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22 * @file include/gnunet_hello_lib.h
23 * @brief helper library for handling HELLOs
24 * @author Christian Grothoff
27 #ifndef GNUNET_HELLO_LIB_H
28 #define GNUNET_HELLO_LIB_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_util_lib.h"
42 * Prefix that every HELLO URI must start with.
44 #define GNUNET_HELLO_URI_PREFIX "gnunet://hello/"
47 * Prefix that every FRIEND HELLO URI must start with.
49 #define GNUNET_FRIEND_HELLO_URI_PREFIX "gnunet://friend-hello/"
53 * Additional local information about an address
55 * These information are only valid for the local peer and are not serialized
56 * when a #GNUNET_HELLO_Message is created
58 enum GNUNET_HELLO_AddressInfo
61 * No additional information
63 GNUNET_HELLO_ADDRESS_INFO_NONE = 0,
66 * This is an inbound address and cannot be used to initiate an outbound
67 * connection to another peer
69 GNUNET_HELLO_ADDRESS_INFO_INBOUND = 1
74 * An address for communicating with a peer. We frequently
75 * need this tuple and the components cannot really be
76 * separated. This is NOT the format that would be used
79 struct GNUNET_HELLO_Address
83 * For which peer is this an address?
85 struct GNUNET_PeerIdentity peer;
88 * Name of the transport plugin enabling the communication using
91 const char *transport_name;
94 * Binary representation of the address (plugin-specific).
99 * Number of bytes in @e address.
101 size_t address_length;
104 * Extended information about address
106 * This field contains additional #GNUNET_HELLO_AddressInfo flags e.g.
107 * to indicate an address is inbound and cannot be used to initiate an
108 * outbound connection.
110 * These information are only valid for the local peer and are not serialized
111 * when a #GNUNET_HELLO_Message is created
113 enum GNUNET_HELLO_AddressInfo local_info;
119 * Allocate an address struct.
121 * @param peer the peer
122 * @param transport_name plugin name
123 * @param address binary address
124 * @param address_length number of bytes in @a address
125 * @param local_info additional local information for the address
126 * @return the address struct
128 struct GNUNET_HELLO_Address *
129 GNUNET_HELLO_address_allocate (const struct GNUNET_PeerIdentity *peer,
130 const char *transport_name,
132 size_t address_length,
133 enum GNUNET_HELLO_AddressInfo local_info);
137 * Copy an address struct.
139 * @param address address to copy
140 * @return a copy of the address struct
142 struct GNUNET_HELLO_Address *
143 GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
147 * Compare two addresses. Does NOT compare the peer identity,
148 * that is assumed already to match!
150 * @param a1 first address
151 * @param a2 second address
152 * @return 0 if the addresses are equal, -1 if @a a1< @a a2, 1 if @a a1> @a a2.
155 GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
156 const struct GNUNET_HELLO_Address *a2);
160 * Get the size of an address struct.
162 * @param address address
166 GNUNET_HELLO_address_get_size (const struct GNUNET_HELLO_Address *address);
170 * Check if an address has a local option set
172 * @param address the address to check
173 * @param option the respective option to check for
174 * @return #GNUNET_YES or #GNUNET_NO
177 GNUNET_HELLO_address_check_option (const struct GNUNET_HELLO_Address *address,
178 enum GNUNET_HELLO_AddressInfo option);
184 * @param addr address to free
186 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
190 * A HELLO message is used to exchange information about
191 * transports with other peers. This struct is guaranteed
192 * to start with a `struct GNUNET_MessageHeader`, everything else
193 * should be internal to the HELLO library.
195 struct GNUNET_HELLO_Message;
201 * @param h HELLO Message to test
202 * @return #GNUNET_YES or #GNUNET_NO
205 GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h);
209 * Copy the given address information into
210 * the given buffer using the format of HELLOs.
212 * @param address address to add
213 * @param expiration expiration for the address
214 * @param target where to copy the address
215 * @param max maximum number of bytes to copy to @a target
216 * @return number of bytes copied, 0 if
217 * the target buffer was not big enough.
220 GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
221 struct GNUNET_TIME_Absolute expiration,
227 * Callback function used to fill a buffer of max bytes with a list of
228 * addresses in the format used by HELLOs. Should use
229 * #GNUNET_HELLO_add_address() as a helper function.
232 * @param max maximum number of bytes that can be written to @a buf
233 * @param buf where to write the address information
234 * @return number of bytes written or 0, #GNUNET_SYSERR to signal the
235 * end of the iteration.
238 (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
244 * Construct a HELLO message given the public key,
245 * expiration time and an iterator that spews the
246 * transport addresses.
248 * If friend only is set to #GNUNET_YES we create a FRIEND_HELLO which
249 * will not be gossiped to other peers.
251 * @param publicKey public key to include in the HELLO
252 * @param addrgen callback to invoke to get addresses
253 * @param addrgen_cls closure for @a addrgen
254 * @param friend_only should the returned HELLO be only visible to friends?
255 * @return the hello message
257 struct GNUNET_HELLO_Message *
258 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *publicKey,
259 GNUNET_HELLO_GenerateAddressListCallback addrgen,
265 * Return the size of the given HELLO message.
267 * @param hello to inspect
268 * @return the size, 0 if HELLO is invalid
271 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
275 * Construct a HELLO message by merging the
276 * addresses in two existing HELLOs (which
277 * must be for the same peer).
279 * @param h1 first HELLO message
280 * @param h2 the second HELLO message
281 * @return the combined hello message
283 struct GNUNET_HELLO_Message *
284 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
285 const struct GNUNET_HELLO_Message *h2);
289 * Test if two HELLO messages contain the same addresses.
290 * If they only differ in expiration time, the lowest
291 * expiration time larger than 'now' where they differ
294 * @param h1 first HELLO message
295 * @param h2 the second HELLO message
296 * @param now time to use for deciding which addresses have
297 * expired and should not be considered at all
298 * @return absolute time forever if the two HELLOs are
299 * totally identical; smallest timestamp >= now if
300 * they only differ in timestamps;
301 * zero if the some addresses with expirations >= now
302 * do not match at all
304 struct GNUNET_TIME_Absolute
305 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
306 const struct GNUNET_HELLO_Message *h2,
307 struct GNUNET_TIME_Absolute now);
311 * Iterator callback to go over all addresses.
314 * @param address the address
315 * @param expiration expiration time
316 * @return #GNUNET_OK to keep the address,
317 * #GNUNET_NO to delete it from the HELLO
318 * #GNUNET_SYSERR to stop iterating (but keep current address)
321 (*GNUNET_HELLO_AddressIterator) (void *cls,
322 const struct GNUNET_HELLO_Address *address,
323 struct GNUNET_TIME_Absolute expiration);
327 * When does the last address in the given HELLO expire?
329 * @param msg HELLO to inspect
330 * @return time the last address expires, 0 if there are no addresses in the HELLO
332 struct GNUNET_TIME_Absolute
333 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
337 * Iterate over all of the addresses in the HELLO.
339 * @param msg HELLO to iterate over; client does not need to
340 * have verified that msg is well-formed (beyond starting
341 * with a GNUNET_MessageHeader of the right type).
342 * @param return_modified if a modified copy should be returned,
343 * otherwise NULL will be returned
344 * @param it iterator to call on each address
345 * @param it_cls closure for @a it
346 * @return the modified HELLO or NULL
348 struct GNUNET_HELLO_Message *
349 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
351 GNUNET_HELLO_AddressIterator it, void *it_cls);
355 * Iterate over addresses in "new_hello" that
356 * are NOT already present in "old_hello".
358 * @param new_hello a HELLO message
359 * @param old_hello a HELLO message
360 * @param expiration_limit ignore addresses in old_hello
361 * that expired before the given time stamp
362 * @param it iterator to call on each address
363 * @param it_cls closure for @a it
366 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message *new_hello,
367 const struct GNUNET_HELLO_Message *old_hello,
368 struct GNUNET_TIME_Absolute expiration_limit,
369 GNUNET_HELLO_AddressIterator it,
374 * Get the public key from a HELLO message.
376 * @param hello the hello message
377 * @param publicKey where to copy the public key information, can be NULL
378 * @return #GNUNET_SYSERR if the HELLO was malformed
381 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
382 struct GNUNET_CRYPTO_EddsaPublicKey *publicKey);
386 * Get the peer identity from a HELLO message.
388 * @param hello the hello message
389 * @param peer where to store the peer's identity
390 * @return #GNUNET_SYSERR if the HELLO was malformed
393 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
394 struct GNUNET_PeerIdentity *peer);
398 * Get the header from a HELLO message, used so other code
399 * can correctly send HELLO messages.
401 * @param hello the hello message
403 * @return header or NULL if the HELLO was malformed
405 struct GNUNET_MessageHeader *
406 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
409 typedef struct GNUNET_TRANSPORT_PluginFunctions *
410 (*GNUNET_HELLO_TransportPluginsFind) (const char *name);
414 * Compose a hello URI string from a hello message.
416 * @param hello Hello message
417 * @param plugins_find Function to find transport plugins by name
418 * @return Hello URI string
421 GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello,
422 GNUNET_HELLO_TransportPluginsFind plugins_find);
426 * Parse a hello URI string to a hello message.
428 * @param uri URI string to parse
429 * @param pubkey Pointer to struct where public key is parsed
430 * @param hello Pointer to struct where hello message is parsed
431 * @param plugins_find Function to find transport plugins by name
432 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the URI was invalid, #GNUNET_NO on other errors
435 GNUNET_HELLO_parse_uri (const char *uri,
436 struct GNUNET_CRYPTO_EddsaPublicKey *pubkey,
437 struct GNUNET_HELLO_Message **hello,
438 GNUNET_HELLO_TransportPluginsFind plugins_find);
440 #if 0 /* keep Emacsens' auto-indent happy */
448 /* ifndef GNUNET_HELLO_LIB_H */
450 /* end of gnunet_hello_lib.h */