tools: bpftool: add JSON output for `bpftool prog dump jited *` command

Reuse the json_writer API introduced in an earlier commit to make
bpftool able to generate JSON output on `bpftool prog show *` commands.
A new printing function is created to be passed as an argument to the
disassembler.

Similarly to plain output, opcodes are printed on request.

Outputs from sample programs have been successfully tested against a
JSON validator.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Quentin Monnet 2017-10-23 09:24:09 -07:00 коммит произвёл David S. Miller
Родитель 743cc665d5
Коммит 107f041212
1 изменённых файлов: 80 добавлений и 6 удалений

Просмотреть файл

@ -10,6 +10,7 @@
* Licensed under the GNU General Public License, version 2.0 (GPLv2)
*/
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
@ -21,6 +22,9 @@
#include <sys/types.h>
#include <sys/stat.h>
#include "json_writer.h"
#include "main.h"
static void get_exec_path(char *tpath, size_t size)
{
ssize_t len;
@ -39,6 +43,38 @@ static void get_exec_path(char *tpath, size_t size)
free(path);
}
static int oper_count;
static int fprintf_json(void *out, const char *fmt, ...)
{
va_list ap;
char *s;
va_start(ap, fmt);
if (!oper_count) {
int i;
s = va_arg(ap, char *);
/* Strip trailing spaces */
i = strlen(s) - 1;
while (s[i] == ' ')
s[i--] = '\0';
jsonw_string_field(json_wtr, "operation", s);
jsonw_name(json_wtr, "operands");
jsonw_start_array(json_wtr);
oper_count++;
} else if (!strcmp(fmt, ",")) {
/* Skip */
} else {
s = va_arg(ap, char *);
jsonw_string(json_wtr, s);
oper_count++;
}
va_end(ap);
return 0;
}
void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
{
disassembler_ftype disassemble;
@ -57,7 +93,12 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
assert(bfdf);
assert(bfd_check_format(bfdf, bfd_object));
init_disassemble_info(&info, stdout, (fprintf_ftype) fprintf);
if (json_output)
init_disassemble_info(&info, stdout,
(fprintf_ftype) fprintf_json);
else
init_disassemble_info(&info, stdout,
(fprintf_ftype) fprintf);
info.arch = bfd_get_arch(bfdf);
info.mach = bfd_get_mach(bfdf);
info.buffer = image;
@ -68,20 +109,53 @@ void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes)
disassemble = disassembler(bfdf);
assert(disassemble);
if (json_output)
jsonw_start_array(json_wtr);
do {
printf("%4x:\t", pc);
if (json_output) {
jsonw_start_object(json_wtr);
oper_count = 0;
jsonw_name(json_wtr, "pc");
jsonw_printf(json_wtr, "\"0x%x\"", pc);
} else {
printf("%4x:\t", pc);
}
count = disassemble(pc, &info);
if (json_output) {
/* Operand array, was started in fprintf_json. Before
* that, make sure we have a _null_ value if no operand
* other than operation code was present.
*/
if (oper_count == 1)
jsonw_null(json_wtr);
jsonw_end_array(json_wtr);
}
if (opcodes) {
printf("\n\t");
for (i = 0; i < count; ++i)
printf("%02x ", (uint8_t) image[pc + i]);
if (json_output) {
jsonw_name(json_wtr, "opcodes");
jsonw_start_array(json_wtr);
for (i = 0; i < count; ++i)
jsonw_printf(json_wtr, "\"0x%02hhx\"",
(uint8_t)image[pc + i]);
jsonw_end_array(json_wtr);
} else {
printf("\n\t");
for (i = 0; i < count; ++i)
printf("%02x ",
(uint8_t)image[pc + i]);
}
}
printf("\n");
if (json_output)
jsonw_end_object(json_wtr);
else
printf("\n");
pc += count;
} while (count > 0 && pc < len);
if (json_output)
jsonw_end_array(json_wtr);
bfd_close(bfdf);
}