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- /*
- This file is part of GNUnet
- Copyright (C) 2009-2014 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
- * Transport service plugin API
- *
- * @defgroup transport-plugin Transport Service plugin API
- *
- * Specifies the struct that is given to the plugin's entry method and the other
- * struct that must be returned. Note that the destructors of transport plugins
- * will be given the value returned by the constructor and is expected to return
- * a NULL pointer.
- *
- * @{
- */
- #ifndef PLUGIN_TRANSPORT_H
- #define PLUGIN_TRANSPORT_H
- #include "gnunet_configuration_lib.h"
- #include "gnunet_scheduler_lib.h"
- #include "gnunet_statistics_service.h"
- #include "gnunet_transport_service.h"
- #include "gnunet_ats_service.h"
- #define TRANSPORT_SESSION_INBOUND_STRING "<inbound>"
- /**
- * Opaque pointer that plugins can use to distinguish specific
- * connections to a given peer. Typically used by stateful plugins to
- * allow the service to refer to specific streams instead of a more
- * general notion of "some connection" to the given peer. This is
- * useful since sometimes (i.e. for inbound TCP connections) a
- * connection may not have an address that can be used for meaningful
- * distinction between sessions to the same peer.
- *
- * Each 'struct GNUNET_ATS_Session' MUST start with the 'struct GNUNET_PeerIdentity'
- * of the peer the session is for (which will be used for some error
- * checking by the ATS code).
- */
- struct GNUNET_ATS_Session;
- /**
- * Function that will be called whenever the plugin internally
- * cleans up a session pointer and hence the service needs to
- * discard all of those sessions as well. Plugins that do not
- * use sessions can simply omit calling this function and always
- * use NULL wherever a session pointer is needed. This function
- * should be called BEFORE a potential "TransmitContinuation"
- * from the "TransmitFunction".
- *
- * @param cls closure
- * @param peer which peer was the session for
- * @param session which session is being destroyed
- */
- typedef void
- (*GNUNET_TRANSPORT_SessionEnd) (void *cls,
- const struct GNUNET_HELLO_Address *address,
- struct GNUNET_ATS_Session *session);
- /**
- * Plugin tells transport service about a new inbound session
- *
- * @param cls unused
- * @param address the address
- * @param session the new session
- * @param net network information
- */
- typedef void
- (*GNUNET_TRANSPORT_SessionStart) (void *cls,
- const struct GNUNET_HELLO_Address *address,
- struct GNUNET_ATS_Session *session,
- enum GNUNET_NetworkType net);
- /**
- * Function called by the transport for each received message.
- * This function should also be called with "NULL" for the
- * message to signal that the other peer disconnected.
- *
- * @param cls closure
- * @param peer (claimed) identity of the other peer
- * @param message the message, NULL if we only care about
- * learning about the delay until we should receive again
- * @param session identifier used for this session (NULL for plugins
- * that do not offer bi-directional communication to the sender
- * using the same "connection")
- * @param sender_address binary address of the sender (if we established the
- * connection or are otherwise sure of it; should be NULL
- * for inbound TCP/UDP connections since it it not clear
- * that we could establish ourselves a connection to that
- * IP address and get the same system)
- * @param sender_address_len number of bytes in @a sender_address
- * @return how long the plugin should wait until receiving more data;
- * returning #GNUNET_TIME_UNIT_FOREVER_REL means that the
- * connection should be closed
- */
- typedef struct GNUNET_TIME_Relative
- (*GNUNET_TRANSPORT_PluginReceiveCallback) (void *cls,
- const struct
- GNUNET_HELLO_Address *address,
- struct GNUNET_ATS_Session *session,
- const struct
- GNUNET_MessageHeader *message);
- /**
- * Function that can be called by plugins to figure if an address is
- * an loopback, LAN or WAN address. Ultimately invokes
- * #GNUNET_ATS_address_get_type().
- *
- * @param cls closure
- * @param addr binary address
- * @param addrlen length of the @a addr
- * @return type of the network the address belongs to
- */
- typedef enum GNUNET_NetworkType
- (*GNUNET_TRANSPORT_AddressToType)(void *cls,
- const struct sockaddr *addr,
- size_t addrlen);
- /**
- * Function called when distance of an address changes.
- *
- * @param cls closure
- * @param peer peer
- * @param distance new distance
- */
- typedef void
- (*GNUNET_TRANSPORT_UpdateAddressDistance) (void *cls,
- const struct
- GNUNET_HELLO_Address *address,
- uint32_t distance);
- /**
- * Function that will be called for each address the transport
- * is aware that it might be reachable under.
- *
- * @param cls closure
- * @param add_remove should the address added (#GNUNET_YES) or removed (#GNUNET_NO) from the
- * set of valid addresses?
- * @param address the address to add or remove
- */
- typedef void
- (*GNUNET_TRANSPORT_AddressNotification) (void *cls,
- int add_remove,
- const struct
- GNUNET_HELLO_Address *address);
- /**
- * Function that will be called whenever the plugin receives data over
- * the network and wants to determine how long it should wait until
- * the next time it reads from the given peer. Note that some plugins
- * (such as UDP) may not be able to wait (for a particular peer), so
- * the waiting part is optional. Plugins that can wait should call
- * this function, sleep the given amount of time, and call it again
- * (with zero bytes read) UNTIL it returns zero and only then read.
- *
- * @param cls closure
- * @param peer which peer did we read data from
- * @param amount_recved number of bytes read (can be zero)
- * @return how long to wait until reading more from this peer
- * (to enforce inbound quotas); returning #GNUNET_TIME_UNIT_FOREVER_REL
- * means that the connection should be closed
- */
- typedef struct GNUNET_TIME_Relative
- (*GNUNET_TRANSPORT_TrafficReport) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- size_t amount_recved);
- /**
- * Function that returns a HELLO message.
- *
- * @return HELLO message (FIXME with what?)
- */
- typedef const struct GNUNET_MessageHeader *
- (*GNUNET_TRANSPORT_GetHelloCallback) (void);
- /**
- * The transport service will pass a pointer to a struct
- * of this type as the first and only argument to the
- * entry point of each transport plugin.
- */
- struct GNUNET_TRANSPORT_PluginEnvironment
- {
- /**
- * Configuration to use.
- */
- const struct GNUNET_CONFIGURATION_Handle *cfg;
- /**
- * Identity of this peer.
- */
- const struct GNUNET_PeerIdentity *my_identity;
- /**
- * Closure for the various callbacks.
- */
- void *cls;
- /**
- * Handle for reporting statistics.
- */
- struct GNUNET_STATISTICS_Handle *stats;
- /**
- * Function that should be called by the transport plugin
- * whenever a message is received. If this field is "NULL",
- * the plugin should load in 'stub' mode and NOT fully
- * initialize and instead only return an API with the
- * @e address_pretty_printer, @e address_to_string and
- * @e string_to_address functions.
- */
- GNUNET_TRANSPORT_PluginReceiveCallback receive;
- /**
- * Function that returns our HELLO.
- */
- GNUNET_TRANSPORT_GetHelloCallback get_our_hello;
- /**
- * Function that must be called by each plugin to notify the
- * transport service about the addresses under which the transport
- * provided by the plugin can be reached.
- */
- GNUNET_TRANSPORT_AddressNotification notify_address;
- /**
- * Function that must be called by the plugin when a non-NULL
- * session handle stops being valid (is destroyed).
- */
- GNUNET_TRANSPORT_SessionEnd session_end;
- /**
- * Function called by the plugin when a new (incoming) session was created
- * not explicitly created using the the get_session function
- */
- GNUNET_TRANSPORT_SessionStart session_start;
- /**
- * Function that will be called to figure if an address is an loopback,
- * LAN, WAN etc. address
- */
- GNUNET_TRANSPORT_AddressToType get_address_type;
- /**
- * Function that will be called by DV to update distance for
- * an address.
- */
- GNUNET_TRANSPORT_UpdateAddressDistance update_address_distance;
- /**
- * What is the maximum number of connections that this transport
- * should allow? Transports that do not have sessions (such as
- * UDP) can ignore this value.
- */
- uint32_t max_connections;
- };
- /**
- * Function called by the #GNUNET_TRANSPORT_TransmitFunction
- * upon "completion". In the case that a peer disconnects,
- * this function must be called for each pending request
- * (with a 'failure' indication) AFTER notifying the service
- * about the disconnect event (so that the service won't try
- * to transmit more messages, believing the connection still
- * exists...).
- *
- * @param cls closure
- * @param target who was the recipient of the message?
- * @param result #GNUNET_OK on success
- * #GNUNET_SYSERR if the target disconnected;
- * disconnect will ALSO be signalled using
- * the ReceiveCallback.
- * @param size_payload bytes of payload from transport service in message
- * @param size_on_wire bytes required on wire for transmission,
- * 0 if result == #GNUNET_SYSERR
- */
- typedef void
- (*GNUNET_TRANSPORT_TransmitContinuation) (void *cls,
- const struct
- GNUNET_PeerIdentity *target,
- int result,
- size_t size_payload,
- size_t size_on_wire);
- /**
- * The new send function with just the session and no address
- *
- * Function that can be used by the transport service to transmit
- * a message using the plugin. Note that in the case of a
- * peer disconnecting, the continuation MUST be called
- * prior to the disconnect notification itself. This function
- * will be called with this peer's HELLO message to initiate
- * a fresh connection to another peer.
- *
- * @param cls closure
- * @param session which session must be used
- * @param msgbuf the message to transmit
- * @param msgbuf_size number of bytes in @a msgbuf
- * @param priority how important is the message (most plugins will
- * ignore message priority and just FIFO)
- * @param to how long to wait at most for the transmission (does not
- * require plugins to discard the message after the timeout,
- * just advisory for the desired delay; most plugins will ignore
- * this as well)
- * @param cont continuation to call once the message has
- * been transmitted (or if the transport is ready
- * for the next transmission call; or if the
- * peer disconnected...); can be NULL
- * @param cont_cls closure for @a cont
- * @return number of bytes used (on the physical network, with overheads);
- * -1 on hard errors (i.e. address invalid); 0 is a legal value
- * and does NOT mean that the message was not transmitted (DV)
- */
- typedef ssize_t
- (*GNUNET_TRANSPORT_TransmitFunction) (void *cls,
- struct GNUNET_ATS_Session *session,
- const char *msgbuf,
- size_t msgbuf_size,
- unsigned int priority,
- struct GNUNET_TIME_Relative to,
- GNUNET_TRANSPORT_TransmitContinuation cont,
- void *cont_cls);
- /**
- * Function that can be called to force a disconnect from the
- * specified neighbour for the given session only. . This should
- * also cancel all previously scheduled transmissions for this
- * session. Obviously the transmission may have been partially
- * completed already, which is OK. The plugin is supposed to close
- * the connection (if applicable).
- *
- * @param cls closure with the `struct Plugin`
- * @param session session to destroy
- * @return #GNUNET_OK on success
- */
- typedef int
- (*GNUNET_TRANSPORT_DisconnectSessionFunction) (void *cls,
- struct GNUNET_ATS_Session *
- session);
- /**
- * Function that is called to get the keepalive factor.
- * #GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to
- * calculate the interval between keepalive packets.
- *
- * @param cls closure with the `struct Plugin`
- * @return keepalive factor
- */
- typedef unsigned int
- (*GNUNET_TRANSPORT_QueryKeepaliveFactorFunction) (void *cls);
- /**
- * Function that can be called to force a disconnect from the
- * specified neighbour. This should also cancel all previously
- * scheduled transmissions. Obviously the transmission may have been
- * partially completed already, which is OK. The plugin is supposed
- * to close the connection (if applicable) and no longer call the
- * transmit continuation(s).
- *
- * @param cls closure
- * @param target peer for which the last transmission is
- * to be cancelled
- */
- typedef void
- (*GNUNET_TRANSPORT_DisconnectPeerFunction) (void *cls,
- const struct
- GNUNET_PeerIdentity *target);
- /**
- * Function called by the pretty printer for the resolved address for
- * each human-readable address obtained. The callback can be called
- * several times. The last invocation must be with a @a address of
- * NULL and a @a res of #GNUNET_OK. Thus, to indicate conversion
- * errors, the callback might be called first with @a address NULL and
- * @a res being #GNUNET_SYSERR. In that case, there must still be a
- * subsequent call later with @a address NULL and @a res #GNUNET_OK.
- *
- * @param cls closure
- * @param address one of the names for the host, NULL on last callback
- * @param res #GNUNET_OK if conversion was successful, #GNUNET_SYSERR on failure,
- * #GNUNET_OK on last callback
- */
- typedef void
- (*GNUNET_TRANSPORT_AddressStringCallback) (void *cls,
- const char *address,
- int res);
- /**
- * Convert the transports address to a nice, human-readable
- * format.
- *
- * @param cls closure
- * @param type name of the transport that generated the address
- * @param addr one of the addresses of the host, NULL for the last address
- * the specific address format depends on the transport
- * @param addrlen length of the @a addr
- * @param numeric should (IP) addresses be displayed in numeric form?
- * @param timeout after how long should we give up?
- * @param asc function to call on each string
- * @param asc_cls closure for @a asc
- */
- typedef void
- (*GNUNET_TRANSPORT_AddressPrettyPrinter) (void *cls,
- const char *type,
- const void *addr,
- size_t addrlen,
- int numeric,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_TRANSPORT_AddressStringCallback
- asc,
- void *asc_cls);
- /**
- * Another peer has suggested an address for this peer and transport
- * plugin. Check that this could be a valid address. This function
- * is not expected to 'validate' the address in the sense of trying to
- * connect to it but simply to see if the binary format is technically
- * legal for establishing a connection to this peer (and make sure that
- * the address really corresponds to our network connection/settings
- * and not some potential man-in-the-middle).
- *
- * @param addr pointer to the address
- * @param addrlen length of @a addr
- * @return #GNUNET_OK if this is a plausible address for this peer
- * and transport, #GNUNET_SYSERR if not
- */
- typedef int
- (*GNUNET_TRANSPORT_CheckAddress) (void *cls,
- const void *addr,
- size_t addrlen);
- /**
- * Create a new session to transmit data to the target
- * This session will used to send data to this peer and the plugin will
- * notify us by calling the env->session_end function
- *
- * @param cls the plugin
- * @param address the hello address
- * @return the session if the address is valid, NULL otherwise
- */
- typedef struct GNUNET_ATS_Session *
- (*GNUNET_TRANSPORT_CreateSession) (void *cls,
- const struct GNUNET_HELLO_Address *address);
- /**
- * Function that will be called whenever the transport service wants to
- * notify the plugin that a session is still active and in use and
- * therefore the session timeout for this session has to be updated
- *
- * @param cls closure
- * @param peer which peer was the session for
- * @param session which session is being updated
- */
- typedef void
- (*GNUNET_TRANSPORT_UpdateSessionTimeout) (void *cls,
- const struct
- GNUNET_PeerIdentity *peer,
- struct GNUNET_ATS_Session *session);
- /**
- * Function that will be called whenever the transport service wants to
- * notify the plugin that the inbound quota changed and that the plugin
- * should update it's delay for the next receive value
- *
- * @param cls closure
- * @param peer which peer was the session for
- * @param session which session is being updated
- * @param delay new delay to use for receiving
- */
- typedef void
- (*GNUNET_TRANSPORT_UpdateInboundDelay) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- struct GNUNET_ATS_Session *session,
- struct GNUNET_TIME_Relative delay);
- /**
- * Function called for a quick conversion of the binary address to
- * a numeric address. Note that the caller must not free the
- * address and that the next call to this function is allowed
- * to override the address again.
- *
- * @param cls closure
- * @param addr binary address
- * @param addr_len length of the @a addr
- * @return string representing the same address
- */
- typedef const char *
- (*GNUNET_TRANSPORT_AddressToString) (void *cls,
- const void *addr,
- size_t addrlen);
- /**
- * Function called to convert a string address to
- * a binary address.
- *
- * @param cls closure (`struct Plugin*`)
- * @param addr string address
- * @param addrlen length of the @a addr including \0 termination
- * @param buf location to store the buffer
- * If the function returns #GNUNET_SYSERR, its contents are undefined.
- * @param added length of created address
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
- */
- typedef int
- (*GNUNET_TRANSPORT_StringToAddress) (void *cls,
- const char *addr,
- uint16_t addrlen,
- void **buf,
- size_t *added);
- /**
- * Function to obtain the network type for a session
- *
- * @param cls closure (`struct Plugin *`)
- * @param session the session
- * @return the network type
- */
- typedef enum GNUNET_NetworkType
- (*GNUNET_TRANSPORT_GetNetworkType)(void *cls,
- struct GNUNET_ATS_Session *session);
- /**
- * Function to obtain the network type for an address.
- *
- * @param cls closure (`struct Plugin *`)
- * @param address the address
- * @return the network type
- */
- typedef enum GNUNET_NetworkType
- (*GNUNET_TRANSPORT_GetNetworkTypeForAddress)(void *cls,
- const struct
- GNUNET_HELLO_Address *address);
- /**
- * Function called by the plugin with information about the
- * current sessions managed by the plugin (for monitoring).
- *
- * @param cls closure
- * @param session session handle this information is about,
- * NULL to indicate that we are "in sync" (initial
- * iteration complete)
- * @param info information about the state of the session,
- * NULL if @a session is also NULL and we are
- * merely signalling that the initial iteration is over
- */
- typedef void
- (*GNUNET_TRANSPORT_SessionInfoCallback) (void *cls,
- struct GNUNET_ATS_Session *session,
- const struct
- GNUNET_TRANSPORT_SessionInfo *info);
- /**
- * Begin monitoring sessions of a plugin. There can only
- * be one active monitor per plugin (i.e. if there are
- * multiple monitors, the transport service needs to
- * multiplex the generated events over all of them).
- *
- * @param cls closure of the plugin
- * @param sic callback to invoke, NULL to disable monitor;
- * plugin will being by iterating over all active
- * sessions immediately and then enter monitor mode
- * @param sic_cls closure for @a sic
- */
- typedef void
- (*GNUNET_TRANSPORT_SessionMonitorSetup) (void *cls,
- GNUNET_TRANSPORT_SessionInfoCallback
- sic,
- void *sic_cls);
- /**
- * Each plugin is required to return a pointer to a struct of this
- * type as the return value from its entry point.
- */
- struct GNUNET_TRANSPORT_PluginFunctions
- {
- /**
- * Closure for all of the callbacks.
- */
- void *cls;
- /**
- * Function that the transport service will use to transmit data to
- * another peer. May be NULL for plugins that only support
- * receiving data. After this call, the plugin call the specified
- * continuation with success or error before notifying us about the
- * target having disconnected.
- */
- GNUNET_TRANSPORT_TransmitFunction send;
- /**
- * Function that can be used to force the plugin to disconnect from
- * the given peer and cancel all previous transmissions (and their
- * continuations).
- */
- GNUNET_TRANSPORT_DisconnectPeerFunction disconnect_peer;
- /**
- * Function that can be used to force the plugin to disconnect from
- * the given peer and cancel all previous transmissions (and their
- * continuations).
- */
- GNUNET_TRANSPORT_DisconnectSessionFunction disconnect_session;
- /**
- * Function that will be called whenever the transport service wants to
- * notify the plugin that a session is still active and in use and
- * therefore the session timeout for this session has to be updated
- */
- GNUNET_TRANSPORT_UpdateSessionTimeout update_session_timeout;
- /**
- * Function that will be called whenever the transport service wants to
- * notify the plugin that the inbound quota changed and that the plugin
- * should update it's delay for the next receive value
- */
- GNUNET_TRANSPORT_UpdateInboundDelay update_inbound_delay;
- /**
- * Function that is used to query keepalive factor.
- * #GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to
- * calculate the interval between keepalive packets.
- */
- GNUNET_TRANSPORT_QueryKeepaliveFactorFunction query_keepalive_factor;
- /**
- * Function to pretty-print addresses.
- */
- GNUNET_TRANSPORT_AddressPrettyPrinter address_pretty_printer;
- /**
- * Function that will be called to check if a binary address
- * for this plugin is well-formed and corresponds to an
- * address for THIS peer (as per our configuration). Naturally,
- * if absolutely necessary, plugins can be a bit conservative in
- * their answer, but in general plugins should make sure that the
- * address does not redirect traffic to a 3rd party that might
- * try to man-in-the-middle our traffic.
- */
- GNUNET_TRANSPORT_CheckAddress check_address;
- /**
- * Function that will be called to convert a binary address
- * to a string (numeric conversion only).
- */
- GNUNET_TRANSPORT_AddressToString address_to_string;
- /**
- * Function that will be called to convert a string address
- * to binary (numeric conversion only).
- */
- GNUNET_TRANSPORT_StringToAddress string_to_address;
- /**
- * Function that will be called tell the plugin to create a session
- * object.
- */
- GNUNET_TRANSPORT_CreateSession get_session;
- /**
- * Function to obtain the network type for a session
- */
- GNUNET_TRANSPORT_GetNetworkType get_network;
- /**
- * Function to obtain the network type for an address
- */
- GNUNET_TRANSPORT_GetNetworkTypeForAddress get_network_for_address;
- /**
- * Function to monitor the sessions managed by the plugin.
- */
- GNUNET_TRANSPORT_SessionMonitorSetup setup_monitor;
- };
- /*#ifndef PLUGIN_TRANSPORT_H*/
- #endif
- /** @} */ /* end of group */
- /* end of gnunet_transport_plugin.h */
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