It turns out you need to ask for 16 byte block descriptors. We don't,

so eliminate code dealing with 16 byte block descriptors. No one else
seems to use them anyway. Add define for appropriate permission bit in
case we ever need it.

Simplify and clean up scsi_do_mode_sense() code as a result.

Strengthen check to ensure block descriptor data is a valid by
checking if it is a multiple of 8 bytes rather than just > 8 bytes.

Moves code to closer to what it was before scsi_do_mode_sense().

2 files changed, 37 insertions, 52 deletions

diff --git a/sys/scsi/scsi_all.h b/sys/scsi/scsi_all.h
index 16dee41469c..25ebe9d3c7e 100644
--- a/sys/scsi/scsi_all.h
+++ b/sys/scsi/scsi_all.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsi_all.h,v 1.25 2005/06/03 15:50:10 krw Exp $	*/
+/*	$OpenBSD: scsi_all.h,v 1.26 2005/06/12 21:40:05 krw Exp $	*/
 /*	$NetBSD: scsi_all.h,v 1.10 1996/09/12 01:57:17 thorpej Exp $	*/
 
 /*
@@ -88,7 +88,7 @@ struct scsi_inquiry {
 struct scsi_mode_sense {
 	u_int8_t opcode;
 	u_int8_t byte2;
-#define	SMS_DBD				0x08
+#define	SMS_DBD				0x08	/* Disable Block Descriptors */
 	u_int8_t page;
 #define	SMS_PAGE_CODE 			0x3F
 #define	SMS_PAGE_CTRL 			0xC0
@@ -103,8 +103,9 @@ struct scsi_mode_sense {
 
 struct scsi_mode_sense_big {
 	u_int8_t opcode;
-	u_int8_t byte2;		/* same bits as small version */
-	u_int8_t page; 		/* same bits as small version */
+	u_int8_t byte2;				/* same bits as small version */
+#define SMS_LLBAA			0x10	/*    plus: Long LBA Accepted */
+	u_int8_t page;				/* same bits as small version */
 	u_int8_t unused[4];
 	u_int8_t length[2];
 	u_int8_t control;
diff --git a/sys/scsi/scsi_base.c b/sys/scsi/scsi_base.c
index f0b686f262a..5080605d2a5 100644
--- a/sys/scsi/scsi_base.c
+++ b/sys/scsi/scsi_base.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsi_base.c,v 1.81 2005/06/09 00:16:09 krw Exp $	*/
+/*	$OpenBSD: scsi_base.c,v 1.82 2005/06/12 21:40:05 krw Exp $	*/
 /*	$NetBSD: scsi_base.c,v 1.43 1997/04/02 02:29:36 mycroft Exp $	*/
 
 /*
@@ -464,13 +464,9 @@ scsi_do_mode_sense(sc_link, page, buf, page_data, density, block_count,
 	u_int64_t *block_count;
 	void **page_data;
 {
-	struct scsi_mode_blk_desc_big *desc_big;
 	struct scsi_mode_direct_blk_desc *direct;
-	struct scsi_mode_header_big *hdr_big;
-	struct scsi_mode_header *hdr;
 	struct scsi_blk_desc *general;
-	u_char *cbuf = (u_char *)buf;
-	int error, blk_desc_len;
+	int error, blk_desc_len, offset;
 	
 	*page_data = NULL;
 
@@ -483,60 +479,47 @@ scsi_do_mode_sense(sc_link, page, buf, page_data, density, block_count,
 	if (big)
 		*big = 0;
 
-	/* Try 10 byte mode sense request. Don't bother with SMS_DBD. */
+	/*
+	 * Try 10 byte mode sense request. Don't bother with SMS_DBD or
+	 * SMS_LLBAA.
+	 */
 	error = scsi_mode_sense_big(sc_link, 0, page, &buf->headers.hdr_big,
 	    sizeof(*buf), flags, 20000);
-	hdr_big = &buf->headers.hdr_big;
-	if (error == 0 && _2btol(hdr_big->data_length) > 0) {
+
+	if (error == 0 && _2btol(buf->headers.hdr_big.data_length) > 0) {
 		if (big)
 			*big = 1;
-		cbuf += sizeof(struct scsi_mode_header_big);
-		*page_data = scsi_mode_sense_big_page(hdr_big, page_len);
-		blk_desc_len = _2btol(hdr_big->blk_desc_len);
-		if ((hdr_big->reserved & LONGLBA) == 0)
-			goto eight_byte;
-		/* 16 byte block descriptors. */
-		if (blk_desc_len < sizeof(struct scsi_mode_blk_desc_big))
-			return (0);
-		desc_big = (struct scsi_mode_blk_desc_big *)cbuf;
-		if (density)
-			*density = desc_big->density;
-		if (block_size)
-			*block_size = _4btol(desc_big->blklen);
-		if (block_count)
-			*block_count = _8btol(desc_big->nblocks);
-		return (0);
+		offset = sizeof(struct scsi_mode_header_big);
+		*page_data = scsi_mode_sense_big_page(&buf->headers.hdr_big,
+		    page_len);
+		blk_desc_len = _2btol(buf->headers.hdr_big.blk_desc_len);
+	} else {
+		/*
+		 * Try 6 byte mode sense request. Don't bother with SMS_DBD.
+		 */
+		if (sc_link->flags & SDEV_ONLYBIG)
+			return (EIO);
+		error = scsi_mode_sense(sc_link, 0, page, &buf->headers.hdr,
+		    sizeof(*buf), flags, 20000);
+		if (error != 0)
+			return (error);
+		if (buf->headers.hdr.data_length == 0)
+			return (EIO);
+		offset = sizeof(struct scsi_mode_header);
+		*page_data = scsi_mode_sense_page(&buf->headers.hdr, page_len);
+		blk_desc_len = buf->headers.hdr.blk_desc_len;
 	}
 
-	if (sc_link->flags & SDEV_ONLYBIG)
-		return (EIO);
-
-	/* Try 6 byte mode sense request. Don't bother with SMS_DBD. */
-	error = scsi_mode_sense(sc_link, 0, page, &buf->headers.hdr,
-	    sizeof(*buf), flags, 20000);
-	if (error != 0)
-		return (error);
-
-	hdr = &buf->headers.hdr;
-	if (hdr->data_length == 0)
-		return (EIO);
-		
-	cbuf += sizeof(struct scsi_mode_header);
-	*page_data = scsi_mode_sense_page(hdr, page_len);
-	blk_desc_len = hdr->blk_desc_len;
-
-eight_byte:			
 	/* Both scsi_blk_desc and scsi_mode_direct_blk_desc are 8 bytes. */
-	if (blk_desc_len < sizeof(struct scsi_mode_direct_blk_desc))
+	if (blk_desc_len == 0 || (blk_desc_len % 8 != 0))
 		return (0);
 
 	switch (sc_link->inqdata.device & SID_TYPE) {
 	case T_SEQUENTIAL:
 		/*
-		 * XXX What other device types will return general block
-		 * descriptors other than tape drives?
+		 * XXX What other device types return general block descriptors?
 		 */
-		general = (struct scsi_blk_desc *)cbuf;	
+		general = (struct scsi_blk_desc *)&buf->headers.buf[offset];	
 		if (density)
 			*density = general->density;
 		if (block_size)
@@ -546,7 +529,8 @@ eight_byte:
 		break;
 
 	default:
-		direct = (struct scsi_mode_direct_blk_desc *)cbuf;	
+		direct = (struct scsi_mode_direct_blk_desc *)&buf->
+		    headers.buf[offset];
 		if (density)
 			*density = direct->density;
 		if (block_size)