diff mbox series

[v4,1/7] target: use consistent left-aligned ASCII INQUIRY data

Message ID 20181129010157.12687-2-ddiss@suse.de (mailing list archive)
State New, archived
Headers show
Series target: user configurable T10 Vendor ID | expand

Commit Message

David Disseldorp Nov. 29, 2018, 1:01 a.m. UTC 
spc5r17.pdf specifies:
  4.3.1 ASCII data field requirements
  ASCII data fields shall contain only ASCII printable characters (i.e.,
  code values 20h to 7Eh) and may be terminated with one or more ASCII
  null (00h) characters.
  ASCII data fields described as being left-aligned shall have any
  unused bytes at the end of the field (i.e., highest offset) and the
  unused bytes shall be filled with ASCII space characters (20h).

LIO currently space-pads the T10 VENDOR IDENTIFICATION and PRODUCT
IDENTIFICATION fields in the standard INQUIRY data. However, the
PRODUCT REVISION LEVEL field in the standard INQUIRY data as well as the
T10 VENDOR IDENTIFICATION field in the INQUIRY Device Identification VPD
Page are zero-terminated/zero-padded.

Fix this inconsistency by using space-padding for all of the above
fields.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/target/target_core_spc.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

Comments

Ly, Bryant Nov. 29, 2018, 1:17 a.m. UTC | #1 
> On Nov 28, 2018, at 7:01 PM, David Disseldorp <ddiss@suse.de> wrote:
> 
> spc5r17.pdf specifies:
>  4.3.1 ASCII data field requirements
>  ASCII data fields shall contain only ASCII printable characters (i.e.,
>  code values 20h to 7Eh) and may be terminated with one or more ASCII
>  null (00h) characters.
>  ASCII data fields described as being left-aligned shall have any
>  unused bytes at the end of the field (i.e., highest offset) and the
>  unused bytes shall be filled with ASCII space characters (20h).
> 
> LIO currently space-pads the T10 VENDOR IDENTIFICATION and PRODUCT
> IDENTIFICATION fields in the standard INQUIRY data. However, the
> PRODUCT REVISION LEVEL field in the standard INQUIRY data as well as the
> T10 VENDOR IDENTIFICATION field in the INQUIRY Device Identification VPD
> Page are zero-terminated/zero-padded.
> 
> Fix this inconsistency by using space-padding for all of the above
> fields.
> 
> Signed-off-by: David Disseldorp <ddiss@suse.de>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/target/target_core_spc.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
> 

Reviewed-by: Bryant G. Ly bly@catalogicsoftware.com
Lee Duncan Nov. 29, 2018, 1:23 a.m. UTC | #2 
On 11/28/18 5:01 PM, David Disseldorp wrote:
> spc5r17.pdf specifies:
>   4.3.1 ASCII data field requirements
>   ASCII data fields shall contain only ASCII printable characters (i.e.,
>   code values 20h to 7Eh) and may be terminated with one or more ASCII
>   null (00h) characters.
>   ASCII data fields described as being left-aligned shall have any
>   unused bytes at the end of the field (i.e., highest offset) and the
>   unused bytes shall be filled with ASCII space characters (20h).
> 
> LIO currently space-pads the T10 VENDOR IDENTIFICATION and PRODUCT
> IDENTIFICATION fields in the standard INQUIRY data. However, the
> PRODUCT REVISION LEVEL field in the standard INQUIRY data as well as the
> T10 VENDOR IDENTIFICATION field in the INQUIRY Device Identification VPD
> Page are zero-terminated/zero-padded.
> 
> Fix this inconsistency by using space-padding for all of the above
> fields.
> 
> Signed-off-by: David Disseldorp <ddiss@suse.de>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/target/target_core_spc.c | 17 ++++++++++++-----
>  1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
> index f459118bc11b..c37dd36ec77d 100644
> --- a/drivers/target/target_core_spc.c
> +++ b/drivers/target/target_core_spc.c
> @@ -108,12 +108,17 @@ spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
>  
>  	buf[7] = 0x2; /* CmdQue=1 */
>  
> -	memcpy(&buf[8], "LIO-ORG ", 8);
> -	memset(&buf[16], 0x20, 16);
> +	/*
> +	 * ASCII data fields described as being left-aligned shall have any
> +	 * unused bytes at the end of the field (i.e., highest offset) and the
> +	 * unused bytes shall be filled with ASCII space characters (20h).
> +	 */
> +	memset(&buf[8], 0x20, 8 + 16 + 4);

I dislike that you are using 0x20 here (and below) instead of ' '.

> +	memcpy(&buf[8], "LIO-ORG", sizeof("LIO-ORG") - 1);
>  	memcpy(&buf[16], dev->t10_wwn.model,
> -	       min_t(size_t, strlen(dev->t10_wwn.model), 16));
> +	       strnlen(dev->t10_wwn.model, 16));
>  	memcpy(&buf[32], dev->t10_wwn.revision,
> -	       min_t(size_t, strlen(dev->t10_wwn.revision), 4));
> +	       strnlen(dev->t10_wwn.revision, 4));
>  	buf[4] = 31; /* Set additional length to 31 */
>  
>  	return 0;
> @@ -251,7 +256,9 @@ spc_emulate_evpd_83(struct se_cmd *cmd, unsigned char *buf)
>  	buf[off] = 0x2; /* ASCII */
>  	buf[off+1] = 0x1; /* T10 Vendor ID */
>  	buf[off+2] = 0x0;
> -	memcpy(&buf[off+4], "LIO-ORG", 8);
> +	/* left align Vendor ID and pad with spaces */
> +	memset(&buf[off+4], 0x20, 8);
> +	memcpy(&buf[off+4], "LIO-ORG", sizeof("LIO-ORG") - 1);
>  	/* Extra Byte for NULL Terminator */
>  	id_len++;
>  	/* Identifier Length */
>
David Disseldorp Nov. 30, 2018, 12:44 p.m. UTC | #3 
On Wed, 28 Nov 2018 17:23:07 -0800, Lee Duncan wrote:

> > +	 * unused bytes at the end of the field (i.e., highest offset) and the
> > +	 * unused bytes shall be filled with ASCII space characters (20h).
> > +	 */
> > +	memset(&buf[8], 0x20, 8 + 16 + 4);  
> 
> I dislike that you are using 0x20 here (and below) instead of ' '.

Given that this patch already has a couple of reviewed-bys, I'd prefer
to avoid respinning it for this. Besides, I think the comment above
makes it pretty clear.

Thanks for your feedback.

Cheers, David
Lee Duncan Nov. 30, 2018, 8:02 p.m. UTC | #4 
On 11/30/18 4:44 AM, David Disseldorp wrote:
> On Wed, 28 Nov 2018 17:23:07 -0800, Lee Duncan wrote:
> 
>>> +	 * unused bytes at the end of the field (i.e., highest offset) and the
>>> +	 * unused bytes shall be filled with ASCII space characters (20h).
>>> +	 */
>>> +	memset(&buf[8], 0x20, 8 + 16 + 4);  
>>
>> I dislike that you are using 0x20 here (and below) instead of ' '.
> 
> Given that this patch already has a couple of reviewed-bys, I'd prefer
> to avoid respinning it for this. Besides, I think the comment above
> makes it pretty clear.
> 
> Thanks for your feedback.
> 
> Cheers, David
> 

Also, the "0x20" is in use widely, I see, so your patch is fine with me.

Please feel free to also add my:

Reviewed-by: Lee Duncan <lduncan@suse.com>

If you wish.
diff mbox series

Patch

diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index f459118bc11b..c37dd36ec77d 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -108,12 +108,17 @@  spc_emulate_inquiry_std(struct se_cmd *cmd, unsigned char *buf)
 
 	buf[7] = 0x2; /* CmdQue=1 */
 
-	memcpy(&buf[8], "LIO-ORG ", 8);
-	memset(&buf[16], 0x20, 16);
+	/*
+	 * ASCII data fields described as being left-aligned shall have any
+	 * unused bytes at the end of the field (i.e., highest offset) and the
+	 * unused bytes shall be filled with ASCII space characters (20h).
+	 */
+	memset(&buf[8], 0x20, 8 + 16 + 4);
+	memcpy(&buf[8], "LIO-ORG", sizeof("LIO-ORG") - 1);
 	memcpy(&buf[16], dev->t10_wwn.model,
-	       min_t(size_t, strlen(dev->t10_wwn.model), 16));
+	       strnlen(dev->t10_wwn.model, 16));
 	memcpy(&buf[32], dev->t10_wwn.revision,
-	       min_t(size_t, strlen(dev->t10_wwn.revision), 4));
+	       strnlen(dev->t10_wwn.revision, 4));
 	buf[4] = 31; /* Set additional length to 31 */
 
 	return 0;
@@ -251,7 +256,9 @@  spc_emulate_evpd_83(struct se_cmd *cmd, unsigned char *buf)
 	buf[off] = 0x2; /* ASCII */
 	buf[off+1] = 0x1; /* T10 Vendor ID */
 	buf[off+2] = 0x0;
-	memcpy(&buf[off+4], "LIO-ORG", 8);
+	/* left align Vendor ID and pad with spaces */
+	memset(&buf[off+4], 0x20, 8);
+	memcpy(&buf[off+4], "LIO-ORG", sizeof("LIO-ORG") - 1);
 	/* Extra Byte for NULL Terminator */
 	id_len++;
 	/* Identifier Length */