vfs/shared_tar_ext.c

   1 /*
   2  * Large portions of tar.c & extfs.c were nearly same. I killed this
   3  * redundancy, so code is maintainable, again.
   4  *
   5  * Actually, tar no longer uses this code :-).
   6  *
   7  * 1998 Pavel Machek
   8  *
   9  * Namespace: no pollution.
  10  */
  11
  12 static char *get_path (char *inname, struct archive **archive, int is_dir,
  13     int do_not_open)
  14 {
  15     char *buf = g_strdup (inname);
  16     char *res = get_path_mangle( buf, archive, is_dir, do_not_open );
  17     char *res2 = NULL;
  18     if (res)
  19         res2 = g_strdup(res);
  20     g_free(buf);
  21     return res2;
  22 }
  23
  24 static struct entry*
  25 __find_entry (struct entry *dir, char *name,
  26                      struct loop_protect *list, int make_dirs, int make_file)
  27 {
  28     struct entry *pent, *pdir;
  29     char *p, *q, *name_end;
  30     char c;
  31
  32     if (*name == '/') { /* Handle absolute paths */
  33         name++;
  34         dir = dir->inode->archive->root_entry;
  35     }
  36
  37     pent = dir;
  38     p = name;
  39     name_end = name + strlen (name);
  40     q = strchr (p, '/');
  41     c = '/';
  42     if (!q)
  43         q = strchr (p, 0);
  44
  45     for (; pent != NULL && c && *p; ){
  46         c = *q;
  47         *q = 0;
  48
  49         if (strcmp (p, ".")){
  50             if (!strcmp (p, ".."))
  51                 pent = pent->dir;
  52             else {
  53                 if ((pent = __resolve_symlinks (pent, list))==NULL){
  54                     *q = c;
  55                     return NULL;
  56                 }
  57                 if (c == '/' && !S_ISDIR (pent->inode->mode)){
  58                     *q = c;
  59                     notadir = 1;
  60                     return NULL;
  61                 }
  62                 pdir = pent;
  63                 for (pent = pent->inode->first_in_subdir; pent; pent = pent->next_in_dir)
  64                     /* Hack: I keep the original semanthic unless
  65                        q+1 would break in the strchr */
  66                     if (!strcmp (pent->name, p)){
  67                         if (q + 1 > name_end){
  68                             *q = c;
  69                             notadir = !S_ISDIR (pent->inode->mode);
  70                             return pent;
  71                         }
  72                         break;
  73                     }
  74
  75                 /* When we load archive, we create automagically
  76                  * non-existant directories
  77                  */
  78                 if (pent == NULL && make_dirs) {
  79                     pent = generate_entry (dir->inode->archive, p, pdir, S_IFDIR | 0777);
  80                 }
  81                 if (pent == NULL && make_file) {
  82                     pent = generate_entry (dir->inode->archive, p, pdir, 0777);
  83                 }
  84             }
  85         }
  86         /* Next iteration */
  87         *q = c;
  88         p = q + 1;
  89         q = strchr (p, '/');
  90         if (!q)
  91             q = strchr (p, 0);
  92     }
  93     if (pent == NULL)
  94         my_errno = ENOENT;
  95     return pent;
  96 }
  97
  98 static struct entry *find_entry (struct entry *dir, char *name, int make_dirs, int make_file)
  99 {
 100     struct entry *res;
 101
 102     errloop = 0;
 103     notadir = 0;
 104     res = __find_entry (dir, name, NULL, make_dirs, make_file);
 105     if (res == NULL) {
 106         if (errloop)
 107             my_errno = ELOOP;
 108         else if (notadir)
 109             my_errno = ENOTDIR;
 110     }
 111     return res;
 112 }
 113
 114
 115 static int s_errno (vfs *me)
 116 {
 117     return my_errno;
 118 }
 119
 120 static void * s_opendir (vfs *me, char *dirname)
 121 {
 122     struct archive *archive;
 123     char *q;
 124     struct entry *entry;
 125     struct entry **info;
 126
 127     if ((q = get_path_mangle (dirname, &archive, 1, 0)) == NULL)
 128         return NULL;
 129     entry = find_entry (archive->root_entry, q, 0, 0);
 130     if (entry == NULL)
 131         return NULL;
 132     if ((entry = my_resolve_symlinks (entry)) == NULL)
 133         return NULL;
 134     if (!S_ISDIR (entry->inode->mode)) ERRNOR (ENOTDIR, NULL);
 135
 136     info = g_new (struct entry *, 2);
 137     info[0] = entry->inode->first_in_subdir;
 138     info[1] = entry->inode->first_in_subdir;
 139
 140     return info;
 141 }
 142
 143 static void * s_readdir (void *data)
 144 {
 145     static struct {
 146         struct dirent dir;
 147 #ifdef NEED_EXTRA_DIRENT_BUFFER
 148         char extra_buffer [MC_MAXPATHLEN];
 149 #endif
 150     } dir;
 151
 152     struct entry **info = (struct entry **) data;
 153
 154     if (!*info)
 155         return NULL;
 156
 157     strcpy (&(dir.dir.d_name [0]), (*info)->name);
 158
 159 #ifndef DIRENT_LENGTH_COMPUTED
 160     dir.d_namlen = strlen (dir.dir.d_name);
 161 #endif
 162     *info = (*info)->next_in_dir;
 163
 164     return (void *)&dir;
 165 }
 166
 167 static int s_telldir (void *data)
 168 {
 169     struct entry **info = (struct entry **) data;
 170     struct entry *cur;
 171     int num = 0;
 172
 173     cur = info[1];
 174     while (cur!=NULL) {
 175         if (cur == info[0]) return num;
 176         num++;
 177         cur = cur->next_in_dir;
 178     }
 179     return -1;
 180 }
 181
 182 static void s_seekdir (void *data, int offset)
 183 {
 184     struct entry **info = (struct entry **) data;
 185     int i;
 186     info[0] = info[1];
 187     for (i=0; i<offset; i++)
 188         s_readdir( data );
 189 }
 190
 191 static int s_closedir (void *data)
 192 {
 193     g_free (data);
 194     return 0;
 195 }
 196
 197 static void stat_move( struct stat *buf, struct inode *inode )
 198 {
 199     buf->st_dev = inode->dev;
 200     buf->st_ino = inode->inode;
 201     buf->st_mode = inode->mode;
 202     buf->st_nlink = inode->nlink;
 203     buf->st_uid = inode->uid;
 204     buf->st_gid = inode->gid;
 205 #ifdef HAVE_ST_RDEV
 206     buf->st_rdev = inode->rdev;
 207 #endif
 208     buf->st_size = inode->size;
 209 #ifdef HAVE_ST_BLKSIZE
 210     buf->st_blksize = RECORDSIZE;
 211 #endif
 212 #ifdef HAVE_ST_BLOCKS
 213     buf->st_blocks = (inode->size + RECORDSIZE - 1) / RECORDSIZE;
 214 #endif
 215     buf->st_atime = inode->atime;
 216     buf->st_mtime = inode->mtime;
 217     buf->st_ctime = inode->ctime;
 218 }
 219
 220 static int s_internal_stat (char *path, struct stat *buf, int resolve)
 221 {
 222     struct archive *archive;
 223     char *q;
 224     struct entry *entry;
 225     struct inode *inode;
 226
 227     if ((q = get_path_mangle (path, &archive, 0, 0)) == NULL)
 228         return -1;
 229     entry = find_entry (archive->root_entry, q, 0, 0);
 230     if (entry == NULL)
 231         return -1;
 232     if (resolve && (entry = my_resolve_symlinks (entry)) == NULL)
 233         return -1;
 234     inode = entry->inode;
 235     stat_move( buf, inode );
 236     return 0;
 237 }
 238
 239 static int s_stat (vfs *me, char *path, struct stat *buf)
 240 {
 241     return s_internal_stat (path, buf, 1);
 242 }
 243
 244 static int s_lstat (vfs *me, char *path, struct stat *buf)
 245 {
 246     return s_internal_stat (path, buf, 0);
 247 }
 248
 249 static int s_fstat (void *data, struct stat *buf)
 250 {
 251     struct pseudofile *file = (struct pseudofile *)data;
 252     struct inode *inode;
 253
 254     inode = file->entry->inode;
 255     stat_move( buf, inode );
 256     return 0;
 257 }
 258
 259 static int s_readlink (vfs *me, char *path, char *buf, int size)
 260 {
 261     struct archive *archive;
 262     char *q;
 263     int i;
 264     struct entry *entry;
 265
 266     if ((q = get_path_mangle (path, &archive, 0, 0)) == NULL)
 267         return -1;
 268     entry = find_entry (archive->root_entry, q, 0, 0);
 269     if (entry == NULL)
 270         return -1;
 271     if (!S_ISLNK (entry->inode->mode)) ERRNOR (EINVAL, -1);
 272     if (size > (i = strlen (entry->inode->linkname))) {
 273         size = i;
 274     }
 275     strncpy (buf, entry->inode->linkname, i);
 276     return i;
 277 }