/* * Copyright (c) 1984, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Sun Microsystems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static char copyright[] = "@(#) Copyright (c) 1984, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint static char sccsid[] = "@(#)arp.c 8.2 (Berkeley) 1/2/94"; #endif /* not lint */ /* * set arp table entries */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static pid_t pid; static int s = -1; void getsocket() { s = socket(PF_ROUTE, SOCK_RAW, 0); if (s < 0) { perror("arp: socket"); exit(1); } } struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}}; struct sockaddr_inarp blank_sin = {sizeof(blank_sin), AF_INET }, sin_m; struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m; int expire_time, flags, export_only, doing_proxy; struct { struct rt_msghdr m_rtm; char m_space[512]; } m_rtmsg; int arptab_set(u_char *, u_int32_t); int rtmsg(int); /* * Set an individual arp entry */ int arptab_set(eaddr, host) u_char *eaddr; u_int32_t host; { struct sockaddr_inarp *sin = &sin_m; struct sockaddr_dl *sdl; struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); struct timeval time; int rt; getsocket(); pid = getpid(); sdl_m = blank_sdl; sin_m = blank_sin; sin->sin_addr.s_addr = host; memcpy((u_char *)LLADDR(&sdl_m), (char *)eaddr, 6); sdl_m.sdl_alen = 6; doing_proxy = flags = export_only = expire_time = 0; gettimeofday(&time, 0); expire_time = time.tv_sec + 20 * 60; tryagain: if (rtmsg(RTM_GET) < 0) { syslog(LOG_ERR,"%s: %m", inet_ntoa(sin->sin_addr)); close(s); s = -1; return (1); } sin = (struct sockaddr_inarp *)(rtm + 1); sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin); if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) { if (sdl->sdl_family == AF_LINK && (rtm->rtm_flags & RTF_LLINFO) && !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) { case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023: case IFT_ISO88024: case IFT_ISO88025: goto overwrite; } if (doing_proxy == 0) { syslog(LOG_ERR, "arptab_set: can only proxy for %s", inet_ntoa(sin->sin_addr)); close(s); s = -1; return (1); } if (sin_m.sin_other & SIN_PROXY) { syslog(LOG_ERR, "arptab_set: proxy entry exists for non 802 device"); close(s); s = -1; return(1); } sin_m.sin_other = SIN_PROXY; export_only = 1; goto tryagain; } overwrite: if (sdl->sdl_family != AF_LINK) { syslog(LOG_ERR, "arptab_set: cannot intuit interface index and type for %s", inet_ntoa(sin->sin_addr)); close(s); s = -1; return (1); } sdl_m.sdl_type = sdl->sdl_type; sdl_m.sdl_index = sdl->sdl_index; rt = rtmsg(RTM_ADD); close(s); s = -1; return (rt); } int rtmsg(cmd) int cmd; { static int seq; int rlen; struct rt_msghdr *rtm = &m_rtmsg.m_rtm; char *cp = m_rtmsg.m_space; int l; errno = 0; if (cmd == RTM_DELETE) goto doit; memset((char *)&m_rtmsg, 0, sizeof(m_rtmsg)); rtm->rtm_flags = flags; rtm->rtm_version = RTM_VERSION; switch (cmd) { default: syslog(LOG_ERR, "arptab_set: internal wrong cmd"); exit(1); case RTM_ADD: rtm->rtm_addrs |= RTA_GATEWAY; rtm->rtm_rmx.rmx_expire = expire_time; rtm->rtm_inits = RTV_EXPIRE; rtm->rtm_flags |= (RTF_HOST | RTF_STATIC); sin_m.sin_other = 0; if (doing_proxy) { if (export_only) sin_m.sin_other = SIN_PROXY; else { rtm->rtm_addrs |= RTA_NETMASK; rtm->rtm_flags &= ~RTF_HOST; } } /* FALLTHROUGH */ case RTM_GET: rtm->rtm_addrs |= RTA_DST; } #define NEXTADDR(w, s) \ if (rtm->rtm_addrs & (w)) { \ memcpy(cp, (char *)&s, sizeof(s)); \ cp += sizeof(s); \ } NEXTADDR(RTA_DST, sin_m); NEXTADDR(RTA_GATEWAY, sdl_m); NEXTADDR(RTA_NETMASK, so_mask); rtm->rtm_msglen = cp - (char *)&m_rtmsg; doit: l = rtm->rtm_msglen; rtm->rtm_seq = ++seq; rtm->rtm_type = cmd; if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) { if (errno != ESRCH && errno != EEXIST) { syslog(LOG_ERR, "writing to routing socket: %m"); return (-1); } } do { l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg)); } while (l > 0 && (rtm->rtm_seq != seq || rtm->rtm_pid != pid)); if (l < 0) syslog(LOG_ERR, "arptab_set: read from routing socket: %m"); return (0); }