/*
* Copyright © 2011, 2013, 2017, 2020 Guillem Jover
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#ifdef HAVE_FOPENCOOKIE
struct funopen_cookie {
void *orig_cookie;
int (*readfn)(void *cookie, char *buf, int size);
int (*writefn)(void *cookie, const char *buf, int size);
off_t (*seekfn)(void *cookie, off_t offset, int whence);
int (*closefn)(void *cookie);
};
static ssize_t
funopen_read(void *cookie, char *buf, size_t size)
{
struct funopen_cookie *cookiewrap = cookie;
if (cookiewrap->readfn == NULL) {
errno = EBADF;
return -1;
}
return cookiewrap->readfn(cookiewrap->orig_cookie, buf, size);
}
static ssize_t
funopen_write(void *cookie, const char *buf, size_t size)
{
struct funopen_cookie *cookiewrap = cookie;
if (cookiewrap->writefn == NULL)
return EOF;
return cookiewrap->writefn(cookiewrap->orig_cookie, buf, size);
}
static int
funopen_seek(void *cookie, off64_t *offset, int whence)
{
struct funopen_cookie *cookiewrap = cookie;
off_t soff = *offset;
if (cookiewrap->seekfn == NULL) {
errno = ESPIPE;
return -1;
}
soff = cookiewrap->seekfn(cookiewrap->orig_cookie, soff, whence);
*offset = soff;
return *offset;
}
static int
funopen_close(void *cookie)
{
struct funopen_cookie *cookiewrap = cookie;
int rc;
if (cookiewrap->closefn)
rc = cookiewrap->closefn(cookiewrap->orig_cookie);
else
rc = 0;
free(cookiewrap);
return rc;
}
FILE *
funopen(const void *cookie,
int (*readfn)(void *cookie, char *buf, int size),
int (*writefn)(void *cookie, const char *buf, int size),
off_t (*seekfn)(void *cookie, off_t offset, int whence),
int (*closefn)(void *cookie))
{
struct funopen_cookie *cookiewrap;
cookie_io_functions_t funcswrap = {
.read = funopen_read,
.write = funopen_write,
.seek = funopen_seek,
.close = funopen_close,
};
const char *mode;
if (readfn) {
if (writefn == NULL)
mode = "r";
else
mode = "r+";
} else if (writefn) {
mode = "w";
} else {
errno = EINVAL;
return NULL;
}
cookiewrap = malloc(sizeof(*cookiewrap));
if (cookiewrap == NULL)
return NULL;
cookiewrap->orig_cookie = (void *)cookie;
cookiewrap->readfn = readfn;
cookiewrap->writefn = writefn;
cookiewrap->seekfn = seekfn;
cookiewrap->closefn = closefn;
return fopencookie(cookiewrap, mode, funcswrap);
}
#elif defined(__MUSL__)
/*
* This is unimplementable on musl based systems, and upstream has stated
* they will not add the needed support to implement it. Just ignore this
* interface there, as it has never been provided anyway.
*/
#else
#error "Function funopen() needs to be ported or disabled."
#endif
