76 lines
1.8 KiB
Python
Executable File
76 lines
1.8 KiB
Python
Executable File
#!/usr/bin/python
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# Carlos Neira <cneirabustos@gmail.com>
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# This is a Hello World example that uses BPF_PERF_OUTPUT.
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# in this example bpf_get_ns_current_pid_tgid(), this helper
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# works inside pid namespaces.
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# bpf_get_current_pid_tgid() only returns the host pid outside any
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# namespace and this will not work when the script is run inside a pid namespace.
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from bcc import BPF
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from bcc.utils import printb
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import sys, os
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from stat import *
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# define BPF program
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prog = """
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#include <linux/sched.h>
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// define output data structure in C
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struct data_t {
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u32 pid;
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u64 ts;
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char comm[TASK_COMM_LEN];
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};
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BPF_PERF_OUTPUT(events);
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int hello(struct pt_regs *ctx) {
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struct data_t data = {};
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struct bpf_pidns_info ns = {};
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if(bpf_get_ns_current_pid_tgid(DEV, INO, &ns, sizeof(struct bpf_pidns_info)))
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return 0;
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data.pid = ns.pid;
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data.ts = bpf_ktime_get_ns();
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bpf_get_current_comm(&data.comm, sizeof(data.comm));
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events.perf_submit(ctx, &data, sizeof(data));
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return 0;
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}
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"""
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devinfo = os.stat("/proc/self/ns/pid")
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for r in (("DEV", str(devinfo.st_dev)), ("INO", str(devinfo.st_ino))):
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prog = prog.replace(*r)
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# load BPF program
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b = BPF(text=prog)
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b.attach_kprobe(event=b.get_syscall_fnname("clone"), fn_name="hello")
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# header
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print("%-18s %-16s %-6s %s" % ("TIME(s)", "COMM", "PID", "MESSAGE"))
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# process event
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start = 0
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def print_event(cpu, data, size):
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global start
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event = b["events"].event(data)
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if start == 0:
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start = event.ts
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time_s = (float(event.ts - start)) / 1000000000
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printb(
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b"%-18.9f %-16s %-6d %s"
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% (time_s, event.comm, event.pid, b"Hello, perf_output!")
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)
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# loop with callback to print_event
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b["events"].open_perf_buffer(print_event)
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while 1:
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try:
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b.perf_buffer_poll()
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except KeyboardInterrupt:
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exit()
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