*vc-diff*.diff

diff --git a/sbin/disklabel64/disklabel64.c b/sbin/disklabel64/disklabel64.c
index afd77ec..05d4747 100644
--- a/sbin/disklabel64/disklabel64.c
+++ b/sbin/disklabel64/disklabel64.c
@@ -119,8 +119,11 @@ extern uint32_t crc32(const void *buf, size_t size);
 #define BIG_NEWFS_FRAG   2048U
 #define BIG_NEWFS_CPG    64U
 
+#define PARTOFF(p)	(parts[p-1].dp_start * 512LU)
+
 void	makelabel(const char *, const char *, struct disklabel64 *);
 int	writelabel(int, struct disklabel64 *);
+static void readpartdata(int);
 void	l_perror(const char *);
 struct disklabel64 *readlabel(int);
 struct disklabel64 *makebootarea(int);
@@ -140,6 +143,7 @@ struct disklabel64 *getvirginlabel(void);
 #define	DEFEDITOR	_PATH_VI
 #define	streq(a,b)	(strcmp(a,b) == 0)
 
+int	is_file;
 char	*dkname;
 char	*specname;
 char	tmpfil[] = PATH_TMPFILE;
@@ -151,7 +155,9 @@ struct	disklabel64 lab;
 char    part_size_type[MAX_NUM_PARTS];
 char    part_offset_type[MAX_NUM_PARTS];
 int     part_set[MAX_NUM_PARTS];
+struct dos_partition parts[4];
 
+int	partition;
 int	installboot;	/* non-zero if we should install a boot program */
 int	boot1size;
 int	boot1lsize;
@@ -172,15 +178,16 @@ u_int32_t slice_start_lba;
 
 #ifdef DEBUG
 int	debug;
-#define OPTIONS	"BNRWb:denrs:Vw"
+#define OPTIONS	"BNRWb:denrs:Vwp:"
 #else
-#define OPTIONS	"BNRWb:enrs:Vw"
+#define OPTIONS	"BNRWb:enrs:Vwp:"
 #endif
 
 int
 main(int argc, char *argv[])
 {
 	struct disklabel64 *lp;
+	struct stat st;
 	FILE *t;
 	int ch, f = 0, flag, error = 0;
 	char *name = NULL;
@@ -231,6 +238,12 @@ main(int argc, char *argv[])
 					usage();
 				op = WRITE;
 				break;
+			case 'p':
+				partition = strtol(optarg, NULL, 10);
+				if (partition < 1 || partition > 4)
+					usage();
+				break;
+
 #ifdef DEBUG
 			case 'd':
 				debug++;
@@ -255,12 +268,31 @@ main(int argc, char *argv[])
 	if (argc < 1)
 		usage();
 
-	dkname = getdevpath(argv[0], 0);
-	specname = dkname;
+	/*
+	 * Check if we're passed a regular file. If so, set
+	 * rflag as this is the only way to operate it, ioctl(2)
+	 * won't work.
+	 */
+	if ((stat(argv[0], &st) != -1)
+	    && (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode))) {
+		is_file = 1;
+		rflag++;
+		specname = argv[0];
+	} else {
+		dkname = getdevpath(argv[0], 0);
+		specname = dkname;
+	}
 	f = open(specname, op == READ ? O_RDONLY : O_RDWR);
 	if (f < 0)
 		err(4, "%s", specname);
 
+	/*
+	 * Read in all DOS partitions, starting sector
+	 * offsets will be needed later on.
+	 */
+	if (is_file)
+		readpartdata(f);
+
 	switch(op) {
 
 	case UNSPEC:
@@ -275,7 +307,9 @@ main(int argc, char *argv[])
 
 	case NOWRITE:
 		flag = 0;
-		if (ioctl(f, DIOCWLABEL, (char *)&flag) < 0)
+		if (is_file)
+			errx(4, "can't disable label writing for files");
+		else if (ioctl(f, DIOCWLABEL, (char *)&flag) < 0)
 			err(4, "ioctl DIOCWLABEL");
 		break;
 
@@ -329,7 +363,9 @@ main(int argc, char *argv[])
 
 	case WRITEABLE:
 		flag = 1;
-		if (ioctl(f, DIOCWLABEL, (char *)&flag) < 0)
+		if (is_file)
+			errx(4, "can't enable label writing for files");
+		else if (ioctl(f, DIOCWLABEL, (char *)&flag) < 0)
 			err(4, "ioctl DIOCWLABEL");
 		break;
 
@@ -353,6 +389,26 @@ main(int argc, char *argv[])
 }
 
 /*
+ * Read dos partitions from file
+ */
+static
+void
+readpartdata(int f)
+{
+	char buf[512];
+	ssize_t bytes;
+
+	/*
+	 * Read in DOS partitions to get the start offset
+	 * for each one of them.
+	 */
+	if ((bytes = read(f, buf, 512)) < 512)
+		errx(1, "Unexpected error when reading from file %s\n",
+		    specname);
+	memcpy(parts, &buf[DOSPARTOFF], sizeof(parts));
+}
+
+/*
  * Construct a prototype disklabel from /etc/disktab.  As a side
  * effect, set the names of the primary and secondary boot files
  * if specified.
@@ -422,12 +478,19 @@ writelabel(int f, struct disklabel64 *lp)
 			 * consistency checks may prevent us from changing
 			 * the current (in-core) label.
 			 */
-			if (ioctl(f, DIOCSDINFO64, lp) < 0 &&
-				errno != ENODEV && errno != ENOTTY) {
-				l_perror("ioctl DIOCSDINFO");
-				return (1);
+			if (is_file) {
+				/* Seek file descriptor f to the desired offset */
+				if (lseek(f, PARTOFF(partition), SEEK_SET) < 0)
+					err(1, "lseek");
+			} else {
+				if (ioctl(f, DIOCSDINFO64, lp) < 0 &&
+				    errno != ENODEV && errno != ENOTTY) {
+					l_perror("ioctl DIOCSDINFO");
+					return (1);
+				}
+				lseek(f, (off_t)0, SEEK_SET);
 			}
-			lseek(f, (off_t)0, SEEK_SET);
+
 
 			/*
 			 * The disklabel embeds areas which we may not
@@ -440,13 +503,13 @@ writelabel(int f, struct disklabel64 *lp)
 				      sizeof(*lp) -
 				      offsetof(struct disklabel64, d_magic));
 			}
-			
+
 			/*
 			 * write enable label sector before write
 			 * (if necessary), disable after writing.
 			 */
 			flag = 1;
-			if (ioctl(f, DIOCWLABEL, &flag) < 0)
+			if (!is_file && (ioctl(f, DIOCWLABEL, &flag) < 0))
 				warn("ioctl DIOCWLABEL");
 
 			r = write(f, boot1buf, boot1lsize);
@@ -465,8 +528,10 @@ writelabel(int f, struct disklabel64 *lp)
 					return(1);
 				}
 			}
-			flag = 0;
-			ioctl(f, DIOCWLABEL, &flag);
+			if (!is_file) {
+				flag = 0;
+				ioctl(f, DIOCWLABEL, &flag);
+			}
 		} else if (ioctl(f, DIOCWDINFO64, lp) < 0) {
 			l_perror("ioctl DIOCWDINFO64");
 			return (1);
@@ -579,6 +644,12 @@ makebootarea(int f)
 	else
 		secsize = 512;
 
+	if (is_file) {
+		/* Seek file descriptor f to the desired offset */
+		if (lseek(f, PARTOFF(partition), SEEK_SET) < 0)
+			err(1, "lseek");
+	}
+
 	if (boot1buf == NULL) {
 		size_t rsize;
 
@@ -1470,6 +1541,47 @@ checklabel(struct disklabel64 *lp)
 }
 
 /*
+ * Create a dummy disklabel for files
+ */
+static
+void
+getvirginlabel_file(struct disklabel64 *lp)
+{
+	struct stat st;
+	uint32_t blksize = 4096;	/* XXX - hardcoding defaults uh? */
+	uint32_t ressize;
+	uint64_t blkmask = blksize - 1;
+	size_t lpcrcsize;
+
+	if (lp == NULL)
+		return;
+
+	bzero(lp, sizeof(*lp));
+	if (stat(specname, &st) < 0)
+		err(1, "Failed to stat file");
+	lp->d_total_size = st.st_size;
+	lp->d_magic = DISKMAGIC64;
+	lp->d_align = blksize;
+	lp->d_npartitions = MAXPARTITIONS64;
+	uuidgen(&lp->d_stor_uuid, 1);
+
+	ressize = offsetof(struct disklabel64, d_partitions[RESPARTITIONS64]);
+	ressize = (ressize + (uint32_t)blkmask) & ~blkmask;
+
+	lp->d_bbase = ressize;
+//	lp->d_pbase = lp->d_bbase + ((32768 + blkmask) & ~blkmask);
+//	lp->d_pbase = (lp->d_pbase + PALIGN_MASK) & ~(uint64_t)PALIGN_MASK;
+
+	lp->d_pbase += 32768 - (PARTOFF(partition)) % 32768;
+	lp->d_pstop = (lp->d_total_size - lp->d_bbase) & ~blkmask;
+	lp->d_abase = lp->d_pstop;
+	lpcrcsize = offsetof(struct disklabel64,
+	    d_partitions[lp->d_npartitions]) -
+	    offsetof(struct disklabel64, d_magic);
+	lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
+}
+
+/*
  * When operating on a "virgin" disk, try getting an initial label
  * from the associated device driver.  This might work for all device
  * drivers that are able to fetch some initial device parameters
@@ -1486,6 +1598,11 @@ getvirginlabel(void)
 	struct disklabel64 *dl = &dlab;
 	int f;
 
+	if (is_file) {
+		getvirginlabel_file(dl);
+		return (dl);
+	}
+
 	if ((f = open(dkname, O_RDONLY)) == -1) {
 		warn("cannot open %s", dkname);
 		return (NULL);