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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 "libbb.h"
#include <string.h>
#include "libnetlink.h"
#include "ll_map.h"
#include <sys/socket.h> /* socket() */
#include <net/if.h> /* struct ifreq and co. */
#include <sys/ioctl.h> /* ioctl() & SIOCGIFINDEX */
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];
int ll_remember_index(struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
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)
break;
if (im == NULL) {
im = xmalloc(sizeof(*im));
im->next = *imp;
im->index = ifi->ifi_index;
*imp = im;
}
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 > 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 *ll_idx_n2a(int idx, char *buf)
{
struct idxmap *im;
if (idx == 0)
return "*";
for (im = idxmap[idx & 0xF]; im; im = im->next)
if (im->index == idx)
return im->name;
snprintf(buf, 16, "if%d", idx);
return buf;
}
const char *ll_index_to_name(int idx)
{
static char nbuf[16];
return ll_idx_n2a(idx, nbuf);
}
int ll_index_to_type(int idx)
{
struct idxmap *im;
if (idx == 0)
return -1;
for (im = idxmap[idx & 0xF]; im; im = im->next)
if (im->index == idx)
return im->type;
return -1;
}
unsigned ll_index_to_flags(int idx)
{
struct idxmap *im;
if (idx == 0)
return 0;
for (im = idxmap[idx & 0xF]; im; im = im->next)
if (im->index == idx)
return im->flags;
return 0;
}
// TODO: caching is not warranted - no users which repeatedly call it
int ll_name_to_index(char *name)
{
static char ncache[16];
static int icache;
struct idxmap *im;
int sock_fd;
int i;
if (name == NULL)
return 0;
if (icache && strcmp(name, ncache) == 0)
return icache;
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);
return im->index;
}
}
}
/* 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 */
sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
if (sock_fd) {
struct ifreq ifr;
int ret;
strncpy(ifr.ifr_name, name, IFNAMSIZ);
ifr.ifr_ifindex = -1;
ret = ioctl(sock_fd, SIOCGIFINDEX, &ifr);
close(sock_fd);
if (ret >= 0)
/* In theory, we should redump the interface list
* to update our cache, this is left as an exercise
* to the reader... Jean II */
return ifr.ifr_ifindex;
}
return 0;
}
int ll_init_map(struct rtnl_handle *rth)
{
if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
bb_perror_msg_and_die("cannot send dump request");
}
if (rtnl_dump_filter(rth, ll_remember_index, &idxmap, NULL, NULL) < 0) {
bb_error_msg_and_die("dump terminated");
}
return 0;
}
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