libblkid/src/config.c

   1 /*
   2  * config.c - blkid.conf routines
   3  *
   4  * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
   5  *
   6  * This file may be redistributed under the terms of the
   7  * GNU Lesser General Public License.
   8  */
   9
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <fcntl.h>
  15 #include <ctype.h>
  16 #include <sys/types.h>
  17 #ifdef HAVE_SYS_STAT_H
  18 #include <sys/stat.h>
  19 #endif
  20 #ifdef HAVE_ERRNO_H
  21 #include <errno.h>
  22 #endif
  23 #include <stdint.h>
  24 #include <stdarg.h>
  25
  26 #include "blkidP.h"
  27 #include "env.h"
  28
  29 static int parse_evaluate(struct blkid_config *conf, char *s)
  30 {
  31         while(s && *s) {
  32                 char *sep;
  33
  34                 if (conf->nevals >= __BLKID_EVAL_LAST)
  35                         goto err;
  36                 sep = strchr(s, ',');
  37                 if (sep)
  38                         *sep = '\0';
  39                 if (strcmp(s, "udev") == 0)
  40                         conf->eval[conf->nevals] = BLKID_EVAL_UDEV;
  41                 else if (strcmp(s, "scan") == 0)
  42                         conf->eval[conf->nevals] = BLKID_EVAL_SCAN;
  43                 else
  44                         goto err;
  45                 conf->nevals++;
  46                 if (sep)
  47                         s = sep + 1;
  48                 else
  49                         break;
  50         }
  51         return 0;
  52 err:
  53         DBG(CONFIG, ul_debug(
  54                 "config file: unknown evaluation method '%s'.", s));
  55         return -1;
  56 }
  57
  58 static int parse_next(FILE *fd, struct blkid_config *conf)
  59 {
  60         char buf[BUFSIZ];
  61         char *s;
  62
  63         /* read the next non-blank non-comment line */
  64         do {
  65                 if (fgets (buf, sizeof(buf), fd) == NULL)
  66                         return feof(fd) ? 0 : -1;
  67                 s = strchr (buf, '\n');
  68                 if (!s) {
  69                         /* Missing final newline?  Otherwise extremely */
  70                         /* long line - assume file was corrupted */
  71                         if (feof(fd))
  72                                 s = strchr (buf, '\0');
  73                         else {
  74                                 DBG(CONFIG, ul_debug(
  75                                         "config file: missing newline at line '%s'.",
  76                                         buf));
  77                                 return -1;
  78                         }
  79                 }
  80                 *s = '\0';
  81                 if (--s >= buf && *s == '\r')
  82                         *s = '\0';
  83
  84                 s = buf;
  85                 while (*s == ' ' || *s == '\t')         /* skip space */
  86                         s++;
  87
  88         } while (*s == '\0' || *s == '#');
  89
  90         if (!strncmp(s, "SEND_UEVENT=", 12)) {
  91                 s += 12;
  92                 if (*s && !strcasecmp(s, "yes"))
  93                         conf->uevent = TRUE;
  94                 else if (*s)
  95                         conf->uevent = FALSE;
  96         } else if (!strncmp(s, "CACHE_FILE=", 11)) {
  97                 s += 11;
  98                 if (*s)
  99                         conf->cachefile = strdup(s);
 100         } else if (!strncmp(s, "EVALUATE=", 9)) {
 101                 s += 9;
 102                 if (*s && parse_evaluate(conf, s) == -1)
 103                         return -1;
 104         } else {
 105                 DBG(CONFIG, ul_debug(
 106                         "config file: unknown option '%s'.", s));
 107                 return -1;
 108         }
 109         return 0;
 110 }
 111
 112 /* return real config data or built-in default */
 113 struct blkid_config *blkid_read_config(const char *filename)
 114 {
 115         struct blkid_config *conf;
 116         FILE *f;
 117
 118         if (!filename)
 119                 filename = safe_getenv("BLKID_CONF");
 120         if (!filename)
 121                 filename = BLKID_CONFIG_FILE;
 122
 123         conf = calloc(1, sizeof(*conf));
 124         if (!conf)
 125                 return NULL;
 126         conf->uevent = -1;
 127
 128         DBG(CONFIG, ul_debug("reading config file: %s.", filename));
 129
 130         f = fopen(filename, "r" UL_CLOEXECSTR);
 131         if (!f) {
 132                 DBG(CONFIG, ul_debug("%s: does not exist, using built-in default", filename));
 133                 goto dflt;
 134         }
 135         while (!feof(f)) {
 136                 if (parse_next(f, conf)) {
 137                         DBG(CONFIG, ul_debug("%s: parse error", filename));
 138                         goto err;
 139                 }
 140         }
 141 dflt:
 142         if (!conf->nevals) {
 143                 conf->eval[0] = BLKID_EVAL_UDEV;
 144                 conf->eval[1] = BLKID_EVAL_SCAN;
 145                 conf->nevals = 2;
 146         }
 147         if (!conf->cachefile)
 148                 conf->cachefile = strdup(BLKID_CACHE_FILE);
 149         if (conf->uevent == -1)
 150                 conf->uevent = TRUE;
 151         if (f)
 152                 fclose(f);
 153         return conf;
 154 err:
 155         free(conf);
 156         fclose(f);
 157         return NULL;
 158 }
 159
 160 void blkid_free_config(struct blkid_config *conf)
 161 {
 162         if (!conf)
 163                 return;
 164         free(conf->cachefile);
 165         free(conf);
 166 }
 167
 168 #ifdef TEST_PROGRAM
 169 /*
 170  * usage: tst_config [<filename>]
 171  */
 172 int main(int argc, char *argv[])
 173 {
 174         int i;
 175         struct blkid_config *conf;
 176         char *filename = NULL;
 177
 178         blkid_init_debug(BLKID_DEBUG_ALL);
 179
 180         if (argc == 2)
 181                 filename = argv[1];
 182
 183         conf = blkid_read_config(filename);
 184         if (!conf)
 185                 return EXIT_FAILURE;
 186
 187         printf("EVALUATE:    ");
 188         for (i = 0; i < conf->nevals; i++)
 189                 printf("%s ", conf->eval[i] == BLKID_EVAL_UDEV ? "udev" : "scan");
 190         printf("\n");
 191
 192         printf("SEND UEVENT: %s\n", conf->uevent ? "TRUE" : "FALSE");
 193         printf("CACHE_FILE:  %s\n", conf->cachefile);
 194
 195         blkid_free_config(conf);
 196         return EXIT_SUCCESS;
 197 }
 198 #endif