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13 Affero General Public License for more details.
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18 SPDX-License-Identifier: AGPL3.0-or-later
21 * @file nt/nt_api_scanner.c
22 * @brief LAN interface scanning to determine IPs in LAN
23 * @author Christian Grothoff
24 * @author Matthias Wachs
27 #include "gnunet_util_lib.h"
28 #include "gnunet_nt_lib.h"
31 * How frequently do we scan the interfaces for changes to the addresses?
33 #define INTERFACE_PROCESSING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
37 * Convert a `enum GNUNET_NetworkType` to a string
39 * @param net the network type
40 * @return a string or NULL if invalid
43 GNUNET_NT_to_string (enum GNUNET_NetworkType net)
47 case GNUNET_NT_UNSPECIFIED:
49 case GNUNET_NT_LOOPBACK:
66 * We keep a list of our local networks so we can answer
67 * LAN vs. WAN questions. Note: WLAN is not detected yet.
68 * (maybe we can do that heuristically based on interface
69 * name in the future?).
76 struct NT_Network *next;
81 struct NT_Network *prev;
86 struct sockaddr *network;
89 * Netmask to determine what is in the LAN.
91 struct sockaddr *netmask;
94 * How long are @e network and @e netmask?
101 * Handle to the interface scanner.
103 struct GNUNET_NT_InterfaceScanner
107 * Head of LAN networks list.
109 struct NT_Network *net_head;
112 * Tail of LAN networks list.
114 struct NT_Network *net_tail;
117 * Task for periodically refreshing our LAN network list.
119 struct GNUNET_SCHEDULER_Task *interface_task;
125 * Delete all entries from the current network list.
127 * @param is scanner to clean up
130 delete_networks (struct GNUNET_NT_InterfaceScanner *is)
132 struct NT_Network *cur;
134 while (NULL != (cur = is->net_head))
136 GNUNET_CONTAINER_DLL_remove (is->net_head,
145 * Function invoked for each interface found. Adds the interface's
146 * network addresses to the respective DLL, so we can distinguish
147 * between LAN and WAN.
149 * @param cls closure with the `struct GNUNET_NT_InterfaceScanner`
150 * @param name name of the interface (can be NULL for unknown)
151 * @param isDefault is this presumably the default interface
152 * @param addr address of this interface (can be NULL for unknown or unassigned)
153 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
154 * @param netmask the network mask (can be NULL for unknown or unassigned)
155 * @param addrlen length of the address
156 * @return #GNUNET_OK to continue iteration
159 interface_proc (void *cls,
162 const struct sockaddr *addr,
163 const struct sockaddr *broadcast_addr,
164 const struct sockaddr *netmask,
167 struct GNUNET_NT_InterfaceScanner *is = cls;
168 /* Calculate network */
169 struct NT_Network *net = NULL;
172 (void) broadcast_addr;
174 /* Skipping IPv4 loopback addresses since we have special check */
175 if (addr->sa_family == AF_INET)
177 const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
179 if ((a4->sin_addr.s_addr & htonl(0xff000000)) == htonl (0x7f000000))
182 /* Skipping IPv6 loopback addresses since we have special check */
183 if (addr->sa_family == AF_INET6)
185 const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
186 if (IN6_IS_ADDR_LOOPBACK (&a6->sin6_addr))
190 if (addr->sa_family == AF_INET)
192 const struct sockaddr_in *addr4 = (const struct sockaddr_in *) addr;
193 const struct sockaddr_in *netmask4 = (const struct sockaddr_in *) netmask;
194 struct sockaddr_in *tmp;
195 struct sockaddr_in network4;
197 net = GNUNET_malloc (sizeof (struct NT_Network) + 2 * sizeof (struct sockaddr_in));
198 tmp = (struct sockaddr_in *) &net[1];
199 net->network = (struct sockaddr *) &tmp[0];
200 net->netmask = (struct sockaddr *) &tmp[1];
201 net->length = addrlen;
206 network4.sin_family = AF_INET;
207 #if HAVE_SOCKADDR_IN_SIN_LEN
208 network4.sin_len = sizeof (network4);
210 network4.sin_addr.s_addr = (addr4->sin_addr.s_addr & netmask4->sin_addr.s_addr);
212 GNUNET_memcpy (net->netmask,
214 sizeof (struct sockaddr_in));
215 GNUNET_memcpy (net->network,
217 sizeof (struct sockaddr_in));
220 if (addr->sa_family == AF_INET6)
222 const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *) addr;
223 const struct sockaddr_in6 *netmask6 = (const struct sockaddr_in6 *) netmask;
224 struct sockaddr_in6 * tmp;
225 struct sockaddr_in6 network6;
227 net = GNUNET_malloc (sizeof (struct NT_Network) + 2 * sizeof (struct sockaddr_in6));
228 tmp = (struct sockaddr_in6 *) &net[1];
229 net->network = (struct sockaddr *) &tmp[0];
230 net->netmask = (struct sockaddr *) &tmp[1];
231 net->length = addrlen;
233 memset (&network6, 0, sizeof (network6));
234 network6.sin6_family = AF_INET6;
235 #if HAVE_SOCKADDR_IN_SIN_LEN
236 network6.sin6_len = sizeof (network6);
239 uint32_t *addr_elem = (uint32_t *) &addr6->sin6_addr;
240 uint32_t *mask_elem = (uint32_t *) &netmask6->sin6_addr;
241 uint32_t *net_elem = (uint32_t *) &network6.sin6_addr;
242 for (c = 0; c < 4; c++)
243 net_elem[c] = addr_elem[c] & mask_elem[c];
245 GNUNET_memcpy (net->netmask,
247 sizeof (struct sockaddr_in6));
248 GNUNET_memcpy (net->network,
250 sizeof (struct sockaddr_in6));
253 return GNUNET_OK; /* odd / unsupported address family */
257 char * netmask = GNUNET_strdup (GNUNET_a2s((struct sockaddr *) net->netmask, addrlen));
258 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
260 "Adding network `%s', netmask `%s'\n",
261 GNUNET_a2s ((struct sockaddr *) net->network,
264 GNUNET_free (netmask);
266 GNUNET_CONTAINER_DLL_insert (is->net_head,
275 * Periodically get list of network addresses from our interfaces.
280 get_addresses (void *cls)
282 struct GNUNET_NT_InterfaceScanner *is = cls;
284 is->interface_task = NULL;
285 delete_networks (is);
286 GNUNET_OS_network_interfaces_list (&interface_proc,
288 is->interface_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_PROCESSING_INTERVAL,
295 * Returns where the address is located: LAN or WAN or ...
297 * @param is the interface scanner handle
298 * @param addr address
299 * @param addrlen address length
300 * @return type of the network the address belongs to
302 enum GNUNET_NetworkType
303 GNUNET_NT_scanner_get_type (struct GNUNET_NT_InterfaceScanner *is,
304 const struct sockaddr *addr,
307 struct NT_Network *cur = is->net_head;
308 enum GNUNET_NetworkType type = GNUNET_NT_UNSPECIFIED;
310 switch (addr->sa_family)
313 type = GNUNET_NT_LOOPBACK;
317 const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
319 if ((a4->sin_addr.s_addr & htonl(0xff000000)) == htonl (0x7f000000))
320 type = GNUNET_NT_LOOPBACK;
325 const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
327 if (IN6_IS_ADDR_LOOPBACK (&a6->sin6_addr))
328 type = GNUNET_NT_LOOPBACK;
336 /* Check local networks */
337 while ((NULL != cur) && (GNUNET_NT_UNSPECIFIED == type))
339 if (addrlen != cur->length)
344 if (addr->sa_family == AF_INET)
346 const struct sockaddr_in *a4 = (const struct sockaddr_in *) addr;
347 const struct sockaddr_in *net4 = (const struct sockaddr_in *) cur->network;
348 const struct sockaddr_in *mask4 = (const struct sockaddr_in *) cur->netmask;
350 if (((a4->sin_addr.s_addr & mask4->sin_addr.s_addr)) == net4->sin_addr.s_addr)
351 type = GNUNET_NT_LAN;
353 if (addr->sa_family == AF_INET6)
355 const struct sockaddr_in6 *a6 = (const struct sockaddr_in6 *) addr;
356 const struct sockaddr_in6 *net6 = (const struct sockaddr_in6 *) cur->network;
357 const struct sockaddr_in6 *mask6 = (const struct sockaddr_in6 *) cur->netmask;
359 int res = GNUNET_YES;
361 uint32_t *addr_elem = (uint32_t *) &a6->sin6_addr;
362 uint32_t *mask_elem = (uint32_t *) &mask6->sin6_addr;
363 uint32_t *net_elem = (uint32_t *) &net6->sin6_addr;
364 for (c = 0; c < 4; c++)
365 if ((addr_elem[c] & mask_elem[c]) != net_elem[c])
368 if (res == GNUNET_YES)
369 type = GNUNET_NT_LAN;
374 /* no local network found for this address, default: WAN */
375 if (type == GNUNET_NT_UNSPECIFIED)
376 type = GNUNET_NT_WAN;
377 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
379 "`%s' is in network `%s'\n",
382 GNUNET_NT_to_string (type));
388 * Initialize the interface scanner.
390 * @return interface scanner
392 struct GNUNET_NT_InterfaceScanner *
393 GNUNET_NT_scanner_init ()
395 struct GNUNET_NT_InterfaceScanner *is;
397 is = GNUNET_new (struct GNUNET_NT_InterfaceScanner);
398 GNUNET_OS_network_interfaces_list (&interface_proc,
400 is->interface_task = GNUNET_SCHEDULER_add_delayed (INTERFACE_PROCESSING_INTERVAL,
408 * Client is done with the interface scanner, release resources.
410 * @param is handle to release
413 GNUNET_NT_scanner_done (struct GNUNET_NT_InterfaceScanner *is)
415 if (NULL != is->interface_task)
417 GNUNET_SCHEDULER_cancel (is->interface_task);
418 is->interface_task = NULL;
420 delete_networks (is);