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 /*LINTLIBRARY*/ 32 33 /* 34 * devattr.c 35 * 36 * Contents: 37 * devattr() Get the value of a attribute for a specific device 38 */ 39 40 /* 41 * Header files needed 42 * <sys/types.h> System Data Types 43 * <stdio.h> Standard I/O Definitions 44 * <errno.h> Error-value definitions 45 * <string.h> String function and constant definitions 46 * <devmgmt.h> Device table definitions available to the world 47 * "devtab.h" Local device table definitions 48 */ 49 50 #include <sys/types.h> 51 #include <stdio.h> 52 #include <errno.h> 53 #include <string.h> 54 #include <stdlib.h> 55 #include <devmgmt.h> 56 #include "devtab.h" 57 58 /* 59 * Local constant definitions 60 */ 61 62 63 /* 64 * Local static data 65 */ 66 67 /* 68 * char *devattr(device, attr) 69 * 70 * This function searches the device table, looking for the device 71 * specified by <device>. If it finds a record corresponding to that 72 * device (see below for a definition of that correspondence), it 73 * extracts the value of the field <attr> from that record, if any. 74 * It returns a pointer to that value, or (char *) NULL if none. 75 * 76 * Arguments: 77 * device Pointer to the character-string that describes the 78 * device whose record is to be looked for 79 * attr The device's attribute to be looked for 80 * 81 * Returns: char * 82 * A pointer to the character-string containing the value of the 83 * attribute <attr> for the device <device>, or (char *) NULL if none 84 * was found. If the function returns (char *) NULL and the error was 85 * detected by this function, it sets "errno" to indicate the problem. 86 * 87 * "errno" Values: 88 * EPERM Permissions deny reading access of the device-table 89 * file 90 * ENOENT The specified device-table file could not be found 91 * ENODEV Device not found in the device table 92 * EINVAL The device does not have that attribute defined 93 * ENOMEM No memory available 94 */ 95 96 char * 97 devattr( 98 char *device, /* The device ) we're to look for */ 99 char *attribute) /* The attribute to extract */ 100 { 101 /* Automatic data */ 102 struct devtabent *record; /* Retrieved record */ 103 struct attrval *p; /* attr/val records */ 104 char *val; /* Extracted value */ 105 char *rtnval; /* Value to return */ 106 int found; /* TRUE if attribute found */ 107 108 109 /* Get the record for the specified device */ 110 if (!(record = _getdevrec(device))) { 111 _enddevtab(); 112 return (NULL); 113 } 114 115 /* Search the record for the specified attribute */ 116 found = FALSE; 117 118 /* Did they ask for the device alias? */ 119 if (strcmp(attribute, DTAB_ALIAS) == 0) { 120 val = (record->alias != NULL) ? record->alias : ""; 121 found = TRUE; 122 } 123 124 /* Did they ask for the character-special device? */ 125 else if (strcmp(attribute, DTAB_CDEVICE) == 0) { 126 val = (record->cdevice != NULL) ? record->cdevice : ""; 127 found = TRUE; 128 } 129 130 /* Did they ask for the block-special device? */ 131 else if (strcmp(attribute, DTAB_BDEVICE) == 0) { 132 val = (record->bdevice != NULL) ? record->bdevice : ""; 133 found = TRUE; 134 } 135 136 /* Did they ask for the pathname? */ 137 else if (strcmp(attribute, DTAB_PATHNAME) == 0) { 138 val = (record->pathname != NULL) ? record->pathname : ""; 139 found = TRUE; 140 } 141 142 else { 143 144 /* 145 * Didn't ask for one of the easy ones, search the attr/val 146 * structure 147 */ 148 149 p = record->attrlist; 150 while (!found && (p)) { 151 if (strcmp(p->attr, attribute) == 0) { 152 val = p->val; 153 found = TRUE; 154 } else p = p->next; 155 } 156 } 157 158 /* 159 * If the attribute was found, copy it into malloc()ed space. 160 * If not, set errno appropriately; we'll return NULL 161 */ 162 163 if (found) { 164 if (rtnval = malloc(strlen(val)+1)) 165 (void) strcpy(rtnval, val); 166 else errno = ENOMEM; 167 } else { 168 rtnval = NULL; 169 errno = EINVAL; 170 } 171 172 /* Free the space allocated to the struct devtabent structure */ 173 _freedevtabent(record); 174 175 _enddevtab(); 176 177 /* Fini */ 178 return (rtnval); 179 } 180