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6 under the terms of the GNU Affero General Public License as published
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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.
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18 SPDX-License-Identifier: AGPL3.0-or-later
21 * Code to figure out what our external IPv4 address(es) might
22 * be (external IPv4s are what is seen on the rest of the Internet).
24 * This can be implemented using different methods, and we allow
25 * the main service to be notified about changes to what we believe
26 * is our external IPv4 address.
28 * Note that this is explicitly only about NATed systems; if one
29 * of our network interfaces has a global IP address this does
30 * not count as "external".
32 * @file nat/gnunet-service-nat_externalip.c
33 * @brief Functions for monitoring external IPv4 addresses
34 * @author Christian Grothoff
38 #include "gnunet_util_lib.h"
39 #include "gnunet_protocols.h"
40 #include "gnunet_signatures.h"
41 #include "gnunet_statistics_service.h"
42 #include "gnunet_resolver_service.h"
43 #include "gnunet_nat_service.h"
44 #include "gnunet-service-nat.h"
45 #include "gnunet-service-nat_externalip.h"
46 #include "gnunet-service-nat_stun.h"
47 #include "gnunet-service-nat_mini.h"
48 #include "gnunet-service-nat_helper.h"
54 * How long do we wait until we re-try running `external-ip` if the
55 * command failed to terminate nicely?
57 #define EXTERN_IP_RETRY_TIMEOUT GNUNET_TIME_relative_multiply ( \
58 GNUNET_TIME_UNIT_MINUTES, 15)
61 * How long do we wait until we re-try running `external-ip` if the
62 * command failed (but terminated)?
64 #define EXTERN_IP_RETRY_FAILURE GNUNET_TIME_relative_multiply ( \
65 GNUNET_TIME_UNIT_MINUTES, 30)
68 * How long do we wait until we re-try running `external-ip` if the
71 #define EXTERN_IP_RETRY_SUCCESS GNUNET_TIME_relative_multiply ( \
72 GNUNET_TIME_UNIT_MINUTES, 5)
76 * Handle to monitor for external IP changes.
78 struct GN_ExternalIPMonitor
83 struct GN_ExternalIPMonitor *next;
88 struct GN_ExternalIPMonitor *prev;
91 * Function to call when we believe our external IPv4 address changed.
93 GN_NotifyExternalIPv4Change cb;
103 * List of monitors, kept in DLL.
105 static struct GN_ExternalIPMonitor *mon_head;
108 * List of monitors, kept in DLL.
110 static struct GN_ExternalIPMonitor *mon_tail;
113 * Task run to obtain our external IP (if #enable_upnp is set
114 * and if we find we have a NATed IP address).
116 static struct GNUNET_SCHEDULER_Task *probe_external_ip_task;
119 * Handle to our operation to run `external-ip`.
121 static struct GNUNET_NAT_ExternalHandle *probe_external_ip_op;
124 * What is our external IP address as claimed by `external-ip`?
127 static struct in_addr mini_external_ipv4;
131 * Tell relevant clients about a change in our external
134 * @param add #GNUNET_YES to add, #GNUNET_NO to remove
135 * @param v4 the external address that changed
138 notify_monitors_external_ipv4_change (int add,
139 const struct in_addr *v4)
141 for (struct GN_ExternalIPMonitor *mon = mon_head;
144 mon->cb (mon->cb_cls,
151 * Task used to run `external-ip` to get our external IPv4
152 * address and pass it to NATed clients if possible.
157 run_external_ip (void *cls);
161 * We learn our current external IP address. If it changed,
162 * notify all of our applicable clients. Also re-schedule
163 * #run_external_ip with an appropriate timeout.
166 * @param addr the address, NULL on errors
167 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
170 handle_external_ip (void *cls,
171 const struct in_addr *addr,
172 enum GNUNET_NAT_StatusCode result)
174 char buf[INET_ADDRSTRLEN];
176 probe_external_ip_op = NULL;
177 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
178 probe_external_ip_task
179 = GNUNET_SCHEDULER_add_delayed ((NULL == addr)
180 ? EXTERN_IP_RETRY_FAILURE
181 : EXTERN_IP_RETRY_SUCCESS,
186 case GNUNET_NAT_ERROR_SUCCESS:
187 GNUNET_assert (NULL != addr);
188 if (addr->s_addr == mini_external_ipv4.s_addr)
189 return; /* not change */
190 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
191 "Our external IP is now %s\n",
196 if (0 != mini_external_ipv4.s_addr)
197 notify_monitors_external_ipv4_change (GNUNET_NO,
198 &mini_external_ipv4);
199 mini_external_ipv4 = *addr;
200 notify_monitors_external_ipv4_change (GNUNET_YES,
201 &mini_external_ipv4);
205 if (0 != mini_external_ipv4.s_addr)
206 notify_monitors_external_ipv4_change (GNUNET_NO,
207 &mini_external_ipv4);
208 mini_external_ipv4.s_addr = 0;
215 * Task used to run `external-ip` to get our external IPv4
216 * address and pass it to NATed clients if possible.
221 run_external_ip (void *cls)
223 probe_external_ip_task
224 = GNUNET_SCHEDULER_add_delayed (EXTERN_IP_RETRY_TIMEOUT,
227 if (NULL != probe_external_ip_op)
229 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
230 probe_external_ip_op = NULL;
233 = GNUNET_NAT_mini_get_external_ipv4_ (&handle_external_ip,
239 * We have changed our opinion about being NATed in the first
240 * place. Adapt our probing.
242 * @param have_nat #GNUNET_YES if we believe we are behind NAT
245 GN_nat_status_changed (int have_nat)
247 if (GNUNET_YES != enable_upnp)
249 if ((GNUNET_YES == have_nat) &&
250 (NULL == probe_external_ip_task) &&
251 (NULL == probe_external_ip_op))
253 probe_external_ip_task
254 = GNUNET_SCHEDULER_add_now (&run_external_ip,
258 if (GNUNET_NO == have_nat)
260 if (NULL != probe_external_ip_task)
262 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
263 probe_external_ip_task = NULL;
265 if (NULL != probe_external_ip_op)
267 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
268 probe_external_ip_op = NULL;
275 * Start monitoring external IPv4 addresses.
277 * @param cb function to call on changes
278 * @param cb_cls closure for @a cb
279 * @return handle to cancel
281 struct GN_ExternalIPMonitor *
282 GN_external_ipv4_monitor_start (GN_NotifyExternalIPv4Change cb,
285 struct GN_ExternalIPMonitor *mon;
287 mon = GNUNET_new (struct GN_ExternalIPMonitor);
289 mon->cb_cls = cb_cls;
290 GNUNET_CONTAINER_DLL_insert (mon_head,
293 if (0 != mini_external_ipv4.s_addr)
302 * Stop calling monitor.
304 * @param mon monitor to call
307 GN_external_ipv4_monitor_stop (struct GN_ExternalIPMonitor *mon)
309 GNUNET_CONTAINER_DLL_remove (mon_head,
316 /* end of gnunet-service-nat_externalip.c */