[SCTP]: API updates to suport SCTP-AUTH extensions.

Add SCTP-AUTH API.  The API implemented here was
agreed to between implementors at the 9th SCTP Interop.
It will be documented in the next revision of the
SCTP socket API spec.

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

net/sctp/auth.c

@@ -743,3 +743,196 @@ free:
 	if (free_key)
 		sctp_auth_key_put(asoc_key);
 }
+
+/* API Helpers */
+
+/* Add a chunk to the endpoint authenticated chunk list */
+int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id)
+{
+	struct sctp_chunks_param *p = ep->auth_chunk_list;
+	__u16 nchunks;
+	__u16 param_len;
+
+	/* If this chunk is already specified, we are done */
+	if (__sctp_auth_cid(chunk_id, p))
+		return 0;
+
+	/* Check if we can add this chunk to the array */
+	param_len = ntohs(p->param_hdr.length);
+	nchunks = param_len - sizeof(sctp_paramhdr_t);
+	if (nchunks == SCTP_NUM_CHUNK_TYPES)
+		return -EINVAL;
+
+	p->chunks[nchunks] = chunk_id;
+	p->param_hdr.length = htons(param_len + 1);
+	return 0;
+}
+
+/* Add hmac identifires to the endpoint list of supported hmac ids */
+int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
+			   struct sctp_hmacalgo *hmacs)
+{
+	int has_sha1 = 0;
+	__u16 id;
+	int i;
+
+	/* Scan the list looking for unsupported id.  Also make sure that
+	 * SHA1 is specified.
+	 */
+	for (i = 0; i < hmacs->shmac_num_idents; i++) {
+		id = hmacs->shmac_idents[i];
+
+		if (SCTP_AUTH_HMAC_ID_SHA1 == id)
+			has_sha1 = 1;
+
+		if (!sctp_hmac_list[id].hmac_name)
+			return -EOPNOTSUPP;
+	}
+
+	if (!has_sha1)
+		return -EINVAL;
+
+	memcpy(ep->auth_hmacs_list->hmac_ids, &hmacs->shmac_idents[0],
+		hmacs->shmac_num_idents * sizeof(__u16));
+	ep->auth_hmacs_list->param_hdr.length = htons(sizeof(sctp_paramhdr_t) +
+				hmacs->shmac_num_idents * sizeof(__u16));
+	return 0;
+}
+
+/* Set a new shared key on either endpoint or association.  If the
+ * the key with a same ID already exists, replace the key (remove the
+ * old key and add a new one).
+ */
+int sctp_auth_set_key(struct sctp_endpoint *ep,
+		      struct sctp_association *asoc,
+		      struct sctp_authkey *auth_key)
+{
+	struct sctp_shared_key *cur_key = NULL;
+	struct sctp_auth_bytes *key;
+	struct list_head *sh_keys;
+	int replace = 0;
+
+	/* Try to find the given key id to see if
+	 * we are doing a replace, or adding a new key
+	 */
+	if (asoc)
+		sh_keys = &asoc->endpoint_shared_keys;
+	else
+		sh_keys = &ep->endpoint_shared_keys;
+
+	key_for_each(cur_key, sh_keys) {
+		if (cur_key->key_id == auth_key->sca_keynumber) {
+			replace = 1;
+			break;
+		}
+	}
+
+	/* If we are not replacing a key id, we need to allocate
+	 * a shared key.
+	 */
+	if (!replace) {
+		cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber,
+						 GFP_KERNEL);
+		if (!cur_key)
+			return -ENOMEM;
+	}
+
+	/* Create a new key data based on the info passed in */
+	key = sctp_auth_create_key(auth_key->sca_keylen, GFP_KERNEL);
+	if (!key)
+		goto nomem;
+
+	memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylen);
+
+	/* If we are replacing, remove the old keys data from the
+	 * key id.  If we are adding new key id, add it to the
+	 * list.
+	 */
+	if (replace)
+		sctp_auth_key_put(cur_key->key);
+	else
+		list_add(&cur_key->key_list, sh_keys);
+
+	cur_key->key = key;
+	sctp_auth_key_hold(key);
+
+	return 0;
+nomem:
+	if (!replace)
+		sctp_auth_shkey_free(cur_key);
+
+	return -ENOMEM;
+}
+
+int sctp_auth_set_active_key(struct sctp_endpoint *ep,
+			     struct sctp_association *asoc,
+			     __u16  key_id)
+{
+	struct sctp_shared_key *key;
+	struct list_head *sh_keys;
+	int found = 0;
+
+	/* The key identifier MUST correst to an existing key */
+	if (asoc)
+		sh_keys = &asoc->endpoint_shared_keys;
+	else
+		sh_keys = &ep->endpoint_shared_keys;
+
+	key_for_each(key, sh_keys) {
+		if (key->key_id == key_id) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	if (asoc) {
+		asoc->active_key_id = key_id;
+		sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
+	} else
+		ep->active_key_id = key_id;
+
+	return 0;
+}
+
+int sctp_auth_del_key_id(struct sctp_endpoint *ep,
+			 struct sctp_association *asoc,
+			 __u16  key_id)
+{
+	struct sctp_shared_key *key;
+	struct list_head *sh_keys;
+	int found = 0;
+
+	/* The key identifier MUST NOT be the current active key
+	 * The key identifier MUST correst to an existing key
+	 */
+	if (asoc) {
+		if (asoc->active_key_id == key_id)
+			return -EINVAL;
+
+		sh_keys = &asoc->endpoint_shared_keys;
+	} else {
+		if (ep->active_key_id == key_id)
+			return -EINVAL;
+
+		sh_keys = &ep->endpoint_shared_keys;
+	}
+
+	key_for_each(key, sh_keys) {
+		if (key->key_id == key_id) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	/* Delete the shared key */
+	list_del_init(&key->key_list);
+	sctp_auth_shkey_free(key);
+
+	return 0;
+}