+++ /dev/null
-/*
- * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>
- * Copyright (c) 2007-2010 Niels Provos and Nick Mathewson
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- * derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-#ifndef _EVENT2_RPC_H_
-#define _EVENT2_RPC_H_
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/** @file rpc.h
- *
- * This header files provides basic support for an RPC server and client.
- *
- * To support RPCs in a server, every supported RPC command needs to be
- * defined and registered.
- *
- * EVRPC_HEADER(SendCommand, Request, Reply);
- *
- * SendCommand is the name of the RPC command.
- * Request is the name of a structure generated by event_rpcgen.py.
- * It contains all parameters relating to the SendCommand RPC. The
- * server needs to fill in the Reply structure.
- * Reply is the name of a structure generated by event_rpcgen.py. It
- * contains the answer to the RPC.
- *
- * To register an RPC with an HTTP server, you need to first create an RPC
- * base with:
- *
- * struct evrpc_base *base = evrpc_init(http);
- *
- * A specific RPC can then be registered with
- *
- * EVRPC_REGISTER(base, SendCommand, Request, Reply, FunctionCB, arg);
- *
- * when the server receives an appropriately formatted RPC, the user callback
- * is invoked. The callback needs to fill in the reply structure.
- *
- * void FunctionCB(EVRPC_STRUCT(SendCommand)* rpc, void *arg);
- *
- * To send the reply, call EVRPC_REQUEST_DONE(rpc);
- *
- * See the regression test for an example.
- */
-
-/**
- Determines if the member has been set in the message
-
- @param msg the message to inspect
- @param member the member variable to test for presences
- @return 1 if it's present or 0 otherwise.
-*/
-#define EVTAG_HAS(msg, member) \
- ((msg)->member##_set == 1)
-
-#ifndef _EVENT2_RPC_COMPAT_H_
-
-/**
- Assigns a value to the member in the message.
-
- @param msg the message to which to assign a value
- @param member the name of the member variable
- @param value the value to assign
-*/
-#define EVTAG_ASSIGN(msg, member, value) \
- (*(msg)->base->member##_assign)((msg), (value))
-/**
- Assigns a value to the member in the message.
-
- @param msg the message to which to assign a value
- @param member the name of the member variable
- @param value the value to assign
- @param len the length of the value
-*/
-#define EVTAG_ASSIGN_WITH_LEN(msg, member, value, len) \
- (*(msg)->base->member##_assign)((msg), (value), (len))
-/**
- Returns the value for a member.
-
- @param msg the message from which to get the value
- @param member the name of the member variable
- @param pvalue a pointer to the variable to hold the value
- @return 0 on success, -1 otherwise.
-*/
-#define EVTAG_GET(msg, member, pvalue) \
- (*(msg)->base->member##_get)((msg), (pvalue))
-/**
- Returns the value for a member.
-
- @param msg the message from which to get the value
- @param member the name of the member variable
- @param pvalue a pointer to the variable to hold the value
- @param plen a pointer to the length of the value
- @return 0 on success, -1 otherwise.
-*/
-#define EVTAG_GET_WITH_LEN(msg, member, pvalue, plen) \
- (*(msg)->base->member##_get)((msg), (pvalue), (plen))
-
-#endif /* _EVENT2_RPC_COMPAT_H_ */
-
-/**
- Adds a value to an array.
-*/
-#define EVTAG_ARRAY_ADD_VALUE(msg, member, value) \
- (*(msg)->base->member##_add)((msg), (value))
-/**
- Allocates a new entry in the array and returns it.
-*/
-#define EVTAG_ARRAY_ADD(msg, member) \
- (*(msg)->base->member##_add)(msg)
-/**
- Gets a variable at the specified offset from the array.
-*/
-#define EVTAG_ARRAY_GET(msg, member, offset, pvalue) \
- (*(msg)->base->member##_get)((msg), (offset), (pvalue))
-/**
- Returns the number of entries in the array.
-*/
-#define EVTAG_ARRAY_LEN(msg, member) ((msg)->member##_length)
-
-
-struct evbuffer;
-struct event_base;
-struct evrpc_req_generic;
-struct evrpc_request_wrapper;
-struct evrpc;
-
-/** The type of a specific RPC Message
- *
- * @param rpcname the name of the RPC message
- */
-#define EVRPC_STRUCT(rpcname) struct evrpc_req__##rpcname
-
-struct evhttp_request;
-struct evrpc_status;
-struct evrpc_hook_meta;
-
-/** Creates the definitions and prototypes for an RPC
- *
- * You need to use EVRPC_HEADER to create structures and function prototypes
- * needed by the server and client implementation. The structures have to be
- * defined in an .rpc file and converted to source code via event_rpcgen.py
- *
- * @param rpcname the name of the RPC
- * @param reqstruct the name of the RPC request structure
- * @param replystruct the name of the RPC reply structure
- * @see EVRPC_GENERATE()
- */
-#define EVRPC_HEADER(rpcname, reqstruct, rplystruct) \
-EVRPC_STRUCT(rpcname) { \
- struct evrpc_hook_meta *hook_meta; \
- struct reqstruct* request; \
- struct rplystruct* reply; \
- struct evrpc* rpc; \
- struct evhttp_request* http_req; \
- struct evbuffer* rpc_data; \
-}; \
-int evrpc_send_request_##rpcname(struct evrpc_pool *, \
- struct reqstruct *, struct rplystruct *, \
- void (*)(struct evrpc_status *, \
- struct reqstruct *, struct rplystruct *, void *cbarg), \
- void *);
-
-struct evrpc_pool;
-
-/** use EVRPC_GENERATE instead */
-struct evrpc_request_wrapper *evrpc_make_request_ctx(
- struct evrpc_pool *pool, void *request, void *reply,
- const char *rpcname,
- void (*req_marshal)(struct evbuffer*, void *),
- void (*rpl_clear)(void *),
- int (*rpl_unmarshal)(void *, struct evbuffer *),
- void (*cb)(struct evrpc_status *, void *, void *, void *),
- void *cbarg);
-
-/** Creates a context structure that contains rpc specific information.
- *
- * EVRPC_MAKE_CTX is used to populate a RPC specific context that
- * contains information about marshaling the RPC data types.
- *
- * @param rpcname the name of the RPC
- * @param reqstruct the name of the RPC request structure
- * @param replystruct the name of the RPC reply structure
- * @param pool the evrpc_pool over which to make the request
- * @param request a pointer to the RPC request structure object
- * @param reply a pointer to the RPC reply structure object
- * @param cb the callback function to call when the RPC has completed
- * @param cbarg the argument to supply to the callback
- */
-#define EVRPC_MAKE_CTX(rpcname, reqstruct, rplystruct, \
- pool, request, reply, cb, cbarg) \
- evrpc_make_request_ctx(pool, request, reply, \
- #rpcname, \
- (void (*)(struct evbuffer *, void *))reqstruct##_marshal, \
- (void (*)(void *))rplystruct##_clear, \
- (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal, \
- (void (*)(struct evrpc_status *, void *, void *, void *))cb, \
- cbarg)
-
-/** Generates the code for receiving and sending an RPC message
- *
- * EVRPC_GENERATE is used to create the code corresponding to sending
- * and receiving a particular RPC message
- *
- * @param rpcname the name of the RPC
- * @param reqstruct the name of the RPC request structure
- * @param replystruct the name of the RPC reply structure
- * @see EVRPC_HEADER()
- */
-#define EVRPC_GENERATE(rpcname, reqstruct, rplystruct) \
- int evrpc_send_request_##rpcname(struct evrpc_pool *pool, \
- struct reqstruct *request, struct rplystruct *reply, \
- void (*cb)(struct evrpc_status *, \
- struct reqstruct *, struct rplystruct *, void *cbarg), \
- void *cbarg) { \
- return evrpc_send_request_generic(pool, request, reply, \
- (void (*)(struct evrpc_status *, void *, void *, void *))cb, \
- cbarg, \
- #rpcname, \
- (void (*)(struct evbuffer *, void *))reqstruct##_marshal, \
- (void (*)(void *))rplystruct##_clear, \
- (int (*)(void *, struct evbuffer *))rplystruct##_unmarshal); \
-}
-
-/** Provides access to the HTTP request object underlying an RPC
- *
- * Access to the underlying http object; can be used to look at headers or
- * for getting the remote ip address
- *
- * @param rpc_req the rpc request structure provided to the server callback
- * @return an struct evhttp_request object that can be inspected for
- * HTTP headers or sender information.
- */
-#define EVRPC_REQUEST_HTTP(rpc_req) (rpc_req)->http_req
-
-/** completes the server response to an rpc request */
-void evrpc_request_done(struct evrpc_req_generic *req);
-
-/** accessors for request and reply */
-void *evrpc_get_request(struct evrpc_req_generic *req);
-void *evrpc_get_reply(struct evrpc_req_generic *req);
-
-/** Creates the reply to an RPC request
- *
- * EVRPC_REQUEST_DONE is used to answer a request; the reply is expected
- * to have been filled in. The request and reply pointers become invalid
- * after this call has finished.
- *
- * @param rpc_req the rpc request structure provided to the server callback
- */
-#define EVRPC_REQUEST_DONE(rpc_req) do { \
- struct evrpc_req_generic *_req = (struct evrpc_req_generic *)(rpc_req); \
- evrpc_request_done(_req); \
-} while (0)
-
-
-struct evrpc_base;
-struct evhttp;
-
-/* functions to start up the rpc system */
-
-/** Creates a new rpc base from which RPC requests can be received
- *
- * @param server a pointer to an existing HTTP server
- * @return a newly allocated evrpc_base struct
- * @see evrpc_free()
- */
-struct evrpc_base *evrpc_init(struct evhttp *server);
-
-/**
- * Frees the evrpc base
- *
- * For now, you are responsible for making sure that no rpcs are ongoing.
- *
- * @param base the evrpc_base object to be freed
- * @see evrpc_init
- */
-void evrpc_free(struct evrpc_base *base);
-
-/** register RPCs with the HTTP Server
- *
- * registers a new RPC with the HTTP server, each RPC needs to have
- * a unique name under which it can be identified.
- *
- * @param base the evrpc_base structure in which the RPC should be
- * registered.
- * @param name the name of the RPC
- * @param request the name of the RPC request structure
- * @param reply the name of the RPC reply structure
- * @param callback the callback that should be invoked when the RPC
- * is received. The callback has the following prototype
- * void (*callback)(EVRPC_STRUCT(Message)* rpc, void *arg)
- * @param cbarg an additional parameter that can be passed to the callback.
- * The parameter can be used to carry around state.
- */
-#define EVRPC_REGISTER(base, name, request, reply, callback, cbarg) \
- evrpc_register_generic(base, #name, \
- (void (*)(struct evrpc_req_generic *, void *))callback, cbarg, \
- (void *(*)(void *))request##_new, NULL, \
- (void (*)(void *))request##_free, \
- (int (*)(void *, struct evbuffer *))request##_unmarshal, \
- (void *(*)(void *))reply##_new, NULL, \
- (void (*)(void *))reply##_free, \
- (int (*)(void *))reply##_complete, \
- (void (*)(struct evbuffer *, void *))reply##_marshal)
-
-/**
- Low level function for registering an RPC with a server.
-
- Use EVRPC_REGISTER() instead.
-
- @see EVRPC_REGISTER()
-*/
-int evrpc_register_rpc(struct evrpc_base *, struct evrpc *,
- void (*)(struct evrpc_req_generic*, void *), void *);
-
-/**
- * Unregisters an already registered RPC
- *
- * @param base the evrpc_base object from which to unregister an RPC
- * @param name the name of the rpc to unregister
- * @return -1 on error or 0 when successful.
- * @see EVRPC_REGISTER()
- */
-#define EVRPC_UNREGISTER(base, name) evrpc_unregister_rpc((base), #name)
-
-int evrpc_unregister_rpc(struct evrpc_base *base, const char *name);
-
-/*
- * Client-side RPC support
- */
-
-struct evhttp_connection;
-struct evrpc_status;
-
-/** launches an RPC and sends it to the server
- *
- * EVRPC_MAKE_REQUEST() is used by the client to send an RPC to the server.
- *
- * @param name the name of the RPC
- * @param pool the evrpc_pool that contains the connection objects over which
- * the request should be sent.
- * @param request a pointer to the RPC request structure - it contains the
- * data to be sent to the server.
- * @param reply a pointer to the RPC reply structure. It is going to be filled
- * if the request was answered successfully
- * @param cb the callback to invoke when the RPC request has been answered
- * @param cbarg an additional argument to be passed to the client
- * @return 0 on success, -1 on failure
- */
-#define EVRPC_MAKE_REQUEST(name, pool, request, reply, cb, cbarg) \
- evrpc_send_request_##name((pool), (request), (reply), (cb), (cbarg))
-
-/**
- Makes an RPC request based on the provided context.
-
- This is a low-level function and should not be used directly
- unless a custom context object is provided. Use EVRPC_MAKE_REQUEST()
- instead.
-
- @param ctx a context from EVRPC_MAKE_CTX()
- @returns 0 on success, -1 otherwise.
- @see EVRPC_MAKE_REQUEST(), EVRPC_MAKE_CTX()
-*/
-int evrpc_make_request(struct evrpc_request_wrapper *ctx);
-
-/** creates an rpc connection pool
- *
- * a pool has a number of connections associated with it.
- * rpc requests are always made via a pool.
- *
- * @param base a pointer to an struct event_based object; can be left NULL
- * in singled-threaded applications
- * @return a newly allocated struct evrpc_pool object
- * @see evrpc_pool_free()
- */
-struct evrpc_pool *evrpc_pool_new(struct event_base *base);
-/** frees an rpc connection pool
- *
- * @param pool a pointer to an evrpc_pool allocated via evrpc_pool_new()
- * @see evrpc_pool_new()
- */
-void evrpc_pool_free(struct evrpc_pool *pool);
-
-/**
- * Adds a connection over which rpc can be dispatched to the pool.
- *
- * The connection object must have been newly created.
- *
- * @param pool the pool to which to add the connection
- * @param evcon the connection to add to the pool.
- */
-void evrpc_pool_add_connection(struct evrpc_pool *pool,
- struct evhttp_connection *evcon);
-
-/**
- * Removes a connection from the pool.
- *
- * The connection object must have been newly created.
- *
- * @param pool the pool from which to remove the connection
- * @param evcon the connection to remove from the pool.
- */
-void evrpc_pool_remove_connection(struct evrpc_pool *pool,
- struct evhttp_connection *evcon);
-
-/**
- * Sets the timeout in secs after which a request has to complete. The
- * RPC is completely aborted if it does not complete by then. Setting
- * the timeout to 0 means that it never timeouts and can be used to
- * implement callback type RPCs.
- *
- * Any connection already in the pool will be updated with the new
- * timeout. Connections added to the pool after set_timeout has be
- * called receive the pool timeout only if no timeout has been set
- * for the connection itself.
- *
- * @param pool a pointer to a struct evrpc_pool object
- * @param timeout_in_secs the number of seconds after which a request should
- * timeout and a failure be returned to the callback.
- */
-void evrpc_pool_set_timeout(struct evrpc_pool *pool, int timeout_in_secs);
-
-/**
- * Hooks for changing the input and output of RPCs; this can be used to
- * implement compression, authentication, encryption, ...
- */
-
-enum EVRPC_HOOK_TYPE {
- EVRPC_INPUT, /**< apply the function to an input hook */
- EVRPC_OUTPUT /**< apply the function to an output hook */
-};
-
-#ifndef WIN32
-/** Deprecated alias for EVRPC_INPUT. Not available on windows, where it
- * conflicts with platform headers. */
-#define INPUT EVRPC_INPUT
-/** Deprecated alias for EVRPC_OUTPUT. Not available on windows, where it
- * conflicts with platform headers. */
-#define OUTPUT EVRPC_OUTPUT
-#endif
-
-/**
- * Return value from hook processing functions
- */
-
-enum EVRPC_HOOK_RESULT {
- EVRPC_TERMINATE = -1, /**< indicates the rpc should be terminated */
- EVRPC_CONTINUE = 0, /**< continue processing the rpc */
- EVRPC_PAUSE = 1 /**< pause processing request until resumed */
-};
-
-/** adds a processing hook to either an rpc base or rpc pool
- *
- * If a hook returns TERMINATE, the processing is aborted. On CONTINUE,
- * the request is immediately processed after the hook returns. If the
- * hook returns PAUSE, request processing stops until evrpc_resume_request()
- * has been called.
- *
- * The add functions return handles that can be used for removing hooks.
- *
- * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool
- * @param hook_type either INPUT or OUTPUT
- * @param cb the callback to call when the hook is activated
- * @param cb_arg an additional argument for the callback
- * @return a handle to the hook so it can be removed later
- * @see evrpc_remove_hook()
- */
-void *evrpc_add_hook(void *vbase,
- enum EVRPC_HOOK_TYPE hook_type,
- int (*cb)(void *, struct evhttp_request *, struct evbuffer *, void *),
- void *cb_arg);
-
-/** removes a previously added hook
- *
- * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool
- * @param hook_type either INPUT or OUTPUT
- * @param handle a handle returned by evrpc_add_hook()
- * @return 1 on success or 0 on failure
- * @see evrpc_add_hook()
- */
-int evrpc_remove_hook(void *vbase,
- enum EVRPC_HOOK_TYPE hook_type,
- void *handle);
-
-/** resume a paused request
- *
- * @param vbase a pointer to either struct evrpc_base or struct evrpc_pool
- * @param ctx the context pointer provided to the original hook call
- */
-int
-evrpc_resume_request(void *vbase, void *ctx, enum EVRPC_HOOK_RESULT res);
-
-/** adds meta data to request
- *
- * evrpc_hook_add_meta() allows hooks to add meta data to a request. for
- * a client request, the meta data can be inserted by an outgoing request hook
- * and retrieved by the incoming request hook.
- *
- * @param ctx the context provided to the hook call
- * @param key a NUL-terminated c-string
- * @param data the data to be associated with the key
- * @param data_size the size of the data
- */
-void evrpc_hook_add_meta(void *ctx, const char *key,
- const void *data, size_t data_size);
-
-/** retrieves meta data previously associated
- *
- * evrpc_hook_find_meta() can be used to retrieve meta data associated to a
- * request by a previous hook.
- * @param ctx the context provided to the hook call
- * @param key a NUL-terminated c-string
- * @param data pointer to a data pointer that will contain the retrieved data
- * @param data_size pointer to the size of the data
- * @return 0 on success or -1 on failure
- */
-int evrpc_hook_find_meta(void *ctx, const char *key,
- void **data, size_t *data_size);
-
-/**
- * returns the connection object associated with the request
- *
- * @param ctx the context provided to the hook call
- * @return a pointer to the evhttp_connection object
- */
-struct evhttp_connection *evrpc_hook_get_connection(void *ctx);
-
-/**
- Function for sending a generic RPC request.
-
- Do not call this function directly, use EVRPC_MAKE_REQUEST() instead.
-
- @see EVRPC_MAKE_REQUEST()
- */
-int evrpc_send_request_generic(struct evrpc_pool *pool,
- void *request, void *reply,
- void (*cb)(struct evrpc_status *, void *, void *, void *),
- void *cb_arg,
- const char *rpcname,
- void (*req_marshal)(struct evbuffer *, void *),
- void (*rpl_clear)(void *),
- int (*rpl_unmarshal)(void *, struct evbuffer *));
-
-/**
- Function for registering a generic RPC with the RPC base.
-
- Do not call this function directly, use EVRPC_REGISTER() instead.
-
- @see EVRPC_REGISTER()
- */
-int
-evrpc_register_generic(struct evrpc_base *base, const char *name,
- void (*callback)(struct evrpc_req_generic *, void *), void *cbarg,
- void *(*req_new)(void *), void *req_new_arg, void (*req_free)(void *),
- int (*req_unmarshal)(void *, struct evbuffer *),
- void *(*rpl_new)(void *), void *rpl_new_arg, void (*rpl_free)(void *),
- int (*rpl_complete)(void *),
- void (*rpl_marshal)(struct evbuffer *, void *));
-
-/** accessors for obscure and undocumented functionality */
-struct evrpc_pool* evrpc_request_get_pool(struct evrpc_request_wrapper *ctx);
-void evrpc_request_set_pool(struct evrpc_request_wrapper *ctx,
- struct evrpc_pool *pool);
-void evrpc_request_set_cb(struct evrpc_request_wrapper *ctx,
- void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg),
- void *cb_arg);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _EVENT2_RPC_H_ */
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