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
32struct evrpc;
33struct evrpc_request_wrapper;
34
35#define EVRPC_URI_PREFIX "/.rpc."
36
37struct 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
48TAILQ_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
56struct evrpc_hook_ctx;
57TAILQ_HEAD(evrpc_pause_list, evrpc_hook_ctx);
58
59struct _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
71struct 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
81struct evrpc_req_generic;
82void evrpc_reqstate_free(struct evrpc_req_generic* rpc_state);
83
84/* A pool for holding evhttp_connection objects */
85struct 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
97struct evrpc_hook_ctx {
98	TAILQ_ENTRY(evrpc_hook_ctx) next;
99
100	void *ctx;
101	void (*cb)(void *, enum EVRPC_HOOK_RESULT);
102};
103
104struct evrpc_meta {
105	TAILQ_ENTRY(evrpc_meta) next;
106	char *key;
107
108	void *data;
109	size_t data_size;
110};
111
112TAILQ_HEAD(evrpc_meta_list, evrpc_meta);
113
114struct 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 */
120static void evrpc_hook_associate_meta(struct evrpc_hook_meta **pctx,
121    struct evhttp_connection *evcon);
122
123/* creates a new meta data store */
124static struct evrpc_hook_meta *evrpc_hook_meta_new(void);
125
126/* frees the meta data associated with a request */
127static 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 */
132struct 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 */
163struct 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_ */
205