Fixes a bug where SACKs in the face of

mapping_array expansion would break. Basically
once we expanded the array we no longer had both
mapping arrays in sync which the sack processing code depends on.
This would mean we were randomly referring to memory that was probably
not there. This mostly just gave us bad sack results going back to the peer.
If INVARIENTS was on of course we would hit the panic routine in the sack_check
call.

We also add a print routine for the place where one would panic in
invarients so one can see what the main mapping array holds.

Reviewed by: tuexen@freebsd.org
MFC after:	2 weeks

3 files changed, 35 insertions, 50 deletions

diff --git a/sys/netinet/sctp_indata.c b/sys/netinet/sctp_indata.c
index cdb78af..65eb086 100644
--- a/sys/netinet/sctp_indata.c
+++ b/sys/netinet/sctp_indata.c
@@ -2540,15 +2540,7 @@ sctp_sack_check(struct sctp_tcb *stcb, int ok_to_sack, int was_a_gap, int *abort
 	/* int nr_at; */
 	/* int nr_last_all_ones = 0; */
 	/* int nr_slide_from, nr_slide_end, nr_lgap, nr_distance; */
-
 	uint32_t old_cumack, old_base, old_highest;
-	unsigned char aux_array[64];
-
-	/*
-	 * EY! Don't think this is required but I am immitating the code for
-	 * map just to make sure
-	 */
-	unsigned char nr_aux_array[64];
 
 	asoc = &stcb->asoc;
 	at = 0;
@@ -2556,33 +2548,6 @@ sctp_sack_check(struct sctp_tcb *stcb, int ok_to_sack, int was_a_gap, int *abort
 	old_cumack = asoc->cumulative_tsn;
 	old_base = asoc->mapping_array_base_tsn;
 	old_highest = asoc->highest_tsn_inside_map;
-	if (asoc->mapping_array_size < 64)
-		memcpy(aux_array, asoc->mapping_array,
-		    asoc->mapping_array_size);
-	else
-		memcpy(aux_array, asoc->mapping_array, 64);
-	/* EY do the same for nr_mapping_array */
-	if (SCTP_BASE_SYSCTL(sctp_nr_sack_on_off) && asoc->peer_supports_nr_sack) {
-		if (asoc->nr_mapping_array_size != asoc->mapping_array_size) {
-			/*
-			 * printf("\nEY-IN sack_check method: \nEY-" "The
-			 * size of map and nr_map are inconsitent")
-			 */ ;
-		}
-		if (asoc->nr_mapping_array_base_tsn != asoc->mapping_array_base_tsn) {
-			/*
-			 * printf("\nEY-IN sack_check method VERY CRUCIAL
-			 * error: \nEY-" "The base tsns of map and nr_map
-			 * are inconsitent")
-			 */ ;
-		}
-		/* EY! just immitating the above code */
-		if (asoc->nr_mapping_array_size < 64)
-			memcpy(nr_aux_array, asoc->nr_mapping_array,
-			    asoc->nr_mapping_array_size);
-		else
-			memcpy(aux_array, asoc->nr_mapping_array, 64);
-	}
 	/*
 	 * We could probably improve this a small bit by calculating the
 	 * offset of the current cum-ack as the starting point.
@@ -2618,6 +2583,7 @@ sctp_sack_check(struct sctp_tcb *stcb, int ok_to_sack, int was_a_gap, int *abort
 #else
 		SCTP_PRINTF("huh, cumack 0x%x greater than high-tsn 0x%x in map - should panic?\n",
 		    asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
+		sctp_print_mapping_array(asoc);
 		if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
 			sctp_log_map(0, 6, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
 		}
diff --git a/sys/netinet/sctputil.c b/sys/netinet/sctputil.c
index 658dc55..c03b9d0 100644
--- a/sys/netinet/sctputil.c
+++ b/sys/netinet/sctputil.c
@@ -1180,6 +1180,25 @@ sctp_init_asoc(struct sctp_inpcb *m, struct sctp_tcb *stcb,
 	return (0);
 }
 
+void
+sctp_print_mapping_array(struct sctp_association *asoc)
+{
+	int i;
+
+	printf("Mapping size:%d baseTSN:%8.8x cumAck:%8.8x highestTSN:%8.8x\n",
+	    asoc->mapping_array_size,
+	    asoc->mapping_array_base_tsn,
+	    asoc->cumulative_tsn,
+	    asoc->highest_tsn_inside_map
+	    );
+	for (i = 0; i < asoc->mapping_array_size; i++) {
+		printf("%8.8x ", asoc->mapping_array[i]);
+		if (((i + 1) % 8) == 0)
+			printf("\n");
+	}
+	printf("\n");
+}
+
 int
 sctp_expand_mapping_array(struct sctp_association *asoc, uint32_t needed)
 {
@@ -1187,7 +1206,9 @@ sctp_expand_mapping_array(struct sctp_association *asoc, uint32_t needed)
 	uint8_t *new_array;
 	uint32_t new_size;
 
+
 	new_size = asoc->mapping_array_size + ((needed + 7) / 8 + SCTP_MAPPING_ARRAY_INCR);
+
 	SCTP_MALLOC(new_array, uint8_t *, new_size, SCTP_M_MAP);
 	if (new_array == NULL) {
 		/* can't get more, forget it */
@@ -1200,21 +1221,19 @@ sctp_expand_mapping_array(struct sctp_association *asoc, uint32_t needed)
 	SCTP_FREE(asoc->mapping_array, SCTP_M_MAP);
 	asoc->mapping_array = new_array;
 	asoc->mapping_array_size = new_size;
-	if (asoc->peer_supports_nr_sack) {
-		new_size = asoc->nr_mapping_array_size + ((needed + 7) / 8 + SCTP_NR_MAPPING_ARRAY_INCR);
-		SCTP_MALLOC(new_array, uint8_t *, new_size, SCTP_M_MAP);
-		if (new_array == NULL) {
-			/* can't get more, forget it */
-			SCTP_PRINTF("No memory for expansion of SCTP mapping array %d\n",
-			    new_size);
-			return (-1);
-		}
-		memset(new_array, 0, new_size);
-		memcpy(new_array, asoc->nr_mapping_array, asoc->nr_mapping_array_size);
-		SCTP_FREE(asoc->nr_mapping_array, SCTP_M_MAP);
-		asoc->nr_mapping_array = new_array;
-		asoc->nr_mapping_array_size = new_size;
+	new_size = asoc->nr_mapping_array_size + ((needed + 7) / 8 + SCTP_NR_MAPPING_ARRAY_INCR);
+	SCTP_MALLOC(new_array, uint8_t *, new_size, SCTP_M_MAP);
+	if (new_array == NULL) {
+		/* can't get more, forget it */
+		SCTP_PRINTF("No memory for expansion of SCTP mapping array %d\n",
+		    new_size);
+		return (-1);
 	}
+	memset(new_array, 0, new_size);
+	memcpy(new_array, asoc->nr_mapping_array, asoc->nr_mapping_array_size);
+	SCTP_FREE(asoc->nr_mapping_array, SCTP_M_MAP);
+	asoc->nr_mapping_array = new_array;
+	asoc->nr_mapping_array_size = new_size;
 	return (0);
 }
 
diff --git a/sys/netinet/sctputil.h b/sys/netinet/sctputil.h
index f3a731e..8d663ab 100644
--- a/sys/netinet/sctputil.h
+++ b/sys/netinet/sctputil.h
@@ -376,7 +376,7 @@ int sctp_fill_stat_log(void *, size_t *);
 void sctp_log_fr(uint32_t, uint32_t, uint32_t, int);
 void sctp_log_sack(uint32_t, uint32_t, uint32_t, uint16_t, uint16_t, int);
 void sctp_log_map(uint32_t, uint32_t, uint32_t, int);
-
+void sctp_print_mapping_array(struct sctp_association *asoc);
 void sctp_clr_stat_log(void);