url.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2004, 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.
 *
 * $Id$
 ***************************************************************************/

/* -- WIN32 approved -- */

#include "setup.h"

#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <errno.h>

#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__)
#include <time.h>
#include <io.h>
#else
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
#include <sys/time.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <netdb.h>
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <sys/ioctl.h>
#include <signal.h>

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#ifdef VMS
#include <in.h>
#include <inet.h>
#endif

#ifdef HAVE_SETJMP_H
#include <setjmp.h>
#endif

#ifndef HAVE_SELECT
#error "We can't compile without select() support!"
#endif
#ifndef HAVE_SOCKET
#error "We can't compile without socket() support!"
#endif


#endif

#ifdef USE_LIBIDN
#include <idna.h>
#include <stringprep.h>
#endif

#ifdef HAVE_OPENSSL_ENGINE_H
#include <openssl/engine.h>
#endif
#include "urldata.h"
#include "netrc.h"

#include "formdata.h"
#include "base64.h"
#include "ssluse.h"
#include "hostip.h"
#include "if2ip.h"
#include "transfer.h"
#include "sendf.h"
#include "progress.h"
#include "cookie.h"
#include "strequal.h"
#include "escape.h"
#include "strtok.h"
#include "share.h"
#include "content_encoding.h"
#include "http_digest.h"
#include "http_negotiate.h"

/* And now for the protocols */
#include "ftp.h"
#include "dict.h"
#include "telnet.h"
#include "http.h"
#include "file.h"
#include "ldap.h"
#include "url.h"
#include "connect.h"
#include "inet_ntop.h"
#include <ca-bundle.h>

#if defined(HAVE_INET_NTOA_R) && !defined(HAVE_INET_NTOA_R_DECL)
#include "inet_ntoa_r.h"
#endif

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

#ifdef HAVE_KRB4
#include "security.h"
#endif
#include "memory.h"

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

/* Local static prototypes */
static int ConnectionKillOne(struct SessionHandle *data);
static bool ConnectionExists(struct SessionHandle *data,
                             struct connectdata *needle,
                             struct connectdata **usethis);
static unsigned int ConnectionStore(struct SessionHandle *data,
                                    struct connectdata *conn);
static bool safe_strequal(char* str1, char* str2);

#ifndef USE_ARES
/* not for Win32, unless it is cygwin
   not for ares builds */
#if !defined(WIN32) || defined(__CYGWIN32__)

#ifndef RETSIGTYPE
#define RETSIGTYPE void
#endif
#ifdef HAVE_SIGSETJMP
extern sigjmp_buf curl_jmpenv;
#endif
static
RETSIGTYPE alarmfunc(int sig)
{
  /* this is for "-ansi -Wall -pedantic" to stop complaining!   (rabe) */
  (void)sig;
#ifdef HAVE_SIGSETJMP
  siglongjmp(curl_jmpenv, 1);
#endif
  return;
}
#endif
#endif /* USE_ARES */

void Curl_safefree(void *ptr)
{
  if(ptr)
    free(ptr);
}

/*
 * This is the internal function curl_easy_cleanup() calls. This should
 * cleanup and free all resources associated with this sessionhandle.
 *
 * NOTE: if we ever add something that attempts to write to a socket or
 * similar here, we must ignore SIGPIPE first. It is currently only done
 * when curl_easy_perform() is invoked.
 */

CURLcode Curl_close(struct SessionHandle *data)
{
  /* Loop through all open connections and kill them one by one */
  while(-1 != ConnectionKillOne(data));

#ifdef USE_SSLEAY
  /* Close down all open SSL info and sessions */
  Curl_SSL_Close_All(data);
#endif

  if(data->change.cookielist) /* clean up list if any */
    curl_slist_free_all(data->change.cookielist);

  Curl_safefree(data->state.auth_host);
  Curl_safefree(data->state.scratch);

  if(data->change.proxy_alloc)
    free(data->change.proxy);

  if(data->change.referer_alloc)
    free(data->change.referer);

  if(data->change.url_alloc)
    free(data->change.url);

  Curl_safefree(data->state.headerbuff);

#ifndef CURL_DISABLE_HTTP
  Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);
  if(data->set.cookiejar) {
    /* we have a "destination" for all the cookies to get dumped to */
    if(Curl_cookie_output(data->cookies, data->set.cookiejar))
      infof(data, "WARNING: failed to save cookies in %s\n",
            data->set.cookiejar);
  }

  if( !data->share || (data->cookies != data->share->cookies) ) {
    Curl_cookie_cleanup(data->cookies);
  }
  Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
#endif

  /* free the connection cache */
  free(data->state.connects);

  Curl_safefree(data->info.contenttype);

  Curl_digest_cleanup(data);

#ifdef USE_ARES
  /* this destroys the channel and we cannot use it anymore after this */
  ares_destroy(data->state.areschannel);
#endif

  /* No longer a dirty share, if it exists */
  if (data->share)
    data->share->dirty--;

  free(data);
  return CURLE_OK;
}

/**
 * Curl_open()
 *
 * @param curl is a pointer to a sessionhandle pointer that gets set by this
 * function.
 * @return CURLcode
 */

CURLcode Curl_open(struct SessionHandle **curl)
{
  /* We don't yet support specifying the URL at this point */
  struct SessionHandle *data;
  /* Very simple start-up: alloc the struct, init it with zeroes and return */
  data = (struct SessionHandle *)malloc(sizeof(struct SessionHandle));
  if(!data)
    /* this is a very serious error */
    return CURLE_OUT_OF_MEMORY;

  memset(data, 0, sizeof(struct SessionHandle));

#ifdef USE_ARES
  if(ARES_SUCCESS != ares_init(&data->state.areschannel)) {
    free(data);
    return CURLE_FAILED_INIT;
  }
  /* make sure that all other returns from this function should destroy the
     ares channel before returning error! */
#endif

  /* We do some initial setup here, all those fields that can't be just 0 */

  data->state.headerbuff=(char*)malloc(HEADERSIZE);
  if(!data->state.headerbuff) {
    free(data); /* free the memory again */
    return CURLE_OUT_OF_MEMORY;
  }

  data->state.headersize=HEADERSIZE;

  data->set.out = stdout; /* default output to stdout */
  data->set.in  = stdin;  /* default input from stdin */
  data->set.err  = stderr;  /* default stderr to stderr */

  /* use fwrite as default function to store output */
  data->set.fwrite = (curl_write_callback)fwrite;

  /* use fread as default function to read input */
  data->set.fread = (curl_read_callback)fread;

  data->set.infilesize = -1; /* we don't know any size */

  data->state.current_speed = -1; /* init to negative == impossible */

  data->set.httpreq = HTTPREQ_GET; /* Default HTTP request */
  data->set.ftp_use_epsv = TRUE;   /* FTP defaults to EPSV operations */
  data->set.ftp_use_eprt = TRUE;   /* FTP defaults to EPRT operations */

  data->set.dns_cache_timeout = 60; /* Timeout every 60 seconds by default */

  /* make libcurl quiet by default: */
  data->set.hide_progress = TRUE;  /* CURLOPT_NOPROGRESS changes these */
  data->progress.flags |= PGRS_HIDE;

  /* Set the default size of the SSL session ID cache */
  data->set.ssl.numsessions = 5;

  data->set.proxyport = 1080;

  data->set.proxytype = CURLPROXY_HTTP; /* defaults to HTTP proxy */

  data->set.httpauth = CURLAUTH_BASIC; /* defaults to basic authentication */
  data->set.proxyauth = CURLAUTH_BASIC; /* defaults to basic authentication */

  /* create an array with connection data struct pointers */
  data->state.numconnects = 5; /* hard-coded right now */
  data->state.connects = (struct connectdata **)
    malloc(sizeof(struct connectdata *) * data->state.numconnects);

  if(!data->state.connects) {
    free(data->state.headerbuff);
    free(data);
    return CURLE_OUT_OF_MEMORY;
  }

  /*
   * libcurl 7.10 introduces SSL verification *by default*! This needs to be
   * switched off unless wanted.
   */
  data->set.ssl.verifypeer = TRUE;
  data->set.ssl.verifyhost = 2;
#ifdef CURL_CA_BUNDLE
  /* This is our prefered CA cert bundle since install time */
  data->set.ssl.CAfile = (char *)CURL_CA_BUNDLE;
#endif

  memset(data->state.connects, 0,
         sizeof(struct connectdata *)*data->state.numconnects);

  *curl = data;
  return CURLE_OK;
}

CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option, ...)
{
  va_list param;
  char *cookiefile;

  va_start(param, option);

  switch(option) {
  case CURLOPT_DNS_CACHE_TIMEOUT:
    data->set.dns_cache_timeout = va_arg(param, int);
    break;
  case CURLOPT_DNS_USE_GLOBAL_CACHE:
    {
      int use_cache = va_arg(param, int);
      if (use_cache) {
        Curl_global_host_cache_init();
      }

      data->set.global_dns_cache = use_cache;
    }
    break;
  case CURLOPT_SSL_CIPHER_LIST:
    /* set a list of cipher we want to use in the SSL connection */
    data->set.ssl.cipher_list = va_arg(param, char *);
    break;

  case CURLOPT_RANDOM_FILE:
    /*
     * This is the path name to a file that contains random data to seed
     * the random SSL stuff with. The file is only used for reading.
     */
    data->set.ssl.random_file = va_arg(param, char *);
    break;
  case CURLOPT_EGDSOCKET:
    /*
     * The Entropy Gathering Daemon socket pathname
     */
    data->set.ssl.egdsocket = va_arg(param, char *);
    break;
  case CURLOPT_MAXCONNECTS:
    /*
     * Set the absolute number of maximum simultaneous alive connection that
     * libcurl is allowed to have.
     */
    {
      long newconnects= va_arg(param, long);
      struct connectdata **newptr;

      if(newconnects < data->state.numconnects) {
        /* Since this number is *decreased* from the existing number, we must
           close the possibly open connections that live on the indexes that
           are being removed! */
        int i;
        for(i=newconnects; i< data->state.numconnects; i++)
          Curl_disconnect(data->state.connects[i]);
      }
      if(newconnects) {
        int i;
        newptr= (struct connectdata **)
          realloc(data->state.connects,
                  sizeof(struct connectdata *) * newconnects);
        if(!newptr)
          /* we closed a few connections in vain, but so what? */
          return CURLE_OUT_OF_MEMORY;

        /* nullify the newly added pointers */
        for(i=data->state.numconnects; i<newconnects; i++) {
          newptr[i] = NULL;
        }

        data->state.connects = newptr;
        data->state.numconnects = newconnects;
      }
      else {
        /* zero makes NO cache at all */
        if(data->state.connects)
          free(data->state.connects);
        data->state.connects=NULL;
        data->state.numconnects=0;
      }
    }
    break;
  case CURLOPT_FORBID_REUSE:
    /*
     * When this transfer is done, it must not be left to be reused by a
     * subsequent transfer but shall be closed immediately.
     */
    data->set.reuse_forbid = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_FRESH_CONNECT:
    /*
     * This transfer shall not use a previously cached connection but
     * should be made with a fresh new connect!
     */
    data->set.reuse_fresh = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_VERBOSE:
    /*
     * Verbose means infof() calls that give a lot of information about
     * the connection and transfer procedures as well as internal choices.
     */
    data->set.verbose = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_HEADER:
    /*
     * Set to include the header in the general data output stream.
     */
    data->set.include_header = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_NOPROGRESS:
    /*
     * Shut off the internal supported progress meter
     */
    data->set.hide_progress = va_arg(param, long)?TRUE:FALSE;
    if(data->set.hide_progress)
      data->progress.flags |= PGRS_HIDE;
    else
      data->progress.flags &= ~PGRS_HIDE;
    break;
  case CURLOPT_NOBODY:
    /*
     * Do not include the body part in the output data stream.
     */
    data->set.opt_no_body = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_FAILONERROR:
    /*
     * Don't output the >=300 error code HTML-page, but instead only
     * return error.
     */
    data->set.http_fail_on_error = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_UPLOAD:
    /*
     * We want to sent data to the remote host
     */
    data->set.upload = va_arg(param, long)?TRUE:FALSE;
    if(data->set.upload)
      /* If this is HTTP, PUT is what's needed to "upload" */
      data->set.httpreq = HTTPREQ_PUT;
    break;
  case CURLOPT_FILETIME:
    /*
     * Try to get the file time of the remote document. The time will
     * later (possibly) become available using curl_easy_getinfo().
     */
    data->set.get_filetime = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_FTP_CREATE_MISSING_DIRS:
    /*
     * An FTP option that modifies an upload to create missing directories on
     * the server.
     */ 
    data->set.ftp_create_missing_dirs = va_arg( param , long )?TRUE:FALSE;
    break;
  case CURLOPT_FTP_RESPONSE_TIMEOUT:
    /*
     * An FTP option that specifies how quickly an FTP response must be 
     * obtained before it is considered failure.
     */
    data->set.ftp_response_timeout = va_arg( param , long );
    break;
  case CURLOPT_FTPLISTONLY:
    /*
     * An FTP option that changes the command to one that asks for a list
     * only, no file info details.
     */
    data->set.ftp_list_only = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_FTPAPPEND:
    /*
     * We want to upload and append to an existing (FTP) file.
     */
    data->set.ftp_append = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_NETRC:
    /*
     * Parse the $HOME/.netrc file
     */
    data->set.use_netrc = (enum CURL_NETRC_OPTION)va_arg(param, long);
    break;
  case CURLOPT_NETRC_FILE:
    /*
     * Use this file instead of the $HOME/.netrc file
     */
    data->set.netrc_file = va_arg(param, char *);
    break;
  case CURLOPT_FOLLOWLOCATION:
    /*
     * Follow Location: header hints on a HTTP-server.
     */
    data->set.http_follow_location = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_UNRESTRICTED_AUTH:
    /*
     * Send authentication (user+password) when following locations, even when
     * hostname changed.
     */
    data->set.http_disable_hostname_check_before_authentication =
      va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_HTTP_VERSION:
    /*
     * This sets a requested HTTP version to be used. The value is one of
     * the listed enums in curl/curl.h.
     */
    data->set.httpversion = va_arg(param, long);
    break;
  case CURLOPT_TRANSFERTEXT:
    /*
     * This option was previously named 'FTPASCII'. Renamed to work with
     * more protocols than merely FTP.
     *
     * Transfer using ASCII (instead of BINARY).
     */
    data->set.ftp_ascii = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_PUT:
    /*
     * Use the HTTP PUT request to transfer data if this is TRUE.  If this is
     * FALSE, don't set the httpreq. We can't know what to revert it to!
     */
    if(va_arg(param, long))
      data->set.httpreq = HTTPREQ_PUT;
    break;
  case CURLOPT_TIMECONDITION:
    /*
     * Set HTTP time condition. This must be one of the defines in the
     * curl/curl.h header file.
     */
    data->set.timecondition = (curl_TimeCond)va_arg(param, long);
    break;
  case CURLOPT_TIMEVALUE:
    /*
     * This is the value to compare with the remote document with the
     * method set with CURLOPT_TIMECONDITION
     */
    data->set.timevalue = va_arg(param, long);
    break;
  case CURLOPT_SSLVERSION:
    /*
     * Set explicit SSL version to try to connect with, as some SSL
     * implementations are lame.
     */
    data->set.ssl.version = va_arg(param, long);
    break;

  case CURLOPT_COOKIESESSION:
    /*
     * Set this option to TRUE to start a new "cookie session". It will
     * prevent the forthcoming read-cookies-from-file actions to accept
     * cookies that are marked as being session cookies, as they belong to a
     * previous session.
     *
     * In the original Netscape cookie spec, "session cookies" are cookies
     * with no expire date set. RFC2109 describes the same action if no
     * 'Max-Age' is set and RFC2965 includes the RFC2109 description and adds
     * a 'Discard' action that can enforce the discard even for cookies that
     * have a Max-Age.
     *
     * We run mostly with the original cookie spec, as hardly anyone implements
     * anything else.
     */
    data->set.cookiesession = (bool)va_arg(param, long);
    break;

#ifndef CURL_DISABLE_HTTP
  case CURLOPT_COOKIEFILE:
    /*
     * Set cookie file to read and parse. Can be used multiple times.
     */
    cookiefile = (char *)va_arg(param, void *);
    if(cookiefile)
      /* append the cookie file name to the list of file names, and deal with
         them later */
      data->change.cookielist =
        curl_slist_append(data->change.cookielist, cookiefile);
    break;

  case CURLOPT_COOKIEJAR:
    /*
     * Set cookie file name to dump all cookies to when we're done.
     */
    data->set.cookiejar = (char *)va_arg(param, void *);

    /*
     * Activate the cookie parser. This may or may not already
     * have been made.
     */
    data->cookies = Curl_cookie_init(data, NULL, data->cookies,
                                     data->set.cookiesession);
    break;
#endif

  case CURLOPT_WRITEHEADER:
    /*
     * Custom pointer to pass the header write callback function
     */
    data->set.writeheader = (void *)va_arg(param, void *);
    break;
  case CURLOPT_COOKIE:
    /*
     * Cookie string to send to the remote server in the request.
     */
    data->set.cookie = va_arg(param, char *);
    break;
  case CURLOPT_ERRORBUFFER:
    /*
     * Error buffer provided by the caller to get the human readable
     * error string in.
     */
    data->set.errorbuffer = va_arg(param, char *);
    break;
  case CURLOPT_FILE:
    /*
     * FILE pointer to write to or include in the data write callback
     */
    data->set.out = va_arg(param, FILE *);
    break;
  case CURLOPT_FTPPORT:
    /*
     * Use FTP PORT, this also specifies which IP address to use
     */
    data->set.ftpport = va_arg(param, char *);
    data->set.ftp_use_port = data->set.ftpport?1:0;
    break;

  case CURLOPT_FTP_USE_EPRT:
    data->set.ftp_use_eprt = va_arg(param, long)?TRUE:FALSE;
    break;

  case CURLOPT_FTP_USE_EPSV:
    data->set.ftp_use_epsv = va_arg(param, long)?TRUE:FALSE;
    break;
    
  case CURLOPT_HTTPHEADER:
    /*
     * Set a list with HTTP headers to use (or replace internals with)
     */
    data->set.headers = va_arg(param, struct curl_slist *);
    break;
  case CURLOPT_CUSTOMREQUEST:
    /*
     * Set a custom string to use as request
     */
    data->set.customrequest = va_arg(param, char *);

    /* we don't set
       data->set.httpreq = HTTPREQ_CUSTOM;
       here, we continue as if we were using the already set type
       and this just changes the actual request keyword */
    break;
  case CURLOPT_HTTPPOST:
    /*
     * Set to make us do HTTP POST
     */
    data->set.httppost = va_arg(param, struct curl_httppost *);
    if(data->set.httppost)
      data->set.httpreq = HTTPREQ_POST_FORM;
    break;

  case CURLOPT_HTTPGET:
    /*
     * Set to force us do HTTP GET
     */
    if(va_arg(param, long)) {
      data->set.httpreq = HTTPREQ_GET;
      data->set.upload = FALSE; /* switch off upload */
    }
    break;

  case CURLOPT_INFILE:
    /*
     * FILE pointer to read the file to be uploaded from. Or possibly
     * used as argument to the read callback.
     */
    data->set.in = va_arg(param, FILE *);
    break;
  case CURLOPT_INFILESIZE:
    /*
     * If known, this should inform curl about the file size of the
     * to-be-uploaded file.
     */
    data->set.infilesize = va_arg(param, long);
    break;
  case CURLOPT_INFILESIZE_LARGE:
    /*
     * If known, this should inform curl about the file size of the
     * to-be-uploaded file.
     */
    data->set.infilesize = va_arg(param, curl_off_t);
    break;
  case CURLOPT_LOW_SPEED_LIMIT:
    /*
     * The low speed limit that if transfers are below this for
     * CURLOPT_LOW_SPEED_TIME, the transfer is aborted.
     */
    data->set.low_speed_limit=va_arg(param, long);
    break;
  case CURLOPT_LOW_SPEED_TIME:
    /*
     * The low speed time that if transfers are below the set
     * CURLOPT_LOW_SPEED_LIMIT during this time, the transfer is aborted.
     */
    data->set.low_speed_time=va_arg(param, long);
    break;
  case CURLOPT_URL:
    /*
     * The URL to fetch.
     */
    if(data->change.url_alloc) {
      /* the already set URL is allocated, free it first! */
      free(data->change.url);
      data->change.url_alloc=FALSE;
    }
    data->set.set_url = va_arg(param, char *);
    data->change.url = data->set.set_url;
    data->change.url_changed = TRUE;
    break;
  case CURLOPT_PORT:
    /*
     * The port number to use when getting the URL
     */
    data->set.use_port = va_arg(param, long);
    break;
  case CURLOPT_POST:
    /* Does this option serve a purpose anymore? Yes it does, when
       CURLOPT_POSTFIELDS isn't used and the POST data is read off the
       callback! */
    if(va_arg(param, long))
      data->set.httpreq = HTTPREQ_POST;
    break;
  case CURLOPT_POSTFIELDS:
    /*
     * A string with POST data. Makes curl HTTP POST.
     */
    data->set.postfields = va_arg(param, char *);
    if(data->set.postfields)
      data->set.httpreq = HTTPREQ_POST;
    break;
  case CURLOPT_POSTFIELDSIZE:
    /*
     * The size of the POSTFIELD data to prevent libcurl to do strlen() to
     * figure it out. Enables binary posts.
     */
    data->set.postfieldsize = va_arg(param, long);
    break;
  case CURLOPT_POSTFIELDSIZE_LARGE:
    /*
     * The size of the POSTFIELD data to prevent libcurl to do strlen() to
     * figure it out. Enables binary posts.
     */
    data->set.postfieldsize = va_arg(param, curl_off_t);
    break;
  case CURLOPT_REFERER:
    /*
     * String to set in the HTTP Referer: field.
     */
    if(data->change.referer_alloc) {
      free(data->change.referer);
      data->change.referer_alloc = FALSE;
    }
    data->set.set_referer = va_arg(param, char *);
    data->change.referer = data->set.set_referer;
    break;
  case CURLOPT_AUTOREFERER:
    /*
     * Switch on automatic referer that gets set if curl follows locations.
     */
    data->set.http_auto_referer = va_arg(param, long)?1:0;
    break;
  case CURLOPT_PROXY:
    /*
     * Set proxy server:port to use as HTTP proxy.
     *
     * If the proxy is set to "" we explicitly say that we don't want to use a
     * proxy (even though there might be environment variables saying so).
     *
     * Setting it to NULL, means no proxy but allows the environment variables
     * to decide for us.
     */
    if(data->change.proxy_alloc) {
      /*
       * The already set string is allocated, free that first
       */
      data->change.proxy_alloc=FALSE;;
      free(data->change.proxy);
    }
    data->set.set_proxy = va_arg(param, char *);
    data->change.proxy = data->set.set_proxy;
    break;
  case CURLOPT_HTTPPROXYTUNNEL:
    /*
     * Tunnel operations through the proxy instead of normal proxy use
     */
    data->set.tunnel_thru_httpproxy = va_arg(param, long)?TRUE:FALSE;
    break;
  case CURLOPT_PROXYPORT:
    /*
     * Explicitly set HTTP proxy port number.
     */
    data->set.proxyport = va_arg(param, long);
    break;
  case CURLOPT_TIMEOUT:
    /*
     * The maximum time you allow curl to use for a single transfer
     * operation.
     */
    data->set.timeout = va_arg(param, long);
    break;
  case CURLOPT_CONNECTTIMEOUT:
    /*
     * The maximum time you allow curl to use to connect.
     */
    data->set.connecttimeout = va_arg(param, long);
    break;
  case CURLOPT_MAXREDIRS:
    /*
     * The maximum amount of hops you allow curl to follow Location:
     * headers. This should mostly be used to detect never-ending loops.
     */
    data->set.maxredirs = va_arg(param, long);
    break;
  case CURLOPT_USERAGENT:
    /*
     * String to use in the HTTP User-Agent field
     */
    data->set.useragent = va_arg(param, char *);
    break;
  case CURLOPT_ENCODING:
    /*
     * String to use at the value of Accept-Encoding header. 08/28/02 jhrg
     *
     * If the encoding is set to "" we use an Accept-Encoding header that
     * encompasses all the encodings we support.
     * If the encoding is set to NULL we don't send an Accept-Encoding header
     * and ignore an received Content-Encoding header.
     *
     */
    data->set.encoding = va_arg(param, char *);
    if(data->set.encoding && !*data->set.encoding)
      data->set.encoding = (char*)ALL_CONTENT_ENCODINGS;
    break;

  case CURLOPT_HTTPAUTH:
    /*
     * Set HTTP Authentication type BITMASK.
     */
  {
    long auth = va_arg(param, long);
    /* switch off bits we can't support */
#ifndef USE_SSLEAY
    auth &= ~CURLAUTH_NTLM; /* no NTLM without SSL */
#endif
#ifndef HAVE_GSSAPI
    auth &= ~CURLAUTH_GSSNEGOTIATE; /* no GSS-Negotiate without GSSAPI */
#endif
    if(!auth)
      return CURLE_FAILED_INIT; /* no supported types left! */

    data->set.httpauth = auth;
  }
  break;
  
  case CURLOPT_PROXYAUTH:
    /*
     * Set HTTP Authentication type BITMASK.
     */
  {
    long auth = va_arg(param, long);
    /* switch off bits we can't support */
#ifndef USE_SSLEAY
    auth &= ~CURLAUTH_NTLM; /* no NTLM without SSL */
#endif
#ifndef HAVE_GSSAPI
    auth &= ~CURLAUTH_GSSNEGOTIATE; /* no GSS-Negotiate without GSSAPI */
#endif
    if(!auth)
      return CURLE_FAILED_INIT; /* no supported types left! */

    data->set.proxyauth = auth;
  }
  break;

  case CURLOPT_USERPWD:
    /*
     * user:password to use in the operation
     */
    data->set.userpwd = va_arg(param, char *);
    break;
  case CURLOPT_POSTQUOTE:
    /*
     * List of RAW FTP commands to use after a transfer
     */
    data->set.postquote = va_arg(param, struct curl_slist *);
    break;
  case CURLOPT_PREQUOTE:
    /*
     * List of RAW FTP commands to use prior to RETR (Wesley Laxton)
     */
    data->set.prequote = va_arg(param, struct curl_slist *);
    break;
  case CURLOPT_QUOTE:
    /*
     * List of RAW FTP commands to use before a transfer
     */
    data->set.quote = va_arg(param, struct curl_slist *);
    break;
  case CURLOPT_PROGRESSFUNCTION:
    /*
     * Progress callback function
     */
    data->set.fprogress = va_arg(param, curl_progress_callback);
    if(data->set.fprogress)
      data->progress.callback = TRUE; /* no longer internal */
    else
      data->progress.callback = FALSE; /* NULL enforces internal */

    break;
  case CURLOPT_PROGRESSDATA:
    /*
     * Custom client data to pass to the progress callback
     */
    data->set.progress_client = va_arg(param, void *);
    break;
  case CURLOPT_PROXYUSERPWD:
    /*
     * user:password needed to use the proxy
     */
    data->set.proxyuserpwd = va_arg(param, char *);
    break;
  case CURLOPT_RANGE:
    /*
     * What range of the file you want to transfer
     */
    data->set.set_range = va_arg(param, char *);
    break;
  case CURLOPT_RESUME_FROM:
    /*
     * Resume transfer at the give file position
     */
    data->set.set_resume_from = va_arg(param, long);
    break;
  case CURLOPT_RESUME_FROM_LARGE:
    /*
     * Resume transfer at the give file position
     */