url.c

        protop = "LDAP";
      else if(checkprefix("IMAP.", conn->host.name))
        protop = "IMAP";
      else if(checkprefix("SMTP.", conn->host.name))
        protop = "smtp";
      else if(checkprefix("POP3.", conn->host.name))
        protop = "pop3";
      else {
        protop = "http";
      }

      *prot_missing = TRUE; /* not given in URL */
    }
    else
      protop = protobuf;
  }

  /* We search for '?' in the host name (but only on the right side of a
   * @-letter to allow ?-letters in username and password) to handle things
   * like http://example.com?param= (notice the missing '/').
   */
  at = strchr(conn->host.name, '@');
  if(at)
    query = strchr(at+1, '?');
  else
    query = strchr(conn->host.name, '?');

  if(query) {
    /* We must insert a slash before the '?'-letter in the URL. If the URL had
       a slash after the '?', that is where the path currently begins and the
       '?string' is still part of the host name.

       We must move the trailing part from the host name and put it first in
       the path. And have it all prefixed with a slash.
    */

    size_t hostlen = strlen(query);
    size_t pathlen = strlen(path);

    /* move the existing path plus the zero byte forward, to make room for
       the host-name part */
    memmove(path+hostlen+1, path, pathlen+1);

     /* now copy the trailing host part in front of the existing path */
    memcpy(path+1, query, hostlen);

    path[0]='/'; /* prepend the missing slash */
    rebuild_url = TRUE;

    *query=0; /* now cut off the hostname at the ? */
  }
  else if(!path[0]) {
    /* if there's no path set, use a single slash */
    strcpy(path, "/");
    rebuild_url = TRUE;
  }

  /* If the URL is malformatted (missing a '/' after hostname before path) we
   * insert a slash here. The only letter except '/' we accept to start a path
   * is '?'.
   */
  if(path[0] == '?') {
    /* We need this function to deal with overlapping memory areas. We know
       that the memory area 'path' points to is 'urllen' bytes big and that
       is bigger than the path. Use +1 to move the zero byte too. */
    memmove(&path[1], path, strlen(path)+1);
    path[0] = '/';
    rebuild_url = TRUE;
  }
  else if(!data->set.path_as_is) {
    /* sanitise paths and remove ../ and ./ sequences according to RFC3986 */
    char *newp = Curl_dedotdotify(path);
    if(!newp)
      return CURLE_OUT_OF_MEMORY;

    if(strcmp(newp, path)) {
      rebuild_url = TRUE;
      free(data->state.pathbuffer);
      data->state.pathbuffer = newp;
      data->state.path = newp;
      path = newp;
    }
    else
      free(newp);
  }

  /*
   * "rebuild_url" means that one or more URL components have been modified so
   * we need to generate an updated full version.  We need the corrected URL
   * when communicating over HTTP proxy and we don't know at this point if
   * we're using a proxy or not.
   */
  if(rebuild_url) {
    char *reurl;

    size_t plen = strlen(path); /* new path, should be 1 byte longer than
                                   the original */
    size_t urllen = strlen(data->change.url); /* original URL length */

    size_t prefixlen = strlen(conn->host.name);

    if(!*prot_missing)
      prefixlen += strlen(protop) + strlen("://");

    reurl = malloc(urllen + 2); /* 2 for zerobyte + slash */
    if(!reurl)
      return CURLE_OUT_OF_MEMORY;

    /* copy the prefix */
    memcpy(reurl, data->change.url, prefixlen);

    /* append the trailing piece + zerobyte */
    memcpy(&reurl[prefixlen], path, plen + 1);

    /* possible free the old one */
    if(data->change.url_alloc) {
      Curl_safefree(data->change.url);
      data->change.url_alloc = FALSE;
    }

    infof(data, "Rebuilt URL to: %s\n", reurl);

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

  /*
   * Parse the login details from the URL and strip them out of
   * the host name
   */
  result = parse_url_login(data, conn, userp, passwdp, optionsp);
  if(result)
    return result;

  if(conn->host.name[0] == '[') {
    /* This looks like an IPv6 address literal.  See if there is an address
       scope if there is no location header */
    char *percent = strchr(conn->host.name, '%');
    if(percent) {
      unsigned int identifier_offset = 3;
      char *endp;
      unsigned long scope;
      if(strncmp("%25", percent, 3) != 0) {
        infof(data,
              "Please URL encode %% as %%25, see RFC 6874.\n");
        identifier_offset = 1;
      }
      scope = strtoul(percent + identifier_offset, &endp, 10);
      if(*endp == ']') {
        /* The address scope was well formed.  Knock it out of the
           hostname. */
        memmove(percent, endp, strlen(endp)+1);
        conn->scope_id = (unsigned int)scope;
      }
      else {
        /* Zone identifier is not numeric */
#if defined(HAVE_NET_IF_H) && defined(IFNAMSIZ) && defined(HAVE_IF_NAMETOINDEX)
        char ifname[IFNAMSIZ + 2];
        char *square_bracket;
        unsigned int scopeidx = 0;
        strncpy(ifname, percent + identifier_offset, IFNAMSIZ + 2);
        /* Ensure nullbyte termination */
        ifname[IFNAMSIZ + 1] = '\0';
        square_bracket = strchr(ifname, ']');
        if(square_bracket) {
          /* Remove ']' */
          *square_bracket = '\0';
          scopeidx = if_nametoindex(ifname);
          if(scopeidx == 0) {
            infof(data, "Invalid network interface: %s; %s\n", ifname,
                  strerror(errno));
          }
        }
        if(scopeidx > 0) {
          char *p = percent + identifier_offset + strlen(ifname);

          /* Remove zone identifier from hostname */
          memmove(percent, p, strlen(p) + 1);
          conn->scope_id = scopeidx;
        }
        else
#endif /* HAVE_NET_IF_H && IFNAMSIZ */
          infof(data, "Invalid IPv6 address format\n");
      }
    }
  }

  if(data->set.scope_id)
    /* Override any scope that was set above.  */
    conn->scope_id = data->set.scope_id;

  /* Remove the fragment part of the path. Per RFC 2396, this is always the
     last part of the URI. We are looking for the first '#' so that we deal
     gracefully with non conformant URI such as http://example.com#foo#bar. */
  fragment = strchr(path, '#');
  if(fragment) {
    *fragment = 0;

    /* we know the path part ended with a fragment, so we know the full URL
       string does too and we need to cut it off from there so it isn't used
       over proxy */
    fragment = strchr(data->change.url, '#');
    if(fragment)
      *fragment = 0;
  }

  /*
   * So if the URL was A://B/C#D,
   *   protop is A
   *   conn->host.name is B
   *   data->state.path is /C
   */

  return findprotocol(data, conn, protop);
}

/*
 * If we're doing a resumed transfer, we need to setup our stuff
 * properly.
 */
static CURLcode setup_range(struct SessionHandle *data)
{
  struct UrlState *s = &data->state;
  s->resume_from = data->set.set_resume_from;
  if(s->resume_from || data->set.str[STRING_SET_RANGE]) {
    if(s->rangestringalloc)
      free(s->range);

    if(s->resume_from)
      s->range = aprintf("%" CURL_FORMAT_CURL_OFF_TU "-", s->resume_from);
    else
      s->range = strdup(data->set.str[STRING_SET_RANGE]);

    s->rangestringalloc = (s->range)?TRUE:FALSE;

    if(!s->range)
      return CURLE_OUT_OF_MEMORY;

    /* tell ourselves to fetch this range */
    s->use_range = TRUE;        /* enable range download */
  }
  else
    s->use_range = FALSE; /* disable range download */

  return CURLE_OK;
}


/*
 * setup_connection_internals() -
 *
 * Setup connection internals specific to the requested protocol in the
 * SessionHandle. This is inited and setup before the connection is made but
 * is about the particular protocol that is to be used.
 *
 * This MUST get called after proxy magic has been figured out.
 */
static CURLcode setup_connection_internals(struct connectdata *conn)
{
  const struct Curl_handler * p;
  CURLcode result;
  struct SessionHandle *data = conn->data;

  /* in some case in the multi state-machine, we go back to the CONNECT state
     and then a second (or third or...) call to this function will be made
     without doing a DISCONNECT or DONE in between (since the connection is
     yet in place) and therefore this function needs to first make sure
     there's no lingering previous data allocated. */
  Curl_free_request_state(data);

  memset(&data->req, 0, sizeof(struct SingleRequest));
  data->req.maxdownload = -1;

  conn->socktype = SOCK_STREAM; /* most of them are TCP streams */

  /* Perform setup complement if some. */
  p = conn->handler;

  if(p->setup_connection) {
    result = (*p->setup_connection)(conn);

    if(result)
      return result;

    p = conn->handler;              /* May have changed. */
  }

  if(conn->port < 0)
    /* we check for -1 here since if proxy was detected already, this
       was very likely already set to the proxy port */
    conn->port = p->defport;

  /* only if remote_port was not already parsed off the URL we use the
     default port number */
  if(conn->remote_port < 0)
    conn->remote_port = (unsigned short)conn->given->defport;

  return CURLE_OK;
}

/*
 * Curl_free_request_state() should free temp data that was allocated in the
 * SessionHandle for this single request.
 */

void Curl_free_request_state(struct SessionHandle *data)
{
  Curl_safefree(data->req.protop);
  Curl_safefree(data->req.newurl);
}


#ifndef CURL_DISABLE_PROXY
/****************************************************************
* Checks if the host is in the noproxy list. returns true if it matches
* and therefore the proxy should NOT be used.
****************************************************************/
static bool check_noproxy(const char* name, const char* no_proxy)
{
  /* no_proxy=domain1.dom,host.domain2.dom
   *   (a comma-separated list of hosts which should
   *   not be proxied, or an asterisk to override
   *   all proxy variables)
   */
  size_t tok_start;
  size_t tok_end;
  const char* separator = ", ";
  size_t no_proxy_len;
  size_t namelen;
  char *endptr;

  if(no_proxy && no_proxy[0]) {
    if(Curl_raw_equal("*", no_proxy)) {
      return TRUE;
    }

    /* NO_PROXY was specified and it wasn't just an asterisk */

    no_proxy_len = strlen(no_proxy);
    endptr = strchr(name, ':');
    if(endptr)
      namelen = endptr - name;
    else
      namelen = strlen(name);

    for(tok_start = 0; tok_start < no_proxy_len; tok_start = tok_end + 1) {
      while(tok_start < no_proxy_len &&
            strchr(separator, no_proxy[tok_start]) != NULL) {
        /* Look for the beginning of the token. */
        ++tok_start;
      }

      if(tok_start == no_proxy_len)
        break; /* It was all trailing separator chars, no more tokens. */

      for(tok_end = tok_start; tok_end < no_proxy_len &&
            strchr(separator, no_proxy[tok_end]) == NULL; ++tok_end)
        /* Look for the end of the token. */
        ;

      /* To match previous behaviour, where it was necessary to specify
       * ".local.com" to prevent matching "notlocal.com", we will leave
       * the '.' off.
       */
      if(no_proxy[tok_start] == '.')
        ++tok_start;

      if((tok_end - tok_start) <= namelen) {
        /* Match the last part of the name to the domain we are checking. */
        const char *checkn = name + namelen - (tok_end - tok_start);
        if(Curl_raw_nequal(no_proxy + tok_start, checkn,
                           tok_end - tok_start)) {
          if((tok_end - tok_start) == namelen || *(checkn - 1) == '.') {
            /* We either have an exact match, or the previous character is a .
             * so it is within the same domain, so no proxy for this host.
             */
            return TRUE;
          }
        }
      } /* if((tok_end - tok_start) <= namelen) */
    } /* for(tok_start = 0; tok_start < no_proxy_len;
         tok_start = tok_end + 1) */
  } /* NO_PROXY was specified and it wasn't just an asterisk */

  return FALSE;
}

/****************************************************************
* Detect what (if any) proxy to use. Remember that this selects a host
* name and is not limited to HTTP proxies only.
* The returned pointer must be freed by the caller (unless NULL)
****************************************************************/
static char *detect_proxy(struct connectdata *conn)
{
  char *proxy = NULL;

#ifndef CURL_DISABLE_HTTP
  /* If proxy was not specified, we check for default proxy environment
   * variables, to enable i.e Lynx compliance:
   *
   * http_proxy=http://some.server.dom:port/
   * https_proxy=http://some.server.dom:port/
   * ftp_proxy=http://some.server.dom:port/
   * no_proxy=domain1.dom,host.domain2.dom
   *   (a comma-separated list of hosts which should
   *   not be proxied, or an asterisk to override
   *   all proxy variables)
   * all_proxy=http://some.server.dom:port/
   *   (seems to exist for the CERN www lib. Probably
   *   the first to check for.)
   *
   * For compatibility, the all-uppercase versions of these variables are
   * checked if the lowercase versions don't exist.
   */
  char *no_proxy=NULL;
  char proxy_env[128];

  no_proxy=curl_getenv("no_proxy");
  if(!no_proxy)
    no_proxy=curl_getenv("NO_PROXY");

  if(!check_noproxy(conn->host.name, no_proxy)) {
    /* It was not listed as without proxy */
    const char *protop = conn->handler->scheme;
    char *envp = proxy_env;
    char *prox;

    /* Now, build <protocol>_proxy and check for such a one to use */
    while(*protop)
      *envp++ = (char)tolower((int)*protop++);

    /* append _proxy */
    strcpy(envp, "_proxy");

    /* read the protocol proxy: */
    prox=curl_getenv(proxy_env);

    /*
     * We don't try the uppercase version of HTTP_PROXY because of
     * security reasons:
     *
     * When curl is used in a webserver application
     * environment (cgi or php), this environment variable can
     * be controlled by the web server user by setting the
     * http header 'Proxy:' to some value.
     *
     * This can cause 'internal' http/ftp requests to be
     * arbitrarily redirected by any external attacker.
     */
    if(!prox && !Curl_raw_equal("http_proxy", proxy_env)) {
      /* There was no lowercase variable, try the uppercase version: */
      Curl_strntoupper(proxy_env, proxy_env, sizeof(proxy_env));
      prox=curl_getenv(proxy_env);
    }

    if(prox)
      proxy = prox; /* use this */
    else {
      proxy = curl_getenv("all_proxy"); /* default proxy to use */
      if(!proxy)
        proxy=curl_getenv("ALL_PROXY");
    }
  } /* if(!check_noproxy(conn->host.name, no_proxy)) - it wasn't specified
       non-proxy */
  free(no_proxy);

#else /* !CURL_DISABLE_HTTP */

  (void)conn;
#endif /* CURL_DISABLE_HTTP */

  return proxy;
}

/*
 * If this is supposed to use a proxy, we need to figure out the proxy
 * host name, so that we can re-use an existing connection
 * that may exist registered to the same proxy host.
 * proxy will be freed before this function returns.
 */
static CURLcode parse_proxy(struct SessionHandle *data,
                            struct connectdata *conn, char *proxy)
{
  char *prox_portno;
  char *endofprot;

  /* We use 'proxyptr' to point to the proxy name from now on... */
  char *proxyptr;
  char *portptr;
  char *atsign;

  /* We do the proxy host string parsing here. We want the host name and the
   * port name. Accept a protocol:// prefix
   */

  /* Parse the protocol part if present */
  endofprot = strstr(proxy, "://");
  if(endofprot) {
    proxyptr = endofprot+3;
    if(checkprefix("socks5h", proxy))
      conn->proxytype = CURLPROXY_SOCKS5_HOSTNAME;
    else if(checkprefix("socks5", proxy))
      conn->proxytype = CURLPROXY_SOCKS5;
    else if(checkprefix("socks4a", proxy))
      conn->proxytype = CURLPROXY_SOCKS4A;
    else if(checkprefix("socks4", proxy) || checkprefix("socks", proxy))
      conn->proxytype = CURLPROXY_SOCKS4;
    /* Any other xxx:// : change to http proxy */
  }
  else
    proxyptr = proxy; /* No xxx:// head: It's a HTTP proxy */

  /* Is there a username and password given in this proxy url? */
  atsign = strchr(proxyptr, '@');
  if(atsign) {
    char *proxyuser = NULL;
    char *proxypasswd = NULL;
    CURLcode result =
      parse_login_details(proxyptr, atsign - proxyptr,
                          &proxyuser, &proxypasswd, NULL);
    if(!result) {
      /* found user and password, rip them out.  note that we are
         unescaping them, as there is otherwise no way to have a
         username or password with reserved characters like ':' in
         them. */
      Curl_safefree(conn->proxyuser);
      if(proxyuser && strlen(proxyuser) < MAX_CURL_USER_LENGTH)
        conn->proxyuser = curl_easy_unescape(data, proxyuser, 0, NULL);
      else
        conn->proxyuser = strdup("");

      if(!conn->proxyuser)
        result = CURLE_OUT_OF_MEMORY;
      else {
        Curl_safefree(conn->proxypasswd);
        if(proxypasswd && strlen(proxypasswd) < MAX_CURL_PASSWORD_LENGTH)
          conn->proxypasswd = curl_easy_unescape(data, proxypasswd, 0, NULL);
        else
          conn->proxypasswd = strdup("");

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

      if(!result) {
        conn->bits.proxy_user_passwd = TRUE; /* enable it */
        atsign++; /* the right side of the @-letter */

        proxyptr = atsign; /* now use this instead */
      }
    }

    free(proxyuser);
    free(proxypasswd);

    if(result)
      return result;
  }

  /* start scanning for port number at this point */
  portptr = proxyptr;

  /* detect and extract RFC6874-style IPv6-addresses */
  if(*proxyptr == '[') {
    char *ptr = ++proxyptr; /* advance beyond the initial bracket */
    while(*ptr && (ISXDIGIT(*ptr) || (*ptr == ':') || (*ptr == '.')))
      ptr++;
    if(*ptr == '%') {
      /* There might be a zone identifier */
      if(strncmp("%25", ptr, 3))
        infof(data, "Please URL encode %% as %%25, see RFC 6874.\n");
      ptr++;
      /* Allow unresered characters as defined in RFC 3986 */
      while(*ptr && (ISALPHA(*ptr) || ISXDIGIT(*ptr) || (*ptr == '-') ||
                     (*ptr == '.') || (*ptr == '_') || (*ptr == '~')))
        ptr++;
    }
    if(*ptr == ']')
      /* yeps, it ended nicely with a bracket as well */
      *ptr++ = 0;
    else
      infof(data, "Invalid IPv6 address format\n");
    portptr = ptr;
    /* Note that if this didn't end with a bracket, we still advanced the
     * proxyptr first, but I can't see anything wrong with that as no host
     * name nor a numeric can legally start with a bracket.
     */
  }

  /* Get port number off proxy.server.com:1080 */
  prox_portno = strchr(portptr, ':');
  if(prox_portno) {
    *prox_portno = 0x0; /* cut off number from host name */
    prox_portno ++;
    /* now set the local port number */
    conn->port = strtol(prox_portno, NULL, 10);
  }
  else {
    if(proxyptr[0]=='/')
      /* If the first character in the proxy string is a slash, fail
         immediately. The following code will otherwise clear the string which
         will lead to code running as if no proxy was set! */
      return CURLE_COULDNT_RESOLVE_PROXY;

    /* without a port number after the host name, some people seem to use
       a slash so we strip everything from the first slash */
    atsign = strchr(proxyptr, '/');
    if(atsign)
      *atsign = 0x0; /* cut off path part from host name */

    if(data->set.proxyport)
      /* None given in the proxy string, then get the default one if it is
         given */
      conn->port = data->set.proxyport;
  }

  /* now, clone the cleaned proxy host name */
  conn->proxy.rawalloc = strdup(proxyptr);
  conn->proxy.name = conn->proxy.rawalloc;

  if(!conn->proxy.rawalloc)
    return CURLE_OUT_OF_MEMORY;

  return CURLE_OK;
}

/*
 * Extract the user and password from the authentication string
 */
static CURLcode parse_proxy_auth(struct SessionHandle *data,
                                 struct connectdata *conn)
{
  char proxyuser[MAX_CURL_USER_LENGTH]="";
  char proxypasswd[MAX_CURL_PASSWORD_LENGTH]="";

  if(data->set.str[STRING_PROXYUSERNAME] != NULL) {
    strncpy(proxyuser, data->set.str[STRING_PROXYUSERNAME],
            MAX_CURL_USER_LENGTH);
    proxyuser[MAX_CURL_USER_LENGTH-1] = '\0';   /*To be on safe side*/
  }
  if(data->set.str[STRING_PROXYPASSWORD] != NULL) {
    strncpy(proxypasswd, data->set.str[STRING_PROXYPASSWORD],
            MAX_CURL_PASSWORD_LENGTH);
    proxypasswd[MAX_CURL_PASSWORD_LENGTH-1] = '\0'; /*To be on safe side*/
  }

  conn->proxyuser = curl_easy_unescape(data, proxyuser, 0, NULL);
  if(!conn->proxyuser)
    return CURLE_OUT_OF_MEMORY;

  conn->proxypasswd = curl_easy_unescape(data, proxypasswd, 0, NULL);
  if(!conn->proxypasswd)
    return CURLE_OUT_OF_MEMORY;

  return CURLE_OK;
}
#endif /* CURL_DISABLE_PROXY */

/*
 * parse_url_login()
 *
 * Parse the login details (user name, password and options) from the URL and
 * strip them out of the host name
 *
 * Inputs: data->set.use_netrc (CURLOPT_NETRC)
 *         conn->host.name
 *
 * Outputs: (almost :- all currently undefined)
 *          conn->bits.user_passwd  - non-zero if non-default passwords exist
 *          user                    - non-zero length if defined
 *          passwd                  - non-zero length if defined
 *          options                 - non-zero length if defined
 *          conn->host.name         - remove user name and password
 */
static CURLcode parse_url_login(struct SessionHandle *data,
                                struct connectdata *conn,
                                char **user, char **passwd, char **options)
{
  CURLcode result = CURLE_OK;
  char *userp = NULL;
  char *passwdp = NULL;
  char *optionsp = NULL;

  /* At this point, we're hoping all the other special cases have
   * been taken care of, so conn->host.name is at most
   *    [user[:password][;options]]@]hostname
   *
   * We need somewhere to put the embedded details, so do that first.
   */

  char *ptr = strchr(conn->host.name, '@');
  char *login = conn->host.name;

  DEBUGASSERT(!**user);
  DEBUGASSERT(!**passwd);
  DEBUGASSERT(!**options);

  if(!ptr)
    goto out;

  /* We will now try to extract the
   * possible login information in a string like:
   * ftp://user:password@ftp.my.site:8021/README */
  conn->host.name = ++ptr;

  /* So the hostname is sane.  Only bother interpreting the
   * results if we could care.  It could still be wasted
   * work because it might be overtaken by the programmatically
   * set user/passwd, but doing that first adds more cases here :-(
   */

  if(data->set.use_netrc == CURL_NETRC_REQUIRED)
    goto out;

  /* We could use the login information in the URL so extract it */
  result = parse_login_details(login, ptr - login - 1,
                               &userp, &passwdp, &optionsp);
  if(result)
    goto out;

  if(userp) {
    char *newname;

    /* We have a user in the URL */
    conn->bits.userpwd_in_url = TRUE;
    conn->bits.user_passwd = TRUE; /* enable user+password */

    /* Decode the user */
    newname = curl_easy_unescape(data, userp, 0, NULL);
    if(!newname) {
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }

    free(*user);
    *user = newname;
  }

  if(passwdp) {
    /* We have a password in the URL so decode it */
    char *newpasswd = curl_easy_unescape(data, passwdp, 0, NULL);
    if(!newpasswd) {
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }

    free(*passwd);
    *passwd = newpasswd;
  }

  if(optionsp) {
    /* We have an options list in the URL so decode it */
    char *newoptions = curl_easy_unescape(data, optionsp, 0, NULL);
    if(!newoptions) {
      result = CURLE_OUT_OF_MEMORY;
      goto out;
    }

    free(*options);
    *options = newoptions;
  }


  out:

  free(userp);
  free(passwdp);
  free(optionsp);

  return result;
}

/*
 * parse_login_details()
 *
 * This is used to parse a login string for user name, password and options in
 * the following formats:
 *
 *   user
 *   user:password
 *   user:password;options
 *   user;options
 *   user;options:password
 *   :password
 *   :password;options
 *   ;options
 *   ;options:password
 *
 * Parameters:
 *
 * login    [in]     - The login string.
 * len      [in]     - The length of the login string.
 * userp    [in/out] - The address where a pointer to newly allocated memory
 *                     holding the user will be stored upon completion.
 * passdwp  [in/out] - The address where a pointer to newly allocated memory
 *                     holding the password will be stored upon completion.
 * optionsp [in/out] - The address where a pointer to newly allocated memory
 *                     holding the options will be stored upon completion.
 *
 * Returns CURLE_OK on success.
 */
static CURLcode parse_login_details(const char *login, const size_t len,
                                    char **userp, char **passwdp,
                                    char **optionsp)
{
  CURLcode result = CURLE_OK;
  char *ubuf = NULL;
  char *pbuf = NULL;
  char *obuf = NULL;
  const char *psep = NULL;
  const char *osep = NULL;
  size_t ulen;
  size_t plen;
  size_t olen;

  /* Attempt to find the password separator */
  if(passwdp) {
    psep = strchr(login, ':');

    /* Within the constraint of the login string */
    if(psep >= login + len)
      psep = NULL;
  }

  /* Attempt to find the options separator */
  if(optionsp) {
    osep = strchr(login, ';');

    /* Within the constraint of the login string */
    if(osep >= login + len)
      osep = NULL;
  }

  /* Calculate the portion lengths */
  ulen = (psep ?
          (size_t)(osep && psep > osep ? osep - login : psep - login) :
          (osep ? (size_t)(osep - login) : len));
  plen = (psep ?
          (osep && osep > psep ? (size_t)(osep - psep) :
                                 (size_t)(login + len - psep)) - 1 : 0);
  olen = (osep ?
          (psep && psep > osep ? (size_t)(psep - osep) :
                                 (size_t)(login + len - osep)) - 1 : 0);

  /* Allocate the user portion buffer */
  if(userp && ulen) {
    ubuf = malloc(ulen + 1);
    if(!ubuf)
      result = CURLE_OUT_OF_MEMORY;
  }

  /* Allocate the password portion buffer */
  if(!result && passwdp && plen) {
    pbuf = malloc(plen + 1);
    if(!pbuf) {
      free(ubuf);
      result = CURLE_OUT_OF_MEMORY;
    }
  }

  /* Allocate the options portion buffer */
  if(!result && optionsp && olen) {
    obuf = malloc(olen + 1);
    if(!obuf) {
      free(pbuf);
      free(ubuf);
      result = CURLE_OUT_OF_MEMORY;
    }
  }

  if(!result) {
    /* Store the user portion if necessary */
    if(ubuf) {
      memcpy(ubuf, login, ulen);
      ubuf[ulen] = '\0';
      Curl_safefree(*userp);
      *userp = ubuf;
    }

    /* Store the password portion if necessary */
    if(pbuf) {
      memcpy(pbuf, psep + 1, plen);
      pbuf[plen] = '\0';
      Curl_safefree(*passwdp);
      *passwdp = pbuf;
    }

    /* Store the options portion if necessary */
    if(obuf) {
      memcpy(obuf, osep + 1, olen);
      obuf[olen] = '\0';
      Curl_safefree(*optionsp);
      *optionsp = obuf;
    }
  }

  return result;
}

/*************************************************************
 * Figure out the remote port number and fix it in the URL
 *
 * No matter if we use a proxy or not, we have to figure out the remote
 * port number of various reasons.
 *
 * To be able to detect port number flawlessly, we must not confuse them
 * IPv6-specified addresses in the [0::1] style. (RFC2732)
 *
 * The conn->host.name is currently [user:passwd@]host[:port] where host
 * could be a hostname, IPv4 address or IPv6 address.
 *
 * The port number embedded in the URL is replaced, if necessary.
 *************************************************************/
static CURLcode parse_remote_port(struct SessionHandle *data,
                                  struct connectdata *conn)
{
  char *portptr;
  char endbracket;

  /* Note that at this point, the IPv6 address cannot contain any scope
     suffix as that has already been removed in the parseurlandfillconn()
     function */
  if((1 == sscanf(conn->host.name, "[%*45[0123456789abcdefABCDEF:.]%c",
                  &endbracket)) &&
     (']' == endbracket)) {
    /* this is a RFC2732-style specified IP-address */
    conn->bits.ipv6_ip = TRUE;

    conn->host.name++; /* skip over the starting bracket */
    portptr = strchr(conn->host.name, ']');
    if(portptr) {
      *portptr++ = '\0'; /* zero terminate, killing the bracket */
      if(':' != *portptr)
        portptr = NULL; /* no port number available */
    }
  }
  else {
#ifdef ENABLE_IPV6
    struct in6_addr in6;
    if(Curl_inet_pton(AF_INET6, conn->host.name, &in6) > 0) {
      /* This is a numerical IPv6 address, meaning this is a wrongly formatted
         URL */
      failf(data, "IPv6 numerical address used in URL without brackets");
      return CURLE_URL_MALFORMAT;
    }
#endif

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

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

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

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

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

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

    char *rest;
    long port;

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

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