代码拉取完成，页面将自动刷新
/*
* arp This file contains an implementation of the command
* that maintains the kernel's ARP cache. It is derived
* from Berkeley UNIX arp(8), but cleaner and with sup-
* port for devices other than Ethernet.
*
* NET-TOOLS A collection of programs that form the base set of the
* NET-3 Networking Distribution for the LINUX operating
* system.
*
* Version: $Id: arp.c,v 1.27 2009/09/06 22:50:11 vapier Exp $
*
* Maintainer: Bernd 'eckes' Eckenfels, <[email protected]>
*
* Author: Fred N. van Kempen, <[email protected]>
*
* Changes:
* (based on work from Fred N. van Kempen, <[email protected]>)
* Alan Cox : modified for NET3
* Andrew Tridgell : proxy arp netmasks
* Bernd Eckenfels : -n option
* Bernd Eckenfels : Use only /proc for display
* {1.60} Bernd Eckenfels : new arpcode (-i) for 1.3.42 but works
* with 1.2.x, too
* {1.61} Bernd Eckenfels : more verbose messages
* {1.62} Bernd Eckenfels : check -t for hw adresses and try to
* explain EINVAL (jeff)
*970125 {1.63} Bernd Eckenfels : -a print hardwarename instead of tiltle
*970201 {1.64} Bernd Eckenfels : net-features.h support
*970203 {1.65} Bernd Eckenfels : "#define" in "#if",
* -H|-A additional to -t|-p
*970214 {1.66} Bernd Eckenfels : Fix optarg required for -H and -A
*970412 {1.67} Bernd Eckenfels : device=""; is default
*970514 {1.68} Bernd Eckenfels : -N and -D
*970517 {1.69} Bernd Eckenfels : usage() fixed
*970622 {1.70} Bernd Eckenfels : arp -d priv
*970106 {1.80} Bernd Eckenfels : new syntax without -D and with "dev <If>",
* ATF_MAGIC, ATF_DONTPUB support.
* Typo fix (Debian Bug#5728 Giuliano Procida)
*970803 {1.81} Bernd Eckenfels : removed junk comment line 1
*970925 {1.82} Bernd Eckenfels : include fix for libc6
*980213 (1.83) Phil Blundell: set ATF_COM on new entries
*980629 (1.84) Arnaldo Carvalho de Melo: gettext instead of catgets
*990101 {1.85} Bernd Eckenfels fixed usage and return codes
*990105 (1.86) Phil Blundell: don't ignore EINVAL in arp_set
*991121 (1.87) Bernd Eckenfels: yes --device has a mandatory arg
*010404 (1.88) Arnaldo Carvalho de Melo: use setlocale
*
* 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.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
/* #include <linux/netdevice.h> */
/* #include <linux/if_arp.h> */
#include <net/if_arp.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <ctype.h>
#include <fcntl.h>
#include <string.h>
#include <getopt.h>
#include <unistd.h>
#include "net-support.h"
#include "pathnames.h"
#include "version.h"
#include "config.h"
#include "intl.h"
#include "util.h"
#define DFLT_AF "inet"
#define DFLT_HW "ether"
#define FEATURE_ARP
#include "lib/net-features.h"
static char *Release = RELEASE;
int opt_n = 0; /* do not resolve addresses */
int opt_N = 0; /* use symbolic names */
int opt_v = 0; /* debugging output flag */
int opt_D = 0; /* HW-address is devicename */
int opt_e = 0; /* 0=BSD output, 1=new linux */
int opt_a = 0; /* all entries, substring match */
const struct aftype *ap;/* current address family */
const struct hwtype *hw;/* current hardware type */
int sockfd = 0; /* active socket descriptor */
int hw_set = 0; /* flag if hw-type was set (-H) */
char device[16] = ""; /* current device */
static void usage(int);
/* Delete an entry from the ARP cache. */
static int arp_del(char **args)
{
char host[128];
struct arpreq req;
struct sockaddr_storage ss;
struct sockaddr *sa = (struct sockaddr *)&ss;
int flags = 0;
int deleted = 0;
memset((char *) &req, 0, sizeof(req));
/* Resolve the host name. */
if (*args == NULL) {
fprintf(stderr, _("arp: need host name\n"));
return (-1);
}
safe_strncpy(host, *args, (sizeof host));
if (ap->input(0, host, &ss) < 0) {
ap->herror(host);
return (-1);
}
/* If a host has more than one address, use the correct one! */
memcpy((char *) &req.arp_pa, (char *) sa, sizeof(struct sockaddr));
if (hw_set)
req.arp_ha.sa_family = hw->type;
req.arp_flags = ATF_PERM;
args++;
while (*args != NULL) {
if (opt_v)
fprintf(stderr, "args=%s\n", *args);
if (!strcmp(*args, "pub")) {
flags |= 1;
args++;
continue;
}
if (!strcmp(*args, "priv")) {
flags |= 2;
args++;
continue;
}
if (!strcmp(*args, "temp")) {
req.arp_flags &= ~ATF_PERM;
args++;
continue;
}
if (!strcmp(*args, "trail")) {
req.arp_flags |= ATF_USETRAILERS;
args++;
continue;
}
if (!strcmp(*args, "dontpub")) {
#ifdef ATF_DONTPUB
req.arp_flags |= ATF_DONTPUB;
#else
ENOSUPP("arp", "ATF_DONTPUB");
#endif
args++;
continue;
}
if (!strcmp(*args, "auto")) {
#ifdef ATF_MAGIC
req.arp_flags |= ATF_MAGIC;
#else
ENOSUPP("arp", "ATF_MAGIC");
#endif
args++;
continue;
}
if (!strcmp(*args, "dev")) {
if (*++args == NULL)
usage(E_OPTERR);
safe_strncpy(device, *args, sizeof(device));
args++;
continue;
}
if (!strcmp(*args, "netmask")) {
if (*++args == NULL)
usage(E_OPTERR);
if (strcmp(*args, "255.255.255.255") != 0) {
safe_strncpy(host, *args, (sizeof host));
if (ap->input(0, host, &ss) < 0) {
ap->herror(host);
return (-1);
}
memcpy((char *) &req.arp_netmask, (char *) sa,
sizeof(struct sockaddr));
req.arp_flags |= ATF_NETMASK;
}
args++;
continue;
}
usage(E_OPTERR);
}
// if neighter priv nor pub is given, work on both
if (flags == 0)
flags = 3;
safe_strncpy(req.arp_dev, device, sizeof(req.arp_dev));
/* unfortuatelly the kernel interface does not allow us to
delete private entries anlone, so we need this hack
to avoid "not found" errors if we try both. */
deleted = 0;
/* Call the kernel. */
if (flags & 2) {
if (opt_v)
fprintf(stderr, "arp: SIOCDARP(dontpub)\n");
if (ioctl(sockfd, SIOCDARP, &req) < 0) {
if ((errno == ENXIO) || (errno == ENOENT)) {
if (flags & 1)
goto dontpub;
printf(_("No ARP entry for %s\n"), host);
return (-1);
}
perror("SIOCDARP(dontpub)");
return (-1);
} else
deleted = 1;
}
if (!deleted && (flags & 1)) {
dontpub:
req.arp_flags |= ATF_PUBL;
if (opt_v)
fprintf(stderr, "arp: SIOCDARP(pub)\n");
if (ioctl(sockfd, SIOCDARP, &req) < 0) {
if ((errno == ENXIO) || (errno == ENOENT)) {
printf(_("No ARP entry for %s\n"), host);
return (-1);
}
perror("SIOCDARP(pub)");
return (-1);
}
}
return (0);
}
/* Get the hardware address to a specified interface name */
static int arp_getdevhw(char *ifname, struct sockaddr *sa, const struct hwtype *hw)
{
struct ifreq ifr;
const struct hwtype *xhw;
safe_strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) < 0) {
fprintf(stderr, _("arp: cant get HW-Address for `%s': %s.\n"), ifname, strerror(errno));
return (-1);
}
if (hw && (ifr.ifr_hwaddr.sa_family != hw->type)) {
fprintf(stderr, _("arp: protocol type mismatch.\n"));
return (-1);
}
memcpy((char *) sa, (char *) &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
if (opt_v) {
if (!(xhw = get_hwntype(ifr.ifr_hwaddr.sa_family)) || (xhw->print == 0)) {
xhw = get_hwntype(-1);
}
fprintf(stderr, _("arp: device `%s' has HW address %s `%s'.\n"), ifname, xhw->name, xhw->print((char *)&ifr.ifr_hwaddr.sa_data));
}
return (0);
}
/* Set an entry in the ARP cache. */
static int arp_set(char **args)
{
char host[128];
struct arpreq req;
struct sockaddr_storage ss;
struct sockaddr *sa = (struct sockaddr *)&ss;
int flags;
memset((char *) &req, 0, sizeof(req));
/* Resolve the host name. */
if (*args == NULL) {
fprintf(stderr, _("arp: need host name\n"));
return (-1);
}
safe_strncpy(host, *args++, (sizeof host));
if (ap->input(0, host, &ss) < 0) {
ap->herror(host);
return (-1);
}
/* If a host has more than one address, use the correct one! */
memcpy((char *) &req.arp_pa, (char *) sa, sizeof(struct sockaddr));
/* Fetch the hardware address. */
if (*args == NULL) {
fprintf(stderr, _("arp: need hardware address\n"));
return (-1);
}
if (opt_D) {
if (arp_getdevhw(*args++, &req.arp_ha, hw_set ? hw : NULL) < 0)
return (-1);
} else {
if (hw->input(*args++, &ss) < 0) {
fprintf(stderr, _("arp: invalid hardware address\n"));
return (-1);
}
memcpy(&req.arp_ha, sa, sizeof(*sa));
}
/* Check out any modifiers. */
flags = ATF_PERM | ATF_COM;
while (*args != NULL) {
if (!strcmp(*args, "temp")) {
flags &= ~ATF_PERM;
args++;
continue;
}
if (!strcmp(*args, "pub")) {
flags |= ATF_PUBL;
args++;
continue;
}
if (!strcmp(*args, "priv")) {
flags &= ~ATF_PUBL;
args++;
continue;
}
if (!strcmp(*args, "trail")) {
flags |= ATF_USETRAILERS;
args++;
continue;
}
if (!strcmp(*args, "dontpub")) {
#ifdef ATF_DONTPUB
flags |= ATF_DONTPUB;
#else
ENOSUPP("arp", "ATF_DONTPUB");
#endif
args++;
continue;
}
if (!strcmp(*args, "auto")) {
#ifdef ATF_MAGIC
flags |= ATF_MAGIC;
#else
ENOSUPP("arp", "ATF_MAGIC");
#endif
args++;
continue;
}
if (!strcmp(*args, "dev")) {
if (*++args == NULL)
usage(E_OPTERR);
safe_strncpy(device, *args, sizeof(device));
args++;
continue;
}
if (!strcmp(*args, "netmask")) {
if (*++args == NULL)
usage(E_OPTERR);
if (strcmp(*args, "255.255.255.255") != 0) {
safe_strncpy(host, *args, (sizeof host));
if (ap->input(0, host, &ss) < 0) {
ap->herror(host);
return (-1);
}
memcpy((char *) &req.arp_netmask, (char *) sa,
sizeof(struct sockaddr));
flags |= ATF_NETMASK;
}
args++;
continue;
}
usage(E_OPTERR);
}
/* Fill in the remainder of the request. */
req.arp_flags = flags;
safe_strncpy(req.arp_dev, device, sizeof(req.arp_dev));
/* Call the kernel. */
if (opt_v)
fprintf(stderr, "arp: SIOCSARP()\n");
if (ioctl(sockfd, SIOCSARP, &req) < 0) {
perror("SIOCSARP");
return (-1);
}
return (0);
}
/* Process an EtherFile */
static int arp_file(char *name)
{
char buff[1024];
char *sp, *args[32];
int linenr, argc;
FILE *fp;
if ((fp = fopen(name, "r")) == NULL) {
fprintf(stderr, _("arp: cannot open etherfile %s !\n"), name);
return (-1);
}
/* Read the lines in the file. */
linenr = 0;
while (fgets(buff, sizeof(buff), fp) != (char *) NULL) {
linenr++;
if (opt_v == 1)
fprintf(stderr, ">> %s", buff);
if ((sp = strchr(buff, '\n')) != (char *) NULL)
*sp = '\0';
if (buff[0] == '#' || buff[0] == '\0')
continue;
argc = getargs(buff, args);
if (argc < 2) {
fprintf(stderr, _("arp: format error on line %u of etherfile %s !\n"),
linenr, name);
continue;
}
if (strchr (args[0], ':') != NULL) {
/* We have a correct ethers file, switch hw adress and hostname
for arp */
char *cp;
cp = args[1];
args[1] = args[0];
args[0] = cp;
}
if (arp_set(args) != 0)
fprintf(stderr, _("arp: cannot set entry on line %u of etherfile %s !\n"),
linenr, name);
}
(void) fclose(fp);
return (0);
}
/* Print the contents of an ARP request block. */
static void arp_disp_2(const char *name, int type, int arp_flags, const char *hwa, const char *mask, const char *dev)
{
static int title = 0;
const struct hwtype *xhw;
char flags[10];
xhw = get_hwntype(type);
if (xhw == NULL)
xhw = get_hwtype(DFLT_HW);
if (title++ == 0) {
printf(_("Address HWtype HWaddress Flags Mask Iface\n"));
}
/* Setup the flags. */
flags[0] = '\0';
if (arp_flags & ATF_COM)
strcat(flags, "C");
if (arp_flags & ATF_PERM)
strcat(flags, "M");
if (arp_flags & ATF_PUBL)
strcat(flags, "P");
#ifdef ATF_MAGIC
if (arp_flags & ATF_MAGIC)
strcat(flags, "A");
#endif
#ifdef ATF_DONTPUB
if (arp_flags & ATF_DONTPUB)
strcat(flags, "!");
#endif
if (arp_flags & ATF_USETRAILERS)
strcat(flags, "T");
if (!(arp_flags & ATF_NETMASK))
mask = "";
printf("%-23.23s ", name);
if (!(arp_flags & ATF_COM)) {
if (arp_flags & ATF_PUBL)
printf("%-8.8s%-20.20s", "*", _("<from_interface>"));
else
printf("%-8.8s%-20.20s", "", _("(incomplete)"));
} else {
printf("%-8.8s%-20.20s", xhw->name, hwa);
}
printf("%-6.6s%-15.15s %s\n", flags, mask, dev);
}
/* Print the contents of an ARP request block. */
static void arp_disp(const char *name, const char *ip, int type, int arp_flags, const char *hwa, const char *mask, const 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("<from_interface> ");
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("PUB ");
#ifdef ATF_MAGIC
if (arp_flags & ATF_MAGIC)
printf("AUTO ");
#endif
#ifdef 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. */
static int arp_show(char *name)
{
char host[100];
struct sockaddr_storage ss;
char ip[100];
char hwa[100];
char mask[100];
char line[200];
char dev[100];
int type, flags;
FILE *fp;
const char *hostname;
int num, entries = 0, showed = 0;
host[0] = '\0';
if (name != NULL) {
/* Resolve the host name. */
safe_strncpy(host, name, (sizeof host));
if (ap->input(0, host, &ss) < 0) {
ap->herror(host);
return (-1);
}
safe_strncpy(host, ap->sprint(&ss, 1), sizeof(host));
}
/* Open the PROCps kernel table. */
if ((fp = fopen(_PATH_PROCNET_ARP, "r")) == NULL) {
perror(_PATH_PROCNET_ARP);
return (-1);
}
/* Bypass header -- read until newline */
if (fgets(line, sizeof(line), fp) != (char *) NULL) {
safe_strncpy(mask, "-", sizeof(mask));
safe_strncpy(dev, "-", sizeof(dev));
/* Read the ARP cache entries. */
for (; fgets(line, sizeof(line), fp);) {
num = sscanf(line, "%s 0x%x 0x%x %99s %99s %99s\n",
ip, &type, &flags, hwa, mask, dev);
if (num < 4)
break;
if (num == 5) {
/*
* This happens for incomplete ARP entries for which there is
* no hardware address in the line.
*/
num = sscanf(line, "%s 0x%x 0x%x %99s %99s\n",
ip, &type, &flags, mask, dev);
hwa[0] = 0;
}
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))
continue;
/* if the user specified device differs, skip it */
if (device[0] && strcmp(dev, device))
continue;
showed++;
/* This IS ugly but it works -be */
if (opt_n)
hostname = "?";
else {
if (ap->input(0, ip, &ss) < 0)
hostname = ip;
else
hostname = ap->sprint(&ss, opt_n | 0x8000);
if (strcmp(hostname, ip) == 0)
hostname = "?";
}
if (opt_e)
arp_disp_2(hostname[0] == '?' ? ip : hostname, type, flags, hwa, mask, dev);
else
arp_disp(hostname, ip, type, flags, hwa, mask, dev);
}
}
if (opt_v)
printf(_("Entries: %d\tSkipped: %d\tFound: %d\n"), entries, entries - showed, showed);
if (!showed) {
if (host[0] && !opt_a)
printf(_("%s (%s) -- no entry\n"), name, host);
else if (hw_set || host[0] || device[0]) {
printf(_("arp: in %d entries no match found.\n"), entries);
}
}
(void) fclose(fp);
return (0);
}
static void version(void)
{
printf("%s\n%s\n", Release, Features);
exit(E_VERSION);
}
static void usage(int rc)
{
FILE *fp = rc ? stderr : stdout;
fprintf(fp, _("Usage:\n arp [-vn] [<HW>] [-i <if>] [-a] [<hostname>] <-Display ARP cache\n"));
fprintf(fp, _(" arp [-v] [-i <if>] -d <host> [pub] <-Delete ARP entry\n"));
fprintf(fp, _(" arp [-vnD] [<HW>] [-i <if>] -f [<filename>] <-Add entry from file\n"));
fprintf(fp, _(" arp [-v] [<HW>] [-i <if>] -s <host> <hwaddr> [temp] <-Add entry\n"));
fprintf(fp, _(" arp [-v] [<HW>] [-i <if>] -Ds <host> <if> [netmask <nm>] pub <-''-\n\n"));
fprintf(fp, _(" -a display (all) hosts in alternative (BSD) style\n"));
fprintf(fp, _(" -e display (all) hosts in default (Linux) style\n"));
fprintf(fp, _(" -s, --set set a new ARP entry\n"));
fprintf(fp, _(" -d, --delete delete a specified entry\n"));
fprintf(fp, _(" -v, --verbose be verbose\n"));
fprintf(fp, _(" -n, --numeric don't resolve names\n"));
fprintf(fp, _(" -i, --device specify network interface (e.g. eth0)\n"));
fprintf(fp, _(" -D, --use-device read <hwaddr> from given device\n"));
fprintf(fp, _(" -A, -p, --protocol specify protocol family\n"));
fprintf(fp, _(" -f, --file read new entries from file or from /etc/ethers\n\n"));
fprintf(fp, _(" <HW>=Use '-H <hw>' to specify hardware address type. Default: %s\n"), DFLT_HW);
fprintf(fp, _(" List of possible hardware types (which support ARP):\n"));
print_hwlist(1); /* 1 = ARPable */
exit(rc);
}
int main(int argc, char **argv)
{
int i, lop, what;
struct option longopts[] =
{
{"verbose", 0, 0, 'v'},
{"version", 0, 0, 'V'},
{"all", 0, 0, 'a'},
{"delete", 0, 0, 'd'},
{"file", 0, 0, 'f'},
{"numeric", 0, 0, 'n'},
{"set", 0, 0, 's'},
{"protocol", 1, 0, 'A'},
{"hw-type", 1, 0, 'H'},
{"device", 1, 0, 'i'},
{"help", 0, 0, 'h'},
{"use-device", 0, 0, 'D'},
{"symbolic", 0, 0, 'N'},
{NULL, 0, 0, 0}
};
#if I18N
setlocale (LC_ALL, "");
bindtextdomain("net-tools", "/usr/share/locale");
textdomain("net-tools");
#endif
/* Initialize variables... */
if ((hw = get_hwtype(DFLT_HW)) == NULL) {
fprintf(stderr, _("%s: hardware type not supported!\n"), DFLT_HW);
return (-1);
}
if ((ap = get_aftype(DFLT_AF)) == NULL) {
fprintf(stderr, _("%s: address family not supported!\n"), DFLT_AF);
return (-1);
}
what = 0;
/* Fetch the command-line arguments. */
/* opterr = 0; */
while ((i = getopt_long(argc, argv, "A:H:adfp:nsei:t:vh?DNV", longopts, &lop)) != EOF)
switch (i) {
case 'a':
what = 1;
opt_a = 1;
break;
case 'f':
what = 2;
break;
case 'd':
what = 3;
break;
case 's':
what = 4;
break;
case 'e':
opt_e = 1;
break;
case 'n':
opt_n = FLAG_NUM;
break;
case 'D':
opt_D = 1;
break;
case 'N':
opt_N = FLAG_SYM;
fprintf(stderr, _("arp: -N not yet supported.\n"));
break;
case 'v':
opt_v = 1;
break;
case 'A':
case 'p':
ap = get_aftype(optarg);
if (ap == NULL) {
fprintf(stderr, _("arp: %s: unknown address family.\n"),
optarg);
exit(-1);
}
break;
case 'H':
case 't':
hw = get_hwtype(optarg);
if (hw == NULL) {
fprintf(stderr, _("arp: %s: unknown hardware type.\n"),
optarg);
exit(-1);
}
hw_set = 1;
break;
case 'i':
safe_strncpy(device, optarg, sizeof(device));
break;
case 'V':
version();
case 'h':
usage(E_USAGE);
case '?':
default:
usage(E_OPTERR);
}
if (ap->af != AF_INET) {
fprintf(stderr, _("arp: %s: kernel only supports 'inet'.\n"),
ap->name);
exit(-1);
}
/* If not hw type specified get default */
if(hw_set==0)
if ((hw = get_hwtype(DFLT_HW)) == NULL) {
fprintf(stderr, _("%s: hardware type not supported!\n"), DFLT_HW);
return (-1);
}
if (hw->alen <= 0) {
fprintf(stderr, _("arp: %s: hardware type without ARP support.\n"),
hw->name);
exit(-1);
}
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("socket");
exit(-1);
}
/* Now see what we have to do here... */
switch (what) {
case 0:
opt_e = 1;
what = arp_show(argv[optind]);
break;
case 1: /* show an ARP entry in the cache */
what = arp_show(argv[optind]);
break;
case 2: /* process an EtherFile */
what = arp_file(argv[optind] ? argv[optind] : "/etc/ethers");
break;
case 3: /* delete an ARP entry from the cache */
what = arp_del(&argv[optind]);
break;
case 4: /* set an ARP entry in the cache */
what = arp_set(&argv[optind]);
break;
default:
usage(E_OPTERR);
}
exit(what);
}
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