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/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
* io_stdin.c
*
* Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
*/
#include "config.h"
#include "highlevel.h"
#include "sqfs/error.h"
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
typedef struct {
sqfs_file_t base;
uint64_t offset;
uint64_t size;
} sqfs_file_stdin_t;
static void stdin_destroy(sqfs_file_t *base)
{
free(base);
}
static int stdin_read_at(sqfs_file_t *base, uint64_t offset,
void *buffer, size_t size)
{
sqfs_file_stdin_t *file = (sqfs_file_stdin_t *)base;
size_t temp_size = 0;
uint8_t *temp = NULL;
uint64_t diff;
ssize_t ret;
if (offset < file->offset)
return SQFS_ERROR_IO;
if (offset > file->offset) {
temp_size = 1024;
temp = alloca(temp_size);
}
if (offset >= file->size || (offset + size) > file->size)
return SQFS_ERROR_OUT_OF_BOUNDS;
while (size > 0) {
if (offset > file->offset) {
diff = file->offset - offset;
diff = diff > (uint64_t)temp_size ? temp_size : diff;
ret = read(STDIN_FILENO, temp, diff);
} else {
ret = read(STDIN_FILENO, buffer, size);
}
if (ret < 0) {
if (errno == EINTR)
continue;
return SQFS_ERROR_IO;
}
if (ret == 0)
return SQFS_ERROR_OUT_OF_BOUNDS;
if (offset <= file->offset) {
buffer = (char *)buffer + ret;
size -= ret;
offset += ret;
}
file->offset += ret;
}
return 0;
}
static int stdin_write_at(sqfs_file_t *base, uint64_t offset,
const void *buffer, size_t size)
{
(void)base; (void)offset; (void)buffer; (void)size;
return SQFS_ERROR_IO;
}
static uint64_t stdin_get_size(const sqfs_file_t *base)
{
return ((const sqfs_file_stdin_t *)base)->size;
}
static int stdin_truncate(sqfs_file_t *base, uint64_t size)
{
(void)base; (void)size;
return SQFS_ERROR_IO;
}
sqfs_file_t *sqfs_get_stdin_file(uint64_t size)
{
sqfs_file_stdin_t *file = calloc(1, sizeof(*file));
sqfs_file_t *base = (sqfs_file_t *)file;
if (file == NULL)
return NULL;
file->size = size;
base->destroy = stdin_destroy;
base->read_at = stdin_read_at;
base->write_at = stdin_write_at;
base->get_size = stdin_get_size;
base->truncate = stdin_truncate;
return base;
}
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