diff options
Diffstat (limited to 'src/nat/gnunet-nat-server.c')
-rw-r--r-- | src/nat/gnunet-nat-server.c | 631 |
1 files changed, 25 insertions, 606 deletions
diff --git a/src/nat/gnunet-nat-server.c b/src/nat/gnunet-nat-server.c index ffc570146..c1f1be668 100644 --- a/src/nat/gnunet-nat-server.c +++ b/src/nat/gnunet-nat-server.c | |||
@@ -20,49 +20,12 @@ | |||
20 | 20 | ||
21 | /** | 21 | /** |
22 | * @file src/nat/gnunet-nat-server.c | 22 | * @file src/nat/gnunet-nat-server.c |
23 | * @brief Tool to help bypass NATs using ICMP method; must run as root (SUID will do) | 23 | * @brief Daemon to run on 'gnunet.org' to help test NAT traversal code |
24 | * This code will work under GNU/Linux only (or maybe BSDs, but never W32) | ||
25 | * @author Christian Grothoff | 24 | * @author Christian Grothoff |
26 | * | 25 | * |
27 | * This program will send ONE ICMP message every 500 ms RAW sockets | ||
28 | * to a DUMMY IP address and also listens for ICMP replies. Since | ||
29 | * it uses RAW sockets, it must be installed SUID or run as 'root'. | ||
30 | * In order to keep the security risk of the resulting SUID binary | ||
31 | * minimal, the program ONLY opens the two RAW sockets with root | ||
32 | * privileges, then drops them and only then starts to process | ||
33 | * command line arguments. The code also does not link against | ||
34 | * any shared libraries (except libc) and is strictly minimal | ||
35 | * (except for checking for errors). The following list of people | ||
36 | * have reviewed this code and considered it safe since the last | ||
37 | * modification (if you reviewed it, please have your name added | ||
38 | * to the list): | ||
39 | * | ||
40 | * - Christian Grothoff | ||
41 | * - Nathan Evans | ||
42 | * - Benjamin Kuperman (22 Aug 2010) | ||
43 | */ | 26 | */ |
44 | #if HAVE_CONFIG_H | 27 | #include "platform.h" |
45 | /* Just needed for HAVE_SOCKADDR_IN_SIN_LEN test macro! */ | 28 | #include "gnunet_util_lib.h" |
46 | #include "gnunet_config.h" | ||
47 | #else | ||
48 | #define _GNU_SOURCE | ||
49 | #endif | ||
50 | #include <sys/types.h> | ||
51 | #include <sys/socket.h> | ||
52 | #include <arpa/inet.h> | ||
53 | #include <sys/select.h> | ||
54 | #include <sys/time.h> | ||
55 | #include <sys/types.h> | ||
56 | #include <unistd.h> | ||
57 | #include <stdio.h> | ||
58 | #include <string.h> | ||
59 | #include <errno.h> | ||
60 | #include <stdlib.h> | ||
61 | #include <stdint.h> | ||
62 | #include <time.h> | ||
63 | #include <netinet/ip.h> | ||
64 | #include <netinet/ip_icmp.h> | ||
65 | #include <netinet/in.h> | ||
66 | 29 | ||
67 | /** | 30 | /** |
68 | * Should we print some debug output? | 31 | * Should we print some debug output? |
@@ -70,581 +33,37 @@ | |||
70 | #define VERBOSE 0 | 33 | #define VERBOSE 0 |
71 | 34 | ||
72 | /** | 35 | /** |
73 | * Must match IP given in the client. | 36 | * Main function that will be run. |
74 | */ | ||
75 | #define DUMMY_IP "192.0.2.86" | ||
76 | |||
77 | /** | ||
78 | * Port for UDP | ||
79 | */ | ||
80 | #define NAT_TRAV_PORT 22225 | ||
81 | |||
82 | /** | ||
83 | * How often do we send our ICMP messages to receive replies? | ||
84 | */ | ||
85 | #define ICMP_SEND_FREQUENCY_MS 500 | ||
86 | |||
87 | /** | ||
88 | * IPv4 header. | ||
89 | */ | ||
90 | struct ip_header | ||
91 | { | ||
92 | |||
93 | /** | ||
94 | * Version (4 bits) + Internet header length (4 bits) | ||
95 | */ | ||
96 | uint8_t vers_ihl; | ||
97 | |||
98 | /** | ||
99 | * Type of service | ||
100 | */ | ||
101 | uint8_t tos; | ||
102 | |||
103 | /** | ||
104 | * Total length | ||
105 | */ | ||
106 | uint16_t pkt_len; | ||
107 | |||
108 | /** | ||
109 | * Identification | ||
110 | */ | ||
111 | uint16_t id; | ||
112 | |||
113 | /** | ||
114 | * Flags (3 bits) + Fragment offset (13 bits) | ||
115 | */ | ||
116 | uint16_t flags_frag_offset; | ||
117 | |||
118 | /** | ||
119 | * Time to live | ||
120 | */ | ||
121 | uint8_t ttl; | ||
122 | |||
123 | /** | ||
124 | * Protocol | ||
125 | */ | ||
126 | uint8_t proto; | ||
127 | |||
128 | /** | ||
129 | * Header checksum | ||
130 | */ | ||
131 | uint16_t checksum; | ||
132 | |||
133 | /** | ||
134 | * Source address | ||
135 | */ | ||
136 | uint32_t src_ip; | ||
137 | |||
138 | /** | ||
139 | * Destination address | ||
140 | */ | ||
141 | uint32_t dst_ip; | ||
142 | }; | ||
143 | |||
144 | /** | ||
145 | * Format of ICMP packet. | ||
146 | */ | ||
147 | struct icmp_ttl_exceeded_header | ||
148 | { | ||
149 | uint8_t type; | ||
150 | |||
151 | uint8_t code; | ||
152 | |||
153 | uint16_t checksum; | ||
154 | |||
155 | uint32_t unused; | ||
156 | |||
157 | /* followed by original payload */ | ||
158 | }; | ||
159 | |||
160 | struct icmp_echo_header | ||
161 | { | ||
162 | uint8_t type; | ||
163 | |||
164 | uint8_t code; | ||
165 | |||
166 | uint16_t checksum; | ||
167 | |||
168 | uint32_t reserved; | ||
169 | }; | ||
170 | |||
171 | |||
172 | /** | ||
173 | * Beginning of UDP packet. | ||
174 | */ | ||
175 | struct udp_header | ||
176 | { | ||
177 | uint16_t src_port; | ||
178 | |||
179 | uint16_t dst_port; | ||
180 | |||
181 | uint16_t length; | ||
182 | |||
183 | uint16_t crc; | ||
184 | }; | ||
185 | |||
186 | /** | ||
187 | * Socket we use to receive "fake" ICMP replies. | ||
188 | */ | ||
189 | static int icmpsock; | ||
190 | |||
191 | /** | ||
192 | * Socket we use to send our ICMP requests. | ||
193 | */ | ||
194 | static int rawsock; | ||
195 | |||
196 | /** | ||
197 | * Socket we use to send our UDP requests. | ||
198 | */ | ||
199 | static int udpsock; | ||
200 | |||
201 | /** | ||
202 | * Target "dummy" address. | ||
203 | */ | ||
204 | static struct in_addr dummy; | ||
205 | |||
206 | |||
207 | /** | ||
208 | * CRC-16 for IP/ICMP headers. | ||
209 | * | ||
210 | * @param data what to calculate the CRC over | ||
211 | * @param bytes number of bytes in data (must be multiple of 2) | ||
212 | * @return the CRC 16. | ||
213 | */ | ||
214 | static uint16_t | ||
215 | calc_checksum(const uint16_t *data, | ||
216 | unsigned int bytes) | ||
217 | { | ||
218 | uint32_t sum; | ||
219 | unsigned int i; | ||
220 | |||
221 | sum = 0; | ||
222 | for (i=0;i<bytes/2;i++) | ||
223 | sum += data[i]; | ||
224 | sum = (sum & 0xffff) + (sum >> 16); | ||
225 | sum = htons(0xffff - sum); | ||
226 | return sum; | ||
227 | } | ||
228 | |||
229 | |||
230 | /** | ||
231 | * Send an ICMP message to the dummy IP. | ||
232 | * | 37 | * |
233 | * @param my_ip source address (our ip address) | 38 | * @param cls closure |
234 | */ | 39 | * @param args remaining command-line arguments |
235 | static void | 40 | * @param cfgfile name of the configuration file used (for saving, can be NULL!) |
236 | send_icmp_echo (const struct in_addr *my_ip) | 41 | * @param c configuration |
237 | { | ||
238 | char packet[sizeof (struct ip_header) + sizeof (struct icmp_echo_header)]; | ||
239 | struct icmp_echo_header icmp_echo; | ||
240 | struct ip_header ip_pkt; | ||
241 | struct sockaddr_in dst; | ||
242 | size_t off; | ||
243 | int err; | ||
244 | |||
245 | off = 0; | ||
246 | ip_pkt.vers_ihl = 0x45; | ||
247 | ip_pkt.tos = 0; | ||
248 | ip_pkt.pkt_len = htons (sizeof (packet)); | ||
249 | ip_pkt.id = htons (256); | ||
250 | ip_pkt.flags_frag_offset = 0; | ||
251 | ip_pkt.ttl = IPDEFTTL; | ||
252 | ip_pkt.proto = IPPROTO_ICMP; | ||
253 | ip_pkt.checksum = 0; | ||
254 | ip_pkt.src_ip = my_ip->s_addr; | ||
255 | ip_pkt.dst_ip = dummy.s_addr; | ||
256 | ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, | ||
257 | sizeof (struct ip_header))); | ||
258 | memcpy (&packet[off], | ||
259 | &ip_pkt, | ||
260 | sizeof (struct ip_header)); | ||
261 | off += sizeof (struct ip_header); | ||
262 | |||
263 | icmp_echo.type = ICMP_ECHO; | ||
264 | icmp_echo.code = 0; | ||
265 | icmp_echo.checksum = 0; | ||
266 | icmp_echo.reserved = 0; | ||
267 | icmp_echo.checksum = htons(calc_checksum((uint16_t*)&icmp_echo, | ||
268 | sizeof (struct icmp_echo_header))); | ||
269 | memcpy (&packet[off], | ||
270 | &icmp_echo, | ||
271 | sizeof (struct icmp_echo_header)); | ||
272 | off += sizeof (struct icmp_echo_header); | ||
273 | |||
274 | memset (&dst, 0, sizeof (dst)); | ||
275 | dst.sin_family = AF_INET; | ||
276 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
277 | dst.sin_len = sizeof (struct sockaddr_in); | ||
278 | #endif | ||
279 | dst.sin_addr = dummy; | ||
280 | err = sendto(rawsock, | ||
281 | packet, off, 0, | ||
282 | (struct sockaddr*)&dst, | ||
283 | sizeof(dst)); | ||
284 | if (err < 0) | ||
285 | { | ||
286 | #if VERBOSE | ||
287 | fprintf(stderr, | ||
288 | "sendto failed: %s\n", strerror(errno)); | ||
289 | #endif | ||
290 | } | ||
291 | else if (sizeof (packet) != err) | ||
292 | { | ||
293 | fprintf(stderr, | ||
294 | "Error: partial send of ICMP message\n"); | ||
295 | } | ||
296 | } | ||
297 | |||
298 | |||
299 | /** | ||
300 | * Send a UDP message to the dummy IP. | ||
301 | */ | ||
302 | static void | ||
303 | send_udp () | ||
304 | { | ||
305 | struct sockaddr_in dst; | ||
306 | ssize_t err; | ||
307 | |||
308 | memset (&dst, 0, sizeof (dst)); | ||
309 | dst.sin_family = AF_INET; | ||
310 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
311 | dst.sin_len = sizeof (struct sockaddr_in); | ||
312 | #endif | ||
313 | dst.sin_addr = dummy; | ||
314 | dst.sin_port = htons (NAT_TRAV_PORT); | ||
315 | err = sendto(udpsock, | ||
316 | NULL, 0, 0, | ||
317 | (struct sockaddr*)&dst, | ||
318 | sizeof(dst)); | ||
319 | if (err < 0) | ||
320 | { | ||
321 | #if VERBOSE | ||
322 | fprintf(stderr, | ||
323 | "sendto failed: %s\n", strerror(errno)); | ||
324 | #endif | ||
325 | } | ||
326 | else if (0 != err) | ||
327 | { | ||
328 | fprintf(stderr, | ||
329 | "Error: partial send of ICMP message\n"); | ||
330 | } | ||
331 | } | ||
332 | |||
333 | |||
334 | /** | ||
335 | * We've received an ICMP response. Process it. | ||
336 | */ | 42 | */ |
337 | static void | 43 | static void |
338 | process_icmp_response () | 44 | run (void *cls, |
339 | { | 45 | char *const *args, |
340 | char buf[65536]; | 46 | const char *cfgfile, |
341 | ssize_t have; | 47 | const struct GNUNET_CONFIGURATION_Handle * c) |
342 | struct in_addr source_ip; | ||
343 | struct ip_header ip_pkt; | ||
344 | struct icmp_ttl_exceeded_header icmp_ttl; | ||
345 | struct icmp_echo_header icmp_echo; | ||
346 | struct udp_header udp_pkt; | ||
347 | size_t off; | ||
348 | uint16_t port; | ||
349 | |||
350 | have = read (icmpsock, buf, sizeof (buf)); | ||
351 | if (-1 == have) | ||
352 | { | ||
353 | fprintf (stderr, | ||
354 | "Error reading raw socket: %s\n", | ||
355 | strerror (errno)); | ||
356 | return; | ||
357 | } | ||
358 | #if VERBOSE | ||
359 | fprintf (stderr, | ||
360 | "Received message of %u bytes\n", | ||
361 | (unsigned int) have); | ||
362 | #endif | ||
363 | if (have < (ssize_t) (sizeof (struct ip_header) + sizeof (struct icmp_ttl_exceeded_header) + sizeof (struct ip_header))) | ||
364 | { | ||
365 | /* malformed */ | ||
366 | return; | ||
367 | } | ||
368 | off = 0; | ||
369 | memcpy (&ip_pkt, | ||
370 | &buf[off], | ||
371 | sizeof (struct ip_header)); | ||
372 | off += sizeof (struct ip_header); | ||
373 | memcpy(&source_ip, | ||
374 | &ip_pkt.src_ip, | ||
375 | sizeof (source_ip)); | ||
376 | memcpy (&icmp_ttl, | ||
377 | &buf[off], | ||
378 | sizeof (struct icmp_ttl_exceeded_header)); | ||
379 | off += sizeof (struct icmp_ttl_exceeded_header); | ||
380 | if ( (ICMP_TIME_EXCEEDED != icmp_ttl.type) || | ||
381 | (0 != icmp_ttl.code) ) | ||
382 | { | ||
383 | /* different type than what we want */ | ||
384 | return; | ||
385 | } | ||
386 | /* skip 2nd IP header */ | ||
387 | memcpy (&ip_pkt, | ||
388 | &buf[off], | ||
389 | sizeof (struct ip_header)); | ||
390 | off += sizeof (struct ip_header); | ||
391 | |||
392 | switch (ip_pkt.proto) | ||
393 | { | ||
394 | case IPPROTO_ICMP: | ||
395 | if (have != (sizeof (struct ip_header) * 2 + | ||
396 | sizeof (struct icmp_ttl_exceeded_header) + | ||
397 | sizeof (struct icmp_echo_header)) ) | ||
398 | { | ||
399 | /* malformed */ | ||
400 | return; | ||
401 | } | ||
402 | /* grab ICMP ECHO content */ | ||
403 | memcpy (&icmp_echo, | ||
404 | &buf[off], | ||
405 | sizeof (struct icmp_echo_header)); | ||
406 | port = (uint16_t) ntohl (icmp_echo.reserved); | ||
407 | break; | ||
408 | case IPPROTO_UDP: | ||
409 | if (have != (sizeof (struct ip_header) * 2 + | ||
410 | sizeof (struct icmp_ttl_exceeded_header) + | ||
411 | sizeof (struct udp_header)) ) | ||
412 | { | ||
413 | /* malformed */ | ||
414 | return; | ||
415 | } | ||
416 | /* grab UDP content */ | ||
417 | memcpy (&udp_pkt, | ||
418 | &buf[off], | ||
419 | sizeof (struct udp_header)); | ||
420 | port = ntohs (udp_pkt.length); | ||
421 | break; | ||
422 | default: | ||
423 | /* different type than what we want */ | ||
424 | return; | ||
425 | } | ||
426 | |||
427 | if (port == 0) | ||
428 | fprintf (stdout, | ||
429 | "%s\n", | ||
430 | inet_ntop (AF_INET, | ||
431 | &source_ip, | ||
432 | buf, | ||
433 | sizeof (buf))); | ||
434 | else | ||
435 | fprintf (stdout, | ||
436 | "%s:%u\n", | ||
437 | inet_ntop (AF_INET, | ||
438 | &source_ip, | ||
439 | buf, | ||
440 | sizeof (buf)), | ||
441 | (unsigned int) port); | ||
442 | fflush (stdout); | ||
443 | } | ||
444 | |||
445 | |||
446 | /** | ||
447 | * Create an ICMP raw socket for reading. | ||
448 | * | ||
449 | * @return -1 on error | ||
450 | */ | ||
451 | static int | ||
452 | make_icmp_socket () | ||
453 | { | ||
454 | int ret; | ||
455 | |||
456 | ret = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP); | ||
457 | if (-1 == ret) | ||
458 | { | ||
459 | fprintf (stderr, | ||
460 | "Error opening RAW socket: %s\n", | ||
461 | strerror (errno)); | ||
462 | return -1; | ||
463 | } | ||
464 | if (ret >= FD_SETSIZE) | ||
465 | { | ||
466 | fprintf (stderr, | ||
467 | "Socket number too large (%d > %u)\n", | ||
468 | ret, | ||
469 | (unsigned int) FD_SETSIZE); | ||
470 | close (ret); | ||
471 | return -1; | ||
472 | } | ||
473 | return ret; | ||
474 | } | ||
475 | |||
476 | |||
477 | /** | ||
478 | * Create an ICMP raw socket for writing. | ||
479 | * | ||
480 | * @return -1 on error | ||
481 | */ | ||
482 | static int | ||
483 | make_raw_socket () | ||
484 | { | ||
485 | const int one = 1; | ||
486 | int ret; | ||
487 | |||
488 | ret = socket (AF_INET, SOCK_RAW, IPPROTO_RAW); | ||
489 | if (-1 == ret) | ||
490 | { | ||
491 | fprintf (stderr, | ||
492 | "Error opening RAW socket: %s\n", | ||
493 | strerror (errno)); | ||
494 | return -1; | ||
495 | } | ||
496 | if (-1 == setsockopt(ret, | ||
497 | SOL_SOCKET, | ||
498 | SO_BROADCAST, | ||
499 | (char *)&one, sizeof(one))) | ||
500 | { | ||
501 | fprintf(stderr, | ||
502 | "setsockopt failed: %s\n", | ||
503 | strerror (errno)); | ||
504 | close (ret); | ||
505 | return -1; | ||
506 | } | ||
507 | if (-1 == setsockopt(ret, | ||
508 | IPPROTO_IP, | ||
509 | IP_HDRINCL, | ||
510 | (char *)&one, sizeof(one))) | ||
511 | { | ||
512 | fprintf(stderr, | ||
513 | "setsockopt failed: %s\n", | ||
514 | strerror (errno)); | ||
515 | close (ret); | ||
516 | return -1; | ||
517 | } | ||
518 | return ret; | ||
519 | } | ||
520 | |||
521 | |||
522 | /** | ||
523 | * Create a UDP socket for writinging. | ||
524 | * | ||
525 | * @param my_ip source address (our ip address) | ||
526 | * @return -1 on error | ||
527 | */ | ||
528 | static int | ||
529 | make_udp_socket (const struct in_addr *my_ip) | ||
530 | { | 48 | { |
531 | int ret; | ||
532 | struct sockaddr_in addr; | ||
533 | |||
534 | ret = socket (AF_INET, SOCK_DGRAM, 0); | ||
535 | if (-1 == ret) | ||
536 | { | ||
537 | fprintf (stderr, | ||
538 | "Error opening UDP socket: %s\n", | ||
539 | strerror (errno)); | ||
540 | return -1; | ||
541 | } | ||
542 | memset (&addr, | ||
543 | 0, | ||
544 | sizeof (addr)); | ||
545 | addr.sin_family = AF_INET; | ||
546 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
547 | addr.sin_len = sizeof (struct sockaddr_in); | ||
548 | #endif | ||
549 | addr.sin_addr = *my_ip; | ||
550 | addr.sin_port = htons (NAT_TRAV_PORT); | ||
551 | |||
552 | if (0 != bind (ret, | ||
553 | &addr, | ||
554 | sizeof(addr))) | ||
555 | { | ||
556 | fprintf (stderr, | ||
557 | "Error binding UDP socket to port %u: %s\n", | ||
558 | NAT_TRAV_PORT, | ||
559 | strerror (errno)); | ||
560 | /* likely problematic, but not certain, try to continue */ | ||
561 | } | ||
562 | return ret; | ||
563 | } | 49 | } |
564 | 50 | ||
565 | 51 | ||
566 | int | 52 | int |
567 | main (int argc, | 53 | main (int argc, char *const argv[]) |
568 | char *const *argv) | ||
569 | { | 54 | { |
570 | struct in_addr external; | 55 | static const struct GNUNET_GETOPT_CommandLineOption options[] = { |
571 | fd_set rs; | 56 | GNUNET_GETOPT_OPTION_END |
572 | struct timeval tv; | 57 | }; |
573 | uid_t uid; | 58 | |
574 | unsigned int alt; | 59 | if (GNUNET_OK != |
575 | 60 | GNUNET_PROGRAM_run (argc, argv, | |
576 | if (2 != argc) | 61 | "gnunet-nat-server", |
577 | { | 62 | _("GNUnet NAT traversal test helper daemon"), |
578 | fprintf (stderr, | 63 | options, |
579 | "This program must be started with our (internal NAT) IP as the only argument.\n"); | 64 | &run, NULL)) |
580 | return 1; | 65 | return 1; |
581 | } | 66 | return 0; |
582 | if (1 != inet_pton (AF_INET, argv[1], &external)) | ||
583 | { | ||
584 | fprintf (stderr, | ||
585 | "Error parsing IPv4 address: %s\n", | ||
586 | strerror (errno)); | ||
587 | return 1; | ||
588 | } | ||
589 | if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy)) | ||
590 | { | ||
591 | fprintf (stderr, | ||
592 | "Internal error converting dummy IP to binary.\n"); | ||
593 | return 2; | ||
594 | } | ||
595 | if (-1 == (icmpsock = make_icmp_socket())) | ||
596 | { | ||
597 | return 3; | ||
598 | } | ||
599 | if (-1 == (rawsock = make_raw_socket())) | ||
600 | { | ||
601 | close (icmpsock); | ||
602 | return 3; | ||
603 | } | ||
604 | uid = getuid (); | ||
605 | if (0 != setresuid (uid, uid, uid)) | ||
606 | { | ||
607 | fprintf (stderr, | ||
608 | "Failed to setresuid: %s\n", | ||
609 | strerror (errno)); | ||
610 | /* not critical, continue anyway */ | ||
611 | } | ||
612 | if (-1 == (udpsock = make_udp_socket(&external))) | ||
613 | { | ||
614 | close (icmpsock); | ||
615 | close (rawsock); | ||
616 | return 3; | ||
617 | } | ||
618 | alt = 0; | ||
619 | while (1) | ||
620 | { | ||
621 | FD_ZERO (&rs); | ||
622 | FD_SET (icmpsock, &rs); | ||
623 | tv.tv_sec = 0; | ||
624 | tv.tv_usec = ICMP_SEND_FREQUENCY_MS * 1000; | ||
625 | if (-1 == select (icmpsock + 1, &rs, NULL, NULL, &tv)) | ||
626 | { | ||
627 | if (errno == EINTR) | ||
628 | continue; | ||
629 | fprintf (stderr, | ||
630 | "select failed: %s\n", | ||
631 | strerror (errno)); | ||
632 | break; | ||
633 | } | ||
634 | if (1 == getppid()) /* Check the parent process id, if 1 the parent has died, so we should die too */ | ||
635 | break; | ||
636 | if (FD_ISSET (icmpsock, &rs)) | ||
637 | process_icmp_response (); | ||
638 | if (0 == (++alt % 2)) | ||
639 | send_icmp_echo (&external); | ||
640 | else | ||
641 | send_udp (); | ||
642 | } | ||
643 | /* select failed (internal error or OS out of resources) */ | ||
644 | close (icmpsock); | ||
645 | close (rawsock); | ||
646 | close (udpsock); | ||
647 | return 4; | ||
648 | } | 67 | } |
649 | 68 | ||
650 | 69 | ||