sctp: add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT

This patch is to add SCTP_AUTH_NO_AUTH type for AUTHENTICATION_EVENT,
as described in section 6.1.8 of RFC6458.

SCTP_AUTH_NO_AUTH: This report indicates that the peer does not
support SCTP authentication as defined in [RFC4895].

Note that the implementation is quite similar as that of
SCTP_ADAPTATION_INDICATION.

Signed-off-by: Xin Long <[e-mail]>
Acked-by: Marcelo Ricardo Leitner <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/net/sctp/command.h

···
 	SCTP_CMD_SET_SK_ERR,	 /* Set sk_err */
 	SCTP_CMD_ASSOC_CHANGE,	 /* generate and send assoc_change event */
 	SCTP_CMD_ADAPTATION_IND, /* generate and send adaptation event */
+	SCTP_CMD_PEER_NO_AUTH,   /* generate and send authentication event */
 	SCTP_CMD_ASSOC_SHKEY,    /* generate the association shared keys */
 	SCTP_CMD_T1_RETRAN,	 /* Mark for retransmission after T1 timeout  */
 	SCTP_CMD_UPDATE_INITTAG, /* Update peer inittag */

include/uapi/linux/sctp.h

···
 	SCTP_AUTH_NEW_KEY,
 #define	SCTP_AUTH_NEWKEY	SCTP_AUTH_NEW_KEY /* compatible with before */
 	SCTP_AUTH_FREE_KEY,
+	SCTP_AUTH_NO_AUTH,
 };
 
 /*

net/sctp/sm_sideeffect.c

···
 		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 }
 
+static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
+				  struct sctp_association *asoc)
+{
+	struct sctp_ulpevent *ev;
+
+	ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
+	if (ev)
+		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
+}
+
 /* Helper function to generate an adaptation indication event */
 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
 				    struct sctp_association *asoc)
···
 			break;
 		case SCTP_CMD_ADAPTATION_IND:
 			sctp_cmd_adaptation_ind(commands, asoc);
+			break;
+		case SCTP_CMD_PEER_NO_AUTH:
+			sctp_cmd_peer_no_auth(commands, asoc);
 			break;
 
 		case SCTP_CMD_ASSOC_SHKEY:

net/sctp/sm_statefuns.c

···
 					 void *arg,
 					 struct sctp_cmd_seq *commands)
 {
-	struct sctp_ulpevent *ev, *ai_ev = NULL;
+	struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL;
 	struct sctp_association *new_asoc;
 	struct sctp_init_chunk *peer_init;
 	struct sctp_chunk *chunk = arg;
···
 			goto nomem_aiev;
 	}
 
+	if (!new_asoc->peer.auth_capable) {
+		auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0,
+						     SCTP_AUTH_NO_AUTH,
+						     GFP_ATOMIC);
+		if (!auth_ev)
+			goto nomem_authev;
+	}
+
 	/* Add all the state machine commands now since we've created
 	 * everything.  This way we don't introduce memory corruptions
 	 * during side-effect processing and correclty count established
···
 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 				SCTP_ULPEVENT(ai_ev));
 
+	if (auth_ev)
+		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+				SCTP_ULPEVENT(auth_ev));
+
 	return SCTP_DISPOSITION_CONSUME;
 
+nomem_authev:
+	sctp_ulpevent_free(ai_ev);
 nomem_aiev:
 	sctp_ulpevent_free(ev);
 nomem_ev:
···
 		if (!ev)
 			goto nomem;
 
+		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+				SCTP_ULPEVENT(ev));
+	}
+
+	if (!asoc->peer.auth_capable) {
+		ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH,
+						GFP_ATOMIC);
+		if (!ev)
+			goto nomem;
 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 				SCTP_ULPEVENT(ev));
 	}
···
 	if (asoc->peer.adaptation_ind)
 		sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
 
+	if (!asoc->peer.auth_capable)
+		sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL());
+
 	return SCTP_DISPOSITION_CONSUME;
 
 nomem:
···
 					struct sctp_cmd_seq *commands,
 					struct sctp_association *new_asoc)
 {
-	struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
+	struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL;
 	struct sctp_chunk *repl;
 
 	/* Clarification from Implementor's Guide:
···
 				goto nomem;
 
 		}
+
+		if (!asoc->peer.auth_capable) {
+			auth_ev = sctp_ulpevent_make_authkey(asoc, 0,
+							     SCTP_AUTH_NO_AUTH,
+							     GFP_ATOMIC);
+			if (!auth_ev)
+				goto nomem;
+		}
 	}
 
 	repl = sctp_make_cookie_ack(new_asoc, chunk);
···
 	if (ai_ev)
 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 					SCTP_ULPEVENT(ai_ev));
+	if (auth_ev)
+		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
+				SCTP_ULPEVENT(auth_ev));
 
 	return SCTP_DISPOSITION_CONSUME;
 
 nomem:
+	if (auth_ev)
+		sctp_ulpevent_free(auth_ev);
 	if (ai_ev)
 		sctp_ulpevent_free(ai_ev);
 	if (ev)