Change disklabel policy, and allow writing disklabel to any media that does

not carry MacOS fingerprints. Media shared with MacOS will still use the
Apple partition map information, and no native BSD disklabel will be allowed
on it.

1 files changed, 87 insertions, 71 deletions

diff --git a/sys/arch/mac68k/mac68k/disksubr.c b/sys/arch/mac68k/mac68k/disksubr.c
index c10e98b568f..5a193f9a150 100644
--- a/sys/arch/mac68k/mac68k/disksubr.c
+++ b/sys/arch/mac68k/mac68k/disksubr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: disksubr.c,v 1.18 2002/04/18 22:11:41 miod Exp $	*/
+/*	$OpenBSD: disksubr.c,v 1.19 2002/04/21 23:35:33 miod Exp $	*/
 /*	$NetBSD: disksubr.c,v 1.22 1997/11/26 04:18:20 briggs Exp $	*/
 
 /*
@@ -98,23 +98,23 @@
 #define HFS_PART 4
 #define SCRATCH_PART 5
 
-static int getFreeLabelEntry(struct disklabel *);
-static int whichType(struct partmapentry *);
-static void fixPartTable(struct partmapentry *, long, char *, int *);
-static void setRoot(struct partmapentry *, struct disklabel *, int);
-static void setSwap(struct partmapentry *, struct disklabel *, int);
-static void setUfs(struct partmapentry *, struct disklabel *, int);
-static void setHfs(struct partmapentry *, struct disklabel *, int);
-static void setScratch(struct partmapentry *, struct disklabel *, int);
-static int getNamedType(struct partmapentry *, int, struct disklabel *, int, int, int *);
-static char *read_mac_label(dev_t, void (*)(struct buf *),
-		register struct disklabel *, struct cpu_disklabel *);
+int getFreeLabelEntry(struct disklabel *);
+int whichType(struct partmapentry *);
+void fixPartTable(struct partmapentry *, long, char *, int *);
+void setRoot(struct partmapentry *, struct disklabel *, int);
+void setSwap(struct partmapentry *, struct disklabel *, int);
+void setUfs(struct partmapentry *, struct disklabel *, int);
+void setHfs(struct partmapentry *, struct disklabel *, int);
+void setScratch(struct partmapentry *, struct disklabel *, int);
+int getNamedType(struct partmapentry *, int, struct disklabel *, int, int, int *);
+char *read_mac_label(dev_t, void (*)(struct buf *),
+    struct disklabel *, struct cpu_disklabel *);
 
 /*
  * Find an entry in the disk label that is unused and return it
  * or -1 if no entry
  */
-static int 
+int 
 getFreeLabelEntry(lp)
 	struct disklabel *lp;
 {
@@ -132,7 +132,7 @@ getFreeLabelEntry(lp)
 /*
  * figure out what the type of the given part is and return it
  */
-static int 
+int 
 whichType(part)
 	struct partmapentry *part;
 {
@@ -185,7 +185,7 @@ whichType(part)
  * upon.  Make sure names are NUL terminated.  Capitalize the names
  * of part types.
  */
-static void
+void
 fixPartTable(partTable, size, base, num)
 	struct partmapentry *partTable;
 	long size;
@@ -217,7 +217,7 @@ fixPartTable(partTable, size, base, num)
 	}
 }
 
-static void 
+void 
 setRoot(part, lp, slot)
 	struct partmapentry *part;
 	struct disklabel *lp;
@@ -237,7 +237,7 @@ setRoot(part, lp, slot)
 	part->pmPartType[0] = '\0';
 }
 
-static void 
+void 
 setSwap(part, lp, slot)
 	struct partmapentry *part;
 	struct disklabel *lp;
@@ -257,7 +257,7 @@ setSwap(part, lp, slot)
 	part->pmPartType[0] = '\0';
 }
 
-static void 
+void 
 setUfs(part, lp, slot)
 	struct partmapentry *part;
 	struct disklabel *lp;
@@ -277,7 +277,7 @@ setUfs(part, lp, slot)
 	part->pmPartType[0] = '\0';
 }
 
-static void 
+void 
 setHfs(part, lp, slot)
 	struct partmapentry *part;
 	struct disklabel *lp;
@@ -297,7 +297,7 @@ setHfs(part, lp, slot)
 	part->pmPartType[0] = '\0';
 }
 
-static void 
+void 
 setScratch(part, lp, slot)
 	struct partmapentry *part;
 	struct disklabel *lp;
@@ -318,7 +318,7 @@ setScratch(part, lp, slot)
 	part->pmPartType[0] = '\0';
 }
 
-static int 
+int 
 getNamedType(part, num_parts, lp, type, alt, maxslot)
 	struct partmapentry *part;
 	int num_parts;
@@ -380,11 +380,11 @@ skip:
  *	NetBSD to live on cluster 0--regardless of the actual order on the
  *	disk.  This whole algorithm should probably be changed in the future.
  */
-static char *
+char *
 read_mac_label(dev, strat, lp, osdep)
 	dev_t dev;
 	void (*strat)(struct buf *);
-	register struct disklabel *lp;
+	struct disklabel *lp;
 	struct cpu_disklabel *osdep;
 {
 	struct buf *bp;
@@ -392,7 +392,7 @@ read_mac_label(dev, strat, lp, osdep)
 	int i = 0, num_parts = 0, maxslot = 0;
 	struct partmapentry pmap[NUM_PARTS_PROBED];
 
-	bp = geteblk((int) lp->d_secsize * NUM_PARTS_PROBED);
+	bp = geteblk((int)lp->d_secsize * NUM_PARTS_PROBED);
 	bp->b_dev = dev;
 	bp->b_blkno = 1;	/* partition map starts at blk 1 */
 	bp->b_bcount = lp->d_secsize * NUM_PARTS_PROBED;
@@ -465,62 +465,68 @@ done:
  *
  * This will read sector zero.  If this contains what looks like a valid
  * Macintosh boot sector, we attempt to fill in the disklabel structure.
- * If the first longword of the disk is a NetBSD disk label magic number,
+ * If the first longword of the disk is a OpenBSD disk label magic number,
  * then we assume that it's a real disklabel and return it.
  */
 char *
 readdisklabel(dev, strat, lp, osdep, spoofonly)
 	dev_t dev;
 	void (*strat)(struct buf *);
-	register struct disklabel *lp;
+	struct disklabel *lp;
 	struct cpu_disklabel *osdep;
 	int spoofonly;
 {
-	register struct buf *bp;
+	struct buf *bp;
 	char *msg = NULL;
 	struct disklabel *dlp;
 	int i;
 
+	/* minimal requirements for achetypal disk label */
 	if (lp->d_secsize == 0)
 		lp->d_secsize = DEV_BSIZE;
 	if (lp->d_secperunit == 0)
 		lp->d_secperunit = 0x1fffffff;
-
+	if (lp->d_secpercyl == 0)
+		lp->d_secpercyl = 1;
 	lp->d_npartitions = RAW_PART + 1;
 	for (i = 0; i < RAW_PART; i++) {
 		lp->d_partitions[i].p_size = 0;
 		lp->d_partitions[i].p_offset = 0;
 	}
-	if (lp->d_partitions[i].p_size == 0)
-		lp->d_partitions[i].p_size = lp->d_secperunit;
+	if (lp->d_partitions[RAW_PART].p_size == 0)
+		lp->d_partitions[RAW_PART].p_size = lp->d_secperunit;
+	lp->d_partitions[RAW_PART].p_offset = 0;
 
 	/* don't read the on-disk label if we are in spoofed-only mode */
 	if (spoofonly)
 		return (NULL);
 
 	bp = geteblk((int)lp->d_secsize * MAXPARTITIONS);
-
 	bp->b_dev = dev;
 	bp->b_blkno = LABELSECTOR;
-	bp->b_resid = 0;
 	bp->b_bcount = lp->d_secsize;
 	bp->b_flags = B_BUSY | B_READ;
-	bp->b_cylin = 0; /* contained in block 0 */
+	bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
 	(*strat)(bp);
-	if (biowait(bp)) {
-		msg = "I/O error reading block zero";
-	} else {
-		u_int16_t	*sbSigp;
+	if (biowait(bp))
+		msg = "disk label I/O error";
+	else {
+		u_int16_t *sbSigp;
 
-		sbSigp = (u_int16_t *) bp->b_un.b_addr;
+		sbSigp = (u_int16_t *)bp->b_un.b_addr;
 		if (*sbSigp == 0x4552) {
 			msg = read_mac_label(dev, strat, lp, osdep);
 		} else {
-			dlp = (struct disklabel *)(bp->b_un.b_addr + 0);
-			if (dlp->d_magic == DISKMAGIC) {
-				*lp = *dlp;
+			dlp = (struct disklabel *)(bp->b_un.b_addr +
+			    LABELOFFSET);
+			if (dlp->d_magic != DISKMAGIC ||
+			    dlp->d_magic2 != DISKMAGIC) {
+				msg = "no OpenBSD or MacOS disk label";
+			} else if (dlp->d_npartitions > MAXPARTITIONS ||
+			    dkcksum(dlp) != 0) {
+				msg = "disk label corrupted";
 			} else {
-				msg = "no disk label--OpenBSD or Macintosh";
+				*lp = *dlp;
 			}
 		}
 	}
@@ -530,7 +536,7 @@ readdisklabel(dev, strat, lp, osdep, spoofonly)
 		msg = NULL;
 #endif
 
-	bp->b_flags = B_INVAL | B_AGE | B_READ;
+	bp->b_flags = B_INVAL | B_AGE;
 	brelse(bp);
 	return (msg);
 }
@@ -540,17 +546,28 @@ readdisklabel(dev, strat, lp, osdep, spoofonly)
  */
 int
 setdisklabel(olp, nlp, openmask, osdep)
-	register struct disklabel *olp, *nlp;
+	struct disklabel *olp, *nlp;
 	u_long openmask;
 	struct cpu_disklabel *osdep;
 {
-#if 0
-	register i;
-	register struct partition *opp, *npp;
+	int i;
+	struct partition *opp, *npp;
+
+	/* sanity clause */
+	if (nlp->d_secpercyl == 0 || nlp->d_secsize == 0 ||
+	    (nlp->d_secsize % DEV_BSIZE) != 0)
+		return (EINVAL);
+
+	/* special case to allow disklabel to be invalidated */
+	if (nlp->d_magic == 0xffffffff) {
+		*olp = *nlp;
+		return (0);
+	}
 
 	if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC ||
 	    dkcksum(nlp) != 0)
 		return (EINVAL);
+
 	while ((i = ffs((long)openmask)) != 0) {
 		i--;
 		openmask &= ~(1 << i);
@@ -574,28 +591,28 @@ setdisklabel(olp, nlp, openmask, osdep)
 	nlp->d_checksum = 0;
 	nlp->d_checksum = dkcksum(nlp);
 	*olp = *nlp;
-#endif /* #if 0 */
 	return (0);
 }
 
 /*
  * Write disk label back to device after modification.
  *
- *  MF - 8-14-93 This function is never called.  It is here just in case
- *  we want to write dos disklabels some day. Really!
+ * To avaid sperading havoc into the MacOS partition structures, we will
+ * refuse to write a disklabel if the media has a MacOS signature.
+ * Otherwise, it will be 
  */
 int
 writedisklabel(dev, strat, lp, osdep)
 	dev_t dev;
 	void (*strat)(struct buf *);
-	register struct disklabel *lp;
+	struct disklabel *lp;
 	struct cpu_disklabel *osdep;
 {
-#if 0
 	struct buf *bp;
 	struct disklabel *dlp;
 	int labelpart;
 	int error = 0;
+	u_int16_t *sbSigp;
 
 	labelpart = DISKPART(dev);
 	if (lp->d_partitions[labelpart].p_offset != 0) {
@@ -607,30 +624,30 @@ writedisklabel(dev, strat, lp, osdep)
 	bp->b_dev = MAKEDISKDEV(major(dev), DISKUNIT(dev), labelpart);
 	bp->b_blkno = LABELSECTOR;
 	bp->b_bcount = lp->d_secsize;
-	bp->b_flags = B_READ;
+	bp->b_flags = B_BUSY | B_READ;
+	bp->b_cylin = LABELSECTOR / lp->d_secpercyl;
 	(*strat)(bp);
-	if (error = biowait(bp))
+	if ((error = biowait(bp)) != 0)
+		goto done;
+
+	/*
+	 * Check for MacOS fingerprints
+	 */
+	sbSigp = (u_int16_t *)bp->b_un.b_addr;
+	if (*sbSigp == 0x4552) {
+		error = ENODEV;
 		goto done;
-	for (dlp = (struct disklabel *)bp->b_un.b_addr;
-	    dlp <= (struct disklabel *)
-	    (bp->b_un.b_addr + lp->d_secsize - sizeof(*dlp));
-	    dlp = (struct disklabel *)((char *)dlp + sizeof(long))) {
-		if (dlp->d_magic == DISKMAGIC && dlp->d_magic2 == DISKMAGIC &&
-		    dkcksum(dlp) == 0) {
-			*dlp = *lp;
-			bp->b_flags = B_WRITE;
-			(*strat)(bp);
-			error = biowait(bp);
-			goto done;
-		}
 	}
-	error = ESRCH;
+	
+	dlp = (struct disklabel *)(bp->b_un.b_addr + LABELOFFSET);
+	bcopy(lp, dlp, sizeof(struct disklabel));
+	bp->b_flags = B_WRITE;
+	(*strat)(bp);
+	error = biowait(bp);
+
 done:
 	brelse(bp);
 	return (error);
-#else
-	return (ENODEV);
-#endif /* #if 0 */
 }
 
 /*
@@ -707,5 +724,4 @@ dk_establish(dk, dev)
 	struct disk *dk;
 	struct device *dev;
 {
-	/* Empty for now. -- XXX */
 }