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/* vi: set sw=4 ts=4: */
/*
* ll_map.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
*/
#include <net/if.h> /* struct ifreq and co. */
#include "libbb.h"
#include "libnetlink.h"
#include "ll_map.h"
struct idxmap {
struct idxmap *next;
int index;
int type;
int alen;
unsigned flags;
unsigned char addr[8];
char name[16];
};
static struct idxmap *idxmap[16];
static struct idxmap *find_by_index(int idx)
{
struct idxmap *im;
for (im = idxmap[idx & 0xF]; im; im = im->next)
if (im->index == idx)
return im;
return NULL;
}
int FAST_FUNC ll_remember_index(const struct sockaddr_nl *who UNUSED_PARAM,
struct nlmsghdr *n,
void *arg UNUSED_PARAM)
{
int h;
struct ifinfomsg *ifi = NLMSG_DATA(n);
struct idxmap *im, **imp;
struct rtattr *tb[IFLA_MAX+1];
if (n->nlmsg_type != RTM_NEWLINK)
return 0;
if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
return -1;
memset(tb, 0, sizeof(tb));
parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
if (tb[IFLA_IFNAME] == NULL)
return 0;
h = ifi->ifi_index & 0xF;
for (imp = &idxmap[h]; (im = *imp) != NULL; imp = &im->next)
if (im->index == ifi->ifi_index)
goto found;
im = xmalloc(sizeof(*im));
im->next = *imp;
im->index = ifi->ifi_index;
*imp = im;
found:
im->type = ifi->ifi_type;
im->flags = ifi->ifi_flags;
if (tb[IFLA_ADDRESS]) {
int alen;
im->alen = alen = RTA_PAYLOAD(tb[IFLA_ADDRESS]);
if (alen > (int)sizeof(im->addr))
alen = sizeof(im->addr);
memcpy(im->addr, RTA_DATA(tb[IFLA_ADDRESS]), alen);
} else {
im->alen = 0;
memset(im->addr, 0, sizeof(im->addr));
}
strcpy(im->name, RTA_DATA(tb[IFLA_IFNAME]));
return 0;
}
const char FAST_FUNC *ll_idx_n2a(int idx, char *buf)
{
struct idxmap *im;
if (idx == 0)
return "*";
im = find_by_index(idx);
if (im)
return im->name;
snprintf(buf, 16, "if%d", idx);
return buf;
}
const char FAST_FUNC *ll_index_to_name(int idx)
{
static char nbuf[16];
return ll_idx_n2a(idx, nbuf);
}
#ifdef UNUSED
int ll_index_to_type(int idx)
{
struct idxmap *im;
if (idx == 0)
return -1;
im = find_by_index(idx);
if (im)
return im->type;
return -1;
}
#endif
unsigned FAST_FUNC ll_index_to_flags(int idx)
{
struct idxmap *im;
if (idx == 0)
return 0;
im = find_by_index(idx);
if (im)
return im->flags;
return 0;
}
int FAST_FUNC xll_name_to_index(const char *name)
{
int ret = 0;
int sock_fd;
/* caching is not warranted - no users which repeatedly call it */
#ifdef UNUSED
static char ncache[16];
static int icache;
struct idxmap *im;
int i;
if (name == NULL)
goto out;
if (icache && strcmp(name, ncache) == 0) {
ret = icache;
goto out;
}
for (i = 0; i < 16; i++) {
for (im = idxmap[i]; im; im = im->next) {
if (strcmp(im->name, name) == 0) {
icache = im->index;
strcpy(ncache, name);
ret = im->index;
goto out;
}
}
}
/* We have not found the interface in our cache, but the kernel
* may still know about it. One reason is that we may be using
* module on-demand loading, which means that the kernel will
* load the module and make the interface exist only when
* we explicitely request it (check for dev_load() in net/core/dev.c).
* I can think of other similar scenario, but they are less common...
* Jean II */
#endif
sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (sock_fd >= 0) {
struct ifreq ifr;
int tmp;
strncpy_IFNAMSIZ(ifr.ifr_name, name);
ifr.ifr_ifindex = -1;
tmp = ioctl(sock_fd, SIOCGIFINDEX, &ifr);
close(sock_fd);
if (tmp >= 0)
/* In theory, we should redump the interface list
* to update our cache, this is left as an exercise
* to the reader... Jean II */
ret = ifr.ifr_ifindex;
}
/* out:*/
if (ret <= 0)
bb_error_msg_and_die("cannot find device \"%s\"", name);
return ret;
}
int FAST_FUNC ll_init_map(struct rtnl_handle *rth)
{
xrtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK);
xrtnl_dump_filter(rth, ll_remember_index, &idxmap);
return 0;
}
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