1 /* $NetBSD: mkarp.c,v 1.1 1997/11/24 18:43:14 is Exp $ */ 2 3 /* 4 * Copyright (c) 1984, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Sun Microsystems, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 __COPYRIGHT("@(#) Copyright (c) 1984, 1993\n\ 42 The Regents of the University of California. All rights reserved.\n"); 43 #endif /* not lint */ 44 45 #ifndef lint 46 #if 0 47 static char sccsid[] = "@(#)arp.c 8.3 (Berkeley) 4/28/95"; 48 #else 49 __RCSID("$NetBSD: mkarp.c,v 1.1 1997/11/24 18:43:14 is Exp $"); 50 #endif 51 #endif /* not lint */ 52 53 /* 54 * mkarp - set an arp table entry 55 */ 56 57 #include <sys/param.h> 58 #include <sys/file.h> 59 #include <sys/socket.h> 60 #include <sys/sysctl.h> 61 62 #include <net/if.h> 63 #include <net/if_dl.h> 64 #include <net/if_ether.h> 65 #include <net/if_types.h> 66 #include <net/route.h> 67 #include <netinet/in.h> 68 #include <netinet/if_inarp.h> 69 #include <arpa/inet.h> 70 71 #include <err.h> 72 #include <errno.h> 73 #include <netdb.h> 74 #include <nlist.h> 75 #include <paths.h> 76 #include <stdio.h> 77 #include <stdlib.h> 78 #include <string.h> 79 #include <unistd.h> 80 81 #include "mkarp.h" 82 83 int rtmsg __P((int, struct rt_msghdr *, struct sockaddr_inarp *, 84 struct sockaddr_dl *)); 85 struct { 86 struct rt_msghdr m_rtm; 87 char m_space[512]; 88 } m_rtmsg; 89 90 /* 91 * Set an individual arp entry 92 */ 93 int 94 mkarp(haddr, ipaddr) 95 u_char *haddr; 96 u_int32_t ipaddr; 97 { 98 static struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }; 99 static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }; 100 101 struct sockaddr_inarp *sin; 102 struct sockaddr_dl *sdl; 103 struct rt_msghdr *rtm; 104 u_int8_t *p, *endp; 105 106 struct sockaddr_inarp sin_m; 107 struct sockaddr_dl sdl_m; 108 109 sin = &sin_m; 110 rtm = &(m_rtmsg.m_rtm); 111 112 sdl_m = blank_sdl; /* struct copy */ 113 sin_m = blank_sin; /* struct copy */ 114 115 sin->sin_addr.s_addr = ipaddr; 116 117 p = LLADDR(&sdl_m); 118 endp = ((caddr_t)&sdl_m) + sdl_m.sdl_len; 119 if (endp > (p + 6)) 120 endp = p + 6; 121 122 while (p < endp) { 123 *p++ = *haddr++; 124 } 125 126 rtm->rtm_flags = 0; 127 128 if (rtmsg(RTM_GET, rtm, &sin_m, &sdl_m) < 0) { 129 #if 0 130 warn("%s", host); 131 #endif 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: case IFT_ARCNET: 142 goto overwrite; 143 } 144 #if 0 145 (void)printf("set: can only proxy for %s\n", host); 146 #endif 147 return (1); 148 } 149 overwrite: 150 if (sdl->sdl_family != AF_LINK) { 151 #if 0 152 (void)printf("cannot intuit interface index and type for %s\n", 153 host); 154 #endif 155 return (1); 156 } 157 sdl_m.sdl_type = sdl->sdl_type; 158 sdl_m.sdl_index = sdl->sdl_index; 159 return (rtmsg(RTM_ADD, rtm, &sin_m, &sdl_m)); 160 } 161 162 int 163 rtmsg(cmd, rtm, sin_m, sdl_m) 164 int cmd; 165 struct rt_msghdr *rtm; 166 struct sockaddr_inarp *sin_m; 167 struct sockaddr_dl *sdl_m; 168 { 169 static int seq; 170 static int s = -1; 171 int rlen; 172 char *cp; 173 int l; 174 pid_t pid; 175 struct timeval time; 176 177 rtm = &m_rtmsg.m_rtm; 178 cp = m_rtmsg.m_space; 179 errno = 0; 180 181 if (s < 0) { 182 s = socket(PF_ROUTE, SOCK_RAW, 0); 183 if (s < 0) 184 err(1, "socket"); 185 } 186 pid = getpid(); 187 188 (void)memset(&m_rtmsg, 0, sizeof(m_rtmsg)); 189 rtm->rtm_version = RTM_VERSION; 190 191 switch (cmd) { 192 default: 193 errx(1, "internal wrong cmd"); 194 /*NOTREACHED*/ 195 case RTM_ADD: 196 rtm->rtm_addrs |= RTA_GATEWAY; 197 (void)gettimeofday(&time, 0); 198 rtm->rtm_rmx.rmx_expire = time.tv_sec + 20 * 60; 199 rtm->rtm_inits = RTV_EXPIRE; 200 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); 201 sin_m->sin_other = 0; 202 203 /* FALLTHROUGH */ 204 case RTM_GET: 205 rtm->rtm_addrs |= RTA_DST; 206 } 207 #define NEXTADDR(w, s) \ 208 if (rtm->rtm_addrs & (w)) { \ 209 (void)memcpy(cp, s, ((struct sockaddr *)s)->sa_len); \ 210 cp += ((struct sockaddr *)s)->sa_len;} 211 212 NEXTADDR(RTA_DST, sin_m); 213 NEXTADDR(RTA_GATEWAY, sdl_m); 214 215 rtm->rtm_msglen = cp - (char *)&m_rtmsg; 216 217 l = rtm->rtm_msglen; 218 rtm->rtm_seq = ++seq; 219 rtm->rtm_type = cmd; 220 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { 221 if (errno != ESRCH && errno != EEXIST) { 222 warn("writing to routing socket"); 223 return (-1); 224 } 225 } 226 do { 227 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); 228 } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid)); 229 if (l < 0) 230 warn("read from routing socket"); 231 return (0); 232 } 233