2 This file is part of GNUnet.
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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_common.h"
39 #include "gnunet_crypto_lib.h"
43 * An address for communicating with a peer. We frequently
44 * need this tuple and the components cannot really be
45 * separated. This is NOT the format that would be used
48 struct GNUNET_HELLO_Address
52 * For which peer is this an address?
54 struct GNUNET_PeerIdentity peer;
57 * Name of the transport plugin enabling the communication using
60 const char *transport_name;
63 * Binary representation of the address (plugin-specific).
68 * Number of bytes in 'address'.
70 size_t address_length;
76 * Allocate an address struct.
78 * @param peer the peer
79 * @param transport_name plugin name
80 * @param address binary address
81 * @param address_length number of bytes in 'address'
82 * @return the address struct
84 struct GNUNET_HELLO_Address *
85 GNUNET_HELLO_address_allocate (const struct GNUNET_PeerIdentity *peer,
86 const char *transport_name,
88 size_t address_length);
92 * Copy an address struct.
94 * @param address address to copy
95 * @return a copy of the address struct
97 struct GNUNET_HELLO_Address *
98 GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
102 * Compare two addresses. Does NOT compare the peer identity,
103 * that is assumed already to match!
105 * @param a1 first address
106 * @param a2 second address
107 * @return 0 if the addresses are equal, -1 if a1<a2, 1 if a1>a2.
110 GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
111 const struct GNUNET_HELLO_Address *a2);
118 * @param addr address to free
120 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
124 * A HELLO message is used to exchange information about
125 * transports with other peers. This struct is guaranteed
126 * to start with a "GNUNET_MessageHeader", everything else
127 * should be internal to the HELLO library.
129 struct GNUNET_HELLO_Message;
133 * Copy the given address information into
134 * the given buffer using the format of HELLOs.
136 * @param address address to add
137 * @param expiration expiration for the address
138 * @param target where to copy the address
139 * @param max maximum number of bytes to copy to target
140 * @return number of bytes copied, 0 if
141 * the target buffer was not big enough.
144 GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
145 struct GNUNET_TIME_Absolute expiration,
151 * Callback function used to fill a buffer of max bytes with a list of
152 * addresses in the format used by HELLOs. Should use
153 * "GNUNET_HELLO_add_address" as a helper function.
156 * @param max maximum number of bytes that can be written to buf
157 * @param buf where to write the address information
158 * @return number of bytes written, 0 to signal the
159 * end of the iteration.
161 typedef size_t (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
167 * Construct a HELLO message given the public key,
168 * expiration time and an iterator that spews the
169 * transport addresses.
171 * @return the hello message
173 struct GNUNET_HELLO_Message *
174 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
176 GNUNET_HELLO_GenerateAddressListCallback addrgen,
181 * Return the size of the given HELLO message.
182 * @param hello to inspect
183 * @return the size, 0 if HELLO is invalid
186 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
190 * Construct a HELLO message by merging the
191 * addresses in two existing HELLOs (which
192 * must be for the same peer).
194 * @param h1 first HELLO message
195 * @param h2 the second HELLO message
196 * @return the combined hello message
198 struct GNUNET_HELLO_Message *
199 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
200 const struct GNUNET_HELLO_Message *h2);
204 * Test if two HELLO messages contain the same addresses.
205 * If they only differ in expiration time, the lowest
206 * expiration time larger than 'now' where they differ
209 * @param h1 first HELLO message
210 * @param h2 the second HELLO message
211 * @param now time to use for deciding which addresses have
212 * expired and should not be considered at all
213 * @return absolute time forever if the two HELLOs are
214 * totally identical; smallest timestamp >= now if
215 * they only differ in timestamps;
216 * zero if the some addresses with expirations >= now
217 * do not match at all
219 struct GNUNET_TIME_Absolute
220 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
221 const struct GNUNET_HELLO_Message *h2,
222 struct GNUNET_TIME_Absolute now);
226 * Iterator callback to go over all addresses.
229 * @param address the address
230 * @param expiration expiration time
231 * @return GNUNET_OK to keep the address,
232 * GNUNET_NO to delete it from the HELLO
233 * GNUNET_SYSERR to stop iterating (but keep current address)
235 typedef int (*GNUNET_HELLO_AddressIterator) (void *cls,
236 const struct GNUNET_HELLO_Address *address,
237 struct GNUNET_TIME_Absolute expiration);
241 * When does the last address in the given HELLO expire?
243 * @param msg HELLO to inspect
244 * @return time the last address expires, 0 if there are no addresses in the HELLO
246 struct GNUNET_TIME_Absolute
247 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
251 * Iterate over all of the addresses in the HELLO.
253 * @param msg HELLO to iterate over; client does not need to
254 * have verified that msg is well-formed (beyond starting
255 * with a GNUNET_MessageHeader of the right type).
256 * @param return_modified if a modified copy should be returned,
257 * otherwise NULL will be returned
258 * @param it iterator to call on each address
259 * @param it_cls closure for it
260 * @return the modified HELLO or NULL
262 struct GNUNET_HELLO_Message *
263 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
265 GNUNET_HELLO_AddressIterator it, void *it_cls);
269 * Iterate over addresses in "new_hello" that
270 * are NOT already present in "old_hello".
272 * @param new_hello a HELLO message
273 * @param old_hello a HELLO message
274 * @param expiration_limit ignore addresses in old_hello
275 * that expired before the given time stamp
276 * @param it iterator to call on each address
277 * @param it_cls closure for it
280 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message
282 const struct GNUNET_HELLO_Message
284 struct GNUNET_TIME_Absolute
286 GNUNET_HELLO_AddressIterator it,
291 * Get the public key from a HELLO message.
293 * @param hello the hello message
294 * @param publicKey where to copy the public key information, can be NULL
295 * @return GNUNET_SYSERR if the HELLO was malformed
298 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
299 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
304 * Get the peer identity from a HELLO message.
306 * @param hello the hello message
307 * @param peer where to store the peer's identity
308 * @return GNUNET_SYSERR if the HELLO was malformed
311 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
312 struct GNUNET_PeerIdentity *peer);
316 * Get the header from a HELLO message, used so other code
317 * can correctly send HELLO messages.
319 * @param hello the hello message
321 * @return header or NULL if the HELLO was malformed
323 struct GNUNET_MessageHeader *
324 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
326 /* ifndef GNUNET_HELLO_LIB_H */
328 /* end of gnunet_hello_lib.h */