source: MondoRescue/branches/2.2.5/mindi-busybox/networking/arp.c@ 1765

Last change on this file since 1765 was 1765, checked in by Bruno Cornec, 16 years ago

Update to busybox 1.7.2
  • Property svn:eol-style set to native
File size: 11.2 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#include "libbb.h"
17#include "inet_common.h"
18
19#include <arpa/inet.h>
20#include <net/if.h>
21#include <net/if_arp.h>
22#include <netinet/ether.h>
23#include <netpacket/packet.h>
24
25#define DEBUG 0
26
27#define DFLT_AF "inet"
28#define DFLT_HW "ether"
29
30#define ARP_OPT_A (0x1)
31#define ARP_OPT_p (0x2)
32#define ARP_OPT_H (0x4)
33#define ARP_OPT_t (0x8)
34#define ARP_OPT_i (0x10)
35#define ARP_OPT_a (0x20)
36#define ARP_OPT_d (0x40)
37#define ARP_OPT_n (0x80) /* do not resolve addresses */
38#define ARP_OPT_D (0x100) /* HW-address is devicename */
39#define ARP_OPT_s (0x200)
40#define ARP_OPT_v (0x400 * DEBUG) /* debugging output flag */
41
42
43static const struct aftype *ap; /* current address family */
44static const struct hwtype *hw; /* current hardware type */
45static int sockfd; /* active socket descriptor */
46static smallint hw_set; /* flag if hw-type was set (-H) */
47static const char *device = ""; /* current device */
48
49static const char options[] ALIGN1 =
50 "pub\0"
51 "priv\0"
52 "temp\0"
53 "trail\0"
54 "dontpub\0"
55 "auto\0"
56 "dev\0"
57 "netmask\0";
58
59/* Delete an entry from the ARP cache. */
60/* Called only from main, once */
61static int arp_del(char **args)
62{
63 char *host;
64 struct arpreq req;
65 struct sockaddr sa;
66 int flags = 0;
67 int err;
68
69 memset(&req, 0, sizeof(req));
70
71 /* Resolve the host name. */
72 host = *args;
73 if (ap->input(host, &sa) < 0) {
74 bb_herror_msg_and_die("%s", host);
75 }
76
77 /* If a host has more than one address, use the correct one! */
78 memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
79
80 if (hw_set)
81 req.arp_ha.sa_family = hw->type;
82
83 req.arp_flags = ATF_PERM;
84 args++;
85 while (*args != NULL) {
86 switch (index_in_strings(options, *args)) {
87 case 0: /* "pub" */
88 flags |= 1;
89 args++;
90 break;
91 case 1: /* "priv" */
92 flags |= 2;
93 args++;
94 break;
95 case 2: /* "temp" */
96 req.arp_flags &= ~ATF_PERM;
97 args++;
98 break;
99 case 3: /* "trail" */
100 req.arp_flags |= ATF_USETRAILERS;
101 args++;
102 break;
103 case 4: /* "dontpub" */
104#ifdef HAVE_ATF_DONTPUB
105 req.arp_flags |= ATF_DONTPUB;
106#else
107 bb_error_msg("feature ATF_DONTPUB is not supported");
108#endif
109 args++;
110 break;
111 case 5: /* "auto" */
112#ifdef HAVE_ATF_MAGIC
113 req.arp_flags |= ATF_MAGIC;
114#else
115 bb_error_msg("feature ATF_MAGIC is not supported");
116#endif
117 args++;
118 break;
119 case 6: /* "dev" */
120 if (*++args == NULL)
121 bb_show_usage();
122 device = *args;
123 args++;
124 break;
125 case 7: /* "netmask" */
126 if (*++args == NULL)
127 bb_show_usage();
128 if (strcmp(*args, "255.255.255.255") != 0) {
129 host = *args;
130 if (ap->input(host, &sa) < 0) {
131 bb_herror_msg_and_die("%s", host);
132 }
133 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
134 req.arp_flags |= ATF_NETMASK;
135 }
136 args++;
137 break;
138 default:
139 bb_show_usage();
140 break;
141 }
142 }
143 if (flags == 0)
144 flags = 3;
145
146 strncpy(req.arp_dev, device, sizeof(req.arp_dev));
147
148 err = -1;
149
150 /* Call the kernel. */
151 if (flags & 2) {
152 if (option_mask32 & ARP_OPT_v)
153 bb_error_msg("SIOCDARP(nopub)");
154 err = ioctl(sockfd, SIOCDARP, &req);
155 if (err < 0) {
156 if (errno == ENXIO) {
157 if (flags & 1)
158 goto nopub;
159 printf("No ARP entry for %s\n", host);
160 return -1;
161 }
162 bb_perror_msg_and_die("SIOCDARP(priv)");
163 }
164 }
165 if ((flags & 1) && err) {
166 nopub:
167 req.arp_flags |= ATF_PUBL;
168 if (option_mask32 & ARP_OPT_v)
169 bb_error_msg("SIOCDARP(pub)");
170 if (ioctl(sockfd, SIOCDARP, &req) < 0) {
171 if (errno == ENXIO) {
172 printf("No ARP entry for %s\n", host);
173 return -1;
174 }
175 bb_perror_msg_and_die("SIOCDARP(pub)");
176 }
177 }
178 return 0;
179}
180
181/* Get the hardware address to a specified interface name */
182static void arp_getdevhw(char *ifname, struct sockaddr *sa,
183 const struct hwtype *hwt)
184{
185 struct ifreq ifr;
186 const struct hwtype *xhw;
187
188 strcpy(ifr.ifr_name, ifname);
189 ioctl_or_perror_and_die(sockfd, SIOCGIFHWADDR, &ifr,
190 "cant get HW-Address for '%s'", ifname);
191 if (hwt && (ifr.ifr_hwaddr.sa_family != hw->type)) {
192 bb_error_msg_and_die("protocol type mismatch");
193 }
194 memcpy(sa, &(ifr.ifr_hwaddr), sizeof(struct sockaddr));
195
196 if (option_mask32 & ARP_OPT_v) {
197 xhw = get_hwntype(ifr.ifr_hwaddr.sa_family);
198 if (!xhw || !xhw->print) {
199 xhw = get_hwntype(-1);
200 }
201 bb_error_msg("device '%s' has HW address %s '%s'",
202 ifname, xhw->name,
203 xhw->print((char *) &ifr.ifr_hwaddr.sa_data));
204 }
205}
206
207/* Set an entry in the ARP cache. */
208/* Called only from main, once */
209static int arp_set(char **args)
210{
211 char *host;
212 struct arpreq req;
213 struct sockaddr sa;
214 int flags;
215
216 memset(&req, 0, sizeof(req));
217
218 host = *args++;
219 if (ap->input(host, &sa) < 0) {
220 bb_herror_msg_and_die("%s", host);
221 }
222 /* If a host has more than one address, use the correct one! */
223 memcpy(&req.arp_pa, &sa, sizeof(struct sockaddr));
224
225 /* Fetch the hardware address. */
226 if (*args == NULL) {
227 bb_error_msg_and_die("need hardware address");
228 }
229 if (option_mask32 & ARP_OPT_D) {
230 arp_getdevhw(*args++, &req.arp_ha, hw_set ? hw : NULL);
231 } else {
232 if (hw->input(*args++, &req.arp_ha) < 0) {
233 bb_error_msg_and_die("invalid hardware address");
234 }
235 }
236
237 /* Check out any modifiers. */
238 flags = ATF_PERM | ATF_COM;
239 while (*args != NULL) {
240 switch (index_in_strings(options, *args)) {
241 case 0: /* "pub" */
242 flags |= ATF_PUBL;
243 args++;
244 break;
245 case 1: /* "priv" */
246 flags &= ~ATF_PUBL;
247 args++;
248 break;
249 case 2: /* "temp" */
250 flags &= ~ATF_PERM;
251 args++;
252 break;
253 case 3: /* "trail" */
254 flags |= ATF_USETRAILERS;
255 args++;
256 break;
257 case 4: /* "dontpub" */
258#ifdef HAVE_ATF_DONTPUB
259 flags |= ATF_DONTPUB;
260#else
261 bb_error_msg("feature ATF_DONTPUB is not supported");
262#endif
263 args++;
264 break;
265 case 5: /* "auto" */
266#ifdef HAVE_ATF_MAGIC
267 flags |= ATF_MAGIC;
268#else
269 bb_error_msg("feature ATF_MAGIC is not supported");
270#endif
271 args++;
272 break;
273 case 6: /* "dev" */
274 if (*++args == NULL)
275 bb_show_usage();
276 device = *args;
277 args++;
278 break;
279 case 7: /* "netmask" */
280 if (*++args == NULL)
281 bb_show_usage();
282 if (strcmp(*args, "255.255.255.255") != 0) {
283 host = *args;
284 if (ap->input(host, &sa) < 0) {
285 bb_herror_msg_and_die("%s", host);
286 }
287 memcpy(&req.arp_netmask, &sa, sizeof(struct sockaddr));
288 flags |= ATF_NETMASK;
289 }
290 args++;
291 break;
292 default:
293 bb_show_usage();
294 break;
295 }
296 }
297
298 /* Fill in the remainder of the request. */
299 req.arp_flags = flags;
300
301 strncpy(req.arp_dev, device, sizeof(req.arp_dev));
302
303 /* Call the kernel. */
304 if (option_mask32 & ARP_OPT_v)
305 bb_error_msg("SIOCSARP()");
306 xioctl(sockfd, SIOCSARP, &req);
307 return 0;
308}
309
310
311/* Print the contents of an ARP request block. */
312static void
313arp_disp(const char *name, char *ip, int type, int arp_flags,
314 char *hwa, char *mask, char *dev)
315{
316 const struct hwtype *xhw;
317
318 xhw = get_hwntype(type);
319 if (xhw == NULL)
320 xhw = get_hwtype(DFLT_HW);
321
322 printf("%s (%s) at ", name, ip);
323
324 if (!(arp_flags & ATF_COM)) {
325 if (arp_flags & ATF_PUBL)
326 printf("* ");
327 else
328 printf("<incomplete> ");
329 } else {
330 printf("%s [%s] ", hwa, xhw->name);
331 }
332
333 if (arp_flags & ATF_NETMASK)
334 printf("netmask %s ", mask);
335
336 if (arp_flags & ATF_PERM)
337 printf("PERM ");
338 if (arp_flags & ATF_PUBL)
339 printf("PUP ");
340#ifdef HAVE_ATF_MAGIC
341 if (arp_flags & ATF_MAGIC)
342 printf("AUTO ");
343#endif
344#ifdef HAVE_ATF_DONTPUB
345 if (arp_flags & ATF_DONTPUB)
346 printf("DONTPUB ");
347#endif
348 if (arp_flags & ATF_USETRAILERS)
349 printf("TRAIL ");
350
351 printf("on %s\n", dev);
352}
353
354/* Display the contents of the ARP cache in the kernel. */
355/* Called only from main, once */
356static int arp_show(char *name)
357{
358 const char *host;
359 const char *hostname;
360 FILE *fp;
361 struct sockaddr sa;
362 int type, flags;
363 int num;
364 unsigned entries = 0, shown = 0;
365 char ip[128];
366 char hwa[128];
367 char mask[128];
368 char line[128];
369 char dev[128];
370
371 host = NULL;
372 if (name != NULL) {
373 /* Resolve the host name. */
374 if (ap->input(name, &sa) < 0) {
375 bb_herror_msg_and_die("%s", name);
376 }
377 host = xstrdup(ap->sprint(&sa, 1));
378 }
379 fp = xfopen("/proc/net/arp", "r");
380 /* Bypass header -- read one line */
381 fgets(line, sizeof(line), fp);
382
383 /* Read the ARP cache entries. */
384 while (fgets(line, sizeof(line), fp)) {
385
386 mask[0] = '-'; mask[1] = '\0';
387 dev[0] = '-'; dev[1] = '\0';
388 /* All these strings can't overflow
389 * because fgets above reads limited amount of data */
390 num = sscanf(line, "%s 0x%x 0x%x %s %s %s\n",
391 ip, &type, &flags, hwa, mask, dev);
392 if (num < 4)
393 break;
394
395 entries++;
396 /* if the user specified hw-type differs, skip it */
397 if (hw_set && (type != hw->type))
398 continue;
399
400 /* if the user specified address differs, skip it */
401 if (host && strcmp(ip, host) != 0)
402 continue;
403
404 /* if the user specified device differs, skip it */
405 if (device[0] && strcmp(dev, device) != 0)
406 continue;
407
408 shown++;
409 /* This IS ugly but it works -be */
410 hostname = "?";
411 if (!(option_mask32 & ARP_OPT_n)) {
412 if (ap->input(ip, &sa) < 0)
413 hostname = ip;
414 else
415 hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000);
416 if (strcmp(hostname, ip) == 0)
417 hostname = "?";
418 }
419
420 arp_disp(hostname, ip, type, flags, hwa, mask, dev);
421 }
422 if (option_mask32 & ARP_OPT_v)
423 printf("Entries: %d\tSkipped: %d\tFound: %d\n",
424 entries, entries - shown, shown);
425
426 if (!shown) {
427 if (hw_set || host || device[0])
428 printf("No match found in %d entries\n", entries);
429 }
430 if (ENABLE_FEATURE_CLEAN_UP) {
431 free((char*)host);
432 fclose(fp);
433 }
434 return 0;
435}
436
437int arp_main(int argc, char **argv);
438int arp_main(int argc, char **argv)
439{
440 char *hw_type;
441 char *protocol;
442
443 /* Initialize variables... */
444 ap = get_aftype(DFLT_AF);
445 if (!ap)
446 bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family");
447
448 getopt32(argv, "A:p:H:t:i:adnDsv", &protocol, &protocol,
449 &hw_type, &hw_type, &device);
450 argv += optind;
451 if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) {
452 ap = get_aftype(protocol);
453 if (ap == NULL)
454 bb_error_msg_and_die("%s: unknown %s", protocol, "address family");
455 }
456 if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) {
457 hw = get_hwtype(hw_type);
458 if (hw == NULL)
459 bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type");
460 hw_set = 1;
461 }
462 //if (option_mask32 & ARP_OPT_i)... -i
463
464 if (ap->af != AF_INET) {
465 bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name);
466 }
467
468 /* If no hw type specified get default */
469 if (!hw) {
470 hw = get_hwtype(DFLT_HW);
471 if (!hw)
472 bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type");
473 }
474
475 if (hw->alen <= 0) {
476 bb_error_msg_and_die("%s: %s without ARP support",
477 hw->name, "hardware type");
478 }
479 sockfd = xsocket(AF_INET, SOCK_DGRAM, 0);
480
481 /* Now see what we have to do here... */
482 if (option_mask32 & (ARP_OPT_d|ARP_OPT_s)) {
483 if (argv[0] == NULL)
484 bb_error_msg_and_die("need host name");
485 if (option_mask32 & ARP_OPT_s)
486 return arp_set(argv);
487 return arp_del(argv);
488 }
489 //if (option_mask32 & ARP_OPT_a) - default
490 return arp_show(argv[0]);
491}
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