minix/fs/isofs/susp_rock_ridge.c

   1 /*
   2  * This file contains support for Rock Ridge Interchange Protocol (RRIP)
   3  * extension to ISO 9660.
   4  */
   5
   6 #include "inc.h"
   7 #include <sys/stat.h>
   8
   9 #ifdef ISO9660_OPTION_ROCKRIDGE
  10
  11 void parse_susp_rock_ridge_plcl(struct rrii_dir_record *dir, u32_t block) {
  12         struct inode *rep_inode;
  13         struct buf *bp;
  14         struct iso9660_dir_record *dir_rec;
  15         struct dir_extent extent;
  16         struct inode_dir_entry dummy_dir_entry;
  17         size_t dummy_offset = 0;
  18
  19         /* Check if inode wasn't already parsed. */
  20         rep_inode = inode_cache_get(block);
  21         if (rep_inode != NULL) {
  22                 rep_inode->i_refcount++;
  23                 dir->reparented_inode = rep_inode;
  24                 return;
  25         }
  26
  27         /* Peek ahead to build extent for read_inode. */
  28         if (lmfs_get_block(&bp, fs_dev, block, NORMAL) != OK)
  29                 return;
  30
  31         dir_rec = (struct iso9660_dir_record*)b_data(bp);
  32
  33         extent.location = block;
  34         extent.length = dir_rec->data_length_l / v_pri.logical_block_size_l;
  35         if (dir_rec->data_length_l % v_pri.logical_block_size_l)
  36                 extent.length++;
  37         extent.next = NULL;
  38         lmfs_put_block(bp);
  39
  40         memset(&dummy_dir_entry, 0, sizeof(struct inode_dir_entry));
  41         /* XXX what if this fails? */
  42         read_inode(&dummy_dir_entry, &extent, &dummy_offset);
  43         free(dummy_dir_entry.r_name);
  44         dir->reparented_inode = dummy_dir_entry.i_node;
  45 }
  46
  47 void parse_susp_rock_ridge_sl(struct rrii_dir_record *dir, char *buffer, int length)
  48 {
  49         /* Parse a Rock Ridge SUSP symbolic link entry (SL). */
  50         int offset = 0;
  51         int slink_size;
  52         u8_t flags, component_length;
  53
  54         while (offset + 2 <= length) {
  55                 flags = *((u8_t*)(buffer + offset));
  56                 component_length = *((u8_t*)(buffer + offset + 1));
  57
  58                 /* Add directory separator if necessary. */
  59                 if (strcmp(dir->slink_rrip, "") != 0 &&
  60                     strcmp(dir->slink_rrip, "/") != 0) {
  61                         slink_size = strlen(dir->slink_rrip);
  62                         if (slink_size + 2 >= ISO9660_RRIP_MAX_FILE_ID_LEN)
  63                                 return;
  64
  65                         dir->slink_rrip[slink_size++] = '/';
  66                         dir->slink_rrip[slink_size] = '\0';
  67                 }
  68                 else
  69                         slink_size = strlen(dir->slink_rrip);
  70
  71                 switch (flags & 0xF) {
  72                         case 0:
  73                         case 1: {
  74                                 /*
  75                                  * Directory path component.
  76                                  * Check if component fits within SL entry and
  77                                  * within symbolic link field.
  78                                  */
  79                                 if ((component_length > length - offset) ||
  80                                     (slink_size + component_length + 1 >=
  81                                     ISO9660_RRIP_MAX_FILE_ID_LEN)) {
  82                                         return;
  83                                 }
  84
  85                                 strlcat(&dir->slink_rrip[slink_size],
  86                                         buffer + offset + 2,
  87                                         component_length + 1);
  88
  89                                 break;
  90                         }
  91                         case 2: {
  92                                 /* Current directory path component. */
  93                                 if (slink_size + 2 >=
  94                                     ISO9660_RRIP_MAX_FILE_ID_LEN) {
  95                                         return;
  96                                 }
  97
  98                                 strcat(&dir->slink_rrip[slink_size], ".");
  99
 100                                 break;
 101                         }
 102                         case 4: {
 103                                 /* Parent directory path component. */
 104                                 if (slink_size + 3 >=
 105                                     ISO9660_RRIP_MAX_FILE_ID_LEN) {
 106                                         return;
 107                                 }
 108
 109                                 strcat(&dir->slink_rrip[slink_size], "..");
 110
 111                                 break;
 112                         }
 113                         case 8: {
 114                                 /* Root directory path component relative to
 115                                    the current process. */
 116                                 if (slink_size + 2 >=
 117                                     ISO9660_RRIP_MAX_FILE_ID_LEN) {
 118                                         return;
 119                                 }
 120
 121                                 strcat(&dir->slink_rrip[slink_size], "/");
 122
 123                                 break;
 124                         }
 125                         default: {
 126                                 /* Unsupported/invalid flags. */
 127                                 return;
 128                         }
 129                 }
 130
 131                 offset += component_length + 2;
 132         }
 133 }
 134
 135 int parse_susp_rock_ridge(struct rrii_dir_record *dir, char *buffer)
 136 {
 137         /* Parse Rock Ridge SUSP entries for a directory entry. */
 138         char susp_signature[2];
 139         u8_t susp_length;
 140         u8_t susp_version;
 141
 142         int rrii_name_current_size;
 143         int rrii_name_append_size;
 144         int rrii_tf_flags;
 145         int rrii_tf_offset;
 146         u32_t rrii_pn_rdev_major;
 147         u32_t rrii_pn_rdev_minor;
 148         mode_t rrii_px_posix_mode;
 149         u32_t rrii_pcl_block;
 150
 151         susp_signature[0] = buffer[0];
 152         susp_signature[1] = buffer[1];
 153         susp_length = *((u8_t*)buffer + 2);
 154         susp_version = *((u8_t*)buffer + 3);
 155
 156         if ((susp_signature[0] == 'P') && (susp_signature[1] == 'X') &&
 157             (susp_length >= 36) && (susp_version >= 1)) {
 158                 /* POSIX file mode, UID and GID. */
 159                 dir->d_mode = *((u32_t*)(buffer + 4));
 160                 dir->uid = *((u32_t*)(buffer + 20));
 161                 dir->gid = *((u32_t*)(buffer + 28));
 162
 163                 return OK;
 164         }
 165         else if ((susp_signature[0] == 'P') && (susp_signature[1] == 'N') &&
 166                  (susp_length >= 20) && (susp_version >= 1)) {
 167                 /* Device ID (for character or block special inode). */
 168
 169                 /*
 170                  * XXX: Specific to how Minix ISO is generated, will have to
 171                  * investigate why makefs does that later.
 172                  */
 173 #if 0
 174                 rrii_pn_rdev_major = *((u32_t*)(buffer + 4));
 175                 rrii_pn_rdev_minor = *((u32_t*)(buffer + 12));
 176 #else
 177                 rrii_pn_rdev_major = *((u32_t*)(buffer + 12)) >> 8;
 178                 rrii_pn_rdev_minor = *((u32_t*)(buffer + 12)) & 0xFF;
 179 #endif
 180                 dir->rdev = makedev(rrii_pn_rdev_major, rrii_pn_rdev_minor);
 181
 182                 return OK;
 183         }
 184         else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'L') &&
 185                  (susp_length > 5) && (susp_version >= 1)) {
 186                 /* Symbolic link target. Multiple entries may be used to
 187                    concatenate the complete path target. */
 188                 parse_susp_rock_ridge_sl(dir, buffer + 5, susp_length - 5);
 189
 190                 return OK;
 191         }
 192         else if ((susp_signature[0] == 'N') && (susp_signature[1] == 'M') &&
 193                  (susp_length > 5) && (susp_version >= 1)) {
 194                 /* Alternate POSIX name. Multiple entries may be used to
 195                    concatenate the complete filename. */
 196                 rrii_name_current_size = strlen(dir->file_id_rrip);
 197                 rrii_name_append_size = susp_length - 5;
 198
 199                 /* Concatenate only if name component fits. */
 200                 if (rrii_name_current_size + rrii_name_append_size + 1 <
 201                     ISO9660_RRIP_MAX_FILE_ID_LEN) {
 202                         strlcpy(dir->file_id_rrip + rrii_name_current_size,
 203                             buffer + 5, rrii_name_append_size+1);
 204                 }
 205
 206                 return OK;
 207         }
 208         else if ((susp_signature[0] == 'P') && (susp_signature[1] == 'L') &&
 209                  (susp_length >= 12) && (susp_version >= 1)) {
 210                 /* Reparenting ".." directory entry. */
 211                 rrii_pcl_block = *((u32_t*)(buffer + 4));
 212                 parse_susp_rock_ridge_plcl(dir, rrii_pcl_block);
 213
 214                 return OK;
 215         }
 216         else if ((susp_signature[0] == 'C') && (susp_signature[1] == 'L') &&
 217                  (susp_length >= 12) && (susp_version >= 1)) {
 218                 /* Reorganize deep directory entry. */
 219                 rrii_pcl_block = *((u32_t*)(buffer + 4));
 220                 parse_susp_rock_ridge_plcl(dir, rrii_pcl_block);
 221
 222                 return OK;
 223         }
 224         else if ((susp_signature[0] == 'R') && (susp_signature[1] == 'E')) {
 225                 /* Ignored, skip. */
 226
 227                 return OK;
 228         }
 229         else if ((susp_signature[0] == 'T') && (susp_signature[1] == 'F') &&
 230                  (susp_length >= 5) && (susp_version >= 1)) {
 231                 /* POSIX timestamp. */
 232                 rrii_tf_flags = buffer[5];
 233                 rrii_tf_offset = 5;
 234
 235                 /*
 236                  * ISO 9660 17-byte time format.
 237                  * FIXME: 17-byte time format not supported in TF entry.
 238                  */
 239                 if (rrii_tf_flags & (1 << 7)) { }
 240
 241                 /* ISO 9660 7-byte time format. */
 242                 else {
 243                         /* Creation time  */
 244                         if ((rrii_tf_flags & (1 << 0)) &&
 245                             (rrii_tf_offset + ISO9660_SIZE_DATE7 <= susp_length)) {
 246                                 memcpy(dir->birthtime, buffer+rrii_tf_offset,
 247                                        ISO9660_SIZE_DATE7);
 248                                 rrii_tf_offset += ISO9660_SIZE_DATE7;
 249                         }
 250
 251                         /* Modification time */
 252                         if ((rrii_tf_flags & (1 << 1)) &&
 253                             (rrii_tf_offset + ISO9660_SIZE_DATE7 <= susp_length)) {
 254                                 memcpy(dir->mtime, buffer+rrii_tf_offset,
 255                                        ISO9660_SIZE_DATE7);
 256                                 rrii_tf_offset += ISO9660_SIZE_DATE7;
 257                         }
 258
 259                         /* Last access time. */
 260                         if ((rrii_tf_flags & (1 << 2)) &&
 261                             (rrii_tf_offset + ISO9660_SIZE_DATE7 <= susp_length)) {
 262                                 memcpy(dir->atime, buffer+rrii_tf_offset,
 263                                        ISO9660_SIZE_DATE7);
 264                                 rrii_tf_offset += ISO9660_SIZE_DATE7;
 265                         }
 266
 267                         /* Last attribute change time. */
 268                         if ((rrii_tf_flags & (1 << 3)) &&
 269                             (rrii_tf_offset + ISO9660_SIZE_DATE7 <= susp_length)) {
 270                                 memcpy(dir->ctime, buffer+rrii_tf_offset,
 271                                        ISO9660_SIZE_DATE7);
 272                                 rrii_tf_offset += ISO9660_SIZE_DATE7;
 273                         }
 274
 275                         /* The rest is ignored. */
 276                 }
 277
 278                 return OK;
 279         }
 280         else if ((susp_signature[0] == 'S') && (susp_signature[1] == 'F')) {
 281                 /* Ignored, skip. */
 282                 return OK;
 283         }
 284
 285         /* Not a Rock Ridge entry. */
 286         return EINVAL;
 287 }
 288
 289 #endif