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authorQuentin Monnet <quentin.monnet@netronome.com>2017-10-23 09:24:09 -0700
committerDavid S. Miller <davem@davemloft.net>2017-10-24 01:25:08 +0100
commit107f041212c1dfd3bf72b01c0d2013e98b6f32c2 (patch)
tree37d4592e19f1de25f2c42a77bd4e8a1cf571eba8 /tools/bpf
parent743cc665d5f62d2c75eceb59c461e653ad6ea58c (diff)
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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>
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/jit_disasm.c86
1 files changed, 80 insertions, 6 deletions
diff --git a/tools/bpf/bpftool/jit_disasm.c b/tools/bpf/bpftool/jit_disasm.c
index 70e480b59e9d..5937e134e408 100644
--- a/tools/bpf/bpftool/jit_disasm.c
+++ b/tools/bpf/bpftool/jit_disasm.c
@@ -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);
}