--- /dev/null
+/* vi: set sw=4 ts=4: */
+/*
+ * arp.c - Manipulate the system ARP cache
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Author: Fred N. van Kempen, <waltje at uwalt.nl.mugnet.org>
+ * Busybox port: Paul van Gool <pvangool at mimotech.com>
+ *
+ * modified for getopt32 by Arne Bernin <arne [at] alamut.de>
+ */
+
+#include "busybox.h"
+#include "inet_common.h"
+
+#include <arpa/inet.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <netinet/ether.h>
+#include <netpacket/packet.h>
+
+#define DEBUG 0
+
+#define DFLT_AF "inet"
+#define DFLT_HW "ether"
+
+#define _PATH_PROCNET_ARP "/proc/net/arp"
+
+#define ARP_OPT_A (0x1)
+#define ARP_OPT_p (0x2)
+#define ARP_OPT_H (0x4)
+#define ARP_OPT_t (0x8)
+#define ARP_OPT_i (0x10)
+#define ARP_OPT_a (0x20)
+#define ARP_OPT_d (0x40)
+#define ARP_OPT_n (0x80) /* do not resolve addresses */
+#define ARP_OPT_D (0x100) /* HW-address is devicename */
+#define ARP_OPT_s (0x200)
+#define ARP_OPT_v (0x400 * DEBUG) /* debugging output flag */
+
+
+static const struct aftype *ap; /* current address family */
+static const struct hwtype *hw; /* current hardware type */
+static int sockfd; /* active socket descriptor */
+static smallint hw_set; /* flag if hw-type was set (-H) */
+static char *device = ""; /* current device */
+
+static const char *const options[] = {
+ "pub",
+ "priv",
+ "temp",
+ "trail",
+ "dontpub",
+ "auto",
+ "dev",
+ "netmask",
+ NULL
+};
+
+/* Delete an entry from the ARP cache. */
+/* Called only from main, once */
+static int arp_del(char **args)
+{
+ char host[128];
+ struct arpreq req;
+ struct sockaddr sa;
+ int flags = 0;
+ int err;
+
+ memset(&req, 0, sizeof(req));
+
+ /* Resolve the host name. */
+ safe_strncpy(host, *args, 128);
+ if (ap->input(0, host, &sa) < 0) {
+ bb_herror_msg_and_die("%s", host);
+ }
+
+ /* If a host has more than one address, use the correct one! */
+ memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
+
+ if (hw_set)
+ req.arp_ha.sa_family = hw->type;
+
+ req.arp_flags = ATF_PERM;
+ args++;
+ while (*args != NULL) {
+ if (option_mask32 & ARP_OPT_v)
+ bb_error_msg("args=%s", *args);
+
+ switch (index_in_str_array(options, *args)) {
+ case 0: // "pub"
+ flags |= 1;
+ args++;
+ break;
+ case 1: // "priv"
+ flags |= 2;
+ args++;
+ break;
+ case 2: // "temp"
+ req.arp_flags &= ~ATF_PERM;
+ args++;
+ break;
+ case 3: // "trail"
+ req.arp_flags |= ATF_USETRAILERS;
+ args++;
+ break;
+ case 4: // "dontpub"
+#ifdef HAVE_ATF_DONTPUB
+ req.arp_flags |= ATF_DONTPUB;
+#else
+ bb_error_msg("feature ATF_DONTPUB is not supported");
+#endif
+ args++;
+ break;
+ case 5: // "auto"
+#ifdef HAVE_ATF_MAGIC
+ req.arp_flags |= ATF_MAGIC;
+#else
+ bb_error_msg("feature ATF_MAGIC is not supported");
+#endif
+ args++;
+ break;
+ case 6: // "dev"
+ if (*++args == NULL)
+ bb_show_usage();
+ device = *args;
+ args++;
+ break;
+ case 7: // "netmask"
+ if (*++args == NULL)
+ bb_show_usage();
+ if (strcmp(*args, "255.255.255.255") != 0) {
+ safe_strncpy(host, *args, 128);
+ if (ap->input(0, host, &sa) < 0) {
+ bb_herror_msg("%s", host);
+ return -1;
+ }
+ memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
+ req.arp_flags |= ATF_NETMASK;
+ }
+ args++;
+ break;
+ default:
+ bb_show_usage();
+ break;
+ }
+ }
+ if (flags == 0)
+ flags = 3;
+
+ strncpy(req.arp_dev, device, sizeof(req.arp_dev));
+
+ err = -1;
+
+ /* Call the kernel. */
+ if (flags & 2) {
+ if (option_mask32 & ARP_OPT_v)
+ bb_error_msg("SIOCDARP(nopub)");
+ err = ioctl(sockfd, SIOCDARP, &req);
+ if (err < 0) {
+ if (errno == ENXIO) {
+ if (flags & 1)
+ goto nopub;
+ printf("No ARP entry for %s\n", host);
+ return -1;
+ }
+ bb_perror_msg_and_die("SIOCDARP(priv)");
+ }
+ }
+ if ((flags & 1) && err) {
+ nopub:
+ req.arp_flags |= ATF_PUBL;
+ if (option_mask32 & ARP_OPT_v)
+ bb_error_msg("SIOCDARP(pub)");
+ if (ioctl(sockfd, SIOCDARP, &req) < 0) {
+ if (errno == ENXIO) {
+ printf("No ARP entry for %s\n", host);
+ return -1;
+ }
+ bb_perror_msg_and_die("SIOCDARP(pub)");
+ }
+ }
+ return 0;
+}
+
+/* Get the hardware address to a specified interface name */
+static void
+arp_getdevhw(char *ifname, struct sockaddr *sa, const struct hwtype *hwt)
+{
+ struct ifreq ifr;
+ const struct hwtype *xhw;
+
+ strcpy(ifr.ifr_name, ifname);
+ if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) < 0) {
+ bb_perror_msg_and_die("cant get HW-Address for '%s'", ifname);
+ }
+ if (hwt && (ifr.ifr_hwaddr.sa_family != hw->type)) {
+ bb_error_msg_and_die("protocol type mismatch");
+ }
+ memcpy(sa, &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
+
+ if (option_mask32 & ARP_OPT_v) {
+ xhw = get_hwntype(ifr.ifr_hwaddr.sa_family);
+ if (!xhw || !xhw->print) {
+ xhw = get_hwntype(-1);
+ }
+ bb_error_msg("device '%s' has HW address %s '%s'",
+ ifname, xhw->name,
+ xhw->print((char *) &ifr.ifr_hwaddr.sa_data));
+ }
+}
+
+/* Set an entry in the ARP cache. */
+/* Called only from main, once */
+static int arp_set(char **args)
+{
+ char host[128];
+ struct arpreq req;
+ struct sockaddr sa;
+ int flags;
+
+ memset(&req, 0, sizeof(req));
+
+ safe_strncpy(host, *args++, 128);
+ if (ap->input(0, host, &sa) < 0) {
+ bb_herror_msg_and_die("%s", host);
+ }
+ /* If a host has more than one address, use the correct one! */
+ memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
+
+ /* Fetch the hardware address. */
+ if (*args == NULL) {
+ bb_error_msg_and_die("need hardware address");
+ }
+ if (option_mask32 & ARP_OPT_D) {
+ arp_getdevhw(*args++, &req.arp_ha, hw_set ? hw : NULL);
+ } else {
+ if (hw->input(*args++, &req.arp_ha) < 0) {
+ bb_error_msg_and_die("invalid hardware address");
+ }
+ }
+
+ /* Check out any modifiers. */
+ flags = ATF_PERM | ATF_COM;
+ while (*args != NULL) {
+ switch (index_in_str_array(options, *args)) {
+ case 0: // "pub"
+ flags |= ATF_PUBL;
+ args++;
+ break;
+ case 1: // "priv"
+ flags &= ~ATF_PUBL;
+ args++;
+ break;
+ case 2: // "temp"
+ flags &= ~ATF_PERM;
+ args++;
+ break;
+ case 3: // "trail"
+ flags |= ATF_USETRAILERS;
+ args++;
+ break;
+ case 4: // "dontpub"
+#ifdef HAVE_ATF_DONTPUB
+ flags |= ATF_DONTPUB;
+#else
+ bb_error_msg("feature ATF_DONTPUB is not supported");
+#endif
+ args++;
+ break;
+ case 5: // "auto"
+#ifdef HAVE_ATF_MAGIC
+ flags |= ATF_MAGIC;
+#else
+ bb_error_msg("feature ATF_MAGIC is not supported");
+#endif
+ args++;
+ break;
+ case 6: // "dev"
+ if (*++args == NULL)
+ bb_show_usage();
+ device = *args;
+ args++;
+ break;
+ case 7: // "netmask"
+ if (*++args == NULL)
+ bb_show_usage();
+ if (strcmp(*args, "255.255.255.255") != 0) {
+ safe_strncpy(host, *args++, 128);
+ if (ap->input(0, host, &sa) < 0) {
+ bb_herror_msg_and_die("%s", host);
+ }
+ memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
+ flags |= ATF_NETMASK;
+ }
+ args++;
+ break;
+ default:
+ bb_show_usage();
+ break;
+ }
+ }
+
+ /* Fill in the remainder of the request. */
+ req.arp_flags = flags;
+
+ strncpy(req.arp_dev, device, sizeof(req.arp_dev));
+
+ /* Call the kernel. */
+ if (option_mask32 & ARP_OPT_v)
+ bb_error_msg("SIOCSARP()");
+ if (ioctl(sockfd, SIOCSARP, &req) < 0) {
+ bb_perror_msg_and_die("SIOCSARP");
+ }
+ return 0;
+}
+
+
+/* Print the contents of an ARP request block. */
+static void
+arp_disp(char *name, char *ip, int type, int arp_flags,
+ char *hwa, char *mask, char *dev)
+{
+ const struct hwtype *xhw;
+
+ xhw = get_hwntype(type);
+ if (xhw == NULL)
+ xhw = get_hwtype(DFLT_HW);
+
+ printf("%s (%s) at ", name, ip);
+
+ if (!(arp_flags & ATF_COM)) {
+ if (arp_flags & ATF_PUBL)
+ printf("* ");
+ else
+ printf("<incomplete> ");
+ } else {
+ printf("%s [%s] ", hwa, xhw->name);
+ }
+
+ if (arp_flags & ATF_NETMASK)
+ printf("netmask %s ", mask);
+
+ if (arp_flags & ATF_PERM)
+ printf("PERM ");
+ if (arp_flags & ATF_PUBL)
+ printf("PUP ");
+#ifdef HAVE_ATF_MAGIC
+ if (arp_flags & ATF_MAGIC)
+ printf("AUTO ");
+#endif
+#ifdef HAVE_ATF_DONTPUB
+ if (arp_flags & ATF_DONTPUB)
+ printf("DONTPUB ");
+#endif
+ if (arp_flags & ATF_USETRAILERS)
+ printf("TRAIL ");
+
+ printf("on %s\n", dev);
+}
+
+/* Display the contents of the ARP cache in the kernel. */
+/* Called only from main, once */
+static int arp_show(char *name)
+{
+ char host[100];
+ struct sockaddr sa;
+ char ip[100];
+ char hwa[100];
+ char mask[100];
+ char line[200];
+ char dev[100];
+ int type, flags;
+ FILE *fp;
+ char *hostname;
+ int num, entries = 0, shown = 0;
+
+ host[0] = '\0';
+
+ if (name != NULL) {
+ /* Resolve the host name. */
+ safe_strncpy(host, name, (sizeof host));
+ if (ap->input(0, host, &sa) < 0) {
+ bb_herror_msg_and_die("%s", host);
+ }
+ safe_strncpy(host, ap->sprint(&sa, 1), sizeof(host));
+ }
+ /* Open the PROCps kernel table. */
+ fp = xfopen(_PATH_PROCNET_ARP, "r");
+ /* Bypass header -- read until newline */
+ if (fgets(line, sizeof(line), fp) != (char *) NULL) {
+ mask[0] = '-'; mask[1] = '\0';
+ dev[0] = '-'; dev[1] = '\0';
+ /* Read the ARP cache entries. */
+ for (; fgets(line, sizeof(line), fp);) {
+ num = sscanf(line, "%s 0x%x 0x%x %100s %100s %100s\n",
+ ip, &type, &flags, hwa, mask, dev);
+ if (num < 4)
+ break;
+
+ entries++;
+ /* if the user specified hw-type differs, skip it */
+ if (hw_set && (type != hw->type))
+ continue;
+
+ /* if the user specified address differs, skip it */
+ if (host[0] && strcmp(ip, host) != 0)
+ continue;
+
+ /* if the user specified device differs, skip it */
+ if (device && strcmp(dev, device) != 0)
+ continue;
+
+ shown++;
+ /* This IS ugly but it works -be */
+ if (option_mask32 & ARP_OPT_n)
+ hostname = "?";
+ else {
+ if (ap->input(0, ip, &sa) < 0)
+ hostname = ip;
+ else
+ hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000);
+ if (strcmp(hostname, ip) == 0)
+ hostname = "?";
+ }
+
+ arp_disp(hostname, ip, type, flags, hwa, mask, dev);
+ }
+ }
+ if (option_mask32 & ARP_OPT_v)
+ printf("Entries: %d\tSkipped: %d\tFound: %d\n",
+ entries, entries - shown, shown);
+
+ if (!shown) {
+ if (hw_set || host[0] || device)
+ printf("No match found in %d entries\n", entries);
+ }
+
+ fclose(fp);
+
+ return 0;
+}
+
+int arp_main(int argc, char **argv)
+{
+ char *hw_type;
+ char *protocol;
+
+ /* Initialize variables... */
+ ap = get_aftype(DFLT_AF);
+ if (!ap)
+ bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family");
+
+ getopt32(argc, argv, "A:p:H:t:i:adnDsv", &protocol, &protocol,
+ &hw_type, &hw_type, &device);
+ argv += optind;
+ if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) {
+ ap = get_aftype(protocol);
+ if (ap == NULL)
+ bb_error_msg_and_die("%s: unknown %s", protocol, "address family");
+ }
+ if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) {
+ hw = get_hwtype(hw_type);
+ if (hw == NULL)
+ bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type");
+ hw_set = 1;
+ }
+ //if (option_mask32 & ARP_OPT_i)... -i
+
+ if (ap->af != AF_INET) {
+ bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name);
+ }
+
+ /* If no hw type specified get default */
+ if (!hw) {
+ hw = get_hwtype(DFLT_HW);
+ if (!hw)
+ bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type");
+ }
+
+ if (hw->alen <= 0) {
+ bb_error_msg_and_die("%s: %s without ARP support",
+ hw->name, "hardware type");
+ }
+ sockfd = xsocket(AF_INET, SOCK_DGRAM, 0);
+
+ /* Now see what we have to do here... */
+ if (option_mask32 & (ARP_OPT_d|ARP_OPT_s)) {
+ if (argv[0] == NULL)
+ bb_error_msg_and_die("need host name");
+ if (option_mask32 & ARP_OPT_s)
+ return arp_set(argv);
+ return arp_del(argv);
+ }
+ //if (option_mask32 & ARP_OPT_a) - default
+ return arp_show(argv[0]);
+}
projects / oweals / busybox.git / commitdiff