BSD 4_4_Lite1 release

[unix-history] / usr / src / usr.sbin / arp / arp.c

diff --git a/usr/src/usr.sbin/arp/arp.c b/usr/src/usr.sbin/arp/arp.c
index b4b79ce..2182dc8 100644 (file)
--- a/usr/src/usr.sbin/arp/arp.c
+++ b/usr/src/usr.sbin/arp/arp.c
@@ -1,55 +1,113 @@
+/*
+ * 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
 #ifndef lint

-static char *sccsid = "@(#)arp.c       1.1 (Berkeley) %G%";
-#endif
+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
  */
 
 
 /*
  * arp - display, set, and delete arp table entries
  */
 

-#include <stdio.h>
-#include <sys/types.h>
+
+#include <sys/param.h>
+#include <sys/file.h>

 #include <sys/socket.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/in.h>

-#include <sys/ioctl.h>
-#include <errno.h>
+#include <netinet/if_ether.h>
+
+#include <arpa/inet.h>
+

 #include <netdb.h>
 #include <netdb.h>

+#include <errno.h>

 #include <nlist.h>
 #include <nlist.h>

-#include <net/if.h>
-#include <netinet/if_ether.h>
+#include <stdio.h>
+#include <paths.h>

 
 extern int errno;
 
 extern int errno;

+static int pid;
+static int kflag;
+static int nflag;
+static int s = -1;

 
 main(argc, argv)
 
 main(argc, argv)

+       int argc;

        char **argv;
 {
        char **argv;
 {

-       if (argc >= 2 && strcmp(argv[1], "-a") == 0) {
-               char *kernel = "/vmunix", *mem = "/dev/kmem";
-
-               if (argc >= 3)
-                       kernel = argv[2];
-               if (argc >= 4)
-                       mem = argv[3];
-               dump(kernel, mem);
-               exit(0);
-       }
-       if (argc == 2) {
-               get(argv[1]);
-               exit(0);
-       }
-       if (argc >= 4 && strcmp(argv[1], "-s") == 0) {
-               set(argc-2, &argv[2]);
-               exit(0);
-       }
-       if (argc == 3 && strcmp(argv[1], "-d") == 0) {
-               delete(argv[2]);
-               exit(0);
-       }
-       if (argc == 3 && strcmp(argv[1], "-f") == 0) {
-               file(argv[2]);
-               exit(0);
-       }
-       usage();
-       exit(1);
+       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);

 }
 
 /*
 }
 
 /*


@@ -59,8 +117,8 @@ file(name)
        char *name;
 {
        FILE *fp;
        char *name;
 {
        FILE *fp;

-       int i;
-       char line[100], arg[4][50], *args[4];
+       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);
 
        if ((fp = fopen(name, "r")) == NULL) {
                fprintf(stderr, "arp: cannot open %s\n", name);


@@ -70,227 +128,295 @@ file(name)
        args[1] = &arg[1][0];
        args[2] = &arg[2][0];
        args[3] = &arg[3][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) {
        while(fgets(line, 100, fp) != NULL) {

-               i = sscanf(line, "%s %s %s %s", arg[0], arg[1], arg[2], arg[3]);
+               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);
                if (i < 2) {
                        fprintf(stderr, "arp: bad line: %s\n", line);

+                       retval = 1;

                        continue;
                }
                        continue;
                }

-               set(i, args);
+               if (set(i, args))
+                       retval = 1;

        }
        fclose(fp);
        }
        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)
 /*
  * Set an individual arp entry 
  */
 set(argc, argv)

+       int argc;

        char **argv;
 {
        char **argv;
 {

-       struct arpreq ar;

        struct hostent *hp;
        struct hostent *hp;

-       struct sockaddr_in *sin;
-       struct ether_addr *ea;
-       int s;
+       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];
 
        char *host = argv[0], *eaddr = argv[1];
 

+       getsocket();

        argc -= 2;
        argv += 2;
        argc -= 2;
        argv += 2;

-       hp = gethostbyname(host);
-       if (hp == NULL) {
-               fprintf(stderr, "arp: %s: unknown host\n", host);
-               return (1);
+       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);

        }
        }

-       bzero((caddr_t)&ar, sizeof ar);
-       ar.arp_pa.sa_family = AF_INET;
-       sin = (struct sockaddr_in *)&ar.arp_pa;
-       sin->sin_addr = *(struct in_addr *)hp->h_addr;
-       ea = (struct ether_addr *)ar.arp_ha.sa_data;
-       if (ether_aton(eaddr, ea))
-               return;
-       ar.arp_flags = ATF_PERM;
-       while(argc-- > 0) {
-               if (strncmp(argv[0], "temp", 4) == 0)
-                       ar.arp_flags &= ~ATF_PERM;
-               if (strncmp(argv[0], "pub", 3) == 0)
-                       ar.arp_flags |= ATF_PUBL;
+       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++;
        }
                argv++;
        }

-       
-       s = socket(AF_INET, SOCK_DGRAM, 0);
-       if (s < 0) {
-                perror("arp: socket");
-                exit(1);
-        }
-       if (ioctl(s, SIOCSARP, (caddr_t)&ar) < 0) {
+tryagain:
+       if (rtmsg(RTM_GET) < 0) {

                perror(host);
                perror(host);

-               exit(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) {
+                       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);

        }
        }

-       close(s);
+       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;
 {
 /*
  * Display an individual arp entry
  */
 get(host)
        char *host;
 {

-       struct arpreq ar;

        struct hostent *hp;
        struct hostent *hp;

-       struct sockaddr_in *sin;
-       struct ether_addr *ea;
-       int s;
+       struct sockaddr_inarp *sin = &sin_m;
+       u_char *ea;

 
 

-       hp = gethostbyname(host);
-       if (hp == NULL) {
-               fprintf(stderr, "arp: %s: unknown host\n", host);
-               exit(1);
+       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);

        }
        }

-       bzero((caddr_t)&ar, sizeof ar);
-       ar.arp_pa.sa_family = AF_INET;
-       sin = (struct sockaddr_in *)&ar.arp_pa;
-       sin->sin_addr = *(struct in_addr *)hp->h_addr;
-       s = socket(AF_INET, SOCK_DGRAM, 0);
-       if (s < 0) {
-                perror("arp: socket");
-                exit(1);
-        }
-       if (ioctl(s, SIOCGARP, (caddr_t)&ar) < 0) {
-               if (errno == ENXIO)
-                       printf("%s (%s) -- no entry\n",
-                           host, inet_ntoa(sin->sin_addr));
-               else
-                       perror("SIOCGARP");
+       dump(sin->sin_addr.s_addr);
+       if (found_entry == 0) {
+               printf("%s (%s) -- no entry\n",
+                   host, inet_ntoa(sin->sin_addr));

                exit(1);
        }
                exit(1);
        }

-       close(s);
-       ea = (struct ether_addr *)ar.arp_ha.sa_data;
-       printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr));
-       if (ar.arp_flags & ATF_COM)
-               ether_print(ea);
-       else
-               printf("(incomplete)");
-       if (!(ar.arp_flags & ATF_PERM)) printf(" temporary");
-       if (ar.arp_flags & ATF_PUBL) printf(" published");
-       printf("\n");

 }
 
 /*
  * Delete an arp entry 
  */
 }
 
 /*
  * Delete an arp entry 
  */

-delete(host)
+delete(host, info)

        char *host;
        char *host;

+       char *info;

 {
 {

-       struct arpreq ar;

        struct hostent *hp;
        struct hostent *hp;

-       struct sockaddr_in *sin;
-       int s;
+       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;

 
 

-       hp = gethostbyname(host);
-       if (hp == NULL) {
-               fprintf(stderr, "arp: %s: unknown host\n", host);
-               exit(1);
+       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);

        }
        }

-       bzero((caddr_t)&ar, sizeof ar);
-       ar.arp_pa.sa_family = AF_INET;
-       sin = (struct sockaddr_in *)&ar.arp_pa;
-       sin->sin_addr = *(struct in_addr *)hp->h_addr;
-       s = socket(AF_INET, SOCK_DGRAM, 0);
-       if (s < 0) {
-                perror("arp: socket");
-                exit(1);
-        }
-       if (ioctl(s, SIOCDARP, (caddr_t)&ar) < 0) {
-               if (errno == ENXIO)
-                       printf("%s (%s) -- no entry\n",
-                           host, inet_ntoa(sin->sin_addr));
-               else
-                       perror("SIOCDARP");
-               exit(1);
+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);

        }
        }

-       close(s);
-       printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));
+       if (rtmsg(RTM_DELETE) == 0)
+               printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr));

 }
 
 }
 

-struct nlist nl[] = {
-#define        X_ARPTAB        0
-       { "_arptab" },
-#define        X_ARPTAB_SIZE   1
-       { "_arptab_size" },
-       { "" },
-};
-

 /*
  * Dump the entire arp table
  */
 /*
  * Dump the entire arp table
  */

-dump(kernel, mem)
-       char *kernel, *mem;
+dump(addr)
+u_long addr;

 {
 {

-       int mf, arptab_size, sz;
-       struct arptab *at;
+       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;
        struct hostent *hp;

-       char *host;

 
 

-       nlist(kernel, nl);
-       if(nl[X_ARPTAB_SIZE].n_type == 0) {
-               fprintf(stderr, "arp: %s: bad namelist\n", kernel);
-               exit(1);
-       }
-       mf = open(mem, 0);
-       if(mf < 0) {
-               fprintf(fprintf, "arp: cannot open %s\n", mem);
-               exit(1);
-       }
-       lseek(mf, (long)nl[X_ARPTAB_SIZE].n_value, 0);
-       read(mf, &arptab_size, sizeof arptab_size);
-       if (arptab_size <=0 || arptab_size > 1000) {
-               fprintf(stderr, "arp: %s: namelist wrong\n", kernel);
-               exit(1);
-       }
-       sz = arptab_size * sizeof (struct arptab);
-       at = (struct arptab *)malloc(sz);
-       if (at == NULL) {
-               fprintf(stderr, "arp: can't get memory for arptab\n");
-               exit(1);
-       }
-       lseek(mf, (long)nl[X_ARPTAB].n_value, 0);
-       if (read(mf, (char *)at, sz) != sz) {
-               perror("arp: error reading arptab");
-               exit(1);
-       }
-       close(mf);
-       for (; arptab_size-- > 0; at++) {
-               if (at->at_iaddr.s_addr == 0 || at->at_flags == 0)
-                       continue;
-               hp = gethostbyaddr((caddr_t)&at->at_iaddr, sizeof at->at_iaddr,
-                       AF_INET);
+       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;
                if (hp)
                        host = hp->h_name;

-               else
+               else {

                        host = "?";
                        host = "?";

-               printf("%s (%s) at ", host, inet_ntoa(at->at_iaddr));
-               if (at->at_flags & ATF_COM)
-                       ether_print(&at->at_enaddr);
+                       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)");
                else
                        printf("(incomplete)");

-               if (!(at->at_flags & ATF_PERM)) printf(" temporary");
-               if (at->at_flags & ATF_PUBL) printf(" published");
+               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");
        }
 }
 
                printf("\n");
        }
 }
 

-ether_print(ea)
-       struct ether_addr *ea;
+ether_print(cp)
+       u_char *cp;

 {
 {

-       u_char *cp = &ea->ether_addr_octet[0];
-

        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;
        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;

-       struct ether_addr *n;
+       u_char *n;

 {
        int i, o[6];
 
 {
        int i, o[6];
 


@@ -301,15 +427,88 @@ ether_aton(a, n)
                return (1);
        }
        for (i=0; i<6; i++)
                return (1);
        }
        for (i=0; i<6; i++)

-               n->ether_addr_octet[i] = o[i];
+               n[i] = o[i];

        return (0);
 }
 
 usage()
 {
        return (0);
 }
 
 usage()
 {

-       printf("Usage: arp hostname\n");
-       printf("       arp -a [/vmunix] [/dev/kmem]\n");
+       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");
        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);

 }
 }