Contents of /trunk/mkinitrd-magellan/busybox/networking/arping.c
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Wed Aug 18 21:56:57 2010 UTC (14 years, 1 month ago) by niro
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Wed Aug 18 21:56:57 2010 UTC (14 years, 1 month ago) by niro
File MIME type: text/plain
File size: 10782 byte(s)
-updated to busybox-1.17.1
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * arping.c - Ping hosts by ARP requests/replies |
4 | * |
5 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
6 | * |
7 | * Author: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> |
8 | * Busybox port: Nick Fedchik <nick@fedchik.org.ua> |
9 | */ |
10 | |
11 | #include <arpa/inet.h> |
12 | #include <net/if.h> |
13 | #include <netinet/ether.h> |
14 | #include <netpacket/packet.h> |
15 | |
16 | #include "libbb.h" |
17 | |
18 | /* We don't expect to see 1000+ seconds delay, unsigned is enough */ |
19 | #define MONOTONIC_US() ((unsigned)monotonic_us()) |
20 | |
21 | enum { |
22 | DAD = 1, |
23 | UNSOLICITED = 2, |
24 | ADVERT = 4, |
25 | QUIET = 8, |
26 | QUIT_ON_REPLY = 16, |
27 | BCAST_ONLY = 32, |
28 | UNICASTING = 64 |
29 | }; |
30 | |
31 | struct globals { |
32 | struct in_addr src; |
33 | struct in_addr dst; |
34 | struct sockaddr_ll me; |
35 | struct sockaddr_ll he; |
36 | int sock_fd; |
37 | |
38 | int count; // = -1; |
39 | unsigned last; |
40 | unsigned timeout_us; |
41 | unsigned start; |
42 | |
43 | unsigned sent; |
44 | unsigned brd_sent; |
45 | unsigned received; |
46 | unsigned brd_recv; |
47 | unsigned req_recv; |
48 | } FIX_ALIASING; |
49 | #define G (*(struct globals*)&bb_common_bufsiz1) |
50 | #define src (G.src ) |
51 | #define dst (G.dst ) |
52 | #define me (G.me ) |
53 | #define he (G.he ) |
54 | #define sock_fd (G.sock_fd ) |
55 | #define count (G.count ) |
56 | #define last (G.last ) |
57 | #define timeout_us (G.timeout_us) |
58 | #define start (G.start ) |
59 | #define sent (G.sent ) |
60 | #define brd_sent (G.brd_sent ) |
61 | #define received (G.received ) |
62 | #define brd_recv (G.brd_recv ) |
63 | #define req_recv (G.req_recv ) |
64 | #define INIT_G() do { \ |
65 | count = -1; \ |
66 | } while (0) |
67 | |
68 | // If GNUisms are not available... |
69 | //static void *mempcpy(void *_dst, const void *_src, int n) |
70 | //{ |
71 | // memcpy(_dst, _src, n); |
72 | // return (char*)_dst + n; |
73 | //} |
74 | |
75 | static int send_pack(struct in_addr *src_addr, |
76 | struct in_addr *dst_addr, struct sockaddr_ll *ME, |
77 | struct sockaddr_ll *HE) |
78 | { |
79 | int err; |
80 | unsigned char buf[256]; |
81 | struct arphdr *ah = (struct arphdr *) buf; |
82 | unsigned char *p = (unsigned char *) (ah + 1); |
83 | |
84 | ah->ar_hrd = htons(ARPHRD_ETHER); |
85 | ah->ar_pro = htons(ETH_P_IP); |
86 | ah->ar_hln = ME->sll_halen; |
87 | ah->ar_pln = 4; |
88 | ah->ar_op = option_mask32 & ADVERT ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST); |
89 | |
90 | p = mempcpy(p, &ME->sll_addr, ah->ar_hln); |
91 | p = mempcpy(p, src_addr, 4); |
92 | |
93 | if (option_mask32 & ADVERT) |
94 | p = mempcpy(p, &ME->sll_addr, ah->ar_hln); |
95 | else |
96 | p = mempcpy(p, &HE->sll_addr, ah->ar_hln); |
97 | |
98 | p = mempcpy(p, dst_addr, 4); |
99 | |
100 | err = sendto(sock_fd, buf, p - buf, 0, (struct sockaddr *) HE, sizeof(*HE)); |
101 | if (err == p - buf) { |
102 | last = MONOTONIC_US(); |
103 | sent++; |
104 | if (!(option_mask32 & UNICASTING)) |
105 | brd_sent++; |
106 | } |
107 | return err; |
108 | } |
109 | |
110 | static void finish(void) NORETURN; |
111 | static void finish(void) |
112 | { |
113 | if (!(option_mask32 & QUIET)) { |
114 | printf("Sent %u probe(s) (%u broadcast(s))\n" |
115 | "Received %u repl%s" |
116 | " (%u request(s), %u broadcast(s))\n", |
117 | sent, brd_sent, |
118 | received, (received == 1) ? "ies" : "y", |
119 | req_recv, brd_recv); |
120 | } |
121 | if (option_mask32 & DAD) |
122 | exit(!!received); |
123 | if (option_mask32 & UNSOLICITED) |
124 | exit(EXIT_SUCCESS); |
125 | exit(!received); |
126 | } |
127 | |
128 | static void catcher(void) |
129 | { |
130 | unsigned now; |
131 | |
132 | now = MONOTONIC_US(); |
133 | if (start == 0) |
134 | start = now; |
135 | |
136 | if (count == 0 || (timeout_us && (now - start) > timeout_us)) |
137 | finish(); |
138 | |
139 | /* count < 0 means "infinite count" */ |
140 | if (count > 0) |
141 | count--; |
142 | |
143 | if (last == 0 || (now - last) > 500000) { |
144 | send_pack(&src, &dst, &me, &he); |
145 | if (count == 0 && (option_mask32 & UNSOLICITED)) |
146 | finish(); |
147 | } |
148 | alarm(1); |
149 | } |
150 | |
151 | static bool recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) |
152 | { |
153 | struct arphdr *ah = (struct arphdr *) buf; |
154 | unsigned char *p = (unsigned char *) (ah + 1); |
155 | struct in_addr src_ip, dst_ip; |
156 | /* moves below assume in_addr is 4 bytes big, ensure that */ |
157 | struct BUG_in_addr_must_be_4 { |
158 | char BUG_in_addr_must_be_4[ |
159 | sizeof(struct in_addr) == 4 ? 1 : -1 |
160 | ]; |
161 | char BUG_s_addr_must_be_4[ |
162 | sizeof(src_ip.s_addr) == 4 ? 1 : -1 |
163 | ]; |
164 | }; |
165 | |
166 | /* Filter out wild packets */ |
167 | if (FROM->sll_pkttype != PACKET_HOST |
168 | && FROM->sll_pkttype != PACKET_BROADCAST |
169 | && FROM->sll_pkttype != PACKET_MULTICAST) |
170 | return false; |
171 | |
172 | /* Only these types are recognized */ |
173 | if (ah->ar_op != htons(ARPOP_REQUEST) && ah->ar_op != htons(ARPOP_REPLY)) |
174 | return false; |
175 | |
176 | /* ARPHRD check and this darned FDDI hack here :-( */ |
177 | if (ah->ar_hrd != htons(FROM->sll_hatype) |
178 | && (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER))) |
179 | return false; |
180 | |
181 | /* Protocol must be IP. */ |
182 | if (ah->ar_pro != htons(ETH_P_IP) |
183 | || (ah->ar_pln != 4) |
184 | || (ah->ar_hln != me.sll_halen) |
185 | || (len < (int)(sizeof(*ah) + 2 * (4 + ah->ar_hln)))) |
186 | return false; |
187 | |
188 | move_from_unaligned32(src_ip.s_addr, p + ah->ar_hln); |
189 | move_from_unaligned32(dst_ip.s_addr, p + ah->ar_hln + 4 + ah->ar_hln); |
190 | |
191 | if (dst.s_addr != src_ip.s_addr) |
192 | return false; |
193 | if (!(option_mask32 & DAD)) { |
194 | if ((src.s_addr != dst_ip.s_addr) |
195 | || (memcmp(p + ah->ar_hln + 4, &me.sll_addr, ah->ar_hln))) |
196 | return false; |
197 | } else { |
198 | /* DAD packet was: |
199 | src_ip = 0 (or some src) |
200 | src_hw = ME |
201 | dst_ip = tested address |
202 | dst_hw = <unspec> |
203 | |
204 | We fail, if receive request/reply with: |
205 | src_ip = tested_address |
206 | src_hw != ME |
207 | if src_ip in request was not zero, check |
208 | also that it matches to dst_ip, otherwise |
209 | dst_ip/dst_hw do not matter. |
210 | */ |
211 | if ((memcmp(p, &me.sll_addr, me.sll_halen) == 0) |
212 | || (src.s_addr && src.s_addr != dst_ip.s_addr)) |
213 | return false; |
214 | } |
215 | if (!(option_mask32 & QUIET)) { |
216 | int s_printed = 0; |
217 | |
218 | printf("%scast re%s from %s [%s]", |
219 | FROM->sll_pkttype == PACKET_HOST ? "Uni" : "Broad", |
220 | ah->ar_op == htons(ARPOP_REPLY) ? "ply" : "quest", |
221 | inet_ntoa(src_ip), |
222 | ether_ntoa((struct ether_addr *) p)); |
223 | if (dst_ip.s_addr != src.s_addr) { |
224 | printf("for %s ", inet_ntoa(dst_ip)); |
225 | s_printed = 1; |
226 | } |
227 | if (memcmp(p + ah->ar_hln + 4, me.sll_addr, ah->ar_hln)) { |
228 | if (!s_printed) |
229 | printf("for "); |
230 | printf("[%s]", |
231 | ether_ntoa((struct ether_addr *) p + ah->ar_hln + 4)); |
232 | } |
233 | |
234 | if (last) { |
235 | unsigned diff = MONOTONIC_US() - last; |
236 | printf(" %u.%03ums\n", diff / 1000, diff % 1000); |
237 | } else { |
238 | printf(" UNSOLICITED?\n"); |
239 | } |
240 | fflush_all(); |
241 | } |
242 | received++; |
243 | if (FROM->sll_pkttype != PACKET_HOST) |
244 | brd_recv++; |
245 | if (ah->ar_op == htons(ARPOP_REQUEST)) |
246 | req_recv++; |
247 | if (option_mask32 & QUIT_ON_REPLY) |
248 | finish(); |
249 | if (!(option_mask32 & BCAST_ONLY)) { |
250 | memcpy(he.sll_addr, p, me.sll_halen); |
251 | option_mask32 |= UNICASTING; |
252 | } |
253 | return true; |
254 | } |
255 | |
256 | int arping_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
257 | int arping_main(int argc UNUSED_PARAM, char **argv) |
258 | { |
259 | const char *device = "eth0"; |
260 | char *source = NULL; |
261 | char *target; |
262 | unsigned char *packet; |
263 | char *err_str; |
264 | |
265 | INIT_G(); |
266 | |
267 | sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0); |
268 | |
269 | // Drop suid root privileges |
270 | // Need to remove SUID_NEVER from applets.h for this to work |
271 | //xsetuid(getuid()); |
272 | |
273 | err_str = xasprintf("interface %s %%s", device); |
274 | { |
275 | unsigned opt; |
276 | char *str_timeout; |
277 | |
278 | /* Dad also sets quit_on_reply. |
279 | * Advert also sets unsolicited. |
280 | */ |
281 | opt_complementary = "=1:Df:AU:c+"; |
282 | opt = getopt32(argv, "DUAqfbc:w:I:s:", |
283 | &count, &str_timeout, &device, &source); |
284 | if (opt & 0x80) /* -w: timeout */ |
285 | timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000; |
286 | //if (opt & 0x200) /* -s: source */ |
287 | option_mask32 &= 0x3f; /* set respective flags */ |
288 | } |
289 | |
290 | target = argv[optind]; |
291 | |
292 | xfunc_error_retval = 2; |
293 | |
294 | { |
295 | struct ifreq ifr; |
296 | |
297 | memset(&ifr, 0, sizeof(ifr)); |
298 | strncpy_IFNAMSIZ(ifr.ifr_name, device); |
299 | /* We use ifr.ifr_name in error msg so that problem |
300 | * with truncated name will be visible */ |
301 | ioctl_or_perror_and_die(sock_fd, SIOCGIFINDEX, &ifr, err_str, "not found"); |
302 | me.sll_ifindex = ifr.ifr_ifindex; |
303 | |
304 | xioctl(sock_fd, SIOCGIFFLAGS, (char *) &ifr); |
305 | |
306 | if (!(ifr.ifr_flags & IFF_UP)) { |
307 | bb_error_msg_and_die(err_str, "is down"); |
308 | } |
309 | if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) { |
310 | bb_error_msg(err_str, "is not ARPable"); |
311 | return (option_mask32 & DAD ? 0 : 2); |
312 | } |
313 | } |
314 | |
315 | /* if (!inet_aton(target, &dst)) - not needed */ { |
316 | len_and_sockaddr *lsa; |
317 | lsa = xhost_and_af2sockaddr(target, 0, AF_INET); |
318 | dst = lsa->u.sin.sin_addr; |
319 | if (ENABLE_FEATURE_CLEAN_UP) |
320 | free(lsa); |
321 | } |
322 | |
323 | if (source && !inet_aton(source, &src)) { |
324 | bb_error_msg_and_die("invalid source address %s", source); |
325 | } |
326 | |
327 | if ((option_mask32 & (DAD|UNSOLICITED)) == UNSOLICITED && src.s_addr == 0) |
328 | src = dst; |
329 | |
330 | if (!(option_mask32 & DAD) || src.s_addr) { |
331 | struct sockaddr_in saddr; |
332 | int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0); |
333 | |
334 | setsockopt_bindtodevice(probe_fd, device); |
335 | memset(&saddr, 0, sizeof(saddr)); |
336 | saddr.sin_family = AF_INET; |
337 | if (src.s_addr) { |
338 | /* Check that this is indeed our IP */ |
339 | saddr.sin_addr = src; |
340 | xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)); |
341 | } else { /* !(option_mask32 & DAD) case */ |
342 | /* Find IP address on this iface */ |
343 | socklen_t alen = sizeof(saddr); |
344 | |
345 | saddr.sin_port = htons(1025); |
346 | saddr.sin_addr = dst; |
347 | |
348 | if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, &const_int_1, sizeof(const_int_1)) == -1) |
349 | bb_perror_msg("setsockopt(SO_DONTROUTE)"); |
350 | xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr)); |
351 | getsockname(probe_fd, (struct sockaddr *) &saddr, &alen); |
352 | //never happens: |
353 | //if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) |
354 | // bb_perror_msg_and_die("getsockname"); |
355 | if (saddr.sin_family != AF_INET) |
356 | bb_error_msg_and_die("no IP address configured"); |
357 | src = saddr.sin_addr; |
358 | } |
359 | close(probe_fd); |
360 | } |
361 | |
362 | me.sll_family = AF_PACKET; |
363 | //me.sll_ifindex = ifindex; - done before |
364 | me.sll_protocol = htons(ETH_P_ARP); |
365 | xbind(sock_fd, (struct sockaddr *) &me, sizeof(me)); |
366 | |
367 | { |
368 | socklen_t alen = sizeof(me); |
369 | getsockname(sock_fd, (struct sockaddr *) &me, &alen); |
370 | //never happens: |
371 | //if (getsockname(sock_fd, (struct sockaddr *) &me, &alen) == -1) |
372 | // bb_perror_msg_and_die("getsockname"); |
373 | } |
374 | if (me.sll_halen == 0) { |
375 | bb_error_msg(err_str, "is not ARPable (no ll address)"); |
376 | return (option_mask32 & DAD ? 0 : 2); |
377 | } |
378 | he = me; |
379 | memset(he.sll_addr, -1, he.sll_halen); |
380 | |
381 | if (!(option_mask32 & QUIET)) { |
382 | /* inet_ntoa uses static storage, can't use in same printf */ |
383 | printf("ARPING to %s", inet_ntoa(dst)); |
384 | printf(" from %s via %s\n", inet_ntoa(src), device); |
385 | } |
386 | |
387 | signal_SA_RESTART_empty_mask(SIGINT, (void (*)(int))finish); |
388 | signal_SA_RESTART_empty_mask(SIGALRM, (void (*)(int))catcher); |
389 | |
390 | catcher(); |
391 | |
392 | packet = xmalloc(4096); |
393 | while (1) { |
394 | sigset_t sset, osset; |
395 | struct sockaddr_ll from; |
396 | socklen_t alen = sizeof(from); |
397 | int cc; |
398 | |
399 | cc = recvfrom(sock_fd, packet, 4096, 0, (struct sockaddr *) &from, &alen); |
400 | if (cc < 0) { |
401 | bb_perror_msg("recvfrom"); |
402 | continue; |
403 | } |
404 | sigemptyset(&sset); |
405 | sigaddset(&sset, SIGALRM); |
406 | sigaddset(&sset, SIGINT); |
407 | sigprocmask(SIG_BLOCK, &sset, &osset); |
408 | recv_pack(packet, cc, &from); |
409 | sigprocmask(SIG_SETMASK, &osset, NULL); |
410 | } |
411 | } |