view src/stream/ngx_stream_quic_module.c @ 8514:52c88f41d24c quic

QUIC: handling packets with send time equal to lost send time. Previously, such packets weren't handled as the resulting zero remaining time prevented setting the loss detection timer, which, instead, could be disarmed. For implementation details, see quic-recovery draft 29, appendix A.10.
author Sergey Kandaurov <pluknet@nginx.com>
date Wed, 19 Aug 2020 13:24:30 +0300
parents 893b3313f53c
children bed310672f39
line wrap: on
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/*
 * Copyright (C) Nginx, Inc.
 * Copyright (C) Roman Arutyunyan
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>


static ngx_int_t ngx_stream_variable_quic(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_quic_add_variables(ngx_conf_t *cf);
static void *ngx_stream_quic_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_quic_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static char *ngx_stream_quic_max_ack_delay(ngx_conf_t *cf, void *post,
    void *data);
static char *ngx_stream_quic_max_udp_payload_size(ngx_conf_t *cf, void *post,
    void *data);


static ngx_conf_post_t  ngx_stream_quic_max_ack_delay_post =
    { ngx_stream_quic_max_ack_delay };
static ngx_conf_post_t  ngx_stream_quic_max_udp_payload_size_post =
    { ngx_stream_quic_max_udp_payload_size };
static ngx_conf_num_bounds_t  ngx_stream_quic_ack_delay_exponent_bounds =
    { ngx_conf_check_num_bounds, 0, 20 };
static ngx_conf_num_bounds_t 
                            ngx_stream_quic_active_connection_id_limit_bounds =
    { ngx_conf_check_num_bounds, 2, -1 };


static ngx_command_t  ngx_stream_quic_commands[] = {

    { ngx_string("quic_max_idle_timeout"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.max_idle_timeout),
      NULL },

    { ngx_string("quic_max_ack_delay"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.max_ack_delay),
      &ngx_stream_quic_max_ack_delay_post },

    { ngx_string("quic_max_udp_payload_size"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.max_udp_payload_size),
      &ngx_stream_quic_max_udp_payload_size_post },

    { ngx_string("quic_initial_max_data"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_data),
      NULL },

    { ngx_string("quic_initial_max_stream_data_bidi_local"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_stream_data_bidi_local),
      NULL },

    { ngx_string("quic_initial_max_stream_data_bidi_remote"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_stream_data_bidi_remote),
      NULL },

    { ngx_string("quic_initial_max_stream_data_uni"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_stream_data_uni),
      NULL },

    { ngx_string("quic_initial_max_streams_bidi"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_streams_bidi),
      NULL },

    { ngx_string("quic_initial_max_streams_uni"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.initial_max_streams_uni),
      NULL },

    { ngx_string("quic_ack_delay_exponent"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.ack_delay_exponent),
      &ngx_stream_quic_ack_delay_exponent_bounds },

    { ngx_string("quic_active_migration"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.disable_active_migration),
      NULL },

    { ngx_string("quic_active_connection_id_limit"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, tp.active_connection_id_limit),
      &ngx_stream_quic_active_connection_id_limit_bounds },

    { ngx_string("quic_retry"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_conf_set_flag_slot,
      NGX_STREAM_SRV_CONF_OFFSET,
      offsetof(ngx_quic_conf_t, retry),
      NULL },

      ngx_null_command
};


static ngx_stream_module_t  ngx_stream_quic_module_ctx = {
    ngx_stream_quic_add_variables,         /* preconfiguration */
    NULL,                                  /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_stream_quic_create_srv_conf,       /* create server configuration */
    ngx_stream_quic_merge_srv_conf,        /* merge server configuration */
};


ngx_module_t  ngx_stream_quic_module = {
    NGX_MODULE_V1,
    &ngx_stream_quic_module_ctx,           /* module context */
    ngx_stream_quic_commands,              /* module directives */
    NGX_STREAM_MODULE,                     /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_stream_variable_t  ngx_stream_quic_vars[] = {

    { ngx_string("quic"), NULL, ngx_stream_variable_quic, 0, 0, 0 },

      ngx_stream_null_variable
};


static ngx_int_t
ngx_stream_variable_quic(ngx_stream_session_t *s,
    ngx_stream_variable_value_t *v, uintptr_t data)
{
    if (s->connection->qs) {

        v->len = 4;
        v->valid = 1;
        v->no_cacheable = 1;
        v->not_found = 0;
        v->data = (u_char *) "quic";
        return NGX_OK;
    }

    v->not_found = 1;

    return NGX_OK;
}


static ngx_int_t
ngx_stream_quic_add_variables(ngx_conf_t *cf)
{
    ngx_stream_variable_t  *var, *v;

    for (v = ngx_stream_quic_vars; v->name.len; v++) {
        var = ngx_stream_add_variable(cf, &v->name, v->flags);
        if (var == NULL) {
            return NGX_ERROR;
        }

        var->get_handler = v->get_handler;
        var->data = v->data;
    }

    return NGX_OK;
}


static void *
ngx_stream_quic_create_srv_conf(ngx_conf_t *cf)
{
    ngx_quic_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_quic_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    /*
     * set by ngx_pcalloc():
     *
     *     conf->tp.original_dcid = { 0, NULL };
     *     conf->tp.initial_scid = { 0, NULL };
     *     conf->tp.retry_scid = { 0, NULL };
     *     conf->tp.stateless_reset_token = { 0 }
     *     conf->tp.preferred_address = NULL
     *     conf->require_alpn = 0;
     */

    conf->tp.max_idle_timeout = NGX_CONF_UNSET_MSEC;
    conf->tp.max_ack_delay = NGX_CONF_UNSET_MSEC;
    conf->tp.max_udp_payload_size = NGX_CONF_UNSET_SIZE;
    conf->tp.initial_max_data = NGX_CONF_UNSET_SIZE;
    conf->tp.initial_max_stream_data_bidi_local = NGX_CONF_UNSET_SIZE;
    conf->tp.initial_max_stream_data_bidi_remote = NGX_CONF_UNSET_SIZE;
    conf->tp.initial_max_stream_data_uni = NGX_CONF_UNSET_SIZE;
    conf->tp.initial_max_streams_bidi = NGX_CONF_UNSET_UINT;
    conf->tp.initial_max_streams_uni = NGX_CONF_UNSET_UINT;
    conf->tp.ack_delay_exponent = NGX_CONF_UNSET_UINT;
    conf->tp.disable_active_migration = NGX_CONF_UNSET_UINT;
    conf->tp.active_connection_id_limit = NGX_CONF_UNSET_UINT;

    conf->retry = NGX_CONF_UNSET;

    return conf;
}


static char *
ngx_stream_quic_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_quic_conf_t *prev = parent;
    ngx_quic_conf_t *conf = child;

    ngx_conf_merge_msec_value(conf->tp.max_idle_timeout,
                              prev->tp.max_idle_timeout, 60000);

    ngx_conf_merge_msec_value(conf->tp.max_ack_delay,
                              prev->tp.max_ack_delay,
                              NGX_QUIC_DEFAULT_MAX_ACK_DELAY);

    ngx_conf_merge_size_value(conf->tp.max_udp_payload_size,
                              prev->tp.max_udp_payload_size,
                              NGX_QUIC_MAX_UDP_PAYLOAD_SIZE);

    ngx_conf_merge_size_value(conf->tp.initial_max_data,
                              prev->tp.initial_max_data,
                              16 * NGX_QUIC_STREAM_BUFSIZE);

    ngx_conf_merge_size_value(conf->tp.initial_max_stream_data_bidi_local,
                              prev->tp.initial_max_stream_data_bidi_local,
                              NGX_QUIC_STREAM_BUFSIZE);

    ngx_conf_merge_size_value(conf->tp.initial_max_stream_data_bidi_remote,
                              prev->tp.initial_max_stream_data_bidi_remote,
                              NGX_QUIC_STREAM_BUFSIZE);

    ngx_conf_merge_size_value(conf->tp.initial_max_stream_data_uni,
                              prev->tp.initial_max_stream_data_uni,
                              NGX_QUIC_STREAM_BUFSIZE);

    ngx_conf_merge_uint_value(conf->tp.initial_max_streams_bidi,
                              prev->tp.initial_max_streams_bidi, 16);

    ngx_conf_merge_uint_value(conf->tp.initial_max_streams_uni,
                              prev->tp.initial_max_streams_uni, 16);

    ngx_conf_merge_uint_value(conf->tp.ack_delay_exponent,
                              prev->tp.ack_delay_exponent,
                              NGX_QUIC_DEFAULT_ACK_DELAY_EXPONENT);

    ngx_conf_merge_uint_value(conf->tp.disable_active_migration,
                              prev->tp.disable_active_migration, 1);

    ngx_conf_merge_uint_value(conf->tp.active_connection_id_limit,
                              prev->tp.active_connection_id_limit, 2);

    ngx_conf_merge_value(conf->retry, prev->retry, 0);

    if (conf->retry) {
        if (RAND_bytes(conf->token_key, sizeof(conf->token_key)) <= 0) {
            return NGX_CONF_ERROR;
        }
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_quic_max_ack_delay(ngx_conf_t *cf, void *post, void *data)
{
    ngx_msec_t *sp = data;

    if (*sp > 16384) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "\"quic_max_ack_delay\" must be less than 16384");

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_stream_quic_max_udp_payload_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp < NGX_QUIC_MIN_INITIAL_SIZE
        || *sp > NGX_QUIC_MAX_UDP_PAYLOAD_SIZE)
    {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "\"quic_max_udp_payload_size\" must be between "
                           "%d and %d",
                           NGX_QUIC_MIN_INITIAL_SIZE,
                           NGX_QUIC_MAX_UDP_PAYLOAD_SIZE);

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}