--- /dev/null
+/*
+ * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/* For generating debug statistics during congestion controller development. */
+/*#define GENERATE_LOG*/
+
+#include "testutil.h"
+#include <openssl/ssl.h>
+#include "internal/quic_cc.h"
+#include "internal/priority_queue.h"
+
+/*
+ * Time Simulation
+ * ===============
+ */
+static OSSL_TIME fake_time = {0};
+
+#define TIME_BASE (ossl_ticks2time(5 * OSSL_TIME_SECOND))
+
+static OSSL_TIME fake_now(void *arg)
+{
+ return fake_time;
+}
+
+static void step_time(uint32_t ms)
+{
+ fake_time = ossl_time_add(fake_time, ossl_ms2time(ms));
+}
+
+/*
+ * Network Simulation
+ * ==================
+ *
+ * This is a simple 'network simulator' which emulates a network with a certain
+ * bandwidth and latency. Sending a packet into the network causes it to consume
+ * some capacity of the network until the packet exits the network. Note that
+ * the capacity is not known to the congestion controller as the entire point of
+ * a congestion controller is to correctly estimate this capacity and this is
+ * what we are testing. The network simulator does take care of informing the
+ * congestion controller of ack/loss events automatically but the caller is
+ * responsible for querying the congestion controller and choosing the size of
+ * simulated transmitted packets.
+ */
+typedef struct net_pkt_st {
+ /*
+ * The time at which the packet was sent.
+ */
+ OSSL_TIME tx_time;
+
+ /*
+ * The time at which the simulated packet arrives at the RX side (success)
+ * or is dropped (!success).
+ */
+ OSSL_TIME arrive_time;
+
+ /*
+ * The time at which the transmitting side makes a determination of
+ * acknowledgement (if success) or loss (if !success).
+ */
+ OSSL_TIME determination_time;
+
+ /*
+ * Current earliest time there is something to be done for this packet.
+ * min(arrive_time, determination_time).
+ */
+ OSSL_TIME next_time;
+
+ /* 1 if the packet will be successfully delivered, 0 if it is to be lost. */
+ int success;
+
+ /* 1 if we have already processed packet arrival. */
+ int arrived;
+
+ /* Size of simulated packet in bytes. */
+ size_t size;
+
+ /* pqueue internal index. */
+ size_t idx;
+} NET_PKT;
+
+DEFINE_PRIORITY_QUEUE_OF(NET_PKT);
+
+static int net_pkt_cmp(const NET_PKT *a, const NET_PKT *b)
+{
+ return ossl_time_compare(a->next_time, b->next_time);
+}
+
+struct net_sim {
+ const OSSL_CC_METHOD *ccm;
+ OSSL_CC_DATA *cc;
+
+ uint64_t capacity; /* bytes/s */
+ uint64_t latency; /* ms */
+
+ uint64_t spare_capacity;
+ PRIORITY_QUEUE_OF(NET_PKT) *pkts;
+
+ uint64_t total_acked, total_lost; /* bytes */
+};
+
+static int net_sim_init(struct net_sim *s,
+ const OSSL_CC_METHOD *ccm, OSSL_CC_DATA *cc,
+ uint64_t capacity, uint64_t latency)
+{
+ s->ccm = ccm;
+ s->cc = cc;
+
+ s->capacity = capacity;
+ s->latency = latency;
+
+ s->spare_capacity = capacity;
+
+ s->total_acked = 0;
+ s->total_lost = 0;
+
+ if (!TEST_ptr(s->pkts = ossl_pqueue_NET_PKT_new(net_pkt_cmp)))
+ return 0;
+
+ return 1;
+}
+
+static void net_sim_cleanup(struct net_sim *s)
+{
+ NET_PKT *pkt;
+
+ while ((pkt = ossl_pqueue_NET_PKT_pop(s->pkts)) != NULL)
+ OPENSSL_free(pkt);
+
+ ossl_pqueue_NET_PKT_free(s->pkts);
+}
+
+static int net_sim_process(struct net_sim *s, size_t skip_forward);
+
+static int net_sim_send(struct net_sim *s, size_t sz)
+{
+ NET_PKT *pkt = OPENSSL_zalloc(sizeof(*pkt));
+ int success;
+
+ if (!TEST_ptr(pkt))
+ return 0;
+
+ /*
+ * Ensure we have processed any events which have come due as these might
+ * increase our spare capacity.
+ */
+ if (!TEST_true(net_sim_process(s, 0)))
+ return 0;
+
+ /* Do we have room for the packet in the network? */
+ success = (sz <= s->spare_capacity);
+
+ pkt->tx_time = fake_time;
+ pkt->success = success;
+ if (success) {
+ /* This packet will arrive successfully after |latency| time. */
+ pkt->arrive_time = ossl_time_add(pkt->tx_time,
+ ossl_ms2time(s->latency));
+ /* Assume all received packets are acknowledged immediately. */
+ pkt->determination_time = ossl_time_add(pkt->arrive_time,
+ ossl_ms2time(s->latency));
+ pkt->next_time = pkt->arrive_time;
+ s->spare_capacity -= sz;
+ } else {
+ /*
+ * In our network model, assume all packets are dropped due to a
+ * bottleneck at the peer's NIC RX queue; thus dropping occurs after
+ * |latency|.
+ */
+ pkt->arrive_time = ossl_time_add(pkt->tx_time,
+ ossl_ms2time(s->latency));
+ /*
+ * It will take longer to detect loss than to detect acknowledgement.
+ */
+ pkt->determination_time = ossl_time_add(pkt->tx_time,
+ ossl_ms2time(3 * s->latency));
+ pkt->next_time = pkt->determination_time;
+ }
+
+ pkt->size = sz;
+
+ if (!TEST_true(s->ccm->on_data_sent(s->cc, sz)))
+ return 0;
+
+ if (!TEST_true(ossl_pqueue_NET_PKT_push(s->pkts, pkt, &pkt->idx)))
+ return 0;
+
+ return 1;
+}
+
+static int net_sim_process_one(struct net_sim *s, int skip_forward)
+{
+ NET_PKT *pkt = ossl_pqueue_NET_PKT_peek(s->pkts);
+
+ if (pkt == NULL)
+ return 3;
+
+ /* Jump forward to the next significant point in time. */
+ if (skip_forward && ossl_time_compare(pkt->next_time, fake_time) > 0)
+ fake_time = pkt->next_time;
+
+ if (pkt->success && !pkt->arrived
+ && ossl_time_compare(fake_time, pkt->arrive_time) >= 0) {
+ /* Packet arrives */
+ s->spare_capacity += pkt->size;
+ pkt->arrived = 1;
+
+ ossl_pqueue_NET_PKT_pop(s->pkts);
+ pkt->next_time = pkt->determination_time;
+ if (!ossl_pqueue_NET_PKT_push(s->pkts, pkt, &pkt->idx))
+ return 0;
+
+ return 1;
+ }
+
+ if (ossl_time_compare(fake_time, pkt->determination_time) < 0)
+ return 2;
+
+ if (!ossl_assert(!pkt->success || pkt->arrived))
+ return 0;
+
+ if (!pkt->success) {
+ OSSL_CC_LOSS_INFO loss_info = {0};
+
+ loss_info.tx_time = pkt->tx_time;
+ loss_info.tx_size = pkt->size;
+
+ if (!TEST_true(s->ccm->on_data_lost(s->cc, &loss_info)))
+ return 0;
+
+ if (!TEST_true(s->ccm->on_data_lost_finished(s->cc, 0)))
+ return 0;
+
+ s->total_lost += pkt->size;
+ ossl_pqueue_NET_PKT_pop(s->pkts);
+ OPENSSL_free(pkt);
+ } else {
+ OSSL_CC_ACK_INFO ack_info = {0};
+
+ ack_info.tx_time = pkt->tx_time;
+ ack_info.tx_size = pkt->size;
+
+ if (!TEST_true(s->ccm->on_data_acked(s->cc, &ack_info)))
+ return 0;
+
+ s->total_acked += pkt->size;
+ ossl_pqueue_NET_PKT_pop(s->pkts);
+ OPENSSL_free(pkt);
+ }
+
+ return 1;
+}
+
+static int net_sim_process(struct net_sim *s, size_t skip_forward)
+{
+ int rc;
+
+ while ((rc = net_sim_process_one(s, skip_forward > 0 ? 1 : 0)) == 1)
+ if (skip_forward > 0)
+ --skip_forward;
+
+ return rc;
+}
+
+/*
+ * State Dumping Utilities
+ * =======================
+ *
+ * Utilities for outputting CC state information.
+ */
+#ifdef GENERATE_LOG
+static FILE *logfile;
+#endif
+
+static int dump_state(const OSSL_CC_METHOD *ccm, OSSL_CC_DATA *cc,
+ struct net_sim *s)
+{
+#ifdef GENERATE_LOG
+ uint64_t cwnd_size, cur_bytes, state;
+
+ if (logfile == NULL)
+ return 1;
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_CWND_SIZE,
+ &cwnd_size)))
+ return 0;
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_BYTES_IN_FLIGHT,
+ &cur_bytes)))
+ return 0;
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_STATE,
+ &state)))
+ return 0;
+
+ fprintf(logfile, "%10lu,%10lu,%10lu,%10lu,%10lu,%10lu,%10lu,%10lu,\"%c\"\n",
+ ossl_time2ms(fake_time),
+ ccm->get_tx_allowance(cc),
+ cwnd_size,
+ cur_bytes,
+ s->total_acked,
+ s->total_lost,
+ s->capacity,
+ s->spare_capacity,
+ (char)state);
+#endif
+
+ return 1;
+}
+
+/*
+ * Simulation Test
+ * ===============
+ *
+ * Simulator-based unit test in which we simulate a network with a certain
+ * capacity. The average estimated channel capacity should not be too far from
+ * the actual channel capacity.
+ */
+static int test_simulate(void)
+{
+ int testresult = 0;
+ int rc;
+ int have_sim = 0;
+ const OSSL_CC_METHOD *ccm = &ossl_cc_newreno_method;
+ OSSL_CC_DATA *cc = NULL;
+ uint64_t mdpl = 1472;
+ uint64_t total_sent = 0, total_to_send, allowance;
+ uint64_t actual_capacity = 16000; /* B/s - 128kb/s */
+ uint64_t cwnd_sample_sum = 0, cwnd_sample_count = 0;
+ struct net_sim sim;
+
+ fake_time = TIME_BASE;
+
+ if (!TEST_ptr(cc = ccm->new(fake_now, NULL)))
+ goto err;
+
+ if (!TEST_true(net_sim_init(&sim, ccm, cc, actual_capacity, 100)))
+ goto err;
+
+ have_sim = 1;
+
+ if (!TEST_true(ccm->set_option_uint(cc, OSSL_CC_OPTION_MAX_DGRAM_PAYLOAD_LEN,
+ mdpl)))
+ goto err;
+
+ ccm->reset(cc);
+
+ if (!TEST_uint64_t_ge(allowance = ccm->get_tx_allowance(cc), mdpl))
+ goto err;
+
+ /*
+ * Start generating traffic. Stop when we've sent 30 MiB.
+ */
+ total_to_send = 30 * 1024 * 1024;
+
+ while (total_sent < total_to_send) {
+ /*
+ * Assume we are bottlenecked by the network (which is the interesting
+ * case for testing a congestion controller) and always fill our entire
+ * TX allowance as and when it becomes available.
+ */
+ for (;;) {
+ uint64_t sz;
+
+ dump_state(ccm, cc, &sim);
+
+ allowance = ccm->get_tx_allowance(cc);
+ sz = allowance > mdpl ? mdpl : allowance;
+
+ /*
+ * QUIC minimum packet sizes, etc. mean that in practice we will not
+ * consume the allowance exactly, so only send above a certain size.
+ */
+ if (sz < 30)
+ break;
+
+ step_time(7);
+
+ if (!TEST_true(net_sim_send(&sim, sz)))
+ goto err;
+
+ total_sent += sz;
+ }
+
+ /* Skip to next event. */
+ rc = net_sim_process(&sim, 1);
+ if (!TEST_int_gt(rc, 0))
+ goto err;
+
+ /*
+ * If we are out of any events to handle at all we definitely should
+ * have at least one MDPL's worth of allowance as nothing is in flight.
+ */
+ if (rc == 3) {
+ uint64_t v = 1;
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_BYTES_IN_FLIGHT,
+ &v)))
+ goto err;
+
+ if (!TEST_uint64_t_eq(v, 0))
+ goto err;
+
+ if (!TEST_uint64_t_ge(ccm->get_tx_allowance(cc), mdpl))
+ goto err;
+ }
+
+ /* Update our average of the estimated channel capacity. */
+ {
+ uint64_t v = 1;
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_CWND_SIZE,
+ &v)))
+ goto err;
+
+ cwnd_sample_sum += v;
+ ++cwnd_sample_count;
+ }
+ }
+
+ /*
+ * Ensure estimated channel capacity is not too far off from actual channel
+ * capacity.
+ */
+ {
+ uint64_t estimated_capacity = cwnd_sample_sum / cwnd_sample_count;
+
+ double error = ((double)estimated_capacity / (double)actual_capacity) - 1.0;
+
+ TEST_info("est = %6lu kB/s, act=%6lu kB/s (error=%.02f%%)\n",
+ estimated_capacity, actual_capacity, error * 100.0);
+
+ /* Max 5% error */
+ if (!TEST_double_le(error, 0.05))
+ goto err;
+ }
+
+ testresult = 1;
+err:
+ if (have_sim)
+ net_sim_cleanup(&sim);
+
+ if (cc != NULL)
+ ccm->free(cc);
+
+#ifdef GENERATE_LOG
+ if (logfile != NULL)
+ fflush(logfile);
+#endif
+
+ return testresult;
+}
+
+/*
+ * Sanity Test
+ * ===========
+ *
+ * Basic test of the congestion control APIs.
+ */
+static int test_sanity(void)
+{
+ int testresult = 0;
+ OSSL_CC_DATA *cc = NULL;
+ const OSSL_CC_METHOD *ccm = &ossl_cc_newreno_method;
+ OSSL_CC_LOSS_INFO loss_info = {0};
+ OSSL_CC_ACK_INFO ack_info = {0};
+ uint64_t allowance, allowance2, v = 1;
+
+ fake_time = TIME_BASE;
+
+ if (!TEST_ptr(cc = ccm->new(fake_now, NULL)))
+ goto err;
+
+ /* Test configuration of options. */
+ if (!TEST_true(ccm->set_option_uint(cc, OSSL_CC_OPTION_MAX_DGRAM_PAYLOAD_LEN,
+ 1472)))
+ goto err;
+
+ ccm->reset(cc);
+
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_MAX_DGRAM_PAYLOAD_LEN,
+ &v))
+ || !TEST_uint64_t_eq(v, 1472))
+ goto err;
+
+ if (!TEST_uint64_t_ge(allowance = ccm->get_tx_allowance(cc), 1472))
+ goto err;
+
+ /*
+ * No wakeups should be scheduled currently as we don't currently implement
+ * pacing.
+ */
+ if (!TEST_true(ossl_time_is_infinite(ccm->get_wakeup_deadline(cc))))
+ goto err;
+
+ /* No bytes should currently be in flight. */
+ if (!TEST_true(ccm->get_option_uint(cc, OSSL_CC_OPTION_CUR_BYTES_IN_FLIGHT,
+ &v))
+ || !TEST_uint64_t_eq(v, 0))
+ goto err;
+
+ /* Tell the CC we have sent some data. */
+ if (!TEST_true(ccm->on_data_sent(cc, 1200)))
+ goto err;
+
+ /* Allowance should have decreased. */
+ if (!TEST_uint64_t_eq(ccm->get_tx_allowance(cc), allowance - 1200))
+ goto err;
+
+ /* Acknowledge the data. */
+ ack_info.tx_time = fake_time;
+ ack_info.tx_size = 1200;
+ step_time(100);
+ if (!TEST_true(ccm->on_data_acked(cc, &ack_info)))
+ goto err;
+
+ /* Allowance should have returned. */
+ if (!TEST_uint64_t_ge(allowance2 = ccm->get_tx_allowance(cc), allowance))
+ goto err;
+
+ /* Test invalidation. */
+ if (!TEST_true(ccm->on_data_sent(cc, 1200)))
+ goto err;
+
+ /* Allowance should have decreased. */
+ if (!TEST_uint64_t_eq(ccm->get_tx_allowance(cc), allowance - 1200))
+ goto err;
+
+ if (!TEST_true(ccm->on_data_invalidated(cc, 1200)))
+ goto err;
+
+ /* Allowance should have returned. */
+ if (!TEST_uint64_t_eq(ccm->get_tx_allowance(cc), allowance2))
+ goto err;
+
+ /* Test loss. */
+ if (!TEST_uint64_t_ge(allowance = ccm->get_tx_allowance(cc), 1200 + 1300))
+ goto err;
+
+ if (!TEST_true(ccm->on_data_sent(cc, 1200)))
+ goto err;
+
+ if (!TEST_true(ccm->on_data_sent(cc, 1300)))
+ goto err;
+
+ if (!TEST_uint64_t_eq(allowance2 = ccm->get_tx_allowance(cc),
+ allowance - 1200 - 1300))
+ goto err;
+
+ loss_info.tx_time = fake_time;
+ loss_info.tx_size = 1200;
+ step_time(100);
+
+ if (!TEST_true(ccm->on_data_lost(cc, &loss_info)))
+ goto err;
+
+ loss_info.tx_size = 1300;
+ if (!TEST_true(ccm->on_data_lost(cc, &loss_info)))
+ goto err;
+
+ if (!TEST_true(ccm->on_data_lost_finished(cc, 0)))
+ goto err;
+
+ /* Allowance should have changed due to the lost calls */
+ if (!TEST_uint64_t_ne(ccm->get_tx_allowance(cc), allowance2))
+ goto err;
+
+ /* But it should not be as high as the origina value */
+ if (!TEST_uint64_t_lt(ccm->get_tx_allowance(cc), allowance))
+ goto err;
+
+ testresult = 1;
+
+err:
+ if (cc != NULL)
+ ccm->free(cc);
+
+ return testresult;
+}
+
+int setup_tests(void)
+{
+
+#ifdef GENERATE_LOG
+ logfile = fopen("quic_cc_stats.csv", "w");
+ fprintf(logfile,
+ "\"Time\","
+ "\"TX Allowance\","
+ "\"CWND Size\","
+ "\"Bytes in Flight\","
+ "\"Total Acked\",\"Total Lost\","
+ "\"Capacity\",\"Spare Capacity\","
+ "\"State\"\n");
+#endif
+
+ ADD_TEST(test_simulate);
+ ADD_TEST(test_sanity);
+ return 1;
+}
projects / thirdparty / openssl.git / commitdiff
