libbpf-tools/exitsnoop.c - platform/external/bcc - Git at Google

 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */

 /*
  * exitsnoop	Trace process termination.
  *
  * Copyright (c) 2021 Hengqi Chen
  *
  * Based on exitsnoop(8) from BCC by Arturo Martin-de-Nicolas & Jeroen Soeters.
  * 05-Aug-2021   Hengqi Chen   Created this.
  */
 #include <argp.h>
 #include <errno.h>
 #include <signal.h>
 #include <string.h>
 #include <time.h>
 #include <fcntl.h>
 #include <unistd.h>

 #include <bpf/libbpf.h>
 #include <bpf/bpf.h>
 #include "exitsnoop.h"
 #include "exitsnoop.skel.h"
 #include "btf_helpers.h"
 #include "trace_helpers.h"

 #define PERF_BUFFER_PAGES	16
 #define PERF_POLL_TIMEOUT_MS	100
 #define warn(...) fprintf(stderr, __VA_ARGS__)

 static volatile sig_atomic_t exiting = 0;

 static bool emit_timestamp = false;
 static pid_t target_pid = 0;
 static bool trace_failed_only = false;
 static bool trace_by_process = true;
 static bool verbose = false;

 static struct env {
 	char *cgroupspath;
 	bool cg;
 } env;

 const char *argp_program_version = "exitsnoop 0.1";
 const char *argp_program_bug_address =
 	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
 const char argp_program_doc[] =
 "Trace process termination.\n"
 "\n"
 "USAGE: exitsnoop [-h] [-t] [-x] [-p PID] [-T] [-c CG]\n"
 "\n"
 "EXAMPLES:\n"
 "    exitsnoop             # trace process exit events\n"
 "    exitsnoop -t          # include timestamps\n"
 "    exitsnoop -x          # trace error exits only\n"
 "    exitsnoop -p 1216     # only trace PID 1216\n"
 "    exitsnoop -T          # trace by thread\n"
 "    exitsnoop -c CG       # Trace process under cgroupsPath CG\n";

 static const struct argp_option opts[] = {
 	{ "timestamp", 't', NULL, 0, "Include timestamp on output" },
 	{ "failed", 'x', NULL, 0, "Trace error exits only." },
 	{ "pid", 'p', "PID", 0, "Process ID to trace" },
 	{ "threaded", 'T', NULL, 0, "Trace by thread." },
 	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
 	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
 	{ "cgroup", 'c', "/sys/fs/cgroup/unified", 0, "Trace process in cgroup path"},
 	{},
 };

 static error_t parse_arg(int key, char *arg, struct argp_state *state)
 {
 	long pid;

 	switch (key) {
 	case 'p':
 		errno = 0;
 		pid = strtol(arg, NULL, 10);
 		if (errno || pid <= 0) {
 			warn("Invalid PID: %s\n", arg);
 			argp_usage(state);
 		}
 		target_pid = pid;
 		break;
 	case 't':
 		emit_timestamp = true;
 		break;
 	case 'x':
 		trace_failed_only = true;
 		break;
 	case 'T':
 		trace_by_process = false;
 		break;
 	case 'v':
 		verbose = true;
 		break;
 	case 'c':
 		env.cgroupspath = arg;
 		env.cg = true;
 		break;
 	case 'h':
 		argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
 		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 && !verbose)
 		return 0;
 	return vfprintf(stderr, format, args);
 }

 static void sig_int(int signo)
 {
 	exiting = 1;
 }

 static void handle_event(void *ctx, int cpu, void *data, __u32 data_sz)
 {
 	struct event *e = data;
 	time_t t;
 	struct tm *tm;
 	char ts[32];
 	double age;
 	int sig, coredump;

 	if (emit_timestamp) {
 		time(&t);
 		tm = localtime(&t);
 		strftime(ts, sizeof(ts), "%H:%M:%S", tm);
 		printf("%8s ", ts);
 	}

 	age = (e->exit_time - e->start_time) / 1e9;
 	printf("%-16s %-7d %-7d %-7d %-7.2f ",
 	       e->comm, e->pid, e->ppid, e->tid, age);

 	if (!e->sig) {
 		if (!e->exit_code)
 			printf("0\n");
 		else
 			printf("code %d\n", e->exit_code);
 	} else {
 		sig = e->sig & 0x7f;
 		coredump = e->sig & 0x80;
 		if (sig)
 			printf("signal %d (%s)", sig, strsignal(sig));
 		if (coredump)
 			printf(", core dumped");
 		printf("\n");
 	}
 }

 static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
 {
 	warn("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 exitsnoop_bpf *obj;
 	int err;
 	int idx, cg_map_fd;
 	int cgfd = -1;

 	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 = exitsnoop_bpf__open_opts(&open_opts);
 	if (!obj) {
 		warn("failed to open BPF object\n");
 		return 1;
 	}

 	obj->rodata->target_pid = target_pid;
 	obj->rodata->trace_failed_only = trace_failed_only;
 	obj->rodata->trace_by_process = trace_by_process;
 	obj->rodata->filter_cg = env.cg;

 	err = exitsnoop_bpf__load(obj);
 	if (err) {
 		warn("failed to load BPF object: %d\n", err);
 		goto cleanup;
 	}

 	/* update cgroup path fd to map */
 	if (env.cg) {
 		idx = 0;
 		cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
 		cgfd = open(env.cgroupspath, O_RDONLY);
 		if (cgfd < 0) {
 			fprintf(stderr, "Failed opening Cgroup path: %s", env.cgroupspath);
 			goto cleanup;
 		}
 		if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
 			fprintf(stderr, "Failed adding target cgroup to map");
 			goto cleanup;
 		}
 	}

 	err = exitsnoop_bpf__attach(obj);
 	if (err) {
 		warn("failed to attach BPF programs: %d\n", err);
 		goto cleanup;
 	}

 	pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
 			      handle_event, handle_lost_events, NULL, NULL);
 	if (!pb) {
 		err = -errno;
 		warn("failed to open perf buffer: %d\n", err);
 		goto cleanup;
 	}

 	if (signal(SIGINT, sig_int) == SIG_ERR) {
 		warn("can't set signal handler: %s\n", strerror(errno));
 		err = 1;
 		goto cleanup;
 	}

 	if (emit_timestamp)
 		printf("%-8s ", "TIME(s)");
 	printf("%-16s %-7s %-7s %-7s %-7s %-s\n",
 	       "PCOMM", "PID", "PPID", "TID", "AGE(s)", "EXIT_CODE");

 	while (!exiting) {
 		err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
 		if (err < 0 && err != -EINTR) {
 			warn("error polling perf buffer: %s\n", strerror(-err));
 			goto cleanup;
 		}
 		/* reset err to return 0 if exiting */
 		err = 0;
 	}

 cleanup:
 	perf_buffer__free(pb);
 	exitsnoop_bpf__destroy(obj);
 	cleanup_core_btf(&open_opts);
 	if (cgfd > 0)
 		close(cgfd);

 	return err != 0;
 }
	/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */

	/*
	* exitsnoop Trace process termination.
	*
	* Copyright (c) 2021 Hengqi Chen
	*
	* Based on exitsnoop(8) from BCC by Arturo Martin-de-Nicolas & Jeroen Soeters.
	* 05-Aug-2021 Hengqi Chen Created this.
	*/
	#include <argp.h>
	#include <errno.h>
	#include <signal.h>
	#include <string.h>
	#include <time.h>
	#include <fcntl.h>
	#include <unistd.h>

	#include <bpf/libbpf.h>
	#include <bpf/bpf.h>
	#include "exitsnoop.h"
	#include "exitsnoop.skel.h"
	#include "btf_helpers.h"
	#include "trace_helpers.h"

	#define PERF_BUFFER_PAGES 16
	#define PERF_POLL_TIMEOUT_MS 100
	#define warn(...) fprintf(stderr, __VA_ARGS__)

	static volatile sig_atomic_t exiting = 0;

	static bool emit_timestamp = false;
	static pid_t target_pid = 0;
	static bool trace_failed_only = false;
	static bool trace_by_process = true;
	static bool verbose = false;

	static struct env {
	char *cgroupspath;
	bool cg;
	} env;

	const char *argp_program_version = "exitsnoop 0.1";
	const char *argp_program_bug_address =
	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
	const char argp_program_doc[] =
	"Trace process termination.\n"
	"\n"
	"USAGE: exitsnoop [-h] [-t] [-x] [-p PID] [-T] [-c CG]\n"
	"\n"
	"EXAMPLES:\n"
	" exitsnoop # trace process exit events\n"
	" exitsnoop -t # include timestamps\n"
	" exitsnoop -x # trace error exits only\n"
	" exitsnoop -p 1216 # only trace PID 1216\n"
	" exitsnoop -T # trace by thread\n"
	" exitsnoop -c CG # Trace process under cgroupsPath CG\n";

	static const struct argp_option opts[] = {
	{ "timestamp", 't', NULL, 0, "Include timestamp on output" },
	{ "failed", 'x', NULL, 0, "Trace error exits only." },
	{ "pid", 'p', "PID", 0, "Process ID to trace" },
	{ "threaded", 'T', NULL, 0, "Trace by thread." },
	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
	{ "cgroup", 'c', "/sys/fs/cgroup/unified", 0, "Trace process in cgroup path"},
	{},
	};

	static error_t parse_arg(int key, char arg, struct argp_state state)
	{
	long pid;

	switch (key) {
	case 'p':
	errno = 0;
	pid = strtol(arg, NULL, 10);
	if (errno \|\| pid <= 0) {
	warn("Invalid PID: %s\n", arg);
	argp_usage(state);
	}
	target_pid = pid;
	break;
	case 't':
	emit_timestamp = true;
	break;
	case 'x':
	trace_failed_only = true;
	break;
	case 'T':
	trace_by_process = false;
	break;
	case 'v':
	verbose = true;
	break;
	case 'c':
	env.cgroupspath = arg;
	env.cg = true;
	break;
	case 'h':
	argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
	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 && !verbose)
	return 0;
	return vfprintf(stderr, format, args);
	}

	static void sig_int(int signo)
	{
	exiting = 1;
	}

	static void handle_event(void ctx, int cpu, void data, __u32 data_sz)
	{
	struct event *e = data;
	time_t t;
	struct tm *tm;
	char ts[32];
	double age;
	int sig, coredump;

	if (emit_timestamp) {
	time(&t);
	tm = localtime(&t);
	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
	printf("%8s ", ts);
	}

	age = (e->exit_time - e->start_time) / 1e9;
	printf("%-16s %-7d %-7d %-7d %-7.2f ",
	e->comm, e->pid, e->ppid, e->tid, age);

	if (!e->sig) {
	if (!e->exit_code)
	printf("0\n");
	else
	printf("code %d\n", e->exit_code);
	} else {
	sig = e->sig & 0x7f;
	coredump = e->sig & 0x80;
	if (sig)
	printf("signal %d (%s)", sig, strsignal(sig));
	if (coredump)
	printf(", core dumped");
	printf("\n");
	}
	}

	static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
	{
	warn("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 exitsnoop_bpf *obj;
	int err;
	int idx, cg_map_fd;
	int cgfd = -1;

	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 = exitsnoop_bpf__open_opts(&open_opts);
	if (!obj) {
	warn("failed to open BPF object\n");
	return 1;
	}

	obj->rodata->target_pid = target_pid;
	obj->rodata->trace_failed_only = trace_failed_only;
	obj->rodata->trace_by_process = trace_by_process;
	obj->rodata->filter_cg = env.cg;

	err = exitsnoop_bpf__load(obj);
	if (err) {
	warn("failed to load BPF object: %d\n", err);
	goto cleanup;
	}

	/* update cgroup path fd to map */
	if (env.cg) {
	idx = 0;
	cg_map_fd = bpf_map__fd(obj->maps.cgroup_map);
	cgfd = open(env.cgroupspath, O_RDONLY);
	if (cgfd < 0) {
	fprintf(stderr, "Failed opening Cgroup path: %s", env.cgroupspath);
	goto cleanup;
	}
	if (bpf_map_update_elem(cg_map_fd, &idx, &cgfd, BPF_ANY)) {
	fprintf(stderr, "Failed adding target cgroup to map");
	goto cleanup;
	}
	}

	err = exitsnoop_bpf__attach(obj);
	if (err) {
	warn("failed to attach BPF programs: %d\n", err);
	goto cleanup;
	}

	pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES,
	handle_event, handle_lost_events, NULL, NULL);
	if (!pb) {
	err = -errno;
	warn("failed to open perf buffer: %d\n", err);
	goto cleanup;
	}

	if (signal(SIGINT, sig_int) == SIG_ERR) {
	warn("can't set signal handler: %s\n", strerror(errno));
	err = 1;
	goto cleanup;
	}

	if (emit_timestamp)
	printf("%-8s ", "TIME(s)");
	printf("%-16s %-7s %-7s %-7s %-7s %-s\n",
	"PCOMM", "PID", "PPID", "TID", "AGE(s)", "EXIT_CODE");

	while (!exiting) {
	err = perf_buffer__poll(pb, PERF_POLL_TIMEOUT_MS);
	if (err < 0 && err != -EINTR) {
	warn("error polling perf buffer: %s\n", strerror(-err));
	goto cleanup;
	}
	/* reset err to return 0 if exiting */
	err = 0;
	}

	cleanup:
	perf_buffer__free(pb);
	exitsnoop_bpf__destroy(obj);
	cleanup_core_btf(&open_opts);
	if (cgfd > 0)
	close(cgfd);

	return err != 0;
	}