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/* <!-- copyright */
/*
* aria2 - The high speed download utility
*
* Copyright (C) 2014 Nils Maier
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of portions of this program with the
* OpenSSL library under certain conditions as described in each
* individual source file, and distribute linked combinations
* including the two.
* You must obey the GNU General Public License in all respects
* for all of the code used other than OpenSSL. If you modify
* file(s) with this exception, you may extend this exception to your
* version of the file(s), but you are not obligated to do so. If you
* do not wish to do so, delete this exception statement from your
* version. If you delete this exception statement from all source
* files in the program, then also delete it here.
*/
/* copyright --> */
#define _GNUSOURCE
#include <unistd.h>
#include <sys/syscall.h>
#include <linux/random.h>
#include <errno.h>
#include <linux/errno.h>
#include <stdint.h>
#include <stdio.h>
#include "config.h"
#include "getrandom_linux.h"
int getrandom_linux(void* buf, size_t buflen)
{
int rv = 0;
uint8_t* p = buf;
/* Loop while we did not fully retrieve what the user asked for.
* This may happen in particular when a call was EINTRupted.
*/
while (buflen) {
int read;
#ifdef HAVE_GETRANDOM
/* libc already has support */
read = getrandom(p, buflen, 0);
#else // HAVE_GETRANDOM
/* libc has no support, make the syscall ourselves */
read = syscall(SYS_getrandom, p, buflen, 0);
/* Some libc impl. might mess -ERESTART up */
if (read == -EINTR || read == -ERESTART) {
/* ERESTART, like EINTR, should restart the call, later, so handle both
* the same way.
*/
errno = EINTR;
read = -1;
}
/* Some other non-interrupted error happened, put error code into errno and
* switch read to -1 (return value).
*/
if (read < -1) {
errno = -read;
read = -1;
}
#endif // HAVE_GETRANDOM
if (read < 0) {
if (errno == EINTR) {
/* Restart call */
continue;
}
/* Call failed, return -1, errno should be set up correctly at this
* point.
*/
return -1;
}
/* We got some more randomness */
p += read;
rv += read;
buflen -= read;
}
return rv;
}
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