Contents of /tags/mkinitrd-6_1_12/busybox/networking/arp.c
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Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
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File size: 11595 byte(s)
Tue Nov 17 21:24:51 2009 UTC (14 years, 10 months ago) by niro
File MIME type: text/plain
File size: 11595 byte(s)
tagged 'mkinitrd-6_1_12'
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 | |
43 | static const struct aftype *ap; /* current address family */ |
44 | static const struct hwtype *hw; /* current hardware type */ |
45 | static int sockfd; /* active socket descriptor */ |
46 | static smallint hw_set; /* flag if hw-type was set (-H) */ |
47 | static const char *device = ""; /* current device */ |
48 | |
49 | static 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 */ |
61 | static 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 */ |
182 | static 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((unsigned char *) &ifr.ifr_hwaddr.sa_data)); |
204 | } |
205 | } |
206 | |
207 | /* Set an entry in the ARP cache. */ |
208 | /* Called only from main, once */ |
209 | static 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. */ |
312 | static void |
313 | arp_disp(const char *name, char *ip, int type, int arp_flags, |
314 | char *hwa, char *mask, char *dev) |
315 | { |
316 | static const int arp_masks[] = { |
317 | ATF_PERM, ATF_PUBL, |
318 | #ifdef HAVE_ATF_MAGIC |
319 | ATF_MAGIC, |
320 | #endif |
321 | #ifdef HAVE_ATF_DONTPUB |
322 | ATF_DONTPUB, |
323 | #endif |
324 | ATF_USETRAILERS, |
325 | }; |
326 | static const char arp_labels[] ALIGN1 = "PERM\0""PUP\0" |
327 | #ifdef HAVE_ATF_MAGIC |
328 | "AUTO\0" |
329 | #endif |
330 | #ifdef HAVE_ATF_DONTPUB |
331 | "DONTPUB\0" |
332 | #endif |
333 | "TRAIL\0" |
334 | ; |
335 | |
336 | const struct hwtype *xhw; |
337 | |
338 | xhw = get_hwntype(type); |
339 | if (xhw == NULL) |
340 | xhw = get_hwtype(DFLT_HW); |
341 | |
342 | printf("%s (%s) at ", name, ip); |
343 | |
344 | if (!(arp_flags & ATF_COM)) { |
345 | if (arp_flags & ATF_PUBL) |
346 | printf("* "); |
347 | else |
348 | printf("<incomplete> "); |
349 | } else { |
350 | printf("%s [%s] ", hwa, xhw->name); |
351 | } |
352 | |
353 | if (arp_flags & ATF_NETMASK) |
354 | printf("netmask %s ", mask); |
355 | |
356 | print_flags_separated(arp_masks, arp_labels, arp_flags, " "); |
357 | printf(" on %s\n", dev); |
358 | } |
359 | |
360 | /* Display the contents of the ARP cache in the kernel. */ |
361 | /* Called only from main, once */ |
362 | static int arp_show(char *name) |
363 | { |
364 | const char *host; |
365 | const char *hostname; |
366 | FILE *fp; |
367 | struct sockaddr sa; |
368 | int type, flags; |
369 | int num; |
370 | unsigned entries = 0, shown = 0; |
371 | char ip[128]; |
372 | char hwa[128]; |
373 | char mask[128]; |
374 | char line[128]; |
375 | char dev[128]; |
376 | |
377 | host = NULL; |
378 | if (name != NULL) { |
379 | /* Resolve the host name. */ |
380 | if (ap->input(name, &sa) < 0) { |
381 | bb_herror_msg_and_die("%s", name); |
382 | } |
383 | host = xstrdup(ap->sprint(&sa, 1)); |
384 | } |
385 | fp = xfopen_for_read("/proc/net/arp"); |
386 | /* Bypass header -- read one line */ |
387 | fgets(line, sizeof(line), fp); |
388 | |
389 | /* Read the ARP cache entries. */ |
390 | while (fgets(line, sizeof(line), fp)) { |
391 | |
392 | mask[0] = '-'; mask[1] = '\0'; |
393 | dev[0] = '-'; dev[1] = '\0'; |
394 | /* All these strings can't overflow |
395 | * because fgets above reads limited amount of data */ |
396 | num = sscanf(line, "%s 0x%x 0x%x %s %s %s\n", |
397 | ip, &type, &flags, hwa, mask, dev); |
398 | if (num < 4) |
399 | break; |
400 | |
401 | entries++; |
402 | /* if the user specified hw-type differs, skip it */ |
403 | if (hw_set && (type != hw->type)) |
404 | continue; |
405 | |
406 | /* if the user specified address differs, skip it */ |
407 | if (host && strcmp(ip, host) != 0) |
408 | continue; |
409 | |
410 | /* if the user specified device differs, skip it */ |
411 | if (device[0] && strcmp(dev, device) != 0) |
412 | continue; |
413 | |
414 | shown++; |
415 | /* This IS ugly but it works -be */ |
416 | hostname = "?"; |
417 | if (!(option_mask32 & ARP_OPT_n)) { |
418 | if (ap->input(ip, &sa) < 0) |
419 | hostname = ip; |
420 | else |
421 | hostname = ap->sprint(&sa, (option_mask32 & ARP_OPT_n) | 0x8000); |
422 | if (strcmp(hostname, ip) == 0) |
423 | hostname = "?"; |
424 | } |
425 | |
426 | arp_disp(hostname, ip, type, flags, hwa, mask, dev); |
427 | } |
428 | if (option_mask32 & ARP_OPT_v) |
429 | printf("Entries: %d\tSkipped: %d\tFound: %d\n", |
430 | entries, entries - shown, shown); |
431 | |
432 | if (!shown) { |
433 | if (hw_set || host || device[0]) |
434 | printf("No match found in %d entries\n", entries); |
435 | } |
436 | if (ENABLE_FEATURE_CLEAN_UP) { |
437 | free((char*)host); |
438 | fclose(fp); |
439 | } |
440 | return 0; |
441 | } |
442 | |
443 | int arp_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
444 | int arp_main(int argc UNUSED_PARAM, char **argv) |
445 | { |
446 | const char *hw_type = "ether"; |
447 | const char *protocol; |
448 | |
449 | /* Initialize variables... */ |
450 | ap = get_aftype(DFLT_AF); |
451 | if (!ap) |
452 | bb_error_msg_and_die("%s: %s not supported", DFLT_AF, "address family"); |
453 | |
454 | getopt32(argv, "A:p:H:t:i:adnDsv", &protocol, &protocol, |
455 | &hw_type, &hw_type, &device); |
456 | argv += optind; |
457 | if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) { |
458 | ap = get_aftype(protocol); |
459 | if (ap == NULL) |
460 | bb_error_msg_and_die("%s: unknown %s", protocol, "address family"); |
461 | } |
462 | if (option_mask32 & ARP_OPT_A || option_mask32 & ARP_OPT_p) { |
463 | hw = get_hwtype(hw_type); |
464 | if (hw == NULL) |
465 | bb_error_msg_and_die("%s: unknown %s", hw_type, "hardware type"); |
466 | hw_set = 1; |
467 | } |
468 | //if (option_mask32 & ARP_OPT_i)... -i |
469 | |
470 | if (ap->af != AF_INET) { |
471 | bb_error_msg_and_die("%s: kernel only supports 'inet'", ap->name); |
472 | } |
473 | |
474 | /* If no hw type specified get default */ |
475 | if (!hw) { |
476 | hw = get_hwtype(DFLT_HW); |
477 | if (!hw) |
478 | bb_error_msg_and_die("%s: %s not supported", DFLT_HW, "hardware type"); |
479 | } |
480 | |
481 | if (hw->alen <= 0) { |
482 | bb_error_msg_and_die("%s: %s without ARP support", |
483 | hw->name, "hardware type"); |
484 | } |
485 | sockfd = xsocket(AF_INET, SOCK_DGRAM, 0); |
486 | |
487 | /* Now see what we have to do here... */ |
488 | if (option_mask32 & (ARP_OPT_d|ARP_OPT_s)) { |
489 | if (argv[0] == NULL) |
490 | bb_error_msg_and_die("need host name"); |
491 | if (option_mask32 & ARP_OPT_s) |
492 | return arp_set(argv); |
493 | return arp_del(argv); |
494 | } |
495 | //if (option_mask32 & ARP_OPT_a) - default |
496 | return arp_show(argv[0]); |
497 | } |