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#!/usr/bin/env python
from __future__ import print_function
# Based on the `exitsnoop` script at https://github.com/iovisor/bcc/blob/master/tools/exitsnoop.py
# Based on the `execsnoop` script at https://github.com/iovisor/bcc/blob/master/tools/execsnoop.py
import argparse
import os
import platform
import re
import signal
import sys
from bcc import BPF
from collections import defaultdict
from datetime import datetime
from time import strftime
bpf_src = """
#include <uapi/linux/ptrace.h>
#include <linux/sched.h>
#define ARGSIZE 128
#define MAXARG 19
struct data_t {
u8 isArgv;
u64 start_time;
u64 exit_time;
u32 pid;
u32 ppid;
char comm[TASK_COMM_LEN];
char argv[ARGSIZE];
};
BPF_PERF_OUTPUT(events);
TRACEPOINT_PROBE(sched, sched_process_exit)
{
struct task_struct *task = (typeof(task))bpf_get_current_task();
if (task->pid != task->tgid) { return 0; }
struct data_t data = {};
data.start_time = task->start_time,
data.exit_time = bpf_ktime_get_ns(),
data.pid = task->pid,
data.ppid = task->real_parent->tgid,
bpf_get_current_comm(&data.comm, sizeof(data.comm));
events.perf_submit(args, &data, sizeof(data));
return 0;
}
static int __submit_arg(struct pt_regs *ctx, void *ptr, struct data_t *data)
{
bpf_probe_read_user(data->argv, sizeof(data->argv), ptr);
events.perf_submit(ctx, data, sizeof(struct data_t));
return 1;
}
static int submit_arg(struct pt_regs *ctx, void *ptr, struct data_t *data)
{
const char *argp = NULL;
bpf_probe_read_user(&argp, sizeof(argp), ptr);
if (argp) {
return __submit_arg(ctx, (void *)(argp), data);
}
return 0;
}
int syscall__execve(struct pt_regs *ctx,
const char __user *filename,
const char __user *const __user *__argv,
const char __user *const __user *__envp)
{
struct task_struct *task = (typeof(task))bpf_get_current_task();
struct data_t data = {};
data.pid = bpf_get_current_pid_tgid() >> 32;
data.isArgv = 1;
bpf_get_current_comm(&data.comm, sizeof(data.comm));
__submit_arg(ctx, (void *)filename, &data);
// skip first arg, as we submitted filename
#pragma unroll
for (int i = 1; i < MAXARG; i++) {
if (submit_arg(ctx, (void *)&__argv[i], &data) == 0)
goto out;
}
// handle truncated argument list
char ellipsis[] = "...";
__submit_arg(ctx, (void *)ellipsis, &data);
out:
return 0;
}
int do_ret_sys_execve(struct pt_regs *ctx)
{
struct task_struct *task = (typeof(task))bpf_get_current_task();
struct data_t data = {};
data.pid = bpf_get_current_pid_tgid() >> 32;
bpf_get_current_comm(&data.comm, sizeof(data.comm));
events.perf_submit(ctx, &data, sizeof(data));
return 0;
}
"""
def _print_header():
print("%-16s %-7s %-7s %-7s %s" %
("PCOMM", "PID", "PPID", "AGE(ms)", "ARGV"))
buffer = None
pidToArgv = defaultdict(list)
def _print_event(cpu, data, size): # callback
"""Print the exit event."""
global buffer
e = buffer["events"].event(data)
comm = e.comm.decode()
if comm == "3":
# Because of CVE-2019-5736, crun copies itself on a memfd or temp file, add seals,
# then goes fexecve. The linux kernel will then set comm as the basename of
# /dev/fd/<fdnum>, which happens to be 3 being the first available file descriptor.
# runc implementation is slightly different, with multiple processes, and they also
# set the process name to make them intelligible (i.e. "runc:[0:PARENT]", "runc:[1:CHILD]")
# so it doesn't fall into this case.
comm = "crun"
if e.isArgv:
pidToArgv[e.pid].append(e.argv)
return
if comm not in ["podman", "crun", "runc", "conmon", "netavark", "aardvark-dns"]:
try:
del(pidToArgv[e.pid])
except Exception:
pass
return
age = (e.exit_time - e.start_time) / 1e6
argv = b' '.join(pidToArgv[e.pid]).replace(b'\n', b'\\n')
print("%-16s %-7d %-7d %-7.2f %s" %
(comm, e.pid, e.ppid, age, argv.decode()), end="")
print()
try:
del(pidToArgv[e.pid])
except Exception:
pass
def snoop(bpf, event_handler):
bpf["events"].open_perf_buffer(event_handler)
while True:
bpf.perf_buffer_poll()
def main():
global buffer
try:
buffer = BPF(text=bpf_src)
execve_fnname = buffer.get_syscall_fnname("execve")
buffer.attach_kprobe(event=execve_fnname, fn_name="syscall__execve")
_print_header()
snoop(buffer, _print_event)
except KeyboardInterrupt:
print()
sys.exit()
return 0
if __name__ == '__main__':
main()
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