/***************************************************************************

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) 1998 - 2022, 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.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.

 *

 * SPDX-License-Identifier: curl

 *

 ***************************************************************************/

#include "curl_setup.h"

#ifndef CURL_DISABLE_GOPHER

#include "urldata.h"

#include <curl/curl.h>

#include "transfer.h"

#include "sendf.h"

#include "connect.h"

#include "progress.h"

#include "gopher.h"

#include "select.h"

#include "strdup.h"

#include "vtls/vtls.h"

#include "url.h"

#include "escape.h"

#include "warnless.h"

#include "curl_printf.h"

#include "curl_memory.h"

/* The last #include file should be: */

#include "memdebug.h"

/*

 * Forward declarations.

 */

static CURLcode gopher_do(struct Curl_easy *data, bool *done);

#ifdef USE_SSL

static CURLcode gopher_connect(struct Curl_easy *data, bool *done);

static CURLcode gopher_connecting(struct Curl_easy *data, bool *done);

#endif

/*

 * 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 */

  ZERO_NULL,                            /* attach connection */

  PORT_GOPHER,                          /* defport */

  CURLPROTO_GOPHER,                     /* protocol */

  CURLPROTO_GOPHER,                     /* family */

  PROTOPT_NONE                          /* flags */

};

#ifdef USE_SSL

const struct Curl_handler Curl_handler_gophers = {

  "GOPHERS",                            /* scheme */

  ZERO_NULL,                            /* setup_connection */

  gopher_do,                            /* do_it */

  ZERO_NULL,                            /* done */

  ZERO_NULL,                            /* do_more */

  gopher_connect,                       /* connect_it */

  gopher_connecting,                    /* 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 */

  ZERO_NULL,                            /* attach connection */

  PORT_GOPHER,                          /* defport */

  CURLPROTO_GOPHERS,                    /* protocol */

  CURLPROTO_GOPHER,                     /* family */

  PROTOPT_SSL                           /* flags */

};

static CURLcode gopher_connect(struct Curl_easy *data, bool *done)

{

  (void)data;

  (void)done;

  return CURLE_OK;

}

static CURLcode gopher_connecting(struct Curl_easy *data, bool *done)

{

  struct connectdata *conn = data->conn;

  CURLcode result = Curl_ssl_connect(data, conn, FIRSTSOCKET);

  if(result)

    connclose(conn, "Failed TLS connection");

  *done = TRUE;

  return result;

}

#endif

static CURLcode gopher_do(struct Curl_easy *data, bool *done)

{

  CURLcode result = CURLE_OK;

  struct connectdata *conn = data->conn;

  curl_socket_t sockfd = conn->sock[FIRSTSOCKET];

  char *gopherpath;

  char *path = data->state.up.path;

  char *query = data->state.up.query;

  char *sel = NULL;

  char *sel_org = NULL;

  timediff_t timeout_ms;

  ssize_t amount, k;

  size_t len;

  int what;

  *done = TRUE; /* unconditionally */

  /* path is guaranteed non-NULL */

  DEBUGASSERT(path);

  if(query)

    gopherpath = aprintf("%s?%s", path, query);

  else

    gopherpath = strdup(path);

  if(!gopherpath)

    return CURLE_OUT_OF_MEMORY;

  /* Create selector. Degenerate cases: / and /1 => convert to "" */

  if(strlen(gopherpath) <= 2) {

    sel = (char *)"";

    len = strlen(sel);

    free(gopherpath);

  }

  else {

    char *newp;

    /* Otherwise, drop / and the first character (i.e., item type) ... */

    newp = gopherpath;

    newp += 2;

    /* ... and finally unescape */

    result = Curl_urldecode(newp, 0, &sel, &len, REJECT_ZERO);

    free(gopherpath);

    if(result)

      return result;

    sel_org = sel;

  }

  k = curlx_uztosz(len);

  for(;;) {

    /* Break out of the loop if the selector is empty because OpenSSL and/or

       LibreSSL fail with errno 0 if this is the case. */

    if(strlen(sel) < 1)

      break;

    result = Curl_write(data, sockfd, sel, k, &amount);

    if(!result) { /* Which may not have written it all! */

      result = Curl_client_write(data, CLIENTWRITE_HEADER, sel, amount);

      if(result)

        break;

      k -= amount;

      sel += amount;

      if(k < 1)

        break; /* but it did write it all */

    }

    else

      break;

    timeout_ms = Curl_timeleft(data, NULL, FALSE);

    if(timeout_ms < 0) {

      result = CURLE_OPERATION_TIMEDOUT;

      break;

    }

    if(!timeout_ms)

      timeout_ms = TIMEDIFF_T_MAX;

    /* 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.

    */

    what = SOCKET_WRITABLE(sockfd, timeout_ms);

    if(what < 0) {

      result = CURLE_SEND_ERROR;

      break;

    }

    else if(!what) {

      result = CURLE_OPERATION_TIMEDOUT;

      break;

    }

  }

  free(sel_org);

  if(!result)

    result = Curl_write(data, sockfd, "\r\n", 2, &amount);

  if(result) {

    failf(data, "Failed sending Gopher request");

    return result;

  }

  result = Curl_client_write(data, CLIENTWRITE_HEADER, (char *)"\r\n", 2);

  if(result)

    return result;

  Curl_setup_transfer(data, FIRSTSOCKET, -1, FALSE, -1);

  return CURLE_OK;

}

#endif /*CURL_DISABLE_GOPHER*/