GNUnet  0.11.x
gnunet-service-nat_helper.c
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1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2009, 2010, 2011, 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  */
20 
27 #include "platform.h"
28 #include "gnunet_util_lib.h"
30 
31 
36 {
40  struct in_addr internal_address;
41 
46 
50  void *cb_cls;
51 
56 
61 
66 
71 
76 
81 };
82 
83 
90 static void
91 restart_nat_server (void *cls);
92 
93 
99 static void
101 {
102  GNUNET_assert (NULL == h->server_read_task);
106  h);
107 }
108 
109 
117 static void
118 nat_server_read (void *cls)
119 {
120  struct HelperContext *h = cls;
121  char mybuf[40];
122  ssize_t bytes;
123  int port;
124  const char *port_start;
125  struct sockaddr_in sin_addr;
126 
127  h->server_read_task = NULL;
128  memset (mybuf, 0, sizeof(mybuf));
129  bytes =
130  GNUNET_DISK_file_read (h->server_stdout_handle, mybuf, sizeof(mybuf));
131  if (bytes < 1)
132  {
134  "Finished reading from server stdout with code: %d\n",
135  (int) bytes);
140  h->server_proc = NULL;
142  h->server_stdout = NULL;
143  h->server_stdout_handle = NULL;
144  try_again (h);
145  return;
146  }
147 
148  port_start = NULL;
149  for (size_t i = 0; i < sizeof(mybuf); i++)
150  {
151  if (mybuf[i] == '\n')
152  {
153  mybuf[i] = '\0';
154  break;
155  }
156  if ((mybuf[i] == ':') && (i + 1 < sizeof(mybuf)))
157  {
158  mybuf[i] = '\0';
159  port_start = &mybuf[i + 1];
160  }
161  }
162 
163  /* construct socket address of sender */
164  memset (&sin_addr, 0, sizeof(sin_addr));
165  sin_addr.sin_family = AF_INET;
166 #if HAVE_SOCKADDR_IN_SIN_LEN
167  sin_addr.sin_len = sizeof(sin_addr);
168 #endif
169  if ((NULL == port_start) || (1 != sscanf (port_start, "%d", &port)) ||
170  (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr)))
171  {
172  /* should we restart gnunet-helper-nat-server? */
174  _ (
175  "gnunet-helper-nat-server generated malformed address `%s'\n"),
176  mybuf);
177  h->server_read_task =
181  h);
182  return;
183  }
184  sin_addr.sin_port = htons ((uint16_t) port);
186  "gnunet-helper-nat-server read: %s:%d\n",
187  mybuf,
188  port);
189  h->cb (h->cb_cls, &sin_addr);
190  h->server_read_task =
194  h);
195 }
196 
197 
204 static void
206 {
207  struct HelperContext *h = cls;
208  char *binary;
209  char ia[INET_ADDRSTRLEN];
210 
211  h->server_read_task = NULL;
212  GNUNET_assert (NULL !=
213  inet_ntop (AF_INET, &h->internal_address, ia, sizeof(ia)));
214  /* Start the server process */
215  binary = GNUNET_OS_get_suid_binary_path (h->cfg, "gnunet-helper-nat-server");
217  {
218  /* move instantly to max delay, as this is unlikely to be fixed */
220  GNUNET_free (binary);
221  try_again (h);
222  return;
223  }
224  h->server_stdout =
226  if (NULL == h->server_stdout)
227  {
229  GNUNET_free (binary);
230  try_again (h);
231  return;
232  }
234  "Starting `%s' at `%s'\n",
235  "gnunet-helper-nat-server",
236  ia);
238  0,
239  NULL,
240  h->server_stdout,
241  NULL,
242  binary,
243  "gnunet-helper-nat-server",
244  ia,
245  NULL);
246  GNUNET_free (binary);
247  if (NULL == h->server_proc)
248  {
250  _ ("Failed to start %s\n"),
251  "gnunet-helper-nat-server");
253  h->server_stdout = NULL;
254  try_again (h);
255  return;
256  }
257  /* Close the write end of the read pipe */
261  h->server_read_task =
265  h);
266 }
267 
268 
279 struct HelperContext *
282  void *cb_cls,
283  const struct GNUNET_CONFIGURATION_Handle *cfg)
284 {
285  struct HelperContext *h;
286 
287  h = GNUNET_new (struct HelperContext);
288  h->cb = cb;
289  h->cb_cls = cb_cls;
291  h->cfg = cfg;
292  restart_nat_server (h);
293  if (NULL == h->server_stdout)
294  {
296  return NULL;
297  }
298  return h;
299 }
300 
301 
308 void
310 {
311  if (NULL != h->server_read_task)
312  {
314  h->server_read_task = NULL;
315  }
316  if (NULL != h->server_proc)
317  {
322  h->server_proc = NULL;
324  h->server_stdout = NULL;
325  h->server_stdout_handle = NULL;
326  }
327  if (NULL != h->server_stdout)
328  {
330  h->server_stdout = NULL;
331  h->server_stdout_handle = NULL;
332  }
333  GNUNET_free (h);
334 }
335 
336 
349 int
351  uint16_t internal_port,
352  const struct in_addr *remote_v4,
353  const struct GNUNET_CONFIGURATION_Handle *cfg)
354 {
355  char intv4[INET_ADDRSTRLEN];
356  char remv4[INET_ADDRSTRLEN];
357  char port_as_string[6];
358  struct GNUNET_OS_Process *proc;
359  char *binary;
360 
361  if (NULL == inet_ntop (AF_INET, internal_address, intv4, INET_ADDRSTRLEN))
362  {
364  return GNUNET_SYSERR;
365  }
366  if (NULL == inet_ntop (AF_INET, remote_v4, remv4, INET_ADDRSTRLEN))
367  {
369  return GNUNET_SYSERR;
370  }
371  GNUNET_snprintf (port_as_string,
372  sizeof(port_as_string),
373  "%d",
374  internal_port);
376  "Running gnunet-helper-nat-client %s %s %u\n",
377  intv4,
378  remv4,
379  internal_port);
380  binary = GNUNET_OS_get_suid_binary_path (cfg, "gnunet-helper-nat-client");
382  0,
383  NULL,
384  NULL,
385  NULL,
386  binary,
387  "gnunet-helper-nat-client",
388  intv4,
389  remv4,
390  port_as_string,
391  NULL);
392  GNUNET_free (binary);
393  if (NULL == proc)
394  return GNUNET_SYSERR;
395  /* we know that the gnunet-helper-nat-client will terminate virtually
396  * instantly */
397  GNUNET_OS_process_wait (proc);
399  return GNUNET_OK;
400 }
401 
402 
403 /* end of gnunet-service-nat_helper.c */
struct GNUNET_OS_Process * server_proc
The process id of the server process (if behind NAT)
GN_ReversalCallback cb
Function to call if we receive a reversal request.
static void try_again(struct HelperContext *h)
Try again starting the helper later.
void GNUNET_OS_process_destroy(struct GNUNET_OS_Process *proc)
Cleans up process structure contents (OS-dependent) and deallocates it.
Definition: os_priority.c:287
#define GNUNET_log_from_strerror(level, component, cmd)
Log an error message at log-level &#39;level&#39; that indicates a failure of the command &#39;cmd&#39; with the mess...
int GNUNET_snprintf(char *buf, size_t size, const char *format,...)
Like snprintf, just aborts if the buffer is of insufficient size.
ssize_t GNUNET_DISK_file_read(const struct GNUNET_DISK_FileHandle *h, void *result, size_t len)
Read the contents of a binary file into a buffer.
Definition: disk.c:732
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct GNUNET_OS_Process * GNUNET_OS_start_process(int pipe_control, enum GNUNET_OS_InheritStdioFlags std_inheritance, struct GNUNET_DISK_PipeHandle *pipe_stdin, struct GNUNET_DISK_PipeHandle *pipe_stdout, struct GNUNET_DISK_PipeHandle *pipe_stderr, const char *filename,...)
Start a process.
Definition: os_priority.c:687
void GN_stop_gnunet_nat_server_(struct HelperContext *h)
Start the gnunet-helper-nat-server and process incoming requests.
#define GNUNET_NO
Definition: gnunet_common.h:78
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_read_file(struct GNUNET_TIME_Relative delay, const struct GNUNET_DISK_FileHandle *rfd, GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run with a specified delay or when the specified file descriptor is ready f...
Definition: scheduler.c:1636
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
int GNUNET_OS_check_helper_binary(const char *binary, int check_suid, const char *params)
Check whether an executable exists and possibly if the suid bit is set on the file.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
struct GNUNET_TIME_Relative server_retry_delay
How long do we wait for restarting a crashed gnunet-helper-nat-server?
runs the gnunet-helper-nat-server
const struct GNUNET_DISK_FileHandle * GNUNET_DISK_pipe_handle(const struct GNUNET_DISK_PipeHandle *p, enum GNUNET_DISK_PipeEnd n)
Get the handle to a particular pipe end.
Definition: disk.c:1753
static struct GNUNET_ARM_Handle * h
Connection with ARM.
Definition: gnunet-arm.c:99
struct GNUNET_SCHEDULER_Task * server_read_task
ID of select gnunet-helper-nat-server stdout read task.
#define _(String)
GNU gettext support macro.
Definition: platform.h:181
#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...
struct GNUNET_SCHEDULER_Task * GNUNET_SCHEDULER_add_delayed(struct GNUNET_TIME_Relative delay, GNUNET_SCHEDULER_TaskCallback task, void *task_cls)
Schedule a new task to be run with a specified delay.
Definition: scheduler.c:1253
#define GNUNET_TIME_STD_EXPONENTIAL_BACKOFF_THRESHOLD
Threshold after which exponential backoff should not increase (15 m).
char * GNUNET_OS_get_suid_binary_path(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *progname)
Given the name of a helper, service or daemon binary construct the full path to the binary using the ...
#define GNUNET_TIME_UNIT_FOREVER_REL
Constant used to specify "forever".
The writing-end of a pipe.
The reading-end of a pipe.
struct GNUNET_DISK_PipeHandle * GNUNET_DISK_pipe(int blocking_read, int blocking_write, int inherit_read, int inherit_write)
Creates an interprocess channel.
Definition: disk.c:1526
struct GNUNET_DISK_PipeHandle * server_stdout
stdout pipe handle for the gnunet-helper-nat-server process
#define GNUNET_SYSERR
Definition: gnunet_common.h:76
static void restart_nat_server(void *cls)
Task that restarts the gnunet-helper-nat-server process after a crash after a certain delay...
#define GNUNET_TIME_STD_BACKOFF(r)
Perform our standard exponential back-off calculation, starting at 1 ms and then going by a factor of...
int GNUNET_DISK_pipe_close(struct GNUNET_DISK_PipeHandle *p)
Closes an interprocess channel.
Definition: disk.c:1715
struct in_addr internal_address
IP address we pass to the NAT helper.
int GNUNET_DISK_pipe_close_end(struct GNUNET_DISK_PipeHandle *p, enum GNUNET_DISK_PipeEnd end)
Closes one half of an interprocess channel.
Definition: disk.c:1643
int GN_request_connection_reversal(const struct in_addr *internal_address, uint16_t internal_port, const struct in_addr *remote_v4, const struct GNUNET_CONFIGURATION_Handle *cfg)
We want to connect to a peer that is behind NAT.
static void nat_server_read(void *cls)
We have been notified that gnunet-helper-nat-server has written something to stdout.
int GNUNET_OS_process_wait(struct GNUNET_OS_Process *proc)
Wait for a process to terminate.
Definition: os_priority.c:1000
static uint16_t port
Port number.
Definition: gnunet-bcd.c:81
configuration data
Definition: configuration.c:85
void * cb_cls
Closure for cb.
#define GNUNET_log(kind,...)
Entry in list of pending tasks.
Definition: scheduler.c:134
void(* GN_ReversalCallback)(void *cls, const struct sockaddr_in *ra)
Function called whenever we get a connection reversal request from another peer.
#define GNUNET_YES
Definition: gnunet_common.h:77
const struct GNUNET_DISK_FileHandle * server_stdout_handle
stdout file handle (for reading) for the gnunet-helper-nat-server process
#define GNUNET_TERM_SIG
The termination signal.
Definition: platform.h:242
Information we keep per NAT helper process.
Handle used to access files (and pipes).
Handle used to manage a pipe.
Definition: disk.c:68
const struct GNUNET_CONFIGURATION_Handle * cfg
Handle to the GNUnet configuration.
struct HelperContext * GN_start_gnunet_nat_server_(const struct in_addr *internal_address, GN_ReversalCallback cb, void *cb_cls, const struct GNUNET_CONFIGURATION_Handle *cfg)
Start the gnunet-helper-nat-server and process incoming requests.
#define GNUNET_free(ptr)
Wrapper around free.
Time for relative time used by GNUnet, in microseconds.
int GNUNET_OS_process_kill(struct GNUNET_OS_Process *proc, int sig)
Sends a signal to the process.
Definition: os_priority.c:225
void * GNUNET_SCHEDULER_cancel(struct GNUNET_SCHEDULER_Task *task)
Cancel the task with the specified identifier.
Definition: scheduler.c:966