xref: /freebsd/lib/libmt/mtlib.c (revision 1719886f6d08408b834d270c59ffcfd821c8f63a)
1 /*-
2  * Copyright (c) 2013, 2014, 2015 Spectra Logic Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    substantially similar to the "NO WARRANTY" disclaimer below
13  *    ("Disclaimer") and any redistribution must be conditioned upon
14  *    including a substantially similar Disclaimer requirement for further
15  *    binary redistribution.
16  *
17  * NO WARRANTY
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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,
26  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
27  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGES.
29  *
30  * Authors: Ken Merry           (Spectra Logic Corporation)
31  */
32 
33 #include <sys/types.h>
34 #include <sys/ioctl.h>
35 #include <sys/mtio.h>
36 #include <sys/queue.h>
37 #include <sys/sbuf.h>
38 
39 #include <ctype.h>
40 #include <err.h>
41 #include <fcntl.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 #include <stdint.h>
47 #include <errno.h>
48 #include <bsdxml.h>
49 #include <mtlib.h>
50 
51 /*
52  * Called at the start of each XML element, and includes the list of
53  * attributes for the element.
54  */
55 void
56 mt_start_element(void *user_data, const char *name, const char **attr)
57 {
58 	int i;
59 	struct mt_status_data *mtinfo;
60 	struct mt_status_entry *entry;
61 
62 	mtinfo = (struct mt_status_data *)user_data;
63 
64 	if (mtinfo->error != 0)
65 		return;
66 
67 	mtinfo->level++;
68 	if ((u_int)mtinfo->level >= (sizeof(mtinfo->cur_sb) /
69             sizeof(mtinfo->cur_sb[0]))) {
70 		mtinfo->error = 1;
71                 snprintf(mtinfo->error_str, sizeof(mtinfo->error_str),
72 		    "%s: too many nesting levels, %zd max", __func__,
73 		    sizeof(mtinfo->cur_sb) / sizeof(mtinfo->cur_sb[0]));
74 		return;
75 	}
76 
77         mtinfo->cur_sb[mtinfo->level] = sbuf_new_auto();
78         if (mtinfo->cur_sb[mtinfo->level] == NULL) {
79 		mtinfo->error = 1;
80                 snprintf(mtinfo->error_str, sizeof(mtinfo->error_str),
81 		    "%s: Unable to allocate sbuf", __func__);
82 		return;
83 	}
84 
85 	entry = malloc(sizeof(*entry));
86 	if (entry == NULL) {
87 		mtinfo->error = 1;
88 		snprintf(mtinfo->error_str, sizeof(mtinfo->error_str),
89 		    "%s: unable to allocate %zd bytes", __func__,
90 		    sizeof(*entry));
91 		return;
92 	}
93 	bzero(entry, sizeof(*entry));
94 	STAILQ_INIT(&entry->nv_list);
95 	STAILQ_INIT(&entry->child_entries);
96 	entry->entry_name = strdup(name);
97 	mtinfo->cur_entry[mtinfo->level] = entry;
98 	if (mtinfo->cur_entry[mtinfo->level - 1] == NULL) {
99 		STAILQ_INSERT_TAIL(&mtinfo->entries, entry, links);
100 	} else {
101 		STAILQ_INSERT_TAIL(
102 		    &mtinfo->cur_entry[mtinfo->level - 1]->child_entries,
103 		    entry, links);
104 		entry->parent = mtinfo->cur_entry[mtinfo->level - 1];
105 	}
106 	for (i = 0; attr[i] != NULL; i+=2) {
107 		struct mt_status_nv *nv;
108 		int need_nv;
109 
110 		need_nv = 0;
111 
112 		if (strcmp(attr[i], "size") == 0) {
113 			entry->size = strtoull(attr[i+1], NULL, 0);
114 		} else if (strcmp(attr[i], "type") == 0) {
115 			if (strcmp(attr[i+1], "int") == 0) {
116 				entry->var_type = MT_TYPE_INT;
117 			} else if (strcmp(attr[i+1], "uint") == 0) {
118 				entry->var_type = MT_TYPE_UINT;
119 			} else if (strcmp(attr[i+1], "str") == 0) {
120 				entry->var_type = MT_TYPE_STRING;
121 			} else if (strcmp(attr[i+1], "node") == 0) {
122 				entry->var_type = MT_TYPE_NODE;
123 			} else {
124 				need_nv = 1;
125 			}
126 		} else if (strcmp(attr[i], "fmt") == 0) {
127 			entry->fmt = strdup(attr[i+1]);
128 		} else if (strcmp(attr[i], "desc") == 0) {
129 			entry->desc = strdup(attr[i+1]);
130 		} else {
131 			need_nv = 1;
132 		}
133 		if (need_nv != 0) {
134 			nv = malloc(sizeof(*nv));
135 			if (nv == NULL) {
136 				mtinfo->error = 1;
137 				snprintf(mtinfo->error_str,
138 				    sizeof(mtinfo->error_str),
139 				    "%s: error allocating %zd bytes",
140 				    __func__, sizeof(*nv));
141 			}
142 			bzero(nv, sizeof(*nv));
143 			nv->name = strdup(attr[i]);
144 			nv->value = strdup(attr[i+1]);
145 			STAILQ_INSERT_TAIL(&entry->nv_list, nv, links);
146 		}
147 	}
148 }
149 
150 /*
151  * Called on XML element close.
152  */
153 void
154 mt_end_element(void *user_data, const char *name)
155 {
156 	struct mt_status_data *mtinfo;
157 	char *str;
158 
159 	mtinfo = (struct mt_status_data *)user_data;
160 
161 	if (mtinfo->error != 0)
162 		return;
163 
164 	if (mtinfo->cur_sb[mtinfo->level] == NULL) {
165 		mtinfo->error = 1;
166 		snprintf(mtinfo->error_str, sizeof(mtinfo->error_str),
167 		    "%s: no valid sbuf at level %d (name %s)", __func__,
168 		    mtinfo->level, name);
169 		return;
170 	}
171 	sbuf_finish(mtinfo->cur_sb[mtinfo->level]);
172 	str = strdup(sbuf_data(mtinfo->cur_sb[mtinfo->level]));
173 	if (str == NULL) {
174 		mtinfo->error = 1;
175 		snprintf(mtinfo->error_str, sizeof(mtinfo->error_str),
176 		    "%s can't allocate %zd bytes for string", __func__,
177 		    sbuf_len(mtinfo->cur_sb[mtinfo->level]));
178 		return;
179 	}
180 
181 	if (strlen(str) == 0) {
182 		free(str);
183 		str = NULL;
184 	}
185 	if (str != NULL) {
186 		struct mt_status_entry *entry;
187 
188 		entry = mtinfo->cur_entry[mtinfo->level];
189 		switch(entry->var_type) {
190 		case MT_TYPE_INT:
191 			entry->value_signed = strtoll(str, NULL, 0);
192 			break;
193 		case MT_TYPE_UINT:
194 			entry->value_unsigned = strtoull(str, NULL, 0);
195 			break;
196 		default:
197 			break;
198 		}
199 	}
200 
201 	mtinfo->cur_entry[mtinfo->level]->value = str;
202 
203 	sbuf_delete(mtinfo->cur_sb[mtinfo->level]);
204 	mtinfo->cur_sb[mtinfo->level] = NULL;
205 	mtinfo->cur_entry[mtinfo->level] = NULL;
206 	mtinfo->level--;
207 }
208 
209 /*
210  * Called to handle character strings in the current element.
211  */
212 void
213 mt_char_handler(void *user_data, const XML_Char *str, int len)
214 {
215 	struct mt_status_data *mtinfo;
216 
217 	mtinfo = (struct mt_status_data *)user_data;
218 	if (mtinfo->error != 0)
219 		return;
220 
221 	sbuf_bcat(mtinfo->cur_sb[mtinfo->level], str, len);
222 }
223 
224 void
225 mt_status_tree_sbuf(struct sbuf *sb, struct mt_status_entry *entry, int indent,
226     void (*sbuf_func)(struct sbuf *sb, struct mt_status_entry *entry,
227     void *arg), void *arg)
228 {
229 	struct mt_status_nv *nv;
230 	struct mt_status_entry *entry2;
231 
232 	if (sbuf_func != NULL) {
233 		sbuf_func(sb, entry, arg);
234 	} else {
235 		sbuf_printf(sb, "%*sname: %s, value: %s, fmt: %s, size: %zd, "
236 		    "type: %d, desc: %s\n", indent, "", entry->entry_name,
237 		    entry->value, entry->fmt, entry->size, entry->var_type,
238 		    entry->desc);
239 		STAILQ_FOREACH(nv, &entry->nv_list, links) {
240 			sbuf_printf(sb, "%*snv: name: %s, value: %s\n",
241 			    indent + 1, "", nv->name, nv->value);
242 		}
243 	}
244 
245 	STAILQ_FOREACH(entry2, &entry->child_entries, links)
246 		mt_status_tree_sbuf(sb, entry2, indent + 2, sbuf_func, arg);
247 }
248 
249 void
250 mt_status_tree_print(struct mt_status_entry *entry, int indent,
251     void (*print_func)(struct mt_status_entry *entry, void *arg), void *arg)
252 {
253 
254 	if (print_func != NULL) {
255 		struct mt_status_entry *entry2;
256 
257 		print_func(entry, arg);
258 		STAILQ_FOREACH(entry2, &entry->child_entries, links)
259 			mt_status_tree_print(entry2, indent + 2, print_func,
260 			    arg);
261 	} else {
262 		struct sbuf *sb;
263 
264 		sb = sbuf_new_auto();
265 		if (sb == NULL)
266 			return;
267 		mt_status_tree_sbuf(sb, entry, indent, NULL, NULL);
268 		sbuf_finish(sb);
269 
270 		printf("%s", sbuf_data(sb));
271 		sbuf_delete(sb);
272 	}
273 }
274 
275 /*
276  * Given a parameter name in the form "foo" or "foo.bar.baz", traverse the
277  * tree looking for the parameter (the first case) or series of parameters
278  * (second case).
279  */
280 struct mt_status_entry *
281 mt_entry_find(struct mt_status_entry *entry, char *name)
282 {
283 	struct mt_status_entry *entry2;
284 	char *tmpname = NULL, *tmpname2 = NULL, *tmpstr = NULL;
285 
286 	tmpname = strdup(name);
287 	if (tmpname == NULL)
288 		goto bailout;
289 
290 	/* Save a pointer so we can free this later */
291 	tmpname2 = tmpname;
292 
293 	tmpstr = strsep(&tmpname, ".");
294 
295 	/*
296 	 * Is this the entry we're looking for?  Or do we have further
297 	 * child entries that we need to grab?
298 	 */
299 	if (strcmp(entry->entry_name, tmpstr) == 0) {
300 	 	if (tmpname == NULL) {
301 			/*
302 			 * There are no further child entries to find.  We
303 			 * have a complete match.
304 			 */
305 			free(tmpname2);
306 			return (entry);
307 		} else {
308 			/*
309 			 * There are more child entries that we need to find.
310 			 * Fall through to the recursive search off of this
311 			 * entry, below.  Use tmpname, which will contain
312 			 * everything after the first period.
313 			 */
314 			name = tmpname;
315 		}
316 	}
317 
318 	/*
319 	 * Recursively look for further entries.
320 	 */
321 	STAILQ_FOREACH(entry2, &entry->child_entries, links) {
322 		struct mt_status_entry *entry3;
323 
324 		entry3 = mt_entry_find(entry2, name);
325 		if (entry3 != NULL) {
326 			free(tmpname2);
327 			return (entry3);
328 		}
329 	}
330 
331 bailout:
332 	free(tmpname2);
333 
334 	return (NULL);
335 }
336 
337 struct mt_status_entry *
338 mt_status_entry_find(struct mt_status_data *status_data, char *name)
339 {
340 	struct mt_status_entry *entry, *entry2;
341 
342 	STAILQ_FOREACH(entry, &status_data->entries, links) {
343 		entry2 = mt_entry_find(entry, name);
344 		if (entry2 != NULL)
345 			return (entry2);
346 	}
347 
348 	return (NULL);
349 }
350 
351 void
352 mt_status_entry_free(struct mt_status_entry *entry)
353 {
354 	struct mt_status_entry *entry2, *entry3;
355 	struct mt_status_nv *nv, *nv2;
356 
357 	STAILQ_FOREACH_SAFE(entry2, &entry->child_entries, links, entry3) {
358 		STAILQ_REMOVE(&entry->child_entries, entry2, mt_status_entry,
359 		    links);
360 		mt_status_entry_free(entry2);
361 	}
362 
363 	free(entry->entry_name);
364 	free(entry->value);
365 	free(entry->fmt);
366 	free(entry->desc);
367 
368 	STAILQ_FOREACH_SAFE(nv, &entry->nv_list, links, nv2) {
369 		STAILQ_REMOVE(&entry->nv_list, nv, mt_status_nv, links);
370 		free(nv->name);
371 		free(nv->value);
372 		free(nv);
373 	}
374 	free(entry);
375 }
376 
377 void
378 mt_status_free(struct mt_status_data *status_data)
379 {
380 	struct mt_status_entry *entry, *entry2;
381 
382 	STAILQ_FOREACH_SAFE(entry, &status_data->entries, links, entry2) {
383 		STAILQ_REMOVE(&status_data->entries, entry, mt_status_entry,
384 		    links);
385 		mt_status_entry_free(entry);
386 	}
387 }
388 
389 void
390 mt_entry_sbuf(struct sbuf *sb, struct mt_status_entry *entry, char *fmt)
391 {
392 	switch(entry->var_type) {
393 	case MT_TYPE_INT:
394 		if (fmt != NULL)
395 			sbuf_printf(sb, fmt, (intmax_t)entry->value_signed);
396 		else
397 			sbuf_printf(sb, "%jd",
398 				    (intmax_t)entry->value_signed);
399 		break;
400 	case MT_TYPE_UINT:
401 		if (fmt != NULL)
402 			sbuf_printf(sb, fmt, (uintmax_t)entry->value_unsigned);
403 		else
404 			sbuf_printf(sb, "%ju",
405 				    (uintmax_t)entry->value_unsigned);
406 		break;
407 	default:
408 		if (fmt != NULL)
409 			sbuf_printf(sb, fmt, entry->value);
410 		else
411 			sbuf_printf(sb, "%s", entry->value);
412 		break;
413 	}
414 }
415 
416 void
417 mt_param_parent_print(struct mt_status_entry *entry,
418     struct mt_print_params *print_params)
419 {
420 	if (entry->parent != NULL)
421 		mt_param_parent_print(entry->parent, print_params);
422 
423 	if (((print_params->flags & MT_PF_INCLUDE_ROOT) == 0)
424 	 && (strcmp(entry->entry_name, print_params->root_name) == 0))
425 		return;
426 
427 	printf("%s.", entry->entry_name);
428 }
429 
430 void
431 mt_param_parent_sbuf(struct sbuf *sb, struct mt_status_entry *entry,
432     struct mt_print_params *print_params)
433 {
434 	if (entry->parent != NULL)
435 		mt_param_parent_sbuf(sb, entry->parent, print_params);
436 
437 	if (((print_params->flags & MT_PF_INCLUDE_ROOT) == 0)
438 	 && (strcmp(entry->entry_name, print_params->root_name) == 0))
439 		return;
440 
441 	sbuf_printf(sb, "%s.", entry->entry_name);
442 }
443 
444 void
445 mt_param_entry_sbuf(struct sbuf *sb, struct mt_status_entry *entry, void *arg)
446 {
447 	struct mt_print_params *print_params;
448 
449 	print_params = (struct mt_print_params *)arg;
450 
451 	/*
452 	 * We don't want to print nodes.
453 	 */
454 	if (entry->var_type == MT_TYPE_NODE)
455 		return;
456 
457 	if ((print_params->flags & MT_PF_FULL_PATH)
458 	 && (entry->parent != NULL))
459 		mt_param_parent_sbuf(sb, entry->parent, print_params);
460 
461 	sbuf_printf(sb, "%s: %s", entry->entry_name, entry->value);
462 	if ((print_params->flags & MT_PF_VERBOSE)
463 	 && (entry->desc != NULL)
464 	 && (strlen(entry->desc) > 0))
465 		sbuf_printf(sb, " (%s)", entry->desc);
466 	sbuf_printf(sb, "\n");
467 
468 }
469 
470 void
471 mt_param_entry_print(struct mt_status_entry *entry, void *arg)
472 {
473 	struct mt_print_params *print_params;
474 
475 	print_params = (struct mt_print_params *)arg;
476 
477 	/*
478 	 * We don't want to print nodes.
479 	 */
480 	if (entry->var_type == MT_TYPE_NODE)
481 		return;
482 
483 	if ((print_params->flags & MT_PF_FULL_PATH)
484 	 && (entry->parent != NULL))
485 		mt_param_parent_print(entry->parent, print_params);
486 
487 	printf("%s: %s", entry->entry_name, entry->value);
488 	if ((print_params->flags & MT_PF_VERBOSE)
489 	 && (entry->desc != NULL)
490 	 && (strlen(entry->desc) > 0))
491 		printf(" (%s)", entry->desc);
492 	printf("\n");
493 }
494 
495 int
496 mt_protect_print(struct mt_status_data *status_data, int verbose)
497 {
498 	struct mt_status_entry *entry;
499 	const char *prot_name = MT_PROTECTION_NAME;
500 	struct mt_print_params print_params;
501 
502 	snprintf(print_params.root_name, sizeof(print_params.root_name),
503 	    MT_PARAM_ROOT_NAME);
504 	print_params.flags = MT_PF_FULL_PATH;
505 	if (verbose != 0)
506 		print_params.flags |= MT_PF_VERBOSE;
507 
508 	entry = mt_status_entry_find(status_data, __DECONST(char *,prot_name));
509 	if (entry == NULL)
510 		return (1);
511 	mt_status_tree_print(entry, 0, mt_param_entry_print, &print_params);
512 
513 	return (0);
514 }
515 
516 int
517 mt_param_list(struct mt_status_data *status_data, char *param_name, int quiet)
518 {
519 	struct mt_status_entry *entry;
520 	struct mt_print_params print_params;
521 	char root_name[20];
522 
523 	snprintf(root_name, sizeof(root_name), "mtparamget");
524 	strlcpy(print_params.root_name, root_name,
525 	    sizeof(print_params.root_name));
526 
527 	print_params.flags = MT_PF_FULL_PATH;
528 	if (quiet == 0)
529 		print_params.flags |= MT_PF_VERBOSE;
530 
531 	if (param_name != NULL) {
532 		entry = mt_status_entry_find(status_data, param_name);
533 		if (entry == NULL)
534 			return (1);
535 
536 		mt_param_entry_print(entry, &print_params);
537 
538 		return (0);
539 	} else {
540 		entry = mt_status_entry_find(status_data, root_name);
541 
542 		STAILQ_FOREACH(entry, &status_data->entries, links)
543 			mt_status_tree_print(entry, 0, mt_param_entry_print,
544 			    &print_params);
545 	}
546 
547 	return (0);
548 }
549 
550 static struct densities {
551 	int dens;
552 	int bpmm;
553 	int bpi;
554 	const char *name;
555 } dens[] = {
556 	/*
557 	 * Taken from T10 Project 997D
558 	 * SCSI-3 Stream Device Commands (SSC)
559 	 * Revision 11, 4-Nov-97
560 	 *
561 	 * LTO 1-6 definitions obtained from the eighth edition of the
562 	 * IBM TotalStorage LTO Ultrium Tape Drive SCSI Reference
563 	 * (July 2007) and the second edition of the IBM System Storage LTO
564 	 * Tape Drive SCSI Reference (February 13, 2013).
565 	 *
566 	 * IBM 3592 definitions obtained from second edition of the IBM
567 	 * System Storage Tape Drive 3592 SCSI Reference (May 25, 2012).
568 	 *
569 	 * DAT-72 and DAT-160 bpi values taken from "HP StorageWorks DAT160
570 	 * tape drive white paper", dated June 2007.
571 	 *
572 	 * DAT-160 / SDLT220 density code (0x48) conflict information
573 	 * found here:
574 	 *
575 	 * http://h20564.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c01065117&sp4ts.oid=429311
576  	 * (Document ID c01065117)
577 	 */
578 	/*Num.  bpmm    bpi     Reference     */
579 	{ 0x1,	32,	800,	"X3.22-1983" },
580 	{ 0x2,	63,	1600,	"X3.39-1986" },
581 	{ 0x3,	246,	6250,	"X3.54-1986" },
582 	{ 0x5,	315,	8000,	"X3.136-1986" },
583 	{ 0x6,	126,	3200,	"X3.157-1987" },
584 	{ 0x7,	252,	6400,	"X3.116-1986" },
585 	{ 0x8,	315,	8000,	"X3.158-1987" },
586 	{ 0x9,	491,	37871,	"X3.180" },
587 	{ 0xA,	262,	6667,	"X3B5/86-199" },
588 	{ 0xB,	63,	1600,	"X3.56-1986" },
589 	{ 0xC,	500,	12690,	"HI-TC1" },
590 	{ 0xD,	999,	25380,	"HI-TC2" },
591 	{ 0xF,	394,	10000,	"QIC-120" },
592 	{ 0x10,	394,	10000,	"QIC-150" },
593 	{ 0x11,	630,	16000,	"QIC-320" },
594 	{ 0x12,	2034,	51667,	"QIC-1350" },
595 	{ 0x13,	2400,	61000,	"X3B5/88-185A" },
596 	{ 0x14,	1703,	43245,	"X3.202-1991" },
597 	{ 0x15,	1789,	45434,	"ECMA TC17" },
598 	{ 0x16,	394,	10000,	"X3.193-1990" },
599 	{ 0x17,	1673,	42500,	"X3B5/91-174" },
600 	{ 0x18,	1673,	42500,	"X3B5/92-50" },
601 	{ 0x19, 2460,   62500,  "DLTapeIII" },
602 	{ 0x1A, 3214,   81633,  "DLTapeIV(20GB)" },
603 	{ 0x1B, 3383,   85937,  "DLTapeIV(35GB)" },
604 	{ 0x1C, 1654,	42000,	"QIC-385M" },
605 	{ 0x1D,	1512,	38400,	"QIC-410M" },
606 	{ 0x1E, 1385,	36000,	"QIC-1000C" },
607 	{ 0x1F,	2666,	67733,	"QIC-2100C" },
608 	{ 0x20, 2666,	67733,	"QIC-6GB(M)" },
609 	{ 0x21,	2666,	67733,	"QIC-20GB(C)" },
610 	{ 0x22,	1600,	40640,	"QIC-2GB(C)" },
611 	{ 0x23, 2666,	67733,	"QIC-875M" },
612 	{ 0x24,	2400,	61000,	"DDS-2" },
613 	{ 0x25,	3816,	97000,	"DDS-3" },
614 	{ 0x26,	3816,	97000,	"DDS-4" },
615 	{ 0x27,	3056,	77611,	"Mammoth" },
616 	{ 0x28,	1491,	37871,	"X3.224" },
617 	{ 0x40, 4880,   123952, "LTO-1" },
618 	{ 0x41, 3868,   98250,  "DLTapeIV(40GB)" },
619 	{ 0x42, 7398,   187909, "LTO-2" },
620 	{ 0x44, 9638,   244805, "LTO-3" },
621 	{ 0x46, 12725,  323215, "LTO-4" },
622 	{ 0x47, 6417,   163000, "DAT-72" },
623 	/*
624 	 * XXX KDM note that 0x48 is also the density code for DAT-160.
625 	 * For some reason they used overlapping density codes.
626 	 */
627 #if 0
628 	{ 0x48, 6870,   174500, "DAT-160" },
629 #endif
630 	{ 0x48, 5236,   133000, "SDLTapeI(110)" },
631 	{ 0x49, 7598,   193000, "SDLTapeI(160)" },
632 	{ 0x4a,     0,       0, "T10000A" },
633 	{ 0x4b,     0,       0, "T10000B" },
634 	{ 0x4c,     0,       0, "T10000C" },
635 	{ 0x4d,     0,       0, "T10000D" },
636 	{ 0x51, 11800,  299720, "3592A1 (unencrypted)" },
637 	{ 0x52, 11800,  299720, "3592A2 (unencrypted)" },
638 	{ 0x53, 13452,  341681, "3592A3 (unencrypted)" },
639 	{ 0x54, 19686,  500024, "3592A4 (unencrypted)" },
640 	{ 0x55, 20670,  525018, "3592A5 (unencrypted)" },
641 	{ 0x56, 20670,  525018, "3592B5 (unencrypted)" },
642 	{ 0x57, 21850,  554990, "3592A6 (unencrypted)" },
643 	{ 0x58, 15142,  384607, "LTO-5" },
644 	{ 0x59, 21850,  554990, "3592A7 (unencrypted)" },
645 	{ 0x5A, 15142,  384607, "LTO-6" },
646 	{ 0x5C, 19107,  485318, "LTO-7" },
647 	{ 0x5D, 19107,  485318, "LTO-M8" },
648 	{ 0x5E, 20669,  524993, "LTO-8" },
649 	{ 0x60, 23031,  584987, "LTO-9" },
650 	{ 0x71, 11800,  299720, "3592A1 (encrypted)" },
651 	{ 0x72, 11800,  299720, "3592A2 (encrypted)" },
652 	{ 0x73, 13452,  341681, "3592A3 (encrypted)" },
653 	{ 0x74, 19686,  500024, "3592A4 (encrypted)" },
654 	{ 0x75, 20670,  525018, "3592A5 (encrypted)" },
655 	{ 0x76, 20670,  525018, "3592B5 (encrypted)" },
656 	{ 0x77, 21850,  554990, "3592A6 (encrypted)" },
657 	{ 0x79, 21850,  554990, "3592A7 (encrypted)" },
658 	{ 0x8c,  1789,   45434, "EXB-8500c" },
659 	{ 0x90,  1703,   43245, "EXB-8200c" },
660 	{ 0, 0, 0, NULL }
661 };
662 
663 const char *
664 mt_density_name(int density_num)
665 {
666 	struct densities *sd;
667 
668 	/* densities 0 and 0x7f are handled as special cases */
669 	if (density_num == 0)
670 		return ("default");
671 	if (density_num == 0x7f)
672 		return ("same");
673 
674 	for (sd = dens; sd->dens != 0; sd++)
675 		if (sd->dens == density_num)
676 			break;
677 	if (sd->dens == 0)
678 		return ("UNKNOWN");
679 	return (sd->name);
680 }
681 
682 /*
683  * Given a specific density number, return either the bits per inch or bits
684  * per millimeter for the given density.
685  */
686 int
687 mt_density_bp(int density_num, int bpi)
688 {
689 	struct densities *sd;
690 
691 	for (sd = dens; sd->dens; sd++)
692 		if (sd->dens == density_num)
693 			break;
694 	if (sd->dens == 0)
695 		return (0);
696 	if (bpi)
697 		return (sd->bpi);
698 	else
699 		return (sd->bpmm);
700 }
701 
702 int
703 mt_density_num(const char *density_name)
704 {
705 	struct densities *sd;
706 	size_t l = strlen(density_name);
707 
708 	for (sd = dens; sd->dens; sd++)
709 		if (strncasecmp(sd->name, density_name, l) == 0)
710 			break;
711 	return (sd->dens);
712 }
713 
714 /*
715  * Get the current status XML string.
716  * Returns 0 on success, -1 on failure (with errno set, and *xml_str == NULL).
717  */
718 int
719 mt_get_xml_str(int mtfd, unsigned long cmd, char **xml_str)
720 {
721 	size_t alloc_len = 32768;
722 	struct mtextget extget;
723 	int error;
724 
725 	*xml_str = NULL;
726 
727 	for (;;) {
728 		bzero(&extget, sizeof(extget));
729 		*xml_str = malloc(alloc_len);
730 		if (*xml_str == NULL)
731 			return (-1);
732 		extget.status_xml = *xml_str;
733 		extget.alloc_len = alloc_len;
734 
735 		error = ioctl(mtfd, cmd, (caddr_t)&extget);
736 		if (error == 0 && extget.status == MT_EXT_GET_OK)
737 			break;
738 
739 		free(*xml_str);
740 		*xml_str = NULL;
741 
742 		if (error != 0 || extget.status != MT_EXT_GET_NEED_MORE_SPACE)
743 			return (-1);
744 
745 		/* The driver needs more space, so double and try again. */
746 		alloc_len *= 2;
747 	}
748 	return (0);
749 }
750 
751 /*
752  * Populate a struct mt_status_data from the XML string via mt_get_xml_str().
753  *
754  * Returns XML_STATUS_OK on success.
755  * If XML_STATUS_ERROR is returned, errno may be set to indicate the reason.
756  * The caller must check status_data->error.
757  */
758 int
759 mt_get_status(char *xml_str, struct mt_status_data *status_data)
760 {
761 	XML_Parser parser;
762 	int retval;
763 
764 	bzero(status_data, sizeof(*status_data));
765 	STAILQ_INIT(&status_data->entries);
766 
767 	parser = XML_ParserCreate(NULL);
768 	if (parser == NULL) {
769 		errno = ENOMEM;
770 		return (XML_STATUS_ERROR);
771 	}
772 
773 	XML_SetUserData(parser, status_data);
774 	XML_SetElementHandler(parser, mt_start_element, mt_end_element);
775 	XML_SetCharacterDataHandler(parser, mt_char_handler);
776 
777 	retval = XML_Parse(parser, xml_str, strlen(xml_str), 1);
778 	XML_ParserFree(parser);
779 	return (retval);
780 }
781