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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 23 /* All Rights Reserved */ 24 25 26 /* 27 * Copyright (c) 1997, by Sun Microsystems, Inc. 28 * All rights reserved. 29 */ 30 31 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.2 */ 32 33 /*LINTLIBRARY*/ 34 35 /* 36 * devattr.c 37 * 38 * Contents: 39 * devattr() Get the value of a attribute for a specific device 40 */ 41 42 /* 43 * Header files needed 44 * <sys/types.h> System Data Types 45 * <stdio.h> Standard I/O Definitions 46 * <errno.h> Error-value definitions 47 * <string.h> String function and constant definitions 48 * <devmgmt.h> Device table definitions available to the world 49 * "devtab.h" Local device table definitions 50 */ 51 52 #include <sys/types.h> 53 #include <stdio.h> 54 #include <errno.h> 55 #include <string.h> 56 #include <stdlib.h> 57 #include <devmgmt.h> 58 #include "devtab.h" 59 60 /* 61 * Local constant definitions 62 */ 63 64 65 /* 66 * Local static data 67 */ 68 69 /* 70 * char *devattr(device, attr) 71 * 72 * This function searches the device table, looking for the device 73 * specified by <device>. If it finds a record corresponding to that 74 * device (see below for a definition of that correspondence), it 75 * extracts the value of the field <attr> from that record, if any. 76 * It returns a pointer to that value, or (char *) NULL if none. 77 * 78 * Arguments: 79 * device Pointer to the character-string that describes the 80 * device whose record is to be looked for 81 * attr The device's attribute to be looked for 82 * 83 * Returns: char * 84 * A pointer to the character-string containing the value of the 85 * attribute <attr> for the device <device>, or (char *) NULL if none 86 * was found. If the function returns (char *) NULL and the error was 87 * detected by this function, it sets "errno" to indicate the problem. 88 * 89 * "errno" Values: 90 * EPERM Permissions deny reading access of the device-table 91 * file 92 * ENOENT The specified device-table file could not be found 93 * ENODEV Device not found in the device table 94 * EINVAL The device does not have that attribute defined 95 * ENOMEM No memory available 96 */ 97 98 char * 99 devattr( 100 char *device, /* The device ) we're to look for */ 101 char *attribute) /* The attribute to extract */ 102 { 103 /* Automatic data */ 104 struct devtabent *record; /* Retrieved record */ 105 struct attrval *p; /* attr/val records */ 106 char *val; /* Extracted value */ 107 char *rtnval; /* Value to return */ 108 int found; /* TRUE if attribute found */ 109 110 111 /* Get the record for the specified device */ 112 if (!(record = _getdevrec(device))) { 113 _enddevtab(); 114 return (NULL); 115 } 116 117 /* Search the record for the specified attribute */ 118 found = FALSE; 119 120 /* Did they ask for the device alias? */ 121 if (strcmp(attribute, DTAB_ALIAS) == 0) { 122 val = (record->alias != NULL) ? record->alias : ""; 123 found = TRUE; 124 } 125 126 /* Did they ask for the character-special device? */ 127 else if (strcmp(attribute, DTAB_CDEVICE) == 0) { 128 val = (record->cdevice != NULL) ? record->cdevice : ""; 129 found = TRUE; 130 } 131 132 /* Did they ask for the block-special device? */ 133 else if (strcmp(attribute, DTAB_BDEVICE) == 0) { 134 val = (record->bdevice != NULL) ? record->bdevice : ""; 135 found = TRUE; 136 } 137 138 /* Did they ask for the pathname? */ 139 else if (strcmp(attribute, DTAB_PATHNAME) == 0) { 140 val = (record->pathname != NULL) ? record->pathname : ""; 141 found = TRUE; 142 } 143 144 else { 145 146 /* 147 * Didn't ask for one of the easy ones, search the attr/val 148 * structure 149 */ 150 151 p = record->attrlist; 152 while (!found && (p)) { 153 if (strcmp(p->attr, attribute) == 0) { 154 val = p->val; 155 found = TRUE; 156 } else p = p->next; 157 } 158 } 159 160 /* 161 * If the attribute was found, copy it into malloc()ed space. 162 * If not, set errno appropriately; we'll return NULL 163 */ 164 165 if (found) { 166 if (rtnval = malloc(strlen(val)+1)) 167 (void) strcpy(rtnval, val); 168 else errno = ENOMEM; 169 } else { 170 rtnval = NULL; 171 errno = EINVAL; 172 } 173 174 /* Free the space allocated to the struct devtabent structure */ 175 _freedevtabent(record); 176 177 _enddevtab(); 178 179 /* Fini */ 180 return (rtnval); 181 } 182