/*	$OpenBSD: interface.c,v 1.32 2016/05/23 16:20:59 renato Exp $ */

/*
 * Copyright (c) 2005 Claudio Jeker <claudio@openbsd.org>
 * Copyright (c) 2004, 2005, 2008 Esben Norby <norby@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_types.h>
#include <fcntl.h>
#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <event.h>

#include "ldpd.h"
#include "ldp.h"
#include "log.h"
#include "ldpe.h"

extern struct ldpd_conf        *leconf;

void		 if_hello_timer(int, short, void *);
void		 if_start_hello_timer(struct iface *);
void		 if_stop_hello_timer(struct iface *);

struct iface *
if_new(struct kif *kif)
{
	struct iface		*iface;

	if ((iface = calloc(1, sizeof(*iface))) == NULL)
		fatal("if_new: calloc");

	iface->state = IF_STA_DOWN;

	LIST_INIT(&iface->addr_list);
	LIST_INIT(&iface->adj_list);

	strlcpy(iface->name, kif->ifname, sizeof(iface->name));

	/* get type */
	if (kif->flags & IFF_POINTOPOINT)
		iface->type = IF_TYPE_POINTOPOINT;
	if (kif->flags & IFF_BROADCAST &&
	    kif->flags & IFF_MULTICAST)
		iface->type = IF_TYPE_BROADCAST;

	/* get index and flags */
	iface->ifindex = kif->ifindex;
	iface->flags = kif->flags;
	iface->linkstate = kif->link_state;
	iface->if_type = kif->if_type;

	return (iface);
}

void
if_del(struct iface *iface)
{
	struct if_addr		*if_addr;

	if (iface->state == IF_STA_ACTIVE)
		if_reset(iface);

	log_debug("%s: interface %s", __func__, iface->name);

	while ((if_addr = LIST_FIRST(&iface->addr_list)) != NULL) {
		LIST_REMOVE(if_addr, entry);
		free(if_addr);
	}

	free(iface);
}

void
if_init(struct ldpd_conf *xconf, struct iface *iface)
{
	/* set event handlers for interface */
	evtimer_set(&iface->hello_timer, if_hello_timer, iface);

	iface->discovery_fd = xconf->ldp_discovery_socket;
}

struct iface *
if_lookup(struct ldpd_conf *xconf, u_short ifindex)
{
	struct iface *iface;

	LIST_FOREACH(iface, &xconf->iface_list, entry)
		if (iface->ifindex == ifindex)
			return (iface);

	return (NULL);
}

struct if_addr *
if_addr_new(struct kaddr *ka)
{
	struct if_addr	*if_addr;

	if ((if_addr = calloc(1, sizeof(*if_addr))) == NULL)
		fatal(__func__);

	if_addr->addr.s_addr = ka->addr.s_addr;
	if_addr->mask.s_addr = ka->mask.s_addr;
	if_addr->dstbrd.s_addr = ka->dstbrd.s_addr;

	return (if_addr);
}

struct if_addr *
if_addr_lookup(struct if_addr_head *addr_list, struct kaddr *ka)
{
	struct if_addr *if_addr;

	LIST_FOREACH(if_addr, addr_list, entry)
		if (if_addr->addr.s_addr == ka->addr.s_addr &&
		    if_addr->mask.s_addr == ka->mask.s_addr &&
		    if_addr->dstbrd.s_addr == ka->dstbrd.s_addr)
			return (if_addr);

	return (NULL);
}

void
if_addr_add(struct kaddr *ka)
{
	struct iface		*iface;
	struct if_addr		*if_addr;
	struct nbr		*nbr;

	if (if_addr_lookup(&global.addr_list, ka) == NULL) {
		if_addr = if_addr_new(ka);

		LIST_INSERT_HEAD(&global.addr_list, if_addr, entry);
		RB_FOREACH(nbr, nbr_id_head, &nbrs_by_id) {
			if (nbr->state != NBR_STA_OPER)
				continue;

			send_address(nbr, if_addr, 0);
		}
	}

	iface = if_lookup(leconf, ka->ifindex);
	if (iface &&
	    if_addr_lookup(&iface->addr_list, ka) == NULL) {
		if_addr = if_addr_new(ka);
		LIST_INSERT_HEAD(&iface->addr_list, if_addr, entry);
		if_update(iface);
	}
}

void
if_addr_del(struct kaddr *ka)
{
	struct iface		*iface;
	struct if_addr		*if_addr;
	struct nbr		*nbr;

	iface = if_lookup(leconf, ka->ifindex);
	if (iface) {
		if_addr = if_addr_lookup(&iface->addr_list, ka);
		if (if_addr) {
			LIST_REMOVE(if_addr, entry);
			free(if_addr);
			if_update(iface);
		}
	}

	if_addr = if_addr_lookup(&global.addr_list, ka);
	if (if_addr) {
		RB_FOREACH(nbr, nbr_id_head, &nbrs_by_id) {
			if (nbr->state != NBR_STA_OPER)
				continue;
			send_address(nbr, if_addr, 1);
		}
		LIST_REMOVE(if_addr, entry);
		free(if_addr);
	}
}

int
if_start(struct iface *iface)
{
	struct in_addr		 addr;
	struct timeval		 now;

	log_debug("%s: %s", __func__, iface->name);

	gettimeofday(&now, NULL);
	iface->uptime = now.tv_sec;

	inet_aton(AllRouters, &addr);
	if (if_join_group(iface, &addr))
		return (-1);

	send_hello(HELLO_LINK, iface, NULL);
	if_start_hello_timer(iface);
	return (0);
}

int
if_reset(struct iface *iface)
{
	struct in_addr		 addr;
	struct adj		*adj;

	log_debug("%s: %s", __func__, iface->name);

	while ((adj = LIST_FIRST(&iface->adj_list)) != NULL) {
		LIST_REMOVE(adj, iface_entry);
		adj_del(adj);
	}

	if_stop_hello_timer(iface);

	/* try to cleanup */
	inet_aton(AllRouters, &addr);
	if_leave_group(iface, &addr);

	return (0);
}

int
if_update(struct iface *iface)
{
	int ret;

	if (iface->state == IF_STA_DOWN) {
		if (!(iface->flags & IFF_UP) ||
		    !LINK_STATE_IS_UP(iface->linkstate) ||
		    LIST_EMPTY(&iface->addr_list))
			return (0);

		iface->state = IF_STA_ACTIVE;
		ret = if_start(iface);
	} else {
		if ((iface->flags & IFF_UP) &&
		    LINK_STATE_IS_UP(iface->linkstate) &&
		    !LIST_EMPTY(&iface->addr_list))
			return (0);

		iface->state = IF_STA_DOWN;
		ret = if_reset(iface);
	}

	return (ret);
}

/* timers */
/* ARGSUSED */
void
if_hello_timer(int fd, short event, void *arg)
{
	struct iface		*iface = arg;

	send_hello(HELLO_LINK, iface, NULL);
	if_start_hello_timer(iface);
}

void
if_start_hello_timer(struct iface *iface)
{
	struct timeval		 tv;

	timerclear(&tv);
	tv.tv_sec = iface->hello_interval;
	if (evtimer_add(&iface->hello_timer, &tv) == -1)
		fatal(__func__);
}

void
if_stop_hello_timer(struct iface *iface)
{
	if (evtimer_pending(&iface->hello_timer, NULL) &&
	    evtimer_del(&iface->hello_timer) == -1)
		fatal(__func__);
}

struct ctl_iface *
if_to_ctl(struct iface *iface)
{
	static struct ctl_iface	 ictl;
	struct timeval		 now;
	struct adj		*adj;

	memcpy(ictl.name, iface->name, sizeof(ictl.name));
	ictl.ifindex = iface->ifindex;
	ictl.state = iface->state;
	ictl.hello_holdtime = iface->hello_holdtime;
	ictl.hello_interval = iface->hello_interval;
	ictl.flags = iface->flags;
	ictl.type = iface->type;
	ictl.linkstate = iface->linkstate;
	ictl.if_type = iface->if_type;

	gettimeofday(&now, NULL);
	if (iface->state != IF_STA_DOWN &&
	    iface->uptime != 0) {
		ictl.uptime = now.tv_sec - iface->uptime;
	} else
		ictl.uptime = 0;

	ictl.adj_cnt = 0;
	LIST_FOREACH(adj, &iface->adj_list, iface_entry)
		ictl.adj_cnt++;

	return (&ictl);
}

/* misc */
int
if_set_mcast_ttl(int fd, u_int8_t ttl)
{
	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
	    (char *)&ttl, sizeof(ttl)) < 0) {
		log_warn("%s: error setting IP_MULTICAST_TTL to %d",
		    __func__, ttl);
		return (-1);
	}

	return (0);
}

int
if_set_tos(int fd, int tos)
{
	if (setsockopt(fd, IPPROTO_IP, IP_TOS, (int *)&tos, sizeof(tos)) < 0) {
		log_warn("%s: error setting IP_TOS to 0x%x", __func__, tos);
		return (-1);
	}

	return (0);
}

int
if_set_recvif(int fd, int enable)
{
	if (setsockopt(fd, IPPROTO_IP, IP_RECVIF, &enable,
	    sizeof(enable)) < 0) {
		log_warn("%s: error setting IP_RECVIF", __func__);
		return (-1);
	}
	return (0);
}

void
if_set_recvbuf(int fd)
{
	int	bsize;

	bsize = 65535;
	while (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &bsize,
	    sizeof(bsize)) == -1)
		bsize /= 2;
}

int
if_set_reuse(int fd, int enable)
{
	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &enable,
	    sizeof(int)) < 0) {
		log_warn("%s: error setting SO_REUSEADDR", __func__);
		return (-1);
	}

	return (0);
}

/*
 * only one JOIN or DROP per interface and address is allowed so we need
 * to keep track of what is added and removed.
 */
struct if_group_count {
	LIST_ENTRY(if_group_count)	entry;
	struct in_addr			addr;
	unsigned int			ifindex;
	int				count;
};

LIST_HEAD(,if_group_count) ifglist = LIST_HEAD_INITIALIZER(ifglist);

int
if_join_group(struct iface *iface, struct in_addr *addr)
{
	struct ip_mreq		 mreq;
	struct if_group_count	*ifg;
	struct if_addr		*if_addr;

	LIST_FOREACH(ifg, &ifglist, entry)
		if (iface->ifindex == ifg->ifindex &&
		    addr->s_addr == ifg->addr.s_addr)
			break;
	if (ifg == NULL) {
		if ((ifg = calloc(1, sizeof(*ifg))) == NULL)
			fatal(__func__);
		ifg->addr.s_addr = addr->s_addr;
		ifg->ifindex = iface->ifindex;
		LIST_INSERT_HEAD(&ifglist, ifg, entry);
	}

	if (ifg->count++ != 0)
		/* already joined */
		return (0);

	if_addr = LIST_FIRST(&iface->addr_list);
	mreq.imr_multiaddr.s_addr = addr->s_addr;
	mreq.imr_interface.s_addr = if_addr->addr.s_addr;

	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
	    IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
		log_warn("%s: error IP_ADD_MEMBERSHIP, "
		    "interface %s address %s", __func__, iface->name,
		    inet_ntoa(*addr));
		LIST_REMOVE(ifg, entry);
		free(ifg);
		return (-1);
	}
	return (0);
}

int
if_leave_group(struct iface *iface, struct in_addr *addr)
{
	struct ip_mreq		 mreq;
	struct if_group_count	*ifg;
	struct if_addr		*if_addr;

	LIST_FOREACH(ifg, &ifglist, entry)
		if (iface->ifindex == ifg->ifindex &&
		    addr->s_addr == ifg->addr.s_addr)
			break;

	/* if interface is not found just try to drop membership */
	if (ifg) {
		if (--ifg->count != 0)
			/* others still joined */
			return (0);

		LIST_REMOVE(ifg, entry);
		free(ifg);
	}

	if_addr = LIST_FIRST(&iface->addr_list);
	if (!if_addr)
		return (0);

	mreq.imr_multiaddr.s_addr = addr->s_addr;
	mreq.imr_interface.s_addr = if_addr->addr.s_addr;

	if (setsockopt(iface->discovery_fd, IPPROTO_IP,
	    IP_DROP_MEMBERSHIP, (void *)&mreq, sizeof(mreq)) < 0) {
		log_warn("%s: error IP_DROP_MEMBERSHIP, interface %s "
		    "address %s", __func__, iface->name, inet_ntoa(*addr));
		return (-1);
	}

	return (0);
}

int
if_set_mcast(struct iface *iface)
{
	struct if_addr		*if_addr;

	if_addr = LIST_FIRST(&iface->addr_list);

	if (setsockopt(iface->discovery_fd, IPPROTO_IP, IP_MULTICAST_IF,
	    &if_addr->addr.s_addr, sizeof(if_addr->addr.s_addr)) < 0) {
		log_debug("%s: error setting IP_MULTICAST_IF, interface %s",
		    __func__, iface->name);
		return (-1);
	}

	return (0);
}

int
if_set_mcast_loop(int fd)
{
	u_int8_t	loop = 0;

	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
	    (char *)&loop, sizeof(loop)) < 0) {
		log_warn("%s: error setting IP_MULTICAST_LOOP", __func__);
		return (-1);
	}

	return (0);
}