diff mupdf-source/thirdparty/curl/lib/telnet.c @ 2:b50eed0cc0ef upstream

ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.
author Franz Glasner <fzglas.hg@dom66.de>
date Mon, 15 Sep 2025 11:43:07 +0200
parents
children
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/thirdparty/curl/lib/telnet.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,1699 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2019, 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_TELNET
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef HAVE_NET_IF_H
+#include <net/if.h>
+#endif
+#ifdef HAVE_SYS_IOCTL_H
+#include <sys/ioctl.h>
+#endif
+
+#ifdef HAVE_SYS_PARAM_H
+#include <sys/param.h>
+#endif
+
+#include "urldata.h"
+#include <curl/curl.h>
+#include "transfer.h"
+#include "sendf.h"
+#include "telnet.h"
+#include "connect.h"
+#include "progress.h"
+#include "system_win32.h"
+#include "arpa_telnet.h"
+#include "select.h"
+#include "strcase.h"
+#include "warnless.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+#define SUBBUFSIZE 512
+
+#define CURL_SB_CLEAR(x)  x->subpointer = x->subbuffer
+#define CURL_SB_TERM(x)                                 \
+  do {                                                  \
+    x->subend = x->subpointer;                          \
+    CURL_SB_CLEAR(x);                                   \
+  } WHILE_FALSE
+#define CURL_SB_ACCUM(x,c)                                      \
+  do {                                                          \
+    if(x->subpointer < (x->subbuffer + sizeof(x->subbuffer)))   \
+      *x->subpointer++ = (c);                                   \
+  } WHILE_FALSE
+
+#define  CURL_SB_GET(x) ((*x->subpointer++)&0xff)
+#define  CURL_SB_LEN(x) (x->subend - x->subpointer)
+
+/* For posterity:
+#define  CURL_SB_PEEK(x) ((*x->subpointer)&0xff)
+#define  CURL_SB_EOF(x) (x->subpointer >= x->subend) */
+
+#ifdef CURL_DISABLE_VERBOSE_STRINGS
+#define printoption(a,b,c,d)  Curl_nop_stmt
+#endif
+
+#ifdef USE_WINSOCK
+typedef WSAEVENT (WINAPI *WSOCK2_EVENT)(void);
+typedef FARPROC WSOCK2_FUNC;
+static CURLcode check_wsock2(struct Curl_easy *data);
+#endif
+
+static
+CURLcode telrcv(struct connectdata *,
+                const unsigned char *inbuf, /* Data received from socket */
+                ssize_t count);             /* Number of bytes received */
+
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+static void printoption(struct Curl_easy *data,
+                        const char *direction,
+                        int cmd, int option);
+#endif
+
+static void negotiate(struct connectdata *);
+static void send_negotiation(struct connectdata *, int cmd, int option);
+static void set_local_option(struct connectdata *conn,
+                             int option, int newstate);
+static void set_remote_option(struct connectdata *conn,
+                              int option, int newstate);
+
+static void printsub(struct Curl_easy *data,
+                     int direction, unsigned char *pointer,
+                     size_t length);
+static void suboption(struct connectdata *);
+static void sendsuboption(struct connectdata *conn, int option);
+
+static CURLcode telnet_do(struct connectdata *conn, bool *done);
+static CURLcode telnet_done(struct connectdata *conn,
+                                 CURLcode, bool premature);
+static CURLcode send_telnet_data(struct connectdata *conn,
+                                 char *buffer, ssize_t nread);
+
+/* For negotiation compliant to RFC 1143 */
+#define CURL_NO          0
+#define CURL_YES         1
+#define CURL_WANTYES     2
+#define CURL_WANTNO      3
+
+#define CURL_EMPTY       0
+#define CURL_OPPOSITE    1
+
+/*
+ * Telnet receiver states for fsm
+ */
+typedef enum
+{
+   CURL_TS_DATA = 0,
+   CURL_TS_IAC,
+   CURL_TS_WILL,
+   CURL_TS_WONT,
+   CURL_TS_DO,
+   CURL_TS_DONT,
+   CURL_TS_CR,
+   CURL_TS_SB,   /* sub-option collection */
+   CURL_TS_SE   /* looking for sub-option end */
+} TelnetReceive;
+
+struct TELNET {
+  int please_negotiate;
+  int already_negotiated;
+  int us[256];
+  int usq[256];
+  int us_preferred[256];
+  int him[256];
+  int himq[256];
+  int him_preferred[256];
+  int subnegotiation[256];
+  char subopt_ttype[32];             /* Set with suboption TTYPE */
+  char subopt_xdisploc[128];         /* Set with suboption XDISPLOC */
+  unsigned short subopt_wsx;         /* Set with suboption NAWS */
+  unsigned short subopt_wsy;         /* Set with suboption NAWS */
+  struct curl_slist *telnet_vars;    /* Environment variables */
+
+  /* suboptions */
+  unsigned char subbuffer[SUBBUFSIZE];
+  unsigned char *subpointer, *subend;      /* buffer for sub-options */
+
+  TelnetReceive telrcv_state;
+};
+
+
+/*
+ * TELNET protocol handler.
+ */
+
+const struct Curl_handler Curl_handler_telnet = {
+  "TELNET",                             /* scheme */
+  ZERO_NULL,                            /* setup_connection */
+  telnet_do,                            /* do_it */
+  telnet_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,                            /* domore_getsock */
+  ZERO_NULL,                            /* perform_getsock */
+  ZERO_NULL,                            /* disconnect */
+  ZERO_NULL,                            /* readwrite */
+  ZERO_NULL,                            /* connection_check */
+  PORT_TELNET,                          /* defport */
+  CURLPROTO_TELNET,                     /* protocol */
+  PROTOPT_NONE | PROTOPT_NOURLQUERY     /* flags */
+};
+
+
+#ifdef USE_WINSOCK
+static CURLcode
+check_wsock2(struct Curl_easy *data)
+{
+  int err;
+  WORD wVersionRequested;
+  WSADATA wsaData;
+
+  DEBUGASSERT(data);
+
+  /* telnet requires at least WinSock 2.0 so ask for it. */
+  wVersionRequested = MAKEWORD(2, 0);
+
+  err = WSAStartup(wVersionRequested, &wsaData);
+
+  /* We must've called this once already, so this call */
+  /* should always succeed.  But, just in case... */
+  if(err != 0) {
+    failf(data,"WSAStartup failed (%d)",err);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* We have to have a WSACleanup call for every successful */
+  /* WSAStartup call. */
+  WSACleanup();
+
+  /* Check that our version is supported */
+  if(LOBYTE(wsaData.wVersion) != LOBYTE(wVersionRequested) ||
+      HIBYTE(wsaData.wVersion) != HIBYTE(wVersionRequested)) {
+      /* Our version isn't supported */
+    failf(data, "insufficient winsock version to support "
+          "telnet");
+    return CURLE_FAILED_INIT;
+  }
+
+  /* Our version is supported */
+  return CURLE_OK;
+}
+#endif
+
+static
+CURLcode init_telnet(struct connectdata *conn)
+{
+  struct TELNET *tn;
+
+  tn = calloc(1, sizeof(struct TELNET));
+  if(!tn)
+    return CURLE_OUT_OF_MEMORY;
+
+  conn->data->req.protop = tn; /* make us known */
+
+  tn->telrcv_state = CURL_TS_DATA;
+
+  /* Init suboptions */
+  CURL_SB_CLEAR(tn);
+
+  /* Set the options we want by default */
+  tn->us_preferred[CURL_TELOPT_SGA] = CURL_YES;
+  tn->him_preferred[CURL_TELOPT_SGA] = CURL_YES;
+
+  /* To be compliant with previous releases of libcurl
+     we enable this option by default. This behaviour
+         can be changed thanks to the "BINARY" option in
+         CURLOPT_TELNETOPTIONS
+  */
+  tn->us_preferred[CURL_TELOPT_BINARY] = CURL_YES;
+  tn->him_preferred[CURL_TELOPT_BINARY] = CURL_YES;
+
+  /* We must allow the server to echo what we sent
+         but it is not necessary to request the server
+         to do so (it might forces the server to close
+         the connection). Hence, we ignore ECHO in the
+         negotiate function
+  */
+  tn->him_preferred[CURL_TELOPT_ECHO] = CURL_YES;
+
+  /* Set the subnegotiation fields to send information
+    just after negotiation passed (do/will)
+
+     Default values are (0,0) initialized by calloc.
+     According to the RFC1013 it is valid:
+     A value equal to zero is acceptable for the width (or height),
+         and means that no character width (or height) is being sent.
+         In this case, the width (or height) that will be assumed by the
+         Telnet server is operating system specific (it will probably be
+         based upon the terminal type information that may have been sent
+         using the TERMINAL TYPE Telnet option). */
+  tn->subnegotiation[CURL_TELOPT_NAWS] = CURL_YES;
+  return CURLE_OK;
+}
+
+static void negotiate(struct connectdata *conn)
+{
+  int i;
+  struct TELNET *tn = (struct TELNET *) conn->data->req.protop;
+
+  for(i = 0; i < CURL_NTELOPTS; i++) {
+    if(i == CURL_TELOPT_ECHO)
+      continue;
+
+    if(tn->us_preferred[i] == CURL_YES)
+      set_local_option(conn, i, CURL_YES);
+
+    if(tn->him_preferred[i] == CURL_YES)
+      set_remote_option(conn, i, CURL_YES);
+  }
+}
+
+#ifndef CURL_DISABLE_VERBOSE_STRINGS
+static void printoption(struct Curl_easy *data,
+                        const char *direction, int cmd, int option)
+{
+  if(data->set.verbose) {
+    if(cmd == CURL_IAC) {
+      if(CURL_TELCMD_OK(option))
+        infof(data, "%s IAC %s\n", direction, CURL_TELCMD(option));
+      else
+        infof(data, "%s IAC %d\n", direction, option);
+    }
+    else {
+      const char *fmt = (cmd == CURL_WILL) ? "WILL" :
+                        (cmd == CURL_WONT) ? "WONT" :
+                        (cmd == CURL_DO) ? "DO" :
+                        (cmd == CURL_DONT) ? "DONT" : 0;
+      if(fmt) {
+        const char *opt;
+        if(CURL_TELOPT_OK(option))
+          opt = CURL_TELOPT(option);
+        else if(option == CURL_TELOPT_EXOPL)
+          opt = "EXOPL";
+        else
+          opt = NULL;
+
+        if(opt)
+          infof(data, "%s %s %s\n", direction, fmt, opt);
+        else
+          infof(data, "%s %s %d\n", direction, fmt, option);
+      }
+      else
+        infof(data, "%s %d %d\n", direction, cmd, option);
+    }
+  }
+}
+#endif
+
+static void send_negotiation(struct connectdata *conn, int cmd, int option)
+{
+   unsigned char buf[3];
+   ssize_t bytes_written;
+   struct Curl_easy *data = conn->data;
+
+   buf[0] = CURL_IAC;
+   buf[1] = (unsigned char)cmd;
+   buf[2] = (unsigned char)option;
+
+   bytes_written = swrite(conn->sock[FIRSTSOCKET], buf, 3);
+   if(bytes_written < 0) {
+     int err = SOCKERRNO;
+     failf(data,"Sending data failed (%d)",err);
+   }
+
+   printoption(conn->data, "SENT", cmd, option);
+}
+
+static
+void set_remote_option(struct connectdata *conn, int option, int newstate)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  if(newstate == CURL_YES) {
+    switch(tn->him[option]) {
+    case CURL_NO:
+      tn->him[option] = CURL_WANTYES;
+      send_negotiation(conn, CURL_DO, option);
+      break;
+
+    case CURL_YES:
+      /* Already enabled */
+      break;
+
+    case CURL_WANTNO:
+      switch(tn->himq[option]) {
+      case CURL_EMPTY:
+        /* Already negotiating for CURL_YES, queue the request */
+        tn->himq[option] = CURL_OPPOSITE;
+        break;
+      case CURL_OPPOSITE:
+        /* Error: already queued an enable request */
+        break;
+      }
+      break;
+
+    case CURL_WANTYES:
+      switch(tn->himq[option]) {
+      case CURL_EMPTY:
+        /* Error: already negotiating for enable */
+        break;
+      case CURL_OPPOSITE:
+        tn->himq[option] = CURL_EMPTY;
+        break;
+      }
+      break;
+    }
+  }
+  else { /* NO */
+    switch(tn->him[option]) {
+    case CURL_NO:
+      /* Already disabled */
+      break;
+
+    case CURL_YES:
+      tn->him[option] = CURL_WANTNO;
+      send_negotiation(conn, CURL_DONT, option);
+      break;
+
+    case CURL_WANTNO:
+      switch(tn->himq[option]) {
+      case CURL_EMPTY:
+        /* Already negotiating for NO */
+        break;
+      case CURL_OPPOSITE:
+        tn->himq[option] = CURL_EMPTY;
+        break;
+      }
+      break;
+
+    case CURL_WANTYES:
+      switch(tn->himq[option]) {
+      case CURL_EMPTY:
+        tn->himq[option] = CURL_OPPOSITE;
+        break;
+      case CURL_OPPOSITE:
+        break;
+      }
+      break;
+    }
+  }
+}
+
+static
+void rec_will(struct connectdata *conn, int option)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  switch(tn->him[option]) {
+  case CURL_NO:
+    if(tn->him_preferred[option] == CURL_YES) {
+      tn->him[option] = CURL_YES;
+      send_negotiation(conn, CURL_DO, option);
+    }
+    else
+      send_negotiation(conn, CURL_DONT, option);
+
+    break;
+
+  case CURL_YES:
+    /* Already enabled */
+    break;
+
+  case CURL_WANTNO:
+    switch(tn->himq[option]) {
+    case CURL_EMPTY:
+      /* Error: DONT answered by WILL */
+      tn->him[option] = CURL_NO;
+      break;
+    case CURL_OPPOSITE:
+      /* Error: DONT answered by WILL */
+      tn->him[option] = CURL_YES;
+      tn->himq[option] = CURL_EMPTY;
+      break;
+    }
+    break;
+
+  case CURL_WANTYES:
+    switch(tn->himq[option]) {
+    case CURL_EMPTY:
+      tn->him[option] = CURL_YES;
+      break;
+    case CURL_OPPOSITE:
+      tn->him[option] = CURL_WANTNO;
+      tn->himq[option] = CURL_EMPTY;
+      send_negotiation(conn, CURL_DONT, option);
+      break;
+    }
+    break;
+  }
+}
+
+static
+void rec_wont(struct connectdata *conn, int option)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  switch(tn->him[option]) {
+  case CURL_NO:
+    /* Already disabled */
+    break;
+
+  case CURL_YES:
+    tn->him[option] = CURL_NO;
+    send_negotiation(conn, CURL_DONT, option);
+    break;
+
+  case CURL_WANTNO:
+    switch(tn->himq[option]) {
+    case CURL_EMPTY:
+      tn->him[option] = CURL_NO;
+      break;
+
+    case CURL_OPPOSITE:
+      tn->him[option] = CURL_WANTYES;
+      tn->himq[option] = CURL_EMPTY;
+      send_negotiation(conn, CURL_DO, option);
+      break;
+    }
+    break;
+
+  case CURL_WANTYES:
+    switch(tn->himq[option]) {
+    case CURL_EMPTY:
+      tn->him[option] = CURL_NO;
+      break;
+    case CURL_OPPOSITE:
+      tn->him[option] = CURL_NO;
+      tn->himq[option] = CURL_EMPTY;
+      break;
+    }
+    break;
+  }
+}
+
+static void
+set_local_option(struct connectdata *conn, int option, int newstate)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  if(newstate == CURL_YES) {
+    switch(tn->us[option]) {
+    case CURL_NO:
+      tn->us[option] = CURL_WANTYES;
+      send_negotiation(conn, CURL_WILL, option);
+      break;
+
+    case CURL_YES:
+      /* Already enabled */
+      break;
+
+    case CURL_WANTNO:
+      switch(tn->usq[option]) {
+      case CURL_EMPTY:
+        /* Already negotiating for CURL_YES, queue the request */
+        tn->usq[option] = CURL_OPPOSITE;
+        break;
+      case CURL_OPPOSITE:
+        /* Error: already queued an enable request */
+        break;
+      }
+      break;
+
+    case CURL_WANTYES:
+      switch(tn->usq[option]) {
+      case CURL_EMPTY:
+        /* Error: already negotiating for enable */
+        break;
+      case CURL_OPPOSITE:
+        tn->usq[option] = CURL_EMPTY;
+        break;
+      }
+      break;
+    }
+  }
+  else { /* NO */
+    switch(tn->us[option]) {
+    case CURL_NO:
+      /* Already disabled */
+      break;
+
+    case CURL_YES:
+      tn->us[option] = CURL_WANTNO;
+      send_negotiation(conn, CURL_WONT, option);
+      break;
+
+    case CURL_WANTNO:
+      switch(tn->usq[option]) {
+      case CURL_EMPTY:
+        /* Already negotiating for NO */
+        break;
+      case CURL_OPPOSITE:
+        tn->usq[option] = CURL_EMPTY;
+        break;
+      }
+      break;
+
+    case CURL_WANTYES:
+      switch(tn->usq[option]) {
+      case CURL_EMPTY:
+        tn->usq[option] = CURL_OPPOSITE;
+        break;
+      case CURL_OPPOSITE:
+        break;
+      }
+      break;
+    }
+  }
+}
+
+static
+void rec_do(struct connectdata *conn, int option)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  switch(tn->us[option]) {
+  case CURL_NO:
+    if(tn->us_preferred[option] == CURL_YES) {
+      tn->us[option] = CURL_YES;
+      send_negotiation(conn, CURL_WILL, option);
+      if(tn->subnegotiation[option] == CURL_YES)
+        /* transmission of data option */
+        sendsuboption(conn, option);
+    }
+    else if(tn->subnegotiation[option] == CURL_YES) {
+      /* send information to achieve this option*/
+      tn->us[option] = CURL_YES;
+      send_negotiation(conn, CURL_WILL, option);
+      sendsuboption(conn, option);
+    }
+    else
+      send_negotiation(conn, CURL_WONT, option);
+    break;
+
+  case CURL_YES:
+    /* Already enabled */
+    break;
+
+  case CURL_WANTNO:
+    switch(tn->usq[option]) {
+    case CURL_EMPTY:
+      /* Error: DONT answered by WILL */
+      tn->us[option] = CURL_NO;
+      break;
+    case CURL_OPPOSITE:
+      /* Error: DONT answered by WILL */
+      tn->us[option] = CURL_YES;
+      tn->usq[option] = CURL_EMPTY;
+      break;
+    }
+    break;
+
+  case CURL_WANTYES:
+    switch(tn->usq[option]) {
+    case CURL_EMPTY:
+      tn->us[option] = CURL_YES;
+      if(tn->subnegotiation[option] == CURL_YES) {
+        /* transmission of data option */
+        sendsuboption(conn, option);
+      }
+      break;
+    case CURL_OPPOSITE:
+      tn->us[option] = CURL_WANTNO;
+      tn->himq[option] = CURL_EMPTY;
+      send_negotiation(conn, CURL_WONT, option);
+      break;
+    }
+    break;
+  }
+}
+
+static
+void rec_dont(struct connectdata *conn, int option)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  switch(tn->us[option]) {
+  case CURL_NO:
+    /* Already disabled */
+    break;
+
+  case CURL_YES:
+    tn->us[option] = CURL_NO;
+    send_negotiation(conn, CURL_WONT, option);
+    break;
+
+  case CURL_WANTNO:
+    switch(tn->usq[option]) {
+    case CURL_EMPTY:
+      tn->us[option] = CURL_NO;
+      break;
+
+    case CURL_OPPOSITE:
+      tn->us[option] = CURL_WANTYES;
+      tn->usq[option] = CURL_EMPTY;
+      send_negotiation(conn, CURL_WILL, option);
+      break;
+    }
+    break;
+
+  case CURL_WANTYES:
+    switch(tn->usq[option]) {
+    case CURL_EMPTY:
+      tn->us[option] = CURL_NO;
+      break;
+    case CURL_OPPOSITE:
+      tn->us[option] = CURL_NO;
+      tn->usq[option] = CURL_EMPTY;
+      break;
+    }
+    break;
+  }
+}
+
+
+static void printsub(struct Curl_easy *data,
+                     int direction,             /* '<' or '>' */
+                     unsigned char *pointer,    /* where suboption data is */
+                     size_t length)             /* length of suboption data */
+{
+  if(data->set.verbose) {
+    unsigned int i = 0;
+    if(direction) {
+      infof(data, "%s IAC SB ", (direction == '<')? "RCVD":"SENT");
+      if(length >= 3) {
+        int j;
+
+        i = pointer[length-2];
+        j = pointer[length-1];
+
+        if(i != CURL_IAC || j != CURL_SE) {
+          infof(data, "(terminated by ");
+          if(CURL_TELOPT_OK(i))
+            infof(data, "%s ", CURL_TELOPT(i));
+          else if(CURL_TELCMD_OK(i))
+            infof(data, "%s ", CURL_TELCMD(i));
+          else
+            infof(data, "%u ", i);
+          if(CURL_TELOPT_OK(j))
+            infof(data, "%s", CURL_TELOPT(j));
+          else if(CURL_TELCMD_OK(j))
+            infof(data, "%s", CURL_TELCMD(j));
+          else
+            infof(data, "%d", j);
+          infof(data, ", not IAC SE!) ");
+        }
+      }
+      length -= 2;
+    }
+    if(length < 1) {
+      infof(data, "(Empty suboption?)");
+      return;
+    }
+
+    if(CURL_TELOPT_OK(pointer[0])) {
+      switch(pointer[0]) {
+      case CURL_TELOPT_TTYPE:
+      case CURL_TELOPT_XDISPLOC:
+      case CURL_TELOPT_NEW_ENVIRON:
+      case CURL_TELOPT_NAWS:
+        infof(data, "%s", CURL_TELOPT(pointer[0]));
+        break;
+      default:
+        infof(data, "%s (unsupported)", CURL_TELOPT(pointer[0]));
+        break;
+      }
+    }
+    else
+      infof(data, "%d (unknown)", pointer[i]);
+
+    switch(pointer[0]) {
+    case CURL_TELOPT_NAWS:
+      if(length > 4)
+        infof(data, "Width: %d ; Height: %d", (pointer[1]<<8) | pointer[2],
+              (pointer[3]<<8) | pointer[4]);
+      break;
+    default:
+      switch(pointer[1]) {
+      case CURL_TELQUAL_IS:
+        infof(data, " IS");
+        break;
+      case CURL_TELQUAL_SEND:
+        infof(data, " SEND");
+        break;
+      case CURL_TELQUAL_INFO:
+        infof(data, " INFO/REPLY");
+        break;
+      case CURL_TELQUAL_NAME:
+        infof(data, " NAME");
+        break;
+      }
+
+      switch(pointer[0]) {
+      case CURL_TELOPT_TTYPE:
+      case CURL_TELOPT_XDISPLOC:
+        pointer[length] = 0;
+        infof(data, " \"%s\"", &pointer[2]);
+        break;
+      case CURL_TELOPT_NEW_ENVIRON:
+        if(pointer[1] == CURL_TELQUAL_IS) {
+          infof(data, " ");
+          for(i = 3; i < length; i++) {
+            switch(pointer[i]) {
+            case CURL_NEW_ENV_VAR:
+              infof(data, ", ");
+              break;
+            case CURL_NEW_ENV_VALUE:
+              infof(data, " = ");
+              break;
+            default:
+              infof(data, "%c", pointer[i]);
+              break;
+            }
+          }
+        }
+        break;
+      default:
+        for(i = 2; i < length; i++)
+          infof(data, " %.2x", pointer[i]);
+        break;
+      }
+    }
+    if(direction)
+      infof(data, "\n");
+  }
+}
+
+static CURLcode check_telnet_options(struct connectdata *conn)
+{
+  struct curl_slist *head;
+  struct curl_slist *beg;
+  char option_keyword[128] = "";
+  char option_arg[256] = "";
+  struct Curl_easy *data = conn->data;
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  CURLcode result = CURLE_OK;
+  int binary_option;
+
+  /* Add the user name as an environment variable if it
+     was given on the command line */
+  if(conn->bits.user_passwd) {
+    msnprintf(option_arg, sizeof(option_arg), "USER,%s", conn->user);
+    beg = curl_slist_append(tn->telnet_vars, option_arg);
+    if(!beg) {
+      curl_slist_free_all(tn->telnet_vars);
+      tn->telnet_vars = NULL;
+      return CURLE_OUT_OF_MEMORY;
+    }
+    tn->telnet_vars = beg;
+    tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES;
+  }
+
+  for(head = data->set.telnet_options; head; head = head->next) {
+    if(sscanf(head->data, "%127[^= ]%*[ =]%255s",
+              option_keyword, option_arg) == 2) {
+
+      /* Terminal type */
+      if(strcasecompare(option_keyword, "TTYPE")) {
+        strncpy(tn->subopt_ttype, option_arg, 31);
+        tn->subopt_ttype[31] = 0; /* String termination */
+        tn->us_preferred[CURL_TELOPT_TTYPE] = CURL_YES;
+        continue;
+      }
+
+      /* Display variable */
+      if(strcasecompare(option_keyword, "XDISPLOC")) {
+        strncpy(tn->subopt_xdisploc, option_arg, 127);
+        tn->subopt_xdisploc[127] = 0; /* String termination */
+        tn->us_preferred[CURL_TELOPT_XDISPLOC] = CURL_YES;
+        continue;
+      }
+
+      /* Environment variable */
+      if(strcasecompare(option_keyword, "NEW_ENV")) {
+        beg = curl_slist_append(tn->telnet_vars, option_arg);
+        if(!beg) {
+          result = CURLE_OUT_OF_MEMORY;
+          break;
+        }
+        tn->telnet_vars = beg;
+        tn->us_preferred[CURL_TELOPT_NEW_ENVIRON] = CURL_YES;
+        continue;
+      }
+
+      /* Window Size */
+      if(strcasecompare(option_keyword, "WS")) {
+        if(sscanf(option_arg, "%hu%*[xX]%hu",
+                  &tn->subopt_wsx, &tn->subopt_wsy) == 2)
+          tn->us_preferred[CURL_TELOPT_NAWS] = CURL_YES;
+        else {
+          failf(data, "Syntax error in telnet option: %s", head->data);
+          result = CURLE_TELNET_OPTION_SYNTAX;
+          break;
+        }
+        continue;
+      }
+
+      /* To take care or not of the 8th bit in data exchange */
+      if(strcasecompare(option_keyword, "BINARY")) {
+        binary_option = atoi(option_arg);
+        if(binary_option != 1) {
+          tn->us_preferred[CURL_TELOPT_BINARY] = CURL_NO;
+          tn->him_preferred[CURL_TELOPT_BINARY] = CURL_NO;
+        }
+        continue;
+      }
+
+      failf(data, "Unknown telnet option %s", head->data);
+      result = CURLE_UNKNOWN_OPTION;
+      break;
+    }
+    failf(data, "Syntax error in telnet option: %s", head->data);
+    result = CURLE_TELNET_OPTION_SYNTAX;
+    break;
+  }
+
+  if(result) {
+    curl_slist_free_all(tn->telnet_vars);
+    tn->telnet_vars = NULL;
+  }
+
+  return result;
+}
+
+/*
+ * suboption()
+ *
+ * Look at the sub-option buffer, and try to be helpful to the other
+ * side.
+ */
+
+static void suboption(struct connectdata *conn)
+{
+  struct curl_slist *v;
+  unsigned char temp[2048];
+  ssize_t bytes_written;
+  size_t len;
+  int err;
+  char varname[128] = "";
+  char varval[128] = "";
+  struct Curl_easy *data = conn->data;
+  struct TELNET *tn = (struct TELNET *)data->req.protop;
+
+  printsub(data, '<', (unsigned char *)tn->subbuffer, CURL_SB_LEN(tn) + 2);
+  switch(CURL_SB_GET(tn)) {
+    case CURL_TELOPT_TTYPE:
+      len = strlen(tn->subopt_ttype) + 4 + 2;
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_TTYPE,
+                CURL_TELQUAL_IS, tn->subopt_ttype, CURL_IAC, CURL_SE);
+      bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
+      if(bytes_written < 0) {
+        err = SOCKERRNO;
+        failf(data,"Sending data failed (%d)",err);
+      }
+      printsub(data, '>', &temp[2], len-2);
+      break;
+    case CURL_TELOPT_XDISPLOC:
+      len = strlen(tn->subopt_xdisploc) + 4 + 2;
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c%s%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_XDISPLOC,
+                CURL_TELQUAL_IS, tn->subopt_xdisploc, CURL_IAC, CURL_SE);
+      bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
+      if(bytes_written < 0) {
+        err = SOCKERRNO;
+        failf(data,"Sending data failed (%d)",err);
+      }
+      printsub(data, '>', &temp[2], len-2);
+      break;
+    case CURL_TELOPT_NEW_ENVIRON:
+      msnprintf((char *)temp, sizeof(temp),
+                "%c%c%c%c", CURL_IAC, CURL_SB, CURL_TELOPT_NEW_ENVIRON,
+                CURL_TELQUAL_IS);
+      len = 4;
+
+      for(v = tn->telnet_vars; v; v = v->next) {
+        size_t tmplen = (strlen(v->data) + 1);
+        /* Add the variable only if it fits */
+        if(len + tmplen < (int)sizeof(temp)-6) {
+          if(sscanf(v->data, "%127[^,],%127s", varname, varval)) {
+            msnprintf((char *)&temp[len], sizeof(temp) - len,
+                      "%c%s%c%s", CURL_NEW_ENV_VAR, varname,
+                      CURL_NEW_ENV_VALUE, varval);
+            len += tmplen;
+          }
+        }
+      }
+      msnprintf((char *)&temp[len], sizeof(temp) - len,
+                "%c%c", CURL_IAC, CURL_SE);
+      len += 2;
+      bytes_written = swrite(conn->sock[FIRSTSOCKET], temp, len);
+      if(bytes_written < 0) {
+        err = SOCKERRNO;
+        failf(data,"Sending data failed (%d)",err);
+      }
+      printsub(data, '>', &temp[2], len-2);
+      break;
+  }
+  return;
+}
+
+
+/*
+ * sendsuboption()
+ *
+ * Send suboption information to the server side.
+ */
+
+static void sendsuboption(struct connectdata *conn, int option)
+{
+  ssize_t bytes_written;
+  int err;
+  unsigned short x, y;
+  unsigned char *uc1, *uc2;
+
+  struct Curl_easy *data = conn->data;
+  struct TELNET *tn = (struct TELNET *)data->req.protop;
+
+  switch(option) {
+  case CURL_TELOPT_NAWS:
+    /* We prepare data to be sent */
+    CURL_SB_CLEAR(tn);
+    CURL_SB_ACCUM(tn, CURL_IAC);
+    CURL_SB_ACCUM(tn, CURL_SB);
+    CURL_SB_ACCUM(tn, CURL_TELOPT_NAWS);
+    /* We must deal either with little or big endian processors */
+    /* Window size must be sent according to the 'network order' */
+    x = htons(tn->subopt_wsx);
+    y = htons(tn->subopt_wsy);
+    uc1 = (unsigned char *)&x;
+    uc2 = (unsigned char *)&y;
+    CURL_SB_ACCUM(tn, uc1[0]);
+    CURL_SB_ACCUM(tn, uc1[1]);
+    CURL_SB_ACCUM(tn, uc2[0]);
+    CURL_SB_ACCUM(tn, uc2[1]);
+
+    CURL_SB_ACCUM(tn, CURL_IAC);
+    CURL_SB_ACCUM(tn, CURL_SE);
+    CURL_SB_TERM(tn);
+    /* data suboption is now ready */
+
+    printsub(data, '>', (unsigned char *)tn->subbuffer + 2,
+             CURL_SB_LEN(tn)-2);
+
+    /* we send the header of the suboption... */
+    bytes_written = swrite(conn->sock[FIRSTSOCKET], tn->subbuffer, 3);
+    if(bytes_written < 0) {
+      err = SOCKERRNO;
+      failf(data, "Sending data failed (%d)", err);
+    }
+    /* ... then the window size with the send_telnet_data() function
+       to deal with 0xFF cases ... */
+    send_telnet_data(conn, (char *)tn->subbuffer + 3, 4);
+    /* ... and the footer */
+    bytes_written = swrite(conn->sock[FIRSTSOCKET], tn->subbuffer + 7, 2);
+    if(bytes_written < 0) {
+      err = SOCKERRNO;
+      failf(data, "Sending data failed (%d)", err);
+    }
+    break;
+  }
+}
+
+
+static
+CURLcode telrcv(struct connectdata *conn,
+                const unsigned char *inbuf, /* Data received from socket */
+                ssize_t count)              /* Number of bytes received */
+{
+  unsigned char c;
+  CURLcode result;
+  int in = 0;
+  int startwrite = -1;
+  struct Curl_easy *data = conn->data;
+  struct TELNET *tn = (struct TELNET *)data->req.protop;
+
+#define startskipping()                                       \
+  if(startwrite >= 0) {                                       \
+    result = Curl_client_write(conn,                          \
+                               CLIENTWRITE_BODY,              \
+                               (char *)&inbuf[startwrite],    \
+                               in-startwrite);                \
+    if(result)                                                \
+      return result;                                          \
+  }                                                           \
+  startwrite = -1
+
+#define writebyte() \
+    if(startwrite < 0) \
+      startwrite = in
+
+#define bufferflush() startskipping()
+
+  while(count--) {
+    c = inbuf[in];
+
+    switch(tn->telrcv_state) {
+    case CURL_TS_CR:
+      tn->telrcv_state = CURL_TS_DATA;
+      if(c == '\0') {
+        startskipping();
+        break;   /* Ignore \0 after CR */
+      }
+      writebyte();
+      break;
+
+    case CURL_TS_DATA:
+      if(c == CURL_IAC) {
+        tn->telrcv_state = CURL_TS_IAC;
+        startskipping();
+        break;
+      }
+      else if(c == '\r')
+        tn->telrcv_state = CURL_TS_CR;
+      writebyte();
+      break;
+
+    case CURL_TS_IAC:
+    process_iac:
+      DEBUGASSERT(startwrite < 0);
+      switch(c) {
+      case CURL_WILL:
+        tn->telrcv_state = CURL_TS_WILL;
+        break;
+      case CURL_WONT:
+        tn->telrcv_state = CURL_TS_WONT;
+        break;
+      case CURL_DO:
+        tn->telrcv_state = CURL_TS_DO;
+        break;
+      case CURL_DONT:
+        tn->telrcv_state = CURL_TS_DONT;
+        break;
+      case CURL_SB:
+        CURL_SB_CLEAR(tn);
+        tn->telrcv_state = CURL_TS_SB;
+        break;
+      case CURL_IAC:
+        tn->telrcv_state = CURL_TS_DATA;
+        writebyte();
+        break;
+      case CURL_DM:
+      case CURL_NOP:
+      case CURL_GA:
+      default:
+        tn->telrcv_state = CURL_TS_DATA;
+        printoption(data, "RCVD", CURL_IAC, c);
+        break;
+      }
+      break;
+
+      case CURL_TS_WILL:
+        printoption(data, "RCVD", CURL_WILL, c);
+        tn->please_negotiate = 1;
+        rec_will(conn, c);
+        tn->telrcv_state = CURL_TS_DATA;
+        break;
+
+      case CURL_TS_WONT:
+        printoption(data, "RCVD", CURL_WONT, c);
+        tn->please_negotiate = 1;
+        rec_wont(conn, c);
+        tn->telrcv_state = CURL_TS_DATA;
+        break;
+
+      case CURL_TS_DO:
+        printoption(data, "RCVD", CURL_DO, c);
+        tn->please_negotiate = 1;
+        rec_do(conn, c);
+        tn->telrcv_state = CURL_TS_DATA;
+        break;
+
+      case CURL_TS_DONT:
+        printoption(data, "RCVD", CURL_DONT, c);
+        tn->please_negotiate = 1;
+        rec_dont(conn, c);
+        tn->telrcv_state = CURL_TS_DATA;
+        break;
+
+      case CURL_TS_SB:
+        if(c == CURL_IAC)
+          tn->telrcv_state = CURL_TS_SE;
+        else
+          CURL_SB_ACCUM(tn, c);
+        break;
+
+      case CURL_TS_SE:
+        if(c != CURL_SE) {
+          if(c != CURL_IAC) {
+            /*
+             * This is an error.  We only expect to get "IAC IAC" or "IAC SE".
+             * Several things may have happened.  An IAC was not doubled, the
+             * IAC SE was left off, or another option got inserted into the
+             * suboption are all possibilities.  If we assume that the IAC was
+             * not doubled, and really the IAC SE was left off, we could get
+             * into an infinite loop here.  So, instead, we terminate the
+             * suboption, and process the partial suboption if we can.
+             */
+            CURL_SB_ACCUM(tn, CURL_IAC);
+            CURL_SB_ACCUM(tn, c);
+            tn->subpointer -= 2;
+            CURL_SB_TERM(tn);
+
+            printoption(data, "In SUBOPTION processing, RCVD", CURL_IAC, c);
+            suboption(conn);   /* handle sub-option */
+            tn->telrcv_state = CURL_TS_IAC;
+            goto process_iac;
+          }
+          CURL_SB_ACCUM(tn, c);
+          tn->telrcv_state = CURL_TS_SB;
+        }
+        else {
+          CURL_SB_ACCUM(tn, CURL_IAC);
+          CURL_SB_ACCUM(tn, CURL_SE);
+          tn->subpointer -= 2;
+          CURL_SB_TERM(tn);
+          suboption(conn);   /* handle sub-option */
+          tn->telrcv_state = CURL_TS_DATA;
+        }
+        break;
+    }
+    ++in;
+  }
+  bufferflush();
+  return CURLE_OK;
+}
+
+/* Escape and send a telnet data block */
+static CURLcode send_telnet_data(struct connectdata *conn,
+                                 char *buffer, ssize_t nread)
+{
+  ssize_t escapes, i, outlen;
+  unsigned char *outbuf = NULL;
+  CURLcode result = CURLE_OK;
+  ssize_t bytes_written, total_written;
+
+  /* Determine size of new buffer after escaping */
+  escapes = 0;
+  for(i = 0; i < nread; i++)
+    if((unsigned char)buffer[i] == CURL_IAC)
+      escapes++;
+  outlen = nread + escapes;
+
+  if(outlen == nread)
+    outbuf = (unsigned char *)buffer;
+  else {
+    ssize_t j;
+    outbuf = malloc(nread + escapes + 1);
+    if(!outbuf)
+      return CURLE_OUT_OF_MEMORY;
+
+    j = 0;
+    for(i = 0; i < nread; i++) {
+      outbuf[j++] = buffer[i];
+      if((unsigned char)buffer[i] == CURL_IAC)
+        outbuf[j++] = CURL_IAC;
+    }
+    outbuf[j] = '\0';
+  }
+
+  total_written = 0;
+  while(!result && total_written < outlen) {
+    /* Make sure socket is writable to avoid EWOULDBLOCK condition */
+    struct pollfd pfd[1];
+    pfd[0].fd = conn->sock[FIRSTSOCKET];
+    pfd[0].events = POLLOUT;
+    switch(Curl_poll(pfd, 1, -1)) {
+      case -1:                    /* error, abort writing */
+      case 0:                     /* timeout (will never happen) */
+        result = CURLE_SEND_ERROR;
+        break;
+      default:                    /* write! */
+        bytes_written = 0;
+        result = Curl_write(conn, conn->sock[FIRSTSOCKET],
+                            outbuf + total_written,
+                            outlen - total_written,
+                            &bytes_written);
+        total_written += bytes_written;
+        break;
+    }
+  }
+
+  /* Free malloc copy if escaped */
+  if(outbuf != (unsigned char *)buffer)
+    free(outbuf);
+
+  return result;
+}
+
+static CURLcode telnet_done(struct connectdata *conn,
+                                 CURLcode status, bool premature)
+{
+  struct TELNET *tn = (struct TELNET *)conn->data->req.protop;
+  (void)status; /* unused */
+  (void)premature; /* not used */
+
+  if(!tn)
+    return CURLE_OK;
+
+  curl_slist_free_all(tn->telnet_vars);
+  tn->telnet_vars = NULL;
+
+  Curl_safefree(conn->data->req.protop);
+
+  return CURLE_OK;
+}
+
+static CURLcode telnet_do(struct connectdata *conn, bool *done)
+{
+  CURLcode result;
+  struct Curl_easy *data = conn->data;
+  curl_socket_t sockfd = conn->sock[FIRSTSOCKET];
+#ifdef USE_WINSOCK
+  HMODULE wsock2;
+  WSOCK2_FUNC close_event_func;
+  WSOCK2_EVENT create_event_func;
+  WSOCK2_FUNC event_select_func;
+  WSOCK2_FUNC enum_netevents_func;
+  WSAEVENT event_handle;
+  WSANETWORKEVENTS events;
+  HANDLE stdin_handle;
+  HANDLE objs[2];
+  DWORD  obj_count;
+  DWORD  wait_timeout;
+  DWORD readfile_read;
+  int err;
+#else
+  int interval_ms;
+  struct pollfd pfd[2];
+  int poll_cnt;
+  curl_off_t total_dl = 0;
+  curl_off_t total_ul = 0;
+#endif
+  ssize_t nread;
+  struct curltime now;
+  bool keepon = TRUE;
+  char *buf = data->state.buffer;
+  struct TELNET *tn;
+
+  *done = TRUE; /* unconditionally */
+
+  result = init_telnet(conn);
+  if(result)
+    return result;
+
+  tn = (struct TELNET *)data->req.protop;
+
+  result = check_telnet_options(conn);
+  if(result)
+    return result;
+
+#ifdef USE_WINSOCK
+  /*
+  ** This functionality only works with WinSock >= 2.0.  So,
+  ** make sure we have it.
+  */
+  result = check_wsock2(data);
+  if(result)
+    return result;
+
+  /* OK, so we have WinSock 2.0.  We need to dynamically */
+  /* load ws2_32.dll and get the function pointers we need. */
+  wsock2 = Curl_load_library(TEXT("WS2_32.DLL"));
+  if(wsock2 == NULL) {
+    failf(data, "failed to load WS2_32.DLL (%u)", GetLastError());
+    return CURLE_FAILED_INIT;
+  }
+
+  /* Grab a pointer to WSACreateEvent */
+  create_event_func =
+    CURLX_FUNCTION_CAST(WSOCK2_EVENT,
+                        (GetProcAddress(wsock2, "WSACreateEvent")));
+  if(create_event_func == NULL) {
+    failf(data, "failed to find WSACreateEvent function (%u)", GetLastError());
+    FreeLibrary(wsock2);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* And WSACloseEvent */
+  close_event_func = GetProcAddress(wsock2, "WSACloseEvent");
+  if(close_event_func == NULL) {
+    failf(data, "failed to find WSACloseEvent function (%u)", GetLastError());
+    FreeLibrary(wsock2);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* And WSAEventSelect */
+  event_select_func = GetProcAddress(wsock2, "WSAEventSelect");
+  if(event_select_func == NULL) {
+    failf(data, "failed to find WSAEventSelect function (%u)", GetLastError());
+    FreeLibrary(wsock2);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* And WSAEnumNetworkEvents */
+  enum_netevents_func = GetProcAddress(wsock2, "WSAEnumNetworkEvents");
+  if(enum_netevents_func == NULL) {
+    failf(data, "failed to find WSAEnumNetworkEvents function (%u)",
+          GetLastError());
+    FreeLibrary(wsock2);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* We want to wait for both stdin and the socket. Since
+  ** the select() function in winsock only works on sockets
+  ** we have to use the WaitForMultipleObjects() call.
+  */
+
+  /* First, create a sockets event object */
+  event_handle = (WSAEVENT)create_event_func();
+  if(event_handle == WSA_INVALID_EVENT) {
+    failf(data, "WSACreateEvent failed (%d)", SOCKERRNO);
+    FreeLibrary(wsock2);
+    return CURLE_FAILED_INIT;
+  }
+
+  /* Tell winsock what events we want to listen to */
+  if(event_select_func(sockfd, event_handle, FD_READ|FD_CLOSE) ==
+     SOCKET_ERROR) {
+    close_event_func(event_handle);
+    FreeLibrary(wsock2);
+    return CURLE_OK;
+  }
+
+  /* The get the Windows file handle for stdin */
+  stdin_handle = GetStdHandle(STD_INPUT_HANDLE);
+
+  /* Create the list of objects to wait for */
+  objs[0] = event_handle;
+  objs[1] = stdin_handle;
+
+  /* If stdin_handle is a pipe, use PeekNamedPipe() method to check it,
+     else use the old WaitForMultipleObjects() way */
+  if(GetFileType(stdin_handle) == FILE_TYPE_PIPE ||
+     data->set.is_fread_set) {
+    /* Don't wait for stdin_handle, just wait for event_handle */
+    obj_count = 1;
+    /* Check stdin_handle per 100 milliseconds */
+    wait_timeout = 100;
+  }
+  else {
+    obj_count = 2;
+    wait_timeout = 1000;
+  }
+
+  /* Keep on listening and act on events */
+  while(keepon) {
+    const DWORD buf_size = (DWORD)data->set.buffer_size;
+    DWORD waitret = WaitForMultipleObjects(obj_count, objs,
+                                           FALSE, wait_timeout);
+    switch(waitret) {
+    case WAIT_TIMEOUT:
+    {
+      for(;;) {
+        if(data->set.is_fread_set) {
+          size_t n;
+          /* read from user-supplied method */
+          n = data->state.fread_func(buf, 1, buf_size, data->state.in);
+          if(n == CURL_READFUNC_ABORT) {
+            keepon = FALSE;
+            result = CURLE_READ_ERROR;
+            break;
+          }
+
+          if(n == CURL_READFUNC_PAUSE)
+            break;
+
+          if(n == 0)                        /* no bytes */
+            break;
+
+          /* fall through with number of bytes read */
+          readfile_read = (DWORD)n;
+        }
+        else {
+          /* read from stdin */
+          if(!PeekNamedPipe(stdin_handle, NULL, 0, NULL,
+                            &readfile_read, NULL)) {
+            keepon = FALSE;
+            result = CURLE_READ_ERROR;
+            break;
+          }
+
+          if(!readfile_read)
+            break;
+
+          if(!ReadFile(stdin_handle, buf, buf_size,
+                       &readfile_read, NULL)) {
+            keepon = FALSE;
+            result = CURLE_READ_ERROR;
+            break;
+          }
+        }
+
+        result = send_telnet_data(conn, buf, readfile_read);
+        if(result) {
+          keepon = FALSE;
+          break;
+        }
+      }
+    }
+    break;
+
+    case WAIT_OBJECT_0 + 1:
+    {
+      if(!ReadFile(stdin_handle, buf, buf_size,
+                   &readfile_read, NULL)) {
+        keepon = FALSE;
+        result = CURLE_READ_ERROR;
+        break;
+      }
+
+      result = send_telnet_data(conn, buf, readfile_read);
+      if(result) {
+        keepon = FALSE;
+        break;
+      }
+    }
+    break;
+
+    case WAIT_OBJECT_0:
+
+      events.lNetworkEvents = 0;
+      if(SOCKET_ERROR == enum_netevents_func(sockfd, event_handle, &events)) {
+        err = SOCKERRNO;
+        if(err != EINPROGRESS) {
+          infof(data, "WSAEnumNetworkEvents failed (%d)", err);
+          keepon = FALSE;
+          result = CURLE_READ_ERROR;
+        }
+        break;
+      }
+      if(events.lNetworkEvents & FD_READ) {
+        /* read data from network */
+        result = Curl_read(conn, sockfd, buf, data->set.buffer_size, &nread);
+        /* read would've blocked. Loop again */
+        if(result == CURLE_AGAIN)
+          break;
+        /* returned not-zero, this an error */
+        else if(result) {
+          keepon = FALSE;
+          break;
+        }
+        /* returned zero but actually received 0 or less here,
+           the server closed the connection and we bail out */
+        else if(nread <= 0) {
+          keepon = FALSE;
+          break;
+        }
+
+        result = telrcv(conn, (unsigned char *) buf, nread);
+        if(result) {
+          keepon = FALSE;
+          break;
+        }
+
+        /* Negotiate if the peer has started negotiating,
+           otherwise don't. We don't want to speak telnet with
+           non-telnet servers, like POP or SMTP. */
+        if(tn->please_negotiate && !tn->already_negotiated) {
+          negotiate(conn);
+          tn->already_negotiated = 1;
+        }
+      }
+      if(events.lNetworkEvents & FD_CLOSE) {
+        keepon = FALSE;
+      }
+      break;
+
+    }
+
+    if(data->set.timeout) {
+      now = Curl_now();
+      if(Curl_timediff(now, conn->created) >= data->set.timeout) {
+        failf(data, "Time-out");
+        result = CURLE_OPERATION_TIMEDOUT;
+        keepon = FALSE;
+      }
+    }
+  }
+
+  /* We called WSACreateEvent, so call WSACloseEvent */
+  if(!close_event_func(event_handle)) {
+    infof(data, "WSACloseEvent failed (%d)", SOCKERRNO);
+  }
+
+  /* "Forget" pointers into the library we're about to free */
+  create_event_func = NULL;
+  close_event_func = NULL;
+  event_select_func = NULL;
+  enum_netevents_func = NULL;
+
+  /* We called LoadLibrary, so call FreeLibrary */
+  if(!FreeLibrary(wsock2))
+    infof(data, "FreeLibrary(wsock2) failed (%u)", GetLastError());
+#else
+  pfd[0].fd = sockfd;
+  pfd[0].events = POLLIN;
+
+  if(data->set.is_fread_set) {
+    poll_cnt = 1;
+    interval_ms = 100; /* poll user-supplied read function */
+  }
+  else {
+    /* really using fread, so infile is a FILE* */
+    pfd[1].fd = fileno((FILE *)data->state.in);
+    pfd[1].events = POLLIN;
+    poll_cnt = 2;
+    interval_ms = 1 * 1000;
+  }
+
+  while(keepon) {
+    switch(Curl_poll(pfd, poll_cnt, interval_ms)) {
+    case -1:                    /* error, stop reading */
+      keepon = FALSE;
+      continue;
+    case 0:                     /* timeout */
+      pfd[0].revents = 0;
+      pfd[1].revents = 0;
+      /* FALLTHROUGH */
+    default:                    /* read! */
+      if(pfd[0].revents & POLLIN) {
+        /* read data from network */
+        result = Curl_read(conn, sockfd, buf, data->set.buffer_size, &nread);
+        /* read would've blocked. Loop again */
+        if(result == CURLE_AGAIN)
+          break;
+        /* returned not-zero, this an error */
+        if(result) {
+          keepon = FALSE;
+          break;
+        }
+        /* returned zero but actually received 0 or less here,
+           the server closed the connection and we bail out */
+        else if(nread <= 0) {
+          keepon = FALSE;
+          break;
+        }
+
+        total_dl += nread;
+        Curl_pgrsSetDownloadCounter(data, total_dl);
+        result = telrcv(conn, (unsigned char *)buf, nread);
+        if(result) {
+          keepon = FALSE;
+          break;
+        }
+
+        /* Negotiate if the peer has started negotiating,
+           otherwise don't. We don't want to speak telnet with
+           non-telnet servers, like POP or SMTP. */
+        if(tn->please_negotiate && !tn->already_negotiated) {
+          negotiate(conn);
+          tn->already_negotiated = 1;
+        }
+      }
+
+      nread = 0;
+      if(poll_cnt == 2) {
+        if(pfd[1].revents & POLLIN) { /* read from in file */
+          nread = read(pfd[1].fd, buf, data->set.buffer_size);
+        }
+      }
+      else {
+        /* read from user-supplied method */
+        nread = (int)data->state.fread_func(buf, 1, data->set.buffer_size,
+                                            data->state.in);
+        if(nread == CURL_READFUNC_ABORT) {
+          keepon = FALSE;
+          break;
+        }
+        if(nread == CURL_READFUNC_PAUSE)
+          break;
+      }
+
+      if(nread > 0) {
+        result = send_telnet_data(conn, buf, nread);
+        if(result) {
+          keepon = FALSE;
+          break;
+        }
+        total_ul += nread;
+        Curl_pgrsSetUploadCounter(data, total_ul);
+      }
+      else if(nread < 0)
+        keepon = FALSE;
+
+      break;
+    } /* poll switch statement */
+
+    if(data->set.timeout) {
+      now = Curl_now();
+      if(Curl_timediff(now, conn->created) >= data->set.timeout) {
+        failf(data, "Time-out");
+        result = CURLE_OPERATION_TIMEDOUT;
+        keepon = FALSE;
+      }
+    }
+
+    if(Curl_pgrsUpdate(conn)) {
+      result = CURLE_ABORTED_BY_CALLBACK;
+      break;
+    }
+  }
+#endif
+  /* mark this as "no further transfer wanted" */
+  Curl_setup_transfer(data, -1, -1, FALSE, -1);
+
+  return result;
+}
+#endif