shlibs/blkid/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_SYS_MKDEV_H
  21 #include <sys/mkdev.h>
  22 #endif
  23 #ifdef HAVE_ERRNO_H
  24 #include <errno.h>
  25 #endif
  26 #include <stdint.h>
  27 #include <stdarg.h>
  28
  29 #include "blkdev.h"
  30 #include "blkidP.h"
  31
  32
  33 static int parse_evaluate(struct blkid_config *conf, char *s)
  34 {
  35         while(s && *s) {
  36                 char *sep;
  37
  38                 if (conf->nevals >= __BLKID_EVAL_LAST)
  39                         goto err;
  40                 sep = strchr(s, ',');
  41                 if (sep)
  42                         *sep = '\0';
  43                 if (strcmp(s, "udev") == 0)
  44                         conf->eval[conf->nevals] = BLKID_EVAL_UDEV;
  45                 else if (strcmp(s, "scan") == 0)
  46                         conf->eval[conf->nevals] = BLKID_EVAL_SCAN;
  47                 else
  48                         goto err;
  49                 conf->nevals++;
  50                 if (sep)
  51                         s = sep + 1;
  52                 else
  53                         break;
  54         }
  55         return 0;
  56 err:
  57         DBG(DEBUG_CONFIG, printf(
  58                 "config file: unknown evaluation method '%s'.\n", s));
  59         return -1;
  60 }
  61
  62 static int parse_next(FILE *fd, struct blkid_config *conf)
  63 {
  64         char buf[BUFSIZ];
  65         char *s;
  66
  67         /* read the next non-blank non-comment line */
  68         do {
  69                 if (fgets (buf, sizeof(buf), fd) == NULL)
  70                         return feof(fd) ? 0 : -1;
  71                 s = strchr (buf, '\n');
  72                 if (!s) {
  73                         /* Missing final newline?  Otherwise extremely */
  74                         /* long line - assume file was corrupted */
  75                         if (feof(fd))
  76                                 s = strchr (buf, '\0');
  77                         else {
  78                                 DBG(DEBUG_CONFIG, fprintf(stderr,
  79                                         "libblkid: config file: missing newline at line '%s'.\n",
  80                                         buf));
  81                                 return -1;
  82                         }
  83                 }
  84                 *s = '\0';
  85                 if (--s >= buf && *s == '\r')
  86                         *s = '\0';
  87
  88                 s = buf;
  89                 while (*s == ' ' || *s == '\t')         /* skip space */
  90                         s++;
  91
  92         } while (*s == '\0' || *s == '#');
  93
  94         if (!strncmp(s, "SEND_UEVENT=", 12)) {
  95                 s += 13;
  96                 if (*s && !strcasecmp(s, "yes"))
  97                         conf->uevent = TRUE;
  98                 else if (*s)
  99                         conf->uevent = FALSE;
 100         } else if (!strncmp(s, "CACHE_FILE=", 11)) {
 101                 s += 11;
 102                 if (*s)
 103                         conf->cachefile = blkid_strdup(s);
 104         } else if (!strncmp(s, "EVALUATE=", 9)) {
 105                 s += 9;
 106                 if (*s && parse_evaluate(conf, s) == -1)
 107                         return -1;
 108         } else {
 109                 DBG(DEBUG_CONFIG, printf(
 110                         "config file: unknown option '%s'.\n", s));
 111                 return -1;
 112         }
 113         return 0;
 114 }
 115
 116 /* return real config data or built-in default */
 117 struct blkid_config *blkid_read_config(const char *filename)
 118 {
 119         struct blkid_config *conf;
 120         FILE *f;
 121
 122         if (!filename)
 123                 filename = blkid_safe_getenv("BLKID_CONF");
 124         if (!filename)
 125                 filename = BLKID_CONFIG_FILE;
 126
 127         conf = (struct blkid_config *) calloc(1, sizeof(*conf));
 128         if (!conf)
 129                 return NULL;
 130         conf->uevent = -1;
 131
 132         DBG(DEBUG_CONFIG, fprintf(stderr,
 133                 "reading config file: %s.\n", filename));
 134
 135         f = fopen(filename, "r");
 136         if (!f) {
 137                 DBG(DEBUG_CONFIG, fprintf(stderr,
 138                         "%s: does not exist, using built-in default\n", filename));
 139                 goto dflt;
 140         }
 141         while (!feof(f)) {
 142                 if (parse_next(f, conf)) {
 143                         DBG(DEBUG_CONFIG, fprintf(stderr,
 144                                 "%s: parse error\n", filename));
 145                         goto err;
 146                 }
 147         }
 148 dflt:
 149         if (!conf->nevals) {
 150                 conf->eval[0] = BLKID_EVAL_UDEV;
 151                 conf->eval[1] = BLKID_EVAL_SCAN;
 152                 conf->nevals = 2;
 153         }
 154         if (!conf->cachefile)
 155                 conf->cachefile = blkid_strdup(BLKID_CACHE_FILE);
 156         if (conf->uevent == -1)
 157                 conf->uevent = TRUE;
 158         if (f)
 159                 fclose(f);
 160         return conf;
 161 err:
 162         free(conf);
 163         fclose(f);
 164         return NULL;
 165 }
 166
 167 void blkid_free_config(struct blkid_config *conf)
 168 {
 169         if (!conf)
 170                 return;
 171         free(conf->cachefile);
 172         free(conf);
 173 }
 174
 175 #ifdef TEST_PROGRAM
 176 /*
 177  * usage: tst_config [<filename>]
 178  */
 179 int main(int argc, char *argv[])
 180 {
 181         int i;
 182         struct blkid_config *conf;
 183         char *filename = NULL;
 184
 185         blkid_init_debug(DEBUG_ALL);
 186
 187         if (argc == 2)
 188                 filename = argv[1];
 189
 190         conf = blkid_read_config(filename);
 191         if (!conf)
 192                 return EXIT_FAILURE;
 193
 194         printf("EVALUATE:    ");
 195         for (i = 0; i < conf->nevals; i++)
 196                 printf("%s ", conf->eval[i] == BLKID_EVAL_UDEV ? "udev" : "scan");
 197         printf("\n");
 198
 199         printf("SEND UEVENT: %s\n", conf->uevent ? "TRUE" : "FALSE");
 200         printf("CACHE_FILE:  %s\n", conf->cachefile);
 201
 202         blkid_free_config(conf);
 203         return EXIT_SUCCESS;
 204 }
 205 #endif