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18 SPDX-License-Identifier: AGPL3.0-or-later
22 * @file nat/gnunet-service-nat_mini.c
23 * @brief functions for interaction with miniupnp; tested with miniupnpc 1.5
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_nat_service.h"
29 #include "gnunet-service-nat_mini.h"
32 #define LOG(kind,...) GNUNET_log_from (kind, "nat", __VA_ARGS__)
35 * How long do we give upnpc to create a mapping?
37 #define MAP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
40 * How long do we give upnpc to remove a mapping?
42 #define UNMAP_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
45 * How often do we check for changes in the mapping?
47 #define MAP_REFRESH_FREQ GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
50 /* ************************* external-ip calling ************************ */
53 * Opaque handle to cancel "GNUNET_NAT_mini_get_external_ipv4" operation.
55 struct GNUNET_NAT_ExternalHandle
59 * Function to call with the result.
61 GNUNET_NAT_IPCallback cb;
71 struct GNUNET_SCHEDULER_Task *task;
74 * Handle to `external-ip` process.
76 struct GNUNET_OS_Process *eip;
79 * Handle to stdout pipe of `external-ip`.
81 struct GNUNET_DISK_PipeHandle *opipe;
84 * Read handle of @e opipe.
86 const struct GNUNET_DISK_FileHandle *r;
89 * Number of bytes in @e buf that are valid.
94 * Destination of our read operation (output of 'external-ip').
99 * Error code for better debugging and user feedback
101 enum GNUNET_NAT_StatusCode ret;
106 * Read the output of `external-ip` into `buf`. When complete, parse
107 * the address and call our callback.
109 * @param cls the `struct GNUNET_NAT_ExternalHandle`
112 read_external_ipv4 (void *cls)
114 struct GNUNET_NAT_ExternalHandle *eh = cls;
119 ret = GNUNET_DISK_file_read (eh->r,
121 sizeof (eh->buf) - eh->off);
124 /* try to read more */
127 = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
133 eh->ret = GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID;
134 if ( (eh->off > 7) &&
135 (eh->buf[eh->off - 1] == '\n') )
137 eh->buf[eh->off - 1] = '\0';
138 if (1 == inet_pton (AF_INET,
142 if (0 == addr.s_addr)
143 eh->ret = GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID; /* got 0.0.0.0 */
145 eh->ret = GNUNET_NAT_ERROR_SUCCESS;
149 (GNUNET_NAT_ERROR_SUCCESS == eh->ret) ? &addr : NULL,
151 GNUNET_NAT_mini_get_external_ipv4_cancel_ (eh);
156 * (Asynchronously) signal error invoking `external-ip` to client.
158 * @param cls the `struct GNUNET_NAT_ExternalHandle` (freed)
161 signal_external_ip_error (void *cls)
163 struct GNUNET_NAT_ExternalHandle *eh = cls;
174 * Try to get the external IPv4 address of this peer.
176 * @param cb function to call with result
177 * @param cb_cls closure for @a cb
178 * @return handle for cancellation (can only be used until @a cb is called), never NULL
180 struct GNUNET_NAT_ExternalHandle *
181 GNUNET_NAT_mini_get_external_ipv4_ (GNUNET_NAT_IPCallback cb,
184 struct GNUNET_NAT_ExternalHandle *eh;
186 eh = GNUNET_new (struct GNUNET_NAT_ExternalHandle);
189 eh->ret = GNUNET_NAT_ERROR_SUCCESS;
191 GNUNET_OS_check_helper_binary ("external-ip",
195 LOG (GNUNET_ERROR_TYPE_INFO,
196 _("`external-ip' command not found\n"));
197 eh->ret = GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND;
198 eh->task = GNUNET_SCHEDULER_add_now (&signal_external_ip_error,
202 LOG (GNUNET_ERROR_TYPE_DEBUG,
203 "Running `external-ip' to determine our external IP\n");
204 eh->opipe = GNUNET_DISK_pipe (GNUNET_YES,
208 if (NULL == eh->opipe)
210 eh->ret = GNUNET_NAT_ERROR_IPC_FAILURE;
211 eh->task = GNUNET_SCHEDULER_add_now (&signal_external_ip_error,
216 GNUNET_OS_start_process (GNUNET_NO,
226 GNUNET_DISK_pipe_close (eh->opipe);
227 eh->ret = GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED;
228 eh->task = GNUNET_SCHEDULER_add_now (&signal_external_ip_error,
232 GNUNET_DISK_pipe_close_end (eh->opipe,
233 GNUNET_DISK_PIPE_END_WRITE);
234 eh->r = GNUNET_DISK_pipe_handle (eh->opipe,
235 GNUNET_DISK_PIPE_END_READ);
237 = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
248 * @param eh operation to cancel
251 GNUNET_NAT_mini_get_external_ipv4_cancel_ (struct GNUNET_NAT_ExternalHandle *eh)
255 (void) GNUNET_OS_process_kill (eh->eip,
257 GNUNET_break (GNUNET_OK ==
258 GNUNET_OS_process_wait (eh->eip));
259 GNUNET_OS_process_destroy (eh->eip);
261 if (NULL != eh->opipe)
263 GNUNET_DISK_pipe_close (eh->opipe);
266 if (NULL != eh->task)
268 GNUNET_SCHEDULER_cancel (eh->task);
275 /* ************************* upnpc calling ************************ */
279 * Handle to a mapping created with upnpc.
281 struct GNUNET_NAT_MiniHandle
285 * Function to call on mapping changes.
287 GNUNET_NAT_MiniAddressCallback ac;
295 * Command used to install the map.
297 struct GNUNET_OS_CommandHandle *map_cmd;
300 * Command used to refresh our map information.
302 struct GNUNET_OS_CommandHandle *refresh_cmd;
305 * Command used to remove the mapping.
307 struct GNUNET_OS_CommandHandle *unmap_cmd;
310 * Our current external mapping (if we have one).
312 struct sockaddr_in current_addr;
315 * We check the mapping periodically to see if it
316 * still works. This task triggers the check.
318 struct GNUNET_SCHEDULER_Task *refresh_task;
321 * Are we mapping TCP or UDP?
326 * Did we succeed with creating a mapping?
331 * Did we find our mapping during refresh scan?
336 * Which port are we mapping?
344 * Run "upnpc -l" to find out if our mapping changed.
346 * @param cls the `struct GNUNET_NAT_MiniHandle`
349 do_refresh (void *cls);
353 * Process the output from the "upnpc -r" command.
355 * @param cls the `struct GNUNET_NAT_MiniHandle`
356 * @param line line of output, NULL at the end
359 process_map_output (void *cls,
364 * Run "upnpc -r" to map our internal port.
366 * @param mini our handle
369 run_upnpc_r (struct GNUNET_NAT_MiniHandle *mini)
373 GNUNET_snprintf (pstr,
376 (unsigned int) mini->port);
378 = GNUNET_OS_command_run (&process_map_output,
385 mini->is_tcp ? "tcp" : "udp",
387 if (NULL == mini->map_cmd)
389 mini->ac (mini->ac_cls,
393 GNUNET_NAT_ERROR_UPNPC_FAILED);
400 * Process the output from "upnpc -l" to see if our
401 * external mapping changed. If so, do the notifications.
403 * @param cls the `struct GNUNET_NAT_MiniHandle`
404 * @param line line of output, NULL at the end
407 process_refresh_output (void *cls,
410 struct GNUNET_NAT_MiniHandle *mini = cls;
418 GNUNET_OS_command_stop (mini->refresh_cmd);
419 mini->refresh_cmd = NULL;
420 if (GNUNET_NO == mini->found)
422 /* mapping disappeared, try to re-create */
423 if (GNUNET_YES == mini->did_map)
425 mini->ac (mini->ac_cls,
427 (const struct sockaddr *) &mini->current_addr,
428 sizeof (mini->current_addr),
429 GNUNET_NAT_ERROR_SUCCESS);
430 mini->did_map = GNUNET_NO;
437 return; /* never mapped, won't find our mapping anyway */
439 /* we're looking for output of the form:
440 * "ExternalIPAddress = 12.134.41.124" */
443 "ExternalIPAddress = ");
446 s += strlen ("ExternalIPAddress = ");
447 if (1 != inet_pton (AF_INET,
451 if (exip.s_addr == mini->current_addr.sin_addr.s_addr)
452 return; /* no change */
454 mini->ac (mini->ac_cls,
456 (const struct sockaddr *) &mini->current_addr,
457 sizeof (mini->current_addr),
458 GNUNET_NAT_ERROR_SUCCESS);
459 mini->current_addr.sin_addr = exip;
460 mini->ac (mini->ac_cls,
462 (const struct sockaddr *) &mini->current_addr,
463 sizeof (mini->current_addr),
464 GNUNET_NAT_ERROR_SUCCESS);
468 * we're looking for output of the form:
470 * "0 TCP 3000->192.168.2.150:3000 'libminiupnpc' ''"
471 * "1 UDP 3001->192.168.2.150:3001 'libminiupnpc' ''"
473 * the pattern we look for is:
475 * "%s TCP PORT->STRING:OURPORT *" or
476 * "%s UDP PORT->STRING:OURPORT *"
478 GNUNET_snprintf (pstr,
482 if (NULL == (s = strstr (line, "->")))
484 if (NULL == strstr (s, pstr))
488 (mini->is_tcp) ? "%*u TCP %u->%*s:%*u %*s" :
489 "%*u UDP %u->%*s:%*u %*s", &nport))
491 mini->found = GNUNET_YES;
492 if (nport == ntohs (mini->current_addr.sin_port))
493 return; /* no change */
495 /* external port changed, update mapping */
496 mini->ac (mini->ac_cls,
498 (const struct sockaddr *) &mini->current_addr,
499 sizeof (mini->current_addr),
500 GNUNET_NAT_ERROR_SUCCESS);
501 mini->current_addr.sin_port = htons ((uint16_t) nport);
502 mini->ac (mini->ac_cls,
504 (const struct sockaddr *) &mini->current_addr,
505 sizeof (mini->current_addr),
506 GNUNET_NAT_ERROR_SUCCESS);
511 * Run "upnpc -l" to find out if our mapping changed.
513 * @param cls the 'struct GNUNET_NAT_MiniHandle'
516 do_refresh (void *cls)
518 struct GNUNET_NAT_MiniHandle *mini = cls;
522 = GNUNET_SCHEDULER_add_delayed (MAP_REFRESH_FREQ,
525 LOG (GNUNET_ERROR_TYPE_DEBUG,
526 "Running `upnpc' to check if our mapping still exists\n");
527 mini->found = GNUNET_NO;
529 if (NULL != mini->map_cmd)
531 /* took way too long, abort it! */
532 GNUNET_OS_command_stop (mini->map_cmd);
533 mini->map_cmd = NULL;
536 if (NULL != mini->refresh_cmd)
538 /* took way too long, abort it! */
539 GNUNET_OS_command_stop (mini->refresh_cmd);
540 mini->refresh_cmd = NULL;
544 = GNUNET_OS_command_run (&process_refresh_output,
551 if (GNUNET_YES == ac)
552 mini->ac (mini->ac_cls,
556 GNUNET_NAT_ERROR_UPNPC_TIMEOUT);
561 * Process the output from the 'upnpc -r' command.
563 * @param cls the `struct GNUNET_NAT_MiniHandle`
564 * @param line line of output, NULL at the end
567 process_map_output (void *cls,
570 struct GNUNET_NAT_MiniHandle *mini = cls;
578 GNUNET_OS_command_stop (mini->map_cmd);
579 mini->map_cmd = NULL;
580 if (GNUNET_YES != mini->did_map)
581 mini->ac (mini->ac_cls,
585 GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED);
586 if (NULL == mini->refresh_task)
588 = GNUNET_SCHEDULER_add_delayed (MAP_REFRESH_FREQ,
594 * The upnpc output we're after looks like this:
596 * "external 87.123.42.204:3000 TCP is redirected to internal 192.168.2.150:3000"
598 if ((NULL == (ipaddr = strstr (line, " "))) ||
599 (NULL == (pstr = strstr (ipaddr, ":"))) ||
600 (1 != SSCANF (pstr + 1, "%u", &port)))
602 return; /* skip line */
604 ipa = GNUNET_strdup (ipaddr + 1);
605 strstr (ipa, ":")[0] = '\0';
606 if (1 != inet_pton (AF_INET,
608 &mini->current_addr.sin_addr))
611 return; /* skip line */
615 mini->current_addr.sin_port = htons (port);
616 mini->current_addr.sin_family = AF_INET;
617 #if HAVE_SOCKADDR_IN_SIN_LEN
618 mini->current_addr.sin_len = sizeof (struct sockaddr_in);
620 mini->did_map = GNUNET_YES;
621 mini->ac (mini->ac_cls,
623 (const struct sockaddr *) &mini->current_addr,
624 sizeof (mini->current_addr),
625 GNUNET_NAT_ERROR_SUCCESS);
630 * Start mapping the given port using (mini)upnpc. This function
631 * should typically not be used directly (it is used within the
632 * general-purpose #GNUNET_NAT_register() code). However, it can be
633 * used if specifically UPnP-based NAT traversal is to be used or
636 * @param port port to map
637 * @param is_tcp #GNUNET_YES to map TCP, #GNUNET_NO for UDP
638 * @param ac function to call with mapping result
639 * @param ac_cls closure for @a ac
640 * @return NULL on error (no 'upnpc' installed)
642 struct GNUNET_NAT_MiniHandle *
643 GNUNET_NAT_mini_map_start (uint16_t port,
645 GNUNET_NAT_MiniAddressCallback ac,
648 struct GNUNET_NAT_MiniHandle *ret;
651 GNUNET_OS_check_helper_binary ("upnpc",
655 LOG (GNUNET_ERROR_TYPE_INFO,
656 _("`upnpc' command not found\n"));
660 GNUNET_NAT_ERROR_UPNPC_NOT_FOUND);
663 LOG (GNUNET_ERROR_TYPE_DEBUG,
664 "Running `upnpc' to install mapping\n");
665 ret = GNUNET_new (struct GNUNET_NAT_MiniHandle);
667 ret->ac_cls = ac_cls;
668 ret->is_tcp = is_tcp;
671 GNUNET_SCHEDULER_add_delayed (MAP_REFRESH_FREQ,
680 * Process output from our 'unmap' command.
682 * @param cls the `struct GNUNET_NAT_MiniHandle`
683 * @param line line of output, NULL at the end
686 process_unmap_output (void *cls,
689 struct GNUNET_NAT_MiniHandle *mini = cls;
693 LOG (GNUNET_ERROR_TYPE_DEBUG,
694 "UPnP unmap done\n");
695 GNUNET_OS_command_stop (mini->unmap_cmd);
696 mini->unmap_cmd = NULL;
700 /* we don't really care about the output... */
705 * Remove a mapping created with (mini)upnpc. Calling
706 * this function will give 'upnpc' 1s to remove tha mapping,
707 * so while this function is non-blocking, a task will be
708 * left with the scheduler for up to 1s past this call.
710 * @param mini the handle
713 GNUNET_NAT_mini_map_stop (struct GNUNET_NAT_MiniHandle *mini)
717 if (NULL != mini->refresh_task)
719 GNUNET_SCHEDULER_cancel (mini->refresh_task);
720 mini->refresh_task = NULL;
722 if (NULL != mini->refresh_cmd)
724 GNUNET_OS_command_stop (mini->refresh_cmd);
725 mini->refresh_cmd = NULL;
727 if (NULL != mini->map_cmd)
729 GNUNET_OS_command_stop (mini->map_cmd);
730 mini->map_cmd = NULL;
732 if (GNUNET_NO == mini->did_map)
737 mini->ac (mini->ac_cls,
739 (const struct sockaddr *) &mini->current_addr,
740 sizeof (mini->current_addr),
741 GNUNET_NAT_ERROR_SUCCESS);
742 /* Note: oddly enough, deletion uses the external port whereas
743 * addition uses the internal port; this rarely matters since they
744 * often are the same, but it might... */
745 GNUNET_snprintf (pstr,
748 (unsigned int) ntohs (mini->current_addr.sin_port));
749 LOG (GNUNET_ERROR_TYPE_DEBUG,
750 "Unmapping port %u with UPnP\n",
751 ntohs (mini->current_addr.sin_port));
753 = GNUNET_OS_command_run (&process_unmap_output,
760 mini->is_tcp ? "tcp" : "udp",
765 /* end of gnunet-service-nat_mini.c */