gluon/package/gluon-mesh-batman-adv-core/src/batadv-netlink.c
Sven Eckelmann 22946b14b6 gluon-mesh-batman-adv-core: 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. The respondd module of
gluon-mesh-batman-adv-core 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

150 lines
3.6 KiB
C

/*
* Copyright (C) 2009-2016 B.A.T.M.A.N. contributors:
*
* Marek Lindner <mareklindner@neomailbox.ch>, Andrew Lunn <andrew@lunn.ch>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*
*/
#include "batadv-netlink.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <netlink/netlink.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/ctrl.h>
#include <net/ethernet.h>
#include "batman_adv.h"
#ifndef __maybe_unused
#define __maybe_unused __attribute__((unused))
#endif
struct nla_policy batadv_netlink_policy[NUM_BATADV_ATTR] = {
[BATADV_ATTR_HARD_IFINDEX] = { .type = NLA_U32 },
[BATADV_ATTR_ORIG_ADDRESS] = { .type = NLA_UNSPEC,
.minlen = ETH_ALEN,
.maxlen = ETH_ALEN },
[BATADV_ATTR_TT_FLAGS] = { .type = NLA_U32 },
[BATADV_ATTR_FLAG_BEST] = { .type = NLA_FLAG },
[BATADV_ATTR_LAST_SEEN_MSECS] = { .type = NLA_U32 },
[BATADV_ATTR_NEIGH_ADDRESS] = { .type = NLA_UNSPEC,
.minlen = ETH_ALEN,
.maxlen = ETH_ALEN },
[BATADV_ATTR_TQ] = { .type = NLA_U8 },
[BATADV_ATTR_ROUTER] = { .type = NLA_UNSPEC,
.minlen = ETH_ALEN,
.maxlen = ETH_ALEN },
};
static int nlquery_error_cb(struct sockaddr_nl *nla __maybe_unused,
struct nlmsgerr *nlerr, void *arg)
{
struct batadv_nlquery_opts *query_opts = arg;
query_opts->err = nlerr->error;
return NL_STOP;
}
static int nlquery_stop_cb(struct nl_msg *msg, void *arg)
{
struct nlmsghdr *nlh = nlmsg_hdr(msg);
struct batadv_nlquery_opts *query_opts = arg;
int *error = nlmsg_data(nlh);
if (*error)
query_opts->err = *error;
return NL_STOP;
}
int batadv_nl_query_common(const char *mesh_iface,
enum batadv_nl_commands nl_cmd,
nl_recvmsg_msg_cb_t callback, int flags,
struct batadv_nlquery_opts *query_opts)
{
struct nl_sock *sock;
struct nl_msg *msg;
struct nl_cb *cb;
int ifindex;
int family;
int ret;
query_opts->err = 0;
sock = nl_socket_alloc();
if (!sock)
return -ENOMEM;
ret = genl_connect(sock);
if (ret < 0) {
query_opts->err = ret;
goto err_free_sock;
}
family = genl_ctrl_resolve(sock, BATADV_NL_NAME);
if (family < 0) {
query_opts->err = -EOPNOTSUPP;
goto err_free_sock;
}
ifindex = if_nametoindex(mesh_iface);
if (!ifindex) {
query_opts->err = -ENODEV;
goto err_free_sock;
}
cb = nl_cb_alloc(NL_CB_DEFAULT);
if (!cb) {
query_opts->err = -ENOMEM;
goto err_free_sock;
}
nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, callback, query_opts);
nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, nlquery_stop_cb, query_opts);
nl_cb_err(cb, NL_CB_CUSTOM, nlquery_error_cb, query_opts);
msg = nlmsg_alloc();
if (!msg) {
query_opts->err = -ENOMEM;
goto err_free_cb;
}
genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, family, 0, flags,
nl_cmd, 1);
nla_put_u32(msg, BATADV_ATTR_MESH_IFINDEX, ifindex);
nl_send_auto_complete(sock, msg);
nlmsg_free(msg);
nl_recvmsgs(sock, cb);
err_free_cb:
nl_cb_put(cb);
err_free_sock:
nl_socket_free(sock);
return query_opts->err;
}