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

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

[David Disseldorp]

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);
+	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 */
-- 
2.13.7

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

[Ly, Bryant]

> 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

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

[Lee Duncan]

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 */
> 

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

[David Disseldorp]

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

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

[Lee Duncan]

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.