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API/ABI change: XCBSendRequest callers must pad to 4-byte boundaries now. When not in RAW mode, a null pointer for iov_base is replaced by up to 3 padding bytes.

This commit is contained in:
Jamey Sharp 2006-03-02 15:35:31 -08:00
parent ed823bf651
commit 5e115e2441
3 changed files with 29 additions and 54 deletions
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1
configure.ac
View File

@ -45,7 +45,6 @@ AC_MSG_RESULT($XCBPROTO_XCBINCLUDEDIR)
AC_SUBST(XCBPROTO_XCBINCLUDEDIR)
AC_HEADER_STDC
AC_FUNC_ALLOCA
AC_SEARCH_LIBS(gethostbyname, nsl)
AC_SEARCH_LIBS(connect, socket)

12
src/c-client.xsl
View File

@ -567,7 +567,7 @@ authorization from the authors.
<xsl:variable name="struct"
select="$pass1/xcb/struct[@name=current()/@ref]" />
<xsl:variable name="num-parts" select="1+count($struct/list)" />
<xsl:variable name="num-parts" select="1+count($struct/list)*2" />
<l>static const XCBProtocolRequest xcb_req = {</l>
<indent>
@ -586,7 +586,7 @@ authorization from the authors.
<l>};</l>
<l />
<l>struct iovec xcb_parts[<xsl:value-of select="$num-parts" />];</l>
<l>struct iovec xcb_parts[<xsl:value-of select="$num-parts+2" />];</l>
<l><xsl:value-of select="../@type" /> xcb_ret;</l>
<l><xsl:value-of select="@ref" /> xcb_out;</l>
@ -598,17 +598,21 @@ authorization from the authors.
<l />
<l>xcb_parts[0].iov_base = &amp;xcb_out;</l>
<l>xcb_parts[0].iov_len = sizeof(xcb_out);</l>
<l>xcb_parts[1].iov_base = 0;</l>
<l>xcb_parts[1].iov_len = -xcb_parts[0].iov_len &amp; 3;</l>
<xsl:for-each select="$struct/list">
<l>xcb_parts[<xsl:number />].iov_base = (void *) <!--
<l>xcb_parts[<xsl:number /> * 2].iov_base = (void *) <!--
--><xsl:value-of select="@name" />;</l>
<l>xcb_parts[<xsl:number />].iov_len = <!--
<l>xcb_parts[<xsl:number /> * 2].iov_len = <!--
--><xsl:apply-templates mode="output-expression" /><!--
--><xsl:if test="not(@type = 'void')">
<xsl:text> * sizeof(</xsl:text>
<xsl:value-of select="@type" />
<xsl:text>)</xsl:text>
</xsl:if>;</l>
<l>xcb_parts[<xsl:number /> * 2 + 1].iov_base = 0;</l>
<l>xcb_parts[<xsl:number /> * 2 + 1].iov_len = -xcb_parts[<xsl:number /> * 2].iov_len &amp; 3;</l>
</xsl:for-each>
<l>XCBSendRequest(c, &amp;xcb_ret.sequence, <!--

70
src/xcb_out.c
View File

@ -31,16 +31,6 @@
#include <string.h>
#include <errno.h>
#ifndef __GNUC__
# if HAVE_ALLOCA_H
# include <alloca.h>
# else
# ifdef _AIX
#pragma alloca
# endif
# endif
#endif
#include "xcb.h"
#include "xcbext.h"
#include "xcbint.h"
@ -81,12 +71,9 @@ CARD32 XCBGetMaximumRequestLength(XCBConnection *c)
int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct iovec *vector, const XCBProtocolRequest *req)
{
static const char pad[3];
int ret;
int i;
CARD32 prefix[2];
struct iovec *padded;
int padlen = 0;
int veclen = req->count;
enum workarounds workaround = WORKAROUND_NONE;
assert(c != 0);
@ -94,18 +81,12 @@ int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct io
assert(vector != 0);
assert(req->count > 0);
padded =
#ifdef HAVE_ALLOCA
alloca
#else
malloc
#endif
((req->count * 2 + 2) * sizeof(struct iovec));
if(!(flags & XCB_REQUEST_RAW))
{
static const char pad[3];
int i;
CARD16 shortlen = 0;
CARD32 longlen = 0;
size_t longlen = 0;
/* set the major opcode, and the minor opcode for extensions */
if(req->ext)
{
@ -120,7 +101,16 @@ int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct io
/* put together the length field, possibly using BIGREQUESTS */
for(i = 0; i < req->count; ++i)
longlen += (vector[i].iov_len + 3) >> 2;
{
longlen += vector[i].iov_len;
if(!vector[i].iov_base)
{
vector[i].iov_base = (caddr_t) pad;
assert(vector[i].iov_len <= sizeof(pad));
}
}
assert((longlen & 3) == 0);
longlen >>= 2;
if(longlen <= c->setup->maximum_request_length)
{
@ -135,29 +125,18 @@ int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct io
((CARD16 *) vector[0].iov_base)[1] = shortlen;
if(!shortlen)
{
padded[0].iov_base = prefix;
padded[0].iov_len = sizeof(prefix);
memmove(vector + 1, vector, veclen++ * sizeof(*vector));
++veclen;
vector[0].iov_base = prefix;
vector[0].iov_len = sizeof(prefix);
prefix[0] = ((CARD32 *) vector[0].iov_base)[0];
prefix[1] = ++longlen;
vector[0].iov_base = ((char *) vector[0].iov_base) + sizeof(CARD32);
vector[0].iov_len -= sizeof(CARD32);
padlen = 1;
vector[1].iov_base = ((char *) vector[1].iov_base) + sizeof(CARD32);
vector[1].iov_len -= sizeof(CARD32);
}
}
flags &= ~XCB_REQUEST_RAW;
for(i = 0; i < req->count; ++i)
{
if(!vector[i].iov_len)
continue;
padded[padlen].iov_base = vector[i].iov_base;
padded[padlen++].iov_len = vector[i].iov_len;
if(!XCB_PAD(vector[i].iov_len))
continue;
padded[padlen].iov_base = (caddr_t) pad;
padded[padlen++].iov_len = XCB_PAD(vector[i].iov_len);
}
/* do we need to work around the X server bug described in glx.xml? */
if(req->ext && !req->isvoid && strcmp(req->ext->name, "GLX") &&
((req->opcode == 17 && ((CARD32 *) vector[0].iov_base)[0] == 0x10004) ||
@ -169,9 +148,6 @@ int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct io
if(req->isvoid && !force_sequence_wrap(c))
{
pthread_mutex_unlock(&c->iolock);
#ifndef HAVE_ALLOCA
free(padded);
#endif
return -1;
}
@ -183,12 +159,8 @@ int XCBSendRequest(XCBConnection *c, unsigned int *request, int flags, struct io
_xcb_in_expect_reply(c, *request, workaround, flags);
ret = _xcb_out_write_block(c, padded, padlen);
ret = _xcb_out_write_block(c, vector, veclen);
pthread_mutex_unlock(&c->iolock);
#ifndef HAVE_ALLOCA
free(padded);
#endif
return ret;
}