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13 Affero General Public License for more details.
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19 * Code to figure out what our external IPv4 address(es) might
20 * be (external IPv4s are what is seen on the rest of the Internet).
22 * This can be implemented using different methods, and we allow
23 * the main service to be notified about changes to what we believe
24 * is our external IPv4 address.
26 * Note that this is explicitly only about NATed systems; if one
27 * of our network interfaces has a global IP address this does
28 * not count as "external".
30 * @file nat/gnunet-service-nat_externalip.c
31 * @brief Functions for monitoring external IPv4 addresses
32 * @author Christian Grothoff
36 #include "gnunet_util_lib.h"
37 #include "gnunet_protocols.h"
38 #include "gnunet_signatures.h"
39 #include "gnunet_statistics_service.h"
40 #include "gnunet_resolver_service.h"
41 #include "gnunet_nat_service.h"
42 #include "gnunet-service-nat.h"
43 #include "gnunet-service-nat_externalip.h"
44 #include "gnunet-service-nat_stun.h"
45 #include "gnunet-service-nat_mini.h"
46 #include "gnunet-service-nat_helper.h"
52 * How long do we wait until we re-try running `external-ip` if the
53 * command failed to terminate nicely?
55 #define EXTERN_IP_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
58 * How long do we wait until we re-try running `external-ip` if the
59 * command failed (but terminated)?
61 #define EXTERN_IP_RETRY_FAILURE GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
64 * How long do we wait until we re-try running `external-ip` if the
67 #define EXTERN_IP_RETRY_SUCCESS GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 5)
71 * Handle to monitor for external IP changes.
73 struct GN_ExternalIPMonitor
78 struct GN_ExternalIPMonitor *next;
83 struct GN_ExternalIPMonitor *prev;
86 * Function to call when we believe our external IPv4 address changed.
88 GN_NotifyExternalIPv4Change cb;
99 * List of monitors, kept in DLL.
101 static struct GN_ExternalIPMonitor *mon_head;
104 * List of monitors, kept in DLL.
106 static struct GN_ExternalIPMonitor *mon_tail;
109 * Task run to obtain our external IP (if #enable_upnp is set
110 * and if we find we have a NATed IP address).
112 static struct GNUNET_SCHEDULER_Task *probe_external_ip_task;
115 * Handle to our operation to run `external-ip`.
117 static struct GNUNET_NAT_ExternalHandle *probe_external_ip_op;
120 * What is our external IP address as claimed by `external-ip`?
123 static struct in_addr mini_external_ipv4;
127 * Tell relevant clients about a change in our external
130 * @param add #GNUNET_YES to add, #GNUNET_NO to remove
131 * @param v4 the external address that changed
134 notify_monitors_external_ipv4_change (int add,
135 const struct in_addr *v4)
137 for (struct GN_ExternalIPMonitor *mon = mon_head;
140 mon->cb (mon->cb_cls,
147 * Task used to run `external-ip` to get our external IPv4
148 * address and pass it to NATed clients if possible.
153 run_external_ip (void *cls);
157 * We learn our current external IP address. If it changed,
158 * notify all of our applicable clients. Also re-schedule
159 * #run_external_ip with an appropriate timeout.
162 * @param addr the address, NULL on errors
163 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
166 handle_external_ip (void *cls,
167 const struct in_addr *addr,
168 enum GNUNET_NAT_StatusCode result)
170 char buf[INET_ADDRSTRLEN];
172 probe_external_ip_op = NULL;
173 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
174 probe_external_ip_task
175 = GNUNET_SCHEDULER_add_delayed ((NULL == addr)
176 ? EXTERN_IP_RETRY_FAILURE
177 : EXTERN_IP_RETRY_SUCCESS,
182 case GNUNET_NAT_ERROR_SUCCESS:
183 GNUNET_assert (NULL != addr);
184 if (addr->s_addr == mini_external_ipv4.s_addr)
185 return; /* not change */
186 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
187 "Our external IP is now %s\n",
192 if (0 != mini_external_ipv4.s_addr)
193 notify_monitors_external_ipv4_change (GNUNET_NO,
194 &mini_external_ipv4);
195 mini_external_ipv4 = *addr;
196 notify_monitors_external_ipv4_change (GNUNET_YES,
197 &mini_external_ipv4);
200 if (0 != mini_external_ipv4.s_addr)
201 notify_monitors_external_ipv4_change (GNUNET_NO,
202 &mini_external_ipv4);
203 mini_external_ipv4.s_addr = 0;
210 * Task used to run `external-ip` to get our external IPv4
211 * address and pass it to NATed clients if possible.
216 run_external_ip (void *cls)
218 probe_external_ip_task
219 = GNUNET_SCHEDULER_add_delayed (EXTERN_IP_RETRY_TIMEOUT,
222 if (NULL != probe_external_ip_op)
224 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
225 probe_external_ip_op = NULL;
228 = GNUNET_NAT_mini_get_external_ipv4_ (&handle_external_ip,
234 * We have changed our opinion about being NATed in the first
235 * place. Adapt our probing.
237 * @param have_nat #GNUNET_YES if we believe we are behind NAT
240 GN_nat_status_changed (int have_nat)
242 if (GNUNET_YES != enable_upnp)
244 if ( (GNUNET_YES == have_nat) &&
245 (NULL == probe_external_ip_task) &&
246 (NULL == probe_external_ip_op) )
248 probe_external_ip_task
249 = GNUNET_SCHEDULER_add_now (&run_external_ip,
253 if (GNUNET_NO == have_nat)
255 if (NULL != probe_external_ip_task)
257 GNUNET_SCHEDULER_cancel (probe_external_ip_task);
258 probe_external_ip_task = NULL;
260 if (NULL != probe_external_ip_op)
262 GNUNET_NAT_mini_get_external_ipv4_cancel_ (probe_external_ip_op);
263 probe_external_ip_op = NULL;
270 * Start monitoring external IPv4 addresses.
272 * @param cb function to call on changes
273 * @param cb_cls closure for @a cb
274 * @return handle to cancel
276 struct GN_ExternalIPMonitor *
277 GN_external_ipv4_monitor_start (GN_NotifyExternalIPv4Change cb,
280 struct GN_ExternalIPMonitor *mon;
282 mon = GNUNET_new (struct GN_ExternalIPMonitor);
284 mon->cb_cls = cb_cls;
285 GNUNET_CONTAINER_DLL_insert (mon_head,
288 if (0 != mini_external_ipv4.s_addr)
297 * Stop calling monitor.
299 * @param mon monitor to call
302 GN_external_ipv4_monitor_stop (struct GN_ExternalIPMonitor *mon)
304 GNUNET_CONTAINER_DLL_remove (mon_head,
310 /* end of gnunet-service-nat_externalip.c */