blob: ce7136dcf48518f0802ef20a6f7b792aaa5cd23b [file] [log] [blame]
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
// Copyright (c) 2019 Facebook
// Copyright (c) 2020 Netflix
//
// Based on opensnoop(8) from BCC by Brendan Gregg and others.
// 14-Feb-2020 Brendan Gregg Created this.
#include <argp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <bpf/libbpf.h>
#include <bpf/bpf.h>
#include "opensnoop.h"
#include "opensnoop.skel.h"
#include "btf_helpers.h"
#include "trace_helpers.h"
#ifdef USE_BLAZESYM
#include "blazesym.h"
#endif
/* Tune the buffer size and wakeup rate. These settings cope with roughly
* 50k opens/sec.
*/
#define PERF_BUFFER_PAGES 64
#define PERF_BUFFER_TIME_MS 10
/* Set the poll timeout when no events occur. This can affect -d accuracy. */
#define PERF_POLL_TIMEOUT_MS 100
#define NSEC_PER_SEC 1000000000ULL
static volatile sig_atomic_t exiting = 0;
#ifdef USE_BLAZESYM
static blazesym *symbolizer;
#endif
static struct env {
pid_t pid;
pid_t tid;
uid_t uid;
int duration;
bool verbose;
bool timestamp;
bool print_uid;
bool extended;
bool failed;
char *name;
#ifdef USE_BLAZESYM
bool callers;
#endif
} env = {
.uid = INVALID_UID
};
const char *argp_program_version = "opensnoop 0.1";
const char *argp_program_bug_address =
"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
const char argp_program_doc[] =
"Trace open family syscalls\n"
"\n"
"USAGE: opensnoop [-h] [-T] [-U] [-x] [-p PID] [-t TID] [-u UID] [-d DURATION]\n"
#ifdef USE_BLAZESYM
" [-n NAME] [-e] [-c]\n"
#else
" [-n NAME] [-e]\n"
#endif
"\n"
"EXAMPLES:\n"
" ./opensnoop # trace all open() syscalls\n"
" ./opensnoop -T # include timestamps\n"
" ./opensnoop -U # include UID\n"
" ./opensnoop -x # only show failed opens\n"
" ./opensnoop -p 181 # only trace PID 181\n"
" ./opensnoop -t 123 # only trace TID 123\n"
" ./opensnoop -u 1000 # only trace UID 1000\n"
" ./opensnoop -d 10 # trace for 10 seconds only\n"
" ./opensnoop -n main # only print process names containing \"main\"\n"
" ./opensnoop -e # show extended fields\n"
#ifdef USE_BLAZESYM
" ./opensnoop -c # show calling functions\n"
#endif
"";
static const struct argp_option opts[] = {
{ "duration", 'd', "DURATION", 0, "Duration to trace"},
{ "extended-fields", 'e', NULL, 0, "Print extended fields"},
{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help"},
{ "name", 'n', "NAME", 0, "Trace process names containing this"},
{ "pid", 'p', "PID", 0, "Process ID to trace"},
{ "tid", 't', "TID", 0, "Thread ID to trace"},
{ "timestamp", 'T', NULL, 0, "Print timestamp"},
{ "uid", 'u', "UID", 0, "User ID to trace"},
{ "print-uid", 'U', NULL, 0, "Print UID"},
{ "verbose", 'v', NULL, 0, "Verbose debug output" },
{ "failed", 'x', NULL, 0, "Failed opens only"},
#ifdef USE_BLAZESYM
{ "callers", 'c', NULL, 0, "Show calling functions"},
#endif
{},
};
static error_t parse_arg(int key, char *arg, struct argp_state *state)
{
static int pos_args;
long int pid, uid, duration;
switch (key) {
case 'e':
env.extended = true;
break;
case 'h':
argp_usage(state);
break;
case 'T':
env.timestamp = true;
break;
case 'U':
env.print_uid = true;
break;
case 'v':
env.verbose = true;
break;
case 'x':
env.failed = true;
break;
case 'd':
errno = 0;
duration = strtol(arg, NULL, 10);
if (errno || duration <= 0) {
fprintf(stderr, "Invalid duration: %s\n", arg);
argp_usage(state);
}
env.duration = duration;
break;
case 'n':
errno = 0;
env.name = arg;
break;
case 'p':
errno = 0;
pid = strtol(arg, NULL, 10);
if (errno || pid <= 0) {
fprintf(stderr, "Invalid PID: %s\n", arg);
argp_usage(state);
}
env.pid = pid;
break;
case 't':
errno = 0;
pid = strtol(arg, NULL, 10);
if (errno || pid <= 0) {
fprintf(stderr, "Invalid TID: %s\n", arg);
argp_usage(state);
}
env.tid = pid;
break;
case 'u':
errno = 0;
uid = strtol(arg, NULL, 10);
if (errno || uid < 0 || uid >= INVALID_UID) {
fprintf(stderr, "Invalid UID %s\n", arg);
argp_usage(state);
}
env.uid = uid;
break;
#ifdef USE_BLAZESYM
case 'c':
env.callers = true;
break;
#endif
case ARGP_KEY_ARG:
if (pos_args++) {
fprintf(stderr,
"Unrecognized positional argument: %s\n", arg);
argp_usage(state);
}
errno = 0;
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
{
if (level == LIBBPF_DEBUG && !env.verbose)
return 0;
return vfprintf(stderr, format, args);
}
static void sig_int(int signo)
{
exiting = 1;
}
void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
{
const struct event *e = data;
struct tm *tm;
#ifdef USE_BLAZESYM
sym_src_cfg cfgs[] = {
{ .src_type = SRC_T_PROCESS, .params = { .process = { .pid = e->pid }}},
};
const blazesym_result *result = NULL;
const blazesym_csym *sym;
int i, j;
#endif
int sps_cnt;
char ts[32];
time_t t;
int fd, err;
/* name filtering is currently done in user space */
if (env.name && strstr(e->comm, env.name) == NULL)
return;
/* prepare fields */
time(&t);
tm = localtime(&t);
strftime(ts, sizeof(ts), "%H:%M:%S", tm);
if (e->ret >= 0) {
fd = e->ret;
err = 0;
} else {
fd = -1;
err = - e->ret;
}
#ifdef USE_BLAZESYM
if (env.callers)
result = blazesym_symbolize(symbolizer, cfgs, 1, (const uint64_t *)&e->callers, 2);
#endif
/* print output */
sps_cnt = 0;
if (env.timestamp) {
printf("%-8s ", ts);
sps_cnt += 9;
}
if (env.print_uid) {
printf("%-7d ", e->uid);
sps_cnt += 8;
}
printf("%-6d %-16s %3d %3d ", e->pid, e->comm, fd, err);
sps_cnt += 7 + 17 + 4 + 4;
if (env.extended) {
printf("%08o ", e->flags);
sps_cnt += 9;
}
printf("%s\n", e->fname);
#ifdef USE_BLAZESYM
for (i = 0; result && i < result->size; i++) {
if (result->entries[i].size == 0)
continue;
sym = &result->entries[i].syms[0];
for (j = 0; j < sps_cnt; j++)
printf(" ");
if (sym->line_no)
printf("%s:%ld\n", sym->symbol, sym->line_no);
else
printf("%s\n", sym->symbol);
}
blazesym_result_free(result);
#endif
}
void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
{
fprintf(stderr, "Lost %llu events on CPU #%d!\n", lost_cnt, cpu);
}
int main(int argc, char **argv)
{
LIBBPF_OPTS(bpf_object_open_opts, open_opts);
static const struct argp argp = {
.options = opts,
.parser = parse_arg,
.doc = argp_program_doc,
};
struct perf_buffer *pb = NULL;
struct opensnoop_bpf *obj;
__u64 time_end = 0;
int err;
err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
if (err)
return err;
libbpf_set_print(libbpf_print_fn);
err = ensure_core_btf(&open_opts);
if (err) {
fprintf(stderr, "failed to fetch necessary BTF for CO-RE: %s\n", strerror(-err));
return 1;
}
obj = opensnoop_bpf__open_opts(&open_opts);
if (!obj) {
fprintf(stderr, "failed to open BPF object\n");
return 1;
}
/* initialize global data (filtering options) */
obj->rodata->targ_tgid = env.pid;
obj->rodata->targ_pid = env.tid;
obj->rodata->targ_uid = env.uid;
obj->rodata->targ_failed = env.failed;
/* aarch64 and riscv64 don't have open syscall */
if (!tracepoint_exists("syscalls", "sys_enter_open")) {
bpf_program__set_autoload(obj->progs.tracepoint__syscalls__sys_enter_open, false);
bpf_program__set_autoload(obj->progs.tracepoint__syscalls__sys_exit_open, false);
}
err = opensnoop_bpf__load(obj);
if (err) {
fprintf(stderr, "failed to load BPF object: %d\n", err);
goto cleanup;
}
err = opensnoop_bpf__attach(obj);
if (err) {
fprintf(stderr, "failed to attach BPF programs\n");
goto cleanup;
}
#ifdef USE_BLAZESYM
if (env.callers)
symbolizer = blazesym_new();
#endif
/* print headers */
if (env.timestamp)
printf("%-8s ", "TIME");
if (env.print_uid)
printf("%-7s ", "UID");
printf("%-6s %-16s %3s %3s ", "PID", "COMM", "FD", "ERR");
if (env.extended)
printf("%-8s ", "FLAGS");
printf("%s", "PATH");
#ifdef USE_BLAZESYM
if (env.callers)
printf("/CALLER");
#endif
printf("\n");
/* setup event callbacks */
pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
handle_event, handle_lost_events, NULL, NULL);
if (!pb) {
err = -errno;
fprintf(stderr, "failed to open perf buffer: %d\n", err);
goto cleanup;
}
/* setup duration */
if (env.duration)
time_end = get_ktime_ns() + env.duration * NSEC_PER_SEC;
if (signal(SIGINT, sig_int) == SIG_ERR) {
fprintf(stderr, "can't set signal handler: %s\n", strerror(errno));
err = 1;
goto cleanup;
}
/* main: poll */
while (!exiting) {
err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
if (err < 0 && err != -EINTR) {
fprintf(stderr, "error polling perf buffer: %s\n", strerror(-err));
goto cleanup;
}
if (env.duration && get_ktime_ns() > time_end)
goto cleanup;
/* reset err to return 0 if exiting */
err = 0;
}
cleanup:
perf_buffer__free(pb);
opensnoop_bpf__destroy(obj);
cleanup_core_btf(&open_opts);
#ifdef USE_BLAZESYM
blazesym_free(symbolizer);
#endif
return err != 0;
}