netsukuku/src/ll_map.c

/*
 * 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>
 *
 *
 * Alpt: Added ll_first_up_if
 */

#include "includes.h"

#include "libnetlink.h"
#include "ll_map.h"
#include "xmalloc.h"
#include "log.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];

void
ll_free_index(void)
{
	struct idxmap *im, **imp;
	int i;
	for (i = 0; i < 16; i++)
		for (imp = &idxmap[i]; (im = *imp) != NULL;) {
			imp = &im->next;
			xfree(im);
		}
}

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));
		if (im == NULL)
			return 0;
		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;
}

int
ll_name_to_index(const char *name)
{
	static char ncache[16];
	static int icache;
	struct idxmap *im;
	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;
			}
		}
	}
	return 0;
}

/* It returns the idx of the `n'th interface it finds up in the map */
int
ll_nth_up_if(int n)
{
	unsigned char i, found;
	unsigned flags;

	if (n <= 0)
		fatal("%s:%d: Bad argument given", ERROR_POS);

	for (found = 0, i = 1; i <= 16; i++) {
		flags = ll_index_to_flags(i);
		if ((flags & IFF_UP) && !(flags & IFF_LOOPBACK)) {
			found++;
			if (found == n)
				return i;
		}
	}

	return -1;
}

/* It returns the first the idx of the first interface it finds up in the map */
int
ll_first_up_if(void)
{
	return ll_nth_up_if(1);
}

int
ll_init_map(struct rtnl_handle *rth)
{
	if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0)
		fatal("%s:%d: Cannot send dump request", ERROR_POS);

	if (rtnl_dump_filter
		(rth, (rtnl_filter_t) ll_remember_index, &idxmap, NULL, NULL) < 0)
		fatal(ERROR_MSG "Dump terminated", ERROR_POS);

	return 0;
}