view src/stream/ngx_stream_quic_module.c @ 8700:b09f055daa4e quic

QUIC: fixed handling of RETIRE_CONNECTION_ID frame. Previously, the retired socket was not closed if it didn't match active or backup. New sockets could not be created (due to count limit), since retired socket was not closed before calling ngx_quic_create_sockets(). When replacing retired socket, new socket is only requested after closing old one, to avoid hitting the limit on the number of active connection ids. Together with added restrictions, this fixes an issue when a current socket could be closed during migration, recreated and erroneously reused leading to null pointer dereference.
author Vladimir Homutov <vl@nginx.com>
date Thu, 18 Nov 2021 14:19:36 +0300
parents 41caf5410110
children d6ef13c5fd8e
line wrap: on
line source


/*
 * 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 char *ngx_stream_quic_host_key(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


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_disable_active_migration"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_flag_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_string("quic_gso"),
      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, gso_enabled),
      NULL },

    { ngx_string("quic_host_key"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_FLAG,
      ngx_stream_quic_host_key,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      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_str_t  ngx_stream_quic_salt = ngx_string("ngx_quic");


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->quic) {

        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.preferred_address = NULL
     *     conf->host_key = { 0, NULL }
     *     conf->stream_close_code = 0;
     *     conf->stream_reject_code_uni = 0;
     *     conf->stream_reject_code_bidi= 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;
    conf->tp.active_connection_id_limit = NGX_CONF_UNSET_UINT;

    conf->retry = NGX_CONF_UNSET;
    conf->gso_enabled = 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_stream_ssl_conf_t  *scf;

    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_value(conf->tp.disable_active_migration,
                              prev->tp.disable_active_migration, 0);

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

    ngx_conf_merge_str_value(conf->host_key, prev->host_key, "");

    if (conf->host_key.len == 0) {

        conf->host_key.len = NGX_QUIC_DEFAULT_HOST_KEY_LEN;
        conf->host_key.data = ngx_palloc(cf->pool, conf->host_key.len);
        if (conf->host_key.data == NULL) {
            return NGX_CONF_ERROR;
        }

        if (RAND_bytes(conf->host_key.data, NGX_QUIC_DEFAULT_HOST_KEY_LEN)
            <= 0)
        {
            return NGX_CONF_ERROR;
        }
    }

    if (ngx_quic_derive_key(cf->log, "av_token_key",
                            &conf->host_key, &ngx_stream_quic_salt,
                            conf->av_token_key, NGX_QUIC_AV_KEY_LEN)
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    if (ngx_quic_derive_key(cf->log, "sr_token_key",
                            &conf->host_key, &ngx_stream_quic_salt,
                            conf->sr_token_key, NGX_QUIC_SR_KEY_LEN)
        != NGX_OK)
    {
        return NGX_CONF_ERROR;
    }

    scf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_ssl_module);
    conf->ssl = &scf->ssl;

    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;
}


static char *
ngx_stream_quic_host_key(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_quic_conf_t  *qcf = conf;

    u_char           *buf;
    size_t            size;
    ssize_t           n;
    ngx_str_t        *value;
    ngx_file_t        file;
    ngx_file_info_t   fi;

    if (qcf->host_key.len) {
        return "is duplicate";
    }

    buf = NULL;
#if (NGX_SUPPRESS_WARN)
    size = 0;
#endif

    value = cf->args->elts;

    if (ngx_conf_full_name(cf->cycle, &value[1], 1) != NGX_OK) {
        return NGX_CONF_ERROR;
    }

    ngx_memzero(&file, sizeof(ngx_file_t));
    file.name = value[1];
    file.log = cf->log;

    file.fd = ngx_open_file(file.name.data, NGX_FILE_RDONLY, NGX_FILE_OPEN, 0);

    if (file.fd == NGX_INVALID_FILE) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, ngx_errno,
                           ngx_open_file_n " \"%V\" failed", &file.name);
        return NGX_CONF_ERROR;
    }

    if (ngx_fd_info(file.fd, &fi) == NGX_FILE_ERROR) {
        ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
                           ngx_fd_info_n " \"%V\" failed", &file.name);
        goto failed;
    }

    size = ngx_file_size(&fi);

    if (size == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "\"%V\" zero key size", &file.name);
        goto failed;
    }

    buf = ngx_pnalloc(cf->pool, size);
    if (buf == NULL) {
        goto failed;
    }

    n = ngx_read_file(&file, buf, size, 0);

    if (n == NGX_ERROR) {
        ngx_conf_log_error(NGX_LOG_CRIT, cf, ngx_errno,
                           ngx_read_file_n " \"%V\" failed", &file.name);
        goto failed;
    }

    if ((size_t) n != size) {
        ngx_conf_log_error(NGX_LOG_CRIT, cf, 0,
                           ngx_read_file_n " \"%V\" returned only "
                           "%z bytes instead of %uz", &file.name, n, size);
        goto failed;
    }

    qcf->host_key.data = buf;
    qcf->host_key.len = n;

    if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
        ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                      ngx_close_file_n " \"%V\" failed", &file.name);
    }

    return NGX_CONF_OK;

failed:

    if (ngx_close_file(file.fd) == NGX_FILE_ERROR) {
        ngx_log_error(NGX_LOG_ALERT, cf->log, ngx_errno,
                      ngx_close_file_n " \"%V\" failed", &file.name);
    }

    if (buf) {
        ngx_explicit_memzero(buf, size);
    }

    return NGX_CONF_ERROR;
}