79 lines
2.1 KiB
Python
Executable File
79 lines
2.1 KiB
Python
Executable File
#!/usr/bin/python
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# @lint-avoid-python-3-compatibility-imports
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#
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# tcpsynbl Show TCP SYN backlog.
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# For Linux, uses BCC, eBPF. Embedded C.
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#
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# USAGE: tcpsynbl [-4 | -6] [-h]
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#
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# Copyright (c) 2019 Brendan Gregg.
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# Licensed under the Apache License, Version 2.0 (the "License").
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# This was originally created for the BPF Performance Tools book
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# published by Addison Wesley. ISBN-13: 9780136554820
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# When copying or porting, include this comment.
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#
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# 03-Jul-2019 Brendan Gregg Ported from bpftrace to BCC.
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from __future__ import print_function
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import argparse
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from bcc import BPF
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from time import sleep
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# load BPF program
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bpf_text = """
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#include <net/sock.h>
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typedef struct backlog_key {
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u32 backlog;
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u64 slot;
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} backlog_key_t;
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BPF_HISTOGRAM(dist, backlog_key_t);
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int do_entry(struct pt_regs *ctx) {
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struct sock *sk = (struct sock *)PT_REGS_PARM1(ctx);
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backlog_key_t key = {};
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key.backlog = sk->sk_max_ack_backlog;
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key.slot = bpf_log2l(sk->sk_ack_backlog);
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dist.atomic_increment(key);
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return 0;
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};
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"""
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examples = """examples:
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./tcpsynbl # trace syn backlog
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./tcpsynbl -4 # trace IPv4 family only
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./tcpsynbl -6 # trace IPv6 family only
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"""
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parser = argparse.ArgumentParser(
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description="Show TCP SYN backlog.",
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formatter_class=argparse.RawDescriptionHelpFormatter,
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epilog=examples)
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group = parser.add_mutually_exclusive_group()
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group.add_argument("-4", "--ipv4", action="store_true",
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help="trace IPv4 family only")
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group.add_argument("-6", "--ipv6", action="store_true",
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help="trace IPv6 family only")
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args = parser.parse_args()
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b = BPF(text=bpf_text)
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if args.ipv4:
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b.attach_kprobe(event="tcp_v4_syn_recv_sock", fn_name="do_entry")
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elif args.ipv6:
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b.attach_kprobe(event="tcp_v6_syn_recv_sock", fn_name="do_entry")
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else:
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b.attach_kprobe(event="tcp_v4_syn_recv_sock", fn_name="do_entry")
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b.attach_kprobe(event="tcp_v6_syn_recv_sock", fn_name="do_entry")
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print("Tracing SYN backlog size. Ctrl-C to end.");
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try:
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sleep(99999999)
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except KeyboardInterrupt:
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print()
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dist = b.get_table("dist")
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dist.print_log2_hist("backlog", "backlog_max")
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