SCTP: Clean up OOTB handling and fix infinite loop processing

While processing OOTB chunks as well as chunks with an invalid
length of 0, it was possible to SCTP to get wedged inside an
infinite loop because we didn't catch the condition correctly,
or didn't mark the packet for discard correctly.
This work is based on original findings and work by
Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

include/net/sctp/sm.h

@@ -114,7 +114,6 @@ sctp_state_fn_t sctp_sf_do_4_C;
 sctp_state_fn_t sctp_sf_eat_data_6_2;
 sctp_state_fn_t sctp_sf_eat_data_fast_4_4;
 sctp_state_fn_t sctp_sf_eat_sack_6_2;
-sctp_state_fn_t sctp_sf_tabort_8_4_8;
 sctp_state_fn_t sctp_sf_operr_notify;
 sctp_state_fn_t sctp_sf_t1_init_timer_expire;
 sctp_state_fn_t sctp_sf_t1_cookie_timer_expire;

net/sctp/sm_statetable.c

@@ -110,7 +110,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/* SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -173,7 +173,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/*  SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -194,7 +194,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/*  SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -216,7 +216,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/*  SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_violation), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -258,7 +258,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/* SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -300,7 +300,7 @@ const sctp_sm_table_entry_t *sctp_sm_lookup_event(sctp_event_t event_type,
 	/* SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -499,7 +499,7 @@ static const sctp_sm_table_entry_t addip_chunk_event_table[SCTP_NUM_ADDIP_CHUNK_
 	/* SCTP_STATE_EMPTY */ \
 	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_CLOSED */ \
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8), \
+	TYPE_SCTP_FUNC(sctp_sf_ootb), \
 	/* SCTP_STATE_COOKIE_WAIT */ \
 	TYPE_SCTP_FUNC(sctp_sf_discard_chunk), \
 	/* SCTP_STATE_COOKIE_ECHOED */ \
@@ -528,7 +528,7 @@ chunk_event_table_unknown[SCTP_STATE_NUM_STATES] = {
 	/* SCTP_STATE_EMPTY */
 	TYPE_SCTP_FUNC(sctp_sf_ootb),
 	/* SCTP_STATE_CLOSED */
-	TYPE_SCTP_FUNC(sctp_sf_tabort_8_4_8),
+	TYPE_SCTP_FUNC(sctp_sf_ootb),
 	/* SCTP_STATE_COOKIE_WAIT */
 	TYPE_SCTP_FUNC(sctp_sf_unk_chunk),
 	/* SCTP_STATE_COOKIE_ECHOED */