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
44 #include <sys/ioctl.h>
47 #include <sys/queue.h>
48 #ifdef EVENT__HAVE_SYS_TIME_H
59 #ifdef EVENT__HAVE_UNISTD_H
64 #include "event2/event.h"
65 #include "event2/tag.h"
66 #include "event2/buffer.h"
67 #include "log-internal.h"
68 #include "mm-internal.h"
69 #include "util-internal.h"
72 Here's our wire format:
76 TaggedData = Tag Length Data
77 where the integer value of 'Length' is the length of 'data'.
80 where HByte is a byte with the high bit set, and LByte is a byte
81 with the high bit clear. The integer value of the tag is taken
82 by concatenating the lower 7 bits from all the tags. So for example,
83 the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as
88 Integer = NNibbles Nibble* Padding?
89 where NNibbles is a 4-bit value encoding the number of nibbles-1,
90 and each Nibble is 4 bits worth of encoded integer, in big-endian
91 order. If the total encoded integer size is an odd number of nibbles,
92 a final padding nibble with value 0 is appended.
95 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf);
96 int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf);
97 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag);
98 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf);
106 * We encode integers by nibbles; the first nibble contains the number
107 * of significant nibbles - 1; this allows us to encode up to 64-bit
108 * integers. This function is byte-order independent.
110 * @param number a 32-bit unsigned integer to encode
111 * @param data a pointer to where the data should be written. Must
112 * have at least 5 bytes free.
113 * @return the number of bytes written into data.
116 #define ENCODE_INT_INTERNAL(data, number) do { \
117 int off = 1, nibbles = 0; \
119 memset(data, 0, sizeof(number)+1); \
122 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \
124 data[off/2] = (data[off/2] & 0x0f) | \
125 ((number & 0x0f) << 4); \
133 /* Off - 1 is the number of encoded nibbles */ \
134 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \
136 return ((off + 1) / 2); \
140 encode_int_internal(ev_uint8_t *data, ev_uint32_t number)
142 ENCODE_INT_INTERNAL(data, number);
146 encode_int64_internal(ev_uint8_t *data, ev_uint64_t number)
148 ENCODE_INT_INTERNAL(data, number);
152 evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number)
155 int len = encode_int_internal(data, number);
156 evbuffer_add(evbuf, data, len);
160 evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number)
163 int len = encode_int64_internal(data, number);
164 evbuffer_add(evbuf, data, len);
168 * Support variable length encoding of tags; we use the high bit in each
169 * octet as a continuation signal.
173 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag)
178 memset(data, 0, sizeof(data));
180 ev_uint8_t lower = tag & 0x7f;
186 data[bytes++] = lower;
190 evbuffer_add(evbuf, data, bytes);
196 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain)
198 ev_uint32_t number = 0;
199 size_t len = evbuffer_get_length(evbuf);
202 int shift = 0, done = 0;
205 * the encoding of a number is at most one byte more than its
206 * storage size. however, it may also be much smaller.
208 data = evbuffer_pullup(
209 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1);
213 while (count++ < len) {
214 ev_uint8_t lower = *data++;
216 /* Make sure it fits into 32 bits */
219 if ((lower & 0x7f) > 15)
222 number |= (lower & (unsigned)0x7f) << shift;
225 if (!(lower & 0x80)) {
235 evbuffer_drain(evbuf, count);
240 return count > INT_MAX ? INT_MAX : (int)(count);
244 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf)
246 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */));
250 * Marshal a data type, the general format is as follows:
252 * tag number: one byte; length: var bytes; payload: var bytes
256 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag,
257 const void *data, ev_uint32_t len)
259 evtag_encode_tag(evbuf, tag);
260 evtag_encode_int(evbuf, len);
261 evbuffer_add(evbuf, (void *)data, len);
265 evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
266 struct evbuffer *data)
268 evtag_encode_tag(evbuf, tag);
269 /* XXX support more than UINT32_MAX data */
270 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data));
271 evbuffer_add_buffer(evbuf, data);
274 /* Marshaling for integers */
276 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
279 int len = encode_int_internal(data, integer);
281 evtag_encode_tag(evbuf, tag);
282 evtag_encode_int(evbuf, len);
283 evbuffer_add(evbuf, data, len);
287 evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
291 int len = encode_int64_internal(data, integer);
293 evtag_encode_tag(evbuf, tag);
294 evtag_encode_int(evbuf, len);
295 evbuffer_add(evbuf, data, len);
299 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string)
301 /* TODO support strings longer than UINT32_MAX ? */
302 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string));
306 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
309 int len = encode_int_internal(data, tv->tv_sec);
310 len += encode_int_internal(data + len, tv->tv_usec);
311 evtag_marshal(evbuf, tag, data, len);
314 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \
317 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \
323 /* XXX(niels): faster? */ \
324 data = evbuffer_pullup(evbuf, offset + 1) + offset; \
328 nibbles = ((data[0] & 0xf0) >> 4) + 1; \
329 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \
331 len = (nibbles >> 1) + 1; \
333 data = evbuffer_pullup(evbuf, offset + len) + offset; \
337 while (nibbles > 0) { \
340 number |= data[nibbles >> 1] & 0x0f; \
342 number |= (data[nibbles >> 1] & 0xf0) >> 4; \
351 /* Internal: decode an integer from an evbuffer, without draining it.
352 * Only integers up to 32-bits are supported.
354 * @param evbuf the buffer to read from
355 * @param offset an index into the buffer at which we should start reading.
356 * @param pnumber a pointer to receive the integer.
357 * @return The length of the number as encoded, or -1 on error.
361 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset)
363 ev_uint32_t number = 0;
364 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset);
368 decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset)
370 ev_uint64_t number = 0;
371 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset);
375 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf)
377 int res = decode_int_internal(pnumber, evbuf, 0);
379 evbuffer_drain(evbuf, res);
381 return (res == -1 ? -1 : 0);
385 evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf)
387 int res = decode_int64_internal(pnumber, evbuf, 0);
389 evbuffer_drain(evbuf, res);
391 return (res == -1 ? -1 : 0);
395 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag)
397 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */));
401 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength)
405 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
409 res = decode_int_internal(plength, evbuf, len);
413 *plength += res + len;
419 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength)
423 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
427 res = decode_int_internal(plength, evbuf, len);
434 /* just unmarshals the header and returns the length of the remaining data */
437 evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag)
441 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1)
443 if (evtag_decode_int(&len, evbuf) == -1)
446 if (evbuffer_get_length(evbuf) < len)
453 evtag_consume(struct evbuffer *evbuf)
456 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1)
458 evbuffer_drain(evbuf, len);
463 /* Reads the data type from an event buffer */
466 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst)
470 if ((len = evtag_unmarshal_header(src, ptag)) == -1)
473 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1)
476 evbuffer_drain(src, len);
481 /* Marshaling for integers */
484 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
485 ev_uint32_t *pinteger)
491 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
495 if (evtag_decode_int(&len, evbuf) == -1)
498 if (evbuffer_get_length(evbuf) < len)
501 result = decode_int_internal(pinteger, evbuf, 0);
502 evbuffer_drain(evbuf, len);
503 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
510 evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
511 ev_uint64_t *pinteger)
517 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
521 if (evtag_decode_int(&len, evbuf) == -1)
524 if (evbuffer_get_length(evbuf) < len)
527 result = decode_int64_internal(pinteger, evbuf, 0);
528 evbuffer_drain(evbuf, len);
529 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
535 /* Unmarshal a fixed length tag */
538 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data,
544 /* Now unmarshal a tag and check that it matches the tag we want */
545 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 ||
549 if ((size_t)tag_len != len)
552 evbuffer_remove(src, data, len);
557 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
563 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 ||
567 *pstring = mm_malloc(tag_len + 1);
568 if (*pstring == NULL) {
569 event_warn("%s: malloc", __func__);
572 evbuffer_remove(evbuf, *pstring, tag_len);
573 (*pstring)[tag_len] = '\0';
579 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
584 int len, offset, offset2;
587 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1)
591 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1)
593 ptv->tv_sec = integer;
594 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1)
596 ptv->tv_usec = integer;
597 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */
602 evbuffer_drain(evbuf, len);