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- /*
- This file is part of GNUnet.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2010, 2011 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- or (at your option) any later version.
- GNUnet is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @author Christian Grothoff
- * @file
- * Helper library for handling HELLOs
- *
- * @defgroup hello Hello library
- * Helper library for handling HELLOs
- *
- * @see [Documentation](https://gnunet.org/gnunets-hostlist-subsystem)
- *
- * @{
- */
- #ifndef GNUNET_HELLO_LIB_H
- #define GNUNET_HELLO_LIB_H
- #ifdef __cplusplus
- extern "C" {
- #if 0 /* keep Emacsens' auto-indent happy */
- }
- #endif
- #endif
- #include "gnunet_util_lib.h"
- /**
- * Prefix that every HELLO URI must start with.
- */
- #define GNUNET_HELLO_URI_PREFIX "gnunet://hello/"
- /**
- * Prefix that every FRIEND HELLO URI must start with.
- */
- #define GNUNET_FRIEND_HELLO_URI_PREFIX "gnunet://friend-hello/"
- /**
- * Separator used in HELLO URI
- */
- #define GNUNET_HELLO_URI_SEP '+'
- /**
- * Additional local information about an address
- *
- * These information are only valid for the local peer and are not serialized
- * when a #GNUNET_HELLO_Message is created
- */
- enum GNUNET_HELLO_AddressInfo
- {
- /**
- * No additional information
- */
- GNUNET_HELLO_ADDRESS_INFO_NONE = 0,
- /**
- * This is an inbound address and cannot be used to initiate an outbound
- * connection to another peer
- */
- GNUNET_HELLO_ADDRESS_INFO_INBOUND = 1
- };
- /**
- * An address for communicating with a peer. We frequently
- * need this tuple and the components cannot really be
- * separated. This is NOT the format that would be used
- * on the wire.
- */
- struct GNUNET_HELLO_Address
- {
- /**
- * For which peer is this an address?
- */
- struct GNUNET_PeerIdentity peer;
- /**
- * Name of the transport plugin enabling the communication using
- * this address.
- */
- const char *transport_name;
- /**
- * Binary representation of the address (plugin-specific).
- */
- const void *address;
- /**
- * Number of bytes in @e address.
- */
- size_t address_length;
- /**
- * Extended information about address
- *
- * This field contains additional #GNUNET_HELLO_AddressInfo flags e.g.
- * to indicate an address is inbound and cannot be used to initiate an
- * outbound connection.
- *
- * These information are only valid for the local peer and are not serialized
- * when a #GNUNET_HELLO_Message is created
- */
- enum GNUNET_HELLO_AddressInfo local_info;
- };
- /**
- * Allocate an address struct.
- *
- * @param peer the peer
- * @param transport_name plugin name
- * @param address binary address
- * @param address_length number of bytes in @a address
- * @param local_info additional local information for the address
- * @return the address struct
- */
- struct GNUNET_HELLO_Address *
- GNUNET_HELLO_address_allocate (const struct GNUNET_PeerIdentity *peer,
- const char *transport_name,
- const void *address,
- size_t address_length,
- enum GNUNET_HELLO_AddressInfo local_info);
- /**
- * Copy an address struct.
- *
- * @param address address to copy
- * @return a copy of the address struct
- */
- struct GNUNET_HELLO_Address *
- GNUNET_HELLO_address_copy (const struct GNUNET_HELLO_Address *address);
- /**
- * Compare two addresses. Does NOT compare the peer identity,
- * that is assumed already to match!
- *
- * @param a1 first address
- * @param a2 second address
- * @return 0 if the addresses are equal, -1 if @a a1< @a a2, 1 if @a a1> @a a2.
- */
- int
- GNUNET_HELLO_address_cmp (const struct GNUNET_HELLO_Address *a1,
- const struct GNUNET_HELLO_Address *a2);
- /**
- * Get the size of an address struct.
- *
- * @param address address
- * @return the size
- */
- size_t
- GNUNET_HELLO_address_get_size (const struct GNUNET_HELLO_Address *address);
- /**
- * Check if an address has a local option set
- *
- * @param address the address to check
- * @param option the respective option to check for
- * @return #GNUNET_YES or #GNUNET_NO
- */
- int
- GNUNET_HELLO_address_check_option (const struct GNUNET_HELLO_Address *address,
- enum GNUNET_HELLO_AddressInfo option);
- /**
- * Free an address.
- *
- * @param addr address to free
- */
- #define GNUNET_HELLO_address_free(addr) GNUNET_free (addr)
- GNUNET_NETWORK_STRUCT_BEGIN
- /**
- * A HELLO message is used to exchange information about
- * transports with other peers. This struct is always
- * followed by the actual network addresses which have
- * the format:
- *
- * 1) transport-name (0-terminated)
- * 2) address-length (uint16_t, network byte order; possibly
- * unaligned!)
- * 3) address expiration (`struct GNUNET_TIME_AbsoluteNBO`); possibly
- * unaligned!)
- * 4) address (address-length bytes; possibly unaligned!)
- */
- struct GNUNET_HELLO_Message
- {
- /**
- * Type will be #GNUNET_MESSAGE_TYPE_HELLO.
- */
- struct GNUNET_MessageHeader header;
- /**
- * Use in F2F mode: Do not gossip this HELLO message
- */
- uint32_t friend_only GNUNET_PACKED;
- /**
- * The public key of the peer.
- */
- struct GNUNET_CRYPTO_EddsaPublicKey publicKey;
- };
- GNUNET_NETWORK_STRUCT_END
- /**
- * Return HELLO type
- *
- * @param h HELLO Message to test
- * @return #GNUNET_YES for friend-only or #GNUNET_NO otherwise
- */
- int
- GNUNET_HELLO_is_friend_only (const struct GNUNET_HELLO_Message *h);
- /**
- * Copy the given address information into
- * the given buffer using the format of HELLOs.
- *
- * @param address address to add
- * @param expiration expiration for the address
- * @param target where to copy the address
- * @param max maximum number of bytes to copy to @a target
- * @return number of bytes copied, 0 if
- * the target buffer was not big enough.
- */
- size_t
- GNUNET_HELLO_add_address (const struct GNUNET_HELLO_Address *address,
- struct GNUNET_TIME_Absolute expiration,
- char *target,
- size_t max);
- /**
- * Callback function used to fill a buffer of max bytes with a list of
- * addresses in the format used by HELLOs. Should use
- * #GNUNET_HELLO_add_address() as a helper function.
- *
- * @param cls closure
- * @param max maximum number of bytes that can be written to @a buf
- * @param buf where to write the address information
- * @return number of bytes written or 0, #GNUNET_SYSERR to signal the
- * end of the iteration.
- */
- typedef ssize_t (*GNUNET_HELLO_GenerateAddressListCallback) (void *cls,
- size_t max,
- void *buf);
- /**
- * Construct a HELLO message given the public key,
- * expiration time and an iterator that spews the
- * transport addresses.
- *
- * If friend only is set to #GNUNET_YES we create a FRIEND_HELLO which
- * will not be gossiped to other peers.
- *
- * @param public_key public key to include in the HELLO
- * @param addrgen callback to invoke to get addresses
- * @param addrgen_cls closure for @a addrgen
- * @param friend_only should the returned HELLO be only visible to friends?
- * @return the hello message
- */
- struct GNUNET_HELLO_Message *
- GNUNET_HELLO_create (const struct GNUNET_CRYPTO_EddsaPublicKey *public_key,
- GNUNET_HELLO_GenerateAddressListCallback addrgen,
- void *addrgen_cls,
- int friend_only);
- /**
- * Return the size of the given HELLO message.
- *
- * @param hello to inspect
- * @return the size, 0 if HELLO is invalid
- */
- uint16_t
- GNUNET_HELLO_size (const struct GNUNET_HELLO_Message *hello);
- /**
- * Construct a HELLO message by merging the
- * addresses in two existing HELLOs (which
- * must be for the same peer).
- *
- * @param h1 first HELLO message
- * @param h2 the second HELLO message
- * @return the combined hello message
- */
- struct GNUNET_HELLO_Message *
- GNUNET_HELLO_merge (const struct GNUNET_HELLO_Message *h1,
- const struct GNUNET_HELLO_Message *h2);
- /**
- * Test if two HELLO messages contain the same addresses.
- * If they only differ in expiration time, the lowest
- * expiration time larger than 'now' where they differ
- * is returned.
- *
- * @param h1 first HELLO message
- * @param h2 the second HELLO message
- * @param now time to use for deciding which addresses have
- * expired and should not be considered at all
- * @return absolute time forever if the two HELLOs are
- * totally identical; smallest timestamp >= now if
- * they only differ in timestamps;
- * zero if the some addresses with expirations >= now
- * do not match at all
- */
- struct GNUNET_TIME_Absolute
- GNUNET_HELLO_equals (const struct GNUNET_HELLO_Message *h1,
- const struct GNUNET_HELLO_Message *h2,
- struct GNUNET_TIME_Absolute now);
- /**
- * Iterator callback to go over all addresses.
- *
- * @param cls closure
- * @param address the address
- * @param expiration expiration time
- * @return #GNUNET_OK to keep the address,
- * #GNUNET_NO to delete it from the HELLO
- * #GNUNET_SYSERR to stop iterating (but keep current address)
- */
- typedef int (*GNUNET_HELLO_AddressIterator) (
- void *cls,
- const struct GNUNET_HELLO_Address *address,
- struct GNUNET_TIME_Absolute expiration);
- /**
- * When does the last address in the given HELLO expire?
- *
- * @param msg HELLO to inspect
- * @return time the last address expires, 0 if there are no addresses in the HELLO
- */
- struct GNUNET_TIME_Absolute
- GNUNET_HELLO_get_last_expiration (const struct GNUNET_HELLO_Message *msg);
- /**
- * Iterate over all of the addresses in the HELLO.
- *
- * @param msg HELLO to iterate over; client does not need to
- * have verified that msg is well-formed (beyond starting
- * with a GNUNET_MessageHeader of the right type).
- * @param return_modified if a modified copy should be returned,
- * otherwise NULL will be returned
- * @param it iterator to call on each address
- * @param it_cls closure for @a it
- * @return the modified HELLO or NULL
- */
- struct GNUNET_HELLO_Message *
- GNUNET_HELLO_iterate_addresses (const struct GNUNET_HELLO_Message *msg,
- int return_modified,
- GNUNET_HELLO_AddressIterator it,
- void *it_cls);
- /**
- * Iterate over addresses in @a new_hello that are NOT already present
- * in @a old_hello. Note that if the address is present in @a old_hello
- * but the expiration time in @a new_hello is more recent, the
- * iterator is also called.
- *
- * @param new_hello a HELLO message
- * @param old_hello a HELLO message
- * @param expiration_limit ignore addresses in old_hello
- * that expired before the given time stamp
- * @param it iterator to call on each address
- * @param it_cls closure for @a it
- */
- void
- GNUNET_HELLO_iterate_new_addresses (
- const struct GNUNET_HELLO_Message *new_hello,
- const struct GNUNET_HELLO_Message *old_hello,
- struct GNUNET_TIME_Absolute expiration_limit,
- GNUNET_HELLO_AddressIterator it,
- void *it_cls);
- /**
- * Get the peer identity from a HELLO message.
- *
- * @param hello the hello message
- * @param peer where to store the peer's identity
- * @return #GNUNET_SYSERR if the HELLO was malformed
- */
- int
- GNUNET_HELLO_get_id (const struct GNUNET_HELLO_Message *hello,
- struct GNUNET_PeerIdentity *peer);
- /**
- * Get the header from a HELLO message, used so other code
- * can correctly send HELLO messages.
- *
- * @param hello the hello message
- *
- * @return header or NULL if the HELLO was malformed
- */
- struct GNUNET_MessageHeader *
- GNUNET_HELLO_get_header (struct GNUNET_HELLO_Message *hello);
- /**
- * Helper function to load/access transport plugins.
- * FIXME: pass closure!
- *
- * @param name name of the transport plugin to load
- * @return NULL if a plugin with name @a name is not known/loadable
- */
- typedef struct GNUNET_TRANSPORT_PluginFunctions *(
- *GNUNET_HELLO_TransportPluginsFind) (const char *name);
- /**
- * Compose a hello URI string from a hello message.
- *
- * @param hello Hello message
- * @param plugins_find Function to find transport plugins by name
- * @return Hello URI string
- */
- char *
- GNUNET_HELLO_compose_uri (const struct GNUNET_HELLO_Message *hello,
- GNUNET_HELLO_TransportPluginsFind plugins_find);
- /**
- * Parse a hello URI string to a hello message.
- *
- * @param uri URI string to parse
- * @param pubkey Pointer to struct where public key is parsed
- * @param hello Pointer to struct where hello message is parsed
- * @param plugins_find Function to find transport plugins by name
- * @return #GNUNET_OK on success, #GNUNET_SYSERR if the URI was invalid, #GNUNET_NO on other errors
- */
- int
- GNUNET_HELLO_parse_uri (const char *uri,
- struct GNUNET_CRYPTO_EddsaPublicKey *pubkey,
- struct GNUNET_HELLO_Message **hello,
- GNUNET_HELLO_TransportPluginsFind plugins_find);
- /* NG API */
- #include "gnunet_nt_lib.h"
- /**
- * Build address record by signing raw information with private key.
- *
- * @param address text address to sign
- * @param nt network type of @a address
- * @param mono_time when was @a address valid
- * @param private_key signing key to use
- * @param result[out] where to write address record (allocated)
- * @param result_size[out] set to size of @a result
- */
- void
- GNUNET_HELLO_sign_address (
- const char *address,
- enum GNUNET_NetworkType nt,
- struct GNUNET_TIME_Absolute mono_time,
- const struct GNUNET_CRYPTO_EddsaPrivateKey *private_key,
- void **result,
- size_t *result_size);
- /**
- * Check signature and extract address record.
- *
- * @param raw raw signed address
- * @param raw_size size of @a raw
- * @param pid public key to use for signature verification
- * @param nt[out] set to network type
- * @param mono_time[out] when was the address generated
- * @return NULL on error, otherwise the address
- */
- char *
- GNUNET_HELLO_extract_address (const void *raw,
- size_t raw_size,
- const struct GNUNET_PeerIdentity *pid,
- enum GNUNET_NetworkType *nt,
- struct GNUNET_TIME_Absolute *mono_time);
- /**
- * Given an address as a string, extract the prefix that identifies
- * the communicator offering transmissions to that address.
- *
- * @param address a peer's address
- * @return NULL if the address is mal-formed, otherwise the prefix
- */
- char *
- GNUNET_HELLO_address_to_prefix (const char *address);
- #if 0 /* keep Emacsens' auto-indent happy */
- {
- #endif
- #ifdef __cplusplus
- }
- #endif
- /* ifndef GNUNET_HELLO_LIB_H */
- #endif
- /** @} */ /* end of group */
- /* end of gnunet_hello_lib.h */
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