/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
#include <assert.h>

#include <apr_optional.h>
#include <apr_optional_hooks.h>
#include <apr_strings.h>
#include <apr_cstr.h>
#include <apr_time.h>
#include <apr_want.h>

#include <httpd.h>
#include <http_protocol.h>
#include <http_request.h>
#include <http_log.h>

#define SECS_PER_HOUR      (60 * 60)
#define SECS_PER_DAY       (24 * SECS_PER_HOUR)

static apr_status_t duration_parse(apr_interval_time_t *ptimeout,
                                   const char *value, const char *def_unit)
{
  char *endp;
  apr_int64_t n;

  n = apr_strtoi64(value, &endp, 10);
  if(errno) {
    return errno;
  }
  if(!endp || !*endp) {
    if(!def_unit)
      def_unit = "s";
  }
  else if(endp == value) {
    return APR_EINVAL;
  }
  else {
    def_unit = endp;
  }

  switch(*def_unit) {
  case 'D':
  case 'd':
    *ptimeout = apr_time_from_sec(n * SECS_PER_DAY);
    break;
  case 's':
  case 'S':
    *ptimeout = (apr_interval_time_t)apr_time_from_sec(n);
    break;
  case 'h':
  case 'H':
    /* Time is in hours */
    *ptimeout = (apr_interval_time_t)apr_time_from_sec(n * SECS_PER_HOUR);
    break;
  case 'm':
  case 'M':
    switch(*(++def_unit)) {
    /* Time is in milliseconds */
    case 's':
    case 'S':
      *ptimeout = (apr_interval_time_t)n * 1000;
      break;
    /* Time is in minutes */
    case 'i':
    case 'I':
      *ptimeout = (apr_interval_time_t)apr_time_from_sec(n * 60);
      break;
    default:
      return APR_EGENERAL;
    }
    break;
  case 'u':
  case 'U':
    switch(*(++def_unit)) {
    /* Time is in microseconds */
    case 's':
    case 'S':
      *ptimeout = (apr_interval_time_t)n;
      break;
    default:
      return APR_EGENERAL;
    }
    break;
  default:
    return APR_EGENERAL;
  }
  return APR_SUCCESS;
}

static int status_from_str(const char *s, apr_status_t *pstatus)
{
  if(!strcmp("timeout", s)) {
    *pstatus = APR_TIMEUP;
    return 1;
  }
  else if(!strcmp("reset", s)) {
    *pstatus = APR_ECONNRESET;
    return 1;
  }
  return 0;
}

static int curltest_echo_handler(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  char buffer[8192];
  const char *ct;
  apr_off_t die_after_len = -1, total_read_len = 0;
  apr_time_t read_delay = 0;
  int just_die = 0, die_after_100 = 0;
  long l;

  if(strcmp(r->handler, "curltest-echo")) {
    return DECLINED;
  }
  if(r->method_number != M_GET && r->method_number != M_POST) {
    return DECLINED;
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "echo_handler: processing");
  if(r->args) {
    apr_array_header_t *args = NULL;
    int i;
    args = apr_cstr_split(r->args, "&", 1, r->pool);
    for(i = 0; i < args->nelts; ++i) {
      char *s, *val, *arg = APR_ARRAY_IDX(args, i, char *);
      s = strchr(arg, '=');
      if(s) {
        *s = '\0';
        val = s + 1;
        if(!strcmp("die_after", arg)) {
          die_after_len = (apr_off_t)apr_atoi64(val);
          continue;
        }
        else if(!strcmp("just_die", arg)) {
          just_die = 1;
          continue;
        }
        else if(!strcmp("die_after_100", arg)) {
          die_after_100 = 1;
          continue;
        }
        else if(!strcmp("read_delay", arg)) {
          rv = duration_parse(&read_delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
      }
    }
  }

  if(just_die) {
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r,
                  "echo_handler: dying right away");
    /* Generate no HTTP response at all. */
    ap_remove_output_filter_byhandle(r->output_filters, "HTTP_HEADER");
    r->connection->keepalive = AP_CONN_CLOSE;
    return AP_FILTER_ERROR;
  }

  r->status = 200;
  if(die_after_len >= 0) {
    r->clength = die_after_len + 1;
    r->chunked = 0;
    apr_table_set(r->headers_out, "Content-Length",
                  apr_ltoa(r->pool, (long)r->clength));
  }
  else {
    r->clength = -1;
    r->chunked = 1;
    apr_table_unset(r->headers_out, "Content-Length");
  }
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");

  ct = apr_table_get(r->headers_in, "content-type");
  ap_set_content_type(r, ct ? ct : "application/octet-stream");

  if(apr_table_get(r->headers_in, "TE"))
    apr_table_setn(r->headers_out, "Request-TE",
                   apr_table_get(r->headers_in, "TE"));

  if(read_delay) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "put_handler: read_delay");
    apr_sleep(read_delay);
  }

  bb = apr_brigade_create(r->pool, c->bucket_alloc);
  /* copy any request body into the response */
  rv = ap_setup_client_block(r, REQUEST_CHUNKED_DECHUNK);
  if(rv)
    goto cleanup;
  if(die_after_100) {
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r,
                  "echo_handler: dying after 100-continue");
    /* Generate no HTTP response at all. */
    ap_remove_output_filter_byhandle(r->output_filters, "HTTP_HEADER");
    r->connection->keepalive = AP_CONN_CLOSE;
    return AP_FILTER_ERROR;
  }
  if(ap_should_client_block(r)) {
    while(0 < (l = ap_get_client_block(r, &buffer[0], sizeof(buffer)))) {
      total_read_len += l;
      if(die_after_len >= 0 && total_read_len >= die_after_len) {
        ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r,
                      "echo_handler: dying after %ld bytes as requested",
                      (long)total_read_len);
        ap_pass_brigade(r->output_filters, bb);
        ap_remove_output_filter_byhandle(r->output_filters, "HTTP_HEADER");
        r->connection->keepalive = AP_CONN_CLOSE;
        return DONE;
      }
      ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                    "echo_handler: copying %ld bytes from request body", l);
      rv = apr_brigade_write(bb, NULL, NULL, buffer, l);
      if(APR_SUCCESS != rv)
        goto cleanup;
      rv = ap_pass_brigade(r->output_filters, bb);
      if(APR_SUCCESS != rv)
        goto cleanup;
      ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                    "echo_handler: passed %ld bytes from request body", l);
    }
  }
  /* we are done */
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "echo_handler: request read");

  if(r->trailers_in && !apr_is_empty_table(r->trailers_in)) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
                  "echo_handler: seeing incoming trailers");
    apr_table_setn(r->trailers_out, "h2test-trailers-in",
                   apr_itoa(r->pool, 1));
  }

  rv = ap_pass_brigade(r->output_filters, bb);

cleanup:
  if(rv == APR_SUCCESS ||
     r->status != HTTP_OK ||
     c->aborted) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "echo_handler: done");
    return OK;
  }
  else {
    /* no way to know what type of error occurred */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "echo_handler failed");
    return AP_FILTER_ERROR;
  }
  return DECLINED;
}

static int curltest_tweak_handler(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  char buffer[16 * 1024];
  int i, chunks = 3, error_bucket = 1;
  size_t chunk_size = sizeof(buffer);
  const char *request_id = "none";
  apr_time_t delay = 0, chunk_delay = 0, close_delay = 0;
  apr_array_header_t *args = NULL;
  int http_status = 200;
  apr_status_t error = APR_SUCCESS, body_error = APR_SUCCESS;
  int close_conn = 0, with_cl = 0;
  int x_hd_len = 0, x_hd1_len = 0;

  if(strcmp(r->handler, "curltest-tweak")) {
    return DECLINED;
  }
  if(r->method_number == M_DELETE) {
    http_status = 204;
    chunks = 0;
  }
  else if(r->method_number != M_GET && r->method_number != M_POST) {
    return DECLINED;
  }

  if(r->args) {
    args = apr_cstr_split(r->args, "&", 1, r->pool);
    for(i = 0; i < args->nelts; ++i) {
      char *s, *val, *arg = APR_ARRAY_IDX(args, i, char *);
      s = strchr(arg, '=');
      if(s) {
        *s = '\0';
        val = s + 1;
        if(!strcmp("status", arg)) {
          http_status = (int)apr_atoi64(val);
          if(http_status > 0) {
            continue;
          }
        }
        else if(!strcmp("chunks", arg)) {
          chunks = (int)apr_atoi64(val);
          if(chunks >= 0) {
            continue;
          }
        }
        else if(!strcmp("chunk_size", arg)) {
          chunk_size = (int)apr_atoi64(val);
          if(chunk_size >= 0) {
            if(chunk_size > sizeof(buffer)) {
              ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                            "chunk_size %zu too large", chunk_size);
              ap_die(HTTP_BAD_REQUEST, r);
              return OK;
            }
            continue;
          }
        }
        else if(!strcmp("id", arg)) {
          /* an id for repeated requests with curl's URL globbing */
          request_id = val;
          continue;
        }
        else if(!strcmp("error", arg)) {
          if(status_from_str(val, &error)) {
            continue;
          }
        }
        else if(!strcmp("error_bucket", arg)) {
          error_bucket = (int)apr_atoi64(val);
          if(error_bucket >= 0) {
            continue;
          }
        }
        else if(!strcmp("body_error", arg)) {
          if(status_from_str(val, &body_error)) {
            continue;
          }
        }
        else if(!strcmp("delay", arg)) {
          rv = duration_parse(&delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
        else if(!strcmp("chunk_delay", arg)) {
          rv = duration_parse(&chunk_delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
        else if(!strcmp("close_delay", arg)) {
          rv = duration_parse(&close_delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
        else if(!strcmp("x-hd", arg)) {
          x_hd_len = (int)apr_atoi64(val);
          continue;
        }
        else if(!strcmp("x-hd1", arg)) {
          x_hd1_len = (int)apr_atoi64(val);
          continue;
        }
      }
      else if(!strcmp("close", arg)) {
        /* we are asked to close the connection */
        close_conn = 1;
        continue;
      }
      else if(!strcmp("with_cl", arg)) {
        with_cl = 1;
        continue;
      }
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "query parameter not "
                    "understood: '%s' in %s",
                    arg, r->args);
      ap_die(HTTP_BAD_REQUEST, r);
      return OK;
    }
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "error_handler: processing "
                "request, %s", r->args? r->args : "(no args)");
  r->status = http_status;
  r->clength = with_cl ? (chunks * chunk_size) : -1;
  r->chunked = (r->proto_num >= HTTP_VERSION(1, 1)) && !with_cl;
  apr_table_setn(r->headers_out, "request-id", request_id);
  if(r->clength >= 0) {
    apr_table_set(r->headers_out, "Content-Length",
                  apr_ltoa(r->pool, (long)r->clength));
  }
  else
    apr_table_unset(r->headers_out, "Content-Length");
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  if(x_hd_len > 0) {
    int i, hd_len = (16 * 1024);
    int n = (x_hd_len / hd_len);
    char *hd_val = apr_palloc(r->pool, hd_len);
    memset(hd_val, 'X', hd_len);
    hd_val[hd_len - 1] = 0;
    for(i = 0; i < n; ++i) {
      apr_table_setn(r->headers_out,
                     apr_psprintf(r->pool, "X-Header-%d", i), hd_val);
    }
    if(x_hd_len % hd_len) {
      hd_val[(x_hd_len % hd_len)] = 0;
      apr_table_setn(r->headers_out,
                     apr_psprintf(r->pool, "X-Header-%d", i), hd_val);
    }
  }
  if(x_hd1_len > 0) {
    char *hd_val = apr_palloc(r->pool, x_hd1_len);
    memset(hd_val, 'Y', x_hd1_len);
    hd_val[x_hd1_len - 1] = 0;
    apr_table_setn(r->headers_out, "X-Mega-Header", hd_val);
  }

  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");
  ap_set_content_type(r, "application/octet-stream");
  bb = apr_brigade_create(r->pool, c->bucket_alloc);

  if(delay) {
    apr_sleep(delay);
  }
  if(error != APR_SUCCESS) {
    return ap_map_http_request_error(error, HTTP_BAD_REQUEST);
  }
  /* flush response */
  b = apr_bucket_flush_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);
  if(APR_SUCCESS != rv)
    goto cleanup;

  memset(buffer, 'X', sizeof(buffer));
  for(i = 0; i < chunks; ++i) {
    if(chunk_delay) {
      apr_sleep(chunk_delay);
    }
    rv = apr_brigade_write(bb, NULL, NULL, buffer, chunk_size);
    if(APR_SUCCESS != rv)
      goto cleanup;
    rv = ap_pass_brigade(r->output_filters, bb);
    if(APR_SUCCESS != rv)
      goto cleanup;
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                  "error_handler: passed %lu bytes as response body",
                  (unsigned long)chunk_size);
    if(body_error != APR_SUCCESS) {
      rv = body_error;
      goto cleanup;
    }
  }
  /* we are done */
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);
  apr_brigade_cleanup(bb);
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r,
                "error_handler: response passed");

cleanup:
  if(close_conn) {
    if(close_delay) {
      b = apr_bucket_flush_create(c->bucket_alloc);
      APR_BRIGADE_INSERT_TAIL(bb, b);
      rv = ap_pass_brigade(r->output_filters, bb);
      apr_brigade_cleanup(bb);
      apr_sleep(close_delay);
    }
    r->connection->keepalive = AP_CONN_CLOSE;
  }
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r,
                "error_handler: request cleanup, r->status=%d, aborted=%d, "
                "close=%d", r->status, c->aborted, close_conn);
  if(rv == APR_SUCCESS) {
    return OK;
  }
  if(error_bucket) {
    http_status = ap_map_http_request_error(rv, HTTP_BAD_REQUEST);
    b = ap_bucket_error_create(http_status, NULL, r->pool, c->bucket_alloc);
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r,
                  "error_handler: passing error bucket, status=%d",
                  http_status);
    APR_BRIGADE_INSERT_TAIL(bb, b);
    ap_pass_brigade(r->output_filters, bb);
  }
  if(rv == APR_ECONNRESET) {
    r->connection->aborted = 1;
    return rv;
  }
  return AP_FILTER_ERROR;
}

static int curltest_put_handler(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  char buffer[128 * 1024];
  const char *ct;
  apr_off_t rbody_len = 0;
  apr_off_t rbody_max_len = -1;
  const char *s_rbody_len;
  const char *request_id = "none";
  apr_time_t read_delay = 0, chunk_delay = 0;
  apr_array_header_t *args = NULL;
  long l;
  int i;

  if(strcmp(r->handler, "curltest-put")) {
    return DECLINED;
  }
  if(r->method_number != M_PUT) {
    return DECLINED;
  }

  if(r->args) {
    args = apr_cstr_split(r->args, "&", 1, r->pool);
    for(i = 0; i < args->nelts; ++i) {
      char *s, *val, *arg = APR_ARRAY_IDX(args, i, char *);
      s = strchr(arg, '=');
      if(s) {
        *s = '\0';
        val = s + 1;
        if(!strcmp("id", arg)) {
          /* an id for repeated requests with curl's URL globbing */
          request_id = val;
          continue;
        }
        else if(!strcmp("read_delay", arg)) {
          rv = duration_parse(&read_delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
        else if(!strcmp("chunk_delay", arg)) {
          rv = duration_parse(&chunk_delay, val, "s");
          if(APR_SUCCESS == rv) {
            continue;
          }
        }
        else if(!strcmp("max_upload", arg)) {
          rbody_max_len = (apr_off_t)apr_atoi64(val);
          continue;
        }
      }
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "query parameter not "
                    "understood: '%s' in %s",
                    arg, r->args);
      ap_die(HTTP_BAD_REQUEST, r);
      return OK;
    }
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "put_handler: processing");
  r->status = 200;
  r->clength = -1;
  r->chunked = 1;
  apr_table_unset(r->headers_out, "Content-Length");
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  apr_table_setn(r->headers_out, "request-id", request_id);
  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");

  ct = apr_table_get(r->headers_in, "content-type");
  ap_set_content_type(r, ct ? ct : "text/plain");

  if(read_delay) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "put_handler: read_delay");
    apr_sleep(read_delay);
  }
  bb = apr_brigade_create(r->pool, c->bucket_alloc);
  /* copy any request body into the response */
  rv = ap_setup_client_block(r, REQUEST_CHUNKED_DECHUNK);
  if(rv)
    goto cleanup;
  if(ap_should_client_block(r)) {
    while(0 < (l = ap_get_client_block(r, &buffer[0], sizeof(buffer)))) {
      ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                    "put_handler: read %ld bytes from request body", l);
      if(chunk_delay) {
        apr_sleep(chunk_delay);
      }
      rbody_len += l;
      if((rbody_max_len > 0) && (rbody_len > rbody_max_len)) {
        r->status = 413;
        break;
      }
    }
  }
  /* we are done */
  s_rbody_len = apr_psprintf(r->pool, "%" APR_OFF_T_FMT, rbody_len);
  apr_table_setn(r->headers_out, "Received-Length", s_rbody_len);
  rv = apr_brigade_puts(bb, NULL, NULL, s_rbody_len);
  if(APR_SUCCESS != rv)
    goto cleanup;
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "put_handler: request read");

  rv = ap_pass_brigade(r->output_filters, bb);

  if(r->status == 413) {
    apr_sleep(apr_time_from_sec(1));
  }

cleanup:
  if(rv == APR_SUCCESS ||
     r->status != HTTP_OK ||
     c->aborted) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "put_handler: done");
    return OK;
  }
  else {
    /* no way to know what type of error occurred */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "put_handler failed");
    return AP_FILTER_ERROR;
  }
  return DECLINED;
}

static int curltest_1_1_required(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  const char *ct;

  if(strcmp(r->handler, "curltest-1_1-required")) {
    return DECLINED;
  }

  if(HTTP_VERSION_MAJOR(r->proto_num) > 1) {
    apr_table_setn(r->notes, "ssl-renegotiate-forbidden", "1");
    ap_die(HTTP_FORBIDDEN, r);
    return OK;
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "1_1_handler: processing");
  r->status = 200;
  r->clength = -1;
  r->chunked = 1;
  apr_table_unset(r->headers_out, "Content-Length");
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");

  ct = apr_table_get(r->headers_in, "content-type");
  ap_set_content_type(r, ct ? ct : "text/plain");

  bb = apr_brigade_create(r->pool, c->bucket_alloc);
  /* flush response */
  b = apr_bucket_flush_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);
  if(APR_SUCCESS != rv)
    goto cleanup;

  /* we are done */
  rv = apr_brigade_printf(bb, NULL, NULL, "well done!");
  if(APR_SUCCESS != rv)
    goto cleanup;
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "1_1_handler: request read");

  rv = ap_pass_brigade(r->output_filters, bb);

cleanup:
  if(rv == APR_SUCCESS ||
     r->status != HTTP_OK ||
     c->aborted) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "1_1_handler: done");
    return OK;
  }
  else {
    /* no way to know what type of error occurred */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "1_1_handler failed");
    return AP_FILTER_ERROR;
  }
  return DECLINED;
}

static int brigade_env_var(request_rec *r, apr_bucket_brigade *bb,
                           const char *name)
{
  const char *s;
  s = apr_table_get(r->subprocess_env, name);
  if(s)
    return apr_brigade_printf(bb, NULL, NULL, ",\n  \"%s\": \"%s\"", name, s);
  return 0;
}

static int curltest_sslinfo_handler(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  const char *request_id = NULL;
  int close_conn = 0;
  int i;

  if(strcmp(r->handler, "curltest-sslinfo")) {
    return DECLINED;
  }
  if(r->method_number != M_GET) {
    return DECLINED;
  }

  if(r->args) {
    apr_array_header_t *args = apr_cstr_split(r->args, "&", 1, r->pool);
    for(i = 0; i < args->nelts; ++i) {
      char *s, *val, *arg = APR_ARRAY_IDX(args, i, char *);
      s = strchr(arg, '=');
      if(s) {
        *s = '\0';
        val = s + 1;
        if(!strcmp("id", arg)) {
          /* an id for repeated requests with curl's URL globbing */
          request_id = val;
          continue;
        }
      }
      else if(!strcmp("close", arg)) {
        /* we are asked to close the connection */
        close_conn = 1;
        continue;
      }
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "query parameter not "
                    "understood: '%s' in %s",
                    arg, r->args);
      ap_die(HTTP_BAD_REQUEST, r);
      return OK;
    }
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "sslinfo: processing");
  r->status = 200;
  r->clength = -1;
  r->chunked = 1;
  apr_table_unset(r->headers_out, "Content-Length");
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  if(request_id)
    apr_table_setn(r->headers_out, "request-id", request_id);
  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");

  ap_set_content_type(r, "application/json");

  bb = apr_brigade_create(r->pool, c->bucket_alloc);

  apr_brigade_puts(bb, NULL, NULL, "{\n  \"Name\": \"SSL-Information\"");
  brigade_env_var(r, bb, "HTTPS");
  brigade_env_var(r, bb, "SSL_PROTOCOL");
  brigade_env_var(r, bb, "SSL_CIPHER");
  brigade_env_var(r, bb, "SSL_SESSION_ID");
  brigade_env_var(r, bb, "SSL_SESSION_RESUMED");
  brigade_env_var(r, bb, "SSL_SRP_USER");
  brigade_env_var(r, bb, "SSL_SRP_USERINFO");
  brigade_env_var(r, bb, "SSL_TLS_SNI");
  apr_brigade_puts(bb, NULL, NULL, "}\n");

  /* flush response */
  b = apr_bucket_flush_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);
  if(APR_SUCCESS != rv)
    goto cleanup;

  /* we are done */
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "1_1_handler: request read");

  rv = ap_pass_brigade(r->output_filters, bb);

cleanup:
  if(close_conn)
    r->connection->keepalive = AP_CONN_CLOSE;
  if(rv == APR_SUCCESS ||
     r->status != HTTP_OK ||
     c->aborted) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "1_1_handler: done");
    return OK;
  }
  else {
    /* no way to know what type of error occurred */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "1_1_handler failed");
    return AP_FILTER_ERROR;
  }
  return DECLINED;
}

struct curltest_limit_rec {
  int rcount;
  int rlimit;
  apr_time_t end;
  apr_time_t duration_sec;
  struct apr_thread_mutex_t *lock;
};

static struct curltest_limit_rec limitrec = {
  0, 5, 0, 2
};

static int curltest_limit_handler(request_rec *r)
{
  conn_rec *c = r->connection;
  apr_bucket_brigade *bb;
  apr_bucket *b;
  apr_status_t rv;
  const char *request_id = NULL;
  int i, denied;
  apr_time_t now;

  if(strcmp(r->handler, "curltest-limit")) {
    return DECLINED;
  }
  if(r->method_number != M_GET) {
    return DECLINED;
  }

  if(r->args) {
    apr_array_header_t *args = apr_cstr_split(r->args, "&", 1, r->pool);
    for(i = 0; i < args->nelts; ++i) {
      char *s, *val, *arg = APR_ARRAY_IDX(args, i, char *);
      s = strchr(arg, '=');
      if(s) {
        *s = '\0';
        val = s + 1;
        if(!strcmp("id", arg)) {
          /* an id for repeated requests with curl's URL globbing */
          request_id = val;
          continue;
        }
      }
      ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, "query parameter not "
                    "understood: '%s' in %s",
                    arg, r->args);
      ap_die(HTTP_BAD_REQUEST, r);
      return OK;
    }
  }

  ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "limit: processing");

  now = apr_time_now();
  apr_thread_mutex_lock(limitrec.lock);
  if(limitrec.end && (now > limitrec.end)) {
    /* reset limit */
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "limit: reset");
    limitrec.rcount = 0;
    limitrec.end = 0;
  }
  limitrec.rcount += 1;
  denied = (limitrec.rcount > limitrec.rlimit);
  if(denied) {
    /* extend limit duration */
    limitrec.end = now + apr_time_from_sec(limitrec.duration_sec);
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "limit: denied, %d request %s",
                  limitrec.rcount, request_id);
  }
  else {
    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, "limit: ok, %d request %s",
                  limitrec.rcount, request_id);
  }
  apr_thread_mutex_unlock(limitrec.lock);

  r->status = denied ? 429 : 200;
  r->clength = -1;
  r->chunked = 1;
  apr_table_unset(r->headers_out, "Content-Length");
  /* Discourage content-encodings */
  apr_table_unset(r->headers_out, "Content-Encoding");
  if(request_id)
    apr_table_setn(r->headers_out, "request-id", request_id);
  apr_table_setn(r->subprocess_env, "no-brotli", "1");
  apr_table_setn(r->subprocess_env, "no-gzip", "1");

  if(denied) {
    char *v = apr_psprintf(r->pool, "%d", limitrec.duration_sec);
    apr_table_set(r->headers_out, "Retry-After", v);
  }

  ap_set_content_type(r, "text/plain");

  bb = apr_brigade_create(r->pool, c->bucket_alloc);

  apr_brigade_puts(bb, NULL, NULL, "The resource served with limits.\n");

  /* flush response */
  b = apr_bucket_flush_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);
  if(APR_SUCCESS != rv)
    goto cleanup;

  /* we are done */
  b = apr_bucket_eos_create(c->bucket_alloc);
  APR_BRIGADE_INSERT_TAIL(bb, b);
  rv = ap_pass_brigade(r->output_filters, bb);

cleanup:
  if(rv == APR_SUCCESS ||
     r->status != HTTP_OK ||
     c->aborted) {
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "limit: done");
    return OK;
  }
  else {
    /* no way to know what type of error occurred */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, rv, r, "limit failed");
    return AP_FILTER_ERROR;
  }
  return DECLINED;
}

static int curltest_post_config(apr_pool_t *p, apr_pool_t *plog,
                                apr_pool_t *ptemp, server_rec *s)
{
  void *data = NULL;
  const char *key = "mod_curltest_init_counter";
  apr_status_t rv;

  (void)p;
  (void)plog;
  (void)ptemp;

  apr_pool_userdata_get(&data, key, s->process->pool);
  if(!data) {
    /* dry run */
    apr_pool_userdata_set((const void *)1, key,
                          apr_pool_cleanup_null, s->process->pool);
    return APR_SUCCESS;
  }

  return apr_thread_mutex_create(&limitrec.lock, APR_THREAD_MUTEX_DEFAULT, p);
}

static void curltest_hooks(apr_pool_t *pool)
{
  ap_log_perror(APLOG_MARK, APLOG_TRACE1, 0, pool, "installing hooks");

  /* Run once after configuration is set, but before mpm children initialize.
   */
  ap_hook_post_config(curltest_post_config, NULL, NULL, APR_HOOK_MIDDLE);

  /* curl test handlers */
  ap_hook_handler(curltest_echo_handler, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(curltest_put_handler, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(curltest_tweak_handler, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(curltest_1_1_required, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(curltest_sslinfo_handler, NULL, NULL, APR_HOOK_MIDDLE);
  ap_hook_handler(curltest_limit_handler, NULL, NULL, APR_HOOK_MIDDLE);
}

AP_DECLARE_MODULE(curltest) =
{
  STANDARD20_MODULE_STUFF,
  NULL, /* func to create per-directory config */
  NULL,  /* func to merge per-directory config */
  NULL, /* func to create per-server config */
  NULL,  /* func to merge per-server config */
  NULL,              /* command handlers */
  curltest_hooks,
#ifdef AP_MODULE_FLAG_NONE
  AP_MODULE_FLAG_ALWAYS_MERGE
#endif
};
