1 files changed, 313 insertions, 0 deletions

diff --git a/fs/udf/misc.c b/fs/udf/misc.c
new file mode 100644
index 000000000000..fd321f9ace83
--- /dev/null
+++ b/fs/udf/misc.c
@@ -0,0 +1,313 @@
+/*
+ * misc.c
+ *
+ * PURPOSE
+ *      Miscellaneous routines for the OSTA-UDF(tm) filesystem.
+ *
+ * CONTACTS
+ *      E-mail regarding any portion of the Linux UDF file system should be
+ *      directed to the development team mailing list (run by majordomo):
+ *              linux_udf@hpesjro.fc.hp.com
+ *
+ * COPYRIGHT
+ *      This file is distributed under the terms of the GNU General Public
+ *      License (GPL). Copies of the GPL can be obtained from:
+ *              ftp://prep.ai.mit.edu/pub/gnu/GPL
+ *      Each contributing author retains all rights to their own work.
+ *
+ *  (C) 1998 Dave Boynton
+ *  (C) 1998-2004 Ben Fennema
+ *  (C) 1999-2000 Stelias Computing Inc
+ *
+ * HISTORY
+ *
+ *  04/19/99 blf  partial support for reading/writing specific EA's
+ */
+
+#include "udfdecl.h"
+
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/udf_fs.h>
+#include <linux/buffer_head.h>
+
+#include "udf_i.h"
+#include "udf_sb.h"
+
+struct buffer_head *
+udf_tgetblk(struct super_block *sb, int block)
+{
+        if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
+                return sb_getblk(sb, udf_fixed_to_variable(block));
+        else
+                return sb_getblk(sb, block);
+}
+
+struct buffer_head *
+udf_tread(struct super_block *sb, int block)
+{
+        if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
+                return sb_bread(sb, udf_fixed_to_variable(block));
+        else
+                return sb_bread(sb, block);
+}
+
+struct genericFormat *
+udf_add_extendedattr(struct inode * inode, uint32_t size, uint32_t type,
+        uint8_t loc)
+{
+        uint8_t *ea = NULL, *ad = NULL;
+        int offset;
+        uint16_t crclen;
+        int i;
+
+        ea = UDF_I_DATA(inode);
+        if (UDF_I_LENEATTR(inode))
+                ad = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode);
+        else
+        {
+                ad = ea;
+                size += sizeof(struct extendedAttrHeaderDesc);
+        }
+
+        offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
+                UDF_I_LENALLOC(inode);
+
+        /* TODO - Check for FreeEASpace */
+
+        if (loc & 0x01 && offset >= size)
+        {
+                struct extendedAttrHeaderDesc *eahd;
+                eahd = (struct extendedAttrHeaderDesc *)ea;
+
+                if (UDF_I_LENALLOC(inode))
+                {
+                        memmove(&ad[size], ad, UDF_I_LENALLOC(inode));
+                }
+
+                if (UDF_I_LENEATTR(inode))
+                {
+                        /* check checksum/crc */
+                        if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||
+                                le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
+                        {
+                                return NULL;
+                        }
+                }
+                else
+                {
+                        size -= sizeof(struct extendedAttrHeaderDesc);
+                        UDF_I_LENEATTR(inode) += sizeof(struct extendedAttrHeaderDesc);
+                        eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
+                        if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200)
+                                eahd->descTag.descVersion = cpu_to_le16(3);
+                        else
+                                eahd->descTag.descVersion = cpu_to_le16(2);
+                        eahd->descTag.tagSerialNum = cpu_to_le16(UDF_SB_SERIALNUM(inode->i_sb));
+                        eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
+                        eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
+                        eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
+                }
+
+                offset = UDF_I_LENEATTR(inode);
+                if (type < 2048)
+                {
+                        if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
+                        {
+                                uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
+                                memmove(&ea[offset - aal + size],
+                                        &ea[aal], offset - aal);
+                                offset -= aal;
+                                eahd->appAttrLocation = cpu_to_le32(aal + size);
+                        }
+                        if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode))
+                        {
+                                uint32_t ial = le32_to_cpu(eahd->impAttrLocation);
+                                memmove(&ea[offset - ial + size],
+                                        &ea[ial], offset - ial);
+                                offset -= ial;
+                                eahd->impAttrLocation = cpu_to_le32(ial + size);
+                        }
+                }
+                else if (type < 65536)
+                {
+                        if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
+                        {
+                                uint32_t aal = le32_to_cpu(eahd->appAttrLocation);
+                                memmove(&ea[offset - aal + size],
+                                        &ea[aal], offset - aal);
+                                offset -= aal;
+                                eahd->appAttrLocation = cpu_to_le32(aal + size);
+                        }
+                }
+                /* rewrite CRC + checksum of eahd */
+                crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
+                eahd->descTag.descCRCLength = cpu_to_le16(crclen);
+                eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd + sizeof(tag), crclen, 0));
+                eahd->descTag.tagChecksum = 0;
+                for (i=0; i<16; i++)
+                        if (i != 4)
+                                eahd->descTag.tagChecksum += ((uint8_t *)&(eahd->descTag))[i];
+                UDF_I_LENEATTR(inode) += size;
+                return (struct genericFormat *)&ea[offset];
+        }
+        if (loc & 0x02)
+        {
+        }
+        return NULL;
+}
+
+struct genericFormat *
+udf_get_extendedattr(struct inode *inode, uint32_t type, uint8_t subtype)
+{
+        struct genericFormat *gaf;
+        uint8_t *ea = NULL;
+        uint32_t offset;
+
+        ea = UDF_I_DATA(inode);
+
+        if (UDF_I_LENEATTR(inode))
+        {
+                struct extendedAttrHeaderDesc *eahd;
+                eahd = (struct extendedAttrHeaderDesc *)ea;
+
+                /* check checksum/crc */
+                if (le16_to_cpu(eahd->descTag.tagIdent) != TAG_IDENT_EAHD ||
+                        le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
+                {
+                        return NULL;
+                }
+        
+                if (type < 2048)
+                        offset = sizeof(struct extendedAttrHeaderDesc);
+                else if (type < 65536)
+                        offset = le32_to_cpu(eahd->impAttrLocation);
+                else
+                        offset = le32_to_cpu(eahd->appAttrLocation);
+
+                while (offset < UDF_I_LENEATTR(inode))
+                {
+                        gaf = (struct genericFormat *)&ea[offset];
+                        if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
+                                return gaf;
+                        else
+                                offset += le32_to_cpu(gaf->attrLength);
+                }
+        }
+        return NULL;
+}
+
+/*
+ * udf_read_tagged
+ *
+ * PURPOSE
+ *      Read the first block of a tagged descriptor.
+ *
+ * HISTORY
+ *      July 1, 1997 - Andrew E. Mileski
+ *      Written, tested, and released.
+ */
+struct buffer_head *
+udf_read_tagged(struct super_block *sb, uint32_t block, uint32_t location, uint16_t *ident)
+{
+        tag *tag_p;
+        struct buffer_head *bh = NULL;
+        register uint8_t checksum;
+        register int i;
+
+        /* Read the block */
+        if (block == 0xFFFFFFFF)
+                return NULL;
+
+        bh = udf_tread(sb, block + UDF_SB_SESSION(sb));
+        if (!bh)
+        {
+                udf_debug("block=%d, location=%d: read failed\n", block + UDF_SB_SESSION(sb), location);
+                return NULL;
+        }
+
+        tag_p = (tag *)(bh->b_data);
+
+        *ident = le16_to_cpu(tag_p->tagIdent);
+
+        if ( location != le32_to_cpu(tag_p->tagLocation) )
+        {
+                udf_debug("location mismatch block %u, tag %u != %u\n",
+                        block + UDF_SB_SESSION(sb), le32_to_cpu(tag_p->tagLocation), location);
+                goto error_out;
+        }
+        
+        /* Verify the tag checksum */
+        checksum = 0U;
+        for (i = 0; i < 4; i++)
+                checksum += (uint8_t)(bh->b_data[i]);
+        for (i = 5; i < 16; i++)
+                checksum += (uint8_t)(bh->b_data[i]);
+        if (checksum != tag_p->tagChecksum) {
+                printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
+                goto error_out;
+        }
+
+        /* Verify the tag version */
+        if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
+                le16_to_cpu(tag_p->descVersion) != 0x0003U)
+        {
+                udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n",
+                        le16_to_cpu(tag_p->descVersion), block);
+                goto error_out;
+        }
+
+        /* Verify the descriptor CRC */
+        if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize ||
+                le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
+                        le16_to_cpu(tag_p->descCRCLength), 0))
+        {
+                return bh;
+        }
+        udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
+                block + UDF_SB_SESSION(sb), le16_to_cpu(tag_p->descCRC), le16_to_cpu(tag_p->descCRCLength));
+
+error_out:
+        brelse(bh);
+        return NULL;
+}
+
+struct buffer_head *
+udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc, uint32_t offset, uint16_t *ident)
+{
+        return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
+                loc.logicalBlockNum + offset, ident);
+}
+
+void udf_release_data(struct buffer_head *bh)
+{
+        if (bh)
+                brelse(bh);
+}
+
+void udf_update_tag(char *data, int length)
+{
+        tag *tptr = (tag *)data;
+        int i;
+
+        length -= sizeof(tag);
+
+        tptr->tagChecksum = 0;
+        tptr->descCRCLength = cpu_to_le16(length);
+        tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
+
+        for (i=0; i<16; i++)
+                if (i != 4)
+                        tptr->tagChecksum += (uint8_t)(data[i]);
+}
+
+void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
+        uint32_t loc, int length)
+{
+        tag *tptr = (tag *)data;
+        tptr->tagIdent = cpu_to_le16(ident);
+        tptr->descVersion = cpu_to_le16(version);
+        tptr->tagSerialNum = cpu_to_le16(snum);
+        tptr->tagLocation = cpu_to_le32(loc);
+        udf_update_tag(data, length);
+}