diff options
author | Christian Grothoff <christian@grothoff.org> | 2010-02-04 11:03:27 +0000 |
---|---|---|
committer | Christian Grothoff <christian@grothoff.org> | 2010-02-04 11:03:27 +0000 |
commit | 4a091fe51761db20dea1a3325dfff89209e907b4 (patch) | |
tree | 4ebe14e219a69e69b081eb76a9b2f748181f344b /src | |
parent | be9fae753af6321bfb6d25e0f9d4a7d91ce01295 (diff) | |
download | gnunet-4a091fe51761db20dea1a3325dfff89209e907b4.tar.gz gnunet-4a091fe51761db20dea1a3325dfff89209e907b4.zip |
client
Diffstat (limited to 'src')
-rw-r--r-- | src/transport/Makefile.am | 7 | ||||
-rw-r--r-- | src/transport/gnunet-nat-client.c | 563 | ||||
-rw-r--r-- | src/transport/gnunet-nat-server.c | 34 |
3 files changed, 588 insertions, 16 deletions
diff --git a/src/transport/Makefile.am b/src/transport/Makefile.am index 0580ad603..3d690f44a 100644 --- a/src/transport/Makefile.am +++ b/src/transport/Makefile.am | |||
@@ -30,11 +30,16 @@ libgnunettransport_la_LDFLAGS = \ | |||
30 | bin_PROGRAMS = \ | 30 | bin_PROGRAMS = \ |
31 | gnunet-transport \ | 31 | gnunet-transport \ |
32 | gnunet-service-transport \ | 32 | gnunet-service-transport \ |
33 | gnunet-nat-server | 33 | gnunet-nat-server \ |
34 | gnunet-nat-client | ||
34 | 35 | ||
35 | gnunet_nat_server_SOURCES = \ | 36 | gnunet_nat_server_SOURCES = \ |
36 | gnunet-nat-server.c | 37 | gnunet-nat-server.c |
37 | 38 | ||
39 | gnunet_nat_client_SOURCES = \ | ||
40 | gnunet-nat-client.c | ||
41 | |||
42 | |||
38 | 43 | ||
39 | gnunet_transport_SOURCES = \ | 44 | gnunet_transport_SOURCES = \ |
40 | gnunet-transport.c | 45 | gnunet-transport.c |
diff --git a/src/transport/gnunet-nat-client.c b/src/transport/gnunet-nat-client.c new file mode 100644 index 000000000..c4b327aac --- /dev/null +++ b/src/transport/gnunet-nat-client.c | |||
@@ -0,0 +1,563 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | (C) 2010 Christian Grothoff (and other contributing authors) | ||
4 | |||
5 | GNUnet is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published | ||
7 | by the Free Software Foundation; either version 3, or (at your | ||
8 | option) any later version. | ||
9 | |||
10 | GNUnet is distributed in the hope that it will be useful, but | ||
11 | WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
13 | General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with GNUnet; see the file COPYING. If not, write to the | ||
17 | Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
18 | Boston, MA 02111-1307, USA. | ||
19 | */ | ||
20 | |||
21 | /** | ||
22 | * @file src/transport/gnunet-nat-client.c | ||
23 | * @brief Tool to help bypass NATs using ICMP method; must run as root (for now, later SUID will do) | ||
24 | * This code will work under GNU/Linux only (or maybe BSDs, but never W32) | ||
25 | * @author Christian Grothoff | ||
26 | */ | ||
27 | |||
28 | #include <sys/types.h> | ||
29 | #include <sys/socket.h> | ||
30 | #include <arpa/inet.h> | ||
31 | #include <sys/select.h> | ||
32 | #include <sys/time.h> | ||
33 | #include <sys/types.h> | ||
34 | #include <unistd.h> | ||
35 | #include <stdio.h> | ||
36 | #include <string.h> | ||
37 | #include <errno.h> | ||
38 | #include <stdlib.h> | ||
39 | #include <stdint.h> | ||
40 | #include <netinet/ip.h> | ||
41 | #include <netinet/ip_icmp.h> | ||
42 | #include <netinet/in.h> | ||
43 | |||
44 | /** | ||
45 | * Number of UDP ports to keep open. | ||
46 | */ | ||
47 | #define NUM_UDP_PORTS 512 | ||
48 | |||
49 | /** | ||
50 | * How often do we send our UDP messages to keep ports open? | ||
51 | */ | ||
52 | #define UDP_SEND_FREQUENCY_MS 500 | ||
53 | |||
54 | /** | ||
55 | * Port we use for the dummy target. | ||
56 | */ | ||
57 | #define NAT_TRAV_PORT 2222 | ||
58 | |||
59 | /** | ||
60 | * How often do we retry to open and bind a UDP socket before giving up? | ||
61 | */ | ||
62 | #define MAX_TRIES 10 | ||
63 | |||
64 | |||
65 | struct ip_packet | ||
66 | { | ||
67 | uint8_t vers_ihl; | ||
68 | uint8_t tos; | ||
69 | uint16_t pkt_len; | ||
70 | uint16_t id; | ||
71 | uint16_t flags_frag_offset; | ||
72 | uint8_t ttl; | ||
73 | uint8_t proto; | ||
74 | uint16_t checksum; | ||
75 | uint32_t src_ip; | ||
76 | uint32_t dst_ip; | ||
77 | }; | ||
78 | |||
79 | struct icmp_packet | ||
80 | { | ||
81 | uint8_t type; | ||
82 | uint8_t code; | ||
83 | uint16_t checksum; | ||
84 | uint32_t reserved; | ||
85 | }; | ||
86 | |||
87 | struct udp_packet | ||
88 | { | ||
89 | uint16_t source_port; | ||
90 | uint16_t dst_port; | ||
91 | uint16_t mlen_aka_reply_port_magic; | ||
92 | uint16_t checksum_aka_my_magic; | ||
93 | }; | ||
94 | |||
95 | |||
96 | /** | ||
97 | * Structure of the data we tack on to the fake ICMP reply | ||
98 | * (last 4 bytes of the 64 bytes). | ||
99 | */ | ||
100 | struct extra_packet | ||
101 | { | ||
102 | /** | ||
103 | * if this is a reply to an icmp, what was the 'my_magic' | ||
104 | * value from the original icmp? | ||
105 | */ | ||
106 | uint16_t reply_port_magic; | ||
107 | |||
108 | /** | ||
109 | * magic value of the sender of this icmp message. | ||
110 | */ | ||
111 | uint16_t my_magic; | ||
112 | }; | ||
113 | |||
114 | static int udpsocks[NUM_UDP_PORTS]; | ||
115 | |||
116 | static uint16_t udpports[NUM_UDP_PORTS]; | ||
117 | |||
118 | static int icmpsock; | ||
119 | |||
120 | static int rawsock; | ||
121 | |||
122 | static struct in_addr dummy; | ||
123 | |||
124 | |||
125 | /** | ||
126 | * create a random port number that is not totally | ||
127 | * unlikely to be chosen by the nat box. | ||
128 | */ | ||
129 | static uint16_t make_port () | ||
130 | { | ||
131 | return 1024 + ( (unsigned int)rand ()) % (63 * 1024 - 2); | ||
132 | } | ||
133 | |||
134 | |||
135 | /** | ||
136 | * create a fresh udp socket bound to a random local port. | ||
137 | */ | ||
138 | static int | ||
139 | make_udp_socket (uint16_t *port) | ||
140 | { | ||
141 | int ret; | ||
142 | int tries; | ||
143 | struct sockaddr_in src; | ||
144 | |||
145 | for (tries=0;tries<MAX_TRIES;tries++) | ||
146 | { | ||
147 | ret = socket (AF_INET, SOCK_DGRAM, 0); | ||
148 | if (-1 == ret) | ||
149 | { | ||
150 | fprintf (stderr, | ||
151 | "Error opening udp socket: %s\n", | ||
152 | strerror (errno)); | ||
153 | return -1; | ||
154 | } | ||
155 | if (ret >= FD_SETSIZE) | ||
156 | { | ||
157 | fprintf (stderr, | ||
158 | "Socket number too large (%d > %u)\n", | ||
159 | ret, | ||
160 | (unsigned int) FD_SETSIZE); | ||
161 | close (ret); | ||
162 | return -1; | ||
163 | } | ||
164 | memset (&src, 0, sizeof (src)); | ||
165 | src.sin_family = AF_INET; | ||
166 | src.sin_port = htons (make_port ()); | ||
167 | if (0 != bind (ret, (struct sockaddr*) &src, sizeof (src))) | ||
168 | { | ||
169 | close (ret); | ||
170 | continue; | ||
171 | } | ||
172 | *port = ntohs (src.sin_port); | ||
173 | return ret; | ||
174 | } | ||
175 | fprintf (stderr, | ||
176 | "Error binding udp socket: %s\n", | ||
177 | strerror (errno)); | ||
178 | return -1; | ||
179 | } | ||
180 | |||
181 | |||
182 | static uint16_t | ||
183 | calc_checksum(const uint16_t *data, | ||
184 | unsigned int bytes) | ||
185 | { | ||
186 | uint32_t sum; | ||
187 | unsigned int i; | ||
188 | |||
189 | sum = 0; | ||
190 | for (i=0;i<bytes/2;i++) | ||
191 | sum += data[i]; | ||
192 | sum = (sum & 0xffff) + (sum >> 16); | ||
193 | sum = htons(0xffff - sum); | ||
194 | return sum; | ||
195 | } | ||
196 | |||
197 | |||
198 | /** | ||
199 | * send an icmp message to the target. | ||
200 | * | ||
201 | * @param my_ip source address (our ip address) | ||
202 | * @param other target address | ||
203 | * @param target_port_number fake port number to put into icmp response | ||
204 | * as well as the icmpextradata as 'my_magic' | ||
205 | * @param source_port_number magic_number that enables the other peer to | ||
206 | * identify our port number ('reply in response to') to | ||
207 | * put in the data portion; 0 if we are initiating; | ||
208 | * goes into 'reply_port_magic' of the icmpextradata | ||
209 | */ | ||
210 | static void | ||
211 | send_icmp (const struct in_addr *my_ip, | ||
212 | const struct in_addr *other, | ||
213 | uint16_t target_port_number, | ||
214 | uint16_t source_port_number) | ||
215 | { | ||
216 | struct ip_packet ip_pkt; | ||
217 | struct icmp_packet icmp_pkt; | ||
218 | struct udp_packet udp_pkt; | ||
219 | struct sockaddr_in dst; | ||
220 | char packet[sizeof (ip_pkt) + sizeof (icmp_pkt) + sizeof (udp_pkt)]; | ||
221 | size_t off; | ||
222 | int err; | ||
223 | |||
224 | /* ip header: send to (known) ip address */ | ||
225 | off = 0; | ||
226 | memset(&ip_pkt, 0, sizeof(ip_pkt)); | ||
227 | ip_pkt.vers_ihl = 0x45;//|(pkt_len>>2);//5;//(ipversion << 4) | (iphdr_size >> 2); | ||
228 | ip_pkt.tos = 0; | ||
229 | ip_pkt.pkt_len = sizeof (packet); /* huh? */ | ||
230 | ip_pkt.id = 1; /* kernel will change anyway!? */ | ||
231 | ip_pkt.flags_frag_offset = 0; | ||
232 | ip_pkt.ttl = IPDEFTTL; | ||
233 | ip_pkt.proto = IPPROTO_ICMP; | ||
234 | ip_pkt.checksum = 0; /* maybe the kernel helps us out..? */ | ||
235 | ip_pkt.src_ip = my_ip->s_addr; | ||
236 | ip_pkt.dst_ip = other->s_addr; | ||
237 | ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt))); | ||
238 | memcpy (packet, &ip_pkt, sizeof (ip_pkt)); | ||
239 | off += sizeof (ip_pkt); | ||
240 | |||
241 | /* icmp reply: time exceeded */ | ||
242 | memset(&icmp_pkt, 0, sizeof(icmp_pkt)); | ||
243 | icmp_pkt.type = ICMP_TIME_EXCEEDED; | ||
244 | icmp_pkt.code = ICMP_NET_UNREACH; | ||
245 | icmp_pkt.reserved = 0; | ||
246 | icmp_pkt.checksum = 0; | ||
247 | icmp_pkt.checksum = htons(calc_checksum((uint16_t*)&icmp_pkt, sizeof (icmp_pkt))); | ||
248 | memcpy (&packet[off], &icmp_pkt, sizeof (icmp_pkt)); | ||
249 | off += sizeof (icmp_pkt); | ||
250 | |||
251 | /* ip header of the presumably 'lost' udp packet */ | ||
252 | memset(&ip_pkt, 0, sizeof (ip_pkt)); | ||
253 | ip_pkt.vers_ihl = 0x45; | ||
254 | ip_pkt.tos = 0; | ||
255 | /* no idea why i need to shift the bits here, but not on ip_pkt->pkt_len... */ | ||
256 | ip_pkt.pkt_len = (sizeof (ip_pkt) + sizeof (icmp_pkt)) << 8; | ||
257 | ip_pkt.id = 1; /* kernel sets proper value htons(ip_id_counter); */ | ||
258 | ip_pkt.flags_frag_offset = 0; | ||
259 | ip_pkt.ttl = 1; /* real TTL would be 1 on a time exceeded packet */ | ||
260 | ip_pkt.proto = IPPROTO_UDP; | ||
261 | ip_pkt.src_ip = other->s_addr; | ||
262 | ip_pkt.dst_ip = dummy.s_addr; | ||
263 | ip_pkt.checksum = 0; | ||
264 | ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt))); | ||
265 | memcpy (&packet[off], &ip_pkt, sizeof (ip_pkt)); | ||
266 | off += sizeof (ip_pkt); | ||
267 | |||
268 | memset(&udp_pkt, 0, sizeof (udp_pkt)); | ||
269 | udp_pkt.source_port = htons (target_port_number); | ||
270 | udp_pkt.dst_port = htons (NAT_TRAV_PORT); | ||
271 | fprintf (stderr, | ||
272 | "** Generating ICMP with rpm %u\n", | ||
273 | target_port_number); | ||
274 | udp_pkt.mlen_aka_reply_port_magic = htons (source_port_number); | ||
275 | udp_pkt.checksum_aka_my_magic = htons (target_port_number); | ||
276 | memcpy (&packet[off], &udp_pkt, sizeof (udp_pkt)); | ||
277 | off += sizeof (udp_pkt); | ||
278 | |||
279 | memset (&dst, 0, sizeof (dst)); | ||
280 | dst.sin_family = AF_INET; | ||
281 | dst.sin_addr = *other; | ||
282 | err = sendto(rawsock, | ||
283 | packet, | ||
284 | off, 0, | ||
285 | (struct sockaddr*)&dst, | ||
286 | sizeof(dst)); /* or sizeof 'struct sockaddr'? */ | ||
287 | if (err < 0) { | ||
288 | fprintf(stderr, | ||
289 | "sendto failed: %s\n", strerror(errno)); | ||
290 | } else if (err != off) | ||
291 | fprintf(stderr, | ||
292 | "Error: partial send of ICMP message\n"); | ||
293 | } | ||
294 | |||
295 | |||
296 | /** | ||
297 | * We discovered the IP address of the other peer. | ||
298 | * Try to connect back to it. | ||
299 | */ | ||
300 | static void | ||
301 | try_connect (const struct in_addr *my_ip, | ||
302 | const struct in_addr *other, | ||
303 | uint16_t port_magic) | ||
304 | { | ||
305 | unsigned int i; | ||
306 | char sbuf [INET_ADDRSTRLEN]; | ||
307 | |||
308 | fprintf (stderr, | ||
309 | "Sending %u ICMPs to `%s' with reply magic %u\n", | ||
310 | NUM_UDP_PORTS, | ||
311 | inet_ntop (AF_INET, | ||
312 | other, | ||
313 | sbuf, | ||
314 | sizeof (sbuf)), | ||
315 | port_magic); | ||
316 | for (i=0;i<NUM_UDP_PORTS;i++) | ||
317 | send_icmp (my_ip, other, make_port(), port_magic); | ||
318 | } | ||
319 | |||
320 | |||
321 | static void | ||
322 | process_icmp_response (const struct in_addr *my_ip, | ||
323 | int s) | ||
324 | { | ||
325 | char buf[65536]; | ||
326 | ssize_t have; | ||
327 | struct in_addr sip; | ||
328 | uint16_t my_magic; | ||
329 | uint16_t reply_magic; | ||
330 | struct ip_packet ip_pkt; | ||
331 | struct icmp_packet icmp_pkt; | ||
332 | struct udp_packet udp_pkt; | ||
333 | size_t off; | ||
334 | |||
335 | have = read (s, buf, sizeof (buf)); | ||
336 | if (have == -1) | ||
337 | { | ||
338 | fprintf (stderr, | ||
339 | "Error reading raw socket: %s\n", | ||
340 | strerror (errno)); | ||
341 | /* What now? */ | ||
342 | return; | ||
343 | } | ||
344 | if (have != sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) + | ||
345 | sizeof (struct udp_packet)) | ||
346 | { | ||
347 | fprintf (stderr, | ||
348 | "Received ICMP message of unexpected size: %u bytes\n", | ||
349 | (unsigned int) have); | ||
350 | return; | ||
351 | } | ||
352 | off = 0; | ||
353 | memcpy (&ip_pkt, &buf[off], sizeof (ip_pkt)); | ||
354 | off += sizeof (ip_pkt); | ||
355 | memcpy (&icmp_pkt, &buf[off], sizeof (icmp_pkt)); | ||
356 | off += sizeof (icmp_pkt); | ||
357 | off += sizeof (ip_pkt); | ||
358 | memcpy (&udp_pkt, &buf[off], sizeof (udp_pkt)); | ||
359 | off += sizeof (struct udp_packet); | ||
360 | |||
361 | if ( (ip_pkt.proto == IPPROTO_ICMP) && | ||
362 | (icmp_pkt.type == ICMP_DEST_UNREACH) && | ||
363 | (icmp_pkt.code == ICMP_HOST_UNREACH) ) | ||
364 | { | ||
365 | /* this is what is normal due to our UDP traffic */ | ||
366 | return; | ||
367 | } | ||
368 | if ( (ip_pkt.proto != IPPROTO_ICMP) || | ||
369 | (icmp_pkt.type != ICMP_TIME_EXCEEDED) || | ||
370 | (icmp_pkt.code != ICMP_NET_UNREACH) ) | ||
371 | { | ||
372 | /* Note the expected client response and not the normal network response */ | ||
373 | fprintf (stderr, | ||
374 | "Received unexpected ICMP message contents (%u, %u, %u), ignoring\n", | ||
375 | ip_pkt.proto, | ||
376 | icmp_pkt.type, | ||
377 | icmp_pkt.code); | ||
378 | return; | ||
379 | } | ||
380 | memcpy(&sip, &ip_pkt.src_ip, sizeof (sip)); | ||
381 | my_magic = ntohs (udp_pkt.checksum_aka_my_magic); | ||
382 | reply_magic = ntohs (udp_pkt.mlen_aka_reply_port_magic); | ||
383 | if (my_magic == 0) | ||
384 | { | ||
385 | #if 0 | ||
386 | /* we get these a lot during loopback testing... */ | ||
387 | fprintf (stderr, | ||
388 | "Received ICMP without hint as to which port worked, dropping\n"); | ||
389 | #endif | ||
390 | return; | ||
391 | } | ||
392 | fprintf (stderr, | ||
393 | "Received ICMP from `%s' with hints %u and %u\n", | ||
394 | inet_ntop (AF_INET, | ||
395 | &sip, | ||
396 | buf, | ||
397 | sizeof (buf)), | ||
398 | my_magic, | ||
399 | reply_magic); | ||
400 | if (my_magic == 0) | ||
401 | { | ||
402 | try_connect (my_ip, &sip, reply_magic); | ||
403 | } | ||
404 | else | ||
405 | { | ||
406 | printf ("%s:%u\n", | ||
407 | inet_ntop (AF_INET, | ||
408 | &sip, | ||
409 | buf, | ||
410 | sizeof(buf)), | ||
411 | my_magic); | ||
412 | } | ||
413 | } | ||
414 | |||
415 | |||
416 | static int | ||
417 | make_icmp_socket () | ||
418 | { | ||
419 | int ret; | ||
420 | |||
421 | ret = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP); | ||
422 | if (-1 == ret) | ||
423 | { | ||
424 | fprintf (stderr, | ||
425 | "Error opening RAW socket: %s\n", | ||
426 | strerror (errno)); | ||
427 | return -1; | ||
428 | } | ||
429 | if (ret >= FD_SETSIZE) | ||
430 | { | ||
431 | fprintf (stderr, | ||
432 | "Socket number too large (%d > %u)\n", | ||
433 | ret, | ||
434 | (unsigned int) FD_SETSIZE); | ||
435 | close (ret); | ||
436 | return -1; | ||
437 | } | ||
438 | return ret; | ||
439 | } | ||
440 | |||
441 | |||
442 | static int | ||
443 | make_raw_socket () | ||
444 | { | ||
445 | const int one = 1; | ||
446 | int ret; | ||
447 | |||
448 | ret = socket (AF_INET, SOCK_RAW, IPPROTO_RAW); | ||
449 | if (-1 == ret) | ||
450 | { | ||
451 | fprintf (stderr, | ||
452 | "Error opening RAW socket: %s\n", | ||
453 | strerror (errno)); | ||
454 | return -1; | ||
455 | } | ||
456 | if (ret >= FD_SETSIZE) | ||
457 | { | ||
458 | fprintf (stderr, | ||
459 | "Socket number too large (%d > %u)\n", | ||
460 | ret, | ||
461 | (unsigned int) FD_SETSIZE); | ||
462 | close (ret); | ||
463 | return -1; | ||
464 | } | ||
465 | if (setsockopt(ret, SOL_SOCKET, SO_BROADCAST, | ||
466 | (char *)&one, sizeof(one)) == -1) | ||
467 | fprintf(stderr, | ||
468 | "setsockopt failed: %s\n", | ||
469 | strerror (errno)); | ||
470 | if (setsockopt(ret, IPPROTO_IP, IP_HDRINCL, | ||
471 | (char *)&one, sizeof(one)) == -1) | ||
472 | fprintf(stderr, | ||
473 | "setsockopt failed: %s\n", | ||
474 | strerror (errno)); | ||
475 | return ret; | ||
476 | } | ||
477 | |||
478 | |||
479 | int | ||
480 | main (int argc, char *const *argv) | ||
481 | { | ||
482 | struct in_addr target; | ||
483 | struct in_addr external; | ||
484 | unsigned int i; | ||
485 | unsigned int pos; | ||
486 | fd_set rs; | ||
487 | struct timeval tv; | ||
488 | struct sockaddr_in dst; | ||
489 | uint16_t p; | ||
490 | |||
491 | if (argc != 4) | ||
492 | { | ||
493 | fprintf (stderr, | ||
494 | "This program must be started with our IP, the targets external IP and the dummy IP address as arguments.\n"); | ||
495 | return 1; | ||
496 | } | ||
497 | if ( (1 != inet_pton (AF_INET, argv[1], &external)) || | ||
498 | (1 != inet_pton (AF_INET, argv[2], &target)) || | ||
499 | (1 != inet_pton (AF_INET, argv[3], &dummy)) ) | ||
500 | { | ||
501 | fprintf (stderr, | ||
502 | "Error parsing IPv4 address: %s\n", | ||
503 | strerror (errno)); | ||
504 | return 1; | ||
505 | } | ||
506 | memset (&dst, 0, sizeof (dst)); | ||
507 | dst.sin_family = AF_INET; | ||
508 | dst.sin_port = htons (NAT_TRAV_PORT); | ||
509 | dst.sin_addr = dummy; | ||
510 | |||
511 | if (-1 == (icmpsock = make_icmp_socket())) | ||
512 | return 1; | ||
513 | if (-1 == (rawsock = make_raw_socket())) | ||
514 | { | ||
515 | close (icmpsock); | ||
516 | return 1; | ||
517 | } | ||
518 | for (i=0;i<NUM_UDP_PORTS;i++) | ||
519 | udpsocks[i] = make_udp_socket (&udpports[i]); | ||
520 | pos = 0; | ||
521 | while (1) | ||
522 | { | ||
523 | FD_ZERO (&rs); | ||
524 | FD_SET (icmpsock, &rs); | ||
525 | tv.tv_sec = 0; | ||
526 | tv.tv_usec = UDP_SEND_FREQUENCY_MS * 1000; | ||
527 | select (icmpsock + 1, &rs, NULL, NULL, &tv); | ||
528 | /* FIXME: do I need my external IP here? */ | ||
529 | if (FD_ISSET (icmpsock, &rs)) | ||
530 | { | ||
531 | process_icmp_response (&external, icmpsock); | ||
532 | continue; | ||
533 | } | ||
534 | fprintf (stderr, | ||
535 | "Sending UDP message to %s:%u\n", | ||
536 | argv[3], | ||
537 | NAT_TRAV_PORT); | ||
538 | if (-1 == sendto (udpsocks[pos], | ||
539 | NULL, 0, 0, | ||
540 | (struct sockaddr*) &dst, sizeof (dst))) | ||
541 | { | ||
542 | fprintf (stderr, | ||
543 | "sendto failed: %s\n", | ||
544 | strerror (errno)); | ||
545 | close (udpsocks[pos]); | ||
546 | udpsocks[pos] = make_udp_socket (&udpports[pos]); | ||
547 | } | ||
548 | p = make_port (); | ||
549 | fprintf (stderr, | ||
550 | "Sending fake ICMP message to %s with port %u\n", | ||
551 | argv[1], | ||
552 | p); | ||
553 | send_icmp (&external, | ||
554 | &target, | ||
555 | p, | ||
556 | 0); | ||
557 | pos = (pos+1) % NUM_UDP_PORTS; | ||
558 | } | ||
559 | return 0; | ||
560 | } | ||
561 | |||
562 | |||
563 | /* end of gnunet-nat-client.c */ | ||
diff --git a/src/transport/gnunet-nat-server.c b/src/transport/gnunet-nat-server.c index 11e4e905a..77b73b708 100644 --- a/src/transport/gnunet-nat-server.c +++ b/src/transport/gnunet-nat-server.c | |||
@@ -49,7 +49,7 @@ | |||
49 | /** | 49 | /** |
50 | * How often do we send our UDP messages to keep ports open? | 50 | * How often do we send our UDP messages to keep ports open? |
51 | */ | 51 | */ |
52 | #define UDP_SEND_FREQUENCY_MS 50 | 52 | #define UDP_SEND_FREQUENCY_MS 500 |
53 | 53 | ||
54 | /** | 54 | /** |
55 | * Port we use for the dummy target. | 55 | * Port we use for the dummy target. |
@@ -219,18 +219,9 @@ send_icmp (const struct in_addr *my_ip, | |||
219 | struct udp_packet udp_pkt; | 219 | struct udp_packet udp_pkt; |
220 | struct sockaddr_in dst; | 220 | struct sockaddr_in dst; |
221 | char packet[sizeof (ip_pkt) + sizeof (icmp_pkt) + sizeof (udp_pkt)]; | 221 | char packet[sizeof (ip_pkt) + sizeof (icmp_pkt) + sizeof (udp_pkt)]; |
222 | char sbuf [INET_ADDRSTRLEN]; | ||
223 | size_t off; | 222 | size_t off; |
224 | int err; | 223 | int err; |
225 | 224 | ||
226 | fprintf (stderr, | ||
227 | "Sending ICMP to `%s' at %u with reply magic %u\n", | ||
228 | inet_ntop (AF_INET, | ||
229 | other, | ||
230 | sbuf, | ||
231 | sizeof (sbuf)), | ||
232 | target_port_number, | ||
233 | source_port_number); | ||
234 | /* ip header: send to (known) ip address */ | 225 | /* ip header: send to (known) ip address */ |
235 | off = 0; | 226 | off = 0; |
236 | memset(&ip_pkt, 0, sizeof(ip_pkt)); | 227 | memset(&ip_pkt, 0, sizeof(ip_pkt)); |
@@ -310,7 +301,16 @@ try_connect (const struct in_addr *my_ip, | |||
310 | uint16_t port_magic) | 301 | uint16_t port_magic) |
311 | { | 302 | { |
312 | unsigned int i; | 303 | unsigned int i; |
313 | 304 | char sbuf [INET_ADDRSTRLEN]; | |
305 | |||
306 | fprintf (stderr, | ||
307 | "Sending %u ICMPs to `%s' with reply magic %u\n", | ||
308 | NUM_UDP_PORTS, | ||
309 | inet_ntop (AF_INET, | ||
310 | other, | ||
311 | sbuf, | ||
312 | sizeof (sbuf)), | ||
313 | port_magic); | ||
314 | for (i=0;i<NUM_UDP_PORTS;i++) | 314 | for (i=0;i<NUM_UDP_PORTS;i++) |
315 | send_icmp (my_ip, other, make_port(), port_magic); | 315 | send_icmp (my_ip, other, make_port(), port_magic); |
316 | } | 316 | } |
@@ -339,11 +339,11 @@ process_icmp_response (const struct in_addr *my_ip, | |||
339 | /* What now? */ | 339 | /* What now? */ |
340 | return; | 340 | return; |
341 | } | 341 | } |
342 | if (have < sizeof (struct ip_packet) + sizeof (struct icmp_packet) + | 342 | if (have != 2 * sizeof (struct ip_packet) + sizeof (struct icmp_packet) + |
343 | sizeof (struct udp_packet)) | 343 | sizeof (struct udp_packet)) |
344 | { | 344 | { |
345 | fprintf (stderr, | 345 | fprintf (stderr, |
346 | "Received invalid ICMP message: only %u bytes\n", | 346 | "Received ICMP message of unexpected size: %u bytes\n", |
347 | (unsigned int) have); | 347 | (unsigned int) have); |
348 | return; | 348 | return; |
349 | } | 349 | } |
@@ -352,10 +352,10 @@ process_icmp_response (const struct in_addr *my_ip, | |||
352 | off += sizeof (ip_pkt); | 352 | off += sizeof (ip_pkt); |
353 | memcpy (&icmp_pkt, &buf[off], sizeof (icmp_pkt)); | 353 | memcpy (&icmp_pkt, &buf[off], sizeof (icmp_pkt)); |
354 | off += sizeof (icmp_pkt); | 354 | off += sizeof (icmp_pkt); |
355 | off += sizeof (ip_pkt); | ||
355 | memcpy (&udp_pkt, &buf[off], sizeof (udp_pkt)); | 356 | memcpy (&udp_pkt, &buf[off], sizeof (udp_pkt)); |
356 | off += sizeof (struct udp_packet); | 357 | off += sizeof (struct udp_packet); |
357 | 358 | ||
358 | /* If not ICMP and not TTL exceeded */ | ||
359 | if ( (ip_pkt.proto == IPPROTO_ICMP) && | 359 | if ( (ip_pkt.proto == IPPROTO_ICMP) && |
360 | (icmp_pkt.type == ICMP_DEST_UNREACH) && | 360 | (icmp_pkt.type == ICMP_DEST_UNREACH) && |
361 | (icmp_pkt.code == ICMP_HOST_UNREACH) ) | 361 | (icmp_pkt.code == ICMP_HOST_UNREACH) ) |
@@ -367,6 +367,7 @@ process_icmp_response (const struct in_addr *my_ip, | |||
367 | (icmp_pkt.type != ICMP_TIME_EXCEEDED) || | 367 | (icmp_pkt.type != ICMP_TIME_EXCEEDED) || |
368 | (icmp_pkt.code != ICMP_NET_UNREACH) ) | 368 | (icmp_pkt.code != ICMP_NET_UNREACH) ) |
369 | { | 369 | { |
370 | /* Note the expected client response and not the normal network response */ | ||
370 | fprintf (stderr, | 371 | fprintf (stderr, |
371 | "Received unexpected ICMP message contents (%u, %u, %u), ignoring\n", | 372 | "Received unexpected ICMP message contents (%u, %u, %u), ignoring\n", |
372 | ip_pkt.proto, | 373 | ip_pkt.proto, |
@@ -512,7 +513,10 @@ main (int argc, char *const *argv) | |||
512 | select (icmpsock + 1, &rs, NULL, NULL, &tv); | 513 | select (icmpsock + 1, &rs, NULL, NULL, &tv); |
513 | /* FIXME: do I need my external IP here? */ | 514 | /* FIXME: do I need my external IP here? */ |
514 | if (FD_ISSET (icmpsock, &rs)) | 515 | if (FD_ISSET (icmpsock, &rs)) |
515 | process_icmp_response (&external, icmpsock); | 516 | { |
517 | process_icmp_response (&external, icmpsock); | ||
518 | continue; | ||
519 | } | ||
516 | fprintf (stderr, | 520 | fprintf (stderr, |
517 | "Sending UDP message to %s:%u\n", | 521 | "Sending UDP message to %s:%u\n", |
518 | argv[2], | 522 | argv[2], |