#!/usr/bin/env python # @lint-avoid-python-3-compatibility-imports # # tcptop Summarize TCP send/recv throughput by host. # For Linux, uses BCC, eBPF. Embedded C. # # USAGE: tcptop [-h] [-C] [-S] [-p PID] [interval [count]] # # This uses dynamic tracing of kernel functions, and will need to be updated # to match kernel changes. # # WARNING: This traces all send/receives at the TCP level, and while it # summarizes data in-kernel to reduce overhead, there may still be some # overhead at high TCP send/receive rates (eg, ~13% of one CPU at 100k TCP # events/sec. This is not the same as packet rate: funccount can be used to # count the kprobes below to find out the TCP rate). Test in a lab environment # first. If your send/receive rate is low (eg, <1k/sec) then the overhead is # expected to be negligible. # # ToDo: Fit output to screen size (top X only) in default (not -C) mode. # # Copyright 2016 Netflix, Inc. # Licensed under the Apache License, Version 2.0 (the "License") # # 02-Sep-2016 Brendan Gregg Created this. from __future__ import print_function from bcc import BPF import argparse from socket import inet_ntop, AF_INET, AF_INET6 from struct import pack from time import sleep, strftime from subprocess import call import ctypes as ct from collections import namedtuple, defaultdict # arguments def range_check(string): value = int(string) if value < 1: msg = "value must be stricly positive, got %d" % (value,) raise argparse.ArgumentTypeError(msg) return value examples = """examples: ./tcptop # trace TCP send/recv by host ./tcptop -C # don't clear the screen ./tcptop -p 181 # only trace PID 181 """ parser = argparse.ArgumentParser( description="Summarize TCP send/recv throughput by host", formatter_class=argparse.RawDescriptionHelpFormatter, epilog=examples) parser.add_argument("-C", "--noclear", action="store_true", help="don't clear the screen") parser.add_argument("-S", "--nosummary", action="store_true", help="skip system summary line") parser.add_argument("-p", "--pid", help="trace this PID only") parser.add_argument("interval", nargs="?", default=1, type=range_check, help="output interval, in seconds (default 1)") parser.add_argument("count", nargs="?", default=-1, type=range_check, help="number of outputs") parser.add_argument("--ebpf", action="store_true", help=argparse.SUPPRESS) args = parser.parse_args() debug = 0 # linux stats loadavg = "/proc/loadavg" # define BPF program bpf_text = """ #include #include #include struct ipv4_key_t { u32 pid; u32 saddr; u32 daddr; u16 lport; u16 dport; }; BPF_HASH(ipv4_send_bytes, struct ipv4_key_t); BPF_HASH(ipv4_recv_bytes, struct ipv4_key_t); struct ipv6_key_t { u32 pid; unsigned __int128 saddr; unsigned __int128 daddr; u16 lport; u16 dport; }; BPF_HASH(ipv6_send_bytes, struct ipv6_key_t); BPF_HASH(ipv6_recv_bytes, struct ipv6_key_t); int kprobe__tcp_sendmsg(struct pt_regs *ctx, struct sock *sk, struct msghdr *msg, size_t size) { u32 pid = bpf_get_current_pid_tgid(); FILTER u16 dport = 0, family = sk->__sk_common.skc_family; if (family == AF_INET) { struct ipv4_key_t ipv4_key = {.pid = pid}; ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr; ipv4_key.daddr = sk->__sk_common.skc_daddr; ipv4_key.lport = sk->__sk_common.skc_num; dport = sk->__sk_common.skc_dport; ipv4_key.dport = ntohs(dport); ipv4_send_bytes.increment(ipv4_key, size); } else if (family == AF_INET6) { struct ipv6_key_t ipv6_key = {.pid = pid}; __builtin_memcpy(&ipv6_key.saddr, sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32, sizeof(ipv6_key.saddr)); __builtin_memcpy(&ipv6_key.daddr, sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32, sizeof(ipv6_key.daddr)); ipv6_key.lport = sk->__sk_common.skc_num; dport = sk->__sk_common.skc_dport; ipv6_key.dport = ntohs(dport); ipv6_send_bytes.increment(ipv6_key, size); } // else drop return 0; } /* * tcp_recvmsg() would be obvious to trace, but is less suitable because: * - we'd need to trace both entry and return, to have both sock and size * - misses tcp_read_sock() traffic * we'd much prefer tracepoints once they are available. */ int kprobe__tcp_cleanup_rbuf(struct pt_regs *ctx, struct sock *sk, int copied) { u32 pid = bpf_get_current_pid_tgid(); FILTER u16 dport = 0, family = sk->__sk_common.skc_family; u64 *val, zero = 0; if (copied <= 0) return 0; if (family == AF_INET) { struct ipv4_key_t ipv4_key = {.pid = pid}; ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr; ipv4_key.daddr = sk->__sk_common.skc_daddr; ipv4_key.lport = sk->__sk_common.skc_num; dport = sk->__sk_common.skc_dport; ipv4_key.dport = ntohs(dport); ipv4_recv_bytes.increment(ipv4_key, copied); } else if (family == AF_INET6) { struct ipv6_key_t ipv6_key = {.pid = pid}; __builtin_memcpy(&ipv6_key.saddr, sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32, sizeof(ipv6_key.saddr)); __builtin_memcpy(&ipv6_key.daddr, sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32, sizeof(ipv6_key.daddr)); ipv6_key.lport = sk->__sk_common.skc_num; dport = sk->__sk_common.skc_dport; ipv6_key.dport = ntohs(dport); ipv6_recv_bytes.increment(ipv6_key, copied); } // 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 or args.ebpf: print(bpf_text) if args.ebpf: exit() TCPSessionKey = namedtuple('TCPSession', ['pid', 'laddr', 'lport', 'daddr', 'dport']) def pid_to_comm(pid): try: comm = open("/proc/%d/comm" % pid, "r").read().rstrip() return comm except IOError: return str(pid) def get_ipv4_session_key(k): return TCPSessionKey(pid=k.pid, laddr=inet_ntop(AF_INET, pack("I", k.saddr)), lport=k.lport, daddr=inet_ntop(AF_INET, pack("I", k.daddr)), dport=k.dport) def get_ipv6_session_key(k): return TCPSessionKey(pid=k.pid, laddr=inet_ntop(AF_INET6, k.saddr), lport=k.lport, daddr=inet_ntop(AF_INET6, k.daddr), dport=k.dport) # initialize BPF b = BPF(text=bpf_text) ipv4_send_bytes = b["ipv4_send_bytes"] ipv4_recv_bytes = b["ipv4_recv_bytes"] ipv6_send_bytes = b["ipv6_send_bytes"] ipv6_recv_bytes = b["ipv6_recv_bytes"] print('Tracing... Output every %s secs. Hit Ctrl-C to end' % args.interval) # output i = 0 exiting = False while i != args.count and not exiting: try: sleep(args.interval) except KeyboardInterrupt: exiting = True # header if args.noclear: print() else: call("clear") if not args.nosummary: with open(loadavg) as stats: print("%-8s loadavg: %s" % (strftime("%H:%M:%S"), stats.read())) # IPv4: build dict of all seen keys ipv4_throughput = defaultdict(lambda: [0, 0]) for k, v in ipv4_send_bytes.items(): key = get_ipv4_session_key(k) ipv4_throughput[key][0] = v.value ipv4_send_bytes.clear() for k, v in ipv4_recv_bytes.items(): key = get_ipv4_session_key(k) ipv4_throughput[key][1] = v.value ipv4_recv_bytes.clear() if ipv4_throughput: print("%-6s %-12s %-21s %-21s %6s %6s" % ("PID", "COMM", "LADDR", "RADDR", "RX_KB", "TX_KB")) # output for k, (send_bytes, recv_bytes) in sorted(ipv4_throughput.items(), key=lambda kv: sum(kv[1]), reverse=True): print("%-6d %-12.12s %-21s %-21s %6d %6d" % (k.pid, pid_to_comm(k.pid), k.laddr + ":" + str(k.lport), k.daddr + ":" + str(k.dport), int(recv_bytes / 1024), int(send_bytes / 1024))) # IPv6: build dict of all seen keys ipv6_throughput = defaultdict(lambda: [0, 0]) for k, v in ipv6_send_bytes.items(): key = get_ipv6_session_key(k) ipv6_throughput[key][0] = v.value ipv6_send_bytes.clear() for k, v in ipv6_recv_bytes.items(): key = get_ipv6_session_key(k) ipv6_throughput[key][1] = v.value ipv6_recv_bytes.clear() if ipv6_throughput: # more than 80 chars, sadly. print("\n%-6s %-12s %-32s %-32s %6s %6s" % ("PID", "COMM", "LADDR6", "RADDR6", "RX_KB", "TX_KB")) # output for k, (send_bytes, recv_bytes) in sorted(ipv6_throughput.items(), key=lambda kv: sum(kv[1]), reverse=True): print("%-6d %-12.12s %-32s %-32s %6d %6d" % (k.pid, pid_to_comm(k.pid), k.laddr + ":" + str(k.lport), k.daddr + ":" + str(k.dport), int(recv_bytes / 1024), int(send_bytes / 1024))) i += 1