util/mount.fuse.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <unistd.h>
  13 #include <errno.h>
  14
  15 static char *progname;
  16
  17 static char *xstrdup(const char *s)
  18 {
  19         char *t = strdup(s);
  20         if (!t) {
  21                 fprintf(stderr, "%s: failed to allocate memory\n", progname);
  22                 exit(1);
  23         }
  24         return t;
  25 }
  26
  27 static void *xrealloc(void *oldptr, size_t size)
  28 {
  29         void *ptr = realloc(oldptr, size);
  30         if (!ptr) {
  31                 fprintf(stderr, "%s: failed to allocate memory\n", progname);
  32                 exit(1);
  33         }
  34         return ptr;
  35 }
  36
  37 static void add_arg(char **cmdp, const char *opt)
  38 {
  39         size_t optlen = strlen(opt);
  40         size_t cmdlen = *cmdp ? strlen(*cmdp) : 0;
  41         char *cmd = xrealloc(*cmdp, cmdlen + optlen * 4 + 4);
  42         char *s;
  43         s = cmd + cmdlen;
  44         if (*cmdp)
  45                 *s++ = ' ';
  46
  47         *s++ = '\'';
  48         for (; *opt; opt++) {
  49                 if (*opt == '\'') {
  50                         *s++ = '\'';
  51                         *s++ = '\\';
  52                         *s++ = '\'';
  53                         *s++ = '\'';
  54                 } else
  55                         *s++ = *opt;
  56         }
  57         *s++ = '\'';
  58         *s = '\0';
  59         *cmdp = cmd;
  60 }
  61
  62 static char *add_option(const char *opt, char *options)
  63 {
  64         int oldlen = options ? strlen(options) : 0;
  65
  66         options = xrealloc(options, oldlen + 1 + strlen(opt) + 1);
  67         if (!oldlen)
  68                 strcpy(options, opt);
  69         else {
  70                 strcat(options, ",");
  71                 strcat(options, opt);
  72         }
  73         return options;
  74 }
  75
  76 int main(int argc, char *argv[])
  77 {
  78         char *type = NULL;
  79         char *source;
  80         const char *mountpoint;
  81         char *basename;
  82         char *options = NULL;
  83         char *command = NULL;
  84         char *setuid = NULL;
  85         int i;
  86         int dev = 1;
  87         int suid = 1;
  88
  89         progname = argv[0];
  90         basename = strrchr(argv[0], '/');
  91         if (basename)
  92                 basename++;
  93         else
  94                 basename = argv[0];
  95
  96         if (strncmp(basename, "mount.fuse.", 11) == 0)
  97                 type = basename + 11;
  98         if (strncmp(basename, "mount.fuseblk.", 14) == 0)
  99                 type = basename + 14;
 100
 101         if (type && !type[0])
 102                 type = NULL;
 103
 104         if (argc < 3) {
 105                 fprintf(stderr,
 106                         "usage: %s %s destination [-t type] [-o opt[,opts...]]\n",
 107                         progname, type ? "source" : "type#[source]");
 108                 exit(1);
 109         }
 110
 111         source = argv[1];
 112         if (!source[0])
 113                 source = NULL;
 114
 115         mountpoint = argv[2];
 116
 117         for (i = 3; i < argc; i++) {
 118                 if (strcmp(argv[i], "-v") == 0) {
 119                         continue;
 120                 } else if (strcmp(argv[i], "-t") == 0) {
 121                         i++;
 122
 123                         if (i == argc) {
 124                                 fprintf(stderr,
 125                                         "%s: missing argument to option '-t'\n",
 126                                         progname);
 127                                 exit(1);
 128                         }
 129                         type = argv[i];
 130                         if (strncmp(type, "fuse.", 5) == 0)
 131                                 type += 5;
 132                         else if (strncmp(type, "fuseblk.", 8) == 0)
 133                                 type += 8;
 134
 135                         if (!type[0]) {
 136                                 fprintf(stderr,
 137                                         "%s: empty type given as argument to option '-t'\n",
 138                                         progname);
 139                                 exit(1);
 140                         }
 141                 } else  if (strcmp(argv[i], "-o") == 0) {
 142                         char *opts;
 143                         char *opt;
 144                         i++;
 145                         if (i == argc)
 146                                 break;
 147
 148                         opts = xstrdup(argv[i]);
 149                         opt = strtok(opts, ",");
 150                         while (opt) {
 151                                 int j;
 152                                 int ignore = 0;
 153                                 const char *ignore_opts[] = { "",
 154                                                               "user",
 155                                                               "nouser",
 156                                                               "users",
 157                                                               "auto",
 158                                                               "noauto",
 159                                                               "_netdev",
 160                                                               NULL};
 161                                 if (strncmp(opt, "setuid=", 7) == 0) {
 162                                         setuid = xstrdup(opt + 7);
 163                                         ignore = 1;
 164                                 }
 165                                 for (j = 0; ignore_opts[j]; j++)
 166                                         if (strcmp(opt, ignore_opts[j]) == 0)
 167                                                 ignore = 1;
 168
 169                                 if (!ignore) {
 170                                         if (strcmp(opt, "nodev") == 0)
 171                                                 dev = 0;
 172                                         else if (strcmp(opt, "nosuid") == 0)
 173                                                 suid = 0;
 174
 175                                         options = add_option(opt, options);
 176                                 }
 177                                 opt = strtok(NULL, ",");
 178                         }
 179                 }
 180         }
 181
 182         if (dev)
 183                 options = add_option("dev", options);
 184         if (suid)
 185                 options = add_option("suid", options);
 186
 187         if (!type) {
 188                 if (source) {
 189                         type = xstrdup(source);
 190                         source = strchr(type, '#');
 191                         if (source)
 192                                 *source++ = '\0';
 193                         if (!type[0]) {
 194                                 fprintf(stderr, "%s: empty filesystem type\n",
 195                                         progname);
 196                                 exit(1);
 197                         }
 198                 } else {
 199                         fprintf(stderr, "%s: empty source\n", progname);
 200                         exit(1);
 201                 }
 202         }
 203
 204         add_arg(&command, type);
 205         if (source)
 206                 add_arg(&command, source);
 207         add_arg(&command, mountpoint);
 208         if (options) {
 209                 add_arg(&command, "-o");
 210                 add_arg(&command, options);
 211         }
 212
 213         if (setuid && setuid[0]) {
 214                 char *sucommand = command;
 215                 command = NULL;
 216                 add_arg(&command, "su");
 217                 add_arg(&command, "-");
 218                 add_arg(&command, setuid);
 219                 add_arg(&command, "-c");
 220                 add_arg(&command, sucommand);
 221         } else if (!getenv("HOME")) {
 222                 /* Hack to make filesystems work in the boot environment */
 223                 setenv("HOME", "/root", 0);
 224         }
 225
 226         execl("/bin/sh", "/bin/sh", "-c", command, NULL);
 227         fprintf(stderr, "%s: failed to execute /bin/sh: %s\n", progname,
 228                 strerror(errno));
 229         return 1;
 230 }