89 lines
2.5 KiB
C
89 lines
2.5 KiB
C
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/* $OpenBSD: arc4random_linux.h,v 1.12 2019/07/11 10:37:28 inoguchi Exp $ */
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/*
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* Copyright (c) 1996, David Mazieres <dm@uun.org>
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* Copyright (c) 2008, Damien Miller <djm@openbsd.org>
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* Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
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* Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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/*
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* Stub functions for portability.
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*/
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#include <sys/mman.h>
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#include <pthread.h>
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#include <signal.h>
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static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
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#define _ARC4_LOCK() pthread_mutex_lock(&arc4random_mtx)
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#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
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#if defined(__GLIBC__) && !(defined(__UCLIBC__) && !defined(__ARCH_USE_MMU__))
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extern void *__dso_handle;
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extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
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#define _ARC4_ATFORK(f) __register_atfork(NULL, NULL, (f), __dso_handle)
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#else
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#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
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#endif
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static inline void
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_getentropy_fail(void)
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{
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raise(SIGKILL);
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}
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static volatile sig_atomic_t _rs_forked;
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static inline void
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_rs_forkhandler(void)
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{
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_rs_forked = 1;
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}
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static inline void
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_rs_forkdetect(void)
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{
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static pid_t _rs_pid = 0;
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pid_t pid = getpid();
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/* XXX unusual calls to clone() can bypass checks */
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if (_rs_pid == 0 || _rs_pid == 1 || _rs_pid != pid || _rs_forked) {
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_rs_pid = pid;
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_rs_forked = 0;
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if (rs)
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memset(rs, 0, sizeof(*rs));
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}
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}
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static inline int
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_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
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{
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if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
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return (-1);
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if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
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MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
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munmap(*rsp, sizeof(**rsp));
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*rsp = NULL;
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return (-1);
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}
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_ARC4_ATFORK(_rs_forkhandler);
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return (0);
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}
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