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 <config.h>
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <unistd.h>
  15 #include <errno.h>
  16
  17 static char *progname;
  18
  19 static char *xstrdup(const char *s)
  20 {
  21         char *t = strdup(s);
  22         if (!t) {
  23                 fprintf(stderr, "%s: failed to allocate memory\n", progname);
  24                 exit(1);
  25         }
  26         return t;
  27 }
  28
  29 static void *xrealloc(void *oldptr, size_t size)
  30 {
  31         void *ptr = realloc(oldptr, size);
  32         if (!ptr) {
  33                 fprintf(stderr, "%s: failed to allocate memory\n", progname);
  34                 exit(1);
  35         }
  36         return ptr;
  37 }
  38
  39 static void add_arg(char **cmdp, const char *opt)
  40 {
  41         size_t optlen = strlen(opt);
  42         size_t cmdlen = *cmdp ? strlen(*cmdp) : 0;
  43         char *cmd = xrealloc(*cmdp, cmdlen + optlen * 4 + 4);
  44         char *s;
  45         s = cmd + cmdlen;
  46         if (*cmdp)
  47                 *s++ = ' ';
  48
  49         *s++ = '\'';
  50         for (; *opt; opt++) {
  51                 if (*opt == '\'') {
  52                         *s++ = '\'';
  53                         *s++ = '\\';
  54                         *s++ = '\'';
  55                         *s++ = '\'';
  56                 } else
  57                         *s++ = *opt;
  58         }
  59         *s++ = '\'';
  60         *s = '\0';
  61         *cmdp = cmd;
  62 }
  63
  64 static char *add_option(const char *opt, char *options)
  65 {
  66         int oldlen = options ? strlen(options) : 0;
  67
  68         options = xrealloc(options, oldlen + 1 + strlen(opt) + 1);
  69         if (!oldlen)
  70                 strcpy(options, opt);
  71         else {
  72                 strcat(options, ",");
  73                 strcat(options, opt);
  74         }
  75         return options;
  76 }
  77
  78 int main(int argc, char *argv[])
  79 {
  80         char *type = NULL;
  81         char *source;
  82         const char *mountpoint;
  83         char *basename;
  84         char *options = NULL;
  85         char *command = NULL;
  86         char *setuid = NULL;
  87         int i;
  88         int dev = 1;
  89         int suid = 1;
  90
  91         progname = argv[0];
  92         basename = strrchr(argv[0], '/');
  93         if (basename)
  94                 basename++;
  95         else
  96                 basename = argv[0];
  97
  98         if (strncmp(basename, "mount.fuse.", 11) == 0)
  99                 type = basename + 11;
 100         if (strncmp(basename, "mount.fuseblk.", 14) == 0)
 101                 type = basename + 14;
 102
 103         if (type && !type[0])
 104                 type = NULL;
 105
 106         if (argc < 3) {
 107                 fprintf(stderr,
 108                         "usage: %s %s destination [-t type] [-o opt[,opts...]]\n",
 109                         progname, type ? "source" : "type#[source]");
 110                 exit(1);
 111         }
 112
 113         source = argv[1];
 114         if (!source[0])
 115                 source = NULL;
 116
 117         mountpoint = argv[2];
 118
 119         for (i = 3; i < argc; i++) {
 120                 if (strcmp(argv[i], "-v") == 0) {
 121                         continue;
 122                 } else if (strcmp(argv[i], "-t") == 0) {
 123                         i++;
 124
 125                         if (i == argc) {
 126                                 fprintf(stderr,
 127                                         "%s: missing argument to option '-t'\n",
 128                                         progname);
 129                                 exit(1);
 130                         }
 131                         type = argv[i];
 132                         if (strncmp(type, "fuse.", 5) == 0)
 133                                 type += 5;
 134                         else if (strncmp(type, "fuseblk.", 8) == 0)
 135                                 type += 8;
 136
 137                         if (!type[0]) {
 138                                 fprintf(stderr,
 139                                         "%s: empty type given as argument to option '-t'\n",
 140                                         progname);
 141                                 exit(1);
 142                         }
 143                 } else  if (strcmp(argv[i], "-o") == 0) {
 144                         char *opts;
 145                         char *opt;
 146                         i++;
 147                         if (i == argc)
 148                                 break;
 149
 150                         opts = xstrdup(argv[i]);
 151                         opt = strtok(opts, ",");
 152                         while (opt) {
 153                                 int j;
 154                                 int ignore = 0;
 155                                 const char *ignore_opts[] = { "",
 156                                                               "user",
 157                                                               "nouser",
 158                                                               "users",
 159                                                               "auto",
 160                                                               "noauto",
 161                                                               "_netdev",
 162                                                               NULL};
 163                                 if (strncmp(opt, "setuid=", 7) == 0) {
 164                                         setuid = xstrdup(opt + 7);
 165                                         ignore = 1;
 166                                 }
 167                                 for (j = 0; ignore_opts[j]; j++)
 168                                         if (strcmp(opt, ignore_opts[j]) == 0)
 169                                                 ignore = 1;
 170
 171                                 if (!ignore) {
 172                                         if (strcmp(opt, "nodev") == 0)
 173                                                 dev = 0;
 174                                         else if (strcmp(opt, "nosuid") == 0)
 175                                                 suid = 0;
 176
 177                                         options = add_option(opt, options);
 178                                 }
 179                                 opt = strtok(NULL, ",");
 180                         }
 181                 }
 182         }
 183
 184         if (dev)
 185                 options = add_option("dev", options);
 186         if (suid)
 187                 options = add_option("suid", options);
 188
 189         if (!type) {
 190                 if (source) {
 191                         type = xstrdup(source);
 192                         source = strchr(type, '#');
 193                         if (source)
 194                                 *source++ = '\0';
 195                         if (!type[0]) {
 196                                 fprintf(stderr, "%s: empty filesystem type\n",
 197                                         progname);
 198                                 exit(1);
 199                         }
 200                 } else {
 201                         fprintf(stderr, "%s: empty source\n", progname);
 202                         exit(1);
 203                 }
 204         }
 205
 206         add_arg(&command, type);
 207         if (source)
 208                 add_arg(&command, source);
 209         add_arg(&command, mountpoint);
 210         if (options) {
 211                 add_arg(&command, "-o");
 212                 add_arg(&command, options);
 213         }
 214
 215         if (setuid && setuid[0]) {
 216                 char *sucommand = command;
 217                 command = NULL;
 218                 add_arg(&command, "su");
 219                 add_arg(&command, "-");
 220                 add_arg(&command, setuid);
 221                 add_arg(&command, "-c");
 222                 add_arg(&command, sucommand);
 223         } else if (!getenv("HOME")) {
 224                 /* Hack to make filesystems work in the boot environment */
 225                 setenv("HOME", "/root", 0);
 226         }
 227
 228         execl("/bin/sh", "/bin/sh", "-c", command, NULL);
 229         fprintf(stderr, "%s: failed to execute /bin/sh: %s\n", progname,
 230                 strerror(errno));
 231         return 1;
 232 }