url.c

    return CURLE_SSL_ENGINE_NOTFOUND;
#endif
    break;
  case CURLOPT_SSLENGINE_DEFAULT:
    /*
     * flag to set engine as default.
     */
#ifdef HAVE_OPENSSL_ENGINE_H
    if (data->engine) {
      if (ENGINE_set_default(data->engine, ENGINE_METHOD_ALL) > 0) {
#ifdef DEBUG
        fprintf(stderr,"set default crypto engine\n");
#endif
      }
      else {
#ifdef DEBUG
        failf(data, "set default crypto engine failed");
#endif
        return CURLE_SSL_ENGINE_SETFAILED;
      }
    }
#endif
    break;
  case CURLOPT_CRLF:
    /*
     * Kludgy option to enable CRLF convertions. Subject for removal.
     */
    data->set.crlf = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_INTERFACE:
    /*
     * Set what interface to bind to when performing an operation and thus
     * what from-IP your connection will use.
     */
    data->set.device = va_arg(param, char *);
    break;
  case CURLOPT_KRB4LEVEL:
    /*
     * A string that defines the krb4 security level.
     */
    data->set.krb4_level = va_arg(param, char *);
    data->set.krb4=data->set.krb4_level?TRUE:FALSE;
    break;
  case CURLOPT_SSL_VERIFYPEER:
    /*
     * Enable peer SSL verifying.
     */
    data->set.ssl.verifypeer = va_arg(param, long);
    break;
  case CURLOPT_SSL_VERIFYHOST:
    /*
     * Enable verification of the CN contained in the peer certificate
     */
    data->set.ssl.verifyhost = va_arg(param, long);
    break;
  case CURLOPT_CAINFO:
    /*
     * Set CA info for SSL connection. Specify file name of the CA certificate
     */
    data->set.ssl.CAfile = va_arg(param, char *);
    break;
  case CURLOPT_CAPATH:
    /*
     * Set CA path info for SSL connection. Specify directory name of the CA
     * certificates which have been prepared using openssl c_rehash utility.
     */
    /* This does not work on windows. */
    data->set.ssl.CApath = va_arg(param, char *);
    break;
  case CURLOPT_TELNETOPTIONS:
    /*
     * Set a linked list of telnet options
     */
    data->set.telnet_options = va_arg(param, struct curl_slist *);
    break;

  case CURLOPT_BUFFERSIZE:
    /*
     * The application kindly asks for a differently sized receive buffer.
     * If it seems reasonable, we'll use it.
     */
    data->set.buffer_size = va_arg(param, long);

    if(data->set.buffer_size> (BUFSIZE -1 ))
      data->set.buffer_size = 0; /* huge internal default */

    break;

  case CURLOPT_NOSIGNAL:
    /*
     * The application asks not to set any signal() or alarm() handlers,
     * even when using a timeout.
     */
    data->set.no_signal = va_arg(param, long) ? TRUE : FALSE;
    break;

  case CURLOPT_SHARE:
    {
      struct Curl_share *set;
      set = va_arg(param, struct Curl_share *);
      if(data->share)
      {
        Curl_share_lock(data, CURL_LOCK_DATA_SHARE, CURL_LOCK_ACCESS_SINGLE);

        /* checking the dns cache stuff */
        if(data->share->hostcache == data->hostcache)
        {
          data->hostcache = NULL;
        }

        data->share->dirty--;

        Curl_share_unlock(data, CURL_LOCK_DATA_SHARE);
      }

      data->share = set;

      Curl_share_lock(data, CURL_LOCK_DATA_SHARE, CURL_LOCK_ACCESS_SINGLE);

      data->share->dirty++;

      if( data->hostcache )
      {
        Curl_hash_destroy(data->hostcache);
        data->hostcache = data->share->hostcache;
      }

      Curl_share_unlock(data, CURL_LOCK_DATA_SHARE);
    }
    break;

  case CURLOPT_PROXYTYPE:
    /*
     * Set proxy type. HTTP/SOCKS4/SOCKS5
     */
    data->set.proxytype = va_arg(param, long);
    break;

  case CURLOPT_PRIVATE:
    /*
     * Set private data pointer.
     */
    data->set.private = va_arg(param, char *);
    break;

  case CURLOPT_HTTP200ALIASES:
    /*
     * Set a list of aliases for HTTP 200 in response header
     */
    data->set.http200aliases = va_arg(param, struct curl_slist *);
    break;

  default:
    /* unknown tag and its companion, just ignore: */
    return CURLE_FAILED_INIT; /* correct this */
  }
  return CURLE_OK;
}

CURLcode Curl_disconnect(struct connectdata *conn)
{
  if(!conn)
    return CURLE_OK; /* this is closed and fine already */

  /*
   * The range string is usually freed in curl_done(), but we might
   * get here *instead* if we fail prematurely. Thus we need to be able
   * to free this resource here as well.
   */
  if(conn->bits.rangestringalloc) {
    free(conn->range);
    conn->bits.rangestringalloc = FALSE;
  }

  if(-1 != conn->connectindex) {
    /* unlink ourselves! */
    infof(conn->data, "Closing connection #%d\n", conn->connectindex);
    conn->data->state.connects[conn->connectindex] = NULL;
  }

  if(conn->curl_disconnect)
    /* This is set if protocol-specific cleanups should be made */
    conn->curl_disconnect(conn);

  if(conn->proto.generic)
    free(conn->proto.generic);

  if(conn->newurl)
    free(conn->newurl);

  if(conn->path) /* the URL path part */
    free(conn->path);

#ifdef USE_SSLEAY
  Curl_SSL_Close(conn);
#endif /* USE_SSLEAY */

  /* close possibly still open sockets */
  if(-1 != conn->secondarysocket)
    sclose(conn->secondarysocket);
  if(-1 != conn->firstsocket)
    sclose(conn->firstsocket);

  if(conn->allocptr.proxyuserpwd)
    free(conn->allocptr.proxyuserpwd);
  if(conn->allocptr.uagent)
    free(conn->allocptr.uagent);
  if(conn->allocptr.userpwd)
    free(conn->allocptr.userpwd);
  if(conn->allocptr.accept_encoding)
    free(conn->allocptr.accept_encoding);
  if(conn->allocptr.rangeline)
    free(conn->allocptr.rangeline);
  if(conn->allocptr.ref)
    free(conn->allocptr.ref);
  if(conn->allocptr.cookie)
    free(conn->allocptr.cookie);
  if(conn->allocptr.host)
    free(conn->allocptr.host);
  if(conn->allocptr.cookiehost)
    free(conn->allocptr.cookiehost);

  if(conn->proxyhost)
    free(conn->proxyhost);

  Curl_free_ssl_config(&conn->ssl_config);

  free(conn); /* free all the connection oriented data */

  return CURLE_OK;
}

/*
 * This function should return TRUE if the socket is to be assumed to
 * be dead. Most commonly this happens when the server has closed the
 * connection due to inactivity.
 */
static bool SocketIsDead(int sock)
{
  int sval;
  bool ret_val = TRUE;
  fd_set check_set;
  struct timeval to;

  FD_ZERO(&check_set);
  FD_SET(sock,&check_set);

  to.tv_sec = 0;
  to.tv_usec = 0;

  sval = select(sock + 1, &check_set, 0, 0, &to);
  if(sval == 0)
    /* timeout */
    ret_val = FALSE;

  return ret_val;
}

/*
 * Given one filled in connection struct (named needle), this function should
 * detect if there already is one that have all the significant details
 * exactly the same and thus should be used instead.
 */
static bool
ConnectionExists(struct SessionHandle *data,
                 struct connectdata *needle,
                 struct connectdata **usethis)
{
  long i;
  struct connectdata *check;

  for(i=0; i< data->state.numconnects; i++) {
    bool match = FALSE;
    /*
     * Note that if we use a HTTP proxy, we check connections to that
     * proxy and not to the actual remote server.
     */
    check = data->state.connects[i];
    if(!check)
      /* NULL pointer means not filled-in entry */
      continue;

    if((needle->protocol&PROT_SSL) != (check->protocol&PROT_SSL))
      /* don't do mixed SSL and non-SSL connections */
      continue;

    if(!needle->bits.httpproxy || needle->protocol&PROT_SSL) {
      /* The requested connection does not use a HTTP proxy or it
         uses SSL. */

      if(!(needle->protocol&PROT_SSL) && check->bits.httpproxy)
        /* we don't do SSL but the cached connection has a proxy,
           then don't match this */
        continue;

      if(strequal(needle->protostr, check->protostr) &&
         strequal(needle->name, check->name) &&
         (needle->remote_port == check->remote_port) ) {
        if(needle->protocol & PROT_SSL) {
          /* This is SSL, verify that we're using the same
             ssl options as well */
          if(!Curl_ssl_config_matches(&needle->ssl_config,
                                      &check->ssl_config)) {
            continue;
          }
        }
        if(needle->protocol & PROT_FTP) {
          /* This is FTP, verify that we're using the same name and
             password as well */
          if(!strequal(needle->data->state.user, check->proto.ftp->user) ||
             !strequal(needle->data->state.passwd, check->proto.ftp->passwd)) {
            /* one of them was different */
            continue;
          }
        }
        match = TRUE;
      }
    }
    else { /* The requested needle connection is using a proxy,
              is the checked one using the same? */
      if(check->bits.httpproxy &&
         strequal(needle->proxyhost, check->proxyhost) &&
         needle->port == check->port) {
        /* This is the same proxy connection, use it! */
        match = TRUE;
      }
    }

    if(match) {
      bool dead = SocketIsDead(check->firstsocket);
      if(dead) {
        /*
         */
        infof(data, "Connection %d seems to be dead!\n", i);
        Curl_disconnect(check); /* disconnect resources */
        data->state.connects[i]=NULL; /* nothing here */

        /* There's no need to continue searching, because we only store
           one connection for each unique set of identifiers */
        return FALSE;
      }

      *usethis = check;
      return TRUE; /* yes, we found one to use! */
    }
  }
  return FALSE; /* no matching connecting exists */
}

/*
 * This function frees/closes a connection in the connection cache. This
 * should take the previously set policy into account when deciding which
 * of the connections to kill.
 */
static int
ConnectionKillOne(struct SessionHandle *data)
{
  long i;
  struct connectdata *conn;
  int highscore=-1;
  int connindex=-1;
  int score;
  CURLcode result;
  struct timeval now;

  now = Curl_tvnow();

  for(i=0; i< data->state.numconnects; i++) {
    conn = data->state.connects[i];

    if(!conn)
      continue;

    /*
     * By using the set policy, we score each connection.
     */
    switch(data->set.closepolicy) {
    case CURLCLOSEPOLICY_LEAST_RECENTLY_USED:
    default:
      /*
       * Set higher score for the age passed since the connection
       * was used.
       */
      score = Curl_tvdiff(now, conn->now);
      break;
    case CURLCLOSEPOLICY_OLDEST:
      /*
       * Set higher score for the age passed since the connection
       * was created.
       */
      score = Curl_tvdiff(now, conn->created);
      break;
    }

    if(score > highscore) {
      highscore = score;
      connindex = i;
    }
  }
  if(connindex >= 0) {

    /* the winner gets the honour of being disconnected */
    result = Curl_disconnect(data->state.connects[connindex]);

    /* clean the array entry */
    data->state.connects[connindex] = NULL;
  }

  return connindex; /* return the available index or -1 */
}

/*
 * The given input connection struct pointer is to be stored. If the "cache"
 * is already full, we must clean out the most suitable using the previously
 * set policy.
 *
 * The given connection should be unique. That must've been checked prior to
 * this call.
 */
static unsigned int
ConnectionStore(struct SessionHandle *data,
                struct connectdata *conn)
{
  long i;
  for(i=0; i< data->state.numconnects; i++) {
    if(!data->state.connects[i])
      break;
  }
  if(i == data->state.numconnects) {
    /* there was no room available, kill one */
    i = ConnectionKillOne(data);
    infof(data, "Connection (#%d) was killed to make room\n", i);
  }

  if(-1 != i) {
    /* only do this if a true index was returned, if -1 was returned there
       is no room in the cache for an unknown reason and we cannot store
       this there. */
    data->state.connects[i] = conn; /* fill in this */
    conn->connectindex = i; /* make the child know where the pointer to this
                               particular data is stored */
  }
  return i;
}

/*
 * This function logs in to a SOCKS5 proxy and sends the specifies the final
 * desitination server.
 */
static int handleSock5Proxy(
    const char *proxy_name,
    const char *proxy_password,
    struct connectdata *conn,
    int sock)
{
  unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
  ssize_t actualread;
  ssize_t written;
  CURLcode result;

  Curl_nonblock(sock, FALSE);

  socksreq[0] = 5; /* version */
  socksreq[1] = (char)(proxy_name[0] ? 2 : 1); /* number of methods (below) */
  socksreq[2] = 0; /* no authentication */
  socksreq[3] = 2; /* username/password */

  result = Curl_write(conn, sock, (char *)socksreq, (2 + (int)socksreq[1]),
                      &written);
  if ((result != CURLE_OK) || (written != (2 + (int)socksreq[1]))) {
    failf(conn->data, "Unable to send initial SOCKS5 request.");
    return 1;
  }

  result=Curl_read(conn, sock, (char *)socksreq, 2, &actualread);
  if ((result != CURLE_OK) || (actualread != 2)) {
    failf(conn->data, "Unable to receive initial SOCKS5 response.");
    return 1;
  }

  if (socksreq[0] != 5) {
    failf(conn->data, "Received invalid version in initial SOCKS5 response.");
    return 1;
  }
  if (socksreq[1] == 0) {
    /* Nothing to do, no authentication needed */
    ;
  }
  else if (socksreq[1] == 2) {
    /* Needs user name and password */
    int userlen, pwlen, len;

    userlen = strlen(proxy_name);
    pwlen = strlen(proxy_password);

    /*   username/password request looks like
     * +----+------+----------+------+----------+
     * |VER | ULEN |  UNAME   | PLEN |  PASSWD  |
     * +----+------+----------+------+----------+
     * | 1  |  1   | 1 to 255 |  1   | 1 to 255 |
     * +----+------+----------+------+----------+
     */
    len = 0;
    socksreq[len++] = 1;    /* username/pw subnegotiation version */
    socksreq[len++] = (char) userlen;
    memcpy(socksreq + len, proxy_name, (int) userlen);
    len += userlen;
    socksreq[len++] = (char) pwlen;
    memcpy(socksreq + len, proxy_password, (int) pwlen);
    len += pwlen;

    result = Curl_write(conn, sock, (char *)socksreq, len, &written);
    if ((result != CURLE_OK) || (len != written)) {
      failf(conn->data, "Failed to send SOCKS5 sub-negotiation request.");
      return 1;
    }

    result=Curl_read(conn, sock, (char *)socksreq, 2, &actualread);
    if ((result != CURLE_OK) || (actualread != 2)) {
      failf(conn->data, "Unable to receive SOCKS5 sub-negotiation response.");
      return 1;
    }

    if ((socksreq[0] != 5) || /* version */
        (socksreq[1] != 0)) { /* status */
      failf(conn->data, "User was rejected by the SOCKS5 server (%d %d).",
            socksreq[0], socksreq[1]);
      return 1;
    }

    /* Everything is good so far, user was authenticated! */
  }
  else {
    /* error */
    if (socksreq[1] == 1) {
      failf(conn->data,
            "SOCKS5 GSSAPI per-message authentication is not supported.");
      return 1;
    }
    else if (socksreq[1] == 255) {
      if (proxy_name[0] == 0) {
        failf(conn->data,
              "No authentication method was acceptable. (It is quite likely"
              " that the SOCKS5 server wanted a username/password, since none"
              " was supplied to the server on this connection.)");
      }
      else {
        failf(conn->data, "No authentication method was acceptable.");
      }
      return 1;
    }
    else {
      failf(conn->data,
            "Undocumented SOCKS5 mode attempted to be used by server.");
      return 1;
    }
  }

  /* Authentication is complete, now specify destination to the proxy */
  socksreq[0] = 5; /* version (SOCKS5) */
  socksreq[1] = 1; /* connect */
  socksreq[2] = 0; /* must be zero */
  socksreq[3] = 1; /* IPv4 = 1 */

  {
#ifndef ENABLE_IPV6
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    dns = Curl_resolv(conn->data, conn->hostname, conn->remote_port);
    /*
     * We cannot use 'hostent' as a struct that Curl_resolv() returns.  It
     * returns a Curl_addrinfo pointer that may not always look the same.
     */
    if(dns)
      hp=dns->addr;
    if (hp && hp->h_addr_list[0]) {
      socksreq[4] = ((char*)hp->h_addr_list[0])[0];
      socksreq[5] = ((char*)hp->h_addr_list[0])[1];
      socksreq[6] = ((char*)hp->h_addr_list[0])[2];
      socksreq[7] = ((char*)hp->h_addr_list[0])[3];

      Curl_resolv_unlock(conn->data, dns); /* not used anymore from now on */
    }
    else {
      failf(conn->data, "Failed to resolve \"%s\" for SOCKS5 connect.",
            conn->hostname);
      return 1;
    }
#else
    failf(conn->data,
          "%s:%d has an internal error an needs to be fixed to work",
          __FILE__, __LINE__);
    return 1;
#endif
  }

  *((unsigned short*)&socksreq[8]) = htons(conn->remote_port);

  {
    const int packetsize = 10;

    result = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
    if ((result != CURLE_OK) || (written != packetsize)) {
      failf(conn->data, "Failed to send SOCKS5 connect request.");
      return 1;
    }

    result = Curl_read(conn, sock, (char *)socksreq, packetsize, &actualread);
    if ((result != CURLE_OK) || (actualread != packetsize)) {
      failf(conn->data, "Failed to receive SOCKS5 connect request ack.");
      return 1;
    }

    if (socksreq[0] != 5) { /* version */
      failf(conn->data,
            "SOCKS5 reply has wrong version, version should be 5.");
      return 1;
    }
    if (socksreq[1] != 0) { /* Anything besides 0 is an error */
        failf(conn->data,
              "Can't complete SOCKS5 connection to %d.%d.%d.%d:%d. (%d)",
              (unsigned char)socksreq[4], (unsigned char)socksreq[5],
              (unsigned char)socksreq[6], (unsigned char)socksreq[7],
              (unsigned int)ntohs(*(unsigned short*)(&socksreq[8])),
              socksreq[1]);
        return 1;
    }
  }

  Curl_nonblock(sock, TRUE);
  return 0; /* Proxy was successful! */
}

static CURLcode ConnectPlease(struct connectdata *conn,
                              struct Curl_dns_entry *hostaddr,
                              bool *connected)
{
  CURLcode result;
  Curl_ipconnect *addr;

  /*************************************************************
   * Connect to server/proxy
   *************************************************************/
  result= Curl_connecthost(conn,
                           hostaddr,
                           conn->port,
                           &conn->firstsocket,
                           &addr,
                           connected);
  if(CURLE_OK == result) {
    /* All is cool, then we store the current information from the hostaddr
       struct to the serv_addr, as it might be needed later. The address
       returned from the function above is crucial here. */
    conn->connect_addr = hostaddr;

#ifdef ENABLE_IPV6
    conn->serv_addr = addr;
#else
    memset((char *) &conn->serv_addr, '\0', sizeof(conn->serv_addr));
    memcpy((char *)&(conn->serv_addr.sin_addr),
           (struct in_addr *)addr, sizeof(struct in_addr));
    conn->serv_addr.sin_family = hostaddr->addr->h_addrtype;
    conn->serv_addr.sin_port = htons((unsigned short)conn->port);
#endif

    if (conn->data->set.proxytype == CURLPROXY_SOCKS5) {
      return handleSock5Proxy(conn->data->state.proxyuser,
                              conn->data->state.proxypasswd,
                              conn,
                              conn->firstsocket) ?
        CURLE_COULDNT_CONNECT : CURLE_OK;
    }
    else if (conn->data->set.proxytype == CURLPROXY_HTTP) {
      /* do nothing here. handled later. */
    }
    else {
      failf(conn->data, "unknown proxytype option given");
      return CURLE_COULDNT_CONNECT;
    }
  }

  return result;
}

/*
 * ALERT! The 'dns' pointer being passed in here might be NULL at times.
 */
static void verboseconnect(struct connectdata *conn,
                           struct Curl_dns_entry *dns)
{
#ifdef HAVE_INET_NTOA_R
  char ntoa_buf[64];
#endif
  struct SessionHandle *data = conn->data;

  /* Figure out the ip-number and display the first host name it shows: */
#ifdef ENABLE_IPV6
  (void)dns; /* not used in the IPv6 enabled version */
  {
    char hbuf[NI_MAXHOST];
#ifdef NI_WITHSCOPEID
    const int niflags = NI_NUMERICHOST | NI_WITHSCOPEID;
#else
    const int niflags = NI_NUMERICHOST;
#endif
    struct addrinfo *ai = conn->serv_addr;

    if (getnameinfo(ai->ai_addr, ai->ai_addrlen, hbuf, sizeof(hbuf), NULL, 0,
	niflags)) {
      snprintf(hbuf, sizeof(hbuf), "?");
    }
    if (ai->ai_canonname) {
      infof(data, "Connected to %s (%s) port %d\n", ai->ai_canonname, hbuf,
            conn->port);
    } else {
      infof(data, "Connected to %s port %d\n", hbuf, conn->port);
    }
  }
#else
  {
    Curl_addrinfo *hostaddr=dns?dns->addr:NULL;
    struct in_addr in;
    (void) memcpy(&in.s_addr, &conn->serv_addr.sin_addr, sizeof (in.s_addr));
    infof(data, "Connected to %s (%s) port %d\n",
          hostaddr?hostaddr->h_name:"",
#if defined(HAVE_INET_NTOA_R)
          inet_ntoa_r(in, ntoa_buf, sizeof(ntoa_buf)),
#else
          inet_ntoa(in),
#endif
          conn->port);
  }
#endif
}

/*
 * We have discovered that the TCP connection has been successful, we can now
 * proceed with some action.
 *
 * If we're using the multi interface, this host address pointer is most
 * likely NULL at this point as we can't keep the resolved info around. This
 * may call for some reworking, like a reference counter in the struct or
 * something. The hostaddr is not used for very much though, we have the
 * 'serv_addr' field in the connectdata struct for most of it.
 */
CURLcode Curl_protocol_connect(struct connectdata *conn,
                               struct Curl_dns_entry *hostaddr)
{
  struct SessionHandle *data = conn->data;
  CURLcode result=CURLE_OK;

  if(conn->bits.tcpconnect)
    /* We already are connected, get back. This may happen when the connect
       worked fine in the first call, like when we connect to a local server
       or proxy. */
    return CURLE_OK;

  Curl_pgrsTime(data, TIMER_CONNECT); /* connect done */

  if(data->set.verbose)
    verboseconnect(conn, hostaddr);

  if(conn->curl_connect) {
    /* is there a protocol-specific connect() procedure? */

    /* set start time here for timeout purposes in the
     * connect procedure, it is later set again for the
     * progress meter purpose */
    conn->now = Curl_tvnow();

    /* Call the protocol-specific connect function */
    result = conn->curl_connect(conn);
  }

  return result; /* pass back status */
}

static CURLcode CreateConnection(struct SessionHandle *data,
                                 struct connectdata **in_connect)
{
  char *tmp;
  CURLcode result=CURLE_OK;
  char resumerange[40]="";
  struct connectdata *conn;
  struct connectdata *conn_temp;
  int urllen;
  struct Curl_dns_entry *hostaddr;
#ifdef HAVE_ALARM
  unsigned int prev_alarm=0;
#endif
  char endbracket;

#ifdef HAVE_SIGACTION
  struct sigaction keep_sigact;   /* store the old struct here */
  bool keep_copysig=FALSE;        /* did copy it? */
#else
#ifdef HAVE_SIGNAL
  void *keep_sigact;              /* store the old handler here */
#endif
#endif

  /*************************************************************
   * Check input data
   *************************************************************/

  if(!data->change.url)
    return CURLE_URL_MALFORMAT;

  /* First, split up the current URL in parts so that we can use the
     parts for checking against the already present connections. In order
     to not have to modify everything at once, we allocate a temporary
     connection data struct and fill in for comparison purposes. */

  conn = (struct connectdata *)malloc(sizeof(struct connectdata));
  if(!conn) {
    *in_connect = NULL; /* clear the pointer */
    return CURLE_OUT_OF_MEMORY;
  }
  /* We must set the return variable as soon as possible, so that our
     parent can cleanup any possible allocs we may have done before
     any failure */
  *in_connect = conn;

  /* we have to init the struct */
  memset(conn, 0, sizeof(struct connectdata));

  /* and we setup a few fields in case we end up actually using this struct */
  conn->data = data;           /* remember our daddy */
  conn->firstsocket = -1;     /* no file descriptor */
  conn->secondarysocket = -1; /* no file descriptor */
  conn->connectindex = -1;    /* no index */
  conn->bits.httpproxy = (data->change.proxy && *data->change.proxy &&
                          (data->set.proxytype == CURLPROXY_HTTP))?
    TRUE:FALSE; /* http proxy or not */

  /* Default protocol-independent behavior doesn't support persistant
     connections, so we set this to force-close. Protocols that support
     this need to set this to FALSE in their "curl_do" functions. */
  conn->bits.close = TRUE;

  /* maxdownload must be -1 on init, as 0 is a valid value! */
  conn->maxdownload = -1;  /* might have been used previously! */

  /* Store creation time to help future close decision making */
  conn->created = Curl_tvnow();

  conn->bits.use_range = data->set.set_range?TRUE:FALSE; /* range status */
  conn->range = data->set.set_range;              /* clone the range setting */
  conn->resume_from = data->set.set_resume_from;   /* inherite resume_from */

  /* Set the start time temporary to this creation time to allow easier
     timeout checks before the transfer has started for real. The start time
     is later set "for real" using Curl_pgrsStartNow(). */
  conn->data->progress.start = conn->created;

  conn->bits.user_passwd = data->set.userpwd?1:0;
  conn->bits.proxy_user_passwd = data->set.proxyuserpwd?1:0;

  /* This initing continues below, see the comment "Continue connectdata
   * initialization here" */

  /***********************************************************
   * We need to allocate memory to store the path in. We get the size of the
   * full URL to be sure, and we need to make it at least 256 bytes since
   * other parts of the code will rely on this fact
   ***********************************************************/
#define LEAST_PATH_ALLOC 256
  urllen=strlen(data->change.url);
  if(urllen < LEAST_PATH_ALLOC)
    urllen=LEAST_PATH_ALLOC;

  conn->path=(char *)malloc(urllen);
  if(NULL == conn->path)
    return CURLE_OUT_OF_MEMORY; /* really bad error */

  /*************************************************************
   * Parse the URL.
   *
   * We need to parse the url even when using the proxy, because we will need
   * the hostname and port in case we are trying to SSL connect through the
   * proxy -- and we don't know if we will need to use SSL until we parse the
   * url ...
   ************************************************************/
  if((2 == sscanf(data->change.url, "%64[^:]://%[^\n]",
                  conn->protostr,
                  conn->path)) && strequal(conn->protostr, "file")) {
    /*
     * we deal with file://<host>/<path> differently since it supports no
     * hostname other than "localhost" and "127.0.0.1", which is unique among
     * the URL protocols specified in RFC 1738
     */
    if(conn->path[0] != '/') {
      /* the URL included a host name, we ignore host names in file:// URLs
         as the standards don't define what to do with them */
      char *ptr=strchr(conn->path, '/');
      if(ptr) {
        /* there was a slash present

           RFC1738 (section 3.1, page 5) says:

           The rest of the locator consists of data specific to the scheme,
           and is known as the "url-path". It supplies the details of how the
           specified resource can be accessed. Note that the "/" between the
           host (or port) and the url-path is NOT part of the url-path.

           As most agents use file://localhost/foo to get '/foo' although the
           slash preceeding foo is a separator and not a slash for the path,
           a URL as file://localhost//foo must be valid as well, to refer to
           the same file with an absolute path.
        */

        if(ptr[1] && ('/' == ptr[1]))
          /* if there was two slashes, we skip the first one as that is then
             used truly as a separator */
          ptr++;

        strcpy(conn->path, ptr);
      }
    }

    strcpy(conn->protostr, "file"); /* store protocol string lowercase */
  }
  else {
    /* Set default host and default path */
    strcpy(conn->gname, "curl.haxx.se");
    strcpy(conn->path, "/");
    /* We need to search for '/' OR '?' - whichever comes first after host
     * name but before the path. We need to change that to handle things like
     * http://example.com?param= (notice the missing '/'). Later we'll insert
     * that missing slash at the beginning of the path.
     */
    if (2 > sscanf(data->change.url,
                   "%64[^\n:]://%512[^\n/?]%[^\n]",
                   conn->protostr, conn->gname, conn->path)) {

      /*
       * The URL was badly formatted, let's try the browser-style _without_
       * protocol specified like 'http://'.
       */
      if((1 > sscanf(data->change.url, "%512[^\n/?]%[^\n]",
                     conn->gname, conn->path)) ) {
        /*
         * We couldn't even get this format.
         */
        failf(data, "<url> malformed");
        return CURLE_URL_MALFORMAT;
      }

      /*
       * Since there was no protocol part specified, we guess what protocol it
       * is based on the first letters of the server name.
       */

      /* Note: if you add a new protocol, please update the list in
       * lib/version.c too! */

      if(checkprefix("FTP", conn->gname)) {
        strcpy(conn->protostr, "ftp");
      }
      else if(checkprefix("GOPHER", conn->gname))
        strcpy(conn->protostr, "gopher");
#ifdef USE_SSLEAY
      else if(checkprefix("HTTPS", conn->gname))
        strcpy(conn->protostr, "https");
      else if(checkprefix("FTPS", conn->gname))
        strcpy(conn->protostr, "ftps");
#endif /* USE_SSLEAY */
      else if(checkprefix("TELNET", conn->gname))
        strcpy(conn->protostr, "telnet");
      else if (checkprefix("DICT", conn->gname))
        strcpy(conn->protostr, "DICT");
      else if (checkprefix("LDAP", conn->gname))
        strcpy(conn->protostr, "LDAP");
      else {
        strcpy(conn->protostr, "http");
      }

      conn->protocol |= PROT_MISSING; /* not given in URL */
    }
  }

  /* If the URL is malformatted (missing a '/' after hostname before path) we
   * insert a slash here. The only letter except '/' we accept to start a path
   * is '?'.
   */
  if(conn->path[0] == '?') {
    /* We need this function to deal with overlapping memory areas. We know
       that the memory area 'path' points to is 'urllen' bytes big and that
       is bigger than the path. Use +1 to move the zero byte too. */
    memmove(&conn->path[1], conn->path, strlen(conn->path)+1);
    conn->path[0] = '/';
  }

  /*
   * So if the URL was A://B/C,
   *   conn->protostr is A
   *   conn->gname is B
   *   conn->path is /C
   */