Edit: /usr/sbin/opensnoop-bpfcc (14581B)
#! /usr/bin/python3
# @lint-avoid-python-3-compatibility-imports
#
# opensnoop Trace open() syscalls.
# For Linux, uses BCC, eBPF. Embedded C.
#
# USAGE: opensnoop [-h] [-T] [-U] [-x] [-p PID] [-t TID]
# [--cgroupmap CGROUPMAP] [--mntnsmap MNTNSMAP] [-u UID]
# [-d DURATION] [-n NAME] [-F] [-e] [-f FLAG_FILTER]
# [-b BUFFER_PAGES]
#
# Copyright (c) 2015 Brendan Gregg.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 17-Sep-2015 Brendan Gregg Created this.
# 29-Apr-2016 Allan McAleavy Updated for BPF_PERF_OUTPUT.
# 08-Oct-2016 Dina Goldshtein Support filtering by PID and TID.
# 28-Dec-2018 Tim Douglas Print flags argument, enable filtering
# 06-Jan-2019 Takuma Kume Support filtering by UID
# 21-Aug-2022 Rocky Xing Support showing full path for an open file.
# 06-Sep-2022 Rocky Xing Support setting size of the perf ring buffer.
from __future__ import print_function
from bcc import ArgString, BPF
from bcc.containers import filter_by_containers
from bcc.utils import printb
import argparse
from collections import defaultdict
from datetime import datetime, timedelta
import os
# arguments
examples = """examples:
./opensnoop # trace all open() syscalls
./opensnoop -T # include timestamps
./opensnoop -U # include UID
./opensnoop -x # only show failed opens
./opensnoop -p 181 # only trace PID 181
./opensnoop -t 123 # only trace TID 123
./opensnoop -u 1000 # only trace UID 1000
./opensnoop -d 10 # trace for 10 seconds only
./opensnoop -n main # only print process names containing "main"
./opensnoop -e # show extended fields
./opensnoop -f O_WRONLY -f O_RDWR # only print calls for writing
./opensnoop -F # show full path for an open file with relative path
./opensnoop --cgroupmap mappath # only trace cgroups in this BPF map
./opensnoop --mntnsmap mappath # only trace mount namespaces in the map
"""
parser = argparse.ArgumentParser(
description="Trace open() syscalls",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-T", "--timestamp", action="store_true",
help="include timestamp on output")
parser.add_argument("-U", "--print-uid", action="store_true",
help="print UID column")
parser.add_argument("-x", "--failed", action="store_true",
help="only show failed opens")
parser.add_argument("-p", "--pid",
help="trace this PID only")
parser.add_argument("-t", "--tid",
help="trace this TID only")
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("-u", "--uid",
help="trace this UID only")
parser.add_argument("-d", "--duration",
help="total duration of trace in seconds")
parser.add_argument("-n", "--name",
type=ArgString,
help="only print process names containing this name")
parser.add_argument("--ebpf", action="store_true",
help=argparse.SUPPRESS)
parser.add_argument("-e", "--extended_fields", action="store_true",
help="show extended fields")
parser.add_argument("-f", "--flag_filter", action="append",
help="filter on flags argument (e.g., O_WRONLY)")
parser.add_argument("-F", "--full-path", action="store_true",
help="show full path for an open file with relative path")
parser.add_argument("-b", "--buffer-pages", type=int, default=64,
help="size of the perf ring buffer "
"(must be a power of two number of pages and defaults to 64)")
args = parser.parse_args()
debug = 0
if args.duration:
args.duration = timedelta(seconds=int(args.duration))
flag_filter_mask = 0
for flag in args.flag_filter or []:
if not flag.startswith('O_'):
exit("Bad flag: %s" % flag)
try:
flag_filter_mask |= getattr(os, flag)
except AttributeError:
exit("Bad flag: %s" % flag)
# define BPF program
bpf_text = """
#include
#include
#include
#ifdef FULLPATH
#include
#include
#define MAX_ENTRIES 32
enum event_type {
EVENT_ENTRY,
EVENT_END,
};
#endif
struct val_t {
u64 id;
char comm[TASK_COMM_LEN];
const char *fname;
int flags; // EXTENDED_STRUCT_MEMBER
};
struct data_t {
u64 id;
u64 ts;
u32 uid;
int ret;
char comm[TASK_COMM_LEN];
#ifdef FULLPATH
enum event_type type;
#endif
char name[NAME_MAX];
int flags; // EXTENDED_STRUCT_MEMBER
};
BPF_PERF_OUTPUT(events);
"""
bpf_text_kprobe = """
BPF_HASH(infotmp, u64, struct val_t);
int trace_return(struct pt_regs *ctx)
{
u64 id = bpf_get_current_pid_tgid();
struct val_t *valp;
struct data_t data = {};
u64 tsp = bpf_ktime_get_ns();
valp = infotmp.lookup(&id);
if (valp == 0) {
// missed entry
return 0;
}
bpf_probe_read_kernel(&data.comm, sizeof(data.comm), valp->comm);
bpf_probe_read_user_str(&data.name, sizeof(data.name), (void *)valp->fname);
data.id = valp->id;
data.ts = tsp / 1000;
data.uid = bpf_get_current_uid_gid();
data.flags = valp->flags; // EXTENDED_STRUCT_MEMBER
data.ret = PT_REGS_RC(ctx);
SUBMIT_DATA
infotmp.delete(&id);
return 0;
}
"""
bpf_text_kprobe_header_open = """
int syscall__trace_entry_open(struct pt_regs *ctx, const char __user *filename, int flags)
{
"""
bpf_text_kprobe_header_openat = """
int syscall__trace_entry_openat(struct pt_regs *ctx, int dfd, const char __user *filename, int flags)
{
"""
bpf_text_kprobe_header_openat2 = """
#include
int syscall__trace_entry_openat2(struct pt_regs *ctx, int dfd, const char __user *filename, struct open_how *how)
{
int flags = how->flags;
"""
bpf_text_kprobe_body = """
struct val_t val = {};
u64 id = bpf_get_current_pid_tgid();
u32 pid = id >> 32; // PID is higher part
u32 tid = id; // Cast and get the lower part
u32 uid = bpf_get_current_uid_gid();
PID_TID_FILTER
UID_FILTER
FLAGS_FILTER
if (container_should_be_filtered()) {
return 0;
}
if (bpf_get_current_comm(&val.comm, sizeof(val.comm)) == 0) {
val.id = id;
val.fname = filename;
val.flags = flags; // EXTENDED_STRUCT_MEMBER
infotmp.update(&id, &val);
}
return 0;
};
"""
bpf_text_kfunc_header_open = """
#if defined(CONFIG_ARCH_HAS_SYSCALL_WRAPPER) && !defined(__s390x__)
KRETFUNC_PROBE(FNNAME, struct pt_regs *regs, int ret)
{
const char __user *filename = (char *)PT_REGS_PARM1(regs);
int flags = PT_REGS_PARM2(regs);
#else
KRETFUNC_PROBE(FNNAME, const char __user *filename, int flags, int ret)
{
#endif
"""
bpf_text_kfunc_header_openat = """
#if defined(CONFIG_ARCH_HAS_SYSCALL_WRAPPER) && !defined(__s390x__)
KRETFUNC_PROBE(FNNAME, struct pt_regs *regs, int ret)
{
int dfd = PT_REGS_PARM1(regs);
const char __user *filename = (char *)PT_REGS_PARM2(regs);
int flags = PT_REGS_PARM3(regs);
#else
KRETFUNC_PROBE(FNNAME, int dfd, const char __user *filename, int flags, int ret)
{
#endif
"""
bpf_text_kfunc_header_openat2 = """
#include
#if defined(CONFIG_ARCH_HAS_SYSCALL_WRAPPER) && !defined(__s390x__)
KRETFUNC_PROBE(FNNAME, struct pt_regs *regs, int ret)
{
int dfd = PT_REGS_PARM1(regs);
const char __user *filename = (char *)PT_REGS_PARM2(regs);
struct open_how __user how;
int flags;
bpf_probe_read_user(&how, sizeof(struct open_how), (struct open_how*)PT_REGS_PARM3(regs));
flags = how.flags;
#else
KRETFUNC_PROBE(FNNAME, int dfd, const char __user *filename, struct open_how __user *how, int ret)
{
int flags = how->flags;
#endif
"""
bpf_text_kfunc_body = """
u64 id = bpf_get_current_pid_tgid();
u32 pid = id >> 32; // PID is higher part
u32 tid = id; // Cast and get the lower part
u32 uid = bpf_get_current_uid_gid();
PID_TID_FILTER
UID_FILTER
FLAGS_FILTER
if (container_should_be_filtered()) {
return 0;
}
struct data_t data = {};
bpf_get_current_comm(&data.comm, sizeof(data.comm));
u64 tsp = bpf_ktime_get_ns();
bpf_probe_read_user_str(&data.name, sizeof(data.name), (void *)filename);
data.id = id;
data.ts = tsp / 1000;
data.uid = bpf_get_current_uid_gid();
data.flags = flags; // EXTENDED_STRUCT_MEMBER
data.ret = ret;
SUBMIT_DATA
return 0;
}
"""
b = BPF(text='')
# open and openat are always in place since 2.6.16
fnname_open = b.get_syscall_prefix().decode() + 'open'
fnname_openat = b.get_syscall_prefix().decode() + 'openat'
fnname_openat2 = b.get_syscall_prefix().decode() + 'openat2'
if b.ksymname(fnname_openat2) == -1:
fnname_openat2 = None
if args.full_path:
bpf_text = "#define FULLPATH\n" + bpf_text
is_support_kfunc = BPF.support_kfunc()
if is_support_kfunc:
bpf_text += bpf_text_kfunc_header_open.replace('FNNAME', fnname_open)
bpf_text += bpf_text_kfunc_body
bpf_text += bpf_text_kfunc_header_openat.replace('FNNAME', fnname_openat)
bpf_text += bpf_text_kfunc_body
if fnname_openat2:
bpf_text += bpf_text_kfunc_header_openat2.replace('FNNAME', fnname_openat2)
bpf_text += bpf_text_kfunc_body
else:
bpf_text += bpf_text_kprobe
bpf_text += bpf_text_kprobe_header_open
bpf_text += bpf_text_kprobe_body
bpf_text += bpf_text_kprobe_header_openat
bpf_text += bpf_text_kprobe_body
if fnname_openat2:
bpf_text += bpf_text_kprobe_header_openat2
bpf_text += bpf_text_kprobe_body
if args.tid: # TID trumps PID
bpf_text = bpf_text.replace('PID_TID_FILTER',
'if (tid != %s) { return 0; }' % args.tid)
elif args.pid:
bpf_text = bpf_text.replace('PID_TID_FILTER',
'if (pid != %s) { return 0; }' % args.pid)
else:
bpf_text = bpf_text.replace('PID_TID_FILTER', '')
if args.uid:
bpf_text = bpf_text.replace('UID_FILTER',
'if (uid != %s) { return 0; }' % args.uid)
else:
bpf_text = bpf_text.replace('UID_FILTER', '')
bpf_text = filter_by_containers(args) + bpf_text
if args.flag_filter:
bpf_text = bpf_text.replace('FLAGS_FILTER',
'if (!(flags & %d)) { return 0; }' % flag_filter_mask)
else:
bpf_text = bpf_text.replace('FLAGS_FILTER', '')
if not (args.extended_fields or args.flag_filter):
bpf_text = '\n'.join(x for x in bpf_text.split('\n')
if 'EXTENDED_STRUCT_MEMBER' not in x)
if args.full_path:
bpf_text = bpf_text.replace('SUBMIT_DATA', """
data.type = EVENT_ENTRY;
events.perf_submit(ctx, &data, sizeof(data));
if (data.name[0] != '/') { // relative path
struct task_struct *task;
struct dentry *dentry;
int i;
task = (struct task_struct *)bpf_get_current_task_btf();
dentry = task->fs->pwd.dentry;
for (i = 1; i < MAX_ENTRIES; i++) {
bpf_probe_read_kernel(&data.name, sizeof(data.name), (void *)dentry->d_name.name);
data.type = EVENT_ENTRY;
events.perf_submit(ctx, &data, sizeof(data));
if (dentry == dentry->d_parent) { // root directory
break;
}
dentry = dentry->d_parent;
}
}
data.type = EVENT_END;
events.perf_submit(ctx, &data, sizeof(data));
""")
else:
bpf_text = bpf_text.replace('SUBMIT_DATA', """
events.perf_submit(ctx, &data, sizeof(data));
""")
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
# initialize BPF
b = BPF(text=bpf_text)
if not is_support_kfunc:
b.attach_kprobe(event=fnname_open, fn_name="syscall__trace_entry_open")
b.attach_kretprobe(event=fnname_open, fn_name="trace_return")
b.attach_kprobe(event=fnname_openat, fn_name="syscall__trace_entry_openat")
b.attach_kretprobe(event=fnname_openat, fn_name="trace_return")
if fnname_openat2:
b.attach_kprobe(event=fnname_openat2, fn_name="syscall__trace_entry_openat2")
b.attach_kretprobe(event=fnname_openat2, fn_name="trace_return")
initial_ts = 0
# header
if args.timestamp:
print("%-14s" % ("TIME(s)"), end="")
if args.print_uid:
print("%-6s" % ("UID"), end="")
print("%-6s %-16s %4s %3s " %
("TID" if args.tid else "PID", "COMM", "FD", "ERR"), end="")
if args.extended_fields:
print("%-9s" % ("FLAGS"), end="")
print("PATH")
class EventType(object):
EVENT_ENTRY = 0
EVENT_END = 1
entries = defaultdict(list)
# process event
def print_event(cpu, data, size):
event = b["events"].event(data)
global initial_ts
if not args.full_path or event.type == EventType.EVENT_END:
skip = False
# split return value into FD and errno columns
if event.ret >= 0:
fd_s = event.ret
err = 0
else:
fd_s = -1
err = - event.ret
if not initial_ts:
initial_ts = event.ts
if args.failed and (event.ret >= 0):
skip = True
if args.name and bytes(args.name) not in event.comm:
skip = True
if not skip:
if args.timestamp:
delta = event.ts - initial_ts
printb(b"%-14.9f" % (float(delta) / 1000000), nl="")
if args.print_uid:
printb(b"%-6d" % event.uid, nl="")
printb(b"%-6d %-16s %4d %3d " %
(event.id & 0xffffffff if args.tid else event.id >> 32,
event.comm, fd_s, err), nl="")
if args.extended_fields:
printb(b"%08o " % event.flags, nl="")
if not args.full_path:
printb(b"%s" % event.name)
else:
paths = entries[event.id]
paths.reverse()
printb(b"%s" % os.path.join(*paths))
if args.full_path:
try:
del(entries[event.id])
except Exception:
pass
elif event.type == EventType.EVENT_ENTRY:
entries[event.id].append(event.name)
# loop with callback to print_event
b["events"].open_perf_buffer(print_event, page_cnt=args.buffer_pages)
start_time = datetime.now()
while not args.duration or datetime.now() - start_time < args.duration:
try:
b.perf_buffer_poll()
except KeyboardInterrupt:
exit()