1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1997, 1998 Kenneth D. Merry.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 *    derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/types.h>
32#include <sys/sysctl.h>
33#include <sys/errno.h>
34#include <sys/resource.h>
35#include <sys/queue.h>
36
37#include <ctype.h>
38#include <err.h>
39#include <fcntl.h>
40#include <limits.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <stdarg.h>
45#include <kvm.h>
46#include <nlist.h>
47
48#include "devstat.h"
49
50int
51compute_stats(struct devstat *current, struct devstat *previous,
52	      long double etime, u_int64_t *total_bytes,
53	      u_int64_t *total_transfers, u_int64_t *total_blocks,
54	      long double *kb_per_transfer, long double *transfers_per_second,
55	      long double *mb_per_second, long double *blocks_per_second,
56	      long double *ms_per_transaction);
57
58typedef enum {
59	DEVSTAT_ARG_NOTYPE,
60	DEVSTAT_ARG_UINT64,
61	DEVSTAT_ARG_LD,
62	DEVSTAT_ARG_SKIP
63} devstat_arg_type;
64
65char devstat_errbuf[DEVSTAT_ERRBUF_SIZE];
66
67/*
68 * Table to match descriptive strings with device types.  These are in
69 * order from most common to least common to speed search time.
70 */
71struct devstat_match_table match_table[] = {
72	{"da",		DEVSTAT_TYPE_DIRECT,	DEVSTAT_MATCH_TYPE},
73	{"cd",		DEVSTAT_TYPE_CDROM,	DEVSTAT_MATCH_TYPE},
74	{"scsi",	DEVSTAT_TYPE_IF_SCSI,	DEVSTAT_MATCH_IF},
75	{"ide",		DEVSTAT_TYPE_IF_IDE,	DEVSTAT_MATCH_IF},
76	{"other",	DEVSTAT_TYPE_IF_OTHER,	DEVSTAT_MATCH_IF},
77	{"nvme",	DEVSTAT_TYPE_IF_NVME,	DEVSTAT_MATCH_IF},
78	{"worm",	DEVSTAT_TYPE_WORM,	DEVSTAT_MATCH_TYPE},
79	{"sa",		DEVSTAT_TYPE_SEQUENTIAL,DEVSTAT_MATCH_TYPE},
80	{"pass",	DEVSTAT_TYPE_PASS,	DEVSTAT_MATCH_PASS},
81	{"optical",	DEVSTAT_TYPE_OPTICAL,	DEVSTAT_MATCH_TYPE},
82	{"array",	DEVSTAT_TYPE_STORARRAY,	DEVSTAT_MATCH_TYPE},
83	{"changer",	DEVSTAT_TYPE_CHANGER,	DEVSTAT_MATCH_TYPE},
84	{"scanner",	DEVSTAT_TYPE_SCANNER,	DEVSTAT_MATCH_TYPE},
85	{"printer",	DEVSTAT_TYPE_PRINTER,	DEVSTAT_MATCH_TYPE},
86	{"floppy",	DEVSTAT_TYPE_FLOPPY,	DEVSTAT_MATCH_TYPE},
87	{"proc",	DEVSTAT_TYPE_PROCESSOR,	DEVSTAT_MATCH_TYPE},
88	{"comm",	DEVSTAT_TYPE_COMM,	DEVSTAT_MATCH_TYPE},
89	{"enclosure",	DEVSTAT_TYPE_ENCLOSURE,	DEVSTAT_MATCH_TYPE},
90	{NULL,		0,			0}
91};
92
93struct devstat_args {
94	devstat_metric 		metric;
95	devstat_arg_type	argtype;
96} devstat_arg_list[] = {
97	{ DSM_NONE, DEVSTAT_ARG_NOTYPE },
98	{ DSM_TOTAL_BYTES, DEVSTAT_ARG_UINT64 },
99	{ DSM_TOTAL_BYTES_READ, DEVSTAT_ARG_UINT64 },
100	{ DSM_TOTAL_BYTES_WRITE, DEVSTAT_ARG_UINT64 },
101	{ DSM_TOTAL_TRANSFERS, DEVSTAT_ARG_UINT64 },
102	{ DSM_TOTAL_TRANSFERS_READ, DEVSTAT_ARG_UINT64 },
103	{ DSM_TOTAL_TRANSFERS_WRITE, DEVSTAT_ARG_UINT64 },
104	{ DSM_TOTAL_TRANSFERS_OTHER, DEVSTAT_ARG_UINT64 },
105	{ DSM_TOTAL_BLOCKS, DEVSTAT_ARG_UINT64 },
106	{ DSM_TOTAL_BLOCKS_READ, DEVSTAT_ARG_UINT64 },
107	{ DSM_TOTAL_BLOCKS_WRITE, DEVSTAT_ARG_UINT64 },
108	{ DSM_KB_PER_TRANSFER, DEVSTAT_ARG_LD },
109	{ DSM_KB_PER_TRANSFER_READ, DEVSTAT_ARG_LD },
110	{ DSM_KB_PER_TRANSFER_WRITE, DEVSTAT_ARG_LD },
111	{ DSM_TRANSFERS_PER_SECOND, DEVSTAT_ARG_LD },
112	{ DSM_TRANSFERS_PER_SECOND_READ, DEVSTAT_ARG_LD },
113	{ DSM_TRANSFERS_PER_SECOND_WRITE, DEVSTAT_ARG_LD },
114	{ DSM_TRANSFERS_PER_SECOND_OTHER, DEVSTAT_ARG_LD },
115	{ DSM_MB_PER_SECOND, DEVSTAT_ARG_LD },
116	{ DSM_MB_PER_SECOND_READ, DEVSTAT_ARG_LD },
117	{ DSM_MB_PER_SECOND_WRITE, DEVSTAT_ARG_LD },
118	{ DSM_BLOCKS_PER_SECOND, DEVSTAT_ARG_LD },
119	{ DSM_BLOCKS_PER_SECOND_READ, DEVSTAT_ARG_LD },
120	{ DSM_BLOCKS_PER_SECOND_WRITE, DEVSTAT_ARG_LD },
121	{ DSM_MS_PER_TRANSACTION, DEVSTAT_ARG_LD },
122	{ DSM_MS_PER_TRANSACTION_READ, DEVSTAT_ARG_LD },
123	{ DSM_MS_PER_TRANSACTION_WRITE, DEVSTAT_ARG_LD },
124	{ DSM_SKIP, DEVSTAT_ARG_SKIP },
125	{ DSM_TOTAL_BYTES_FREE, DEVSTAT_ARG_UINT64 },
126	{ DSM_TOTAL_TRANSFERS_FREE, DEVSTAT_ARG_UINT64 },
127	{ DSM_TOTAL_BLOCKS_FREE, DEVSTAT_ARG_UINT64 },
128	{ DSM_KB_PER_TRANSFER_FREE, DEVSTAT_ARG_LD },
129	{ DSM_MB_PER_SECOND_FREE, DEVSTAT_ARG_LD },
130	{ DSM_TRANSFERS_PER_SECOND_FREE, DEVSTAT_ARG_LD },
131	{ DSM_BLOCKS_PER_SECOND_FREE, DEVSTAT_ARG_LD },
132	{ DSM_MS_PER_TRANSACTION_OTHER, DEVSTAT_ARG_LD },
133	{ DSM_MS_PER_TRANSACTION_FREE, DEVSTAT_ARG_LD },
134	{ DSM_BUSY_PCT, DEVSTAT_ARG_LD },
135	{ DSM_QUEUE_LENGTH, DEVSTAT_ARG_UINT64 },
136	{ DSM_TOTAL_DURATION, DEVSTAT_ARG_LD },
137	{ DSM_TOTAL_DURATION_READ, DEVSTAT_ARG_LD },
138	{ DSM_TOTAL_DURATION_WRITE, DEVSTAT_ARG_LD },
139	{ DSM_TOTAL_DURATION_FREE, DEVSTAT_ARG_LD },
140	{ DSM_TOTAL_DURATION_OTHER, DEVSTAT_ARG_LD },
141	{ DSM_TOTAL_BUSY_TIME, DEVSTAT_ARG_LD },
142};
143
144static const char *namelist[] = {
145#define X_NUMDEVS	0
146	"_devstat_num_devs",
147#define X_GENERATION	1
148	"_devstat_generation",
149#define X_VERSION	2
150	"_devstat_version",
151#define X_DEVICE_STATQ	3
152	"_device_statq",
153#define X_TIME_UPTIME	4
154	"_time_uptime",
155#define X_END		5
156};
157
158/*
159 * Local function declarations.
160 */
161static int compare_select(const void *arg1, const void *arg2);
162static int readkmem(kvm_t *kd, unsigned long addr, void *buf, size_t nbytes);
163static int readkmem_nl(kvm_t *kd, const char *name, void *buf, size_t nbytes);
164static char *get_devstat_kvm(kvm_t *kd);
165
166#define KREADNL(kd, var, val) \
167	readkmem_nl(kd, namelist[var], &val, sizeof(val))
168
169int
170devstat_getnumdevs(kvm_t *kd)
171{
172	size_t numdevsize;
173	int numdevs;
174
175	numdevsize = sizeof(int);
176
177	/*
178	 * Find out how many devices we have in the system.
179	 */
180	if (kd == NULL) {
181		if (sysctlbyname("kern.devstat.numdevs", &numdevs,
182				 &numdevsize, NULL, 0) == -1) {
183			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
184				 "%s: error getting number of devices\n"
185				 "%s: %s", __func__, __func__,
186				 strerror(errno));
187			return(-1);
188		} else
189			return(numdevs);
190	} else {
191
192		if (KREADNL(kd, X_NUMDEVS, numdevs) == -1)
193			return(-1);
194		else
195			return(numdevs);
196	}
197}
198
199/*
200 * This is an easy way to get the generation number, but the generation is
201 * supplied in a more atmoic manner by the kern.devstat.all sysctl.
202 * Because this generation sysctl is separate from the statistics sysctl,
203 * the device list and the generation could change between the time that
204 * this function is called and the device list is retrieved.
205 */
206long
207devstat_getgeneration(kvm_t *kd)
208{
209	size_t gensize;
210	long generation;
211
212	gensize = sizeof(long);
213
214	/*
215	 * Get the current generation number.
216	 */
217	if (kd == NULL) {
218		if (sysctlbyname("kern.devstat.generation", &generation,
219				 &gensize, NULL, 0) == -1) {
220			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
221				 "%s: error getting devstat generation\n%s: %s",
222				 __func__, __func__, strerror(errno));
223			return(-1);
224		} else
225			return(generation);
226	} else {
227		if (KREADNL(kd, X_GENERATION, generation) == -1)
228			return(-1);
229		else
230			return(generation);
231	}
232}
233
234/*
235 * Get the current devstat version.  The return value of this function
236 * should be compared with DEVSTAT_VERSION, which is defined in
237 * sys/devicestat.h.  This will enable userland programs to determine
238 * whether they are out of sync with the kernel.
239 */
240int
241devstat_getversion(kvm_t *kd)
242{
243	size_t versize;
244	int version;
245
246	versize = sizeof(int);
247
248	/*
249	 * Get the current devstat version.
250	 */
251	if (kd == NULL) {
252		if (sysctlbyname("kern.devstat.version", &version, &versize,
253				 NULL, 0) == -1) {
254			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
255				 "%s: error getting devstat version\n%s: %s",
256				 __func__, __func__, strerror(errno));
257			return(-1);
258		} else
259			return(version);
260	} else {
261		if (KREADNL(kd, X_VERSION, version) == -1)
262			return(-1);
263		else
264			return(version);
265	}
266}
267
268/*
269 * Check the devstat version we know about against the devstat version the
270 * kernel knows about.  If they don't match, print an error into the
271 * devstat error buffer, and return -1.  If they match, return 0.
272 */
273int
274devstat_checkversion(kvm_t *kd)
275{
276	int buflen, res, retval = 0, version;
277
278	version = devstat_getversion(kd);
279
280	if (version != DEVSTAT_VERSION) {
281		/*
282		 * If getversion() returns an error (i.e. -1), then it
283		 * has printed an error message in the buffer.  Therefore,
284		 * we need to add a \n to the end of that message before we
285		 * print our own message in the buffer.
286		 */
287		if (version == -1)
288			buflen = strlen(devstat_errbuf);
289		else
290			buflen = 0;
291
292		res = snprintf(devstat_errbuf + buflen,
293			       DEVSTAT_ERRBUF_SIZE - buflen,
294			       "%s%s: userland devstat version %d is not "
295			       "the same as the kernel\n%s: devstat "
296			       "version %d\n", version == -1 ? "\n" : "",
297			       __func__, DEVSTAT_VERSION, __func__, version);
298
299		if (res < 0)
300			devstat_errbuf[buflen] = '\0';
301
302		buflen = strlen(devstat_errbuf);
303		if (version < DEVSTAT_VERSION)
304			res = snprintf(devstat_errbuf + buflen,
305				       DEVSTAT_ERRBUF_SIZE - buflen,
306				       "%s: libdevstat newer than kernel\n",
307				       __func__);
308		else
309			res = snprintf(devstat_errbuf + buflen,
310				       DEVSTAT_ERRBUF_SIZE - buflen,
311				       "%s: kernel newer than libdevstat\n",
312				       __func__);
313
314		if (res < 0)
315			devstat_errbuf[buflen] = '\0';
316
317		retval = -1;
318	}
319
320	return(retval);
321}
322
323/*
324 * Get the current list of devices and statistics, and the current
325 * generation number.
326 *
327 * Return values:
328 * -1  -- error
329 *  0  -- device list is unchanged
330 *  1  -- device list has changed
331 */
332int
333devstat_getdevs(kvm_t *kd, struct statinfo *stats)
334{
335	int error;
336	size_t dssize;
337	long oldgeneration;
338	int retval = 0;
339	struct devinfo *dinfo;
340	struct timespec ts;
341
342	dinfo = stats->dinfo;
343
344	if (dinfo == NULL) {
345		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
346			 "%s: stats->dinfo was NULL", __func__);
347		return(-1);
348	}
349
350	oldgeneration = dinfo->generation;
351
352	if (kd == NULL) {
353		clock_gettime(CLOCK_MONOTONIC, &ts);
354		stats->snap_time = ts.tv_sec + ts.tv_nsec * 1e-9;
355
356		/* If this is our first time through, mem_ptr will be null. */
357		if (dinfo->mem_ptr == NULL) {
358			/*
359			 * Get the number of devices.  If it's negative, it's an
360			 * error.  Don't bother setting the error string, since
361			 * getnumdevs() has already done that for us.
362			 */
363			if ((dinfo->numdevs = devstat_getnumdevs(kd)) < 0)
364				return(-1);
365
366			/*
367			 * The kern.devstat.all sysctl returns the current
368			 * generation number, as well as all the devices.
369			 * So we need four bytes more.
370			 */
371			dssize = (dinfo->numdevs * sizeof(struct devstat)) +
372				 sizeof(long);
373			dinfo->mem_ptr = (u_int8_t *)malloc(dssize);
374			if (dinfo->mem_ptr == NULL) {
375				snprintf(devstat_errbuf, sizeof(devstat_errbuf),
376					 "%s: Cannot allocate memory for mem_ptr element",
377					 __func__);
378				return(-1);
379			}
380		} else
381			dssize = (dinfo->numdevs * sizeof(struct devstat)) +
382				 sizeof(long);
383
384		/*
385		 * Request all of the devices.  We only really allow for one
386		 * ENOMEM failure.  It would, of course, be possible to just go
387		 * in a loop and keep reallocing the device structure until we
388		 * don't get ENOMEM back.  I'm not sure it's worth it, though.
389		 * If devices are being added to the system that quickly, maybe
390		 * the user can just wait until all devices are added.
391		 */
392		for (;;) {
393			error = sysctlbyname("kern.devstat.all",
394					     dinfo->mem_ptr,
395					     &dssize, NULL, 0);
396			if (error != -1 || errno != EBUSY)
397				break;
398		}
399		if (error == -1) {
400			/*
401			 * If we get ENOMEM back, that means that there are
402			 * more devices now, so we need to allocate more
403			 * space for the device array.
404			 */
405			if (errno == ENOMEM) {
406				/*
407				 * No need to set the error string here,
408				 * devstat_getnumdevs() will do that if it fails.
409				 */
410				if ((dinfo->numdevs = devstat_getnumdevs(kd)) < 0)
411					return(-1);
412
413				dssize = (dinfo->numdevs *
414					sizeof(struct devstat)) + sizeof(long);
415				dinfo->mem_ptr = (u_int8_t *)
416					realloc(dinfo->mem_ptr, dssize);
417				if ((error = sysctlbyname("kern.devstat.all",
418				    dinfo->mem_ptr, &dssize, NULL, 0)) == -1) {
419					snprintf(devstat_errbuf,
420						 sizeof(devstat_errbuf),
421					    	 "%s: error getting device "
422					    	 "stats\n%s: %s", __func__,
423					    	 __func__, strerror(errno));
424					return(-1);
425				}
426			} else {
427				snprintf(devstat_errbuf, sizeof(devstat_errbuf),
428					 "%s: error getting device stats\n"
429					 "%s: %s", __func__, __func__,
430					 strerror(errno));
431				return(-1);
432			}
433		}
434
435	} else {
436		if (KREADNL(kd, X_TIME_UPTIME, ts.tv_sec) == -1)
437			return(-1);
438		else
439			stats->snap_time = ts.tv_sec;
440
441		/*
442		 * This is of course non-atomic, but since we are working
443		 * on a core dump, the generation is unlikely to change
444		 */
445		if ((dinfo->numdevs = devstat_getnumdevs(kd)) == -1)
446			return(-1);
447		if ((dinfo->mem_ptr = (u_int8_t *)get_devstat_kvm(kd)) == NULL)
448			return(-1);
449	}
450	/*
451	 * The sysctl spits out the generation as the first four bytes,
452	 * then all of the device statistics structures.
453	 */
454	dinfo->generation = *(long *)dinfo->mem_ptr;
455
456	/*
457	 * If the generation has changed, and if the current number of
458	 * devices is not the same as the number of devices recorded in the
459	 * devinfo structure, it is likely that the device list has shrunk.
460	 * The reason that it is likely that the device list has shrunk in
461	 * this case is that if the device list has grown, the sysctl above
462	 * will return an ENOMEM error, and we will reset the number of
463	 * devices and reallocate the device array.  If the second sysctl
464	 * fails, we will return an error and therefore never get to this
465	 * point.  If the device list has shrunk, the sysctl will not
466	 * return an error since we have more space allocated than is
467	 * necessary.  So, in the shrinkage case, we catch it here and
468	 * reallocate the array so that we don't use any more space than is
469	 * necessary.
470	 */
471	if (oldgeneration != dinfo->generation) {
472		if (devstat_getnumdevs(kd) != dinfo->numdevs) {
473			if ((dinfo->numdevs = devstat_getnumdevs(kd)) < 0)
474				return(-1);
475			dssize = (dinfo->numdevs * sizeof(struct devstat)) +
476				sizeof(long);
477			dinfo->mem_ptr = (u_int8_t *)realloc(dinfo->mem_ptr,
478							     dssize);
479		}
480		retval = 1;
481	}
482
483	dinfo->devices = (struct devstat *)(dinfo->mem_ptr + sizeof(long));
484
485	return(retval);
486}
487
488/*
489 * selectdevs():
490 *
491 * Devices are selected/deselected based upon the following criteria:
492 * - devices specified by the user on the command line
493 * - devices matching any device type expressions given on the command line
494 * - devices with the highest I/O, if 'top' mode is enabled
495 * - the first n unselected devices in the device list, if maxshowdevs
496 *   devices haven't already been selected and if the user has not
497 *   specified any devices on the command line and if we're in "add" mode.
498 *
499 * Input parameters:
500 * - device selection list (dev_select)
501 * - current number of devices selected (num_selected)
502 * - total number of devices in the selection list (num_selections)
503 * - devstat generation as of the last time selectdevs() was called
504 *   (select_generation)
505 * - current devstat generation (current_generation)
506 * - current list of devices and statistics (devices)
507 * - number of devices in the current device list (numdevs)
508 * - compiled version of the command line device type arguments (matches)
509 *   - This is optional.  If the number of devices is 0, this will be ignored.
510 *   - The matching code pays attention to the current selection mode.  So
511 *     if you pass in a matching expression, it will be evaluated based
512 *     upon the selection mode that is passed in.  See below for details.
513 * - number of device type matching expressions (num_matches)
514 *   - Set to 0 to disable the matching code.
515 * - list of devices specified on the command line by the user (dev_selections)
516 * - number of devices selected on the command line by the user
517 *   (num_dev_selections)
518 * - Our selection mode.  There are four different selection modes:
519 *      - add mode.  (DS_SELECT_ADD) Any devices matching devices explicitly
520 *        selected by the user or devices matching a pattern given by the
521 *        user will be selected in addition to devices that are already
522 *        selected.  Additional devices will be selected, up to maxshowdevs
523 *        number of devices.
524 *      - only mode. (DS_SELECT_ONLY)  Only devices matching devices
525 *        explicitly given by the user or devices matching a pattern
526 *        given by the user will be selected.  No other devices will be
527 *        selected.
528 *      - addonly mode.  (DS_SELECT_ADDONLY)  This is similar to add and
529 *        only.  Basically, this will not de-select any devices that are
530 *        current selected, as only mode would, but it will also not
531 *        gratuitously select up to maxshowdevs devices as add mode would.
532 *      - remove mode.  (DS_SELECT_REMOVE)  Any devices matching devices
533 *        explicitly selected by the user or devices matching a pattern
534 *        given by the user will be de-selected.
535 * - maximum number of devices we can select (maxshowdevs)
536 * - flag indicating whether or not we're in 'top' mode (perf_select)
537 *
538 * Output data:
539 * - the device selection list may be modified and passed back out
540 * - the number of devices selected and the total number of items in the
541 *   device selection list may be changed
542 * - the selection generation may be changed to match the current generation
543 *
544 * Return values:
545 * -1  -- error
546 *  0  -- selected devices are unchanged
547 *  1  -- selected devices changed
548 */
549int
550devstat_selectdevs(struct device_selection **dev_select, int *num_selected,
551		   int *num_selections, long *select_generation,
552		   long current_generation, struct devstat *devices,
553		   int numdevs, struct devstat_match *matches, int num_matches,
554		   char **dev_selections, int num_dev_selections,
555		   devstat_select_mode select_mode, int maxshowdevs,
556		   int perf_select)
557{
558	int i, j, k;
559	int init_selections = 0, init_selected_var = 0;
560	struct device_selection *old_dev_select = NULL;
561	int old_num_selections = 0, old_num_selected;
562	int selection_number = 0;
563	int changed = 0, found = 0;
564
565	if ((dev_select == NULL) || (devices == NULL) || (numdevs < 0))
566		return(-1);
567
568	/*
569	 * We always want to make sure that we have as many dev_select
570	 * entries as there are devices.
571	 */
572	/*
573	 * In this case, we haven't selected devices before.
574	 */
575	if (*dev_select == NULL) {
576		*dev_select = (struct device_selection *)malloc(numdevs *
577			sizeof(struct device_selection));
578		*select_generation = current_generation;
579		init_selections = 1;
580		changed = 1;
581	/*
582	 * In this case, we have selected devices before, but the device
583	 * list has changed since we last selected devices, so we need to
584	 * either enlarge or reduce the size of the device selection list.
585	 * But delay the resizing until after copying the data to old_dev_select
586	 * as to not lose any data in the case of reducing the size.
587	 */
588	} else if (*num_selections != numdevs) {
589		*select_generation = current_generation;
590		init_selections = 1;
591	/*
592	 * In this case, we've selected devices before, and the selection
593	 * list is the same size as it was the last time, but the device
594	 * list has changed.
595	 */
596	} else if (*select_generation < current_generation) {
597		*select_generation = current_generation;
598		init_selections = 1;
599	}
600
601	if (*dev_select == NULL) {
602		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
603			 "%s: Cannot (re)allocate memory for dev_select argument",
604			 __func__);
605		return(-1);
606	}
607
608	/*
609	 * If we're in "only" mode, we want to clear out the selected
610	 * variable since we're going to select exactly what the user wants
611	 * this time through.
612	 */
613	if (select_mode == DS_SELECT_ONLY)
614		init_selected_var = 1;
615
616	/*
617	 * In all cases, we want to back up the number of selected devices.
618	 * It is a quick and accurate way to determine whether the selected
619	 * devices have changed.
620	 */
621	old_num_selected = *num_selected;
622
623	/*
624	 * We want to make a backup of the current selection list if
625	 * the list of devices has changed, or if we're in performance
626	 * selection mode.  In both cases, we don't want to make a backup
627	 * if we already know for sure that the list will be different.
628	 * This is certainly the case if this is our first time through the
629	 * selection code.
630	 */
631	if (((init_selected_var != 0) || (init_selections != 0)
632	 || (perf_select != 0)) && (changed == 0)){
633		old_dev_select = (struct device_selection *)malloc(
634		    *num_selections * sizeof(struct device_selection));
635		if (old_dev_select == NULL) {
636			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
637				 "%s: Cannot allocate memory for selection list backup",
638				 __func__);
639			return(-1);
640		}
641		old_num_selections = *num_selections;
642		bcopy(*dev_select, old_dev_select,
643		    sizeof(struct device_selection) * *num_selections);
644	}
645
646	if (!changed && *num_selections != numdevs) {
647		*dev_select = (struct device_selection *)reallocf(*dev_select,
648			numdevs * sizeof(struct device_selection));
649	}
650
651	if (init_selections != 0) {
652		bzero(*dev_select, sizeof(struct device_selection) * numdevs);
653
654		for (i = 0; i < numdevs; i++) {
655			(*dev_select)[i].device_number =
656				devices[i].device_number;
657			strncpy((*dev_select)[i].device_name,
658				devices[i].device_name,
659				DEVSTAT_NAME_LEN);
660			(*dev_select)[i].device_name[DEVSTAT_NAME_LEN - 1]='\0';
661			(*dev_select)[i].unit_number = devices[i].unit_number;
662			(*dev_select)[i].position = i;
663		}
664		*num_selections = numdevs;
665	} else if (init_selected_var != 0) {
666		for (i = 0; i < numdevs; i++)
667			(*dev_select)[i].selected = 0;
668	}
669
670	/* we haven't gotten around to selecting anything yet.. */
671	if ((select_mode == DS_SELECT_ONLY) || (init_selections != 0)
672	 || (init_selected_var != 0))
673		*num_selected = 0;
674
675	/*
676	 * Look through any devices the user specified on the command line
677	 * and see if they match known devices.  If so, select them.
678	 */
679	for (i = 0; (i < *num_selections) && (num_dev_selections > 0); i++) {
680		char tmpstr[80];
681
682		snprintf(tmpstr, sizeof(tmpstr), "%s%d",
683			 (*dev_select)[i].device_name,
684			 (*dev_select)[i].unit_number);
685		for (j = 0; j < num_dev_selections; j++) {
686			if (strcmp(tmpstr, dev_selections[j]) == 0) {
687				/*
688				 * Here we do different things based on the
689				 * mode we're in.  If we're in add or
690				 * addonly mode, we only select this device
691				 * if it hasn't already been selected.
692				 * Otherwise, we would be unnecessarily
693				 * changing the selection order and
694				 * incrementing the selection count.  If
695				 * we're in only mode, we unconditionally
696				 * select this device, since in only mode
697				 * any previous selections are erased and
698				 * manually specified devices are the first
699				 * ones to be selected.  If we're in remove
700				 * mode, we de-select the specified device and
701				 * decrement the selection count.
702				 */
703				switch(select_mode) {
704				case DS_SELECT_ADD:
705				case DS_SELECT_ADDONLY:
706					if ((*dev_select)[i].selected)
707						break;
708					/* FALLTHROUGH */
709				case DS_SELECT_ONLY:
710					(*dev_select)[i].selected =
711						++selection_number;
712					(*num_selected)++;
713					break;
714				case DS_SELECT_REMOVE:
715					(*dev_select)[i].selected = 0;
716					(*num_selected)--;
717					/*
718					 * This isn't passed back out, we
719					 * just use it to keep track of
720					 * how many devices we've removed.
721					 */
722					num_dev_selections--;
723					break;
724				}
725				break;
726			}
727		}
728	}
729
730	/*
731	 * Go through the user's device type expressions and select devices
732	 * accordingly.  We only do this if the number of devices already
733	 * selected is less than the maximum number we can show.
734	 */
735	for (i = 0; (i < num_matches) && (*num_selected < maxshowdevs); i++) {
736		/* We should probably indicate some error here */
737		if ((matches[i].match_fields == DEVSTAT_MATCH_NONE)
738		 || (matches[i].num_match_categories <= 0))
739			continue;
740
741		for (j = 0; j < numdevs; j++) {
742			int num_match_categories;
743
744			num_match_categories = matches[i].num_match_categories;
745
746			/*
747			 * Determine whether or not the current device
748			 * matches the given matching expression.  This if
749			 * statement consists of three components:
750			 *   - the device type check
751			 *   - the device interface check
752			 *   - the passthrough check
753			 * If a the matching test is successful, it
754			 * decrements the number of matching categories,
755			 * and if we've reached the last element that
756			 * needed to be matched, the if statement succeeds.
757			 *
758			 */
759			if ((((matches[i].match_fields & DEVSTAT_MATCH_TYPE)!=0)
760			  && ((devices[j].device_type & DEVSTAT_TYPE_MASK) ==
761			        (matches[i].device_type & DEVSTAT_TYPE_MASK))
762			  &&(((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
763			   || (((matches[i].match_fields &
764				DEVSTAT_MATCH_PASS) == 0)
765			    && ((devices[j].device_type &
766			        DEVSTAT_TYPE_PASS) == 0)))
767			  && (--num_match_categories == 0))
768			 || (((matches[i].match_fields & DEVSTAT_MATCH_IF) != 0)
769			  && ((devices[j].device_type & DEVSTAT_TYPE_IF_MASK) ==
770			        (matches[i].device_type & DEVSTAT_TYPE_IF_MASK))
771			  &&(((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
772			   || (((matches[i].match_fields &
773				DEVSTAT_MATCH_PASS) == 0)
774			    && ((devices[j].device_type &
775				DEVSTAT_TYPE_PASS) == 0)))
776			  && (--num_match_categories == 0))
777			 || (((matches[i].match_fields & DEVSTAT_MATCH_PASS)!=0)
778			  && ((devices[j].device_type & DEVSTAT_TYPE_PASS) != 0)
779			  && (--num_match_categories == 0))) {
780
781				/*
782				 * This is probably a non-optimal solution
783				 * to the problem that the devices in the
784				 * device list will not be in the same
785				 * order as the devices in the selection
786				 * array.
787				 */
788				for (k = 0; k < numdevs; k++) {
789					if ((*dev_select)[k].position == j) {
790						found = 1;
791						break;
792					}
793				}
794
795				/*
796				 * There shouldn't be a case where a device
797				 * in the device list is not in the
798				 * selection list...but it could happen.
799				 */
800				if (found != 1) {
801					fprintf(stderr, "selectdevs: couldn't"
802						" find %s%d in selection "
803						"list\n",
804						devices[j].device_name,
805						devices[j].unit_number);
806					break;
807				}
808
809				/*
810				 * We do different things based upon the
811				 * mode we're in.  If we're in add or only
812				 * mode, we go ahead and select this device
813				 * if it hasn't already been selected.  If
814				 * it has already been selected, we leave
815				 * it alone so we don't mess up the
816				 * selection ordering.  Manually specified
817				 * devices have already been selected, and
818				 * they have higher priority than pattern
819				 * matched devices.  If we're in remove
820				 * mode, we de-select the given device and
821				 * decrement the selected count.
822				 */
823				switch(select_mode) {
824				case DS_SELECT_ADD:
825				case DS_SELECT_ADDONLY:
826				case DS_SELECT_ONLY:
827					if ((*dev_select)[k].selected != 0)
828						break;
829					(*dev_select)[k].selected =
830						++selection_number;
831					(*num_selected)++;
832					break;
833				case DS_SELECT_REMOVE:
834					(*dev_select)[k].selected = 0;
835					(*num_selected)--;
836					break;
837				}
838			}
839		}
840	}
841
842	/*
843	 * Here we implement "top" mode.  Devices are sorted in the
844	 * selection array based on two criteria:  whether or not they are
845	 * selected (not selection number, just the fact that they are
846	 * selected!) and the number of bytes in the "bytes" field of the
847	 * selection structure.  The bytes field generally must be kept up
848	 * by the user.  In the future, it may be maintained by library
849	 * functions, but for now the user has to do the work.
850	 *
851	 * At first glance, it may seem wrong that we don't go through and
852	 * select every device in the case where the user hasn't specified
853	 * any devices or patterns.  In fact, though, it won't make any
854	 * difference in the device sorting.  In that particular case (i.e.
855	 * when we're in "add" or "only" mode, and the user hasn't
856	 * specified anything) the first time through no devices will be
857	 * selected, so the only criterion used to sort them will be their
858	 * performance.  The second time through, and every time thereafter,
859	 * all devices will be selected, so again selection won't matter.
860	 */
861	if (perf_select != 0) {
862
863		/* Sort the device array by throughput  */
864		qsort(*dev_select, *num_selections,
865		      sizeof(struct device_selection),
866		      compare_select);
867
868		if (*num_selected == 0) {
869			/*
870			 * Here we select every device in the array, if it
871			 * isn't already selected.  Because the 'selected'
872			 * variable in the selection array entries contains
873			 * the selection order, the devstats routine can show
874			 * the devices that were selected first.
875			 */
876			for (i = 0; i < *num_selections; i++) {
877				if ((*dev_select)[i].selected == 0) {
878					(*dev_select)[i].selected =
879						++selection_number;
880					(*num_selected)++;
881				}
882			}
883		} else {
884			selection_number = 0;
885			for (i = 0; i < *num_selections; i++) {
886				if ((*dev_select)[i].selected != 0) {
887					(*dev_select)[i].selected =
888						++selection_number;
889				}
890			}
891		}
892	}
893
894	/*
895	 * If we're in the "add" selection mode and if we haven't already
896	 * selected maxshowdevs number of devices, go through the array and
897	 * select any unselected devices.  If we're in "only" mode, we
898	 * obviously don't want to select anything other than what the user
899	 * specifies.  If we're in "remove" mode, it probably isn't a good
900	 * idea to go through and select any more devices, since we might
901	 * end up selecting something that the user wants removed.  Through
902	 * more complicated logic, we could actually figure this out, but
903	 * that would probably require combining this loop with the various
904	 * selections loops above.
905	 */
906	if ((select_mode == DS_SELECT_ADD) && (*num_selected < maxshowdevs)) {
907		for (i = 0; i < *num_selections; i++)
908			if ((*dev_select)[i].selected == 0) {
909				(*dev_select)[i].selected = ++selection_number;
910				(*num_selected)++;
911			}
912	}
913
914	/*
915	 * Look at the number of devices that have been selected.  If it
916	 * has changed, set the changed variable.  Otherwise, if we've
917	 * made a backup of the selection list, compare it to the current
918	 * selection list to see if the selected devices have changed.
919	 */
920	if ((changed == 0) && (old_num_selected != *num_selected))
921		changed = 1;
922	else if ((changed == 0) && (old_dev_select != NULL)) {
923		/*
924		 * Now we go through the selection list and we look at
925		 * it three different ways.
926		 */
927		for (i = 0; (i < *num_selections) && (changed == 0) &&
928		     (i < old_num_selections); i++) {
929			/*
930			 * If the device at index i in both the new and old
931			 * selection arrays has the same device number and
932			 * selection status, it hasn't changed.  We
933			 * continue on to the next index.
934			 */
935			if (((*dev_select)[i].device_number ==
936			     old_dev_select[i].device_number)
937			 && ((*dev_select)[i].selected ==
938			     old_dev_select[i].selected))
939				continue;
940
941			/*
942			 * Now, if we're still going through the if
943			 * statement, the above test wasn't true.  So we
944			 * check here to see if the device at index i in
945			 * the current array is the same as the device at
946			 * index i in the old array.  If it is, that means
947			 * that its selection number has changed.  Set
948			 * changed to 1 and exit the loop.
949			 */
950			else if ((*dev_select)[i].device_number ==
951			          old_dev_select[i].device_number) {
952				changed = 1;
953				break;
954			}
955			/*
956			 * If we get here, then the device at index i in
957			 * the current array isn't the same device as the
958			 * device at index i in the old array.
959			 */
960			else {
961				found = 0;
962
963				/*
964				 * Search through the old selection array
965				 * looking for a device with the same
966				 * device number as the device at index i
967				 * in the current array.  If the selection
968				 * status is the same, then we mark it as
969				 * found.  If the selection status isn't
970				 * the same, we break out of the loop.
971				 * Since found isn't set, changed will be
972				 * set to 1 below.
973				 */
974				for (j = 0; j < old_num_selections; j++) {
975					if (((*dev_select)[i].device_number ==
976					      old_dev_select[j].device_number)
977					 && ((*dev_select)[i].selected ==
978					      old_dev_select[j].selected)){
979						found = 1;
980						break;
981					}
982					else if ((*dev_select)[i].device_number
983					    == old_dev_select[j].device_number)
984						break;
985				}
986				if (found == 0)
987					changed = 1;
988			}
989		}
990	}
991	if (old_dev_select != NULL)
992		free(old_dev_select);
993
994	return(changed);
995}
996
997/*
998 * Comparison routine for qsort() above.  Note that the comparison here is
999 * backwards -- generally, it should return a value to indicate whether
1000 * arg1 is <, =, or > arg2.  Instead, it returns the opposite.  The reason
1001 * it returns the opposite is so that the selection array will be sorted in
1002 * order of decreasing performance.  We sort on two parameters.  The first
1003 * sort key is whether or not one or the other of the devices in question
1004 * has been selected.  If one of them has, and the other one has not, the
1005 * selected device is automatically more important than the unselected
1006 * device.  If neither device is selected, we judge the devices based upon
1007 * performance.
1008 */
1009static int
1010compare_select(const void *arg1, const void *arg2)
1011{
1012	if ((((const struct device_selection *)arg1)->selected)
1013	 && (((const struct device_selection *)arg2)->selected == 0))
1014		return(-1);
1015	else if ((((const struct device_selection *)arg1)->selected == 0)
1016	      && (((const struct device_selection *)arg2)->selected))
1017		return(1);
1018	else if (((const struct device_selection *)arg2)->bytes <
1019	         ((const struct device_selection *)arg1)->bytes)
1020		return(-1);
1021	else if (((const struct device_selection *)arg2)->bytes >
1022		 ((const struct device_selection *)arg1)->bytes)
1023		return(1);
1024	else
1025		return(0);
1026}
1027
1028/*
1029 * Take a string with the general format "arg1,arg2,arg3", and build a
1030 * device matching expression from it.
1031 */
1032int
1033devstat_buildmatch(char *match_str, struct devstat_match **matches,
1034		   int *num_matches)
1035{
1036	char *tstr[5];
1037	char **tempstr;
1038	int num_args;
1039	int i, j;
1040
1041	/* We can't do much without a string to parse */
1042	if (match_str == NULL) {
1043		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1044			 "%s: no match expression", __func__);
1045		return(-1);
1046	}
1047
1048	/*
1049	 * Break the (comma delimited) input string out into separate strings.
1050	 */
1051	for (tempstr = tstr, num_args  = 0;
1052	     (*tempstr = strsep(&match_str, ",")) != NULL && (num_args < 5);)
1053		if (**tempstr != '\0') {
1054			num_args++;
1055			if (++tempstr >= &tstr[5])
1056				break;
1057		}
1058
1059	/* The user gave us too many type arguments */
1060	if (num_args > 3) {
1061		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1062			 "%s: too many type arguments", __func__);
1063		return(-1);
1064	}
1065
1066	if (*num_matches == 0)
1067		*matches = NULL;
1068
1069	*matches = (struct devstat_match *)reallocf(*matches,
1070		  sizeof(struct devstat_match) * (*num_matches + 1));
1071
1072	if (*matches == NULL) {
1073		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1074			 "%s: Cannot allocate memory for matches list", __func__);
1075		return(-1);
1076	}
1077
1078	/* Make sure the current entry is clear */
1079	bzero(&matches[0][*num_matches], sizeof(struct devstat_match));
1080
1081	/*
1082	 * Step through the arguments the user gave us and build a device
1083	 * matching expression from them.
1084	 */
1085	for (i = 0; i < num_args; i++) {
1086		char *tempstr2, *tempstr3;
1087
1088		/*
1089		 * Get rid of leading white space.
1090		 */
1091		tempstr2 = tstr[i];
1092		while (isspace(*tempstr2) && (*tempstr2 != '\0'))
1093			tempstr2++;
1094
1095		/*
1096		 * Get rid of trailing white space.
1097		 */
1098		tempstr3 = &tempstr2[strlen(tempstr2) - 1];
1099
1100		while ((*tempstr3 != '\0') && (tempstr3 > tempstr2)
1101		    && (isspace(*tempstr3))) {
1102			*tempstr3 = '\0';
1103			tempstr3--;
1104		}
1105
1106		/*
1107		 * Go through the match table comparing the user's
1108		 * arguments to known device types, interfaces, etc.
1109		 */
1110		for (j = 0; match_table[j].match_str != NULL; j++) {
1111			/*
1112			 * We do case-insensitive matching, in case someone
1113			 * wants to enter "SCSI" instead of "scsi" or
1114			 * something like that.  Only compare as many
1115			 * characters as are in the string in the match
1116			 * table.  This should help if someone tries to use
1117			 * a super-long match expression.
1118			 */
1119			if (strncasecmp(tempstr2, match_table[j].match_str,
1120			    strlen(match_table[j].match_str)) == 0) {
1121				/*
1122				 * Make sure the user hasn't specified two
1123				 * items of the same type, like "da" and
1124				 * "cd".  One device cannot be both.
1125				 */
1126				if (((*matches)[*num_matches].match_fields &
1127				    match_table[j].match_field) != 0) {
1128					snprintf(devstat_errbuf,
1129						 sizeof(devstat_errbuf),
1130						 "%s: cannot have more than "
1131						 "one match item in a single "
1132						 "category", __func__);
1133					return(-1);
1134				}
1135				/*
1136				 * If we've gotten this far, we have a
1137				 * winner.  Set the appropriate fields in
1138				 * the match entry.
1139				 */
1140				(*matches)[*num_matches].match_fields |=
1141					match_table[j].match_field;
1142				(*matches)[*num_matches].device_type |=
1143					match_table[j].type;
1144				(*matches)[*num_matches].num_match_categories++;
1145				break;
1146			}
1147		}
1148		/*
1149		 * We should have found a match in the above for loop.  If
1150		 * not, that means the user entered an invalid device type
1151		 * or interface.
1152		 */
1153		if ((*matches)[*num_matches].num_match_categories != (i + 1)) {
1154			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1155				 "%s: unknown match item \"%s\"", __func__,
1156				 tstr[i]);
1157			return(-1);
1158		}
1159	}
1160
1161	(*num_matches)++;
1162
1163	return(0);
1164}
1165
1166/*
1167 * Compute a number of device statistics.  Only one field is mandatory, and
1168 * that is "current".  Everything else is optional.  The caller passes in
1169 * pointers to variables to hold the various statistics he desires.  If he
1170 * doesn't want a particular staistic, he should pass in a NULL pointer.
1171 * Return values:
1172 * 0   -- success
1173 * -1  -- failure
1174 */
1175int
1176compute_stats(struct devstat *current, struct devstat *previous,
1177	      long double etime, u_int64_t *total_bytes,
1178	      u_int64_t *total_transfers, u_int64_t *total_blocks,
1179	      long double *kb_per_transfer, long double *transfers_per_second,
1180	      long double *mb_per_second, long double *blocks_per_second,
1181	      long double *ms_per_transaction)
1182{
1183	return(devstat_compute_statistics(current, previous, etime,
1184	       total_bytes ? DSM_TOTAL_BYTES : DSM_SKIP,
1185	       total_bytes,
1186	       total_transfers ? DSM_TOTAL_TRANSFERS : DSM_SKIP,
1187	       total_transfers,
1188	       total_blocks ? DSM_TOTAL_BLOCKS : DSM_SKIP,
1189	       total_blocks,
1190	       kb_per_transfer ? DSM_KB_PER_TRANSFER : DSM_SKIP,
1191	       kb_per_transfer,
1192	       transfers_per_second ? DSM_TRANSFERS_PER_SECOND : DSM_SKIP,
1193	       transfers_per_second,
1194	       mb_per_second ? DSM_MB_PER_SECOND : DSM_SKIP,
1195	       mb_per_second,
1196	       blocks_per_second ? DSM_BLOCKS_PER_SECOND : DSM_SKIP,
1197	       blocks_per_second,
1198	       ms_per_transaction ? DSM_MS_PER_TRANSACTION : DSM_SKIP,
1199	       ms_per_transaction,
1200	       DSM_NONE));
1201}
1202
1203
1204/* This is 1/2^64 */
1205#define BINTIME_SCALE 5.42101086242752217003726400434970855712890625e-20
1206
1207long double
1208devstat_compute_etime(struct bintime *cur_time, struct bintime *prev_time)
1209{
1210	long double etime;
1211
1212	etime = cur_time->sec;
1213	etime += cur_time->frac * BINTIME_SCALE;
1214	if (prev_time != NULL) {
1215		etime -= prev_time->sec;
1216		etime -= prev_time->frac * BINTIME_SCALE;
1217	}
1218	return(etime);
1219}
1220
1221#define DELTA(field, index)				\
1222	(current->field[(index)] - (previous ? previous->field[(index)] : 0))
1223
1224#define DELTA_T(field)					\
1225	devstat_compute_etime(&current->field,  	\
1226	(previous ? &previous->field : NULL))
1227
1228int
1229devstat_compute_statistics(struct devstat *current, struct devstat *previous,
1230			   long double etime, ...)
1231{
1232	u_int64_t totalbytes, totalbytesread, totalbyteswrite, totalbytesfree;
1233	u_int64_t totaltransfers, totaltransfersread, totaltransferswrite;
1234	u_int64_t totaltransfersother, totalblocks, totalblocksread;
1235	u_int64_t totalblockswrite, totaltransfersfree, totalblocksfree;
1236	long double totalduration, totaldurationread, totaldurationwrite;
1237	long double totaldurationfree, totaldurationother;
1238	va_list ap;
1239	devstat_metric metric;
1240	u_int64_t *destu64;
1241	long double *destld;
1242	int retval;
1243
1244	retval = 0;
1245
1246	/*
1247	 * current is the only mandatory field.
1248	 */
1249	if (current == NULL) {
1250		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1251			 "%s: current stats structure was NULL", __func__);
1252		return(-1);
1253	}
1254
1255	totalbytesread = DELTA(bytes, DEVSTAT_READ);
1256	totalbyteswrite = DELTA(bytes, DEVSTAT_WRITE);
1257	totalbytesfree = DELTA(bytes, DEVSTAT_FREE);
1258	totalbytes = totalbytesread + totalbyteswrite + totalbytesfree;
1259
1260	totaltransfersread = DELTA(operations, DEVSTAT_READ);
1261	totaltransferswrite = DELTA(operations, DEVSTAT_WRITE);
1262	totaltransfersother = DELTA(operations, DEVSTAT_NO_DATA);
1263	totaltransfersfree = DELTA(operations, DEVSTAT_FREE);
1264	totaltransfers = totaltransfersread + totaltransferswrite +
1265			 totaltransfersother + totaltransfersfree;
1266
1267	totalblocks = totalbytes;
1268	totalblocksread = totalbytesread;
1269	totalblockswrite = totalbyteswrite;
1270	totalblocksfree = totalbytesfree;
1271
1272	if (current->block_size > 0) {
1273		totalblocks /= current->block_size;
1274		totalblocksread /= current->block_size;
1275		totalblockswrite /= current->block_size;
1276		totalblocksfree /= current->block_size;
1277	} else {
1278		totalblocks /= 512;
1279		totalblocksread /= 512;
1280		totalblockswrite /= 512;
1281		totalblocksfree /= 512;
1282	}
1283
1284	totaldurationread = DELTA_T(duration[DEVSTAT_READ]);
1285	totaldurationwrite = DELTA_T(duration[DEVSTAT_WRITE]);
1286	totaldurationfree = DELTA_T(duration[DEVSTAT_FREE]);
1287	totaldurationother = DELTA_T(duration[DEVSTAT_NO_DATA]);
1288	totalduration = totaldurationread + totaldurationwrite +
1289	    totaldurationfree + totaldurationother;
1290
1291	va_start(ap, etime);
1292
1293	while ((metric = (devstat_metric)va_arg(ap, devstat_metric)) != 0) {
1294
1295		if (metric == DSM_NONE)
1296			break;
1297
1298		if (metric >= DSM_MAX) {
1299			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1300				 "%s: metric %d is out of range", __func__,
1301				 metric);
1302			retval = -1;
1303			goto bailout;
1304		}
1305
1306		switch (devstat_arg_list[metric].argtype) {
1307		case DEVSTAT_ARG_UINT64:
1308			destu64 = (u_int64_t *)va_arg(ap, u_int64_t *);
1309			break;
1310		case DEVSTAT_ARG_LD:
1311			destld = (long double *)va_arg(ap, long double *);
1312			break;
1313		case DEVSTAT_ARG_SKIP:
1314			destld = (long double *)va_arg(ap, long double *);
1315			break;
1316		default:
1317			retval = -1;
1318			goto bailout;
1319			break; /* NOTREACHED */
1320		}
1321
1322		if (devstat_arg_list[metric].argtype == DEVSTAT_ARG_SKIP)
1323			continue;
1324
1325		switch (metric) {
1326		case DSM_TOTAL_BYTES:
1327			*destu64 = totalbytes;
1328			break;
1329		case DSM_TOTAL_BYTES_READ:
1330			*destu64 = totalbytesread;
1331			break;
1332		case DSM_TOTAL_BYTES_WRITE:
1333			*destu64 = totalbyteswrite;
1334			break;
1335		case DSM_TOTAL_BYTES_FREE:
1336			*destu64 = totalbytesfree;
1337			break;
1338		case DSM_TOTAL_TRANSFERS:
1339			*destu64 = totaltransfers;
1340			break;
1341		case DSM_TOTAL_TRANSFERS_READ:
1342			*destu64 = totaltransfersread;
1343			break;
1344		case DSM_TOTAL_TRANSFERS_WRITE:
1345			*destu64 = totaltransferswrite;
1346			break;
1347		case DSM_TOTAL_TRANSFERS_FREE:
1348			*destu64 = totaltransfersfree;
1349			break;
1350		case DSM_TOTAL_TRANSFERS_OTHER:
1351			*destu64 = totaltransfersother;
1352			break;
1353		case DSM_TOTAL_BLOCKS:
1354			*destu64 = totalblocks;
1355			break;
1356		case DSM_TOTAL_BLOCKS_READ:
1357			*destu64 = totalblocksread;
1358			break;
1359		case DSM_TOTAL_BLOCKS_WRITE:
1360			*destu64 = totalblockswrite;
1361			break;
1362		case DSM_TOTAL_BLOCKS_FREE:
1363			*destu64 = totalblocksfree;
1364			break;
1365		case DSM_KB_PER_TRANSFER:
1366			*destld = totalbytes;
1367			*destld /= 1024;
1368			if (totaltransfers > 0)
1369				*destld /= totaltransfers;
1370			else
1371				*destld = 0.0;
1372			break;
1373		case DSM_KB_PER_TRANSFER_READ:
1374			*destld = totalbytesread;
1375			*destld /= 1024;
1376			if (totaltransfersread > 0)
1377				*destld /= totaltransfersread;
1378			else
1379				*destld = 0.0;
1380			break;
1381		case DSM_KB_PER_TRANSFER_WRITE:
1382			*destld = totalbyteswrite;
1383			*destld /= 1024;
1384			if (totaltransferswrite > 0)
1385				*destld /= totaltransferswrite;
1386			else
1387				*destld = 0.0;
1388			break;
1389		case DSM_KB_PER_TRANSFER_FREE:
1390			*destld = totalbytesfree;
1391			*destld /= 1024;
1392			if (totaltransfersfree > 0)
1393				*destld /= totaltransfersfree;
1394			else
1395				*destld = 0.0;
1396			break;
1397		case DSM_TRANSFERS_PER_SECOND:
1398			if (etime > 0.0) {
1399				*destld = totaltransfers;
1400				*destld /= etime;
1401			} else
1402				*destld = 0.0;
1403			break;
1404		case DSM_TRANSFERS_PER_SECOND_READ:
1405			if (etime > 0.0) {
1406				*destld = totaltransfersread;
1407				*destld /= etime;
1408			} else
1409				*destld = 0.0;
1410			break;
1411		case DSM_TRANSFERS_PER_SECOND_WRITE:
1412			if (etime > 0.0) {
1413				*destld = totaltransferswrite;
1414				*destld /= etime;
1415			} else
1416				*destld = 0.0;
1417			break;
1418		case DSM_TRANSFERS_PER_SECOND_FREE:
1419			if (etime > 0.0) {
1420				*destld = totaltransfersfree;
1421				*destld /= etime;
1422			} else
1423				*destld = 0.0;
1424			break;
1425		case DSM_TRANSFERS_PER_SECOND_OTHER:
1426			if (etime > 0.0) {
1427				*destld = totaltransfersother;
1428				*destld /= etime;
1429			} else
1430				*destld = 0.0;
1431			break;
1432		case DSM_MB_PER_SECOND:
1433			*destld = totalbytes;
1434			*destld /= 1024 * 1024;
1435			if (etime > 0.0)
1436				*destld /= etime;
1437			else
1438				*destld = 0.0;
1439			break;
1440		case DSM_MB_PER_SECOND_READ:
1441			*destld = totalbytesread;
1442			*destld /= 1024 * 1024;
1443			if (etime > 0.0)
1444				*destld /= etime;
1445			else
1446				*destld = 0.0;
1447			break;
1448		case DSM_MB_PER_SECOND_WRITE:
1449			*destld = totalbyteswrite;
1450			*destld /= 1024 * 1024;
1451			if (etime > 0.0)
1452				*destld /= etime;
1453			else
1454				*destld = 0.0;
1455			break;
1456		case DSM_MB_PER_SECOND_FREE:
1457			*destld = totalbytesfree;
1458			*destld /= 1024 * 1024;
1459			if (etime > 0.0)
1460				*destld /= etime;
1461			else
1462				*destld = 0.0;
1463			break;
1464		case DSM_BLOCKS_PER_SECOND:
1465			*destld = totalblocks;
1466			if (etime > 0.0)
1467				*destld /= etime;
1468			else
1469				*destld = 0.0;
1470			break;
1471		case DSM_BLOCKS_PER_SECOND_READ:
1472			*destld = totalblocksread;
1473			if (etime > 0.0)
1474				*destld /= etime;
1475			else
1476				*destld = 0.0;
1477			break;
1478		case DSM_BLOCKS_PER_SECOND_WRITE:
1479			*destld = totalblockswrite;
1480			if (etime > 0.0)
1481				*destld /= etime;
1482			else
1483				*destld = 0.0;
1484			break;
1485		case DSM_BLOCKS_PER_SECOND_FREE:
1486			*destld = totalblocksfree;
1487			if (etime > 0.0)
1488				*destld /= etime;
1489			else
1490				*destld = 0.0;
1491			break;
1492		/*
1493		 * Some devstat callers update the duration and some don't.
1494		 * So this will only be accurate if they provide the
1495		 * duration.
1496		 */
1497		case DSM_MS_PER_TRANSACTION:
1498			if (totaltransfers > 0) {
1499				*destld = totalduration;
1500				*destld /= totaltransfers;
1501				*destld *= 1000;
1502			} else
1503				*destld = 0.0;
1504			break;
1505		case DSM_MS_PER_TRANSACTION_READ:
1506			if (totaltransfersread > 0) {
1507				*destld = totaldurationread;
1508				*destld /= totaltransfersread;
1509				*destld *= 1000;
1510			} else
1511				*destld = 0.0;
1512			break;
1513		case DSM_MS_PER_TRANSACTION_WRITE:
1514			if (totaltransferswrite > 0) {
1515				*destld = totaldurationwrite;
1516				*destld /= totaltransferswrite;
1517				*destld *= 1000;
1518			} else
1519				*destld = 0.0;
1520			break;
1521		case DSM_MS_PER_TRANSACTION_FREE:
1522			if (totaltransfersfree > 0) {
1523				*destld = totaldurationfree;
1524				*destld /= totaltransfersfree;
1525				*destld *= 1000;
1526			} else
1527				*destld = 0.0;
1528			break;
1529		case DSM_MS_PER_TRANSACTION_OTHER:
1530			if (totaltransfersother > 0) {
1531				*destld = totaldurationother;
1532				*destld /= totaltransfersother;
1533				*destld *= 1000;
1534			} else
1535				*destld = 0.0;
1536			break;
1537		case DSM_BUSY_PCT:
1538			*destld = DELTA_T(busy_time);
1539			if (*destld < 0)
1540				*destld = 0;
1541			*destld /= etime;
1542			*destld *= 100;
1543			if (*destld < 0)
1544				*destld = 0;
1545			break;
1546		case DSM_QUEUE_LENGTH:
1547			*destu64 = current->start_count - current->end_count;
1548			break;
1549		case DSM_TOTAL_DURATION:
1550			*destld = totalduration;
1551			break;
1552		case DSM_TOTAL_DURATION_READ:
1553			*destld = totaldurationread;
1554			break;
1555		case DSM_TOTAL_DURATION_WRITE:
1556			*destld = totaldurationwrite;
1557			break;
1558		case DSM_TOTAL_DURATION_FREE:
1559			*destld = totaldurationfree;
1560			break;
1561		case DSM_TOTAL_DURATION_OTHER:
1562			*destld = totaldurationother;
1563			break;
1564		case DSM_TOTAL_BUSY_TIME:
1565			*destld = DELTA_T(busy_time);
1566			break;
1567/*
1568 * XXX: comment out the default block to see if any case's are missing.
1569 */
1570#if 1
1571		default:
1572			/*
1573			 * This shouldn't happen, since we should have
1574			 * caught any out of range metrics at the top of
1575			 * the loop.
1576			 */
1577			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1578				 "%s: unknown metric %d", __func__, metric);
1579			retval = -1;
1580			goto bailout;
1581			break; /* NOTREACHED */
1582#endif
1583		}
1584	}
1585
1586bailout:
1587
1588	va_end(ap);
1589	return(retval);
1590}
1591
1592static int
1593readkmem(kvm_t *kd, unsigned long addr, void *buf, size_t nbytes)
1594{
1595
1596	if (kvm_read(kd, addr, buf, nbytes) == -1) {
1597		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1598			 "%s: error reading value (kvm_read): %s", __func__,
1599			 kvm_geterr(kd));
1600		return(-1);
1601	}
1602	return(0);
1603}
1604
1605static int
1606readkmem_nl(kvm_t *kd, const char *name, void *buf, size_t nbytes)
1607{
1608	struct nlist nl[2];
1609
1610	nl[0].n_name = (char *)name;
1611	nl[1].n_name = NULL;
1612
1613	if (kvm_nlist(kd, nl) == -1) {
1614		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1615			 "%s: error getting name list (kvm_nlist): %s",
1616			 __func__, kvm_geterr(kd));
1617		return(-1);
1618	}
1619	return(readkmem(kd, nl[0].n_value, buf, nbytes));
1620}
1621
1622/*
1623 * This duplicates the functionality of the kernel sysctl handler for poking
1624 * through crash dumps.
1625 */
1626static char *
1627get_devstat_kvm(kvm_t *kd)
1628{
1629	int i, wp;
1630	long gen;
1631	struct devstat *nds;
1632	struct devstat ds;
1633	struct devstatlist dhead;
1634	int num_devs;
1635	char *rv = NULL;
1636
1637	if ((num_devs = devstat_getnumdevs(kd)) <= 0)
1638		return(NULL);
1639	if (KREADNL(kd, X_DEVICE_STATQ, dhead) == -1)
1640		return(NULL);
1641
1642	nds = STAILQ_FIRST(&dhead);
1643
1644	if ((rv = malloc(sizeof(gen))) == NULL) {
1645		snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1646			 "%s: out of memory (initial malloc failed)",
1647			 __func__);
1648		return(NULL);
1649	}
1650	gen = devstat_getgeneration(kd);
1651	memcpy(rv, &gen, sizeof(gen));
1652	wp = sizeof(gen);
1653	/*
1654	 * Now push out all the devices.
1655	 */
1656	for (i = 0; (nds != NULL) && (i < num_devs);
1657	     nds = STAILQ_NEXT(nds, dev_links), i++) {
1658		if (readkmem(kd, (long)nds, &ds, sizeof(ds)) == -1) {
1659			free(rv);
1660			return(NULL);
1661		}
1662		nds = &ds;
1663		rv = (char *)reallocf(rv, sizeof(gen) +
1664				      sizeof(ds) * (i + 1));
1665		if (rv == NULL) {
1666			snprintf(devstat_errbuf, sizeof(devstat_errbuf),
1667				 "%s: out of memory (malloc failed)",
1668				 __func__);
1669			return(NULL);
1670		}
1671		memcpy(rv + wp, &ds, sizeof(ds));
1672		wp += sizeof(ds);
1673	}
1674	return(rv);
1675}
1676