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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;
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 'address'
125 * @param local_info additional address information, will not get serialized
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, const void *address,
131 size_t address_length,
132 enum GNUNET_HELLO_AddressInfo local_info);
136 * Copy an address struct.
138 * @param address address to copy
139 * @return a copy of the address struct
141 struct GNUNET_HELLO_Address *
142 GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
146 * Compare two addresses. Does NOT compare the peer identity,
147 * that is assumed already to match!
149 * @param a1 first address
150 * @param a2 second address
151 * @return 0 if the addresses are equal, -1 if a1<a2, 1 if a1>a2.
154 GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
155 const struct GNUNET_HELLO_Address *a2);
158 * Get the size of an address struct.
160 * @param address address
164 GNUNET_HELLO_address_get_size (const struct GNUNET_HELLO_Address *address);
170 * @param addr address to free
172 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
176 * A HELLO message is used to exchange information about
177 * transports with other peers. This struct is guaranteed
178 * to start with a "GNUNET_MessageHeader", everything else
179 * should be internal to the HELLO library.
181 struct GNUNET_HELLO_Message;
184 /** Return HELLO type
186 * @param h HELLO Message to test
187 * @return GNUNET_YES or GNUNET_NO
190 GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h);
194 * Copy the given address information into
195 * the given buffer using the format of HELLOs.
197 * @param address address to add
198 * @param expiration expiration for the address
199 * @param target where to copy the address
200 * @param max maximum number of bytes to copy to target
201 * @return number of bytes copied, 0 if
202 * the target buffer was not big enough.
205 GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
206 struct GNUNET_TIME_Absolute expiration, char *target,
211 * Callback function used to fill a buffer of max bytes with a list of
212 * addresses in the format used by HELLOs. Should use
213 * "GNUNET_HELLO_add_address" as a helper function.
216 * @param max maximum number of bytes that can be written to buf
217 * @param buf where to write the address information
218 * @return number of bytes written, 0 to signal the
219 * end of the iteration.
221 typedef size_t (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
227 * Construct a HELLO message given the public key,
228 * expiration time and an iterator that spews the
229 * transport addresses.
231 * If friend only is set to GNUNET_YES we create a FRIEND_HELLO which will
232 * not be gossiped to other peers
234 * @return the hello message
236 struct GNUNET_HELLO_Message *
237 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *publicKey,
238 GNUNET_HELLO_GenerateAddressListCallback addrgen,
244 * Return the size of the given HELLO message.
245 * @param hello to inspect
246 * @return the size, 0 if HELLO is invalid
249 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
253 * Construct a HELLO message by merging the
254 * addresses in two existing HELLOs (which
255 * must be for the same peer).
257 * @param h1 first HELLO message
258 * @param h2 the second HELLO message
259 * @return the combined hello message
261 struct GNUNET_HELLO_Message *
262 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
263 const struct GNUNET_HELLO_Message *h2);
267 * Test if two HELLO messages contain the same addresses.
268 * If they only differ in expiration time, the lowest
269 * expiration time larger than 'now' where they differ
272 * @param h1 first HELLO message
273 * @param h2 the second HELLO message
274 * @param now time to use for deciding which addresses have
275 * expired and should not be considered at all
276 * @return absolute time forever if the two HELLOs are
277 * totally identical; smallest timestamp >= now if
278 * they only differ in timestamps;
279 * zero if the some addresses with expirations >= now
280 * do not match at all
282 struct GNUNET_TIME_Absolute
283 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
284 const struct GNUNET_HELLO_Message *h2,
285 struct GNUNET_TIME_Absolute now);
289 * Iterator callback to go over all addresses.
292 * @param address the address
293 * @param expiration expiration time
294 * @return GNUNET_OK to keep the address,
295 * GNUNET_NO to delete it from the HELLO
296 * GNUNET_SYSERR to stop iterating (but keep current address)
298 typedef int (*GNUNET_HELLO_AddressIterator) (void *cls,
299 const struct GNUNET_HELLO_Address *
301 struct GNUNET_TIME_Absolute
306 * When does the last address in the given HELLO expire?
308 * @param msg HELLO to inspect
309 * @return time the last address expires, 0 if there are no addresses in the HELLO
311 struct GNUNET_TIME_Absolute
312 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
316 * Iterate over all of the addresses in the HELLO.
318 * @param msg HELLO to iterate over; client does not need to
319 * have verified that msg is well-formed (beyond starting
320 * with a GNUNET_MessageHeader of the right type).
321 * @param return_modified if a modified copy should be returned,
322 * otherwise NULL will be returned
323 * @param it iterator to call on each address
324 * @param it_cls closure for it
325 * @return the modified HELLO or NULL
327 struct GNUNET_HELLO_Message *
328 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
330 GNUNET_HELLO_AddressIterator it, void *it_cls);
334 * Iterate over addresses in "new_hello" that
335 * are NOT already present in "old_hello".
337 * @param new_hello a HELLO message
338 * @param old_hello a HELLO message
339 * @param expiration_limit ignore addresses in old_hello
340 * that expired before the given time stamp
341 * @param it iterator to call on each address
342 * @param it_cls closure for it
345 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message
347 const struct GNUNET_HELLO_Message
349 struct GNUNET_TIME_Absolute
351 GNUNET_HELLO_AddressIterator it,
356 * Get the public key from a HELLO message.
358 * @param hello the hello message
359 * @param publicKey where to copy the public key information, can be NULL
360 * @return GNUNET_SYSERR if the HELLO was malformed
363 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
364 struct GNUNET_CRYPTO_EddsaPublicKey *publicKey);
368 * Get the peer identity from a HELLO message.
370 * @param hello the hello message
371 * @param peer where to store the peer's identity
372 * @return GNUNET_SYSERR if the HELLO was malformed
375 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
376 struct GNUNET_PeerIdentity *peer);
380 * Get the header from a HELLO message, used so other code
381 * can correctly send HELLO messages.
383 * @param hello the hello message
385 * @return header or NULL if the HELLO was malformed
387 struct GNUNET_MessageHeader *
388 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
391 typedef struct GNUNET_TRANSPORT_PluginFunctions *
392 (*GNUNET_HELLO_TransportPluginsFind) (const char *name);
396 * Compose a hello URI string from a hello message.
398 * @param hello Hello message
399 * @param plugins_find Function to find transport plugins by name
400 * @return Hello URI string
403 GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello,
404 GNUNET_HELLO_TransportPluginsFind plugins_find);
407 * Parse a hello URI string to a hello message.
409 * @param uri URI string to parse
410 * @param pubkey Pointer to struct where public key is parsed
411 * @param hello Pointer to struct where hello message is parsed
412 * @param plugins_find Function to find transport plugins by name
413 * @return GNUNET_OK on success, GNUNET_SYSERR if the URI was invalid, GNUNET_NO on other errors
416 GNUNET_HELLO_parse_uri (const char *uri,
417 struct GNUNET_CRYPTO_EddsaPublicKey *pubkey,
418 struct GNUNET_HELLO_Message **hello,
419 GNUNET_HELLO_TransportPluginsFind plugins_find);
421 #if 0 /* keep Emacsens' auto-indent happy */
429 /* ifndef GNUNET_HELLO_LIB_H */
431 /* end of gnunet_hello_lib.h */