2 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu>
3 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
27 #ifndef EVENT2_TAG_H_INCLUDED_
28 #define EVENT2_TAG_H_INCLUDED_
30 /** @file event2/tag.h
32 Helper functions for reading and writing tagged data onto buffers.
36 #include <event2/visibility.h>
42 #include <event2/event-config.h>
43 #ifdef EVENT__HAVE_SYS_TYPES_H
44 #include <sys/types.h>
46 #ifdef EVENT__HAVE_SYS_TIME_H
51 #include <event2/util.h>
56 * Marshaling tagged data - We assume that all tags are inserted in their
57 * numeric order - so that unknown tags will always be higher than the
58 * known ones - and we can just ignore the end of an event buffer.
62 void evtag_init(void);
65 Unmarshals the header and returns the length of the payload
67 @param evbuf the buffer from which to unmarshal data
68 @param ptag a pointer in which the tag id is being stored
69 @returns -1 on failure or the number of bytes in the remaining payload.
72 int evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag);
75 void evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, const void *data,
78 void evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
79 struct evbuffer *data);
82 Encode an integer and store it in an evbuffer.
84 We encode integers by nybbles; the first nibble contains the number
85 of significant nibbles - 1; this allows us to encode up to 64-bit
86 integers. This function is byte-order independent.
88 @param evbuf evbuffer to store the encoded number
89 @param number a 32-bit integer
92 void evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number);
94 void evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number);
97 void evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag,
100 void evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
101 ev_uint64_t integer);
104 void evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag,
108 void evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag,
112 int evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag,
113 struct evbuffer *dst);
115 int evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag);
117 int evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength);
119 int evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength);
121 int evtag_consume(struct evbuffer *evbuf);
124 int evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
125 ev_uint32_t *pinteger);
127 int evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
128 ev_uint64_t *pinteger);
131 int evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag,
132 void *data, size_t len);
135 int evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
139 int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
140 struct timeval *ptv);
146 #endif /* EVENT2_TAG_H_INCLUDED_ */