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/*
* 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <net/if.h>
#include "libnetlink.h"
#include "ll_map.h"
#include "hlist.h"
struct ll_cache {
struct hlist_node idx_hash;
struct hlist_node name_hash;
unsigned flags;
unsigned index;
unsigned short type;
char name[IFNAMSIZ];
};
#define IDXMAP_SIZE 1024
static struct hlist_head idx_head[IDXMAP_SIZE];
static struct hlist_head name_head[IDXMAP_SIZE];
static struct ll_cache *ll_get_by_index(unsigned index)
{
struct hlist_node *n;
unsigned h = index & (IDXMAP_SIZE - 1);
hlist_for_each(n, &idx_head[h]) {
struct ll_cache *im
= container_of(n, struct ll_cache, idx_hash);
if (im->index == index)
return im;
}
return NULL;
}
unsigned namehash(const char *str)
{
unsigned hash = 5381;
while (*str)
hash = ((hash << 5) + hash) + *str++; /* hash * 33 + c */
return hash;
}
static struct ll_cache *ll_get_by_name(const char *name)
{
struct hlist_node *n;
unsigned h = namehash(name) & (IDXMAP_SIZE - 1);
hlist_for_each(n, &name_head[h]) {
struct ll_cache *im
= container_of(n, struct ll_cache, name_hash);
if (strncmp(im->name, name, IFNAMSIZ) == 0)
return im;
}
return NULL;
}
int ll_remember_index(const struct sockaddr_nl *who,
struct nlmsghdr *n, void *arg)
{
unsigned int h;
const char *ifname;
struct ifinfomsg *ifi = NLMSG_DATA(n);
struct ll_cache *im;
struct rtattr *tb[IFLA_MAX+1];
if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK)
return 0;
if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi)))
return -1;
im = ll_get_by_index(ifi->ifi_index);
if (n->nlmsg_type == RTM_DELLINK) {
if (im) {
hlist_del(&im->name_hash);
hlist_del(&im->idx_hash);
free(im);
}
return 0;
}
memset(tb, 0, sizeof(tb));
parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n));
ifname = rta_getattr_str(tb[IFLA_IFNAME]);
if (ifname == NULL)
return 0;
if (im) {
/* change to existing entry */
if (strcmp(im->name, ifname) != 0) {
hlist_del(&im->name_hash);
h = namehash(ifname) & (IDXMAP_SIZE - 1);
hlist_add_head(&im->name_hash, &name_head[h]);
}
im->flags = ifi->ifi_flags;
return 0;
}
im = malloc(sizeof(*im));
if (im == NULL)
return 0;
im->index = ifi->ifi_index;
strcpy(im->name, ifname);
im->type = ifi->ifi_type;
im->flags = ifi->ifi_flags;
h = ifi->ifi_index & (IDXMAP_SIZE - 1);
hlist_add_head(&im->idx_hash, &idx_head[h]);
h = namehash(ifname) & (IDXMAP_SIZE - 1);
hlist_add_head(&im->name_hash, &name_head[h]);
return 0;
}
const char *ll_idx_n2a(unsigned idx, char *buf)
{
const struct ll_cache *im;
if (idx == 0)
return "*";
im = ll_get_by_index(idx);
if (im)
return im->name;
if (if_indextoname(idx, buf) == NULL)
snprintf(buf, IFNAMSIZ, "if%d", idx);
return buf;
}
const char *ll_index_to_name(unsigned idx)
{
static char nbuf[IFNAMSIZ];
return ll_idx_n2a(idx, nbuf);
}
int ll_index_to_type(unsigned idx)
{
const struct ll_cache *im;
if (idx == 0)
return -1;
im = ll_get_by_index(idx);
return im ? im->type : -1;
}
int ll_index_to_flags(unsigned idx)
{
const struct ll_cache *im;
if (idx == 0)
return 0;
im = ll_get_by_index(idx);
return im ? im->flags : -1;
}
unsigned ll_name_to_index(const char *name)
{
const struct ll_cache *im;
unsigned idx;
if (name == NULL)
return 0;
im = ll_get_by_name(name);
if (im)
return im->index;
idx = if_nametoindex(name);
if (idx == 0)
sscanf(name, "if%u", &idx);
return idx;
}
void ll_init_map(struct rtnl_handle *rth)
{
static int initialized;
if (initialized)
return;
if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) {
perror("Cannot send dump request");
exit(1);
}
if (rtnl_dump_filter(rth, ll_remember_index, NULL) < 0) {
fprintf(stderr, "Dump terminated\n");
exit(1);
}
initialized = 1;
}