commit 6dae9903b1d5fe3c5df712eb99076a9adf9d5c8b Author: Mike Perry mikeperry-git@torproject.org Date: Tue Sep 28 21:19:27 2021 +0000

Turn orconn watermarks into consensus parameters.

Tuning these may reduce memory usage and latency. --- src/app/main/main.c | 2 ++ src/core/or/channeltls.c | 3 ++- src/core/or/congestion_control_common.c | 31 +++++++++++++++++++++++++++++++ src/core/or/congestion_control_common.h | 21 +++++++++++++++++++++ src/core/or/connection_or.c | 7 ++++--- src/core/or/or.h | 12 ------------ src/feature/nodelist/networkstatus.c | 2 ++ src/test/test_channeltls.c | 3 ++- 8 files changed, 64 insertions(+), 17 deletions(-)

diff --git a/src/app/main/main.c b/src/app/main/main.c index 0742abe70a..6043b9589f 100644 --- a/src/app/main/main.c +++ b/src/app/main/main.c @@ -27,6 +27,7 @@ #include "core/or/channel.h" #include "core/or/channelpadding.h" #include "core/or/circuitpadding.h" +#include "core/or/congestion_control_common.h" #include "core/or/congestion_control_flow.h" #include "core/or/circuitlist.h" #include "core/or/command.h" @@ -631,6 +632,7 @@ tor_init(int argc, char *argv[]) * until we get a consensus */ channelpadding_new_consensus_params(NULL); circpad_new_consensus_params(NULL); + congestion_control_new_consensus_params(NULL); flow_control_new_consensus_params(NULL);

/* Initialize circuit padding to defaults+torrc until we get a consensus */ diff --git a/src/core/or/channeltls.c b/src/core/or/channeltls.c index 481dafef91..9db8e2392d 100644 --- a/src/core/or/channeltls.c +++ b/src/core/or/channeltls.c @@ -64,6 +64,7 @@ #include "trunnel/netinfo.h" #include "core/or/channelpadding.h" #include "core/or/extendinfo.h" +#include "core/or/congestion_control_common.h"

#include "core/or/cell_st.h" #include "core/or/cell_queue_st.h" @@ -793,7 +794,7 @@ channel_tls_num_cells_writeable_method(channel_t *chan) cell_network_size = get_cell_network_size(tlschan->conn->wide_circ_ids); outbuf_len = connection_get_outbuf_len(TO_CONN(tlschan->conn)); /* Get the number of cells */ - n = CEIL_DIV(OR_CONN_HIGHWATER - outbuf_len, cell_network_size); + n = CEIL_DIV(or_conn_highwatermark() - outbuf_len, cell_network_size); if (n < 0) n = 0; #if SIZEOF_SIZE_T > SIZEOF_INT if (n > INT_MAX) n = INT_MAX; diff --git a/src/core/or/congestion_control_common.c b/src/core/or/congestion_control_common.c index 51691c106d..393b79459d 100644 --- a/src/core/or/congestion_control_common.c +++ b/src/core/or/congestion_control_common.c @@ -46,6 +46,9 @@

#define BWE_SENDME_MIN_DFLT 5

+#define OR_CONN_HIGHWATER_DFLT (32*1024) +#define OR_CONN_LOWWATER_DFLT (16*1024) + static uint64_t congestion_control_update_circuit_rtt(congestion_control_t *, uint64_t); static bool congestion_control_update_circuit_bdp(congestion_control_t *, @@ -53,6 +56,34 @@ static bool congestion_control_update_circuit_bdp(congestion_control_t *, const crypt_path_t *, uint64_t, uint64_t);

+static uint32_t cwnd_max = CWND_MAX_DFLT; +uint32_t or_conn_highwater = OR_CONN_HIGHWATER_DFLT; +uint32_t or_conn_lowwater = OR_CONN_LOWWATER_DFLT; + +/** + * Update global congestion control related consensus parameter values, + * every consensus update. + */ +void +congestion_control_new_consensus_params(const networkstatus_t *ns) +{ +#define OR_CONN_HIGHWATER_MIN (CELL_PAYLOAD_SIZE) +#define OR_CONN_HIGHWATER_MAX (INT32_MAX) + or_conn_highwater = + networkstatus_get_param(ns, "orconn_high", + OR_CONN_HIGHWATER_DFLT, + OR_CONN_HIGHWATER_MIN, + OR_CONN_HIGHWATER_MAX); + +#define OR_CONN_LOWWATER_MIN (CELL_PAYLOAD_SIZE) +#define OR_CONN_LOWWATER_MAX (INT32_MAX) + or_conn_lowwater = + networkstatus_get_param(ns, "orconn_low", + OR_CONN_LOWWATER_DFLT, + OR_CONN_LOWWATER_MIN, + OR_CONN_LOWWATER_MAX); +} + /** * Set congestion control parameters on a circuit's congestion * control object based on values from the consensus. diff --git a/src/core/or/congestion_control_common.h b/src/core/or/congestion_control_common.h index e8b9681ac6..02fee78013 100644 --- a/src/core/or/congestion_control_common.h +++ b/src/core/or/congestion_control_common.h @@ -41,6 +41,27 @@ int sendme_get_inc_count(const circuit_t *, const crypt_path_t *); bool circuit_sent_cell_for_sendme(const circuit_t *, const crypt_path_t *); bool is_monotime_clock_reliable(void);

+void congestion_control_new_consensus_params(const networkstatus_t *ns); + +/* Ugh, C.. these two are private. Use the getter instead, when + * external to the congestion control code. */ +extern uint32_t or_conn_highwater; +extern uint32_t or_conn_lowwater; + +/** Stop writing on an orconn when its outbuf is this large */ +static inline uint32_t +or_conn_highwatermark(void) +{ + return or_conn_highwater; +} + +/** Resume writing on an orconn when its outbuf is less than this */ +static inline uint32_t +or_conn_lowwatermark(void) +{ + return or_conn_lowwater; +} + /** * Compute an N-count EWMA, aka N-EWMA. N-EWMA is defined as: * EWMA = alpha*value + (1-alpha)*EWMA_prev diff --git a/src/core/or/connection_or.c b/src/core/or/connection_or.c index dd31638eb3..db9f93e6f6 100644 --- a/src/core/or/connection_or.c +++ b/src/core/or/connection_or.c @@ -65,6 +65,7 @@ #include "core/or/scheduler.h" #include "feature/nodelist/torcert.h" #include "core/or/channelpadding.h" +#include "core/or/congestion_control_common.h" #include "feature/dirauth/authmode.h" #include "feature/hs/hs_service.h"

@@ -636,7 +637,7 @@ connection_or_flushed_some(or_connection_t *conn) /* If we're under the low water mark, add cells until we're just over the * high water mark. */ datalen = connection_get_outbuf_len(TO_CONN(conn)); - if (datalen < OR_CONN_LOWWATER) { + if (datalen < or_conn_lowwatermark()) { /* Let the scheduler know */ scheduler_channel_wants_writes(TLS_CHAN_TO_BASE(conn->chan)); } @@ -660,9 +661,9 @@ connection_or_num_cells_writeable(or_connection_t *conn) * used to trigger when to start writing after we've stopped. */ datalen = connection_get_outbuf_len(TO_CONN(conn)); - if (datalen < OR_CONN_HIGHWATER) { + if (datalen < or_conn_highwatermark()) { cell_network_size = get_cell_network_size(conn->wide_circ_ids); - n = CEIL_DIV(OR_CONN_HIGHWATER - datalen, cell_network_size); + n = CEIL_DIV(or_conn_highwatermark() - datalen, cell_network_size); }

return n; diff --git a/src/core/or/or.h b/src/core/or/or.h index ad82130301..392a848ee7 100644 --- a/src/core/or/or.h +++ b/src/core/or/or.h @@ -594,18 +594,6 @@ typedef struct or_handshake_state_t or_handshake_state_t;

/** Length of Extended ORPort connection identifier. */ #define EXT_OR_CONN_ID_LEN DIGEST_LEN /* 20 */ -/* - * OR_CONN_HIGHWATER and OR_CONN_LOWWATER moved from connection_or.c so - * channeltls.c can see them too. - */ - -/** When adding cells to an OR connection's outbuf, keep adding until the - * outbuf is at least this long, or we run out of cells. */ -#define OR_CONN_HIGHWATER (32*1024) - -/** Add cells to an OR connection's outbuf whenever the outbuf's data length - * drops below this size. */ -#define OR_CONN_LOWWATER (16*1024)

typedef struct connection_t connection_t; typedef struct control_connection_t control_connection_t; diff --git a/src/feature/nodelist/networkstatus.c b/src/feature/nodelist/networkstatus.c index 0138dff033..6867d8c98e 100644 --- a/src/feature/nodelist/networkstatus.c +++ b/src/feature/nodelist/networkstatus.c @@ -45,6 +45,7 @@ #include "core/or/channel.h" #include "core/or/channelpadding.h" #include "core/or/circuitpadding.h" +#include "core/or/congestion_control_common.h" #include "core/or/congestion_control_flow.h" #include "core/or/circuitmux.h" #include "core/or/circuitmux_ewma.h" @@ -1700,6 +1701,7 @@ notify_after_networkstatus_changes(void) channelpadding_new_consensus_params(c); circpad_new_consensus_params(c); router_new_consensus_params(c); + congestion_control_new_consensus_params(c); flow_control_new_consensus_params(c);

/* Maintenance of our L2 guard list */ diff --git a/src/test/test_channeltls.c b/src/test/test_channeltls.c index 5219c86097..ca7fee2c53 100644 --- a/src/test/test_channeltls.c +++ b/src/test/test_channeltls.c @@ -20,6 +20,7 @@ #include "lib/tls/tortls.h"

#include "core/or/or_connection_st.h" +#include "core/or/congestion_control_common.h"

/* Test suite stuff */ #include "test/test.h" @@ -155,7 +156,7 @@ test_channeltls_num_bytes_queued(void *arg) * - 2 cells. */ n = ch->num_cells_writeable(ch); - tt_int_op(n, OP_EQ, CEIL_DIV(OR_CONN_HIGHWATER, 512) - 2); + tt_int_op(n, OP_EQ, CEIL_DIV(or_conn_highwatermark(), 512) - 2); UNMOCK(buf_datalen); tlschan_buf_datalen_mock_target = NULL; tlschan_buf_datalen_mock_size = 0;