allow userspace to modify scsi command filter on per device basis

This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.

Original patch from Peter Jones.

Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 5 insertions, 116 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 78199c08ec9..c5b9bcfc0a6 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -105,120 +105,12 @@ static int sg_emulated_host(struct request_queue *q, int __user *p)
 	return put_user(1, p);
 }
 
-#define CMD_READ_SAFE	0x01
-#define CMD_WRITE_SAFE	0x02
-#define CMD_WARNED	0x04
-#define safe_for_read(cmd)	[cmd] = CMD_READ_SAFE
-#define safe_for_write(cmd)	[cmd] = CMD_WRITE_SAFE
-
-int blk_verify_command(unsigned char *cmd, int has_write_perm)
-{
-	static unsigned char cmd_type[256] = {
-
-		/* Basic read-only commands */
-		safe_for_read(TEST_UNIT_READY),
-		safe_for_read(REQUEST_SENSE),
-		safe_for_read(READ_6),
-		safe_for_read(READ_10),
-		safe_for_read(READ_12),
-		safe_for_read(READ_16),
-		safe_for_read(READ_BUFFER),
-		safe_for_read(READ_DEFECT_DATA),
-		safe_for_read(READ_LONG),
-		safe_for_read(INQUIRY),
-		safe_for_read(MODE_SENSE),
-		safe_for_read(MODE_SENSE_10),
-		safe_for_read(LOG_SENSE),
-		safe_for_read(START_STOP),
-		safe_for_read(GPCMD_VERIFY_10),
-		safe_for_read(VERIFY_16),
-
-		/* Audio CD commands */
-		safe_for_read(GPCMD_PLAY_CD),
-		safe_for_read(GPCMD_PLAY_AUDIO_10),
-		safe_for_read(GPCMD_PLAY_AUDIO_MSF),
-		safe_for_read(GPCMD_PLAY_AUDIO_TI),
-		safe_for_read(GPCMD_PAUSE_RESUME),
-
-		/* CD/DVD data reading */
-		safe_for_read(GPCMD_READ_BUFFER_CAPACITY),
-		safe_for_read(GPCMD_READ_CD),
-		safe_for_read(GPCMD_READ_CD_MSF),
-		safe_for_read(GPCMD_READ_DISC_INFO),
-		safe_for_read(GPCMD_READ_CDVD_CAPACITY),
-		safe_for_read(GPCMD_READ_DVD_STRUCTURE),
-		safe_for_read(GPCMD_READ_HEADER),
-		safe_for_read(GPCMD_READ_TRACK_RZONE_INFO),
-		safe_for_read(GPCMD_READ_SUBCHANNEL),
-		safe_for_read(GPCMD_READ_TOC_PMA_ATIP),
-		safe_for_read(GPCMD_REPORT_KEY),
-		safe_for_read(GPCMD_SCAN),
-		safe_for_read(GPCMD_GET_CONFIGURATION),
-		safe_for_read(GPCMD_READ_FORMAT_CAPACITIES),
-		safe_for_read(GPCMD_GET_EVENT_STATUS_NOTIFICATION),
-		safe_for_read(GPCMD_GET_PERFORMANCE),
-		safe_for_read(GPCMD_SEEK),
-		safe_for_read(GPCMD_STOP_PLAY_SCAN),
-
-		/* Basic writing commands */
-		safe_for_write(WRITE_6),
-		safe_for_write(WRITE_10),
-		safe_for_write(WRITE_VERIFY),
-		safe_for_write(WRITE_12),
-		safe_for_write(WRITE_VERIFY_12),
-		safe_for_write(WRITE_16),
-		safe_for_write(WRITE_LONG),
-		safe_for_write(WRITE_LONG_2),
-		safe_for_write(ERASE),
-		safe_for_write(GPCMD_MODE_SELECT_10),
-		safe_for_write(MODE_SELECT),
-		safe_for_write(LOG_SELECT),
-		safe_for_write(GPCMD_BLANK),
-		safe_for_write(GPCMD_CLOSE_TRACK),
-		safe_for_write(GPCMD_FLUSH_CACHE),
-		safe_for_write(GPCMD_FORMAT_UNIT),
-		safe_for_write(GPCMD_REPAIR_RZONE_TRACK),
-		safe_for_write(GPCMD_RESERVE_RZONE_TRACK),
-		safe_for_write(GPCMD_SEND_DVD_STRUCTURE),
-		safe_for_write(GPCMD_SEND_EVENT),
-		safe_for_write(GPCMD_SEND_KEY),
-		safe_for_write(GPCMD_SEND_OPC),
-		safe_for_write(GPCMD_SEND_CUE_SHEET),
-		safe_for_write(GPCMD_SET_SPEED),
-		safe_for_write(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL),
-		safe_for_write(GPCMD_LOAD_UNLOAD),
-		safe_for_write(GPCMD_SET_STREAMING),
-	};
-	unsigned char type = cmd_type[cmd[0]];
-
-	/* Anybody who can open the device can do a read-safe command */
-	if (type & CMD_READ_SAFE)
-		return 0;
-
-	/* Write-safe commands just require a writable open.. */
-	if ((type & CMD_WRITE_SAFE) && has_write_perm)
-		return 0;
-
-	/* And root can do any command.. */
-	if (capable(CAP_SYS_RAWIO))
-		return 0;
-
-	if (!type) {
-		cmd_type[cmd[0]] = CMD_WARNED;
-		printk(KERN_WARNING "scsi: unknown opcode 0x%02x\n", cmd[0]);
-	}
-
-	/* Otherwise fail it with an "Operation not permitted" */
-	return -EPERM;
-}
-EXPORT_SYMBOL_GPL(blk_verify_command);
-
 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
-			     struct sg_io_hdr *hdr, int has_write_perm)
+			     struct sg_io_hdr *hdr, struct file *file)
 {
 	if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
 		return -EFAULT;
-	if (blk_verify_command(rq->cmd, has_write_perm))
+	if (blk_verify_command(file, rq->cmd))
 		return -EPERM;
 
 	/*
@@ -287,7 +179,7 @@ static int sg_io(struct file *file, struct request_queue *q,
 		struct gendisk *bd_disk, struct sg_io_hdr *hdr)
 {
 	unsigned long start_time;
-	int writing = 0, ret = 0, has_write_perm = 0;
+	int writing = 0, ret = 0;
 	struct request *rq;
 	char sense[SCSI_SENSE_BUFFERSIZE];
 	struct bio *bio;
@@ -316,10 +208,7 @@ static int sg_io(struct file *file, struct request_queue *q,
 	if (!rq)
 		return -ENOMEM;
 
-	if (file)
-		has_write_perm = file->f_mode & FMODE_WRITE;
-
-	if (blk_fill_sghdr_rq(q, rq, hdr, has_write_perm)) {
+	if (blk_fill_sghdr_rq(q, rq, hdr, file)) {
 		blk_put_request(rq);
 		return -EFAULT;
 	}
@@ -451,7 +340,7 @@ int sg_scsi_ioctl(struct file *file, struct request_queue *q,
 	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
 		goto error;
 
-	err = blk_verify_command(rq->cmd, file->f_mode & FMODE_WRITE);
+	err = blk_verify_command(file, rq->cmd);
 	if (err)
 		goto error;