Use ata_id, not scsi_id, on ATAPI devices

The major benefit here, is that we get the ATAPI device serial
number. With SCSI ID we didn't get this since it's not part of the
SCSI INQUIRY command. Specifically this means that we get symlinks to
empty optical drives, e.g.

 /dev/disk/by-id/ata-VBOX_CD-ROM_VB2-01700376

which we didn't get earlier. So this is a major win.

Also make ata_id work on CD-ROM devices when using /dev/bsg nodes so
this works on both the scsi_device as well as the block device. We do
this, basically, by issuing the ATA IDENTIFY PACKET DEVICE command
instead of the ATA IDENTIFY command. We also use 16-byte pass-through
ATA passthrough instead of 12-byte passthrough to avoid clashing with
the MMC BLANK command.

This means that we get this output

 # udevadm info -q all -p /sys/devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 P: /devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 E: UDEV_LOG=3
 E: DEVPATH=/devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 E: DEVTYPE=scsi_device
 E: DRIVER=sr
 E: MODALIAS=scsi:t-0x05
 E: SUBSYSTEM=scsi
 E: ID_ATA=1
 E: ID_TYPE=cd
 E: ID_BUS=ata
 E: ID_MODEL=VBOX_CD-ROM
 E: ID_MODEL_ENC=VBOX\x20CD-ROM\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x 20\x20\x20\x20\x20\x20\x20
 E: ID_REVISION=1.0
 E: ID_SERIAL=VBOX_CD-ROM_VB2-01700376
 E: ID_SERIAL_SHORT=VB2-01700376

instead of just

 # udevadm info -q all -p /sys/devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 P: /devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 E: UDEV_LOG=3
 E: DEVPATH=/devices/pci0000:00/0000:00:01.1/host3/target3:0:0/3:0:0:0
 E: DEVTYPE=scsi_device
 E: DRIVER=sr
 E: MODALIAS=scsi:t-0x05
 E: SUBSYSTEM=scsi
 E: ID_SCSI=1
 E: ID_VENDOR=VBOX
 E: ID_VENDOR_ENC=VBOX\x20\x20\x20\x20
 E: ID_MODEL=CD-ROM
 E: ID_MODEL_ENC=CD-ROM\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20
 E: ID_REVISION=1.0
 E: ID_TYPE=cd

Signed-off-by: David Zeuthen <davidz@redhat.com>

1 files changed, 110 insertions, 12 deletions

diff --git a/extras/ata_id/ata_id.c b/extras/ata_id/ata_id.c
index 41544e922e..92387e5077 100644
--- a/extras/ata_id/ata_id.c
+++ b/extras/ata_id/ata_id.c
@@ -202,6 +202,89 @@ static int disk_identify_command(int	  fd,
 	return ret;
 }
 
+static int disk_identify_packet_device_command(int	  fd,
+					       void	 *buf,
+					       size_t	  buf_len)
+{
+	struct sg_io_v4 io_v4;
+	uint8_t cdb[16];
+	uint8_t sense[32];
+	uint8_t *desc = sense+8;
+	int ret;
+
+	/*
+	 * ATA Pass-Through 16 byte command, as described in
+	 *
+	 *  T10 04-262r8 ATA Command Pass-Through
+	 *
+	 * from http://www.t10.org/ftp/t10/document.04/04-262r8.pdf
+	 */
+	memset(cdb, 0, sizeof(cdb));
+	cdb[0] = 0x85;			/* OPERATION CODE: 16 byte pass through */
+	cdb[1] = 4 << 1;		/* PROTOCOL: PIO Data-in */
+	cdb[2] = 0x2e;			/* OFF_LINE=0, CK_COND=1, T_DIR=1, BYT_BLOK=1, T_LENGTH=2 */
+	cdb[3] = 0;			/* FEATURES */
+	cdb[4] = 0;			/* FEATURES */
+	cdb[5] = 0;			/* SECTORS */
+	cdb[6] = 1;			/* SECTORS */
+	cdb[7] = 0;			/* LBA LOW */
+	cdb[8] = 0;			/* LBA LOW */
+	cdb[9] = 0;			/* LBA MID */
+	cdb[10] = 0;			/* LBA MID */
+	cdb[11] = 0;			/* LBA HIGH */
+	cdb[12] = 0;			/* LBA HIGH */
+	cdb[13] = 0;			/* DEVICE */
+	cdb[14] = 0xA1;			/* Command: ATA IDENTIFY PACKET DEVICE */;
+	cdb[15] = 0;			/* CONTROL */
+	memset(sense, 0, sizeof(sense));
+
+	memset(&io_v4, 0, sizeof(struct sg_io_v4));
+	io_v4.guard = 'Q';
+	io_v4.protocol = BSG_PROTOCOL_SCSI;
+	io_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
+	io_v4.request_len = sizeof (cdb);
+	io_v4.request = (uintptr_t) cdb;
+	io_v4.max_response_len = sizeof (sense);
+	io_v4.response = (uintptr_t) sense;
+	io_v4.din_xfer_len = buf_len;
+	io_v4.din_xferp = (uintptr_t) buf;
+	io_v4.timeout = COMMAND_TIMEOUT_MSEC;
+
+	ret = ioctl(fd, SG_IO, &io_v4);
+	if (ret != 0) {
+		/* could be that the driver doesn't do version 4, try version 3 */
+		if (errno == EINVAL) {
+			struct sg_io_hdr io_hdr;
+
+			memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
+			io_hdr.interface_id = 'S';
+			io_hdr.cmdp = (unsigned char*) cdb;
+			io_hdr.cmd_len = sizeof (cdb);
+			io_hdr.dxferp = buf;
+			io_hdr.dxfer_len = buf_len;
+			io_hdr.sbp = sense;
+			io_hdr.mx_sb_len = sizeof (sense);
+			io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
+			io_hdr.timeout = COMMAND_TIMEOUT_MSEC;
+
+			ret = ioctl(fd, SG_IO, &io_hdr);
+			if (ret != 0)
+				goto out;
+		} else {
+			goto out;
+		}
+	}
+
+	if (!(sense[0] == 0x72 && desc[0] == 0x9 && desc[1] == 0x0c)) {
+		errno = EIO;
+		ret = -1;
+		goto out;
+	}
+
+ out:
+	return ret;
+}
+
 /**
  * disk_identify_get_string:
  * @identify: A block of IDENTIFY data
@@ -256,31 +339,36 @@ static void disk_identify_fixup_uint16 (uint8_t identify[512], unsigned int offs
  * @udev: The libudev context.
  * @fd: File descriptor for the block device.
  * @out_identify: Return location for IDENTIFY data.
+ * @out_is_packet_device: Return location for whether returned data is from a IDENTIFY PACKET DEVICE.
  *
- * Sends the IDENTIFY DEVICE command to the device represented by
- * @fd. If successful, then the result will be copied into
- * @out_identify.
+ * Sends the IDENTIFY DEVICE or IDENTIFY PACKET DEVICE command to the
+ * device represented by @fd. If successful, then the result will be
+ * copied into @out_identify and @out_is_packet_device.
  *
  * This routine is based on code from libatasmart, Copyright 2008
  * Lennart Poettering, LGPL v2.1.
  *
- * Returns: 0 if the IDENTIFY data was successfully obtained,
- * otherwise non-zero with errno set.
+ * Returns: 0 if the data was successfully obtained, otherwise
+ * non-zero with errno set.
  */
 static int disk_identify (struct udev *udev,
 			  int	       fd,
-			  uint8_t      out_identify[512])
+			  uint8_t      out_identify[512],
+			  int	      *out_is_packet_device)
 {
 	int ret;
 	uint8_t inquiry_buf[36];
 	int peripheral_device_type;
 	int all_nul_bytes;
 	int n;
+	int is_packet_device;
 
 	assert (out_identify != NULL);
+
 	/* init results */
 	ret = -1;
 	memset (out_identify, '\0', 512);
+	is_packet_device = 0;
 
 	/* If we were to use ATA PASS_THROUGH (12) on an ATAPI device
 	 * we could accidentally blank media. This is because MMC's BLANK
@@ -309,6 +397,12 @@ static int disk_identify (struct udev *udev,
 
 	/* SPC-4, section 6.4.2: Standard INQUIRY data */
 	peripheral_device_type = inquiry_buf[0] & 0x1f;
+	if (peripheral_device_type == 0x05)
+	  {
+	    is_packet_device = 1;
+	    ret = disk_identify_packet_device_command(fd, out_identify, 512);
+	    goto check_nul_bytes;
+	  }
 	if (peripheral_device_type != 0x00) {
 		ret = -1;
 		errno = EIO;
@@ -320,6 +414,7 @@ static int disk_identify (struct udev *udev,
 	if (ret != 0)
 		goto out;
 
+ check_nul_bytes:
 	 /* Check if IDENTIFY data is all NUL bytes - if so, bail */
 	all_nul_bytes = 1;
 	for (n = 0; n < 512; n++) {
@@ -336,6 +431,8 @@ static int disk_identify (struct udev *udev,
 	}
 
 out:
+	if (out_is_packet_device != NULL)
+	  *out_is_packet_device = is_packet_device;
 	return ret;
 }
 
@@ -350,7 +447,7 @@ int main(int argc, char *argv[])
 {
 	struct udev *udev;
 	struct hd_driveid id;
-	 uint8_t identify[512];
+	uint8_t identify[512];
 	char model[41];
 	char model_enc[256];
 	char serial[21];
@@ -358,8 +455,9 @@ int main(int argc, char *argv[])
 	const char *node = NULL;
 	int export = 0;
 	int fd;
-	 uint16_t word;
+	uint16_t word;
 	int rc = 0;
+	int is_packet_device = 0;
 	static const struct option options[] = {
 		{ "export", no_argument, NULL, 'x' },
 		{ "help", no_argument, NULL, 'h' },
@@ -408,7 +506,7 @@ int main(int argc, char *argv[])
 		goto exit;
 	}
 
-	if (disk_identify(udev, fd, identify) == 0) {
+	if (disk_identify(udev, fd, identify, &is_packet_device) == 0) {
 		/*
 		 * fix up only the fields from the IDENTIFY data that we are going to
 		 * use and copy it into the hd_driveid struct for convenience
@@ -416,7 +514,7 @@ int main(int argc, char *argv[])
 		disk_identify_fixup_string (identify,  10, 20);	/* serial */
 		disk_identify_fixup_string (identify,  23,  6);	/* fwrev */
 		disk_identify_fixup_string (identify,  27, 40);	/* model */
-		disk_identify_fixup_uint16 (identify,   0);	/* configuration */
+		disk_identify_fixup_uint16 (identify,	0);	/* configuration */
 		disk_identify_fixup_uint16 (identify,  75);	/* queue depth */
 		disk_identify_fixup_uint16 (identify,  75);	/* SATA capabilities */
 		disk_identify_fixup_uint16 (identify,  82);	/* command set supported */
@@ -457,8 +555,8 @@ int main(int argc, char *argv[])
 	udev_util_replace_chars(revision, NULL);
 
 	if (export) {
-		  /* Set this to convey the disk speaks the ATA protocol */
-		  printf("ID_ATA=1\n");
+		/* Set this to convey the disk speaks the ATA protocol */
+		printf("ID_ATA=1\n");
 
 		if ((id.config >> 8) & 0x80) {
 			/* This is an ATAPI device */