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"
29 #include "evconfig-private.h"
31 #ifdef EVENT__HAVE_SYS_TYPES_H
32 #include <sys/types.h>
34 #ifdef EVENT__HAVE_SYS_PARAM_H
35 #include <sys/param.h>
39 #define WIN32_LEAN_AND_MEAN
42 #undef WIN32_LEAN_AND_MEAN
45 #ifdef EVENT__HAVE_SYS_IOCTL_H
46 #include <sys/ioctl.h>
48 #include <sys/queue.h>
49 #ifdef EVENT__HAVE_SYS_TIME_H
60 #ifdef EVENT__HAVE_UNISTD_H
65 #include "event2/event.h"
66 #include "event2/tag.h"
67 #include "event2/buffer.h"
68 #include "log-internal.h"
69 #include "mm-internal.h"
70 #include "util-internal.h"
73 Here's our wire format:
77 TaggedData = Tag Length Data
78 where the integer value of 'Length' is the length of 'data'.
81 where HByte is a byte with the high bit set, and LByte is a byte
82 with the high bit clear. The integer value of the tag is taken
83 by concatenating the lower 7 bits from all the tags. So for example,
84 the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as
89 Integer = NNibbles Nibble* Padding?
90 where NNibbles is a 4-bit value encoding the number of nibbles-1,
91 and each Nibble is 4 bits worth of encoded integer, in big-endian
92 order. If the total encoded integer size is an odd number of nibbles,
93 a final padding nibble with value 0 is appended.
97 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf);
99 int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf);
101 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag);
103 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf);
111 * We encode integers by nibbles; the first nibble contains the number
112 * of significant nibbles - 1; this allows us to encode up to 64-bit
113 * integers. This function is byte-order independent.
115 * @param number a 32-bit unsigned integer to encode
116 * @param data a pointer to where the data should be written. Must
117 * have at least 5 bytes free.
118 * @return the number of bytes written into data.
121 #define ENCODE_INT_INTERNAL(data, number) do { \
122 int off = 1, nibbles = 0; \
124 memset(data, 0, sizeof(number)+1); \
127 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \
129 data[off/2] = (data[off/2] & 0x0f) | \
130 ((number & 0x0f) << 4); \
138 /* Off - 1 is the number of encoded nibbles */ \
139 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \
141 return ((off + 1) / 2); \
145 encode_int_internal(ev_uint8_t *data, ev_uint32_t number)
147 ENCODE_INT_INTERNAL(data, number);
151 encode_int64_internal(ev_uint8_t *data, ev_uint64_t number)
153 ENCODE_INT_INTERNAL(data, number);
157 evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number)
160 int len = encode_int_internal(data, number);
161 evbuffer_add(evbuf, data, len);
165 evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number)
168 int len = encode_int64_internal(data, number);
169 evbuffer_add(evbuf, data, len);
173 * Support variable length encoding of tags; we use the high bit in each
174 * octet as a continuation signal.
178 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag)
183 memset(data, 0, sizeof(data));
185 ev_uint8_t lower = tag & 0x7f;
191 data[bytes++] = lower;
195 evbuffer_add(evbuf, data, bytes);
201 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain)
203 ev_uint32_t number = 0;
204 size_t len = evbuffer_get_length(evbuf);
207 int shift = 0, done = 0;
210 * the encoding of a number is at most one byte more than its
211 * storage size. however, it may also be much smaller.
213 data = evbuffer_pullup(
214 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1);
218 while (count++ < len) {
219 ev_uint8_t lower = *data++;
221 /* Make sure it fits into 32 bits */
224 if ((lower & 0x7f) > 15)
227 number |= (lower & (unsigned)0x7f) << shift;
230 if (!(lower & 0x80)) {
240 evbuffer_drain(evbuf, count);
245 return count > INT_MAX ? INT_MAX : (int)(count);
249 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf)
251 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */));
255 * Marshal a data type, the general format is as follows:
257 * tag number: one byte; length: var bytes; payload: var bytes
261 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag,
262 const void *data, ev_uint32_t len)
264 evtag_encode_tag(evbuf, tag);
265 evtag_encode_int(evbuf, len);
266 evbuffer_add(evbuf, (void *)data, len);
270 evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
271 struct evbuffer *data)
273 evtag_encode_tag(evbuf, tag);
274 /* XXX support more than UINT32_MAX data */
275 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data));
276 evbuffer_add_buffer(evbuf, data);
279 /* Marshaling for integers */
281 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
284 int len = encode_int_internal(data, integer);
286 evtag_encode_tag(evbuf, tag);
287 evtag_encode_int(evbuf, len);
288 evbuffer_add(evbuf, data, len);
292 evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
296 int len = encode_int64_internal(data, integer);
298 evtag_encode_tag(evbuf, tag);
299 evtag_encode_int(evbuf, len);
300 evbuffer_add(evbuf, data, len);
304 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string)
306 /* TODO support strings longer than UINT32_MAX ? */
307 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string));
311 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
314 int len = encode_int_internal(data, tv->tv_sec);
315 len += encode_int_internal(data + len, tv->tv_usec);
316 evtag_marshal(evbuf, tag, data, len);
319 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \
322 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \
328 /* XXX(niels): faster? */ \
329 data = evbuffer_pullup(evbuf, offset + 1) + offset; \
333 nibbles = ((data[0] & 0xf0) >> 4) + 1; \
334 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \
336 len = (nibbles >> 1) + 1; \
338 data = evbuffer_pullup(evbuf, offset + len) + offset; \
342 while (nibbles > 0) { \
345 number |= data[nibbles >> 1] & 0x0f; \
347 number |= (data[nibbles >> 1] & 0xf0) >> 4; \
356 /* Internal: decode an integer from an evbuffer, without draining it.
357 * Only integers up to 32-bits are supported.
359 * @param evbuf the buffer to read from
360 * @param offset an index into the buffer at which we should start reading.
361 * @param pnumber a pointer to receive the integer.
362 * @return The length of the number as encoded, or -1 on error.
366 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset)
368 ev_uint32_t number = 0;
369 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset);
373 decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset)
375 ev_uint64_t number = 0;
376 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset);
380 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf)
382 int res = decode_int_internal(pnumber, evbuf, 0);
384 evbuffer_drain(evbuf, res);
386 return (res == -1 ? -1 : 0);
390 evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf)
392 int res = decode_int64_internal(pnumber, evbuf, 0);
394 evbuffer_drain(evbuf, res);
396 return (res == -1 ? -1 : 0);
400 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag)
402 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */));
406 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength)
410 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
414 res = decode_int_internal(plength, evbuf, len);
418 *plength += res + len;
424 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength)
428 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
432 res = decode_int_internal(plength, evbuf, len);
439 /* just unmarshals the header and returns the length of the remaining data */
442 evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag)
446 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1)
448 if (evtag_decode_int(&len, evbuf) == -1)
451 if (evbuffer_get_length(evbuf) < len)
458 evtag_consume(struct evbuffer *evbuf)
461 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1)
463 evbuffer_drain(evbuf, len);
468 /* Reads the data type from an event buffer */
471 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst)
475 if ((len = evtag_unmarshal_header(src, ptag)) == -1)
478 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1)
481 evbuffer_drain(src, len);
486 /* Marshaling for integers */
489 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
490 ev_uint32_t *pinteger)
496 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
500 if (evtag_decode_int(&len, evbuf) == -1)
503 if (evbuffer_get_length(evbuf) < len)
506 result = decode_int_internal(pinteger, evbuf, 0);
507 evbuffer_drain(evbuf, len);
508 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
515 evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
516 ev_uint64_t *pinteger)
522 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
526 if (evtag_decode_int(&len, evbuf) == -1)
529 if (evbuffer_get_length(evbuf) < len)
532 result = decode_int64_internal(pinteger, evbuf, 0);
533 evbuffer_drain(evbuf, len);
534 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
540 /* Unmarshal a fixed length tag */
543 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data,
549 /* Now unmarshal a tag and check that it matches the tag we want */
550 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 ||
554 if ((size_t)tag_len != len)
557 evbuffer_remove(src, data, len);
562 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
568 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 ||
572 *pstring = mm_malloc(tag_len + 1);
573 if (*pstring == NULL) {
574 event_warn("%s: malloc", __func__);
577 evbuffer_remove(evbuf, *pstring, tag_len);
578 (*pstring)[tag_len] = '\0';
584 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
589 int len, offset, offset2;
592 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1)
596 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1)
598 ptv->tv_sec = integer;
599 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1)
601 ptv->tv_usec = integer;
602 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */
607 evbuffer_drain(evbuf, len);