kc3-lang/libbsd/src/arc4random_linux.h

• Show log

  Commit

• Hash : 3d88c999
  Author :
  Date : 2018-05-15T00:41:26
  

  Update arc4random() headers from OpenBSD Split Linux support into its own header separate from the generic Unix to fix a Linux-specific issue with clone(). Reset rsp to NULL on failure.

Download

• src/arc4random_linux.h

• /*	$OpenBSD: arc4random_linux.h,v 1.11 2016/06/30 12:19:51 bcook Exp $	*/
  
  /*
   * Copyright (c) 1996, David Mazieres <dm@uun.org>
   * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
   * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
   * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  /*
   * Stub functions for portability.
   */
  
  #include <sys/mman.h>
  
  #include <pthread.h>
  #include <signal.h>
  
  static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
  #define _ARC4_LOCK()   pthread_mutex_lock(&arc4random_mtx)
  #define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
  
  #ifdef __GLIBC__
  extern void *__dso_handle;
  extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
  #define _ARC4_ATFORK(f) __register_atfork(NULL, NULL, (f), __dso_handle)
  #else
  #define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
  #endif
  
  static inline void
  _getentropy_fail(void)
  {
  	raise(SIGKILL);
  }
  
  static volatile sig_atomic_t _rs_forked;
  
  static inline void
  _rs_forkhandler(void)
  {
  	_rs_forked = 1;
  }
  
  static inline void
  _rs_forkdetect(void)
  {
  	static pid_t _rs_pid = 0;
  	pid_t pid = getpid();
  
  	/* XXX unusual calls to clone() can bypass checks */
  	if (_rs_pid == 0 || _rs_pid == 1 || _rs_pid != pid || _rs_forked) {
  		_rs_pid = pid;
  		_rs_forked = 0;
  		if (rs)
  			memset(rs, 0, sizeof(*rs));
  	}
  }
  
  static inline int
  _rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
  {
  	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
  	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
  		return (-1);
  
  	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
  	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
  		munmap(*rsp, sizeof(**rsp));
  		*rsp = NULL;
  		return (-1);
  	}
  
  	_ARC4_ATFORK(_rs_forkhandler);
  	return (0);
  }
  

Download