linux/tools/bpf/bpftool/main.c
Sahid Orentino Ferdjaoui d1313e0127 bpftool: clean-up usage of libbpf_get_error()
bpftool is now totally compliant with libbpf 1.0 mode and is not
expected to be compiled with pre-1.0, let's clean-up the usage of
libbpf_get_error().

The changes stay aligned with returned errors always negative.

- In tools/bpf/bpftool/btf.c This fixes an uninitialized local
variable `err` in function do_dump() because it may now be returned
without having been set.
- This also removes the checks on NULL pointers before calling
btf__free() because that function already does the check.

Signed-off-by: Sahid Orentino Ferdjaoui <sahid.ferdjaoui@industrialdiscipline.com>
Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-11-20 16:17:46 -08:00

548 lines
12 KiB
C

// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2017-2018 Netronome Systems, Inc. */
#include <ctype.h>
#include <errno.h>
#include <getopt.h>
#include <linux/bpf.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <bpf/bpf.h>
#include <bpf/btf.h>
#include <bpf/hashmap.h>
#include <bpf/libbpf.h>
#include "main.h"
#define BATCH_LINE_LEN_MAX 65536
#define BATCH_ARG_NB_MAX 4096
const char *bin_name;
static int last_argc;
static char **last_argv;
static int (*last_do_help)(int argc, char **argv);
json_writer_t *json_wtr;
bool pretty_output;
bool json_output;
bool show_pinned;
bool block_mount;
bool verifier_logs;
bool relaxed_maps;
bool use_loader;
struct btf *base_btf;
struct hashmap *refs_table;
static void __noreturn clean_and_exit(int i)
{
if (json_output)
jsonw_destroy(&json_wtr);
exit(i);
}
void usage(void)
{
last_do_help(last_argc - 1, last_argv + 1);
clean_and_exit(-1);
}
static int do_help(int argc, char **argv)
{
if (json_output) {
jsonw_null(json_wtr);
return 0;
}
fprintf(stderr,
"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
" %s batch file FILE\n"
" %s version\n"
"\n"
" OBJECT := { prog | map | link | cgroup | perf | net | feature | btf | gen | struct_ops | iter }\n"
" " HELP_SPEC_OPTIONS " |\n"
" {-V|--version} }\n"
"",
bin_name, bin_name, bin_name);
return 0;
}
static int do_batch(int argc, char **argv);
static int do_version(int argc, char **argv);
static const struct cmd commands[] = {
{ "help", do_help },
{ "batch", do_batch },
{ "prog", do_prog },
{ "map", do_map },
{ "link", do_link },
{ "cgroup", do_cgroup },
{ "perf", do_perf },
{ "net", do_net },
{ "feature", do_feature },
{ "btf", do_btf },
{ "gen", do_gen },
{ "struct_ops", do_struct_ops },
{ "iter", do_iter },
{ "version", do_version },
{ 0 }
};
#ifndef BPFTOOL_VERSION
/* bpftool's major and minor version numbers are aligned on libbpf's. There is
* an offset of 6 for the version number, because bpftool's version was higher
* than libbpf's when we adopted this scheme. The patch number remains at 0
* for now. Set BPFTOOL_VERSION to override.
*/
#define BPFTOOL_MAJOR_VERSION (LIBBPF_MAJOR_VERSION + 6)
#define BPFTOOL_MINOR_VERSION LIBBPF_MINOR_VERSION
#define BPFTOOL_PATCH_VERSION 0
#endif
static void
print_feature(const char *feature, bool state, unsigned int *nb_features)
{
if (state) {
printf("%s %s", *nb_features ? "," : "", feature);
*nb_features = *nb_features + 1;
}
}
static int do_version(int argc, char **argv)
{
#ifdef HAVE_LIBBFD_SUPPORT
const bool has_libbfd = true;
#else
const bool has_libbfd = false;
#endif
#ifdef HAVE_LLVM_SUPPORT
const bool has_llvm = true;
#else
const bool has_llvm = false;
#endif
#ifdef BPFTOOL_WITHOUT_SKELETONS
const bool has_skeletons = false;
#else
const bool has_skeletons = true;
#endif
bool bootstrap = false;
int i;
for (i = 0; commands[i].cmd; i++) {
if (!strcmp(commands[i].cmd, "prog")) {
/* Assume we run a bootstrap version if "bpftool prog"
* is not available.
*/
bootstrap = !commands[i].func;
break;
}
}
if (json_output) {
jsonw_start_object(json_wtr); /* root object */
jsonw_name(json_wtr, "version");
#ifdef BPFTOOL_VERSION
jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
#else
jsonw_printf(json_wtr, "\"%d.%d.%d\"", BPFTOOL_MAJOR_VERSION,
BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
#endif
jsonw_name(json_wtr, "libbpf_version");
jsonw_printf(json_wtr, "\"%d.%d\"",
libbpf_major_version(), libbpf_minor_version());
jsonw_name(json_wtr, "features");
jsonw_start_object(json_wtr); /* features */
jsonw_bool_field(json_wtr, "libbfd", has_libbfd);
jsonw_bool_field(json_wtr, "llvm", has_llvm);
jsonw_bool_field(json_wtr, "skeletons", has_skeletons);
jsonw_bool_field(json_wtr, "bootstrap", bootstrap);
jsonw_end_object(json_wtr); /* features */
jsonw_end_object(json_wtr); /* root object */
} else {
unsigned int nb_features = 0;
#ifdef BPFTOOL_VERSION
printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
#else
printf("%s v%d.%d.%d\n", bin_name, BPFTOOL_MAJOR_VERSION,
BPFTOOL_MINOR_VERSION, BPFTOOL_PATCH_VERSION);
#endif
printf("using libbpf %s\n", libbpf_version_string());
printf("features:");
print_feature("libbfd", has_libbfd, &nb_features);
print_feature("llvm", has_llvm, &nb_features);
print_feature("skeletons", has_skeletons, &nb_features);
print_feature("bootstrap", bootstrap, &nb_features);
printf("\n");
}
return 0;
}
int cmd_select(const struct cmd *cmds, int argc, char **argv,
int (*help)(int argc, char **argv))
{
unsigned int i;
last_argc = argc;
last_argv = argv;
last_do_help = help;
if (argc < 1 && cmds[0].func)
return cmds[0].func(argc, argv);
for (i = 0; cmds[i].cmd; i++) {
if (is_prefix(*argv, cmds[i].cmd)) {
if (!cmds[i].func) {
p_err("command '%s' is not supported in bootstrap mode",
cmds[i].cmd);
return -1;
}
return cmds[i].func(argc - 1, argv + 1);
}
}
help(argc - 1, argv + 1);
return -1;
}
bool is_prefix(const char *pfx, const char *str)
{
if (!pfx)
return false;
if (strlen(str) < strlen(pfx))
return false;
return !memcmp(str, pfx, strlen(pfx));
}
/* Last argument MUST be NULL pointer */
int detect_common_prefix(const char *arg, ...)
{
unsigned int count = 0;
const char *ref;
char msg[256];
va_list ap;
snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
va_start(ap, arg);
while ((ref = va_arg(ap, const char *))) {
if (!is_prefix(arg, ref))
continue;
count++;
if (count > 1)
strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
}
va_end(ap);
strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
if (count >= 2) {
p_err("%s", msg);
return -1;
}
return 0;
}
void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
{
unsigned char *data = arg;
unsigned int i;
for (i = 0; i < n; i++) {
const char *pfx = "";
if (!i)
/* nothing */;
else if (!(i % 16))
fprintf(f, "\n");
else if (!(i % 8))
fprintf(f, " ");
else
pfx = sep;
fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
}
}
/* Split command line into argument vector. */
static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
{
static const char ws[] = " \t\r\n";
char *cp = line;
int n_argc = 0;
while (*cp) {
/* Skip leading whitespace. */
cp += strspn(cp, ws);
if (*cp == '\0')
break;
if (n_argc >= (maxargs - 1)) {
p_err("too many arguments to command %d", cmd_nb);
return -1;
}
/* Word begins with quote. */
if (*cp == '\'' || *cp == '"') {
char quote = *cp++;
n_argv[n_argc++] = cp;
/* Find ending quote. */
cp = strchr(cp, quote);
if (!cp) {
p_err("unterminated quoted string in command %d",
cmd_nb);
return -1;
}
} else {
n_argv[n_argc++] = cp;
/* Find end of word. */
cp += strcspn(cp, ws);
if (*cp == '\0')
break;
}
/* Separate words. */
*cp++ = 0;
}
n_argv[n_argc] = NULL;
return n_argc;
}
static int do_batch(int argc, char **argv)
{
char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
char *n_argv[BATCH_ARG_NB_MAX];
unsigned int lines = 0;
int n_argc;
FILE *fp;
char *cp;
int err = 0;
int i;
if (argc < 2) {
p_err("too few parameters for batch");
return -1;
} else if (argc > 2) {
p_err("too many parameters for batch");
return -1;
} else if (!is_prefix(*argv, "file")) {
p_err("expected 'file', got: %s", *argv);
return -1;
}
NEXT_ARG();
if (!strcmp(*argv, "-"))
fp = stdin;
else
fp = fopen(*argv, "r");
if (!fp) {
p_err("Can't open file (%s): %s", *argv, strerror(errno));
return -1;
}
if (json_output)
jsonw_start_array(json_wtr);
while (fgets(buf, sizeof(buf), fp)) {
cp = strchr(buf, '#');
if (cp)
*cp = '\0';
if (strlen(buf) == sizeof(buf) - 1) {
errno = E2BIG;
break;
}
/* Append continuation lines if any (coming after a line ending
* with '\' in the batch file).
*/
while ((cp = strstr(buf, "\\\n")) != NULL) {
if (!fgets(contline, sizeof(contline), fp) ||
strlen(contline) == 0) {
p_err("missing continuation line on command %d",
lines);
err = -1;
goto err_close;
}
cp = strchr(contline, '#');
if (cp)
*cp = '\0';
if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
p_err("command %d is too long", lines);
err = -1;
goto err_close;
}
buf[strlen(buf) - 2] = '\0';
strcat(buf, contline);
}
n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
if (!n_argc)
continue;
if (n_argc < 0) {
err = n_argc;
goto err_close;
}
if (json_output) {
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "command");
jsonw_start_array(json_wtr);
for (i = 0; i < n_argc; i++)
jsonw_string(json_wtr, n_argv[i]);
jsonw_end_array(json_wtr);
jsonw_name(json_wtr, "output");
}
err = cmd_select(commands, n_argc, n_argv, do_help);
if (json_output)
jsonw_end_object(json_wtr);
if (err)
goto err_close;
lines++;
}
if (errno && errno != ENOENT) {
p_err("reading batch file failed: %s", strerror(errno));
err = -1;
} else {
if (!json_output)
printf("processed %d commands\n", lines);
}
err_close:
if (fp != stdin)
fclose(fp);
if (json_output)
jsonw_end_array(json_wtr);
return err;
}
int main(int argc, char **argv)
{
static const struct option options[] = {
{ "json", no_argument, NULL, 'j' },
{ "help", no_argument, NULL, 'h' },
{ "pretty", no_argument, NULL, 'p' },
{ "version", no_argument, NULL, 'V' },
{ "bpffs", no_argument, NULL, 'f' },
{ "mapcompat", no_argument, NULL, 'm' },
{ "nomount", no_argument, NULL, 'n' },
{ "debug", no_argument, NULL, 'd' },
{ "use-loader", no_argument, NULL, 'L' },
{ "base-btf", required_argument, NULL, 'B' },
{ 0 }
};
bool version_requested = false;
int opt, ret;
setlinebuf(stdout);
#ifdef USE_LIBCAP
/* Libcap < 2.63 hooks before main() to compute the number of
* capabilities of the running kernel, and doing so it calls prctl()
* which may fail and set errno to non-zero.
* Let's reset errno to make sure this does not interfere with the
* batch mode.
*/
errno = 0;
#endif
last_do_help = do_help;
pretty_output = false;
json_output = false;
show_pinned = false;
block_mount = false;
bin_name = "bpftool";
opterr = 0;
while ((opt = getopt_long(argc, argv, "VhpjfLmndB:l",
options, NULL)) >= 0) {
switch (opt) {
case 'V':
version_requested = true;
break;
case 'h':
return do_help(argc, argv);
case 'p':
pretty_output = true;
/* fall through */
case 'j':
if (!json_output) {
json_wtr = jsonw_new(stdout);
if (!json_wtr) {
p_err("failed to create JSON writer");
return -1;
}
json_output = true;
}
jsonw_pretty(json_wtr, pretty_output);
break;
case 'f':
show_pinned = true;
break;
case 'm':
relaxed_maps = true;
break;
case 'n':
block_mount = true;
break;
case 'd':
libbpf_set_print(print_all_levels);
verifier_logs = true;
break;
case 'B':
base_btf = btf__parse(optarg, NULL);
if (!base_btf) {
p_err("failed to parse base BTF at '%s': %d\n",
optarg, -errno);
return -1;
}
break;
case 'L':
use_loader = true;
break;
default:
p_err("unrecognized option '%s'", argv[optind - 1]);
if (json_output)
clean_and_exit(-1);
else
usage();
}
}
argc -= optind;
argv += optind;
if (argc < 0)
usage();
if (version_requested)
return do_version(argc, argv);
ret = cmd_select(commands, argc, argv, do_help);
if (json_output)
jsonw_destroy(&json_wtr);
btf__free(base_btf);
return ret;
}