GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/rarpd/arptab.c Lines: 0 101 0.0 %
Date: 2017-11-13 Branches: 0 76 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: arptab.c,v 1.28 2016/08/27 01:42:37 guenther Exp $ */
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/*
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 * Copyright (c) 1984, 1993
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 *	The Regents of the University of California.  All rights reserved.
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 *
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 * This code is derived from software contributed to Berkeley by
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 * Sun Microsystems, Inc.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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/*
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 * set arp table entries
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 */
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#include <sys/file.h>
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#include <sys/socket.h>
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#include <sys/sysctl.h>
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#include <sys/time.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/if_types.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/if_ether.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <paths.h>
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#include <syslog.h>
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#include <string.h>
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#include <err.h>
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/* ROUNDUP() is nasty, but it is identical to what's in the kernel. */
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#define ROUNDUP(a)					\
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	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
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static pid_t pid;
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static int s = -1;
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int rtget(struct sockaddr_inarp **, struct sockaddr_dl **);
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void
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arptab_init(void)
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{
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	s = socket(PF_ROUTE, SOCK_RAW, 0);
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	if (s < 0)
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		err(1, "arp: socket");
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}
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struct	sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
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struct	sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
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struct	sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
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struct	sockaddr_dl ifp_m = {sizeof(&ifp_m), AF_LINK};
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time_t	expire_time;
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int	flags, export_only, doing_proxy;
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struct	{
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	struct	rt_msghdr m_rtm;
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	char	m_space[512];
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} m_rtmsg;
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int	arptab_set(u_char *, u_int32_t);
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int	rtmsg(int);
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/*
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 * Set an individual arp entry
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 */
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int
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arptab_set(u_char *eaddr, u_int32_t host)
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{
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	struct sockaddr_inarp *sin = &sin_m;
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	struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
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	struct sockaddr_dl *sdl;
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	struct timeval now;
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	int rt;
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	pid = getpid();
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	sdl_m = blank_sdl;
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	sin_m = blank_sin;
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	sin->sin_addr.s_addr = host;
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	memcpy((u_char *)LLADDR(&sdl_m), (char *)eaddr, 6);
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	sdl_m.sdl_alen = 6;
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	expire_time = 0;
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	doing_proxy = flags = export_only = 0;
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	gettimeofday(&now, 0);
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	expire_time = now.tv_sec + 20 * 60;
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tryagain:
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	if (rtget(&sin, &sdl)) {
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		syslog(LOG_ERR,"%s: %m", inet_ntoa(sin->sin_addr));
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		return (1);
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	}
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	if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
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		if (sdl->sdl_family == AF_LINK &&
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		    (rtm->rtm_flags & RTF_LLINFO) &&
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		    !(rtm->rtm_flags & RTF_GATEWAY))
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			switch (sdl->sdl_type) {
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			case IFT_ETHER:
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			case IFT_FDDI:
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			case IFT_ISO88023:
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			case IFT_ISO88024:
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			case IFT_ISO88025:
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				goto overwrite;
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			default:
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				break;
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		}
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		if (doing_proxy == 0) {
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			syslog(LOG_ERR, "arptab_set: can only proxy for %s",
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			    inet_ntoa(sin->sin_addr));
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			return (1);
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		}
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		if (sin_m.sin_other & SIN_PROXY) {
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			syslog(LOG_ERR,
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			    "arptab_set: proxy entry exists for non 802 device");
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			return(1);
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		}
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		sin_m.sin_other = SIN_PROXY;
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		export_only = 1;
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		goto tryagain;
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	}
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overwrite:
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	if (sdl->sdl_family != AF_LINK) {
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		syslog(LOG_ERR,
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		    "arptab_set: cannot intuit interface index and type for %s",
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		    inet_ntoa(sin->sin_addr));
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		return (1);
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	}
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	sdl_m.sdl_type = sdl->sdl_type;
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	sdl_m.sdl_index = sdl->sdl_index;
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	rt = rtmsg(RTM_ADD);
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	return (rt);
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}
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int
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rtmsg(int cmd)
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{
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	static int seq;
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	struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
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	char *cp = m_rtmsg.m_space;
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	int l;
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retry:
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	errno = 0;
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	if (cmd == RTM_DELETE)
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		goto doit;
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	memset((char *)&m_rtmsg, 0, sizeof(m_rtmsg));
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	rtm->rtm_flags = flags;
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	rtm->rtm_version = RTM_VERSION;
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	switch (cmd) {
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	default:
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		syslog(LOG_ERR, "arptab_set: internal wrong cmd");
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		exit(1);
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	case RTM_ADD:
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		rtm->rtm_addrs |= RTA_GATEWAY;
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		rtm->rtm_rmx.rmx_expire = expire_time;
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		rtm->rtm_inits = RTV_EXPIRE;
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		rtm->rtm_flags |= (RTF_HOST | RTF_STATIC);
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		sin_m.sin_other = 0;
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		if (doing_proxy) {
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			if (export_only)
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				sin_m.sin_other = SIN_PROXY;
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			else {
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				rtm->rtm_addrs |= RTA_NETMASK;
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				rtm->rtm_flags &= ~RTF_HOST;
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			}
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		}
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		/* FALLTHROUGH */
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	case RTM_GET:
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		rtm->rtm_addrs |= (RTA_DST | RTA_IFP);
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	}
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#define NEXTADDR(w, s) \
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	if (rtm->rtm_addrs & (w)) { \
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		memcpy(cp, (char *)&s, sizeof(s)); \
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		cp += sizeof(s); \
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	}
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	NEXTADDR(RTA_DST, sin_m);
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	NEXTADDR(RTA_GATEWAY, sdl_m);
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	NEXTADDR(RTA_NETMASK, so_mask);
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	NEXTADDR(RTA_IFP, ifp_m);
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	rtm->rtm_msglen = cp - (char *)&m_rtmsg;
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doit:
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	l = rtm->rtm_msglen;
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	rtm->rtm_seq = ++seq;
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	rtm->rtm_type = cmd;
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	if (write(s, (char *)&m_rtmsg, l) < 0) {
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		if (errno != ESRCH && errno != EEXIST) {
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			syslog(LOG_ERR, "writing to routing socket: %m");
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			return (-1);
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		}
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	}
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	do {
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		l = recv(s, (char *)&m_rtmsg, sizeof(m_rtmsg), MSG_DONTWAIT);
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	} while (l > 0 && (rtm->rtm_version != RTM_VERSION ||
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	    rtm->rtm_seq != seq || rtm->rtm_pid != pid));
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	if (l < 0) {
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		if (errno == EAGAIN || errno == EINTR)
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			goto retry;
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		syslog(LOG_ERR, "arptab_set: read from routing socket: %m");
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	}
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	return (0);
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}
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int
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rtget(struct sockaddr_inarp **sinp, struct sockaddr_dl **sdlp)
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{
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	struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
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	struct sockaddr_inarp *sin = NULL;
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	struct sockaddr_dl *sdl = NULL;
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	struct sockaddr *sa;
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	char *cp;
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	unsigned int i;
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	if (rtmsg(RTM_GET) < 0)
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		return (1);
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	if (rtm->rtm_addrs) {
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		cp = ((char *)rtm + rtm->rtm_hdrlen);
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		for (i = 1; i; i <<= 1) {
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			if (i & rtm->rtm_addrs) {
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				sa = (struct sockaddr *)cp;
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				switch (i) {
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				case RTA_DST:
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					sin = (struct sockaddr_inarp *)sa;
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					break;
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				case RTA_IFP:
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					sdl = (struct sockaddr_dl *)sa;
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					break;
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				default:
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					break;
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				}
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				cp += ROUNDUP(sa->sa_len);
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			}
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		}
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	}
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	if (sin == NULL || sdl == NULL)
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		return (1);
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	*sinp = sin;
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	*sdlp = sdl;
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	return (0);
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}