linux_dsm_epyc7002/tools/bpf/bpftool/json_writer.h
YiFei Zhu aff52e685e bpftool: Support dumping metadata
Dump metadata in the 'bpftool prog' list if it's present.
For some formatting some BTF code is put directly in the
metadata dumping. Sanity checks on the map and the kind of the btf_type
to make sure we are actually dumping what we are expecting.

A helper jsonw_reset is added to json writer so we can reuse the same
json writer without having extraneous commas.

Sample output:

  $ bpftool prog
  6: cgroup_skb  name prog  tag bcf7977d3b93787c  gpl
  [...]
  	btf_id 4
  	metadata:
  		a = "foo"
  		b = 1

  $ bpftool prog --json --pretty
  [{
          "id": 6,
  [...]
          "btf_id": 4,
          "metadata": {
              "a": "foo",
              "b": 1
          }
      }
  ]

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: YiFei Zhu <zhuyifei1999@gmail.com>
Link: https://lore.kernel.org/bpf/20200915234543.3220146-5-sdf@google.com
2020-09-15 18:28:27 -07:00

74 lines
2.6 KiB
C

/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
/*
* Simple streaming JSON writer
*
* This takes care of the annoying bits of JSON syntax like the commas
* after elements
*
* Authors: Stephen Hemminger <stephen@networkplumber.org>
*/
#ifndef _JSON_WRITER_H_
#define _JSON_WRITER_H_
#include <stdbool.h>
#include <stdint.h>
#include <stdarg.h>
#include <linux/compiler.h>
/* Opaque class structure */
typedef struct json_writer json_writer_t;
/* Create a new JSON stream */
json_writer_t *jsonw_new(FILE *f);
/* End output to JSON stream */
void jsonw_destroy(json_writer_t **self_p);
/* Cause output to have pretty whitespace */
void jsonw_pretty(json_writer_t *self, bool on);
/* Reset separator to create new JSON */
void jsonw_reset(json_writer_t *self);
/* Add property name */
void jsonw_name(json_writer_t *self, const char *name);
/* Add value */
void __printf(2, 0) jsonw_vprintf_enquote(json_writer_t *self, const char *fmt,
va_list ap);
void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...);
void jsonw_string(json_writer_t *self, const char *value);
void jsonw_bool(json_writer_t *self, bool value);
void jsonw_float(json_writer_t *self, double number);
void jsonw_float_fmt(json_writer_t *self, const char *fmt, double num);
void jsonw_uint(json_writer_t *self, uint64_t number);
void jsonw_hu(json_writer_t *self, unsigned short number);
void jsonw_int(json_writer_t *self, int64_t number);
void jsonw_null(json_writer_t *self);
void jsonw_lluint(json_writer_t *self, unsigned long long int num);
/* Useful Combinations of name and value */
void jsonw_string_field(json_writer_t *self, const char *prop, const char *val);
void jsonw_bool_field(json_writer_t *self, const char *prop, bool value);
void jsonw_float_field(json_writer_t *self, const char *prop, double num);
void jsonw_uint_field(json_writer_t *self, const char *prop, uint64_t num);
void jsonw_hu_field(json_writer_t *self, const char *prop, unsigned short num);
void jsonw_int_field(json_writer_t *self, const char *prop, int64_t num);
void jsonw_null_field(json_writer_t *self, const char *prop);
void jsonw_lluint_field(json_writer_t *self, const char *prop,
unsigned long long int num);
void jsonw_float_field_fmt(json_writer_t *self, const char *prop,
const char *fmt, double val);
/* Collections */
void jsonw_start_object(json_writer_t *self);
void jsonw_end_object(json_writer_t *self);
void jsonw_start_array(json_writer_t *self);
void jsonw_end_array(json_writer_t *self);
/* Override default exception handling */
typedef void (jsonw_err_handler_fn)(const char *);
#endif /* _JSON_WRITER_H_ */