sctp: add sctp_auth_init and sctp_auth_free

This patch is to factor out sctp_auth_init and sctp_auth_free
functions, and sctp_auth_init will also be used in the next
patch for SCTP_AUTH_SUPPORTED sockopt.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 69 insertions, 0 deletions

diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index 61b00904d830..4278764d82b8 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -1007,3 +1007,72 @@ int sctp_auth_deact_key_id(struct sctp_endpoint *ep,
 
 	return 0;
 }
+
+int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp)
+{
+	int err = -ENOMEM;
+
+	/* 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.
+	 */
+	if (!ep->auth_hmacs_list) {
+		struct sctp_hmac_algo_param *auth_hmacs;
+
+		auth_hmacs = kzalloc(struct_size(auth_hmacs, hmac_ids,
+						 SCTP_AUTH_NUM_HMACS), gfp);
+		if (!auth_hmacs)
+			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(struct sctp_paramhdr) + 2);
+		auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
+		ep->auth_hmacs_list = auth_hmacs;
+	}
+
+	if (!ep->auth_chunk_list) {
+		struct sctp_chunks_param *auth_chunks;
+
+		auth_chunks = kzalloc(sizeof(*auth_chunks) +
+				      SCTP_NUM_CHUNK_TYPES, gfp);
+		if (!auth_chunks)
+			goto nomem;
+		/* Initialize the CHUNKS parameter */
+		auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
+		auth_chunks->param_hdr.length =
+				htons(sizeof(struct sctp_paramhdr));
+		ep->auth_chunk_list = auth_chunks;
+	}
+
+	/* Allocate and initialize transorms arrays for supported
+	 * HMACs.
+	 */
+	err = sctp_auth_init_hmacs(ep, gfp);
+	if (err)
+		goto nomem;
+
+	return 0;
+
+nomem:
+	/* Free all allocations */
+	kfree(ep->auth_hmacs_list);
+	kfree(ep->auth_chunk_list);
+	ep->auth_hmacs_list = NULL;
+	ep->auth_chunk_list = NULL;
+	return err;
+}
+
+void sctp_auth_free(struct sctp_endpoint *ep)
+{
+	kfree(ep->auth_hmacs_list);
+	kfree(ep->auth_chunk_list);
+	ep->auth_hmacs_list = NULL;
+	ep->auth_chunk_list = NULL;
+	sctp_auth_destroy_hmacs(ep->auth_hmacs);
+	ep->auth_hmacs = NULL;
+}