tag.h revision 1.3 
1/*	$NetBSD: tag.h,v 1.3 2015/07/10 14:20:34 christos Exp $	*/
2
3/*
4 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
5 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29#ifndef EVENT2_TAG_H_INCLUDED_
30#define EVENT2_TAG_H_INCLUDED_
31
32/** @file event2/tag.h
33
34  Helper functions for reading and writing tagged data onto buffers.
35
36 */
37
38#include <event2/visibility.h>
39
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44#include <event2/event-config.h>
45#ifdef EVENT__HAVE_SYS_TYPES_H
46#include <sys/types.h>
47#endif
48#ifdef EVENT__HAVE_SYS_TIME_H
49#include <sys/time.h>
50#endif
51
52/* For int types. */
53#include <event2/util.h>
54
55struct evbuffer;
56
57/*
58 * Marshaling tagged data - We assume that all tags are inserted in their
59 * numeric order - so that unknown tags will always be higher than the
60 * known ones - and we can just ignore the end of an event buffer.
61 */
62
63EVENT2_EXPORT_SYMBOL
64void evtag_init(void);
65
66/**
67   Unmarshals the header and returns the length of the payload
68
69   @param evbuf the buffer from which to unmarshal data
70   @param ptag a pointer in which the tag id is being stored
71   @returns -1 on failure or the number of bytes in the remaining payload.
72*/
73EVENT2_EXPORT_SYMBOL
74int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
75
76EVENT2_EXPORT_SYMBOL
77void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
78    ev_uint32_t len);
79EVENT2_EXPORT_SYMBOL
80void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
81    struct evbuffer *data);
82
83/**
84  Encode an integer and store it in an evbuffer.
85
86  We encode integers by nybbles; the first nibble contains the number
87  of significant nibbles - 1;  this allows us to encode up to 64-bit
88  integers.  This function is byte-order independent.
89
90  @param evbuf evbuffer to store the encoded number
91  @param number a 32-bit integer
92 */
93EVENT2_EXPORT_SYMBOL
94void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
95EVENT2_EXPORT_SYMBOL
96void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
97
98EVENT2_EXPORT_SYMBOL
99void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
100    ev_uint32_t integer);
101EVENT2_EXPORT_SYMBOL
102void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
103    ev_uint64_t integer);
104
105EVENT2_EXPORT_SYMBOL
106void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
107    const char *string);
108
109EVENT2_EXPORT_SYMBOL
110void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
111    struct timeval *tv);
112
113EVENT2_EXPORT_SYMBOL
114int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
115    struct evbuffer *dst);
116EVENT2_EXPORT_SYMBOL
117int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
118EVENT2_EXPORT_SYMBOL
119int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
120EVENT2_EXPORT_SYMBOL
121int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
122EVENT2_EXPORT_SYMBOL
123int evtag_consume(struct evbuffer *evbuf);
124
125EVENT2_EXPORT_SYMBOL
126int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
127    ev_uint32_t *pinteger);
128EVENT2_EXPORT_SYMBOL
129int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
130    ev_uint64_t *pinteger);
131
132EVENT2_EXPORT_SYMBOL
133int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
134    void *data, size_t len);
135
136EVENT2_EXPORT_SYMBOL
137int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
138    char **pstring);
139
140EVENT2_EXPORT_SYMBOL
141int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
142    struct timeval *ptv);
143
144#ifdef __cplusplus
145}
146#endif
147
148#endif /* EVENT2_TAG_H_INCLUDED_ */
149