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3 Copyright (C) 2009, 2015, 2016, 2017 GNUnet e.V.
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6 under the terms of the GNU 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.
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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.
16 * Code to figure out what our external IPv4 address(es) might
17 * be (external IPv4s are what is seen on the rest of the Internet).
19 * This can be implemented using different methods, and we allow
20 * the main service to be notified about changes to what we believe
21 * is our external IPv4 address.
23 * Note that this is explicitly only about NATed systems; if one
24 * of our network interfaces has a global IP address this does
25 * not count as "external".
27 * @file nat/gnunet-service-nat_externalip.c
28 * @brief Functions for monitoring external IPv4 addresses
29 * @author Christian Grothoff
33 #include "gnunet_util_lib.h"
34 #include "gnunet_protocols.h"
35 #include "gnunet_signatures.h"
36 #include "gnunet_statistics_service.h"
37 #include "gnunet_resolver_service.h"
38 #include "gnunet_nat_service.h"
39 #include "gnunet-service-nat.h"
40 #include "gnunet-service-nat_externalip.h"
41 #include "gnunet-service-nat_stun.h"
42 #include "gnunet-service-nat_mini.h"
43 #include "gnunet-service-nat_helper.h"
49 * How long do we wait until we re-try running `external-ip` if the
50 * command failed to terminate nicely?
52 #define EXTERN_IP_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
55 * How long do we wait until we re-try running `external-ip` if the
56 * command failed (but terminated)?
58 #define EXTERN_IP_RETRY_FAILURE GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
61 * How long do we wait until we re-try running `external-ip` if the
64 #define EXTERN_IP_RETRY_SUCCESS GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
68 * Handle to monitor for external IP changes.
70 struct GN_ExternalIPMonitor
75 struct GN_ExternalIPMonitor *next;
80 struct GN_ExternalIPMonitor *prev;
83 * Function to call when we believe our external IPv4 address changed.
85 GN_NotifyExternalIPv4Change cb;
96 * List of monitors, kept in DLL.
98 static struct GN_ExternalIPMonitor *mon_head;
101 * List of monitors, kept in DLL.
103 static struct GN_ExternalIPMonitor *mon_tail;
106 * Task run to obtain our external IP (if #enable_upnp is set
107 * and if we find we have a NATed IP address).
109 static struct GNUNET_SCHEDULER_Task *probe_external_ip_task;
112 * Handle to our operation to run `external-ip`.
114 static struct GNUNET_NAT_ExternalHandle *probe_external_ip_op;
117 * What is our external IP address as claimed by `external-ip`?
120 static struct in_addr mini_external_ipv4;
124 * Tell relevant clients about a change in our external
127 * @param add #GNUNET_YES to add, #GNUNET_NO to remove
128 * @param v4 the external address that changed
131 notify_monitors_external_ipv4_change (int add,
132 const struct in_addr *v4)
134 for (struct GN_ExternalIPMonitor *mon = mon_head;
137 mon->cb (mon->cb_cls,
144 * Task used to run `external-ip` to get our external IPv4
145 * address and pass it to NATed clients if possible.
150 run_external_ip (void *cls);
154 * We learn our current external IP address. If it changed,
155 * notify all of our applicable clients. Also re-schedule
156 * #run_external_ip with an appropriate timeout.
159 * @param addr the address, NULL on errors
160 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
163 handle_external_ip (void *cls,
164 const struct in_addr *addr,
165 enum GNUNET_NAT_StatusCode result)
167 char buf[INET_ADDRSTRLEN];
169 probe_external_ip_op = NULL;
170 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
171 probe_external_ip_task
172 = GNUNET_SCHEDULER_add_delayed ((NULL == addr)
173 ? EXTERN_IP_RETRY_FAILURE
174 : EXTERN_IP_RETRY_SUCCESS,
179 case GNUNET_NAT_ERROR_SUCCESS:
180 GNUNET_assert (NULL != addr);
181 if (addr->s_addr == mini_external_ipv4.s_addr)
182 return; /* not change */
183 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
184 "Our external IP is now %s\n",
189 if (0 != mini_external_ipv4.s_addr)
190 notify_monitors_external_ipv4_change (GNUNET_NO,
191 &mini_external_ipv4);
192 mini_external_ipv4 = *addr;
193 notify_monitors_external_ipv4_change (GNUNET_YES,
194 &mini_external_ipv4);
197 if (0 != mini_external_ipv4.s_addr)
198 notify_monitors_external_ipv4_change (GNUNET_NO,
199 &mini_external_ipv4);
200 mini_external_ipv4.s_addr = 0;
207 * Task used to run `external-ip` to get our external IPv4
208 * address and pass it to NATed clients if possible.
213 run_external_ip (void *cls)
215 probe_external_ip_task
216 = GNUNET_SCHEDULER_add_delayed (EXTERN_IP_RETRY_TIMEOUT,
219 if (NULL != probe_external_ip_op)
221 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
222 probe_external_ip_op = NULL;
225 = GNUNET_NAT_mini_get_external_ipv4_ (&handle_external_ip,
231 * We have changed our opinion about being NATed in the first
232 * place. Adapt our probing.
234 * @param have_nat #GNUNET_YES if we believe we are behind NAT
237 GN_nat_status_changed (int have_nat)
239 if (GNUNET_YES != enable_upnp)
241 if ( (GNUNET_YES == have_nat) &&
242 (NULL == probe_external_ip_task) &&
243 (NULL == probe_external_ip_op) )
245 probe_external_ip_task
246 = GNUNET_SCHEDULER_add_now (&run_external_ip,
250 if (GNUNET_NO == have_nat)
252 if (NULL != probe_external_ip_task)
254 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
255 probe_external_ip_task = NULL;
257 if (NULL != probe_external_ip_op)
259 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
260 probe_external_ip_op = NULL;
267 * Start monitoring external IPv4 addresses.
269 * @param cb function to call on changes
270 * @param cb_cls closure for @a cb
271 * @return handle to cancel
273 struct GN_ExternalIPMonitor *
274 GN_external_ipv4_monitor_start (GN_NotifyExternalIPv4Change cb,
277 struct GN_ExternalIPMonitor *mon;
279 mon = GNUNET_new (struct GN_ExternalIPMonitor);
281 mon->cb_cls = cb_cls;
282 GNUNET_CONTAINER_DLL_insert (mon_head,
285 if (0 != mini_external_ipv4.s_addr)
294 * Stop calling monitor.
296 * @param mon monitor to call
299 GN_external_ipv4_monitor_stop (struct GN_ExternalIPMonitor *mon)
301 GNUNET_CONTAINER_DLL_remove (mon_head,
307 /* end of gnunet-service-nat_externalip.c */