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r15242@tombo: nickm | 2008-04-18 09:24:44 -0400

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Make tagging code thread-safe, and fix a bug in encode_int_internal


svn:r721
This commit is contained in:
Nick Mathewson 2008-04-18 13:25:05 +00:00
parent a2d4a06298
commit 8d2a61605b
2 changed files with 38 additions and 24 deletions
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1
ChangeLog
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@ -67,6 +67,7 @@ Changes in current version:
o Correctly handle timeouts larger than 35 minutes on Linux with epoll.c. This is probably a kernel defect, but we'll have to support old kernels anyway even if it gets fixed.
o Make name_from_addr() threadsafe in http.c
o Add new thread-safe interfaces to evdns functions.
o Make all event_tagging interfaces threadsafe.
Changes in 1.4.0:
o allow \r or \n individually to separate HTTP headers instead of the standard "\r\n"; from Charles Kerr.

61
event_tagging.c
View File

@ -71,22 +71,20 @@ 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
/*
* 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.
*/
static inline int
@ -94,7 +92,7 @@ encode_int_internal(ev_uint8_t *data, ev_uint32_t number)
{
int off = 1, nibbles = 0;
memset(data, 0, sizeof(data));
memset(data, 0, sizeof(uint32_t)+1);
while (number) {
if (off & 0x1)
data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f);
@ -245,6 +243,14 @@ evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *t
evtag_marshal(evbuf, tag, data, len);
}
/* 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)
{
@ -386,6 +392,7 @@ evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
ev_uint32_t tag;
ev_uint32_t len;
ev_uint32_t integer;
int result;
if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1)
return (-1);
@ -397,14 +404,13 @@ evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag,
if (EVBUFFER_LENGTH(evbuf) < len)
return (-1);
evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf));
if (evbuffer_add(_buf, evbuffer_pullup(evbuf, len), len) == -1)
return (-1);
result = decode_int_internal(pinteger, evbuf, 0);
evbuffer_drain(evbuf, len);
return (evtag_decode_int(pinteger, _buf));
if (result < 0 || result > len) /* XXX Should this be != rather than > ?*/
return (-1);
else
return result;
}
/* Unmarshal a fixed length tag */
@ -454,17 +460,24 @@ evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
{
ev_uint32_t tag;
ev_uint32_t integer;
int len, offset, offset2;
int result = -1;
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)
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 (evtag_decode_int(&integer, _buf) == -1)
return (-1);
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;
return (0);
result = 0;
done:
evbuffer_drain(evbuf, len);
return result;
}