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 * $FreeBSD: src/libexec/bootpd/rtmsg.c,v 1.10 1999/08/28 00:09:19 peter Exp $ 43 * $DragonFly: src/libexec/bootpd/rtmsg.c,v 1.4 2007/11/25 01:28:23 swildner Exp $ 44 */ 45 46 #include <sys/param.h> 47 /* 48 * Verify that we are at least 4.4 BSD 49 */ 50 #if defined(BSD) 51 #if BSD >= 199306 52 53 #include <sys/socket.h> 54 #include <sys/filio.h> 55 #include <sys/time.h> 56 57 #include <net/if.h> 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 <stdlib.h> 70 #include <string.h> 71 #include <syslog.h> 72 #include <unistd.h> 73 74 #include "report.h" 75 76 77 static int rtmsg (int); 78 79 static int s = -1; /* routing socket */ 80 81 82 /* 83 * Open the routing socket 84 */ 85 static void getsocket () { 86 if (s < 0) { 87 s = socket(PF_ROUTE, SOCK_RAW, 0); 88 if (s < 0) { 89 report(LOG_ERR, "socket %s", strerror(errno)); 90 exit(1); 91 } 92 } else { 93 /* 94 * Drain the socket of any unwanted routing messages. 95 */ 96 int n; 97 char buf[512]; 98 99 ioctl(s, FIONREAD, &n); 100 while (n > 0) { 101 read(s, buf, sizeof buf); 102 ioctl(s, FIONREAD, &n); 103 } 104 } 105 } 106 107 static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 108 static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 109 static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 110 static int expire_time, flags, export_only, doing_proxy; 111 static struct { 112 struct rt_msghdr m_rtm; 113 char m_space[512]; 114 } m_rtmsg; 115 116 /* 117 * Set an individual arp entry 118 */ 119 int bsd_arp_set(ia, eaddr, len) 120 struct in_addr *ia; 121 char *eaddr; 122 int len; 123 { 124 register struct sockaddr_inarp *sin = &sin_m; 125 register struct sockaddr_dl *sdl; 126 register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); 127 u_char *ea; 128 struct timeval time; 129 int op = RTM_ADD; 130 131 getsocket(); 132 sdl_m = blank_sdl; 133 sin_m = blank_sin; 134 sin->sin_addr = *ia; 135 136 ea = (u_char *)LLADDR(&sdl_m); 137 bcopy(eaddr, ea, len); 138 sdl_m.sdl_alen = len; 139 doing_proxy = flags = export_only = expire_time = 0; 140 141 /* make arp entry temporary */ 142 gettimeofday(&time, 0); 143 expire_time = time.tv_sec + 20 * 60; 144 145 tryagain: 146 if (rtmsg(RTM_GET) < 0) { 147 report(LOG_WARNING, "rtmget: %s", strerror(errno)); 148 return (1); 149 } 150 sin = (struct sockaddr_inarp *)(rtm + 1); 151 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 152 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 153 if (sdl->sdl_family == AF_LINK && 154 (rtm->rtm_flags & RTF_LLINFO) && 155 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 156 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 157 case IFT_ISO88024: case IFT_ISO88025: 158 op = RTM_CHANGE; 159 goto overwrite; 160 } 161 if (doing_proxy == 0) { 162 report(LOG_WARNING, "set: can only proxy for %s\n", 163 inet_ntoa(sin->sin_addr)); 164 return (1); 165 } 166 if (sin_m.sin_other & SIN_PROXY) { 167 report(LOG_WARNING, 168 "set: proxy entry exists for non 802 device\n"); 169 return(1); 170 } 171 sin_m.sin_other = SIN_PROXY; 172 export_only = 1; 173 goto tryagain; 174 } 175 overwrite: 176 if (sdl->sdl_family != AF_LINK) { 177 report(LOG_WARNING, 178 "cannot intuit interface index and type for %s\n", 179 inet_ntoa(sin->sin_addr)); 180 return (1); 181 } 182 sdl_m.sdl_type = sdl->sdl_type; 183 sdl_m.sdl_index = sdl->sdl_index; 184 return (rtmsg(op)); 185 } 186 187 188 static int rtmsg(cmd) 189 int cmd; 190 { 191 static int seq; 192 int rlen; 193 register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 194 register char *cp = m_rtmsg.m_space; 195 register int l; 196 197 errno = 0; 198 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 199 rtm->rtm_flags = flags; 200 rtm->rtm_version = RTM_VERSION; 201 202 switch (cmd) { 203 default: 204 report(LOG_ERR, "set_arp: internal wrong cmd - exiting"); 205 exit(1); 206 case RTM_ADD: 207 case RTM_CHANGE: 208 rtm->rtm_addrs |= RTA_GATEWAY; 209 rtm->rtm_rmx.rmx_expire = expire_time; 210 rtm->rtm_inits = RTV_EXPIRE; 211 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 212 sin_m.sin_other = 0; 213 if (doing_proxy) { 214 if (export_only) 215 sin_m.sin_other = SIN_PROXY; 216 else { 217 rtm->rtm_addrs |= RTA_NETMASK; 218 rtm->rtm_flags &= ~RTF_HOST; 219 } 220 } 221 /* FALLTHROUGH */ 222 case RTM_GET: 223 rtm->rtm_addrs |= RTA_DST; 224 } 225 #define NEXTADDR(w, s) \ 226 if (rtm->rtm_addrs & (w)) { \ 227 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);} 228 229 NEXTADDR(RTA_DST, sin_m); 230 NEXTADDR(RTA_GATEWAY, sdl_m); 231 NEXTADDR(RTA_NETMASK, so_mask); 232 233 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 234 235 l = rtm->rtm_msglen; 236 rtm->rtm_seq = ++seq; 237 rtm->rtm_type = cmd; 238 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 239 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){ 240 report(LOG_WARNING, "writing to routing socket: %s", 241 strerror(errno)); 242 return (-1); 243 } 244 } 245 do { 246 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 247 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid())); 248 if (l < 0) 249 report(LOG_WARNING, "arp: read from routing socket: %s\n", 250 strerror(errno)); 251 return (0); 252 } 253 254 #endif /* BSD */ 255 #endif /* BSD >= 199306 */ 256