From c80f9755bbf64c083d04c613980ea84fd2420560 Mon Sep 17 00:00:00 2001
From: Poul-Henning Kamp <phk@FreeBSD.org>
Date: Fri, 2 May 2003 19:58:08 +0000
Subject: [PATCH] Add three global variables which contain the location, size
 and a flag for the alpha checksum, and set them depending on the specified
 architecture

Don't look for disklabels every 16 bytes, look the only place they should
be for the current architecture.

Always read the label from the raw disk and decode it into struct
disklabel rather than trust a cast from random addresses.

When writing to the raw disk, encode the label properly.
---
 sbin/bsdlabel/bsdlabel.c | 57 ++++++++++++++--------------------------
 1 file changed, 20 insertions(+), 37 deletions(-)

diff --git a/sbin/bsdlabel/bsdlabel.c b/sbin/bsdlabel/bsdlabel.c
index 92e78d2dcb5c..60d6caa539a0 100644
--- a/sbin/bsdlabel/bsdlabel.c
+++ b/sbin/bsdlabel/bsdlabel.c
@@ -168,6 +168,10 @@ int	installboot;	/* non-zero if we should install a boot program */
 char	*xxboot;	/* primary boot */
 char	boot0[MAXPATHLEN];
 
+static int labeloffset;
+static int bbsize;
+static int alphacksum;
+
 enum	{
 	UNSPEC, EDIT, READ, RESTORE, WRITE, WRITEBOOT
 } op = UNSPEC;
@@ -210,6 +214,14 @@ main(int argc, char *argv[])
 				xxboot = optarg;
 				break;
 			case 'm':
+				if (!strcmp(optarg, "i386")) {
+					labeloffset = 512;
+					bbsize = 8192;
+				} else if (!strcmp(optarg, "alpha")) {
+					labeloffset = 64;
+					bbsize = 8192;
+					alphacksum = 1;
+				}
 				for (i = 0; i < NARCHES &&
 				    strcmp(arches[i].name, optarg) != 0;
 				    i++);
@@ -409,19 +421,8 @@ writelabel(int f, void *boot, struct disklabel *lp)
 		return (0);
 	}
 
-	/*
-	 * First set the kernel disk label,
-	 * then write a label to the raw disk.
-	 * If the SDINFO ioctl fails because it is unimplemented,
-	 * keep going; otherwise, the kernel consistency checks
-	 * may prevent us from changing the current (in-core)
-	 * label.
-	 */
-	if (ioctl(f, DIOCSDINFO, lp) < 0 &&
-		errno != ENODEV && errno != ENOTTY) {
-		l_perror("ioctl DIOCSDINFO");
-		return (1);
-	}
+	bsd_disklabel_le_enc((u_char *)boot + labeloffset, lp);
+
 	(void)lseek(f, (off_t)0, SEEK_SET);
 	
 	if (arch->arch == ARCH_ALPHA) {
@@ -434,7 +435,7 @@ writelabel(int f, void *boot, struct disklabel *lp)
 	}
 	if (ioctl(f, DIOCBSDBB, &boot) == 0)
 		return (0);
-	if (write(f, boot, lp->d_bbsize) != (int)lp->d_bbsize) {
+	if (write(f, boot, bbsize) != bbsize) {
 		warn("write");
 		return (1);
 	}
@@ -478,30 +479,12 @@ l_perror(const char *s)
 struct disklabel *
 readlabel(int f)
 {
-	struct disklabel *lp;
 
-	if (rflag) {
-		if (read(f, bootarea, BBSIZE) < BBSIZE)
-			err(4, "%s", specname);
-		for (lp = (struct disklabel *)bootarea;
-		    lp <= (struct disklabel *)
-			((char *)bootarea + BBSIZE - sizeof(*lp));
-		    lp = (struct disklabel *)((char *)lp + 16))
-			if (lp->d_magic == DISKMAGIC &&
-			    lp->d_magic2 == DISKMAGIC)
-				break;
-		if (lp > (struct disklabel *)
-		    ((char *)bootarea + BBSIZE - sizeof(*lp)) ||
-		    lp->d_magic != DISKMAGIC || lp->d_magic2 != DISKMAGIC ||
-		    dkcksum(lp) != 0)
-			errx(1,
-	    "bad pack magic number (label is damaged, or pack is unlabeled)");
-	} else {
-		lp = &lab;
-		if (ioctl(f, DIOCGDINFO, lp) < 0)
-			err(4, "ioctl DIOCGDINFO");
-	}
-	return (lp);
+	(void)lseek(f, (off_t)0, SEEK_SET);
+	if (read(f, bootarea, BBSIZE) < BBSIZE)
+		err(4, "%s", specname);
+	bsd_disklabel_le_dec((u_char *)bootarea + labeloffset, &lab);
+	return (&lab);
 }
 
 /*