On Thursday, 13 May 2021 16:02:34 CEST Alexander Sarmanow wrote:
To print JSON strings in a generic way a second nla_policy is used, with
This is not a nla_policy but a private json translation "policy".
[...]
new file mode 100644 index 0000000..cff54d8 --- /dev/null +++ b/genl_json.c @@ -0,0 +1,359 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors:
- Alexander Sarmanow asarmanow@gmail.com
- License-Filename: LICENSES/preferred/GPL-2.0
- */
+#include <stdbool.h> +#include <stdio.h> +#include <ctype.h> +#include <netlink/netlink.h> +#include <netlink/attr.h>
+#include "genl_json.h" +#include "batman_adv.h" +#include "netlink.h" +#include "main.h"
#include "genl_json.h" #include "main.h"
#include <ctype.h> #include <inttypes.h> #include <netlink/netlink.h> #include <netlink/attr.h> #include <stdbool.h> #include <stdio.h>
#include "batman_adv.h" #include "netlink.h"
+static void nljson_print_uint8_t(struct nlattr *attrs[], int idx) +{
- uint8_t value = nla_get_u8(attrs[idx]);
- printf("%u", value);
+}
"%"PRIu8
+static void nljson_print_uint16_t(struct nlattr *attrs[], int idx) +{
- uint16_t value = nla_get_u16(attrs[idx]);
- printf("%u", value);
+}
"%"PRIu16
+static void nljson_print_uint32_t(struct nlattr *attrs[], int idx) +{
- uint32_t value = nla_get_u32(attrs[idx]);
- printf("%u", value);
+}
"%"PRIu32
+static void nljson_print_uint64_t(struct nlattr *attrs[], int idx) +{
- uint64_t value = nla_get_u64(attrs[idx]);
- printf("%llu", value);
+}
"%"PRIu64
+static void nljson_print_mac(struct nlattr *attrs[], int idx) +{
- uint8_t *value = nla_data(attrs[idx]);
- printf(""%02x:%02x:%02x:%02x:%02x:%02x"",
value[0], value[1], value[2], value[3], value[4], value[5]);+}
Alignment
+static void nljson_print_flag(struct nlattr *attrs[], int idx) +{
- if (nla_get_flag(attrs[idx]))
printf("true");+}
The check is not necessary because it check only if attrs[idx] is != NULL - which you've already checked. If this would not be the case, then this function would create broken json like '{"foobar":}', right?
+void sanitize_string(const char *str) +{
- while (*str) {
if (*str == '"' || *str == '\\') {putchar('\\');putchar(*str);} else if (*str == '\\') {printf("\\\\");} else if (!isprint(*str)) {printf("\\x%02x", *str);} else {printf("%c", *str);}
if (*str == '"' || *str == '\') { putchar('\'); putchar(*str); } else if (!isprint(*str)) { printf("\x%02x", *str); } else { putchar(*str); }
str++;- }
+}
This function should have been static and at the beginning of this file.
+void netlink_print_json_entries(struct nlattr *attrs[], struct json_opts *json_opts) +{
- bool first_valid_attr = true;
- int i;
- if (!json_opts->is_first)
printf(",");
Code to handle the json_opts->is_first = false was again not added to this function.
- printf("{");
- for (i = 0; i < BATADV_ATTR_MAX + 1; i++) {
if (!attrs[i])continue;if (!batadv_netlink_policy_json[i].cb)continue;if (!first_valid_attr)printf(",");putc('"', stdout);sanitize_string(batadv_netlink_policy_json[i].name);printf("\":");batadv_netlink_policy_json[i].cb(attrs, i);first_valid_attr = false;- }
- printf("}");
+}
+struct nla_policy_json batadv_netlink_policy_json[NUM_BATADV_ATTR] = {
this should have been static const
- [BATADV_ATTR_PAD] = {
.name = "pad",- },
I would guess we can ignore this one.
- [BATADV_ATTR_TT_FLAGS] = {
.name = "tt_flags",.cb = nljson_print_uint32_t,- },
Why was the actually decoding removed?
- [BATADV_ATTR_DAT_CACHE_IP4ADDRESS] = {
.name = "dat_cache_ip4_address",- },
IPv4 print code missing
[...]
- [BATADV_ATTR_VLANID] = {
.name = "vlan_id",.cb = nljson_print_uint16_t,- },
wasn't this originally printed in a special way?
- [BATADV_ATTR_AGGREGATED_OGMS_ENABLED] = {
.name = "aggregated_ogms_enabled",.cb = nljson_print_uint8_t,- },
This and other _ENABLED are booleans.
[...]
There were also different other weird names used. Like fragmented_enabled for the fragmentation feature.
diff --git a/genl_json.h b/genl_json.h new file mode 100644 index 0000000..0336b40 --- /dev/null +++ b/genl_json.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (C) B.A.T.M.A.N. contributors:
- Alexander Sarmanow asarmanow@gmail.com
- License-Filename: LICENSES/preferred/GPL-2.0
- */
+#ifndef _BATCTL_GENLJSON_H +#define _BATCTL_GENLJSON_H
+#include <stdint.h>
+#include "netlink.h"
+struct json_opts {
- uint8_t is_first;
is_first:1
- struct nlquery_opts query_opts;
+};
+void netlink_print_json_entries(struct nlattr *attrs[], struct json_opts *json_opts); +void sanitize_string(const char *str);
+#endif /* _BATCTL_GENLJSON_H */ diff --git a/netlink.h b/netlink.h index c93f500..d96935a 100644 --- a/netlink.h +++ b/netlink.h @@ -29,6 +29,11 @@ struct nlquery_opts { int err; };
+struct nla_policy_json {
- const char *name;
- void (*cb)(struct nlattr *attrs[], int idx);
+};
This doesn't belong to netlink.h. If it would really be needed outside of genl_json.c then you should have added it to genl_json.h
struct ether_addr;
int netlink_create(struct state *state); @@ -44,6 +49,7 @@ int get_algoname_netlink(struct state *state, unsigned int mesh_ifindex, char *algoname, size_t algoname_len);
extern struct nla_policy batadv_netlink_policy[]; +extern struct nla_policy_json batadv_netlink_policy_json[];
This doesn't belong to netlink.h. If it would really be needed outside of genl_json.c then you should have added it to genl_json.h
Kind regards, Sven