rtmsg.c revision 22989
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 * $Id$ 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_var.h> /* needed for if_ether.h XXX */ 58#include <net/if_dl.h> 59#include <net/if_types.h> 60#include <net/route.h> 61 62#include <netinet/in.h> 63#include <netinet/if_ether.h> 64 65#include <arpa/inet.h> 66 67#include <errno.h> 68#include <stdio.h> 69#include <string.h> 70#include <syslog.h> 71#include <unistd.h> 72 73#include "report.h" 74 75 76static int rtmsg __P((int)); 77 78static int s = -1; /* routing socket */ 79 80 81/* 82 * Open the routing socket 83 */ 84static void getsocket () { 85 if (s < 0) { 86 s = socket(PF_ROUTE, SOCK_RAW, 0); 87 if (s < 0) { 88 report(LOG_ERR, "socket %s", strerror(errno)); 89 exit(1); 90 } 91 } else { 92 /* 93 * Drain the socket of any unwanted routing messages. 94 */ 95 int n; 96 char buf[512]; 97 98 ioctl(s, FIONREAD, &n); 99 while (n > 0) { 100 read(s, buf, sizeof buf); 101 ioctl(s, FIONREAD, &n); 102 } 103 } 104} 105 106static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 107static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 108static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 109static int expire_time, flags, export_only, doing_proxy; 110static struct { 111 struct rt_msghdr m_rtm; 112 char m_space[512]; 113} m_rtmsg; 114 115/* 116 * Set an individual arp entry 117 */ 118int bsd_arp_set(ia, eaddr, len) 119 struct in_addr *ia; 120 char *eaddr; 121 int len; 122{ 123 register struct sockaddr_inarp *sin = &sin_m; 124 register struct sockaddr_dl *sdl; 125 register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); 126 u_char *ea; 127 struct timeval time; 128 int op = RTM_ADD; 129 130 getsocket(); 131 sdl_m = blank_sdl; 132 sin_m = blank_sin; 133 sin->sin_addr = *ia; 134 135 ea = (u_char *)LLADDR(&sdl_m); 136 bcopy(eaddr, ea, len); 137 sdl_m.sdl_alen = len; 138 doing_proxy = flags = export_only = expire_time = 0; 139 140 /* make arp entry temporary */ 141 gettimeofday(&time, 0); 142 expire_time = time.tv_sec + 20 * 60; 143 144tryagain: 145 if (rtmsg(RTM_GET) < 0) { 146 report(LOG_WARNING, "rtmget: %s", strerror(errno)); 147 return (1); 148 } 149 sin = (struct sockaddr_inarp *)(rtm + 1); 150 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 151 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 152 if (sdl->sdl_family == AF_LINK && 153 (rtm->rtm_flags & RTF_LLINFO) && 154 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 155 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 156 case IFT_ISO88024: case IFT_ISO88025: 157 op = RTM_CHANGE; 158 goto overwrite; 159 } 160 if (doing_proxy == 0) { 161 report(LOG_WARNING, "set: can only proxy for %s\n", 162 inet_ntoa(sin->sin_addr)); 163 return (1); 164 } 165 if (sin_m.sin_other & SIN_PROXY) { 166 report(LOG_WARNING, 167 "set: proxy entry exists for non 802 device\n"); 168 return(1); 169 } 170 sin_m.sin_other = SIN_PROXY; 171 export_only = 1; 172 goto tryagain; 173 } 174overwrite: 175 if (sdl->sdl_family != AF_LINK) { 176 report(LOG_WARNING, 177 "cannot intuit interface index and type for %s\n", 178 inet_ntoa(sin->sin_addr)); 179 return (1); 180 } 181 sdl_m.sdl_type = sdl->sdl_type; 182 sdl_m.sdl_index = sdl->sdl_index; 183 return (rtmsg(op)); 184} 185 186 187static int rtmsg(cmd) 188 int cmd; 189{ 190 static int seq; 191 int rlen; 192 register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 193 register char *cp = m_rtmsg.m_space; 194 register int l; 195 196 errno = 0; 197 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 198 rtm->rtm_flags = flags; 199 rtm->rtm_version = RTM_VERSION; 200 201 switch (cmd) { 202 default: 203 report(LOG_ERR, "set_arp: internal wrong cmd - exiting"); 204 exit(1); 205 case RTM_ADD: 206 case RTM_CHANGE: 207 rtm->rtm_addrs |= RTA_GATEWAY; 208 rtm->rtm_rmx.rmx_expire = expire_time; 209 rtm->rtm_inits = RTV_EXPIRE; 210 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 211 sin_m.sin_other = 0; 212 if (doing_proxy) { 213 if (export_only) 214 sin_m.sin_other = SIN_PROXY; 215 else { 216 rtm->rtm_addrs |= RTA_NETMASK; 217 rtm->rtm_flags &= ~RTF_HOST; 218 } 219 } 220 /* FALLTHROUGH */ 221 case RTM_GET: 222 rtm->rtm_addrs |= RTA_DST; 223 } 224#define NEXTADDR(w, s) \ 225 if (rtm->rtm_addrs & (w)) { \ 226 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);} 227 228 NEXTADDR(RTA_DST, sin_m); 229 NEXTADDR(RTA_GATEWAY, sdl_m); 230 NEXTADDR(RTA_NETMASK, so_mask); 231 232 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 233 234 l = rtm->rtm_msglen; 235 rtm->rtm_seq = ++seq; 236 rtm->rtm_type = cmd; 237 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 238 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){ 239 report(LOG_WARNING, "writing to routing socket: %s", 240 strerror(errno)); 241 return (-1); 242 } 243 } 244 do { 245 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 246 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid())); 247 if (l < 0) 248 report(LOG_WARNING, "arp: read from routing socket: %s\n", 249 strerror(errno)); 250 return (0); 251} 252 253#endif /* BSD */ 254#endif /* BSD >= 199306 */ 255