rtmsg.c revision 32570
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 1.8 1997/02/22 14:21:09 peter 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#include <sys/filio.h> 54#include <sys/time.h> 55 56#include <net/if.h> 57#include <net/if_dl.h> 58#include <net/if_types.h> 59#include <net/route.h> 60 61#include <netinet/in.h> 62#include <netinet/if_ether.h> 63 64#include <arpa/inet.h> 65 66#include <errno.h> 67#include <stdio.h> 68#include <string.h> 69#include <syslog.h> 70#include <unistd.h> 71 72#include "report.h" 73 74 75static int rtmsg __P((int)); 76 77static int s = -1; /* routing socket */ 78 79 80/* 81 * Open the routing socket 82 */ 83static void getsocket () { 84 if (s < 0) { 85 s = socket(PF_ROUTE, SOCK_RAW, 0); 86 if (s < 0) { 87 report(LOG_ERR, "socket %s", strerror(errno)); 88 exit(1); 89 } 90 } else { 91 /* 92 * Drain the socket of any unwanted routing messages. 93 */ 94 int n; 95 char buf[512]; 96 97 ioctl(s, FIONREAD, &n); 98 while (n > 0) { 99 read(s, buf, sizeof buf); 100 ioctl(s, FIONREAD, &n); 101 } 102 } 103} 104 105static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 106static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 107static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 108static int expire_time, flags, export_only, doing_proxy; 109static struct { 110 struct rt_msghdr m_rtm; 111 char m_space[512]; 112} m_rtmsg; 113 114/* 115 * Set an individual arp entry 116 */ 117int bsd_arp_set(ia, eaddr, len) 118 struct in_addr *ia; 119 char *eaddr; 120 int len; 121{ 122 register struct sockaddr_inarp *sin = &sin_m; 123 register struct sockaddr_dl *sdl; 124 register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); 125 u_char *ea; 126 struct timeval time; 127 int op = RTM_ADD; 128 129 getsocket(); 130 sdl_m = blank_sdl; 131 sin_m = blank_sin; 132 sin->sin_addr = *ia; 133 134 ea = (u_char *)LLADDR(&sdl_m); 135 bcopy(eaddr, ea, len); 136 sdl_m.sdl_alen = len; 137 doing_proxy = flags = export_only = expire_time = 0; 138 139 /* make arp entry temporary */ 140 gettimeofday(&time, 0); 141 expire_time = time.tv_sec + 20 * 60; 142 143tryagain: 144 if (rtmsg(RTM_GET) < 0) { 145 report(LOG_WARNING, "rtmget: %s", strerror(errno)); 146 return (1); 147 } 148 sin = (struct sockaddr_inarp *)(rtm + 1); 149 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 150 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 151 if (sdl->sdl_family == AF_LINK && 152 (rtm->rtm_flags & RTF_LLINFO) && 153 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 154 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 155 case IFT_ISO88024: case IFT_ISO88025: 156 op = RTM_CHANGE; 157 goto overwrite; 158 } 159 if (doing_proxy == 0) { 160 report(LOG_WARNING, "set: can only proxy for %s\n", 161 inet_ntoa(sin->sin_addr)); 162 return (1); 163 } 164 if (sin_m.sin_other & SIN_PROXY) { 165 report(LOG_WARNING, 166 "set: proxy entry exists for non 802 device\n"); 167 return(1); 168 } 169 sin_m.sin_other = SIN_PROXY; 170 export_only = 1; 171 goto tryagain; 172 } 173overwrite: 174 if (sdl->sdl_family != AF_LINK) { 175 report(LOG_WARNING, 176 "cannot intuit interface index and type for %s\n", 177 inet_ntoa(sin->sin_addr)); 178 return (1); 179 } 180 sdl_m.sdl_type = sdl->sdl_type; 181 sdl_m.sdl_index = sdl->sdl_index; 182 return (rtmsg(op)); 183} 184 185 186static int rtmsg(cmd) 187 int cmd; 188{ 189 static int seq; 190 int rlen; 191 register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 192 register char *cp = m_rtmsg.m_space; 193 register int l; 194 195 errno = 0; 196 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 197 rtm->rtm_flags = flags; 198 rtm->rtm_version = RTM_VERSION; 199 200 switch (cmd) { 201 default: 202 report(LOG_ERR, "set_arp: internal wrong cmd - exiting"); 203 exit(1); 204 case RTM_ADD: 205 case RTM_CHANGE: 206 rtm->rtm_addrs |= RTA_GATEWAY; 207 rtm->rtm_rmx.rmx_expire = expire_time; 208 rtm->rtm_inits = RTV_EXPIRE; 209 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 210 sin_m.sin_other = 0; 211 if (doing_proxy) { 212 if (export_only) 213 sin_m.sin_other = SIN_PROXY; 214 else { 215 rtm->rtm_addrs |= RTA_NETMASK; 216 rtm->rtm_flags &= ~RTF_HOST; 217 } 218 } 219 /* FALLTHROUGH */ 220 case RTM_GET: 221 rtm->rtm_addrs |= RTA_DST; 222 } 223#define NEXTADDR(w, s) \ 224 if (rtm->rtm_addrs & (w)) { \ 225 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);} 226 227 NEXTADDR(RTA_DST, sin_m); 228 NEXTADDR(RTA_GATEWAY, sdl_m); 229 NEXTADDR(RTA_NETMASK, so_mask); 230 231 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 232 233 l = rtm->rtm_msglen; 234 rtm->rtm_seq = ++seq; 235 rtm->rtm_type = cmd; 236 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 237 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){ 238 report(LOG_WARNING, "writing to routing socket: %s", 239 strerror(errno)); 240 return (-1); 241 } 242 } 243 do { 244 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 245 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid())); 246 if (l < 0) 247 report(LOG_WARNING, "arp: read from routing socket: %s\n", 248 strerror(errno)); 249 return (0); 250} 251 252#endif /* BSD */ 253#endif /* BSD >= 199306 */ 254