[PATCH 09/12] KEYS: RxRPC: Use key preparsing

From: David Howells
Date: Thu Mar 20 2014 - 08:08:05 EST

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Make use of key preparsing in the RxRPC protocol so that quota size
determination can take place prior to keyring locking when a key is being
added.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

net/rxrpc/ar-key.c | 165 +++++++++++++++++++++++++++++++---------------------
1 file changed, 97 insertions(+), 68 deletions(-)

diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 7633a752c65e..58a3641227d4 100644
--- a/net/rxrpc/ar-key.c
+++ b/net/rxrpc/ar-key.c
@@ -26,8 +26,10 @@
#include "ar-internal.h"

static int rxrpc_vet_description_s(const char *);
-static int rxrpc_instantiate(struct key *, struct key_preparsed_payload *);
-static int rxrpc_instantiate_s(struct key *, struct key_preparsed_payload *);
+static int rxrpc_preparse(struct key_preparsed_payload *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
static void rxrpc_destroy(struct key *);
static void rxrpc_destroy_s(struct key *);
static void rxrpc_describe(const struct key *, struct seq_file *);
@@ -39,7 +41,9 @@ static long rxrpc_read(const struct key *, char __user *, size_t);
*/
struct key_type key_type_rxrpc = {
.name = "rxrpc",
- .instantiate = rxrpc_instantiate,
+ .preparse = rxrpc_preparse,
+ .free_preparse = rxrpc_free_preparse,
+ .instantiate = generic_key_instantiate,
.match = user_match,
.destroy = rxrpc_destroy,
.describe = rxrpc_describe,
@@ -54,7 +58,9 @@ EXPORT_SYMBOL(key_type_rxrpc);
struct key_type key_type_rxrpc_s = {
.name = "rxrpc_s",
.vet_description = rxrpc_vet_description_s,
- .instantiate = rxrpc_instantiate_s,
+ .preparse = rxrpc_preparse_s,
+ .free_preparse = rxrpc_free_preparse_s,
+ .instantiate = generic_key_instantiate,
.match = user_match,
.destroy = rxrpc_destroy_s,
.describe = rxrpc_describe,
@@ -81,13 +87,13 @@ static int rxrpc_vet_description_s(const char *desc)
* parse an RxKAD type XDR format token
* - the caller guarantees we have at least 4 words
*/
-static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
- unsigned int toklen)
+static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
+ size_t datalen,
+ const __be32 *xdr, unsigned int toklen)
{
struct rxrpc_key_token *token, **pptoken;
size_t plen;
u32 tktlen;
- int ret;

_enter(",{%x,%x,%x,%x},%u",
ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
@@ -103,9 +109,7 @@ static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
return -EKEYREJECTED;

plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
- ret = key_payload_reserve(key, key->datalen + plen);
- if (ret < 0)
- return ret;
+ prep->quotalen = datalen + plen;

plen -= sizeof(*token);
token = kzalloc(sizeof(*token), GFP_KERNEL);
@@ -146,16 +150,16 @@ static int rxrpc_instantiate_xdr_rxkad(struct key *key, const __be32 *xdr,
token->kad->ticket[6], token->kad->ticket[7]);

/* count the number of tokens attached */
- key->type_data.x[0]++;
+ prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);

/* attach the data */
- for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+ for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
*pptoken;
pptoken = &(*pptoken)->next)
continue;
*pptoken = token;
- if (token->kad->expiry < key->expiry)
- key->expiry = token->kad->expiry;
+ if (token->kad->expiry < prep->expiry)
+ prep->expiry = token->kad->expiry;

_leave(" = 0");
return 0;
@@ -418,8 +422,9 @@ static int rxrpc_krb5_decode_ticket(u8 **_ticket, u16 *_tktlen,
* parse an RxK5 type XDR format token
* - the caller guarantees we have at least 4 words
*/
-static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
- unsigned int toklen)
+static int rxrpc_preparse_xdr_rxk5(struct key_preparsed_payload *prep,
+ size_t datalen,
+ const __be32 *xdr, unsigned int toklen)
{
struct rxrpc_key_token *token, **pptoken;
struct rxk5_key *rxk5;
@@ -432,9 +437,7 @@ static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,

/* reserve some payload space for this subkey - the length of the token
* is a reasonable approximation */
- ret = key_payload_reserve(key, key->datalen + toklen);
- if (ret < 0)
- return ret;
+ prep->quotalen = datalen + toklen;

token = kzalloc(sizeof(*token), GFP_KERNEL);
if (!token)
@@ -520,14 +523,14 @@ static int rxrpc_instantiate_xdr_rxk5(struct key *key, const __be32 *xdr,
if (toklen != 0)
goto inval;

- /* attach the payload to the key */
- for (pptoken = (struct rxrpc_key_token **)&key->payload.data;
+ /* attach the payload */
+ for (pptoken = (struct rxrpc_key_token **)&prep->payload[0];
*pptoken;
pptoken = &(*pptoken)->next)
continue;
*pptoken = token;
- if (token->kad->expiry < key->expiry)
- key->expiry = token->kad->expiry;
+ if (token->kad->expiry < prep->expiry)
+ prep->expiry = token->kad->expiry;

_leave(" = 0");
return 0;
@@ -545,16 +548,17 @@ error:
* attempt to parse the data as the XDR format
* - the caller guarantees we have more than 7 words
*/
-static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datalen)
+static int rxrpc_preparse_xdr(struct key_preparsed_payload *prep)
{
- const __be32 *xdr = data, *token;
+ const __be32 *xdr = prep->data, *token;
const char *cp;
unsigned int len, tmp, loop, ntoken, toklen, sec_ix;
+ size_t datalen = prep->datalen;
int ret;

_enter(",{%x,%x,%x,%x},%zu",
ntohl(xdr[0]), ntohl(xdr[1]), ntohl(xdr[2]), ntohl(xdr[3]),
- datalen);
+ prep->datalen);

if (datalen > AFSTOKEN_LENGTH_MAX)
goto not_xdr;
@@ -635,13 +639,13 @@ static int rxrpc_instantiate_xdr(struct key *key, const void *data, size_t datal

switch (sec_ix) {
case RXRPC_SECURITY_RXKAD:
- ret = rxrpc_instantiate_xdr_rxkad(key, xdr, toklen);
+ ret = rxrpc_preparse_xdr_rxkad(prep, datalen, xdr, toklen);
if (ret != 0)
goto error;
break;

case RXRPC_SECURITY_RXK5:
- ret = rxrpc_instantiate_xdr_rxk5(key, xdr, toklen);
+ ret = rxrpc_preparse_xdr_rxk5(prep, datalen, xdr, toklen);
if (ret != 0)
goto error;
break;
@@ -665,8 +669,9 @@ error:
}

/*
- * instantiate an rxrpc defined key
- * data should be of the form:
+ * Preparse an rxrpc defined key.
+ *
+ * Data should be of the form:
* OFFSET LEN CONTENT
* 0 4 key interface version number
* 4 2 security index (type)
@@ -678,7 +683,7 @@ error:
*
* if no data is provided, then a no-security key is made
*/
-static int rxrpc_instantiate(struct key *key, struct key_preparsed_payload *prep)
+static int rxrpc_preparse(struct key_preparsed_payload *prep)
{
const struct rxrpc_key_data_v1 *v1;
struct rxrpc_key_token *token, **pp;
@@ -686,7 +691,7 @@ static int rxrpc_instantiate(struct key *key, struct key_preparsed_payload *prep
u32 kver;
int ret;

- _enter("{%x},,%zu", key_serial(key), prep->datalen);
+ _enter("%zu", prep->datalen);

/* handle a no-security key */
if (!prep->data && prep->datalen == 0)
@@ -694,7 +699,7 @@ static int rxrpc_instantiate(struct key *key, struct key_preparsed_payload *prep

/* determine if the XDR payload format is being used */
if (prep->datalen > 7 * 4) {
- ret = rxrpc_instantiate_xdr(key, prep->data, prep->datalen);
+ ret = rxrpc_preparse_xdr(prep);
if (ret != -EPROTO)
return ret;
}
@@ -743,9 +748,7 @@ static int rxrpc_instantiate(struct key *key, struct key_preparsed_payload *prep
goto error;

plen = sizeof(*token->kad) + v1->ticket_length;
- ret = key_payload_reserve(key, plen + sizeof(*token));
- if (ret < 0)
- goto error;
+ prep->quotalen = plen + sizeof(*token);

ret = -ENOMEM;
token = kzalloc(sizeof(*token), GFP_KERNEL);
@@ -762,15 +765,16 @@ static int rxrpc_instantiate(struct key *key, struct key_preparsed_payload *prep
memcpy(&token->kad->session_key, &v1->session_key, 8);
memcpy(&token->kad->ticket, v1->ticket, v1->ticket_length);

- /* attach the data */
- key->type_data.x[0]++;
+ /* count the number of tokens attached */
+ prep->type_data[0] = (void *)((unsigned long)prep->type_data[0] + 1);

- pp = (struct rxrpc_key_token **)&key->payload.data;
+ /* attach the data */
+ pp = (struct rxrpc_key_token **)&prep->payload[0];
while (*pp)
pp = &(*pp)->next;
*pp = token;
- if (token->kad->expiry < key->expiry)
- key->expiry = token->kad->expiry;
+ if (token->kad->expiry < prep->expiry)
+ prep->expiry = token->kad->expiry;
token = NULL;
ret = 0;

@@ -781,20 +785,55 @@ error:
}

/*
- * instantiate a server secret key
- * data should be a pointer to the 8-byte secret key
+ * Free token list.
*/
-static int rxrpc_instantiate_s(struct key *key,
- struct key_preparsed_payload *prep)
+static void rxrpc_free_token_list(struct rxrpc_key_token *token)
+{
+ struct rxrpc_key_token *next;
+
+ for (; token; token = next) {
+ next = token->next;
+ switch (token->security_index) {
+ case RXRPC_SECURITY_RXKAD:
+ kfree(token->kad);
+ break;
+ case RXRPC_SECURITY_RXK5:
+ if (token->k5)
+ rxrpc_rxk5_free(token->k5);
+ break;
+ default:
+ printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
+ token->security_index);
+ BUG();
+ }
+
+ kfree(token);
+ }
+}
+
+/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse(struct key_preparsed_payload *prep)
+{
+ rxrpc_free_token_list(prep->payload[0]);
+}
+
+/*
+ * Preparse a server secret key.
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
{
struct crypto_blkcipher *ci;

- _enter("{%x},,%zu", key_serial(key), prep->datalen);
+ _enter("%zu", prep->datalen);

if (prep->datalen != 8)
return -EINVAL;

- memcpy(&key->type_data, prep->data, 8);
+ memcpy(&prep->type_data, prep->data, 8);

ci = crypto_alloc_blkcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(ci)) {
@@ -805,36 +844,26 @@ static int rxrpc_instantiate_s(struct key *key,
if (crypto_blkcipher_setkey(ci, prep->data, 8) < 0)
BUG();

- key->payload.data = ci;
+ prep->payload[0] = ci;
_leave(" = 0");
return 0;
}

/*
+ * Clean up preparse data.
+ */
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+ if (prep->payload[0])
+ crypto_free_blkcipher(prep->payload[0]);
+}
+
+/*
* dispose of the data dangling from the corpse of a rxrpc key
*/
static void rxrpc_destroy(struct key *key)
{
- struct rxrpc_key_token *token;
-
- while ((token = key->payload.data)) {
- key->payload.data = token->next;
- switch (token->security_index) {
- case RXRPC_SECURITY_RXKAD:
- kfree(token->kad);
- break;
- case RXRPC_SECURITY_RXK5:
- if (token->k5)
- rxrpc_rxk5_free(token->k5);
- break;
- default:
- printk(KERN_ERR "Unknown token type %x on rxrpc key\n",
- token->security_index);
- BUG();
- }
-
- kfree(token);
- }
+ rxrpc_free_token_list(key->payload.data);
}

/*

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Next message: Joe Perches: "Re: [PATCH 1/5] mtd: st_spi_fsm: Remove useless consts from function arguments"
Previous message: Cho KyongHo: "Re: [PATCH v11 17/27] iommu/exynos: remove calls to Runtime PM API functions"
In reply to: David Howells: "[PATCH 08/12] KEYS: DNS: Use key preparsing"
Next in thread: David Howells: "[PATCH 10/12] KEYS: big_key: Use key preparsing"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]