linux_dsm_epyc7002/tools/bpf/bpftool/prog.c
Quentin Monnet 52c84d36b7 tools: bpftool: preserve JSON for batch mode when dumping insns to file
Print a "null" JSON object to standard output when bpftool is used to
print program instructions to a file, so as to avoid breaking JSON
output on batch mode.

This null object was added for most commands in a previous commit, but
this specific case had been omitted.

Fixes: 004b45c0e5 ("tools: bpftool: provide JSON output for all possible commands")
Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-02-15 10:01:05 +01:00

883 lines
19 KiB
C

/*
* Copyright (C) 2017 Netronome Systems, Inc.
*
* This software is dual licensed under the GNU General License Version 2,
* June 1991 as shown in the file COPYING in the top-level directory of this
* source tree or the BSD 2-Clause License provided below. You have the
* option to license this software under the complete terms of either license.
*
* The BSD 2-Clause License:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/* Author: Jakub Kicinski <kubakici@wp.pl> */
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <bpf.h>
#include <libbpf.h>
#include "main.h"
#include "disasm.h"
static const char * const prog_type_name[] = {
[BPF_PROG_TYPE_UNSPEC] = "unspec",
[BPF_PROG_TYPE_SOCKET_FILTER] = "socket_filter",
[BPF_PROG_TYPE_KPROBE] = "kprobe",
[BPF_PROG_TYPE_SCHED_CLS] = "sched_cls",
[BPF_PROG_TYPE_SCHED_ACT] = "sched_act",
[BPF_PROG_TYPE_TRACEPOINT] = "tracepoint",
[BPF_PROG_TYPE_XDP] = "xdp",
[BPF_PROG_TYPE_PERF_EVENT] = "perf_event",
[BPF_PROG_TYPE_CGROUP_SKB] = "cgroup_skb",
[BPF_PROG_TYPE_CGROUP_SOCK] = "cgroup_sock",
[BPF_PROG_TYPE_LWT_IN] = "lwt_in",
[BPF_PROG_TYPE_LWT_OUT] = "lwt_out",
[BPF_PROG_TYPE_LWT_XMIT] = "lwt_xmit",
[BPF_PROG_TYPE_SOCK_OPS] = "sock_ops",
[BPF_PROG_TYPE_SK_SKB] = "sk_skb",
[BPF_PROG_TYPE_CGROUP_DEVICE] = "cgroup_device",
};
static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
{
struct timespec real_time_ts, boot_time_ts;
time_t wallclock_secs;
struct tm load_tm;
buf[--size] = '\0';
if (clock_gettime(CLOCK_REALTIME, &real_time_ts) ||
clock_gettime(CLOCK_BOOTTIME, &boot_time_ts)) {
perror("Can't read clocks");
snprintf(buf, size, "%llu", nsecs / 1000000000);
return;
}
wallclock_secs = (real_time_ts.tv_sec - boot_time_ts.tv_sec) +
nsecs / 1000000000;
if (!localtime_r(&wallclock_secs, &load_tm)) {
snprintf(buf, size, "%llu", nsecs / 1000000000);
return;
}
strftime(buf, size, "%b %d/%H:%M", &load_tm);
}
static int prog_fd_by_tag(unsigned char *tag)
{
struct bpf_prog_info info = {};
__u32 len = sizeof(info);
unsigned int id = 0;
int err;
int fd;
while (true) {
err = bpf_prog_get_next_id(id, &id);
if (err) {
p_err("%s", strerror(errno));
return -1;
}
fd = bpf_prog_get_fd_by_id(id);
if (fd < 0) {
p_err("can't get prog by id (%u): %s",
id, strerror(errno));
return -1;
}
err = bpf_obj_get_info_by_fd(fd, &info, &len);
if (err) {
p_err("can't get prog info (%u): %s",
id, strerror(errno));
close(fd);
return -1;
}
if (!memcmp(tag, info.tag, BPF_TAG_SIZE))
return fd;
close(fd);
}
}
int prog_parse_fd(int *argc, char ***argv)
{
int fd;
if (is_prefix(**argv, "id")) {
unsigned int id;
char *endptr;
NEXT_ARGP();
id = strtoul(**argv, &endptr, 0);
if (*endptr) {
p_err("can't parse %s as ID", **argv);
return -1;
}
NEXT_ARGP();
fd = bpf_prog_get_fd_by_id(id);
if (fd < 0)
p_err("get by id (%u): %s", id, strerror(errno));
return fd;
} else if (is_prefix(**argv, "tag")) {
unsigned char tag[BPF_TAG_SIZE];
NEXT_ARGP();
if (sscanf(**argv, BPF_TAG_FMT, tag, tag + 1, tag + 2,
tag + 3, tag + 4, tag + 5, tag + 6, tag + 7)
!= BPF_TAG_SIZE) {
p_err("can't parse tag");
return -1;
}
NEXT_ARGP();
return prog_fd_by_tag(tag);
} else if (is_prefix(**argv, "pinned")) {
char *path;
NEXT_ARGP();
path = **argv;
NEXT_ARGP();
return open_obj_pinned_any(path, BPF_OBJ_PROG);
}
p_err("expected 'id', 'tag' or 'pinned', got: '%s'?", **argv);
return -1;
}
static void show_prog_maps(int fd, u32 num_maps)
{
struct bpf_prog_info info = {};
__u32 len = sizeof(info);
__u32 map_ids[num_maps];
unsigned int i;
int err;
info.nr_map_ids = num_maps;
info.map_ids = ptr_to_u64(map_ids);
err = bpf_obj_get_info_by_fd(fd, &info, &len);
if (err || !info.nr_map_ids)
return;
if (json_output) {
jsonw_name(json_wtr, "map_ids");
jsonw_start_array(json_wtr);
for (i = 0; i < info.nr_map_ids; i++)
jsonw_uint(json_wtr, map_ids[i]);
jsonw_end_array(json_wtr);
} else {
printf(" map_ids ");
for (i = 0; i < info.nr_map_ids; i++)
printf("%u%s", map_ids[i],
i == info.nr_map_ids - 1 ? "" : ",");
}
}
static void print_prog_json(struct bpf_prog_info *info, int fd)
{
char *memlock;
jsonw_start_object(json_wtr);
jsonw_uint_field(json_wtr, "id", info->id);
if (info->type < ARRAY_SIZE(prog_type_name))
jsonw_string_field(json_wtr, "type",
prog_type_name[info->type]);
else
jsonw_uint_field(json_wtr, "type", info->type);
if (*info->name)
jsonw_string_field(json_wtr, "name", info->name);
jsonw_name(json_wtr, "tag");
jsonw_printf(json_wtr, "\"" BPF_TAG_FMT "\"",
info->tag[0], info->tag[1], info->tag[2], info->tag[3],
info->tag[4], info->tag[5], info->tag[6], info->tag[7]);
print_dev_json(info->ifindex, info->netns_dev, info->netns_ino);
if (info->load_time) {
char buf[32];
print_boot_time(info->load_time, buf, sizeof(buf));
/* Piggy back on load_time, since 0 uid is a valid one */
jsonw_string_field(json_wtr, "loaded_at", buf);
jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
}
jsonw_uint_field(json_wtr, "bytes_xlated", info->xlated_prog_len);
if (info->jited_prog_len) {
jsonw_bool_field(json_wtr, "jited", true);
jsonw_uint_field(json_wtr, "bytes_jited", info->jited_prog_len);
} else {
jsonw_bool_field(json_wtr, "jited", false);
}
memlock = get_fdinfo(fd, "memlock");
if (memlock)
jsonw_int_field(json_wtr, "bytes_memlock", atoi(memlock));
free(memlock);
if (info->nr_map_ids)
show_prog_maps(fd, info->nr_map_ids);
if (!hash_empty(prog_table.table)) {
struct pinned_obj *obj;
jsonw_name(json_wtr, "pinned");
jsonw_start_array(json_wtr);
hash_for_each_possible(prog_table.table, obj, hash, info->id) {
if (obj->id == info->id)
jsonw_string(json_wtr, obj->path);
}
jsonw_end_array(json_wtr);
}
jsonw_end_object(json_wtr);
}
static void print_prog_plain(struct bpf_prog_info *info, int fd)
{
char *memlock;
printf("%u: ", info->id);
if (info->type < ARRAY_SIZE(prog_type_name))
printf("%s ", prog_type_name[info->type]);
else
printf("type %u ", info->type);
if (*info->name)
printf("name %s ", info->name);
printf("tag ");
fprint_hex(stdout, info->tag, BPF_TAG_SIZE, "");
print_dev_plain(info->ifindex, info->netns_dev, info->netns_ino);
printf("\n");
if (info->load_time) {
char buf[32];
print_boot_time(info->load_time, buf, sizeof(buf));
/* Piggy back on load_time, since 0 uid is a valid one */
printf("\tloaded_at %s uid %u\n", buf, info->created_by_uid);
}
printf("\txlated %uB", info->xlated_prog_len);
if (info->jited_prog_len)
printf(" jited %uB", info->jited_prog_len);
else
printf(" not jited");
memlock = get_fdinfo(fd, "memlock");
if (memlock)
printf(" memlock %sB", memlock);
free(memlock);
if (info->nr_map_ids)
show_prog_maps(fd, info->nr_map_ids);
if (!hash_empty(prog_table.table)) {
struct pinned_obj *obj;
printf("\n");
hash_for_each_possible(prog_table.table, obj, hash, info->id) {
if (obj->id == info->id)
printf("\tpinned %s\n", obj->path);
}
}
printf("\n");
}
static int show_prog(int fd)
{
struct bpf_prog_info info = {};
__u32 len = sizeof(info);
int err;
err = bpf_obj_get_info_by_fd(fd, &info, &len);
if (err) {
p_err("can't get prog info: %s", strerror(errno));
return -1;
}
if (json_output)
print_prog_json(&info, fd);
else
print_prog_plain(&info, fd);
return 0;
}
static int do_show(int argc, char **argv)
{
__u32 id = 0;
int err;
int fd;
if (show_pinned)
build_pinned_obj_table(&prog_table, BPF_OBJ_PROG);
if (argc == 2) {
fd = prog_parse_fd(&argc, &argv);
if (fd < 0)
return -1;
return show_prog(fd);
}
if (argc)
return BAD_ARG();
if (json_output)
jsonw_start_array(json_wtr);
while (true) {
err = bpf_prog_get_next_id(id, &id);
if (err) {
if (errno == ENOENT) {
err = 0;
break;
}
p_err("can't get next program: %s%s", strerror(errno),
errno == EINVAL ? " -- kernel too old?" : "");
err = -1;
break;
}
fd = bpf_prog_get_fd_by_id(id);
if (fd < 0) {
if (errno == ENOENT)
continue;
p_err("can't get prog by id (%u): %s",
id, strerror(errno));
err = -1;
break;
}
err = show_prog(fd);
close(fd);
if (err)
break;
}
if (json_output)
jsonw_end_array(json_wtr);
return err;
}
#define SYM_MAX_NAME 256
struct kernel_sym {
unsigned long address;
char name[SYM_MAX_NAME];
};
struct dump_data {
unsigned long address_call_base;
struct kernel_sym *sym_mapping;
__u32 sym_count;
char scratch_buff[SYM_MAX_NAME];
};
static int kernel_syms_cmp(const void *sym_a, const void *sym_b)
{
return ((struct kernel_sym *)sym_a)->address -
((struct kernel_sym *)sym_b)->address;
}
static void kernel_syms_load(struct dump_data *dd)
{
struct kernel_sym *sym;
char buff[256];
void *tmp, *address;
FILE *fp;
fp = fopen("/proc/kallsyms", "r");
if (!fp)
return;
while (!feof(fp)) {
if (!fgets(buff, sizeof(buff), fp))
break;
tmp = realloc(dd->sym_mapping,
(dd->sym_count + 1) *
sizeof(*dd->sym_mapping));
if (!tmp) {
out:
free(dd->sym_mapping);
dd->sym_mapping = NULL;
fclose(fp);
return;
}
dd->sym_mapping = tmp;
sym = &dd->sym_mapping[dd->sym_count];
if (sscanf(buff, "%p %*c %s", &address, sym->name) != 2)
continue;
sym->address = (unsigned long)address;
if (!strcmp(sym->name, "__bpf_call_base")) {
dd->address_call_base = sym->address;
/* sysctl kernel.kptr_restrict was set */
if (!sym->address)
goto out;
}
if (sym->address)
dd->sym_count++;
}
fclose(fp);
qsort(dd->sym_mapping, dd->sym_count,
sizeof(*dd->sym_mapping), kernel_syms_cmp);
}
static void kernel_syms_destroy(struct dump_data *dd)
{
free(dd->sym_mapping);
}
static struct kernel_sym *kernel_syms_search(struct dump_data *dd,
unsigned long key)
{
struct kernel_sym sym = {
.address = key,
};
return dd->sym_mapping ?
bsearch(&sym, dd->sym_mapping, dd->sym_count,
sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL;
}
static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
vprintf(fmt, args);
va_end(args);
}
static const char *print_call_pcrel(struct dump_data *dd,
struct kernel_sym *sym,
unsigned long address,
const struct bpf_insn *insn)
{
if (sym)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%+d#%s", insn->off, sym->name);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%+d#0x%lx", insn->off, address);
return dd->scratch_buff;
}
static const char *print_call_helper(struct dump_data *dd,
struct kernel_sym *sym,
unsigned long address)
{
if (sym)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"%s", sym->name);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"0x%lx", address);
return dd->scratch_buff;
}
static const char *print_call(void *private_data,
const struct bpf_insn *insn)
{
struct dump_data *dd = private_data;
unsigned long address = dd->address_call_base + insn->imm;
struct kernel_sym *sym;
sym = kernel_syms_search(dd, address);
if (insn->src_reg == BPF_PSEUDO_CALL)
return print_call_pcrel(dd, sym, address, insn);
else
return print_call_helper(dd, sym, address);
}
static const char *print_imm(void *private_data,
const struct bpf_insn *insn,
__u64 full_imm)
{
struct dump_data *dd = private_data;
if (insn->src_reg == BPF_PSEUDO_MAP_FD)
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"map[id:%u]", insn->imm);
else
snprintf(dd->scratch_buff, sizeof(dd->scratch_buff),
"0x%llx", (unsigned long long)full_imm);
return dd->scratch_buff;
}
static void dump_xlated_plain(struct dump_data *dd, void *buf,
unsigned int len, bool opcodes)
{
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
struct bpf_insn *insn = buf;
bool double_insn = false;
unsigned int i;
for (i = 0; i < len / sizeof(*insn); i++) {
if (double_insn) {
double_insn = false;
continue;
}
double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
printf("% 4d: ", i);
print_bpf_insn(&cbs, NULL, insn + i, true);
if (opcodes) {
printf(" ");
fprint_hex(stdout, insn + i, 8, " ");
if (double_insn && i < len - 1) {
printf(" ");
fprint_hex(stdout, insn + i + 1, 8, " ");
}
printf("\n");
}
}
}
static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...)
{
unsigned int l = strlen(fmt);
char chomped_fmt[l];
va_list args;
va_start(args, fmt);
if (l > 0) {
strncpy(chomped_fmt, fmt, l - 1);
chomped_fmt[l - 1] = '\0';
}
jsonw_vprintf_enquote(json_wtr, chomped_fmt, args);
va_end(args);
}
static void dump_xlated_json(struct dump_data *dd, void *buf,
unsigned int len, bool opcodes)
{
const struct bpf_insn_cbs cbs = {
.cb_print = print_insn_json,
.cb_call = print_call,
.cb_imm = print_imm,
.private_data = dd,
};
struct bpf_insn *insn = buf;
bool double_insn = false;
unsigned int i;
jsonw_start_array(json_wtr);
for (i = 0; i < len / sizeof(*insn); i++) {
if (double_insn) {
double_insn = false;
continue;
}
double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "disasm");
print_bpf_insn(&cbs, NULL, insn + i, true);
if (opcodes) {
jsonw_name(json_wtr, "opcodes");
jsonw_start_object(json_wtr);
jsonw_name(json_wtr, "code");
jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code);
jsonw_name(json_wtr, "src_reg");
jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg);
jsonw_name(json_wtr, "dst_reg");
jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg);
jsonw_name(json_wtr, "off");
print_hex_data_json((uint8_t *)(&insn[i].off), 2);
jsonw_name(json_wtr, "imm");
if (double_insn && i < len - 1)
print_hex_data_json((uint8_t *)(&insn[i].imm),
12);
else
print_hex_data_json((uint8_t *)(&insn[i].imm),
4);
jsonw_end_object(json_wtr);
}
jsonw_end_object(json_wtr);
}
jsonw_end_array(json_wtr);
}
static int do_dump(int argc, char **argv)
{
struct bpf_prog_info info = {};
struct dump_data dd = {};
__u32 len = sizeof(info);
unsigned int buf_size;
char *filepath = NULL;
bool opcodes = false;
unsigned char *buf;
__u32 *member_len;
__u64 *member_ptr;
ssize_t n;
int err;
int fd;
if (is_prefix(*argv, "jited")) {
member_len = &info.jited_prog_len;
member_ptr = &info.jited_prog_insns;
} else if (is_prefix(*argv, "xlated")) {
member_len = &info.xlated_prog_len;
member_ptr = &info.xlated_prog_insns;
} else {
p_err("expected 'xlated' or 'jited', got: %s", *argv);
return -1;
}
NEXT_ARG();
if (argc < 2)
usage();
fd = prog_parse_fd(&argc, &argv);
if (fd < 0)
return -1;
if (is_prefix(*argv, "file")) {
NEXT_ARG();
if (!argc) {
p_err("expected file path");
return -1;
}
filepath = *argv;
NEXT_ARG();
} else if (is_prefix(*argv, "opcodes")) {
opcodes = true;
NEXT_ARG();
}
if (argc) {
usage();
return -1;
}
err = bpf_obj_get_info_by_fd(fd, &info, &len);
if (err) {
p_err("can't get prog info: %s", strerror(errno));
return -1;
}
if (!*member_len) {
p_info("no instructions returned");
close(fd);
return 0;
}
buf_size = *member_len;
buf = malloc(buf_size);
if (!buf) {
p_err("mem alloc failed");
close(fd);
return -1;
}
memset(&info, 0, sizeof(info));
*member_ptr = ptr_to_u64(buf);
*member_len = buf_size;
err = bpf_obj_get_info_by_fd(fd, &info, &len);
close(fd);
if (err) {
p_err("can't get prog info: %s", strerror(errno));
goto err_free;
}
if (*member_len > buf_size) {
p_err("too many instructions returned");
goto err_free;
}
if ((member_len == &info.jited_prog_len &&
info.jited_prog_insns == 0) ||
(member_len == &info.xlated_prog_len &&
info.xlated_prog_insns == 0)) {
p_err("error retrieving insn dump: kernel.kptr_restrict set?");
goto err_free;
}
if (filepath) {
fd = open(filepath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
if (fd < 0) {
p_err("can't open file %s: %s", filepath,
strerror(errno));
goto err_free;
}
n = write(fd, buf, *member_len);
close(fd);
if (n != *member_len) {
p_err("error writing output file: %s",
n < 0 ? strerror(errno) : "short write");
goto err_free;
}
if (json_output)
jsonw_null(json_wtr);
} else {
if (member_len == &info.jited_prog_len) {
const char *name = NULL;
if (info.ifindex) {
name = ifindex_to_bfd_name_ns(info.ifindex,
info.netns_dev,
info.netns_ino);
if (!name)
goto err_free;
}
disasm_print_insn(buf, *member_len, opcodes, name);
} else {
kernel_syms_load(&dd);
if (json_output)
dump_xlated_json(&dd, buf, *member_len, opcodes);
else
dump_xlated_plain(&dd, buf, *member_len, opcodes);
kernel_syms_destroy(&dd);
}
}
free(buf);
return 0;
err_free:
free(buf);
return -1;
}
static int do_pin(int argc, char **argv)
{
int err;
err = do_pin_any(argc, argv, bpf_prog_get_fd_by_id);
if (!err && json_output)
jsonw_null(json_wtr);
return err;
}
static int do_load(int argc, char **argv)
{
struct bpf_object *obj;
int prog_fd;
if (argc != 2)
usage();
if (bpf_prog_load(argv[0], BPF_PROG_TYPE_UNSPEC, &obj, &prog_fd)) {
p_err("failed to load program");
return -1;
}
if (do_pin_fd(prog_fd, argv[1])) {
p_err("failed to pin program");
return -1;
}
if (json_output)
jsonw_null(json_wtr);
return 0;
}
static int do_help(int argc, char **argv)
{
if (json_output) {
jsonw_null(json_wtr);
return 0;
}
fprintf(stderr,
"Usage: %s %s { show | list } [PROG]\n"
" %s %s dump xlated PROG [{ file FILE | opcodes }]\n"
" %s %s dump jited PROG [{ file FILE | opcodes }]\n"
" %s %s pin PROG FILE\n"
" %s %s load OBJ FILE\n"
" %s %s help\n"
"\n"
" " HELP_SPEC_PROGRAM "\n"
" " HELP_SPEC_OPTIONS "\n"
"",
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
return 0;
}
static const struct cmd cmds[] = {
{ "show", do_show },
{ "list", do_show },
{ "help", do_help },
{ "dump", do_dump },
{ "pin", do_pin },
{ "load", do_load },
{ 0 }
};
int do_prog(int argc, char **argv)
{
return cmd_select(cmds, argc, argv, do_help);
}