[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 "isisd/dict.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 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 struct sock_fprog bpf = {
	.len = array_size(isisfilter),
	.filter = isisfilter,
};

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

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

static uint8_t discard_buff[8192];
static uint8_t sock_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;

	if (isisd_privs.change(ZPRIVS_RAISE))
		zlog_err("%s: could not raise privs, %s", __func__,
			 safe_strerror(errno));

	retval = open_packet_socket(circuit);

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

	/* 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;
		goto end;
	}

end:
	if (isisd_privs.change(ZPRIVS_LOWER))
		zlog_err("%s: could not lower privs, %s", __func__,
			 safe_strerror(errno));

	return retval;
}

static inline int llc_check(u_char *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, u_char *ssnpa)
{
	int bytesread, addr_len;
	struct sockaddr_ll s_addr;
	u_char 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;
	}

	/* on lan we have to read to the static buff first */
	bytesread = recvfrom(circuit->fd, sock_buff, sizeof(sock_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;
	}

	/* then we lose the LLC */
	stream_write(circuit->rcv_stream, sock_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, u_char *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 */
	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];

	/* 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 */
	sock_buff[0] = 0xFE;
	sock_buff[1] = 0xFE;
	sock_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 = sock_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"
	33	#include "if.h"
	34
	35	#include "isisd/dict.h"
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 */
9d303b37 DL	48	static struct sock_filter isisfilter[] =
	49	{
	50	/* NB: we're in SOCK_DGRAM, so src/dst mac + length are stripped
	51	* off!
	52	* (OTOH it's a bit more lower-layer agnostic and might work
	53	* over GRE?) */
	54	/* { 0x28, 0, 0, 0x0000000c - 14 }, */
	55	/* { 0x25, 5, 0, 0x000005dc }, */
	56	{0x28, 0, 0, 0x0000000e - 14}, {0x15, 0, 3, 0x0000fefe},
	57	{0x30, 0, 0, 0x00000011 - 14}, {0x15, 0, 1, 0x00000083},
	58	{0x6, 0, 0, 0x00040000}, {0x6, 0, 0, 0x00000000},
4fa80053 DL	59	};
	60
	61	static struct sock_fprog bpf = {
	62	.len = array_size(isisfilter),
	63	.filter = isisfilter,
	64	};
	65
8bc98059 PJ	66	/*
	67	* Table 9 - Architectural constants for use with ISO 8802 subnetworks
	68	* ISO 10589 - 8.4.8
	69	*/
	70
d62a17ae	71	u_char ALL_L1_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14};
	72	u_char ALL_L2_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15};
	73	u_char ALL_ISS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x05};
	74	u_char ALL_ESS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x04};
8bc98059	75
f2bce9a5 DL	76	static uint8_t discard_buff[8192];
f2bce9a5 DL	77	static uint8_t sock_buff[8192];
8bc98059 PJ	78
	79	/*
	80	* if level is 0 we are joining p2p multicast
	81	* FIXME: and the p2p multicast being ???
	82	*/
d62a17ae	83	static int isis_multicast_join(int fd, int registerto, int if_num)
8bc98059	84	{
d62a17ae	85	struct packet_mreq mreq;
	86
	87	memset(&mreq, 0, sizeof(mreq));
	88	mreq.mr_ifindex = if_num;
	89	if (registerto) {
	90	mreq.mr_type = PACKET_MR_MULTICAST;
	91	mreq.mr_alen = ETH_ALEN;
	92	if (registerto == 1)
	93	memcpy(&mreq.mr_address, ALL_L1_ISS, ETH_ALEN);
	94	else if (registerto == 2)
	95	memcpy(&mreq.mr_address, ALL_L2_ISS, ETH_ALEN);
	96	else if (registerto == 3)
	97	memcpy(&mreq.mr_address, ALL_ISS, ETH_ALEN);
	98	else
	99	memcpy(&mreq.mr_address, ALL_ESS, ETH_ALEN);
	100
	101	} else {
	102	mreq.mr_type = PACKET_MR_ALLMULTI;
	103	}
8bc98059	104	#ifdef EXTREME_DEBUG
d62a17ae	105	zlog_debug(
	106	"isis_multicast_join(): fd=%d, reg_to=%d, if_num=%d, "
	107	"address = %02x:%02x:%02x:%02x:%02x:%02x",
	108	fd, registerto, if_num, mreq.mr_address[0], mreq.mr_address[1],
	109	mreq.mr_address[2], mreq.mr_address[3], mreq.mr_address[4],
	110	mreq.mr_address[5]);
8bc98059	111	#endif /* EXTREME_DEBUG */
d62a17ae	112	if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq,
	113	sizeof(struct packet_mreq))) {
	114	zlog_warn("isis_multicast_join(): setsockopt(): %s",
	115	safe_strerror(errno));
	116	return ISIS_WARNING;
	117	}
	118
	119	return ISIS_OK;
8bc98059 PJ	120	}
8bc98059 PJ	121
d62a17ae	122	static int open_packet_socket(struct isis_circuit *circuit)
8bc98059	123	{
d62a17ae	124	struct sockaddr_ll s_addr;
	125	int fd, retval = ISIS_OK;
	126
	127	fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL));
	128	if (fd < 0) {
	129	zlog_warn("open_packet_socket(): socket() failed %s",
	130	safe_strerror(errno));
	131	return ISIS_WARNING;
	132	}
	133
	134	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))) {
	135	zlog_warn("open_packet_socket(): SO_ATTACH_FILTER failed: %s",
	136	safe_strerror(errno));
	137	}
	138
	139	/*
	140	* Bind to the physical interface
	141	*/
	142	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	143	s_addr.sll_family = AF_PACKET;
	144	s_addr.sll_protocol = htons(ETH_P_ALL);
	145	s_addr.sll_ifindex = circuit->interface->ifindex;
	146
	147	if (bind(fd, (struct sockaddr *)(&s_addr), sizeof(struct sockaddr_ll))
	148	< 0) {
	149	zlog_warn("open_packet_socket(): bind() failed: %s",
	150	safe_strerror(errno));
	151	close(fd);
	152	return ISIS_WARNING;
	153	}
	154
	155	circuit->fd = fd;
	156
	157	if (if_is_broadcast(circuit->interface)) {
	158	/*
	159	* Join to multicast groups
	160	* according to
	161	* 8.4.2 - Broadcast subnetwork IIH PDUs
	162	* FIXME: is there a case only one will fail??
	163	*/
	164	/* joining ALL_L1_ISS */
	165	retval \|= isis_multicast_join(circuit->fd, 1,
	166	circuit->interface->ifindex);
	167	/* joining ALL_L2_ISS */
	168	retval \|= isis_multicast_join(circuit->fd, 2,
	169	circuit->interface->ifindex);
	170	/* joining ALL_ISS (used in RFC 5309 p2p-over-lan as well) */
	171	retval \|= isis_multicast_join(circuit->fd, 3,
	172	circuit->interface->ifindex);
	173	} else {
	174	retval = isis_multicast_join(circuit->fd, 0,
	175	circuit->interface->ifindex);
	176	}
	177
	178	return retval;
8bc98059 PJ	179	}
	180
	181	/*
	182	* Create the socket and set the tx/rx funcs
	183	*/
d62a17ae	184	int isis_sock_init(struct isis_circuit *circuit)
8bc98059	185	{
d62a17ae	186	int retval = ISIS_OK;
	187
	188	if (isisd_privs.change(ZPRIVS_RAISE))
	189	zlog_err("%s: could not raise privs, %s", __func__,
	190	safe_strerror(errno));
	191
	192	retval = open_packet_socket(circuit);
	193
	194	if (retval != ISIS_OK) {
	195	zlog_warn("%s: could not initialize the socket", __func__);
	196	goto end;
	197	}
	198
	199	/* Assign Rx and Tx callbacks are based on real if type */
	200	if (if_is_broadcast(circuit->interface)) {
	201	circuit->tx = isis_send_pdu_bcast;
	202	circuit->rx = isis_recv_pdu_bcast;
	203	} else if (if_is_pointopoint(circuit->interface)) {
	204	circuit->tx = isis_send_pdu_p2p;
	205	circuit->rx = isis_recv_pdu_p2p;
	206	} else {
	207	zlog_warn("isis_sock_init(): unknown circuit type");
	208	retval = ISIS_WARNING;
	209	goto end;
	210	}
8bc98059 PJ	211
8bc98059 PJ	212	end:
d62a17ae	213	if (isisd_privs.change(ZPRIVS_LOWER))
	214	zlog_err("%s: could not lower privs, %s", __func__,
	215	safe_strerror(errno));
8bc98059	216
d62a17ae	217	return retval;
8bc98059 PJ	218	}
8bc98059 PJ	219
d62a17ae	220	static inline int llc_check(u_char *llc)
8bc98059	221	{
d62a17ae	222	if (llc != ISO_SAP \|\| (llc + 1) != ISO_SAP \|\| *(llc + 2) != 3)
d62a17ae	223	return 0;
8bc98059	224
d62a17ae	225	return 1;
8bc98059 PJ	226	}
8bc98059 PJ	227
d62a17ae	228	int isis_recv_pdu_bcast(struct isis_circuit circuit, u_char ssnpa)
8bc98059	229	{
d62a17ae	230	int bytesread, addr_len;
	231	struct sockaddr_ll s_addr;
	232	u_char llc[LLC_LEN];
	233
	234	addr_len = sizeof(s_addr);
	235
	236	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	237
	238	bytesread =
	239	recvfrom(circuit->fd, (void *)&llc, LLC_LEN, MSG_PEEK,
	240	(struct sockaddr )&s_addr, (socklen_t )&addr_len);
	241
	242	if ((bytesread < 0)
	243	\|\| (s_addr.sll_ifindex != (int)circuit->interface->ifindex)) {
	244	if (bytesread < 0) {
	245	zlog_warn(
	246	"isis_recv_packet_bcast(): ifname %s, fd %d, "
	247	"bytesread %d, recvfrom(): %s",
	248	circuit->interface->name, circuit->fd,
	249	bytesread, safe_strerror(errno));
	250	}
	251	if (s_addr.sll_ifindex != (int)circuit->interface->ifindex) {
	252	zlog_warn(
	253	"packet is received on multiple interfaces: "
	254	"socket interface %d, circuit interface %d, "
	255	"packet type %u",
	256	s_addr.sll_ifindex, circuit->interface->ifindex,
	257	s_addr.sll_pkttype);
	258	}
	259
	260	/* get rid of the packet */
	261	bytesread = recvfrom(circuit->fd, discard_buff,
	262	sizeof(discard_buff), MSG_DONTWAIT,
	263	(struct sockaddr *)&s_addr,
	264	(socklen_t *)&addr_len);
	265
	266	if (bytesread < 0)
	267	zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
	268
	269	return ISIS_WARNING;
	270	}
	271	/*
	272	* Filtering by llc field, discard packets sent by this host (other
	273	* circuit)
	274	*/
	275	if (!llc_check(llc) \|\| s_addr.sll_pkttype == PACKET_OUTGOING) {
	276	/* Read the packet into discard buff */
	277	bytesread = recvfrom(circuit->fd, discard_buff,
	278	sizeof(discard_buff), MSG_DONTWAIT,
	279	(struct sockaddr *)&s_addr,
	280	(socklen_t *)&addr_len);
	281	if (bytesread < 0)
	282	zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
	283	return ISIS_WARNING;
	284	}
	285
	286	/* on lan we have to read to the static buff first */
	287	bytesread = recvfrom(circuit->fd, sock_buff, sizeof(sock_buff),
	288	MSG_DONTWAIT, (struct sockaddr *)&s_addr,
	289	(socklen_t *)&addr_len);
	290	if (bytesread < 0) {
	291	zlog_warn("isis_recv_pdu_bcast(): recvfrom() failed");
	292	return ISIS_WARNING;
	293	}
294
295	/* then we lose the LLC */
296	stream_write(circuit->rcv_stream, sock_buff + LLC_LEN,
297	bytesread - LLC_LEN);
298
299	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);
300
301	return ISIS_OK;
8bc98059 PJ	302	}
8bc98059 PJ	303
d62a17ae	304	int isis_recv_pdu_p2p(struct isis_circuit circuit, u_char ssnpa)
8bc98059	305	{
d62a17ae	306	int bytesread, addr_len;
	307	struct sockaddr_ll s_addr;
	308
	309	memset(&s_addr, 0, sizeof(struct sockaddr_ll));
	310	addr_len = sizeof(s_addr);
	311
	312	/* we can read directly to the stream */
	313	stream_recvfrom(circuit->rcv_stream, circuit->fd,
	314	circuit->interface->mtu, 0, (struct sockaddr *)&s_addr,
	315	(socklen_t *)&addr_len);
	316
	317	if (s_addr.sll_pkttype == PACKET_OUTGOING) {
	318	/* Read the packet into discard buff */
	319	bytesread = recvfrom(circuit->fd, discard_buff,
	320	sizeof(discard_buff), MSG_DONTWAIT,
	321	(struct sockaddr *)&s_addr,
	322	(socklen_t *)&addr_len);
	323	if (bytesread < 0)
	324	zlog_warn("isis_recv_pdu_p2p(): recvfrom() failed");
	325	return ISIS_WARNING;
	326	}
	327
	328	/* If we don't have protocol type 0x00FE which is
	329	* ISO over GRE we exit with pain :)
	330	*/
	331	if (ntohs(s_addr.sll_protocol) != 0x00FE) {
	332	zlog_warn("isis_recv_pdu_p2p(): protocol mismatch(): %X",
	333	ntohs(s_addr.sll_protocol));
	334	return ISIS_WARNING;
	335	}
	336
	337	memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen);
	338
	339	return ISIS_OK;
8bc98059 PJ	340	}
8bc98059 PJ	341
d62a17ae	342	int isis_send_pdu_bcast(struct isis_circuit *circuit, int level)
8bc98059	343	{
d62a17ae	344	struct msghdr msg;
	345	struct iovec iov[2];
	346
	347	/* we need to do the LLC in here because of P2P circuits, which will
	348	* not need it
	349	*/
	350	struct sockaddr_ll sa;
	351
	352	stream_set_getp(circuit->snd_stream, 0);
	353	memset(&sa, 0, sizeof(struct sockaddr_ll));
	354	sa.sll_family = AF_PACKET;
	355
	356	size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN;
	357	sa.sll_protocol = htons(isis_ethertype(frame_size));
	358	sa.sll_ifindex = circuit->interface->ifindex;
	359	sa.sll_halen = ETH_ALEN;
	360	/* RFC5309 section 4.1 recommends ALL_ISS */
	361	if (circuit->circ_type == CIRCUIT_T_P2P)
	362	memcpy(&sa.sll_addr, ALL_ISS, ETH_ALEN);
	363	else if (level == 1)
	364	memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	365	else
	366	memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);
	367
	368	/* on a broadcast circuit */
	369	/* first we put the LLC in */
	370	sock_buff[0] = 0xFE;
	371	sock_buff[1] = 0xFE;
	372	sock_buff[2] = 0x03;
	373
	374	memset(&msg, 0, sizeof(msg));
	375	msg.msg_name = &sa;
	376	msg.msg_namelen = sizeof(struct sockaddr_ll);
	377	msg.msg_iov = iov;
	378	msg.msg_iovlen = 2;
	379	iov[0].iov_base = sock_buff;
	380	iov[0].iov_len = LLC_LEN;
	381	iov[1].iov_base = circuit->snd_stream->data;
	382	iov[1].iov_len = stream_get_endp(circuit->snd_stream);
	383
	384	if (sendmsg(circuit->fd, &msg, 0) < 0) {
	385	zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
	386	circuit->interface->name, safe_strerror(errno));
	387	if (ERRNO_IO_RETRY(errno))
	388	return ISIS_WARNING;
	389	return ISIS_ERROR;
	390	}
	391	return ISIS_OK;
8bc98059 PJ	392	}
8bc98059 PJ	393
d62a17ae	394	int isis_send_pdu_p2p(struct isis_circuit *circuit, int level)
8bc98059	395	{
d62a17ae	396	struct sockaddr_ll sa;
	397	ssize_t rv;
	398
	399	stream_set_getp(circuit->snd_stream, 0);
	400	memset(&sa, 0, sizeof(struct sockaddr_ll));
	401	sa.sll_family = AF_PACKET;
	402	sa.sll_ifindex = circuit->interface->ifindex;
	403	sa.sll_halen = ETH_ALEN;
	404	if (level == 1)
	405	memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN);
	406	else
	407	memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN);
	408
	409
	410	/* lets try correcting the protocol */
	411	sa.sll_protocol = htons(0x00FE);
	412	rv = sendto(circuit->fd, circuit->snd_stream->data,
	413	stream_get_endp(circuit->snd_stream), 0,
	414	(struct sockaddr *)&sa, sizeof(struct sockaddr_ll));
	415	if (rv < 0) {
	416	zlog_warn("IS-IS pfpacket: could not transmit packet on %s: %s",
	417	circuit->interface->name, safe_strerror(errno));
	418	if (ERRNO_IO_RETRY(errno))
	419	return ISIS_WARNING;
	420	return ISIS_ERROR;
	421	}
	422	return ISIS_OK;
8bc98059	423	}
745bf05f DL	424
745bf05f DL	425	#endif /* ISIS_METHOD == ISIS_METHOD_PFPACKET */