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. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 /* 37 * from arp.c 8.2 (Berkeley) 1/2/94 38 * $FreeBSD: src/libexec/bootpd/rtmsg.c,v 1.10 1999/08/28 00:09:19 peter Exp $ 39 * $DragonFly: src/libexec/bootpd/rtmsg.c,v 1.4 2007/11/25 01:28:23 swildner Exp $ 40 */ 41 42 #include <sys/param.h> 43 /* 44 * Verify that we are at least 4.4 BSD 45 */ 46 #if defined(BSD) 47 #if BSD >= 199306 48 49 #include <sys/socket.h> 50 #include <sys/filio.h> 51 #include <sys/time.h> 52 53 #include <net/if.h> 54 #include <net/if_dl.h> 55 #include <net/if_types.h> 56 #include <net/route.h> 57 58 #include <netinet/in.h> 59 #include <netinet/if_ether.h> 60 61 #include <arpa/inet.h> 62 63 #include <errno.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <syslog.h> 68 #include <unistd.h> 69 70 #include "report.h" 71 72 73 static int rtmsg (int); 74 75 static int s = -1; /* routing socket */ 76 77 78 /* 79 * Open the routing socket 80 */ 81 static void 82 getsocket(void) 83 { 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 } 104 105 static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; 106 static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; 107 static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; 108 static int expire_time, flags, export_only, doing_proxy; 109 static struct { 110 struct rt_msghdr m_rtm; 111 char m_space[512]; 112 } m_rtmsg; 113 114 /* 115 * Set an individual arp entry 116 */ 117 int 118 bsd_arp_set(struct in_addr *ia, char *eaddr, int len) 119 { 120 struct sockaddr_inarp *sin = &sin_m; 121 struct sockaddr_dl *sdl; 122 struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); 123 u_char *ea; 124 struct timespec tp; 125 int op = RTM_ADD; 126 127 getsocket(); 128 sdl_m = blank_sdl; 129 sin_m = blank_sin; 130 sin->sin_addr = *ia; 131 132 ea = (u_char *)LLADDR(&sdl_m); 133 bcopy(eaddr, ea, len); 134 sdl_m.sdl_alen = len; 135 doing_proxy = flags = export_only = expire_time = 0; 136 137 /* make arp entry temporary */ 138 clock_gettime(CLOCK_MONOTONIC, &tp); 139 expire_time = tp.tv_sec + 20 * 60; 140 141 tryagain: 142 if (rtmsg(RTM_GET) < 0) { 143 report(LOG_WARNING, "rtmget: %s", strerror(errno)); 144 return (1); 145 } 146 sin = (struct sockaddr_inarp *)(rtm + 1); 147 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); 148 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { 149 if (sdl->sdl_family == AF_LINK && 150 (rtm->rtm_flags & RTF_LLINFO) && 151 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { 152 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: 153 case IFT_ISO88024: case IFT_ISO88025: 154 op = RTM_CHANGE; 155 goto overwrite; 156 } 157 if (doing_proxy == 0) { 158 report(LOG_WARNING, "set: can only proxy for %s\n", 159 inet_ntoa(sin->sin_addr)); 160 return (1); 161 } 162 if (sin_m.sin_other & SIN_PROXY) { 163 report(LOG_WARNING, 164 "set: proxy entry exists for non 802 device\n"); 165 return(1); 166 } 167 sin_m.sin_other = SIN_PROXY; 168 export_only = 1; 169 goto tryagain; 170 } 171 overwrite: 172 if (sdl->sdl_family != AF_LINK) { 173 report(LOG_WARNING, 174 "cannot intuit interface index and type for %s\n", 175 inet_ntoa(sin->sin_addr)); 176 return (1); 177 } 178 sdl_m.sdl_type = sdl->sdl_type; 179 sdl_m.sdl_index = sdl->sdl_index; 180 return (rtmsg(op)); 181 } 182 183 184 static int 185 rtmsg(int cmd) 186 { 187 static int seq; 188 int rlen; 189 struct rt_msghdr *rtm = &m_rtmsg.m_rtm; 190 char *cp = m_rtmsg.m_space; 191 int l; 192 193 errno = 0; 194 bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); 195 rtm->rtm_flags = flags; 196 rtm->rtm_version = RTM_VERSION; 197 198 switch (cmd) { 199 default: 200 report(LOG_ERR, "set_arp: internal wrong cmd - exiting"); 201 exit(1); 202 case RTM_ADD: 203 case RTM_CHANGE: 204 rtm->rtm_addrs |= RTA_GATEWAY; 205 rtm->rtm_rmx.rmx_expire = expire_time; 206 rtm->rtm_inits = RTV_EXPIRE; 207 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 208 sin_m.sin_other = 0; 209 if (doing_proxy) { 210 if (export_only) 211 sin_m.sin_other = SIN_PROXY; 212 else { 213 rtm->rtm_addrs |= RTA_NETMASK; 214 rtm->rtm_flags &= ~RTF_HOST; 215 } 216 } 217 /* FALLTHROUGH */ 218 case RTM_GET: 219 rtm->rtm_addrs |= RTA_DST; 220 } 221 #define NEXTADDR(w, s) \ 222 if (rtm->rtm_addrs & (w)) { \ 223 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);} 224 225 NEXTADDR(RTA_DST, sin_m); 226 NEXTADDR(RTA_GATEWAY, sdl_m); 227 NEXTADDR(RTA_NETMASK, so_mask); 228 229 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 230 231 l = rtm->rtm_msglen; 232 rtm->rtm_seq = ++seq; 233 rtm->rtm_type = cmd; 234 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 235 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){ 236 report(LOG_WARNING, "writing to routing socket: %s", 237 strerror(errno)); 238 return (-1); 239 } 240 } 241 do { 242 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 243 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid())); 244 if (l < 0) 245 report(LOG_WARNING, "arp: read from routing socket: %s\n", 246 strerror(errno)); 247 return (0); 248 } 249 250 #endif /* BSD */ 251 #endif /* BSD >= 199306 */ 252