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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);
94 * @param addr address to free
96 #define GNUNET_HELLO_address_free(addr) GNUNET_free(addr)
100 * A HELLO message is used to exchange information about
101 * transports with other peers. This struct is guaranteed
102 * to start with a "GNUNET_MessageHeader", everything else
103 * should be internal to the HELLO library.
105 struct GNUNET_HELLO_Message;
109 * Copy the given address information into
110 * the given buffer using the format of HELLOs.
112 * @param tname name of the transport plugin
113 * @param expiration expiration for the address
114 * @param addr the address
115 * @param addr_len length of the address in bytes
116 * @param target where to copy the address
117 * @param max maximum number of bytes to copy to target
118 * @return number of bytes copied, 0 if
119 * the target buffer was not big enough.
122 GNUNET_HELLO_add_address (const char *tname,
123 struct GNUNET_TIME_Absolute expiration,
124 const void *addr, uint16_t addr_len, char *target,
129 * Callback function used to fill a buffer of max bytes with a list of
130 * addresses in the format used by HELLOs. Should use
131 * "GNUNET_HELLO_add_address" as a helper function.
134 * @param max maximum number of bytes that can be written to buf
135 * @param buf where to write the address information
136 * @return number of bytes written, 0 to signal the
137 * end of the iteration.
139 typedef size_t (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
145 * Construct a HELLO message given the public key,
146 * expiration time and an iterator that spews the
147 * transport addresses.
149 * @return the hello message
151 struct GNUNET_HELLO_Message *
152 GNUNET_HELLO_create (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
154 GNUNET_HELLO_GenerateAddressListCallback addrgen,
159 * Return the size of the given HELLO message.
160 * @param hello to inspect
161 * @return the size, 0 if HELLO is invalid
164 GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
168 * Construct a HELLO message by merging the
169 * addresses in two existing HELLOs (which
170 * must be for the same peer).
172 * @param h1 first HELLO message
173 * @param h2 the second HELLO message
174 * @return the combined hello message
176 struct GNUNET_HELLO_Message *
177 GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
178 const struct GNUNET_HELLO_Message *h2);
182 * Test if two HELLO messages contain the same addresses.
183 * If they only differ in expiration time, the lowest
184 * expiration time larger than 'now' where they differ
187 * @param h1 first HELLO message
188 * @param h2 the second HELLO message
189 * @param now time to use for deciding which addresses have
190 * expired and should not be considered at all
191 * @return absolute time forever if the two HELLOs are
192 * totally identical; smallest timestamp >= now if
193 * they only differ in timestamps;
194 * zero if the some addresses with expirations >= now
195 * do not match at all
197 struct GNUNET_TIME_Absolute
198 GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
199 const struct GNUNET_HELLO_Message *h2,
200 struct GNUNET_TIME_Absolute now);
204 * Iterator callback to go over all addresses.
207 * @param tname name of the transport
208 * @param expiration expiration time
209 * @param addr the address
210 * @param addrlen length of the address
211 * @return GNUNET_OK to keep the address,
212 * GNUNET_NO to delete it from the HELLO
213 * GNUNET_SYSERR to stop iterating (but keep current address)
215 typedef int (*GNUNET_HELLO_AddressIterator) (void *cls, const char *tname,
216 struct GNUNET_TIME_Absolute
217 expiration, const void *addr,
222 * When does the last address in the given HELLO expire?
224 * @param msg HELLO to inspect
225 * @return time the last address expires, 0 if there are no addresses in the HELLO
227 struct GNUNET_TIME_Absolute
228 GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
232 * Iterate over all of the addresses in the HELLO.
234 * @param msg HELLO to iterate over; client does not need to
235 * have verified that msg is well-formed (beyond starting
236 * with a GNUNET_MessageHeader of the right type).
237 * @param return_modified if a modified copy should be returned,
238 * otherwise NULL will be returned
239 * @param it iterator to call on each address
240 * @param it_cls closure for it
241 * @return the modified HELLO or NULL
243 struct GNUNET_HELLO_Message *
244 GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
246 GNUNET_HELLO_AddressIterator it, void *it_cls);
250 * Iterate over addresses in "new_hello" that
251 * are NOT already present in "old_hello".
253 * @param new_hello a HELLO message
254 * @param old_hello a HELLO message
255 * @param expiration_limit ignore addresses in old_hello
256 * that expired before the given time stamp
257 * @param it iterator to call on each address
258 * @param it_cls closure for it
261 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message
263 const struct GNUNET_HELLO_Message
265 struct GNUNET_TIME_Absolute
267 GNUNET_HELLO_AddressIterator it,
272 * Get the public key from a HELLO message.
274 * @param hello the hello message
275 * @param publicKey where to copy the public key information, can be NULL
276 * @return GNUNET_SYSERR if the HELLO was malformed
279 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
280 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
285 * Get the peer identity from a HELLO message.
287 * @param hello the hello message
288 * @param peer where to store the peer's identity
289 * @return GNUNET_SYSERR if the HELLO was malformed
292 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
293 struct GNUNET_PeerIdentity *peer);
297 * Get the header from a HELLO message, used so other code
298 * can correctly send HELLO messages.
300 * @param hello the hello message
302 * @return header or NULL if the HELLO was malformed
304 struct GNUNET_MessageHeader *
305 GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
307 /* ifndef GNUNET_HELLO_LIB_H */
309 /* end of gnunet_hello_lib.h */