[SCTP]: Implement SCTP-AUTH initializations.

The patch initializes AUTH related members of the generic SCTP
structures and provides a way to enable/disable auth extension.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 83 insertions, 0 deletions

diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 22371185efb..c8d5023606a 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -69,12 +69,56 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 						struct sock *sk,
 						gfp_t gfp)
 {
+	struct sctp_hmac_algo_param *auth_hmacs = NULL;
+	struct sctp_chunks_param *auth_chunks = NULL;
+	struct sctp_shared_key *null_key;
+	int err;
+
 	memset(ep, 0, sizeof(struct sctp_endpoint));
 
 	ep->digest = kzalloc(SCTP_SIGNATURE_SIZE, gfp);
 	if (!ep->digest)
 		return NULL;
 
+	if (sctp_auth_enable) {
+		/* Allocate space for HMACS and CHUNKS authentication
+		 * variables.  There are arrays that we encode directly
+		 * into parameters to make the rest of the operations easier.
+		 */
+		auth_hmacs = kzalloc(sizeof(sctp_hmac_algo_param_t) +
+				sizeof(__u16) * SCTP_AUTH_NUM_HMACS, gfp);
+		if (!auth_hmacs)
+			goto nomem;
+
+		auth_chunks = kzalloc(sizeof(sctp_chunks_param_t) +
+					SCTP_NUM_CHUNK_TYPES, gfp);
+		if (!auth_chunks)
+			goto nomem;
+
+		/* Initialize the HMACS parameter.
+		 * SCTP-AUTH: Section 3.3
+		 *    Every endpoint supporting SCTP chunk authentication MUST
+		 *    support the HMAC based on the SHA-1 algorithm.
+		 */
+		auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
+		auth_hmacs->param_hdr.length =
+					htons(sizeof(sctp_paramhdr_t) + 2);
+		auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
+
+		/* Initialize the CHUNKS parameter */
+		auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
+
+		/* If the Add-IP functionality is enabled, we must
+		 * authenticate, ASCONF and ASCONF-ACK chunks
+		 */
+		if (sctp_addip_enable) {
+			auth_chunks->chunks[0] = SCTP_CID_ASCONF;
+			auth_chunks->chunks[1] = SCTP_CID_ASCONF_ACK;
+			auth_chunks->param_hdr.length =
+					htons(sizeof(sctp_paramhdr_t) + 2);
+		}
+	}
+
 	/* Initialize the base structure. */
 	/* What type of endpoint are we?  */
 	ep->base.type = SCTP_EP_TYPE_SOCKET;
@@ -114,7 +158,36 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 	ep->last_key = ep->current_key = 0;
 	ep->key_changed_at = jiffies;
 
+	/* SCTP-AUTH extensions*/
+	INIT_LIST_HEAD(&ep->endpoint_shared_keys);
+	null_key = sctp_auth_shkey_create(0, GFP_KERNEL);
+	if (!null_key)
+		goto nomem;
+
+	list_add(&null_key->key_list, &ep->endpoint_shared_keys);
+
+	/* Allocate and initialize transorms arrays for suported HMACs. */
+	err = sctp_auth_init_hmacs(ep, gfp);
+	if (err)
+		goto nomem_hmacs;
+
+	/* Add the null key to the endpoint shared keys list and
+	 * set the hmcas and chunks pointers.
+	 */
+	ep->auth_hmacs_list = auth_hmacs;
+	ep->auth_chunk_list = auth_chunks;
+
 	return ep;
+
+nomem_hmacs:
+	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+nomem:
+	/* Free all allocations */
+	kfree(auth_hmacs);
+	kfree(auth_chunks);
+	kfree(ep->digest);
+	return NULL;
+
 }
 
 /* Create a sctp_endpoint with all that boring stuff initialized.
@@ -187,6 +260,16 @@ static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
 	/* Free the digest buffer */
 	kfree(ep->digest);
 
+	/* SCTP-AUTH: Free up AUTH releated data such as shared keys
+	 * chunks and hmacs arrays that were allocated
+	 */
+	sctp_auth_destroy_keys(&ep->endpoint_shared_keys);
+	kfree(ep->auth_hmacs_list);
+	kfree(ep->auth_chunk_list);
+
+	/* AUTH - Free any allocated HMAC transform containers */
+	sctp_auth_destroy_hmacs(ep->auth_hmacs);
+
 	/* Cleanup. */
 	sctp_inq_free(&ep->base.inqueue);
 	sctp_bind_addr_free(&ep->base.bind_addr);