/***************************************************************************
 *                                  _   _ ____  _
 *  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 "first.h"

/* sws.c: simple (silly?) web server

   This code was originally graciously donated to the project by Juergen
   Wilke. Thanks a bunch!

 */

#ifdef HAVE_NETINET_TCP_H
#include <netinet/tcp.h> /* for TCP_NODELAY */
#endif

static bool use_gopher = FALSE;
static bool is_proxy = FALSE;

#define MAX_SLEEP_TIME_MS 250

static long sws_prevtestno = -1;    /* previous test number we served */
static long sws_prevpartno = -1;    /* previous part number we served */
static bool sws_prevbounce = FALSE; /* instructs the server to override the
                                       requested part number to
                                       prevpartno + 1 when prevtestno and
                                       current test are the same */

#define RCMD_NORMALREQ 0 /* default request, use the tests file normally */
#define RCMD_IDLE      1 /* told to sit idle */
#define RCMD_STREAM    2 /* told to stream */

struct sws_httprequest {
  char reqbuf[2 * 1024 * 1024]; /* buffer area for the incoming request */
  bool connect_request; /* if a CONNECT */
  unsigned short connect_port; /* the port number CONNECT used */
  size_t checkindex; /* where to start checking of the request */
  size_t offset;     /* size of the incoming request */
  long testno;       /* test number found in the request */
  long partno;       /* part number found in the request */
  bool open;      /* keep connection open info, as found in the request */
  bool auth_req;  /* authentication required, do not wait for body unless
                     there is an Authorization header */
  bool auth;      /* Authorization header present in the incoming request */
  size_t cl;      /* Content-Length of the incoming request */
  bool digest;    /* Authorization digest header found */
  bool ntlm;      /* Authorization NTLM header found */
  int delay;      /* if non-zero, delay this number of msec after connect */
  int writedelay; /* if non-zero, delay this number of milliseconds between
                     writes in the response */
  int skip;       /* if non-zero, the server is instructed to not read this
                     many bytes from a PUT/POST request. Ie the client sends N
                     bytes said in Content-Length, but the server only reads N
                     - skip bytes. */
  int rcmd;       /* doing a special command, see defines above */
  int prot_version;  /* HTTP version * 10 */
  int callcount;  /* times sws_ProcessRequest() gets called */
  bool skipall;   /* skip all incoming data */
  bool noexpect;  /* refuse Expect: (do not read the body) */
  bool connmon;   /* monitor the state of the connection, log disconnects */
  bool upgrade;   /* test case allows upgrade */
  bool upgrade_request; /* upgrade request found and allowed */
  bool close;     /* similar to swsclose in response: close connection after
                     response is sent */
  int done_processing;
};

#define MAX_SOCKETS 1024

static curl_socket_t all_sockets[MAX_SOCKETS];
static size_t num_sockets = 0;

#define SWSVERSION "curl test suite HTTP server/0.1"

#define REQUEST_DUMP  "server.input"
#define RESPONSE_DUMP "server.response"

/* when told to run as proxy, we store the logs in different files so that
   they can co-exist with the same program running as a "server" */
#define REQUEST_PROXY_DUMP  "proxy.input"
#define RESPONSE_PROXY_DUMP "proxy.response"

#define REQUEST_DUMP_FILENAME \
  (is_proxy ? REQUEST_PROXY_DUMP : REQUEST_DUMP)

/* file in which additional instructions may be found */
static const char *cmdfile = "log/server.cmd";

/* very-big-path support */
#define MAXDOCNAMELEN     140000
#define MAXDOCNAMELEN_TXT "139999"

#define REQUEST_KEYWORD_SIZE     256
#define REQUEST_KEYWORD_SIZE_TXT "255"

#define CMD_AUTH_REQUIRED "auth_required"

/* 'idle' means that it accepts the request fine but never responds
   any data. Keep the connection alive. */
#define CMD_IDLE "idle"

/* 'stream' means to send a never-ending stream of data */
#define CMD_STREAM "stream"

/* 'connection-monitor' outputs when a server/proxy connection gets
   disconnected as for some cases it is important that it gets done at the
   proper point - like with NTLM */
#define CMD_CONNECTIONMONITOR "connection-monitor"

/* upgrade to http2/websocket/xxxx */
#define CMD_UPGRADE "upgrade"

/* close connection */
#define CMD_SWSCLOSE "swsclose"

/* deny Expect: requests */
#define CMD_NOEXPECT "no-expect"

#define END_OF_HEADERS "\r\n\r\n"

static const char *end_of_headers = END_OF_HEADERS;

/* sent as reply to a QUIT */
static const char *docquit_sws = "HTTP/1.1 200 Goodbye" END_OF_HEADERS;

/* send back this on 404 file not found */
static const char *doc404 =
  "HTTP/1.1 404 Not Found\r\n"
  "Server: " SWSVERSION "\r\n"
  "Connection: close\r\n"
  "Content-Type: text/html"
  END_OF_HEADERS
  "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\n"
  "<HTML><HEAD>\n"
  "<TITLE>404 Not Found</TITLE>\n"
  "</HEAD><BODY>\n"
  "<H1>Not Found</H1>\n"
  "The requested URL was not found on this server.\n"
  "<P><HR><ADDRESS>" SWSVERSION "</ADDRESS>\n"
  "</BODY></HTML>\n";

/* This function returns a pointer to STATIC memory. It converts the given
 * binary lump to a hex formatted string usable for output in logs or
 * whatever.
 */
static char *data_to_hex(const char *data, size_t len)
{
  static char buf[256 * 3];
  size_t i;
  char *optr = buf;
  const char *iptr = data;

  if(len > 255)
    len = 255;

  for(i = 0; i < len; i++) {
    if((data[i] >= 0x20) && (data[i] < 0x7f))
      *optr++ = *iptr++;
    else {
      snprintf(optr, 4, "%%%02x", (unsigned char)*iptr++);
      optr += 3;
    }
  }
  *optr = 0; /* in case no sprintf was used */

  return buf;
}

/* work around for handling trailing headers */
static int already_recv_zeroed_chunk = FALSE;

#if defined(TCP_NODELAY) && defined(CURL_TCP_NODELAY_SUPPORTED)
/* returns true if the current socket is an IP one */
static bool socket_domain_is_ip(void)
{
  switch(socket_domain) {
  case AF_INET:
#ifdef USE_IPV6
  case AF_INET6:
#endif
    return TRUE;
  default:
    /* case AF_UNIX: */
    return FALSE;
  }
}
#endif

/* parse the file on disk that might have a test number for us */
static int parse_cmdfile(struct sws_httprequest *req)
{
  FILE *f = curlx_fopen(cmdfile, FOPEN_READTEXT);
  if(f) {
    int testnum = DOCNUMBER_NOTHING;
    char buf[256];
    while(fgets(buf, sizeof(buf), f)) {
      if(sscanf(buf, "Testnum %d", &testnum) == 1) {
        logmsg("[%s] cmdfile says testnum %d", cmdfile, testnum);
        req->testno = testnum;
      }
    }
    curlx_fclose(f);
  }
  return 0;
}

/* based on the testno, parse the correct server commands */
static int sws_parse_servercmd(struct sws_httprequest *req)
{
  FILE *stream;
  int error;

  stream = test2fopen(req->testno, logdir);
  req->close = FALSE;
  req->connmon = FALSE;

  if(!stream) {
    char errbuf[STRERROR_LEN];
    error = errno;
    logmsg("fopen() failed with error (%d) %s",
           error, curlx_strerror(error, errbuf, sizeof(errbuf)));
    logmsg("  Could not open test file %ld", req->testno);
    req->open = FALSE; /* closes connection */
    return 1; /* done */
  }
  else {
    char *orgcmd = NULL;
    const char *cmd = NULL;
    size_t cmdsize = 0;
    int num = 0;

    /* get the custom server control "commands" */
    error = getpart(&orgcmd, &cmdsize, "reply", "servercmd", stream);
    curlx_fclose(stream);
    if(error) {
      logmsg("getpart() failed with error (%d)", error);
      req->open = FALSE; /* closes connection */
      return 1; /* done */
    }

    cmd = orgcmd;
    while(cmd && cmdsize) {
      const char *check;

      if(!strncmp(CMD_AUTH_REQUIRED, cmd, strlen(CMD_AUTH_REQUIRED))) {
        logmsg("instructed to require authorization header");
        req->auth_req = TRUE;
      }
      else if(!strncmp(CMD_IDLE, cmd, strlen(CMD_IDLE))) {
        logmsg("instructed to idle");
        req->rcmd = RCMD_IDLE;
        req->open = TRUE;
      }
      else if(!strncmp(CMD_STREAM, cmd, strlen(CMD_STREAM))) {
        logmsg("instructed to stream");
        req->rcmd = RCMD_STREAM;
      }
      else if(!strncmp(CMD_CONNECTIONMONITOR, cmd,
                       strlen(CMD_CONNECTIONMONITOR))) {
        logmsg("enabled connection monitoring");
        req->connmon = TRUE;
      }
      else if(!strncmp(CMD_UPGRADE, cmd, strlen(CMD_UPGRADE))) {
        logmsg("enabled upgrade");
        req->upgrade = TRUE;
      }
      else if(!strncmp(CMD_SWSCLOSE, cmd, strlen(CMD_SWSCLOSE))) {
        logmsg("swsclose: close this connection after response");
        req->close = TRUE;
      }
      else if(sscanf(cmd, "skip: %d", &num) == 1) {
        logmsg("instructed to skip this number of bytes %d", num);
        req->skip = num;
      }
      else if(!strncmp(CMD_NOEXPECT, cmd, strlen(CMD_NOEXPECT))) {
        logmsg("instructed to reject Expect: 100-continue");
        req->noexpect = TRUE;
      }
      else if(sscanf(cmd, "delay: %d", &num) == 1) {
        logmsg("instructed to delay %d msecs after connect", num);
        req->delay = num;
      }
      else if(sscanf(cmd, "writedelay: %d", &num) == 1) {
        logmsg("instructed to delay %d msecs between packets", num);
        req->writedelay = num;
      }
      else {
        logmsg("Unknown <servercmd> instruction found: %s", cmd);
      }
      /* try to deal with CRLF or LF */
      check = strchr(cmd, '\r');
      if(!check)
        check = strchr(cmd, '\n');

      if(check) {
        /* get to the letter following the newline */
        while((*check == '\r') || (*check == '\n'))
          check++;

        if(!*check)
          /* if we reached a zero, get out */
          break;
        cmd = check;
      }
      else
        break;
    }
    free(orgcmd);
  }

  return 0; /* OK! */
}

static int sws_ProcessRequest(struct sws_httprequest *req)
{
  const char *line = &req->reqbuf[req->checkindex];
  bool chunked = FALSE;
  static char request[REQUEST_KEYWORD_SIZE];
  int prot_major = 0;
  int prot_minor = 0;
  const char *end = strstr(line, end_of_headers);
  const char *pval;
  curl_off_t num;

  req->callcount++;

  logmsg("Process %zu bytes request%s", req->offset,
         req->callcount > 1 ? " [CONTINUED]" : "");

  /* try to figure out the request characteristics as soon as possible, but
     only once! */

  if(use_gopher &&
     (req->testno == DOCNUMBER_NOTHING) &&
     !strncmp("/verifiedserver", line, 15)) {
    logmsg("Are-we-friendly question received");
    req->testno = DOCNUMBER_WERULEZ;
    return 1; /* done */
  }

  else if(req->testno == DOCNUMBER_NOTHING) {
    const char *http;
    bool fine = FALSE;
    const char *httppath = NULL;
    size_t npath = 0; /* httppath length */

    if(sscanf(line, "%" REQUEST_KEYWORD_SIZE_TXT "s ", request) == 1) {
      http = strstr(line + strlen(request), "HTTP/");

      if(http && sscanf(http, "HTTP/%d.%d", &prot_major, &prot_minor) == 2) {
        /* between the request keyword and HTTP/ there is a path */
        httppath = line + strlen(request);
        npath = http - httppath;

        /* trim leading spaces */
        while(npath && ISSPACE(*httppath)) {
          httppath++;
          npath--;
        }
        /* trim ending spaces */
        while(npath && ISSPACE(httppath[npath - 1])) {
          npath--;
        }
        if(npath)
          fine = TRUE;
      }
    }

    if(fine) {
      const char *ptr;

      req->prot_version = (prot_major * 10) + prot_minor;

      /* find the last slash */
      ptr = &httppath[npath];
      while(ptr >= httppath) {
        if(*ptr == '/')
          break;
        ptr--;
      }

      /* get the number after it */
      if(*ptr == '/') {
        if((npath + strlen(request)) < 400)
          logmsg("Got request: %s %.*s HTTP/%d.%d",
                 request, (int)npath, httppath, prot_major, prot_minor);
        else
          logmsg("Got a *HUGE* request HTTP/%d.%d", prot_major, prot_minor);

        if(!strncmp("/verifiedserver", ptr, 15)) {
          logmsg("Are-we-friendly question received");
          req->testno = DOCNUMBER_WERULEZ;
          return 1; /* done */
        }

        if(!strncmp("/quit", ptr, 5)) {
          logmsg("Request-to-quit received");
          req->testno = DOCNUMBER_QUIT;
          return 1; /* done */
        }

        ptr++; /* skip the slash */

        pval = ptr;
        if(!curlx_str_number(&pval, &num, INT_MAX))
          req->testno = (long)num;

        if(req->testno > 10000) {
          req->partno = req->testno % 10000;
          req->testno /= 10000;
        }
        else
          req->partno = 0;

        if(req->testno) {
          logmsg("Serve test number %ld part %ld", req->testno, req->partno);
        }
        else {
          logmsg("No test number in path");
          req->testno = DOCNUMBER_NOTHING;
        }
      }

      if(req->testno == DOCNUMBER_NOTHING) {
        /* did not find any in the first scan, try alternative test case
           number placements */
        static char doc[MAXDOCNAMELEN];
        if(sscanf(req->reqbuf, "CONNECT %" MAXDOCNAMELEN_TXT "s HTTP/%d.%d",
                  doc, &prot_major, &prot_minor) == 3) {
          const char *portp = NULL;

          logmsg("Received a CONNECT %s HTTP/%d.%d request",
                 doc, prot_major, prot_minor);

          req->connect_request = TRUE;

          if(req->prot_version == 10)
            req->open = FALSE; /* HTTP 1.0 closes connection by default */

          if(doc[0] == '[') {
            const char *p = &doc[1];
            curl_off_t part = 0;
            /* scan through the hexgroups and store the value of the last group
               in the 'part' variable and use as test case number!! */
            while(*p && (ISXDIGIT(*p) || (*p == ':') || (*p == '.'))) {
              const char *endp = p;
              if(!curlx_str_hex(&endp, &part, 0xffff))
                p = endp;
              else
                p++;
            }
            if(*p != ']')
              logmsg("Invalid CONNECT IPv6 address format");
            else if(*(p + 1) != ':')
              logmsg("Invalid CONNECT IPv6 port format");
            else
              portp = p + 1;

            req->testno = (long)part;
          }
          else
            portp = strchr(doc, ':');

          if(portp && (*(portp + 1) != '\0') && ISDIGIT(*(portp + 1))) {
            pval = portp + 1;
            if(curlx_str_number(&pval, &num, 0xffff) ||
               (num <= 0) || (num > 65535))
              logmsg("Invalid CONNECT port received");
            else
              req->connect_port = (unsigned short)num;
          }
          logmsg("Port number: %d, test case number: %ld",
                 req->connect_port, req->testno);
        }
      }

      if(req->testno == DOCNUMBER_NOTHING)
        /* might get the test number */
        parse_cmdfile(req);

      if(req->testno == DOCNUMBER_NOTHING) {
        logmsg("Did not find test number in PATH");
        req->testno = DOCNUMBER_404;
      }
      else
        sws_parse_servercmd(req);
    }
    else if((req->offset >= 3)) {
      const unsigned char *l = (const unsigned char *)line;
      logmsg("** Unusual request. Starts with %02x %02x %02x (%c%c%c)",
             l[0], l[1], l[2], l[0], l[1], l[2]);
    }
  }

  if(!end) {
    /* we do not have a complete request yet! */
    logmsg("request not complete yet");
    return 0; /* not complete yet */
  }
  logmsg("- request found to be complete (%ld)", req->testno);

  if(req->testno == DOCNUMBER_NOTHING) {
    /* check for a Testno: header with the test case number */
    const char *testno = strstr(line, "\nTestno: ");
    if(testno) {
      pval = &testno[9];
      if(!curlx_str_number(&pval, &num, INT_MAX)) {
        req->testno = (long)num;
        logmsg("Found test number %ld in Testno: header!", req->testno);
      }
      else
        logmsg("No Testno: number");
    }
    else {
      logmsg("No Testno: header");
    }
  }

  /* find and parse <servercmd> for this test */
  sws_parse_servercmd(req);

  if(use_gopher) {
    /* when using gopher we cannot check the request until the entire
       thing has been received */
    const char *ptr;

    /* find the last slash in the line */
    ptr = strrchr(line, '/');

    if(ptr) {
      ptr++; /* skip the slash */

      /* skip all non-numericals following the slash */
      while(*ptr && !ISDIGIT(*ptr))
        ptr++;

      pval = ptr;
      if(!curlx_str_number(&pval, &num, INT_MAX))
        req->testno = (long)num;

      if(req->testno > 10000) {
        req->partno = req->testno % 10000;
        req->testno /= 10000;
      }
      else
        req->partno = 0;

      logmsg("Requested GOPHER test number %ld part %ld",
             req->testno, req->partno);
    }
  }

  /* **** Persistence ****
   *
   * If the request is an HTTP/1.0 one, we close the connection unconditionally
   * when we are done.
   *
   * If the request is an HTTP/1.1 one, we MUST check for a "Connection:"
   * header that might say "close". If it does, we close a connection when
   * this request is processed. Otherwise, we keep the connection alive for X
   * seconds.
   */

  do {
    if(got_exit_signal)
      return 1; /* done */

    if((req->cl == 0) && !CURL_STRNICMP("Content-Length:", line, 15)) {
      /* If we do not ignore content-length, we read it and we read the whole
         request including the body before we return. If we have been told to
         ignore the content-length, we return as soon as all headers
         have been received */
      curl_off_t clen;
      const char *p = line + strlen("Content-Length:");
      if(curlx_str_numblanks(&p, &clen)) {
        /* this assumes that a zero Content-Length is valid */
        logmsg("Found invalid '%s' in the request", line);
        req->open = FALSE; /* closes connection */
        return 1; /* done */
      }
      if(req->skipall)
        req->cl = 0;
      else
        req->cl = (size_t)clen - req->skip;

      logmsg("Found Content-Length: %zu in the request", (size_t)clen);
      if(req->skip)
        logmsg("... but going to abort after %zu bytes", req->cl);
    }
    else if(!CURL_STRNICMP("Transfer-Encoding: chunked", line,
                           strlen("Transfer-Encoding: chunked"))) {
      /* chunked data coming in */
      chunked = TRUE;
    }
    else if(req->noexpect && !CURL_STRNICMP("Expect: 100-continue", line,
                                            strlen("Expect: 100-continue"))) {
      if(req->cl)
        req->cl = 0;
      req->skipall = TRUE;
      logmsg("Found Expect: 100-continue, ignore body");
    }

    if(chunked) {
      if(strstr(req->reqbuf, "\r\n0\r\n\r\n")) {
        /* end of chunks reached */
        return 1; /* done */
      }
      else if(strstr(req->reqbuf, "\r\n0\r\n")) {
        const char *last_crlf_char = strstr(req->reqbuf, "\r\n\r\n");
        while(TRUE) {
          if(!strstr(last_crlf_char + 4, "\r\n\r\n"))
            break;
          last_crlf_char = strstr(last_crlf_char + 4, "\r\n\r\n");
        }
        if(last_crlf_char &&
           last_crlf_char > strstr(req->reqbuf, "\r\n0\r\n"))
          return 1;
        already_recv_zeroed_chunk = TRUE;
        return 0;
      }
      else if(already_recv_zeroed_chunk && strstr(req->reqbuf, "\r\n\r\n"))
        return 1;
      else
        return 0; /* not done */
    }

    line = strchr(line, '\n');
    if(line)
      line++;

  } while(line);

  if(!req->auth && strstr(req->reqbuf, "Authorization:")) {
    req->auth = TRUE; /* Authorization: header present! */
    if(req->auth_req)
      logmsg("Authorization header found, as required");
  }

  if(strstr(req->reqbuf, "Authorization: Negotiate")) {
    /* Negotiate iterations */
    static long prev_testno = -1;
    static long prev_partno = -1;
    logmsg("Negotiate: prev_testno: %ld, prev_partno: %ld",
           prev_testno, prev_partno);
    if(req->testno != prev_testno) {
      prev_testno = req->testno;
      prev_partno = req->partno;
    }
    prev_partno += 1;
    req->partno = prev_partno;
  }
  else if(!req->digest && strstr(req->reqbuf, "Authorization: Digest")) {
    /* If the client is passing this Digest-header, we set the part number
       to 1000. Not only to spice up the complexity of this, but to make
       Digest stuff to work in the test suite. */
    req->partno += 1000;
    req->digest = TRUE; /* header found */
    logmsg("Received Digest request, sending back data %ld", req->partno);
  }
  else if(!req->ntlm &&
          strstr(req->reqbuf, "Authorization: NTLM TlRMTVNTUAAD")) {
    /* If the client is passing this type-3 NTLM header */
    req->partno += 1002;
    req->ntlm = TRUE; /* NTLM found */
    logmsg("Received NTLM type-3, sending back data %ld", req->partno);
    if(req->cl) {
      logmsg("  Expecting %zu POSTed bytes", req->cl);
    }
  }
  else if(!req->ntlm &&
          strstr(req->reqbuf, "Authorization: NTLM TlRMTVNTUAAB")) {
    /* If the client is passing this type-1 NTLM header */
    req->partno += 1001;
    req->ntlm = TRUE; /* NTLM found */
    logmsg("Received NTLM type-1, sending back data %ld", req->partno);
  }
  else if((req->partno >= 1000) &&
          strstr(req->reqbuf, "Authorization: Basic")) {
    /* If the client is passing this Basic-header and the part number is
       already >=1000, we add 1 to the part number.  This allows simple Basic
       authentication negotiation to work in the test suite. */
    req->partno += 1;
    logmsg("Received Basic request, sending back data %ld", req->partno);
  }
  if(strstr(req->reqbuf, "Connection: close"))
    req->open = FALSE; /* close connection after this request */

  if(req->open &&
     req->prot_version >= 11 &&
     req->reqbuf + req->offset > end + strlen(end_of_headers) &&
     !req->cl &&
     (!strncmp(req->reqbuf, "GET", strlen("GET")) ||
      !strncmp(req->reqbuf, "HEAD", strlen("HEAD")))) {
    /* If we have a persistent connection, HTTP version >= 1.1
       and GET/HEAD request, enable pipelining. */
    req->checkindex = (end - req->reqbuf) + strlen(end_of_headers);
  }

  /* If authentication is required and no auth was provided, end now. This
     makes the server NOT wait for PUT/POST data and you can then make the
     test case send a rejection before any such data has been sent. Test case
     154 uses this.*/
  if(req->auth_req && !req->auth) {
    logmsg("Return early due to auth requested but none provided");
    return 1; /* done */
  }

  if(req->upgrade && strstr(req->reqbuf, "Upgrade:")) {
    /* we allow upgrade and there was one! */
    logmsg("Found Upgrade: in request and allow it");
    req->upgrade_request = TRUE;
    return 0; /* not done */
  }

  if(req->cl > 0) {
    if(req->cl <= req->offset - (end - req->reqbuf) - strlen(end_of_headers))
      return 1; /* done */
    else
      return 0; /* not complete yet */
  }

  return 1; /* done */
}

/* returns -1 on failure */
static int sws_send_doc(curl_socket_t sock, struct sws_httprequest *req)
{
  ssize_t written;
  size_t count;
  const char *buffer;
  char *ptr = NULL;
  FILE *stream;
  char *cmd = NULL;
  size_t cmdsize = 0;
  FILE *dump;
  bool persistent = TRUE;
  bool sendfailure = FALSE;
  size_t responsesize;
  int error = 0;
  char errbuf[STRERROR_LEN];
  static char weare[256];
  char responsedump[256];

  snprintf(responsedump, sizeof(responsedump), "%s/%s",
           logdir, is_proxy ? RESPONSE_PROXY_DUMP : RESPONSE_DUMP);

  switch(req->rcmd) {
  default:
  case RCMD_NORMALREQ:
    break; /* continue with business as usual */
  case RCMD_STREAM: {
    static const char streamthis[] = "a string to stream 01234567890\n";
    for(;;) {
      written = swrite(sock, streamthis, sizeof(streamthis) - 1);
      if(got_exit_signal)
        return -1;
      if(written != (ssize_t)(sizeof(streamthis) - 1)) {
        logmsg("Stopped streaming");
        break;
      }
    }
    return -1;
  }
  case RCMD_IDLE:
    /* Do nothing. Sit idle. Pretend it rains. */
    return 0;
  }

  req->open = FALSE;

  if(req->testno < 0) {
    size_t msglen;
    char msgbuf[64];

    switch(req->testno) {
    case DOCNUMBER_QUIT:
      logmsg("Replying to QUIT");
      buffer = docquit_sws;
      break;
    case DOCNUMBER_WERULEZ:
      /* we got a "friends?" question, reply back that we sure are */
      logmsg("Identifying ourselves as friends");
      snprintf(msgbuf, sizeof(msgbuf), "WE ROOLZ: %ld\r\n",
               (long)our_getpid());
      msglen = strlen(msgbuf);
      if(use_gopher)
        snprintf(weare, sizeof(weare), "%s", msgbuf);
      else
        snprintf(weare, sizeof(weare),
                 "HTTP/1.1 200 OK\r\nContent-Length: %u\r\n\r\n%s",
                 (unsigned int)msglen, msgbuf);
      buffer = weare;
      break;
    case DOCNUMBER_404:
    default:
      logmsg("Replying with a 404");
      buffer = doc404;
      break;
    }

    count = strlen(buffer);
  }
  else {
    char partbuf[80];

    /* select the <data> tag for "normal" requests and the <connect> one
       for CONNECT requests (within the <reply> section) */
    const char *section = req->connect_request ? "connect" : "data";

    if(req->partno)
      snprintf(partbuf, sizeof(partbuf), "%s%ld", section, req->partno);
    else
      snprintf(partbuf, sizeof(partbuf), "%s", section);

    logmsg("Send response test%ld section <%s>", req->testno, partbuf);

    stream = test2fopen(req->testno, logdir);
    if(!stream) {
      error = errno;
      logmsg("fopen() failed with error (%d) %s",
             error, curlx_strerror(error, errbuf, sizeof(errbuf)));
      return 0;
    }
    else {
      error = getpart(&ptr, &count, "reply", partbuf, stream);
      curlx_fclose(stream);
      if(error) {
        logmsg("getpart() failed with error (%d)", error);
        return 0;
      }
      buffer = ptr;
    }

    if(got_exit_signal) {
      free(ptr);
      return -1;
    }

    /* re-open the same file again */
    stream = test2fopen(req->testno, logdir);
    if(!stream) {
      error = errno;
      logmsg("fopen() failed with error (%d) %s",
             error, curlx_strerror(error, errbuf, sizeof(errbuf)));
      free(ptr);
      return 0;
    }
    else {
      /* get the custom server control "commands" */
      error = getpart(&cmd, &cmdsize, "reply", "postcmd", stream);
      curlx_fclose(stream);
      if(error) {
        logmsg("getpart() failed with error (%d)", error);
        free(ptr);
        return 0;
      }
    }
  }

  if(got_exit_signal) {
    free(ptr);
    free(cmd);
    return -1;
  }

  /* If the word 'swsclose' is present anywhere in the reply chunk, the
     connection is closed after the data has been sent to the requesting
     client... */
  if(strstr(buffer, "swsclose") || !count || req->close) {
    persistent = FALSE;
    logmsg("connection close instruction \"swsclose\" found in response");
  }
  if(strstr(buffer, "swsbounce")) {
    sws_prevbounce = TRUE;
    logmsg("enable \"swsbounce\" in the next request");
  }
  else
    sws_prevbounce = FALSE;

  dump = curlx_fopen(responsedump, "ab");
  if(!dump) {
    error = errno;
    logmsg("fopen() failed with error (%d) %s",
           error, curlx_strerror(error, errbuf, sizeof(errbuf)));
    logmsg("  [5] Error opening file '%s'", responsedump);
    free(ptr);
    free(cmd);
    return -1;
  }

  responsesize = count;
  do {
    /* Ok, we send no more than N bytes at a time, to make sure that
       larger chunks are split up so that the client needs to do multiple
       recv() calls to get it and thus we exercise that code better */
    size_t num = count;
    if(num > 20)
      num = 20;

retry:
    written = swrite(sock, buffer, num);
    if(written < 0) {
      if(SOCK_EAGAIN(SOCKERRNO)) {
        curlx_wait_ms(10);
        goto retry;
      }
      sendfailure = TRUE;
      break;
    }

    /* write to file as well */
    fwrite(buffer, 1, (size_t)written, dump);

    count -= written;
    buffer += written;

    if(req->writedelay) {
      int msecs_left = req->writedelay;
      int intervals = msecs_left / MAX_SLEEP_TIME_MS;
      if(msecs_left % MAX_SLEEP_TIME_MS)
        intervals++;
      logmsg("Pausing %d milliseconds after writing %zd bytes",
             msecs_left, written);
      while((intervals > 0) && !got_exit_signal) {
        int sleep_time = msecs_left > MAX_SLEEP_TIME_MS ?
          MAX_SLEEP_TIME_MS : msecs_left;
        intervals--;
        curlx_wait_ms(sleep_time);
        msecs_left -= sleep_time;
      }
    }
  } while((count > 0) && !got_exit_signal);

  if(curlx_fclose(dump))
    logmsg("Error closing file %s error (%d) %s", responsedump,
           errno, curlx_strerror(errno, errbuf, sizeof(errbuf)));

  if(got_exit_signal) {
    free(ptr);
    free(cmd);
    return -1;
  }

  if(sendfailure) {
    logmsg("Sending response failed. Only (%zu bytes) of (%zu bytes) "
           "were sent",
           responsesize - count, responsesize);
    sws_prevtestno = req->testno;
    sws_prevpartno = req->partno;
    free(ptr);
    free(cmd);
    return -1;
  }

  logmsg("Response sent (%zu bytes) and written to %s",
         responsesize, responsedump);
  free(ptr);

  if(cmdsize > 0) {
    char command[32];
    int quarters;
    int num;
    ptr = cmd;
    do {
      if(sscanf(ptr, "%31s %d", command, &num) == 2) {
        if(!strcmp("wait", command)) {
          logmsg("Told to sleep for %d seconds", num);
          quarters = num * 4;
          while((quarters > 0) && !got_exit_signal) {
            quarters--;
            if(curlx_wait_ms(250)) {
              /* should not happen */
              int sockerr = SOCKERRNO;
              logmsg("curlx_wait_ms() failed with error (%d) %s",
                     sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
              break;
            }
          }
          if(!quarters)
            logmsg("Continuing after sleeping %d seconds", num);
        }
        else
          logmsg("Unknown command in reply command section");
      }
      ptr = strchr(ptr, '\n');
      if(ptr)
        ptr++;
      else
        ptr = NULL;
    } while(ptr && *ptr);
  }
  free(cmd);
  req->open = use_gopher ? FALSE : persistent;

  sws_prevtestno = req->testno;
  sws_prevpartno = req->partno;

  return 0;
}

static void init_httprequest(struct sws_httprequest *req)
{
  req->checkindex = 0;
  req->offset = 0;
  req->testno = DOCNUMBER_NOTHING;
  req->partno = 0;
  req->connect_request = FALSE;
  req->open = TRUE;
  req->auth_req = FALSE;
  req->auth = FALSE;
  req->cl = 0;
  req->digest = FALSE;
  req->ntlm = FALSE;
  req->skip = 0;
  req->skipall = FALSE;
  req->noexpect = FALSE;
  req->delay = 0;
  req->writedelay = 0;
  req->rcmd = RCMD_NORMALREQ;
  req->prot_version = 0;
  req->callcount = 0;
  req->connect_port = 0;
  req->done_processing = 0;
  req->upgrade = 0;
  req->upgrade_request = 0;
}

/* returns 1 if the connection should be serviced again immediately, 0 if there
   is no data waiting, or < 0 if it should be closed */
static int sws_get_request(curl_socket_t sock, struct sws_httprequest *req)
{
  int fail = 0;
  char *reqbuf = req->reqbuf;
  ssize_t got = 0;
  int overflow = 0;

  if(req->upgrade_request) {
    /* upgraded connection, work it differently until end of connection */
    logmsg("Upgraded connection, this is no longer HTTP/1");
    sws_send_doc(sock, req);

    /* dump the request received so far to the external file */
    reqbuf[req->offset] = '\0';
    storerequest(reqbuf, req->offset, REQUEST_DUMP_FILENAME);
    req->offset = 0;

    /* read websocket traffic */
    if(req->open) {
      logmsg("wait for websocket traffic");
      do {
        got = sread(sock, reqbuf + req->offset,
                    sizeof(req->reqbuf) - 1 - req->offset);
        if(got > 0) {
          req->offset += got;
          logmsg("Got %zd bytes from client", got);
        }

        if((got == -1) && SOCK_EAGAIN(SOCKERRNO)) {
          int rc;
          fd_set input;
          fd_set output;
          struct timeval timeout = { 0 };
          timeout.tv_sec = 1; /* 1000 ms */

          logmsg("Got EAGAIN from sread");
          FD_ZERO(&input);
          FD_ZERO(&output);
          got = 0;
          FD_SET(sock, &input);
          do {
            logmsg("Wait until readable");
            rc = select((int)sock + 1, &input, &output, NULL, &timeout);
          } while(rc < 0 && SOCKERRNO == SOCKEINTR && !got_exit_signal);
          logmsg("readable %d", rc);
          if(rc)
            got = 1;
        }
      } while(got > 0);
    }
    else {
      logmsg("NO wait for websocket traffic");
    }
    if(req->offset) {
      logmsg("log the websocket traffic");
      /* dump the incoming websocket traffic to the external file */
      reqbuf[req->offset] = '\0';
      storerequest(reqbuf, req->offset, REQUEST_DUMP_FILENAME);
      req->offset = 0;
    }
    init_httprequest(req);

    return -1;
  }

  if(req->offset >= sizeof(req->reqbuf) - 1) {
    /* buffer is already full; do nothing */
    overflow = 1;
  }
  else {
    if(req->skip)
      /* we are instructed to not read the entire thing, so we make sure to
         only read what we are supposed to and NOT read the entire thing the
         client wants to send! */
      got = sread(sock, reqbuf + req->offset, req->cl);
    else
      got = sread(sock, reqbuf + req->offset,
                  sizeof(req->reqbuf) - 1 - req->offset);

    if(got_exit_signal)
      return -1;
    if(got == 0) {
      logmsg("Connection closed by client");
      fail = 1;
    }
    else if(got < 0) {
      char errbuf[STRERROR_LEN];
      int sockerr = SOCKERRNO;
      if(SOCK_EAGAIN(sockerr)) {
        /* nothing to read at the moment */
        return 0;
      }
      logmsg("recv() returned error (%d) %s",
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
      fail = 1;
    }
    if(fail) {
      /* dump the request received so far to the external file */
      reqbuf[req->offset] = '\0';
      storerequest(reqbuf, req->offset, REQUEST_DUMP_FILENAME);
      return -1;
    }

    logmsg("Read %zd bytes", got);

    req->offset += (size_t)got;
    reqbuf[req->offset] = '\0';

    req->done_processing = sws_ProcessRequest(req);
    if(got_exit_signal)
      return -1;
  }

  if(overflow || (req->offset == sizeof(req->reqbuf) - 1 && got > 0)) {
    logmsg("Request would overflow buffer, closing connection");
    /* dump request received so far to external file anyway */
    reqbuf[sizeof(req->reqbuf) - 1] = '\0';
    fail = 1;
  }
  else if(req->offset > sizeof(req->reqbuf) - 1) {
    logmsg("Request buffer overflow, closing connection");
    /* dump request received so far to external file anyway */
    reqbuf[sizeof(req->reqbuf) - 1] = '\0';
    fail = 1;
  }
  else
    reqbuf[req->offset] = '\0';

  /* at the end of a request dump it to an external file */
  if(fail || req->done_processing)
    storerequest(reqbuf, req->offset, REQUEST_DUMP_FILENAME);
  if(got_exit_signal)
    return -1;

  return fail ? -1 : 1;
}

static curl_socket_t connect_to(const char *ipaddr, unsigned short port)
{
  srvr_sockaddr_union_t serveraddr;
  curl_socket_t serverfd;
  int sockerr;
  char errbuf[STRERROR_LEN];
  int rc = 0;
  const char *op_br = "";
  const char *cl_br = "";

#ifdef USE_IPV6
  if(socket_domain == AF_INET6) {
    op_br = "[";
    cl_br = "]";
  }
#endif

  if(!ipaddr)
    return CURL_SOCKET_BAD;

  logmsg("about to connect to %s%s%s:%hu", op_br, ipaddr, cl_br, port);

  serverfd = socket(socket_domain, SOCK_STREAM, 0);
  if(serverfd == CURL_SOCKET_BAD) {
    sockerr = SOCKERRNO;
    logmsg("Error creating socket for server connection (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    return CURL_SOCKET_BAD;
  }

#if defined(TCP_NODELAY) && defined(CURL_TCP_NODELAY_SUPPORTED)
  if(socket_domain_is_ip()) {
    /* Disable the Nagle algorithm */
    curl_socklen_t flag = 1;
    if(setsockopt(serverfd, IPPROTO_TCP, TCP_NODELAY,
                  (void *)&flag, sizeof(flag)))
      logmsg("====> TCP_NODELAY for server connection failed");
  }
#endif

  /* We want to do the connect() in a non-blocking mode, since
   * Windows has an internal retry logic that may lead to long
   * timeouts if the peer is not listening. */
  if(curlx_nonblock(serverfd, TRUE)) {
    sockerr = SOCKERRNO;
    logmsg("curlx_nonblock(TRUE) failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    sclose(serverfd);
    return CURL_SOCKET_BAD;
  }

  switch(socket_domain) {
  case AF_INET:
    memset(&serveraddr.sa4, 0, sizeof(serveraddr.sa4));
    serveraddr.sa4.sin_family = AF_INET;
    serveraddr.sa4.sin_port = htons(port);
    if(curlx_inet_pton(AF_INET, ipaddr, &serveraddr.sa4.sin_addr) < 1) {
      logmsg("Error inet_pton failed AF_INET conversion of '%s'", ipaddr);
      sclose(serverfd);
      return CURL_SOCKET_BAD;
    }

    rc = connect(serverfd, &serveraddr.sa, sizeof(serveraddr.sa4));
    break;
#ifdef USE_IPV6
  case AF_INET6:
    memset(&serveraddr.sa6, 0, sizeof(serveraddr.sa6));
    serveraddr.sa6.sin6_family = AF_INET6;
    serveraddr.sa6.sin6_port = htons(port);
    if(curlx_inet_pton(AF_INET6, ipaddr, &serveraddr.sa6.sin6_addr) < 1) {
      logmsg("Error inet_pton failed AF_INET6 conversion of '%s'", ipaddr);
      sclose(serverfd);
      return CURL_SOCKET_BAD;
    }

    rc = connect(serverfd, &serveraddr.sa, sizeof(serveraddr.sa6));
    break;
#endif /* USE_IPV6 */
#ifdef USE_UNIX_SOCKETS
  case AF_UNIX:
    logmsg("Proxying through Unix socket is not (yet?) supported.");
    return CURL_SOCKET_BAD;
#endif /* USE_UNIX_SOCKETS */
  }

  if(got_exit_signal) {
    sclose(serverfd);
    return CURL_SOCKET_BAD;
  }

  if(rc) {
    sockerr = SOCKERRNO;
    if((sockerr == SOCKEINPROGRESS) || SOCK_EAGAIN(sockerr)) {
      fd_set output;
      struct timeval timeout = { 0 };
      timeout.tv_sec = 1; /* 1000 ms */

      FD_ZERO(&output);
      FD_SET(serverfd, &output);
      while(1) {
        rc = select((int)serverfd + 1, NULL, &output, NULL, &timeout);
        sockerr = SOCKERRNO;
        if(rc < 0 && sockerr != SOCKEINTR)
          goto error;
        else if(rc > 0) {
          curl_socklen_t errSize = sizeof(sockerr);
          if(getsockopt(serverfd, SOL_SOCKET, SO_ERROR,
                        (void *)&sockerr, &errSize))
            sockerr = SOCKERRNO;
          if((sockerr == 0) || (SOCKEISCONN == sockerr))
            goto success;
          else if((sockerr != SOCKEINPROGRESS) && !SOCK_EAGAIN(sockerr))
            goto error;
        }
        else if(!rc) {
          logmsg("Timeout connecting to server port %hu", port);
          sclose(serverfd);
          return CURL_SOCKET_BAD;
        }
      }
    }
error:
    logmsg("Error connecting to server port %hu (%d) %s", port,
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    sclose(serverfd);
    return CURL_SOCKET_BAD;
  }
success:
  logmsg("connected fine to %s%s%s:%hu, now tunnel",
         op_br, ipaddr, cl_br, port);

  if(curlx_nonblock(serverfd, FALSE)) {
    sockerr = SOCKERRNO;
    logmsg("curlx_nonblock(FALSE) failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    sclose(serverfd);
    return CURL_SOCKET_BAD;
  }

  return serverfd;
}

/*
 * A CONNECT has been received, a CONNECT response has been sent.
 *
 * This function needs to connect to the server, and then pass data between
 * the client and the server back and forth until the connection is closed by
 * either end.
 *
 * When doing FTP through a CONNECT proxy, we expect that the data connection
 * is setup while the first connect is still being kept up. Therefore we
 * must accept a new connection and deal with it appropriately.
 */

#define data_or_ctrl(x) ((x) ? "DATA" : "CTRL")

#define SWS_CTRL 0
#define SWS_DATA 1

static void http_connect(curl_socket_t *infdp,
                         curl_socket_t rootfd,
                         const char *ipaddr,
                         unsigned short ipport,
                         int keepalive_secs)
{
  curl_socket_t serverfd[2] = { CURL_SOCKET_BAD, CURL_SOCKET_BAD };
  curl_socket_t clientfd[2] = { CURL_SOCKET_BAD, CURL_SOCKET_BAD };
  ssize_t toc[2] = { 0, 0 }; /* number of bytes to client */
  ssize_t tos[2] = { 0, 0 }; /* number of bytes to server */
  char readclient[2][256];
  char readserver[2][256];
  bool poll_client_rd[2] = { TRUE, TRUE };
  bool poll_server_rd[2] = { TRUE, TRUE };
  bool poll_client_wr[2] = { TRUE, TRUE };
  bool poll_server_wr[2] = { TRUE, TRUE };
  bool primary = FALSE;
  bool secondary = FALSE;
  int max_tunnel_idx; /* SWS_CTRL or SWS_DATA */
  int loop;
  int i;
  int timeout_count = 0;

  /* primary tunnel client endpoint already connected */
  clientfd[SWS_CTRL] = *infdp;

  /* Sleep here to make sure the client reads CONNECT response's
     'end of headers' separate from the server data that follows.
     This is done to prevent triggering libcurl known bug #39. */
  for(loop = 2; (loop > 0) && !got_exit_signal; loop--)
    curlx_wait_ms(250);
  if(got_exit_signal)
    goto http_connect_cleanup;

  serverfd[SWS_CTRL] = connect_to(ipaddr, ipport);
  if(serverfd[SWS_CTRL] == CURL_SOCKET_BAD)
    goto http_connect_cleanup;

  /* Primary tunnel socket endpoints are now connected. Tunnel data back and
     forth over the primary tunnel until client or server breaks the primary
     tunnel, simultaneously allowing establishment, operation and teardown of
     a secondary tunnel that may be used for passive FTP data connection. */

  max_tunnel_idx = SWS_CTRL;
  primary = TRUE;

  while(!got_exit_signal) {

    fd_set input;
    fd_set output;
    ssize_t rc;
    curl_socket_t maxfd = (curl_socket_t)-1;
    struct timeval timeout = { 0 };
    timeout.tv_sec = 1; /* 1000 ms */

    FD_ZERO(&input);
    FD_ZERO(&output);

    if((clientfd[SWS_DATA] == CURL_SOCKET_BAD) &&
       (serverfd[SWS_DATA] == CURL_SOCKET_BAD) &&
       poll_client_rd[SWS_CTRL] && poll_client_wr[SWS_CTRL] &&
       poll_server_rd[SWS_CTRL] && poll_server_wr[SWS_CTRL]) {
      /* listener socket is monitored to allow client to establish
         secondary tunnel only when this tunnel is not established
         and primary one is fully operational */
      FD_SET(rootfd, &input);
      maxfd = rootfd;
    }

    /* set tunnel sockets to wait for */
    for(i = 0; i <= max_tunnel_idx; i++) {
      /* client side socket monitoring */
      if(clientfd[i] != CURL_SOCKET_BAD) {
        if(poll_client_rd[i]) {
          /* unless told not to do so, monitor readability */
          FD_SET(clientfd[i], &input);
          if(clientfd[i] > maxfd)
            maxfd = clientfd[i];
        }
        if(poll_client_wr[i] && toc[i]) {
          /* unless told not to do so, monitor writability
             if there is data ready to be sent to client */
          FD_SET(clientfd[i], &output);
          if(clientfd[i] > maxfd)
            maxfd = clientfd[i];
        }
      }
      /* server side socket monitoring */
      if(serverfd[i] != CURL_SOCKET_BAD) {
        if(poll_server_rd[i]) {
          /* unless told not to do so, monitor readability */
          FD_SET(serverfd[i], &input);
          if(serverfd[i] > maxfd)
            maxfd = serverfd[i];
        }
        if(poll_server_wr[i] && tos[i]) {
          /* unless told not to do so, monitor writability
             if there is data ready to be sent to server */
          FD_SET(serverfd[i], &output);
          if(serverfd[i] > maxfd)
            maxfd = serverfd[i];
        }
      }
    }
    if(got_exit_signal)
      break;

    do {
      rc = select((int)maxfd + 1, &input, &output, NULL, &timeout);
    } while(rc < 0 && SOCKERRNO == SOCKEINTR && !got_exit_signal);

    if(got_exit_signal)
      break;

    if(rc > 0) {
      /* socket action */
      bool tcp_fin_wr = FALSE;
      timeout_count = 0;

      /* ---------------------------------------------------------- */

      /* passive mode FTP may establish a secondary tunnel */
      if((clientfd[SWS_DATA] == CURL_SOCKET_BAD) &&
         (serverfd[SWS_DATA] == CURL_SOCKET_BAD) && FD_ISSET(rootfd, &input)) {
        /* a new connection on listener socket (most likely from client) */
        curl_socket_t datafd = accept(rootfd, NULL, NULL);
        if(datafd != CURL_SOCKET_BAD) {
          static struct sws_httprequest *req2;
          int err = 0;
          if(!req2) {
            req2 = malloc(sizeof(*req2));
            if(!req2)
              goto http_connect_cleanup;  /* fail */
          }
          memset(req2, 0, sizeof(*req2));
          logmsg("====> Client connect DATA");
#if defined(TCP_NODELAY) && defined(CURL_TCP_NODELAY_SUPPORTED)
          if(socket_domain_is_ip()) {
            /* Disable the Nagle algorithm */
            curl_socklen_t flag = 1;
            if(setsockopt(datafd, IPPROTO_TCP, TCP_NODELAY,
                          (void *)&flag, sizeof(flag)))
              logmsg("====> TCP_NODELAY for client DATA connection failed");
          }
#endif
          init_httprequest(req2);
          while(!req2->done_processing) {
            err = sws_get_request(datafd, req2);
            if(err < 0) {
              /* this socket must be closed, done or not */
              break;
            }
          }

          /* skip this and close the socket if err < 0 */
          if(err >= 0) {
            err = sws_send_doc(datafd, req2);
            if(!err && req2->connect_request) {
              /* sleep to prevent triggering libcurl known bug #39. */
              for(loop = 2; (loop > 0) && !got_exit_signal; loop--)
                curlx_wait_ms(250);
              if(!got_exit_signal) {
                /* connect to the server */
                serverfd[SWS_DATA] = connect_to(ipaddr, req2->connect_port);
                if(serverfd[SWS_DATA] != CURL_SOCKET_BAD) {
                  /* secondary tunnel established, now we have two
                     connections */
                  poll_client_rd[SWS_DATA] = TRUE;
                  poll_client_wr[SWS_DATA] = TRUE;
                  poll_server_rd[SWS_DATA] = TRUE;
                  poll_server_wr[SWS_DATA] = TRUE;
                  max_tunnel_idx = SWS_DATA;
                  secondary = TRUE;
                  toc[SWS_DATA] = 0;
                  tos[SWS_DATA] = 0;
                  clientfd[SWS_DATA] = datafd;
                  datafd = CURL_SOCKET_BAD;
                }
              }
            }
          }
          if(datafd != CURL_SOCKET_BAD) {
            /* secondary tunnel not established */
            shutdown(datafd, SHUT_RDWR);
            sclose(datafd);
          }
        }
        if(got_exit_signal)
          break;
      }

      /* ---------------------------------------------------------- */

      /* react to tunnel endpoint readable/writable notifications */
      for(i = 0; i <= max_tunnel_idx; i++) {
        size_t len;
        if(clientfd[i] != CURL_SOCKET_BAD) {
          len = sizeof(readclient[i]) - tos[i];
          if(len && FD_ISSET(clientfd[i], &input)) {
            /* read from client */
            rc = sread(clientfd[i], &readclient[i][tos[i]], len);
            if(rc <= 0) {
              logmsg("[%s] got %zd, STOP READING client", data_or_ctrl(i), rc);
              shutdown(clientfd[i], SHUT_RD);
              poll_client_rd[i] = FALSE;
            }
            else {
              logmsg("[%s] READ %zd bytes from client", data_or_ctrl(i), rc);
              logmsg("[%s] READ \"%s\"", data_or_ctrl(i),
                     data_to_hex(&readclient[i][tos[i]], rc));
              tos[i] += rc;
            }
          }
        }
        if(serverfd[i] != CURL_SOCKET_BAD) {
          len = sizeof(readserver[i]) - toc[i];
          if(len && FD_ISSET(serverfd[i], &input)) {
            /* read from server */
            rc = sread(serverfd[i], &readserver[i][toc[i]], len);
            if(rc <= 0) {
              logmsg("[%s] got %zd, STOP READING server", data_or_ctrl(i), rc);
              shutdown(serverfd[i], SHUT_RD);
              poll_server_rd[i] = FALSE;
            }
            else {
              logmsg("[%s] READ %zd bytes from server", data_or_ctrl(i), rc);
              logmsg("[%s] READ \"%s\"", data_or_ctrl(i),
                     data_to_hex(&readserver[i][toc[i]], rc));
              toc[i] += rc;
            }
          }
        }
        if(clientfd[i] != CURL_SOCKET_BAD) {
          if(toc[i] && FD_ISSET(clientfd[i], &output)) {
            /* write to client */
            rc = swrite(clientfd[i], readserver[i], toc[i]);
            if(rc <= 0) {
              logmsg("[%s] got %zd, STOP WRITING client", data_or_ctrl(i), rc);
              shutdown(clientfd[i], SHUT_WR);
              poll_client_wr[i] = FALSE;
              tcp_fin_wr = TRUE;
            }
            else {
              logmsg("[%s] SENT %zd bytes to client", data_or_ctrl(i), rc);
              logmsg("[%s] SENT \"%s\"", data_or_ctrl(i),
                     data_to_hex(readserver[i], rc));
              if(toc[i] - rc)
                memmove(&readserver[i][0], &readserver[i][rc], toc[i] - rc);
              toc[i] -= rc;
            }
          }
        }
        if(serverfd[i] != CURL_SOCKET_BAD) {
          if(tos[i] && FD_ISSET(serverfd[i], &output)) {
            /* write to server */
            rc = swrite(serverfd[i], readclient[i], tos[i]);
            if(rc <= 0) {
              logmsg("[%s] got %zd, STOP WRITING server", data_or_ctrl(i), rc);
              shutdown(serverfd[i], SHUT_WR);
              poll_server_wr[i] = FALSE;
              tcp_fin_wr = TRUE;
            }
            else {
              logmsg("[%s] SENT %zd bytes to server", data_or_ctrl(i), rc);
              logmsg("[%s] SENT \"%s\"", data_or_ctrl(i),
                     data_to_hex(readclient[i], rc));
              if(tos[i] - rc)
                memmove(&readclient[i][0], &readclient[i][rc], tos[i] - rc);
              tos[i] -= rc;
            }
          }
        }
      }
      if(got_exit_signal)
        break;

      /* ---------------------------------------------------------- */

      /* endpoint read/write disabling, endpoint closing and tunnel teardown */
      for(i = 0; i <= max_tunnel_idx; i++) {
        for(loop = 2; loop > 0; loop--) {
          /* loop twice to satisfy condition interdependencies without
             having to await select timeout or another socket event */
          if(clientfd[i] != CURL_SOCKET_BAD) {
            if(poll_client_rd[i] && !poll_server_wr[i]) {
              logmsg("[%s] DISABLED READING client", data_or_ctrl(i));
              shutdown(clientfd[i], SHUT_RD);
              poll_client_rd[i] = FALSE;
            }
            if(poll_client_wr[i] && !poll_server_rd[i] && !toc[i]) {
              logmsg("[%s] DISABLED WRITING client", data_or_ctrl(i));
              shutdown(clientfd[i], SHUT_WR);
              poll_client_wr[i] = FALSE;
              tcp_fin_wr = TRUE;
            }
          }
          if(serverfd[i] != CURL_SOCKET_BAD) {
            if(poll_server_rd[i] && !poll_client_wr[i]) {
              logmsg("[%s] DISABLED READING server", data_or_ctrl(i));
              shutdown(serverfd[i], SHUT_RD);
              poll_server_rd[i] = FALSE;
            }
            if(poll_server_wr[i] && !poll_client_rd[i] && !tos[i]) {
              logmsg("[%s] DISABLED WRITING server", data_or_ctrl(i));
              shutdown(serverfd[i], SHUT_WR);
              poll_server_wr[i] = FALSE;
              tcp_fin_wr = TRUE;
            }
          }
        }
      }

      if(tcp_fin_wr)
        /* allow kernel to place FIN bit packet on the wire */
        curlx_wait_ms(250);

      /* socket clearing */
      for(i = 0; i <= max_tunnel_idx; i++) {
        for(loop = 2; loop > 0; loop--) {
          if(clientfd[i] != CURL_SOCKET_BAD) {
            if(!poll_client_wr[i] && !poll_client_rd[i]) {
              logmsg("[%s] CLOSING client socket", data_or_ctrl(i));
              sclose(clientfd[i]);
              clientfd[i] = CURL_SOCKET_BAD;
              if(serverfd[i] == CURL_SOCKET_BAD) {
                logmsg("[%s] ENDING", data_or_ctrl(i));
                if(i == SWS_DATA)
                  secondary = FALSE;
                else
                  primary = FALSE;
              }
            }
          }
          if(serverfd[i] != CURL_SOCKET_BAD) {
            if(!poll_server_wr[i] && !poll_server_rd[i]) {
              logmsg("[%s] CLOSING server socket", data_or_ctrl(i));
              sclose(serverfd[i]);
              serverfd[i] = CURL_SOCKET_BAD;
              if(clientfd[i] == CURL_SOCKET_BAD) {
                logmsg("[%s] ENDING", data_or_ctrl(i));
                if(i == SWS_DATA)
                  secondary = FALSE;
                else
                  primary = FALSE;
              }
            }
          }
        }
      }

      /* ---------------------------------------------------------- */

      max_tunnel_idx = secondary ? SWS_DATA : SWS_CTRL;

      if(!primary)
        /* exit loop upon primary tunnel teardown */
        break;

    } /* (rc > 0) */
    else {
      timeout_count++;
      if(timeout_count > keepalive_secs) {
        logmsg("CONNECT proxy timeout after %d idle seconds!", timeout_count);
        break;
      }
    }
  }

http_connect_cleanup:

  for(i = SWS_DATA; i >= SWS_CTRL; i--) {
    if(serverfd[i] != CURL_SOCKET_BAD) {
      logmsg("[%s] CLOSING server socket (cleanup)", data_or_ctrl(i));
      shutdown(serverfd[i], SHUT_RDWR);
      sclose(serverfd[i]);
    }
    if(clientfd[i] != CURL_SOCKET_BAD) {
      logmsg("[%s] CLOSING client socket (cleanup)", data_or_ctrl(i));
      shutdown(clientfd[i], SHUT_RDWR);
      sclose(clientfd[i]);
    }
    if((serverfd[i] != CURL_SOCKET_BAD) ||
       (clientfd[i] != CURL_SOCKET_BAD)) {
      logmsg("[%s] ABORTING", data_or_ctrl(i));
    }
  }

  *infdp = CURL_SOCKET_BAD;
}

static void http_upgrade(struct sws_httprequest *req)
{
  (void)req;
  logmsg("Upgraded to ... %d", (int)req->upgrade_request);
  /* left to implement */
}

/* returns a socket handle, or 0 if there are no more waiting sockets,
   or < 0 if there was an error */
static curl_socket_t accept_connection(curl_socket_t sock)
{
  curl_socket_t msgsock = CURL_SOCKET_BAD;
  int sockerr;
  char errbuf[STRERROR_LEN];
  int flag = 1;

  if(MAX_SOCKETS == num_sockets) {
    logmsg("Too many open sockets!");
    return CURL_SOCKET_BAD;
  }

  msgsock = accept(sock, NULL, NULL);

  if(got_exit_signal) {
    if(msgsock != CURL_SOCKET_BAD)
      sclose(msgsock);
    return CURL_SOCKET_BAD;
  }

  if(msgsock == CURL_SOCKET_BAD) {
    sockerr = SOCKERRNO;
    if(SOCK_EAGAIN(sockerr)) {
      /* nothing to accept */
      return 0;
    }
    logmsg("MAJOR ERROR, accept() failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    return CURL_SOCKET_BAD;
  }

  if(curlx_nonblock(msgsock, TRUE)) {
    sockerr = SOCKERRNO;
    logmsg("curlx_nonblock failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    sclose(msgsock);
    return CURL_SOCKET_BAD;
  }

#if defined(_WIN32) && defined(USE_UNIX_SOCKETS)
  if(socket_domain != AF_UNIX) {
#endif
    if(setsockopt(msgsock, SOL_SOCKET, SO_KEEPALIVE,
                  (void *)&flag, sizeof(flag))) {
      sockerr = SOCKERRNO;
      logmsg("setsockopt(SO_KEEPALIVE) failed with error (%d) %s",
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
      sclose(msgsock);
      return CURL_SOCKET_BAD;
    }
#if defined(_WIN32) && defined(USE_UNIX_SOCKETS)
  }
#endif

  /*
   * As soon as this server accepts a connection from the test harness it
   * must set the server logs advisor read lock to indicate that server
   * logs should not be read until this lock is removed by this server.
   */

  if(!serverlogslocked)
    set_advisor_read_lock(loglockfile);
  serverlogslocked += 1;

  logmsg("====> Client connect");

  all_sockets[num_sockets] = msgsock;
  num_sockets += 1;

#if defined(TCP_NODELAY) && defined(CURL_TCP_NODELAY_SUPPORTED)
  if(socket_domain_is_ip()) {
    /*
     * Disable the Nagle algorithm to make it easier to send out a large
     * response in many small segments to torture the clients more.
     */
    if(setsockopt(msgsock, IPPROTO_TCP, TCP_NODELAY,
                  (void *)&flag, sizeof(flag)))
      logmsg("====> TCP_NODELAY failed");
  }
#endif

  return msgsock;
}

/* returns 1 if the connection should be serviced again immediately, 0 if there
   is no data waiting, or < 0 if it should be closed */
static int service_connection(curl_socket_t *msgsock,
                              struct sws_httprequest *req,
                              curl_socket_t listensock,
                              const char *connecthost,
                              int keepalive_secs)
{
  if(got_exit_signal)
    return -1;

  while(!req->done_processing) {
    int rc = sws_get_request(*msgsock, req);
    if(rc <= 0) {
      /* Nothing further to read now, possibly because the socket was closed */
      return rc;
    }
  }

  if(sws_prevbounce) {
    /* bounce treatment requested */
    if(req->testno == sws_prevtestno) {
      req->partno = sws_prevpartno + 1;
      logmsg("BOUNCE part number to %ld", req->partno);
    }
    else {
      sws_prevbounce = FALSE;
      sws_prevtestno = -1;
      sws_prevpartno = -1;
    }
  }

  sws_send_doc(*msgsock, req);
  if(got_exit_signal)
    return -1;

  if(req->testno < 0) {
    logmsg("special request received, no persistency");
    return -1;
  }
  if(!req->open) {
    logmsg("instructed to close connection after server-reply");
    return -1;
  }

  if(req->connect_request) {
    /* a CONNECT request, setup and talk the tunnel */
    if(!is_proxy) {
      logmsg("received CONNECT but not running as proxy!");
      return 1;
    }
    else {
      http_connect(msgsock, listensock, connecthost, req->connect_port,
                   keepalive_secs);
      return -1;
    }
  }

  if(req->upgrade_request) {
    /* an upgrade request, switch to another protocol here */
    http_upgrade(req);
    return 1;
  }

  /* if we got a CONNECT, loop and get another request as well! */

  if(req->open) {
    logmsg("=> persistent connection request ended, awaits new request");
    return 1;
  }
  else {
    logmsg("=> NOT a persistent connection, close close CLOSE");
  }

  return -1;
}

static int test_sws(int argc, const char *argv[])
{
  srvr_sockaddr_union_t me;
  curl_socket_t sock = CURL_SOCKET_BAD;
  int wrotepidfile = 0;
  int wroteportfile = 0;
  int flag;
  unsigned short port = 8999;
#ifdef USE_UNIX_SOCKETS
  const char *unix_socket = NULL;
  bool unlink_socket = FALSE;
#endif
  struct sws_httprequest *req = NULL;
  int rc = 0;
  int sockerr;
  char errbuf[STRERROR_LEN];
  int arg = 1;
  const char *connecthost = "127.0.0.1";
  char port_str[11];
  const char *location_str = port_str;
  int keepalive_secs = 5;
  const char *protocol_type = "HTTP";

  /* a default CONNECT port is pointless, but still ... */
  size_t socket_idx;

  pidname = ".http.pid";
  portname = ".http.port";
  serverlogfile = "log/sws.log";
  serverlogslocked = 0;

  while(argc > arg) {
    const char *opt;
    curl_off_t num;
    if(!strcmp("--version", argv[arg])) {
      puts("sws IPv4"
#ifdef USE_IPV6
           "/IPv6"
#endif
#ifdef USE_UNIX_SOCKETS
           "/unix"
#endif
      );
      return 0;
    }
    else if(!strcmp("--pidfile", argv[arg])) {
      arg++;
      if(argc > arg)
        pidname = argv[arg++];
    }
    else if(!strcmp("--portfile", argv[arg])) {
      arg++;
      if(argc > arg)
        portname = argv[arg++];
    }
    else if(!strcmp("--logfile", argv[arg])) {
      arg++;
      if(argc > arg)
        serverlogfile = argv[arg++];
    }
    else if(!strcmp("--logdir", argv[arg])) {
      arg++;
      if(argc > arg)
        logdir = argv[arg++];
    }
    else if(!strcmp("--cmdfile", argv[arg])) {
      arg++;
      if(argc > arg)
        cmdfile = argv[arg++];
    }
    else if(!strcmp("--gopher", argv[arg])) {
      arg++;
      use_gopher = TRUE;
      protocol_type = "GOPHER";
      end_of_headers = "\r\n"; /* gopher style is much simpler */
    }
    else if(!strcmp("--ipv4", argv[arg])) {
      socket_type = "IPv4";
      socket_domain = AF_INET;
      location_str = port_str;
      arg++;
    }
    else if(!strcmp("--ipv6", argv[arg])) {
#ifdef USE_IPV6
      socket_type = "IPv6";
      socket_domain = AF_INET6;
      location_str = port_str;
#endif
      arg++;
    }
    else if(!strcmp("--unix-socket", argv[arg])) {
      arg++;
      if(argc > arg) {
#ifdef USE_UNIX_SOCKETS
        unix_socket = argv[arg];
        if(strlen(unix_socket) >= sizeof(me.sau.sun_path)) {
          fprintf(stderr,
                  "sws: socket path must be shorter than %u chars: %s\n",
                  (unsigned int)sizeof(me.sau.sun_path), unix_socket);
          return 0;
        }
        socket_type = "unix";
        socket_domain = AF_UNIX;
        location_str = unix_socket;
#endif
        arg++;
      }
    }
    else if(!strcmp("--port", argv[arg])) {
      arg++;
      if(argc > arg) {
        opt = argv[arg];
        if(curlx_str_number(&opt, &num, 0xffff)) {
          fprintf(stderr, "sws: invalid --port argument (%s)\n", argv[arg]);
          return 0;
        }
        port = (unsigned short)num;
        arg++;
      }
    }
    else if(!strcmp("--srcdir", argv[arg])) {
      arg++;
      if(argc > arg) {
        srcpath = argv[arg];
        arg++;
      }
    }
    else if(!strcmp("--keepalive", argv[arg])) {
      arg++;
      if(argc > arg) {
        opt = argv[arg];
        if(curlx_str_number(&opt, &num, 0xffff)) {
          fprintf(stderr, "sws: invalid --keepalive argument (%s), must "
                  "be a number of seconds\n", argv[arg]);
          return 0;
        }
        keepalive_secs = (unsigned short)num;
        arg++;
      }
    }
    else if(!strcmp("--connect", argv[arg])) {
      /* The connect host IP number that the proxy connects to no matter
         what the client asks for, but also use this as a hint that we run as
         a proxy and do a few different internal choices */
      arg++;
      if(argc > arg) {
        connecthost = argv[arg];
        arg++;
        is_proxy = TRUE;
        logmsg("Run as proxy, CONNECT to host %s", connecthost);
      }
    }
    else {
      puts("Usage: sws [option]\n"
           " --version\n"
           " --logfile [file]\n"
           " --logdir [directory]\n"
           " --pidfile [file]\n"
           " --portfile [file]\n"
           " --ipv4\n"
           " --ipv6\n"
           " --unix-socket [file]\n"
           " --port [port]\n"
           " --srcdir [path]\n"
           " --connect [ip4-addr]\n"
           " --gopher");
      return 0;
    }
  }

  snprintf(loglockfile, sizeof(loglockfile), "%s/%s/sws-%s%s-%s.lock",
           logdir, SERVERLOGS_LOCKDIR, protocol_type,
           is_proxy ? "-proxy" : "", socket_type);

  install_signal_handlers(FALSE);

  req = calloc(1, sizeof(*req));
  if(!req)
    goto sws_cleanup;

  sock = socket(socket_domain, SOCK_STREAM, 0);

  all_sockets[0] = sock;
  num_sockets = 1;

  if(sock == CURL_SOCKET_BAD) {
    sockerr = SOCKERRNO;
    logmsg("Error creating socket (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    goto sws_cleanup;
  }

#if defined(_WIN32) && defined(USE_UNIX_SOCKETS)
  if(socket_domain != AF_UNIX) {
#endif
    flag = 1;
    if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
                  (void *)&flag, sizeof(flag))) {
      sockerr = SOCKERRNO;
      logmsg("setsockopt(SO_REUSEADDR) failed with error (%d) %s",
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
      goto sws_cleanup;
    }
#if defined(_WIN32) && defined(USE_UNIX_SOCKETS)
  }
#endif
  if(curlx_nonblock(sock, TRUE)) {
    sockerr = SOCKERRNO;
    logmsg("curlx_nonblock failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    goto sws_cleanup;
  }

  switch(socket_domain) {
  case AF_INET:
    memset(&me.sa4, 0, sizeof(me.sa4));
    me.sa4.sin_family = AF_INET;
    me.sa4.sin_addr.s_addr = INADDR_ANY;
    me.sa4.sin_port = htons(port);
    rc = bind(sock, &me.sa, sizeof(me.sa4));
    break;
#ifdef USE_IPV6
  case AF_INET6:
    memset(&me.sa6, 0, sizeof(me.sa6));
    me.sa6.sin6_family = AF_INET6;
    me.sa6.sin6_addr = in6addr_any;
    me.sa6.sin6_port = htons(port);
    rc = bind(sock, &me.sa, sizeof(me.sa6));
    break;
#endif /* USE_IPV6 */
#ifdef USE_UNIX_SOCKETS
  case AF_UNIX:
    rc = bind_unix_socket(sock, unix_socket, &me.sau);
#endif /* USE_UNIX_SOCKETS */
  }
  if(rc) {
    sockerr = SOCKERRNO;
#ifdef USE_UNIX_SOCKETS
    if(socket_domain == AF_UNIX)
      logmsg("Error binding socket on path %s (%d) %s", unix_socket,
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    else
#endif
      logmsg("Error binding socket on port %hu (%d) %s", port,
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    goto sws_cleanup;
  }

  if(!port) {
    /* The system was supposed to choose a port number, figure out which
       port we actually got and update the listener port value with it. */
    curl_socklen_t la_size;
    srvr_sockaddr_union_t localaddr;
    memset(&localaddr, 0, sizeof(localaddr));
#ifdef USE_IPV6
    if(socket_domain != AF_INET6)
#endif
      la_size = sizeof(localaddr.sa4);
#ifdef USE_IPV6
    else
      la_size = sizeof(localaddr.sa6);
#endif
    if(getsockname(sock, &localaddr.sa, &la_size) < 0) {
      sockerr = SOCKERRNO;
      logmsg("getsockname() failed with error (%d) %s",
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
      sclose(sock);
      goto sws_cleanup;
    }
    switch(localaddr.sa.sa_family) {
    case AF_INET:
      port = ntohs(localaddr.sa4.sin_port);
      break;
#ifdef USE_IPV6
    case AF_INET6:
      port = ntohs(localaddr.sa6.sin6_port);
      break;
#endif
    default:
      break;
    }
    if(!port) {
      /* Real failure, listener port shall not be zero beyond this point. */
      logmsg("Apparently getsockname() succeeded, with listener port zero.");
      logmsg("A valid reason for this failure is a binary built without");
      logmsg("proper network library linkage. This might not be the only");
      logmsg("reason, but double check it before anything else.");
      sclose(sock);
      goto sws_cleanup;
    }
  }
#ifdef USE_UNIX_SOCKETS
  if(socket_domain != AF_UNIX)
#endif
    snprintf(port_str, sizeof(port_str), "port %hu", port);

  logmsg("Running %s %s version on %s",
         protocol_type, socket_type, location_str);

  /* start accepting connections */
  if(listen(sock, 50)) {
    sockerr = SOCKERRNO;
    logmsg("listen() failed with error (%d) %s",
           sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
    goto sws_cleanup;
  }

#ifdef USE_UNIX_SOCKETS
  /* listen succeeds, so let's assume a valid listening Unix socket */
  unlink_socket = TRUE;
#endif

  /*
   * As soon as this server writes its pid file the test harness attempts
   * to connect to this server and initiate its verification.
   */

  wrotepidfile = write_pidfile(pidname);
  if(!wrotepidfile)
    goto sws_cleanup;

  wroteportfile = write_portfile(portname, port);
  if(!wroteportfile)
    goto sws_cleanup;

  /* initialization of httprequest struct is done before sws_get_request(),
     but the pipelining struct field must be initialized previously to FALSE
     every time a new connection arrives. */

  init_httprequest(req);

  for(;;) {
    fd_set input;
    fd_set output;
    curl_socket_t maxfd = (curl_socket_t)-1;
    int active;
    struct timeval timeout = { 0 };
    timeout.tv_usec = 250000L; /* 250 ms */

    /* Clear out closed sockets */
    for(socket_idx = num_sockets - 1; socket_idx >= 1; --socket_idx) {
      if(all_sockets[socket_idx] == CURL_SOCKET_BAD) {
        char *dst = (char *)(all_sockets + socket_idx);
        char *src = (char *)(all_sockets + socket_idx + 1);
        char *end = (char *)(all_sockets + num_sockets);
        memmove(dst, src, end - src);
        num_sockets -= 1;
      }
    }

    if(got_exit_signal)
      goto sws_cleanup;

    /* Set up for select */
    FD_ZERO(&input);
    FD_ZERO(&output);

    for(socket_idx = 0; socket_idx < num_sockets; ++socket_idx) {
      /* Listen on all sockets */
      FD_SET(all_sockets[socket_idx], &input);
      if(all_sockets[socket_idx] > maxfd)
        maxfd = all_sockets[socket_idx];
    }

    if(got_exit_signal)
      goto sws_cleanup;

    sockerr = 0;
    do {
      rc = select((int)maxfd + 1, &input, &output, NULL, &timeout);
    } while(rc < 0 && ((sockerr = SOCKERRNO) == SOCKEINTR &&
            !got_exit_signal));

    if(got_exit_signal)
      goto sws_cleanup;

    if(rc < 0) {
      logmsg("select() failed with error (%d) %s",
             sockerr, curlx_strerror(sockerr, errbuf, sizeof(errbuf)));
      goto sws_cleanup;
    }

    if(rc == 0) {
      /* Timed out - try again */
      continue;
    }
    active = rc; /* a positive number */

    /* Check if the listening socket is ready to accept */
    if(FD_ISSET(all_sockets[0], &input)) {
      /* Service all queued connections */
      curl_socket_t msgsock;
      do {
        msgsock = accept_connection(sock);
        logmsg("accept_connection %ld returned %ld",
               (long)sock, (long)msgsock);
        if(msgsock == CURL_SOCKET_BAD)
          goto sws_cleanup;
        if(req->delay)
          curlx_wait_ms(req->delay);
      } while(msgsock > 0);
      active--;
    }

    /* Service all connections that are ready */
    for(socket_idx = 1; (socket_idx < num_sockets) && active; ++socket_idx) {
      if(FD_ISSET(all_sockets[socket_idx], &input)) {
        active--;
        if(got_exit_signal)
          goto sws_cleanup;

        /* Service this connection until it has nothing available */
        do {
          rc = service_connection(&all_sockets[socket_idx], req, sock,
                                  connecthost, keepalive_secs);
          if(got_exit_signal)
            goto sws_cleanup;

          if(rc < 0) {
            logmsg("====> Client disconnect %d", req->connmon);

            if(req->connmon) {
              const char *keepopen = "[DISCONNECT]\n";
              storerequest(keepopen, strlen(keepopen), REQUEST_DUMP_FILENAME);
            }

            if(!req->open)
              /* When instructed to close connection after server-reply we
                 wait a small amount of time before doing so. If this
                 is not done client might get an ECONNRESET before reading
                 a single byte of server-reply. */
              curlx_wait_ms(50);

            if(all_sockets[socket_idx] != CURL_SOCKET_BAD) {
              sclose(all_sockets[socket_idx]);
              all_sockets[socket_idx] = CURL_SOCKET_BAD;
            }

            serverlogslocked -= 1;
            if(!serverlogslocked)
              clear_advisor_read_lock(loglockfile);

            if(req->testno == DOCNUMBER_QUIT)
              goto sws_cleanup;
          }

          /* Reset the request, unless we are still in the middle of reading */
          if(rc && !req->upgrade_request)
            /* Note: resetting the HTTP request here can cause problems if:
             * 1) req->skipall is TRUE,
             * 2) the socket is still open, and
             * 3) (stale) data is still available (or about to be available)
             *    on that socket
             * In that case, this loop runs once more and treat that stale
             * data (in service_connection()) as the first data received on
             * this new HTTP request and report "** Unusual request" (skipall
             * would have otherwise caused that data to be ignored). Normally,
             * that socket is closed by the client and there is no stale data
             * to cause this, but stranger things have happened
             * (see issue #11678).
             */
            init_httprequest(req);
        } while(rc > 0);
      }
    }

    if(got_exit_signal)
      goto sws_cleanup;
  }

sws_cleanup:

  for(socket_idx = 1; socket_idx < num_sockets; ++socket_idx)
    if((all_sockets[socket_idx] != sock) &&
       (all_sockets[socket_idx] != CURL_SOCKET_BAD))
      sclose(all_sockets[socket_idx]);

  if(sock != CURL_SOCKET_BAD)
    sclose(sock);

#ifdef USE_UNIX_SOCKETS
  if(unlink_socket && socket_domain == AF_UNIX && unix_socket &&
     unlink(unix_socket))
    logmsg("unlink(%s): %d (%s)", unix_socket,
           errno, curlx_strerror(errno, errbuf, sizeof(errbuf)));
#endif

  free(req);

  if(got_exit_signal)
    logmsg("signalled to die");

  if(wrotepidfile)
    unlink(pidname);
  if(wroteportfile)
    unlink(portname);

  if(serverlogslocked) {
    serverlogslocked = 0;
    clear_advisor_read_lock(loglockfile);
  }

  restore_signal_handlers(FALSE);

  if(got_exit_signal) {
    logmsg("========> %s sws (%s pid: %ld) exits with signal (%d)",
           socket_type, location_str, (long)our_getpid(), exit_signal);
    /*
     * To properly set the return status of the process we
     * must raise the same signal SIGINT or SIGTERM that we
     * caught and let the old handler take care of it.
     */
    raise(exit_signal);
  }

  logmsg("========> sws quits");
  return 0;
}
