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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/"
52 * An address for communicating with a peer. We frequently
53 * need this tuple and the components cannot really be
54 * separated. This is NOT the format that would be used
57 struct GNUNET_HELLO_Address
61 * For which peer is this an address?
63 struct GNUNET_PeerIdentity peer;
66 * Name of the transport plugin enabling the communication using
69 const char *transport_name;
72 * Binary representation of the address (plugin-specific).
77 * Number of bytes in 'address'.
79 size_t address_length;
85 * Allocate an address struct.
87 * @param peer the peer
88 * @param transport_name plugin name
89 * @param address binary address
90 * @param address_length number of bytes in 'address'
91 * @return the address struct
93 struct GNUNET_HELLO_Address *
94 GNUNET_HELLO_address_allocate (const struct GNUNET_PeerIdentity *peer,
95 const char *transport_name, const void *address,
96 size_t address_length);
100 * Copy an address struct.
102 * @param address address to copy
103 * @return a copy of the address struct
105 struct GNUNET_HELLO_Address *
106 GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
110 * Compare two addresses. Does NOT compare the peer identity,
111 * that is assumed already to match!
113 * @param a1 first address
114 * @param a2 second address
115 * @return 0 if the addresses are equal, -1 if a1<a2, 1 if a1>a2.
118 GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
119 const struct GNUNET_HELLO_Address *a2);
123 * Get the size of an address struct.
125 * @param address address
129 GNUNET_HELLO_address_get_size (const struct GNUNET_HELLO_Address *address);
134 * @param addr address to free
136 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
140 * A HELLO message is used to exchange information about
141 * transports with other peers. This struct is guaranteed
142 * to start with a "GNUNET_MessageHeader", everything else
143 * should be internal to the HELLO library.
145 struct GNUNET_HELLO_Message;
148 /** Return HELLO type
150 * @param h HELLO Message to test
151 * @return GNUNET_YES or GNUNET_NO
154 GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h);
158 * Copy the given address information into
159 * the given buffer using the format of HELLOs.
161 * @param address address to add
162 * @param expiration expiration for the address
163 * @param target where to copy the address
164 * @param max maximum number of bytes to copy to target
165 * @return number of bytes copied, 0 if
166 * the target buffer was not big enough.
169 GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
170 struct GNUNET_TIME_Absolute expiration, char *target,
175 * Callback function used to fill a buffer of max bytes with a list of
176 * addresses in the format used by HELLOs. Should use
177 * "GNUNET_HELLO_add_address" as a helper function.
180 * @param max maximum number of bytes that can be written to buf
181 * @param buf where to write the address information
182 * @return number of bytes written, 0 to signal the
183 * end of the iteration.
185 typedef size_t (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
191 * Construct a HELLO message given the public key,
192 * expiration time and an iterator that spews the
193 * transport addresses.
195 * If friend only is set to GNUNET_YES we create a FRIEND_HELLO which will
196 * not be gossiped to other peers
198 * @return the hello message
200 struct GNUNET_HELLO_Message *
201 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EccPublicSignKey *publicKey,
202 GNUNET_HELLO_GenerateAddressListCallback addrgen,
208 * Return the size of the given HELLO message.
209 * @param hello to inspect
210 * @return the size, 0 if HELLO is invalid
213 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
217 * Construct a HELLO message by merging the
218 * addresses in two existing HELLOs (which
219 * must be for the same peer).
221 * @param h1 first HELLO message
222 * @param h2 the second HELLO message
223 * @return the combined hello message
225 struct GNUNET_HELLO_Message *
226 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
227 const struct GNUNET_HELLO_Message *h2);
231 * Test if two HELLO messages contain the same addresses.
232 * If they only differ in expiration time, the lowest
233 * expiration time larger than 'now' where they differ
236 * @param h1 first HELLO message
237 * @param h2 the second HELLO message
238 * @param now time to use for deciding which addresses have
239 * expired and should not be considered at all
240 * @return absolute time forever if the two HELLOs are
241 * totally identical; smallest timestamp >= now if
242 * they only differ in timestamps;
243 * zero if the some addresses with expirations >= now
244 * do not match at all
246 struct GNUNET_TIME_Absolute
247 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
248 const struct GNUNET_HELLO_Message *h2,
249 struct GNUNET_TIME_Absolute now);
253 * Iterator callback to go over all addresses.
256 * @param address the address
257 * @param expiration expiration time
258 * @return GNUNET_OK to keep the address,
259 * GNUNET_NO to delete it from the HELLO
260 * GNUNET_SYSERR to stop iterating (but keep current address)
262 typedef int (*GNUNET_HELLO_AddressIterator) (void *cls,
263 const struct GNUNET_HELLO_Address *
265 struct GNUNET_TIME_Absolute
270 * When does the last address in the given HELLO expire?
272 * @param msg HELLO to inspect
273 * @return time the last address expires, 0 if there are no addresses in the HELLO
275 struct GNUNET_TIME_Absolute
276 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
280 * Iterate over all of the addresses in the HELLO.
282 * @param msg HELLO to iterate over; client does not need to
283 * have verified that msg is well-formed (beyond starting
284 * with a GNUNET_MessageHeader of the right type).
285 * @param return_modified if a modified copy should be returned,
286 * otherwise NULL will be returned
287 * @param it iterator to call on each address
288 * @param it_cls closure for it
289 * @return the modified HELLO or NULL
291 struct GNUNET_HELLO_Message *
292 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
294 GNUNET_HELLO_AddressIterator it, void *it_cls);
298 * Iterate over addresses in "new_hello" that
299 * are NOT already present in "old_hello".
301 * @param new_hello a HELLO message
302 * @param old_hello a HELLO message
303 * @param expiration_limit ignore addresses in old_hello
304 * that expired before the given time stamp
305 * @param it iterator to call on each address
306 * @param it_cls closure for it
309 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message
311 const struct GNUNET_HELLO_Message
313 struct GNUNET_TIME_Absolute
315 GNUNET_HELLO_AddressIterator it,
320 * Get the public key from a HELLO message.
322 * @param hello the hello message
323 * @param publicKey where to copy the public key information, can be NULL
324 * @return GNUNET_SYSERR if the HELLO was malformed
327 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
328 struct GNUNET_CRYPTO_EccPublicSignKey *publicKey);
332 * Get the peer identity from a HELLO message.
334 * @param hello the hello message
335 * @param peer where to store the peer's identity
336 * @return GNUNET_SYSERR if the HELLO was malformed
339 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
340 struct GNUNET_PeerIdentity *peer);
344 * Get the header from a HELLO message, used so other code
345 * can correctly send HELLO messages.
347 * @param hello the hello message
349 * @return header or NULL if the HELLO was malformed
351 struct GNUNET_MessageHeader *
352 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
355 typedef struct GNUNET_TRANSPORT_PluginFunctions *
356 (*GNUNET_HELLO_TransportPluginsFind) (const char *name);
360 * Compose a hello URI string from a hello message.
362 * @param hello Hello message
363 * @param plugins_find Function to find transport plugins by name
364 * @return Hello URI string
367 GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello,
368 GNUNET_HELLO_TransportPluginsFind plugins_find);
371 * Parse a hello URI string to a hello message.
373 * @param uri URI string to parse
374 * @param pubkey Pointer to struct where public key is parsed
375 * @param hello Pointer to struct where hello message is parsed
376 * @param plugins_find Function to find transport plugins by name
377 * @return GNUNET_OK on success, GNUNET_SYSERR if the URI was invalid, GNUNET_NO on other errors
380 GNUNET_HELLO_parse_uri (const char *uri,
381 struct GNUNET_CRYPTO_EccPublicSignKey *pubkey,
382 struct GNUNET_HELLO_Message **hello,
383 GNUNET_HELLO_TransportPluginsFind plugins_find);
385 #if 0 /* keep Emacsens' auto-indent happy */
393 /* ifndef GNUNET_HELLO_LIB_H */
395 /* end of gnunet_hello_lib.h */