Clear pollin flag when input buffer is flushed

The pollin flag must be cleared when the input buffer (pty slave) is
flushed. This ensures that the POLLIN event is not signaled to the application,
when there is not data to read.

.gitignore

@@ -20,7 +20,7 @@ Makefile
 
 # build
 *.o
-/ttynvt
+/src/ttynvt
 
 /ttynvt-*.tar.gz
 /ttynvt-*.tar.xz

.indent.pro

@@ -0,0 +1,6 @@
+-kr -i4 --no-tabs --line-length79 -di16
+--braces-after-if-line --brace-indent0 --dont-cuddle-else --cuddle-do-while
+--blank-lines-after-declarations --blank-lines-after-procedures
+--break-after-boolean-operator
+--no-space-after-casts
+--else-endif-column0

Makefile.am

@@ -1,20 +1,7 @@
-# Build ttynvt
-#
 
 MAINTAINERCLEANFILES = \
 	aclocal.m4 autom4te.cache compile config.h.in config.h.in~ configure \
 	depcomp install-sh missing \
-	Makefile.in
+	Makefile.in */Makefile.in
 
-CFLAGS_OPT  = -O3
-CFLAGS_WARN = -Wall -Wextra -Werror -Wno-unused-parameter
-
-bin_PROGRAMS = ttynvt
-
-ttynvt_SOURCES = \
-	ttynvt.c \
-	telnet_basic.c telnet_rfc2217.c telnet.h telnet_param.h
-
-ttynvt_CPPFLAGS = -I$(top_builddir) $(FUSE_CFLAGS) $(CFLAGS_OPT) $(CFLAGS_WARN)
-
-ttynvt_LDADD = $(FUSE_LIBS)
+SUBDIRS = src

configure.ac

@@ -1,4 +1,4 @@
-m4_define([pkg_version],  [0.11])
+m4_define([pkg_version],  [0.14])
 #m4_define([pkg_revision], [005])
 m4_define([pkg_version],  m4_ifdef([pkg_revision], [pkg_version.pkg_revision], [pkg_version]))
 
@@ -32,6 +32,7 @@ PKG_CHECK_MODULES(FUSE, fuse)
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([
 Makefile
+src/Makefile
 ])
 AC_OUTPUT
 

src/Makefile.am

@@ -0,0 +1,12 @@
+
+CFLAGS_WARN = -Wall -Wextra -Werror -Wno-unused-parameter
+
+bin_PROGRAMS = ttynvt
+
+ttynvt_SOURCES = \
+	ttynvt.c nvt_log.c nvt_log.h \
+	telnet_basic.c telnet_rfc2217.c telnet.h telnet_param.h
+
+ttynvt_CPPFLAGS = -I$(top_builddir) $(FUSE_CFLAGS) $(CFLAGS_WARN)
+
+ttynvt_LDADD = $(FUSE_LIBS)

src/nvt_log.c

@@ -0,0 +1,84 @@
+/*
+ * Logging functions
+ */
+#include <stdarg.h>
+#include <stdio.h>
+#include <syslog.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/types.h>
+
+#include "nvt_log.h"
+
+#include <sys/syscall.h>
+#define gettid() (pid_t)syscall(__NR_gettid)
+
+char            log_level = 0;
+char            log_stdout = 0;
+
+static const char *_hms_txt(char *buf, unsigned int len)
+{
+    struct timeval  tv;
+    unsigned int    sod, hh, mm, ss;
+
+    gettimeofday(&tv, NULL);
+
+    sod = tv.tv_sec % (24 * 3600);
+    hh = sod / 3600;
+    mm = (sod - hh * 3600) / 60;
+    ss = sod - hh * 3600 - mm * 60;
+    snprintf(buf, len, "%02d:%02d:%02d.%06d",
+             hh, mm, ss, (unsigned int)tv.tv_usec);
+
+    return buf;
+}
+
+void nvt_log(int prio, const char *fmt, ...)
+{
+    va_list         arg;
+    char            buf[256], buft[64];
+    const char     *eol;
+    int             len;
+
+    va_start(arg, fmt);
+    len = vsnprintf(buf, sizeof(buf), fmt, arg);
+
+    if (log_stdout)
+    {
+        eol = (len > 0 && buf[len - 1] != '\n') ? "\n" : "";
+        printf("%s: [%d] %d: %s%s",
+               _hms_txt(buft, sizeof(buft)), gettid(), prio, buf, eol);
+    }
+    else
+    {
+        syslog(prio, "[%d] %s", gettid(), buf);
+    }
+
+    va_end(arg);
+}
+
+#define BPL 16                  /* Bytes per line */
+
+void nvt_log_buf(int prio, const char *txt, const void *ptr_, unsigned int len)
+{
+    unsigned int    ix, i, imax;
+    int             l, n;
+    char            buf[128];
+    const unsigned char *ptr = ptr_;
+
+    for (ix = 0; ix < len || (len == 0 && ix == 0); ix += BPL)
+    {
+        n = snprintf(buf, sizeof(buf), "%s: %04x:", txt, ix);
+        if (n <= 0)
+            return;             /* Just playing it safe */
+        imax = (len - ix < BPL) ? len - ix : BPL;
+        for (i = 0; i < imax; i++)
+        {
+            l = snprintf(buf + n, sizeof(buf) - n, " %02x", *ptr++);
+            if (l <= 0)
+                return;         /* Just playing it safe */
+            n += l;
+        }
+        nvt_log(prio, "%s\n", buf);
+    }
+}

src/nvt_log.h

@@ -0,0 +1,26 @@
+/*
+ * Logging functions
+ */
+#ifndef NVT_LOG_H
+#define NVT_LOG_H
+
+#include <syslog.h>
+
+#define _PRF_N_(no) __attribute__((__format__(__printf__, (no), (no) + 1)))
+#define _PRF2_ _PRF_N_(2)
+
+_PRF2_ void     nvt_log(int prio, const char *fmt, ...);
+void            nvt_log_buf(int prio, const char *txt,
+                            const void *ptr, unsigned int len);
+
+extern char     log_level;
+extern char     log_stdout;
+
+#define DBG(...) \
+    if (log_level > 0) nvt_log(LOG_DEBUG, __VA_ARGS__)
+#define DBG2(...) \
+    if (log_level > 1) nvt_log(LOG_DEBUG, __VA_ARGS__)
+#define DBG2_BUF(txt, ptr, len) \
+    if (log_level > 1) nvt_log_buf(LOG_DEBUG, txt, ptr, len)
+
+#endif /* NVT_LOG_H */

src/telnet.h

@@ -31,7 +31,7 @@ extern tn_ctx_t *telnet_ctx_init(void *cctx, srv_tx_f * ftx, srv_rx_f * frx,
 
 extern int      telnet_open(tn_ctx_t * tcc);
 
-extern int      telnet_rx(tn_ctx_t * tcc, char *buf, size_t * plen);
+extern int      telnet_rx(tn_ctx_t * tcc, char *buf, int *plen);
 extern int      telnet_tx(tn_ctx_t * tcc, const char *buf, int len);
 
 extern void     telnet_set_opt(tn_ctx_t * tcc, int opt, int prm,
@@ -42,10 +42,10 @@ extern void     telnet_rfc2217_handle_opt(tn_ctx_t * tcc, int opt,
 
 extern void     telnet_rfc2217_cfg(tn_ctx_t * tcc, int cmd,
                                    const void *val, int nd);
-extern void     telnet_rfc2217_ctl(tn_ctx_t * tcc, int cmd);
+extern void     telnet_rfc2217_ctl(tn_ctx_t * tcc, unsigned int val);
 
 /*RFC2217 modem state*/
-#define TNS_STATE_CD     0x80
+#define TNS_STATE_DCD    0x80
 #define TNS_STATE_RI     0x40
 #define TNS_STATE_DSR    0x20
 #define TNS_STATE_CTS    0x10

src/telnet_basic.c

@@ -121,18 +121,18 @@ static void _telnet_handle_opt(tn_ctx_t * tcc, int opt,
     }
 }
 
-int telnet_rx(tn_ctx_t * tcc, char *buf, size_t * plen)
+int telnet_rx(tn_ctx_t * tcc, char *buf, int *plen)
 {
     char           *s, *p;
     unsigned char  *pu;
-    size_t          len, rem;
+    int             len, rem;
     int             np, nd;
     int             b1, b2;
 
     len = *plen;
     tcc->bytes_rx += len;
 
-    if (len < (size_t) tcc->off_rx)
+    if (len < (int)tcc->off_rx)
         tcc->off_rx = 0;
 
     for (s = buf + tcc->off_rx, rem = len - tcc->off_rx; rem > 0; s = p)

src/telnet_param.h

@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2018 Lars Thrane A/S
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * Telnet parameters
+ */
+#ifndef TELNET_PARAM_H
+#define TELNET_PARAM_H
+
+
+/*
+ * Telnet commands
+ */
+
+#define TNC_F0_SE   (0xf0)      /* End of subnegotiation parameters */
+#define TNC_F1_NOP  (0xf1)      /* No operation                     */
+#define TNC_F2_MARK (0xf2)      /* The data stream portion of a Synch.
+                                   This should always be accompanied
+                                   by a TCP Urgent notification. */
+#define TNC_F3_BRK  (0xf3)      /* NVT character BRK.               */
+#define TNC_F4_IP   (0xf4)      /* The function IP (interrupt process) */
+#define TNC_F5_AO   (0xf5)      /* The function AO (abort output)   */
+#define TNC_F6_AYT  (0xf6)      /* The function AYT (are you there) */
+#define TNC_F7_EC   (0xf7)      /* The function EC (erase charceter) */
+#define TNC_F8_EL   (0xf8)      /* The function EL (erase line)     */
+#define TNC_F9_GA   (0xf9)      /* The GA signal (go ahead)         */
+#define TNC_FA_SB   (0xfa)      /* Subnegotiation begin             */
+#define TNC_FB_WILL (0xfb)      /* Indicates the desire to begin
+                                   performing, or confirmation that
+                                   you are now performing, the
+                                   indicated option. */
+#define TNC_FC_WONT (0xfc)      /* Indicates the refusal to perform,
+                                   or continue performing, the
+                                   indicated option. */
+#define TNC_FD_DO   (0xfd)      /* Indicates the request that the
+                                   other party perform, or
+                                   confirmation that you are expecting
+                                   the other party to perform, the
+                                   indicated option. */
+#define TNC_FE_DONT (0xfe)      /* Indicates the demand that the
+                                   other party stop performing,
+                                   or confirmation that you are no
+                                   longer expecting the other party
+                                   to perform, the indicated option. */
+#define TNC_FF_IAC  (0xff)      /* Interpret as Command / data byte */
+
+
+/*
+ * Telnet options
+ */
+
+/*
+ * https://www.iana.org/assignments/telnet-options/telnet-options.xhtml
+ *
+ *   0  00  Binary Transmission                 [RFC856]
+ *   1  01  Echo                                [RFC857]
+ *   2  02  Reconnection                        [DDN Protocol Handbook, ... ]
+ *   3  03  Suppress Go Ahead                   [RFC858]
+ *   4  04  Approx Message Size Negotiation     ["The Ethernet, ..." ]
+ *   5  05  Status                              [RFC859]
+ *   6  06  Timing Mark                         [RFC860]
+ *   7  07  Remote Controlled Trans and Echo    [RFC726]
+ *   8  08  Output Line Width                   [DDN Protocol Handbook, ... ]
+ *   9  09  Output Page Size                    [DDN Protocol Handbook, ... ]
+ *  10  0a  Output Carriage-Return Disposition  [RFC652]
+ *  11  0b  Output Horizontal Tab Stops         [RFC653]
+ *  12  0c  Output Horizontal Tab Disposition   [RFC654]
+ *  13  0d  Output Formfeed Disposition         [RFC655]
+ *  14  0e  Output Vertical Tabstops            [RFC656]
+ *  15  0f  Output Vertical Tab Disposition     [RFC657]
+ *  16  10  Output Linefeed Disposition         [RFC658]
+ *  17  11  Extended ASCII                      [RFC698]
+ *  18  12  Logout                              [RFC727]
+ *  19  13  Byte Macro                          [RFC735]
+ *  20  14  Data Entry Terminal                 [RFC1043][RFC732]
+ *  21  15  SUPDUP                              [RFC736][RFC734]
+ *  22  16  SUPDUP Output                       [RFC749]
+ *  23  17  Send Location                       [RFC779]
+ *  24  18  Terminal Type                       [RFC1091]
+ *  25  19  End of Record                       [RFC885]
+ *  26  1a  TACACS User Identification          [RFC927]
+ *  27  1b  Output Marking                      [RFC933]
+ *  28  1c  Terminal Location Number            [RFC946]
+ *  29  1d  Telnet 3270 Regime                  [RFC1041]
+ *  30  1e  X.3 PAD                             [RFC1053]
+ *  31  1f  Negotiate About Window Size         [RFC1073]
+ *  32  20  Terminal Speed                      [RFC1079]
+ *  33  21  Remote Flow Control                 [RFC1372]
+ *  34  22  Linemode                            [RFC1184]
+ *  35  23  X Display Location                  [RFC1096]
+ *  36  24  Environment Option                  [RFC1408]
+ *  37  25  Authentication Option               [RFC2941]
+ *  38  26  Encryption Option                   [RFC2946]
+ *  39  27  New Environment Option              [RFC1572]
+ *  40  28  TN3270E                             [RFC2355]
+ *  41  29  XAUTH                               [Rob_Earhart]
+ *  42  2a  CHARSET                             [RFC2066]
+ *  43  2b  Telnet Remote Serial Port (RSP)     [Robert_Barnes]
+ *  44  2c  Com Port Control Option             [RFC2217]
+ *  45  2d  Telnet Suppress Local Echo          [Wirt_Atmar]
+ *  46  2e  Telnet Start TLS                    [Michael_Boe]
+ *  47  2f  KERMIT                              [RFC2840]
+ *  48  30  SEND-URL                            [David_Croft]
+ *  49  31  FORWARD_X                           [Jeffrey_Altman]
+ *  50-137  32-89  Unassigned                   [IANA]
+ * 138  8a  TELOPT PRAGMA LOGON                 [Steve_McGregory]
+ * 139  8b  TELOPT SSPI LOGON                   [Steve_McGregory]
+ * 140  8c  TELOPT PRAGMA HEARTBEAT             [Steve_McGregory]
+ * 141-254  8d-fe  Unassigned
+ * 255  ff  Extended-Options-List               [RFC861]
+*/
+
+#define TNO_BINARY   0          /* 00  Binary Transmission          */
+#define TNO_ECHO     1          /* 01  Echo                         */
+#define TNO_SUPP_GA  3          /* 03  Suppress Go Ahead            */
+#define TNO_LOGOUT  18          /* 12  Logout                       */
+#define TNO_TTYP    24          /* 18  Terminal Type                */
+#define TNO_NAWS    31          /* 1f  Negotiate About Window Size  */
+#define TNO_NEO     39          /* 27  New Environment Option       */
+#define TNO_CPCO    44          /* 2c  RFC 2217                     */
+#define TNO_KERMIT  47          /* 2f  Kermit                       */
+
+#endif /* TELNET_PARAM_H */

src/telnet_rfc2217.c

@@ -43,10 +43,12 @@ void telnet_rfc2217_cfg(tn_ctx_t * tcc, int cmd, const void *val, int nd)
     telnet_set_opt(tcc, TNO_CPCO, cmd, val, nd);
 }
 
-void telnet_rfc2217_ctl(tn_ctx_t * tcc, int cmd)
+void telnet_rfc2217_ctl(tn_ctx_t * tcc, unsigned int val)
 {
+    unsigned char   byte = val;
+
     if (!tcc->mode_rfc2217)
         return;
 
-    telnet_set_opt(tcc, TNO_CPCO, TNS_SET_CONTROL, &cmd, 1);
+    telnet_set_opt(tcc, TNO_CPCO, TNS_SET_CONTROL, &byte, 1);
 }

src/ttynvt.c

@@ -8,8 +8,10 @@
 #include <errno.h>
 #include <fuse_opt.h>
 #include <netdb.h>
+#include <poll.h>
 #include <pthread.h>
 #include <signal.h>
+#include <stdint.h>
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -17,26 +19,23 @@
 #include <string.h>
 #include <syslog.h>
 #include <unistd.h>
+#include <asm/ioctls.h>
 #include <asm/termbits.h>
 #include <linux/sockios.h>
 #include <linux/ppp-ioctl.h>
 #include <netinet/in.h>
 #include <sys/ioctl.h>
-#include <sys/poll.h>
 #include <sys/socket.h>
-#include <sys/types.h>
 
+#include "nvt_log.h"
 #include "telnet.h"
 
 #define NET_BUF_SIZE 1024
 #define TMP_BUF_SIZE 1024
 
 #define FD_NET     0
-#define FD_SLAVE   1
-#define FD_MASTER  2
-
-#define _PRF_N_(no) __attribute__((__format__(__printf__, (no), (no) + 1)))
-#define _PRF2_ _PRF_N_(2)
+#define FD_MASTER  1
+#define FD_SLAVE   2
 
 
 static struct ttynvt_param {
@@ -45,6 +44,7 @@ static struct ttynvt_param {
     const char     *dev_name;
     char           *server;
     unsigned int    debug;
+    int             logstd;
     /* Derived */
     char            host[64];
     unsigned int    port;
@@ -55,56 +55,47 @@ static struct ttynvt_param {
 typedef struct {
     pthread_mutex_t tty_lock;
     pthread_mutex_t poll_lock;
-    pthread_t       thread_id;
+    pthread_t       ptid_poll;
+    pthread_t       ptid_read;
 
     struct fuse_pollhandle *ph;
 
+    volatile int    rel_pending;
+    volatile int    slave_suspended;    /*waiting for application to read data */
+    volatile int    master_suspended;   /*server is not ready to receive data */
     struct pollfd   fds[3];
 
     char            net_buf[NET_BUF_SIZE];
-    size_t          net_cnt;
-    char            tmp_buf[TMP_BUF_SIZE];
+    int             net_cnt;
 
-    struct termios  tio;
-    int             cmcr;
-    int             epipe;
+    struct termios2 tio;
+
+    int             cmcr;       /* Commanded by ioctl */
+    volatile int    smcr;       /* Status from modem */
+    int             smcr_last;
 
-    volatile int    smcr;
-    volatile int    error;
     volatile int    pollin;
+    volatile int    pollout;
+    volatile int    error;
+    int             epipe;
 
     tn_ctx_t       *tn;
 } ttynvt_t;
 
-#include <sys/syscall.h>
-#define gettid() (pid_t)syscall(__NR_gettid)
-
-_PRF2_ static void _log(int prio, const char *fmt, ...)
+static void _fd_close(int fd)
 {
-    va_list         arg;
-    char            buf[256];
-
-    va_start(arg, fmt);
-#if 0
-    vsyslog(prio, fmt, arg);
-#else
-    vsnprintf(buf, sizeof(buf), fmt, arg);
-    syslog(prio, "[%d] %s", gettid(), buf);
-#endif
-    va_end(arg);
+    if (fd >= 0)
+        close(fd);
 }
 
-#define DBG(...) \
-    if (ttynvt_param.debug > 0) _log(LOG_DEBUG, __VA_ARGS__)
-#define DBG2(...) \
-    if (ttynvt_param.debug > 1) _log(LOG_DEBUG, __VA_ARGS__)
-
 static volatile char _is_interrupted = 0;
 
 static void sig_handler(int sig)
 {
     DBG("Interruped, signal = %d\n", sig);
     _is_interrupted = 1;
+    if (sig != SIGUSR2)
+        exit(0);
 }
 
 static void set_signal_handler(void)
@@ -116,6 +107,7 @@ static void set_signal_handler(void)
     sigemptyset(&(sa.sa_mask));
     sa.sa_flags = 0;
     sigaction(SIGUSR2, &sa, NULL);
+    sigaction(SIGTERM, &sa, NULL);
 }
 
 static void ttynvt_interrupted(fuse_req_t req, void *data)
@@ -145,14 +137,15 @@ static void ttynvt_release(fuse_req_t req, struct fuse_file_info *info)
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
 
-    _log(LOG_INFO, "connection closed\n");
+    nvt_log(LOG_INFO, "connection closed\n");
 
-    close(tty->fds[FD_NET].fd);
-    close(tty->fds[FD_MASTER].fd);
-    close(tty->fds[FD_SLAVE].fd);
+    tty->rel_pending = 1;
+    _fd_close(tty->fds[FD_NET].fd);
+    _fd_close(tty->fds[FD_MASTER].fd);
+    _fd_close(tty->fds[FD_SLAVE].fd);
 
-    pthread_cancel(tty->thread_id);
-    pthread_join(tty->thread_id, NULL);
+    pthread_cancel(tty->ptid_poll);
+    pthread_join(tty->ptid_poll, NULL);
     pthread_mutex_destroy(&tty->tty_lock);
     pthread_mutex_destroy(&tty->poll_lock);
 
@@ -187,68 +180,117 @@ static void _update_notify(ttynvt_t * tty, struct fuse_pollhandle *ph)
         fuse_pollhandle_destroy(tmp_ph);
 }
 
+static int _net_read_check_exit(ttynvt_t * tty)
+{
+    if ((tty->tio.c_cflag & CLOCAL) == 0 &&
+        (tty->smcr_last & TIOCM_CD) != 0 && (tty->smcr & TIOCM_CD) == 0)
+    {
+        /* CLOCAL is not set (i.e. do not ignore modem control lines) AND
+         * DCD dropped */
+        DBG("GOT DCD DROP\n");
+        close(tty->fds[FD_MASTER].fd);
+        tty->fds[FD_MASTER].fd = -1;
+        return 1;
+    }
+
+    return 0;
+}
+
 static void    *_read_net(void *arg)
 {
     ttynvt_t       *tty = (ttynvt_t *) arg;
-    ssize_t         res;
+    char            buf[TMP_BUF_SIZE];
+    int             res;
 
     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+    DBG2("%s: net_cnt=%d\n", __func__, tty->net_cnt);
 
-    while (1)
+    while (!tty->rel_pending)
     {
+        tty->fds[FD_NET].revents = tty->fds[FD_MASTER].revents =
+            tty->fds[FD_SLAVE].revents = 0;
+        tty->fds[FD_SLAVE].events = tty->slave_suspended ? POLLPRI : POLLIN;
+        tty->fds[FD_MASTER].events = tty->master_suspended ? POLLPRI : POLLIN;
+
         res = poll(tty->fds, 3, -1);
+        DBG2("%s: res=%d events-N/M/S=%x:%x/%x:%x/%x:%x SS=%d MS=%d\n",
+             __func__, res, tty->fds[FD_NET].events, tty->fds[FD_NET].revents,
+             tty->fds[FD_MASTER].events, tty->fds[FD_MASTER].revents,
+             tty->fds[FD_SLAVE].events, tty->fds[FD_SLAVE].revents,
+             tty->slave_suspended, tty->master_suspended);
         if (res < 0)
         {
             if (errno == EINTR)
                 continue;
-            else
             break;
         }
+        if (tty->rel_pending)
+            break;
+
         if (tty->fds[FD_NET].revents & POLLIN)
         {
             res = read(tty->fds[FD_NET].fd, tty->net_buf + tty->net_cnt,
                        NET_BUF_SIZE - tty->net_cnt);
             if (res < 0)
             {
-                _log(LOG_ERR, "net read error: %s\n", strerror(errno));
+                nvt_log(LOG_ERR, "net read error: %m\n");
                 break;
             }
-            else if (res == 0)
+            if (res == 0)
             {
-                _log(LOG_INFO, "Connection closed by remote host\n");
+                nvt_log(LOG_INFO, "Connection closed by remote host\n");
                 break;
             }
             tty->net_cnt += res;
+            DBG2_BUF("Serv in A", tty->net_buf, tty->net_cnt);
             res = telnet_rx(tty->tn, tty->net_buf, &tty->net_cnt);
+            DBG2_BUF("Serv in B", tty->net_buf, tty->net_cnt);
             if (tty->net_cnt > 0 && res == 0)
             {
+                DBG2_BUF("TtyM out ", tty->net_buf, tty->net_cnt);
                 res =
                     write(tty->fds[FD_MASTER].fd, tty->net_buf, tty->net_cnt);
                 if (res < 0)
                 {
-                    _log(LOG_ERR, "master write error:%s\n", strerror(errno));
+                    nvt_log(LOG_ERR, "master write error: %m\n");
                     break;
                 }
                 tty->net_cnt = 0;
             }
-        }
-        if (tty->fds[FD_MASTER].revents & POLLIN)
-        {
-            res = read(tty->fds[FD_MASTER].fd, tty->tmp_buf, TMP_BUF_SIZE);
-            if (res < 0)
-            {
-                _log(LOG_ERR, "master read error:%s\n", strerror(errno));
+            if (_net_read_check_exit(tty))
                 break;
         }
-            telnet_tx(tty->tn, tty->tmp_buf, res);
+
+        if ((tty->fds[FD_MASTER].revents & POLLIN) && !tty->master_suspended)
+        {
+            res = read(tty->fds[FD_MASTER].fd, buf, TMP_BUF_SIZE);
+            DBG("%s: read res=%d pollout=%d\n", __func__, res, tty->pollout);
+            if (res < 0)
+            {
+                nvt_log(LOG_ERR, "master read error: %m\n");
+                break;
             }
+            if (tty->pollout == 0)
+            {
+                tty->pollout = 1;
+                _notify(tty);
+            }
+            DBG2_BUF("TtyM in  ", buf, res);
+            telnet_tx(tty->tn, buf, res);
+        }
+
         if (tty->fds[FD_SLAVE].revents & POLLIN)
         {
             tty->pollin = 1;
+            tty->slave_suspended = 1;   /* Disable polling of Slave */
             _notify(tty);
         }
     }
 
+    DBG2("%s: done\n", __func__);
+    if (tty->ptid_read)
+        pthread_kill(tty->ptid_read, SIGUSR2);
+
     tty->error = 1;
     _notify(tty);
 
@@ -264,14 +306,14 @@ static int _srv_connect(const char *host, unsigned int port)
     sockfd = socket(AF_INET, SOCK_STREAM, 0);
     if (sockfd < 0)
     {
-        _log(LOG_ERR, "Socket open failed: %s\n", strerror(errno));
+        nvt_log(LOG_ERR, "Socket open failed: %m\n");
         return sockfd;
     }
 
     server = gethostbyname(host);
     if (server == NULL)
     {
-        _log(LOG_ERR, "Cannot resolve host name: %s\n", strerror(errno));
+        nvt_log(LOG_ERR, "Cannot resolve host name: %m\n");
         close(sockfd);
         return -1;
     }
@@ -285,8 +327,7 @@ static int _srv_connect(const char *host, unsigned int port)
     err = connect(sockfd, (struct sockaddr *)&serveraddr, sizeof(serveraddr));
     if (err < 0)
     {
-        _log(LOG_ERR, "Failed to connect to: %s:%u:%s\n",
-             host, port, strerror(errno));
+        nvt_log(LOG_ERR, "Failed to connect to: %s:%u: %m\n", host, port);
         close(sockfd);
         return -1;
     }
@@ -299,8 +340,13 @@ static int _srv_write(void *cctx, const void *buf, int len)
     ttynvt_t       *tty = cctx;
     int             res;
 
+    DBG2_BUF("Serv out ", buf, len);
+
     res = write(tty->fds[FD_NET].fd, buf, len);
 
+    DBG2("%s: fd=%d: len=%u: res=%d\n", __func__,
+         tty->fds[FD_NET].fd, len, res);
+
     return res;
 }
 
@@ -309,9 +355,12 @@ static int _srv_read(void *cctx, int timeout)
     ttynvt_t       *tty = cctx;
     int             res;
 
+    DBG2("%s: net_cnt=%d\n", __func__, tty->net_cnt);
     while (1)
     {
         res = poll(&tty->fds[FD_NET], 1, timeout);
+        DBG("%s: res=%d events-N=%#x\n",
+            __func__, res, tty->fds[FD_NET].revents);
         if (res <= 0)
             return res;
 
@@ -319,10 +368,15 @@ static int _srv_read(void *cctx, int timeout)
         {
             res = read(tty->fds[FD_NET].fd, tty->net_buf + tty->net_cnt,
                        NET_BUF_SIZE - tty->net_cnt);
+            DBG2("%s: fd=%d: res=%d net_cnt=%d\n", __func__,
+                 tty->fds[FD_NET].fd, res, tty->net_cnt);
             if (res <= 0)
                 return res;
-            tty->net_cnt += (size_t) res;
+            tty->net_cnt += res;
+            DBG2_BUF("Serv in a", tty->net_buf, tty->net_cnt);
             res = telnet_rx(tty->tn, tty->net_buf, &tty->net_cnt);
+            DBG2_BUF("Serv in b", tty->net_buf, tty->net_cnt);
+            DBG2("%s: res=%d net_cnt=%d\n", __func__, res, tty->net_cnt);
             if (res == 0)
                 break;
         }
@@ -335,21 +389,26 @@ static void _modem_status_cb(void *cctx, int status)
     ttynvt_t       *tty = cctx;
     int             mcr = 0;
 
-    DBG("MCR: DSR=%c CTS=%c RI=%c CD=%c\n",
-        status & TNS_STATE_DSR ? '1' : '0',
-        status & TNS_STATE_CTS ? '1' : '0',
-        status & TNS_STATE_RI ? '1' : '0', status & TNS_STATE_CD ? '1' : '0');
+    DBG("MCR: CTS=%c DSR=%c RI=%c DCD=%c\n",
+        status & TNS_STATE_CTS ? '1' : '0', status & TNS_STATE_DSR ? '1' : '0',
+        status & TNS_STATE_RI ? '1' : '0', status & TNS_STATE_DCD ? '1' : '0');
 
-    if (status & TNS_STATE_CD)
+    if (status & TNS_STATE_DCD)
         mcr |= TIOCM_CD;
     if (status & TNS_STATE_RI)
         mcr |= TIOCM_RI;
-    if (status & TNS_STATE_CTS)
-        mcr |= TIOCM_CTS;
     if (status & TNS_STATE_DSR)
         mcr |= TIOCM_DSR;
+    if (status & TNS_STATE_CTS)
+        mcr |= TIOCM_CTS;
+
+    if (tty->tio.c_cflag & CRTSCTS)
+        tty->master_suspended = (mcr & TIOCM_CTS) ? 0 : 1;
+    DBG("%s: tty=%p mcr=%x MS=%d\n", __func__, tty, mcr,
+        tty->master_suspended);
 
     pthread_mutex_lock(&tty->tty_lock);
+    tty->smcr_last = tty->smcr;
     tty->smcr = mcr;
     pthread_mutex_unlock(&tty->tty_lock);
 }
@@ -369,7 +428,7 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     int             res;
     int             n;
 
-    DBG2("open: thread:%lu\n", pthread_self());
+    DBG("%s\n", __func__);
 
     tty = calloc(1, sizeof(*tty));
     if (!tty)
@@ -380,6 +439,8 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     for (n = 0; n < 3; n++)
         tty->fds[n].fd = -1;
 
+    tty->pollout = 1;
+
     tty->tn = telnet_ctx_init(tty, _srv_write, _srv_read, _modem_status_cb);
     if (!tty->tn)
     {
@@ -407,6 +468,8 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     tty->fds[FD_MASTER].fd = fd;
     tty->fds[FD_MASTER].events = POLLIN;
 
+    memset(&ios, 0, sizeof(ios));
+
     ios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP
                      | INLCR | IGNCR | ICRNL | IXON);
     ios.c_oflag &= ~OPOST;
@@ -424,6 +487,11 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     if ((fd = open(slave_name, O_RDWR | O_NOCTTY)) < 0) /* open slave */
         goto open_err;
 
+    ioctl(fd, TCGETS, &tty->tio);
+    tty->tio.c_cflag &= ~(CSIZE | PARENB);
+    tty->tio.c_cflag |= B115200 | CS8 | CREAD | CLOCAL;
+    ioctl(fd, TCSETS, &tty->tio);
+
     tty->fds[FD_SLAVE].fd = fd;
     tty->fds[FD_SLAVE].events = POLLIN;
 
@@ -435,7 +503,7 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     }
     if ((res = pthread_mutex_init(&tty->tty_lock, NULL) < 0) ||
         (res = pthread_mutex_init(&tty->poll_lock, NULL) < 0) ||
-        (res = pthread_create(&tty->thread_id, NULL, &_read_net, tty)))
+        (res = pthread_create(&tty->ptid_poll, NULL, &_read_net, tty)))
     {
         errno = res;
         goto open_err;
@@ -445,7 +513,7 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
     info->nonseekable = 1;
     info->direct_io = 1;
 
-    _log(LOG_INFO, "Connected to server: %s:%d\n",
+    nvt_log(LOG_INFO, "Connected to server: %s:%d\n",
             ttynvt_param.host, ttynvt_param.port);
 
     fuse_reply_open(req, info);
@@ -454,12 +522,11 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
 
   open_err:
 
-    _log(LOG_INFO, "Connection to server: %s:%d failed:%s\n",
-         ttynvt_param.host, ttynvt_param.port, strerror(errno));
+    nvt_log(LOG_INFO, "Connection to server: %s:%d failed: %m\n",
+            ttynvt_param.host, ttynvt_param.port);
 
     for (n = 0; n < 3; n++)
-        if (tty->fds[n].fd >= 0)
-            close(tty->fds[n].fd);
+        _fd_close(tty->fds[n].fd);
 
     free(tty->tn);
     free(tty);
@@ -471,16 +538,19 @@ ttynvt_read(fuse_req_t req, size_t size, off_t off,
             struct fuse_file_info *info)
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
-    int             res;
+    char            buf[TMP_BUF_SIZE];
+    int             res, nr;
+
+    DBG2("%s\n", __func__);
 
     if (tty->error)
     {
-        DBG2("read (slave) in error state, thread:%lu\n", pthread_self());
+        DBG2("%s: tty->error=%d\n", __func__, tty->error);
         if (tty->epipe == 0)
         {
-            _log(LOG_WARNING, "Rx EPIPE\n");
+            nvt_log(LOG_WARNING, "Rx EPIPE\n");
             tty->epipe = 1;
-            fuse_reply_buf(req, tty->tmp_buf, 0);
+            fuse_reply_buf(req, NULL, 0);
         }
         else
             fuse_reply_err(req, EBADFD);
@@ -491,21 +561,34 @@ ttynvt_read(fuse_req_t req, size_t size, off_t off,
     if (size > TMP_BUF_SIZE)
         size = TMP_BUF_SIZE;
 
-    fuse_req_interrupt_func(req, ttynvt_interrupted, (void *)pthread_self());
-    res =
-        _is_interrupted ? -2 : read(tty->fds[FD_SLAVE].fd, tty->tmp_buf, size);
+    tty->ptid_read = pthread_self();
+    fuse_req_interrupt_func(req, ttynvt_interrupted, (void *)tty->ptid_read);
+    res = _is_interrupted ? -2 : read(tty->fds[FD_SLAVE].fd, buf, size);
     _is_interrupted = 0;
+    tty->ptid_read = 0;
+    tty->slave_suspended = 0;   /* Enable polling of Slave */
     fuse_req_interrupt_func(req, NULL, NULL);
+    if (res < (int)size)
+    {
+        tty->pollin = 0;
+    }
+    else
+    {
+        nr = 0;
+        ioctl(tty->fds[FD_SLAVE].fd, FIONREAD, &nr);
+        tty->pollin = nr > 0;
+    }
     if (res < 0)
     {
-        DBG2("read (slave) error: %s\n", strerror(errno));
+        DBG2("%s: error: %m\n", __func__);
         fuse_reply_err(req, errno);
         return;
     }
 
-    DBG2("read (slave): size:%d, thread:%lu\n", res, pthread_self());
+    DBG2("%s: fd=%d: sz=%u/%u: '%.*s'\n", __func__,
+         tty->fds[FD_SLAVE].fd, res, (int)size, res, buf);
 
-    fuse_reply_buf(req, tty->tmp_buf, res);
+    fuse_reply_buf(req, buf, res);
 }
 
 static void
@@ -513,8 +596,10 @@ ttynvt_write(fuse_req_t req, const char *data, size_t size, off_t off,
              struct fuse_file_info *info)
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
-    ssize_t         res;
+    int             res;
 
+    DBG2("%s: fd=%d: sz=%u: '%.*s'\n", __func__,
+         tty->fds[FD_SLAVE].fd, (int)size, (int)size, data);
 
     if (size == 0)
     {
@@ -524,6 +609,7 @@ ttynvt_write(fuse_req_t req, const char *data, size_t size, off_t off,
 
     if (tty->error)
     {
+        DBG2("%s: tty->error=%d\n", __func__, tty->error);
         fuse_reply_err(req, EPIPE);
         return;
     }
@@ -531,22 +617,29 @@ ttynvt_write(fuse_req_t req, const char *data, size_t size, off_t off,
     res = write(tty->fds[FD_SLAVE].fd, data, size);
     if (res < 0)
     {
-        DBG2("write (slave) error: %s\n", strerror(errno));
+        DBG2("%s: error: %m\n", __func__);
         tty->error = 1;
         fuse_reply_err(req, errno);
         return;
     }
-
-    DBG2("write (slave): size:%d, thread:%lu\n", (int)size, pthread_self());
+    else if (res != (int)size)
+    {
+        DBG("%s: caution: tty->pollout set to 0\n", __func__);
+        tty->pollout = 0;
+    }
 
     fuse_reply_write(req, res);
 }
 
 static int baudrate(speed_t speed)
 {
+/**INDENT-OFF**/
     return speed == B50 ? 50 :
         speed == B75 ? 75 :
         speed == B110 ? 110 :
+        speed == B134 ? 134 :
+        speed == B150 ? 150 :
+        speed == B200 ? 200 :
         speed == B300 ? 300 :
         speed == B600 ? 600 :
         speed == B1200 ? 1200 :
@@ -557,7 +650,21 @@ static int baudrate(speed_t speed)
         speed == B19200 ? 19200 :
         speed == B38400 ? 38400 :
         speed == B57600 ? 57600 :
-        speed == B115200 ? 115200 : speed == B230400 ? 230400 : 0;
+        speed == B115200 ? 115200 :
+        speed == B230400 ? 230400 :
+        speed == B460800 ? 460800 :
+        speed == B500000 ? 500000 :
+        speed == B576000 ? 576000 :
+        speed == B921600 ? 921600 :
+        speed == B1000000 ? 1000000 :
+        speed == B1152000 ? 1152000 :
+        speed == B1500000 ? 1500000 :
+        speed == B2000000 ? 2000000 :
+        speed == B2500000 ? 2500000 :
+        speed == B3000000 ? 3000000 :
+        speed == B3500000 ? 3500000 :
+        speed == B4000000 ? 4000000 : 0;
+/**INDENT-ON**/
 }
 
 static const char pstr[] = { ' ', 'N', 'O', 'E', 'M', 'S' };
@@ -574,15 +681,16 @@ static const char *_ioctl_name(int cmd)
         snprintf(buf, sizeof(buf), "0x%x", cmd);
         return buf;
         CASE(TCSETSF);
+        CASE(TCSETSF2);
         CASE(TCSETSW);
+        CASE(TCSETSW2);
         CASE(TCSETS);
+        CASE(TCSETS2);
         CASE(TCGETS);
+        CASE(TCGETS2);
         CASE(TIOCINQ);
         CASE(TIOCOUTQ);
         CASE(TCFLSH);
-        CASE(TCIFLUSH);
-        CASE(TCOFLUSH);
-        CASE(TCIOFLUSH);
         CASE(TIOCMGET);
         CASE(TIOCMBIS);
         CASE(TIOCMBIC);
@@ -590,6 +698,9 @@ static const char *_ioctl_name(int cmd)
         CASE(TCSBRK);
         CASE(TIOCGWINSZ);
         CASE(TIOCSWINSZ);
+        /* Controlling terminal */
+        CASE(TIOCSCTTY);
+        CASE(TIOCNOTTY);
         /* Exclusive mode */
         CASE(TIOCEXCL);
         CASE(TIOCGEXCL);
@@ -602,6 +713,89 @@ static const char *_ioctl_name(int cmd)
     }
 }
 
+static unsigned int _tio_parity(const struct termios2 *tio)
+{
+    unsigned int    par;
+
+    if (tio->c_cflag & PARENB && tio->c_iflag & IGNPAR)
+        par = 1;
+#ifdef CMSPAR
+    else if (tio->c_cflag & PARENB && tio->c_iflag & CMSPAR)
+    {
+        if (tio->c_cflag & PARODD)
+            par = 4;
+        else
+            par = 5;
+    }
+#endif
+    else if (tio->c_cflag & PARENB)
+        par = 3;
+    else
+        par = 1;
+
+    return par;
+}
+
+static unsigned int _tio_baud(const struct termios2 *tio)
+{
+    return baudrate(tio->c_cflag & (CBAUD | CBAUDEX));
+}
+
+static unsigned int _tio2_baud(const struct termios2 *tio2)
+{
+    if ((tio2->c_cflag & CBAUD) == BOTHER)
+        return tio2->c_ospeed;
+
+    return _tio_baud(tio2);
+}
+
+static unsigned int _tio_csize(const struct termios2 *tio)
+{
+    unsigned int    csize;
+
+    if ((tio->c_cflag & CSIZE) == CS5)
+        csize = 5;
+    else if ((tio->c_cflag & CSIZE) == CS6)
+        csize = 6;
+    else if ((tio->c_cflag & CSIZE) == CS7)
+        csize = 7;
+    else
+        csize = 8;
+
+    return csize;
+}
+
+static unsigned int _tio_stopb(const struct termios2 *tio)
+{
+    unsigned int    stopb;
+
+    if (tio->c_cflag & CSTOPB)
+        stopb = 2;
+    else
+        stopb = 1;
+
+    return stopb;
+}
+
+static void _show_termios(const char *txt, const struct termios2 *tio)
+{
+    DBG("%s: %u%c%u%u %cCTSRTS %cCREAD %cHUPCL %cCLOCAL\n", txt,
+        _tio_baud(tio), pstr[_tio_parity(tio)], _tio_csize(tio),
+        _tio_stopb(tio),
+        tio->c_cflag & CRTSCTS ? '+' : '-', tio->c_cflag & CREAD ? '+' : '-',
+        tio->c_cflag & HUPCL ? '+' : '-', tio->c_cflag & CLOCAL ? '+' : '-');
+}
+
+static void _show_termios2(const char *txt, const struct termios2 *tio)
+{
+    DBG("%s: %u%c%u%u %cCTSRTS %cCREAD %cHUPCL %cCLOCAL\n", txt,
+        _tio2_baud(tio), pstr[_tio_parity(tio)], _tio_csize(tio),
+        _tio_stopb(tio),
+        tio->c_cflag & CRTSCTS ? '+' : '-', tio->c_cflag & CREAD ? '+' : '-',
+        tio->c_cflag & HUPCL ? '+' : '-', tio->c_cflag & CLOCAL ? '+' : '-');
+}
+
+
 #define CHECK_BUF_IN(sz) \
     if (in_bufsz < sz)  do { in_bufsz  = sz; goto retry_in;  } while(0)
 #define CHECK_BUF_OUT(sz) \
@@ -613,14 +807,14 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
              const void *in_buf, size_t in_bufsz, size_t out_bufsz)
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
+    struct termios2 *tio = &tty->tio;
     struct winsize  ws;
-    unsigned int    tiocm = 0;
+    unsigned int    tiocm, baud;
     int             mcr;
-    static struct termios tio = {
-        .c_cflag = B115200 | CS8 | PARODD | CREAD | CLOCAL,
-    };
     int             val;
     int             res;
+    uint8_t         byte;
+    uint32_t        byte4;
 
     DBG("%s: cmd=%s arg=%p ibuf=%p:%u obuf=:%u\n", __func__,
         _ioctl_name(cmd), arg, in_buf,
@@ -632,73 +826,78 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
     case TCSETSW:
     case TCSETS:
         CHECK_BUF_IN(sizeof(struct termios));
+        memcpy(tio, in_buf, in_bufsz);
+        baud = _tio_baud(tio);
+        goto do_tcset;
+    case TCSETSF2:
+    case TCSETSW2:
+    case TCSETS2:
+        CHECK_BUF_IN(sizeof(struct termios2));
+        memcpy(tio, in_buf, in_bufsz);
+        baud = _tio2_baud(tio);
+        goto do_tcset;
+      do_tcset:
+        /* BEWARE of termios/termios2 buf structure difference! */
+        byte4 = htonl(baud);
+        telnet_rfc2217_cfg(tty->tn, TNS_SET_BAUDRATE, &byte4, 4);
+
+        byte = _tio_csize(tio);
+        telnet_rfc2217_cfg(tty->tn, TNS_SET_DATASIZE, &byte, 1);
+
+        byte = _tio_parity(tio);
+        telnet_rfc2217_cfg(tty->tn, TNS_SET_PARITY, &byte, 1);
+
+        byte = _tio_stopb(tio);
+        telnet_rfc2217_cfg(tty->tn, TNS_SET_STOPSIZE, &byte, 1);
+
+        if (tio->c_cflag & CRTSCTS)
         {
-            speed_t         speed;
-            int             csize, par, sb;
-
-            memcpy(&tio, in_buf, in_bufsz);
-
-            speed = tio.c_cflag & (CBAUD | CBAUDEX);
-            val = htonl(baudrate(speed));
-            telnet_rfc2217_cfg(tty->tn, TNS_SET_BAUDRATE, &val, 4);
-
-            if ((tio.c_cflag & CSIZE) == CS5)
-                csize = 5;
-            else if ((tio.c_cflag & CSIZE) == CS6)
-                csize = 6;
-            else if ((tio.c_cflag & CSIZE) == CS7)
-                csize = 7;
-            else
-                csize = 8;
-            telnet_rfc2217_cfg(tty->tn, TNS_SET_DATASIZE, &csize, 1);
-
-            if (tio.c_cflag & PARENB && tio.c_iflag & IGNPAR)
-                par = 1;
-#ifdef CMSPAR
-            else if (tio.c_cflag & PARENB && tio.c_iflag & CMSPAR)
-            {
-                if (tio.c_cflag & PARODD)
-                    par = 4;
-                else
-                    par = 5;
-            }
-#endif
-            else if (tio.c_cflag & PARENB)
-                par = 3;
-            else
-                par = 1;
-            telnet_rfc2217_cfg(tty->tn, TNS_SET_PARITY, &par, 1);
-
-            if (tio.c_cflag & CSTOPB)
-                sb = 2;
-            else
-                sb = 1;
-            telnet_rfc2217_cfg(tty->tn, TNS_SET_STOPSIZE, &sb, 1);
-
-            if (tio.c_cflag & CRTSCTS)
+            tty->master_suspended = (tty->smcr & TIOCM_CTS) ? 0 : 1;
             telnet_rfc2217_ctl(tty->tn, TNS_CTL_CTSRTS);
+        }
+        else
+        {
+            tty->master_suspended = 0;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_NOFLOW);
+        }
 
-            if (!(tty->cmcr & TIOCM_DTR) && speed != B0)
+        if (!(tty->cmcr & TIOCM_DTR) && baud != 0)
         {
             tty->cmcr |= TIOCM_DTR;
             telnet_rfc2217_ctl(tty->tn, TNS_CTL_DTR_ON);
         }
 
-            DBG("termios: %u%c%u%u %cCTSRTS %cCREAD %cHUPCL %cCLOCAL\n",
-                baudrate(speed), pstr[par], csize, sb,
-                tio.c_cflag & CRTSCTS ? '+' : '-',
-                tio.c_cflag & CREAD ? '+' : '-',
-                tio.c_cflag & HUPCL ? '+' : '-',
-                tio.c_cflag & CLOCAL ? '+' : '-');
+        switch (cmd)
+        {
+        case TCSETSF:
+        case TCSETSW:
+        case TCSETS:
+            _show_termios("TCSETS", tio);
+            break;
+        case TCSETSF2:
+        case TCSETSW2:
+        case TCSETS2:
+            _show_termios2("TCSETS2", tio);
+            break;
+        }
+        ioctl(tty->fds[FD_SLAVE].fd, cmd, tio);
 
-            ioctl(tty->fds[FD_SLAVE].fd, cmd, &tio);
+        if (cmd == TCSETSF || cmd == TCSETSF2)
+            tty->slave_suspended = 0;   /* Re-enable polling of Slave */
 
         fuse_reply_ioctl(req, 0, 0, 0);
-        }
         break;
     case TCGETS:
         CHECK_BUF_OUT(sizeof(struct termios));
-        fuse_reply_ioctl(req, 0, &tio, sizeof(struct termios));
+        ioctl(tty->fds[FD_SLAVE].fd, TCGETS, tio);
+        _show_termios("TCGETS", tio);
+        fuse_reply_ioctl(req, 0, tio, sizeof(struct termios));
+        break;
+    case TCGETS2:
+        CHECK_BUF_OUT(sizeof(struct termios2));
+        ioctl(tty->fds[FD_SLAVE].fd, TCGETS2, tio);
+        _show_termios2("TCGETS2", tio);
+        fuse_reply_ioctl(req, 0, tio, sizeof(struct termios2));
         break;
     case TIOCINQ:              /* Get the number of bytes in the input
                                  * buffer */
@@ -713,33 +912,27 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
         fuse_reply_ioctl(req, 0, &val, sizeof(int));
         break;
     case TCFLSH:
-        if (arg == TCIFLUSH)
+        switch ((size_t)arg)
         {
-            /*todo */
-        }
-        else if ((size_t) arg == TCOFLUSH)
-        {
-            /*todo */
-        }
-        else if ((size_t) arg == TCIOFLUSH)
-        {
-            /*todo */
-        }
-        fuse_reply_ioctl(req, 0, 0, 0);
-        break;
+        default:
         case TCIFLUSH:
-        val = 1;
-        telnet_rfc2217_cfg(tty->tn, TNS_SET_PURGE, &val, 1);
-        fuse_reply_ioctl(req, 0, 0, 0);
+            byte = 1;
+            tty->slave_suspended = 0;   /* Re-enable polling of Slave */
+            tty->pollin = 0;
             break;
         case TCOFLUSH:
-        val = 2;
-        telnet_rfc2217_cfg(tty->tn, TNS_SET_PURGE, &val, 1);
-        fuse_reply_ioctl(req, 0, 0, 0);
+            byte = 2;
+            tty->pollout = 1;
             break;
         case TCIOFLUSH:
-        val = 3;
-        telnet_rfc2217_cfg(tty->tn, TNS_SET_PURGE, &val, 1);
+            byte = 3;
+            tty->slave_suspended = 0;   /* Re-enable polling of Slave */
+            tty->pollout = 1;
+            tty->pollin = 0;
+            break;
+        }
+        telnet_rfc2217_cfg(tty->tn, TNS_SET_PURGE, &byte, 1);
+        ioctl(tty->fds[FD_SLAVE].fd, TCFLSH, arg);
         fuse_reply_ioctl(req, 0, 0, 0);
         break;
     case TIOCMGET:
@@ -794,9 +987,9 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
                            TNS_CTL_RTS_ON : TNS_CTL_RTS_OFF);
         goto show_mctl;
       show_mctl:
-        DBG("MCR: DTR=%c RTS=%c\n",
-            tty->cmcr & TIOCM_DTR ? '1' : '0',
-            tty->cmcr & TIOCM_RTS ? '1' : '0');
+        DBG("MCR: RTS=%c DTR=%c\n",
+            tty->cmcr & TIOCM_RTS ? '1' : '0',
+            tty->cmcr & TIOCM_DTR ? '1' : '0');
         break;
     case TCSBRK:
         fuse_reply_ioctl(req, 0, 0, 0);
@@ -838,7 +1031,6 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
     case TIOCSETD:
         CHECK_BUF_IN(sizeof(int));
         val = *(int *)in_buf;
-
         res = ioctl(tty->fds[FD_SLAVE].fd, TIOCSETD, &val);
         if (res < 0)
             fuse_reply_err(req, errno);
@@ -862,6 +1054,7 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
             fuse_reply_ioctl(req, 0, &val, sizeof(int));
         break;
     default:
+        DBG("ERROR: Unsupported IOCTL\n");
         fuse_reply_err(req, ENOSYS);
         break;
 
@@ -888,21 +1081,29 @@ ttynvt_poll(fuse_req_t req, struct fuse_file_info *info,
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
     int             revents = 0;
 
+    DBG2("%s: tty->pollin=%d tty->error/epipe=%d/%d\n",
+         __func__, tty->pollin, tty->error, tty->epipe);
+
     _update_notify(tty, ph);
 
+    if (tty->pollout)
+    {
+        revents = POLLOUT;
+    }
     if (tty->pollin)
     {
-        tty->pollin = 0;
         revents |= POLLIN;
     }
     if (tty->error)
     {
         if (tty->epipe == 0)
-            revents = POLLHUP | POLLIN;
+            revents |= POLLHUP | POLLIN;
         else
             revents = 0;
     }
 
+    DBG2("%s: revents=%#x\n", __func__, revents);
+
     fuse_reply_poll(req, revents);
 }
 
@@ -920,6 +1121,7 @@ static const struct cuse_lowlevel_ops ttynvt_op = {
 
 static const struct fuse_opt ttynvt_opts[] = {
     TTYNET_OPT("-D %d", debug, 1),
+    TTYNET_OPT("-E", logstd, 1),
     TTYNET_OPT("-M %u", major, 1),
     TTYNET_OPT("--maj=%u", major, 1),
     TTYNET_OPT("-m %u", minor, 1),
@@ -937,6 +1139,9 @@ static void print_help(void)
 {
     fprintf(stderr, "ttynvt Usage:\n"
             "\t-D level\tEnable debug\n"
+            "\t-d\t\tStay in foreground, do not detach\n"
+            "\t-f\t\tStay in foreground, do not detach\n"
+            "\t-E\t\tPrint debug to stdout (default is syslog)\n"
             "\t-M major, --maj=major\n"
             "\t-m minor, --min=minor\n"
             "\t-n name, --name=name (default: ttyNVT0)\n"
@@ -976,6 +1181,9 @@ int main(int argc, char *argv[])
         return 1;
     }
 
+    log_level = ttynvt_param.debug;
+    log_stdout = ttynvt_param.logstd;
+
     if (!ttynvt_param.dev_name)
         ttynvt_param.dev_name = "ttyNVT0";
 
@@ -1018,14 +1226,14 @@ int main(int argc, char *argv[])
     switch (cpid)
     {
     case -1:
-        _log(LOG_ERR, "fork(): %m");
+        nvt_log(LOG_ERR, "fork(): %m\n");
         return -1;
 
     case 0:                    /* Child */
         DBG("Child proceeding...\n");
         rc = cuse_lowlevel_main(args.argc, args.argv, &ci, &ttynvt_op, NULL);
         if (rc != 0)
-            _log(LOG_ERR, "ttynvt failed rc=%d", rc);
+            nvt_log(LOG_ERR, "ttynvt failed rc=%d\n", rc);
         else
             DBG("Child exited\n");
         return rc;

telnet_param.h

@@ -1,123 +0,0 @@
-/*
- * Copyright (c) 2018 Lars Thrane A/S
- * SPDX-License-Identifier: GPL-2.0
- *
- * Telnet parameters
- */
-#ifndef TELNET_PARAM_H
-#define TELNET_PARAM_H
-
-
-/*
- * Telnet commands
- */
-
-#define TNC_F0_SE   (0xf0)      /* End of subnegotiation parameters */
-#define TNC_F1_NOP  (0xf1)      /* No operation                     */
-#define TNC_F2_MARK (0xf2)      /* The data stream portion of a Synch.
-                                   This should always be accompanied
-                                   by a TCP Urgent notification. */
-#define TNC_F3_BRK  (0xf3)      /* NVT character BRK.               */
-#define TNC_F4_IP   (0xf4)      /* The function IP (interrupt process) */
-#define TNC_F5_AO   (0xf5)      /* The function AO (abort output)   */
-#define TNC_F6_AYT  (0xf6)      /* The function AYT (are you there) */
-#define TNC_F7_EC   (0xf7)      /* The function EC (erase charceter) */
-#define TNC_F8_EL   (0xf8)      /* The function EL (erase line)     */
-#define TNC_F9_GA   (0xf9)      /* The GA signal (go ahead)         */
-#define TNC_FA_SB   (0xfa)      /* Subnegotiation begin             */
-#define TNC_FB_WILL (0xfb)      /* Indicates the desire to begin
-                                   performing, or confirmation that
-                                   you are now performing, the
-                                   indicated option. */
-#define TNC_FC_WONT (0xfc)      /* Indicates the refusal to perform,
-                                   or continue performing, the
-                                   indicated option. */
-#define TNC_FD_DO   (0xfd)      /* Indicates the request that the
-                                   other party perform, or
-                                   confirmation that you are expecting
-                                   the other party to perform, the
-                                   indicated option. */
-#define TNC_FE_DONT (0xfe)      /* Indicates the demand that the
-                                   other party stop performing,
-                                   or confirmation that you are no
-                                   longer expecting the other party
-                                   to perform, the indicated option. */
-#define TNC_FF_IAC  (0xff)      /* Interpret as Command / data byte */
-
-
-/*
- * Telnet options
- */
-
-/*
- * https://www.iana.org/assignments/telnet-options/telnet-options.xhtml
- *
- * 0 	Binary Transmission					[RFC856]
- * 1 	Echo								[RFC857]
- * 2 	Reconnection						[DDN Protocol Handbook, ... ]
- * 3 	Suppress Go Ahead					[RFC858]
- * 4 	Approx Message Size Negotiation		["The Ethernet, ... ]
- * 5 	Status								[RFC859]
- * 6 	Timing Mark							[RFC860]
- * 7 	Remote Controlled Trans and Echo	[RFC726]
- * 8 	Output Line Width					[DDN Protocol Handbook, ... ]
- * 9 	Output Page Size					[DDN Protocol Handbook, ... ]
- * 10 	Output Carriage-Return Disposition	[RFC652]
- * 11 	Output Horizontal Tab Stops			[RFC653]
- * 12 	Output Horizontal Tab Disposition	[RFC654]
- * 13 	Output Formfeed Disposition			[RFC655]
- * 14 	Output Vertical Tabstops			[RFC656]
- * 15 	Output Vertical Tab Disposition		[RFC657]
- * 16 	Output Linefeed Disposition			[RFC658]
- * 17 	Extended ASCII						[RFC698]
- * 18 	Logout								[RFC727]
- * 19 	Byte Macro							[RFC735]
- * 20 	Data Entry Terminal					[RFC1043][RFC732]
- * 21 	SUPDUP								[RFC736][RFC734]
- * 22 	SUPDUP Output						[RFC749]
- * 23 	Send Location						[RFC779]
- * 24 	Terminal Type						[RFC1091]
- * 25 	End of Record						[RFC885]
- * 26 	TACACS User Identification			[RFC927]
- * 27 	Output Marking						[RFC933]
- * 28 	Terminal Location Number			[RFC946]
- * 29 	Telnet 3270 Regime					[RFC1041]
- * 30 	X.3 PAD								[RFC1053]
- * 31 	Negotiate About Window Size			[RFC1073]
- * 32 	Terminal Speed						[RFC1079]
- * 33 	Remote Flow Control					[RFC1372]
- * 34 	Linemode							[RFC1184]
- * 35 	X Display Location					[RFC1096]
- * 36 	Environment Option					[RFC1408]
- * 37 	Authentication Option				[RFC2941]
- * 38 	Encryption Option					[RFC2946]
- * 39 	New Environment Option				[RFC1572]
- * 40 	TN3270E								[RFC2355]
- * 41 	XAUTH								[Rob_Earhart]
- * 42 	CHARSET								[RFC2066]
- * 43 	Telnet Remote Serial Port (RSP)		[Robert_Barnes]
- * 44 	Com Port Control Option				[RFC2217]
- * 45 	Telnet Suppress Local Echo			[Wirt_Atmar]
- * 46 	Telnet Start TLS					[Michael_Boe]
- * 47 	KERMIT								[RFC2840]
- * 48 	SEND-URL							[David_Croft]
- * 49 	FORWARD_X							[Jeffrey_Altman]
- * 50-137 	Unassigned						[IANA]
- * 138 	TELOPT PRAGMA LOGON					[Steve_McGregory]
- * 139 	TELOPT SSPI LOGON					[Steve_McGregory]
- * 140 	TELOPT PRAGMA HEARTBEAT				[Steve_McGregory]
- * 141-254 	Unassigned
- * 255 	Extended-Options-List				[RFC861]
-*/
-
-#define TNO_BINARY   0          /* Binary Transmission          */
-#define TNO_ECHO     1          /* Echo                         */
-#define TNO_SUPP_GA  3          /* Suppress Go Ahead            */
-#define TNO_LOGOUT  18          /* Logout                       */
-#define TNO_TTYP    24          /* Terminal Type                */
-#define TNO_NAWS    31          /* Negotiate About Window Size  */
-#define TNO_NEO     39          /* New Environment Option       */
-#define TNO_CPCO    44          /* RFC 2217                     */
-#define TNO_KERMIT  47          /* Kermit                       */
-
-#endif /* TELNET_PARAM_H */