1/*	$NetBSD: tag.h,v 1.1.1.3 2017/01/31 21:14:53 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_INCLUDED_
29#define EVENT2_TAG_H_INCLUDED_
30
31/** @file event2/tag.h
32
33  Helper functions for reading and writing tagged data onto buffers.
34
35 */
36
37#include <event2/visibility.h>
38
39#ifdef __cplusplus
40extern "C" {
41#endif
42
43#include <event2/event-config.h>
44#ifdef EVENT__HAVE_SYS_TYPES_H
45#include <sys/types.h>
46#endif
47#ifdef EVENT__HAVE_SYS_TIME_H
48#include <sys/time.h>
49#endif
50
51/* For int types. */
52#include <event2/util.h>
53
54struct evbuffer;
55
56/*
57 * Marshaling tagged data - We assume that all tags are inserted in their
58 * numeric order - so that unknown tags will always be higher than the
59 * known ones - and we can just ignore the end of an event buffer.
60 */
61
62EVENT2_EXPORT_SYMBOL
63void evtag_init(void);
64
65/**
66   Unmarshals the header and returns the length of the payload
67
68   @param evbuf the buffer from which to unmarshal data
69   @param ptag a pointer in which the tag id is being stored
70   @returns -1 on failure or the number of bytes in the remaining payload.
71*/
72EVENT2_EXPORT_SYMBOL
73int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
74
75EVENT2_EXPORT_SYMBOL
76void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
77    ev_uint32_t len);
78EVENT2_EXPORT_SYMBOL
79void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
80    struct evbuffer *data);
81
82/**
83  Encode an integer and store it in an evbuffer.
84
85  We encode integers by nybbles; the first nibble contains the number
86  of significant nibbles - 1;  this allows us to encode up to 64-bit
87  integers.  This function is byte-order independent.
88
89  @param evbuf evbuffer to store the encoded number
90  @param number a 32-bit integer
91 */
92EVENT2_EXPORT_SYMBOL
93void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
94EVENT2_EXPORT_SYMBOL
95void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
96
97EVENT2_EXPORT_SYMBOL
98void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
99    ev_uint32_t integer);
100EVENT2_EXPORT_SYMBOL
101void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
102    ev_uint64_t integer);
103
104EVENT2_EXPORT_SYMBOL
105void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
106    const char *string);
107
108EVENT2_EXPORT_SYMBOL
109void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
110    struct timeval *tv);
111
112EVENT2_EXPORT_SYMBOL
113int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
114    struct evbuffer *dst);
115EVENT2_EXPORT_SYMBOL
116int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
117EVENT2_EXPORT_SYMBOL
118int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
119EVENT2_EXPORT_SYMBOL
120int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
121EVENT2_EXPORT_SYMBOL
122int evtag_consume(struct evbuffer *evbuf);
123
124EVENT2_EXPORT_SYMBOL
125int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
126    ev_uint32_t *pinteger);
127EVENT2_EXPORT_SYMBOL
128int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
129    ev_uint64_t *pinteger);
130
131EVENT2_EXPORT_SYMBOL
132int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
133    void *data, size_t len);
134
135EVENT2_EXPORT_SYMBOL
136int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
137    char **pstring);
138
139EVENT2_EXPORT_SYMBOL
140int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
141    struct timeval *ptv);
142
143#ifdef __cplusplus
144}
145#endif
146
147#endif /* EVENT2_TAG_H_INCLUDED_ */
148