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/* libguestfs
* Copyright (C) 2011-2020 Red Hat Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <libintl.h>
#include "guestfs.h"
#include "guestfs-internal.h"
/**
* Read the whole file C<filename> into a memory buffer.
*
* The memory buffer is initialized and returned in C<data_r>. The
* size of the file in bytes is returned in C<size_r>. The return
* buffer must be freed by the caller.
*
* On error this sets the error in the handle and returns C<-1>.
*
* For the convenience of callers, the returned buffer is
* NUL-terminated (the NUL is not included in the size).
*
* The file must be a B<regular>, B<local>, B<trusted> file. In
* particular, do not use this function to read files that might be
* under control of an untrusted user since that will lead to a
* denial-of-service attack.
*/
int
guestfs_int_read_whole_file (guestfs_h *g, const char *filename,
char **data_r, size_t *size_r)
{
int fd;
char *data;
off_t size;
off_t n;
ssize_t r;
struct stat statbuf;
fd = open (filename, O_RDONLY|O_CLOEXEC);
if (fd == -1) {
perrorf (g, "open: %s", filename);
return -1;
}
if (fstat (fd, &statbuf) == -1) {
perrorf (g, "stat: %s", filename);
close (fd);
return -1;
}
size = statbuf.st_size;
data = safe_malloc (g, size + 1);
n = 0;
while (n < size) {
r = read (fd, &data[n], size - n);
if (r == -1) {
perrorf (g, "read: %s", filename);
free (data);
close (fd);
return -1;
}
if (r == 0) {
error (g, _("read: %s: unexpected end of file"), filename);
free (data);
close (fd);
return -1;
}
n += r;
}
if (close (fd) == -1) {
perrorf (g, "close: %s", filename);
free (data);
return -1;
}
/* For convenience of callers, \0-terminate the data. */
data[size] = '\0';
*data_r = data;
if (size_r != NULL)
*size_r = size;
return 0;
}
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