release/src/router/dnscrypt/src/libevent/evrpc-internal.h

   1 /*
   2  * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>
   3  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. The name of the author may not be used to endorse or promote products
  14  *    derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27 #ifndef _EVRPC_INTERNAL_H_
  28 #define _EVRPC_INTERNAL_H_
  29
  30 #include "http-internal.h"
  31
  32 struct evrpc;
  33 struct evrpc_request_wrapper;
  34
  35 #define EVRPC_URI_PREFIX "/.rpc."
  36
  37 struct evrpc_hook {
  38         TAILQ_ENTRY(evrpc_hook) next;
  39
  40         /* returns EVRPC_TERMINATE; if the rpc should be aborted.
  41          * a hook is is allowed to rewrite the evbuffer
  42          */
  43         int (*process)(void *, struct evhttp_request *,
  44             struct evbuffer *, void *);
  45         void *process_arg;
  46 };
  47
  48 TAILQ_HEAD(evrpc_hook_list, evrpc_hook);
  49
  50 /*
  51  * this is shared between the base and the pool, so that we can reuse
  52  * the hook adding functions; we alias both evrpc_pool and evrpc_base
  53  * to this common structure.
  54  */
  55
  56 struct evrpc_hook_ctx;
  57 TAILQ_HEAD(evrpc_pause_list, evrpc_hook_ctx);
  58
  59 struct _evrpc_hooks {
  60         /* hooks for processing outbound and inbound rpcs */
  61         struct evrpc_hook_list in_hooks;
  62         struct evrpc_hook_list out_hooks;
  63
  64         struct evrpc_pause_list pause_requests;
  65 };
  66
  67 #define input_hooks common.in_hooks
  68 #define output_hooks common.out_hooks
  69 #define paused_requests common.pause_requests
  70
  71 struct evrpc_base {
  72         struct _evrpc_hooks common;
  73
  74         /* the HTTP server under which we register our RPC calls */
  75         struct evhttp* http_server;
  76
  77         /* a list of all RPCs registered with us */
  78         TAILQ_HEAD(evrpc_list, evrpc) registered_rpcs;
  79 };
  80
  81 struct evrpc_req_generic;
  82 void evrpc_reqstate_free(struct evrpc_req_generic* rpc_state);
  83
  84 /* A pool for holding evhttp_connection objects */
  85 struct evrpc_pool {
  86         struct _evrpc_hooks common;
  87
  88         struct event_base *base;
  89
  90         struct evconq connections;
  91
  92         int timeout;
  93
  94         TAILQ_HEAD(evrpc_requestq, evrpc_request_wrapper) (requests);
  95 };
  96
  97 struct evrpc_hook_ctx {
  98         TAILQ_ENTRY(evrpc_hook_ctx) next;
  99
 100         void *ctx;
 101         void (*cb)(void *, enum EVRPC_HOOK_RESULT);
 102 };
 103
 104 struct evrpc_meta {
 105         TAILQ_ENTRY(evrpc_meta) next;
 106         char *key;
 107
 108         void *data;
 109         size_t data_size;
 110 };
 111
 112 TAILQ_HEAD(evrpc_meta_list, evrpc_meta);
 113
 114 struct evrpc_hook_meta {
 115         struct evrpc_meta_list meta_data;
 116         struct evhttp_connection *evcon;
 117 };
 118
 119 /* allows association of meta data with a request */
 120 static void evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,
 121     struct evhttp_connection *evcon);
 122
 123 /* creates a new meta data store */
 124 static struct evrpc_hook_meta *evrpc_hook_meta_new(void);
 125
 126 /* frees the meta data associated with a request */
 127 static void evrpc_hook_context_free(struct evrpc_hook_meta *ctx);
 128
 129 /* the server side of an rpc */
 130
 131 /* We alias the RPC specific structs to this voided one */
 132 struct evrpc_req_generic {
 133         /*
 134          * allows association of meta data via hooks - needs to be
 135          * synchronized with evrpc_request_wrapper
 136          */
 137         struct evrpc_hook_meta *hook_meta;
 138
 139         /* the unmarshaled request object */
 140         void *request;
 141
 142         /* the empty reply object that needs to be filled in */
 143         void *reply;
 144
 145         /*
 146          * the static structure for this rpc; that can be used to
 147          * automatically unmarshal and marshal the http buffers.
 148          */
 149         struct evrpc *rpc;
 150
 151         /*
 152          * the http request structure on which we need to answer.
 153          */
 154         struct evhttp_request* http_req;
 155
 156         /*
 157          * Temporary data store for marshaled data
 158          */
 159         struct evbuffer* rpc_data;
 160 };
 161
 162 /* the client side of an rpc request */
 163 struct evrpc_request_wrapper {
 164         /*
 165          * allows association of meta data via hooks - needs to be
 166          * synchronized with evrpc_req_generic.
 167          */
 168         struct evrpc_hook_meta *hook_meta;
 169
 170         TAILQ_ENTRY(evrpc_request_wrapper) next;
 171
 172         /* pool on which this rpc request is being made */
 173         struct evrpc_pool *pool;
 174
 175         /* connection on which the request is being sent */
 176         struct evhttp_connection *evcon;
 177
 178         /* the actual  request */
 179         struct evhttp_request *req;
 180
 181         /* event for implementing request timeouts */
 182         struct event ev_timeout;
 183
 184         /* the name of the rpc */
 185         char *name;
 186
 187         /* callback */
 188         void (*cb)(struct evrpc_status*, void *request, void *reply, void *arg);
 189         void *cb_arg;
 190
 191         void *request;
 192         void *reply;
 193
 194         /* unmarshals the buffer into the proper request structure */
 195         void (*request_marshal)(struct evbuffer *, void *);
 196
 197         /* removes all stored state in the reply */
 198         void (*reply_clear)(void *);
 199
 200         /* marshals the reply into a buffer */
 201         int (*reply_unmarshal)(void *, struct evbuffer*);
 202 };
 203
 204 #endif /* _EVRPC_INTERNAL_H_ */