connect_v6_return(struct pt_regs *ctx) { return trace_connect_return(ctx, 6); } """ struct_init = { 'ipv4': { 'count' : """ struct ipv4_flow_key_t flow_key = {}; flow_key.saddr = skp->__sk_common.skc_rcv_saddr; flow_key.daddr = skp->__sk_common.skc_daddr; flow_key.dport = ntohs(dport); ipv4_count.increment(flow_key);""", 'trace' : """ struct ipv4_data_t data4 = {.pid = pid, .ip = ipver}; data4.uid = bpf_get_current_uid_gid(); data4.ts_us = bpf_ktime_get_ns() / 1000; data4.saddr = skp->__sk_common.skc_rcv_saddr; data4.daddr = skp->__sk_common.skc_daddr; data4.dport = ntohs(dport); bpf_get_current_comm(&data4.task, sizeof(data4.task)); ipv4_events.perf_submit(ctx, &data4, sizeof(data4));""" }, 'ipv6': { 'count' : """ struct ipv6_flow_key_t flow_key = {}; bpf_probe_read_kernel(&flow_key.saddr, sizeof(flow_key.saddr), skp->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32); bpf_probe_read_kernel(&flow_key.daddr, sizeof(flow_key.daddr), skp->__sk_common.skc_v6_daddr.in6_u.u6_addr32); flow_key.dport = ntohs(dport); ipv6_count.increment(flow_key);""", 'trace' : """ struct ipv6_data_t data6 = {.pid = pid, .ip = ipver}; data6.uid = bpf_get_current_uid_gid(); data6.ts_us = bpf_ktime_get_ns() / 1000; bpf_probe_read_kernel(&data6.saddr, sizeof(data6.saddr), skp->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32); bpf_probe_read_kernel(&data6.daddr, sizeof(data6.daddr), skp->__sk_common.skc_v6_daddr.in6_u.u6_addr32); data6.dport = ntohs(dport); bpf_get_current_comm(&data6.task, sizeof(data6.task)); ipv6_events.perf_submit(ctx, &data6, sizeof(data6));""" } } # code substitutions if args.count: bpf_text = bpf_text.replace("IPV4_CODE", struct_init['ipv4']['count']) bpf_text = bpf_text.replace("IPV6_CODE", struct_init['ipv6']['count']) else: bpf_text = bpf_text.replace("IPV4_CODE", struct_init['ipv4']['trace']) bpf_text = bpf_text.replace("IPV6_CODE", struct_init['ipv6']['trace']) if args.pid: bpf_text = bpf_text.replace('FILTER_PID', 'if (pid != %s) { return 0; }' % args.pid) if args.port: dports = [int(dport) for dport in args.port.split(',')] dports_if = ' && '.join(['dport != %d' % ntohs(dport) for dport in dports]) bpf_text = bpf_text.replace('FILTER_PORT', 'if (%s) { currsock.delete(&pid); return 0; }' % dports_if) if args.uid: bpf_text = bpf_text.replace('FILTER_UID', 'if (uid != %s) { return 0; }' % args.uid) bpf_text = filter_by_containers(args) + bpf_text bpf_text = bpf_text.replace('FILTER_PID', '') bpf_text = bpf_text.replace('FILTER_PORT', '') bpf_text = bpf_text.replace('FILTER_UID', '') if debug or args.ebpf: print(bpf_text) if args.ebpf: exit() # process event def print_ipv4_event(cpu, data, size): event = b["ipv4_events"].event(data) global start_ts if args.timestamp: if start_ts == 0: start_ts = event.ts_us printb(b"%-9.3f" % ((float(event.ts_us) - start_ts) / 1000000), nl="") if args.print_uid: printb(b"%-6d" % event.uid, nl="") printb(b"%-6d %-12.12s %-2d %-16s %-16s %-4d" % (event.pid, event.task, event.ip, inet_ntop(AF_INET, pack("I", event.saddr)).encode(), inet_ntop(AF_INET, pack("I", event.daddr)).encode(), event.dport)) def print_ipv6_event(cpu, data, size): event = b["ipv6_events"].event(data) global start_ts if args.timestamp: if start_ts == 0: start_ts = event.ts_us printb(b"%-9.3f" % ((float(event.ts_us) - start_ts) / 1000000), nl="") if args.print_uid: printb(b"%-6d" % event.uid, nl="") printb(b"%-6d %-12.12s %-2d %-16s %-16s %-4d" % (event.pid, event.task, event.ip, inet_ntop(AF_INET6, event.saddr).encode(), inet_ntop(AF_INET6, event.daddr).encode(), event.dport)) def depict_cnt(counts_tab, l3prot='ipv4'): for k, v in sorted(counts_tab.items(), key=lambda counts: counts[1].value, reverse=True): depict_key = "" if l3prot == 'ipv4': depict_key = "%-25s %-25s %-20s" % ((inet_ntop(AF_INET, pack('I', k.saddr))), inet_ntop(AF_INET, pack('I', k.daddr)), k.dport) else: depict_key = "%-25s %-25s %-20s" % ((inet_ntop(AF_INET6, k.saddr)), inet_ntop(AF_INET6, k.daddr), k.dport) print ("%s %-10d" % (depict_key, v.value)) # initialize BPF b = BPF(text=bpf_text) b.attach_kprobe(event="tcp_v4_connect", fn_name="trace_connect_entry") b.attach_kprobe(event="tcp_v6_connect", fn_name="trace_connect_entry") b.attach_kretprobe(event="tcp_v4_connect", fn_name="trace_connect_v4_return") b.attach_kretprobe(event="tcp_v6_connect", fn_name="trace_connect_v6_return") print("Tracing connect ... Hit Ctrl-C to end") if args.count: try: while 1: sleep(99999999) except KeyboardInterrupt: pass # header print("\n%-25s %-25s %-20s %-10s" % ( "LADDR", "RADDR", "RPORT", "CONNECTS")) depict_cnt(b["ipv4_count"]) depict_cnt(b["ipv6_count"], l3prot='ipv6') # read events else: # header if args.timestamp: print("%-9s" % ("TIME(s)"), end="") if args.print_uid: print("%-6s" % ("UID"), end="") print("%-6s %-12s %-2s %-16s %-16s %-4s" % ("PID", "COMM", "IP", "SADDR", "DADDR", "DPORT")) 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()