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

From: Derrick, Jonathan
Date: Tue Mar 06 2018 - 19:23:44 EST


This looks correct.

Adding my Ack unless Scott has objections

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

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@xxxxxxxxxxxxxxxxxxx
> 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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