ftp.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2009, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at http://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * $Id$
 ***************************************************************************/

#include "setup.h"

#ifndef CURL_DISABLE_FTP
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <ctype.h>

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_UTSNAME_H
#include <sys/utsname.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef  VMS
#include <in.h>
#include <inet.h>
#endif

#if (defined(NETWARE) && defined(__NOVELL_LIBC__))
#undef in_addr_t
#define in_addr_t unsigned long
#endif

#include <curl/curl.h>
#include "urldata.h"
#include "sendf.h"
#include "easyif.h" /* for Curl_convert_... prototypes */

#include "if2ip.h"
#include "hostip.h"
#include "progress.h"
#include "transfer.h"
#include "escape.h"
#include "http.h" /* for HTTP proxy tunnel stuff */
#include "socks.h"
#include "ftp.h"

#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
#include "krb4.h"
#endif

#include "strtoofft.h"
#include "strequal.h"
#include "sslgen.h"
#include "connect.h"
#include "strerror.h"
#include "inet_ntop.h"
#include "inet_pton.h"
#include "select.h"
#include "parsedate.h" /* for the week day and month names */
#include "sockaddr.h" /* required for Curl_sockaddr_storage */
#include "multiif.h"
#include "url.h"
#include "rawstr.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

#include "memory.h"
/* The last #include file should be: */
#include "memdebug.h"

#ifdef HAVE_NI_WITHSCOPEID
#define NIFLAGS NI_NUMERICHOST | NI_NUMERICSERV | NI_WITHSCOPEID
#else
#define NIFLAGS NI_NUMERICHOST | NI_NUMERICSERV
#endif

#ifdef __SYMBIAN32__
/* Symbian OS panics when given a timeout much greater than 1/2 hour */
#define RESP_TIMEOUT (1800*1000)
#else
/* Default response timeout in milliseconds */
#define RESP_TIMEOUT (3600*1000)
#endif

#ifdef CURL_DISABLE_VERBOSE_STRINGS
#define ftp_pasv_verbose(a,b,c,d)  do { } while(0)
#endif

/* Local API functions */
static CURLcode ftp_sendquote(struct connectdata *conn,
                              struct curl_slist *quote);
static CURLcode ftp_quit(struct connectdata *conn);
static CURLcode ftp_parse_url_path(struct connectdata *conn);
static CURLcode ftp_regular_transfer(struct connectdata *conn, bool *done);
#ifndef CURL_DISABLE_VERBOSE_STRINGS
static void ftp_pasv_verbose(struct connectdata *conn,
                             Curl_addrinfo *ai,
                             char *newhost, /* ascii version */
                             int port);
#endif
static CURLcode ftp_state_post_rest(struct connectdata *conn);
static CURLcode ftp_state_post_cwd(struct connectdata *conn);
static CURLcode ftp_state_quote(struct connectdata *conn,
                                bool init, ftpstate instate);
static CURLcode ftp_nb_type(struct connectdata *conn,
                            bool ascii, ftpstate newstate);
static int ftp_need_type(struct connectdata *conn,
                         bool ascii);
static CURLcode ftp_do(struct connectdata *conn, bool *done);
static CURLcode ftp_done(struct connectdata *conn,
                              CURLcode, bool premature);
static CURLcode ftp_connect(struct connectdata *conn, bool *done);
static CURLcode ftp_disconnect(struct connectdata *conn);
static CURLcode ftp_nextconnect(struct connectdata *conn);
static CURLcode ftp_multi_statemach(struct connectdata *conn, bool *done);
static int ftp_getsock(struct connectdata *conn,
                            curl_socket_t *socks,
                            int numsocks);
static CURLcode ftp_doing(struct connectdata *conn,
                               bool *dophase_done);
static CURLcode ftp_setup_connection(struct connectdata * conn);

/* easy-to-use macro: */
#define FTPSENDF(x,y,z)    if((result = Curl_ftpsendf(x,y,z)) != CURLE_OK) \
                              return result
#define NBFTPSENDF(x,y,z)  if((result = Curl_nbftpsendf(x,y,z)) != CURLE_OK) \
                              return result


/*
 * FTP protocol handler.
 */

const struct Curl_handler Curl_handler_ftp = {
  "FTP",                                /* scheme */
  ftp_setup_connection,            /* setup_connection */
  ftp_do,                          /* do_it */
  ftp_done,                        /* done */
  ftp_nextconnect,                 /* do_more */
  ftp_connect,                     /* connect_it */
  ftp_multi_statemach,             /* connecting */
  ftp_doing,                       /* doing */
  ftp_getsock,                     /* proto_getsock */
  ftp_getsock,                     /* doing_getsock */
  ZERO_NULL,                       /* perform_getsock */
  ftp_disconnect,                  /* disconnect */
  PORT_FTP,                        /* defport */
  PROT_FTP                         /* protocol */
};


#ifdef USE_SSL
/*
 * FTPS protocol handler.
 */

const struct Curl_handler Curl_handler_ftps = {
  "FTPS",                               /* scheme */
  ftp_setup_connection,            /* setup_connection */
  ftp_do,                          /* do_it */
  ftp_done,                        /* done */
  ftp_nextconnect,                 /* do_more */
  ftp_connect,                     /* connect_it */
  ftp_multi_statemach,             /* connecting */
  ftp_doing,                       /* doing */
  ftp_getsock,                     /* proto_getsock */
  ftp_getsock,                     /* doing_getsock */
  ZERO_NULL,                       /* perform_getsock */
  ftp_disconnect,                  /* disconnect */
  PORT_FTPS,                       /* defport */
  PROT_FTP | PROT_FTPS | PROT_SSL  /* protocol */
};
#endif

#ifndef CURL_DISABLE_HTTP
/*
 * HTTP-proxyed FTP protocol handler.
 */

const struct Curl_handler Curl_handler_ftp_proxy = {
  "FTP",                                /* scheme */
  ZERO_NULL,                            /* setup_connection */
  Curl_http,                            /* do_it */
  Curl_http_done,                       /* done */
  ZERO_NULL,                            /* do_more */
  ZERO_NULL,                            /* connect_it */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  ZERO_NULL,                            /* doing_getsock */
  ZERO_NULL,                            /* perform_getsock */
  ZERO_NULL,                            /* disconnect */
  PORT_FTP,                             /* defport */
  PROT_HTTP                             /* protocol */
};


#ifdef USE_SSL
/*
 * HTTP-proxyed FTPS protocol handler.
 */

const struct Curl_handler Curl_handler_ftps_proxy = {
  "FTPS",                               /* scheme */
  ZERO_NULL,                            /* setup_connection */
  Curl_http,                            /* do_it */
  Curl_http_done,                       /* done */
  ZERO_NULL,                            /* do_more */
  ZERO_NULL,                            /* connect_it */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  ZERO_NULL,                            /* doing_getsock */
  ZERO_NULL,                            /* perform_getsock */
  ZERO_NULL,                            /* disconnect */
  PORT_FTPS,                            /* defport */
  PROT_HTTP                             /* protocol */
};
#endif
#endif


/*
 * NOTE: back in the old days, we added code in the FTP code that made NOBODY
 * requests on files respond with headers passed to the client/stdout that
 * looked like HTTP ones.
 *
 * This approach is not very elegant, it causes confusion and is error-prone.
 * It is subject for removal at the next (or at least a future) soname bump.
 * Until then you can test the effects of the removal by undefining the
 * following define named CURL_FTP_HTTPSTYLE_HEAD.
 */
#define CURL_FTP_HTTPSTYLE_HEAD 1

static void freedirs(struct ftp_conn *ftpc)
{
  int i;
  if(ftpc->dirs) {
    for (i=0; i < ftpc->dirdepth; i++){
      if(ftpc->dirs[i]) {
        free(ftpc->dirs[i]);
        ftpc->dirs[i]=NULL;
      }
    }
    free(ftpc->dirs);
    ftpc->dirs = NULL;
    ftpc->dirdepth = 0;
  }
  if(ftpc->file) {
    free(ftpc->file);
    ftpc->file = NULL;
  }
}

/* Returns non-zero if the given string contains CR (\r) or LF (\n),
   which are not allowed within RFC 959 <string>.
   Note: The input string is in the client's encoding which might
   not be ASCII, so escape sequences \r & \n must be used instead
   of hex values 0x0d & 0x0a.
*/
static bool isBadFtpString(const char *string)
{
  return (bool)((NULL != strchr(string, '\r')) || (NULL != strchr(string, '\n')));
}

/***********************************************************************
 *
 * AllowServerConnect()
 *
 * When we've issue the PORT command, we have told the server to connect
 * to us. This function will sit and wait here until the server has
 * connected.
 *
 */
static CURLcode AllowServerConnect(struct connectdata *conn)
{
  struct SessionHandle *data = conn->data;
  curl_socket_t sock = conn->sock[SECONDARYSOCKET];
  long timeout_ms = Curl_timeleft(conn, NULL, TRUE);

  if(timeout_ms < 0) {
    /* if a timeout was already reached, bail out */
    failf(data, "Timed out before server could connect to us");
    return CURLE_OPERATION_TIMEDOUT;
  }

  switch (Curl_socket_ready(sock, CURL_SOCKET_BAD, (int)timeout_ms)) {
  case -1: /* error */
    /* let's die here */
    failf(data, "Error while waiting for server connect");
    return CURLE_FTP_PORT_FAILED;
  case 0:  /* timeout */
    /* let's die here */
    failf(data, "Timeout while waiting for server connect");
    return CURLE_FTP_PORT_FAILED;
  default:
    /* we have received data here */
    {
      curl_socket_t s = CURL_SOCKET_BAD;
#ifdef ENABLE_IPV6
      struct Curl_sockaddr_storage add;
#else
      struct sockaddr_in add;
#endif
      socklen_t size = (socklen_t) sizeof(add);

      if(0 == getsockname(sock, (struct sockaddr *) &add, &size)) {
        size = sizeof(add);

        s=accept(sock, (struct sockaddr *) &add, &size);
      }
      sclose(sock); /* close the first socket */

      if(CURL_SOCKET_BAD == s) {
        /* DIE! */
        failf(data, "Error accept()ing server connect");
        return CURLE_FTP_PORT_FAILED;
      }
      infof(data, "Connection accepted from server\n");

      conn->sock[SECONDARYSOCKET] = s;
      Curl_nonblock(s, TRUE); /* enable non-blocking */
    }
    break;
  }

  return CURLE_OK;
}

/* initialize stuff to prepare for reading a fresh new response */
static void ftp_respinit(struct connectdata *conn)
{
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  ftpc->nread_resp = 0;
  ftpc->linestart_resp = conn->data->state.buffer;
  ftpc->pending_resp = TRUE;
}

/* macro to check for a three-digit ftp status code at the start of the
   given string */
#define STATUSCODE(line) (ISDIGIT(line[0]) && ISDIGIT(line[1]) && \
                        ISDIGIT(line[2]))

/* macro to check for the last line in an FTP server response */
#define LASTLINE(line) (STATUSCODE(line) && (' ' == line[3]))

static CURLcode ftp_readresp(curl_socket_t sockfd,
                             struct connectdata *conn,
                             int *ftpcode, /* return the ftp-code if done */
                             size_t *size) /* size of the response */
{
  ssize_t perline; /* count bytes per line */
  bool keepon=TRUE;
  ssize_t gotbytes;
  char *ptr;
  struct SessionHandle *data = conn->data;
  char * const buf = data->state.buffer;
  CURLcode result = CURLE_OK;
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  int code = 0;

  *ftpcode = 0; /* 0 for errors or not done */
  *size = 0;

  ptr=buf + ftpc->nread_resp;

  /* number of bytes in the current line, so far */
  perline = (ssize_t)(ptr-ftpc->linestart_resp);

  keepon=TRUE;

  while((ftpc->nread_resp<BUFSIZE) && (keepon && !result)) {

    if(ftpc->cache) {
      /* we had data in the "cache", copy that instead of doing an actual
       * read
       *
       * ftp->cache_size is cast to int here.  This should be safe,
       * because it would have been populated with something of size
       * int to begin with, even though its datatype may be larger
       * than an int.
       */
      DEBUGASSERT((ptr+ftpc->cache_size) <= (buf+BUFSIZE+1));
      memcpy(ptr, ftpc->cache, (int)ftpc->cache_size);
      gotbytes = (int)ftpc->cache_size;
      free(ftpc->cache);    /* free the cache */
      ftpc->cache = NULL;   /* clear the pointer */
      ftpc->cache_size = 0; /* zero the size just in case */
    }
    else {
      int res;
#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
      enum protection_level prot = conn->data_prot;

      conn->data_prot = 0;
#endif
      DEBUGASSERT((ptr+BUFSIZE-ftpc->nread_resp) <= (buf+BUFSIZE+1));
      res = Curl_read(conn, sockfd, ptr, BUFSIZE-ftpc->nread_resp,
                      &gotbytes);
#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
      conn->data_prot = prot;
#endif
      if(res < 0)
        /* EWOULDBLOCK */
        return CURLE_OK; /* return */

#ifdef CURL_DOES_CONVERSIONS
      if((res == CURLE_OK) && (gotbytes > 0)) {
        /* convert from the network encoding */
        result = res = Curl_convert_from_network(data, ptr, gotbytes);
        /* Curl_convert_from_network calls failf if unsuccessful */
      }
#endif /* CURL_DOES_CONVERSIONS */

      if(CURLE_OK != res)
        keepon = FALSE;
    }

    if(!keepon)
      ;
    else if(gotbytes <= 0) {
      keepon = FALSE;
      result = CURLE_RECV_ERROR;
      failf(data, "FTP response reading failed");
    }
    else {
      /* we got a whole chunk of data, which can be anything from one
       * byte to a set of lines and possible just a piece of the last
       * line */
      ssize_t i;
      ssize_t clipamount = 0;
      bool restart = FALSE;

      data->req.headerbytecount += gotbytes;

      ftpc->nread_resp += gotbytes;
      for(i = 0; i < gotbytes; ptr++, i++) {
        perline++;
        if(*ptr=='\n') {
          /* a newline is CRLF in ftp-talk, so the CR is ignored as
             the line isn't really terminated until the LF comes */

          /* output debug output if that is requested */
#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
          if(!conn->sec_complete)
#endif
          if(data->set.verbose)
            Curl_debug(data, CURLINFO_HEADER_IN,
                       ftpc->linestart_resp, (size_t)perline, conn);

          /*
           * We pass all response-lines to the callback function registered
           * for "headers". The response lines can be seen as a kind of
           * headers.
           */
          result = Curl_client_write(conn, CLIENTWRITE_HEADER,
                                     ftpc->linestart_resp, perline);
          if(result)
            return result;

          if(perline>3 && LASTLINE(ftpc->linestart_resp)) {
            /* This is the end of the last line, copy the last line to the
               start of the buffer and zero terminate, for old times sake (and
               krb4)! */
            char *meow;
            int n;
            for(meow=ftpc->linestart_resp, n=0; meow<ptr; meow++, n++)
              buf[n] = *meow;
            *meow=0; /* zero terminate */
            keepon=FALSE;
            ftpc->linestart_resp = ptr+1; /* advance pointer */
            i++; /* skip this before getting out */

            *size = ftpc->nread_resp; /* size of the response */
            ftpc->nread_resp = 0; /* restart */
            break;
          }
          perline=0; /* line starts over here */
          ftpc->linestart_resp = ptr+1;
        }
      }

      if(!keepon && (i != gotbytes)) {
        /* We found the end of the response lines, but we didn't parse the
           full chunk of data we have read from the server. We therefore need
           to store the rest of the data to be checked on the next invoke as
           it may actually contain another end of response already! */
        clipamount = gotbytes - i;
        restart = TRUE;
      }
      else if(keepon) {

        if((perline == gotbytes) && (gotbytes > BUFSIZE/2)) {
          /* We got an excessive line without newlines and we need to deal
             with it. First, check if it seems to start with a valid status
             code and then we keep just that in the line cache. Then throw
             away the rest. */
          infof(data, "Excessive FTP response line length received, %zd bytes."
                " Stripping\n", gotbytes);
          restart = TRUE;
          if(STATUSCODE(ftpc->linestart_resp))
            /* we copy 4 bytes since after the three-digit number there is a
               dash or a space and it is significant */
            clipamount = 4;
        }
        else if(ftpc->nread_resp > BUFSIZE/2) {
          /* We got a large chunk of data and there's potentially still trailing
             data to take care of, so we put any such part in the "cache", clear
             the buffer to make space and restart. */
          clipamount = perline;
          restart = TRUE;
        }
      }
      else if(i == gotbytes)
        restart = TRUE;

      if(clipamount) {
        ftpc->cache_size = clipamount;
        ftpc->cache = malloc((int)ftpc->cache_size);
        if(ftpc->cache)
          memcpy(ftpc->cache, ftpc->linestart_resp, (int)ftpc->cache_size);
        else
          return CURLE_OUT_OF_MEMORY;
      }
      if(restart) {
        /* now reset a few variables to start over nicely from the start of
           the big buffer */
        ftpc->nread_resp = 0; /* start over from scratch in the buffer */
        ptr = ftpc->linestart_resp = buf;
        perline = 0;
      }

    } /* there was data */

  } /* while there's buffer left and loop is requested */

  if(!result)
    code = atoi(buf);

#if defined(HAVE_KRB4) || defined(HAVE_GSSAPI)
  /* handle the security-oriented responses 6xx ***/
  /* FIXME: some errorchecking perhaps... ***/
  switch(code) {
  case 631:
    code = Curl_sec_read_msg(conn, buf, prot_safe);
    break;
  case 632:
    code = Curl_sec_read_msg(conn, buf, prot_private);
    break;
  case 633:
    code = Curl_sec_read_msg(conn, buf, prot_confidential);
    break;
  default:
    /* normal ftp stuff we pass through! */
    break;
  }
#endif

  *ftpcode=code; /* return the initial number like this */

  /* store the latest code for later retrieval */
  conn->data->info.httpcode=code;

  ftpc->pending_resp = FALSE;

  return result;
}

/* --- parse FTP server responses --- */

/*
 * Curl_GetFTPResponse() is a BLOCKING function to read the full response
 * from a server after a command.
 *
 */

CURLcode Curl_GetFTPResponse(ssize_t *nreadp, /* return number of bytes read */
                             struct connectdata *conn,
                             int *ftpcode) /* return the ftp-code */
{
  /*
   * We cannot read just one byte per read() and then go back to select() as
   * the OpenSSL read() doesn't grok that properly.
   *
   * Alas, read as much as possible, split up into lines, use the ending
   * line in a response or continue reading.  */

  curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
  long timeout;              /* timeout in milliseconds */
  long interval_ms;
  struct SessionHandle *data = conn->data;
  CURLcode result = CURLE_OK;
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  struct timeval now = Curl_tvnow();
  size_t nread;
  int cache_skip=0;
  int value_to_be_ignored=0;

  if(ftpcode)
    *ftpcode = 0; /* 0 for errors */
  else
    /* make the pointer point to something for the rest of this function */
    ftpcode = &value_to_be_ignored;

  *nreadp=0;

  while(!*ftpcode && !result) {
    /* check and reset timeout value every lap */
    if(data->set.ftp_response_timeout )
      /* if CURLOPT_FTP_RESPONSE_TIMEOUT is set, use that to determine
         remaining time.  Also, use "now" as opposed to "conn->now"
         because ftp_response_timeout is only supposed to govern
         the response for any given ftp response, not for the time
         from connect to the given ftp response. */
      timeout = data->set.ftp_response_timeout - /* timeout time */
        Curl_tvdiff(Curl_tvnow(), now); /* spent time */
    else if(data->set.timeout)
      /* if timeout is requested, find out how much remaining time we have */
      timeout = data->set.timeout - /* timeout time */
        Curl_tvdiff(Curl_tvnow(), conn->now); /* spent time */
    else
      /* Even without a requested timeout, we only wait response_time
         seconds for the full response to arrive before we bail out */
      timeout = ftpc->response_time -
        Curl_tvdiff(Curl_tvnow(), now); /* spent time */

    if(timeout <=0 ) {
      failf(data, "FTP response timeout");
      return CURLE_OPERATION_TIMEDOUT; /* already too little time */
    }

    interval_ms = 1 * 1000;  /* use 1 second timeout intervals */
    if(timeout < interval_ms)
      interval_ms = timeout;

    /*
     * Since this function is blocking, we need to wait here for input on the
     * connection and only then we call the response reading function. We do
     * timeout at least every second to make the timeout check run.
     *
     * A caution here is that the ftp_readresp() function has a cache that may
     * contain pieces of a response from the previous invoke and we need to
     * make sure we don't just wait for input while there is unhandled data in
     * that cache. But also, if the cache is there, we call ftp_readresp() and
     * the cache wasn't good enough to continue we must not just busy-loop
     * around this function.
     *
     */

    if(ftpc->cache && (cache_skip < 2)) {
      /*
       * There's a cache left since before. We then skipping the wait for
       * socket action, unless this is the same cache like the previous round
       * as then the cache was deemed not enough to act on and we then need to
       * wait for more data anyway.
       */
    }
    else {
      switch (Curl_socket_ready(sockfd, CURL_SOCKET_BAD, (int)interval_ms)) {
      case -1: /* select() error, stop reading */
        failf(data, "FTP response aborted due to select/poll error: %d",
              SOCKERRNO);
        return CURLE_RECV_ERROR;

      case 0: /* timeout */
        if(Curl_pgrsUpdate(conn))
          return CURLE_ABORTED_BY_CALLBACK;
        continue; /* just continue in our loop for the timeout duration */

      default: /* for clarity */
        break;
      }
    }
    result = ftp_readresp(sockfd, conn, ftpcode, &nread);
    if(result)
      break;

    if(!nread && ftpc->cache)
      /* bump cache skip counter as on repeated skips we must wait for more
         data */
      cache_skip++;
    else
      /* when we got data or there is no cache left, we reset the cache skip
         counter */
      cache_skip=0;

    *nreadp += nread;

  } /* while there's buffer left and loop is requested */

  ftpc->pending_resp = FALSE;

  return result;
}

/* This is the ONLY way to change FTP state! */
static void state(struct connectdata *conn,
                  ftpstate newstate)
{
#if defined(CURLDEBUG) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
  /* for debug purposes */
  static const char * const names[]={
    "STOP",
    "WAIT220",
    "AUTH",
    "USER",
    "PASS",
    "ACCT",
    "PBSZ",
    "PROT",
    "CCC",
    "PWD",
    "QUOTE",
    "RETR_PREQUOTE",
    "STOR_PREQUOTE",
    "POSTQUOTE",
    "CWD",
    "MKD",
    "MDTM",
    "TYPE",
    "LIST_TYPE",
    "RETR_TYPE",
    "STOR_TYPE",
    "SIZE",
    "RETR_SIZE",
    "STOR_SIZE",
    "REST",
    "RETR_REST",
    "PORT",
    "PASV",
    "LIST",
    "RETR",
    "STOR",
    "QUIT"
  };
#endif
  struct ftp_conn *ftpc = &conn->proto.ftpc;
#if defined(CURLDEBUG) && !defined(CURL_DISABLE_VERBOSE_STRINGS)
  if(ftpc->state != newstate)
    infof(conn->data, "FTP %p state change from %s to %s\n",
          ftpc, names[ftpc->state], names[newstate]);
#endif
  ftpc->state = newstate;
}

static CURLcode ftp_state_user(struct connectdata *conn)
{
  CURLcode result;
  struct FTP *ftp = conn->data->state.proto.ftp;
  /* send USER */
  NBFTPSENDF(conn, "USER %s", ftp->user?ftp->user:"");

  state(conn, FTP_USER);
  conn->data->state.ftp_trying_alternative = FALSE;

  return CURLE_OK;
}

static CURLcode ftp_state_pwd(struct connectdata *conn)
{
  CURLcode result;

  /* send PWD to discover our entry point */
  NBFTPSENDF(conn, "PWD", NULL);
  state(conn, FTP_PWD);

  return CURLE_OK;
}

/* For the FTP "protocol connect" and "doing" phases only */
static int ftp_getsock(struct connectdata *conn,
                            curl_socket_t *socks,
                            int numsocks)
{
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if(!numsocks)
    return GETSOCK_BLANK;

  socks[0] = conn->sock[FIRSTSOCKET];

  if(ftpc->sendleft) {
    /* write mode */
    return GETSOCK_WRITESOCK(0);
  }

  /* read mode */
  return GETSOCK_READSOCK(0);
}

/* This is called after the FTP_QUOTE state is passed.

   ftp_state_cwd() sends the range of CWD commands to the server to change to
   the correct directory. It may also need to send MKD commands to create
   missing ones, if that option is enabled.
*/
static CURLcode ftp_state_cwd(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if(ftpc->cwddone)
    /* already done and fine */
    result = ftp_state_post_cwd(conn);
  else {
    ftpc->count2 = 0; /* count2 counts failed CWDs */

    /* count3 is set to allow a MKD to fail once. In the case when first CWD
       fails and then MKD fails (due to another session raced it to create the
       dir) this then allows for a second try to CWD to it */
    ftpc->count3 = (conn->data->set.ftp_create_missing_dirs==2)?1:0;

    if(conn->bits.reuse && ftpc->entrypath) {
      /* This is a re-used connection. Since we change directory to where the
         transfer is taking place, we must first get back to the original dir
         where we ended up after login: */
      ftpc->count1 = 0; /* we count this as the first path, then we add one
                          for all upcoming ones in the ftp->dirs[] array */
      NBFTPSENDF(conn, "CWD %s", ftpc->entrypath);
      state(conn, FTP_CWD);
    }
    else {
      if(ftpc->dirdepth) {
        ftpc->count1 = 1;
        /* issue the first CWD, the rest is sent when the CWD responses are
           received... */
        NBFTPSENDF(conn, "CWD %s", ftpc->dirs[ftpc->count1 -1]);
        state(conn, FTP_CWD);
      }
      else {
        /* No CWD necessary */
        result = ftp_state_post_cwd(conn);
      }
    }
  }
  return result;
}

typedef enum {
  EPRT,
  PORT,
  DONE
} ftpport;

static CURLcode ftp_state_use_port(struct connectdata *conn,
                                   ftpport fcmd) /* start with this */

{
  CURLcode result = CURLE_OK;
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  struct SessionHandle *data=conn->data;
  curl_socket_t portsock= CURL_SOCKET_BAD;
  char myhost[256] = "";

#ifdef ENABLE_IPV6
  /******************************************************************
   * IPv6-specific section
   */
  struct Curl_sockaddr_storage ss;
  Curl_addrinfo *res, *ai;
  socklen_t sslen;
  char hbuf[NI_MAXHOST];
  struct sockaddr *sa=(struct sockaddr *)&ss;
  struct sockaddr_in * const sa4 = (void *)sa;
  struct sockaddr_in6 * const sa6 = (void *)sa;
  char tmp[1024];
  static const char mode[][5] = { "EPRT", "PORT" };
  int rc;
  int error;
  char *host=NULL;
  struct Curl_dns_entry *h=NULL;
  unsigned short port = 0;

  /* Step 1, figure out what address that is requested */

  if(data->set.str[STRING_FTPPORT] &&
     (strlen(data->set.str[STRING_FTPPORT]) > 1)) {
    /* attempt to get the address of the given interface name */
    if(!Curl_if2ip(conn->ip_addr->ai_family, data->set.str[STRING_FTPPORT],
                   hbuf, sizeof(hbuf)))
      /* not an interface, use the given string as host name instead */
      host = data->set.str[STRING_FTPPORT];
    else
      host = hbuf; /* use the hbuf for host name */
  } /* data->set.ftpport */

  if(!host) {
    /* not an interface and not a host name, get default by extracting
       the IP from the control connection */

    sslen = sizeof(ss);
    if(getsockname(conn->sock[FIRSTSOCKET], (struct sockaddr *)&ss, &sslen)) {
      failf(data, "getsockname() failed: %s",
          Curl_strerror(conn, SOCKERRNO) );
      return CURLE_FTP_PORT_FAILED;
    }

    if(sslen > (socklen_t)sizeof(ss))
      sslen = sizeof(ss);
    rc = getnameinfo((struct sockaddr *)&ss, sslen, hbuf, sizeof(hbuf), NULL,
                     0, NIFLAGS);
    if(rc) {
      failf(data, "getnameinfo() returned %d", rc);
      return CURLE_FTP_PORT_FAILED;
    }
    host = hbuf; /* use this host name */
  }

  rc = Curl_resolv(conn, host, 0, &h);
  if(rc == CURLRESOLV_PENDING)
    rc = Curl_wait_for_resolv(conn, &h);
  if(h) {
    res = h->addr;
    /* when we return from this function, we can forget about this entry
       to we can unlock it now already */
    Curl_resolv_unlock(data, h);
  } /* (h) */
  else
    res = NULL; /* failure! */


  /* step 2, create a socket for the requested address */

  portsock = CURL_SOCKET_BAD;
  error = 0;
  for (ai = res; ai; ai = ai->ai_next) {
    /*
     * Workaround for AIX5 getaddrinfo() problem (it doesn't set ai_socktype):
     */
    if(ai->ai_socktype == 0)
      ai->ai_socktype = conn->socktype;

    portsock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
    if(portsock == CURL_SOCKET_BAD) {
      error = SOCKERRNO;
      continue;
    }
    break;
  }
  if(!ai) {
    failf(data, "socket failure: %s", Curl_strerror(conn, error));
    return CURLE_FTP_PORT_FAILED;
  }

  /* step 3, bind to a suitable local address */

  /* Try binding the given address. */
  if(bind(portsock, ai->ai_addr, ai->ai_addrlen)) {

    /* It failed. Bind the address used for the control connection instead */
    sslen = sizeof(ss);
    if(getsockname(conn->sock[FIRSTSOCKET], sa, &sslen)) {
      failf(data, "getsockname() failed: %s",
          Curl_strerror(conn, SOCKERRNO) );
      sclose(portsock);
      return CURLE_FTP_PORT_FAILED;
    }

    /* set port number to zero to make bind() pick "any" */
    if(sa->sa_family == AF_INET)
      sa4->sin_port = 0;
    else
      sa6->sin6_port = 0;

    if(sslen > (socklen_t)sizeof(ss))
      sslen = sizeof(ss);

    if(bind(portsock, sa, sslen)) {
      failf(data, "bind failed: %s", Curl_strerror(conn, SOCKERRNO));
      sclose(portsock);
      return CURLE_FTP_PORT_FAILED;
    }
  }

  /* get the name again after the bind() so that we can extract the
     port number it uses now */
  sslen = sizeof(ss);
  if(getsockname(portsock, (struct sockaddr *)sa, &sslen)) {
    failf(data, "getsockname() failed: %s",
          Curl_strerror(conn, SOCKERRNO) );
    sclose(portsock);
    return CURLE_FTP_PORT_FAILED;
  }

  /* step 4, listen on the socket */

  if(listen(portsock, 1)) {
    failf(data, "socket failure: %s", Curl_strerror(conn, SOCKERRNO));
    sclose(portsock);
    return CURLE_FTP_PORT_FAILED;
  }

  /* step 5, send the proper FTP command */

  /* get a plain printable version of the numerical address to work with
     below */
  Curl_printable_address(ai, myhost, sizeof(myhost));

#ifdef PF_INET6
  if(!conn->bits.ftp_use_eprt && conn->bits.ipv6)
    /* EPRT is disabled but we are connected to a IPv6 host, so we ignore the
       request and enable EPRT again! */
    conn->bits.ftp_use_eprt = TRUE;
#endif

  for (; fcmd != DONE; fcmd++) {

    if(!conn->bits.ftp_use_eprt && (EPRT == fcmd))
      /* if disabled, goto next */
      continue;

    switch (sa->sa_family) {
    case AF_INET:
      port = ntohs(sa4->sin_port);
      break;
    case AF_INET6:
      port = ntohs(sa6->sin6_port);
      break;
    default:
      break;
    }

    if(EPRT == fcmd) {
      /*
       * Two fine examples from RFC2428;
       *
       * EPRT |1|132.235.1.2|6275|
       *
       * EPRT |2|1080::8:800:200C:417A|5282|
       */

      result = Curl_nbftpsendf(conn, "%s |%d|%s|%d|", mode[fcmd],
                               ai->ai_family == AF_INET?1:2,
                               myhost, port);
      if(result)
        return result;
      break;
    }
    else if(PORT == fcmd) {
      char *source = myhost;
      char *dest = tmp;

      if((PORT == fcmd) && ai->ai_family != AF_INET)
        continue;

      /* translate x.x.x.x to x,x,x,x */
      while(source && *source) {
        if(*source == '.')
          *dest=',';
        else
          *dest = *source;
        dest++;
        source++;
      }
      *dest = 0;
      snprintf(dest, 20, ",%d,%d", port>>8, port&0xff);

      result = Curl_nbftpsendf(conn, "%s %s", mode[fcmd], tmp);
      if(result)
        return result;
      break;
    }
  }

  /* store which command was sent */
  ftpc->count1 = fcmd;

  /* we set the secondary socket variable to this for now, it is only so that
     the cleanup function will close it in case we fail before the true
     secondary stuff is made */
  if(CURL_SOCKET_BAD != conn->sock[SECONDARYSOCKET])
    sclose(conn->sock[SECONDARYSOCKET]);
  conn->sock[SECONDARYSOCKET] = portsock;

#else
  /******************************************************************
   * IPv4-specific section
   */
  struct sockaddr_in sa;
  unsigned short porttouse;
  bool sa_filled_in = FALSE;
  Curl_addrinfo *addr = NULL;
  unsigned short ip[4];
  bool freeaddr = TRUE;
  socklen_t sslen = sizeof(sa);
  const char *ftpportstr = data->set.str[STRING_FTPPORT];

  (void)fcmd; /* not used in the IPv4 code */
  if(ftpportstr) {
    struct in_addr in;

    /* First check if the given string is an IP address */
    if(Curl_inet_pton(AF_INET, ftpportstr, &in) > 0) {
      /* this is an IPv4 address */
      addr = Curl_ip2addr(AF_INET, &in, ftpportstr, 0);
    }
    /* otherwise check if the given string is an interface */
    else if(Curl_if2ip(AF_INET, ftpportstr, myhost, sizeof(myhost))) {
      /* The interface to IP conversion provided a dotted address */
      if(Curl_inet_pton(AF_INET, myhost, &in) > 0)
        addr = Curl_ip2addr(AF_INET, &in, myhost, 0);
    }
    else if(strlen(ftpportstr)> 1) {
      /* might be a host name! */
      struct Curl_dns_entry *h=NULL;
      int rc = Curl_resolv(conn, ftpportstr, 0, &h);
      if(rc == CURLRESOLV_PENDING)
        /* BLOCKING */
        rc = Curl_wait_for_resolv(conn, &h);
      if(h) {
        addr = h->addr;
        /* when we return from this function, we can forget about this entry
           so we can unlock it now already */
        Curl_resolv_unlock(data, h);

        freeaddr = FALSE; /* make sure we don't free 'addr' in this function
                             since it points to a DNS cache entry! */
      } /* (h) */
      else {
        infof(data, "Failed to resolve host name %s\n", ftpportstr);
      }
    } /* strlen */
  } /* ftpportstr */

  if(!addr) {
    /* pick a suitable default here */

    if(getsockname(conn->sock[FIRSTSOCKET],
                    (struct sockaddr *)&sa, &sslen)) {
      failf(data, "getsockname() failed: %s",
          Curl_strerror(conn, SOCKERRNO) );
      return CURLE_FTP_PORT_FAILED;
    }
    if(sslen > (socklen_t)sizeof(sa))
      sslen = sizeof(sa);

    sa_filled_in = TRUE; /* the sa struct is filled in */
  }

  if(addr || sa_filled_in) {
    portsock = socket(AF_INET, SOCK_STREAM, 0);
    if(CURL_SOCKET_BAD != portsock) {

      /* we set the secondary socket variable to this for now, it
         is only so that the cleanup function will close it in case
         we fail before the true secondary stuff is made */
      if(CURL_SOCKET_BAD != conn->sock[SECONDARYSOCKET])
        sclose(conn->sock[SECONDARYSOCKET]);
      conn->sock[SECONDARYSOCKET] = portsock;

      if(!sa_filled_in) {
        memcpy(&sa, addr->ai_addr, sslen);
        sa.sin_addr.s_addr = INADDR_ANY;
      }

      sa.sin_port = 0;
      sslen = sizeof(sa);

      if(bind(portsock, (struct sockaddr *)&sa, sslen) == 0) {
        /* we succeeded to bind */
        struct sockaddr_in add;
        socklen_t socksize = sizeof(add);

        if(getsockname(portsock, (struct sockaddr *) &add,
                       &socksize)) {
          failf(data, "getsockname() failed: %s",
            Curl_strerror(conn, SOCKERRNO) );
          return CURLE_FTP_PORT_FAILED;
        }
        porttouse = ntohs(add.sin_port);

        if( listen(portsock, 1) < 0 ) {
          failf(data, "listen(2) failed on socket");
          return CURLE_FTP_PORT_FAILED;
        }
      }
      else {
        failf(data, "bind(2) failed on socket");
        return CURLE_FTP_PORT_FAILED;
      }
    }
    else {
      failf(data, "socket(2) failed (%s)");
      return CURLE_FTP_PORT_FAILED;
    }
  }
  else {
    failf(data, "couldn't find IP address to use");
    return CURLE_FTP_PORT_FAILED;
  }

  if(sa_filled_in)
    Curl_inet_ntop(AF_INET, &((struct sockaddr_in *)&sa)->sin_addr,
                   myhost, sizeof(myhost));
  else
    Curl_printable_address(addr, myhost, sizeof(myhost));

  if(4 == sscanf(myhost, "%hu.%hu.%hu.%hu",
                 &ip[0], &ip[1], &ip[2], &ip[3])) {

    infof(data, "Telling server to connect to %d.%d.%d.%d:%d\n",
          ip[0], ip[1], ip[2], ip[3], porttouse);

    result=Curl_nbftpsendf(conn, "PORT %d,%d,%d,%d,%d,%d",
                           ip[0], ip[1], ip[2], ip[3],
                           porttouse >> 8, porttouse & 255);
    if(result)
      return result;
  }
  else
    return CURLE_FTP_PORT_FAILED;

  if(freeaddr)
    Curl_freeaddrinfo(addr);

  ftpc->count1 = PORT;

#endif /* end of ipv4-specific code */

  /* this tcpconnect assignment below is a hackish work-around to make the
     multi interface with active FTP work - as it will not wait for a
     (passive) connect in Curl_is_connected().

     The *proper* fix is to make sure that the active connection from the
     server is done in a non-blocking way. Currently, it is still BLOCKING.
  */
  conn->bits.tcpconnect = TRUE;

  state(conn, FTP_PORT);
  return result;
}

static CURLcode ftp_state_use_pasv(struct connectdata *conn)
{
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  CURLcode result = CURLE_OK;
  /*
    Here's the excecutive summary on what to do:

    PASV is RFC959, expect:
    227 Entering Passive Mode (a1,a2,a3,a4,p1,p2)

    LPSV is RFC1639, expect:
    228 Entering Long Passive Mode (4,4,a1,a2,a3,a4,2,p1,p2)

    EPSV is RFC2428, expect:
    229 Entering Extended Passive Mode (|||port|)

  */

  static const char mode[][5] = { "EPSV", "PASV" };
  int modeoff;

#ifdef PF_INET6
  if(!conn->bits.ftp_use_epsv && conn->bits.ipv6)
    /* EPSV is disabled but we are connected to a IPv6 host, so we ignore the
       request and enable EPSV again! */
    conn->bits.ftp_use_epsv = TRUE;
#endif

  modeoff = conn->bits.ftp_use_epsv?0:1;

  result = Curl_nbftpsendf(conn, "%s", mode[modeoff]);
  if(result)
    return result;

  ftpc->count1 = modeoff;
  state(conn, FTP_PASV);
  infof(conn->data, "Connect data stream passively\n");

  return result;
}

/* REST is the last command in the chain of commands when a "head"-like
   request is made. Thus, if an actual transfer is to be made this is where
   we take off for real. */
static CURLcode ftp_state_post_rest(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct FTP *ftp = conn->data->state.proto.ftp;
  struct SessionHandle *data = conn->data;

  if(ftp->transfer != FTPTRANSFER_BODY) {
    /* doesn't transfer any data */

    /* still possibly do PRE QUOTE jobs */
    state(conn, FTP_RETR_PREQUOTE);
    result = ftp_state_quote(conn, TRUE, FTP_RETR_PREQUOTE);
  }
  else if(data->set.ftp_use_port) {
    /* We have chosen to use the PORT (or similar) command */
    result = ftp_state_use_port(conn, EPRT);
  }
  else {
    /* We have chosen (this is default) to use the PASV (or similar) command */
    result = ftp_state_use_pasv(conn);
  }
  return result;
}

static CURLcode ftp_state_post_size(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct FTP *ftp = conn->data->state.proto.ftp;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if((ftp->transfer != FTPTRANSFER_BODY) && ftpc->file) {
    /* if a "head"-like request is being made (on a file) */

    /* Determine if server can respond to REST command and therefore
       whether it supports range */
    NBFTPSENDF(conn, "REST %d", 0);

    state(conn, FTP_REST);
  }
  else
    result = ftp_state_post_rest(conn);

  return result;
}

static CURLcode ftp_state_post_type(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct FTP *ftp = conn->data->state.proto.ftp;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if((ftp->transfer == FTPTRANSFER_INFO) && ftpc->file) {
    /* if a "head"-like request is being made (on a file) */

    /* we know ftpc->file is a valid pointer to a file name */
    NBFTPSENDF(conn, "SIZE %s", ftpc->file);

    state(conn, FTP_SIZE);
  }
  else
    result = ftp_state_post_size(conn);

  return result;
}

static CURLcode ftp_state_post_listtype(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data = conn->data;

  /* If this output is to be machine-parsed, the NLST command might be better
     to use, since the LIST command output is not specified or standard in any
     way. It has turned out that the NLST list output is not the same on all
     servers either... */

  /*
     if FTPFILE_NOCWD was specified, we are currently in
     the user's home directory, so we should add the path
     as argument for the LIST / NLST / or custom command.
     Whether the server will support this, is uncertain.

     The other ftp_filemethods will CWD into dir/dir/ first and
     then just do LIST (in that case: nothing to do here)
  */
  char *cmd,*lstArg,*slashPos;

  lstArg = NULL;
  if((data->set.ftp_filemethod == FTPFILE_NOCWD) &&
     data->state.path &&
     data->state.path[0] &&
     strchr(data->state.path,'/')) {

    lstArg = strdup(data->state.path);
    if(!lstArg)
      return CURLE_OUT_OF_MEMORY;

    /* Check if path does not end with /, as then we cut off the file part */
    if(lstArg[strlen(lstArg) - 1] != '/')  {

      /* chop off the file part if format is dir/dir/file */
      slashPos = strrchr(lstArg,'/');
      if(slashPos)
        *(slashPos+1) = '\0';
    }
  }

  cmd = aprintf( "%s%s%s",
                 data->set.str[STRING_CUSTOMREQUEST]?
                 data->set.str[STRING_CUSTOMREQUEST]:
                 (data->set.ftp_list_only?"NLST":"LIST"),
                 lstArg? " ": "",
                 lstArg? lstArg: "" );

  if(!cmd) {
    if(lstArg)
      free(lstArg);
    return CURLE_OUT_OF_MEMORY;
  }

  NBFTPSENDF(conn, "%s",cmd);

  if(lstArg)
    free(lstArg);

  free(cmd);

  state(conn, FTP_LIST);

  return result;
}

static CURLcode ftp_state_post_retrtype(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;

  /* We've sent the TYPE, now we must send the list of prequote strings */

  result = ftp_state_quote(conn, TRUE, FTP_RETR_PREQUOTE);

  return result;
}

static CURLcode ftp_state_post_stortype(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;

  /* We've sent the TYPE, now we must send the list of prequote strings */

  result = ftp_state_quote(conn, TRUE, FTP_STOR_PREQUOTE);

  return result;
}

static CURLcode ftp_state_post_mdtm(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct FTP *ftp = conn->data->state.proto.ftp;
  struct SessionHandle *data = conn->data;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  /* If we have selected NOBODY and HEADER, it means that we only want file
     information. Which in FTP can't be much more than the file size and
     date. */
  if(data->set.opt_no_body && ftpc->file &&
     ftp_need_type(conn, data->set.prefer_ascii)) {
    /* The SIZE command is _not_ RFC 959 specified, and therefor many servers
       may not support it! It is however the only way we have to get a file's
       size! */

    ftp->transfer = FTPTRANSFER_INFO;
    /* this means no actual transfer will be made */

    /* Some servers return different sizes for different modes, and thus we
       must set the proper type before we check the size */
    result = ftp_nb_type(conn, data->set.prefer_ascii, FTP_TYPE);
    if(result)
      return result;
  }
  else
    result = ftp_state_post_type(conn);

  return result;
}

/* This is called after the CWD commands have been done in the beginning of
   the DO phase */
static CURLcode ftp_state_post_cwd(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data = conn->data;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  /* Requested time of file or time-depended transfer? */
  if((data->set.get_filetime || data->set.timecondition) && ftpc->file) {

    /* we have requested to get the modified-time of the file, this is a white
       spot as the MDTM is not mentioned in RFC959 */
    NBFTPSENDF(conn, "MDTM %s", ftpc->file);

    state(conn, FTP_MDTM);
  }
  else
    result = ftp_state_post_mdtm(conn);

  return result;
}


/* This is called after the TYPE and possible quote commands have been sent */
static CURLcode ftp_state_ul_setup(struct connectdata *conn,
                                   bool sizechecked)
{
  CURLcode result = CURLE_OK;
  struct FTP *ftp = conn->data->state.proto.ftp;
  struct SessionHandle *data = conn->data;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if((data->state.resume_from && !sizechecked) ||
     ((data->state.resume_from > 0) && sizechecked)) {
    /* we're about to continue the uploading of a file */
    /* 1. get already existing file's size. We use the SIZE command for this
       which may not exist in the server!  The SIZE command is not in
       RFC959. */

    /* 2. This used to set REST. But since we can do append, we
       don't another ftp command. We just skip the source file
       offset and then we APPEND the rest on the file instead */

    /* 3. pass file-size number of bytes in the source file */
    /* 4. lower the infilesize counter */
    /* => transfer as usual */

    if(data->state.resume_from < 0 ) {
      /* Got no given size to start from, figure it out */
      NBFTPSENDF(conn, "SIZE %s", ftpc->file);
      state(conn, FTP_STOR_SIZE);
      return result;
    }

    /* enable append */
    data->set.ftp_append = TRUE;

    /* Let's read off the proper amount of bytes from the input. */
    if(conn->seek_func) {
      curl_off_t readthisamountnow = data->state.resume_from;

      if(conn->seek_func(conn->seek_client,
                         readthisamountnow, SEEK_SET) != 0) {
        failf(data, "Could not seek stream");
        return CURLE_FTP_COULDNT_USE_REST;
      }
    }

    else {
      curl_off_t passed=0;
      do {
        curl_off_t readthisamountnow = (data->state.resume_from - passed);
        curl_off_t actuallyread;

        if(readthisamountnow > BUFSIZE)
          readthisamountnow = BUFSIZE;

        actuallyread = (curl_off_t)
          conn->fread_func(data->state.buffer, 1, (size_t)readthisamountnow,
                      conn->fread_in);

        passed += actuallyread;
        if((actuallyread <= 0) || (actuallyread > readthisamountnow)) {
          /* this checks for greater-than only to make sure that the
             CURL_READFUNC_ABORT return code still aborts */
          failf(data, "Failed to read data");
          return CURLE_FTP_COULDNT_USE_REST;
        }
      } while(passed < data->state.resume_from);
    }

    /* now, decrease the size of the read */
    if(data->set.infilesize>0) {
      data->set.infilesize -= data->state.resume_from;

      if(data->set.infilesize <= 0) {
        infof(data, "File already completely uploaded\n");

        /* no data to transfer */
        result=Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);

        /* Set ->transfer so that we won't get any error in
         * ftp_done() because we didn't transfer anything! */
        ftp->transfer = FTPTRANSFER_NONE;

        state(conn, FTP_STOP);
        return CURLE_OK;
      }
    }
    /* we've passed, proceed as normal */
  } /* resume_from */

  NBFTPSENDF(conn, data->set.ftp_append?"APPE %s":"STOR %s",
             ftpc->file);

  state(conn, FTP_STOR);

  return result;
}

static CURLcode ftp_state_quote(struct connectdata *conn,
                                bool init,
                                ftpstate instate)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data = conn->data;
  struct FTP *ftp = data->state.proto.ftp;
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  bool quote=FALSE;
  struct curl_slist *item;

  switch(instate) {
  case FTP_QUOTE:
  default:
    item = data->set.quote;
    break;
  case FTP_RETR_PREQUOTE:
  case FTP_STOR_PREQUOTE:
    item = data->set.prequote;
    break;
  case FTP_POSTQUOTE:
    item = data->set.postquote;
    break;
  }

  if(init)
    ftpc->count1 = 0;
  else
    ftpc->count1++;

  if(item) {
    int i = 0;

    /* Skip count1 items in the linked list */
    while((i< ftpc->count1) && item) {
      item = item->next;
      i++;
    }
    if(item) {
      NBFTPSENDF(conn, "%s", item->data);
      state(conn, instate);
      quote = TRUE;
    }
  }

  if(!quote) {
    /* No more quote to send, continue to ... */
    switch(instate) {
    case FTP_QUOTE:
    default:
      result = ftp_state_cwd(conn);
      break;
    case FTP_RETR_PREQUOTE:
      if(ftp->transfer != FTPTRANSFER_BODY)
        state(conn, FTP_STOP);
      else {
        NBFTPSENDF(conn, "SIZE %s", ftpc->file);
        state(conn, FTP_RETR_SIZE);
      }
      break;
    case FTP_STOR_PREQUOTE:
      result = ftp_state_ul_setup(conn, FALSE);
      break;
    case FTP_POSTQUOTE:
      break;
    }
  }

  return result;
}

static CURLcode ftp_state_pasv_resp(struct connectdata *conn,
                                    int ftpcode)
{
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  CURLcode result;
  struct SessionHandle *data=conn->data;
  Curl_addrinfo *conninfo;
  struct Curl_dns_entry *addr=NULL;
  int rc;
  unsigned short connectport; /* the local port connect() should use! */
  unsigned short newport=0; /* remote port */
  bool connected;

  /* newhost must be able to hold a full IP-style address in ASCII, which
     in the IPv6 case means 5*8-1 = 39 letters */
#define NEWHOST_BUFSIZE 48
  char newhost[NEWHOST_BUFSIZE];
  char *str=&data->state.buffer[4];  /* start on the first letter */

  if((ftpc->count1 == 0) &&
     (ftpcode == 229)) {
    /* positive EPSV response */
    char *ptr = strchr(str, '(');
    if(ptr) {
      unsigned int num;
      char separator[4];
      ptr++;
      if(5  == sscanf(ptr, "%c%c%c%u%c",
                      &separator[0],
                      &separator[1],
                      &separator[2],
                      &num,
                      &separator[3])) {
        const char sep1 = separator[0];
        int i;

        /* The four separators should be identical, or else this is an oddly
           formatted reply and we bail out immediately. */
        for(i=1; i<4; i++) {
          if(separator[i] != sep1) {
            ptr=NULL; /* set to NULL to signal error */
            break;
          }
        }
        if(ptr) {
          newport = (unsigned short)(num & 0xffff);

          if(conn->bits.tunnel_proxy ||
             data->set.proxytype == CURLPROXY_SOCKS5 ||
             data->set.proxytype == CURLPROXY_SOCKS5_HOSTNAME ||
             data->set.proxytype == CURLPROXY_SOCKS4 ||
             data->set.proxytype == CURLPROXY_SOCKS4A)
            /* proxy tunnel -> use other host info because ip_addr_str is the
               proxy address not the ftp host */
            snprintf(newhost, sizeof(newhost), "%s", conn->host.name);
          else
            /* use the same IP we are already connected to */
            snprintf(newhost, NEWHOST_BUFSIZE, "%s", conn->ip_addr_str);
        }
      }
      else
        ptr=NULL;
    }
    if(!ptr) {
      failf(data, "Weirdly formatted EPSV reply");
      return CURLE_FTP_WEIRD_PASV_REPLY;
    }
  }
  else if((ftpc->count1 == 1) &&
          (ftpcode == 227)) {
    /* positive PASV response */
    int ip[4];
    int port[2];

    /*
     * Scan for a sequence of six comma-separated numbers and use them as
     * IP+port indicators.
     *
     * Found reply-strings include:
     * "227 Entering Passive Mode (127,0,0,1,4,51)"
     * "227 Data transfer will passively listen to 127,0,0,1,4,51"
     * "227 Entering passive mode. 127,0,0,1,4,51"
     */
    while(*str) {
      if(6 == sscanf(str, "%d,%d,%d,%d,%d,%d",
                      &ip[0], &ip[1], &ip[2], &ip[3],
                      &port[0], &port[1]))
        break;
      str++;
    }

    if(!*str) {
      failf(data, "Couldn't interpret the 227-response");
      return CURLE_FTP_WEIRD_227_FORMAT;
    }

    /* we got OK from server */
    if(data->set.ftp_skip_ip) {
      /* told to ignore the remotely given IP but instead use the one we used
         for the control connection */
      infof(data, "Skips %d.%d.%d.%d for data connection, uses %s instead\n",
            ip[0], ip[1], ip[2], ip[3],
            conn->ip_addr_str);
      if(conn->bits.tunnel_proxy ||
          data->set.proxytype == CURLPROXY_SOCKS5 ||
          data->set.proxytype == CURLPROXY_SOCKS5_HOSTNAME ||
          data->set.proxytype == CURLPROXY_SOCKS4 ||
          data->set.proxytype == CURLPROXY_SOCKS4A)
        /* proxy tunnel -> use other host info because ip_addr_str is the
           proxy address not the ftp host */
        snprintf(newhost, sizeof(newhost), "%s", conn->host.name);
      else
        snprintf(newhost, sizeof(newhost), "%s", conn->ip_addr_str);
    }
    else
      snprintf(newhost, sizeof(newhost),
               "%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
    newport = (unsigned short)(((port[0]<<8) + port[1]) & 0xffff);
  }
  else if(ftpc->count1 == 0) {
    /* EPSV failed, move on to PASV */

    /* disable it for next transfer */
    conn->bits.ftp_use_epsv = FALSE;
    infof(data, "disabling EPSV usage\n");

    NBFTPSENDF(conn, "PASV", NULL);
    ftpc->count1++;
    /* remain in the FTP_PASV state */
    return result;
  }
  else {
    failf(data, "Bad PASV/EPSV response: %03d", ftpcode);
    return CURLE_FTP_WEIRD_PASV_REPLY;
  }

  if(data->set.str[STRING_PROXY] && *data->set.str[STRING_PROXY]) {
    /*
     * This is a tunnel through a http proxy and we need to connect to the
     * proxy again here.
     *
     * We don't want to rely on a former host lookup that might've expired
     * now, instead we remake the lookup here and now!
     */
    rc = Curl_resolv(conn, conn->proxy.name, (int)conn->port, &addr);
    if(rc == CURLRESOLV_PENDING)
      /* BLOCKING */
      rc = Curl_wait_for_resolv(conn, &addr);

    connectport =
      (unsigned short)conn->port; /* we connect to the proxy's port */

    if(!addr) {
      failf(data, "Can't resolve proxy host %s:%d",
            conn->proxy.name, connectport);
      return CURLE_FTP_CANT_GET_HOST;
    }
  }
  else {
    /* normal, direct, ftp connection */
    rc = Curl_resolv(conn, newhost, newport, &addr);
    if(rc == CURLRESOLV_PENDING)
      /* BLOCKING */
      rc = Curl_wait_for_resolv(conn, &addr);

    connectport = newport; /* we connect to the remote port */

    if(!addr) {
      failf(data, "Can't resolve new host %s:%d", newhost, connectport);
      return CURLE_FTP_CANT_GET_HOST;
    }
  }

  result = Curl_connecthost(conn,
                            addr,
                            &conn->sock[SECONDARYSOCKET],
                            &conninfo,
                            &connected);

  Curl_resolv_unlock(data, addr); /* we're done using this address */

  if(result && ftpc->count1 == 0 && ftpcode == 229) {
    infof(data, "got positive EPSV response, but can't connect. "
          "Disabling EPSV\n");
    /* disable it for next transfer */
    conn->bits.ftp_use_epsv = FALSE;
    data->state.errorbuf = FALSE; /* allow error message to get rewritten */
    NBFTPSENDF(conn, "PASV", NULL);
    ftpc->count1++;
    /* remain in the FTP_PASV state */
    return result;
 }

  if(result)
    return result;

  conn->bits.tcpconnect = connected; /* simply TRUE or FALSE */

  /*
   * When this is used from the multi interface, this might've returned with
   * the 'connected' set to FALSE and thus we are now awaiting a non-blocking
   * connect to connect and we should not be "hanging" here waiting.
   */

  if(data->set.verbose)
    /* this just dumps information about this second connection */
    ftp_pasv_verbose(conn, conninfo, newhost, connectport);

  switch(data->set.proxytype) {
#ifndef CURL_DISABLE_PROXY
  case CURLPROXY_SOCKS5:
  case CURLPROXY_SOCKS5_HOSTNAME:
    result = Curl_SOCKS5(conn->proxyuser, conn->proxypasswd, newhost, newport,
                         SECONDARYSOCKET, conn);
    break;
  case CURLPROXY_SOCKS4:
    result = Curl_SOCKS4(conn->proxyuser, newhost, newport,
                         SECONDARYSOCKET, conn, FALSE);
    break;
  case CURLPROXY_SOCKS4A:
    result = Curl_SOCKS4(conn->proxyuser, newhost, newport,
                         SECONDARYSOCKET, conn, TRUE);
    break;
#endif /* CURL_DISABLE_PROXY */
  case CURLPROXY_HTTP:
  case CURLPROXY_HTTP_1_0:
    /* do nothing here. handled later. */
    break;
  default:
    failf(data, "unknown proxytype option given");
    result = CURLE_COULDNT_CONNECT;
    break;
  }
#if !defined(CURL_DISABLE_HTTP) && !defined(CURL_DISABLE_PROXY)
  if(conn->bits.tunnel_proxy && conn->bits.httpproxy) {
    /* FIX: this MUST wait for a proper connect first if 'connected' is
     * FALSE */

    /* BLOCKING */
    /* We want "seamless" FTP operations through HTTP proxy tunnel */

    /* Curl_proxyCONNECT is based on a pointer to a struct HTTP at the member
     * conn->proto.http; we want FTP through HTTP and we have to change the
     * member temporarily for connecting to the HTTP proxy. After
     * Curl_proxyCONNECT we have to set back the member to the original struct
     * FTP pointer
     */
    struct HTTP http_proxy;
    struct FTP *ftp_save = data->state.proto.ftp;
    memset(&http_proxy, 0, sizeof(http_proxy));
    data->state.proto.http = &http_proxy;

    result = Curl_proxyCONNECT(conn, SECONDARYSOCKET, newhost, newport);

    data->state.proto.ftp = ftp_save;

    if(CURLE_OK != result)
      return result;
  }
#endif /* !CURL_DISABLE_HTTP && !CURL_DISABLE_PROXY */

  state(conn, FTP_STOP); /* this phase is completed */

  return result;
}

static CURLcode ftp_state_port_resp(struct connectdata *conn,
                                    int ftpcode)
{
  struct SessionHandle *data = conn->data;
  struct ftp_conn *ftpc = &conn->proto.ftpc;
  ftpport fcmd = (ftpport)ftpc->count1;
  CURLcode result = CURLE_OK;

  if(ftpcode != 200) {
    /* the command failed */

    if(EPRT == fcmd) {
      infof(data, "disabling EPRT usage\n");
      conn->bits.ftp_use_eprt = FALSE;
    }
    fcmd++;

    if(fcmd == DONE) {
      failf(data, "Failed to do PORT");
      result = CURLE_FTP_PORT_FAILED;
    }
    else
      /* try next */
      result = ftp_state_use_port(conn, fcmd);
  }
  else {
    infof(data, "Connect data stream actively\n");
    state(conn, FTP_STOP); /* end of DO phase */
  }

  return result;
}

static CURLcode ftp_state_mdtm_resp(struct connectdata *conn,
                                    int ftpcode)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data=conn->data;
  struct FTP *ftp = data->state.proto.ftp;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  switch(ftpcode) {
  case 213:
    {
      /* we got a time. Format should be: "YYYYMMDDHHMMSS[.sss]" where the
         last .sss part is optional and means fractions of a second */
      int year, month, day, hour, minute, second;
      char *buf = data->state.buffer;
      if(6 == sscanf(buf+4, "%04d%02d%02d%02d%02d%02d",
                     &year, &month, &day, &hour, &minute, &second)) {
        /* we have a time, reformat it */
        time_t secs=time(NULL);
        /* using the good old yacc/bison yuck */
        snprintf(buf, sizeof(conn->data->state.buffer),
                 "%04d%02d%02d %02d:%02d:%02d GMT",
                 year, month, day, hour, minute, second);
        /* now, convert this into a time() value: */
        data->info.filetime = (long)curl_getdate(buf, &secs);
      }

#ifdef CURL_FTP_HTTPSTYLE_HEAD
      /* If we asked for a time of the file and we actually got one as well,
         we "emulate" a HTTP-style header in our output. */

      if(data->set.opt_no_body &&
         ftpc->file &&
         data->set.get_filetime &&
         (data->info.filetime>=0) ) {
        struct tm *tm;
        time_t filetime = (time_t)data->info.filetime;
#ifdef HAVE_GMTIME_R
        struct tm buffer;
        tm = (struct tm *)gmtime_r(&filetime, &buffer);
#else
        tm = gmtime(&filetime);
#endif
        /* format: "Tue, 15 Nov 1994 12:45:26" */
        snprintf(buf, BUFSIZE-1,
                 "Last-Modified: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
                 Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
                 tm->tm_mday,
                 Curl_month[tm->tm_mon],
                 tm->tm_year + 1900,
                 tm->tm_hour,
                 tm->tm_min,
                 tm->tm_sec);
        result = Curl_client_write(conn, CLIENTWRITE_BOTH, buf, 0);
        if(result)
          return result;
      } /* end of a ridiculous amount of conditionals */
#endif
    }
    break;
  default:
    infof(data, "unsupported MDTM reply format\n");
    break;
  case 550: /* "No such file or directory" */
    failf(data, "Given file does not exist");
    result = CURLE_FTP_COULDNT_RETR_FILE;
    break;
  }

  if(data->set.timecondition) {
    if((data->info.filetime > 0) && (data->set.timevalue > 0)) {
      switch(data->set.timecondition) {
      case CURL_TIMECOND_IFMODSINCE:
      default:
        if(data->info.filetime <= data->set.timevalue) {
          infof(data, "The requested document is not new enough\n");
          ftp->transfer = FTPTRANSFER_NONE; /* mark this to not transfer data */
          data->info.timecond = TRUE;
          state(conn, FTP_STOP);
          return CURLE_OK;
        }
        break;
      case CURL_TIMECOND_IFUNMODSINCE:
        if(data->info.filetime > data->set.timevalue) {
          infof(data, "The requested document is not old enough\n");
          ftp->transfer = FTPTRANSFER_NONE; /* mark this to not transfer data */
          data->info.timecond = TRUE;
          state(conn, FTP_STOP);
          return CURLE_OK;
        }
        break;
      } /* switch */
    }
    else {
      infof(data, "Skipping time comparison\n");
    }
  }

  if(!result)
    result = ftp_state_post_mdtm(conn);

  return result;
}

static CURLcode ftp_state_type_resp(struct connectdata *conn,
                                    int ftpcode,
                                    ftpstate instate)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data=conn->data;

  if(ftpcode/100 != 2) {
    /* "sasserftpd" and "(u)r(x)bot ftpd" both responds with 226 after a
       successful 'TYPE I'. While that is not as RFC959 says, it is still a
       positive response code and we allow that. */
    failf(data, "Couldn't set desired mode");
    return CURLE_FTP_COULDNT_SET_TYPE;
  }
  if(ftpcode != 200)
    infof(data, "Got a %03d response code instead of the assumed 200\n",
          ftpcode);

  if(instate == FTP_TYPE)
    result = ftp_state_post_type(conn);
  else if(instate == FTP_LIST_TYPE)
    result = ftp_state_post_listtype(conn);
  else if(instate == FTP_RETR_TYPE)
    result = ftp_state_post_retrtype(conn);
  else if(instate == FTP_STOR_TYPE)
    result = ftp_state_post_stortype(conn);

  return result;
}

static CURLcode ftp_state_post_retr_size(struct connectdata *conn,
                                         curl_off_t filesize)
{
  CURLcode result = CURLE_OK;
  struct SessionHandle *data=conn->data;
  struct FTP *ftp = data->state.proto.ftp;
  struct ftp_conn *ftpc = &conn->proto.ftpc;

  if(data->set.max_filesize && (filesize > data->set.max_filesize)) {
    failf(data, "Maximum file size exceeded");
    return CURLE_FILESIZE_EXCEEDED;
  }
  ftp->downloadsize = filesize;

  if(data->state.resume_from) {
    /* We always (attempt to) get the size of downloads, so it is done before
       this even when not doing resumes. */
    if(filesize == -1) {
      infof(data, "ftp server doesn't support SIZE\n");
      /* We couldn't get the size and therefore we can't know if there really
         is a part of the file left to get, although the server will just
         close the connection when we start the connection so it won't cause
         us any harm, just not make us exit as nicely. */
    }
    else {
      /* We got a file size report, so we check that there actually is a
         part of the file left to get, or else we go home.  */
      if(data->state.resume_from< 0) {
        /* We're supposed to download the last abs(from) bytes */
        if(filesize < -data->state.resume_from) {
          failf(data, "Offset (%" FORMAT_OFF_T
                ") was beyond file size (%" FORMAT_OFF_T ")",
                data->state.resume_from, filesize);
          return CURLE_BAD_DOWNLOAD_RESUME;
        }
        /* convert to size to download */
        ftp->downloadsize = -data->state.resume_from;
        /* download from where? */
        data->state.resume_from = filesize - ftp->downloadsize;
      }
      else {
        if(filesize < data->state.resume_from) {
          failf(data, "Offset (%" FORMAT_OFF_T
                ") was beyond file size (%" FORMAT_OFF_T ")",
                data->state.resume_from, filesize);
          return CURLE_BAD_DOWNLOAD_RESUME;
        }
        /* Now store the number of bytes we are expected to download */
        ftp->downloadsize = filesize-data->state.resume_from;
      }
    }

    if(ftp->downloadsize == 0) {
      /* no data to transfer */
      result = Curl_setup_transfer(conn, -1, -1, FALSE, NULL, -1, NULL);
      infof(data, "File already completely downloaded\n");

      /* Set ->transfer so that we won't get any error in ftp_done()
       * because we didn't transfer the any file */
      ftp->transfer = FTPTRANSFER_NONE;
      state(conn, FTP_STOP);
      return CURLE_OK;
    }

    /* Set resume file transfer offset */
    infof(data, "Instructs server to resume from offset %" FORMAT_OFF_T
          "\n", data->state.resume_from);

    NBFTPSENDF(conn, "REST %" FORMAT_OFF_T, data->state.resume_from);

    state(conn, FTP_RETR_REST);

  }
  else {
    /* no resume */
    NBFTPSENDF(conn, "RETR %s", ftpc->file);
    state(conn, FTP_RETR);
  }

  return result;
}

static CURLcode ftp_state_size_resp(struct connectdata *conn,
                                    int ftpcode,
                                    ftpstate instate)