url.c

  else {
#ifdef ENABLE_IPV6
    struct in6_addr in6;
    if(Curl_inet_pton(AF_INET6, conn->host.name, &in6) > 0) {
      /* This is a numerical IPv6 address, meaning this is a wrongly formatted
         URL */
      failf(data, "IPv6 numerical address used in URL without brackets");
      return CURLE_URL_MALFORMAT;
    }
#endif

    portptr = strrchr(conn->host.name, ':');
  }

  if(data->set.use_port && data->state.allow_port) {
    /* if set, we use this and ignore the port possibly given in the URL */
    conn->remote_port = (unsigned short)data->set.use_port;
    if(portptr)
      *portptr = '\0'; /* cut off the name there anyway - if there was a port
                      number - since the port number is to be ignored! */
    if(conn->bits.httpproxy) {
      /* we need to create new URL with the new port number */
      char *url;
      char type[12]="";

      if(conn->bits.type_set)
        snprintf(type, sizeof(type), ";type=%c",
                 data->set.prefer_ascii?'A':
                 (data->set.ftp_list_only?'D':'I'));

      /*
       * This synthesized URL isn't always right--suffixes like ;type=A are
       * stripped off. It would be better to work directly from the original
       * URL and simply replace the port part of it.
       */
      url = aprintf("%s://%s%s%s:%hu%s%s%s", conn->given->scheme,
                    conn->bits.ipv6_ip?"[":"", conn->host.name,
                    conn->bits.ipv6_ip?"]":"", conn->remote_port,
                    data->state.slash_removed?"/":"", data->state.path,
                    type);
      if(!url)
        return CURLE_OUT_OF_MEMORY;

      if(data->change.url_alloc) {
        Curl_safefree(data->change.url);
        data->change.url_alloc = FALSE;
      }

      data->change.url = url;
      data->change.url_alloc = TRUE;
    }
  }
  else if(portptr) {
    /* no CURLOPT_PORT given, extract the one from the URL */

    char *rest;
    long port;

    port=strtol(portptr+1, &rest, 10);  /* Port number must be decimal */

    if((port < 0) || (port > 0xffff)) {
      /* Single unix standard says port numbers are 16 bits long */
      failf(data, "Port number out of range");
      return CURLE_URL_MALFORMAT;
    }

    else if(rest != &portptr[1]) {
      *portptr = '\0'; /* cut off the name there */
      conn->remote_port = curlx_ultous(port);
    }
    else
      /* Browser behavior adaptation. If there's a colon with no digits after,
         just cut off the name there which makes us ignore the colon and just
         use the default port. Firefox and Chrome both do that. */
      *portptr = '\0';
  }
  return CURLE_OK;
}

/*
 * Override the login details from the URL with that in the CURLOPT_USERPWD
 * option or a .netrc file, if applicable.
 */
static CURLcode override_login(struct SessionHandle *data,
                               struct connectdata *conn,
                               char **userp, char **passwdp, char **optionsp)
{
  if(data->set.str[STRING_USERNAME]) {
    free(*userp);
    *userp = strdup(data->set.str[STRING_USERNAME]);
    if(!*userp)
      return CURLE_OUT_OF_MEMORY;
  }

  if(data->set.str[STRING_PASSWORD]) {
    free(*passwdp);
    *passwdp = strdup(data->set.str[STRING_PASSWORD]);
    if(!*passwdp)
      return CURLE_OUT_OF_MEMORY;
  }

  if(data->set.str[STRING_OPTIONS]) {
    free(*optionsp);
    *optionsp = strdup(data->set.str[STRING_OPTIONS]);
    if(!*optionsp)
      return CURLE_OUT_OF_MEMORY;
  }

  conn->bits.netrc = FALSE;
  if(data->set.use_netrc != CURL_NETRC_IGNORED) {
    int ret = Curl_parsenetrc(conn->host.name,
                              userp, passwdp,
                              data->set.str[STRING_NETRC_FILE]);
    if(ret > 0) {
      infof(data, "Couldn't find host %s in the "
            DOT_CHAR "netrc file; using defaults\n",
            conn->host.name);
    }
    else if(ret < 0 ) {
      return CURLE_OUT_OF_MEMORY;
    }
    else {
      /* set bits.netrc TRUE to remember that we got the name from a .netrc
         file, so that it is safe to use even if we followed a Location: to a
         different host or similar. */
      conn->bits.netrc = TRUE;

      conn->bits.user_passwd = TRUE; /* enable user+password */
    }
  }

  return CURLE_OK;
}

/*
 * Set the login details so they're available in the connection
 */
static CURLcode set_login(struct connectdata *conn,
                          const char *user, const char *passwd,
                          const char *options)
{
  CURLcode result = CURLE_OK;

  /* If our protocol needs a password and we have none, use the defaults */
  if((conn->handler->flags & PROTOPT_NEEDSPWD) && !conn->bits.user_passwd) {
    /* Store the default user */
    conn->user = strdup(CURL_DEFAULT_USER);

    /* Store the default password */
    if(conn->user)
      conn->passwd = strdup(CURL_DEFAULT_PASSWORD);
    else
      conn->passwd = NULL;

    /* This is the default password, so DON'T set conn->bits.user_passwd */
  }
  else {
    /* Store the user, zero-length if not set */
    conn->user = strdup(user);

    /* Store the password (only if user is present), zero-length if not set */
    if(conn->user)
      conn->passwd = strdup(passwd);
    else
      conn->passwd = NULL;
  }

  if(!conn->user || !conn->passwd)
    result = CURLE_OUT_OF_MEMORY;

  /* Store the options, null if not set */
  if(!result && options[0]) {
    conn->options = strdup(options);

    if(!conn->options)
      result = CURLE_OUT_OF_MEMORY;
  }

  return result;
}

/*************************************************************
 * Resolve the address of the server or proxy
 *************************************************************/
static CURLcode resolve_server(struct SessionHandle *data,
                               struct connectdata *conn,
                               bool *async)
{
  CURLcode result=CURLE_OK;
  long timeout_ms = Curl_timeleft(data, NULL, TRUE);

  /*************************************************************
   * Resolve the name of the server or proxy
   *************************************************************/
  if(conn->bits.reuse)
    /* We're reusing the connection - no need to resolve anything, and
       fix_hostname() was called already in create_conn() for the re-use
       case. */
    *async = FALSE;

  else {
    /* this is a fresh connect */
    int rc;
    struct Curl_dns_entry *hostaddr;

    /* set a pointer to the hostname we display */
    fix_hostname(data, conn, &conn->host);

#ifdef USE_UNIX_SOCKETS
    if(data->set.str[STRING_UNIX_SOCKET_PATH]) {
      /* Unix domain sockets are local. The host gets ignored, just use the
       * specified domain socket address. Do not cache "DNS entries". There is
       * no DNS involved and we already have the filesystem path available */
      const char *path = data->set.str[STRING_UNIX_SOCKET_PATH];

      hostaddr = calloc(1, sizeof(struct Curl_dns_entry));
      if(!hostaddr)
        result = CURLE_OUT_OF_MEMORY;
      else if((hostaddr->addr = Curl_unix2addr(path)) != NULL)
        hostaddr->inuse++;
      else {
        /* Long paths are not supported for now */
        if(strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) {
          failf(data, "Unix socket path too long: '%s'", path);
          result = CURLE_COULDNT_RESOLVE_HOST;
        }
        else
          result = CURLE_OUT_OF_MEMORY;
        free(hostaddr);
        hostaddr = NULL;
      }
    }
    else
#endif
    if(!conn->proxy.name || !*conn->proxy.name) {
      /* If not connecting via a proxy, extract the port from the URL, if it is
       * there, thus overriding any defaults that might have been set above. */
      conn->port =  conn->remote_port; /* it is the same port */

      /* Resolve target host right on */
      rc = Curl_resolv_timeout(conn, conn->host.name, (int)conn->port,
                               &hostaddr, timeout_ms);
      if(rc == CURLRESOLV_PENDING)
        *async = TRUE;

      else if(rc == CURLRESOLV_TIMEDOUT)
        result = CURLE_OPERATION_TIMEDOUT;

      else if(!hostaddr) {
        failf(data, "Couldn't resolve host '%s'", conn->host.dispname);
        result =  CURLE_COULDNT_RESOLVE_HOST;
        /* don't return yet, we need to clean up the timeout first */
      }
    }
    else {
      /* This is a proxy that hasn't been resolved yet. */

      /* IDN-fix the proxy name */
      fix_hostname(data, conn, &conn->proxy);

      /* resolve proxy */
      rc = Curl_resolv_timeout(conn, conn->proxy.name, (int)conn->port,
                               &hostaddr, timeout_ms);

      if(rc == CURLRESOLV_PENDING)
        *async = TRUE;

      else if(rc == CURLRESOLV_TIMEDOUT)
        result = CURLE_OPERATION_TIMEDOUT;

      else if(!hostaddr) {
        failf(data, "Couldn't resolve proxy '%s'", conn->proxy.dispname);
        result = CURLE_COULDNT_RESOLVE_PROXY;
        /* don't return yet, we need to clean up the timeout first */
      }
    }
    DEBUGASSERT(conn->dns_entry == NULL);
    conn->dns_entry = hostaddr;
  }

  return result;
}

/*
 * Cleanup the connection just allocated before we can move along and use the
 * previously existing one.  All relevant data is copied over and old_conn is
 * ready for freeing once this function returns.
 */
static void reuse_conn(struct connectdata *old_conn,
                       struct connectdata *conn)
{
  free(old_conn->proxy.rawalloc);

  /* free the SSL config struct from this connection struct as this was
     allocated in vain and is targeted for destruction */
  Curl_free_ssl_config(&old_conn->ssl_config);

  conn->data = old_conn->data;

  /* get the user+password information from the old_conn struct since it may
   * be new for this request even when we re-use an existing connection */
  conn->bits.user_passwd = old_conn->bits.user_passwd;
  if(conn->bits.user_passwd) {
    /* use the new user name and password though */
    Curl_safefree(conn->user);
    Curl_safefree(conn->passwd);
    conn->user = old_conn->user;
    conn->passwd = old_conn->passwd;
    old_conn->user = NULL;
    old_conn->passwd = NULL;
  }

  conn->bits.proxy_user_passwd = old_conn->bits.proxy_user_passwd;
  if(conn->bits.proxy_user_passwd) {
    /* use the new proxy user name and proxy password though */
    Curl_safefree(conn->proxyuser);
    Curl_safefree(conn->proxypasswd);
    conn->proxyuser = old_conn->proxyuser;
    conn->proxypasswd = old_conn->proxypasswd;
    old_conn->proxyuser = NULL;
    old_conn->proxypasswd = NULL;
  }

  /* host can change, when doing keepalive with a proxy or if the case is
     different this time etc */
  Curl_safefree(conn->host.rawalloc);
  conn->host=old_conn->host;

  /* persist connection info in session handle */
  Curl_persistconninfo(conn);

  /* re-use init */
  conn->bits.reuse = TRUE; /* yes, we're re-using here */

  Curl_safefree(old_conn->user);
  Curl_safefree(old_conn->passwd);
  Curl_safefree(old_conn->proxyuser);
  Curl_safefree(old_conn->proxypasswd);
  Curl_safefree(old_conn->localdev);

  Curl_llist_destroy(old_conn->send_pipe, NULL);
  Curl_llist_destroy(old_conn->recv_pipe, NULL);

  old_conn->send_pipe = NULL;
  old_conn->recv_pipe = NULL;

  Curl_safefree(old_conn->master_buffer);
}

/**
 * create_conn() sets up a new connectdata struct, or re-uses an already
 * existing one, and resolves host name.
 *
 * if this function returns CURLE_OK and *async is set to TRUE, the resolve
 * response will be coming asynchronously. If *async is FALSE, the name is
 * already resolved.
 *
 * @param data The sessionhandle pointer
 * @param in_connect is set to the next connection data pointer
 * @param async is set TRUE when an async DNS resolution is pending
 * @see Curl_setup_conn()
 *
 * *NOTE* this function assigns the conn->data pointer!
 */

static CURLcode create_conn(struct SessionHandle *data,
                            struct connectdata **in_connect,
                            bool *async)
{
  CURLcode result = CURLE_OK;
  struct connectdata *conn;
  struct connectdata *conn_temp = NULL;
  size_t urllen;
  char *user = NULL;
  char *passwd = NULL;
  char *options = NULL;
  bool reuse;
  char *proxy = NULL;
  bool prot_missing = FALSE;
  bool connections_available = TRUE;
  bool force_reuse = FALSE;
  bool waitpipe = FALSE;
  size_t max_host_connections = Curl_multi_max_host_connections(data->multi);
  size_t max_total_connections = Curl_multi_max_total_connections(data->multi);

  *async = FALSE;

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

  if(!data->change.url) {
    result = CURLE_URL_MALFORMAT;
    goto out;
  }

  /* 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 = allocate_conn(data);

  if(!conn) {
    result = CURLE_OUT_OF_MEMORY;
    goto out;
  }

  /* 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;

  /* 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;

  /*
   * We malloc() the buffers below urllen+2 to make room for 2 possibilities:
   * 1 - an extra terminating zero
   * 2 - an extra slash (in case a syntax like "www.host.com?moo" is used)
   */

  Curl_safefree(data->state.pathbuffer);
  data->state.path = NULL;

  data->state.pathbuffer = malloc(urllen+2);
  if(NULL == data->state.pathbuffer) {
    result = CURLE_OUT_OF_MEMORY; /* really bad error */
    goto out;
  }
  data->state.path = data->state.pathbuffer;

  conn->host.rawalloc = malloc(urllen+2);
  if(NULL == conn->host.rawalloc) {
    Curl_safefree(data->state.pathbuffer);
    data->state.path = NULL;
    result = CURLE_OUT_OF_MEMORY;
    goto out;
  }

  conn->host.name = conn->host.rawalloc;
  conn->host.name[0] = 0;

  user = strdup("");
  passwd = strdup("");
  options = strdup("");
  if(!user || !passwd || !options) {
    result = CURLE_OUT_OF_MEMORY;
    goto out;
  }

  result = parseurlandfillconn(data, conn, &prot_missing, &user, &passwd,
                               &options);
  if(result)
    goto out;

  /*************************************************************
   * No protocol part in URL was used, add it!
   *************************************************************/
  if(prot_missing) {
    /* We're guessing prefixes here and if we're told to use a proxy or if
       we're gonna follow a Location: later or... then we need the protocol
       part added so that we have a valid URL. */
    char *reurl;

    reurl = aprintf("%s://%s", conn->handler->scheme, data->change.url);

    if(!reurl) {
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }

    if(data->change.url_alloc) {
      Curl_safefree(data->change.url);
      data->change.url_alloc = FALSE;
    }

    data->change.url = reurl;
    data->change.url_alloc = TRUE; /* free this later */
  }

  /*************************************************************
   * If the protocol can't handle url query strings, then cut
   * off the unhandable part
   *************************************************************/
  if((conn->given->flags&PROTOPT_NOURLQUERY)) {
    char *path_q_sep = strchr(conn->data->state.path, '?');
    if(path_q_sep) {
      /* according to rfc3986, allow the query (?foo=bar)
         also on protocols that can't handle it.

         cut the string-part after '?'
      */

      /* terminate the string */
      path_q_sep[0] = 0;
    }
  }

  if(data->set.str[STRING_BEARER]) {
    conn->xoauth2_bearer = strdup(data->set.str[STRING_BEARER]);
    if(!conn->xoauth2_bearer) {
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }
  }

#ifndef CURL_DISABLE_PROXY
  /*************************************************************
   * Extract the user and password from the authentication string
   *************************************************************/
  if(conn->bits.proxy_user_passwd) {
    result = parse_proxy_auth(data, conn);
    if(result)
      goto out;
  }

  /*************************************************************
   * Detect what (if any) proxy to use
   *************************************************************/
  if(data->set.str[STRING_PROXY]) {
    proxy = strdup(data->set.str[STRING_PROXY]);
    /* if global proxy is set, this is it */
    if(NULL == proxy) {
      failf(data, "memory shortage");
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }
  }

  if(data->set.str[STRING_NOPROXY] &&
     check_noproxy(conn->host.name, data->set.str[STRING_NOPROXY])) {
    free(proxy);  /* proxy is in exception list */
    proxy = NULL;
  }
  else if(!proxy)
    proxy = detect_proxy(conn);

#ifdef USE_UNIX_SOCKETS
  if(proxy && data->set.str[STRING_UNIX_SOCKET_PATH]) {
    free(proxy);  /* Unix domain sockets cannot be proxied, so disable it */
    proxy = NULL;
  }
#endif

  if(proxy && (!*proxy || (conn->handler->flags & PROTOPT_NONETWORK))) {
    free(proxy);  /* Don't bother with an empty proxy string or if the
                     protocol doesn't work with network */
    proxy = NULL;
  }

  /***********************************************************************
   * If this is supposed to use a proxy, we need to figure out the proxy host
   * name, proxy type and port number, so that we can re-use an existing
   * connection that may exist registered to the same proxy host.
   ***********************************************************************/
  if(proxy) {
    result = parse_proxy(data, conn, proxy);

    free(proxy); /* parse_proxy copies the proxy string */
    proxy = NULL;

    if(result)
      goto out;

    if((conn->proxytype == CURLPROXY_HTTP) ||
       (conn->proxytype == CURLPROXY_HTTP_1_0)) {
#ifdef CURL_DISABLE_HTTP
      /* asking for a HTTP proxy is a bit funny when HTTP is disabled... */
      result = CURLE_UNSUPPORTED_PROTOCOL;
      goto out;
#else
      /* force this connection's protocol to become HTTP if not already
         compatible - if it isn't tunneling through */
      if(!(conn->handler->protocol & PROTO_FAMILY_HTTP) &&
         !conn->bits.tunnel_proxy)
        conn->handler = &Curl_handler_http;

      conn->bits.httpproxy = TRUE;
#endif
    }
    else {
      conn->bits.httpproxy = FALSE; /* not a HTTP proxy */
      conn->bits.tunnel_proxy = FALSE; /* no tunneling if not HTTP */
    }
    conn->bits.proxy = TRUE;
  }
  else {
    /* we aren't using the proxy after all... */
    conn->bits.proxy = FALSE;
    conn->bits.httpproxy = FALSE;
    conn->bits.proxy_user_passwd = FALSE;
    conn->bits.tunnel_proxy = FALSE;
  }

#endif /* CURL_DISABLE_PROXY */

  /*************************************************************
   * If the protocol is using SSL and HTTP proxy is used, we set
   * the tunnel_proxy bit.
   *************************************************************/
  if((conn->given->flags&PROTOPT_SSL) && conn->bits.httpproxy)
    conn->bits.tunnel_proxy = TRUE;

  /*************************************************************
   * Figure out the remote port number and fix it in the URL
   *************************************************************/
  result = parse_remote_port(data, conn);
  if(result)
    goto out;

  /* Check for overridden login details and set them accordingly so they
     they are known when protocol->setup_connection is called! */
  result = override_login(data, conn, &user, &passwd, &options);
  if(result)
    goto out;
  result = set_login(conn, user, passwd, options);
  if(result)
    goto out;

  /*************************************************************
   * Setup internals depending on protocol. Needs to be done after
   * we figured out what/if proxy to use.
   *************************************************************/
  result = setup_connection_internals(conn);
  if(result)
    goto out;

  conn->recv[FIRSTSOCKET] = Curl_recv_plain;
  conn->send[FIRSTSOCKET] = Curl_send_plain;
  conn->recv[SECONDARYSOCKET] = Curl_recv_plain;
  conn->send[SECONDARYSOCKET] = Curl_send_plain;

  /***********************************************************************
   * file: is a special case in that it doesn't need a network connection
   ***********************************************************************/
#ifndef CURL_DISABLE_FILE
  if(conn->handler->flags & PROTOPT_NONETWORK) {
    bool done;
    /* this is supposed to be the connect function so we better at least check
       that the file is present here! */
    DEBUGASSERT(conn->handler->connect_it);
    result = conn->handler->connect_it(conn, &done);

    /* Setup a "faked" transfer that'll do nothing */
    if(!result) {
      conn->data = data;
      conn->bits.tcpconnect[FIRSTSOCKET] = TRUE; /* we are "connected */

      Curl_conncache_add_conn(data->state.conn_cache, conn);

      /*
       * Setup whatever necessary for a resumed transfer
       */
      result = setup_range(data);
      if(result) {
        DEBUGASSERT(conn->handler->done);
        /* we ignore the return code for the protocol-specific DONE */
        (void)conn->handler->done(conn, result, FALSE);
        goto out;
      }

      Curl_setup_transfer(conn, -1, -1, FALSE, NULL, /* no download */
                          -1, NULL); /* no upload */
    }

    /* since we skip do_init() */
    Curl_init_do(data, conn);

    goto out;
  }
#endif

  /* Get a cloned copy of the SSL config situation stored in the
     connection struct. But to get this going nicely, we must first make
     sure that the strings in the master copy are pointing to the correct
     strings in the session handle strings array!

     Keep in mind that the pointers in the master copy are pointing to strings
     that will be freed as part of the SessionHandle struct, but all cloned
     copies will be separately allocated.
  */
  data->set.ssl.CApath = data->set.str[STRING_SSL_CAPATH];
  data->set.ssl.CAfile = data->set.str[STRING_SSL_CAFILE];
  data->set.ssl.CRLfile = data->set.str[STRING_SSL_CRLFILE];
  data->set.ssl.issuercert = data->set.str[STRING_SSL_ISSUERCERT];
  data->set.ssl.random_file = data->set.str[STRING_SSL_RANDOM_FILE];
  data->set.ssl.egdsocket = data->set.str[STRING_SSL_EGDSOCKET];
  data->set.ssl.cipher_list = data->set.str[STRING_SSL_CIPHER_LIST];
#ifdef USE_TLS_SRP
  data->set.ssl.username = data->set.str[STRING_TLSAUTH_USERNAME];
  data->set.ssl.password = data->set.str[STRING_TLSAUTH_PASSWORD];
#endif

  if(!Curl_clone_ssl_config(&data->set.ssl, &conn->ssl_config)) {
    result = CURLE_OUT_OF_MEMORY;
    goto out;
  }

  prune_dead_connections(data);

  /*************************************************************
   * Check the current list of connections to see if we can
   * re-use an already existing one or if we have to create a
   * new one.
   *************************************************************/

  /* reuse_fresh is TRUE if we are told to use a new connection by force, but
     we only acknowledge this option if this is not a re-used connection
     already (which happens due to follow-location or during a HTTP
     authentication phase). */
  if(data->set.reuse_fresh && !data->state.this_is_a_follow)
    reuse = FALSE;
  else
    reuse = ConnectionExists(data, conn, &conn_temp, &force_reuse, &waitpipe);

  /* If we found a reusable connection, we may still want to
     open a new connection if we are pipelining. */
  if(reuse && !force_reuse && IsPipeliningPossible(data, conn_temp)) {
    size_t pipelen = conn_temp->send_pipe->size + conn_temp->recv_pipe->size;
    if(pipelen > 0) {
      infof(data, "Found connection %ld, with requests in the pipe (%zu)\n",
            conn_temp->connection_id, pipelen);

      if(conn_temp->bundle->num_connections < max_host_connections &&
         data->state.conn_cache->num_connections < max_total_connections) {
        /* We want a new connection anyway */
        reuse = FALSE;

        infof(data, "We can reuse, but we want a new connection anyway\n");
      }
    }
  }

  if(reuse) {
    /*
     * We already have a connection for this, we got the former connection
     * in the conn_temp variable and thus we need to cleanup the one we
     * just allocated before we can move along and use the previously
     * existing one.
     */
    conn_temp->inuse = TRUE; /* mark this as being in use so that no other
                                handle in a multi stack may nick it */
    reuse_conn(conn, conn_temp);
    free(conn);          /* we don't need this anymore */
    conn = conn_temp;
    *in_connect = conn;

    /* set a pointer to the hostname we display */
    fix_hostname(data, conn, &conn->host);

    infof(data, "Re-using existing connection! (#%ld) with %s %s\n",
          conn->connection_id,
          conn->bits.proxy?"proxy":"host",
          conn->proxy.name?conn->proxy.dispname:conn->host.dispname);
  }
  else {
    /* We have decided that we want a new connection. However, we may not
       be able to do that if we have reached the limit of how many
       connections we are allowed to open. */
    struct connectbundle *bundle = NULL;

    if(waitpipe)
      /* There is a connection that *might* become usable for pipelining
         "soon", and we wait for that */
      connections_available = FALSE;
    else
      bundle = Curl_conncache_find_bundle(conn, data->state.conn_cache);

    if(max_host_connections > 0 && bundle &&
       (bundle->num_connections >= max_host_connections)) {
      struct connectdata *conn_candidate;

      /* The bundle is full. Let's see if we can kill a connection. */
      conn_candidate = find_oldest_idle_connection_in_bundle(data, bundle);

      if(conn_candidate) {
        /* Set the connection's owner correctly, then kill it */
        conn_candidate->data = data;
        (void)Curl_disconnect(conn_candidate, /* dead_connection */ FALSE);
      }
      else {
        infof(data, "No more connections allowed to host: %d\n",
              max_host_connections);
        connections_available = FALSE;
      }
    }

    if(connections_available &&
       (max_total_connections > 0) &&
       (data->state.conn_cache->num_connections >= max_total_connections)) {
      struct connectdata *conn_candidate;

      /* The cache is full. Let's see if we can kill a connection. */
      conn_candidate = find_oldest_idle_connection(data);

      if(conn_candidate) {
        /* Set the connection's owner correctly, then kill it */
        conn_candidate->data = data;
        (void)Curl_disconnect(conn_candidate, /* dead_connection */ FALSE);
      }
      else {
        infof(data, "No connections available in cache\n");
        connections_available = FALSE;
      }
    }

    if(!connections_available) {
      infof(data, "No connections available.\n");

      conn_free(conn);
      *in_connect = NULL;

      result = CURLE_NO_CONNECTION_AVAILABLE;
      goto out;
    }
    else {
      /*
       * This is a brand new connection, so let's store it in the connection
       * cache of ours!
       */
      Curl_conncache_add_conn(data->state.conn_cache, conn);
    }

#if defined(USE_NTLM)
    /* If NTLM is requested in a part of this connection, make sure we don't
       assume the state is fine as this is a fresh connection and NTLM is
       connection based. */
    if((data->state.authhost.picked & (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
       data->state.authhost.done) {
      infof(data, "NTLM picked AND auth done set, clear picked!\n");
      data->state.authhost.picked = CURLAUTH_NONE;
    }

    if((data->state.authproxy.picked & (CURLAUTH_NTLM | CURLAUTH_NTLM_WB)) &&
       data->state.authproxy.done) {
      infof(data, "NTLM-proxy picked AND auth done set, clear picked!\n");
      data->state.authproxy.picked = CURLAUTH_NONE;
    }
#endif
  }

  /* Mark the connection as used */
  conn->inuse = TRUE;

  /* Setup and init stuff before DO starts, in preparing for the transfer. */
  Curl_init_do(data, conn);

  /*
   * Setup whatever necessary for a resumed transfer
   */
  result = setup_range(data);
  if(result)
    goto out;

  /* Continue connectdata initialization here. */

  /*
   * Inherit the proper values from the urldata struct AFTER we have arranged
   * the persistent connection stuff
   */
  conn->seek_func = data->set.seek_func;
  conn->seek_client = data->set.seek_client;

  /*************************************************************
   * Resolve the address of the server or proxy
   *************************************************************/
  result = resolve_server(data, conn, async);

  out:

  free(options);
  free(passwd);
  free(user);
  free(proxy);
  return result;
}

/* Curl_setup_conn() is called after the name resolve initiated in
 * create_conn() is all done.
 *
 * Curl_setup_conn() also handles reused connections
 *
 * conn->data MUST already have been setup fine (in create_conn)
 */

CURLcode Curl_setup_conn(struct connectdata *conn,
                         bool *protocol_done)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data = conn->data;

  Curl_pgrsTime(data, TIMER_NAMELOOKUP);

  if(conn->handler->flags & PROTOPT_NONETWORK) {
    /* nothing to setup when not using a network */
    *protocol_done = TRUE;
    return result;
  }
  *protocol_done = FALSE; /* default to not done */

  /* set proxy_connect_closed to false unconditionally already here since it
     is used strictly to provide extra information to a parent function in the
     case of proxy CONNECT failures and we must make sure we don't have it
     lingering set from a previous invoke */
  conn->bits.proxy_connect_closed = FALSE;

  /*
   * Set user-agent. Used for HTTP, but since we can attempt to tunnel
   * basically anything through a http proxy we can't limit this based on
   * protocol.
   */
  if(data->set.str[STRING_USERAGENT]) {
    Curl_safefree(conn->allocptr.uagent);
    conn->allocptr.uagent =
      aprintf("User-Agent: %s\r\n", data->set.str[STRING_USERAGENT]);
    if(!conn->allocptr.uagent)
      return CURLE_OUT_OF_MEMORY;
  }

  data->req.headerbytecount = 0;

#ifdef CURL_DO_LINEEND_CONV
  data->state.crlf_conversions = 0; /* reset CRLF conversion counter */
#endif /* CURL_DO_LINEEND_CONV */

  /* 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();

  if(CURL_SOCKET_BAD == conn->sock[FIRSTSOCKET]) {
    conn->bits.tcpconnect[FIRSTSOCKET] = FALSE;
    result = Curl_connecthost(conn, conn->dns_entry);
    if(result)
      return result;
  }
  else {
    Curl_pgrsTime(data, TIMER_CONNECT);    /* we're connected already */
    Curl_pgrsTime(data, TIMER_APPCONNECT); /* we're connected already */
    conn->bits.tcpconnect[FIRSTSOCKET] = TRUE;
    *protocol_done = TRUE;
    Curl_updateconninfo(conn, conn->sock[FIRSTSOCKET]);
    Curl_verboseconnect(conn);
  }

  conn->now = Curl_tvnow(); /* time this *after* the connect is done, we
                               set this here perhaps a second time */

#ifdef __EMX__
  /*
   * This check is quite a hack. We're calling _fsetmode to fix the problem
   * with fwrite converting newline characters (you get mangled text files,
   * and corrupted binary files when you download to stdout and redirect it to
   * a file).
   */

  if((data->set.out)->_handle == NULL) {
    _fsetmode(stdout, "b");
  }
#endif

  return result;
}

CURLcode Curl_connect(struct SessionHandle *data,
                      struct connectdata **in_connect,
                      bool *asyncp,
                      bool *protocol_done)
{
  CURLcode result;

  *asyncp = FALSE; /* assume synchronous resolves by default */

  /* call the stuff that needs to be called */
  result = create_conn(data, in_connect, asyncp);

  if(!result) {
    /* no error */
    if((*in_connect)->send_pipe->size || (*in_connect)->recv_pipe->size)
      /* pipelining */
      *protocol_done = TRUE;
    else if(!*asyncp) {
      /* DNS resolution is done: that's either because this is a reused
         connection, in which case DNS was unnecessary, or because DNS
         really did finish already (synch resolver/fast async resolve) */
      result = Curl_setup_conn(*in_connect, protocol_done);
    }
  }

  if(result == CURLE_NO_CONNECTION_AVAILABLE) {
    *in_connect = NULL;