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/*
* Unix SMB/CIFS implementation.
* Samba system utilities
* Copyright (C) Andrew Tridgell 1992-1998
* Copyright (C) Jeremy Allison 1998-2005
* Copyright (C) Timur Bakeyev 2005
* Copyright (C) Bjoern Jacke 2006-2007
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "system/filesys.h"
#include "lib/util/sys_rw.h"
bool sys_valid_io_range(off_t offset, size_t length)
{
uint64_t last_byte_ofs;
if (offset < 0) {
return false;
}
if (offset > INT64_MAX) {
return false;
}
if (length > UINT32_MAX) {
return false;
}
last_byte_ofs = (uint64_t)offset + (uint64_t)length;
if (last_byte_ofs > INT64_MAX) {
return false;
}
return true;
}
/*******************************************************************
A read wrapper that will deal with EINTR/EWOULDBLOCK
********************************************************************/
ssize_t sys_read(int fd, void *buf, size_t count)
{
ssize_t ret;
do {
ret = read(fd, buf, count);
} while (ret == -1 && (errno == EINTR || errno == EAGAIN ||
errno == EWOULDBLOCK));
return ret;
}
/**
* read wrapper, void variant:
* This is intended to be used as a void variant of
* read in situations where the caller wants to ignore
* the result. Hence not checking for EAGAIN|EWOULDBLOCK.
*/
void sys_read_v(int fd, void *buf, size_t count)
{
ssize_t ret;
do {
ret = read(fd, buf, count);
} while (ret == -1 && errno == EINTR);
}
/*******************************************************************
A write wrapper that will deal with EINTR/EWOULDBLOCK.
********************************************************************/
ssize_t sys_write(int fd, const void *buf, size_t count)
{
ssize_t ret;
do {
ret = write(fd, buf, count);
} while (ret == -1 && (errno == EINTR || errno == EAGAIN ||
errno == EWOULDBLOCK));
return ret;
}
/**
* write wrapper to deal with EINTR and friends.
* void-variant that ignores the number of bytes written.
* This is intended to be used as a void variant of
* write in situations where the caller wants to ignore
* the result. Hence not checking for EAGAIN|EWOULDBLOCK.
*/
void sys_write_v(int fd, const void *buf, size_t count)
{
ssize_t ret;
do {
ret = write(fd, buf, count);
} while (ret == -1 && errno == EINTR);
}
/*******************************************************************
A writev wrapper that will deal with EINTR.
********************************************************************/
ssize_t sys_writev(int fd, const struct iovec *iov, int iovcnt)
{
ssize_t ret;
do {
ret = writev(fd, iov, iovcnt);
} while (ret == -1 && (errno == EINTR || errno == EAGAIN ||
errno == EWOULDBLOCK));
return ret;
}
/*******************************************************************
A pread wrapper that will deal with EINTR
********************************************************************/
ssize_t sys_pread(int fd, void *buf, size_t count, off_t off)
{
ssize_t ret;
do {
ret = pread(fd, buf, count, off);
} while (ret == -1 && errno == EINTR);
return ret;
}
/*******************************************************************
A pread wrapper that will deal with EINTR and never return a short
read unless pread returns zero meaning EOF.
********************************************************************/
ssize_t sys_pread_full(int fd, void *buf, size_t count, off_t off)
{
ssize_t total_read = 0;
uint8_t *curr_buf = (uint8_t *)buf;
size_t curr_count = count;
off_t curr_off = off;
bool ok;
ok = sys_valid_io_range(off, count);
if (!ok) {
errno = EINVAL;
return -1;
}
while (curr_count != 0) {
ssize_t ret = sys_pread(fd,
curr_buf,
curr_count,
curr_off);
if (ret == -1) {
return -1;
}
if (ret == 0) {
/* EOF */
break;
}
if (ret > curr_count) {
errno = EIO;
return -1;
}
curr_buf += ret;
curr_count -= ret;
curr_off += ret;
total_read += ret;
}
return total_read;
}
/*******************************************************************
A write wrapper that will deal with EINTR
********************************************************************/
ssize_t sys_pwrite(int fd, const void *buf, size_t count, off_t off)
{
ssize_t ret;
do {
ret = pwrite(fd, buf, count, off);
} while (ret == -1 && errno == EINTR);
return ret;
}
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