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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 * Extended information about address
90 * This field contains additional #GNUNET_HELLO_AddressInfo flags e.g.
91 * to indicate an address is inbound and cannot be used to initiate an
92 * outbound connection.
94 * These information are only valid for the local peer and are not serialized
95 * when a #GNUNET_HELLO_Message is created
97 enum GNUNET_HELLO_AddressInfo local_info;
100 * Name of the transport plugin enabling the communication using
103 const char *transport_name;
106 * Binary representation of the address (plugin-specific).
111 * Number of bytes in 'address'.
113 size_t address_length;
118 * Allocate an address struct.
120 * @param peer the peer
121 * @param transport_name plugin name
122 * @param address binary address
123 * @param address_length number of bytes in 'address'
124 * @param local_info additional local information for the address
125 * @return the address struct
127 struct GNUNET_HELLO_Address *
128 GNUNET_HELLO_address_allocate (const struct GNUNET_PeerIdentity *peer,
129 const char *transport_name, const void *address,
130 size_t address_length,
131 enum GNUNET_HELLO_AddressInfo local_info);
134 * Copy an address struct.
136 * @param address address to copy
137 * @return a copy of the address struct
139 struct GNUNET_HELLO_Address *
140 GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
144 * Compare two addresses. Does NOT compare the peer identity,
145 * that is assumed already to match!
147 * @param a1 first address
148 * @param a2 second address
149 * @return 0 if the addresses are equal, -1 if a1<a2, 1 if a1>a2.
152 GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
153 const struct GNUNET_HELLO_Address *a2);
156 * Get the size of an address struct.
158 * @param address address
162 GNUNET_HELLO_address_get_size (const struct GNUNET_HELLO_Address *address);
165 * Check if an address has a local option set
167 * @param address the address to check
168 * @param option the respective option to check for
169 * @return GNUNET_YES or GNUNET_NO
172 GNUNET_HELLO_address_check_option (const struct GNUNET_HELLO_Address * address,
173 enum GNUNET_HELLO_AddressInfo option);
179 * @param addr address to free
181 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
185 * A HELLO message is used to exchange information about
186 * transports with other peers. This struct is guaranteed
187 * to start with a "GNUNET_MessageHeader", everything else
188 * should be internal to the HELLO library.
190 struct GNUNET_HELLO_Message;
196 * @param h HELLO Message to test
197 * @return #GNUNET_YES or #GNUNET_NO
200 GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h);
204 * Copy the given address information into
205 * the given buffer using the format of HELLOs.
207 * @param address address to add
208 * @param expiration expiration for the address
209 * @param target where to copy the address
210 * @param max maximum number of bytes to copy to @a target
211 * @return number of bytes copied, 0 if
212 * the target buffer was not big enough.
215 GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
216 struct GNUNET_TIME_Absolute expiration, char *target,
221 * Callback function used to fill a buffer of max bytes with a list of
222 * addresses in the format used by HELLOs. Should use
223 * #GNUNET_HELLO_add_address() as a helper function.
226 * @param max maximum number of bytes that can be written to @a buf
227 * @param buf where to write the address information
228 * @return number of bytes written, 0 to signal the
229 * end of the iteration.
232 (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
238 * Construct a HELLO message given the public key,
239 * expiration time and an iterator that spews the
240 * transport addresses.
242 * If friend only is set to #GNUNET_YES we create a FRIEND_HELLO which will
243 * not be gossiped to other peers
245 * @return the hello message
247 struct GNUNET_HELLO_Message *
248 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *publicKey,
249 GNUNET_HELLO_GenerateAddressListCallback addrgen,
255 * Return the size of the given HELLO message.
256 * @param hello to inspect
257 * @return the size, 0 if HELLO is invalid
260 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
264 * Construct a HELLO message by merging the
265 * addresses in two existing HELLOs (which
266 * must be for the same peer).
268 * @param h1 first HELLO message
269 * @param h2 the second HELLO message
270 * @return the combined hello message
272 struct GNUNET_HELLO_Message *
273 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
274 const struct GNUNET_HELLO_Message *h2);
278 * Test if two HELLO messages contain the same addresses.
279 * If they only differ in expiration time, the lowest
280 * expiration time larger than 'now' where they differ
283 * @param h1 first HELLO message
284 * @param h2 the second HELLO message
285 * @param now time to use for deciding which addresses have
286 * expired and should not be considered at all
287 * @return absolute time forever if the two HELLOs are
288 * totally identical; smallest timestamp >= now if
289 * they only differ in timestamps;
290 * zero if the some addresses with expirations >= now
291 * do not match at all
293 struct GNUNET_TIME_Absolute
294 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
295 const struct GNUNET_HELLO_Message *h2,
296 struct GNUNET_TIME_Absolute now);
300 * Iterator callback to go over all addresses.
303 * @param address the address
304 * @param expiration expiration time
305 * @return #GNUNET_OK to keep the address,
306 * #GNUNET_NO to delete it from the HELLO
307 * #GNUNET_SYSERR to stop iterating (but keep current address)
310 (*GNUNET_HELLO_AddressIterator) (void *cls,
311 const struct GNUNET_HELLO_Address *address,
312 struct GNUNET_TIME_Absolute expiration);
316 * When does the last address in the given HELLO expire?
318 * @param msg HELLO to inspect
319 * @return time the last address expires, 0 if there are no addresses in the HELLO
321 struct GNUNET_TIME_Absolute
322 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
326 * Iterate over all of the addresses in the HELLO.
328 * @param msg HELLO to iterate over; client does not need to
329 * have verified that msg is well-formed (beyond starting
330 * with a GNUNET_MessageHeader of the right type).
331 * @param return_modified if a modified copy should be returned,
332 * otherwise NULL will be returned
333 * @param it iterator to call on each address
334 * @param it_cls closure for @a it
335 * @return the modified HELLO or NULL
337 struct GNUNET_HELLO_Message *
338 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
340 GNUNET_HELLO_AddressIterator it, void *it_cls);
344 * Iterate over addresses in "new_hello" that
345 * are NOT already present in "old_hello".
347 * @param new_hello a HELLO message
348 * @param old_hello a HELLO message
349 * @param expiration_limit ignore addresses in old_hello
350 * that expired before the given time stamp
351 * @param it iterator to call on each address
352 * @param it_cls closure for it
355 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message *new_hello,
356 const struct GNUNET_HELLO_Message *old_hello,
357 struct GNUNET_TIME_Absolute expiration_limit,
358 GNUNET_HELLO_AddressIterator it,
363 * Get the public key from a HELLO message.
365 * @param hello the hello message
366 * @param publicKey where to copy the public key information, can be NULL
367 * @return #GNUNET_SYSERR if the HELLO was malformed
370 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
371 struct GNUNET_CRYPTO_EddsaPublicKey *publicKey);
375 * Get the peer identity from a HELLO message.
377 * @param hello the hello message
378 * @param peer where to store the peer's identity
379 * @return #GNUNET_SYSERR if the HELLO was malformed
382 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
383 struct GNUNET_PeerIdentity *peer);
387 * Get the header from a HELLO message, used so other code
388 * can correctly send HELLO messages.
390 * @param hello the hello message
392 * @return header or NULL if the HELLO was malformed
394 struct GNUNET_MessageHeader *
395 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
398 typedef struct GNUNET_TRANSPORT_PluginFunctions *
399 (*GNUNET_HELLO_TransportPluginsFind) (const char *name);
403 * Compose a hello URI string from a hello message.
405 * @param hello Hello message
406 * @param plugins_find Function to find transport plugins by name
407 * @return Hello URI string
410 GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello,
411 GNUNET_HELLO_TransportPluginsFind plugins_find);
414 * Parse a hello URI string to a hello message.
416 * @param uri URI string to parse
417 * @param pubkey Pointer to struct where public key is parsed
418 * @param hello Pointer to struct where hello message is parsed
419 * @param plugins_find Function to find transport plugins by name
420 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the URI was invalid, #GNUNET_NO on other errors
423 GNUNET_HELLO_parse_uri (const char *uri,
424 struct GNUNET_CRYPTO_EddsaPublicKey *pubkey,
425 struct GNUNET_HELLO_Message **hello,
426 GNUNET_HELLO_TransportPluginsFind plugins_find);
428 #if 0 /* keep Emacsens' auto-indent happy */
436 /* ifndef GNUNET_HELLO_LIB_H */
438 /* end of gnunet_hello_lib.h */