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-rw-r--r--src/vnet/sctp/sctp.h141
1 files changed, 115 insertions, 26 deletions
diff --git a/src/vnet/sctp/sctp.h b/src/vnet/sctp/sctp.h
index af652dc06dc..0d2e4b3e821 100644
--- a/src/vnet/sctp/sctp.h
+++ b/src/vnet/sctp/sctp.h
@@ -77,7 +77,7 @@ typedef enum _sctp_error
#define IS_B_BIT_SET(var) ((var) & (1<<1))
#define IS_U_BIT_SET(var) ((var) & (1<<2))
-#define MAX_SCTP_CONNECTIONS 32
+#define MAX_SCTP_CONNECTIONS 8
#define MAIN_SCTP_SUB_CONN_IDX 0
#if (VLIB_BUFFER_TRACE_TRAJECTORY)
@@ -96,6 +96,7 @@ enum _sctp_subconn_state
SCTP_SUBCONN_STATE_ALLOW_HB
};
+#define SCTP_INITIAL_SSHTRESH 65535
typedef struct _sctp_sub_connection
{
transport_connection_t connection; /**< Common transport data. First! */
@@ -104,8 +105,10 @@ typedef struct _sctp_sub_connection
u32 error_count; /**< The current error count for this destination. */
u32 error_threshold; /**< Current error threshold for this destination,
i.e. what value marks the destination down if error count reaches this value. */
- u32 cwnd; /**< The current congestion window. */
- u32 ssthresh; /**< The current ssthresh value. */
+ u32 cwnd; /**< Congestion control window (cwnd, in bytes), which is adjusted by
+ the sender based on observed network conditions. */
+ u32 ssthresh; /**< Slow-start threshold (in bytes), which is used by the
+ sender to distinguish slow-start and congestion avoidance phases. */
u32 rtt_ts; /**< USED to hold the timestamp of when the packet has been sent */
@@ -132,12 +135,14 @@ typedef struct _sctp_sub_connection
u32 last_seen; /**< The time to which this destination was last sent a packet to.
This can be used to determine if a HEARTBEAT is needed. */
+ u32 last_data_ts; /**< Used to hold the timestamp value of last time we sent a DATA chunk */
+
u8 unacknowledged_hb; /**< Used to track how many unacknowledged heartbeats we had;
If more than SCTP_PATH_MAX_RETRANS then connection is considered unreachable. */
u8 is_retransmitting; /**< A flag (0 = no, 1 = yes) indicating whether the connection is retransmitting a previous packet */
- u8 enqueue_state;
+ u8 enqueue_state; /**< if set to 1 indicates that DATA is still being handled hence cannot shutdown this connection yet */
} sctp_sub_connection_t;
@@ -203,6 +208,7 @@ typedef struct _sctp_connection
TSN (normally just prior to transmit or during
fragmentation). */
+ u32 last_unacked_tsn; /** < Last TSN number still unacked */
u32 next_tsn_expected; /**< The next TSN number expected to be received. */
u32 last_rcvd_tsn; /**< This is the last TSN received in sequence. This value
@@ -221,25 +227,14 @@ typedef struct _sctp_connection
Note: This is used only when no DATA chunks are received out-of-order.
When DATA chunks are out-of-order, SACKs are not delayed (see Section 6). */
- u32 a_rwnd; /** This value represents the dedicated buffer space, in number of bytes,
- the sender of the INIT has reserved in association with this window.
- During the life of the association, this buffer space SHOULD NOT be lessened
- (i.e., dedicated buffers taken away from this association);
- however, an endpoint MAY change the value of a_rwnd it sends in SACK chunks. */
-
- u32 smallest_PMTU; /** The smallest PMTU discovered for all of the peer's transport addresses. */
-
- u32 rcv_a_rwnd; /**< LOCAL max seg size that includes options. To be updated by congestion algos, etc. */
- u32 snd_a_rwnd; /**< REMOTE max seg size that includes options. To be updated if peer pushes back on window, etc.*/
+ u8 smallest_PMTU_idx; /** The index of the sub-connection with the smallest PMTU discovered across all peer's transport addresses. */
u8 overall_sending_status; /**< 0 indicates first fragment of a user message
1 indicates normal stream
2 indicates last fragment of a user message */
- sctp_options_t rcv_opts;
sctp_options_t snd_opts;
- u32 snd_hdr_length; /**< BASE HEADER LENGTH for the DATA chunk when sending */
u8 next_avail_sub_conn; /**< Represent the index of the next free slot in sub_conn */
} sctp_connection_t;
@@ -413,7 +408,7 @@ sctp_optparam_type_to_string (u8 type)
#define SCTP_RTO_INIT 3 * SHZ /* 3 seconds */
#define SCTP_RTO_MIN 1 * SHZ /* 1 second */
#define SCTP_RTO_MAX 60 * SHZ /* 60 seconds */
-#define SCTP_RTO_BURST 4
+#define SCTP_RTO_BURST 4
#define SCTP_RTO_ALPHA 1/8
#define SCTP_RTO_BETA 1/4
#define SCTP_VALID_COOKIE_LIFE 60 * SHZ /* 60 seconds */
@@ -423,6 +418,8 @@ sctp_optparam_type_to_string (u8 type)
#define SCTP_HB_INTERVAL 30 * SHZ
#define SCTP_HB_MAX_BURST 1
+#define SCTP_DATA_IDLE_INTERVAL 15 * SHZ /* 15 seconds; the time-interval after which the connetion is considered IDLE */
+
#define SCTP_TO_TIMER_TICK SCTP_TICK*10 /* Period for converting from SCTP_TICK */
typedef struct _sctp_lookup_dispatch
@@ -715,17 +712,18 @@ sctp_connection_get (u32 conn_index, u32 thread_index)
always_inline u8
sctp_data_subconn_select (sctp_connection_t * sctp_conn)
{
- u8 i = 0;
- u8 state = SCTP_SUBCONN_STATE_DOWN;
u32 sub = MAIN_SCTP_SUB_CONN_IDX;
- u32 data_subconn_seed = random_default_seed ();
-
- while (state == SCTP_SUBCONN_STATE_DOWN && i < SELECT_MAX_RETRIES)
+ u8 i, cwnd = sctp_conn->sub_conn[MAIN_SCTP_SUB_CONN_IDX].cwnd;
+ for (i = 1; i < MAX_SCTP_CONNECTIONS; i++)
{
- u32 sub = random_u32 (&data_subconn_seed) % MAX_SCTP_CONNECTIONS;
- if (sctp_conn->sub_conn[sub].state == SCTP_SUBCONN_STATE_UP)
- break;
- i++;
+ if (sctp_conn->sub_conn[i].state == SCTP_SUBCONN_STATE_DOWN)
+ continue;
+
+ if (sctp_conn->sub_conn[i].cwnd > cwnd)
+ {
+ sub = i;
+ cwnd = sctp_conn->sub_conn[i].cwnd;
+ }
}
return sub;
}
@@ -813,6 +811,97 @@ vlib_buffer_push_sctp (vlib_buffer_t * b, u16 sp_net, u16 dp_net,
sctp_hdr_opts_len);
}
+always_inline void
+update_smallest_pmtu_idx (sctp_connection_t * sctp_conn)
+{
+ u8 i;
+ u8 smallest_pmtu_index = MAIN_SCTP_SUB_CONN_IDX;
+
+ for (i = 1; i < MAX_SCTP_CONNECTIONS; i++)
+ {
+ if (sctp_conn->sub_conn[i].state != SCTP_SUBCONN_STATE_DOWN)
+ {
+ if (sctp_conn->sub_conn[i].PMTU <
+ sctp_conn->sub_conn[smallest_pmtu_index].PMTU)
+ smallest_pmtu_index = i;
+ }
+ }
+
+ sctp_conn->smallest_PMTU_idx = smallest_pmtu_index;
+}
+
+/* As per RFC4960; section 7.2.1: Slow-Start */
+always_inline void
+sctp_init_cwnd (sctp_connection_t * sctp_conn)
+{
+ u8 i;
+ for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
+ {
+ /* Section 7.2.1; point (1) */
+ sctp_conn->sub_conn[i].cwnd =
+ clib_min (4 * sctp_conn->sub_conn[i].PMTU,
+ clib_max (2 * sctp_conn->sub_conn[i].PMTU, 4380));
+
+ /* Section 7.2.1; point (3) */
+ sctp_conn->sub_conn[i].ssthresh = SCTP_INITIAL_SSHTRESH;
+
+ /* Section 7.2.2; point (1) */
+ sctp_conn->sub_conn[i].partially_acked_bytes = 0;
+ }
+}
+
+always_inline u8
+sctp_in_cong_recovery (sctp_connection_t * sctp_conn, u8 idx)
+{
+ return 0;
+}
+
+always_inline u8
+cwnd_fully_utilized (sctp_connection_t * sctp_conn, u8 idx)
+{
+ return 0;
+}
+
+/* As per RFC4960; section 7.2.1: Slow-Start */
+always_inline void
+update_cwnd (sctp_connection_t * sctp_conn)
+{
+ u8 i;
+
+ for (i = 0; i < MAX_SCTP_CONNECTIONS; i++)
+ {
+ /* Section 7.2.1; point (2) */
+ if (sctp_conn->sub_conn[i].is_retransmitting)
+ {
+ sctp_conn->sub_conn[i].cwnd = 1 * sctp_conn->sub_conn[i].PMTU;
+ continue;
+ }
+
+ /* Section 7.2.2; point (4) */
+ if (sctp_conn->sub_conn[i].last_data_ts >
+ sctp_time_now () + SCTP_DATA_IDLE_INTERVAL)
+ {
+ sctp_conn->sub_conn[i].cwnd =
+ clib_max (sctp_conn->sub_conn[i].cwnd / 2,
+ 4 * sctp_conn->sub_conn[i].PMTU);
+ continue;
+ }
+
+ /* Section 7.2.1; point (5) */
+ if (sctp_conn->sub_conn[i].cwnd <= sctp_conn->sub_conn[i].ssthresh)
+ {
+ if (!cwnd_fully_utilized (sctp_conn, i))
+ continue;
+
+ if (sctp_in_cong_recovery (sctp_conn, i))
+ continue;
+
+ sctp_conn->sub_conn[i].cwnd =
+ clib_min (sctp_conn->sub_conn[i].PMTU, 1);
+ }
+ }
+}
+
/*
* fd.io coding-style-patch-verification: ON
*