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

444 lines (353 sloc) 9.764 kb
/*
* Copyright (c) 2003, 2004 Niels Provos <provos@citi.umich.edu>
* All rights reserved.
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef 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 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 HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "event.h"
#include "evutil.h"
#include "log.h"
int evtag_decode_int(ev_uint32_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);
static struct evbuffer *_buf; /* not thread safe */
void
evtag_init(void)
{
if (_buf != NULL)
return;
if ((_buf = evbuffer_new()) == NULL)
event_err(1, "%s: malloc", __func__);
}
/*
* We encode integer's 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.
*/
void
encode_int(struct evbuffer *evbuf, ev_uint32_t number)
{
int off = 1, nibbles = 0;
ev_uint8_t data[5];
memset(data, 0, sizeof(data));
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);
evbuffer_add(evbuf, data, (off + 1) / 2);
}
/*
* 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;
ev_uint8_t *data = EVBUFFER_DATA(evbuf);
int len = EVBUFFER_LENGTH(evbuf);
int count = 0, shift = 0, done = 0;
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
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);
encode_int(evbuf, len);
evbuffer_add(evbuf, (void *)data, len);
}
/* Marshaling for integers */
void
evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer)
{
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
encode_int(_buf, integer);
evtag_encode_tag(evbuf, tag);
encode_int(evbuf, EVBUFFER_LENGTH(_buf));
evbuffer_add_buffer(evbuf, _buf);
}
void
evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string)
{
evtag_marshal(buf, tag, string, strlen(string));
}
void
evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv)
{
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
encode_int(_buf, tv->tv_sec);
encode_int(_buf, tv->tv_usec);
evtag_marshal(evbuf, tag, EVBUFFER_DATA(_buf),
EVBUFFER_LENGTH(_buf));
}
static int
decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int dodrain)
{
ev_uint32_t number = 0;
ev_uint8_t *data = EVBUFFER_DATA(evbuf);
int len = EVBUFFER_LENGTH(evbuf);
int nibbles = 0;
if (!len)
return (-1);
nibbles = ((data[0] & 0xf0) >> 4) + 1;
if (nibbles > 8 || (nibbles >> 1) + 1 > len)
return (-1);
len = (nibbles >> 1) + 1;
while (nibbles > 0) {
number <<= 4;
if (nibbles & 0x1)
number |= data[nibbles >> 1] & 0x0f;
else
number |= (data[nibbles >> 1] & 0xf0) >> 4;
nibbles--;
}
if (dodrain)
evbuffer_drain(evbuf, len);
*pnumber = number;
return (len);
}
int
evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf)
{
return (decode_int_internal(pnumber, evbuf, 1) == -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)
{
struct evbuffer tmp;
int res, len;
len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
if (len == -1)
return (-1);
tmp = *evbuf;
tmp.buffer += len;
tmp.off -= len;
res = decode_int_internal(plength, &tmp, 0);
if (res == -1)
return (-1);
*plength += res + len;
return (0);
}
int
evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength)
{
struct evbuffer tmp;
int res, len;
len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */);
if (len == -1)
return (-1);
tmp = *evbuf;
tmp.buffer += len;
tmp.off -= len;
res = decode_int_internal(plength, &tmp, 0);
if (res == -1)
return (-1);
return (0);
}
int
evtag_consume(struct evbuffer *evbuf)
{
ev_uint32_t len;
if (decode_tag_internal(NULL, evbuf, 1 /* dodrain */) == -1)
return (-1);
if (evtag_decode_int(&len, evbuf) == -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)
{
ev_uint32_t len;
ev_uint32_t integer;
if (decode_tag_internal(ptag, src, 1 /* dodrain */) == -1)
return (-1);
if (evtag_decode_int(&integer, src) == -1)
return (-1);
len = integer;
if (EVBUFFER_LENGTH(src) < len)
return (-1);
if (evbuffer_add(dst, EVBUFFER_DATA(src), 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;
ev_uint32_t integer;
if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
return (-1);
if (need_tag != tag)
return (-1);
if (evtag_decode_int(&integer, evbuf) == -1)
return (-1);
len = integer;
if (EVBUFFER_LENGTH(evbuf) < len)
return (-1);
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
if (evbuffer_add(_buf, EVBUFFER_DATA(evbuf), len) == -1)
return (-1);
evbuffer_drain(evbuf, len);
return (evtag_decode_int(pinteger, _buf));
}
/* 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;
/* Initialize this event buffer so that we can read into it */
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
/* Now unmarshal a tag and check that it matches the tag we want */
if (evtag_unmarshal(src, &tag, _buf) == -1 || tag != need_tag)
return (-1);
if (EVBUFFER_LENGTH(_buf) != len)
return (-1);
memcpy(data, EVBUFFER_DATA(_buf), len);
return (0);
}
int
evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag,
char **pstring)
{
ev_uint32_t tag;
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag)
return (-1);
*pstring = calloc(EVBUFFER_LENGTH(_buf) + 1, 1);
if (*pstring == NULL)
event_err(1, "%s: calloc", __func__);
evbuffer_remove(_buf, *pstring, EVBUFFER_LENGTH(_buf));
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;
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag)
return (-1);
if (evtag_decode_int(&integer, _buf) == -1)
return (-1);
ptv->tv_sec = integer;
if (evtag_decode_int(&integer, _buf) == -1)
return (-1);
ptv->tv_usec = integer;
return (0);
}
Jump to Line
Something went wrong with that request. Please try again.