extras/fstab_import/fstab_import.c

   1 /*
   2  * find matching entry in fstab and export it
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #ifndef _GNU_SOURCE
  13 #define _GNU_SOURCE 1
  14 #endif
  15
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <unistd.h>
  19 #include <fcntl.h>
  20 #include <ctype.h>
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <getopt.h>
  24 #include <mntent.h>
  25 #include <sys/stat.h>
  26
  27 #include "../../udev/udev.h"
  28
  29 static int debug;
  30 static char root[PATH_SIZE] = "/dev";
  31 static char **devices;
  32
  33 #ifdef USE_LOG
  34 void log_message(int priority, const char *format, ...)
  35 {
  36         va_list args;
  37         static int udev_log = -1;
  38
  39         if (udev_log == -1) {
  40                 const char *value;
  41
  42                 value = getenv("UDEV_LOG");
  43                 if (value)
  44                         udev_log = log_priority(value);
  45                 else
  46                         udev_log = LOG_ERR;
  47
  48                 if (debug && udev_log < LOG_INFO)
  49                         udev_log = LOG_INFO;
  50         }
  51
  52         if (priority > udev_log)
  53                 return;
  54
  55         va_start(args, format);
  56         if (debug) {
  57                 fprintf(stderr, "[%d] ", (int) getpid());
  58                 vfprintf(stderr, format, args);
  59         } else
  60                 vsyslog(priority, format, args);
  61         va_end(args);
  62 }
  63 #endif
  64
  65 static int matches_device_list(const char *name)
  66 {
  67         int i;
  68
  69         for (i = 0; devices[i] != NULL; i++) {
  70                 info("compare '%s' == '%s'\n", name, devices[i]);
  71                 if (strcmp(devices[i], name) == 0)
  72                         return 1;
  73         }
  74         return 0;
  75 }
  76
  77 static void print_fstab_entry(struct mntent *mnt)
  78 {
  79         printf("FSTAB_NAME=%s\n", mnt->mnt_fsname);
  80         printf("FSTAB_DIR=%s\n", mnt->mnt_dir);
  81         printf("FSTAB_TYPE=%s\n", mnt->mnt_type);
  82         printf("FSTAB_OPTS=%s\n", mnt->mnt_opts);
  83         printf("FSTAB_FREQ=%d\n", mnt->mnt_freq);
  84         printf("FSTAB_PASSNO=%d\n", mnt->mnt_passno);
  85 }
  86
  87 int main(int argc, char *argv[])
  88 {
  89         static const struct option options[] = {
  90                 { "export", 0, NULL, 'x' },
  91                 { "root", 1, NULL, 'r' },
  92                 { "debug", 0, NULL, 'd' },
  93                 { "help", 0, NULL, 'h' },
  94                 {}
  95         };
  96
  97         FILE *fp;
  98         struct mntent *mnt;
  99         int rc = 0;
 100
 101         logging_init("fstab_id");
 102
 103         while (1) {
 104                 int option;
 105
 106                 option = getopt_long(argc, argv, "dr:xh", options, NULL);
 107                 if (option == -1)
 108                         break;
 109
 110                 switch (option) {
 111                 case 'r':
 112                         strlcpy(root, optarg, sizeof(root));
 113                         break;
 114                 case 'd':
 115                         debug = 1;
 116                         break;
 117                 case 'h':
 118                         printf("Usage: fstab_id [OPTIONS] name [...]\n"
 119                                "  --export        print environment keys\n"
 120                                "  --root          device node root (default /dev)\n"
 121                                "  --debug         debug to stderr\n"
 122                                "  --help          print this help text\n\n");
 123                 default:
 124                         rc = 1;
 125                         goto exit;
 126                 }
 127         }
 128
 129         devices = &argv[optind];
 130         if (devices[0] == NULL) {
 131                 fprintf(stderr, "error: missing device(s) to match\n");
 132                 rc = 2;
 133                 goto exit;
 134         }
 135
 136         fp = setmntent ("/etc/fstab", "r");
 137         if (fp == NULL) {
 138                 fprintf(stderr, "error: opening fstab: %s\n", strerror(errno));
 139                 rc = 2;
 140                 goto exit;
 141         }
 142
 143         while (1) {
 144                 mnt = getmntent(fp);
 145                 if (mnt == NULL)
 146                         break;
 147
 148                 /* skip root device */
 149                 if (strcmp(mnt->mnt_dir, "/") == 0)
 150                         continue;
 151
 152                 /* match LABEL */
 153                 if (strncmp(mnt->mnt_fsname, "LABEL=", 6) == 0) {
 154                         const char *label;
 155                         char str[256];
 156
 157                         label = &mnt->mnt_fsname[6];
 158                         if (label[0] == '"' || label[0] == '\'') {
 159                                 char *pos;
 160
 161                                 strlcpy(str, &label[1], sizeof(str));
 162                                 pos = strrchr(str, label[0]);
 163                                 if (pos == NULL)
 164                                         continue;
 165                                 pos[0] = '\0';
 166                                 label = str;
 167                         }
 168                         if (matches_device_list(str)) {
 169                                 print_fstab_entry(mnt);
 170                                 break;
 171                         }
 172                         continue;
 173                 }
 174
 175                 /* match UUID */
 176                 if (strncmp(mnt->mnt_fsname, "UUID=", 5) == 0) {
 177                         const char *uuid;
 178                         char str[256];
 179
 180                         uuid = &mnt->mnt_fsname[5];
 181                         if (uuid[0] == '"' || uuid[0] == '\'') {
 182                                 char *pos;
 183
 184                                 strlcpy(str, &uuid[1], sizeof(str));
 185                                 pos = strrchr(str, uuid[0]);
 186                                 if (pos == NULL)
 187                                         continue;
 188                                 pos[0] = '\0';
 189                                 uuid = str;
 190                         }
 191                         if (matches_device_list(str)) {
 192                                 print_fstab_entry(mnt);
 193                                 break;
 194                         }
 195                         continue;
 196                 }
 197
 198                 /* only devices */
 199                 if (strncmp(mnt->mnt_fsname, root, strlen(root)) != 0)
 200                         continue;
 201
 202                 if (matches_device_list(&mnt->mnt_fsname[strlen(root)+1])) {
 203                         print_fstab_entry(mnt);
 204                         break;
 205                 }
 206         }
 207
 208         endmntent(fp);
 209
 210 exit:
 211         logging_close();
 212         return rc;
 213 }