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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"
42 * A HELLO message is used to exchange information about
43 * transports with other peers. This struct is guaranteed
44 * to start with a "GNUNET_MessageHeader", everything else
45 * should be internal to the HELLO library.
47 struct GNUNET_HELLO_Message;
51 * Copy the given address information into
52 * the given buffer using the format of HELLOs.
54 * @param tname name of the transport plugin
55 * @param expiration expiration for the address
56 * @param addr the address
57 * @param addr_len length of the address in bytes
58 * @param target where to copy the address
59 * @param max maximum number of bytes to copy to target
60 * @return number of bytes copied, 0 if
61 * the target buffer was not big enough.
71 GNUNET_HELLO_add_address (const char *tname,
72 struct GNUNET_TIME_Absolute expiration,
74 uint16_t addr_len, char *target, size_t max);
78 * Callback function used to fill a buffer of max bytes with a list of
79 * addresses in the format used by HELLOs. Should use
80 * "GNUNET_HELLO_add_address" as a helper function.
83 * @param max maximum number of bytes that can be written to buf
84 * @param buf where to write the address information
85 * @return number of bytes written, 0 to signal the
86 * end of the iteration.
89 (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
90 size_t max, void *buf);
94 * Construct a HELLO message given the public key,
95 * expiration time and an iterator that spews the
96 * transport addresses.
98 * @return the hello message
100 struct GNUNET_HELLO_Message *GNUNET_HELLO_create (const struct
101 GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
103 GNUNET_HELLO_GenerateAddressListCallback
104 addrgen, void *addrgen_cls);
108 * Return the size of the given HELLO message.
109 * @param hello to inspect
110 * @return the size, 0 if HELLO is invalid
112 uint16_t GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
116 * Construct a HELLO message by merging the
117 * addresses in two existing HELLOs (which
118 * must be for the same peer).
120 * @param h1 first HELLO message
121 * @param h2 the second HELLO message
122 * @return the combined hello message
124 struct GNUNET_HELLO_Message *GNUNET_HELLO_merge (const struct
125 GNUNET_HELLO_Message *h1,
127 GNUNET_HELLO_Message *h2);
131 * Test if two HELLO messages contain the same addresses.
132 * If they only differ in expiration time, the lowest
133 * expiration time larger than 'now' where they differ
136 * @param h1 first HELLO message
137 * @param h2 the second HELLO message
138 * @param now time to use for deciding which addresses have
139 * expired and should not be considered at all
140 * @return absolute time forever if the two HELLOs are
141 * totally identical; smallest timestamp >= now if
142 * they only differ in timestamps;
143 * zero if the some addresses with expirations >= now
144 * do not match at all
146 struct GNUNET_TIME_Absolute
147 GNUNET_HELLO_equals (const struct
148 GNUNET_HELLO_Message *h1,
150 GNUNET_HELLO_Message *h2, struct GNUNET_TIME_Absolute now);
154 * Iterator callback to go over all addresses.
157 * @param tname name of the transport
158 * @param expiration expiration time
159 * @param addr the address
160 * @param addrlen length of the address
161 * @return GNUNET_OK to keep the address,
162 * GNUNET_NO to delete it from the HELLO
163 * GNUNET_SYSERR to stop iterating (but keep current address)
166 (*GNUNET_HELLO_AddressIterator) (void *cls,
168 struct GNUNET_TIME_Absolute expiration,
169 const void *addr, uint16_t addrlen);
173 * Iterate over all of the addresses in the HELLO.
175 * @param msg HELLO to iterate over; client does not need to
176 * have verified that msg is well-formed (beyond starting
177 * with a GNUNET_MessageHeader of the right type).
178 * @param return_modified if a modified copy should be returned,
179 * otherwise NULL will be returned
180 * @param it iterator to call on each address
181 * @param it_cls closure for it
182 * @return the modified HELLO or NULL
184 struct GNUNET_HELLO_Message *GNUNET_HELLO_iterate_addresses (const struct
189 GNUNET_HELLO_AddressIterator
194 * Iterate over addresses in "new_hello" that
195 * are NOT already present in "old_hello".
197 * @param new_hello a HELLO message
198 * @param old_hello a HELLO message
199 * @param expiration_limit ignore addresses in old_hello
200 * that expired before the given time stamp
201 * @param it iterator to call on each address
202 * @param it_cls closure for it
205 GNUNET_HELLO_iterate_new_addresses (const struct GNUNET_HELLO_Message
207 const struct GNUNET_HELLO_Message
209 struct GNUNET_TIME_Absolute
211 GNUNET_HELLO_AddressIterator it,
216 * Get the public key from a HELLO message.
218 * @param hello the hello message
219 * @param publicKey where to copy the public key information, can be NULL
220 * @return GNUNET_SYSERR if the HELLO was malformed
223 GNUNET_HELLO_get_key (const struct GNUNET_HELLO_Message *hello,
224 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
229 * Get the peer identity from a HELLO message.
231 * @param hello the hello message
232 * @param peer where to store the peer's identity
233 * @return GNUNET_SYSERR if the HELLO was malformed
236 GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
237 struct GNUNET_PeerIdentity *peer);
241 * Get the header from a HELLO message, used so other code
242 * can correctly send HELLO messages.
244 * @param hello the hello message
246 * @return header or NULL if the HELLO was malformed
248 struct GNUNET_MessageHeader *GNUNET_HELLO_get_header (struct
252 /* ifndef GNUNET_HELLO_LIB_H */
254 /* end of gnunet_hello_lib.h */