Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

592 lines (494 sloc) 14.347 kb
/*
* Copyright (c) 2003-2009 Niels Provos <provos@citi.umich.edu>
* Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef EVENT__HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef EVENT__HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#else
#include <sys/ioctl.h>
#endif
#include <sys/queue.h>
#ifdef EVENT__HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef _WIN32
#include <syslog.h>
#endif
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <limits.h>
#include "event2/event.h"
#include "event2/tag.h"
#include "event2/buffer.h"
#include "log-internal.h"
#include "mm-internal.h"
#include "util-internal.h"
/*
Here's our wire format:
Stream = TaggedData*
TaggedData = Tag Length Data
where the integer value of 'Length' is the length of 'data'.
Tag = HByte* LByte
where HByte is a byte with the high bit set, and LByte is a byte
with the high bit clear. The integer value of the tag is taken
by concatenating the lower 7 bits from all the tags. So for example,
the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as
[82 66]
Length = Integer
Integer = NNibbles Nibble* Padding?
where NNibbles is a 4-bit value encoding the number of nibbles-1,
and each Nibble is 4 bits worth of encoded integer, in big-endian
order. If the total encoded integer size is an odd number of nibbles,
a final padding nibble with value 0 is appended.
*/
int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf);
int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf);
int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag);
int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf);
void
evtag_init(void)
{
}
/*
* We encode integers by nibbles; the first nibble contains the number
* of significant nibbles - 1; this allows us to encode up to 64-bit
* integers. This function is byte-order independent.
*
* @param number a 32-bit unsigned integer to encode
* @param data a pointer to where the data should be written. Must
* have at least 5 bytes free.
* @return the number of bytes written into data.
*/
#define ENCODE_INT_INTERNAL(data, number) do { \
int off = 1, nibbles = 0; \
\
memset(data, 0, sizeof(number)+1); \
while (number) { \
if (off & 0x1) \
data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \
else \
data[off/2] = (data[off/2] & 0x0f) | \
((number & 0x0f) << 4); \
number >>= 4; \
off++; \
} \
\
if (off > 2) \
nibbles = off - 2; \
\
/* Off - 1 is the number of encoded nibbles */ \
data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \
\
return ((off + 1) / 2); \
} while (0)
static inline int
encode_int_internal(ev_uint8_t *data, ev_uint32_t number)
{
ENCODE_INT_INTERNAL(data, number);
}
static inline int
encode_int64_internal(ev_uint8_t *data, ev_uint64_t number)
{
ENCODE_INT_INTERNAL(data, number);
}
void
evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number)
{
ev_uint8_t data[5];
int len = encode_int_internal(data, number);
evbuffer_add(evbuf, data, len);
}
void
evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number)
{
ev_uint8_t data[9];
int len = encode_int64_internal(data, number);
evbuffer_add(evbuf, data, len);
}
/*
* Support variable length encoding of tags; we use the high bit in each
* octet as a continuation signal.
*/
int
evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag)
{
int bytes = 0;
ev_uint8_t data[5];
memset(data, 0, sizeof(data));
do {
ev_uint8_t lower = tag & 0x7f;
tag >>= 7;
if (tag)
lower |= 0x80;
data[bytes++] = lower;
} while (tag);
if (evbuf != NULL)
evbuffer_add(evbuf, data, bytes);
return (bytes);
}
static int
decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain)
{
ev_uint32_t number = 0;
size_t len = evbuffer_get_length(evbuf);
ev_uint8_t *data;
size_t count = 0;
int shift = 0, done = 0;
/*
* the encoding of a number is at most one byte more than its
* storage size. however, it may also be much smaller.
*/
data = evbuffer_pullup(
evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1);
while (count++ < len) {
ev_uint8_t lower = *data++;
number |= (lower & 0x7f) << shift;
shift += 7;
if (!(lower & 0x80)) {
done = 1;
break;
}
}
if (!done)
return (-1);
if (dodrain)
evbuffer_drain(evbuf, count);
if (ptag != NULL)
*ptag = number;
return count > INT_MAX ? INT_MAX : (int)(count);
}
int
evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf)
{
return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */));
}
/*
* Marshal a data type, the general format is as follows:
*
* tag number: one byte; length: var bytes; payload: var bytes
*/
void
evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag,
const void *data, ev_uint32_t len)
{
evtag_encode_tag(evbuf, tag);
evtag_encode_int(evbuf, len);
evbuffer_add(evbuf, (void *)data, len);
}
void
evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag,
struct evbuffer *data)
{
evtag_encode_tag(evbuf, tag);
/* XXX support more than UINT32_MAX data */
evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data));
evbuffer_add_buffer(evbuf, data);
}
/* Marshaling for integers */
void
evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
{
ev_uint8_t data[5];
int len = encode_int_internal(data, integer);
evtag_encode_tag(evbuf, tag);
evtag_encode_int(evbuf, len);
evbuffer_add(evbuf, data, len);
}
void
evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag,
ev_uint64_t integer)
{
ev_uint8_t data[9];
int len = encode_int64_internal(data, integer);
evtag_encode_tag(evbuf, tag);
evtag_encode_int(evbuf, len);
evbuffer_add(evbuf, data, len);
}
void
evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string)
{
/* TODO support strings longer than UINT32_MAX ? */
evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string));
}
void
evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
{
ev_uint8_t data[10];
int len = encode_int_internal(data, tv->tv_sec);
len += encode_int_internal(data + len, tv->tv_usec);
evtag_marshal(evbuf, tag, data, len);
}
#define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \
do { \
ev_uint8_t *data; \
ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \
int nibbles = 0; \
\
if (len <= 0) \
return (-1); \
\
/* XXX(niels): faster? */ \
data = evbuffer_pullup(evbuf, offset + 1) + offset; \
\
nibbles = ((data[0] & 0xf0) >> 4) + 1; \
if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \
return (-1); \
len = (nibbles >> 1) + 1; \
\
data = evbuffer_pullup(evbuf, offset + len) + offset; \
\
while (nibbles > 0) { \
number <<= 4; \
if (nibbles & 0x1) \
number |= data[nibbles >> 1] & 0x0f; \
else \
number |= (data[nibbles >> 1] & 0xf0) >> 4; \
nibbles--; \
} \
\
*pnumber = number; \
\
return (int)(len); \
} while (0)
/* Internal: decode an integer from an evbuffer, without draining it.
* Only integers up to 32-bits are supported.
*
* @param evbuf the buffer to read from
* @param offset an index into the buffer at which we should start reading.
* @param pnumber a pointer to receive the integer.
* @return The length of the number as encoded, or -1 on error.
*/
static int
decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset)
{
ev_uint32_t number = 0;
DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset);
}
static int
decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset)
{
ev_uint64_t number = 0;
DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset);
}
int
evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf)
{
int res = decode_int_internal(pnumber, evbuf, 0);
if (res != -1)
evbuffer_drain(evbuf, res);
return (res == -1 ? -1 : 0);
}
int
evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf)
{
int res = decode_int64_internal(pnumber, evbuf, 0);
if (res != -1)
evbuffer_drain(evbuf, res);
return (res == -1 ? -1 : 0);
}
int
evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag)
{
return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */));
}
int
evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength)
{
int res, len;
len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
if (len == -1)
return (-1);
res = decode_int_internal(plength, evbuf, len);
if (res == -1)
return (-1);
*plength += res + len;
return (0);
}
int
evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength)
{
int res, len;
len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
if (len == -1)
return (-1);
res = decode_int_internal(plength, evbuf, len);
if (res == -1)
return (-1);
return (0);
}
/* just unmarshals the header and returns the length of the remaining data */
int
evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag)
{
ev_uint32_t len;
if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1)
return (-1);
if (evtag_decode_int(&len, evbuf) == -1)
return (-1);
if (evbuffer_get_length(evbuf) < len)
return (-1);
return (len);
}
int
evtag_consume(struct evbuffer *evbuf)
{
int len;
if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1)
return (-1);
evbuffer_drain(evbuf, len);
return (0);
}
/* Reads the data type from an event buffer */
int
evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst)
{
int len;
if ((len = evtag_unmarshal_header(src, ptag)) == -1)
return (-1);
if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1)
return (-1);
evbuffer_drain(src, len);
return (len);
}
/* Marshaling for integers */
int
evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
ev_uint32_t *pinteger)
{
ev_uint32_t tag;
ev_uint32_t len;
int result;
if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
return (-1);
if (need_tag != tag)
return (-1);
if (evtag_decode_int(&len, evbuf) == -1)
return (-1);
if (evbuffer_get_length(evbuf) < len)
return (-1);
result = decode_int_internal(pinteger, evbuf, 0);
evbuffer_drain(evbuf, len);
if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
return (-1);
else
return result;
}
int
evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag,
ev_uint64_t *pinteger)
{
ev_uint32_t tag;
ev_uint32_t len;
int result;
if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
return (-1);
if (need_tag != tag)
return (-1);
if (evtag_decode_int(&len, evbuf) == -1)
return (-1);
if (evbuffer_get_length(evbuf) < len)
return (-1);
result = decode_int64_internal(pinteger, evbuf, 0);
evbuffer_drain(evbuf, len);
if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/
return (-1);
else
return result;
}
/* Unmarshal a fixed length tag */
int
evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data,
size_t len)
{
ev_uint32_t tag;
int tag_len;
/* Now unmarshal a tag and check that it matches the tag we want */
if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 ||
tag != need_tag)
return (-1);
if ((size_t)tag_len != len)
return (-1);
evbuffer_remove(src, data, len);
return (0);
}
int
evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
char **pstring)
{
ev_uint32_t tag;
int tag_len;
if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 ||
tag != need_tag)
return (-1);
*pstring = mm_malloc(tag_len + 1);
if (*pstring == NULL) {
event_warn("%s: malloc", __func__);
return -1;
}
evbuffer_remove(evbuf, *pstring, tag_len);
(*pstring)[tag_len] = '\0';
return (0);
}
int
evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
struct timeval *ptv)
{
ev_uint32_t tag;
ev_uint32_t integer;
int len, offset, offset2;
int result = -1;
if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1)
return (-1);
if (tag != need_tag)
goto done;
if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1)
goto done;
ptv->tv_sec = integer;
if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1)
goto done;
ptv->tv_usec = integer;
if (offset + offset2 > len) /* XXX Should this be != instead of > ? */
goto done;
result = 0;
done:
evbuffer_drain(evbuf, len);
return result;
}
Jump to Line
Something went wrong with that request. Please try again.