1 /*
2 * Copyright (c) 2000-2007 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 _EVENT2_TAG_H_
28 #define _EVENT2_TAG_H_
29
30 /** @file event2/tag.h
31
32 Helper functions for reading and writing tagged data onto buffers.
33
34 */
35
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
39
40 #include <event2/event-config.h>
41 #ifdef _EVENT_HAVE_SYS_TYPES_H
42 #include <sys/types.h>
43 #endif
44 #ifdef _EVENT_HAVE_SYS_TIME_H
45 #include <sys/time.h>
46 #endif
47
48 /* For int types. */
49 #include <event2/util.h>
50
51 struct evbuffer;
52
53 /*
54 * Marshaling tagged data - We assume that all tags are inserted in their
55 * numeric order - so that unknown tags will always be higher than the
56 * known ones - and we can just ignore the end of an event buffer.
57 */
58
59 void evtag_init(void);
60
61 /**
62 Unmarshals the header and returns the length of the payload
63
64 @param evbuf the buffer from which to unmarshal data
65 @param ptag a pointer in which the tag id is being stored
66 @returns -1 on failure or the number of bytes in the remaining payload.
67 */
68 int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
69
70 void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
71 ev_uint32_t len);
72 void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
73 struct evbuffer *data);
74
75 /**
76 Encode an integer and store it in an evbuffer.
77
78 We encode integers by nybbles; the first nibble contains the number
79 of significant nibbles - 1; this allows us to encode up to 64-bit
80 integers. This function is byte-order independent.
81
82 @param evbuf evbuffer to store the encoded number
83 @param number a 32-bit integer
84 */
85 void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
86 void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
87
88 void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
89 ev_uint32_t integer);
90 void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
91 ev_uint64_t integer);
92
93 void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
94 const char *string);
95
96 void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
97 struct timeval *tv);
98
99 int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
100 struct evbuffer *dst);
101 int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
102 int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
103 int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
104 int evtag_consume(struct evbuffer *evbuf);
105
106 int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
107 ev_uint32_t *pinteger);
108 int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
109 ev_uint64_t *pinteger);
110
111 int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
112 void *data, size_t len);
113
114 int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
115 char **pstring);
116
117 int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
118 struct timeval *ptv);
119
120 #ifdef __cplusplus
121 }
122 #endif
123
124 #endif /* _EVENT2_TAG_H_ */