+#ifndef lint
+static char *sccsid = "@(#)arp.c 1.1 (Berkeley) %G%";
+#endif
+
+/*
+ * arp - display, set, and delete arp table entries
+ */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <netdb.h>
+#include <nlist.h>
+#include <net/if.h>
+#include <netinet/if_ether.h>
+
+extern int errno;
+
+main(argc, 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);
+}
+
+/*
+ * Process a file to set standard arp entries
+ */
+file(name)
+ char *name;
+{
+ FILE *fp;
+ int i;
+ char line[100], arg[4][50], *args[4];
+
+ 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];
+ while(fgets(line, 100, fp) != NULL) {
+ i = sscanf(line, "%s %s %s %s", arg[0], arg[1], arg[2], arg[3]);
+ if (i < 2) {
+ fprintf(stderr, "arp: bad line: %s\n", line);
+ continue;
+ }
+ set(i, args);
+ }
+ fclose(fp);
+}
+
+/*
+ * Set an individual arp entry
+ */
+set(argc, argv)
+ char **argv;
+{
+ struct arpreq ar;
+ struct hostent *hp;
+ struct sockaddr_in *sin;
+ struct ether_addr *ea;
+ int s;
+ char *host = argv[0], *eaddr = argv[1];
+
+ argc -= 2;
+ argv += 2;
+ hp = gethostbyname(host);
+ if (hp == NULL) {
+ fprintf(stderr, "arp: %s: unknown host\n", host);
+ return (1);
+ }
+ 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;
+ argv++;
+ }
+
+ s = socket(AF_INET, SOCK_DGRAM, 0);
+ if (s < 0) {
+ perror("arp: socket");
+ exit(1);
+ }
+ if (ioctl(s, SIOCSARP, (caddr_t)&ar) < 0) {
+ perror(host);
+ exit(1);
+ }
+ close(s);
+}
+
+
+/*
+ * Display an individual arp entry
+ */
+get(host)
+ char *host;
+{
+ struct arpreq ar;
+ struct hostent *hp;
+ struct sockaddr_in *sin;
+ struct ether_addr *ea;
+ int s;
+
+ hp = gethostbyname(host);
+ if (hp == NULL) {
+ fprintf(stderr, "arp: %s: unknown host\n", host);
+ exit(1);
+ }
+ 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");
+ 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(host)
+ char *host;
+{
+ struct arpreq ar;
+ struct hostent *hp;
+ struct sockaddr_in *sin;
+ int s;
+
+ hp = gethostbyname(host);
+ if (hp == NULL) {
+ fprintf(stderr, "arp: %s: unknown host\n", host);
+ exit(1);
+ }
+ 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);
+ }
+ close(s);
+ 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(kernel, mem)
+ char *kernel, *mem;
+{
+ int mf, arptab_size, sz;
+ struct arptab *at;
+ 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);
+ if (hp)
+ host = hp->h_name;
+ else
+ host = "?";
+ printf("%s (%s) at ", host, inet_ntoa(at->at_iaddr));
+ if (at->at_flags & ATF_COM)
+ ether_print(&at->at_enaddr);
+ else
+ printf("(incomplete)");
+ if (!(at->at_flags & ATF_PERM)) printf(" temporary");
+ if (at->at_flags & ATF_PUBL) printf(" published");
+ printf("\n");
+ }
+}
+
+ether_print(ea)
+ struct ether_addr *ea;
+{
+ 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;
+ struct ether_addr *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->ether_addr_octet[i] = o[i];
+ return (0);
+}
+
+usage()
+{
+ printf("Usage: arp hostname\n");
+ printf(" arp -a [/vmunix] [/dev/kmem]\n");
+ printf(" arp -d hostname\n");
+ printf(" arp -s hostname ether_addr [temp] [pub]\n");
+ printf(" arp -f filename\n");
+}
projects / unix-history / commitdiff