2 * Copyright (c) 2003-2009 Niels Provos <provos@citi.umich.edu>
3 * Copyright (c) 2009-2012 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.
28 #include "event2/event-config.h"
30 #ifdef _EVENT_HAVE_SYS_TYPES_H
31 #include <sys/types.h>
33 #ifdef _EVENT_HAVE_SYS_PARAM_H
34 #include <sys/param.h>
38 #define WIN32_LEAN_AND_MEAN
41 #undef WIN32_LEAN_AND_MEAN
43 #include <sys/ioctl.h>
46 #include <sys/queue.h>
47 #ifdef _EVENT_HAVE_SYS_TIME_H
58 #ifdef _EVENT_HAVE_UNISTD_H
63 #include "event2/event.h"
64 #include "event2/tag.h"
65 #include "event2/buffer.h"
66 #include "log-internal.h"
67 #include "mm-internal.h"
68 #include "util-internal.h"
71 Here's our wire format:
75 TaggedData = Tag Length Data
76 where the integer value of 'Length' is the length of 'data'.
79 where HByte is a byte with the high bit set, and LByte is a byte
80 with the high bit clear. The integer value of the tag is taken
81 by concatenating the lower 7 bits from all the tags. So for example,
82 the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as
87 Integer = NNibbles Nibble* Padding?
88 where NNibbles is a 4-bit value encoding the number of nibbles-1,
89 and each Nibble is 4 bits worth of encoded integer, in big-endian
90 order. If the total encoded integer size is an odd number of nibbles,
91 a final padding nibble with value 0 is appended.
94 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf);
95 int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf);
96 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag);
97 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf);
105 * We encode integers by nibbles; the first nibble contains the number
106 * of significant nibbles - 1; this allows us to encode up to 64-bit
107 * integers. This function is byte-order independent.
109 * @param number a 32-bit unsigned integer to encode
110 * @param data a pointer to where the data should be written. Must
111 * have at least 5 bytes free.
112 * @return the number of bytes written into data.
115 #define ENCODE_INT_INTERNAL(data, number) do { \
116 int off = 1, nibbles = 0; \
118 memset(data, 0, sizeof(number)+1); \
121 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \
123 data[off/2] = (data[off/2] & 0x0f) | \
124 ((number & 0x0f) << 4); \
132 /* Off - 1 is the number of encoded nibbles */ \
133 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \
135 return ((off + 1) / 2); \
139 encode_int_internal(ev_uint8_t *data, ev_uint32_t number)
141 ENCODE_INT_INTERNAL(data, number);
145 encode_int64_internal(ev_uint8_t *data, ev_uint64_t number)
147 ENCODE_INT_INTERNAL(data, number);
151 evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number)
154 int len = encode_int_internal(data, number);
155 evbuffer_add(evbuf, data, len);
159 evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number)
162 int len = encode_int64_internal(data, number);
163 evbuffer_add(evbuf, data, len);
167 * Support variable length encoding of tags; we use the high bit in each
168 * octet as a continuation signal.
172 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag)
177 memset(data, 0, sizeof(data));
179 ev_uint8_t lower = tag & 0x7f;
185 data[bytes++] = lower;
189 evbuffer_add(evbuf, data, bytes);
195 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain)
197 ev_uint32_t number = 0;
198 size_t len = evbuffer_get_length(evbuf);
201 int shift = 0, done = 0;
204 * the encoding of a number is at most one byte more than its
205 * storage size. however, it may also be much smaller.
207 data = evbuffer_pullup(
208 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1);
212 while (count++ < len) {
213 ev_uint8_t lower = *data++;
214 number |= (lower & 0x7f) << shift;
217 if (!(lower & 0x80)) {
227 evbuffer_drain(evbuf, count);
232 return count > INT_MAX ? INT_MAX : (int)(count);
236 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf)
238 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */));
242 * Marshal a data type, the general format is as follows:
244 * tag number: one byte; length: var bytes; payload: var bytes
248 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag,
249 const void *data, ev_uint32_t len)
251 evtag_encode_tag(evbuf, tag);
252 evtag_encode_int(evbuf, len);
253 evbuffer_add(evbuf, (void *)data, len);
257 evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
258 struct evbuffer *data)
260 evtag_encode_tag(evbuf, tag);
261 /* XXX support more than UINT32_MAX data */
262 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data));
263 evbuffer_add_buffer(evbuf, data);
266 /* Marshaling for integers */
268 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
271 int len = encode_int_internal(data, integer);
273 evtag_encode_tag(evbuf, tag);
274 evtag_encode_int(evbuf, len);
275 evbuffer_add(evbuf, data, len);
279 evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
283 int len = encode_int64_internal(data, integer);
285 evtag_encode_tag(evbuf, tag);
286 evtag_encode_int(evbuf, len);
287 evbuffer_add(evbuf, data, len);
291 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string)
293 /* TODO support strings longer than UINT32_MAX ? */
294 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string));
298 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
301 int len = encode_int_internal(data, tv->tv_sec);
302 len += encode_int_internal(data + len, tv->tv_usec);
303 evtag_marshal(evbuf, tag, data, len);
306 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \
309 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \
315 /* XXX(niels): faster? */ \
316 data = evbuffer_pullup(evbuf, offset + 1) + offset; \
320 nibbles = ((data[0] & 0xf0) >> 4) + 1; \
321 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \
323 len = (nibbles >> 1) + 1; \
325 data = evbuffer_pullup(evbuf, offset + len) + offset; \
329 while (nibbles > 0) { \
332 number |= data[nibbles >> 1] & 0x0f; \
334 number |= (data[nibbles >> 1] & 0xf0) >> 4; \
343 /* Internal: decode an integer from an evbuffer, without draining it.
344 * Only integers up to 32-bits are supported.
346 * @param evbuf the buffer to read from
347 * @param offset an index into the buffer at which we should start reading.
348 * @param pnumber a pointer to receive the integer.
349 * @return The length of the number as encoded, or -1 on error.
353 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset)
355 ev_uint32_t number = 0;
356 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset);
360 decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset)
362 ev_uint64_t number = 0;
363 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset);
367 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf)
369 int res = decode_int_internal(pnumber, evbuf, 0);
371 evbuffer_drain(evbuf, res);
373 return (res == -1 ? -1 : 0);
377 evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf)
379 int res = decode_int64_internal(pnumber, evbuf, 0);
381 evbuffer_drain(evbuf, res);
383 return (res == -1 ? -1 : 0);
387 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag)
389 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */));
393 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength)
397 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
401 res = decode_int_internal(plength, evbuf, len);
405 *plength += res + len;
411 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength)
415 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
419 res = decode_int_internal(plength, evbuf, len);
426 /* just unmarshals the header and returns the length of the remaining data */
429 evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag)
433 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1)
435 if (evtag_decode_int(&len, evbuf) == -1)
438 if (evbuffer_get_length(evbuf) < len)
445 evtag_consume(struct evbuffer *evbuf)
448 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1)
450 evbuffer_drain(evbuf, len);
455 /* Reads the data type from an event buffer */
458 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst)
462 if ((len = evtag_unmarshal_header(src, ptag)) == -1)
465 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1)
468 evbuffer_drain(src, len);
473 /* Marshaling for integers */
476 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
477 ev_uint32_t *pinteger)
483 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
487 if (evtag_decode_int(&len, evbuf) == -1)
490 if (evbuffer_get_length(evbuf) < len)
493 result = decode_int_internal(pinteger, evbuf, 0);
494 evbuffer_drain(evbuf, len);
495 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
502 evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
503 ev_uint64_t *pinteger)
509 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
513 if (evtag_decode_int(&len, evbuf) == -1)
516 if (evbuffer_get_length(evbuf) < len)
519 result = decode_int64_internal(pinteger, evbuf, 0);
520 evbuffer_drain(evbuf, len);
521 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
527 /* Unmarshal a fixed length tag */
530 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data,
536 /* Now unmarshal a tag and check that it matches the tag we want */
537 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 ||
541 if ((size_t)tag_len != len)
544 evbuffer_remove(src, data, len);
549 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
555 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 ||
559 *pstring = mm_malloc(tag_len + 1);
560 if (*pstring == NULL) {
561 event_warn("%s: malloc", __func__);
564 evbuffer_remove(evbuf, *pstring, tag_len);
565 (*pstring)[tag_len] = '\0';
571 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
576 int len, offset, offset2;
579 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1)
583 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1)
585 ptv->tv_sec = integer;
586 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1)
588 ptv->tv_usec = integer;
589 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */
594 evbuffer_drain(evbuf, len);