KEYS: RxRPC: Use key preparsing

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@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>

1 files changed, 97 insertions, 68 deletions

diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 0ad080790a32..3907add75932 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);
 }
 
 /*