gluon/package/gluon-status-page-api/src/neighbours-batadv.c
Sven Eckelmann 6ac5b9cbc8 gluon-status-page-api: Switch from debugfs to batadv netlink
The batadv debugfs requires large memory blocks to write the text debug
tables. This is inefficient for large tables like the global translation
table or the originators table.

The memory requirement can be reduced by using netlink. It copies smaller
packets in a binary format to the userspace program. gluon-status-page-api
can therefore parse larger originator tables without causing an OOM on
systems which are tight on memory.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
2016-12-11 12:03:12 +01:00

131 lines
3.1 KiB
C

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <json-c/json.h>
#include <net/if.h>
#include "batadv-netlink.h"
#define STR(x) #x
#define XSTR(x) STR(x)
struct neigh_netlink_opts {
struct json_object *obj;
struct batadv_nlquery_opts query_opts;
};
static const enum batadv_nl_attrs parse_orig_list_mandatory[] = {
BATADV_ATTR_ORIG_ADDRESS,
BATADV_ATTR_NEIGH_ADDRESS,
BATADV_ATTR_TQ,
BATADV_ATTR_HARD_IFINDEX,
BATADV_ATTR_LAST_SEEN_MSECS,
};
static int parse_orig_list_netlink_cb(struct nl_msg *msg, void *arg)
{
struct nlattr *attrs[BATADV_ATTR_MAX+1];
struct nlmsghdr *nlh = nlmsg_hdr(msg);
struct batadv_nlquery_opts *query_opts = arg;
struct genlmsghdr *ghdr;
uint8_t *orig;
uint8_t *dest;
uint8_t tq;
uint32_t hardif;
uint32_t lastseen;
char ifname_buf[IF_NAMESIZE], *ifname;
struct neigh_netlink_opts *opts;
char mac1[18];
opts = container_of(query_opts, struct neigh_netlink_opts, query_opts);
if (!genlmsg_valid_hdr(nlh, 0))
return NL_OK;
ghdr = nlmsg_data(nlh);
if (ghdr->cmd != BATADV_CMD_GET_ORIGINATORS)
return NL_OK;
if (nla_parse(attrs, BATADV_ATTR_MAX, genlmsg_attrdata(ghdr, 0),
genlmsg_len(ghdr), batadv_netlink_policy))
return NL_OK;
if (batadv_nl_missing_attrs(attrs, parse_orig_list_mandatory,
ARRAY_SIZE(parse_orig_list_mandatory)))
return NL_OK;
if (!attrs[BATADV_ATTR_FLAG_BEST])
return NL_OK;
orig = nla_data(attrs[BATADV_ATTR_ORIG_ADDRESS]);
dest = nla_data(attrs[BATADV_ATTR_NEIGH_ADDRESS]);
tq = nla_get_u8(attrs[BATADV_ATTR_TQ]);
hardif = nla_get_u32(attrs[BATADV_ATTR_HARD_IFINDEX]);
lastseen = nla_get_u32(attrs[BATADV_ATTR_LAST_SEEN_MSECS]);
if (memcmp(orig, dest, 6) != 0)
return NL_OK;
ifname = if_indextoname(hardif, ifname_buf);
if (!ifname)
return NL_OK;
sprintf(mac1, "%02x:%02x:%02x:%02x:%02x:%02x",
orig[0], orig[1], orig[2], orig[3], orig[4], orig[5]);
struct json_object *neigh = json_object_new_object();
if (!neigh)
return NL_OK;
json_object_object_add(neigh, "tq", json_object_new_int(tq));
json_object_object_add(neigh, "lastseen", json_object_new_double(lastseen / 1000.));
json_object_object_add(neigh, "ifname", json_object_new_string(ifname));
json_object_object_add(opts->obj, mac1, neigh);
return NL_OK;
}
static json_object *neighbours(void) {
struct neigh_netlink_opts opts = {
.query_opts = {
.err = 0,
},
};
int ret;
opts.obj = json_object_new_object();
if (!opts.obj)
return NULL;
ret = batadv_nl_query_common("bat0", BATADV_CMD_GET_ORIGINATORS,
parse_orig_list_netlink_cb, NLM_F_DUMP,
&opts.query_opts);
if (ret < 0) {
json_object_put(opts.obj);
return NULL;
}
return opts.obj;
}
int main(void) {
struct json_object *obj;
printf("Content-type: text/event-stream\n\n");
fflush(stdout);
while (1) {
obj = neighbours();
if (obj) {
printf("data: %s\n\n", json_object_to_json_string_ext(obj, JSON_C_TO_STRING_PLAIN));
fflush(stdout);
json_object_put(obj);
}
sleep(10);
}
return 0;
}