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/*
* Copyright (c) 2015 Pablo Neira Ayuso <pablo@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 (or any
* later) as published by the Free Software Foundation.
*/
#include <stdio.h>
#include <stdlib.h>
#include <net/if.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include <libmnl/libmnl.h>
#include <linux/rtnetlink.h>
#include <nftables.h>
#include <list.h>
#include <netlink.h>
#include <iface.h>
static LIST_HEAD(iface_list);
static bool iface_cache_init;
static int data_attr_cb(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
if (mnl_attr_type_valid(attr, IFLA_MAX) < 0)
return MNL_CB_OK;
switch(type) {
case IFLA_IFNAME:
if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)
netlink_abi_error();
break;
default:
return MNL_CB_OK;
}
tb[type] = attr;
return MNL_CB_OK;
}
static int data_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[IFLA_MAX + 1] = {};
struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh);
struct iface *iface;
iface = xmalloc(sizeof(struct iface));
iface->ifindex = ifm->ifi_index;
mnl_attr_parse(nlh, sizeof(*ifm), data_attr_cb, tb);
snprintf(iface->name, IFNAMSIZ, "%s", mnl_attr_get_str(tb[IFLA_IFNAME]));
list_add(&iface->list, &iface_list);
return MNL_CB_OK;
}
static int iface_mnl_talk(struct mnl_socket *nl, uint32_t portid)
{
char buf[MNL_SOCKET_BUFFER_SIZE];
struct nlmsghdr *nlh;
struct rtgenmsg *rt;
bool eintr = false;
uint32_t seq;
int ret;
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = RTM_GETLINK;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
nlh->nlmsg_seq = seq = time(NULL);
rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));
rt->rtgen_family = AF_PACKET;
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0)
return -1;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, data_cb, NULL);
if (ret == 0)
break;
if (ret < 0) {
if (errno != EINTR)
return ret;
/* process all pending messages before reporting EINTR */
eintr = true;
}
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (eintr) {
ret = -1;
errno = EINTR;
}
return ret;
}
void iface_cache_update(void)
{
struct mnl_socket *nl;
uint32_t portid;
int ret;
nl = mnl_socket_open(NETLINK_ROUTE);
if (nl == NULL)
netlink_init_error();
if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0)
netlink_init_error();
portid = mnl_socket_get_portid(nl);
do {
ret = iface_mnl_talk(nl, portid);
} while (ret < 0 && errno == EINTR);
if (ret == -1)
netlink_init_error();
mnl_socket_close(nl);
iface_cache_init = true;
}
void iface_cache_release(void)
{
struct iface *iface, *next;
if (!iface_cache_init)
return;
list_for_each_entry_safe(iface, next, &iface_list, list) {
list_del(&iface->list);
free(iface);
}
iface_cache_init = false;
}
unsigned int nft_if_nametoindex(const char *name)
{
struct iface *iface;
if (!iface_cache_init)
iface_cache_update();
list_for_each_entry(iface, &iface_list, list) {
if (strncmp(name, iface->name, IFNAMSIZ) == 0)
return iface->ifindex;
}
return 0;
}
char *nft_if_indextoname(unsigned int ifindex, char *name)
{
struct iface *iface;
if (!iface_cache_init)
iface_cache_update();
list_for_each_entry(iface, &iface_list, list) {
if (iface->ifindex == ifindex) {
snprintf(name, IFNAMSIZ, "%s", iface->name);
return name;
}
}
return NULL;
}
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