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os: Return BadLength instead of disconnecting BigReq clients (#4565)

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If a client sends a big request that's too big (i.e. bigger than
maxBigRequestSize << 2 bytes), the server just disconnects it.  This makes the
client receive SIGPIPE the next time it tries to send something.

The X Test Suite sends requests that are too big when the test specifies the
TOO_LONG test type.  When the client receives SIGPIPE, XTS marks it as
UNRESOLVED, which counts as a failure.

Instead, remember how long the request is supposed to be and then return that
size.  Dispatch() checks the length and sends BadLength to the client.  Then,
whenever oci->ignoreBytes is nonzero, ignore the data read instead of trying to
process it as a request.

Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
(cherry picked from commit cf88363db0)
This commit is contained in:
Aaron Plattner 2010-08-27 10:20:29 -07:00
parent 3336e1f7f3
commit 0ca9f07f73
2 changed files with 25 additions and 3 deletions
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27
os/io.c
View File

@ -251,7 +251,14 @@ ReadRequestFromClient(ClientPtr client)
need_header = FALSE;
move_header = FALSE;
gotnow = oci->bufcnt + oci->buffer - oci->bufptr;
if (gotnow < sizeof(xReq))
if (oci->ignoreBytes > 0) {
if (oci->ignoreBytes > oci->size)
needed = oci->size;
else
needed = oci->ignoreBytes;
}
else if (gotnow < sizeof(xReq))
{
/* We don't have an entire xReq yet. Can't tell how big
* the request will be until we get the whole xReq.
@ -294,8 +301,13 @@ ReadRequestFromClient(ClientPtr client)
if (needed > maxBigRequestSize << 2)
{
/* request is too big for us to handle */
YieldControlDeath();
return -1;
/*
* Mark the rest of it as needing to be ignored, and then return
* the full size. Dispatch() will turn it into a BadLength error.
*/
oci->ignoreBytes = needed - gotnow;
oci->lenLastReq = gotnow;
return needed;
}
if ((gotnow == 0) ||
((oci->bufptr - oci->buffer + needed) > oci->size))
@ -400,6 +412,14 @@ ReadRequestFromClient(ClientPtr client)
}
oci->lenLastReq = needed;
/* If there are bytes to ignore, ignore them now. */
if (oci->ignoreBytes > 0) {
assert(needed == oci->ignoreBytes || needed == oci->size);
oci->ignoreBytes -= gotnow;
needed = gotnow = 0;
}
/*
* Check to see if client has at least one whole request in the
* buffer beyond the request we're returning to the caller.
@ -1024,6 +1044,7 @@ AllocateInputBuffer(void)
oci->bufptr = oci->buffer;
oci->bufcnt = 0;
oci->lenLastReq = 0;
oci->ignoreBytes = 0;
return oci;
}

1
os/osdep.h
View File

@ -124,6 +124,7 @@ typedef struct _connectionInput {
int bufcnt; /* count of bytes in buffer */
int lenLastReq;
int size;
unsigned int ignoreBytes; /* bytes to ignore before the next request */
} ConnectionInput, *ConnectionInputPtr;
typedef struct _connectionOutput {