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);
210 while (count
++ < len
) {
211 ev_uint8_t lower
= *data
++;
212 number
|= (lower
& 0x7f) << shift
;
215 if (!(lower
& 0x80)) {
225 evbuffer_drain(evbuf
, count
);
230 return count
> INT_MAX
? INT_MAX
: (int)(count
);
234 evtag_decode_tag(ev_uint32_t
*ptag
, struct evbuffer
*evbuf
)
236 return (decode_tag_internal(ptag
, evbuf
, 1 /* dodrain */));
240 * Marshal a data type, the general format is as follows:
242 * tag number: one byte; length: var bytes; payload: var bytes
246 evtag_marshal(struct evbuffer
*evbuf
, ev_uint32_t tag
,
247 const void *data
, ev_uint32_t len
)
249 evtag_encode_tag(evbuf
, tag
);
250 evtag_encode_int(evbuf
, len
);
251 evbuffer_add(evbuf
, (void *)data
, len
);
255 evtag_marshal_buffer(struct evbuffer
*evbuf
, ev_uint32_t tag
,
256 struct evbuffer
*data
)
258 evtag_encode_tag(evbuf
, tag
);
259 /* XXX support more than UINT32_MAX data */
260 evtag_encode_int(evbuf
, (ev_uint32_t
)evbuffer_get_length(data
));
261 evbuffer_add_buffer(evbuf
, data
);
264 /* Marshaling for integers */
266 evtag_marshal_int(struct evbuffer
*evbuf
, ev_uint32_t tag
, ev_uint32_t integer
)
269 int len
= encode_int_internal(data
, integer
);
271 evtag_encode_tag(evbuf
, tag
);
272 evtag_encode_int(evbuf
, len
);
273 evbuffer_add(evbuf
, data
, len
);
277 evtag_marshal_int64(struct evbuffer
*evbuf
, ev_uint32_t tag
,
281 int len
= encode_int64_internal(data
, integer
);
283 evtag_encode_tag(evbuf
, tag
);
284 evtag_encode_int(evbuf
, len
);
285 evbuffer_add(evbuf
, data
, len
);
289 evtag_marshal_string(struct evbuffer
*buf
, ev_uint32_t tag
, const char *string
)
291 /* TODO support strings longer than UINT32_MAX ? */
292 evtag_marshal(buf
, tag
, string
, (ev_uint32_t
)strlen(string
));
296 evtag_marshal_timeval(struct evbuffer
*evbuf
, ev_uint32_t tag
, struct timeval
*tv
)
299 int len
= encode_int_internal(data
, tv
->tv_sec
);
300 len
+= encode_int_internal(data
+ len
, tv
->tv_usec
);
301 evtag_marshal(evbuf
, tag
, data
, len
);
304 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \
307 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \
313 /* XXX(niels): faster? */ \
314 data = evbuffer_pullup(evbuf, offset + 1) + offset; \
316 nibbles = ((data[0] & 0xf0) >> 4) + 1; \
317 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \
319 len = (nibbles >> 1) + 1; \
321 data = evbuffer_pullup(evbuf, offset + len) + offset; \
323 while (nibbles > 0) { \
326 number |= data[nibbles >> 1] & 0x0f; \
328 number |= (data[nibbles >> 1] & 0xf0) >> 4; \
337 /* Internal: decode an integer from an evbuffer, without draining it.
338 * Only integers up to 32-bits are supported.
340 * @param evbuf the buffer to read from
341 * @param offset an index into the buffer at which we should start reading.
342 * @param pnumber a pointer to receive the integer.
343 * @return The length of the number as encoded, or -1 on error.
347 decode_int_internal(ev_uint32_t
*pnumber
, struct evbuffer
*evbuf
, int offset
)
349 ev_uint32_t number
= 0;
350 DECODE_INT_INTERNAL(number
, 8, pnumber
, evbuf
, offset
);
354 decode_int64_internal(ev_uint64_t
*pnumber
, struct evbuffer
*evbuf
, int offset
)
356 ev_uint64_t number
= 0;
357 DECODE_INT_INTERNAL(number
, 16, pnumber
, evbuf
, offset
);
361 evtag_decode_int(ev_uint32_t
*pnumber
, struct evbuffer
*evbuf
)
363 int res
= decode_int_internal(pnumber
, evbuf
, 0);
365 evbuffer_drain(evbuf
, res
);
367 return (res
== -1 ? -1 : 0);
371 evtag_decode_int64(ev_uint64_t
*pnumber
, struct evbuffer
*evbuf
)
373 int res
= decode_int64_internal(pnumber
, evbuf
, 0);
375 evbuffer_drain(evbuf
, res
);
377 return (res
== -1 ? -1 : 0);
381 evtag_peek(struct evbuffer
*evbuf
, ev_uint32_t
*ptag
)
383 return (decode_tag_internal(ptag
, evbuf
, 0 /* dodrain */));
387 evtag_peek_length(struct evbuffer
*evbuf
, ev_uint32_t
*plength
)
391 len
= decode_tag_internal(NULL
, evbuf
, 0 /* dodrain */);
395 res
= decode_int_internal(plength
, evbuf
, len
);
399 *plength
+= res
+ len
;
405 evtag_payload_length(struct evbuffer
*evbuf
, ev_uint32_t
*plength
)
409 len
= decode_tag_internal(NULL
, evbuf
, 0 /* dodrain */);
413 res
= decode_int_internal(plength
, evbuf
, len
);
420 /* just unmarshals the header and returns the length of the remaining data */
423 evtag_unmarshal_header(struct evbuffer
*evbuf
, ev_uint32_t
*ptag
)
427 if (decode_tag_internal(ptag
, evbuf
, 1 /* dodrain */) == -1)
429 if (evtag_decode_int(&len
, evbuf
) == -1)
432 if (evbuffer_get_length(evbuf
) < len
)
439 evtag_consume(struct evbuffer
*evbuf
)
442 if ((len
= evtag_unmarshal_header(evbuf
, NULL
)) == -1)
444 evbuffer_drain(evbuf
, len
);
449 /* Reads the data type from an event buffer */
452 evtag_unmarshal(struct evbuffer
*src
, ev_uint32_t
*ptag
, struct evbuffer
*dst
)
456 if ((len
= evtag_unmarshal_header(src
, ptag
)) == -1)
459 if (evbuffer_add(dst
, evbuffer_pullup(src
, len
), len
) == -1)
462 evbuffer_drain(src
, len
);
467 /* Marshaling for integers */
470 evtag_unmarshal_int(struct evbuffer
*evbuf
, ev_uint32_t need_tag
,
471 ev_uint32_t
*pinteger
)
477 if (decode_tag_internal(&tag
, evbuf
, 1 /* dodrain */) == -1)
481 if (evtag_decode_int(&len
, evbuf
) == -1)
484 if (evbuffer_get_length(evbuf
) < len
)
487 result
= decode_int_internal(pinteger
, evbuf
, 0);
488 evbuffer_drain(evbuf
, len
);
489 if (result
< 0 || (size_t)result
> len
) /* XXX Should this be != rather than > ?*/
496 evtag_unmarshal_int64(struct evbuffer
*evbuf
, ev_uint32_t need_tag
,
497 ev_uint64_t
*pinteger
)
503 if (decode_tag_internal(&tag
, evbuf
, 1 /* dodrain */) == -1)
507 if (evtag_decode_int(&len
, evbuf
) == -1)
510 if (evbuffer_get_length(evbuf
) < len
)
513 result
= decode_int64_internal(pinteger
, evbuf
, 0);
514 evbuffer_drain(evbuf
, len
);
515 if (result
< 0 || (size_t)result
> len
) /* XXX Should this be != rather than > ?*/
521 /* Unmarshal a fixed length tag */
524 evtag_unmarshal_fixed(struct evbuffer
*src
, ev_uint32_t need_tag
, void *data
,
530 /* Now unmarshal a tag and check that it matches the tag we want */
531 if ((tag_len
= evtag_unmarshal_header(src
, &tag
)) < 0 ||
535 if ((size_t)tag_len
!= len
)
538 evbuffer_remove(src
, data
, len
);
543 evtag_unmarshal_string(struct evbuffer
*evbuf
, ev_uint32_t need_tag
,
549 if ((tag_len
= evtag_unmarshal_header(evbuf
, &tag
)) == -1 ||
553 *pstring
= mm_malloc(tag_len
+ 1);
554 if (*pstring
== NULL
) {
555 event_warn("%s: malloc", __func__
);
558 evbuffer_remove(evbuf
, *pstring
, tag_len
);
559 (*pstring
)[tag_len
] = '\0';
565 evtag_unmarshal_timeval(struct evbuffer
*evbuf
, ev_uint32_t need_tag
,
570 int len
, offset
, offset2
;
573 if ((len
= evtag_unmarshal_header(evbuf
, &tag
)) == -1)
577 if ((offset
= decode_int_internal(&integer
, evbuf
, 0)) == -1)
579 ptv
->tv_sec
= integer
;
580 if ((offset2
= decode_int_internal(&integer
, evbuf
, offset
)) == -1)
582 ptv
->tv_usec
= integer
;
583 if (offset
+ offset2
> len
) /* XXX Should this be != instead of > ? */
588 evbuffer_drain(evbuf
, len
);