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      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 2008 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #include <stdio.h>
     27 #include <stdlib.h>
     28 #include <string.h>
     29 #include <strings.h>
     30 #include <errno.h>
     31 #include <kstat.h>
     32 #include <signal.h>
     33 #include <setjmp.h>
     34 
     35 #include "sdbc_stats.h"
     36 #include "report.h"
     37 #include "common.h"
     38 
     39 static sigjmp_buf env;
     40 static sig_atomic_t sig_raised = 0;
     41 static void sig_handler(int);
     42 
     43 void
     44 sig_handler(int sig)
     45 {
     46 	switch (sig) {
     47 		case SIGSEGV:
     48 			sig_raised = 1;
     49 			siglongjmp(env, sig);
     50 		default:
     51 			exit(sig);
     52 	}
     53 }
     54 
     55 /*
     56  * kstat_retrieve() - populate the ks_data field of the kstat_t structure
     57  *
     58  * This function is a user-land equivalent of a ks_snapshot
     59  *
     60  * parameters
     61  * 	kstat_ctl_t *kc - kstat_ctl_t structure representing returned from
     62  *			  kstat_open()
     63  * 	kstat_t *ksp - kstat_t strcture to popluate ks_data into
     64  *
     65  * returns
     66  * 	NULL pointer on failure
     67  * 	kstat_t * structure on success
     68  */
     69 kstat_t *
     70 kstat_retrieve(kstat_ctl_t *kc, kstat_t *ksp)
     71 {
     72 
     73 	kstat_t *rval;
     74 	kstat_named_t *knp;
     75 	char *end;
     76 	int i;
     77 	struct sigaction segv_act;	/* default actions */
     78 
     79 	if (ksp == NULL)
     80 		return (NULL);
     81 
     82 	if (ksp->ks_data == NULL &&
     83 	    kstat_read(kc, ksp, NULL) == -1)
     84 		return (NULL);
     85 
     86 	rval = (kstat_t *)calloc(1, sizeof (*ksp));
     87 	memcpy(rval, ksp, sizeof (*ksp));
     88 
     89 	rval->ks_data = (void *) calloc(1, ksp->ks_data_size);
     90 	memcpy(rval->ks_data, ksp->ks_data,
     91 	    sizeof (kstat_named_t) * ksp->ks_ndata);
     92 
     93 	/* special handling for variable length string KSTAT_DATA_STRING */
     94 	knp = (kstat_named_t *)rval->ks_data;
     95 	end = (char *)(knp + ksp->ks_ndata);
     96 	for (i = 0; i < ksp->ks_ndata; i++, knp++) {
     97 		if (knp->data_type == KSTAT_DATA_STRING &&
     98 		    KSTAT_NAMED_STR_PTR(knp) != NULL) {
     99 			/* catch SIGSEGV (bug 6384130) */
    100 			sig_raised = 0;
    101 			(void) sigaction(SIGSEGV, NULL, &segv_act);
    102 			(void) signal(SIGSEGV, sig_handler);
    103 
    104 			strncpy(end, KSTAT_NAMED_STR_PTR(knp),
    105 			    KSTAT_NAMED_STR_BUFLEN(knp));
    106 			KSTAT_NAMED_STR_PTR(knp) = end;
    107 			end += KSTAT_NAMED_STR_BUFLEN(knp);
    108 
    109 			/* bug 6384130 */
    110 			(void) sigsetjmp(env, 0);
    111 			if (sig_raised) {
    112 				bzero(end, KSTAT_NAMED_STR_BUFLEN(knp));
    113 				KSTAT_NAMED_STR_PTR(knp) = end;
    114 				end += KSTAT_NAMED_STR_BUFLEN(knp);
    115 			}
    116 			(void) sigaction(SIGSEGV, &segv_act, NULL);
    117 		}
    118 	}
    119 
    120 	return (rval);
    121 }
    122 
    123 /*
    124  * kstat_value() - retrieve value of a field in a kstat_named_t kstat.
    125  *
    126  * parameters
    127  * 	kstat_t *ksp - kstat containing the field
    128  * 	char *name - text string representing the field name
    129  *
    130  * returns
    131  *	void * - pointer to data retrieved
    132  */
    133 void *
    134 kstat_value(kstat_t *ksp, char *name)
    135 {
    136 	kstat_named_t *knm;
    137 
    138 	if ((knm = kstat_data_lookup(ksp, name)) == NULL)
    139 		return (NULL);
    140 
    141 	switch (knm->data_type) {
    142 		case KSTAT_DATA_CHAR :
    143 			return (knm->value.c);
    144 		case KSTAT_DATA_INT32 :
    145 			return (&knm->value.i32);
    146 		case KSTAT_DATA_UINT32 :
    147 			return (&knm->value.ui32);
    148 		case KSTAT_DATA_INT64 :
    149 			return (&knm->value.i64);
    150 		case KSTAT_DATA_UINT64 :
    151 			return (&knm->value.ui64);
    152 		case KSTAT_DATA_STRING :
    153 			return (KSTAT_NAMED_STR_PTR(knm));
    154 	}
    155 
    156 	return (NULL);
    157 }
    158 
    159 /*
    160  * kstat_free() - deallocated memory associated with a kstat
    161  *
    162  * paramters
    163  * 	kstat_t ksp - kstat to be deallocated
    164  *
    165  * returns
    166  * 	void
    167  */
    168 void
    169 kstat_free(kstat_t *ksp)
    170 {
    171 	if (ksp != NULL) {
    172 		if (ksp->ks_data != NULL)
    173 			free(ksp->ks_data);
    174 		free(ksp);
    175 	}
    176 }
    177 
    178 uint32_t
    179 kstat_delta(kstat_t *pksp, kstat_t *cksp, char *name)
    180 {
    181 	uint32_t *pv, *cv;
    182 
    183 	pv = kstat_value(pksp, name);
    184 	cv = kstat_value(cksp, name);
    185 
    186 	return (u32_delta(*pv, *cv));
    187 }
    188