[PATCH][RESEND] block: sed-opal: fix response string extraction

[PATCH][RESEND] block: sed-opal: fix response string extraction

[Jonas Rabenstein]

Tokens are prefixed by a variable length of bytes. If a bytestring is
not stored in an tiny or short atom, we have to skip more than one byte
in order to have the actual bytes not prefixed by the bytes describing
the actual length of the string.

Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlangen.de>
---
 block/sed-opal.c | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 525506bed399..33052d0111de 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -876,6 +876,9 @@ static int response_parse(const u8 *buf, size_t length,
 static size_t response_get_string(const struct parsed_resp *resp, int n,
 				  const char **store)
 {
+	u8 skip;
+	const struct opal_resp_tok *token;
+
 	*store = NULL;
 	if (!resp) {
 		pr_debug("Response is NULL\n");
@@ -888,13 +891,30 @@ static size_t response_get_string(const struct parsed_resp *resp, int n,
 		return 0;
 	}
 
-	if (resp->toks[n].type != OPAL_DTA_TOKENID_BYTESTRING) {
+	token = &resp->toks[n];
+	if (token->type != OPAL_DTA_TOKENID_BYTESTRING) {
 		pr_debug("Token is not a byte string!\n");
 		return 0;
 	}
 
-	*store = resp->toks[n].pos + 1;
-	return resp->toks[n].len - 1;
+	switch (token->width) {
+	case OPAL_WIDTH_TINY:
+	case OPAL_WIDTH_SHORT:
+		skip = 1;
+		break;
+	case OPAL_WIDTH_MEDIUM:
+		skip = 2;
+		break;
+	case OPAL_WIDTH_LONG:
+		skip = 4;
+		break;
+	default:
+		pr_debug("Token has invalid width!\n");
+		return 0;
+	}
+
+	*store = token->pos + skip;
+	return token->len - skip;
 }
 
 static u64 response_get_u64(const struct parsed_resp *resp, int n)
-- 
2.13.6

Re: [PATCH][RESEND] block: sed-opal: fix response string extraction

[Derrick, Jonathan]

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This looks correct.

Adding my Ack unless Scott has objections

Acked-by: Jonathan Derrick <jonathan.derrick@intel.com>

On Thu, 2018-03-01 at 14:26 +0100, Jonas Rabenstein wrote:
> Tokens are prefixed by a variable length of bytes. If a bytestring is
> not stored in an tiny or short atom, we have to skip more than one
> byte
> in order to have the actual bytes not prefixed by the bytes
> describing
> the actual length of the string.
> 
> Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlange
> n.de>
> ---
>  block/sed-opal.c | 26 +++++++++++++++++++++++---
>  1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/block/sed-opal.c b/block/sed-opal.c
> index 525506bed399..33052d0111de 100644
> --- a/block/sed-opal.c
> +++ b/block/sed-opal.c
> @@ -876,6 +876,9 @@ static int response_parse(const u8 *buf, size_t
> length,
>  static size_t response_get_string(const struct parsed_resp *resp,
> int n,
>  				  const char **store)
>  {
> +	u8 skip;
> +	const struct opal_resp_tok *token;
> +
>  	*store = NULL;
>  	if (!resp) {
>  		pr_debug("Response is NULL\n");
> @@ -888,13 +891,30 @@ static size_t response_get_string(const struct
> parsed_resp *resp, int n,
>  		return 0;
>  	}
>  
> -	if (resp->toks[n].type != OPAL_DTA_TOKENID_BYTESTRING) {
> +	token = &resp->toks[n];
> +	if (token->type != OPAL_DTA_TOKENID_BYTESTRING) {
>  		pr_debug("Token is not a byte string!\n");
>  		return 0;
>  	}
>  
> -	*store = resp->toks[n].pos + 1;
> -	return resp->toks[n].len - 1;
> +	switch (token->width) {
> +	case OPAL_WIDTH_TINY:
> +	case OPAL_WIDTH_SHORT:
> +		skip = 1;
> +		break;
> +	case OPAL_WIDTH_MEDIUM:
> +		skip = 2;
> +		break;
> +	case OPAL_WIDTH_LONG:
> +		skip = 4;
> +		break;
> +	default:
> +		pr_debug("Token has invalid width!\n");
> +		return 0;
> +	}
> +
> +	*store = token->pos + skip;
> +	return token->len - skip;
>  }
>  
>  static u64 response_get_u64(const struct parsed_resp *resp, int n)

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Re: [PATCH][RESEND] block: sed-opal: fix response string extraction

[Scott Bauer]

On Tue, Mar 06, 2018 at 04:23:24PM -0800, Derrick, Jonathan wrote:
> This looks correct.
> 
> Adding my Ack unless Scott has objections
> 
> Acked-by: Jonathan Derrick <jonathan.derrick@intel.com>


Reviewed-by: Scott Bauer <scott.bauer@intel.com>

Nice catch Jonas! Sorry you had to resend, my message filtering was a little
too agressive and this slipped through the cracks, that has been remediated.


> 
> On Thu, 2018-03-01 at 14:26 +0100, Jonas Rabenstein wrote:
> > Tokens are prefixed by a variable length of bytes. If a bytestring is
> > not stored in an tiny or short atom, we have to skip more than one
> > byte
> > in order to have the actual bytes not prefixed by the bytes
> > describing
> > the actual length of the string.
> > 
> > Signed-off-by: Jonas Rabenstein <jonas.rabenstein@studium.uni-erlange
> > n.de>
> > ---
> >  block/sed-opal.c | 26 +++++++++++++++++++++++---
> >  1 file changed, 23 insertions(+), 3 deletions(-)