diff options
Diffstat (limited to 'usr.sbin/arp/arp.c')
-rw-r--r-- | usr.sbin/arp/arp.c | 514 |
1 files changed, 514 insertions, 0 deletions
diff --git a/usr.sbin/arp/arp.c b/usr.sbin/arp/arp.c new file mode 100644 index 0000000..2182dc8 --- /dev/null +++ b/usr.sbin/arp/arp.c @@ -0,0 +1,514 @@ +/* + * 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 */ + +/* + * arp - display, set, and delete arp table entries + */ + + +#include <sys/param.h> +#include <sys/file.h> +#include <sys/socket.h> +#include <sys/sysctl.h> + +#include <net/if.h> +#include <net/if_dl.h> +#include <net/if_types.h> +#include <net/route.h> + +#include <netinet/in.h> +#include <netinet/if_ether.h> + +#include <arpa/inet.h> + +#include <netdb.h> +#include <errno.h> +#include <nlist.h> +#include <stdio.h> +#include <paths.h> + +extern int errno; +static int pid; +static int kflag; +static int nflag; +static int s = -1; + +main(argc, argv) + int argc; + char **argv; +{ + int ch; + + pid = getpid(); + while ((ch = getopt(argc, argv, "ands")) != EOF) + switch((char)ch) { + case 'a': + dump(0); + exit(0); + case 'd': + if (argc < 3 || argc > 4) + usage(); + delete(argv[2], argv[3]); + exit(0); + case 'n': + nflag = 1; + continue; + case 's': + if (argc < 4 || argc > 7) + usage(); + exit(set(argc-2, &argv[2]) ? 1 : 0); + case '?': + default: + usage(); + } + if (argc != 2) + usage(); + get(argv[1]); + exit(0); +} + +/* + * Process a file to set standard arp entries + */ +file(name) + char *name; +{ + FILE *fp; + int i, retval; + char line[100], arg[5][50], *args[5]; + + if ((fp = fopen(name, "r")) == NULL) { + fprintf(stderr, "arp: cannot open %s\n", name); + exit(1); + } + args[0] = &arg[0][0]; + args[1] = &arg[1][0]; + args[2] = &arg[2][0]; + args[3] = &arg[3][0]; + args[4] = &arg[4][0]; + retval = 0; + while(fgets(line, 100, fp) != NULL) { + i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2], + arg[3], arg[4]); + if (i < 2) { + fprintf(stderr, "arp: bad line: %s\n", line); + retval = 1; + continue; + } + if (set(i, args)) + retval = 1; + } + fclose(fp); + return (retval); +} + +getsocket() { + if (s < 0) { + 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, found_entry; +struct { + struct rt_msghdr m_rtm; + char m_space[512]; +} m_rtmsg; + +/* + * Set an individual arp entry + */ +set(argc, argv) + int argc; + char **argv; +{ + struct hostent *hp; + register struct sockaddr_inarp *sin = &sin_m; + register struct sockaddr_dl *sdl; + register struct rt_msghdr *rtm = &(m_rtmsg.m_rtm); + u_char *ea; + char *host = argv[0], *eaddr = argv[1]; + + getsocket(); + argc -= 2; + argv += 2; + sdl_m = blank_sdl; + sin_m = blank_sin; + sin->sin_addr.s_addr = inet_addr(host); + if (sin->sin_addr.s_addr == -1) { + if (!(hp = gethostbyname(host))) { + fprintf(stderr, "arp: %s: ", host); + herror((char *)NULL); + return (1); + } + bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, + sizeof sin->sin_addr); + } + ea = (u_char *)LLADDR(&sdl_m); + if (ether_aton(eaddr, ea) == 0) + sdl_m.sdl_alen = 6; + doing_proxy = flags = export_only = expire_time = 0; + while (argc-- > 0) { + if (strncmp(argv[0], "temp", 4) == 0) { + struct timeval time; + gettimeofday(&time, 0); + expire_time = time.tv_sec + 20 * 60; + } + else if (strncmp(argv[0], "pub", 3) == 0) { + flags |= RTF_ANNOUNCE; + doing_proxy = SIN_PROXY; + } else if (strncmp(argv[0], "trail", 5) == 0) { + printf("%s: Sending trailers is no longer supported\n", + host); + } + argv++; + } +tryagain: + if (rtmsg(RTM_GET) < 0) { + perror(host); + 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) { + printf("set: can only proxy for %s\n", host); + return (1); + } + if (sin_m.sin_other & SIN_PROXY) { + printf("set: proxy entry exists for non 802 device\n"); + return(1); + } + sin_m.sin_other = SIN_PROXY; + export_only = 1; + goto tryagain; + } +overwrite: + if (sdl->sdl_family != AF_LINK) { + printf("cannot intuit interface index and type for %s\n", host); + return (1); + } + sdl_m.sdl_type = sdl->sdl_type; + sdl_m.sdl_index = sdl->sdl_index; + return (rtmsg(RTM_ADD)); +} + +/* + * Display an individual arp entry + */ +get(host) + char *host; +{ + struct hostent *hp; + struct sockaddr_inarp *sin = &sin_m; + u_char *ea; + + sin_m = blank_sin; + sin->sin_addr.s_addr = inet_addr(host); + if (sin->sin_addr.s_addr == -1) { + if (!(hp = gethostbyname(host))) { + fprintf(stderr, "arp: %s: ", host); + herror((char *)NULL); + exit(1); + } + bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, + sizeof sin->sin_addr); + } + dump(sin->sin_addr.s_addr); + if (found_entry == 0) { + printf("%s (%s) -- no entry\n", + host, inet_ntoa(sin->sin_addr)); + exit(1); + } +} + +/* + * Delete an arp entry + */ +delete(host, info) + char *host; + char *info; +{ + struct hostent *hp; + register struct sockaddr_inarp *sin = &sin_m; + register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; + struct sockaddr_dl *sdl; + u_char *ea; + char *eaddr; + + if (info && strncmp(info, "pro", 3) ) + export_only = 1; + getsocket(); + sin_m = blank_sin; + sin->sin_addr.s_addr = inet_addr(host); + if (sin->sin_addr.s_addr == -1) { + if (!(hp = gethostbyname(host))) { + fprintf(stderr, "arp: %s: ", host); + herror((char *)NULL); + return (1); + } + bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, + sizeof sin->sin_addr); + } +tryagain: + if (rtmsg(RTM_GET) < 0) { + perror(host); + 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 delete; + } + } + if (sin_m.sin_other & SIN_PROXY) { + fprintf(stderr, "delete: can't locate %s\n",host); + return (1); + } else { + sin_m.sin_other = SIN_PROXY; + goto tryagain; + } +delete: + if (sdl->sdl_family != AF_LINK) { + printf("cannot locate %s\n", host); + return (1); + } + if (rtmsg(RTM_DELETE) == 0) + printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr)); +} + +/* + * Dump the entire arp table + */ +dump(addr) +u_long addr; +{ + int mib[6]; + size_t needed; + char *host, *malloc(), *lim, *buf, *next; + struct rt_msghdr *rtm; + struct sockaddr_inarp *sin; + struct sockaddr_dl *sdl; + extern int h_errno; + struct hostent *hp; + + mib[0] = CTL_NET; + mib[1] = PF_ROUTE; + mib[2] = 0; + mib[3] = AF_INET; + mib[4] = NET_RT_FLAGS; + mib[5] = RTF_LLINFO; + if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) + quit("route-sysctl-estimate"); + if ((buf = malloc(needed)) == NULL) + quit("malloc"); + if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) + quit("actual retrieval of routing table"); + lim = buf + needed; + for (next = buf; next < lim; next += rtm->rtm_msglen) { + rtm = (struct rt_msghdr *)next; + sin = (struct sockaddr_inarp *)(rtm + 1); + sdl = (struct sockaddr_dl *)(sin + 1); + if (addr) { + if (addr != sin->sin_addr.s_addr) + continue; + found_entry = 1; + } + if (nflag == 0) + hp = gethostbyaddr((caddr_t)&(sin->sin_addr), + sizeof sin->sin_addr, AF_INET); + else + hp = 0; + if (hp) + host = hp->h_name; + else { + host = "?"; + if (h_errno == TRY_AGAIN) + nflag = 1; + } + printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); + if (sdl->sdl_alen) + ether_print(LLADDR(sdl)); + else + printf("(incomplete)"); + if (rtm->rtm_rmx.rmx_expire == 0) + printf(" permanent"); + if (sin->sin_other & SIN_PROXY) + printf(" published (proxy only)"); + if (rtm->rtm_addrs & RTA_NETMASK) { + sin = (struct sockaddr_inarp *) + (sdl->sdl_len + (char *)sdl); + if (sin->sin_addr.s_addr == 0xffffffff) + printf(" published"); + if (sin->sin_len != 8) + printf("(wierd)"); + } + printf("\n"); + } +} + +ether_print(cp) + u_char *cp; +{ + printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]); +} + +ether_aton(a, n) + char *a; + u_char *n; +{ + int i, o[6]; + + i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2], + &o[3], &o[4], &o[5]); + if (i != 6) { + fprintf(stderr, "arp: invalid Ethernet address '%s'\n", a); + return (1); + } + for (i=0; i<6; i++) + n[i] = o[i]; + return (0); +} + +usage() +{ + printf("usage: arp hostname\n"); + printf(" arp -a [kernel] [kernel_memory]\n"); + printf(" arp -d hostname\n"); + printf(" arp -s hostname ether_addr [temp] [pub]\n"); + printf(" arp -f filename\n"); + exit(1); +} + +rtmsg(cmd) +{ + static int seq; + int rlen; + register struct rt_msghdr *rtm = &m_rtmsg.m_rtm; + register char *cp = m_rtmsg.m_space; + register int l; + + errno = 0; + if (cmd == RTM_DELETE) + goto doit; + bzero((char *)&m_rtmsg, sizeof(m_rtmsg)); + rtm->rtm_flags = flags; + rtm->rtm_version = RTM_VERSION; + + switch (cmd) { + default: + fprintf(stderr, "arp: internal wrong cmd\n"); + 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)) { \ + bcopy((char *)&s, cp, 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 || cmd != RTM_DELETE) { + perror("writing to routing socket"); + 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) + (void) fprintf(stderr, "arp: read from routing socket: %s\n", + strerror(errno)); + return (0); +} + +quit(msg) +char *msg; +{ + fprintf(stderr, "%s\n", msg); + exit(1); +} |