BFD: echo function

Change-Id: Ib1e301d62b687d4e42434239e7cd412065c28da0
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 66 insertions, 28 deletions

diff --git a/src/vnet/bfd/bfd_main.h b/src/vnet/bfd/bfd_main.h
index 14a54d6f3df..d8063f9de33 100644
--- a/src/vnet/bfd/bfd_main.h
+++ b/src/vnet/bfd/bfd_main.h
@@ -24,17 +24,6 @@
 #include <vnet/bfd/bfd_protocol.h>
 #include <vnet/bfd/bfd_udp.h>
 
-#define foreach_bfd_transport(F) \
-  F (UDP4, "ip4-rewrite")        \
-  F (UDP6, "ip6-rewrite")
-
-typedef enum
-{
-#define F(t, n) BFD_TRANSPORT_##t,
-  foreach_bfd_transport (F)
-#undef F
-} bfd_transport_t;
-
 #define foreach_bfd_mode(F) \
   F (asynchronous)          \
   F (demand)
@@ -64,14 +53,15 @@ typedef struct
   bfd_auth_type_e auth_type;
 } bfd_auth_key_t;
 
-#define foreach_bfd_poll_state(F)\
-  F(NOT_NEEDED)\
-F(NEEDED)\
-F(IN_PROGRESS)
+#define foreach_bfd_poll_state(F) \
+  F (NOT_NEEDED)                  \
+  F (NEEDED)                      \
+  F (IN_PROGRESS)                 \
+  F (IN_PROGRESS_AND_QUEUED)
 
 typedef enum
 {
-#define F(x) POLL_##x,
+#define F(x) BFD_POLL_##x,
   foreach_bfd_poll_state (F)
 #undef F
 } bfd_poll_state_e;
@@ -120,21 +110,27 @@ typedef struct bfd_session_s
   /* remote min rx interval (clocks) */
   u64 remote_min_rx_clocks;
 
+  /* remote min echo rx interval (microseconds) */
+  u64 remote_min_echo_rx_usec;
+
+  /* remote min echo rx interval (clocks) */
+  u64 remote_min_echo_rx_clocks;
+
   /* remote desired min tx interval (clocks) */
   u64 remote_desired_min_tx_clocks;
 
   /* configured detect multiplier */
   u8 local_detect_mult;
 
-  /* 1 if in demand mode, 0 otherwise */
-  u8 local_demand;
-
   /* 1 if remote system sets demand mode, 0 otherwise */
   u8 remote_demand;
 
   /* remote detect multiplier */
   u8 remote_detect_mult;
 
+  /* 1 is echo function is active, 0 otherwise */
+  u8 echo;
+
   /* set to value of timer in timing wheel, 0 if never set */
   u64 wheel_time_clocks;
 
@@ -150,12 +146,33 @@ typedef struct bfd_session_s
   /* timestamp of last packet received */
   u64 last_rx_clocks;
 
+  /* transmit interval for echo packets */
+  u64 echo_transmit_interval_clocks;
+
+  /* next time at which to transmit echo packet */
+  u64 echo_tx_timeout_clocks;
+
+  /* timestamp of last echo packet transmitted */
+  u64 echo_last_tx_clocks;
+
+  /* timestamp of last echo packet received */
+  u64 echo_last_rx_clocks;
+
+  /* secret used for calculating/checking checksum of echo packets */
+  u32 echo_secret;
+
   /* detection time */
   u64 detection_time_clocks;
 
   /* state info regarding poll sequence */
   bfd_poll_state_e poll_state;
 
+  /*
+   * helper for delayed poll sequence - marks either start of running poll
+   * sequence or timeout, after which we can start the next poll sequnce
+   */
+  u64 poll_state_start_or_timeout_clocks;
+
   /* authentication information */
   struct
   {
@@ -191,7 +208,7 @@ typedef struct bfd_session_s
   } auth;
 
   /* transport type for this session */
-  bfd_transport_t transport;
+  bfd_transport_e transport;
 
   /* union of transport-specific data */
   union
@@ -227,6 +244,9 @@ typedef struct
   /* default desired min tx in clocks */
   u64 default_desired_min_tx_clocks;
 
+  /* minimum required min rx while echo function is active - clocks */
+  u64 min_required_min_rx_while_echo_clocks;
+
   /* for generating random numbers */
   u32 random_seed;
 
@@ -268,36 +288,54 @@ enum
   BFD_EVENT_CONFIG_CHANGED,
 } bfd_process_event_e;
 
-u8 *bfd_input_format_trace (u8 * s, va_list * args);
+/* echo packet structure */
+/* *INDENT-OFF* */
+typedef CLIB_PACKED (struct {
+  /* local discriminator */
+  u32 discriminator;
+  /* expire time of this packet - clocks */
+  u64 expire_time_clocks;
+  /* checksum - based on discriminator, local secret and expire time */
+  u64 checksum;
+}) bfd_echo_pkt_t;
+/* *INDENT-ON* */
 
-bfd_session_t *bfd_get_session (bfd_main_t * bm, bfd_transport_t t);
+u8 *bfd_input_format_trace (u8 * s, va_list * args);
+bfd_session_t *bfd_get_session (bfd_main_t * bm, bfd_transport_e t);
 void bfd_put_session (bfd_main_t * bm, bfd_session_t * bs);
 bfd_session_t *bfd_find_session_by_idx (bfd_main_t * bm, uword bs_idx);
 bfd_session_t *bfd_find_session_by_disc (bfd_main_t * bm, u32 disc);
 void bfd_session_start (bfd_main_t * bm, bfd_session_t * bs);
 void bfd_consume_pkt (bfd_main_t * bm, const bfd_pkt_t * bfd, u32 bs_idx);
+int bfd_consume_echo_pkt (bfd_main_t * bm, vlib_buffer_t * b);
 int bfd_verify_pkt_common (const bfd_pkt_t * pkt);
 int bfd_verify_pkt_auth (const bfd_pkt_t * pkt, u16 pkt_size,
 			 bfd_session_t * bs);
 void bfd_event (bfd_main_t * bm, bfd_session_t * bs);
 void bfd_init_final_control_frame (vlib_main_t * vm, vlib_buffer_t * b,
-				   bfd_session_t * bs);
+				   bfd_main_t * bm, bfd_session_t * bs);
 u8 *format_bfd_session (u8 * s, va_list * args);
 void bfd_session_set_flags (bfd_session_t * bs, u8 admin_up_down);
 unsigned bfd_auth_type_supported (bfd_auth_type_e auth_type);
 vnet_api_error_t bfd_auth_activate (bfd_session_t * bs, u32 conf_key_id,
 				    u8 bfd_key_id, u8 is_delayed);
 vnet_api_error_t bfd_auth_deactivate (bfd_session_t * bs, u8 is_delayed);
-vnet_api_error_t
-bfd_session_set_params (bfd_main_t * bm, bfd_session_t * bs,
-			u32 desired_min_tx_usec,
-			u32 required_min_rx_usec, u8 detect_mult);
+vnet_api_error_t bfd_session_set_params (bfd_main_t * bm, bfd_session_t * bs,
+					 u32 desired_min_tx_usec,
+					 u32 required_min_rx_usec,
+					 u8 detect_mult);
 
 #define USEC_PER_MS 1000LL
 #define USEC_PER_SECOND (1000 * USEC_PER_MS)
 
 /* default, slow transmission interval for BFD packets, per spec at least 1s */
-#define BFD_DEFAULT_DESIRED_MIN_TX_US USEC_PER_SECOND
+#define BFD_DEFAULT_DESIRED_MIN_TX_USEC USEC_PER_SECOND
+
+/*
+ * minimum required min rx set locally when echo function is used, per spec
+ * should be set to at least 1s
+ */
+#define BFD_REQUIRED_MIN_RX_USEC_WHILE_ECHO USEC_PER_SECOND
 
 #endif /* __included_bfd_main_h__ */