Annotation of sys/isofs/udf/udf_subr.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: udf_subr.c,v 1.13 2007/06/08 05:35:32 deraadt Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 2006, Miodrag Vallat
! 5: * Copyright (c) 2006, Pedro Martelletto
! 6: *
! 7: * Redistribution and use in source and binary forms, with or without
! 8: * modification, are permitted provided that the following conditions
! 9: * are met:
! 10: * 1. Redistributions of source code must retain the above copyright
! 11: * notice, this list of conditions and the following disclaimer.
! 12: * 2. Redistributions in binary form must reproduce the above copyright
! 13: * notice, this list of conditions and the following disclaimer in the
! 14: * documentation and/or other materials provided with the distribution.
! 15: *
! 16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
! 18: * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
! 19: * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
! 20: * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
! 21: * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
! 22: * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
! 24: * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
! 25: * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
! 26: * POSSIBILITY OF SUCH DAMAGE.
! 27: */
! 28:
! 29: #include <sys/param.h>
! 30: #include <sys/systm.h>
! 31: #include <sys/buf.h>
! 32: #include <sys/kernel.h>
! 33: #include <sys/malloc.h>
! 34: #include <sys/mutex.h>
! 35: #include <sys/stat.h>
! 36: #include <sys/mount.h>
! 37: #include <sys/vnode.h>
! 38: #include <sys/dirent.h>
! 39: #include <sys/unistd.h>
! 40: #include <sys/disklabel.h>
! 41:
! 42: #include <isofs/udf/ecma167-udf.h>
! 43: #include <isofs/udf/udf.h>
! 44: #include <isofs/udf/udf_extern.h>
! 45:
! 46: int udf_vat_read(struct umount *, uint32_t *);
! 47:
! 48: /*
! 49: * Convert a CS0 dstring to a 16-bit Unicode string.
! 50: * Returns the length of the Unicode string, in unicode characters (not
! 51: * bytes!), or -1 if an error arises.
! 52: * Note that the transname destination buffer is expected to be large
! 53: * enough to hold the result, and will not be terminated in any way.
! 54: */
! 55: int
! 56: udf_rawnametounicode(u_int len, char *cs0string, unicode_t *transname)
! 57: {
! 58: unicode_t *origname = transname;
! 59:
! 60: if (len-- == 0)
! 61: return (-1);
! 62:
! 63: switch (*cs0string++) {
! 64: case 8: /* bytes string */
! 65: while (len-- != 0)
! 66: *transname++ = (unicode_t)*cs0string++;
! 67: break;
! 68: case 16: /* 16 bit unicode string */
! 69: if (len & 1)
! 70: return (-1);
! 71: len >>= 1;
! 72: while (len-- != 0) {
! 73: unicode_t tmpchar;
! 74:
! 75: tmpchar = (unicode_t)*cs0string++;
! 76: tmpchar = (tmpchar << 8) | (unicode_t)*cs0string++;
! 77: *transname++ = tmpchar;
! 78: }
! 79: break;
! 80: default:
! 81: return (-1);
! 82: }
! 83:
! 84: return (transname - origname);
! 85: }
! 86:
! 87: /*
! 88: * Do a lazy probe on the underlying media to check if it's a UDF volume, in
! 89: * which case we fake a disk label for it.
! 90: */
! 91: int
! 92: udf_disklabelspoof(dev_t dev, void (*strat)(struct buf *),
! 93: struct disklabel *lp)
! 94: {
! 95: char vid[32];
! 96: int i, bsize = 2048, error = EINVAL;
! 97: uint32_t sector = 256, mvds_start, mvds_end;
! 98: struct buf *bp;
! 99: struct anchor_vdp avdp;
! 100: struct pri_vol_desc *pvd;
! 101:
! 102: /*
! 103: * Get a buffer to work with.
! 104: */
! 105: bp = geteblk(bsize);
! 106: bp->b_dev = dev;
! 107:
! 108: /*
! 109: * Look for an Anchor Volume Descriptor at sector 256.
! 110: */
! 111: bp->b_blkno = sector * btodb(bsize);
! 112: bp->b_bcount = bsize;
! 113: bp->b_flags = B_BUSY | B_READ;
! 114: bp->b_resid = bp->b_blkno / lp->d_secpercyl;
! 115:
! 116: (*strat)(bp);
! 117: if (biowait(bp))
! 118: goto out;
! 119:
! 120: if (udf_checktag((struct desc_tag *)bp->b_data, TAGID_ANCHOR))
! 121: goto out;
! 122:
! 123: bcopy(bp->b_data, &avdp, sizeof(avdp));
! 124: mvds_start = letoh32(avdp.main_vds_ex.loc);
! 125: mvds_end = mvds_start + (letoh32(avdp.main_vds_ex.len) - 1) / bsize;
! 126:
! 127: /*
! 128: * Then try to find a reference to a Primary Volume Descriptor.
! 129: */
! 130: for (sector = mvds_start; sector < mvds_end; sector++) {
! 131: bp->b_blkno = sector * btodb(bsize);
! 132: bp->b_bcount = bsize;
! 133: bp->b_flags = B_BUSY | B_READ;
! 134: bp->b_resid = bp->b_blkno / lp->d_secpercyl;
! 135:
! 136: (*strat)(bp);
! 137: if (biowait(bp))
! 138: goto out;
! 139:
! 140: pvd = (struct pri_vol_desc *)bp->b_data;
! 141: if (!udf_checktag(&pvd->tag, TAGID_PRI_VOL))
! 142: break;
! 143: }
! 144:
! 145: /*
! 146: * If we couldn't find a reference, bail out.
! 147: */
! 148: if (sector == mvds_end)
! 149: goto out;
! 150:
! 151: /*
! 152: * Okay, it's a UDF volume. Spoof a disk label for it.
! 153: */
! 154: if (udf_transname(pvd->vol_id, vid, sizeof(pvd->vol_id) - 1, NULL))
! 155: strlcpy(lp->d_typename, vid, sizeof(lp->d_typename));
! 156:
! 157: for (i = 0; i < MAXPARTITIONS; i++) {
! 158: DL_SETPSIZE(&lp->d_partitions[i], 0);
! 159: DL_SETPOFFSET(&lp->d_partitions[i], 0);
! 160: }
! 161:
! 162: /*
! 163: * Fake two partitions, 'a' and 'c'.
! 164: */
! 165: DL_SETPSIZE(&lp->d_partitions[0], DL_GETDSIZE(lp));
! 166: lp->d_partitions[0].p_fstype = FS_UDF;
! 167: DL_SETPSIZE(&lp->d_partitions[RAW_PART], DL_GETDSIZE(lp));
! 168: lp->d_partitions[RAW_PART].p_fstype = FS_UDF;
! 169: lp->d_npartitions = RAW_PART + 1;
! 170: lp->d_version = 1;
! 171:
! 172: lp->d_bbsize = 8192; /* Fake. */
! 173: lp->d_sbsize = 64*1024; /* Fake. */
! 174: lp->d_magic = DISKMAGIC;
! 175: lp->d_magic2 = DISKMAGIC;
! 176: lp->d_checksum = dkcksum(lp);
! 177:
! 178: error = 0;
! 179: out:
! 180: bp->b_flags |= B_INVAL;
! 181: brelse(bp);
! 182:
! 183: return (error);
! 184: }
! 185:
! 186: /* Get a vnode for the Virtual Allocation Table (VAT) */
! 187: int
! 188: udf_vat_get(struct umount *ump, uint32_t lb)
! 189: {
! 190: struct vnode *vp;
! 191: struct unode *up;
! 192: int error;
! 193:
! 194: error = udf_vget(ump->um_mountp, lb - ump->um_start - 3, &vp);
! 195: if (error)
! 196: return (error);
! 197:
! 198: up = VTOU(vp);
! 199: up->u_vatlen = (letoh64(up->u_fentry->inf_len) - 36) >> 2;
! 200:
! 201: ump->um_vat = malloc(sizeof(struct unode), M_UDFMOUNT, M_WAITOK);
! 202: *ump->um_vat = *up;
! 203:
! 204: ump->um_flags &= ~UDF_MNT_FIND_VAT;
! 205: ump->um_flags |= UDF_MNT_USES_VAT;
! 206:
! 207: vput(vp);
! 208:
! 209: return (0);
! 210: }
! 211:
! 212: /* Look up a sector in the VAT */
! 213: int
! 214: udf_vat_map(struct umount *ump, uint32_t *sector)
! 215: {
! 216: /* If there's no VAT, then it's easy */
! 217: if (!(ump->um_flags & UDF_MNT_USES_VAT)) {
! 218: *sector += ump->um_start;
! 219: return (0);
! 220: }
! 221:
! 222: /* Sanity check the given sector */
! 223: if (*sector >= ump->um_vat->u_vatlen)
! 224: return (EINVAL);
! 225:
! 226: return (udf_vat_read(ump, sector));
! 227: }
! 228:
! 229: /* Read from the VAT */
! 230: int
! 231: udf_vat_read(struct umount *ump, uint32_t *sector)
! 232: {
! 233: struct buf *bp;
! 234: uint8_t *data;
! 235: int error, size;
! 236:
! 237: size = 4;
! 238:
! 239: /*
! 240: * Note that we rely on the buffer cache to keep frequently accessed
! 241: * buffers around to avoid reading them from the disk all the time.
! 242: */
! 243: error = udf_readatoffset(ump->um_vat, &size, *sector << 2, &bp, &data);
! 244: if (error) {
! 245: if (bp != NULL)
! 246: brelse(bp);
! 247:
! 248: return (error);
! 249: }
! 250:
! 251: /* Make sure we read at least a whole entry */
! 252: if (size < 4) {
! 253: if (bp != NULL)
! 254: brelse(bp);
! 255:
! 256: return (EINVAL);
! 257: }
! 258:
! 259: /* Map the sector */
! 260: *sector = letoh32(*(uint32_t *)data) + ump->um_start;
! 261:
! 262: brelse(bp);
! 263:
! 264: return (0);
! 265: }
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