[PATCHv4 2/4] block/sed: Add helper to qualify response tokens

Jon Derrick
2017-02-15T21:46:18Z

Add helper which verifies the response token is valid and matches the
expected value. Merges token_type and response_get_token.

Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Reviewed-by: Scott Bauer <scott.bauer@intel.com>
---
block/sed-opal.c | 61 +++++++++++++++++++++++---------------------------------
1 file changed, 25 insertions(+), 36 deletions(-)

diff --git a/block/sed-opal.c b/block/sed-opal.c
index 77623ad..00673cf 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -591,48 +591,25 @@ static int cmd_finalize(struct opal_dev *cmd, u32 hsn, u32 tsn)
return 0;
}

-static enum opal_response_token token_type(const struct parsed_resp *resp,
- int n)
+static const struct opal_resp_tok *response_get_token(
+ const struct parsed_resp *resp,
+ int n)
{
const struct opal_resp_tok *tok;

if (n >= resp->num) {
pr_err("Token number doesn't exist: %d, resp: %d\n",
n, resp->num);
- return OPAL_DTA_TOKENID_INVALID;
+ return ERR_PTR(-EINVAL);
}

tok = &resp->toks[n];
if (tok->len == 0) {
pr_err("Token length must be non-zero\n");
- return OPAL_DTA_TOKENID_INVALID;
+ return ERR_PTR(-EINVAL);
}

- return tok->type;
-}
-
-/*
- * This function returns 0 in case of invalid token. One should call
- * token_type() first to find out if the token is valid or not.
- */
-static enum opal_token response_get_token(const struct parsed_resp *resp,
- int n)
-{
- const struct opal_resp_tok *tok;
-
- if (n >= resp->num) {
- pr_err("Token number doesn't exist: %d, resp: %d\n",
- n, resp->num);
- return 0;
- }
-
- tok = &resp->toks[n];
- if (tok->len == 0) {
- pr_err("Token length must be non-zero\n");
- return 0;
- }
-
- return tok->pos[0];
+ return tok;
}

static ssize_t response_parse_tiny(struct opal_resp_tok *tok,
@@ -851,20 +828,32 @@ static u64 response_get_u64(const struct parsed_resp *resp, int n)
return resp->toks[n].stored.u;
}

+static bool response_token_matches(const struct opal_resp_tok *token, u8 match)
+{
+ if (IS_ERR(token) ||
+ token->type != OPAL_DTA_TOKENID_TOKEN ||
+ token->pos[0] != match)
+ return false;
+ return true;
+}
+
static u8 response_status(const struct parsed_resp *resp)
{
- if (token_type(resp, 0) == OPAL_DTA_TOKENID_TOKEN &&
- response_get_token(resp, 0) == OPAL_ENDOFSESSION) {
+ const struct opal_resp_tok *tok;
+
+ tok = response_get_token(resp, 0);
+ if (response_token_matches(tok, OPAL_ENDOFSESSION))
return 0;
- }

if (resp->num < 5)
return DTAERROR_NO_METHOD_STATUS;

- if (token_type(resp, resp->num - 1) != OPAL_DTA_TOKENID_TOKEN ||
- token_type(resp, resp->num - 5) != OPAL_DTA_TOKENID_TOKEN ||
- response_get_token(resp, resp->num - 1) != OPAL_ENDLIST ||
- response_get_token(resp, resp->num - 5) != OPAL_STARTLIST)
+ tok = response_get_token(resp, resp->num - 5);
+ if (!response_token_matches(tok, OPAL_STARTLIST))
+ return DTAERROR_NO_METHOD_STATUS;
+
+ tok = response_get_token(resp, resp->num - 1);
+ if (!response_token_matches(tok, OPAL_ENDLIST))
return DTAERROR_NO_METHOD_STATUS;

return response_get_u64(resp, resp->num - 4);
--
1.8.3.1