Fix scsi_mode_select() and scsi_mode_select_big() to send just the

required number of bytes, rather than a full scsi_mode_sense_buf. Some
devices (e.g. my HP SureStore DAT/24) decline to accept such oversized
transfers. Instead, force callers to fill in the data_length field in
the header and use that information to set the size of the transfer.

4 files changed, 25 insertions, 31 deletions

diff --git a/sys/scsi/cd.c b/sys/scsi/cd.c
index 3428b5f0e82..612262c1f45 100644
--- a/sys/scsi/cd.c
+++ b/sys/scsi/cd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cd.c,v 1.83 2005/06/03 17:29:55 krw Exp $	*/
+/*	$OpenBSD: cd.c,v 1.84 2005/06/05 21:27:07 krw Exp $	*/
 /*	$NetBSD: cd.c,v 1.100 1997/04/02 02:29:30 mycroft Exp $	*/
 
 /*
@@ -1382,12 +1382,10 @@ cd_setchan(cd, p0, p1, p2, p3, flags)
 
 	if (big)
 		error = scsi_mode_select_big(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header_big *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header_big *)&data, flags, 20000);
 	else
 		error = scsi_mode_select(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header *)&data, flags, 20000);
 
 	return (error);
 }
@@ -1455,12 +1453,10 @@ cd_setvol(cd, arg, flags)
 
 	if (big)
 		error = scsi_mode_select_big(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header_big *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header_big *)&data, flags, 20000);
 	else
 		error = scsi_mode_select(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header *)&data, flags, 20000);
 
 	return (error);
 }
@@ -1509,12 +1505,10 @@ cd_set_pa_immed(cd, flags)
 
 	if (big)
 		error = scsi_mode_select_big(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header_big *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header_big *)&data, flags, 20000);
 	else
 		error = scsi_mode_select(cd->sc_link, SMS_PF,
-		    (struct scsi_mode_header *)&data, sizeof(data), flags,
-		    20000);
+		    (struct scsi_mode_header *)&data, flags, 20000);
 
 	return (error);
 }
diff --git a/sys/scsi/scsi_base.c b/sys/scsi/scsi_base.c
index 7c6fa23e255..003ef7bcadd 100644
--- a/sys/scsi/scsi_base.c
+++ b/sys/scsi/scsi_base.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsi_base.c,v 1.79 2005/06/04 01:25:02 krw Exp $	*/
+/*	$OpenBSD: scsi_base.c,v 1.80 2005/06/05 21:27:07 krw Exp $	*/
 /*	$NetBSD: scsi_base.c,v 1.43 1997/04/02 02:29:36 mycroft Exp $	*/
 
 /*
@@ -560,10 +560,9 @@ eight_byte:
 }
 
 int
-scsi_mode_select(sc_link, byte2, data, len, flags, timeout)
+scsi_mode_select(sc_link, byte2, data, flags, timeout)
 	struct scsi_link *sc_link;
 	int byte2, flags, timeout;
-	size_t len;
 	struct scsi_mode_header *data;
 {
 	struct scsi_mode_select scsi_cmd;
@@ -572,13 +571,13 @@ scsi_mode_select(sc_link, byte2, data, len, flags, timeout)
 	bzero(&scsi_cmd, sizeof(scsi_cmd));
 	scsi_cmd.opcode = MODE_SELECT;
 	scsi_cmd.byte2 = byte2;
-	scsi_cmd.length = len & 0xff;
+	scsi_cmd.length = data->data_length + 1; /* 1 == sizeof(data_length) */
 
 	/* Length is reserved when doing mode select so zero it. */
 	data->data_length = 0;
 
 	error = scsi_scsi_cmd(sc_link, (struct scsi_generic *)&scsi_cmd,
-	    sizeof(scsi_cmd), (u_char *)data, len, 4, timeout, NULL,
+	    sizeof(scsi_cmd), (u_char *)data, scsi_cmd.length, 4, timeout, NULL,
 	    flags | SCSI_DATA_OUT);
 
 	SC_DEBUG(sc_link, SDEV_DB2, ("scsi_mode_select: error = %d\n", error));
@@ -587,15 +586,17 @@ scsi_mode_select(sc_link, byte2, data, len, flags, timeout)
 }
 
 int
-scsi_mode_select_big(sc_link, byte2, data, len, flags, timeout)
+scsi_mode_select_big(sc_link, byte2, data, flags, timeout)
 	struct scsi_link *sc_link;
 	int byte2, flags, timeout;
-	size_t len;
 	struct scsi_mode_header_big *data;
 {
 	struct scsi_mode_select_big scsi_cmd;
+	u_int32_t len;
 	int error;
 
+	len = _2btol(data->data_length) + 2; /* 2 == sizeof data->data_length */
+
 	bzero(&scsi_cmd, sizeof(scsi_cmd));
 	scsi_cmd.opcode = MODE_SELECT_BIG;
 	scsi_cmd.byte2 = byte2;
diff --git a/sys/scsi/scsiconf.h b/sys/scsi/scsiconf.h
index 3d169a875fc..520a7c36f61 100644
--- a/sys/scsi/scsiconf.h
+++ b/sys/scsi/scsiconf.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: scsiconf.h,v 1.57 2005/06/03 15:50:10 krw Exp $	*/
+/*	$OpenBSD: scsiconf.h,v 1.58 2005/06/05 21:27:07 krw Exp $	*/
 /*	$NetBSD: scsiconf.h,v 1.35 1997/04/02 02:29:38 mycroft Exp $	*/
 
 /*
@@ -341,9 +341,9 @@ int	scsi_do_mode_sense(struct scsi_link *, int,
 	    struct scsi_mode_sense_buf *, void **, u_int32_t *, u_int64_t *,
 	    u_int32_t *, int, int, int *);
 int	scsi_mode_select(struct scsi_link *, int, struct scsi_mode_header *,
-	    size_t, int, int);
+	    int, int);
 int	scsi_mode_select_big(struct scsi_link *, int,
-	    struct scsi_mode_header_big *, size_t, int, int);
+	    struct scsi_mode_header_big *, int, int);
 void	scsi_done(struct scsi_xfer *);
 void	scsi_user_done(struct scsi_xfer *);
 int	scsi_scsi_cmd(struct scsi_link *, struct scsi_generic *,
diff --git a/sys/scsi/st.c b/sys/scsi/st.c
index 9bdb5ba1204..0cc920021de 100644
--- a/sys/scsi/st.c
+++ b/sys/scsi/st.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: st.c,v 1.46 2005/05/14 00:20:43 krw Exp $	*/
+/*	$OpenBSD: st.c,v 1.47 2005/06/05 21:27:07 krw Exp $	*/
 /*	$NetBSD: st.c,v 1.71 1997/02/21 23:03:49 thorpej Exp $	*/
 
 /*
@@ -1479,7 +1479,6 @@ st_mode_select(st, flags)
 	struct st_softc *st;
 	int flags;
 {
-	u_int scsi_select_len;
 	struct scsi_select {
 		struct scsi_mode_header header;
 		struct scsi_blk_desc blk_desc;
@@ -1487,8 +1486,6 @@ st_mode_select(st, flags)
 	} scsi_select;
 	struct scsi_link *sc_link = st->sc_link;
 
-	scsi_select_len = 12 + st->page_0_size;
-
 	/*
 	 * This quirk deals with drives that have only one valid mode
 	 * and think this gives them license to reject all mode selects,
@@ -1505,9 +1502,12 @@ st_mode_select(st, flags)
 		return 0;
 
 	/*
-	 * Set up for a mode select
+	 * Set up for a mode select. Remember that data_length is the 
+	 * size less the size of the data_length field.
 	 */
-	bzero(&scsi_select, scsi_select_len);
+	bzero(&scsi_select, sizeof(scsi_select));
+	scsi_select.header.data_length = sizeof(scsi_select.header) +
+	    sizeof(scsi_select.blk_desc) + st->page_0_size - 1;
 	scsi_select.header.blk_desc_len = sizeof(struct scsi_blk_desc);
 	scsi_select.header.dev_spec &= ~SMH_DSP_BUFF_MODE;
 	scsi_select.blk_desc.density = st->density;
@@ -1524,8 +1524,7 @@ st_mode_select(st, flags)
 	 * do the command
 	 */
 	return (scsi_mode_select(st->sc_link, 0,
-	    (struct scsi_mode_header *)&scsi_select, scsi_select_len, flags,
-	    ST_CTL_TIME)); 
+	    (struct scsi_mode_header *)&scsi_select, flags, ST_CTL_TIME)); 
 }
 
 /*