source: MondoRescue/branches/3.2/mindi-busybox/networking/arp.c@ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 10 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 12.3 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * arp.c - Manipulate the system ARP cache
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
9 *
10 * Author: Fred N. van Kempen, <waltje at uwalt.nl.mugnet.org>
11 * Busybox port: Paul van Gool <pvangool at mimotech.com>
12 *
13 * modified for getopt32 by Arne Bernin <arne [at] alamut.de>
14 */
15
16//usage:#define arp_trivial_usage
17//usage: "\n[-vn] [-H HWTYPE] [-i IF] -a [HOSTNAME]"
18//usage: "\n[-v] [-i IF] -d HOSTNAME [pub]"
19//usage: "\n[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [temp]"
20//usage: "\n[-v] [-H HWTYPE] [-i IF] -s HOSTNAME HWADDR [netmask MASK] pub"
21//usage: "\n[-v] [-H HWTYPE] [-i IF] -Ds HOSTNAME IFACE [netmask MASK] pub"
22//usage:#define arp_full_usage "\n\n"
23//usage: "Manipulate ARP cache\n"
24//usage: "\n -a Display (all) hosts"
25//usage: "\n -s Set new ARP entry"
26//usage: "\n -d Delete a specified entry"
27//usage: "\n -v Verbose"
28//usage: "\n -n Don't resolve names"
29//usage: "\n -i IF Network interface"
30//usage: "\n -D Read <hwaddr> from given device"
31//usage: "\n -A,-p AF Protocol family"
32//usage: "\n -H HWTYPE Hardware address type"
33
34#include "libbb.h"
35#include "inet_common.h"
36
37#include <arpa/inet.h>
38#include <net/if.h>
39#include <net/if_arp.h>
40#include <netinet/ether.h>
41#include <netpacket/packet.h>
42
43#define DEBUG 0
44
45#define DFLT_AF "inet"
46#define DFLT_HW "ether"
47
48enum {
49 ARP_OPT_A = (1 << 0),
50 ARP_OPT_p = (1 << 1),
51 ARP_OPT_H = (1 << 2),
52 ARP_OPT_t = (1 << 3),
53 ARP_OPT_i = (1 << 4),
54 ARP_OPT_a = (1 << 5),
55 ARP_OPT_d = (1 << 6),
56 ARP_OPT_n = (1 << 7), /* do not resolve addresses */
57 ARP_OPT_D = (1 << 8), /* HW-address is devicename */
58 ARP_OPT_s = (1 << 9),
59 ARP_OPT_v = (1 << 10) * DEBUG, /* debugging output flag */
60};
61
62enum {
63 sockfd = 3, /* active socket descriptor */
64};
65
66struct globals {
67 const struct aftype *ap; /* current address family */
68 const struct hwtype *hw; /* current hardware type */
69 const char *device; /* current device */
70 smallint hw_set; /* flag if hw-type was set (-H) */
71
72} FIX_ALIASING;
73#define G (*(struct globals*)&bb_common_bufsiz1)
74#define ap (G.ap )
75#define hw (G.hw )
76#define device (G.device )
77#define hw_set (G.hw_set )
78#define INIT_G() do { \
79 device = ""; \
80} while (0)
81
82
83static const char options[] ALIGN1 =
84 "pub\0"
85 "priv\0"
86 "temp\0"
87 "trail\0"
88 "dontpub\0"
89 "auto\0"
90 "dev\0"
91 "netmask\0";
92
93/* Delete an entry from the ARP cache. */
94/* Called only from main, once */
95static int arp_del(char **args)
96{
97 char *host;
98 struct arpreq req;
99 struct sockaddr sa;
100 int flags = 0;
101 int err;
102
103 memset(&req, 0, sizeof(req));
104
105 /* Resolve the host name. */
106 host = *args;
107 if (ap->input(host, &sa) < 0) {
108 bb_herror_msg_and_die("%s", host);
109 }
110
111 /* If a host has more than one address, use the correct one! */
112 memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
113
114 if (hw_set)
115 req.arp_ha.sa_family = hw->type;
116
117 req.arp_flags = ATF_PERM;
118 args++;
119 while (*args != NULL) {
120 switch (index_in_strings(options, *args)) {
121 case 0: /* "pub" */
122 flags |= 1;
123 args++;
124 break;
125 case 1: /* "priv" */
126 flags |= 2;
127 args++;
128 break;
129 case 2: /* "temp" */
130 req.arp_flags &= ~ATF_PERM;
131 args++;
132 break;
133 case 3: /* "trail" */
134 req.arp_flags |= ATF_USETRAILERS;
135 args++;
136 break;
137 case 4: /* "dontpub" */
138#ifdef HAVE_ATF_DONTPUB
139 req.arp_flags |= ATF_DONTPUB;
140#else
141 bb_error_msg("feature ATF_DONTPUB is not supported");
142#endif
143 args++;
144 break;
145 case 5: /* "auto" */
146#ifdef HAVE_ATF_MAGIC
147 req.arp_flags |= ATF_MAGIC;
148#else
149 bb_error_msg("feature ATF_MAGIC is not supported");
150#endif
151 args++;
152 break;
153 case 6: /* "dev" */
154 if (*++args == NULL)
155 bb_show_usage();
156 device = *args;
157 args++;
158 break;
159 case 7: /* "netmask" */
160 if (*++args == NULL)
161 bb_show_usage();
162 if (strcmp(*args, "255.255.255.255") != 0) {
163 host = *args;
164 if (ap->input(host, &sa) < 0) {
165 bb_herror_msg_and_die("%s", host);
166 }
167 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
168 req.arp_flags |= ATF_NETMASK;
169 }
170 args++;
171 break;
172 default:
173 bb_show_usage();
174 break;
175 }
176 }
177 if (flags == 0)
178 flags = 3;
179
180 strncpy(req.arp_dev, device, sizeof(req.arp_dev));
181
182 err = -1;
183
184 /* Call the kernel. */
185 if (flags & 2) {
186 if (option_mask32 & ARP_OPT_v)
187 bb_error_msg("SIOCDARP(nopub)");
188 err = ioctl(sockfd, SIOCDARP, &req);
189 if (err < 0) {
190 if (errno == ENXIO) {
191 if (flags & 1)
192 goto nopub;
193 printf("No ARP entry for %s\n", host);
194 return -1;
195 }
196 bb_perror_msg_and_die("SIOCDARP(priv)");
197 }
198 }
199 if ((flags & 1) && err) {
200 nopub:
201 req.arp_flags |= ATF_PUBL;
202 if (option_mask32 & ARP_OPT_v)
203 bb_error_msg("SIOCDARP(pub)");
204 if (ioctl(sockfd, SIOCDARP, &req) < 0) {
205 if (errno == ENXIO) {
206 printf("No ARP entry for %s\n", host);
207 return -1;
208 }
209 bb_perror_msg_and_die("SIOCDARP(pub)");
210 }
211 }
212 return 0;
213}
214
215/* Get the hardware address to a specified interface name */
216static void arp_getdevhw(char *ifname, struct sockaddr *sa,
217 const struct hwtype *hwt)
218{
219 struct ifreq ifr;
220 const struct hwtype *xhw;
221
222 strcpy(ifr.ifr_name, ifname);
223 ioctl_or_perror_and_die(sockfd, SIOCGIFHWADDR, &ifr,
224 "cant get HW-Address for '%s'", ifname);
225 if (hwt && (ifr.ifr_hwaddr.sa_family != hw->type)) {
226 bb_error_msg_and_die("protocol type mismatch");
227 }
228 memcpy(sa, &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
229
230 if (option_mask32 & ARP_OPT_v) {
231 xhw = get_hwntype(ifr.ifr_hwaddr.sa_family);
232 if (!xhw || !xhw->print) {
233 xhw = get_hwntype(-1);
234 }
235 bb_error_msg("device '%s' has HW address %s '%s'",
236 ifname, xhw->name,
237 xhw->print((unsigned char *) &ifr.ifr_hwaddr.sa_data));
238 }
239}
240
241/* Set an entry in the ARP cache. */
242/* Called only from main, once */
243static int arp_set(char **args)
244{
245 char *host;
246 struct arpreq req;
247 struct sockaddr sa;
248 int flags;
249
250 memset(&req, 0, sizeof(req));
251
252 host = *args++;
253 if (ap->input(host, &sa) < 0) {
254 bb_herror_msg_and_die("%s", host);
255 }
256 /* If a host has more than one address, use the correct one! */
257 memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
258
259 /* Fetch the hardware address. */
260 if (*args == NULL) {
261 bb_error_msg_and_die("need hardware address");
262 }
263 if (option_mask32 & ARP_OPT_D) {
264 arp_getdevhw(*args++, &req.arp_ha, hw_set ? hw : NULL);
265 } else {
266 if (hw->input(*args++, &req.arp_ha) < 0) {
267 bb_error_msg_and_die("invalid hardware address");
268 }
269 }
270
271 /* Check out any modifiers. */
272 flags = ATF_PERM | ATF_COM;
273 while (*args != NULL) {
274 switch (index_in_strings(options, *args)) {
275 case 0: /* "pub" */
276 flags |= ATF_PUBL;
277 args++;
278 break;
279 case 1: /* "priv" */
280 flags &= ~ATF_PUBL;
281 args++;
282 break;
283 case 2: /* "temp" */
284 flags &= ~ATF_PERM;
285 args++;
286 break;
287 case 3: /* "trail" */
288 flags |= ATF_USETRAILERS;
289 args++;
290 break;
291 case 4: /* "dontpub" */
292#ifdef HAVE_ATF_DONTPUB
293 flags |= ATF_DONTPUB;
294#else
295 bb_error_msg("feature ATF_DONTPUB is not supported");
296#endif
297 args++;
298 break;
299 case 5: /* "auto" */
300#ifdef HAVE_ATF_MAGIC
301 flags |= ATF_MAGIC;
302#else
303 bb_error_msg("feature ATF_MAGIC is not supported");
304#endif
305 args++;
306 break;
307 case 6: /* "dev" */
308 if (*++args == NULL)
309 bb_show_usage();
310 device = *args;
311 args++;
312 break;
313 case 7: /* "netmask" */
314 if (*++args == NULL)
315 bb_show_usage();
316 if (strcmp(*args, "255.255.255.255") != 0) {
317 host = *args;
318 if (ap->input(host, &sa) < 0) {
319 bb_herror_msg_and_die("%s", host);
320 }
321 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
322 flags |= ATF_NETMASK;
323 }
324 args++;
325 break;
326 default:
327 bb_show_usage();
328 break;
329 }
330 }
331
332 /* Fill in the remainder of the request. */
333 req.arp_flags = flags;
334
335 strncpy(req.arp_dev, device, sizeof(req.arp_dev));
336
337 /* Call the kernel. */
338 if (option_mask32 & ARP_OPT_v)
339 bb_error_msg("SIOCSARP()");
340 xioctl(sockfd, SIOCSARP, &req);
341 return 0;
342}
343
344
345/* Print the contents of an ARP request block. */
346static void
347arp_disp(const char *name, char *ip, int type, int arp_flags,
348 char *hwa, char *mask, char *dev)
349{
350 static const int arp_masks[] = {
351 ATF_PERM, ATF_PUBL,
352#ifdef HAVE_ATF_MAGIC
353 ATF_MAGIC,
354#endif
355#ifdef HAVE_ATF_DONTPUB
356 ATF_DONTPUB,
357#endif
358 ATF_USETRAILERS,
359 };
360 static const char arp_labels[] ALIGN1 = "PERM\0""PUP\0"
361#ifdef HAVE_ATF_MAGIC
362 "AUTO\0"
363#endif
364#ifdef HAVE_ATF_DONTPUB
365 "DONTPUB\0"
366#endif
367 "TRAIL\0"
368 ;
369
370 const struct hwtype *xhw;
371
372 xhw = get_hwntype(type);
373 if (xhw == NULL)
374 xhw = get_hwtype(DFLT_HW);
375
376 printf("%s (%s) at ", name, ip);
377
378 if (!(arp_flags & ATF_COM)) {
379 if (arp_flags & ATF_PUBL)
380 printf("* ");
381 else
382 printf("<incomplete> ");
383 } else {
384 printf("%s [%s] ", hwa, xhw->name);
385 }
386
387 if (arp_flags & ATF_NETMASK)
388 printf("netmask %s ", mask);
389
390 print_flags_separated(arp_masks, arp_labels, arp_flags, " ");
391 printf(" on %s\n", dev);
392}
393
394/* Display the contents of the ARP cache in the kernel. */
395/* Called only from main, once */
396static int arp_show(char *name)
397{
398 const char *host;
399 const char *hostname;
400 FILE *fp;
401 struct sockaddr sa;
402 int type, flags;
403 int num;
404 unsigned entries = 0, shown = 0;
405 char ip[128];
406 char hwa[128];
407 char mask[128];
408 char line[128];
409 char dev[128];
410
411 host = NULL;
412 if (name != NULL) {
413 /* Resolve the host name. */
414 if (ap->input(name, &sa) < 0) {
415 bb_herror_msg_and_die("%s", name);
416 }
417 host = xstrdup(ap->sprint(&sa, 1));
418 }
419 fp = xfopen_for_read("/proc/net/arp");
420 /* Bypass header -- read one line */
421 fgets(line, sizeof(line), fp);
422
423 /* Read the ARP cache entries. */
424 while (fgets(line, sizeof(line), fp)) {
425
426 mask[0] = '-'; mask[1] = '\0';
427 dev[0] = '-'; dev[1] = '\0';
428 /* All these strings can't overflow
429 * because fgets above reads limited amount of data */
430 num = sscanf(line, "%s 0x%x 0x%x %s %s %s\n",
431 ip, &type, &flags, hwa, mask, dev);
432 if (num < 4)
433 break;
434
435 entries++;
436 /* if the user specified hw-type differs, skip it */
437 if (hw_set && (type != hw->type))
438 continue;
439
440 /* if the user specified address differs, skip it */
441 if (host && strcmp(ip, host) != 0)
442 continue;
443
444 /* if the user specified device differs, skip it */
445 if (device[0] && strcmp(dev, device) != 0)
446 continue;
447
448 shown++;
449 /* This IS ugly but it works -be */
450 hostname = "?";
451 if (!(option_mask32 & ARP_OPT_n)) {
452 if (ap->input(ip, &sa) < 0)
453 hostname = ip;
454 else
455 hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000);
456 if (strcmp(hostname, ip) == 0)
457 hostname = "?";
458 }
459
460 arp_disp(hostname, ip, type, flags, hwa, mask, dev);
461 }
462 if (option_mask32 & ARP_OPT_v)
463 printf("Entries: %d\tSkipped: %d\tFound: %d\n",
464 entries, entries - shown, shown);
465
466 if (!shown) {
467 if (hw_set || host || device[0])
468 printf("No match found in %d entries\n", entries);
469 }
470 if (ENABLE_FEATURE_CLEAN_UP) {
471 free((char*)host);
472 fclose(fp);
473 }
474 return 0;
475}
476
477int arp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
478int arp_main(int argc UNUSED_PARAM, char **argv)
479{
480 const char *hw_type = "ether";
481 const char *protocol;
482 unsigned opts;
483
484 INIT_G();
485
486 xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), sockfd);
487 ap = get_aftype(DFLT_AF);
488 if (!ap)
489 bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family");
490
491 opts = getopt32(argv, "A:p:H:t:i:adnDsv", &protocol, &protocol,
492 &hw_type, &hw_type, &device);
493 argv += optind;
494 if (opts & (ARP_OPT_A | ARP_OPT_p)) {
495 ap = get_aftype(protocol);
496 if (ap == NULL)
497 bb_error_msg_and_die("%s: unknown %s", protocol, "address family");
498 }
499 if (opts & (ARP_OPT_A | ARP_OPT_p)) {
500 hw = get_hwtype(hw_type);
501 if (hw == NULL)
502 bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type");
503 hw_set = 1;
504 }
505 //if (opts & ARP_OPT_i)... -i
506
507 if (ap->af != AF_INET) {
508 bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name);
509 }
510
511 /* If no hw type specified get default */
512 if (!hw) {
513 hw = get_hwtype(DFLT_HW);
514 if (!hw)
515 bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type");
516 }
517
518 if (hw->alen <= 0) {
519 bb_error_msg_and_die("%s: %s without ARP support",
520 hw->name, "hardware type");
521 }
522
523 /* Now see what we have to do here... */
524 if (opts & (ARP_OPT_d | ARP_OPT_s)) {
525 if (argv[0] == NULL)
526 bb_error_msg_and_die("need host name");
527 if (opts & ARP_OPT_s)
528 return arp_set(argv);
529 return arp_del(argv);
530 }
531 //if (opts & ARP_OPT_a) - default
532 return arp_show(argv[0]);
533}
Note: See TracBrowser for help on using the repository browser.