1 /*	$OpenBSD: arc4random_hpux.h,v 1.3 2016/06/30 12:19:51 bcook Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, David Mazieres <dm@uun.org>
5  * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
6  * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
7  * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20  */
21 
22 /*
23  * Stub functions for portability.
24  */
25 
26 #include <sys/mman.h>
27 
28 #include <pthread.h>
29 #include <signal.h>
30 
31 static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
32 #define _ARC4_LOCK()   pthread_mutex_lock(&arc4random_mtx)
33 #define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
34 
35 #define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
36 
37 static inline void
38 _getentropy_fail(void)
39 {
40 	raise(SIGKILL);
41 }
42 
43 static volatile sig_atomic_t _rs_forked;
44 
45 static inline void
46 _rs_forkhandler(void)
47 {
48 	_rs_forked = 1;
49 }
50 
51 static inline void
52 _rs_forkdetect(void)
53 {
54 	static pid_t _rs_pid = 0;
55 	pid_t pid = getpid();
56 
57 	if (_rs_pid == 0 || _rs_pid != pid || _rs_forked) {
58 		_rs_pid = pid;
59 		_rs_forked = 0;
60 		if (rs)
61 			memset(rs, 0, sizeof(*rs));
62 	}
63 }
64 
65 static inline int
66 _rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
67 {
68 	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
69 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
70 		return (-1);
71 
72 	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
73 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
74 		munmap(*rsp, sizeof(**rsp));
75 		*rsp = NULL;
76 		return (-1);
77 	}
78 
79 	_ARC4_ATFORK(_rs_forkhandler);
80 	return (0);
81 }
82