sctp: cleanup handling of graceful shutdown of the peer

Don't handle a graceful shutdown of the peer as an implicit signal
that all partial messages are complete. First, this is not implemented
correctly and second this should not be done by the peer. It is more
appropriate to handle this as a protocol violation.
Remove the incorrect code and leave detecting the protocol violation
and its handling in a followup commit.

(cherry picked from commit 4f14d4b6b7f0ca49b14379e48117121af3ed2669)

3 files changed, 16 insertions, 67 deletions

diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c
index fa0b9f4894ea..f9e49b7b4f62 100644
--- a/sys/netinet/sctp_input.c
+++ b/sys/netinet/sctp_input.c
@@ -837,8 +837,7 @@ sctp_handle_shutdown(struct sctp_shutdown_chunk *cp,
 	int some_on_streamwheel;
 	int old_state;
 
-	SCTPDBG(SCTP_DEBUG_INPUT2,
-	    "sctp_handle_shutdown: handling SHUTDOWN\n");
+	SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_shutdown: handling SHUTDOWN\n");
 	if (stcb == NULL)
 		return;
 	asoc = &stcb->asoc;
@@ -855,40 +854,12 @@ sctp_handle_shutdown(struct sctp_shutdown_chunk *cp,
 	if (*abort_flag) {
 		return;
 	}
-	if (asoc->control_pdapi) {
-		/*
-		 * With a normal shutdown we assume the end of last record.
-		 */
-		SCTP_INP_READ_LOCK(stcb->sctp_ep);
-		if (asoc->control_pdapi->on_strm_q) {
-			struct sctp_stream_in *strm;
-
-			strm = &asoc->strmin[asoc->control_pdapi->sinfo_stream];
-			if (asoc->control_pdapi->on_strm_q == SCTP_ON_UNORDERED) {
-				/* Unordered */
-				TAILQ_REMOVE(&strm->uno_inqueue, asoc->control_pdapi, next_instrm);
-				asoc->control_pdapi->on_strm_q = 0;
-			} else if (asoc->control_pdapi->on_strm_q == SCTP_ON_ORDERED) {
-				/* Ordered */
-				TAILQ_REMOVE(&strm->inqueue, asoc->control_pdapi, next_instrm);
-				asoc->control_pdapi->on_strm_q = 0;
-#ifdef INVARIANTS
-			} else {
-				panic("Unknown state on ctrl:%p on_strm_q:%d",
-				    asoc->control_pdapi,
-				    asoc->control_pdapi->on_strm_q);
-#endif
-			}
-		}
-		asoc->control_pdapi->end_added = 1;
-		asoc->control_pdapi->pdapi_aborted = 1;
-		asoc->control_pdapi = NULL;
-		SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
-		if (stcb->sctp_socket) {
-			sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
-		}
-	}
-	/* goto SHUTDOWN_RECEIVED state to block new requests */
+	/*
+	 * FIXME MT: Handle the case where there are still incomplete
+	 * received user messages or known missing user messages from the
+	 * peer. One way to handle this is to abort the associations in this
+	 * case.
+	 */
 	if (stcb->sctp_socket) {
 		if ((SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_RECEIVED) &&
 		    (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_ACK_SENT) &&
@@ -949,8 +920,9 @@ sctp_handle_shutdown_ack(struct sctp_shutdown_ack_chunk *cp SCTP_UNUSED,
 
 	SCTPDBG(SCTP_DEBUG_INPUT2,
 	    "sctp_handle_shutdown_ack: handling SHUTDOWN ACK\n");
-	if (stcb == NULL)
+	if (stcb == NULL) {
 		return;
+	}
 
 	asoc = &stcb->asoc;
 	/* process according to association state */
@@ -967,17 +939,12 @@ sctp_handle_shutdown_ack(struct sctp_shutdown_ack_chunk *cp SCTP_UNUSED,
 		SCTP_TCB_UNLOCK(stcb);
 		return;
 	}
-	if (asoc->control_pdapi) {
-		/*
-		 * With a normal shutdown we assume the end of last record.
-		 */
-		SCTP_INP_READ_LOCK(stcb->sctp_ep);
-		asoc->control_pdapi->end_added = 1;
-		asoc->control_pdapi->pdapi_aborted = 1;
-		asoc->control_pdapi = NULL;
-		SCTP_INP_READ_UNLOCK(stcb->sctp_ep);
-		sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
-	}
+	/*
+	 * FIXME MT: Handle the case where there are still incomplete
+	 * received user messages or known missing user messages from the
+	 * peer. One way to handle this is to abort the associations in this
+	 * case.
+	 */
 #ifdef INVARIANTS
 	if (!TAILQ_EMPTY(&asoc->send_queue) ||
 	    !TAILQ_EMPTY(&asoc->sent_queue) ||
diff --git a/sys/netinet/sctp_pcb.c b/sys/netinet/sctp_pcb.c
index 59686f9ff3f9..3435377e1064 100644
--- a/sys/netinet/sctp_pcb.c
+++ b/sys/netinet/sctp_pcb.c
@@ -3404,7 +3404,6 @@ sctp_inpcb_free(struct sctp_inpcb *inp, int immediate, int from)
 				continue;
 			}
 			if ((stcb->asoc.size_on_reasm_queue > 0) ||
-			    (stcb->asoc.control_pdapi) ||
 			    (stcb->asoc.size_on_all_streams > 0) ||
 			    ((so != NULL) && (SCTP_SBAVAIL(&so->so_rcv) > 0))) {
 				/* Left with Data unread */
@@ -4761,18 +4760,10 @@ sctp_free_assoc(struct sctp_inpcb *inp, struct sctp_tcb *stcb, int from_inpcbfre
 				 * now.
 				 */
 				if (sq->end_added == 0) {
-					/* Held for PD-API clear that. */
+					/* Held for PD-API, clear that. */
 					sq->pdapi_aborted = 1;
 					sq->held_length = 0;
 					if (sctp_stcb_is_feature_on(inp, stcb, SCTP_PCB_FLAGS_PDAPIEVNT) && (so != NULL)) {
-						/*
-						 * Need to add a PD-API
-						 * aborted indication.
-						 * Setting the control_pdapi
-						 * assures that it will be
-						 * added right after this
-						 * msg.
-						 */
 						sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
 						    stcb,
 						    SCTP_PARTIAL_DELIVERY_ABORTED,
diff --git a/sys/netinet/sctp_structs.h b/sys/netinet/sctp_structs.h
index fb7deafa9ea3..1d3a3ef72728 100644
--- a/sys/netinet/sctp_structs.h
+++ b/sys/netinet/sctp_structs.h
@@ -956,15 +956,6 @@ struct sctp_association {
 	uint32_t fast_recovery_tsn;
 	uint32_t sat_t3_recovery_tsn;
 	uint32_t tsn_last_delivered;
-	/*
-	 * For the pd-api we should re-write this a bit more efficient. We
-	 * could have multiple sctp_queued_to_read's that we are building at
-	 * once. Now we only do this when we get ready to deliver to the
-	 * socket buffer. Note that we depend on the fact that the struct is
-	 * "stuck" on the read queue until we finish all the pd-api.
-	 */
-	struct sctp_queued_to_read *control_pdapi;
-
 	uint32_t tsn_of_pdapi_last_delivered;
 	uint32_t pdapi_ppid;
 	uint32_t context;