url.c

             and password as well */
          if(!strequal(needle->user, check->user) ||
             !strequal(needle->passwd, check->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->proxy.name, check->proxy.name) &&
         needle->port == check->port) {
        /* This is the same proxy connection, use it! */
        match = TRUE;
      }
    }

    if(match) {
      bool dead = SocketIsDead(check->sock[FIRSTSOCKET]);
      if(dead) {
        /*
         */
        check->data = data;
        infof(data, "Connection %d seems to be dead!\n", i);
        Curl_disconnect(check); /* disconnect resources */
        data->state.connc->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;
      }

      check->inuse = TRUE; /* mark this as being in use so that no other
                              handle in a multi stack may nick it */

      if (canPipeline) {
          /* Mark the connection as being in a pipeline */
          check->is_in_pipeline = TRUE;
      }

      *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 long
ConnectionKillOne(struct SessionHandle *data)
{
  long i;
  struct connectdata *conn;
  long highscore=-1;
  long connindex=-1;
  long score;
  struct timeval now;

  now = Curl_tvnow();

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

    if(!conn || conn->inuse)
      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) {
    /* Set the connection's owner correctly */
    conn = data->state.connc->connects[connindex];
    conn->data = data;

    /* the winner gets the honour of being disconnected */
    (void)Curl_disconnect(conn);

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

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

/* this connection can now be marked 'idle' */
static void
ConnectionDone(struct connectdata *conn)
{
  conn->inuse = FALSE;
  conn->data = NULL;

  if (conn->send_pipe == 0 &&
      conn->recv_pipe == 0)
    conn->is_in_pipeline = FALSE;
}

/*
 * 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 long
ConnectionStore(struct SessionHandle *data,
                struct connectdata *conn)
{
  long i;
  for(i=0; i< data->state.connc->num; i++) {
    if(!data->state.connc->connects[i])
      break;
  }
  if(i == data->state.connc->num) {
    /* there was no room available, kill one */
    i = ConnectionKillOne(data);
    if(-1 != i)
      infof(data, "Connection (#%d) was killed to make room (holds %d)\n",
            i, data->state.connc->num);
    else
      infof(data, "This connection did not fit in the connection cache\n");
  }

  conn->connectindex = i; /* Make the child know where the pointer to this
                             particular data is stored. But note that this -1
                             if this is not within the cache and this is
                             probably not checked for everywhere (yet). */
  conn->inuse = TRUE;
  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.

       TODO: make sure we really can work with more handles than positions in
       the cache, or possibly we should (allow to automatically) resize the
       connection cache when we add more easy handles to a multi handle!
    */
    data->state.connc->connects[i] = conn; /* fill in this */
    conn->data = data;
  }

  return i;
}

/*
* This function logs in to a SOCKS4 proxy and sends the specifics to the final
* destination server.
*
* Reference :
*   http://socks.permeo.com/protocol/socks4.protocol
*
* Note :
*   Nonsupport "SOCKS 4A (Simple Extension to SOCKS 4 Protocol)"
*   Nonsupport "Identification Protocol (RFC1413)"
*/
static int handleSock4Proxy(const char *proxy_name,
                            struct SessionHandle *data,
                            struct connectdata *conn)
{
  unsigned char socksreq[262]; /* room for SOCKS4 request incl. user id */
  int result;
  CURLcode code;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];

  Curl_nonblock(sock, FALSE);

  /*
  * Compose socks4 request
  *
  * Request format
  *
  *     +----+----+----+----+----+----+----+----+----+----+....+----+
  *     | VN | CD | DSTPORT |      DSTIP        | USERID       |NULL|
  *     +----+----+----+----+----+----+----+----+----+----+....+----+
  * # of bytes:  1    1      2              4           variable       1
  */

  socksreq[0] = 4; /* version (SOCKS4) */
  socksreq[1] = 1; /* connect */
  *((unsigned short*)&socksreq[2]) = htons(conn->remote_port);

  /* DNS resolve */
  {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc;

    rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);

    if(rc == CURLRESOLV_ERROR)
      return 1;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
    * 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) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
        &ip[0], &ip[1], &ip[2], &ip[3])) {
          /* Set DSTIP */
          socksreq[4] = (unsigned char)ip[0];
          socksreq[5] = (unsigned char)ip[1];
          socksreq[6] = (unsigned char)ip[2];
          socksreq[7] = (unsigned char)ip[3];
        }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */

    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS4 connect.",
        conn->host.name);
      return 1;
    }
  }

  /*
   * This is currently not supporting "Identification Protocol (RFC1413)".
   */
  socksreq[8] = 0; /* ensure empty userid is NUL-terminated */
  if (proxy_name)
    strlcat((char*)socksreq + 8, proxy_name, sizeof(socksreq) - 8);

  /*
   * Make connection
   */
  {
    ssize_t actualread;
    ssize_t written;
    int packetsize = 9 +
      (int)strlen((char*)socksreq + 8); /* size including NUL */

    /* Send request */
    code = Curl_write(conn, sock, (char *)socksreq, packetsize, &written);
    if ((code != CURLE_OK) || (written != packetsize)) {
      failf(data, "Failed to send SOCKS4 connect request.");
      return 1;
    }

    packetsize = 8; /* receive data size */

    /* Receive response */
    result = Curl_read(conn, sock, (char *)socksreq, packetsize, &actualread);
    if ((result != CURLE_OK) || (actualread != packetsize)) {
      failf(data, "Failed to receive SOCKS4 connect request ack.");
      return 1;
    }

    /*
    * Response format
    *
    *     +----+----+----+----+----+----+----+----+
    *     | VN | CD | DSTPORT |      DSTIP        |
    *     +----+----+----+----+----+----+----+----+
    * # of bytes:  1    1      2              4
    *
    * VN is the version of the reply code and should be 0. CD is the result
    * code with one of the following values:
    *
    * 90: request granted
    * 91: request rejected or failed
    * 92: request rejected because SOCKS server cannot connect to
    *     identd on the client
    * 93: request rejected because the client program and identd
    *     report different user-ids
    */

    /* wrong version ? */
    if (socksreq[0] != 0) {
      failf(data,
        "SOCKS4 reply has wrong version, version should be 4.");
      return 1;
    }

    /* Result */
    switch(socksreq[1])
    {
      case 90:
        infof(data, "SOCKS4 request granted.\n");
        break;
      case 91:
        failf(data,
          "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
          ", request rejected or failed.",
          (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;
      case 92:
        failf(data,
          "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
          ", request rejected because SOCKS server cannot connect to "
          "identd on the client.",
          (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;
      case 93:
        failf(data,
          "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
          ", request rejected because the client program and identd "
          "report different user-ids.",
          (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;
      default :
        failf(data,
          "Can't complete SOCKS4 connection to %d.%d.%d.%d:%d. (%d)"
          ", Unknown.",
          (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! */
}

/*
 * This function logs in to a SOCKS5 proxy and sends the specifics to the final
 * destination server.
 */
static int handleSock5Proxy(const char *proxy_name,
                            const char *proxy_password,
                            struct connectdata *conn)
{
  /*
    According to the RFC1928, section "6.  Replies". This is what a SOCK5
    replies:

        +----+-----+-------+------+----------+----------+
        |VER | REP |  RSV  | ATYP | BND.ADDR | BND.PORT |
        +----+-----+-------+------+----------+----------+
        | 1  |  1  | X'00' |  1   | Variable |    2     |
        +----+-----+-------+------+----------+----------+

    Where:

    o  VER    protocol version: X'05'
    o  REP    Reply field:
    o  X'00' succeeded
  */

  unsigned char socksreq[600]; /* room for large user/pw (255 max each) */
  ssize_t actualread;
  ssize_t written;
  int result;
  CURLcode code;
  curl_socket_t sock = conn->sock[FIRSTSOCKET];
  struct SessionHandle *data = conn->data;
  long timeout;

  /* get timeout */
  if(data->set.timeout && data->set.connecttimeout) {
    if (data->set.timeout < data->set.connecttimeout)
      timeout = data->set.timeout*1000;
    else
      timeout = data->set.connecttimeout*1000;
  }
  else if(data->set.timeout)
    timeout = data->set.timeout*1000;
  else if(data->set.connecttimeout)
    timeout = data->set.connecttimeout*1000;
  else
    timeout = DEFAULT_CONNECT_TIMEOUT;

  Curl_nonblock(sock, TRUE);

  /* wait until socket gets connected */
  result = Curl_select(CURL_SOCKET_BAD, sock, (int)timeout);

  if(-1 == result) {
    failf(conn->data, "SOCKS5: no connection here");
    return 1;
  }
  else if(0 == result) {
    failf(conn->data, "SOCKS5: connection timeout");
    return 1;
  }

  if(result & CSELECT_ERR) {
    failf(conn->data, "SOCKS5: error occured during connection");
    return 1;
  }

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

  Curl_nonblock(sock, FALSE);

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

  Curl_nonblock(sock, TRUE);

  result = Curl_select(sock, CURL_SOCKET_BAD, (int)timeout);

  if(-1 == result) {
    failf(conn->data, "SOCKS5 nothing to read");
    return 1;
  }
  else if(0 == result) {
    failf(conn->data, "SOCKS5 read timeout");
    return 1;
  }

  if(result & CSELECT_ERR) {
    failf(conn->data, "SOCKS5 read error occured");
    return 1;
  }

  Curl_nonblock(sock, FALSE);

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

  if (socksreq[0] != 5) {
    failf(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 */
    size_t userlen, pwlen;
    int len;
    if(proxy_name && proxy_password) {
      userlen = strlen(proxy_name);
      pwlen = proxy_password?strlen(proxy_password):0;
    }
    else {
      userlen = 0;
      pwlen = 0;
    }

    /*   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;

    code = Curl_write(conn, sock, (char *)socksreq, len, &written);
    if ((code != CURLE_OK) || (len != written)) {
      failf(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(data, "Unable to receive SOCKS5 sub-negotiation response.");
      return 1;
    }

    /* ignore the first (VER) byte */
    if (socksreq[1] != 0) { /* status */
      failf(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(data,
            "SOCKS5 GSSAPI per-message authentication is not supported.");
      return 1;
    }
    else if (socksreq[1] == 255) {
      if (!proxy_name || !*proxy_name) {
        failf(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(data, "No authentication method was acceptable.");
      }
      return 1;
    }
    else {
      failf(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 */

  {
    struct Curl_dns_entry *dns;
    Curl_addrinfo *hp=NULL;
    int rc = Curl_resolv(conn, conn->host.name, (int)conn->remote_port, &dns);

    if(rc == CURLRESOLV_ERROR)
      return 1;

    if(rc == CURLRESOLV_PENDING)
      /* this requires that we're in "wait for resolve" state */
      rc = Curl_wait_for_resolv(conn, &dns);

    /*
     * 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) {
      char buf[64];
      unsigned short ip[4];
      Curl_printable_address(hp, buf, sizeof(buf));

      if(4 == sscanf( buf, "%hu.%hu.%hu.%hu",
                      &ip[0], &ip[1], &ip[2], &ip[3])) {
        socksreq[4] = (unsigned char)ip[0];
        socksreq[5] = (unsigned char)ip[1];
        socksreq[6] = (unsigned char)ip[2];
        socksreq[7] = (unsigned char)ip[3];
      }
      else
        hp = NULL; /* fail! */

      Curl_resolv_unlock(data, dns); /* not used anymore from now on */
    }
    if(!hp) {
      failf(data, "Failed to resolve \"%s\" for SOCKS5 connect.",
            conn->host.name);
      return 1;
    }
  }

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

  {
    const int packetsize = 10;

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

    if (socksreq[0] != 5) { /* version */
      failf(data,
            "SOCKS5 reply has wrong version, version should be 5.");
      return 1;
    }
    if (socksreq[1] != 0) { /* Anything besides 0 is an error */
        failf(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 SessionHandle *data,
                              struct connectdata *conn,
                              struct Curl_dns_entry *hostaddr,
                              bool *connected)
{
  CURLcode result;
  Curl_addrinfo *addr;
  char *hostname = data->change.proxy?conn->proxy.name:conn->host.name;

  infof(data, "About to connect() to %s%s port %d\n",
        data->change.proxy?"proxy ":"",
        hostname, conn->port);

  /*************************************************************
   * Connect to server/proxy
   *************************************************************/
  result= Curl_connecthost(conn,
                           hostaddr,
                           &conn->sock[FIRSTSOCKET],
                           &addr,
                           connected);
  if(CURLE_OK == result) {
    /* All is cool, then we store the current information */
    conn->dns_entry = hostaddr;
    conn->ip_addr = addr;

    Curl_store_ip_addr(conn);

    switch(data->set.proxytype) {
    case CURLPROXY_SOCKS5:
      return handleSock5Proxy(conn->proxyuser,
                              conn->proxypasswd,
                              conn) ?
        CURLE_COULDNT_CONNECT : CURLE_OK;
    case CURLPROXY_HTTP:
      /* do nothing here. handled later. */
      break;
    case CURLPROXY_SOCKS4:
      return handleSock4Proxy(conn->proxyuser, data, conn) ?
        CURLE_COULDNT_CONNECT : CURLE_OK;
    default:
      failf(data, "unknown proxytype option given");
      return CURLE_COULDNT_CONNECT;
    }
  }

  return result;
}

/*
 * verboseconnect() displays verbose information after a connect
 */
static void verboseconnect(struct connectdata *conn)
{
  infof(conn->data, "Connected to %s (%s) port %d\n",
        conn->bits.httpproxy ? conn->proxy.dispname : conn->host.dispname,
        conn->ip_addr_str, conn->port);
}

int Curl_protocol_getsock(struct connectdata *conn,
                          curl_socket_t *socks,
                          int numsocks)
{
  if(conn->curl_proto_getsock)
    return conn->curl_proto_getsock(conn, socks, numsocks);
  return GETSOCK_BLANK;
}

int Curl_doing_getsock(struct connectdata *conn,
                       curl_socket_t *socks,
                       int numsocks)
{
  if(conn && conn->curl_doing_getsock)
    return conn->curl_doing_getsock(conn, socks, numsocks);
  return GETSOCK_BLANK;
}

/*
 * We are doing protocol-specific connecting and this is being called over and
 * over from the multi interface until the connection phase is done on
 * protocol layer.
 */

CURLcode Curl_protocol_connecting(struct connectdata *conn,
                                  bool *done)
{
  CURLcode result=CURLE_OK;

  if(conn && conn->curl_connecting) {
    *done = FALSE;
    result = conn->curl_connecting(conn, done);
  }
  else
    *done = TRUE;

  return result;
}

/*
 * We are DOING this is being called over and over from the multi interface
 * until the DOING phase is done on protocol layer.
 */

CURLcode Curl_protocol_doing(struct connectdata *conn, bool *done)
{
  CURLcode result=CURLE_OK;

  if(conn && conn->curl_doing) {
    *done = FALSE;
    result = conn->curl_doing(conn, done);
  }
  else
    *done = TRUE;

  return result;
}

/*
 * We have discovered that the TCP connection has been successful, we can now
 * proceed with some action.
 *
 */
CURLcode Curl_protocol_connect(struct connectdata *conn,
                               bool *protocol_done)
{
  CURLcode result=CURLE_OK;
  struct SessionHandle *data = conn->data;

  *protocol_done = FALSE;

  if(conn->bits.tcpconnect && conn->bits.protoconnstart) {
    /* 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. Note that we don't know if the protocol is actually done.

       Unless this protocol doesn't have any protocol-connect callback, as
       then we know we're done. */
    if(!conn->curl_connecting)
      *protocol_done = TRUE;

    return CURLE_OK;
  }

  if(!conn->bits.tcpconnect) {

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

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

  if(!conn->bits.protoconnstart) {
    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, protocol_done);
    }
    else
      *protocol_done = TRUE;

    /* it has started, possibly even completed but that knowledge isn't stored
       in this bit! */
    conn->bits.protoconnstart = TRUE;
  }

  return result; /* pass back status */
}

/*
 * Helpers for IDNA convertions.
 */
#ifdef USE_LIBIDN
static bool is_ASCII_name(const char *hostname)
{
  const unsigned char *ch = (const unsigned char*)hostname;

  while (*ch) {
    if (*ch++ & 0x80)
      return FALSE;
  }
  return TRUE;
}

/*
 * Check if characters in hostname is allowed in Top Level Domain.
 */
static bool tld_check_name(struct SessionHandle *data,
                           const char *ace_hostname)
{
  size_t err_pos;
  char *uc_name = NULL;
  int rc;

  /* Convert (and downcase) ACE-name back into locale's character set */
  rc = idna_to_unicode_lzlz(ace_hostname, &uc_name, 0);
  if (rc != IDNA_SUCCESS)
    return (FALSE);

  rc = tld_check_lz(uc_name, &err_pos, NULL);
  if (rc == TLD_INVALID)
     infof(data, "WARNING: %s; pos %u = `%c'/0x%02X\n",
#ifdef HAVE_TLD_STRERROR
           tld_strerror((Tld_rc)rc),
#else
           "<no msg>",
#endif
           err_pos, uc_name[err_pos],
           uc_name[err_pos] & 255);
  else if (rc != TLD_SUCCESS)
       infof(data, "WARNING: TLD check for %s failed; %s\n",
             uc_name,
#ifdef HAVE_TLD_STRERROR
             tld_strerror((Tld_rc)rc)
#else
             "<no msg>"
#endif
         );
  if (uc_name)
     idn_free(uc_name);
  return (bool)(rc == TLD_SUCCESS);
}
#endif

static void fix_hostname(struct SessionHandle *data,
                         struct connectdata *conn, struct hostname *host)
{
  /* set the name we use to display the host name */
  host->dispname = host->name;

#ifdef USE_LIBIDN
  /*************************************************************
   * Check name for non-ASCII and convert hostname to ACE form.
   *************************************************************/
  if (!is_ASCII_name(host->name) &&
      stringprep_check_version(LIBIDN_REQUIRED_VERSION)) {
    char *ace_hostname = NULL;
    int rc = idna_to_ascii_lz(host->name, &ace_hostname, 0);
    infof (data, "Input domain encoded as `%s'\n",
           stringprep_locale_charset ());
    if (rc != IDNA_SUCCESS)
      infof(data, "Failed to convert %s to ACE; %s\n",
            host->name, Curl_idn_strerror(conn,rc));
    else {
      /* tld_check_name() displays a warning if the host name contains
         "illegal" characters for this TLD */
      (void)tld_check_name(data, ace_hostname);

      host->encalloc = ace_hostname;
      /* change the name pointer to point to the encoded hostname */
      host->name = host->encalloc;
    }
  }
#else
  (void)data; /* never used */
  (void)conn; /* never used */
#endif
}

/*
 * Parse URL and fill in the relevant members of the connection struct.
 */
static CURLcode ParseURLAndFillConnection(struct SessionHandle *data,
                                          struct connectdata *conn)
{
  char *at;
  char *tmp;

  char *path = data->reqdata.path;

  /*************************************************************
   * 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, "%15[^:]:%[^\n]",
                  conn->protostr,
                  path)) && strequal(conn->protostr, "file")) {
    if(path[0] == '/' && path[1] == '/') {
      /* Allow omitted hostname (e.g. file:/<path>).  This is not strictly
       * speaking a valid file: URL by RFC 1738, but treating file:/<path> as
       * file://localhost/<path> is similar to how other schemes treat missing
       * hostnames.  See RFC 1808. */

      /* This cannot be done with strcpy() in a portable manner, since the
         memory areas overlap! */
      memmove(path, path + 2, strlen(path + 2)+1);
    }
    /*
     * 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(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(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 preceding 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++;

        /* This cannot be made with strcpy, as the memory chunks overlap! */
        memmove(path, ptr, strlen(ptr)+1);
      }
    }

    strcpy(conn->protostr, "file"); /* store protocol string lowercase */
  }
  else {
    /* clear path */
    path[0]=0;

    if (2 > sscanf(data->change.url,
                   "%15[^\n:]://%[^\n/]%[^\n]",
                   conn->protostr,
                   conn->host.name, path)) {

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

      /*