RTOS/rtems
1
0
Fork 0
forked from Imagelibrary/rtems
Code Pull Requests Activity

libcsupport: Add and use rtems_libio_iovec_eval()

Browse Source
This commit is contained in:
Sebastian Huber
2013-12-16 13:12:22 +01:00
parent 7b10f130e6
commit 95a57280eb
5 changed files with 122 additions and 161 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
cpukit/libcsupport/include/rtems/libio_.h
View File

@@ -21,7 +21,9 @@
#ifndef _RTEMS_RTEMS_LIBIO__H
#define _RTEMS_RTEMS_LIBIO__H
#include <sys/uio.h>
#include <errno.h>
#include <limits.h>
#include <rtems.h>
#include <rtems/libio.h>
@@ -839,6 +841,60 @@ static inline bool rtems_filesystem_is_parent_directory(
return tokenlen == 2 && token [0] == '.' && token [1] == '.';
}
static inline ssize_t rtems_libio_iovec_eval(
int fd,
const struct iovec *iov,
int iovcnt,
uint32_t flags,
rtems_libio_t **iopp
)
{
ssize_t total;
int v;
rtems_libio_t *iop;
rtems_libio_check_fd( fd );
iop = rtems_libio_iop( fd );
rtems_libio_check_is_open( iop );
rtems_libio_check_permissions_with_error( iop, flags, EBADF );
*iopp = iop;
/*
* Argument validation on IO vector
*/
if ( iov == NULL )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt <= 0 )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt > IOV_MAX )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* OpenGroup says that you are supposed to return EINVAL if the
* sum of the iov_len values in the iov array would overflow a
* ssize_t.
*/
total = 0;
for ( v = 0 ; v < iovcnt ; ++v ) {
size_t len = iov[ v ].iov_len;
if ( len > ( size_t ) ( SSIZE_MAX - total ) ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
total += ( ssize_t ) len;
if ( iov[ v ].iov_base == NULL ) {
rtems_set_errno_and_return_minus_one( EINVAL );
}
}
return total;
}
/** @} */
#ifdef __cplusplus

88
cpukit/libcsupport/src/readv.c
View File

@@ -18,11 +18,9 @@
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/uio.h>
#include <rtems/libio_.h>
#include <rtems/seterr.h>
/**
* readv() - POSIX 1003.1 - Read a Vector
@@ -39,86 +37,30 @@ ssize_t readv(
{
ssize_t total;
int v;
int bytes;
rtems_libio_t *iop;
bool all_zeros;
rtems_libio_check_fd( fd );
iop = rtems_libio_iop( fd );
rtems_libio_check_is_open( iop );
rtems_libio_check_permissions_with_error( iop, LIBIO_FLAGS_READ, EBADF );
/*
* Argument validation on IO vector
*/
if ( !iov )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt <= 0 )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt > IOV_MAX )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* OpenGroup says that you are supposed to return EINVAL if the
* sum of the iov_len values in the iov array would overflow a
* ssize_t.
*
* Also we would like to ensure that no IO is performed if there
* are obvious errors in the iovec. So this extra loop ensures
* that we do not do anything if there is an argument error.
*/
all_zeros = true;
for ( total=0, v=0 ; v < iovcnt ; v++ ) {
ssize_t old;
total = rtems_libio_iovec_eval( fd, iov, iovcnt, LIBIO_FLAGS_READ, &iop );
if ( total > 0 ) {
/*
* iov[v].iov_len cannot be less than 0 because size_t is unsigned.
* So we only check for zero.
* Now process the readv().
*/
if ( iov[v].iov_base == 0 )
rtems_set_errno_and_return_minus_one( EINVAL );
total = 0;
for ( v = 0 ; v < iovcnt ; v++ ) {
ssize_t bytes = ( *iop->pathinfo.handlers->read_h )(
iop,
iov[ v ].iov_base,
iov[ v ].iov_len
);
/* check for wrap */
old = total;
total += iov[v].iov_len;
if ( total < old )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( bytes < 0 )
return -1;
if ( iov[v].iov_len )
all_zeros = false;
}
total += bytes;
/*
* A readv with all zeros logically has no effect. Even though
* OpenGroup didn't address this case as they did with writev(),
* we will handle it the same way for symmetry.
*/
if ( all_zeros == true ) {
return 0;
}
/*
* Now process the readv().
*/
for ( total=0, v=0 ; v < iovcnt ; v++ ) {
bytes = (*iop->pathinfo.handlers->read_h)(
iop,
iov[v].iov_base,
iov[v].iov_len
);
if ( bytes < 0 )
return -1;
if ( bytes > 0 ) {
total += bytes;
if ( bytes != iov[ v ].iov_len )
break;
}
if (bytes != iov[ v ].iov_len)
break;
}
return total;

98
cpukit/libcsupport/src/writev.c
View File

@@ -1,5 +1,5 @@
/*
* writev() - POSIX 1003.1 - Read a Vector
* writev() - POSIX 1003.1 - Write a Vector
*
* OpenGroup URL:
*
@@ -17,11 +17,9 @@
#include "config.h"
#endif
#include <sys/types.h>
#include <sys/uio.h>
#include <rtems/libio_.h>
#include <rtems/seterr.h>
ssize_t writev(
int fd,
@@ -31,95 +29,31 @@ ssize_t writev(
{
ssize_t total;
int v;
int bytes;
rtems_libio_t *iop;
ssize_t old;
bool all_zeros;
rtems_libio_check_fd( fd );
iop = rtems_libio_iop( fd );
rtems_libio_check_is_open( iop );
rtems_libio_check_permissions_with_error( iop, LIBIO_FLAGS_WRITE, EBADF );
/*
* Argument validation on IO vector
*/
if ( !iov )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt <= 0 )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( iovcnt > IOV_MAX )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* OpenGroup says that you are supposed to return EINVAL if the
* sum of the iov_len values in the iov array would overflow a
* ssize_t.
*
* Also we would like to ensure that no IO is performed if there
* are obvious errors in the iovec. So this extra loop ensures
* that we do not do anything if there is an argument error.
*
* In addition,the OpenGroup specification says that if all the
* iov_len entries are zero, then the call has no effect. So
* this loop does that check as well and sets "all-zero" appropriately.
* The variable "all_zero" is used as an early exit point before
* entering the write loop.
*/
all_zeros = true;
for ( old=0, total=0, v=0 ; v < iovcnt ; v++ ) {
total = rtems_libio_iovec_eval( fd, iov, iovcnt, LIBIO_FLAGS_WRITE, &iop );
if ( total > 0 ) {
/*
* iov[v].iov_len cannot be less than 0 because size_t is unsigned.
* So we only check for zero.
* Now process the writev().
*/
if ( iov[v].iov_base == 0 )
rtems_set_errno_and_return_minus_one( EINVAL );
total = 0;
for ( v = 0 ; v < iovcnt ; v++ ) {
ssize_t bytes = ( *iop->pathinfo.handlers->write_h )(
iop,
iov[ v ].iov_base,
iov[ v ].iov_len
);
if ( iov[v].iov_len )
all_zeros = false;
if ( bytes < 0 )
return -1;
/* check for wrap */
old = total;
total += iov[v].iov_len;
if ( total < old || total > SSIZE_MAX )
rtems_set_errno_and_return_minus_one( EINVAL );
}
total += bytes;
/*
* A writev with all zeros is supposed to have no effect per OpenGroup.
*/
if ( all_zeros == true ) {
return 0;
}
/*
* Now process the writev().
*/
for ( total=0, v=0 ; v < iovcnt ; v++ ) {
/* all zero lengths has no effect */
if ( iov[v].iov_len == 0 )
continue;
bytes = (*iop->pathinfo.handlers->write_h)(
iop,
iov[v].iov_base,
iov[v].iov_len
);
if ( bytes < 0 )
return -1;
if ( bytes > 0 ) {
total += bytes;
if ( bytes != iov[ v ].iov_len )
break;
}
if (bytes != iov[ v ].iov_len)
break;
}
return total;
}