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-rw-r--r--fs/isofs/rock.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/fs/isofs/rock.c b/fs/isofs/rock.c
new file mode 100644
index 0000000..8bdd3e4
--- /dev/null
+++ b/fs/isofs/rock.c
@@ -0,0 +1,565 @@
+/*
+ * linux/fs/isofs/rock.c
+ *
+ * (C) 1992, 1993 Eric Youngdale
+ *
+ * Rock Ridge Extensions to iso9660
+ */
+
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <linux/iso_fs.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/smp_lock.h>
+#include <linux/buffer_head.h>
+#include <asm/page.h>
+
+#include "rock.h"
+
+/* These functions are designed to read the system areas of a directory record
+ * and extract relevant information. There are different functions provided
+ * depending upon what information we need at the time. One function fills
+ * out an inode structure, a second one extracts a filename, a third one
+ * returns a symbolic link name, and a fourth one returns the extent number
+ * for the file. */
+
+#define SIG(A,B) ((A) | ((B) << 8)) /* isonum_721() */
+
+
+/* This is a way of ensuring that we have something in the system
+ use fields that is compatible with Rock Ridge */
+#define CHECK_SP(FAIL) \
+ if(rr->u.SP.magic[0] != 0xbe) FAIL; \
+ if(rr->u.SP.magic[1] != 0xef) FAIL; \
+ ISOFS_SB(inode->i_sb)->s_rock_offset=rr->u.SP.skip;
+/* We define a series of macros because each function must do exactly the
+ same thing in certain places. We use the macros to ensure that everything
+ is done correctly */
+
+#define CONTINUE_DECLS \
+ int cont_extent = 0, cont_offset = 0, cont_size = 0; \
+ void *buffer = NULL
+
+#define CHECK_CE \
+ {cont_extent = isonum_733(rr->u.CE.extent); \
+ cont_offset = isonum_733(rr->u.CE.offset); \
+ cont_size = isonum_733(rr->u.CE.size);}
+
+#define SETUP_ROCK_RIDGE(DE,CHR,LEN) \
+ {LEN= sizeof(struct iso_directory_record) + DE->name_len[0]; \
+ if(LEN & 1) LEN++; \
+ CHR = ((unsigned char *) DE) + LEN; \
+ LEN = *((unsigned char *) DE) - LEN; \
+ if (LEN<0) LEN=0; \
+ if (ISOFS_SB(inode->i_sb)->s_rock_offset!=-1) \
+ { \
+ LEN-=ISOFS_SB(inode->i_sb)->s_rock_offset; \
+ CHR+=ISOFS_SB(inode->i_sb)->s_rock_offset; \
+ if (LEN<0) LEN=0; \
+ } \
+}
+
+#define MAYBE_CONTINUE(LABEL,DEV) \
+ {if (buffer) { kfree(buffer); buffer = NULL; } \
+ if (cont_extent){ \
+ int block, offset, offset1; \
+ struct buffer_head * pbh; \
+ buffer = kmalloc(cont_size,GFP_KERNEL); \
+ if (!buffer) goto out; \
+ block = cont_extent; \
+ offset = cont_offset; \
+ offset1 = 0; \
+ pbh = sb_bread(DEV->i_sb, block); \
+ if(pbh){ \
+ if (offset > pbh->b_size || offset + cont_size > pbh->b_size){ \
+ brelse(pbh); \
+ goto out; \
+ } \
+ memcpy(buffer + offset1, pbh->b_data + offset, cont_size - offset1); \
+ brelse(pbh); \
+ chr = (unsigned char *) buffer; \
+ len = cont_size; \
+ cont_extent = 0; \
+ cont_size = 0; \
+ cont_offset = 0; \
+ goto LABEL; \
+ } \
+ printk("Unable to read rock-ridge attributes\n"); \
+ }}
+
+/* return length of name field; 0: not found, -1: to be ignored */
+int get_rock_ridge_filename(struct iso_directory_record * de,
+ char * retname, struct inode * inode)
+{
+ int len;
+ unsigned char * chr;
+ CONTINUE_DECLS;
+ int retnamlen = 0, truncate=0;
+
+ if (!ISOFS_SB(inode->i_sb)->s_rock) return 0;
+ *retname = 0;
+
+ SETUP_ROCK_RIDGE(de, chr, len);
+ repeat:
+ {
+ struct rock_ridge * rr;
+ int sig;
+
+ while (len > 2){ /* There may be one byte for padding somewhere */
+ rr = (struct rock_ridge *) chr;
+ if (rr->len < 3) goto out; /* Something got screwed up here */
+ sig = isonum_721(chr);
+ chr += rr->len;
+ len -= rr->len;
+ if (len < 0) goto out; /* corrupted isofs */
+
+ switch(sig){
+ case SIG('R','R'):
+ if((rr->u.RR.flags[0] & RR_NM) == 0) goto out;
+ break;
+ case SIG('S','P'):
+ CHECK_SP(goto out);
+ break;
+ case SIG('C','E'):
+ CHECK_CE;
+ break;
+ case SIG('N','M'):
+ if (truncate) break;
+ if (rr->len < 5) break;
+ /*
+ * If the flags are 2 or 4, this indicates '.' or '..'.
+ * We don't want to do anything with this, because it
+ * screws up the code that calls us. We don't really
+ * care anyways, since we can just use the non-RR
+ * name.
+ */
+ if (rr->u.NM.flags & 6) {
+ break;
+ }
+
+ if (rr->u.NM.flags & ~1) {
+ printk("Unsupported NM flag settings (%d)\n",rr->u.NM.flags);
+ break;
+ }
+ if((strlen(retname) + rr->len - 5) >= 254) {
+ truncate = 1;
+ break;
+ }
+ strncat(retname, rr->u.NM.name, rr->len - 5);
+ retnamlen += rr->len - 5;
+ break;
+ case SIG('R','E'):
+ if (buffer) kfree(buffer);
+ return -1;
+ default:
+ break;
+ }
+ }
+ }
+ MAYBE_CONTINUE(repeat,inode);
+ if (buffer) kfree(buffer);
+ return retnamlen; /* If 0, this file did not have a NM field */
+ out:
+ if(buffer) kfree(buffer);
+ return 0;
+}
+
+static int
+parse_rock_ridge_inode_internal(struct iso_directory_record *de,
+ struct inode *inode, int regard_xa)
+{
+ int len;
+ unsigned char * chr;
+ int symlink_len = 0;
+ CONTINUE_DECLS;
+
+ if (!ISOFS_SB(inode->i_sb)->s_rock) return 0;
+
+ SETUP_ROCK_RIDGE(de, chr, len);
+ if (regard_xa)
+ {
+ chr+=14;
+ len-=14;
+ if (len<0) len=0;
+ }
+
+ repeat:
+ {
+ int cnt, sig;
+ struct inode * reloc;
+ struct rock_ridge * rr;
+ int rootflag;
+
+ while (len > 2){ /* There may be one byte for padding somewhere */
+ rr = (struct rock_ridge *) chr;
+ if (rr->len < 3) goto out; /* Something got screwed up here */
+ sig = isonum_721(chr);
+ chr += rr->len;
+ len -= rr->len;
+ if (len < 0) goto out; /* corrupted isofs */
+
+ switch(sig){
+#ifndef CONFIG_ZISOFS /* No flag for SF or ZF */
+ case SIG('R','R'):
+ if((rr->u.RR.flags[0] &
+ (RR_PX | RR_TF | RR_SL | RR_CL)) == 0) goto out;
+ break;
+#endif
+ case SIG('S','P'):
+ CHECK_SP(goto out);
+ break;
+ case SIG('C','E'):
+ CHECK_CE;
+ break;
+ case SIG('E','R'):
+ ISOFS_SB(inode->i_sb)->s_rock = 1;
+ printk(KERN_DEBUG "ISO 9660 Extensions: ");
+ { int p;
+ for(p=0;p<rr->u.ER.len_id;p++) printk("%c",rr->u.ER.data[p]);
+ }
+ printk("\n");
+ break;
+ case SIG('P','X'):
+ inode->i_mode = isonum_733(rr->u.PX.mode);
+ inode->i_nlink = isonum_733(rr->u.PX.n_links);
+ inode->i_uid = isonum_733(rr->u.PX.uid);
+ inode->i_gid = isonum_733(rr->u.PX.gid);
+ break;
+ case SIG('P','N'):
+ { int high, low;
+ high = isonum_733(rr->u.PN.dev_high);
+ low = isonum_733(rr->u.PN.dev_low);
+ /*
+ * The Rock Ridge standard specifies that if sizeof(dev_t) <= 4,
+ * then the high field is unused, and the device number is completely
+ * stored in the low field. Some writers may ignore this subtlety,
+ * and as a result we test to see if the entire device number is
+ * stored in the low field, and use that.
+ */
+ if((low & ~0xff) && high == 0) {
+ inode->i_rdev = MKDEV(low >> 8, low & 0xff);
+ } else {
+ inode->i_rdev = MKDEV(high, low);
+ }
+ }
+ break;
+ case SIG('T','F'):
+ /* Some RRIP writers incorrectly place ctime in the TF_CREATE field.
+ Try to handle this correctly for either case. */
+ cnt = 0; /* Rock ridge never appears on a High Sierra disk */
+ if(rr->u.TF.flags & TF_CREATE) {
+ inode->i_ctime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
+ inode->i_ctime.tv_nsec = 0;
+ }
+ if(rr->u.TF.flags & TF_MODIFY) {
+ inode->i_mtime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
+ inode->i_mtime.tv_nsec = 0;
+ }
+ if(rr->u.TF.flags & TF_ACCESS) {
+ inode->i_atime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
+ inode->i_atime.tv_nsec = 0;
+ }
+ if(rr->u.TF.flags & TF_ATTRIBUTES) {
+ inode->i_ctime.tv_sec = iso_date(rr->u.TF.times[cnt++].time, 0);
+ inode->i_ctime.tv_nsec = 0;
+ }
+ break;
+ case SIG('S','L'):
+ {int slen;
+ struct SL_component * slp;
+ struct SL_component * oldslp;
+ slen = rr->len - 5;
+ slp = &rr->u.SL.link;
+ inode->i_size = symlink_len;
+ while (slen > 1){
+ rootflag = 0;
+ switch(slp->flags &~1){
+ case 0:
+ inode->i_size += slp->len;
+ break;
+ case 2:
+ inode->i_size += 1;
+ break;
+ case 4:
+ inode->i_size += 2;
+ break;
+ case 8:
+ rootflag = 1;
+ inode->i_size += 1;
+ break;
+ default:
+ printk("Symlink component flag not implemented\n");
+ }
+ slen -= slp->len + 2;
+ oldslp = slp;
+ slp = (struct SL_component *) (((char *) slp) + slp->len + 2);
+
+ if(slen < 2) {
+ if( ((rr->u.SL.flags & 1) != 0)
+ && ((oldslp->flags & 1) == 0) ) inode->i_size += 1;
+ break;
+ }
+
+ /*
+ * If this component record isn't continued, then append a '/'.
+ */
+ if (!rootflag && (oldslp->flags & 1) == 0)
+ inode->i_size += 1;
+ }
+ }
+ symlink_len = inode->i_size;
+ break;
+ case SIG('R','E'):
+ printk(KERN_WARNING "Attempt to read inode for relocated directory\n");
+ goto out;
+ case SIG('C','L'):
+ ISOFS_I(inode)->i_first_extent = isonum_733(rr->u.CL.location);
+ reloc = isofs_iget(inode->i_sb, ISOFS_I(inode)->i_first_extent, 0);
+ if (!reloc)
+ goto out;
+ inode->i_mode = reloc->i_mode;
+ inode->i_nlink = reloc->i_nlink;
+ inode->i_uid = reloc->i_uid;
+ inode->i_gid = reloc->i_gid;
+ inode->i_rdev = reloc->i_rdev;
+ inode->i_size = reloc->i_size;
+ inode->i_blocks = reloc->i_blocks;
+ inode->i_atime = reloc->i_atime;
+ inode->i_ctime = reloc->i_ctime;
+ inode->i_mtime = reloc->i_mtime;
+ iput(reloc);
+ break;
+#ifdef CONFIG_ZISOFS
+ case SIG('Z','F'):
+ if ( !ISOFS_SB(inode->i_sb)->s_nocompress ) {
+ int algo;
+ algo = isonum_721(rr->u.ZF.algorithm);
+ if ( algo == SIG('p','z') ) {
+ int block_shift = isonum_711(&rr->u.ZF.parms[1]);
+ if ( block_shift < PAGE_CACHE_SHIFT || block_shift > 17 ) {
+ printk(KERN_WARNING "isofs: Can't handle ZF block size of 2^%d\n", block_shift);
+ } else {
+ /* Note: we don't change i_blocks here */
+ ISOFS_I(inode)->i_file_format = isofs_file_compressed;
+ /* Parameters to compression algorithm (header size, block size) */
+ ISOFS_I(inode)->i_format_parm[0] = isonum_711(&rr->u.ZF.parms[0]);
+ ISOFS_I(inode)->i_format_parm[1] = isonum_711(&rr->u.ZF.parms[1]);
+ inode->i_size = isonum_733(rr->u.ZF.real_size);
+ }
+ } else {
+ printk(KERN_WARNING "isofs: Unknown ZF compression algorithm: %c%c\n",
+ rr->u.ZF.algorithm[0], rr->u.ZF.algorithm[1]);
+ }
+ }
+ break;
+#endif
+ default:
+ break;
+ }
+ }
+ }
+ MAYBE_CONTINUE(repeat,inode);
+ out:
+ if(buffer) kfree(buffer);
+ return 0;
+}
+
+static char *get_symlink_chunk(char *rpnt, struct rock_ridge *rr, char *plimit)
+{
+ int slen;
+ int rootflag;
+ struct SL_component *oldslp;
+ struct SL_component *slp;
+ slen = rr->len - 5;
+ slp = &rr->u.SL.link;
+ while (slen > 1) {
+ rootflag = 0;
+ switch (slp->flags & ~1) {
+ case 0:
+ if (slp->len > plimit - rpnt)
+ return NULL;
+ memcpy(rpnt, slp->text, slp->len);
+ rpnt+=slp->len;
+ break;
+ case 2:
+ if (rpnt >= plimit)
+ return NULL;
+ *rpnt++='.';
+ break;
+ case 4:
+ if (2 > plimit - rpnt)
+ return NULL;
+ *rpnt++='.';
+ *rpnt++='.';
+ break;
+ case 8:
+ if (rpnt >= plimit)
+ return NULL;
+ rootflag = 1;
+ *rpnt++='/';
+ break;
+ default:
+ printk("Symlink component flag not implemented (%d)\n",
+ slp->flags);
+ }
+ slen -= slp->len + 2;
+ oldslp = slp;
+ slp = (struct SL_component *) ((char *) slp + slp->len + 2);
+
+ if (slen < 2) {
+ /*
+ * If there is another SL record, and this component
+ * record isn't continued, then add a slash.
+ */
+ if ((!rootflag) && (rr->u.SL.flags & 1) &&
+ !(oldslp->flags & 1)) {
+ if (rpnt >= plimit)
+ return NULL;
+ *rpnt++='/';
+ }
+ break;
+ }
+
+ /*
+ * If this component record isn't continued, then append a '/'.
+ */
+ if (!rootflag && !(oldslp->flags & 1)) {
+ if (rpnt >= plimit)
+ return NULL;
+ *rpnt++='/';
+ }
+ }
+ return rpnt;
+}
+
+int parse_rock_ridge_inode(struct iso_directory_record * de,
+ struct inode * inode)
+{
+ int result=parse_rock_ridge_inode_internal(de,inode,0);
+ /* if rockridge flag was reset and we didn't look for attributes
+ * behind eventual XA attributes, have a look there */
+ if ((ISOFS_SB(inode->i_sb)->s_rock_offset==-1)
+ &&(ISOFS_SB(inode->i_sb)->s_rock==2))
+ {
+ result=parse_rock_ridge_inode_internal(de,inode,14);
+ }
+ return result;
+}
+
+/* readpage() for symlinks: reads symlink contents into the page and either
+ makes it uptodate and returns 0 or returns error (-EIO) */
+
+static int rock_ridge_symlink_readpage(struct file *file, struct page *page)
+{
+ struct inode *inode = page->mapping->host;
+ struct iso_inode_info *ei = ISOFS_I(inode);
+ char *link = kmap(page);
+ unsigned long bufsize = ISOFS_BUFFER_SIZE(inode);
+ struct buffer_head *bh;
+ char *rpnt = link;
+ unsigned char *pnt;
+ struct iso_directory_record *raw_inode;
+ CONTINUE_DECLS;
+ unsigned long block, offset;
+ int sig;
+ int len;
+ unsigned char *chr;
+ struct rock_ridge *rr;
+
+ if (!ISOFS_SB(inode->i_sb)->s_rock)
+ goto error;
+
+ block = ei->i_iget5_block;
+ lock_kernel();
+ bh = sb_bread(inode->i_sb, block);
+ if (!bh)
+ goto out_noread;
+
+ offset = ei->i_iget5_offset;
+ pnt = (unsigned char *) bh->b_data + offset;
+
+ raw_inode = (struct iso_directory_record *) pnt;
+
+ /*
+ * If we go past the end of the buffer, there is some sort of error.
+ */
+ if (offset + *pnt > bufsize)
+ goto out_bad_span;
+
+ /* Now test for possible Rock Ridge extensions which will override
+ some of these numbers in the inode structure. */
+
+ SETUP_ROCK_RIDGE(raw_inode, chr, len);
+
+ repeat:
+ while (len > 2) { /* There may be one byte for padding somewhere */
+ rr = (struct rock_ridge *) chr;
+ if (rr->len < 3)
+ goto out; /* Something got screwed up here */
+ sig = isonum_721(chr);
+ chr += rr->len;
+ len -= rr->len;
+ if (len < 0)
+ goto out; /* corrupted isofs */
+
+ switch (sig) {
+ case SIG('R', 'R'):
+ if ((rr->u.RR.flags[0] & RR_SL) == 0)
+ goto out;
+ break;
+ case SIG('S', 'P'):
+ CHECK_SP(goto out);
+ break;
+ case SIG('S', 'L'):
+ rpnt = get_symlink_chunk(rpnt, rr,
+ link + (PAGE_SIZE - 1));
+ if (rpnt == NULL)
+ goto out;
+ break;
+ case SIG('C', 'E'):
+ /* This tells is if there is a continuation record */
+ CHECK_CE;
+ default:
+ break;
+ }
+ }
+ MAYBE_CONTINUE(repeat, inode);
+ if (buffer)
+ kfree(buffer);
+
+ if (rpnt == link)
+ goto fail;
+ brelse(bh);
+ *rpnt = '\0';
+ unlock_kernel();
+ SetPageUptodate(page);
+ kunmap(page);
+ unlock_page(page);
+ return 0;
+
+ /* error exit from macro */
+ out:
+ if (buffer)
+ kfree(buffer);
+ goto fail;
+ out_noread:
+ printk("unable to read i-node block");
+ goto fail;
+ out_bad_span:
+ printk("symlink spans iso9660 blocks\n");
+ fail:
+ brelse(bh);
+ unlock_kernel();
+ error:
+ SetPageError(page);
+ kunmap(page);
+ unlock_page(page);
+ return -EIO;
+}
+
+struct address_space_operations isofs_symlink_aops = {
+ .readpage = rock_ridge_symlink_readpage
+};
generated by cgit v1.1 at 2024-12-24 18:28:05 +0000