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>

diff --git a/net/rxrpc/ar-key.c b/net/rxrpc/ar-key.c
index 0ad080790a32a341a1ddc57d632302563964a247..3907add75932d9eafb6fd6de8da225171eb5dae5 100644 (file)
--- 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);
 }
 
 /*