text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2017, 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 https://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.
   *
   ***************************************************************************/
  
  #include "curl_setup.h"
  
  #ifndef CURL_DISABLE_GOPHER
  
  #include "urldata.h"
  #include <curl/curl.h>
  #include "transfer.h"
  #include "sendf.h"
  #include "progress.h"
  #include "gopher.h"
  #include "select.h"
  #include "url.h"
  #include "escape.h"
  #include "warnless.h"
  #include "curl_memory.h"
  /* The last #include file should be: */
  #include "memdebug.h"
  
  /*
   * Forward declarations.
   */
  
  static CURLcode gopher_do(struct connectdata *conn, bool *done);
  
  /*
   * Gopher protocol handler.
   * This is also a nice simple template to build off for simple
   * connect-command-download protocols.
   */
  
  const struct Curl_handler Curl_handler_gopher = {
    "GOPHER",                             /* scheme */
    ZERO_NULL,                            /* setup_connection */
    gopher_do,                            /* do_it */
    ZERO_NULL,                            /* 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,                            /* domore_getsock */
    ZERO_NULL,                            /* perform_getsock */
    ZERO_NULL,                            /* disconnect */
    ZERO_NULL,                            /* readwrite */
    ZERO_NULL,                            /* connection_check */
    PORT_GOPHER,                          /* defport */
    CURLPROTO_GOPHER,                     /* protocol */
    PROTOPT_NONE                          /* flags */
  };
  
  static CURLcode gopher_do(struct connectdata *conn, bool *done)
  {
    CURLcode result = CURLE_OK;
    struct Curl_easy *data = conn->data;
    curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
  
    curl_off_t *bytecount = &data->req.bytecount;
    char *path = data->state.path;
    char *sel = NULL;
    char *sel_org = NULL;
    ssize_t amount, k;
    size_t len;
  
    *done = TRUE; /* unconditionally */
  
    /* Create selector. Degenerate cases: / and /1 => convert to "" */
    if(strlen(path) <= 2) {
      sel = (char *)"";
      len = (int)strlen(sel);
    }
    else {
      char *newp;
      size_t j, i;
  
      /* Otherwise, drop / and the first character (i.e., item type) ... */
      newp = path;
      newp += 2;
  
      /* ... then turn ? into TAB for search servers, Veronica, etc. ... */
      j = strlen(newp);
      for(i = 0; i<j; i++)
        if(newp[i] == '?')
          newp[i] = '\x09';
  
      /* ... and finally unescape */
      result = Curl_urldecode(data, newp, 0, &sel, &len, FALSE);
      if(result)
        return result;
      sel_org = sel;
    }
  
    /* We use Curl_write instead of Curl_sendf to make sure the entire buffer is
       sent, which could be sizeable with long selectors. */
    k = curlx_uztosz(len);
  
    for(;;) {
      result = Curl_write(conn, sockfd, sel, k, &amount);
      if(!result) { /* Which may not have written it all! */
        result = Curl_client_write(conn, CLIENTWRITE_HEADER, sel, amount);
        if(result)
          break;
  
        k -= amount;
        sel += amount;
        if(k < 1)
          break; /* but it did write it all */
      }
      else
        break;
  
      /* Don't busyloop. The entire loop thing is a work-around as it causes a
         BLOCKING behavior which is a NO-NO. This function should rather be
         split up in a do and a doing piece where the pieces that aren't
         possible to send now will be sent in the doing function repeatedly
         until the entire request is sent.
  
         Wait a while for the socket to be writable. Note that this doesn't
         acknowledge the timeout.
      */
      if(SOCKET_WRITABLE(sockfd, 100) < 0) {
        result = CURLE_SEND_ERROR;
        break;
      }
    }
  
    free(sel_org);
  
    if(!result)
      /* We can use Curl_sendf to send the terminal \r\n relatively safely and
         save allocing another string/doing another _write loop. */
      result = Curl_sendf(sockfd, conn, "\r\n");
    if(result) {
      failf(data, "Failed sending Gopher request");
      return result;
    }
    result = Curl_client_write(conn, CLIENTWRITE_HEADER, (char *)"\r\n", 2);
    if(result)
      return result;
  
    Curl_setup_transfer(conn, FIRSTSOCKET, -1, FALSE, bytecount,
                        -1, NULL); /* no upload */
    return CURLE_OK;
  }
  #endif /*CURL_DISABLE_GOPHER*/
  