text: /* Copyright 2015 greenbytes GmbH (https://www.greenbytes.de)
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <assert.h>
  
  #include <apr_strings.h>
  #include <apr_optional.h>
  #include <apr_optional_hooks.h>
  
  #include <httpd.h>
  #include <http_core.h>
  #include <http_config.h>
  #include <http_connection.h>
  #include <http_protocol.h>
  #include <http_request.h>
  #include <http_log.h>
  
  #include "mod_ssl.h"
  
  #include "mod_http2.h"
  #include "h2_private.h"
  
  #include "h2_bucket_beam.h"
  #include "h2_stream.h"
  #include "h2_task.h"
  #include "h2_config.h"
  #include "h2_ctx.h"
  #include "h2_conn.h"
  #include "h2_filter.h"
  #include "h2_request.h"
  #include "h2_headers.h"
  #include "h2_session.h"
  #include "h2_util.h"
  #include "h2_h2.h"
  #include "mod_http2.h"
  
  const char *h2_tls_protos[] = {
      "h2", NULL
  };
  
  const char *h2_clear_protos[] = {
      "h2c", NULL
  };
  
  const char *H2_MAGIC_TOKEN = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n";
  
  /*******************************************************************************
   * The optional mod_ssl functions we need. 
   */
  static APR_OPTIONAL_FN_TYPE(ssl_engine_disable) *opt_ssl_engine_disable;
  static APR_OPTIONAL_FN_TYPE(ssl_is_https) *opt_ssl_is_https;
  static APR_OPTIONAL_FN_TYPE(ssl_var_lookup) *opt_ssl_var_lookup;
  
  
  /*******************************************************************************
   * HTTP/2 error stuff
   */
  static const char *h2_err_descr[] = {
      "no error",                    /* 0x0 */
      "protocol error",
      "internal error",
      "flow control error",
      "settings timeout",
      "stream closed",               /* 0x5 */
      "frame size error",
      "refused stream",
      "cancel",
      "compression error",
      "connect error",               /* 0xa */
      "enhance your calm",
      "inadequate security",
      "http/1.1 required",
  };
  
  const char *h2_h2_err_description(unsigned int h2_error)
  {
      if (h2_error < (sizeof(h2_err_descr)/sizeof(h2_err_descr[0]))) {
          return h2_err_descr[h2_error];
      }
      return "unknown http/2 error code";
  }
  
  /*******************************************************************************
   * Check connection security requirements of RFC 7540
   */
  
  /*
   * Black Listed Ciphers from RFC 7549 Appendix A
   *
   */
  static const char *RFC7540_names[] = {
      /* ciphers with NULL encrpytion */
      "NULL-MD5",                         /* TLS_NULL_WITH_NULL_NULL */
      /* same */                          /* TLS_RSA_WITH_NULL_MD5 */
      "NULL-SHA",                         /* TLS_RSA_WITH_NULL_SHA */
      "NULL-SHA256",                      /* TLS_RSA_WITH_NULL_SHA256 */
      "PSK-NULL-SHA",                     /* TLS_PSK_WITH_NULL_SHA */
      "DHE-PSK-NULL-SHA",                 /* TLS_DHE_PSK_WITH_NULL_SHA */
      "RSA-PSK-NULL-SHA",                 /* TLS_RSA_PSK_WITH_NULL_SHA */
      "PSK-NULL-SHA256",                  /* TLS_PSK_WITH_NULL_SHA256 */
      "PSK-NULL-SHA384",                  /* TLS_PSK_WITH_NULL_SHA384 */
      "DHE-PSK-NULL-SHA256",              /* TLS_DHE_PSK_WITH_NULL_SHA256 */
      "DHE-PSK-NULL-SHA384",              /* TLS_DHE_PSK_WITH_NULL_SHA384 */
      "RSA-PSK-NULL-SHA256",              /* TLS_RSA_PSK_WITH_NULL_SHA256 */
      "RSA-PSK-NULL-SHA384",              /* TLS_RSA_PSK_WITH_NULL_SHA384 */
      "ECDH-ECDSA-NULL-SHA",              /* TLS_ECDH_ECDSA_WITH_NULL_SHA */
      "ECDHE-ECDSA-NULL-SHA",             /* TLS_ECDHE_ECDSA_WITH_NULL_SHA */
      "ECDH-RSA-NULL-SHA",                /* TLS_ECDH_RSA_WITH_NULL_SHA */
      "ECDHE-RSA-NULL-SHA",               /* TLS_ECDHE_RSA_WITH_NULL_SHA */
      "AECDH-NULL-SHA",                   /* TLS_ECDH_anon_WITH_NULL_SHA */
      "ECDHE-PSK-NULL-SHA",               /* TLS_ECDHE_PSK_WITH_NULL_SHA */
      "ECDHE-PSK-NULL-SHA256",            /* TLS_ECDHE_PSK_WITH_NULL_SHA256 */
      "ECDHE-PSK-NULL-SHA384",            /* TLS_ECDHE_PSK_WITH_NULL_SHA384 */
      
      /* DES/3DES ciphers */
      "PSK-3DES-EDE-CBC-SHA",             /* TLS_PSK_WITH_3DES_EDE_CBC_SHA */
      "DHE-PSK-3DES-EDE-CBC-SHA",         /* TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA */
      "RSA-PSK-3DES-EDE-CBC-SHA",         /* TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA */
      "ECDH-ECDSA-DES-CBC3-SHA",          /* TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA */
      "ECDHE-ECDSA-DES-CBC3-SHA",         /* TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA */
      "ECDH-RSA-DES-CBC3-SHA",            /* TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA */
      "ECDHE-RSA-DES-CBC3-SHA",           /* TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA */
      "AECDH-DES-CBC3-SHA",               /* TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA */
      "SRP-3DES-EDE-CBC-SHA",             /* TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA */
      "SRP-RSA-3DES-EDE-CBC-SHA",         /* TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA */
      "SRP-DSS-3DES-EDE-CBC-SHA",         /* TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA */
      "ECDHE-PSK-3DES-EDE-CBC-SHA",       /* TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA */
      "DES-CBC-SHA",                      /* TLS_RSA_WITH_DES_CBC_SHA */
      "DES-CBC3-SHA",                     /* TLS_RSA_WITH_3DES_EDE_CBC_SHA */
      "DHE-DSS-DES-CBC3-SHA",             /* TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA */
      "DHE-RSA-DES-CBC-SHA",              /* TLS_DHE_RSA_WITH_DES_CBC_SHA */
      "DHE-RSA-DES-CBC3-SHA",             /* TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA */
      "ADH-DES-CBC-SHA",                  /* TLS_DH_anon_WITH_DES_CBC_SHA */
      "ADH-DES-CBC3-SHA",                 /* TLS_DH_anon_WITH_3DES_EDE_CBC_SHA */
      "EXP-DH-DSS-DES-CBC-SHA",           /* TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA */
      "DH-DSS-DES-CBC-SHA",               /* TLS_DH_DSS_WITH_DES_CBC_SHA */
      "DH-DSS-DES-CBC3-SHA",              /* TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA */
      "EXP-DH-RSA-DES-CBC-SHA",           /* TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA */
      "DH-RSA-DES-CBC-SHA",               /* TLS_DH_RSA_WITH_DES_CBC_SHA */
      "DH-RSA-DES-CBC3-SHA",              /* TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA */
  
      /* blacklisted EXPORT ciphers */
      "EXP-RC4-MD5",                      /* TLS_RSA_EXPORT_WITH_RC4_40_MD5 */
      "EXP-RC2-CBC-MD5",                  /* TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 */
      "EXP-DES-CBC-SHA",                  /* TLS_RSA_EXPORT_WITH_DES40_CBC_SHA */
      "EXP-DHE-DSS-DES-CBC-SHA",          /* TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA */
      "EXP-DHE-RSA-DES-CBC-SHA",          /* TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA */
      "EXP-ADH-DES-CBC-SHA",              /* TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA */
      "EXP-ADH-RC4-MD5",                  /* TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 */
  
      /* blacklisted RC4 encryption */
      "RC4-MD5",                          /* TLS_RSA_WITH_RC4_128_MD5 */
      "RC4-SHA",                          /* TLS_RSA_WITH_RC4_128_SHA */
      "ADH-RC4-MD5",                      /* TLS_DH_anon_WITH_RC4_128_MD5 */
      "KRB5-RC4-SHA",                     /* TLS_KRB5_WITH_RC4_128_SHA */
      "KRB5-RC4-MD5",                     /* TLS_KRB5_WITH_RC4_128_MD5 */
      "EXP-KRB5-RC4-SHA",                 /* TLS_KRB5_EXPORT_WITH_RC4_40_SHA */
      "EXP-KRB5-RC4-MD5",                 /* TLS_KRB5_EXPORT_WITH_RC4_40_MD5 */
      "PSK-RC4-SHA",                      /* TLS_PSK_WITH_RC4_128_SHA */
      "DHE-PSK-RC4-SHA",                  /* TLS_DHE_PSK_WITH_RC4_128_SHA */
      "RSA-PSK-RC4-SHA",                  /* TLS_RSA_PSK_WITH_RC4_128_SHA */
      "ECDH-ECDSA-RC4-SHA",               /* TLS_ECDH_ECDSA_WITH_RC4_128_SHA */
      "ECDHE-ECDSA-RC4-SHA",              /* TLS_ECDHE_ECDSA_WITH_RC4_128_SHA */
      "ECDH-RSA-RC4-SHA",                 /* TLS_ECDH_RSA_WITH_RC4_128_SHA */
      "ECDHE-RSA-RC4-SHA",                /* TLS_ECDHE_RSA_WITH_RC4_128_SHA */
      "AECDH-RC4-SHA",                    /* TLS_ECDH_anon_WITH_RC4_128_SHA */
      "ECDHE-PSK-RC4-SHA",                /* TLS_ECDHE_PSK_WITH_RC4_128_SHA */
  
      /* blacklisted AES128 encrpytion ciphers */
      "AES128-SHA256",                    /* TLS_RSA_WITH_AES_128_CBC_SHA */
      "DH-DSS-AES128-SHA",                /* TLS_DH_DSS_WITH_AES_128_CBC_SHA */
      "DH-RSA-AES128-SHA",                /* TLS_DH_RSA_WITH_AES_128_CBC_SHA */
      "DHE-DSS-AES128-SHA",               /* TLS_DHE_DSS_WITH_AES_128_CBC_SHA */
      "DHE-RSA-AES128-SHA",               /* TLS_DHE_RSA_WITH_AES_128_CBC_SHA */
      "ADH-AES128-SHA",                   /* TLS_DH_anon_WITH_AES_128_CBC_SHA */
      "AES128-SHA256",                    /* TLS_RSA_WITH_AES_128_CBC_SHA256 */
      "DH-DSS-AES128-SHA256",             /* TLS_DH_DSS_WITH_AES_128_CBC_SHA256 */
      "DH-RSA-AES128-SHA256",             /* TLS_DH_RSA_WITH_AES_128_CBC_SHA256 */
      "DHE-DSS-AES128-SHA256",            /* TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 */
      "DHE-RSA-AES128-SHA256",            /* TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 */
      "ECDH-ECDSA-AES128-SHA",            /* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA */
      "ECDHE-ECDSA-AES128-SHA",           /* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA */
      "ECDH-RSA-AES128-SHA",              /* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA */
      "ECDHE-RSA-AES128-SHA",             /* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA */
      "AECDH-AES128-SHA",                 /* TLS_ECDH_anon_WITH_AES_128_CBC_SHA */
      "ECDHE-ECDSA-AES128-SHA256",        /* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 */
      "ECDH-ECDSA-AES128-SHA256",         /* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 */
      "ECDHE-RSA-AES128-SHA256",          /* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 */
      "ECDH-RSA-AES128-SHA256",           /* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 */
      "ADH-AES128-SHA256",                /* TLS_DH_anon_WITH_AES_128_CBC_SHA256 */
      "PSK-AES128-CBC-SHA",               /* TLS_PSK_WITH_AES_128_CBC_SHA */
      "DHE-PSK-AES128-CBC-SHA",           /* TLS_DHE_PSK_WITH_AES_128_CBC_SHA */
      "RSA-PSK-AES128-CBC-SHA",           /* TLS_RSA_PSK_WITH_AES_128_CBC_SHA */
      "PSK-AES128-CBC-SHA256",            /* TLS_PSK_WITH_AES_128_CBC_SHA256 */
      "DHE-PSK-AES128-CBC-SHA256",        /* TLS_DHE_PSK_WITH_AES_128_CBC_SHA256 */
      "RSA-PSK-AES128-CBC-SHA256",        /* TLS_RSA_PSK_WITH_AES_128_CBC_SHA256 */
      "ECDHE-PSK-AES128-CBC-SHA",         /* TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA */
      "ECDHE-PSK-AES128-CBC-SHA256",      /* TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 */
      "AES128-CCM",                       /* TLS_RSA_WITH_AES_128_CCM */
      "AES128-CCM8",                      /* TLS_RSA_WITH_AES_128_CCM_8 */
      "PSK-AES128-CCM",                   /* TLS_PSK_WITH_AES_128_CCM */
      "PSK-AES128-CCM8",                  /* TLS_PSK_WITH_AES_128_CCM_8 */
      "AES128-GCM-SHA256",                /* TLS_RSA_WITH_AES_128_GCM_SHA256 */
      "DH-RSA-AES128-GCM-SHA256",         /* TLS_DH_RSA_WITH_AES_128_GCM_SHA256 */
      "DH-DSS-AES128-GCM-SHA256",         /* TLS_DH_DSS_WITH_AES_128_GCM_SHA256 */
      "ADH-AES128-GCM-SHA256",            /* TLS_DH_anon_WITH_AES_128_GCM_SHA256 */
      "PSK-AES128-GCM-SHA256",            /* TLS_PSK_WITH_AES_128_GCM_SHA256 */
      "RSA-PSK-AES128-GCM-SHA256",        /* TLS_RSA_PSK_WITH_AES_128_GCM_SHA256 */
      "ECDH-ECDSA-AES128-GCM-SHA256",     /* TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 */
      "ECDH-RSA-AES128-GCM-SHA256",       /* TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 */
      "SRP-AES-128-CBC-SHA",              /* TLS_SRP_SHA_WITH_AES_128_CBC_SHA */
      "SRP-RSA-AES-128-CBC-SHA",          /* TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA */
      "SRP-DSS-AES-128-CBC-SHA",          /* TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA */
      
      /* blacklisted AES256 encrpytion ciphers */
      "AES256-SHA",                       /* TLS_RSA_WITH_AES_256_CBC_SHA */
      "DH-DSS-AES256-SHA",                /* TLS_DH_DSS_WITH_AES_256_CBC_SHA */
      "DH-RSA-AES256-SHA",                /* TLS_DH_RSA_WITH_AES_256_CBC_SHA */
      "DHE-DSS-AES256-SHA",               /* TLS_DHE_DSS_WITH_AES_256_CBC_SHA */
      "DHE-RSA-AES256-SHA",               /* TLS_DHE_RSA_WITH_AES_256_CBC_SHA */
      "ADH-AES256-SHA",                   /* TLS_DH_anon_WITH_AES_256_CBC_SHA */
      "AES256-SHA256",                    /* TLS_RSA_WITH_AES_256_CBC_SHA256 */
      "DH-DSS-AES256-SHA256",             /* TLS_DH_DSS_WITH_AES_256_CBC_SHA256 */
      "DH-RSA-AES256-SHA256",             /* TLS_DH_RSA_WITH_AES_256_CBC_SHA256 */
      "DHE-DSS-AES256-SHA256",            /* TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 */
      "DHE-RSA-AES256-SHA256",            /* TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 */
      "ADH-AES256-SHA256",                /* TLS_DH_anon_WITH_AES_256_CBC_SHA256 */
      "ECDH-ECDSA-AES256-SHA",            /* TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA */
      "ECDHE-ECDSA-AES256-SHA",           /* TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA */
      "ECDH-RSA-AES256-SHA",              /* TLS_ECDH_RSA_WITH_AES_256_CBC_SHA */
      "ECDHE-RSA-AES256-SHA",             /* TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA */
      "AECDH-AES256-SHA",                 /* TLS_ECDH_anon_WITH_AES_256_CBC_SHA */
      "ECDHE-ECDSA-AES256-SHA384",        /* TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 */
      "ECDH-ECDSA-AES256-SHA384",         /* TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 */
      "ECDHE-RSA-AES256-SHA384",          /* TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 */
      "ECDH-RSA-AES256-SHA384",           /* TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 */
      "PSK-AES256-CBC-SHA",               /* TLS_PSK_WITH_AES_256_CBC_SHA */
      "DHE-PSK-AES256-CBC-SHA",           /* TLS_DHE_PSK_WITH_AES_256_CBC_SHA */
      "RSA-PSK-AES256-CBC-SHA",           /* TLS_RSA_PSK_WITH_AES_256_CBC_SHA */
      "PSK-AES256-CBC-SHA384",            /* TLS_PSK_WITH_AES_256_CBC_SHA384 */
      "DHE-PSK-AES256-CBC-SHA384",        /* TLS_DHE_PSK_WITH_AES_256_CBC_SHA384 */
      "RSA-PSK-AES256-CBC-SHA384",        /* TLS_RSA_PSK_WITH_AES_256_CBC_SHA384 */
      "ECDHE-PSK-AES256-CBC-SHA",         /* TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA */
      "ECDHE-PSK-AES256-CBC-SHA384",      /* TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 */
      "SRP-AES-256-CBC-SHA",              /* TLS_SRP_SHA_WITH_AES_256_CBC_SHA */
      "SRP-RSA-AES-256-CBC-SHA",          /* TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA */
      "SRP-DSS-AES-256-CBC-SHA",          /* TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA */
      "AES256-CCM",                       /* TLS_RSA_WITH_AES_256_CCM */
      "AES256-CCM8",                      /* TLS_RSA_WITH_AES_256_CCM_8 */
      "PSK-AES256-CCM",                   /* TLS_PSK_WITH_AES_256_CCM */
      "PSK-AES256-CCM8",                  /* TLS_PSK_WITH_AES_256_CCM_8 */
      "AES256-GCM-SHA384",                /* TLS_RSA_WITH_AES_256_GCM_SHA384 */
      "DH-RSA-AES256-GCM-SHA384",         /* TLS_DH_RSA_WITH_AES_256_GCM_SHA384 */
      "DH-DSS-AES256-GCM-SHA384",         /* TLS_DH_DSS_WITH_AES_256_GCM_SHA384 */
      "ADH-AES256-GCM-SHA384",            /* TLS_DH_anon_WITH_AES_256_GCM_SHA384 */
      "PSK-AES256-GCM-SHA384",            /* TLS_PSK_WITH_AES_256_GCM_SHA384 */
      "RSA-PSK-AES256-GCM-SHA384",        /* TLS_RSA_PSK_WITH_AES_256_GCM_SHA384 */
      "ECDH-ECDSA-AES256-GCM-SHA384",     /* TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 */
      "ECDH-RSA-AES256-GCM-SHA384",       /* TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 */
      
      /* blacklisted CAMELLIA128 encrpytion ciphers */
      "CAMELLIA128-SHA",                  /* TLS_RSA_WITH_CAMELLIA_128_CBC_SHA */
      "DH-DSS-CAMELLIA128-SHA",           /* TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA */
      "DH-RSA-CAMELLIA128-SHA",           /* TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA */
      "DHE-DSS-CAMELLIA128-SHA",          /* TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA */
      "DHE-RSA-CAMELLIA128-SHA",          /* TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA */
      "ADH-CAMELLIA128-SHA",              /* TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA */
      "ECDHE-ECDSA-CAMELLIA128-SHA256",   /* TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "ECDH-ECDSA-CAMELLIA128-SHA256",    /* TLS_ECDH_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "ECDHE-RSA-CAMELLIA128-SHA256",     /* TLS_ECDHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "ECDH-RSA-CAMELLIA128-SHA256",      /* TLS_ECDH_RSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "PSK-CAMELLIA128-SHA256",           /* TLS_PSK_WITH_CAMELLIA_128_CBC_SHA256 */
      "DHE-PSK-CAMELLIA128-SHA256",       /* TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 */
      "RSA-PSK-CAMELLIA128-SHA256",       /* TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256 */
      "ECDHE-PSK-CAMELLIA128-SHA256",     /* TLS_ECDHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 */
      "CAMELLIA128-GCM-SHA256",           /* TLS_RSA_WITH_CAMELLIA_128_GCM_SHA256 */
      "DH-RSA-CAMELLIA128-GCM-SHA256",    /* TLS_DH_RSA_WITH_CAMELLIA_128_GCM_SHA256 */
      "DH-DSS-CAMELLIA128-GCM-SHA256",    /* TLS_DH_DSS_WITH_CAMELLIA_128_GCM_SHA256 */
      "ADH-CAMELLIA128-GCM-SHA256",       /* TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256 */
      "ECDH-ECDSA-CAMELLIA128-GCM-SHA256",/* TLS_ECDH_ECDSA_WITH_CAMELLIA_128_GCM_SHA256 */
      "ECDH-RSA-CAMELLIA128-GCM-SHA256",  /* TLS_ECDH_RSA_WITH_CAMELLIA_128_GCM_SHA256 */
      "PSK-CAMELLIA128-GCM-SHA256",       /* TLS_PSK_WITH_CAMELLIA_128_GCM_SHA256 */
      "RSA-PSK-CAMELLIA128-GCM-SHA256",   /* TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256 */
      "CAMELLIA128-SHA256",               /* TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "DH-DSS-CAMELLIA128-SHA256",        /* TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256 */
      "DH-RSA-CAMELLIA128-SHA256",        /* TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "DHE-DSS-CAMELLIA128-SHA256",       /* TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256 */
      "DHE-RSA-CAMELLIA128-SHA256",       /* TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 */
      "ADH-CAMELLIA128-SHA256",           /* TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256 */
      
      /* blacklisted CAMELLIA256 encrpytion ciphers */
      "CAMELLIA256-SHA",                  /* TLS_RSA_WITH_CAMELLIA_256_CBC_SHA */
      "DH-RSA-CAMELLIA256-SHA",           /* TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA */
      "DH-DSS-CAMELLIA256-SHA",           /* TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA */
      "DHE-DSS-CAMELLIA256-SHA",          /* TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA */
      "DHE-RSA-CAMELLIA256-SHA",          /* TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA */
      "ADH-CAMELLIA256-SHA",              /* TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA */
      "ECDHE-ECDSA-CAMELLIA256-SHA384",   /* TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 */
      "ECDH-ECDSA-CAMELLIA256-SHA384",    /* TLS_ECDH_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 */
      "ECDHE-RSA-CAMELLIA256-SHA384",     /* TLS_ECDHE_RSA_WITH_CAMELLIA_256_CBC_SHA384 */
      "ECDH-RSA-CAMELLIA256-SHA384",      /* TLS_ECDH_RSA_WITH_CAMELLIA_256_CBC_SHA384 */
      "PSK-CAMELLIA256-SHA384",           /* TLS_PSK_WITH_CAMELLIA_256_CBC_SHA384 */
      "DHE-PSK-CAMELLIA256-SHA384",       /* TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 */
      "RSA-PSK-CAMELLIA256-SHA384",       /* TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384 */
      "ECDHE-PSK-CAMELLIA256-SHA384",     /* TLS_ECDHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 */
      "CAMELLIA256-SHA256",               /* TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256 */
      "DH-DSS-CAMELLIA256-SHA256",        /* TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256 */
      "DH-RSA-CAMELLIA256-SHA256",        /* TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256 */
      "DHE-DSS-CAMELLIA256-SHA256",       /* TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256 */
      "DHE-RSA-CAMELLIA256-SHA256",       /* TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 */
      "ADH-CAMELLIA256-SHA256",           /* TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256 */
      "CAMELLIA256-GCM-SHA384",           /* TLS_RSA_WITH_CAMELLIA_256_GCM_SHA384 */
      "DH-RSA-CAMELLIA256-GCM-SHA384",    /* TLS_DH_RSA_WITH_CAMELLIA_256_GCM_SHA384 */
      "DH-DSS-CAMELLIA256-GCM-SHA384",    /* TLS_DH_DSS_WITH_CAMELLIA_256_GCM_SHA384 */
      "ADH-CAMELLIA256-GCM-SHA384",       /* TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384 */
      "ECDH-ECDSA-CAMELLIA256-GCM-SHA384",/* TLS_ECDH_ECDSA_WITH_CAMELLIA_256_GCM_SHA384 */
      "ECDH-RSA-CAMELLIA256-GCM-SHA384",  /* TLS_ECDH_RSA_WITH_CAMELLIA_256_GCM_SHA384 */
      "PSK-CAMELLIA256-GCM-SHA384",       /* TLS_PSK_WITH_CAMELLIA_256_GCM_SHA384 */
      "RSA-PSK-CAMELLIA256-GCM-SHA384",   /* TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384 */
      
      /* The blacklisted ARIA encrpytion ciphers */
      "ARIA128-SHA256",                   /* TLS_RSA_WITH_ARIA_128_CBC_SHA256 */
      "ARIA256-SHA384",                   /* TLS_RSA_WITH_ARIA_256_CBC_SHA384 */
      "DH-DSS-ARIA128-SHA256",            /* TLS_DH_DSS_WITH_ARIA_128_CBC_SHA256 */
      "DH-DSS-ARIA256-SHA384",            /* TLS_DH_DSS_WITH_ARIA_256_CBC_SHA384 */
      "DH-RSA-ARIA128-SHA256",            /* TLS_DH_RSA_WITH_ARIA_128_CBC_SHA256 */
      "DH-RSA-ARIA256-SHA384",            /* TLS_DH_RSA_WITH_ARIA_256_CBC_SHA384 */
      "DHE-DSS-ARIA128-SHA256",           /* TLS_DHE_DSS_WITH_ARIA_128_CBC_SHA256 */
      "DHE-DSS-ARIA256-SHA384",           /* TLS_DHE_DSS_WITH_ARIA_256_CBC_SHA384 */
      "DHE-RSA-ARIA128-SHA256",           /* TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256 */
      "DHE-RSA-ARIA256-SHA384",           /* TLS_DHE_RSA_WITH_ARIA_256_CBC_SHA384 */
      "ADH-ARIA128-SHA256",               /* TLS_DH_anon_WITH_ARIA_128_CBC_SHA256 */
      "ADH-ARIA256-SHA384",               /* TLS_DH_anon_WITH_ARIA_256_CBC_SHA384 */
      "ECDHE-ECDSA-ARIA128-SHA256",       /* TLS_ECDHE_ECDSA_WITH_ARIA_128_CBC_SHA256 */
      "ECDHE-ECDSA-ARIA256-SHA384",       /* TLS_ECDHE_ECDSA_WITH_ARIA_256_CBC_SHA384 */
      "ECDH-ECDSA-ARIA128-SHA256",        /* TLS_ECDH_ECDSA_WITH_ARIA_128_CBC_SHA256 */
      "ECDH-ECDSA-ARIA256-SHA384",        /* TLS_ECDH_ECDSA_WITH_ARIA_256_CBC_SHA384 */
      "ECDHE-RSA-ARIA128-SHA256",         /* TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256 */
      "ECDHE-RSA-ARIA256-SHA384",         /* TLS_ECDHE_RSA_WITH_ARIA_256_CBC_SHA384 */
      "ECDH-RSA-ARIA128-SHA256",          /* TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256 */
      "ECDH-RSA-ARIA256-SHA384",          /* TLS_ECDH_RSA_WITH_ARIA_256_CBC_SHA384 */
      "ARIA128-GCM-SHA256",               /* TLS_RSA_WITH_ARIA_128_GCM_SHA256 */
      "ARIA256-GCM-SHA384",               /* TLS_RSA_WITH_ARIA_256_GCM_SHA384 */
      "DH-DSS-ARIA128-GCM-SHA256",        /* TLS_DH_DSS_WITH_ARIA_128_GCM_SHA256 */
      "DH-DSS-ARIA256-GCM-SHA384",        /* TLS_DH_DSS_WITH_ARIA_256_GCM_SHA384 */
      "DH-RSA-ARIA128-GCM-SHA256",        /* TLS_DH_RSA_WITH_ARIA_128_GCM_SHA256 */
      "DH-RSA-ARIA256-GCM-SHA384",        /* TLS_DH_RSA_WITH_ARIA_256_GCM_SHA384 */
      "ADH-ARIA128-GCM-SHA256",           /* TLS_DH_anon_WITH_ARIA_128_GCM_SHA256 */
      "ADH-ARIA256-GCM-SHA384",           /* TLS_DH_anon_WITH_ARIA_256_GCM_SHA384 */
      "ECDH-ECDSA-ARIA128-GCM-SHA256",    /* TLS_ECDH_ECDSA_WITH_ARIA_128_GCM_SHA256 */
      "ECDH-ECDSA-ARIA256-GCM-SHA384",    /* TLS_ECDH_ECDSA_WITH_ARIA_256_GCM_SHA384 */
      "ECDH-RSA-ARIA128-GCM-SHA256",      /* TLS_ECDH_RSA_WITH_ARIA_128_GCM_SHA256 */
      "ECDH-RSA-ARIA256-GCM-SHA384",      /* TLS_ECDH_RSA_WITH_ARIA_256_GCM_SHA384 */
      "PSK-ARIA128-SHA256",               /* TLS_PSK_WITH_ARIA_128_CBC_SHA256 */
      "PSK-ARIA256-SHA384",               /* TLS_PSK_WITH_ARIA_256_CBC_SHA384 */
      "DHE-PSK-ARIA128-SHA256",           /* TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256 */
      "DHE-PSK-ARIA256-SHA384",           /* TLS_DHE_PSK_WITH_ARIA_256_CBC_SHA384 */
      "RSA-PSK-ARIA128-SHA256",           /* TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256 */
      "RSA-PSK-ARIA256-SHA384",           /* TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384 */
      "ARIA128-GCM-SHA256",               /* TLS_PSK_WITH_ARIA_128_GCM_SHA256 */
      "ARIA256-GCM-SHA384",               /* TLS_PSK_WITH_ARIA_256_GCM_SHA384 */
      "RSA-PSK-ARIA128-GCM-SHA256",       /* TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256 */
      "RSA-PSK-ARIA256-GCM-SHA384",       /* TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384 */
      "ECDHE-PSK-ARIA128-SHA256",         /* TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256 */
      "ECDHE-PSK-ARIA256-SHA384",         /* TLS_ECDHE_PSK_WITH_ARIA_256_CBC_SHA384 */
  
      /* blacklisted SEED encryptions */
      "SEED-SHA",                         /*TLS_RSA_WITH_SEED_CBC_SHA */
      "DH-DSS-SEED-SHA",                  /* TLS_DH_DSS_WITH_SEED_CBC_SHA */
      "DH-RSA-SEED-SHA",                  /* TLS_DH_RSA_WITH_SEED_CBC_SHA */
      "DHE-DSS-SEED-SHA",                 /* TLS_DHE_DSS_WITH_SEED_CBC_SHA */
      "DHE-RSA-SEED-SHA",                 /* TLS_DHE_RSA_WITH_SEED_CBC_SHA */               
      "ADH-SEED-SHA",                     /* TLS_DH_anon_WITH_SEED_CBC_SHA */
  
      /* blacklisted KRB5 ciphers */
      "KRB5-DES-CBC-SHA",                 /* TLS_KRB5_WITH_DES_CBC_SHA */
      "KRB5-DES-CBC3-SHA",                /* TLS_KRB5_WITH_3DES_EDE_CBC_SHA */
      "KRB5-IDEA-CBC-SHA",                /* TLS_KRB5_WITH_IDEA_CBC_SHA */
      "KRB5-DES-CBC-MD5",                 /* TLS_KRB5_WITH_DES_CBC_MD5 */
      "KRB5-DES-CBC3-MD5",                /* TLS_KRB5_WITH_3DES_EDE_CBC_MD5 */
      "KRB5-IDEA-CBC-MD5",                /* TLS_KRB5_WITH_IDEA_CBC_MD5 */
      "EXP-KRB5-DES-CBC-SHA",             /* TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA */
      "EXP-KRB5-DES-CBC-MD5",             /* TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5 */
      "EXP-KRB5-RC2-CBC-SHA",             /* TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA */
      "EXP-KRB5-RC2-CBC-MD5",             /* TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5 */
    
      /* blacklisted exoticas */
      "DHE-DSS-CBC-SHA",                  /* TLS_DHE_DSS_WITH_DES_CBC_SHA */
      "IDEA-CBC-SHA",                     /* TLS_RSA_WITH_IDEA_CBC_SHA */
      
      /* not really sure if the following names are correct */
      "SSL3_CK_SCSV",                     /* TLS_EMPTY_RENEGOTIATION_INFO_SCSV */
      "SSL3_CK_FALLBACK_SCSV"
  };
  static size_t RFC7540_names_LEN = sizeof(RFC7540_names)/sizeof(RFC7540_names[0]);
  
  
  static apr_hash_t *BLCNames;
  
  static void cipher_init(apr_pool_t *pool)
  {
      apr_hash_t *hash = apr_hash_make(pool);
      const char *source;
      unsigned int i;
      
      source = "rfc7540";
      for (i = 0; i < RFC7540_names_LEN; ++i) {
          apr_hash_set(hash, RFC7540_names[i], APR_HASH_KEY_STRING, source);
      }
      
      BLCNames = hash;
  }
  
  static int cipher_is_blacklisted(const char *cipher, const char **psource)
  {   
      *psource = apr_hash_get(BLCNames, cipher, APR_HASH_KEY_STRING);
      return !!*psource;
  }
  
  /*******************************************************************************
   * Hooks for processing incoming connections:
   * - process_conn take over connection in case of h2
   */
  static int h2_h2_process_conn(conn_rec* c);
  static int h2_h2_pre_close_conn(conn_rec* c);
  static int h2_h2_post_read_req(request_rec *r);
  static int h2_h2_late_fixups(request_rec *r);
  
  /*******************************************************************************
   * Once per lifetime init, retrieve optional functions
   */
  apr_status_t h2_h2_init(apr_pool_t *pool, server_rec *s)
  {
      (void)pool;
      ap_log_error(APLOG_MARK, APLOG_TRACE1, 0, s, "h2_h2, child_init");
      opt_ssl_engine_disable = APR_RETRIEVE_OPTIONAL_FN(ssl_engine_disable);
      opt_ssl_is_https = APR_RETRIEVE_OPTIONAL_FN(ssl_is_https);
      opt_ssl_var_lookup = APR_RETRIEVE_OPTIONAL_FN(ssl_var_lookup);
      
      if (!opt_ssl_is_https || !opt_ssl_var_lookup) {
          ap_log_error(APLOG_MARK, APLOG_WARNING, 0, s,
                       APLOGNO(02951) "mod_ssl does not seem to be enabled");
      }
      
      cipher_init(pool);
      
      return APR_SUCCESS;
  }
  
  int h2_h2_is_tls(conn_rec *c)
  {
      return opt_ssl_is_https && opt_ssl_is_https(c);
  }
  
  int h2_is_acceptable_connection(conn_rec *c, int require_all) 
  {
      int is_tls = h2_h2_is_tls(c);
      const h2_config *cfg = h2_config_get(c);
  
      if (is_tls && h2_config_geti(cfg, H2_CONF_MODERN_TLS_ONLY) > 0) {
          /* Check TLS connection for modern TLS parameters, as defined in
           * RFC 7540 and https://wiki.mozilla.org/Security/Server_Side_TLS#Modern_compatibility
           */
          apr_pool_t *pool = c->pool;
          server_rec *s = c->base_server;
          char *val;
          
          if (!opt_ssl_var_lookup) {
              /* unable to check */
              return 0;
          }
          
          /* Need Tlsv1.2 or higher, rfc 7540, ch. 9.2
           */
          val = opt_ssl_var_lookup(pool, s, c, NULL, (char*)"SSL_PROTOCOL");
          if (val && *val) {
              if (strncmp("TLS", val, 3) 
                  || !strcmp("TLSv1", val) 
                  || !strcmp("TLSv1.1", val)) {
                  ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03050)
                                "h2_h2(%ld): tls protocol not suitable: %s", 
                                (long)c->id, val);
                  return 0;
              }
          }
          else if (require_all) {
              ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03051)
                            "h2_h2(%ld): tls protocol is indetermined", (long)c->id);
              return 0;
          }
  
          /* Check TLS cipher blacklist
           */
          val = opt_ssl_var_lookup(pool, s, c, NULL, (char*)"SSL_CIPHER");
          if (val && *val) {
              const char *source;
              if (cipher_is_blacklisted(val, &source)) {
                  ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03052)
                                "h2_h2(%ld): tls cipher %s blacklisted by %s", 
                                (long)c->id, val, source);
                  return 0;
              }
          }
          else if (require_all) {
              ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03053)
                            "h2_h2(%ld): tls cipher is indetermined", (long)c->id);
              return 0;
          }
      }
      return 1;
  }
  
  int h2_allows_h2_direct(conn_rec *c)
  {
      const h2_config *cfg = h2_config_get(c);
      int is_tls = h2_h2_is_tls(c);
      const char *needed_protocol = is_tls? "h2" : "h2c";
      int h2_direct = h2_config_geti(cfg, H2_CONF_DIRECT);
      
      if (h2_direct < 0) {
          h2_direct = is_tls? 0 : 1;
      }
      return (h2_direct 
              && ap_is_allowed_protocol(c, NULL, NULL, needed_protocol));
  }
  
  int h2_allows_h2_upgrade(conn_rec *c)
  {
      const h2_config *cfg = h2_config_get(c);
      int h2_upgrade = h2_config_geti(cfg, H2_CONF_UPGRADE);
      
      return h2_upgrade > 0 || (h2_upgrade < 0 && !h2_h2_is_tls(c));
  }
  
  /*******************************************************************************
   * Register various hooks
   */
  static const char* const mod_ssl[]        = { "mod_ssl.c", NULL};
  static const char* const mod_reqtimeout[] = { "mod_reqtimeout.c", NULL};
  
  void h2_h2_register_hooks(void)
  {
      /* Our main processing needs to run quite late. Definitely after mod_ssl,
       * as we need its connection filters, but also before reqtimeout as its
       * method of timeouts is specific to HTTP/1.1 (as of now).
       * The core HTTP/1 processing run as REALLY_LAST, so we will have
       * a chance to take over before it.
       */
      ap_hook_process_connection(h2_h2_process_conn, 
                                 mod_ssl, mod_reqtimeout, APR_HOOK_LAST);
      
      /* One last chance to properly say goodbye if we have not done so
       * already. */
      ap_hook_pre_close_connection(h2_h2_pre_close_conn, NULL, mod_ssl, APR_HOOK_LAST);
  
      /* With "H2SerializeHeaders On", we install the filter in this hook
       * that parses the response. This needs to happen before any other post
       * read function terminates the request with an error. Otherwise we will
       * never see the response.
       */
      ap_hook_post_read_request(h2_h2_post_read_req, NULL, NULL, APR_HOOK_REALLY_FIRST);
      ap_hook_fixups(h2_h2_late_fixups, NULL, NULL, APR_HOOK_LAST);
  
      /* special bucket type transfer through a h2_bucket_beam */
      h2_register_bucket_beamer(h2_bucket_headers_beam);
      h2_register_bucket_beamer(h2_bucket_observer_beam);
  }
  
  int h2_h2_process_conn(conn_rec* c)
  {
      apr_status_t status;
      h2_ctx *ctx;
      
      if (c->master) {
          return DECLINED;
      }
      
      ctx = h2_ctx_get(c, 0);
      ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, "h2_h2, process_conn");
      if (h2_ctx_is_task(ctx)) {
          /* our stream pseudo connection */
          ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c, "h2_h2, task, declined");
          return DECLINED;
      }
      
      if (!ctx && c->keepalives == 0) {
          const char *proto = ap_get_protocol(c);
          
          if (APLOGctrace1(c)) {
              ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, "h2_h2, process_conn, "
                            "new connection using protocol '%s', direct=%d, "
                            "tls acceptable=%d", proto, h2_allows_h2_direct(c), 
                            h2_is_acceptable_connection(c, 1));
          }
          
          if (!strcmp(AP_PROTOCOL_HTTP1, proto)
              && h2_allows_h2_direct(c) 
              && h2_is_acceptable_connection(c, 1)) {
              /* Fresh connection still is on http/1.1 and H2Direct is enabled. 
               * Otherwise connection is in a fully acceptable state.
               * -> peek at the first 24 incoming bytes
               */
              apr_bucket_brigade *temp;
              char *s = NULL;
              apr_size_t slen;
              
              temp = apr_brigade_create(c->pool, c->bucket_alloc);
              status = ap_get_brigade(c->input_filters, temp,
                                      AP_MODE_SPECULATIVE, APR_BLOCK_READ, 24);
              
              if (status != APR_SUCCESS) {
                  ap_log_cerror(APLOG_MARK, APLOG_DEBUG, status, c, APLOGNO(03054)
                                "h2_h2, error reading 24 bytes speculative");
                  apr_brigade_destroy(temp);
                  return DECLINED;
              }
              
              apr_brigade_pflatten(temp, &s, &slen, c->pool);
              if ((slen >= 24) && !memcmp(H2_MAGIC_TOKEN, s, 24)) {
                  ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c,
                                "h2_h2, direct mode detected");
                  if (!ctx) {
                      ctx = h2_ctx_get(c, 1);
                  }
                  h2_ctx_protocol_set(ctx, h2_h2_is_tls(c)? "h2" : "h2c");
              }
              else {
                  ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c,
                                "h2_h2, not detected in %d bytes: %s", 
                                (int)slen, s);
              }
              
              apr_brigade_destroy(temp);
          }
      }
  
      if (ctx) {
          ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, "process_conn");
          if (!h2_ctx_session_get(ctx)) {
              status = h2_conn_setup(ctx, c, NULL);
              ap_log_cerror(APLOG_MARK, APLOG_TRACE1, status, c, "conn_setup");
              if (status != APR_SUCCESS) {
                  return status;
              }
          }
          return h2_conn_run(ctx, c);
      }
      
      ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, c, "h2_h2, declined");
      return DECLINED;
  }
  
  static int h2_h2_pre_close_conn(conn_rec *c)
  {
      h2_ctx *ctx;
  
      /* slave connection? */
      if (c->master) {
          return DECLINED;
      }
  
      ctx = h2_ctx_get(c, 0);
      if (ctx) {
          /* If the session has been closed correctly already, we will not
           * fiond a h2_ctx here. The presence indicates that the session
           * is still ongoing. */
          return h2_conn_pre_close(ctx, c);
      }
      return DECLINED;
  }
  
  static void check_push(request_rec *r, const char *tag)
  {
      const h2_config *conf = h2_config_rget(r);
      if (!r->expecting_100 
          && conf && conf->push_list && conf->push_list->nelts > 0) {
          int i, old_status;
          const char *old_line;
          ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, 
                        "%s, early announcing %d resources for push",
                        tag, conf->push_list->nelts);
          for (i = 0; i < conf->push_list->nelts; ++i) {
              h2_push_res *push = &APR_ARRAY_IDX(conf->push_list, i, h2_push_res);
              apr_table_addn(r->headers_out, "Link", 
                             apr_psprintf(r->pool, "<%s>; rel=preload%s", 
                                          push->uri_ref, push->critical? "; critical" : ""));
          }
          old_status = r->status;
          old_line = r->status_line;
          r->status = 103;
          r->status_line = "103 Early Hints";
          ap_send_interim_response(r, 1);
          r->status = old_status;
          r->status_line = old_line;
      }
  }
  
  static int h2_h2_post_read_req(request_rec *r)
  {
      /* slave connection? */
      if (r->connection->master) {
          h2_ctx *ctx = h2_ctx_rget(r);
          struct h2_task *task = h2_ctx_get_task(ctx);
          /* This hook will get called twice on internal redirects. Take care
           * that we manipulate filters only once. */
          if (task && !task->filters_set) {
              ap_filter_t *f;
              ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r, 
                            "h2_task(%s): adding request filters", task->id);
  
              /* setup the correct filters to process the request for h2 */
              ap_add_input_filter("H2_REQUEST", task, r, r->connection);
              
              /* replace the core http filter that formats response headers
               * in HTTP/1 with our own that collects status and headers */
              ap_remove_output_filter_byhandle(r->output_filters, "HTTP_HEADER");
              ap_add_output_filter("H2_RESPONSE", task, r, r->connection);
              
              for (f = r->input_filters; f; f = f->next) {
                  if (!strcmp("H2_SLAVE_IN", f->frec->name)) {
                      f->r = r;
                      break;
                  }
              }
              ap_add_output_filter("H2_TRAILERS_OUT", task, r, r->connection);
              task->filters_set = 1;
          }
      }
      return DECLINED;
  }
  
  static int h2_h2_late_fixups(request_rec *r)
  {
      /* slave connection? */
      if (r->connection->master) {
          h2_ctx *ctx = h2_ctx_rget(r);
          struct h2_task *task = h2_ctx_get_task(ctx);
          if (task) {
              /* check if we copy vs. setaside files in this location */
              task->output.copy_files = h2_config_geti(h2_config_rget(r), 
                                                       H2_CONF_COPY_FILES);
              if (task->output.copy_files) {
                  ap_log_cerror(APLOG_MARK, APLOG_TRACE1, 0, task->c,
                                "h2_slave_out(%s): copy_files on", task->id);
                  h2_beam_on_file_beam(task->output.beam, h2_beam_no_files, NULL);
              }
              check_push(r, "late_fixup");
          }
      }
      return DECLINED;
  }
  
  