/*
This file is part of GNUnet
- (C) 2009, 2010 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009-2014 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
*/
/**
- * @file transport/gnunet_transport_plugin.h
+ * @file include/gnunet_transport_plugin.h
* @brief API for the transport services. This header
* specifies the struct that is given to the plugin's entry
* method and the other struct that must be returned.
#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
* 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 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 Session;
-/**
- * Every 'struct Session' must begin with this header.
- */
-struct SessionHeader
-{
-
- /**
- * Cached signature for PONG generation for the session. Do not use
- * in the plugin!
- */
- struct GNUNET_CRYPTO_RsaSignature pong_signature;
-
- /**
- * Expiration time for signature. Do not use in the plugin!
- */
- struct GNUNET_TIME_Absolute pong_sig_expires;
-
-};
/**
* 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.
- *
+ * 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 destoyed
+ * @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 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_SessionEnd) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- struct Session *session);
+typedef void
+(*GNUNET_TRANSPORT_SessionStart) (void *cls,
+ const struct GNUNET_HELLO_Address *address,
+ struct Session *session,
+ enum GNUNET_ATS_Network_Type net);
/**
* @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 -- FIXME!
- * @param distance in overlay hops; use 1 unless DV (or 0 if message == NULL)
+ * 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")
* 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 sender_address
- * @return how long the plugin should wait until receiving more data
- * (plugins that do not support this, can ignore the return value)
+ * @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 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 struct GNUNET_TIME_Relative (*GNUNET_TRANSPORT_PluginReceiveCallback) (void *cls,
- const struct
- GNUNET_PeerIdentity *
- peer,
- const struct
- GNUNET_MessageHeader *
- message,
- const struct GNUNET_TRANSPORT_ATS_Information *ats,
- uint32_t ats_count,
- struct Session *session,
- const char *sender_address,
- uint16_t sender_address_len);
+typedef enum GNUNET_ATS_Network_Type
+(*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);
/**
* is aware that it might be reachable under.
*
* @param cls closure
- * @param name 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 address
- * @param expires when should this address automatically expire?
+ * @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,
- const char *name,
- const void *addr,
- uint16_t addrlen,
- struct
- GNUNET_TIME_Relative
- expires);
+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
* @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)
+ * (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);
+typedef struct GNUNET_TIME_Relative
+(*GNUNET_TRANSPORT_TrafficReport) (void *cls,
+ const struct GNUNET_PeerIdentity *peer,
+ size_t amount_recved);
+
/**
- * Function called whenever the plugin has to notify ATS about costs for using this transport
- *
- * The cost will be passed as struct GNUNET_TRANSPORT_ATS_Cost_Information[]
- * This array is 0-terminated, so the last element will be a pair:
- * ((cost->cost_type==GNUNET_TRANSPORT_ATS_ARRAY_TERMINATOR) && cost->cost_value==0))
+ * Function that returns a HELLO message.
*
- * @param cls closure
- * @param peer peer
- * @param addr peer address
- * @param addrlen address length
- * @param cost pointer to the first element of struct GNUNET_TRANSPORT_ATS_Cost_Information[]
+ * @return HELLO message (FIXME with what?)
*/
-typedef void (*GNUNET_TRANSPORT_CostReport) (void *cls,
- const struct GNUNET_PeerIdentity *peer,
- const void *addr,
- uint16_t addrlen,
- struct GNUNET_TRANSPORT_ATS_Information * cost);
+typedef const struct GNUNET_MessageHeader *
+(*GNUNET_TRANSPORT_GetHelloCallback) (void);
+
/**
* The transport service will pass a pointer to a struct
*/
const struct GNUNET_PeerIdentity *my_identity;
- /**
- * Pointer (!) to our HELLO message. Note that the address
- * referred to "*our_hello" might change over time.
- */
- struct GNUNET_HELLO_Message *const*our_hello;
-
/**
* Closure for the various callbacks.
*/
/**
* Function that should be called by the transport plugin
- * whenever a message is received.
+ * 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
*/
GNUNET_TRANSPORT_AddressNotification notify_address;
- /**
- * Inform service about traffic received, get information
- * about when we might be willing to receive more.
- */
- GNUNET_TRANSPORT_TrafficReport traffic_report;
-
/**
* Function that must be called by the plugin when a non-NULL
* session handle stops being valid (is destroyed).
GNUNET_TRANSPORT_SessionEnd session_end;
/**
- * Inform service about costs for using this transport plugin
+ * Function called by the plugin when a new (incoming) session was created
+ * not explicitly created using the the get_session function
*/
- GNUNET_TRANSPORT_CostReport cost_report;
+ 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
/**
- * Function called by the GNUNET_TRANSPORT_TransmitFunction
- * upon "completion".
+ * 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;
+ * @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);
+(*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
* a fresh connection to another peer.
*
* @param cls closure
- * @param target who should receive this message
+ * @param session which session must be used
* @param msgbuf the message to transmit
- * @param msgbuf_size number of bytes in 'msgbuf'
+ * @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 timeout how long to wait at most for the transmission (does not
+ * @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 session which session must be used (or NULL for "any")
- * @param addr the address to use (can be NULL if the plugin
- * is "on its own" (i.e. re-use existing TCP connection))
- * @param addrlen length of the address in bytes
- * @param force_address GNUNET_YES if the plugin MUST use the given address,
- * GNUNET_NO means the plugin may use any other address and
- * GNUNET_SYSERR means that only reliable existing
- * bi-directional connections should be used (regardless
- * of address)
* @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 cont
+ * @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,
- const struct GNUNET_PeerIdentity *
- target,
- const char *msgbuf,
- size_t msgbuf_size,
- uint32_t priority,
- struct GNUNET_TIME_Relative timeout,
- struct Session *session,
- const void *addr,
- size_t addrlen,
- int force_address,
- GNUNET_TRANSPORT_TransmitContinuation
- cont, void *cont_cls);
+(*GNUNET_TRANSPORT_TransmitFunction) (void *cls,
+ struct 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 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);
/**
* to close the connection (if applicable) and no longer call the
* transmit continuation(s).
*
- * Finally, plugin MUST NOT call the services's receive function to
- * notify the service that the connection to the specified target was
- * closed after a getting this call.
- *
* @param cls closure
* @param target peer for which the last transmission is
* to be cancelled
*/
typedef void
- (*GNUNET_TRANSPORT_DisconnectFunction) (void *cls,
- const struct GNUNET_PeerIdentity *
- target);
+(*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.
+ * 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 hostname one of the names for the host, NULL
- * on the last call to the callback
+ * @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);
+typedef void
+(*GNUNET_TRANSPORT_AddressStringCallback) (void *cls,
+ const char *address,
+ int res);
/**
* format.
*
* @param cls closure
- * @param name name of the transport that generated the address
+ * @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 address
+ * @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 asc
+ * @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);
+(*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);
/**
* and not some potential man-in-the-middle).
*
* @param addr pointer to the address
- * @param addrlen length of addr
- * @return GNUNET_OK if this is a plausible address for this peer
- * and transport, GNUNET_SYSERR if not
+ * @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);
+ 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 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 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 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
+ * 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 address
- * @return string representing the same 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_ATS_Network_Type
+(*GNUNET_TRANSPORT_GetNetworkType) (void *cls,
+ struct Session *session);
+
+
+/**
+ * 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 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 const char* (*GNUNET_TRANSPORT_AddressToString) (void *cls,
- const void *addr,
- size_t addrlen);
+typedef void
+(*GNUNET_TRANSPORT_SessionMonitorSetup) (void *cls,
+ GNUNET_TRANSPORT_SessionInfoCallback sic,
+ void *sic_cls);
/**
/**
* Function that can be used to force the plugin to disconnect from
* the given peer and cancel all previous transmissions (and their
- * continuations). Note that if the transport does not have
- * sessions / persistent connections (for example, UDP), this
- * function may very well do nothing.
+ * 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_DisconnectFunction disconnect;
+ GNUNET_TRANSPORT_UpdateSessionTimeout update_session_timeout;
/**
- * Function to pretty-print addresses. NOTE: this function is not
- * yet used by transport-service, but will be used in the future
- * once the transport-API has been completed.
+ * 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;
*/
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 monitor the sessions managed by the plugin.
+ */
+ GNUNET_TRANSPORT_SessionMonitorSetup setup_monitor;
};
+/*#ifndef PLUGIN_TRANSPORT_H*/
#endif
+/* end of gnunet_transport_plugin.h */
projects / oweals / gnunet.git / blobdiff