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

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

 /*
  * gethostlatency  Show latency for getaddrinfo/gethostbyname[2] calls.
  *
  * Copyright (c) 2021 Hengqi Chen
  *
  * Based on gethostlatency(8) from BCC by Brendan Gregg.
  * 24-Mar-2021   Hengqi Chen   Created this.
  */
 #include <argp.h>
 #include <errno.h>
 #include <signal.h>
 #include <time.h>
 #include <unistd.h>

 #include <bpf/libbpf.h>
 #include <bpf/bpf.h>
 #include "gethostlatency.h"
 #include "gethostlatency.skel.h"
 #include "btf_helpers.h"
 #include "trace_helpers.h"
 #include "uprobe_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 pid_t target_pid = 0;
 static const char *libc_path = NULL;
 static bool verbose = false;

 const char *argp_program_version = "gethostlatency 0.1";
 const char *argp_program_bug_address =
 	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
 const char argp_program_doc[] =
 "Show latency for getaddrinfo/gethostbyname[2] calls.\n"
 "\n"
 "USAGE: gethostlatency [-h] [-p PID] [-l LIBC]\n"
 "\n"
 "EXAMPLES:\n"
 "    gethostlatency             # time getaddrinfo/gethostbyname[2] calls\n"
 "    gethostlatency -p 1216     # only trace PID 1216\n";

 static const struct argp_option opts[] = {
 	{ "pid", 'p', "PID", 0, "Process ID to trace" },
 	{ "libc", 'l', "LIBC", 0, "Specify which libc.so to use" },
 	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
 	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
 	{},
 };

 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 'l':
 		libc_path = strdup(arg);
 		if (access(libc_path, F_OK)) {
 			warn("Invalid libc: %s\n", arg);
 			argp_usage(state);
 		}
 		break;
 	case 'v':
 		verbose = 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)
 {
 	const struct event *e = data;
 	struct tm *tm;
 	char ts[16];
 	time_t t;

 	time(&t);
 	tm = localtime(&t);
 	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
 	printf("%-8s %-7d %-16s %-10.3f %-s\n",
 	       ts, e->pid, e->comm, (double)e->time/1000000, e->host);
 }

 static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
 {
 	warn("lost %llu events on CPU #%d\n", lost_cnt, cpu);
 }

 static int get_libc_path(char *path)
 {
 	FILE *f;
 	char buf[PATH_MAX] = {};
 	char *filename;
 	float version;

 	if (libc_path) {
 		memcpy(path, libc_path, strlen(libc_path));
 		return 0;
 	}

 	f = fopen("/proc/self/maps", "r");
 	if (!f)
 		return -errno;

 	while (fscanf(f, "%*x-%*x %*s %*s %*s %*s %[^\n]\n", buf) != EOF) {
 		if (strchr(buf, '/') != buf)
 			continue;
 		filename = strrchr(buf, '/') + 1;
 		if (sscanf(filename, "libc-%f.so", &version) == 1 ||
 		    sscanf(filename, "libc.so.%f", &version) == 1) {
 			memcpy(path, buf, strlen(buf));
 			fclose(f);
 			return 0;
 		}
 	}

 	fclose(f);
 	return -1;
 }

 static int attach_uprobes(struct gethostlatency_bpf *obj, struct bpf_link *links[])
 {
 	int err;
 	char libc_path[PATH_MAX] = {};
 	off_t func_off;

 	err = get_libc_path(libc_path);
 	if (err) {
 		warn("could not find libc.so\n");
 		return -1;
 	}

 	func_off = get_elf_func_offset(libc_path, "getaddrinfo");
 	if (func_off < 0) {
 		warn("could not find getaddrinfo in %s\n", libc_path);
 		return -1;
 	}
 	links[0] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[0]) {
 		warn("failed to attach getaddrinfo: %d\n", -errno);
 		return -1;
 	}
 	links[1] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[1]) {
 		warn("failed to attach getaddrinfo: %d\n", -errno);
 		return -1;
 	}

 	func_off = get_elf_func_offset(libc_path, "gethostbyname");
 	if (func_off < 0) {
 		warn("could not find gethostbyname in %s\n", libc_path);
 		return -1;
 	}
 	links[2] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[2]) {
 		warn("failed to attach gethostbyname: %d\n", -errno);
 		return -1;
 	}
 	links[3] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[3]) {
 		warn("failed to attach gethostbyname: %d\n", -errno);
 		return -1;
 	}

 	func_off = get_elf_func_offset(libc_path, "gethostbyname2");
 	if (func_off < 0) {
 		warn("could not find gethostbyname2 in %s\n", libc_path);
 		return -1;
 	}
 	links[4] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[4]) {
 		warn("failed to attach gethostbyname2: %d\n", -errno);
 		return -1;
 	}
 	links[5] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
 					      target_pid ?: -1, libc_path, func_off);
 	if (!links[5]) {
 		warn("failed to attach gethostbyname2: %d\n", -errno);
 		return -1;
 	}

 	return 0;
 }

 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 bpf_link *links[6] = {};
 	struct gethostlatency_bpf *obj;
 	int i, 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 = gethostlatency_bpf__open_opts(&open_opts);
 	if (!obj) {
 		warn("failed to open BPF object\n");
 		return 1;
 	}

 	obj->rodata->target_pid = target_pid;

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

 	err = attach_uprobes(obj, links);
 	if (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;
 	}

 	printf("%-8s %-7s %-16s %-10s %-s\n",
 	       "TIME", "PID", "COMM", "LATms", "HOST");

 	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);
 	for (i = 0; i < 6; i++)
 		bpf_link__destroy(links[i]);
 	gethostlatency_bpf__destroy(obj);
 	cleanup_core_btf(&open_opts);

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

	/*
	* gethostlatency Show latency for getaddrinfo/gethostbyname[2] calls.
	*
	* Copyright (c) 2021 Hengqi Chen
	*
	* Based on gethostlatency(8) from BCC by Brendan Gregg.
	* 24-Mar-2021 Hengqi Chen Created this.
	*/
	#include <argp.h>
	#include <errno.h>
	#include <signal.h>
	#include <time.h>
	#include <unistd.h>

	#include <bpf/libbpf.h>
	#include <bpf/bpf.h>
	#include "gethostlatency.h"
	#include "gethostlatency.skel.h"
	#include "btf_helpers.h"
	#include "trace_helpers.h"
	#include "uprobe_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 pid_t target_pid = 0;
	static const char *libc_path = NULL;
	static bool verbose = false;

	const char *argp_program_version = "gethostlatency 0.1";
	const char *argp_program_bug_address =
	"https://github.com/iovisor/bcc/tree/master/libbpf-tools";
	const char argp_program_doc[] =
	"Show latency for getaddrinfo/gethostbyname[2] calls.\n"
	"\n"
	"USAGE: gethostlatency [-h] [-p PID] [-l LIBC]\n"
	"\n"
	"EXAMPLES:\n"
	" gethostlatency # time getaddrinfo/gethostbyname[2] calls\n"
	" gethostlatency -p 1216 # only trace PID 1216\n";

	static const struct argp_option opts[] = {
	{ "pid", 'p', "PID", 0, "Process ID to trace" },
	{ "libc", 'l', "LIBC", 0, "Specify which libc.so to use" },
	{ "verbose", 'v', NULL, 0, "Verbose debug output" },
	{ NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
	{},
	};

	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 'l':
	libc_path = strdup(arg);
	if (access(libc_path, F_OK)) {
	warn("Invalid libc: %s\n", arg);
	argp_usage(state);
	}
	break;
	case 'v':
	verbose = 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)
	{
	const struct event *e = data;
	struct tm *tm;
	char ts[16];
	time_t t;

	time(&t);
	tm = localtime(&t);
	strftime(ts, sizeof(ts), "%H:%M:%S", tm);
	printf("%-8s %-7d %-16s %-10.3f %-s\n",
	ts, e->pid, e->comm, (double)e->time/1000000, e->host);
	}

	static void handle_lost_events(void *ctx, int cpu, __u64 lost_cnt)
	{
	warn("lost %llu events on CPU #%d\n", lost_cnt, cpu);
	}

	static int get_libc_path(char *path)
	{
	FILE *f;
	char buf[PATH_MAX] = {};
	char *filename;
	float version;

	if (libc_path) {
	memcpy(path, libc_path, strlen(libc_path));
	return 0;
	}

	f = fopen("/proc/self/maps", "r");
	if (!f)
	return -errno;

	while (fscanf(f, "%x-%x %s %s %s %s %[^\n]\n", buf) != EOF) {
	if (strchr(buf, '/') != buf)
	continue;
	filename = strrchr(buf, '/') + 1;
	if (sscanf(filename, "libc-%f.so", &version) == 1 \|\|
	sscanf(filename, "libc.so.%f", &version) == 1) {
	memcpy(path, buf, strlen(buf));
	fclose(f);
	return 0;
	}
	}

	fclose(f);
	return -1;
	}

	static int attach_uprobes(struct gethostlatency_bpf obj, struct bpf_link links[])
	{
	int err;
	char libc_path[PATH_MAX] = {};
	off_t func_off;

	err = get_libc_path(libc_path);
	if (err) {
	warn("could not find libc.so\n");
	return -1;
	}

	func_off = get_elf_func_offset(libc_path, "getaddrinfo");
	if (func_off < 0) {
	warn("could not find getaddrinfo in %s\n", libc_path);
	return -1;
	}
	links[0] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
	target_pid ?: -1, libc_path, func_off);
	if (!links[0]) {
	warn("failed to attach getaddrinfo: %d\n", -errno);
	return -1;
	}
	links[1] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
	target_pid ?: -1, libc_path, func_off);
	if (!links[1]) {
	warn("failed to attach getaddrinfo: %d\n", -errno);
	return -1;
	}

	func_off = get_elf_func_offset(libc_path, "gethostbyname");
	if (func_off < 0) {
	warn("could not find gethostbyname in %s\n", libc_path);
	return -1;
	}
	links[2] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
	target_pid ?: -1, libc_path, func_off);
	if (!links[2]) {
	warn("failed to attach gethostbyname: %d\n", -errno);
	return -1;
	}
	links[3] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
	target_pid ?: -1, libc_path, func_off);
	if (!links[3]) {
	warn("failed to attach gethostbyname: %d\n", -errno);
	return -1;
	}

	func_off = get_elf_func_offset(libc_path, "gethostbyname2");
	if (func_off < 0) {
	warn("could not find gethostbyname2 in %s\n", libc_path);
	return -1;
	}
	links[4] = bpf_program__attach_uprobe(obj->progs.handle_entry, false,
	target_pid ?: -1, libc_path, func_off);
	if (!links[4]) {
	warn("failed to attach gethostbyname2: %d\n", -errno);
	return -1;
	}
	links[5] = bpf_program__attach_uprobe(obj->progs.handle_return, true,
	target_pid ?: -1, libc_path, func_off);
	if (!links[5]) {
	warn("failed to attach gethostbyname2: %d\n", -errno);
	return -1;
	}

	return 0;
	}

	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 bpf_link *links[6] = {};
	struct gethostlatency_bpf *obj;
	int i, 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 = gethostlatency_bpf__open_opts(&open_opts);
	if (!obj) {
	warn("failed to open BPF object\n");
	return 1;
	}

	obj->rodata->target_pid = target_pid;

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

	err = attach_uprobes(obj, links);
	if (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;
	}

	printf("%-8s %-7s %-16s %-10s %-s\n",
	"TIME", "PID", "COMM", "LATms", "HOST");

	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);
	for (i = 0; i < 6; i++)
	bpf_link__destroy(links[i]);
	gethostlatency_bpf__destroy(obj);
	cleanup_core_btf(&open_opts);

	return err != 0;
	}