libblkid: iso9660: Implement full High Sierra CDROM format support

Specification of High Sierra CDROM format was lost for a longer time, but
now was found again. So this change improves parsing High Sierra CDROM
images and implements everything which is already supported for ISO9660.

High Sierra and ISO9660 are very similar and there are only few differences
in headers. Most visible is that High Sierra has additional 8 bytes at
beginning of each descriptor with Volume Descriptor LBN value, it has more
locations of path table occurrences in Volume descriptor, has shorten
copyright and abstract file ids, bibliographic file id is missing, standard
version is 0 and it does not have timezone offset field in date structure.
Thus positions of some fields are different between High Sierra and ISO9960.

Code in iso9660.c is adjusted to handle both formats, instead implementing
two very similar parsers.

CDROM image of Microsoft Programmers Library 1.0 (MSPL10) from 1988, which
is in High Sierra format, was before this change parsed as:

ID_FS_BLOCK_SIZE=2048
ID_FS_VERSION=High\x20Sierra
ID_FS_LABEL=MS_PL_VERSION_100
ID_FS_LABEL_ENC=MS_PL_VERSION_100
ID_FS_TYPE=iso9660
ID_FS_USAGE=filesystem

And after this change as:

ID_FS_FSBLOCKSIZE=2048
ID_FS_BLOCK_SIZE=2048
ID_FS_FSSIZE=542998528
ID_FS_PUBLISHER_ID=MICROSOFTCORPORATION16011NE36THWAYREDMONDWA98073
ID_FS_DATA_PREPARER_ID=MERIDIAN_DATA_CD_PUBLISHER
ID_FS_APPLICATION_ID=PL
ID_FS_UUID=1988-07-12-00-37-37-00
ID_FS_UUID_ENC=1988-07-12-00-37-37-00
ID_FS_VERSION=High\x20Sierra
ID_FS_LABEL=MS_PL_VERSION_100
ID_FS_LABEL_ENC=MS_PL_VERSION_100
ID_FS_TYPE=iso9660
ID_FS_USAGE=filesystem

Scan of original hardcopy High Sierra specification:
https://www.os2museum.com/files/docs/cdrom/CDROM_Working_Paper-1986.pdf

HTML version of High Sierra specification:
https://www.os2museum.com/files/docs/cdrom/hsg_wp.html

Archived hardcopy of High Sierra specification:
https://archive.org/details/cdrom-working-paper-1986

Story behind Looking for High Sierra:
https://www.os2museum.com/wp/looking-for-high-sierra/

diff --git a/libblkid/src/superblocks/iso9660.c b/libblkid/src/superblocks/iso9660.c
index 24e3ad56c01e48f731f6f01d4f40db61d647a28d..a7a364f30af8ace0a4aced4ccfd70052f5718398 100644 (file)
--- a/libblkid/src/superblocks/iso9660.c
+++ b/libblkid/src/superblocks/iso9660.c
@@ -22,7 +22,7 @@
 #include "cctype.h"
 #include "iso9660.h"
 
-struct iso9660_date {
+struct hs_date {
        unsigned char year[4];
        unsigned char month[2];
        unsigned char day[2];
@@ -30,11 +30,16 @@ struct iso9660_date {
        unsigned char minute[2];
        unsigned char second[2];
        unsigned char hundredth[2];
+} __attribute__ ((packed));
+
+struct iso9660_date {
+       struct hs_date common;
        unsigned char offset;
 } __attribute__ ((packed));
 
 /* PVD - Primary volume descriptor */
 struct iso_volume_descriptor {
+       /* High Sierra has 8 bytes before descriptor with Volume Descriptor LBN value, those are skipped by blkid_probe_get_buffer() */
        unsigned char   vd_type;
        unsigned char   vd_id[5];
        unsigned char   vd_version;
@@ -48,27 +53,54 @@ struct iso_volume_descriptor {
        unsigned char  vol_seq_num[4];
        unsigned char  logical_block_size[4];
        unsigned char  path_table_size[8];
-       unsigned char  type_l_path_table[4];
-       unsigned char  opt_type_l_path_table[4];
-       unsigned char  type_m_path_table[4];
-       unsigned char  opt_type_m_path_table[4];
-       unsigned char  root_dir_record[34];
-       unsigned char  volume_set_id[128];
-       unsigned char  publisher_id[128];
-       unsigned char  data_preparer_id[128];
-       unsigned char  application_id[128];
-       unsigned char  copyright_file_id[37];
-       unsigned char  abstract_file_id[37];
-       unsigned char  bibliographic_file_id[37];
-       struct iso9660_date created;
-       struct iso9660_date modified;
-       struct iso9660_date expiration;
-       struct iso9660_date effective;
-       unsigned char  std_version;
+       union {
+               struct {
+                       unsigned char type_l_path_table[4];
+                       unsigned char opt_type_l_path_table[4];
+                       unsigned char type_m_path_table[4];
+                       unsigned char opt_type_m_path_table[4];
+                       unsigned char root_dir_record[34];
+                       unsigned char volume_set_id[128];
+                       unsigned char publisher_id[128];
+                       unsigned char data_preparer_id[128];
+                       unsigned char application_id[128];
+                       unsigned char copyright_file_id[37];
+                       unsigned char abstract_file_id[37];
+                       unsigned char bibliographic_file_id[37];
+                       struct iso9660_date created;
+                       struct iso9660_date modified;
+                       struct iso9660_date expiration;
+                       struct iso9660_date effective;
+                       unsigned char std_version;
+               } iso; /* ISO9660 */
+               struct {
+                       unsigned char type_l_path_table[4];
+                       unsigned char opt1_type_l_path_table[4];
+                       unsigned char opt2_type_l_path_table[4];
+                       unsigned char opt3_type_l_path_table[4];
+                       unsigned char type_m_path_table[4];
+                       unsigned char opt1_type_m_path_table[4];
+                       unsigned char opt2_type_m_path_table[4];
+                       unsigned char opt3_type_m_path_table[4];
+                       unsigned char root_dir_record[34];
+                       unsigned char volume_set_id[128];
+                       unsigned char publisher_id[128];
+                       unsigned char data_preparer_id[128];
+                       unsigned char application_id[128];
+                       unsigned char copyright_file_id[32];
+                       unsigned char abstract_file_id[32];
+                       struct hs_date created;
+                       struct hs_date modified;
+                       struct hs_date expiration;
+                       struct hs_date effective;
+                       unsigned char std_version;
+               } hs; /* High Sierra */
+       };
 } __attribute__((packed));
 
 /* Boot Record */
 struct boot_record {
+       /* High Sierra has 8 bytes before descriptor with Volume Descriptor LBN value, those are skipped by blkid_probe_get_buffer() */
        unsigned char   vd_type;
        unsigned char   vd_id[5];
        unsigned char   vd_version;
@@ -85,35 +117,9 @@ struct boot_record {
 #define ISO_VD_END                     0xff
 #define ISO_VD_MAX                     16
 /* maximal string field size used anywhere in ISO; update if necessary */
-#define ISO_MAX_FIELDSIZ  sizeof_member(struct iso_volume_descriptor, volume_set_id)
-
-struct high_sierra_volume_descriptor {
-       unsigned char   foo[8];
-       unsigned char   type;
-       unsigned char   id[5];
-       unsigned char   version;
-       unsigned char   unused1;
-       unsigned char   system_id[32];
-       unsigned char   volume_id[32];
-} __attribute__((packed));
-
-/* old High Sierra format */
-static int probe_iso9660_hsfs(blkid_probe pr, const struct blkid_idmag *mag)
-{
-       struct high_sierra_volume_descriptor *iso;
+#define ISO_MAX_FIELDSIZ  sizeof_member(struct iso_volume_descriptor, iso.volume_set_id)
 
-       iso = blkid_probe_get_sb(pr, mag, struct high_sierra_volume_descriptor);
-       if (!iso)
-               return errno ? -errno : 1;
-
-       blkid_probe_set_fsblocksize(pr, ISO_SECTOR_SIZE);
-       blkid_probe_set_block_size(pr, ISO_SECTOR_SIZE);
-       blkid_probe_set_version(pr, "High Sierra");
-       blkid_probe_set_label(pr, iso->volume_id, sizeof(iso->volume_id));
-       return 0;
-}
-
-static int probe_iso9660_set_uuid (blkid_probe pr, const struct iso9660_date *date)
+static int probe_iso9660_set_uuid (blkid_probe pr, const struct hs_date *date, unsigned char offset)
 {
        unsigned char buffer[16];
        unsigned int i, zeros = 0;
@@ -141,7 +147,7 @@ static int probe_iso9660_set_uuid (blkid_probe pr, const struct iso9660_date *da
                        zeros++;
 
        /* due to the iso9660 standard if all date fields are '0' and offset is 0, the date is unset */
-       if (zeros == sizeof(buffer) && date->offset == 0)
+       if (zeros == sizeof(buffer) && offset == 0)
                return 0;
 
        /* generate an UUID using this date and return success */
@@ -227,9 +233,15 @@ static int probe_iso9660(blkid_probe pr, const struct blkid_idmag *mag)
        struct iso_volume_descriptor *joliet = NULL;
        /* space for merge_utf16be_ascii(ISO_ID_BUFSIZ bytes) */
        unsigned char buf[ISO_MAX_FIELDSIZ * 5 / 2];
+       const struct hs_date *modified;
+       const struct hs_date *created;
+       unsigned char modified_offset;
+       unsigned char created_offset;
        size_t len;
+       int is_hs;
        int is_unicode_empty;
-       int is_ascii_empty;
+       int is_ascii_hs_empty;
+       int is_ascii_iso_empty;
        int i;
        uint64_t off;
 
@@ -239,13 +251,12 @@ static int probe_iso9660(blkid_probe pr, const struct blkid_idmag *mag)
        if (off % ISO_SECTOR_SIZE)
                return 1;
 
-       if (strcmp(mag->magic, "CDROM") == 0)
-               return probe_iso9660_hsfs(pr, mag);
+       is_hs = (strcmp(mag->magic, "CDROM") == 0);
 
-       for (i = 0, off += ISO_SUPERBLOCK_OFFSET; i < ISO_VD_MAX && (!boot || !pvd || !joliet); i++, off += ISO_SECTOR_SIZE) {
+       for (i = 0, off += ISO_SUPERBLOCK_OFFSET; i < ISO_VD_MAX && (!boot || !pvd || (!is_hs && !joliet)); i++, off += ISO_SECTOR_SIZE) {
                const unsigned char *desc =
                        blkid_probe_get_buffer(pr,
-                                       off,
+                                       off + (is_hs ? 8 : 0), /* High Sierra has 8 bytes before descriptor with Volume Descriptor LBN value */
                                        max(sizeof(struct boot_record),
                                            sizeof(struct iso_volume_descriptor)));
 
@@ -255,7 +266,7 @@ static int probe_iso9660(blkid_probe pr, const struct blkid_idmag *mag)
                        boot = (struct boot_record *)desc;
                else if (!pvd && desc[0] == ISO_VD_PRIMARY)
                        pvd = (struct iso_volume_descriptor *)desc;
-               else if (!joliet && desc[0] == ISO_VD_SUPPLEMENTARY) {
+               else if (!is_hs && !joliet && desc[0] == ISO_VD_SUPPLEMENTARY) {
                        joliet = (struct iso_volume_descriptor *)desc;
                        if (memcmp(joliet->escape_sequences, "%/@", 3) != 0 &&
                            memcmp(joliet->escape_sequences, "%/C", 3) != 0 &&
@@ -281,43 +292,66 @@ static int probe_iso9660(blkid_probe pr, const struct blkid_idmag *mag)
        else
                blkid_probe_set_id_label(pr, "SYSTEM_ID", pvd->system_id, sizeof(pvd->system_id));
 
-       if (joliet && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->volume_set_id, pvd->volume_set_id, sizeof(pvd->volume_set_id))) != 0)
+       if (joliet && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->iso.volume_set_id, pvd->iso.volume_set_id, sizeof(pvd->iso.volume_set_id))) != 0)
                blkid_probe_set_utf8_id_label(pr, "VOLUME_SET_ID", buf, len, UL_ENCODE_UTF16BE);
        else if (joliet)
-               blkid_probe_set_utf8_id_label(pr, "VOLUME_SET_ID", joliet->volume_set_id, sizeof(joliet->volume_set_id), UL_ENCODE_UTF16BE);
+               blkid_probe_set_utf8_id_label(pr, "VOLUME_SET_ID", joliet->iso.volume_set_id, sizeof(joliet->iso.volume_set_id), UL_ENCODE_UTF16BE);
+       else if (is_hs)
+               blkid_probe_set_id_label(pr, "VOLUME_SET_ID", pvd->hs.volume_set_id, sizeof(pvd->hs.volume_set_id));
        else
-               blkid_probe_set_id_label(pr, "VOLUME_SET_ID", pvd->volume_set_id, sizeof(pvd->volume_set_id));
+               blkid_probe_set_id_label(pr, "VOLUME_SET_ID", pvd->iso.volume_set_id, sizeof(pvd->iso.volume_set_id));
 
-       is_ascii_empty = (is_str_empty(pvd->publisher_id, sizeof(pvd->publisher_id)) || pvd->publisher_id[0] == '_');
-       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->publisher_id, sizeof(joliet->publisher_id)) || (joliet->publisher_id[0] == 0x00 && joliet->publisher_id[1] == '_'));
-       if (!is_unicode_empty && !is_ascii_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->publisher_id, pvd->publisher_id, sizeof(pvd->publisher_id))) != 0)
+       is_ascii_hs_empty = (!is_hs || is_str_empty(pvd->hs.publisher_id, sizeof(pvd->hs.publisher_id)) || pvd->hs.publisher_id[0] == '_');
+       is_ascii_iso_empty = (is_hs || is_str_empty(pvd->iso.publisher_id, sizeof(pvd->iso.publisher_id)) || pvd->iso.publisher_id[0] == '_');
+       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->iso.publisher_id, sizeof(joliet->iso.publisher_id)) || (joliet->iso.publisher_id[0] == 0x00 && joliet->iso.publisher_id[1] == '_'));
+       if (!is_unicode_empty && !is_ascii_iso_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->iso.publisher_id, pvd->iso.publisher_id, sizeof(pvd->iso.publisher_id))) != 0)
                blkid_probe_set_utf8_id_label(pr, "PUBLISHER_ID", buf, len, UL_ENCODE_UTF16BE);
        else if (!is_unicode_empty)
-               blkid_probe_set_utf8_id_label(pr, "PUBLISHER_ID", joliet->publisher_id, sizeof(joliet->publisher_id), UL_ENCODE_UTF16BE);
-       else if (!is_ascii_empty)
-               blkid_probe_set_id_label(pr, "PUBLISHER_ID", pvd->publisher_id, sizeof(pvd->publisher_id));
-
-       is_ascii_empty = (is_str_empty(pvd->data_preparer_id, sizeof(pvd->data_preparer_id)) || pvd->data_preparer_id[0] == '_');
-       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->data_preparer_id, sizeof(joliet->data_preparer_id)) || (joliet->data_preparer_id[0] == 0x00 && joliet->data_preparer_id[1] == '_'));
-       if (!is_unicode_empty && !is_ascii_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->data_preparer_id, pvd->data_preparer_id, sizeof(pvd->data_preparer_id))) != 0)
+               blkid_probe_set_utf8_id_label(pr, "PUBLISHER_ID", joliet->iso.publisher_id, sizeof(joliet->iso.publisher_id), UL_ENCODE_UTF16BE);
+       else if (!is_ascii_hs_empty)
+               blkid_probe_set_id_label(pr, "PUBLISHER_ID", pvd->hs.publisher_id, sizeof(pvd->hs.publisher_id));
+       else if (!is_ascii_iso_empty)
+               blkid_probe_set_id_label(pr, "PUBLISHER_ID", pvd->iso.publisher_id, sizeof(pvd->iso.publisher_id));
+
+       is_ascii_hs_empty = (!is_hs || is_str_empty(pvd->hs.data_preparer_id, sizeof(pvd->hs.data_preparer_id)) || pvd->hs.data_preparer_id[0] == '_');
+       is_ascii_iso_empty = (is_hs || is_str_empty(pvd->iso.data_preparer_id, sizeof(pvd->iso.data_preparer_id)) || pvd->iso.data_preparer_id[0] == '_');
+       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->iso.data_preparer_id, sizeof(joliet->iso.data_preparer_id)) || (joliet->iso.data_preparer_id[0] == 0x00 && joliet->iso.data_preparer_id[1] == '_'));
+       if (!is_unicode_empty && !is_ascii_iso_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->iso.data_preparer_id, pvd->iso.data_preparer_id, sizeof(pvd->iso.data_preparer_id))) != 0)
                blkid_probe_set_utf8_id_label(pr, "DATA_PREPARER_ID", buf, len, UL_ENCODE_UTF16BE);
        else if (!is_unicode_empty)
-               blkid_probe_set_utf8_id_label(pr, "DATA_PREPARER_ID", joliet->data_preparer_id, sizeof(joliet->data_preparer_id), UL_ENCODE_UTF16BE);
-       else if (!is_ascii_empty)
-               blkid_probe_set_id_label(pr, "DATA_PREPARER_ID", pvd->data_preparer_id, sizeof(pvd->data_preparer_id));
-
-       is_ascii_empty = (is_str_empty(pvd->application_id, sizeof(pvd->application_id)) || pvd->application_id[0] == '_');
-       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->application_id, sizeof(joliet->application_id)) || (joliet->application_id[0] == 0x00 && joliet->application_id[1] == '_'));
-       if (!is_unicode_empty && !is_ascii_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->application_id, pvd->application_id, sizeof(pvd->application_id))) != 0)
+               blkid_probe_set_utf8_id_label(pr, "DATA_PREPARER_ID", joliet->iso.data_preparer_id, sizeof(joliet->iso.data_preparer_id), UL_ENCODE_UTF16BE);
+       else if (!is_ascii_hs_empty)
+               blkid_probe_set_id_label(pr, "DATA_PREPARER_ID", pvd->hs.data_preparer_id, sizeof(pvd->hs.data_preparer_id));
+       else if (!is_ascii_iso_empty)
+               blkid_probe_set_id_label(pr, "DATA_PREPARER_ID", pvd->iso.data_preparer_id, sizeof(pvd->iso.data_preparer_id));
+
+       is_ascii_hs_empty = (!is_hs || is_str_empty(pvd->hs.application_id, sizeof(pvd->hs.application_id)) || pvd->hs.application_id[0] == '_');
+       is_ascii_iso_empty = (is_hs || is_str_empty(pvd->iso.application_id, sizeof(pvd->iso.application_id)) || pvd->iso.application_id[0] == '_');
+       is_unicode_empty = (!joliet || is_utf16be_str_empty(joliet->iso.application_id, sizeof(joliet->iso.application_id)) || (joliet->iso.application_id[0] == 0x00 && joliet->iso.application_id[1] == '_'));
+       if (!is_unicode_empty && !is_ascii_iso_empty && (len = merge_utf16be_ascii(buf, sizeof(buf), joliet->iso.application_id, pvd->iso.application_id, sizeof(pvd->iso.application_id))) != 0)
                blkid_probe_set_utf8_id_label(pr, "APPLICATION_ID", buf, len, UL_ENCODE_UTF16BE);
        else if (!is_unicode_empty)
-               blkid_probe_set_utf8_id_label(pr, "APPLICATION_ID", joliet->application_id, sizeof(joliet->application_id), UL_ENCODE_UTF16BE);
-       else if (!is_ascii_empty)
-               blkid_probe_set_id_label(pr, "APPLICATION_ID", pvd->application_id, sizeof(pvd->application_id));
+               blkid_probe_set_utf8_id_label(pr, "APPLICATION_ID", joliet->iso.application_id, sizeof(joliet->iso.application_id), UL_ENCODE_UTF16BE);
+       else if (!is_ascii_hs_empty)
+               blkid_probe_set_id_label(pr, "APPLICATION_ID", pvd->hs.application_id, sizeof(pvd->hs.application_id));
+       else if (!is_ascii_iso_empty)
+               blkid_probe_set_id_label(pr, "APPLICATION_ID", pvd->iso.application_id, sizeof(pvd->iso.application_id));
+
+       if (is_hs) {
+               modified = &pvd->hs.modified;
+               created = &pvd->hs.created;
+               modified_offset = 0;
+               created_offset = 0;
+       } else {
+               modified = &pvd->iso.modified.common;
+               created = &pvd->iso.created.common;
+               modified_offset = pvd->iso.modified.offset;
+               created_offset = pvd->iso.created.offset;
+       }
 
        /* create an UUID using the modified/created date */
-       if (! probe_iso9660_set_uuid(pr, &pvd->modified))
-               probe_iso9660_set_uuid(pr, &pvd->created);
+       if (! probe_iso9660_set_uuid(pr, modified, modified_offset))
+               probe_iso9660_set_uuid(pr, created, created_offset);
 
        if (boot)
                blkid_probe_set_id_label(pr, "BOOT_SYSTEM_ID",
@@ -326,6 +360,8 @@ static int probe_iso9660(blkid_probe pr, const struct blkid_idmag *mag)
 
        if (joliet)
                blkid_probe_set_version(pr, "Joliet Extension");
+       else if (is_hs)
+               blkid_probe_set_version(pr, "High Sierra");
 
        /* Label in Joliet is UNICODE (UTF16BE) but can contain only 16 characters. Label in PVD is
         * subset of ASCII but can contain up to the 32 characters. Non-representable characters are
@@ -351,6 +387,10 @@ const struct blkid_idinfo iso9660_idinfo =
        .flags          = BLKID_IDINFO_TOLERANT,
        .magics         =
        {
+               /*
+                * Due to different location of vd_id[] in ISO9660 and High Sierra, IS9660 can match
+                * also High Sierra vd_id[]. So always check ISO9660 (CD001) before High Sierra (CDROM).
+                */
                { .magic = "CD001", .len = 5, .kboff = 32, .sboff = 1, .hoff = "session_offset" },
                { .magic = "CDROM", .len = 5, .kboff = 32, .sboff = 9, .hoff = "session_offset" },
                { NULL }