rtmsg.c revision 5661
1/* 2 * Copyright (c) 1984, 1993 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 1994 5 * Geoffrey M. Rehmet, All rights reserved. 6 * 7 * This code is derived from software which forms part of the 4.4-Lite 8 * Berkeley software distribution, which was in derived from software 9 * contributed to Berkeley by Sun Microsystems, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40/* 41 * from arp.c 8.2 (Berkeley) 1/2/94 42 * $Id: rtmsg.c,v 1.1.1.1 1994/09/30 05:45:06 pst Exp $ 43 */ 44 45#include <sys/param.h> 46/* 47 * Verify that we are at least 4.4 BSD 48 */ 49#if defined(BSD) 50#if BSD >= 199306 51 52#include <sys/socket.h> 53 54#include <net/if.h> 55#include <net/if_dl.h> 56#include <net/if_types.h> 57#include <net/route.h> 58 59#include <netinet/in.h> 60#include <netinet/if_ether.h> 61 62#include <arpa/inet.h> 63 64#include <errno.h> 65#include <stdio.h> 66#include <string.h> 67#include <syslog.h> 68#include <unistd.h> 69 70#include "report.h" 71 72 73static int rtmsg __P((int)); 74 75static int s = -1; /* routing socket */ 76 77 78/* 79 * Open the routing socket 80 */ 81static void getsocket () { 82 if (s < 0) { 83 s = socket(PF_ROUTE, SOCK_RAW, 0); 84 if (s < 0) { 85 report(LOG_ERR, "socket %s", strerror(errno)); 86 exit(1); 87 } 88 } 89} 90 91static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 92static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 93static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 94static int expire_time, flags, export_only, doing_proxy; 95static struct { 96 struct rt_msghdr m_rtm; 97 char m_space[512]; 98} m_rtmsg; 99 100/* 101 * Set an individual arp entry 102 */ 103int bsd_arp_set(ia, eaddr, len) 104 struct in_addr *ia; 105 char *eaddr; 106 int len; 107{ 108 register struct sockaddr_inarp *sin = &sin_m; 109 register struct sockaddr_dl *sdl; 110 register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); 111 u_char *ea; 112 struct timeval time; 113 int op = RTM_ADD; 114 115 getsocket(); 116 sdl_m = blank_sdl; 117 sin_m = blank_sin; 118 sin->sin_addr = *ia; 119 120 ea = (u_char *)LLADDR(&sdl_m); 121 bcopy(eaddr, ea, len); 122 sdl_m.sdl_alen = len; 123 doing_proxy = flags = export_only = expire_time = 0; 124 125 /* make arp entry temporary */ 126 gettimeofday(&time, 0); 127 expire_time = time.tv_sec + 20 * 60; 128 129tryagain: 130 if (rtmsg(RTM_GET) < 0) { 131 report(LOG_WARNING, "rtmget: %s", strerror(errno)); 132 return (1); 133 } 134 sin = (struct sockaddr_inarp *)(rtm + 1); 135 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 136 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 137 if (sdl->sdl_family == AF_LINK && 138 (rtm->rtm_flags & RTF_LLINFO) && 139 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 140 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 141 case IFT_ISO88024: case IFT_ISO88025: 142 op = RTM_CHANGE; 143 goto overwrite; 144 } 145 if (doing_proxy == 0) { 146 report(LOG_WARNING, "set: can only proxy for %s\n", 147 inet_ntoa(sin->sin_addr)); 148 return (1); 149 } 150 if (sin_m.sin_other & SIN_PROXY) { 151 report(LOG_WARNING, 152 "set: proxy entry exists for non 802 device\n"); 153 return(1); 154 } 155 sin_m.sin_other = SIN_PROXY; 156 export_only = 1; 157 goto tryagain; 158 } 159overwrite: 160 if (sdl->sdl_family != AF_LINK) { 161 report(LOG_WARNING, 162 "cannot intuit interface index and type for %s\n", 163 inet_ntoa(sin->sin_addr)); 164 return (1); 165 } 166 sdl_m.sdl_type = sdl->sdl_type; 167 sdl_m.sdl_index = sdl->sdl_index; 168 return (rtmsg(op)); 169} 170 171 172static int rtmsg(cmd) 173 int cmd; 174{ 175 static int seq; 176 int rlen; 177 register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 178 register char *cp = m_rtmsg.m_space; 179 register int l; 180 181 errno = 0; 182 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 183 rtm->rtm_flags = flags; 184 rtm->rtm_version = RTM_VERSION; 185 186 switch (cmd) { 187 default: 188 report(LOG_ERR, "set_arp: internal wrong cmd - exiting"); 189 exit(1); 190 case RTM_ADD: 191 case RTM_CHANGE: 192 rtm->rtm_addrs |= RTA_GATEWAY; 193 rtm->rtm_rmx.rmx_expire = expire_time; 194 rtm->rtm_inits = RTV_EXPIRE; 195 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 196 sin_m.sin_other = 0; 197 if (doing_proxy) { 198 if (export_only) 199 sin_m.sin_other = SIN_PROXY; 200 else { 201 rtm->rtm_addrs |= RTA_NETMASK; 202 rtm->rtm_flags &= ~RTF_HOST; 203 } 204 } 205 /* FALLTHROUGH */ 206 case RTM_GET: 207 rtm->rtm_addrs |= RTA_DST; 208 } 209#define NEXTADDR(w, s) \ 210 if (rtm->rtm_addrs & (w)) { \ 211 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);} 212 213 NEXTADDR(RTA_DST, sin_m); 214 NEXTADDR(RTA_GATEWAY, sdl_m); 215 NEXTADDR(RTA_NETMASK, so_mask); 216 217 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 218 219 l = rtm->rtm_msglen; 220 rtm->rtm_seq = ++seq; 221 rtm->rtm_type = cmd; 222 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 223 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){ 224 report(LOG_WARNING, "writing to routing socket: %s", 225 strerror(errno)); 226 return (-1); 227 } 228 } 229 do { 230 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 231 } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != getpid())); 232 if (l < 0) 233 report(LOG_WARNING, "arp: read from routing socket: %s\n", 234 strerror(errno)); 235 return (0); 236} 237 238#endif /* BSD */ 239#endif /* BSD >= 199306 */ 240