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authorNathan S. Evans <evans@in.tum.de>2010-06-08 13:27:51 +0000
committerNathan S. Evans <evans@in.tum.de>2010-06-08 13:27:51 +0000
commite16feb9b6a361a08a37ac80e5f76df70fb89ca70 (patch)
tree2a75028e50eb703290ccf9a1c8875713af935737
parent87f73e3aee4a5f582ffb71e925f1f1d4f30e26d2 (diff)
downloadgnunet-e16feb9b6a361a08a37ac80e5f76df70fb89ca70.tar.gz
gnunet-e16feb9b6a361a08a37ac80e5f76df70fb89ca70.zip
remove unneeded udp crapulence
-rw-r--r--src/transport/gnunet-nat-client-udp.c375
-rw-r--r--src/transport/gnunet-nat-server-udp.c422
2 files changed, 0 insertions, 797 deletions
diff --git a/src/transport/gnunet-nat-client-udp.c b/src/transport/gnunet-nat-client-udp.c
deleted file mode 100644
index 0e925dc5d..000000000
--- a/src/transport/gnunet-nat-client-udp.c
+++ /dev/null
@@ -1,375 +0,0 @@
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-udp.c
23 * @brief Tool to help bypass NATs using ICMP method; must run as root (SUID will do)
24 * This code will work under GNU/Linux only.
25 * @author Christian Grothoff
26 *
27 * This program will send ONE ICMP message using RAW sockets
28 * to the IP address specified as the second argument. The ICMP
29 * message will have as it's payload a UDP packet. Since
30 * it uses RAW sockets, it must be installed SUID or run as 'root'.
31 * In order to keep the security risk of the resulting SUID binary
32 * minimal, the program ONLY opens the RAW socket with root
33 * privileges, then drops them and only then starts to process
34 * command line arguments. The code also does not link against
35 * any shared libraries (except libc) and is strictly minimal
36 * (except for checking for errors). The following list of people
37 * have reviewed this code and considered it safe since the last
38 * modification (if you reviewed it, please have your name added
39 * to the list):
40 *
41 * - Christian Grothoff
42 */
43#define _GNU_SOURCE
44#include <sys/types.h>
45#include <sys/socket.h>
46#include <arpa/inet.h>
47#include <sys/types.h>
48#include <unistd.h>
49#include <stdio.h>
50#include <string.h>
51#include <errno.h>
52#include <stdlib.h>
53#include <stdint.h>
54#include <netinet/ip.h>
55#include <netinet/ip_icmp.h>
56#include <netinet/in.h>
57
58/**
59 * Must match IP given in the server.
60 */
61#define DUMMY_IP "1.2.3.4"
62#define HAVE_PORT 1
63
64/**
65 * Port we always try to use.
66 */
67#define NAT_TRAV_PORT 22225
68
69struct ip_packet
70{
71 uint8_t vers_ihl;
72 uint8_t tos;
73 uint16_t pkt_len;
74 uint16_t id;
75 uint16_t flags_frag_offset;
76 uint8_t ttl;
77 uint8_t proto;
78 uint16_t checksum;
79 uint32_t src_ip;
80 uint32_t dst_ip;
81};
82
83struct icmp_packet
84{
85 uint8_t type;
86 uint8_t code;
87 uint16_t checksum;
88 uint32_t reserved;
89
90};
91
92struct icmp_echo_packet
93{
94 uint8_t type;
95 uint8_t code;
96 uint16_t checksum;
97 uint32_t reserved;
98 uint32_t data;
99};
100
101struct udp_packet
102{
103 uint16_t src_port;
104
105 uint16_t dst_port;
106
107 uint32_t length;
108};
109
110
111static int rawsock;
112
113static struct in_addr dummy;
114
115static struct in_addr target;
116
117#if HAVE_PORT
118 static uint32_t port;
119#endif
120
121static uint16_t
122calc_checksum(const uint16_t *data,
123 unsigned int bytes)
124{
125 uint32_t sum;
126 unsigned int i;
127
128 sum = 0;
129 for (i=0;i<bytes/2;i++)
130 sum += data[i];
131 sum = (sum & 0xffff) + (sum >> 16);
132 sum = htons(0xffff - sum);
133 return sum;
134}
135
136/**
137 * Send an ICMP message to the target.
138 *
139 * @param my_ip source address
140 * @param other target address
141 */
142static void
143send_icmp (const struct in_addr *my_ip,
144 const struct in_addr *other)
145{
146 struct ip_packet ip_pkt;
147 struct icmp_packet icmp_pkt;
148 struct udp_packet udp_pkt;
149
150 struct sockaddr_in dst;
151 char packet[sizeof(ip_pkt) * 2 + sizeof(icmp_pkt) * 2 + sizeof(char)];
152
153#if ORIGINAL
154#if HAVE_PORT
155 char packet[sizeof (struct ip_packet)*2 + sizeof (struct icmp_packet) + sizeof(struct icmp_echo_packet)];
156#else
157 char packet[sizeof (struct ip_packet)*2 + sizeof (struct icmp_packet)*2];
158#endif
159#endif
160 size_t off;
161 int err;
162
163 /* ip header: send to (known) ip address */
164#if ORIGINAL
165 off = 0;
166 memset(&ip_pkt, 0, sizeof(ip_pkt));
167 ip_pkt.vers_ihl = 0x45;
168 ip_pkt.tos = 0;
169 ip_pkt.pkt_len = sizeof (packet); /* huh? */
170 ip_pkt.id = 1;
171 ip_pkt.flags_frag_offset = 0;
172 ip_pkt.ttl = IPDEFTTL;
173 ip_pkt.proto = IPPROTO_ICMP;
174 ip_pkt.checksum = 0;
175 ip_pkt.src_ip = my_ip->s_addr;
176 ip_pkt.dst_ip = other->s_addr;
177 ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (struct ip_packet)));
178 memcpy (packet, &ip_pkt, sizeof (struct ip_packet));
179 off += sizeof (ip_pkt);
180 /* icmp reply: time exceeded */
181 icmp_pkt = (struct icmp_packet*) &packet[off];
182 memset(icmp_pkt, 0, sizeof(struct icmp_packet));
183 icmp_pkt->type = ICMP_TIME_EXCEEDED;
184 icmp_pkt->code = 0;
185 icmp_pkt->reserved = 0;
186 icmp_pkt->checksum = 0;
187
188 off += sizeof (struct icmp_packet);
189#endif
190
191 off = 0;
192 memset(&ip_pkt, 0, sizeof(ip_pkt));
193 ip_pkt.vers_ihl = 0x45;
194 ip_pkt.tos = 0;
195 ip_pkt.pkt_len = htons(sizeof (packet));
196 ip_pkt.id = htons(256);
197 ip_pkt.flags_frag_offset = 0;
198 ip_pkt.ttl = 128;
199 ip_pkt.proto = IPPROTO_ICMP;
200 ip_pkt.checksum = 0;
201 ip_pkt.src_ip = my_ip->s_addr;
202 ip_pkt.dst_ip = other->s_addr;
203 ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt)));
204 memcpy(&packet[off], &ip_pkt, sizeof(ip_pkt));
205 off += sizeof(ip_pkt);
206
207 /* ip header of the presumably 'lost' udp packet */
208 ip_pkt.vers_ihl = 0x45;
209 ip_pkt.tos = 0;
210#if HAVE_PORT
211 ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_echo_packet));
212#else
213 ip_pkt.pkt_len = (sizeof (struct ip_packet) + sizeof (struct icmp_packet));
214#endif
215
216 icmp_pkt.type = 11; // TTL exceeded
217 icmp_pkt.code = 0;
218 icmp_pkt.checksum = 0;
219 icmp_pkt.reserved = 0;
220 memcpy(&packet[off], &icmp_pkt, sizeof(icmp_pkt));
221 off += sizeof(icmp_pkt);
222
223
224 // build inner IP header
225 memset(&ip_pkt, 0, sizeof(ip_pkt));
226 ip_pkt.vers_ihl = 0x45;
227 ip_pkt.tos = 0;
228 ip_pkt.pkt_len = htons(sizeof (ip_pkt) + sizeof(udp_pkt));
229 ip_pkt.id = htons(0);
230 ip_pkt.flags_frag_offset = 0;
231 ip_pkt.ttl = 128;
232 ip_pkt.proto = IPPROTO_UDP;
233 ip_pkt.checksum = 0;
234 ip_pkt.src_ip = other->s_addr;
235 ip_pkt.dst_ip = dummy.s_addr;
236 ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt)));
237 memcpy(&packet[off], &ip_pkt, sizeof(ip_pkt));
238 off += sizeof(ip_pkt);
239
240 // build UDP header
241 udp_pkt.src_port = htons(NAT_TRAV_PORT); /* FIXME: does this port matter? */
242 udp_pkt.dst_port = htons(NAT_TRAV_PORT);
243 uint32_t newval = inet_addr("1.2.3.4");
244 memcpy(&udp_pkt.length, &newval, sizeof(uint32_t));
245 memcpy(&packet[off], &udp_pkt, sizeof(udp_pkt));
246 off += sizeof(udp_pkt);
247
248
249
250 // set ICMP checksum
251 icmp_pkt.checksum = htons(calc_checksum((uint16_t*)&packet[sizeof(ip_pkt)],
252 sizeof (icmp_pkt) + sizeof(ip_pkt) + sizeof(udp_pkt)));
253 memcpy (&packet[sizeof(ip_pkt)], &icmp_pkt, sizeof (icmp_pkt));
254
255 /* End of new code */
256#if ORIGINAL
257 ip_pkt.id = 1;
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_ICMP;
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 (struct ip_packet)));
265 memcpy (&packet[off], &ip_pkt, sizeof (struct ip_packet));
266 off += sizeof (struct ip_packet);
267
268
269#if HAVE_PORT
270 icmp_pkt->checksum = htons(calc_checksum((uint16_t*)icmp_pkt,
271 sizeof (struct icmp_packet) + sizeof(struct ip_packet) + sizeof(struct icmp_echo_packet)));
272
273#else
274 icmp_pkt->checksum = htons(calc_checksum((uint16_t*)icmp_pkt,
275 sizeof (struct icmp_packet)*2 + sizeof(struct ip_packet)));
276
277#endif
278
279
280#endif
281
282 memset (&dst, 0, sizeof (dst));
283 dst.sin_family = AF_INET;
284 dst.sin_addr = *other;
285 err = sendto(rawsock,
286 packet,
287 off, 0,
288 (struct sockaddr*)&dst,
289 sizeof(dst)); /* or sizeof 'struct sockaddr'? */
290 if (err < 0)
291 {
292 fprintf(stderr,
293 "sendto failed: %s\n", strerror(errno));
294 }
295 else if (err != off)
296 {
297 fprintf(stderr,
298 "Error: partial send of ICMP message\n");
299 }
300}
301
302
303static int
304make_raw_socket ()
305{
306 const int one = 1;
307 int ret;
308
309 ret = socket (AF_INET, SOCK_RAW, IPPROTO_RAW);
310 if (-1 == ret)
311 {
312 fprintf (stderr,
313 "Error opening RAW socket: %s\n",
314 strerror (errno));
315 return -1;
316 }
317 if (setsockopt(ret, SOL_SOCKET, SO_BROADCAST,
318 (char *)&one, sizeof(one)) == -1)
319 fprintf(stderr,
320 "setsockopt failed: %s\n",
321 strerror (errno));
322 if (setsockopt(ret, IPPROTO_IP, IP_HDRINCL,
323 (char *)&one, sizeof(one)) == -1)
324 fprintf(stderr,
325 "setsockopt failed: %s\n",
326 strerror (errno));
327 return ret;
328}
329
330
331int
332main (int argc, char *const *argv)
333{
334 struct in_addr external;
335 uid_t uid;
336
337 if (-1 == (rawsock = make_raw_socket()))
338 return 1;
339 uid = getuid ();
340 if (0 != setresuid (uid, uid, uid))
341 fprintf (stderr,
342 "Failed to setresuid: %s\n",
343 strerror (errno));
344#if HAVE_PORT
345 if (argc != 4)
346 {
347 fprintf (stderr,
348 "This program must be started with our IP, the targets external IP, and our port as arguments.\n");
349 return 1;
350 }
351 port = atoi(argv[3]);
352#else
353 if (argc != 3)
354 {
355 fprintf (stderr,
356 "This program must be started with our IP and the targets external IP as arguments.\n");
357 return 1;
358 }
359#endif
360 if ( (1 != inet_pton (AF_INET, argv[1], &external)) ||
361 (1 != inet_pton (AF_INET, argv[2], &target)) )
362 {
363 fprintf (stderr,
364 "Error parsing IPv4 address: %s\n",
365 strerror (errno));
366 return 1;
367 }
368 if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy)) abort ();
369 send_icmp (&external,
370 &target);
371 close (rawsock);
372 return 0;
373}
374
375/* end of gnunet-nat-client-udp.c */
diff --git a/src/transport/gnunet-nat-server-udp.c b/src/transport/gnunet-nat-server-udp.c
deleted file mode 100644
index 02ff65031..000000000
--- a/src/transport/gnunet-nat-server-udp.c
+++ /dev/null
@@ -1,422 +0,0 @@
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-server-udp.c
23 * @brief This program will send ONE UDP message every 500 ms
24 * to a DUMMY IP address and also listens for ICMP replies.
25 *
26 * @author Christian Grothoff
27 */
28#include <sys/types.h>
29#include <sys/socket.h>
30#include <arpa/inet.h>
31#include <sys/types.h>
32#include <unistd.h>
33#include <stdio.h>
34#include <string.h>
35#include <errno.h>
36#include <stdlib.h>
37#include <stdint.h>
38#include <netinet/in.h>
39#include <time.h>
40
41
42#define DUMMY_IP "1.2.3.4"
43
44/**
45 * How often do we send our UDP message to keep ports open (and to
46 * try to connect, of course).
47 */
48#define UDP_SEND_FREQUENCY_MS 500
49
50/**
51 * Port we always try to use.
52 */
53#define NAT_TRAV_PORT 22225
54
55/**
56 * Number of UDP ports to send to
57 */
58#define NUM_UDP_PORTS 1
59
60/**
61 * How often do we retry to open and bind a UDP socket before giving up?
62 */
63#define MAX_BIND_TRIES 10
64
65#define LOW_PORT 32768
66
67static struct in_addr dummy;
68
69static int icmpsock;
70
71struct icmp_packet
72{
73 uint8_t type;
74 uint8_t code;
75 uint16_t checksum;
76 uint32_t reserved;
77
78};
79
80struct udp_packet
81{
82 uint16_t src_port;
83
84 uint16_t dst_port;
85
86 uint32_t length;
87};
88
89struct ip_packet
90{
91 uint8_t vers_ihl;
92 uint8_t tos;
93 uint16_t pkt_len;
94 uint16_t id;
95 uint16_t flags_frag_offset;
96 uint8_t ttl;
97 uint8_t proto;
98 uint16_t checksum;
99 uint32_t src_ip;
100 uint32_t dst_ip;
101};
102
103#if DUMMY
104static uint16_t
105calc_checksum(const uint16_t *data,
106 unsigned int bytes)
107{
108 uint32_t sum;
109 unsigned int i;
110
111 sum = 0;
112 for (i=0;i<bytes/2;i++)
113 sum += data[i];
114 sum = (sum & 0xffff) + (sum >> 16);
115 sum = htons(0xffff - sum);
116 return sum;
117}
118#endif
119
120/**
121 * create a fresh udp socket bound to the NAT_TRAV_PORT.
122 *
123 * @return -1 on error
124 */
125static int
126make_udp_socket ()
127{
128 int ret;
129 int tries;
130 struct sockaddr_in src;
131
132 for (tries=0; tries<MAX_BIND_TRIES; tries++)
133 {
134 ret = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
135 if (-1 == ret)
136 {
137 fprintf (stderr,
138 "Error opening udp socket: %s\n",
139 strerror (errno));
140 return -1;
141 }
142 if (ret >= FD_SETSIZE)
143 {
144 fprintf (stderr,
145 "Socket number too large (%d > %u)\n",
146 ret,
147 (unsigned int) FD_SETSIZE);
148 close (ret);
149 return -1;
150 }
151 memset (&src, 0, sizeof (src));
152 src.sin_family = AF_INET;
153 src.sin_port = htons (NAT_TRAV_PORT);
154
155 if (0 != bind (ret, (struct sockaddr*) &src, sizeof (src)))
156 {
157 close (ret);
158 continue;
159 }
160 return ret;
161 }
162 fprintf (stderr,
163 "Error binding udp socket: %s\n",
164 strerror (errno));
165 return -1;
166}
167
168#define LOW_PORT 32768
169
170/**
171 * create a random port number that is not totally
172 * unlikely to be chosen by the nat box.
173 */
174static uint16_t
175make_port ()
176{
177 return LOW_PORT + ( (unsigned int)rand ()) % (64 * 1024 - LOW_PORT - 2);
178}
179
180static int
181make_icmp_socket ()
182{
183 int ret;
184
185 ret = socket (AF_INET, SOCK_RAW, IPPROTO_ICMP);
186 if (-1 == ret)
187 {
188 fprintf (stderr,
189 "Error opening RAW socket: %s\n",
190 strerror (errno));
191 return -1;
192 }
193 if (ret >= FD_SETSIZE)
194 {
195 fprintf (stderr,
196 "Socket number too large (%d > %u)\n",
197 ret,
198 (unsigned int) FD_SETSIZE);
199 close (ret);
200 return -1;
201 }
202 return ret;
203}
204
205#if DUMMY
206/**
207 * Send a UDP message to the dummy IP.
208 *
209 * @param my_ip source address (our ip address)
210 */
211static void
212send_dummy_udp (const struct in_addr *my_ip)
213{
214 struct sockaddr_in dst;
215 size_t off;
216 int err;
217 struct ip_packet ip_pkt;
218 struct ip_packet udp_pkt;
219 char packet[sizeof (ip_pkt) + sizeof (udp_pkt)];
220
221
222 // build inner IP header
223 memset(&ip_pkt, 0, sizeof(ip_pkt));
224 ip_pkt.vers_ihl = 0x45;
225 ip_pkt.tos = 0;
226 ip_pkt.pkt_len = htons(sizeof (ip_pkt) + sizeof(udp_pkt));
227 ip_pkt.id = htons(0);
228 ip_pkt.flags_frag_offset = 0;
229 ip_pkt.ttl = 128;
230 ip_pkt.proto = IPPROTO_UDP;
231 ip_pkt.checksum = 0;
232 ip_pkt.src_ip = my_ip->s_addr;
233 ip_pkt.dst_ip = inet_addr(dummy.s_addr);
234 ip_pkt.checksum = htons(calc_checksum((uint16_t*)&ip_pkt, sizeof (ip_pkt)));
235 memcpy(&packet[off], &ip_pkt, sizeof(ip_pkt));
236 off += sizeof(ip_pkt);
237
238 // build UDP header
239 udp_pkt.src_port = NAT_TRAV_PORT;
240 udp_pkt.dst_port = htons(NAT_TRAV_PORT);
241
242 uint32_t newval = inet_addr("1.2.3.4");
243 memcpy(&udp_pkt.length, &newval, sizeof(uint32_t));
244
245 off += sizeof(udp_pkt);
246
247 err = sendto(rawsock,
248 ip_pkt, off, 0,
249 (struct sockaddr*)&dst,
250 sizeof(dst));
251 if (err < 0)
252 {
253#if VERBOSE
254 fprintf(stderr,
255 "sendto failed: %s\n", strerror(errno));
256#endif
257 }
258 else if (err != off)
259 {
260 fprintf(stderr,
261 "Error: partial send of UDP message\n");
262 }
263}
264#endif
265
266static void
267process_icmp_response()
268{
269 char buf[65536];
270 ssize_t have;
271 struct in_addr sip;
272 struct ip_packet ip_pkt;
273 struct icmp_packet icmp_pkt;
274 size_t off;
275 int have_port;
276 //uint32_t port;
277
278 have = read (icmpsock, buf, sizeof (buf));
279 if (have == -1)
280 {
281 fprintf (stderr,
282 "Error reading raw socket: %s\n",
283 strerror (errno));
284 return;
285 }
286
287 off = 0;
288 memcpy (&ip_pkt, &buf[off], sizeof (ip_pkt));
289 off += sizeof (ip_pkt);
290 memcpy (&icmp_pkt, &buf[off], sizeof (icmp_pkt));
291 off += sizeof (icmp_pkt);
292 if ( (ip_pkt.proto != IPPROTO_ICMP) ||
293 (icmp_pkt.type != 11) ||
294 (icmp_pkt.code != 0) )
295 {
296 /* maybe we got an actual reply back... */
297 return;
298 }
299
300 memcpy(&sip,
301 &ip_pkt.src_ip,
302 sizeof (sip));
303
304 fprintf (stderr,
305 "Received ICMP message of size: %u bytes from %s\n",
306 (unsigned int) have,
307 inet_ntop (AF_INET,
308 &sip,
309 buf,
310 sizeof (buf)));
311
312 have_port = 0;
313 if (have == sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2 + sizeof(uint32_t))
314 {
315 have_port = 1;
316 }
317 else if (have != sizeof (struct ip_packet) *2 + sizeof (struct icmp_packet) * 2)
318 {
319#if VERBOSE
320 fprintf (stderr,
321 "Received ICMP message of unexpected size: %u bytes\n",
322 (unsigned int) have);
323#endif
324 return;
325 }
326}
327
328int
329main (int argc, char *const *argv)
330{
331 int udpsocks[NUM_UDP_PORTS];
332 struct in_addr external;
333 unsigned int pos;
334 int i;
335 struct sockaddr_in dst;
336 int first_round = 1;
337 unsigned int tries;
338 struct timeval tv;
339 fd_set rs;
340 time_t stime;
341
342 if (argc != 2)
343 {
344 fprintf (stderr,
345 "This program must be started with our (internal) IP as the single argument.\n");
346 return 1;
347 }
348 if ( (1 != inet_pton (AF_INET, argv[1], &external)))
349 {
350 fprintf (stderr,
351 "Error parsing IPv4 address: %s\n",
352 strerror (errno));
353 return 1;
354 }
355
356 if (1 != inet_pton (AF_INET, DUMMY_IP, &dummy)) abort ();
357
358 fprintf (stderr,
359 "Trying to connect to %s\n",
360 DUMMY_IP);
361 srand (stime = time(NULL));
362 for (i=0;i<NUM_UDP_PORTS;i++)
363 udpsocks[i] = make_udp_socket (i);
364
365 if (-1 == (icmpsock = make_icmp_socket()))
366 return 1;
367
368 memset (&dst, 0, sizeof (dst));
369 dst.sin_family = AF_INET;
370 dst.sin_addr = dummy;
371 pos = 0;
372 tries = 0;
373
374 while (1)
375 {
376 tries++;
377
378 FD_ZERO (&rs);
379 FD_SET (icmpsock, &rs);
380 tv.tv_sec = 0;
381 tv.tv_usec = UDP_SEND_FREQUENCY_MS * 1000;
382 select (icmpsock + 1, &rs, NULL, NULL, &tv);
383 if (FD_ISSET (icmpsock, &rs))
384 process_icmp_response ();
385
386 if (udpsocks[pos] == -1)
387 {
388 udpsocks[pos] = make_udp_socket (pos);
389 continue;
390 }
391 if ( (0 == ((unsigned int)rand() % NUM_UDP_PORTS)) ||
392 (1 == first_round) )
393 dst.sin_port = htons (NAT_TRAV_PORT);
394 else
395 dst.sin_port = htons (make_port ());
396#if VERBOSE
397 fprintf (stderr,
398 "Sending UDP packet to `%s:%u'\n",
399 DUMMY_IP,
400 ntohs (dst.sin_port));
401
402#endif
403 first_round = 0;
404 if (-1 == sendto (udpsocks[pos],
405 NULL, 0, 0,
406 (struct sockaddr*) &dst, sizeof (dst)))
407 {
408 fprintf (stderr,
409 "sendto failed: %s\n",
410 strerror (errno));
411 close (udpsocks[pos]);
412 udpsocks[pos] = make_udp_socket (pos);
413 }
414 pos = (pos+1) % NUM_UDP_PORTS;
415 }
416 fprintf (stderr,
417 "Giving up after %u tries.\n",
418 tries);
419 return 3;
420}
421
422/* end of gnunet-nat-server-udp.c */