GNUnet  0.10.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 
35 struct HelperContext {
39  struct in_addr internal_address;
40 
45 
49  void *cb_cls;
50 
55 
60 
65 
70 
75 
80 };
81 
82 
89 static void
90 restart_nat_server(void *cls);
91 
92 
98 static void
100 {
101  GNUNET_assert(NULL == h->server_read_task);
105  h);
106 }
107 
108 
116 static void
117 nat_server_read(void *cls)
118 {
119  struct HelperContext *h = cls;
120  char mybuf[40];
121  ssize_t bytes;
122  int port;
123  const char *port_start;
124  struct sockaddr_in sin_addr;
125 
126  h->server_read_task = NULL;
127  memset(mybuf, 0, sizeof(mybuf));
128  bytes =
129  GNUNET_DISK_file_read(h->server_stdout_handle, mybuf, sizeof(mybuf));
130  if (bytes < 1)
131  {
133  "Finished reading from server stdout with code: %d\n",
134  (int)bytes);
139  h->server_proc = NULL;
141  h->server_stdout = NULL;
142  h->server_stdout_handle = NULL;
143  try_again(h);
144  return;
145  }
146 
147  port_start = NULL;
148  for (size_t i = 0; i < sizeof(mybuf); i++)
149  {
150  if (mybuf[i] == '\n')
151  {
152  mybuf[i] = '\0';
153  break;
154  }
155  if ((mybuf[i] == ':') && (i + 1 < sizeof(mybuf)))
156  {
157  mybuf[i] = '\0';
158  port_start = &mybuf[i + 1];
159  }
160  }
161 
162  /* construct socket address of sender */
163  memset(&sin_addr, 0, sizeof(sin_addr));
164  sin_addr.sin_family = AF_INET;
165 #if HAVE_SOCKADDR_IN_SIN_LEN
166  sin_addr.sin_len = sizeof(sin_addr);
167 #endif
168  if ((NULL == port_start) || (1 != sscanf(port_start, "%d", &port)) ||
169  (-1 == inet_pton(AF_INET, mybuf, &sin_addr.sin_addr)))
170  {
171  /* should we restart gnunet-helper-nat-server? */
173  _(
174  "gnunet-helper-nat-server generated malformed address `%s'\n"),
175  mybuf);
176  h->server_read_task =
180  h);
181  return;
182  }
183  sin_addr.sin_port = htons((uint16_t)port);
185  "gnunet-helper-nat-server read: %s:%d\n",
186  mybuf,
187  port);
188  h->cb(h->cb_cls, &sin_addr);
189  h->server_read_task =
193  h);
194 }
195 
196 
203 static void
205 {
206  struct HelperContext *h = cls;
207  char *binary;
208  char ia[INET_ADDRSTRLEN];
209 
210  h->server_read_task = NULL;
211  GNUNET_assert(NULL !=
212  inet_ntop(AF_INET, &h->internal_address, ia, sizeof(ia)));
213  /* Start the server process */
214  binary = GNUNET_OS_get_suid_binary_path(h->cfg, "gnunet-helper-nat-server");
216  {
217  /* move instantly to max delay, as this is unlikely to be fixed */
219  GNUNET_free(binary);
220  try_again(h);
221  return;
222  }
223  h->server_stdout =
225  if (NULL == h->server_stdout)
226  {
228  GNUNET_free(binary);
229  try_again(h);
230  return;
231  }
233  "Starting `%s' at `%s'\n",
234  "gnunet-helper-nat-server",
235  ia);
237  0,
238  NULL,
239  h->server_stdout,
240  NULL,
241  binary,
242  "gnunet-helper-nat-server",
243  ia,
244  NULL);
245  GNUNET_free(binary);
246  if (NULL == h->server_proc)
247  {
249  _("Failed to start %s\n"),
250  "gnunet-helper-nat-server");
252  h->server_stdout = NULL;
253  try_again(h);
254  return;
255  }
256  /* Close the write end of the read pipe */
260  h->server_read_task =
264  h);
265 }
266 
267 
278 struct HelperContext *
281  void *cb_cls,
282  const struct GNUNET_CONFIGURATION_Handle *cfg)
283 {
284  struct HelperContext *h;
285 
286  h = GNUNET_new(struct HelperContext);
287  h->cb = cb;
288  h->cb_cls = cb_cls;
290  h->cfg = cfg;
292  if (NULL == h->server_stdout)
293  {
295  return NULL;
296  }
297  return h;
298 }
299 
300 
307 void
309 {
310  if (NULL != h->server_read_task)
311  {
313  h->server_read_task = NULL;
314  }
315  if (NULL != h->server_proc)
316  {
321  h->server_proc = NULL;
323  h->server_stdout = NULL;
324  h->server_stdout_handle = NULL;
325  }
326  if (NULL != h->server_stdout)
327  {
329  h->server_stdout = NULL;
330  h->server_stdout_handle = NULL;
331  }
332  GNUNET_free(h);
333 }
334 
335 
348 int
350  uint16_t internal_port,
351  const struct in_addr *remote_v4,
352  const struct GNUNET_CONFIGURATION_Handle *cfg)
353 {
354  char intv4[INET_ADDRSTRLEN];
355  char remv4[INET_ADDRSTRLEN];
356  char port_as_string[6];
357  struct GNUNET_OS_Process *proc;
358  char *binary;
359 
360  if (NULL == inet_ntop(AF_INET, internal_address, intv4, INET_ADDRSTRLEN))
361  {
363  return GNUNET_SYSERR;
364  }
365  if (NULL == inet_ntop(AF_INET, remote_v4, remv4, INET_ADDRSTRLEN))
366  {
368  return GNUNET_SYSERR;
369  }
370  GNUNET_snprintf(port_as_string,
371  sizeof(port_as_string),
372  "%d",
373  internal_port);
375  "Running gnunet-helper-nat-client %s %s %u\n",
376  intv4,
377  remv4,
378  internal_port);
379  binary = GNUNET_OS_get_suid_binary_path(cfg, "gnunet-helper-nat-client");
381  0,
382  NULL,
383  NULL,
384  NULL,
385  binary,
386  "gnunet-helper-nat-client",
387  intv4,
388  remv4,
389  port_as_string,
390  NULL);
391  GNUNET_free(binary);
392  if (NULL == proc)
393  return GNUNET_SYSERR;
394  /* we know that the gnunet-helper-nat-client will terminate virtually
395  * instantly */
398  return GNUNET_OK;
399 }
400 
401 
402 /* 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:286
#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:729
#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:1615
#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:1744
static struct GNUNET_ARM_Handle * h
Connection with ARM.
Definition: gnunet-arm.c:94
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:1237
#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:1518
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:1706
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:1635
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:83
void * cb_cls
Closure for cb.
#define GNUNET_log(kind,...)
Entry in list of pending tasks.
Definition: scheduler.c:131
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:224
void * GNUNET_SCHEDULER_cancel(struct GNUNET_SCHEDULER_Task *task)
Cancel the task with the specified identifier.
Definition: scheduler.c:956