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/*
* Fake write and writev functions for testing xwrite and xwritev.
*
* The canonical version of this file is maintained in the rra-c-util package,
* which can be found at <http://www.eyrie.org/~eagle/software/rra-c-util/>.
*
* Copyright 2000, 2001, 2002, 2004 Russ Allbery <eagle@eyrie.org>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
#include <config.h>
#include <portable/system.h>
#include <portable/uio.h>
#include <errno.h>
#include <util/macros.h>
ssize_t fake_write(int, const void *, size_t);
ssize_t fake_pwrite(int, const void *, size_t, off_t);
ssize_t fake_writev(int, const struct iovec *, int);
/*
* All the data is actually written into this buffer. We use write_offset
* to track how far we've written.
*/
char write_buffer[256];
size_t write_offset = 0;
/*
* If write_interrupt is non-zero, then half of the calls to write or writev
* will fail, returning -1 with errno set to EINTR.
*/
int write_interrupt = 0;
/*
* If write_fail is non-zero, all writes or writevs will return 0, indicating
* no progress in writing out the buffer.
*/
int write_fail = 0;
/*
* Accept a write request and write only the first 32 bytes of it into
* write_buffer (or as much as will fit), returning the amount written.
*/
ssize_t
fake_write(int fd UNUSED, const void *data, size_t n)
{
size_t total;
if (write_fail)
return 0;
if (write_interrupt && (write_interrupt++ % 2) == 0) {
errno = EINTR;
return -1;
}
total = (n < 32) ? n : 32;
if (256 - write_offset < total)
total = 256 - write_offset;
memcpy(write_buffer + write_offset, data, total);
write_offset += total;
return total;
}
/*
* Accept a pwrite request and write only the first 32 bytes of it into
* write_buffer at the specified offset (or as much as will fit), returning
* the amount written.
*/
ssize_t
fake_pwrite(int fd UNUSED, const void *data, size_t n, off_t offset)
{
size_t total;
if (write_fail)
return 0;
if (write_interrupt && (write_interrupt++ % 2) == 0) {
errno = EINTR;
return -1;
}
total = (n < 32) ? n : 32;
if (offset > 256) {
errno = ENOSPC;
return -1;
}
if ((size_t) (256 - offset) < total)
total = 256 - offset;
memcpy(write_buffer + offset, data, total);
return total;
}
/*
* Accept an xwrite request and write only the first 32 bytes of it into
* write_buffer (or as much as will fit), returning the amount written.
*/
ssize_t
fake_writev(int fd UNUSED, const struct iovec *iov, int iovcnt)
{
int total, i;
size_t left, n;
if (write_fail)
return 0;
if (write_interrupt && (write_interrupt++ % 2) == 0) {
errno = EINTR;
return -1;
}
left = 256 - write_offset;
if (left > 32)
left = 32;
total = 0;
for (i = 0; i < iovcnt && left != 0; i++) {
n = ((size_t) iov[i].iov_len < left) ? (size_t) iov[i].iov_len : left;
memcpy(write_buffer + write_offset, iov[i].iov_base, n);
write_offset += n;
total += n;
left -= n;
}
return total;
}
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