tag.h revision 1.1.1.1 
1/*	$NetBSD: tag.h,v 1.1.1.1 2013/04/11 16:43:34 christos Exp $	*/
2/*
3 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
4 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28#ifndef _EVENT2_TAG_H_
29#define _EVENT2_TAG_H_
30
31/** @file event2/tag.h
32
33  Helper functions for reading and writing tagged data onto buffers.
34
35 */
36
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41#include <event2/event-config.h>
42#ifdef _EVENT_HAVE_SYS_TYPES_H
43#include <sys/types.h>
44#endif
45#ifdef _EVENT_HAVE_SYS_TIME_H
46#include <sys/time.h>
47#endif
48
49/* For int types. */
50#include <event2/util.h>
51
52struct evbuffer;
53
54/*
55 * Marshaling tagged data - We assume that all tags are inserted in their
56 * numeric order - so that unknown tags will always be higher than the
57 * known ones - and we can just ignore the end of an event buffer.
58 */
59
60void evtag_init(void);
61
62/**
63   Unmarshals the header and returns the length of the payload
64
65   @param evbuf the buffer from which to unmarshal data
66   @param ptag a pointer in which the tag id is being stored
67   @returns -1 on failure or the number of bytes in the remaining payload.
68*/
69int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
70
71void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
72    ev_uint32_t len);
73void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
74    struct evbuffer *data);
75
76/**
77  Encode an integer and store it in an evbuffer.
78
79  We encode integers by nybbles; the first nibble contains the number
80  of significant nibbles - 1;  this allows us to encode up to 64-bit
81  integers.  This function is byte-order independent.
82
83  @param evbuf evbuffer to store the encoded number
84  @param number a 32-bit integer
85 */
86void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
87void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
88
89void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
90    ev_uint32_t integer);
91void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
92    ev_uint64_t integer);
93
94void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
95    const char *string);
96
97void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
98    struct timeval *tv);
99
100int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
101    struct evbuffer *dst);
102int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
103int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
104int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
105int evtag_consume(struct evbuffer *evbuf);
106
107int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
108    ev_uint32_t *pinteger);
109int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
110    ev_uint64_t *pinteger);
111
112int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
113    void *data, size_t len);
114
115int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
116    char **pstring);
117
118int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
119    struct timeval *ptv);
120
121#ifdef __cplusplus
122}
123#endif
124
125#endif /* _EVENT2_TAG_H_ */
126