/*
* 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 <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 "list.h"
#include "utils.h"
struct ll_cache {
struct hlist_node idx_hash;
struct hlist_node name_hash;
unsigned flags;
unsigned index;
unsigned short type;
struct list_head altnames_list;
char name[];
};
#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 (strcmp(im->name, name) == 0)
return im;
}
return NULL;
}
static struct ll_cache *ll_entry_create(struct ifinfomsg *ifi,
const char *ifname,
struct ll_cache *parent_im)
{
struct ll_cache *im;
unsigned int h;
im = malloc(sizeof(*im) + strlen(ifname) + 1);
if (!im)
return NULL;
im->index = ifi->ifi_index;
strcpy(im->name, ifname);
im->type = ifi->ifi_type;
im->flags = ifi->ifi_flags;
if (parent_im) {
list_add_tail(&im->altnames_list, &parent_im->altnames_list);
} else {
/* This is parent, insert to index hash. */
h = ifi->ifi_index & (IDXMAP_SIZE - 1);
hlist_add_head(&im->idx_hash, &idx_head[h]);
INIT_LIST_HEAD(&im->altnames_list);
}
h = namehash(ifname) & (IDXMAP_SIZE - 1);
hlist_add_head(&im->name_hash, &name_head[h]);
return im;
}
static void ll_entry_destroy(struct ll_cache *im, bool im_is_parent)
{
hlist_del(&im->name_hash);
if (im_is_parent)
hlist_del(&im->idx_hash);
else
list_del(&im->altnames_list);
free(im);
}
static void ll_entry_update(struct ll_cache *im, struct ifinfomsg *ifi,
const char *ifname)
{
unsigned int h;
im->flags = ifi->ifi_flags;
if (!strcmp(im->name, ifname))
return;
hlist_del(&im->name_hash);
h = namehash(ifname) & (IDXMAP_SIZE - 1);
hlist_add_head(&im->name_hash, &name_head[h]);
}
static void ll_altname_entries_create(struct ll_cache *parent_im,
struct ifinfomsg *ifi, struct rtattr **tb)
{
struct rtattr *i, *proplist = tb[IFLA_PROP_LIST];
int rem;
if (!proplist)
return;
rem = RTA_PAYLOAD(proplist);
for (i = RTA_DATA(proplist); RTA_OK(i, rem);
i = RTA_NEXT(i, rem)) {
if (i->rta_type != IFLA_ALT_IFNAME)
continue;
ll_entry_create(ifi, rta_getattr_str(i), parent_im);
}
}
static void ll_altname_entries_destroy(struct ll_cache *parent_im)
{
struct ll_cache *im, *tmp;
list_for_each_entry_safe(im, tmp, &parent_im->altnames_list,
altnames_list)
ll_entry_destroy(im, false);
}
static void ll_altname_entries_update(struct ll_cache *parent_im,
struct ifinfomsg *ifi, struct rtattr **tb)
{
struct rtattr *i, *proplist = tb[IFLA_PROP_LIST];
struct ll_cache *im;
int rem;
if (!proplist) {
ll_altname_entries_destroy(parent_im);
return;
}
/* Simply compare the altname list with the cached one
* and if it does not fit 1:1, recreate the cached list
* from scratch.
*/
im = list_first_entry(&parent_im->altnames_list, typeof(*im),
altnames_list);
rem = RTA_PAYLOAD(proplist);
for (i = RTA_DATA(proplist); RTA_OK(i, rem);
i = RTA_NEXT(i, rem)) {
if (i->rta_type != IFLA_ALT_IFNAME)
continue;
if (!im || strcmp(rta_getattr_str(i), im->name))
goto recreate_altname_entries;
im = list_next_entry(im, altnames_list);
}
if (list_next_entry(im, altnames_list))
goto recreate_altname_entries;
return;
recreate_altname_entries:
ll_altname_entries_destroy(parent_im);
ll_altname_entries_create(parent_im, ifi, tb);
}
static void ll_entries_create(struct ifinfomsg *ifi, struct rtattr **tb)
{
struct ll_cache *parent_im;
if (!tb[IFLA_IFNAME])
return;
parent_im = ll_entry_create(ifi, rta_getattr_str(tb[IFLA_IFNAME]),
NULL);
if (!parent_im)
return;
ll_altname_entries_create(parent_im, ifi, tb);
}
static void ll_entries_destroy(struct ll_cache *parent_im)
{
ll_altname_entries_destroy(parent_im);
ll_entry_destroy(parent_im, true);
}
static void ll_entries_update(struct ll_cache *parent_im,
struct ifinfomsg *ifi, struct rtattr **tb)
{
if (tb[IFLA_IFNAME])
ll_entry_update(parent_im, ifi,
rta_getattr_str(tb[IFLA_IFNAME]));
ll_altname_entries_update(parent_im, ifi, tb);
}
int ll_remember_index(struct nlmsghdr *n, void *arg)
{
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)
ll_entries_destroy(im);
return 0;
}
parse_rtattr_flags(tb, IFLA_MAX, IFLA_RTA(ifi),
IFLA_PAYLOAD(n), NLA_F_NESTED);
if (im)
ll_entries_update(im, ifi, tb);
else
ll_entries_create(ifi, tb);
return 0;
}
const char *ll_idx_n2a(unsigned int idx)
{
static char buf[IFNAMSIZ];
snprintf(buf, sizeof(buf), "if%u", idx);
return buf;
}
static unsigned int ll_idx_a2n(const char *name)
{
unsigned int idx;
if (sscanf(name, "if%u", &idx) != 1)
return 0;
return idx;
}
static int ll_link_get(const char *name, int index)
{
struct {
struct nlmsghdr n;
struct ifinfomsg ifm;
char buf[1024];
} req = {
.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
.n.nlmsg_flags = NLM_F_REQUEST,
.n.nlmsg_type = RTM_GETLINK,
.ifm.ifi_index = index,
};
__u32 filt_mask = RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS;
struct rtnl_handle rth = {};
struct nlmsghdr *answer;
int rc = 0;
if (rtnl_open(&rth, 0) < 0)
return 0;
addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask);
if (name)
addattr_l(&req.n, sizeof(req),
!check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME,
name, strlen(name) + 1);
if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0)
goto out;
/* add entry to cache */
rc = ll_remember_index(answer, NULL);
if (!rc) {
struct ifinfomsg *ifm = NLMSG_DATA(answer);
rc = ifm->ifi_index;
}
free(answer);
out:
rtnl_close(&rth);
return rc;
}
const char *ll_index_to_name(unsigned int idx)
{
static char buf[IFNAMSIZ];
const struct ll_cache *im;
if (idx == 0)
return "*";
im = ll_get_by_index(idx);
if (im)
return im->name;
if (ll_link_get(NULL, idx) == idx) {
im = ll_get_by_index(idx);
if (im)
return im->name;
}
if (if_indextoname(idx, buf) == NULL)
snprintf(buf, IFNAMSIZ, "if%u", idx);
return buf;
}
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 = ll_link_get(name, 0);
if (idx == 0)
idx = if_nametoindex(name);
if (idx == 0)
idx = ll_idx_a2n(name);
return idx;
}
void ll_drop_by_index(unsigned index)
{
struct ll_cache *im;
im = ll_get_by_index(index);
if (!im)
return;
hlist_del(&im->idx_hash);
hlist_del(&im->name_hash);
free(im);
}
void ll_init_map(struct rtnl_handle *rth)
{
static int initialized;
if (initialized)
return;
if (rtnl_linkdump_req(rth, AF_UNSPEC) < 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;
}