[apple/network_cmds.git] / unbound / compat / getentropy_osx.c

/*	$OpenBSD: getentropy_osx.c,v 1.3 2014/07/12 14:48:00 deraadt Exp $	*/

/*
 * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
 * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
 *
 * 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.
 */
#include "config.h"

#include <sys/types.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/statvfs.h>
#include <sys/socket.h>
#include <sys/mount.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <termios.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>
#include <mach/mach_time.h>
#include <mach/mach_host.h>
#include <mach/host_info.h>
#include <sys/socketvar.h>
#include <sys/vmmeter.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip_var.h>
#include <netinet/tcp_var.h>
#include <netinet/udp_var.h>
#include <CommonCrypto/CommonDigest.h>
#define SHA512_Update(a, b, c)	(CC_SHA512_Update((a), (b), (c)))
#define SHA512_Init(xxx) (CC_SHA512_Init((xxx)))
#define SHA512_Final(xxx, yyy) (CC_SHA512_Final((xxx), (yyy)))
#define SHA512_CTX CC_SHA512_CTX
#define SHA512_DIGEST_LENGTH CC_SHA512_DIGEST_LENGTH

#define REPEAT 5
#define min(a, b) (((a) < (b)) ? (a) : (b))

#define HX(a, b) \
	do { \
		if ((a)) \
			HD(errno); \
		else \
			HD(b); \
	} while (0)

#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))

int	getentropy(void *buf, size_t len);

#ifdef CAN_REFERENCE_MAIN
extern int main(int, char *argv[]);
#endif
static int gotdata(char *buf, size_t len);
static int getentropy_urandom(void *buf, size_t len);
static int getentropy_fallback(void *buf, size_t len);

int
getentropy(void *buf, size_t len)
{
	int ret = -1;

	if (len > 256) {
		errno = EIO;
		return -1;
	}

	/*
	 * Try to get entropy with /dev/urandom
	 *
	 * This can fail if the process is inside a chroot or if file
	 * descriptors are exhausted.
	 */
	ret = getentropy_urandom(buf, len);
	if (ret != -1)
		return (ret);

	/*
	 * Entropy collection via /dev/urandom and sysctl have failed.
	 *
	 * No other API exists for collecting entropy, and we have
	 * no failsafe way to get it on OSX that is not sensitive
	 * to resource exhaustion.
	 *
	 * We have very few options:
	 *     - Even syslog_r is unsafe to call at this low level, so
	 *	 there is no way to alert the user or program.
	 *     - Cannot call abort() because some systems have unsafe
	 *	 corefiles.
	 *     - Could raise(SIGKILL) resulting in silent program termination.
	 *     - Return EIO, to hint that arc4random's stir function
	 *       should raise(SIGKILL)
	 *     - Do the best under the circumstances....
	 *
	 * This code path exists to bring light to the issue that OSX
	 * does not provide a failsafe API for entropy collection.
	 *
	 * We hope this demonstrates that OSX should consider
	 * providing a new failsafe API which works in a chroot or
	 * when file descriptors are exhausted.
	 */
#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
	raise(SIGKILL);
#endif
	ret = getentropy_fallback(buf, len);
	if (ret != -1)
		return (ret);

	errno = EIO;
	return (ret);
}

/*
 * Basic sanity checking; wish we could do better.
 */
static int
gotdata(char *buf, size_t len)
{
	char	any_set = 0;
	size_t	i;

	for (i = 0; i < len; ++i)
		any_set |= buf[i];
	if (any_set == 0)
		return -1;
	return 0;
}

static int
getentropy_urandom(void *buf, size_t len)
{
	struct stat st;
	size_t i;
	int fd, flags;
	int save_errno = errno;

start:

	flags = O_RDONLY;
#ifdef O_NOFOLLOW
	flags |= O_NOFOLLOW;
#endif
#ifdef O_CLOEXEC
	flags |= O_CLOEXEC;
#endif
	fd = open("/dev/urandom", flags, 0);
	if (fd == -1) {
		if (errno == EINTR)
			goto start;
		goto nodevrandom;
	}
#ifndef O_CLOEXEC
	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
#endif

	/* Lightly verify that the device node looks sane */
	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
		close(fd);
		goto nodevrandom;
	}
	for (i = 0; i < len; ) {
		size_t wanted = len - i;
		ssize_t ret = read(fd, (char*)buf + i, wanted);

		if (ret == -1) {
			if (errno == EAGAIN || errno == EINTR)
				continue;
			close(fd);
			goto nodevrandom;
		}
		i += ret;
	}
	close(fd);
	if (gotdata(buf, len) == 0) {
		errno = save_errno;
		return 0;		/* satisfied */
	}
nodevrandom:
	errno = EIO;
	return -1;
}

static int tcpmib[] = { CTL_NET, AF_INET, IPPROTO_TCP, TCPCTL_STATS };
static int udpmib[] = { CTL_NET, AF_INET, IPPROTO_UDP, UDPCTL_STATS };
static int ipmib[] = { CTL_NET, AF_INET, IPPROTO_IP, IPCTL_STATS };
static int kmib[] = { CTL_KERN, KERN_USRSTACK };
static int hwmib[] = { CTL_HW, HW_USERMEM };

static int
getentropy_fallback(void *buf, size_t len)
{
	uint8_t results[SHA512_DIGEST_LENGTH];
	int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
	static int cnt;
	struct timespec ts;
	struct timeval tv;
	struct rusage ru;
	sigset_t sigset;
	struct stat st;
	SHA512_CTX ctx;
	static pid_t lastpid;
	pid_t pid;
	size_t i, ii, m;
	char *p;
	struct tcpstat tcpstat;
	struct udpstat udpstat;
	struct ipstat ipstat;
	u_int64_t mach_time;
	unsigned int idata;
	void *addr;

	pid = getpid();
	if (lastpid == pid) {
		faster = 1;
		repeat = 2;
	} else {
		faster = 0;
		lastpid = pid;
		repeat = REPEAT;
	}
	for (i = 0; i < len; ) {
		int j;
		SHA512_Init(&ctx);
		for (j = 0; j < repeat; j++) {
			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
			if (e != -1) {
				cnt += (int)tv.tv_sec;
				cnt += (int)tv.tv_usec;
			}

			mach_time = mach_absolute_time();
			HD(mach_time);

			ii = sizeof(addr);
			HX(sysctl(kmib, sizeof(kmib) / sizeof(kmib[0]),
			    &addr, &ii, NULL, 0) == -1, addr);

			ii = sizeof(idata);
			HX(sysctl(hwmib, sizeof(hwmib) / sizeof(hwmib[0]),
			    &idata, &ii, NULL, 0) == -1, idata);

			ii = sizeof(tcpstat);
			HX(sysctl(tcpmib, sizeof(tcpmib) / sizeof(tcpmib[0]),
			    &tcpstat, &ii, NULL, 0) == -1, tcpstat);

			ii = sizeof(udpstat);
			HX(sysctl(udpmib, sizeof(udpmib) / sizeof(udpmib[0]),
			    &udpstat, &ii, NULL, 0) == -1, udpstat);

			ii = sizeof(ipstat);
			HX(sysctl(ipmib, sizeof(ipmib) / sizeof(ipmib[0]),
			    &ipstat, &ii, NULL, 0) == -1, ipstat);

			HX((pid = getpid()) == -1, pid);
			HX((pid = getsid(pid)) == -1, pid);
			HX((pid = getppid()) == -1, pid);
			HX((pid = getpgid(0)) == -1, pid);
			HX((e = getpriority(0, 0)) == -1, e);

			if (!faster) {
				ts.tv_sec = 0;
				ts.tv_nsec = 1;
				(void) nanosleep(&ts, NULL);
			}

			HX(sigpending(&sigset) == -1, sigset);
			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
			    sigset);

#ifdef CAN_REFERENCE_MAIN
			HF(main);		/* an addr in program */
#endif
			HF(getentropy);	/* an addr in this library */
			HF(printf);		/* an addr in libc */
			p = (char *)&p;
			HD(p);		/* an addr on stack */
			p = (char *)&errno;
			HD(p);		/* the addr of errno */

			if (i == 0) {
				struct sockaddr_storage ss;
				struct statvfs stvfs;
				struct termios tios;
				struct statfs stfs;
				socklen_t ssl;
				off_t off;

				/*
				 * Prime-sized mappings encourage fragmentation;
				 * thus exposing some address entropy.
				 */
				struct mm {
					size_t	npg;
					void	*p;
				} mm[] =	 {
					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
				};

				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
					HX(mm[m].p = mmap(NULL,
					    mm[m].npg * pgs,
					    PROT_READ|PROT_WRITE,
					    MAP_PRIVATE|MAP_ANON, -1,
					    (off_t)0), mm[m].p);
					if (mm[m].p != MAP_FAILED) {
						size_t mo;

						/* Touch some memory... */
						p = mm[m].p;
						mo = cnt %
						    (mm[m].npg * pgs - 1);
						p[mo] = 1;
						cnt += (int)((long)(mm[m].p)
						    / pgs);
					}

					/* Check cnts and times... */
					mach_time = mach_absolute_time();
					HD(mach_time);
					cnt += (int)mach_time;

					HX((e = getrusage(RUSAGE_SELF,
					    &ru)) == -1, ru);
					if (e != -1) {
						cnt += (int)ru.ru_utime.tv_sec;
						cnt += (int)ru.ru_utime.tv_usec;
					}
				}

				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
					if (mm[m].p != MAP_FAILED)
						munmap(mm[m].p, mm[m].npg * pgs);
					mm[m].p = MAP_FAILED;
				}

				HX(stat(".", &st) == -1, st);
				HX(statvfs(".", &stvfs) == -1, stvfs);
				HX(statfs(".", &stfs) == -1, stfs);

				HX(stat("/", &st) == -1, st);
				HX(statvfs("/", &stvfs) == -1, stvfs);
				HX(statfs("/", &stfs) == -1, stfs);

				HX((e = fstat(0, &st)) == -1, st);
				if (e == -1) {
					if (S_ISREG(st.st_mode) ||
					    S_ISFIFO(st.st_mode) ||
					    S_ISSOCK(st.st_mode)) {
						HX(fstatvfs(0, &stvfs) == -1,
						    stvfs);
						HX(fstatfs(0, &stfs) == -1,
						    stfs);
						HX((off = lseek(0, (off_t)0,
						    SEEK_CUR)) < 0, off);
					}
					if (S_ISCHR(st.st_mode)) {
						HX(tcgetattr(0, &tios) == -1,
						    tios);
					} else if (S_ISSOCK(st.st_mode)) {
						memset(&ss, 0, sizeof ss);
						ssl = sizeof(ss);
						HX(getpeername(0,
						    (void *)&ss, &ssl) == -1,
						    ss);
					}
				}

				HX((e = getrusage(RUSAGE_CHILDREN,
				    &ru)) == -1, ru);
				if (e != -1) {
					cnt += (int)ru.ru_utime.tv_sec;
					cnt += (int)ru.ru_utime.tv_usec;
				}
			} else {
				/* Subsequent hashes absorb previous result */
				HD(results);
			}

			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
			if (e != -1) {
				cnt += (int)tv.tv_sec;
				cnt += (int)tv.tv_usec;
			}

			HD(cnt);
		}

		SHA512_Final(results, &ctx);
		memcpy((char*)buf + i, results, min(sizeof(results), len - i));
		i += min(sizeof(results), len - i);
	}
	memset(results, 0, sizeof results);
	if (gotdata(buf, len) == 0) {
		errno = save_errno;
		return 0;		/* satisfied */
	}
	errno = EIO;
	return -1;
}
Commit	Line	Data
89c4ed63 A	1	/* $OpenBSD: getentropy_osx.c,v 1.3 2014/07/12 14:48:00 deraadt Exp $ */
	2
	3	/*
	4	* Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
	5	* Copyright (c) 2014 Bob Beck <beck@obtuse.com>
	6	*
	7	* Permission to use, copy, modify, and distribute this software for any
	8	* purpose with or without fee is hereby granted, provided that the above
	9	* copyright notice and this permission notice appear in all copies.
	10	*
	11	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	12	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	13	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	14	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	15	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	16	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
	17	* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	18	*/
	19	#include "config.h"
	20
	21	#include <sys/types.h>
	22	#include <sys/param.h>
	23	#include <sys/ioctl.h>
	24	#include <sys/resource.h>
	25	#include <sys/syscall.h>
	26	#include <sys/sysctl.h>
	27	#include <sys/statvfs.h>
	28	#include <sys/socket.h>
	29	#include <sys/mount.h>
	30	#include <sys/mman.h>
	31	#include <sys/stat.h>
	32	#include <sys/time.h>
	33	#include <stdlib.h>
	34	#include <stdint.h>
	35	#include <stdio.h>
	36	#include <termios.h>
	37	#include <fcntl.h>
	38	#include <signal.h>
	39	#include <string.h>
	40	#include <errno.h>
	41	#include <unistd.h>
	42	#include <time.h>
	43	#include <mach/mach_time.h>
	44	#include <mach/mach_host.h>
	45	#include <mach/host_info.h>
	46	#include <sys/socketvar.h>
	47	#include <sys/vmmeter.h>
	48	#include <netinet/in.h>
	49	#include <netinet/tcp.h>
	50	#include <netinet/udp.h>
	51	#include <netinet/ip_var.h>
	52	#include <netinet/tcp_var.h>
	53	#include <netinet/udp_var.h>
	54	#include <CommonCrypto/CommonDigest.h>
	55	#define SHA512_Update(a, b, c) (CC_SHA512_Update((a), (b), (c)))
	56	#define SHA512_Init(xxx) (CC_SHA512_Init((xxx)))
	57	#define SHA512_Final(xxx, yyy) (CC_SHA512_Final((xxx), (yyy)))
	58	#define SHA512_CTX CC_SHA512_CTX
	59	#define SHA512_DIGEST_LENGTH CC_SHA512_DIGEST_LENGTH
	60
	61	#define REPEAT 5
	62	#define min(a, b) (((a) < (b)) ? (a) : (b))
	63
	64	#define HX(a, b) \
65	do { \
66	if ((a)) \
67	HD(errno); \
68	else \
69	HD(b); \
70	} while (0)
71
72	#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
73	#define HD(x) (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
74	#define HF(x) (SHA512_Update(&ctx, (char )&(x), sizeof (void)))
75
76	int getentropy(void *buf, size_t len);
77
78	#ifdef CAN_REFERENCE_MAIN
79	extern int main(int, char *argv[]);
80	#endif
81	static int gotdata(char *buf, size_t len);
82	static int getentropy_urandom(void *buf, size_t len);
83	static int getentropy_fallback(void *buf, size_t len);
84
85	int
86	getentropy(void *buf, size_t len)
87	{
88	int ret = -1;
89
90	if (len > 256) {
91	errno = EIO;
92	return -1;
93	}
94
95	/*
96	* Try to get entropy with /dev/urandom
97	*
98	* This can fail if the process is inside a chroot or if file
99	* descriptors are exhausted.
100	*/
101	ret = getentropy_urandom(buf, len);
102	if (ret != -1)
103	return (ret);
104
105	/*
106	* Entropy collection via /dev/urandom and sysctl have failed.
107	*
108	* No other API exists for collecting entropy, and we have
109	* no failsafe way to get it on OSX that is not sensitive
110	* to resource exhaustion.
111	*
112	* We have very few options:
113	* - Even syslog_r is unsafe to call at this low level, so
114	* there is no way to alert the user or program.
115	* - Cannot call abort() because some systems have unsafe
116	* corefiles.
117	* - Could raise(SIGKILL) resulting in silent program termination.
118	* - Return EIO, to hint that arc4random's stir function
119	* should raise(SIGKILL)
120	* - Do the best under the circumstances....
121	*
122	* This code path exists to bring light to the issue that OSX
123	* does not provide a failsafe API for entropy collection.
124	*
125	* We hope this demonstrates that OSX should consider
126	* providing a new failsafe API which works in a chroot or
127	* when file descriptors are exhausted.
128	*/
129	#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
130	#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
131	raise(SIGKILL);
132	#endif
133	ret = getentropy_fallback(buf, len);
134	if (ret != -1)
135	return (ret);
136
137	errno = EIO;
138	return (ret);
139	}
140
141	/*
142	* Basic sanity checking; wish we could do better.
143	*/
144	static int
145	gotdata(char *buf, size_t len)
146	{
147	char any_set = 0;
148	size_t i;
149
150	for (i = 0; i < len; ++i)
151	any_set \|= buf[i];
152	if (any_set == 0)
153	return -1;
154	return 0;
155	}
156
157	static int
158	getentropy_urandom(void *buf, size_t len)
159	{
160	struct stat st;
161	size_t i;
162	int fd, flags;
163	int save_errno = errno;
164
165	start:
166
167	flags = O_RDONLY;
168	#ifdef O_NOFOLLOW
169	flags \|= O_NOFOLLOW;
170	#endif
171	#ifdef O_CLOEXEC
172	flags \|= O_CLOEXEC;
173	#endif
174	fd = open("/dev/urandom", flags, 0);
175	if (fd == -1) {
176	if (errno == EINTR)
177	goto start;
178	goto nodevrandom;
179	}
180	#ifndef O_CLOEXEC
181	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) \| FD_CLOEXEC);
182	#endif
183
184	/* Lightly verify that the device node looks sane */
185	if (fstat(fd, &st) == -1 \|\| !S_ISCHR(st.st_mode)) {
186	close(fd);
187	goto nodevrandom;
188	}
189	for (i = 0; i < len; ) {
190	size_t wanted = len - i;
191	ssize_t ret = read(fd, (char*)buf + i, wanted);
192
193	if (ret == -1) {
194	if (errno == EAGAIN \|\| errno == EINTR)
195	continue;
196	close(fd);
197	goto nodevrandom;
198	}
199	i += ret;
200	}
201	close(fd);
202	if (gotdata(buf, len) == 0) {
203	errno = save_errno;
204	return 0; /* satisfied */
205	}
206	nodevrandom:
207	errno = EIO;
208	return -1;
209	}
210
211	static int tcpmib[] = { CTL_NET, AF_INET, IPPROTO_TCP, TCPCTL_STATS };
212	static int udpmib[] = { CTL_NET, AF_INET, IPPROTO_UDP, UDPCTL_STATS };
213	static int ipmib[] = { CTL_NET, AF_INET, IPPROTO_IP, IPCTL_STATS };
214	static int kmib[] = { CTL_KERN, KERN_USRSTACK };
215	static int hwmib[] = { CTL_HW, HW_USERMEM };
216
217	static int
218	getentropy_fallback(void *buf, size_t len)
219	{
220	uint8_t results[SHA512_DIGEST_LENGTH];
221	int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
222	static int cnt;
223	struct timespec ts;
224	struct timeval tv;
225	struct rusage ru;
226	sigset_t sigset;
227	struct stat st;
228	SHA512_CTX ctx;
229	static pid_t lastpid;
230	pid_t pid;
231	size_t i, ii, m;
232	char *p;
233	struct tcpstat tcpstat;
234	struct udpstat udpstat;
235	struct ipstat ipstat;
236	u_int64_t mach_time;
237	unsigned int idata;
238	void *addr;
239
240	pid = getpid();
241	if (lastpid == pid) {
242	faster = 1;
243	repeat = 2;
244	} else {
245	faster = 0;
246	lastpid = pid;
247	repeat = REPEAT;
248	}
249	for (i = 0; i < len; ) {
250	int j;
251	SHA512_Init(&ctx);
252	for (j = 0; j < repeat; j++) {
253	HX((e = gettimeofday(&tv, NULL)) == -1, tv);
254	if (e != -1) {
255	cnt += (int)tv.tv_sec;
256	cnt += (int)tv.tv_usec;
257	}
258
259	mach_time = mach_absolute_time();
260	HD(mach_time);
261
262	ii = sizeof(addr);
263	HX(sysctl(kmib, sizeof(kmib) / sizeof(kmib[0]),
264	&addr, &ii, NULL, 0) == -1, addr);
265
266	ii = sizeof(idata);
267	HX(sysctl(hwmib, sizeof(hwmib) / sizeof(hwmib[0]),
268	&idata, &ii, NULL, 0) == -1, idata);
269
270	ii = sizeof(tcpstat);
271	HX(sysctl(tcpmib, sizeof(tcpmib) / sizeof(tcpmib[0]),
272	&tcpstat, &ii, NULL, 0) == -1, tcpstat);
273
274	ii = sizeof(udpstat);
275	HX(sysctl(udpmib, sizeof(udpmib) / sizeof(udpmib[0]),
276	&udpstat, &ii, NULL, 0) == -1, udpstat);
277
278	ii = sizeof(ipstat);
279	HX(sysctl(ipmib, sizeof(ipmib) / sizeof(ipmib[0]),
280	&ipstat, &ii, NULL, 0) == -1, ipstat);
281
282	HX((pid = getpid()) == -1, pid);
283	HX((pid = getsid(pid)) == -1, pid);
284	HX((pid = getppid()) == -1, pid);
285	HX((pid = getpgid(0)) == -1, pid);
286	HX((e = getpriority(0, 0)) == -1, e);
287
288	if (!faster) {
289	ts.tv_sec = 0;
290	ts.tv_nsec = 1;
291	(void) nanosleep(&ts, NULL);
292	}
293
294	HX(sigpending(&sigset) == -1, sigset);
295	HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
296	sigset);
297
298	#ifdef CAN_REFERENCE_MAIN
299	HF(main); /* an addr in program */
300	#endif
301	HF(getentropy); /* an addr in this library */
302	HF(printf); /* an addr in libc */
303	p = (char *)&p;
304	HD(p); /* an addr on stack */
305	p = (char *)&errno;
306	HD(p); /* the addr of errno */
307
308	if (i == 0) {
309	struct sockaddr_storage ss;
310	struct statvfs stvfs;
311	struct termios tios;
312	struct statfs stfs;
313	socklen_t ssl;
314	off_t off;
315
316	/*
317	* Prime-sized mappings encourage fragmentation;
318	* thus exposing some address entropy.
319	*/
320	struct mm {
321	size_t npg;
322	void *p;
323	} mm[] = {
324	{ 17, MAP_FAILED }, { 3, MAP_FAILED },
325	{ 11, MAP_FAILED }, { 2, MAP_FAILED },
326	{ 5, MAP_FAILED }, { 3, MAP_FAILED },
327	{ 7, MAP_FAILED }, { 1, MAP_FAILED },
328	{ 57, MAP_FAILED }, { 3, MAP_FAILED },
329	{ 131, MAP_FAILED }, { 1, MAP_FAILED },
330	};
331
332	for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
333	HX(mm[m].p = mmap(NULL,
334	mm[m].npg * pgs,
335	PROT_READ\|PROT_WRITE,
336	MAP_PRIVATE\|MAP_ANON, -1,
337	(off_t)0), mm[m].p);
338	if (mm[m].p != MAP_FAILED) {
339	size_t mo;
340
341	/* Touch some memory... */
342	p = mm[m].p;
343	mo = cnt %
344	(mm[m].npg * pgs - 1);
345	p[mo] = 1;
346	cnt += (int)((long)(mm[m].p)
347	/ pgs);
348	}
349
350	/* Check cnts and times... */
351	mach_time = mach_absolute_time();
352	HD(mach_time);
353	cnt += (int)mach_time;
354
355	HX((e = getrusage(RUSAGE_SELF,
356	&ru)) == -1, ru);
357	if (e != -1) {
358	cnt += (int)ru.ru_utime.tv_sec;
359	cnt += (int)ru.ru_utime.tv_usec;
360	}
361	}
362
363	for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
364	if (mm[m].p != MAP_FAILED)
365	munmap(mm[m].p, mm[m].npg * pgs);
366	mm[m].p = MAP_FAILED;
367	}
368
369	HX(stat(".", &st) == -1, st);
370	HX(statvfs(".", &stvfs) == -1, stvfs);
371	HX(statfs(".", &stfs) == -1, stfs);
372
373	HX(stat("/", &st) == -1, st);
374	HX(statvfs("/", &stvfs) == -1, stvfs);
375	HX(statfs("/", &stfs) == -1, stfs);
376
377	HX((e = fstat(0, &st)) == -1, st);
378	if (e == -1) {
379	if (S_ISREG(st.st_mode) \|\|
380	S_ISFIFO(st.st_mode) \|\|
381	S_ISSOCK(st.st_mode)) {
382	HX(fstatvfs(0, &stvfs) == -1,
383	stvfs);
384	HX(fstatfs(0, &stfs) == -1,
385	stfs);
386	HX((off = lseek(0, (off_t)0,
387	SEEK_CUR)) < 0, off);
388	}
389	if (S_ISCHR(st.st_mode)) {
390	HX(tcgetattr(0, &tios) == -1,
391	tios);
392	} else if (S_ISSOCK(st.st_mode)) {
393	memset(&ss, 0, sizeof ss);
394	ssl = sizeof(ss);
395	HX(getpeername(0,
396	(void *)&ss, &ssl) == -1,
397	ss);
398	}
399	}
400
401	HX((e = getrusage(RUSAGE_CHILDREN,
402	&ru)) == -1, ru);
403	if (e != -1) {
404	cnt += (int)ru.ru_utime.tv_sec;
405	cnt += (int)ru.ru_utime.tv_usec;
406	}
407	} else {
408	/* Subsequent hashes absorb previous result */
409	HD(results);
410	}
411
412	HX((e = gettimeofday(&tv, NULL)) == -1, tv);
413	if (e != -1) {
414	cnt += (int)tv.tv_sec;
415	cnt += (int)tv.tv_usec;
416	}
417
418	HD(cnt);
419	}
420
421	SHA512_Final(results, &ctx);
422	memcpy((char*)buf + i, results, min(sizeof(results), len - i));
423	i += min(sizeof(results), len - i);
424	}
425	memset(results, 0, sizeof results);
426	if (gotdata(buf, len) == 0) {
427	errno = save_errno;
428	return 0; /* satisfied */
429	}
430	errno = EIO;
431	return -1;
432	}