xref: /illumos-gate/usr/src/lib/fm/libseslog/common/libseslog.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 /*
26  * SES Log reader library
27  *
28  * This library is responsible for accessing the SES log at the target address,
29  * formatting and returning any log entries found.
30  *
31  * The data will be returned in an nvlist_t structure allocated here.
32  */
33 
34 #include <assert.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <sys/param.h>
38 #include <libseslog.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include <sys/stat.h>
42 #include <unistd.h>
43 #include <dirent.h>
44 #include <sys/scsi/generic/commands.h>
45 #include <sys/scsi/generic/status.h>
46 #include <sys/scsi/impl/commands.h>
47 
48 /*
49  * open the device with given device name
50  */
51 static int
52 open_device(const char *device_name)
53 {
54 	int oflags = O_NONBLOCK | O_RDWR;
55 	int fd;
56 
57 	fd = open(device_name, oflags);
58 	if (fd < 0)
59 		fd = -errno;
60 	return (fd);
61 }
62 
63 /*
64  * Initialize scsi struct
65  */
66 static void
67 construct_scsi_pt_obj(struct uscsi_cmd *uscsi)
68 {
69 	(void) memset(uscsi, 0, sizeof (struct uscsi_cmd));
70 	uscsi->uscsi_timeout = DEF_PT_TIMEOUT;
71 	uscsi->uscsi_flags = USCSI_READ | USCSI_ISOLATE | USCSI_RQENABLE;
72 }
73 
74 /*
75  * set control cdb of scsi structure
76  */
77 static void
78 set_scsi_pt_cdb(struct uscsi_cmd *uscsi, const unsigned char *cdb,
79     int cdb_len)
80 {
81 	uscsi->uscsi_cdb = (char *)cdb;
82 	uscsi->uscsi_cdblen = cdb_len;
83 }
84 
85 /*
86  * initialize sense data
87  */
88 static void
89 set_scsi_pt_sense(struct uscsi_cmd *uscsi, unsigned char *sense,
90     int max_sense_len)
91 {
92 	(void) memset(sense, 0, max_sense_len);
93 	uscsi->uscsi_rqbuf = (char *)sense;
94 	uscsi->uscsi_rqlen = max_sense_len;
95 }
96 
97 /*
98  * Initialize data going to device
99  */
100 static void
101 set_scsi_pt_data_in(struct uscsi_cmd *uscsi, unsigned char *dxferp,
102 		    int dxfer_len)
103 {
104 	if (dxfer_len > 0) {
105 		uscsi->uscsi_bufaddr = (char *)dxferp;
106 		uscsi->uscsi_buflen = dxfer_len;
107 		uscsi->uscsi_flags = USCSI_READ | USCSI_ISOLATE |
108 		    USCSI_RQENABLE;
109 	}
110 }
111 
112 /*
113  * Executes SCSI command(or at least forwards it to lower layers).
114  */
115 static int
116 do_scsi_pt(struct uscsi_cmd *uscsi, int fd, int time_secs)
117 {
118 	if (time_secs > 0)
119 		uscsi->uscsi_timeout = time_secs;
120 
121 	if (ioctl(fd, USCSICMD, uscsi)) {
122 		/* Took an error */
123 		return (errno);
124 	}
125 	return (0);
126 }
127 
128 
129 /*
130  * Read log from device
131  * Invokes a SCSI LOG SENSE command.
132  * Return:
133  * 0 -> success
134  * SG_LIB_CAT_INVALID_OP -> Log Sense not supported,
135  * SG_LIB_CAT_ILLEGAL_REQ -> bad field in cdb,
136  * SG_LIB_CAT_NOT_READY -> device not ready,
137  * -1 -> other failure
138  */
139 
140 static int
141 read_log(int sg_fd, unsigned char *resp, int mx_resp_len)
142 {
143 	int res, ret;
144 	unsigned char logsCmdBlk[CDB_GROUP1] =
145 	    {SCMD_LOG_SENSE_G1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
146 	unsigned char sense_b[SENSE_BUFF_LEN];
147 	struct uscsi_cmd uscsi;
148 
149 	if (mx_resp_len > 0xffff) {
150 		return (-1);
151 	}
152 	logsCmdBlk[1] = 0;
153 	/* pc = 1, pg_code = 0x7 (logs page) */
154 	/* (((pc << 6) & 0xc0) | (pg_code & 0x3f)) = 0x47; */
155 	logsCmdBlk[2] = 0x47;
156 	/* pc = 1 current values */
157 	logsCmdBlk[3] = 0; /* No subpage code */
158 	logsCmdBlk[5] = 0; /* Want all logs starting from 0 */
159 	logsCmdBlk[6] = 0;
160 	logsCmdBlk[7] = (unsigned char) ((mx_resp_len >> 8) & 0xff);
161 	logsCmdBlk[8] = (unsigned char) (mx_resp_len & 0xff);
162 
163 	construct_scsi_pt_obj(&uscsi);
164 
165 	set_scsi_pt_cdb(&uscsi, logsCmdBlk, sizeof (logsCmdBlk));
166 	set_scsi_pt_sense(&uscsi, sense_b, sizeof (sense_b));
167 	set_scsi_pt_data_in(&uscsi, resp, mx_resp_len);
168 	res = do_scsi_pt(&uscsi, sg_fd, DEF_PT_TIMEOUT);
169 	if (res) {
170 		ret = res;
171 	} else {
172 		ret = uscsi.uscsi_status;
173 	}
174 	return (ret);
175 }
176 
177 /*
178  * Save the logs by walking through the entries in the response buffer.
179  *
180  * resp buffer looks like:
181  *
182  * +=====-========-========-========-========-========-========-========-=====+
183  * |  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0 |
184  * |Byte |        |        |        |        |        |        |        |     |
185  * |=====+====================================================================|
186  * | 0   |  reserved       |     page code                                    |
187  * |-----+--------------------------------------------------------------------|
188  * | 1   |                   Reserved                                         |
189  * |-----+--------------------------------------------------------------------|
190  * | 2   |(MSB)                           Page Length(n-3)                    |
191  * | --  |                                                                    |
192  * | 3   |                                                            (LSB)   |
193  * |-----+--------------------------------------------------------------------|
194  * | 4   |                           Log Parameter (First)(Length X)          |
195  * | --  |                                                                    |
196  * | x+3 |                                                                    |
197  * |-----+--------------------------------------------------------------------|
198  * |n-y+1|                           Log Parameter (Last)(Length y)           |
199  * | --  |                                                                    |
200  * | n   |                                                                    |
201  * +==========================================================================+
202  *
203  * Log parameter field looks like:
204  *
205  * +=====-========-========-========-========-========-========-========-=====+
206  * |  Bit|   7    |   6    |   5    |   4    |   3    |   2    |   1    |   0 |
207  * |Byte |        |        |        |        |        |        |        |     |
208  * |=====+====================================================================|
209  * | 0   |(MSB)                           Parameter Code                      |
210  * | --  |                                                                    |
211  * | 1   |                                                            (LSB)   |
212  * |-----+--------------------------------------------------------------------|
213  * | 2   | DU     |  DS    |  TSD    | ETC   |         TMC     |  LBIN  | LP  |
214  * |-----+--------------------------------------------------------------------|
215  * | 3   |                          Parameter Length(n-3)                     |
216  * |-----+--------------------------------------------------------------------|
217  * | 4   |                           Parameter Values                         |
218  * | --  |                                                                    |
219  * | n	 |                                                                    |
220  * |-----+--------------------------------------------------------------------|
221  */
222 
223 static int
224 save_logs(unsigned char *resp, ses_log_call_t *data)
225 {
226 	int k;
227 	int param_code; 	/* Parameter code */
228 	int param_len = 0; 	/* Paramter length */
229 	unsigned char *log_param_ptr; 	/* Log parameter pointer */
230 	unsigned char *log_str_ptr; /* ptr to ascii str returend by expander */
231 
232 	char log_code[ENTRY_MAX_SIZE];
233 	char log_level[ENTRY_MAX_SIZE];
234 	nvlist_t *entry;
235 	char entry_num[15];
236 	int match_found = 0;
237 	char save_buffer[MAX_LOG_ENTRY_SZ];
238 	char entry_added = 0;
239 	int all_log_data_len;
240 
241 	/*
242 	 * Bytes 2 and 3 of response buffer contain the page length of
243 	 * the log entries returned.
244 	 */
245 	all_log_data_len = SCSI_READ16(&resp[2]);
246 
247 	/*
248 	 * Initialize log parameter pointer to point to first log entry.
249 	 * The resp includes 4 bytes of header info and then log entries
250 	 */
251 	log_param_ptr = &resp[0] + 4;
252 
253 	/*
254 	 * If multiple heads are reading the logs, it is possible that we
255 	 * could be re-reading some of the same log entries plus some
256 	 * new additional entries. Check to see if any entries in this read
257 	 * contain the same log entry as the last entry we read last time.
258 	 */
259 	if (data->last_log_entry != NULL &&
260 	    (strlen(data->last_log_entry) == SES_LOG_VALID_LOG_SIZE)) {
261 		/*
262 		 * We have a valid log entry from a previous read log
263 		 * operation.
264 		 */
265 
266 
267 		/*
268 		 * Start walking each log entry in response buffer looking for
269 		 * a duplicate entry.
270 		 */
271 		for (k = 0; k < all_log_data_len; k += param_len) {
272 			/*
273 			 * Calculate log entry length
274 			 * Log param ptr [3] contains the log length minus the
275 			 * header info which is 4 bytes so add that in.
276 			 */
277 			param_len = log_param_ptr[3] + 4;
278 
279 			if (param_len <= 4) {
280 				/*
281 				 * Only header information in this entry
282 				 * process next log entry
283 				 */
284 				log_param_ptr += param_len;
285 				continue;
286 			}
287 
288 
289 			/*
290 			 * initialize log_str_ptr to point to string info
291 			 * returned by expander
292 			 * first 4 bytes of log parameter contains
293 			 * 2 bytes of parameter code, 1 byte of Control data
294 			 * and 1 byte for parameter length. Log string begins
295 			 * after that so add 4 to log param ptr.
296 			 */
297 			log_str_ptr = log_param_ptr + 4;
298 
299 			/*
300 			 * Check to see if this is the
301 			 * same line
302 			 */
303 			if (strncmp((char *)log_str_ptr, data->last_log_entry,
304 			    SES_LOG_VALID_LOG_SIZE) == 0) {
305 				/* Found an exact match */
306 				log_param_ptr += param_len;
307 				k += param_len;
308 				match_found = 1;
309 				break;
310 			}
311 			log_param_ptr += param_len;
312 		}
313 	}
314 	if (!match_found) {
315 		log_param_ptr = &resp[0] + 4;
316 		k = 0;
317 	}
318 	if (k == all_log_data_len) {
319 		/*
320 		 * Either there was no log data or we have
321 		 * already read these log entries.
322 		 * Just return.
323 		 */
324 		return (0);
325 	}
326 
327 	/* Grab memory to return logs with */
328 	if (nvlist_alloc(&data->log_data, NV_UNIQUE_NAME, 0) != 0) {
329 		/* Couldn't alloc memory for nvlist */
330 		return (SES_LOG_FAILED_NVLIST_CREATE);
331 	}
332 
333 	(void) memset(log_code,		0, sizeof (log_code));
334 	(void) memset(save_buffer,	0, sizeof (save_buffer));
335 	(void) memset(log_level,	0, sizeof (log_level));
336 
337 	/*
338 	 * Start saving new log entries
339 	 * Walk the log data adding any new entries
340 	 */
341 
342 	for (; k < all_log_data_len; k += param_len) {
343 		/*
344 		 * Calculate log entry length
345 		 * Log ptr [3] contains the log length minus the header info
346 		 * which is 4 bytes so add that in
347 		 */
348 		param_len = log_param_ptr[3] + 4;
349 
350 		if (param_len <= 4) {
351 			/* Only header information in this entry */
352 			/* process next log entry */
353 			log_param_ptr += param_len;
354 			continue;
355 		}
356 
357 		/*
358 		 * initialize log_str_ptr to point to string info of the log
359 		 * entry. First 4 bytes of log entry contains param code,
360 		 * control byte, and length. Log string starts after that.
361 		 */
362 		log_str_ptr = log_param_ptr + 4;
363 
364 		/*
365 		 * Format of log str is as follows
366 		 * "%8x %8x %8x %8x %8x %8x %8x %8x",
367 		 * log_entry.log_word0, log_entry.ts_u, log_entry.ts_l,
368 		 * log_entry.seq_num, log_entry.log_code, log_entry.log_word2,
369 		 * log_entry.log_word3, log_entry.log_word4
370 		 * following example has extra spaces removed to fit in 80 char
371 		 * 40004 0 42d5f5fe 185b 630002 fd0800 50800207 e482813
372 		 */
373 
374 		(void) strncpy(save_buffer,
375 		    (const char *)log_str_ptr,
376 		    SES_LOG_VALID_LOG_SIZE);
377 
378 		(void) strncpy(log_code,
379 		    (const char *)log_str_ptr+SES_LOG_CODE_START,
380 		    SES_LOG_SPECIFIC_ENTRY_SIZE);
381 
382 		(void) strncpy(log_level,
383 		    (const char *) log_str_ptr +
384 		    SES_LOG_LEVEL_START, 1);
385 
386 
387 		/* Add this entry to the nvlist log data */
388 		if (nvlist_alloc(&entry, NV_UNIQUE_NAME, 0) != 0) {
389 			/* Couldn't alloc space, return error */
390 			return (SES_LOG_FAILED_NV_UNIQUE);
391 		}
392 
393 
394 		if (nvlist_add_string(entry, ENTRY_LOG, save_buffer) != 0) {
395 			/* Error adding string, return error */
396 			nvlist_free(entry);
397 			return (SES_LOG_FAILED_NV_LOG);
398 		}
399 
400 		if (nvlist_add_string(entry, ENTRY_CODE, log_code) != 0) {
401 			/* Error adding string, return error */
402 			nvlist_free(entry);
403 			return (SES_LOG_FAILED_NV_CODE);
404 		}
405 		if (nvlist_add_string(entry, ENTRY_SEVERITY, log_level) != 0) {
406 			/* Error adding srtring, return error */
407 			nvlist_free(entry);
408 			return (SES_LOG_FAILED_NV_SEV);
409 		}
410 
411 		param_code = SCSI_READ16(&log_param_ptr[0]);
412 
413 		(void) snprintf(entry_num, sizeof (entry_num),
414 		    "%s%d", ENTRY_PREFIX, param_code);
415 
416 		if (nvlist_add_nvlist(data->log_data, entry_num, entry) != 0) {
417 			/* Error adding nvlist, return error */
418 			nvlist_free(entry);
419 			return (SES_LOG_FAILED_NV_ENTRY);
420 		}
421 		nvlist_free(entry);
422 
423 		entry_added = 1;
424 		(data->number_log_entries)++;
425 
426 		log_param_ptr += param_len;
427 
428 	}
429 	if (entry_added) {
430 		/* Update the last log entry string with last one read */
431 		(void) strncpy(data->last_log_entry, save_buffer, MAXNAMELEN);
432 	}
433 	return (0);
434 }
435 
436 
437 
438 /* Setup struct to send command to device */
439 static void
440 set_scsi_pt_data_out(struct uscsi_cmd *uscsi, const unsigned char *dxferp,
441     int dxfer_len)
442 {
443 	if (dxfer_len > 0) {
444 		uscsi->uscsi_bufaddr = (char *)dxferp;
445 		uscsi->uscsi_buflen = dxfer_len;
446 		uscsi->uscsi_flags = USCSI_WRITE | USCSI_ISOLATE |
447 		    USCSI_RQENABLE;
448 	}
449 }
450 
451 /*
452  * Invokes a SCSI MODE SENSE(10) command.
453  * Return:
454  * 0 for success
455  * SG_LIB_CAT_INVALID_OP -> invalid opcode
456  * SG_LIB_CAT_ILLEGAL_REQ -> bad field in cdb
457  * SG_LIB_CAT_NOT_READY -> device not ready
458  * -1 -> other failure
459  */
460 
461 static int
462 sg_ll_mode_sense10(int sg_fd, void * resp, int mx_resp_len)
463 {
464 	int res, ret;
465 	unsigned char modesCmdBlk[MODE_SENSE10_CMDLEN] =
466 	    {SCMD_MODE_SENSE_G1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
467 	unsigned char sense_b[SENSE_BUFF_LEN];
468 	struct uscsi_cmd uscsi;
469 
470 	modesCmdBlk[1] = 0;
471 	modesCmdBlk[2] = 0; /* page code 0 vendor specific */
472 	modesCmdBlk[3] = 0;
473 	modesCmdBlk[7] = (unsigned char) ((mx_resp_len >> 8) & 0xff);
474 	modesCmdBlk[8] = (unsigned char) (mx_resp_len & 0xff);
475 
476 	construct_scsi_pt_obj(&uscsi);
477 	set_scsi_pt_cdb(&uscsi, modesCmdBlk, sizeof (modesCmdBlk));
478 	set_scsi_pt_sense(&uscsi, sense_b, sizeof (sense_b));
479 	set_scsi_pt_data_in(&uscsi, (unsigned char *) resp, mx_resp_len);
480 	res = do_scsi_pt(&uscsi, sg_fd, DEF_PT_TIMEOUT);
481 	if (res) {
482 		ret = res;
483 	} else {
484 		ret = uscsi.uscsi_status;
485 	}
486 	return (ret);
487 }
488 
489 /*
490  * Invokes a SCSI MODE SELECT(10) command.
491  * Return:
492  * 0 for success.
493  * SG_LIB_CAT_INVALID_OP for invalid opcode
494  * SG_LIB_CAT_ILLEGAL_REQ -> bad field in cdb,
495  * SG_LIB_CAT_NOT_READY -> device not ready,
496  * -1 -> other failure
497  */
498 static int
499 sg_ll_mode_select10(int sg_fd, void * paramp, int param_len)
500 {
501 	int res, ret;
502 	unsigned char modesCmdBlk[MODE_SELECT10_CMDLEN] =
503 	    {SCMD_MODE_SELECT_G1, 0, 0, 0, 0, 0, 0, 0, 0, 0};
504 	unsigned char sense_b[SENSE_BUFF_LEN];
505 	struct uscsi_cmd uscsi;
506 
507 
508 	modesCmdBlk[1] = 0;
509 	/*
510 	 * modesCmdBlk 2 equal 0 PC 0 return current page code 0 return
511 	 * vendor specific
512 	 */
513 
514 	modesCmdBlk[7] = (unsigned char)((param_len >> 8) & 0xff);
515 	modesCmdBlk[8] = (unsigned char)(param_len & 0xff);
516 
517 	construct_scsi_pt_obj(&uscsi);
518 
519 	set_scsi_pt_cdb(&uscsi, modesCmdBlk, sizeof (modesCmdBlk));
520 	set_scsi_pt_sense(&uscsi, sense_b, sizeof (sense_b));
521 	set_scsi_pt_data_out(&uscsi, (unsigned char *) paramp, param_len);
522 	res = do_scsi_pt(&uscsi, sg_fd, DEF_PT_TIMEOUT);
523 	if (res) {
524 		ret = res;
525 	} else {
526 		ret = uscsi.uscsi_status;
527 	}
528 	return (ret);
529 }
530 
531 
532 
533 /*
534  * MODE SENSE 10 commands yield a response that has block descriptors followed
535  * by mode pages. In most cases users are interested in the first mode page.
536  * This function returns the(byte) offset of the start of the first mode page.
537  * Returns >= 0 is successful or -1 if failure. If there is a failure
538  * a message is written to err_buff.
539  */
540 
541 /*
542  * return data looks like:
543  * Table 92 - Mode parameter header(10)
544  * Bit
545  * Byte
546  *	7 	6 	5 	4 	3 	2 	1 	0
547  *	----------------------------------------------------------
548  * 0	MSB Data length
549  * 1	LSB Data length
550  *	----------------------------------------------------------
551  * 2	Medium type
552  *	----------------------------------------------------------
553  * 3 	Device-specific parameter
554  *	----------------------------------------------------------
555  * 4 	Reserved
556  *	----------------------------------------------------------
557  * 5	Reserved
558  *	----------------------------------------------------------
559  * 6	MSB block descriptor length
560  * 7	LSB block descriptor length
561  *	----------------------------------------------------------
562  *	block desciptors....
563  *	-----------------------
564  *	mode sense page:
565  *	0 : ps Reserved : page Code
566  *	1 : Page Length(n-1)
567  *	2-N  Mode parameters
568  */
569 static int
570 sg_mode_page_offset(const unsigned char *resp, int resp_len)
571 {
572 	int bd_len;
573 	int calc_len;
574 	int offset;
575 
576 	if ((NULL == resp) || (resp_len < 8)) {
577 		/* Too short of a response buffer */
578 		return (-1);
579 	}
580 
581 	calc_len = (resp[0] << 8) + resp[1] + 2;
582 	bd_len = (resp[6] << 8) + resp[7];
583 
584 	/* LongLBA doesn't change this calculation */
585 	offset = bd_len + MODE10_RESP_HDR_LEN;
586 
587 	if ((offset + 2) > resp_len) {
588 		/* Given response length to small */
589 		offset = -1;
590 	} else if ((offset + 2) > calc_len) {
591 		/* Calculated response length too small */
592 		offset = -1;
593 	}
594 	return (offset);
595 }
596 
597 /*
598  * Clear logs
599  */
600 static int
601 clear_log(int sg_fd, ses_log_call_t *data)
602 {
603 
604 	int res, alloc_len, off;
605 	int md_len;
606 	int read_in_len = 0;
607 	unsigned char ref_md[MAX_ALLOC_LEN];
608 	struct log_clear_control_struct clear_data;
609 	long myhostid;
610 	int error = 0;
611 	long poll_time;
612 	char seq_num_str[10];
613 	unsigned long seq_num = 0;
614 
615 	(void) memset(&clear_data, 0, sizeof (clear_data));
616 
617 	clear_data.pageControls = 0x40;
618 	clear_data.subpage_code = 0;
619 	clear_data.page_lengthLower = 0x16;
620 
621 	myhostid = gethostid();
622 	/* 0 -> 11 are memset to 0 */
623 	clear_data.host_id[12] = (myhostid & 0xff000000) >> 24;
624 	clear_data.host_id[13] = (myhostid & 0xff0000) >> 16;
625 	clear_data.host_id[14] = (myhostid & 0xff00) >> 8;
626 	clear_data.host_id[15] = myhostid & 0xff;
627 
628 	/*
629 	 * convert nanosecond time to seconds
630 	 */
631 	poll_time = data->poll_time / 1000000000;
632 	/* Add 5 minutes to poll time to allow for data retrieval time */
633 	poll_time = poll_time + 300;
634 	clear_data.timeout[0] = (poll_time & 0xff00) >> 8;
635 	clear_data.timeout[1] = poll_time & 0xff;
636 
637 	/*
638 	 * retrieve the last read sequence number from the last
639 	 * log entry read.
640 	 */
641 	if (data->last_log_entry != NULL &&
642 	    (strlen(data->last_log_entry) == SES_LOG_VALID_LOG_SIZE)) {
643 		/*
644 		 * We have a valid log entry from a previous read log
645 		 * operation.
646 		 */
647 		(void) strncpy(seq_num_str,
648 		    (const char *) data->last_log_entry +
649 		    SES_LOG_SEQ_NUM_START, 8);
650 		seq_num = strtoul(seq_num_str, 0, 16);
651 	}
652 	clear_data.seq_clear[0] = (seq_num & 0xff000000) >> 24;
653 	clear_data.seq_clear[1] = (seq_num & 0xff0000) >> 16;
654 	clear_data.seq_clear[2] = (seq_num & 0xff00) >> 8;
655 	clear_data.seq_clear[3] = (seq_num & 0xff);
656 
657 	read_in_len = sizeof (clear_data);
658 
659 
660 	/* do MODE SENSE to fetch current values */
661 	(void) memset(ref_md, 0, MAX_ALLOC_LEN);
662 	alloc_len = MAX_ALLOC_LEN;
663 
664 
665 	res = sg_ll_mode_sense10(sg_fd, ref_md, alloc_len);
666 	if (0 != res) {
667 		/* Error during mode sense */
668 		error = SES_LOG_FAILED_MODE_SENSE;
669 		return (error);
670 	}
671 
672 	/* Setup mode Select to clear logs */
673 	off = sg_mode_page_offset(ref_md, alloc_len);
674 	if (off < 0) {
675 		/* Mode page offset error */
676 		error =  SES_LOG_FAILED_MODE_SENSE_OFFSET;
677 		return (error);
678 	}
679 	md_len = (ref_md[0] << 8) + ref_md[1] + 2;
680 
681 	ref_md[0] = 0;
682 	ref_md[1] = 0;
683 
684 	if (md_len > alloc_len) {
685 		/* Data length to large */
686 		error = SES_LOG_FAILED_BAD_DATA_LEN;
687 		return (error);
688 	}
689 
690 	if ((md_len - off) != read_in_len) {
691 		/* Content length not correct */
692 		error = SES_LOG_FAILED_BAD_CONTENT_LEN;
693 		return (error);
694 	}
695 
696 	if ((clear_data.pageControls & 0x40) != (ref_md[off] & 0x40)) {
697 		/* reference model doesn't have use subpage format bit set */
698 		/* Even though it should have */
699 		/* don't send the command */
700 		error = SES_LOG_FAILED_FORMAT_PAGE_ERR;
701 		return (error);
702 	}
703 
704 	(void) memcpy(ref_md + off, (const void *) &clear_data,
705 	    sizeof (clear_data));
706 
707 	res = sg_ll_mode_select10(sg_fd, ref_md, md_len);
708 	if (res != 0) {
709 		error = SES_LOG_FAILED_MODE_SELECT;
710 		return (error);
711 	}
712 
713 	return (error);
714 }
715 /*
716  * Gather data from given device.
717  */
718 static int
719 gather_data(char *device_name, ses_log_call_t *data)
720 {
721 	int sg_fd;
722 	int resp_len, res;
723 	unsigned char rsp_buff[MAX_ALLOC_LEN];
724 	int error;
725 
726 	/* Open device */
727 	if ((sg_fd = open_device(device_name)) < 0) {
728 		/* Failed to open device */
729 		return (SES_LOG_FAILED_TO_OPEN_DEVICE);
730 	}
731 
732 	/* Read the logs */
733 	(void) memset(rsp_buff, 0, sizeof (rsp_buff));
734 	resp_len = 0x8000; /* Maximum size available to read */
735 	res = read_log(sg_fd, rsp_buff, resp_len);
736 
737 	if (res != 0) {
738 		/* Some sort of Error during read of logs */
739 		(void) close(sg_fd);
740 		return (SES_LOG_FAILED_TO_READ_DEVICE);
741 	}
742 
743 	/* Save the logs */
744 	error = save_logs(rsp_buff, data);
745 	if (error != 0) {
746 		(void) close(sg_fd);
747 		return (error);
748 	}
749 	/* Clear the logs */
750 	error = clear_log(sg_fd, data);
751 
752 	(void) close(sg_fd);
753 
754 	return (error);
755 }
756 
757 /*
758  * Access the SES target identified by the indicated path.  Read the logs
759  * and return them in a nvlist.
760  */
761 int
762 access_ses_log(ses_log_call_t *data)
763 {
764 	char real_path[MAXPATHLEN];
765 	struct stat buffer;
766 	int error;
767 
768 	/* Initialize return data */
769 	data->log_data = NULL;
770 	data->number_log_entries = 0;
771 
772 	if (data->target_path == NULL) {
773 		/* NULL Target path, return error */
774 		return (SES_LOG_FAILED_NULL_TARGET_PATH);
775 	}
776 
777 	/* Try to find a valid path */
778 	(void) snprintf(real_path, sizeof (real_path), "/devices%s:ses",
779 	    data->target_path);
780 
781 	if (stat(real_path, &buffer) != 0) {
782 
783 		(void) snprintf(real_path, sizeof (real_path), "/devices%s:0",
784 		    data->target_path);
785 		if (stat(real_path, &buffer) != 0) {
786 			/* Couldn't find a path that exists */
787 			return (SES_LOG_FAILED_BAD_TARGET_PATH);
788 		}
789 	}
790 
791 	error = gather_data(real_path, data);
792 
793 	/* Update the size of log entries being returned */
794 	data->size_of_log_entries =
795 	    data->number_log_entries * SES_LOG_VALID_LOG_SIZE;
796 
797 	return (error);
798 }
799