1 /* 2 * cache.c - allocation/initialization/free routines for cache 3 * 4 * Copyright (C) 2001 Andreas Dilger 5 * Copyright (C) 2003 Theodore Ts'o 6 * 7 * %Begin-Header% 8 * This file may be redistributed under the terms of the 9 * GNU Lesser General Public License. 10 * %End-Header% 11 */ 12 13 #if HAVE_SECURE_GETENV 14 #define _GNU_SOURCE 15 #endif 16 #if HAVE_UNISTD_H 17 #include <unistd.h> 18 #endif 19 #ifdef HAVE_ERRNO_H 20 #include <errno.h> 21 #endif 22 #include <stdlib.h> 23 #include <string.h> 24 #ifdef HAVE_SYS_PRCTL_H 25 #include <sys/prctl.h> 26 #else 27 #define PR_GET_DUMPABLE 3 28 #endif 29 #if (!defined(HAVE_PRCTL) && defined(linux)) 30 #include <sys/syscall.h> 31 #endif 32 #ifdef HAVE_SYS_STAT_H 33 #include <sys/stat.h> 34 #endif 35 #include "blkidP.h" 36 37 int blkid_debug_mask = 0; 38 39 40 static char *safe_getenv(const char *arg) 41 { 42 if ((getuid() != geteuid()) || (getgid() != getegid())) 43 return NULL; 44 #if HAVE_PRCTL 45 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 46 return NULL; 47 #else 48 #if (defined(linux) && defined(SYS_prctl)) 49 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0) 50 return NULL; 51 #endif 52 #endif 53 54 #if defined(HAVE_SECURE_GETENV) 55 return secure_getenv(arg); 56 #elif defined(HAVE___SECURE_GETENV) 57 return __secure_getenv(arg); 58 #else 59 return getenv(arg); 60 #endif 61 } 62 63 #if 0 /* ifdef CONFIG_BLKID_DEBUG */ 64 static blkid_debug_dump_cache(int mask, blkid_cache cache) 65 { 66 struct list_head *p; 67 68 if (!cache) { 69 printf("cache: NULL\n"); 70 return; 71 } 72 73 printf("cache: time = %lu\n", cache->bic_time); 74 printf("cache: flags = 0x%08X\n", cache->bic_flags); 75 76 list_for_each(p, &cache->bic_devs) { 77 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 78 blkid_debug_dump_dev(dev); 79 } 80 } 81 #endif 82 83 int blkid_get_cache(blkid_cache *ret_cache, const char *filename) 84 { 85 blkid_cache cache; 86 87 #ifdef CONFIG_BLKID_DEBUG 88 if (!(blkid_debug_mask & DEBUG_INIT)) { 89 char *dstr = getenv("BLKID_DEBUG"); 90 91 if (dstr) 92 blkid_debug_mask = strtoul(dstr, 0, 0); 93 blkid_debug_mask |= DEBUG_INIT; 94 } 95 #endif 96 97 DBG(DEBUG_CACHE, printf("creating blkid cache (using %s)\n", 98 filename ? filename : "default cache")); 99 100 if (!(cache = (blkid_cache) calloc(1, sizeof(struct blkid_struct_cache)))) 101 return -BLKID_ERR_MEM; 102 103 INIT_LIST_HEAD(&cache->bic_devs); 104 INIT_LIST_HEAD(&cache->bic_tags); 105 106 if (filename && !strlen(filename)) 107 filename = 0; 108 if (!filename) 109 filename = safe_getenv("BLKID_FILE"); 110 if (!filename) 111 filename = BLKID_CACHE_FILE; 112 cache->bic_filename = blkid_strdup(filename); 113 114 blkid_read_cache(cache); 115 116 *ret_cache = cache; 117 return 0; 118 } 119 120 void blkid_put_cache(blkid_cache cache) 121 { 122 if (!cache) 123 return; 124 125 (void) blkid_flush_cache(cache); 126 127 DBG(DEBUG_CACHE, printf("freeing cache struct\n")); 128 129 /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */ 130 131 while (!list_empty(&cache->bic_devs)) { 132 blkid_dev dev = list_entry(cache->bic_devs.next, 133 struct blkid_struct_dev, 134 bid_devs); 135 blkid_free_dev(dev); 136 } 137 138 while (!list_empty(&cache->bic_tags)) { 139 blkid_tag tag = list_entry(cache->bic_tags.next, 140 struct blkid_struct_tag, 141 bit_tags); 142 143 while (!list_empty(&tag->bit_names)) { 144 blkid_tag bad = list_entry(tag->bit_names.next, 145 struct blkid_struct_tag, 146 bit_names); 147 148 DBG(DEBUG_CACHE, printf("warning: unfreed tag %s=%s\n", 149 bad->bit_name, bad->bit_val)); 150 blkid_free_tag(bad); 151 } 152 blkid_free_tag(tag); 153 } 154 free(cache->bic_filename); 155 156 free(cache); 157 } 158 159 void blkid_gc_cache(blkid_cache cache) 160 { 161 struct list_head *p, *pnext; 162 struct stat st; 163 164 if (!cache) 165 return; 166 167 list_for_each_safe(p, pnext, &cache->bic_devs) { 168 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs); 169 if (!p) 170 break; 171 if (stat(dev->bid_name, &st) < 0) { 172 DBG(DEBUG_CACHE, 173 printf("freeing %s\n", dev->bid_name)); 174 blkid_free_dev(dev); 175 cache->bic_flags |= BLKID_BIC_FL_CHANGED; 176 } else { 177 DBG(DEBUG_CACHE, 178 printf("Device %s exists\n", dev->bid_name)); 179 } 180 } 181 } 182 183 184 #ifdef TEST_PROGRAM 185 int main(int argc, char** argv) 186 { 187 blkid_cache cache = NULL; 188 int ret; 189 190 blkid_debug_mask = DEBUG_ALL; 191 if ((argc > 2)) { 192 fprintf(stderr, "Usage: %s [filename] \n", argv[0]); 193 exit(1); 194 } 195 196 if ((ret = blkid_get_cache(&cache, argv[1])) < 0) { 197 fprintf(stderr, "error %d parsing cache file %s\n", ret, 198 argv[1] ? argv[1] : BLKID_CACHE_FILE); 199 exit(1); 200 } 201 if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) { 202 fprintf(stderr, "%s: error creating cache (%d)\n", 203 argv[0], ret); 204 exit(1); 205 } 206 if ((ret = blkid_probe_all(cache) < 0)) 207 fprintf(stderr, "error probing devices\n"); 208 209 blkid_put_cache(cache); 210 211 return ret; 212 } 213 #endif 214
