GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/ripd/packet.c Lines: 0 108 0.0 %
Date: 2017-11-13 Branches: 0 71 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: packet.c,v 1.13 2016/12/23 14:53:16 jca Exp $ */
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/*
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 * Copyright (c) 2006 Michele Marchetto <mydecay@openbeer.it>
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 * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org>
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 *
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 * Permission to use, copy, modify, and distribute this software for any
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 * purpose with or without fee is hereby granted, provided that the above
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 * copyright notice and this permission notice appear in all copies.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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 */
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/uio.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/udp.h>
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#include <arpa/inet.h>
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#include <net/if_dl.h>
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#include <errno.h>
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#include <event.h>
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#include <stdlib.h>
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#include <string.h>
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#include "ripd.h"
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#include "rip.h"
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#include "log.h"
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#include "ripe.h"
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int		 rip_hdr_sanity_check(struct rip_hdr *);
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struct iface	*find_iface(struct ripd_conf *, unsigned int, struct in_addr);
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int
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gen_rip_hdr(struct ibuf *buf, u_int8_t command)
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{
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	struct rip_hdr	rip_hdr;
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	bzero(&rip_hdr, sizeof(rip_hdr));
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	rip_hdr.version = RIP_VERSION;
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	rip_hdr.command = command;
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	return (ibuf_add(buf, &rip_hdr, sizeof(rip_hdr)));
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}
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/* send and receive packets */
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int
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send_packet(struct iface *iface, void *pkt, size_t len, struct sockaddr_in *dst)
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{
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	/* set outgoing interface for multicast traffic */
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	if (IN_MULTICAST(ntohl(dst->sin_addr.s_addr)))
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		if (if_set_mcast(iface) == -1) {
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			log_warn("send_packet: error setting multicast "
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			    "interface, %s", iface->name);
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			return (-1);
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		}
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	if (sendto(iface->fd, pkt, len, 0,
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	    (struct sockaddr *)dst, sizeof(*dst)) == -1) {
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		log_warn("send_packet: error sending packet on interface %s",
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		    iface->name);
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		return (-1);
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	}
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	return (0);
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}
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void
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recv_packet(int fd, short event, void *bula)
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{
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	union {
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		struct cmsghdr hdr;
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		char	buf[CMSG_SPACE(sizeof(struct sockaddr_dl))];
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	} cmsgbuf;
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	struct sockaddr_in	 src;
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	struct iovec		 iov;
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	struct msghdr		 msg;
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	struct cmsghdr		*cmsg;
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	struct sockaddr_dl	*dst = NULL;
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	struct nbr_failed	*nbr_failed = NULL;
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	struct ripd_conf	*xconf = bula;
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	struct iface		*iface;
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	struct rip_hdr		*rip_hdr;
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	struct nbr		*nbr;
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	u_int8_t		*buf;
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	ssize_t			 r;
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	u_int16_t		 len, srcport;
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	u_int32_t		 auth_crypt_num = 0;
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	if (event != EV_READ)
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		return;
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	/* setup buffer */
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	buf = pkt_ptr;
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	bzero(&msg, sizeof(msg));
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	iov.iov_base = buf;
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	iov.iov_len = IBUF_READ_SIZE;
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	msg.msg_name = &src;
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	msg.msg_namelen = sizeof(src);
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	msg.msg_iov = &iov;
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	msg.msg_iovlen = 1;
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	msg.msg_control = &cmsgbuf.buf;
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	msg.msg_controllen = sizeof(cmsgbuf.buf);
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	if ((r = recvmsg(fd, &msg, 0)) == -1) {
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		if (errno != EINTR && errno != EAGAIN)
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			log_debug("recv_packet: read error: %s",
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			    strerror(errno));
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		return;
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	}
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	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
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	    cmsg = CMSG_NXTHDR(&msg, cmsg)) {
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		if (cmsg->cmsg_level == IPPROTO_IP &&
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		    cmsg->cmsg_type == IP_RECVIF) {
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			dst = (struct sockaddr_dl *)CMSG_DATA(cmsg);
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			break;
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		}
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	}
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	if (dst == NULL)
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		return;
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	len = (u_int16_t)r;
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	/* Check the packet is not from one of the local interfaces */
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	LIST_FOREACH(iface, &xconf->iface_list, entry) {
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		if (iface->addr.s_addr == src.sin_addr.s_addr)
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			return;
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	}
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	/* find a matching interface */
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	if ((iface = find_iface(xconf, dst->sdl_index, src.sin_addr)) == NULL) {
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		log_debug("recv_packet: cannot find a matching interface");
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		return;
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	}
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	srcport = ntohs(src.sin_port);
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	/* RIP header sanity checks */
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	if (len < RIP_HDR_LEN) {
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		log_debug("recv_packet: bad packet size");
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		return;
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	}
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	rip_hdr = (struct rip_hdr *)buf;
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	if (rip_hdr_sanity_check(rip_hdr) == -1)
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		return;
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	nbr = nbr_find_ip(iface, src.sin_addr.s_addr);
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	if (nbr == NULL && iface->auth_type == AUTH_CRYPT)
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		nbr_failed = nbr_failed_find(iface, src.sin_addr.s_addr);
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	/* switch RIP command */
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	switch (rip_hdr->command) {
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	case COMMAND_REQUEST:
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		/* Requests don't create a real neighbor, just a temporary
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		 * one to build the response.
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		 */
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		if ((msg.msg_flags & MSG_MCAST) == 0 && srcport == RIP_PORT)
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			return;
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		if (nbr == NULL) {
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			nbr = nbr_new(src.sin_addr.s_addr, iface);
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			nbr->addr = src.sin_addr;
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		}
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		nbr->port = srcport;
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		nbr_fsm(nbr, NBR_EVT_REQUEST_RCVD);
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		buf += RIP_HDR_LEN;
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		len -= RIP_HDR_LEN;
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		recv_request(iface, nbr, buf, len);
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		break;
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	case COMMAND_RESPONSE:
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		if (srcport != RIP_PORT)
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			return;
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		if (auth_validate(&buf, &len, iface, nbr, nbr_failed,
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		    &auth_crypt_num)) {
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			log_warnx("recv_packet: authentication error, "
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			    "interface %s", iface->name);
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			return;
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		}
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		if (nbr == NULL) {
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			nbr = nbr_new(src.sin_addr.s_addr, iface);
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			if (nbr_failed != NULL)
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				nbr_failed_delete(nbr_failed);
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			nbr->addr = src.sin_addr;
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		}
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		nbr->auth_seq_num = auth_crypt_num;
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		nbr_fsm(nbr, NBR_EVT_RESPONSE_RCVD);
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		recv_response(iface, nbr, buf, len);
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		break;
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	default:
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		log_debug("recv_packet: unknown RIP command, interface %s",
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		    iface->name);
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	}
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}
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int
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rip_hdr_sanity_check(struct rip_hdr *rip_hdr)
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{
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	if (rip_hdr->version != RIP_VERSION) {
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		log_debug("rip_hdr_sanity_check: invalid RIP version %d",
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		    rip_hdr->version);
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		return (-1);
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	}
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	return (0);
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}
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struct iface *
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find_iface(struct ripd_conf *xconf, unsigned int ifindex, struct in_addr src)
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{
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	struct iface	*iface = NULL;
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	/* returned interface needs to be active */
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	LIST_FOREACH(iface, &xconf->iface_list, entry) {
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		if (ifindex == 0 || ifindex != iface->ifindex)
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			continue;
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		if (iface->passive)
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			continue;
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		if ((iface->addr.s_addr & iface->mask.s_addr) ==
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		    (src.s_addr & iface->mask.s_addr))
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			return (iface);
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		if (iface->dst.s_addr && iface->dst.s_addr == src.s_addr)
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			return (iface);
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	}
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	return (NULL);
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}