GNUnet  0.11.x
nat_api_stun.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2009, 2015, 2016 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your 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  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
38 #include "platform.h"
39 #include "gnunet_util_lib.h"
41 #include "gnunet_nat_service.h"
42 
43 
44 #include "nat_stun.h"
45 
46 #define LOG(kind, ...) GNUNET_log_from (kind, "stun", __VA_ARGS__)
47 
48 #define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
49 
50 
57 {
62 
67 
71  char *stun_server;
72 
77 
81  void *cb_cls;
82 
87 
91  uint16_t stun_port;
92 };
93 
94 
102 static int
103 encode_message (enum StunClasses msg_class,
104  enum StunMethods method)
105 {
106  return ((msg_class & 1) << 4) | ((msg_class & 2) << 7)
107  | (method & 0x000f) | ((method & 0x0070) << 1) | ((method & 0x0f800)
108  << 2);
109 }
110 
111 
117 static void
119 {
120  req->magic = htonl (STUN_MAGIC_COOKIE);
121  for (unsigned int x = 0; x < 3; x++)
123  UINT32_MAX);
124 }
125 
126 
134 static void
135 stun_dns_callback (void *cls,
136  const struct sockaddr *addr,
137  socklen_t addrlen)
138 {
139  struct GNUNET_NAT_STUN_Handle *rh = cls;
140  struct stun_header req;
141  struct sockaddr_in server;
142 
143  if (NULL == addr)
144  {
145  rh->dns_active = NULL;
146  if (GNUNET_NO == rh->dns_success)
147  {
149  "Error resolving host %s\n",
150  rh->stun_server);
151  rh->cb (rh->cb_cls,
153  }
154  else if (GNUNET_SYSERR == rh->dns_success)
155  {
156  rh->cb (rh->cb_cls,
158  }
159  else
160  {
161  rh->cb (rh->cb_cls,
163  }
165  return;
166  }
167 
168  rh->dns_success = GNUNET_YES;
169  memset (&server, 0, sizeof(server));
170  server.sin_family = AF_INET;
171  server.sin_addr = ((struct sockaddr_in *) addr)->sin_addr;
172  server.sin_port = htons (rh->stun_port);
173 #if HAVE_SOCKADDR_IN_SIN_LEN
174  server.sin_len = (u_char) sizeof(struct sockaddr_in);
175 #endif
176 
177  /* Craft the simplest possible STUN packet. A request binding */
178  generate_request_id (&req);
179  req.msglen = htons (0);
180  req.msgtype = htons (encode_message (STUN_REQUEST,
181  STUN_BINDING));
182 
183  /* Send the packet */
184  if (-1 ==
186  &req,
187  sizeof(req),
188  (const struct sockaddr *) &server,
189  sizeof(server)))
190  {
192  "sendto");
194  return;
195  }
196 }
197 
198 
210 struct GNUNET_NAT_STUN_Handle *
211 GNUNET_NAT_stun_make_request (const char *server,
212  uint16_t port,
213  struct GNUNET_NETWORK_Handle *sock,
215  void *cb_cls)
216 {
217  struct GNUNET_NAT_STUN_Handle *rh;
218 
219  rh = GNUNET_new (struct GNUNET_NAT_STUN_Handle);
220  rh->sock = sock;
221  rh->cb = cb;
222  rh->cb_cls = cb_cls;
223  rh->stun_server = GNUNET_strdup (server);
224  rh->stun_port = port;
225  rh->dns_success = GNUNET_NO;
227  AF_INET,
228  TIMEOUT,
230  rh);
231  if (NULL == rh->dns_active)
232  {
234  return NULL;
235  }
236  return rh;
237 }
238 
239 
246 void
248 {
249  if (NULL != rh->dns_active)
250  {
252  rh->dns_active = NULL;
253  }
254  GNUNET_free (rh->stun_server);
255  GNUNET_free (rh);
256 }
257 
258 
259 /* end of nat_stun.c */
void GNUNET_RESOLVER_request_cancel(struct GNUNET_RESOLVER_RequestHandle *rh)
Cancel a request that is still pending with the resolver.
struct GNUNET_NAT_STUN_Handle * GNUNET_NAT_stun_make_request(const char *server, uint16_t port, struct GNUNET_NETWORK_Handle *sock, GNUNET_NAT_TestCallback cb, void *cb_cls)
Make Generic STUN request.
Definition: nat_api_stun.c:211
detected that we are offline
void GNUNET_NAT_stun_make_request_cancel(struct GNUNET_NAT_STUN_Handle *rh)
Cancel active STUN request.
Definition: nat_api_stun.c:247
void * cb_cls
Closure for cb.
Definition: nat_api_stun.c:81
uint32_t GNUNET_CRYPTO_random_u32(enum GNUNET_CRYPTO_Quality mode, uint32_t i)
Produce a random value.
Handle to a request given to the resolver.
Definition: nat_api_stun.c:56
Message types for STUN server resolution.
stun_trans_id id
Definition: nat_stun.h:47
void(* GNUNET_NAT_TestCallback)(void *cls, enum GNUNET_NAT_StatusCode result)
Function called to report success or failure for NAT configuration test.
#define GNUNET_NO
Definition: gnunet_common.h:78
struct GNUNET_RESOLVER_RequestHandle * GNUNET_RESOLVER_ip_get(const char *hostname, int af, struct GNUNET_TIME_Relative timeout, GNUNET_RESOLVER_AddressCallback callback, void *callback_cls)
Convert a string to one or more IP addresses.
Definition: resolver_api.c:939
#define GNUNET_new(type)
Allocate a struct or union of the given type.
uint16_t msglen
Definition: nat_stun.h:45
#define GNUNET_strdup(a)
Wrapper around GNUNET_xstrdup_.
StunMethods
Definition: nat_stun.h:94
#define GNUNET_log_strerror(level, cmd)
Log an error message at log-level &#39;level&#39; that indicates a failure of the command &#39;cmd&#39; with the mess...
#define LOG(kind,...)
Definition: nat_api_stun.c:46
ssize_t GNUNET_NETWORK_socket_sendto(const struct GNUNET_NETWORK_Handle *desc, const void *message, size_t length, const struct sockaddr *dest_addr, socklen_t dest_len)
Send data to a particular destination (always non-blocking).
Definition: network.c:850
Randomness for IVs etc.
uint16_t msgtype
Definition: nat_stun.h:44
struct GNUNET_NETWORK_Handle * sock
Handle to the listen socket.
Definition: nat_api_stun.c:66
Failure in network subsystem, check permissions.
char * stun_server
Stun server address.
Definition: nat_api_stun.c:71
struct sockaddr * addr
Address we were bound to, or NULL.
Definition: network.c:74
#define TIMEOUT
Definition: nat_api_stun.c:48
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
GNUNET_NAT_TestCallback cb
Function to call when a error occours.
Definition: nat_api_stun.c:76
Handle to a request given to the resolver.
Definition: resolver_api.c:102
static int encode_message(enum StunClasses msg_class, enum StunMethods method)
Encode a class and method to a compatible STUN format.
Definition: nat_api_stun.c:103
StunClasses
STUN message classes.
Definition: nat_stun.h:85
uint16_t stun_port
STUN port.
Definition: nat_api_stun.c:91
int dns_success
Do we got a DNS resolution successfully?
Definition: nat_api_stun.c:86
static uint16_t port
Port number.
Definition: gnunet-bcd.c:81
socklen_t addrlen
Number of bytes in addr.
Definition: network.c:69
#define STUN_MAGIC_COOKIE
Definition: nat_stun.h:34
static void stun_dns_callback(void *cls, const struct sockaddr *addr, socklen_t addrlen)
Try to establish a connection given the specified address.
Definition: nat_api_stun.c:135
handle to a socket
Definition: network.c:52
uint32_t magic
Definition: nat_stun.h:46
#define GNUNET_YES
Definition: gnunet_common.h:77
uint32_t id[3]
Definition: nat_stun.h:38
static void generate_request_id(struct stun_header *req)
Fill the stun_header with a random request_id.
Definition: nat_api_stun.c:118
#define GNUNET_free(ptr)
Wrapper around free.
struct GNUNET_RESOLVER_RequestHandle * dns_active
Handle to a pending DNS lookup request.
Definition: nat_api_stun.c:61