/*
 * PIM for Quagga
 * Copyright (C) 2008  Everton da Silva Marques
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>
#include "log.h"
#include "privs.h"
#include "if.h"
#include "prefix.h"
#include "vty.h"
#include "plist.h"
#include "sockopt.h"
#include "lib_errors.h"

#include "pimd.h"
#include "pim_rpf.h"
#include "pim_mroute.h"
#include "pim_oil.h"
#include "pim_str.h"
#include "pim_time.h"
#include "pim_iface.h"
#include "pim_macro.h"
#include "pim_rp.h"
#include "pim_oil.h"
#include "pim_register.h"
#include "pim_ifchannel.h"
#include "pim_zlookup.h"
#include "pim_ssm.h"
#include "pim_sock.h"
#include "pim_vxlan.h"

static void mroute_read_on(struct pim_instance *pim);

static int pim_mroute_set(struct pim_instance *pim, int enable)
{
	int err;
	int opt, data;
	socklen_t data_len = sizeof(data);
	long flags;

	/*
	 * We need to create the VRF table for the pim mroute_socket
	 */
	if (pim->vrf->vrf_id != VRF_DEFAULT) {
		frr_with_privs(&pimd_privs) {

			data = pim->vrf->data.l.table_id;
			err = setsockopt(pim->mroute_socket, IPPROTO_IP,
					 MRT_TABLE,
					 &data, data_len);
			if (err) {
				zlog_warn(
					"%s %s: failure: setsockopt(fd=%d,IPPROTO_IP, MRT_TABLE=%d): errno=%d: %s",
					__FILE__, __func__, pim->mroute_socket,
					data, errno, safe_strerror(errno));
				return -1;
			}

		}
	}

	frr_with_privs(&pimd_privs) {
		opt = enable ? MRT_INIT : MRT_DONE;
		/*
		 * *BSD *cares* about what value we pass down
		 * here
		 */
		data = 1;
		err = setsockopt(pim->mroute_socket, IPPROTO_IP,
				 opt, &data, data_len);
		if (err) {
			zlog_warn(
				"%s %s: failure: setsockopt(fd=%d,IPPROTO_IP,%s=%d): errno=%d: %s",
				__FILE__, __func__, pim->mroute_socket,
				enable ? "MRT_INIT" : "MRT_DONE", data, errno,
				safe_strerror(errno));
			return -1;
		}
	}

#if defined(HAVE_IP_PKTINFO)
	if (enable) {
		/* Linux and Solaris IP_PKTINFO */
		data = 1;
		if (setsockopt(pim->mroute_socket, IPPROTO_IP, IP_PKTINFO,
			       &data, data_len)) {
			zlog_warn(
				"Could not set IP_PKTINFO on socket fd=%d: errno=%d: %s",
				pim->mroute_socket, errno,
				safe_strerror(errno));
		}
	}
#endif

	setsockopt_so_recvbuf(pim->mroute_socket, 1024 * 1024 * 8);

	flags = fcntl(pim->mroute_socket, F_GETFL, 0);
	if (flags < 0) {
		zlog_warn("Could not get flags on socket fd:%d %d %s",
			  pim->mroute_socket, errno, safe_strerror(errno));
		close(pim->mroute_socket);
		return -1;
	}
	if (fcntl(pim->mroute_socket, F_SETFL, flags | O_NONBLOCK)) {
		zlog_warn("Could not set O_NONBLOCK on socket fd:%d %d %s",
			  pim->mroute_socket, errno, safe_strerror(errno));
		close(pim->mroute_socket);
		return -1;
	}

	if (enable) {
#if defined linux
		int upcalls = IGMPMSG_WRVIFWHOLE;
		opt = MRT_PIM;

		err = setsockopt(pim->mroute_socket, IPPROTO_IP, opt, &upcalls,
				 sizeof(upcalls));
		if (err) {
			zlog_warn(
				"Failure to register for VIFWHOLE and WRONGVIF upcalls %d %s",
				errno, safe_strerror(errno));
			return -1;
		}
#else
		zlog_warn(
			"PIM-SM will not work properly on this platform, until the ability to receive the WRVIFWHOLE upcall");
#endif
	}

	return 0;
}

#if PIM_IPV == 4
static const char *const igmpmsgtype2str[IGMPMSG_WRVIFWHOLE + 1] = {
	"<unknown_upcall?>", "NOCACHE", "WRONGVIF", "WHOLEPKT", "WRVIFWHOLE"};

static int pim_mroute_msg_nocache(int fd, struct interface *ifp,
				  const struct igmpmsg *msg)
{
	struct pim_interface *pim_ifp = ifp->info;
	struct pim_upstream *up;
	struct pim_rpf *rpg;
	pim_sgaddr sg;

	rpg = pim_ifp ? RP(pim_ifp->pim, msg->im_dst) : NULL;
	/*
	 * If the incoming interface is unknown OR
	 * the Interface type is SSM we don't need to
	 * do anything here
	 */
	if (!rpg || pim_rpf_addr_is_inaddr_none(rpg)) {
		if (PIM_DEBUG_MROUTE_DETAIL)
			zlog_debug(
				"%s: Interface is not configured correctly to handle incoming packet: Could be !pim_ifp, !SM, !RP",
				__func__);

		return 0;
	}

	/*
	 * If we've received a multicast packet that isn't connected to
	 * us
	 */
	if (!pim_if_connected_to_source(ifp, msg->im_src)) {
		if (PIM_DEBUG_MROUTE_DETAIL)
			zlog_debug(
				"%s: Received incoming packet that doesn't originate on our seg",
				__func__);
		return 0;
	}

	memset(&sg, 0, sizeof(sg));
	sg.src = msg->im_src;
	sg.grp = msg->im_dst;

	if (!(PIM_I_am_DR(pim_ifp))) {
		if (PIM_DEBUG_MROUTE_DETAIL)
			zlog_debug("%s: Interface is not the DR blackholing incoming traffic for %pSG",
				   __func__, &sg);

		/*
		 * We are not the DR, but we are still receiving packets
		 * Let's blackhole those packets for the moment
		 * As that they will be coming up to the cpu
		 * and causing us to consider them.
		 *
		 * This *will* create a dangling channel_oil
		 * that I see no way to get rid of.  Just noting
		 * this for future reference.
		 */
		up = pim_upstream_find_or_add(
			&sg, ifp, PIM_UPSTREAM_FLAG_MASK_SRC_NOCACHE, __func__);
		pim_upstream_mroute_add(up->channel_oil, __func__);

		return 0;
	}

	up = pim_upstream_find_or_add(&sg, ifp, PIM_UPSTREAM_FLAG_MASK_FHR,
				      __func__);

	/*
	 * I moved this debug till after the actual add because
	 * I want to take advantage of the up->sg_str being filled in.
	 */
	if (PIM_DEBUG_MROUTE) {
		zlog_debug("%s: Adding a Route %s for WHOLEPKT consumption",
			   __func__, up->sg_str);
	}

	PIM_UPSTREAM_FLAG_SET_SRC_STREAM(up->flags);
	pim_upstream_keep_alive_timer_start(up, pim_ifp->pim->keep_alive_time);

	up->channel_oil->cc.pktcnt++;
	// resolve mfcc_parent prior to mroute_add in channel_add_oif
	if (up->rpf.source_nexthop.interface &&
	    *oil_parent(up->channel_oil) >= MAXVIFS) {
		pim_upstream_mroute_iif_update(up->channel_oil, __func__);
	}
	pim_register_join(up);
	/* if we have receiver, inherit from parent */
	pim_upstream_inherited_olist_decide(pim_ifp->pim, up);

	return 0;
}

static int pim_mroute_msg_wholepkt(int fd, struct interface *ifp,
				   const char *buf)
{
	struct pim_interface *pim_ifp;
	pim_sgaddr sg;
	struct pim_rpf *rpg;
	const struct ip *ip_hdr;
	struct pim_upstream *up;

	pim_ifp = ifp->info;

	ip_hdr = (const struct ip *)buf;

	memset(&sg, 0, sizeof(sg));
	sg.src = ip_hdr->ip_src;
	sg.grp = ip_hdr->ip_dst;

	up = pim_upstream_find(pim_ifp->pim, &sg);
	if (!up) {
		pim_sgaddr star = sg;
		star.src = PIMADDR_ANY;

		up = pim_upstream_find(pim_ifp->pim, &star);

		if (up && PIM_UPSTREAM_FLAG_TEST_CAN_BE_LHR(up->flags)) {
			up = pim_upstream_add(pim_ifp->pim, &sg, ifp,
					      PIM_UPSTREAM_FLAG_MASK_SRC_LHR,
					      __func__, NULL);
			if (!up) {
				if (PIM_DEBUG_MROUTE)
					zlog_debug("%s: Unable to create upstream information for %pSG",
						   __func__, &sg);
				return 0;
			}
			pim_upstream_keep_alive_timer_start(
				up, pim_ifp->pim->keep_alive_time);
			pim_upstream_inherited_olist(pim_ifp->pim, up);
			pim_upstream_update_join_desired(pim_ifp->pim, up);

			if (PIM_DEBUG_MROUTE)
				zlog_debug("%s: Creating %s upstream on LHR",
					   __func__, up->sg_str);
			return 0;
		}
		if (PIM_DEBUG_MROUTE_DETAIL) {
			zlog_debug("%s: Unable to find upstream channel WHOLEPKT%pSG",
				   __func__, &sg);
		}
		return 0;
	}

	if (!up->rpf.source_nexthop.interface) {
		if (PIM_DEBUG_PIM_TRACE)
			zlog_debug("%s: up %s RPF is not present", __func__,
				   up->sg_str);
		return 0;
	}

	pim_ifp = up->rpf.source_nexthop.interface->info;

	rpg = pim_ifp ? RP(pim_ifp->pim, sg.grp) : NULL;

	if ((pim_rpf_addr_is_inaddr_none(rpg)) || (!pim_ifp)
	    || (!(PIM_I_am_DR(pim_ifp)))) {
		if (PIM_DEBUG_MROUTE) {
			zlog_debug("%s: Failed Check send packet", __func__);
		}
		return 0;
	}

	/*
	 * If we've received a register suppress
	 */
	if (!up->t_rs_timer) {
		if (pim_is_grp_ssm(pim_ifp->pim, sg.grp)) {
			if (PIM_DEBUG_PIM_REG)
				zlog_debug("%pSG register forward skipped as group is SSM",
					   &sg);
			return 0;
		}

		if (!PIM_UPSTREAM_FLAG_TEST_FHR(up->flags)) {
			if (PIM_DEBUG_PIM_REG)
				zlog_debug(
					"%s register forward skipped, not FHR",
					up->sg_str);
			return 0;
		}

		pim_register_send((uint8_t *)buf + sizeof(struct ip),
				  ntohs(ip_hdr->ip_len) - sizeof(struct ip),
				  pim_ifp->primary_address, rpg, 0, up);
	}
	return 0;
}

static int pim_mroute_msg_wrongvif(int fd, struct interface *ifp,
				   const struct igmpmsg *msg)
{
	struct pim_ifchannel *ch;
	struct pim_interface *pim_ifp;
	pim_sgaddr sg;

	memset(&sg, 0, sizeof(sg));
	sg.src = msg->im_src;
	sg.grp = msg->im_dst;

	/*
	  Send Assert(S,G) on iif as response to WRONGVIF kernel upcall.

	  RFC 4601 4.8.2.  PIM-SSM-Only Routers

	  iif is the incoming interface of the packet.
	  if (iif is in inherited_olist(S,G)) {
	  send Assert(S,G) on iif
	  }
	*/

	if (!ifp) {
		if (PIM_DEBUG_MROUTE)
			zlog_debug("%s: WRONGVIF (S,G)=%pSG could not find input interface for input_vif_index=%d",
				   __func__, &sg, msg->im_vif);
		return -1;
	}

	pim_ifp = ifp->info;
	if (!pim_ifp) {
		if (PIM_DEBUG_MROUTE)
			zlog_debug("%s: WRONGVIF (S,G)=%pSG multicast not enabled on interface %s",
				   __func__, &sg, ifp->name);
		return -2;
	}

	ch = pim_ifchannel_find(ifp, &sg);
	if (!ch) {
		pim_sgaddr star_g = sg;
		if (PIM_DEBUG_MROUTE)
			zlog_debug("%s: WRONGVIF (S,G)=%pSG could not find channel on interface %s",
				   __func__, &sg, ifp->name);

		star_g.src = PIMADDR_ANY;
		ch = pim_ifchannel_find(ifp, &star_g);
		if (!ch) {
			if (PIM_DEBUG_MROUTE)
				zlog_debug("%s: WRONGVIF (*,G)=%pSG could not find channel on interface %s",
					   __func__, &star_g,
					   ifp->name);
			return -3;
		}
	}

	/*
	  RFC 4601: 4.6.1.  (S,G) Assert Message State Machine

	  Transitions from NoInfo State

	  An (S,G) data packet arrives on interface I, AND
	  CouldAssert(S,G,I)==TRUE An (S,G) data packet arrived on an
	  downstream interface that is in our (S,G) outgoing interface
	  list.  We optimistically assume that we will be the assert
	  winner for this (S,G), and so we transition to the "I am Assert
	  Winner" state and perform Actions A1 (below), which will
	  initiate the assert negotiation for (S,G).
	*/

	if (ch->ifassert_state != PIM_IFASSERT_NOINFO) {
		if (PIM_DEBUG_MROUTE) {
			zlog_debug(
				"%s: WRONGVIF (S,G)=%s channel is not on Assert NoInfo state for interface %s",
				__func__, ch->sg_str, ifp->name);
		}
		return -4;
	}

	if (!PIM_IF_FLAG_TEST_COULD_ASSERT(ch->flags)) {
		if (PIM_DEBUG_MROUTE) {
			zlog_debug(
				"%s: WRONGVIF (S,G)=%s interface %s is not downstream for channel",
				__func__, ch->sg_str, ifp->name);
		}
		return -5;
	}

	if (assert_action_a1(ch)) {
		if (PIM_DEBUG_MROUTE) {
			zlog_debug(
				"%s: WRONGVIF (S,G)=%s assert_action_a1 failure on interface %s",
				__func__, ch->sg_str, ifp->name);
		}
		return -6;
	}

	return 0;
}

static int pim_mroute_msg_wrvifwhole(int fd, struct interface *ifp,
				     const char *buf)
{
	const struct ip *ip_hdr = (const struct ip *)buf;
	struct pim_interface *pim_ifp;
	struct pim_instance *pim;
	struct pim_ifchannel *ch;
	struct pim_upstream *up;
	pim_sgaddr star_g;
	pim_sgaddr sg;

	pim_ifp = ifp->info;

	memset(&sg, 0, sizeof(sg));
	sg.src = ip_hdr->ip_src;
	sg.grp = ip_hdr->ip_dst;

	ch = pim_ifchannel_find(ifp, &sg);
	if (ch) {
		if (PIM_DEBUG_MROUTE)
			zlog_debug(
				"WRVIFWHOLE (S,G)=%s found ifchannel on interface %s",
				ch->sg_str, ifp->name);
		return -1;
	}

	star_g = sg;
	star_g.src = PIMADDR_ANY;

	pim = pim_ifp->pim;
	/*
	 * If the incoming interface is the pimreg, then
	 * we know the callback is associated with a pim register
	 * packet and there is nothing to do here as that
	 * normal pim processing will see the packet and allow
	 * us to do the right thing.
	 */
	if (ifp == pim->regiface) {
		return 0;
	}

	up = pim_upstream_find(pim_ifp->pim, &sg);
	if (up) {
		struct pim_upstream *parent;
		struct pim_nexthop source;
		struct pim_rpf *rpf = RP(pim_ifp->pim, sg.grp);

		/* No RPF or No RPF interface or No mcast on RPF interface */
		if (!rpf || !rpf->source_nexthop.interface
		    || !rpf->source_nexthop.interface->info)
			return 0;

		/*
		 * If we have received a WRVIFWHOLE and are at this
		 * point, we could be receiving the packet on the *,G
		 * tree, let's check and if so we can safely drop
		 * it.
		 */
		parent = pim_upstream_find(pim_ifp->pim, &star_g);
		if (parent && parent->rpf.source_nexthop.interface == ifp)
			return 0;

		pim_ifp = rpf->source_nexthop.interface->info;

		memset(&source, 0, sizeof(source));
		/*
		 * If we are the fhr that means we are getting a callback during
		 * the pimreg period, so I believe we can ignore this packet
		 */
		if (!PIM_UPSTREAM_FLAG_TEST_FHR(up->flags)) {
			/*
			 * No if channel, but upstream we are at the RP.
			 *
			 * This could be a anycast RP too and we may
			 * not have received a register packet from
			 * the source here at all.  So gracefully
			 * bow out of doing a nexthop lookup and
			 * setting the SPTBIT to true
			 */
			if (up->upstream_register.s_addr != INADDR_ANY &&
			    pim_nexthop_lookup(pim_ifp->pim, &source,
					       up->upstream_register, 0)) {
				pim_register_stop_send(source.interface, &sg,
						       pim_ifp->primary_address,
						       up->upstream_register);
				up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;
			}

			pim_upstream_inherited_olist(pim_ifp->pim, up);
			if (!up->channel_oil->installed)
				pim_upstream_mroute_add(up->channel_oil,
							__func__);
		} else {
			if (I_am_RP(pim_ifp->pim, up->sg.grp)) {
				if (pim_nexthop_lookup(pim_ifp->pim, &source,
						       up->upstream_register,
						       0))
					pim_register_stop_send(
						source.interface, &sg,
						pim_ifp->primary_address,
						up->upstream_register);
				up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;
			}
			pim_upstream_keep_alive_timer_start(
				up, pim_ifp->pim->keep_alive_time);
			pim_upstream_inherited_olist(pim_ifp->pim, up);
			pim_mroute_msg_wholepkt(fd, ifp, buf);
		}
		return 0;
	}

	pim_ifp = ifp->info;
	if (pim_if_connected_to_source(ifp, sg.src)) {
		up = pim_upstream_add(pim_ifp->pim, &sg, ifp,
				      PIM_UPSTREAM_FLAG_MASK_FHR, __func__,
				      NULL);
		if (!up) {
			if (PIM_DEBUG_MROUTE)
				zlog_debug("%pSG: WRONGVIF%s unable to create upstream on interface",
					   &sg, ifp->name);
			return -2;
		}
		PIM_UPSTREAM_FLAG_SET_SRC_STREAM(up->flags);
		pim_upstream_keep_alive_timer_start(
			up, pim_ifp->pim->keep_alive_time);
		up->channel_oil->cc.pktcnt++;
		pim_register_join(up);
		pim_upstream_inherited_olist(pim_ifp->pim, up);
		if (!up->channel_oil->installed)
			pim_upstream_mroute_add(up->channel_oil, __func__);

		// Send the packet to the RP
		pim_mroute_msg_wholepkt(fd, ifp, buf);
	} else {
		up = pim_upstream_add(pim_ifp->pim, &sg, ifp,
				      PIM_UPSTREAM_FLAG_MASK_SRC_NOCACHE,
				      __func__, NULL);
		if (!up->channel_oil->installed)
			pim_upstream_mroute_add(up->channel_oil, __func__);
	}

	return 0;
}

static int pim_mroute_msg(struct pim_instance *pim, const char *buf,
			  int buf_size, ifindex_t ifindex)
{
	struct interface *ifp;
	struct pim_interface *pim_ifp;
	const struct ip *ip_hdr;
	const struct igmpmsg *msg;
	struct in_addr ifaddr;
	struct gm_sock *igmp;
	const struct prefix *connected_src;

	if (buf_size < (int)sizeof(struct ip))
		return 0;

	ip_hdr = (const struct ip *)buf;

	if (ip_hdr->ip_p == IPPROTO_IGMP) {

		/* We have the IP packet but we do not know which interface this
		 * packet was
		 * received on. Find the interface that is on the same subnet as
		 * the source
		 * of the IP packet.
		 */
		ifp = if_lookup_by_index(ifindex, pim->vrf->vrf_id);

		if (!ifp || !ifp->info)
			return 0;

		connected_src = pim_if_connected_to_source(ifp, ip_hdr->ip_src);

		if (!connected_src) {
			if (PIM_DEBUG_IGMP_PACKETS) {
				zlog_debug("Recv IGMP packet on interface: %s from a non-connected source: %pI4",
					   ifp->name, &ip_hdr->ip_src);
			}
			return 0;
		}

		pim_ifp = ifp->info;
		ifaddr = connected_src->u.prefix4;
		igmp = pim_igmp_sock_lookup_ifaddr(pim_ifp->gm_socket_list,
						   ifaddr);

		if (PIM_DEBUG_IGMP_PACKETS) {
			zlog_debug(
				"%s(%s): igmp kernel upcall on %s(%p) for %pI4 -> %pI4",
				__func__, pim->vrf->name, ifp->name, igmp,
				&ip_hdr->ip_src, &ip_hdr->ip_dst);
		}
		if (igmp)
			pim_igmp_packet(igmp, (char *)buf, buf_size);
		else if (PIM_DEBUG_IGMP_PACKETS) {
			zlog_debug("No IGMP socket on interface: %s with connected source: %pFX",
				   ifp->name, connected_src);
		}
	} else if (ip_hdr->ip_p) {
		if (PIM_DEBUG_MROUTE_DETAIL) {
			zlog_debug(
				"%s: no kernel upcall proto=%d src: %pI4 dst: %pI4 msg_size=%d",
				__func__, ip_hdr->ip_p, &ip_hdr->ip_src, &ip_hdr->ip_dst,
				buf_size);
		}

	} else {
		msg = (const struct igmpmsg *)buf;

		ifp = pim_if_find_by_vif_index(pim, msg->im_vif);

		if (!ifp)
			return 0;
		if (PIM_DEBUG_MROUTE) {
			zlog_debug(
				"%s: pim kernel upcall %s type=%d ip_p=%d from fd=%d for (S,G)=(%pI4,%pI4) on %s vifi=%d  size=%d",
				__func__, igmpmsgtype2str[msg->im_msgtype],
				msg->im_msgtype, ip_hdr->ip_p,
				pim->mroute_socket, &msg->im_src, &msg->im_dst, ifp->name,
				msg->im_vif, buf_size);
		}

		switch (msg->im_msgtype) {
		case IGMPMSG_WRONGVIF:
			return pim_mroute_msg_wrongvif(pim->mroute_socket, ifp,
						       msg);
		case IGMPMSG_NOCACHE:
			return pim_mroute_msg_nocache(pim->mroute_socket, ifp,
						      msg);
		case IGMPMSG_WHOLEPKT:
			return pim_mroute_msg_wholepkt(pim->mroute_socket, ifp,
						       (const char *)msg);
		case IGMPMSG_WRVIFWHOLE:
			return pim_mroute_msg_wrvifwhole(
				pim->mroute_socket, ifp, (const char *)msg);
		default:
			break;
		}
	}

	return 0;
}
#else /* PIM_IPV != 4 */

static int pim_mroute_msg(struct pim_instance *pim, const char *buf,
			  int buf_size, ifindex_t ifindex)
{
	return 0;
}
#endif /* PIM_IPV != 4 */

static int mroute_read(struct thread *t)
{
	struct pim_instance *pim;
	static long long count;
	char buf[10000];
	int result = 0;
	int cont = 1;
	int rd;
	ifindex_t ifindex;
	pim = THREAD_ARG(t);

	while (cont) {
		rd = pim_socket_recvfromto(pim->mroute_socket, (uint8_t *)buf,
					   sizeof(buf), NULL, NULL, NULL, NULL,
					   &ifindex);
		if (rd <= 0) {
			if (errno == EINTR)
				continue;
			if (errno == EWOULDBLOCK || errno == EAGAIN)
				break;

			zlog_warn(
				"%s: failure reading rd=%d: fd=%d: errno=%d: %s",
				__func__, rd, pim->mroute_socket, errno,
				safe_strerror(errno));
			goto done;
		}

		result = pim_mroute_msg(pim, buf, rd, ifindex);

		count++;
		if (count % router->packet_process == 0)
			cont = 0;
	}
/* Keep reading */
done:
	mroute_read_on(pim);

	return result;
}

static void mroute_read_on(struct pim_instance *pim)
{
	thread_add_read(router->master, mroute_read, pim, pim->mroute_socket,
			&pim->thread);
}

static void mroute_read_off(struct pim_instance *pim)
{
	THREAD_OFF(pim->thread);
}

int pim_mroute_socket_enable(struct pim_instance *pim)
{
	int fd;

	frr_with_privs(&pimd_privs) {

		fd = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP);

		if (fd < 0) {
			zlog_warn("Could not create mroute socket: errno=%d: %s",
				  errno,
				  safe_strerror(errno));
			return -2;
		}

#ifdef SO_BINDTODEVICE
		if (pim->vrf->vrf_id != VRF_DEFAULT
		    && setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
				  pim->vrf->name, strlen(pim->vrf->name))) {
			zlog_warn("Could not setsockopt SO_BINDTODEVICE: %s",
				  safe_strerror(errno));
			close(fd);
			return -3;
		}
#endif

	}

	pim->mroute_socket = fd;
	if (pim_mroute_set(pim, 1)) {
		zlog_warn(
			"Could not enable mroute on socket fd=%d: errno=%d: %s",
			fd, errno, safe_strerror(errno));
		close(fd);
		pim->mroute_socket = -1;
		return -3;
	}

	pim->mroute_socket_creation = pim_time_monotonic_sec();

	mroute_read_on(pim);

	return 0;
}

int pim_mroute_socket_disable(struct pim_instance *pim)
{
	if (pim_mroute_set(pim, 0)) {
		zlog_warn(
			"Could not disable mroute on socket fd=%d: errno=%d: %s",
			pim->mroute_socket, errno, safe_strerror(errno));
		return -2;
	}

	if (close(pim->mroute_socket)) {
		zlog_warn("Failure closing mroute socket: fd=%d errno=%d: %s",
			  pim->mroute_socket, errno, safe_strerror(errno));
		return -3;
	}

	mroute_read_off(pim);
	pim->mroute_socket = -1;

	return 0;
}

/*
  For each network interface (e.g., physical or a virtual tunnel) that
  would be used for multicast forwarding, a corresponding multicast
  interface must be added to the kernel.
 */
int pim_mroute_add_vif(struct interface *ifp, pim_addr ifaddr,
		       unsigned char flags)
{
	struct pim_interface *pim_ifp = ifp->info;
	struct vifctl vc;
	int err;

	if (PIM_DEBUG_MROUTE)
		zlog_debug("%s: Add Vif %d (%s[%s])", __func__,
			   pim_ifp->mroute_vif_index, ifp->name,
			   pim_ifp->pim->vrf->name);

	memset(&vc, 0, sizeof(vc));
	vc.vifc_vifi = pim_ifp->mroute_vif_index;
#ifdef VIFF_USE_IFINDEX
	vc.vifc_lcl_ifindex = ifp->ifindex;
#else
	if (ifaddr.s_addr == INADDR_ANY) {
		zlog_warn(
			"%s: unnumbered interfaces are not supported on this platform",
			__func__);
		return -1;
	}
	memcpy(&vc.vifc_lcl_addr, &ifaddr, sizeof(vc.vifc_lcl_addr));
#endif
	vc.vifc_flags = flags;
	vc.vifc_threshold = PIM_MROUTE_MIN_TTL;
	vc.vifc_rate_limit = 0;

#ifdef PIM_DVMRP_TUNNEL
	if (vc.vifc_flags & VIFF_TUNNEL) {
		memcpy(&vc.vifc_rmt_addr, &vif_remote_addr,
		       sizeof(vc.vifc_rmt_addr));
	}
#endif

	err = setsockopt(pim_ifp->pim->mroute_socket, IPPROTO_IP, MRT_ADD_VIF,
			 (void *)&vc, sizeof(vc));
	if (err) {
		zlog_warn(
			"%s: failure: setsockopt(fd=%d,IPPROTO_IP,MRT_ADD_VIF,vif_index=%d,ifaddr=%pPAs,flag=%d): errno=%d: %s",
			__func__, pim_ifp->pim->mroute_socket, ifp->ifindex,
			&ifaddr, flags, errno, safe_strerror(errno));
		return -2;
	}

	return 0;
}

int pim_mroute_del_vif(struct interface *ifp)
{
	struct pim_interface *pim_ifp = ifp->info;
	struct vifctl vc;
	int err;

	if (PIM_DEBUG_MROUTE)
		zlog_debug("%s: Del Vif %d (%s[%s])", __func__,
			   pim_ifp->mroute_vif_index, ifp->name,
			   pim_ifp->pim->vrf->name);

	memset(&vc, 0, sizeof(vc));
	vc.vifc_vifi = pim_ifp->mroute_vif_index;

	err = setsockopt(pim_ifp->pim->mroute_socket, IPPROTO_IP, MRT_DEL_VIF,
			 (void *)&vc, sizeof(vc));
	if (err) {
		zlog_warn(
			"%s %s: failure: setsockopt(fd=%d,IPPROTO_IP,MRT_DEL_VIF,vif_index=%d): errno=%d: %s",
			__FILE__, __func__, pim_ifp->pim->mroute_socket,
			pim_ifp->mroute_vif_index, errno, safe_strerror(errno));
		return -2;
	}

	return 0;
}

/*
 * Prevent creating MFC entry with OIF=IIF.
 *
 * This is a protection against implementation mistakes.
 *
 * PIM protocol implicitely ensures loopfree multicast topology.
 *
 * IGMP must be protected against adding looped MFC entries created
 * by both source and receiver attached to the same interface. See
 * TODO T22.
 * We shall allow igmp to create upstream when it is DR for the intf.
 * Assume RP reachable via non DR.
 */
bool pim_mroute_allow_iif_in_oil(struct channel_oil *c_oil,
		int oif_index)
{
#ifdef PIM_ENFORCE_LOOPFREE_MFC
	struct interface *ifp_out;
	struct pim_interface *pim_ifp;

	if (c_oil->up &&
		PIM_UPSTREAM_FLAG_TEST_ALLOW_IIF_IN_OIL(c_oil->up->flags))
		return true;

	ifp_out = pim_if_find_by_vif_index(c_oil->pim, oif_index);
	if (!ifp_out)
		return false;
	pim_ifp = ifp_out->info;
	if (!pim_ifp)
		return false;
	if ((c_oil->oif_flags[oif_index] & PIM_OIF_FLAG_PROTO_IGMP) &&
			PIM_I_am_DR(pim_ifp))
		return true;

	return false;
#else
	return true;
#endif
}

static inline void pim_mroute_copy(struct channel_oil *out,
				   struct channel_oil *in)
{
	int i;

	*oil_origin(out) = *oil_origin(in);
	*oil_mcastgrp(out) = *oil_mcastgrp(in);
	*oil_parent(out) = *oil_parent(in);

	for (i = 0; i < MAXVIFS; ++i) {
		if (*oil_parent(out) == i &&
		    !pim_mroute_allow_iif_in_oil(in, i)) {
			oil_if_set(out, i, 0);
			continue;
		}

		if (in->oif_flags[i] & PIM_OIF_FLAG_MUTE)
			oil_if_set(out, i, 0);
		else
			oil_if_set(out, i, oil_if_has(in, i));
	}
}

/* This function must not be called directly 0
 * use pim_upstream_mroute_add or pim_static_mroute_add instead
 */
static int pim_mroute_add(struct channel_oil *c_oil, const char *name)
{
	struct pim_instance *pim = c_oil->pim;
	struct channel_oil tmp_oil[1] = { };
	int err;

	pim->mroute_add_last = pim_time_monotonic_sec();
	++pim->mroute_add_events;

	/* Copy the oil to a temporary structure to fixup (without need to
	 * later restore) before sending the mroute add to the dataplane
	 */
	pim_mroute_copy(tmp_oil, c_oil);

	/* The linux kernel *expects* the incoming
	 * vif to be part of the outgoing list
	 * in the case of a (*,G).
	 */
	if (pim_addr_is_any(*oil_origin(c_oil))) {
		oil_if_set(tmp_oil, *oil_parent(c_oil), 1);
	}

	/*
	 * If we have an unresolved cache entry for the S,G
	 * it is owned by the pimreg for the incoming IIF
	 * So set pimreg as the IIF temporarily to cause
	 * the packets to be forwarded.  Then set it
	 * to the correct IIF afterwords.
	 */
	if (!c_oil->installed && !pim_addr_is_any(*oil_origin(c_oil))
	    && *oil_parent(c_oil) != 0) {
		*oil_parent(tmp_oil) = 0;
	}
	err = setsockopt(pim->mroute_socket, IPPROTO_IP, MRT_ADD_MFC,
			 &tmp_oil->oil, sizeof(tmp_oil->oil));

	if (!err && !c_oil->installed
	    && !pim_addr_is_any(*oil_origin(c_oil))
	    && *oil_parent(c_oil) != 0) {
		*oil_parent(tmp_oil) = *oil_parent(c_oil);
		err = setsockopt(pim->mroute_socket, IPPROTO_IP, MRT_ADD_MFC,
				 &tmp_oil->oil, sizeof(tmp_oil->oil));
	}

	if (err) {
		zlog_warn(
			"%s %s: failure: setsockopt(fd=%d,IPPROTO_IP,MRT_ADD_MFC): errno=%d: %s",
			__FILE__, __func__, pim->mroute_socket, errno,
			safe_strerror(errno));
		return -2;
	}

	if (PIM_DEBUG_MROUTE) {
		char buf[1000];
		zlog_debug("%s(%s), vrf %s Added Route: %s", __func__, name,
			   pim->vrf->name,
			   pim_channel_oil_dump(c_oil, buf, sizeof(buf)));
	}

	if (!c_oil->installed) {
		c_oil->installed = 1;
		c_oil->mroute_creation = pim_time_monotonic_sec();
	}

	return 0;
}

static int pim_upstream_get_mroute_iif(struct channel_oil *c_oil,
		const char *name)
{
	vifi_t iif = MAXVIFS;
	struct interface *ifp = NULL;
	struct pim_interface *pim_ifp;
	struct pim_upstream *up = c_oil->up;

	if (up) {
		if (PIM_UPSTREAM_FLAG_TEST_USE_RPT(up->flags)) {
			if (up->parent)
				ifp = up->parent->rpf.source_nexthop.interface;
		} else {
			ifp = up->rpf.source_nexthop.interface;
		}
		if (ifp) {
			pim_ifp = (struct pim_interface *)ifp->info;
			if (pim_ifp)
				iif = pim_ifp->mroute_vif_index;
		}
	}
	return iif;
}

static int pim_upstream_mroute_update(struct channel_oil *c_oil,
		const char *name)
{
	char buf[1000];

	if (*oil_parent(c_oil) >= MAXVIFS) {
		/* the c_oil cannot be installed as a mroute yet */
		if (PIM_DEBUG_MROUTE)
			zlog_debug(
					"%s(%s) %s mroute not ready to be installed; %s",
					__func__, name,
					pim_channel_oil_dump(c_oil, buf,
						sizeof(buf)),
					c_oil->installed ?
					"uninstall" : "skip");
		/* if already installed flush it out as we are going to stop
		 * updates to it leaving it in a stale state
		 */
		if (c_oil->installed)
			pim_mroute_del(c_oil, name);
		/* return success (skipped) */
		return 0;
	}

	return pim_mroute_add(c_oil, name);
}

/* IIF associated with SGrpt entries are re-evaluated when the parent
 * (*,G) entries IIF changes
 */
static void pim_upstream_all_sources_iif_update(struct pim_upstream *up)
{
	struct listnode *listnode;
	struct pim_upstream *child;

	for (ALL_LIST_ELEMENTS_RO(up->sources, listnode,
				child)) {
		if (PIM_UPSTREAM_FLAG_TEST_USE_RPT(child->flags))
			pim_upstream_mroute_iif_update(child->channel_oil,
					__func__);
	}
}

/* In the case of "PIM state machine" added mroutes an upstream entry
 * must be present to decide on the SPT-forwarding vs. RPT-forwarding.
 */
int pim_upstream_mroute_add(struct channel_oil *c_oil, const char *name)
{
	vifi_t iif;

	iif = pim_upstream_get_mroute_iif(c_oil, name);

	if (*oil_parent(c_oil) != iif) {
		*oil_parent(c_oil) = iif;
		if (pim_addr_is_any(*oil_origin(c_oil)) &&
				c_oil->up)
			pim_upstream_all_sources_iif_update(c_oil->up);
	} else {
		*oil_parent(c_oil) = iif;
	}

	return pim_upstream_mroute_update(c_oil, name);
}

/* Look for IIF changes and update the dateplane entry only if the IIF
 * has changed.
 */
int pim_upstream_mroute_iif_update(struct channel_oil *c_oil, const char *name)
{
	vifi_t iif;
	char buf[1000];

	iif = pim_upstream_get_mroute_iif(c_oil, name);
	if (*oil_parent(c_oil) == iif) {
		/* no change */
		return 0;
	}
	*oil_parent(c_oil) = iif;

	if (pim_addr_is_any(*oil_origin(c_oil)) &&
			c_oil->up)
		pim_upstream_all_sources_iif_update(c_oil->up);

	if (PIM_DEBUG_MROUTE_DETAIL)
		zlog_debug("%s(%s) %s mroute iif update %d",
				__func__, name,
				pim_channel_oil_dump(c_oil, buf,
					sizeof(buf)), iif);
	/* XXX: is this hack needed? */
	c_oil->oil_inherited_rescan = 1;
	return pim_upstream_mroute_update(c_oil, name);
}

int pim_static_mroute_add(struct channel_oil *c_oil, const char *name)
{
	return pim_mroute_add(c_oil, name);
}

void pim_static_mroute_iif_update(struct channel_oil *c_oil,
				int input_vif_index,
				const char *name)
{
	if (*oil_parent(c_oil) == input_vif_index)
		return;

	*oil_parent(c_oil) = input_vif_index;
	if (input_vif_index == MAXVIFS)
		pim_mroute_del(c_oil, name);
	else
		pim_static_mroute_add(c_oil, name);
}

int pim_mroute_del(struct channel_oil *c_oil, const char *name)
{
	struct pim_instance *pim = c_oil->pim;
	int err;

	pim->mroute_del_last = pim_time_monotonic_sec();
	++pim->mroute_del_events;

	if (!c_oil->installed) {
		if (PIM_DEBUG_MROUTE) {
			char buf[1000];
			zlog_debug(
				"%s %s: vifi %d for route is %s not installed, do not need to send del req. ",
				__FILE__, __func__, *oil_parent(c_oil),
				pim_channel_oil_dump(c_oil, buf, sizeof(buf)));
		}
		return -2;
	}

	err = setsockopt(pim->mroute_socket, IPPROTO_IP, MRT_DEL_MFC,
			 &c_oil->oil, sizeof(c_oil->oil));
	if (err) {
		if (PIM_DEBUG_MROUTE)
			zlog_warn(
				"%s %s: failure: setsockopt(fd=%d,IPPROTO_IP,MRT_DEL_MFC): errno=%d: %s",
				__FILE__, __func__, pim->mroute_socket, errno,
				safe_strerror(errno));
		return -2;
	}

	if (PIM_DEBUG_MROUTE) {
		char buf[1000];
		zlog_debug("%s(%s), vrf %s Deleted Route: %s", __func__, name,
			   pim->vrf->name,
			   pim_channel_oil_dump(c_oil, buf, sizeof(buf)));
	}

	// Reset kernel installed flag
	c_oil->installed = 0;

	return 0;
}

void pim_mroute_update_counters(struct channel_oil *c_oil)
{
	struct pim_instance *pim = c_oil->pim;

	c_oil->cc.oldpktcnt = c_oil->cc.pktcnt;
	c_oil->cc.oldbytecnt = c_oil->cc.bytecnt;
	c_oil->cc.oldwrong_if = c_oil->cc.wrong_if;

	if (!c_oil->installed) {
		c_oil->cc.lastused = 100 * pim->keep_alive_time;
		if (PIM_DEBUG_MROUTE) {
			pim_sgaddr sg;

			sg.src = *oil_origin(c_oil);
			sg.grp = *oil_mcastgrp(c_oil);
			zlog_debug("Channel%pSG is not installed no need to collect data from kernel",
				   &sg);
		}
		return;
	}

#if PIM_IPV == 4
	struct sioc_sg_req sgreq;

	memset(&sgreq, 0, sizeof(sgreq));
	sgreq.src = *oil_origin(c_oil);
	sgreq.grp = *oil_mcastgrp(c_oil);

	pim_zlookup_sg_statistics(c_oil);
	if (ioctl(pim->mroute_socket, SIOCGETSGCNT, &sgreq)) {
		pim_sgaddr sg;

		sg.src = *oil_origin(c_oil);
		sg.grp = *oil_mcastgrp(c_oil);

		zlog_warn("ioctl(SIOCGETSGCNT=%lu) failure for (S,G)=%pSG: errno=%d: %s",
			  (unsigned long)SIOCGETSGCNT, &sg,
			  errno, safe_strerror(errno));
		return;
	}

	c_oil->cc.pktcnt = sgreq.pktcnt;
	c_oil->cc.bytecnt = sgreq.bytecnt;
	c_oil->cc.wrong_if = sgreq.wrong_if;
#endif
	return;
}