[mirror_frr.git] / isisd / isis_pfpacket.c

/*
 * IS-IS Rout(e)ing protocol - isis_pfpacket.c
 *
 * Copyright (C) 2001,2002    Sampo Saaristo
 *                            Tampere University of Technology
 *                            Institute of Communications Engineering
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public Licenseas 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>
#if ISIS_METHOD == ISIS_METHOD_PFPACKET
#include <net/ethernet.h> /* the L2 protocols */
#include <netpacket/packet.h>

#include <linux/filter.h>

#include "log.h"
#include "network.h"
#include "stream.h"
#include "if.h"
#include "lib_errors.h"

#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isis_circuit.h"
#include "isisd/isis_flags.h"
#include "isisd/isisd.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_circuit.h"
#include "isisd/isis_network.h"

#include "privs.h"

/* tcpdump -i eth0 'isis' -dd */
static const struct sock_filter isisfilter[] = {
	/* NB: we're in SOCK_DGRAM, so src/dst mac + length are stripped
	 * off!
	 * (OTOH it's a bit more lower-layer agnostic and might work
	 * over GRE?) */
	/*	{ 0x28, 0, 0, 0x0000000c - 14 }, */
	/*	{ 0x25, 5, 0, 0x000005dc }, */
	{0x28, 0, 0, 0x0000000e - 14}, {0x15, 0, 3, 0x0000fefe},
	{0x30, 0, 0, 0x00000011 - 14}, {0x15, 0, 1, 0x00000083},
	{0x6, 0, 0, 0x00040000},       {0x6, 0, 0, 0x00000000},
};

static const struct sock_fprog bpf = {
	.len = array_size(isisfilter),
	.filter = (struct sock_filter *)isisfilter,
};

/*
 * Table 9 - Architectural constants for use with ISO 8802 subnetworks
 * ISO 10589 - 8.4.8
 */

static const uint8_t ALL_L1_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14};
static const uint8_t ALL_L2_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15};
static const uint8_t ALL_ISS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x05};
static const uint8_t ALL_ESS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x04};

static uint8_t discard_buff[8192];

/*
 * if level is 0 we are joining p2p multicast
 * FIXME: and the p2p multicast being ???
 */
static int isis_multicast_join(int fd, int registerto, int if_num)
{
	struct packet_mreq mreq;

	memset(&mreq, 0, sizeof(mreq));
	mreq.mr_ifindex = if_num;
	if (registerto) {
		mreq.mr_type = PACKET_MR_MULTICAST;
		mreq.mr_alen = ETH_ALEN;
		if (registerto == 1)
			memcpy(&mreq.mr_address, ALL_L1_ISS, ETH_ALEN);
		else if (registerto == 2)
			memcpy(&mreq.mr_address, ALL_L2_ISS, ETH_ALEN);
		else if (registerto == 3)
			memcpy(&mreq.mr_address, ALL_ISS, ETH_ALEN);
		else
			memcpy(&mreq.mr_address, ALL_ESS, ETH_ALEN);

	} else {
		mreq.mr_type = PACKET_MR_ALLMULTI;
	}
#ifdef EXTREME_DEBUG
	zlog_debug(
		"isis_multicast_join(): fd=%d, reg_to=%d, if_num=%d, "
		"address = %02x:%02x:%02x:%02x:%02x:%02x",
		fd, registerto, if_num, mreq.mr_address[0], mreq.mr_address[1],
		mreq.mr_address[2], mreq.mr_address[3], mreq.mr_address[4],
		mreq.mr_address[5]);
#endif /* EXTREME_DEBUG */
	if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq,
		       sizeof(struct packet_mreq))) {
		zlog_warn("isis_multicast_join(): setsockopt(): %s",
			  safe_strerror(errno));
		return ISIS_WARNING;
	}

	return ISIS_OK;
}

static int open_packet_socket(struct isis_circuit *circuit)
{
	struct sockaddr_ll s_addr;
	int fd, retval = ISIS_OK;

	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));
	if (fd < 0) {
		zlog_warn("open_packet_socket(): socket() failed %s",
			  safe_strerror(errno));
		return ISIS_WARNING;
	}

	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))) {
		zlog_warn("open_packet_socket(): SO_ATTACH_FILTER failed: %s",
			  safe_strerror(errno));
	}

	/*
	 * Bind to the physical interface
	 */
	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	s_addr.sll_family = AF_PACKET;
	s_addr.sll_protocol = htons(ETH_P_ALL);
	s_addr.sll_ifindex = circuit->interface->ifindex;

	if (bind(fd, (struct sockaddr *)(&s_addr), sizeof(struct sockaddr_ll))
	    < 0) {
		zlog_warn("open_packet_socket(): bind() failed: %s",
			  safe_strerror(errno));
		close(fd);
		return ISIS_WARNING;
	}

	circuit->fd = fd;

	if (if_is_broadcast(circuit->interface)) {
		/*
		 * Join to multicast groups
		 * according to
		 * 8.4.2 - Broadcast subnetwork IIH PDUs
		 * FIXME: is there a case only one will fail??
		 */
		/* joining ALL_L1_ISS */
		retval |= isis_multicast_join(circuit->fd, 1,
					      circuit->interface->ifindex);
		/* joining ALL_L2_ISS */
		retval |= isis_multicast_join(circuit->fd, 2,
					      circuit->interface->ifindex);
		/* joining ALL_ISS (used in RFC 5309 p2p-over-lan as well) */
		retval |= isis_multicast_join(circuit->fd, 3,
					      circuit->interface->ifindex);
	} else {
		retval = isis_multicast_join(circuit->fd, 0,
					     circuit->interface->ifindex);
	}

	return retval;
}

/*
 * Create the socket and set the tx/rx funcs
 */
int isis_sock_init(struct isis_circuit *circuit)
{
	int retval = ISIS_OK;

	frr_with_privs(&isisd_privs) {

		retval = open_packet_socket(circuit);

		if (retval != ISIS_OK) {
			zlog_warn("%s: could not initialize the socket",
				  __func__);
			break;
		}

	/* Assign Rx and Tx callbacks are based on real if type */
		if (if_is_broadcast(circuit->interface)) {
			circuit->tx = isis_send_pdu_bcast;
			circuit->rx = isis_recv_pdu_bcast;
		} else if (if_is_pointopoint(circuit->interface)) {
			circuit->tx = isis_send_pdu_p2p;
			circuit->rx = isis_recv_pdu_p2p;
		} else {
			zlog_warn("isis_sock_init(): unknown circuit type");
			retval = ISIS_WARNING;
			break;
		}
	}

	return retval;
}

static inline int llc_check(uint8_t *llc)
{
	if (*llc != ISO_SAP || *(llc + 1) != ISO_SAP || *(llc + 2) != 3)
		return 0;

	return 1;
}

int isis_recv_pdu_bcast(struct isis_circuit *circuit, uint8_t *ssnpa)
{
	int bytesread, addr_len;
	struct sockaddr_ll s_addr;
	uint8_t llc[LLC_LEN];

	addr_len = sizeof(s_addr);

	memset(&s_addr, 0, sizeof(struct sockaddr_ll));

	bytesread =
		recvfrom(circuit->fd, (void *)&llc, LLC_LEN, MSG_PEEK,
			 (struct sockaddr *)&s_addr, (socklen_t *)&addr_len);

	if ((bytesread < 0)
	    || (s_addr.sll_ifindex != (int)circuit->interface->ifindex)) {
		if (bytesread < 0) {
			zlog_warn(
				"isis_recv_packet_bcast(): ifname %s, fd %d, "
				"bytesread %d, recvfrom(): %s",
				circuit->interface->name, circuit->fd,
				bytesread, safe_strerror(errno));
		}
		if (s_addr.sll_ifindex != (int)circuit->interface->ifindex) {
			zlog_warn(
				"packet is received on multiple interfaces: "
				"socket interface %d, circuit interface %d, "
				"packet type %u",
				s_addr.sll_ifindex, circuit->interface->ifindex,
				s_addr.sll_pkttype);
		}

		/* get rid of the packet */
		bytesread = recvfrom(circuit->fd, discard_buff,
				     sizeof(discard_buff), MSG_DONTWAIT,
				     (struct sockaddr *)&s_addr,
				     (socklen_t *)&addr_len);

		if (bytesread < 0)
			zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");

		return ISIS_WARNING;
	}
	/*
	 * Filtering by llc field, discard packets sent by this host (other
	 * circuit)
	 */
	if (!llc_check(llc) || s_addr.sll_pkttype == PACKET_OUTGOING) {
		/*  Read the packet into discard buff */
		bytesread = recvfrom(circuit->fd, discard_buff,
				     sizeof(discard_buff), MSG_DONTWAIT,
				     (struct sockaddr *)&s_addr,
				     (socklen_t *)&addr_len);
		if (bytesread < 0)
			zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
		return ISIS_WARNING;
	}

	/* Ensure that we have enough space for a pdu padded to fill the mtu */
	unsigned int max_size =
		circuit->interface->mtu > circuit->interface->mtu6
			? circuit->interface->mtu
			: circuit->interface->mtu6;
	uint8_t temp_buff[max_size];
	bytesread =
		recvfrom(circuit->fd, temp_buff, max_size, MSG_DONTWAIT,
			 (struct sockaddr *)&s_addr, (socklen_t *)&addr_len);
	if (bytesread < 0) {
		zlog_warn("%s: recvfrom() failed", __func__);
		return ISIS_WARNING;
	}
	/* then we lose the LLC */
	stream_write(circuit->rcv_stream, temp_buff + LLC_LEN,
		     bytesread - LLC_LEN);
	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);

	return ISIS_OK;
}

int isis_recv_pdu_p2p(struct isis_circuit *circuit, uint8_t *ssnpa)
{
	int bytesread, addr_len;
	struct sockaddr_ll s_addr;

	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	addr_len = sizeof(s_addr);

	/* we can read directly to the stream */
	(void)stream_recvfrom(
		circuit->rcv_stream, circuit->fd, circuit->interface->mtu, 0,
		(struct sockaddr *)&s_addr, (socklen_t *)&addr_len);

	if (s_addr.sll_pkttype == PACKET_OUTGOING) {
		/*  Read the packet into discard buff */
		bytesread = recvfrom(circuit->fd, discard_buff,
				     sizeof(discard_buff), MSG_DONTWAIT,
				     (struct sockaddr *)&s_addr,
				     (socklen_t *)&addr_len);
		if (bytesread < 0)
			zlog_warn("isis_recv_pdu_p2p(): recvfrom() failed");
		return ISIS_WARNING;
	}

	/* If we don't have protocol type 0x00FE which is
	 * ISO over GRE we exit with pain :)
	 */
	if (ntohs(s_addr.sll_protocol) != 0x00FE) {
		zlog_warn("isis_recv_pdu_p2p(): protocol mismatch(): %X",
			  ntohs(s_addr.sll_protocol));
		return ISIS_WARNING;
	}

	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);

	return ISIS_OK;
}

int isis_send_pdu_bcast(struct isis_circuit *circuit, int level)
{
	struct msghdr msg;
	struct iovec iov[2];
	char temp_buff[LLC_LEN];

	/* we need to do the LLC in here because of P2P circuits, which will
	 * not need it
	 */
	struct sockaddr_ll sa;

	stream_set_getp(circuit->snd_stream, 0);
	memset(&sa, 0, sizeof(struct sockaddr_ll));
	sa.sll_family = AF_PACKET;

	size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN;
	sa.sll_protocol = htons(isis_ethertype(frame_size));
	sa.sll_ifindex = circuit->interface->ifindex;
	sa.sll_halen = ETH_ALEN;
	/* RFC5309 section 4.1 recommends ALL_ISS */
	if (circuit->circ_type == CIRCUIT_T_P2P)
		memcpy(&sa.sll_addr, ALL_ISS, ETH_ALEN);
	else if (level == 1)
		memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	else
		memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);

	/* on a broadcast circuit */
	/* first we put the LLC in */
	temp_buff[0] = 0xFE;
	temp_buff[1] = 0xFE;
	temp_buff[2] = 0x03;

	memset(&msg, 0, sizeof(msg));
	msg.msg_name = &sa;
	msg.msg_namelen = sizeof(struct sockaddr_ll);
	msg.msg_iov = iov;
	msg.msg_iovlen = 2;
	iov[0].iov_base = temp_buff;
	iov[0].iov_len = LLC_LEN;
	iov[1].iov_base = circuit->snd_stream->data;
	iov[1].iov_len = stream_get_endp(circuit->snd_stream);

	if (sendmsg(circuit->fd, &msg, 0) < 0) {
		zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
			  circuit->interface->name, safe_strerror(errno));
		if (ERRNO_IO_RETRY(errno))
			return ISIS_WARNING;
		return ISIS_ERROR;
	}
	return ISIS_OK;
}

int isis_send_pdu_p2p(struct isis_circuit *circuit, int level)
{
	struct sockaddr_ll sa;
	ssize_t rv;

	stream_set_getp(circuit->snd_stream, 0);
	memset(&sa, 0, sizeof(struct sockaddr_ll));
	sa.sll_family = AF_PACKET;
	sa.sll_ifindex = circuit->interface->ifindex;
	sa.sll_halen = ETH_ALEN;
	if (level == 1)
		memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	else
		memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);


	/* lets try correcting the protocol */
	sa.sll_protocol = htons(0x00FE);
	rv = sendto(circuit->fd, circuit->snd_stream->data,
		    stream_get_endp(circuit->snd_stream), 0,
		    (struct sockaddr *)&sa, sizeof(struct sockaddr_ll));
	if (rv < 0) {
		zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
			  circuit->interface->name, safe_strerror(errno));
		if (ERRNO_IO_RETRY(errno))
			return ISIS_WARNING;
		return ISIS_ERROR;
	}
	return ISIS_OK;
}

#endif /* ISIS_METHOD == ISIS_METHOD_PFPACKET */
Commit	Line	Data
8bc98059 PJ	1	/*
	2	* IS-IS Rout(e)ing protocol - isis_pfpacket.c
	3	*
	4	* Copyright (C) 2001,2002 Sampo Saaristo
d62a17ae	5	* Tampere University of Technology
8bc98059 PJ	6	* Institute of Communications Engineering
8bc98059 PJ	7	*
d62a17ae	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public Licenseas published by the Free
	10	* Software Foundation; either version 2 of the License, or (at your option)
8bc98059 PJ	11	* any later version.
8bc98059 PJ	12	*
d62a17ae	13	* This program is distributed in the hope that it will be useful,but WITHOUT
	14	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	15	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
8bc98059	16	* more details.
896014f4 DL	17	*
	18	* You should have received a copy of the GNU General Public License along
	19	* with this program; see the file COPYING; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
8bc98059 PJ	21	*/
	22
	23	#include <zebra.h>
745bf05f	24	#if ISIS_METHOD == ISIS_METHOD_PFPACKET
d62a17ae	25	#include <net/ethernet.h> /* the L2 protocols */
8bc98059 PJ	26	#include <netpacket/packet.h>
8bc98059 PJ	27
4fa80053 DL	28	#include <linux/filter.h>
4fa80053 DL	29
8bc98059	30	#include "log.h"
cfd1f27b	31	#include "network.h"
8bc98059 PJ	32	#include "stream.h"
8bc98059 PJ	33	#include "if.h"
38937bd5	34	#include "lib_errors.h"
8bc98059	35
8bc98059 PJ	36	#include "isisd/isis_constants.h"
	37	#include "isisd/isis_common.h"
	38	#include "isisd/isis_circuit.h"
	39	#include "isisd/isis_flags.h"
	40	#include "isisd/isisd.h"
	41	#include "isisd/isis_constants.h"
	42	#include "isisd/isis_circuit.h"
	43	#include "isisd/isis_network.h"
	44
	45	#include "privs.h"
	46
4fa80053	47	/* tcpdump -i eth0 'isis' -dd */
2b64873d	48	static const struct sock_filter isisfilter[] = {
996c9314 LB	49	/* NB: we're in SOCK_DGRAM, so src/dst mac + length are stripped
	50	* off!
	51	* (OTOH it's a bit more lower-layer agnostic and might work
	52	* over GRE?) */
	53	/* { 0x28, 0, 0, 0x0000000c - 14 }, */
	54	/* { 0x25, 5, 0, 0x000005dc }, */
	55	{0x28, 0, 0, 0x0000000e - 14}, {0x15, 0, 3, 0x0000fefe},
	56	{0x30, 0, 0, 0x00000011 - 14}, {0x15, 0, 1, 0x00000083},
	57	{0x6, 0, 0, 0x00040000}, {0x6, 0, 0, 0x00000000},
4fa80053 DL	58	};
4fa80053 DL	59
2b64873d	60	static const struct sock_fprog bpf = {
4fa80053	61	.len = array_size(isisfilter),
2b64873d	62	.filter = (struct sock_filter *)isisfilter,
4fa80053 DL	63	};
4fa80053 DL	64
8bc98059 PJ	65	/*
	66	* Table 9 - Architectural constants for use with ISO 8802 subnetworks
	67	* ISO 10589 - 8.4.8
	68	*/
	69
2b64873d DL	70	static const uint8_t ALL_L1_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14};
	71	static const uint8_t ALL_L2_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15};
	72	static const uint8_t ALL_ISS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x05};
	73	static const uint8_t ALL_ESS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x04};
8bc98059	74
f2bce9a5	75	static uint8_t discard_buff[8192];
8bc98059 PJ	76
	77	/*
	78	* if level is 0 we are joining p2p multicast
	79	* FIXME: and the p2p multicast being ???
	80	*/
d62a17ae	81	static int isis_multicast_join(int fd, int registerto, int if_num)
8bc98059	82	{
d62a17ae	83	struct packet_mreq mreq;
	84
	85	memset(&mreq, 0, sizeof(mreq));
	86	mreq.mr_ifindex = if_num;
	87	if (registerto) {
	88	mreq.mr_type = PACKET_MR_MULTICAST;
	89	mreq.mr_alen = ETH_ALEN;
	90	if (registerto == 1)
	91	memcpy(&mreq.mr_address, ALL_L1_ISS, ETH_ALEN);
	92	else if (registerto == 2)
	93	memcpy(&mreq.mr_address, ALL_L2_ISS, ETH_ALEN);
	94	else if (registerto == 3)
	95	memcpy(&mreq.mr_address, ALL_ISS, ETH_ALEN);
	96	else
	97	memcpy(&mreq.mr_address, ALL_ESS, ETH_ALEN);
	98
	99	} else {
	100	mreq.mr_type = PACKET_MR_ALLMULTI;
	101	}
8bc98059	102	#ifdef EXTREME_DEBUG
d62a17ae	103	zlog_debug(
	104	"isis_multicast_join(): fd=%d, reg_to=%d, if_num=%d, "
	105	"address = %02x:%02x:%02x:%02x:%02x:%02x",
	106	fd, registerto, if_num, mreq.mr_address[0], mreq.mr_address[1],
	107	mreq.mr_address[2], mreq.mr_address[3], mreq.mr_address[4],
	108	mreq.mr_address[5]);
8bc98059	109	#endif /* EXTREME_DEBUG */
d62a17ae	110	if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq,
	111	sizeof(struct packet_mreq))) {
	112	zlog_warn("isis_multicast_join(): setsockopt(): %s",
	113	safe_strerror(errno));
	114	return ISIS_WARNING;
	115	}
	116
	117	return ISIS_OK;
8bc98059 PJ	118	}
8bc98059 PJ	119
d62a17ae	120	static int open_packet_socket(struct isis_circuit *circuit)
8bc98059	121	{
d62a17ae	122	struct sockaddr_ll s_addr;
	123	int fd, retval = ISIS_OK;
	124
	125	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));
	126	if (fd < 0) {
	127	zlog_warn("open_packet_socket(): socket() failed %s",
	128	safe_strerror(errno));
	129	return ISIS_WARNING;
	130	}
	131
	132	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))) {
	133	zlog_warn("open_packet_socket(): SO_ATTACH_FILTER failed: %s",
	134	safe_strerror(errno));
	135	}
	136
	137	/*
	138	* Bind to the physical interface
	139	*/
	140	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	141	s_addr.sll_family = AF_PACKET;
	142	s_addr.sll_protocol = htons(ETH_P_ALL);
	143	s_addr.sll_ifindex = circuit->interface->ifindex;
	144
	145	if (bind(fd, (struct sockaddr *)(&s_addr), sizeof(struct sockaddr_ll))
	146	< 0) {
	147	zlog_warn("open_packet_socket(): bind() failed: %s",
	148	safe_strerror(errno));
	149	close(fd);
	150	return ISIS_WARNING;
	151	}
	152
	153	circuit->fd = fd;
	154
	155	if (if_is_broadcast(circuit->interface)) {
	156	/*
	157	* Join to multicast groups
	158	* according to
	159	* 8.4.2 - Broadcast subnetwork IIH PDUs
	160	* FIXME: is there a case only one will fail??
	161	*/
	162	/* joining ALL_L1_ISS */
	163	retval \|= isis_multicast_join(circuit->fd, 1,
	164	circuit->interface->ifindex);
	165	/* joining ALL_L2_ISS */
	166	retval \|= isis_multicast_join(circuit->fd, 2,
	167	circuit->interface->ifindex);
	168	/* joining ALL_ISS (used in RFC 5309 p2p-over-lan as well) */
	169	retval \|= isis_multicast_join(circuit->fd, 3,
	170	circuit->interface->ifindex);
	171	} else {
	172	retval = isis_multicast_join(circuit->fd, 0,
	173	circuit->interface->ifindex);
	174	}
	175
	176	return retval;
8bc98059 PJ	177	}
	178
	179	/*
	180	* Create the socket and set the tx/rx funcs
	181	*/
d62a17ae	182	int isis_sock_init(struct isis_circuit *circuit)
8bc98059	183	{
d62a17ae	184	int retval = ISIS_OK;
d62a17ae	185
0cf6db21	186	frr_with_privs(&isisd_privs) {
d62a17ae	187
01b9e3fd	188	retval = open_packet_socket(circuit);
d62a17ae	189
01b9e3fd	190	if (retval != ISIS_OK) {
633fc9b1 DL	191	zlog_warn("%s: could not initialize the socket",
633fc9b1 DL	192	__func__);
01b9e3fd DL	193	break;
01b9e3fd DL	194	}
d62a17ae	195
d62a17ae	196	/* Assign Rx and Tx callbacks are based on real if type */
01b9e3fd DL	197	if (if_is_broadcast(circuit->interface)) {
	198	circuit->tx = isis_send_pdu_bcast;
	199	circuit->rx = isis_recv_pdu_bcast;
	200	} else if (if_is_pointopoint(circuit->interface)) {
	201	circuit->tx = isis_send_pdu_p2p;
	202	circuit->rx = isis_recv_pdu_p2p;
	203	} else {
	204	zlog_warn("isis_sock_init(): unknown circuit type");
	205	retval = ISIS_WARNING;
	206	break;
	207	}
633fc9b1	208	}
8bc98059	209
d62a17ae	210	return retval;
8bc98059 PJ	211	}
8bc98059 PJ	212
d7c0a89a	213	static inline int llc_check(uint8_t *llc)
8bc98059	214	{
d62a17ae	215	if (llc != ISO_SAP \|\| (llc + 1) != ISO_SAP \|\| *(llc + 2) != 3)
d62a17ae	216	return 0;
8bc98059	217
d62a17ae	218	return 1;
8bc98059 PJ	219	}
8bc98059 PJ	220
d7c0a89a	221	int isis_recv_pdu_bcast(struct isis_circuit circuit, uint8_t ssnpa)
8bc98059	222	{
d62a17ae	223	int bytesread, addr_len;
d62a17ae	224	struct sockaddr_ll s_addr;
d7c0a89a	225	uint8_t llc[LLC_LEN];
d62a17ae	226
	227	addr_len = sizeof(s_addr);
	228
	229	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	230
	231	bytesread =
	232	recvfrom(circuit->fd, (void *)&llc, LLC_LEN, MSG_PEEK,
	233	(struct sockaddr )&s_addr, (socklen_t )&addr_len);
	234
	235	if ((bytesread < 0)
	236	\|\| (s_addr.sll_ifindex != (int)circuit->interface->ifindex)) {
	237	if (bytesread < 0) {
	238	zlog_warn(
	239	"isis_recv_packet_bcast(): ifname %s, fd %d, "
	240	"bytesread %d, recvfrom(): %s",
	241	circuit->interface->name, circuit->fd,
	242	bytesread, safe_strerror(errno));
	243	}
	244	if (s_addr.sll_ifindex != (int)circuit->interface->ifindex) {
	245	zlog_warn(
	246	"packet is received on multiple interfaces: "
	247	"socket interface %d, circuit interface %d, "
	248	"packet type %u",
	249	s_addr.sll_ifindex, circuit->interface->ifindex,
	250	s_addr.sll_pkttype);
	251	}
	252
	253	/* get rid of the packet */
	254	bytesread = recvfrom(circuit->fd, discard_buff,
	255	sizeof(discard_buff), MSG_DONTWAIT,
	256	(struct sockaddr *)&s_addr,
	257	(socklen_t *)&addr_len);
	258
	259	if (bytesread < 0)
	260	zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
	261
	262	return ISIS_WARNING;
	263	}
	264	/*
	265	* Filtering by llc field, discard packets sent by this host (other
	266	* circuit)
	267	*/
	268	if (!llc_check(llc) \|\| s_addr.sll_pkttype == PACKET_OUTGOING) {
	269	/* Read the packet into discard buff */
	270	bytesread = recvfrom(circuit->fd, discard_buff,
	271	sizeof(discard_buff), MSG_DONTWAIT,
	272	(struct sockaddr *)&s_addr,
	273	(socklen_t *)&addr_len);
	274	if (bytesread < 0)
	275	zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
	276	return ISIS_WARNING;
	277	}
	278
32fed393 EDP	279	/* Ensure that we have enough space for a pdu padded to fill the mtu */
	280	unsigned int max_size =
	281	circuit->interface->mtu > circuit->interface->mtu6
	282	? circuit->interface->mtu
	283	: circuit->interface->mtu6;
	284	uint8_t temp_buff[max_size];
	285	bytesread =
	286	recvfrom(circuit->fd, temp_buff, max_size, MSG_DONTWAIT,
	287	(struct sockaddr )&s_addr, (socklen_t )&addr_len);
d62a17ae	288	if (bytesread < 0) {
32fed393	289	zlog_warn("%s: recvfrom() failed", __func__);
d62a17ae	290	return ISIS_WARNING;
d62a17ae	291	}
d62a17ae	292	/* then we lose the LLC */
32fed393	293	stream_write(circuit->rcv_stream, temp_buff + LLC_LEN,
d62a17ae	294	bytesread - LLC_LEN);
d62a17ae	295	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);
	296
	297	return ISIS_OK;
8bc98059 PJ	298	}
8bc98059 PJ	299
d7c0a89a	300	int isis_recv_pdu_p2p(struct isis_circuit circuit, uint8_t ssnpa)
8bc98059	301	{
d62a17ae	302	int bytesread, addr_len;
	303	struct sockaddr_ll s_addr;
	304
	305	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	306	addr_len = sizeof(s_addr);
	307
	308	/* we can read directly to the stream */
aa979109 A	309	(void)stream_recvfrom(
	310	circuit->rcv_stream, circuit->fd, circuit->interface->mtu, 0,
	311	(struct sockaddr )&s_addr, (socklen_t )&addr_len);
d62a17ae	312
	313	if (s_addr.sll_pkttype == PACKET_OUTGOING) {
	314	/* Read the packet into discard buff */
	315	bytesread = recvfrom(circuit->fd, discard_buff,
	316	sizeof(discard_buff), MSG_DONTWAIT,
	317	(struct sockaddr *)&s_addr,
	318	(socklen_t *)&addr_len);
	319	if (bytesread < 0)
	320	zlog_warn("isis_recv_pdu_p2p(): recvfrom() failed");
	321	return ISIS_WARNING;
	322	}
	323
	324	/* If we don't have protocol type 0x00FE which is
	325	* ISO over GRE we exit with pain :)
	326	*/
	327	if (ntohs(s_addr.sll_protocol) != 0x00FE) {
	328	zlog_warn("isis_recv_pdu_p2p(): protocol mismatch(): %X",
	329	ntohs(s_addr.sll_protocol));
	330	return ISIS_WARNING;
	331	}
	332
	333	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);
	334
	335	return ISIS_OK;
8bc98059 PJ	336	}
8bc98059 PJ	337
d62a17ae	338	int isis_send_pdu_bcast(struct isis_circuit *circuit, int level)
8bc98059	339	{
d62a17ae	340	struct msghdr msg;
d62a17ae	341	struct iovec iov[2];
32fed393	342	char temp_buff[LLC_LEN];
d62a17ae	343
	344	/* we need to do the LLC in here because of P2P circuits, which will
	345	* not need it
	346	*/
	347	struct sockaddr_ll sa;
	348
	349	stream_set_getp(circuit->snd_stream, 0);
	350	memset(&sa, 0, sizeof(struct sockaddr_ll));
	351	sa.sll_family = AF_PACKET;
	352
	353	size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN;
	354	sa.sll_protocol = htons(isis_ethertype(frame_size));
	355	sa.sll_ifindex = circuit->interface->ifindex;
	356	sa.sll_halen = ETH_ALEN;
	357	/* RFC5309 section 4.1 recommends ALL_ISS */
	358	if (circuit->circ_type == CIRCUIT_T_P2P)
	359	memcpy(&sa.sll_addr, ALL_ISS, ETH_ALEN);
	360	else if (level == 1)
	361	memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	362	else
	363	memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);
	364
	365	/* on a broadcast circuit */
	366	/* first we put the LLC in */
32fed393 EDP	367	temp_buff[0] = 0xFE;
	368	temp_buff[1] = 0xFE;
	369	temp_buff[2] = 0x03;
d62a17ae	370
	371	memset(&msg, 0, sizeof(msg));
	372	msg.msg_name = &sa;
	373	msg.msg_namelen = sizeof(struct sockaddr_ll);
	374	msg.msg_iov = iov;
	375	msg.msg_iovlen = 2;
32fed393	376	iov[0].iov_base = temp_buff;
d62a17ae	377	iov[0].iov_len = LLC_LEN;
	378	iov[1].iov_base = circuit->snd_stream->data;
	379	iov[1].iov_len = stream_get_endp(circuit->snd_stream);
	380
	381	if (sendmsg(circuit->fd, &msg, 0) < 0) {
	382	zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
	383	circuit->interface->name, safe_strerror(errno));
	384	if (ERRNO_IO_RETRY(errno))
	385	return ISIS_WARNING;
	386	return ISIS_ERROR;
	387	}
	388	return ISIS_OK;
8bc98059 PJ	389	}
8bc98059 PJ	390
d62a17ae	391	int isis_send_pdu_p2p(struct isis_circuit *circuit, int level)
8bc98059	392	{
d62a17ae	393	struct sockaddr_ll sa;
	394	ssize_t rv;
	395
	396	stream_set_getp(circuit->snd_stream, 0);
	397	memset(&sa, 0, sizeof(struct sockaddr_ll));
	398	sa.sll_family = AF_PACKET;
	399	sa.sll_ifindex = circuit->interface->ifindex;
	400	sa.sll_halen = ETH_ALEN;
	401	if (level == 1)
	402	memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	403	else
	404	memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);
	405
	406
	407	/* lets try correcting the protocol */
	408	sa.sll_protocol = htons(0x00FE);
	409	rv = sendto(circuit->fd, circuit->snd_stream->data,
	410	stream_get_endp(circuit->snd_stream), 0,
	411	(struct sockaddr *)&sa, sizeof(struct sockaddr_ll));
	412	if (rv < 0) {
	413	zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
	414	circuit->interface->name, safe_strerror(errno));
	415	if (ERRNO_IO_RETRY(errno))
	416	return ISIS_WARNING;
	417	return ISIS_ERROR;
	418	}
	419	return ISIS_OK;
8bc98059	420	}
745bf05f DL	421
745bf05f DL	422	#endif /* ISIS_METHOD == ISIS_METHOD_PFPACKET */