Support for software flow control

Based on suggestion by joluxer <linuxer@quantentunnel.de>.

.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],  [0.13])
+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

@@ -60,11 +60,12 @@ extern void     telnet_rfc2217_ctl(tn_ctx_t * tcc, unsigned int val);
 
 /*RFC2217 control commands*/
 #define TNS_CTL_NOFLOW      1
-#define TNS_CTL_XONOFF      2
+#define TNS_CTL_XONOFF_OUT  2
 #define TNS_CTL_CTSRTS      3
 #define TNS_CTL_DTR_ON      8
 #define TNS_CTL_DTR_OFF     9
 #define TNS_CTL_RTS_ON     11
 #define TNS_CTL_RTS_OFF    12
+#define TNS_CTL_XONOFF_IN  15
 
 #endif /*TELNET_H */

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

@@ -45,7 +45,7 @@ void telnet_rfc2217_cfg(tn_ctx_t * tcc, int cmd, const void *val, int nd)
 
 void telnet_rfc2217_ctl(tn_ctx_t * tcc, unsigned int val)
 {
-    unsigned char byte = val;
+    unsigned char   byte = val;
 
     if (!tcc->mode_rfc2217)
         return;

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>
@@ -17,15 +19,15 @@
 #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
@@ -35,9 +37,6 @@
 #define FD_MASTER  1
 #define FD_SLAVE   2
 
-#define _PRF_N_(no) __attribute__((__format__(__printf__, (no), (no) + 1)))
-#define _PRF2_ _PRF_N_(2)
-
 
 static struct ttynvt_param {
     unsigned int    major;
@@ -61,77 +60,28 @@ typedef struct {
 
     struct fuse_pollhandle *ph;
 
-    volatile char   n_fds;
+    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];
     int             net_cnt;
 
-    struct termios  tio;
+    struct termios2 tio;
 
     int             cmcr;       /* Commanded by ioctl */
     volatile int    smcr;       /* Status from modem */
     int             smcr_last;
 
     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, ...)
-{
-    va_list         arg;
-    char            buf[256];
-
-    va_start(arg, fmt);
-    vsnprintf(buf, sizeof(buf), fmt, arg);
-
-    if (ttynvt_param.logstd)
-        printf("[%d] %d: %s", gettid(), prio, buf);
-    else
-        syslog(prio, "[%d] %s", gettid(), buf);
-
-    va_end(arg);
-}
-
-#define BPL 16                  /* Bytes per line */
-
-void _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;
-        }
-        _log(prio, "%s\n", buf);
-    }
-}
-
-#define DBG(...) \
-    if (ttynvt_param.debug > 0) _log(LOG_DEBUG, __VA_ARGS__)
-#define DBG2(...) \
-    if (ttynvt_param.debug > 1) _log(LOG_DEBUG, __VA_ARGS__)
-#define DBG2_BUF(txt, ptr, len) \
-    if (ttynvt_param.debug > 1) _log_buf(LOG_DEBUG, txt, ptr, len)
-
 static void _fd_close(int fd)
 {
     if (fd >= 0)
@@ -187,9 +137,9 @@ 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");
 
-    tty->n_fds = 0;
+    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);
@@ -255,22 +205,26 @@ static void    *_read_net(void *arg)
     pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
     DBG2("%s: net_cnt=%d\n", __func__, tty->net_cnt);
 
-    while (tty->n_fds > 0)
+    while (!tty->rel_pending)
     {
         tty->fds[FD_NET].revents = tty->fds[FD_MASTER].revents =
             tty->fds[FD_SLAVE].revents = 0;
-        res = poll(tty->fds, tty->n_fds, -1);
-        DBG2("%s: res=%d N=%d events-N/M/S=%#x/%#x/%#x\n", __func__,
-             res, tty->n_fds,
-             tty->fds[FD_NET].revents, tty->fds[FD_MASTER].revents,
-             tty->fds[FD_SLAVE].revents);
+        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;
             break;
         }
-        if (tty->n_fds == 0)
+        if (tty->rel_pending)
             break;
 
         if (tty->fds[FD_NET].revents & POLLIN)
@@ -279,12 +233,12 @@ static void    *_read_net(void *arg)
                        NET_BUF_SIZE - tty->net_cnt);
             if (res < 0)
             {
-                _log(LOG_ERR, "net read error: %m\n");
+                nvt_log(LOG_ERR, "net read error: %m\n");
                 break;
             }
             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;
@@ -298,7 +252,7 @@ static void    *_read_net(void *arg)
                     write(tty->fds[FD_MASTER].fd, tty->net_buf, tty->net_cnt);
                 if (res < 0)
                 {
-                    _log(LOG_ERR, "master write error: %m\n");
+                    nvt_log(LOG_ERR, "master write error: %m\n");
                     break;
                 }
                 tty->net_cnt = 0;
@@ -307,14 +261,20 @@ static void    *_read_net(void *arg)
                 break;
         }
 
-        if (tty->fds[FD_MASTER].revents & POLLIN)
+        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)
             {
-                _log(LOG_ERR, "master read error: %m\n");
+                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);
         }
@@ -322,7 +282,7 @@ static void    *_read_net(void *arg)
         if (tty->fds[FD_SLAVE].revents & POLLIN)
         {
             tty->pollin = 1;
-            tty->n_fds = 2;     /* Disable polling of Slave */
+            tty->slave_suspended = 1;   /* Disable polling of Slave */
             _notify(tty);
         }
     }
@@ -346,14 +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: %m\n");
+        nvt_log(LOG_ERR, "Socket open failed: %m\n");
         return sockfd;
     }
 
     server = gethostbyname(host);
     if (server == NULL)
     {
-        _log(LOG_ERR, "Cannot resolve host name: %m\n");
+        nvt_log(LOG_ERR, "Cannot resolve host name: %m\n");
         close(sockfd);
         return -1;
     }
@@ -367,7 +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: %m\n", host, port);
+        nvt_log(LOG_ERR, "Failed to connect to: %s:%u: %m\n", host, port);
         close(sockfd);
         return -1;
     }
@@ -442,6 +402,11 @@ static void _modem_status_cb(void *cctx, int status)
     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;
@@ -474,6 +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)
     {
@@ -542,14 +509,12 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
         goto open_err;
     }
 
-    tty->n_fds = 3;             /* Initially poll Net, Master, and Slave */
-
     info->fh = (uintptr_t) tty;
     info->nonseekable = 1;
     info->direct_io = 1;
 
-    _log(LOG_INFO, "Connected to server: %s:%d\n",
-         ttynvt_param.host, ttynvt_param.port);
+    nvt_log(LOG_INFO, "Connected to server: %s:%d\n",
+            ttynvt_param.host, ttynvt_param.port);
 
     fuse_reply_open(req, info);
 
@@ -557,8 +522,8 @@ static void ttynvt_open(fuse_req_t req, struct fuse_file_info *info)
 
   open_err:
 
-    _log(LOG_INFO, "Connection to server: %s:%d failed: %m\n",
-         ttynvt_param.host, ttynvt_param.port);
+    nvt_log(LOG_INFO, "Connection to server: %s:%d failed: %m\n",
+            ttynvt_param.host, ttynvt_param.port);
 
     for (n = 0; n < 3; n++)
         _fd_close(tty->fds[n].fd);
@@ -574,7 +539,7 @@ ttynvt_read(fuse_req_t req, size_t size, off_t off,
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
     char            buf[TMP_BUF_SIZE];
-    int             res;
+    int             res, nr;
 
     DBG2("%s\n", __func__);
 
@@ -583,7 +548,7 @@ ttynvt_read(fuse_req_t req, size_t size, off_t off,
         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, NULL, 0);
         }
@@ -601,8 +566,18 @@ ttynvt_read(fuse_req_t req, size_t size, off_t off,
     res = _is_interrupted ? -2 : read(tty->fds[FD_SLAVE].fd, buf, size);
     _is_interrupted = 0;
     tty->ptid_read = 0;
-    tty->n_fds = 3;             /* Enable polling of Slave */
+    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("%s: error: %m\n", __func__);
@@ -647,15 +622,24 @@ ttynvt_write(fuse_req_t req, const char *data, size_t size, off_t off,
         fuse_reply_err(req, errno);
         return;
     }
+    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 :
@@ -666,7 +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' };
@@ -683,9 +681,13 @@ 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);
@@ -711,7 +713,7 @@ static const char *_ioctl_name(int cmd)
     }
 }
 
-static unsigned int _tio_parity(const struct termios *tio)
+static unsigned int _tio_parity(const struct termios2 *tio)
 {
     unsigned int    par;
 
@@ -734,12 +736,20 @@ static unsigned int _tio_parity(const struct termios *tio)
     return par;
 }
 
-static unsigned int _tio_baud(const struct termios *tio)
+static unsigned int _tio_baud(const struct termios2 *tio)
 {
     return baudrate(tio->c_cflag & (CBAUD | CBAUDEX));
 }
 
-static unsigned int _tio_csize(const struct termios *tio)
+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;
 
@@ -755,7 +765,7 @@ static unsigned int _tio_csize(const struct termios *tio)
     return csize;
 }
 
-static unsigned int _tio_stopb(const struct termios *tio)
+static unsigned int _tio_stopb(const struct termios2 *tio)
 {
     unsigned int    stopb;
 
@@ -767,7 +777,7 @@ static unsigned int _tio_stopb(const struct termios *tio)
     return stopb;
 }
 
-static void _show_termios(const char *txt, const struct termios *tio)
+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),
@@ -776,6 +786,16 @@ static void _show_termios(const char *txt, const struct termios *tio)
         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) \
@@ -787,14 +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 termios *tio = &tty->tio;
+    struct termios2 *tio = &tty->tio;
     struct winsize  ws;
-    unsigned int    tiocm = 0;
+    unsigned int    tiocm, baud;
     int             mcr;
     int             val;
     int             res;
-    unsigned char   byte;
-    unsigned int    byte4;
+    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,
@@ -806,41 +826,82 @@ 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)
         {
-            memcpy(tio, in_buf, in_bufsz);
-
-            byte4 = htonl(_tio_baud(tio));
-            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)
-            {
-                tty->cmcr |= TIOCM_RTS;
-                telnet_rfc2217_ctl(tty->tn, TNS_CTL_CTSRTS);
-            }
-
-            if (!(tty->cmcr & TIOCM_DTR) && _tio_baud(tio) != 0)
-            {
-                tty->cmcr |= TIOCM_DTR;
-                telnet_rfc2217_ctl(tty->tn, TNS_CTL_DTR_ON);
-            }
-
-            _show_termios("TCSETS", tio);
-            ioctl(tty->fds[FD_SLAVE].fd, cmd, tio);
-
-            if (cmd == TCSETSF)
-                tty->n_fds = 3; /* Re-enable polling of Slave */
-
-            fuse_reply_ioctl(req, 0, 0, 0);
+            tty->master_suspended = (tty->smcr & TIOCM_CTS) ? 0 : 1;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_CTSRTS);
         }
+        else if ((tio->c_iflag & IXON) && (tio->c_iflag & IXOFF))
+        {
+            tty->master_suspended = 0;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_XONOFF_OUT);
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_XONOFF_IN);
+        }
+        else if (tio->c_iflag & IXON)
+        {
+            tty->master_suspended = 0;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_XONOFF_OUT);
+        }
+        else if (tio->c_iflag & IXOFF)
+        {
+            tty->master_suspended = 0;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_XONOFF_IN);
+        }
+        else
+        {
+            tty->master_suspended = 0;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_NOFLOW);
+        }
+
+        if (!(tty->cmcr & TIOCM_DTR) && baud != 0)
+        {
+            tty->cmcr |= TIOCM_DTR;
+            telnet_rfc2217_ctl(tty->tn, TNS_CTL_DTR_ON);
+        }
+
+        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);
+
+        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));
@@ -848,6 +909,12 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
         _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 */
         CHECK_BUF_OUT(sizeof(int));
@@ -861,19 +928,21 @@ ttynvt_ioctl(fuse_req_t req, int cmd, void *arg,
         fuse_reply_ioctl(req, 0, &val, sizeof(int));
         break;
     case TCFLSH:
-        switch ((size_t) arg)
+        switch ((size_t)arg)
         {
         default:
         case TCIFLUSH:
             byte = 1;
-            tty->n_fds = 3;     /* Re-enable polling of Slave */
+            tty->slave_suspended = 0;   /* Re-enable polling of Slave */
             break;
         case TCOFLUSH:
             byte = 2;
+            tty->pollout = 1;
             break;
         case TCIOFLUSH:
             byte = 3;
-            tty->n_fds = 3;     /* Re-enable polling of Slave */
+            tty->slave_suspended = 0;   /* Re-enable polling of Slave */
+            tty->pollout = 1;
             break;
         }
         telnet_rfc2217_cfg(tty->tn, TNS_SET_PURGE, &byte, 1);
@@ -999,6 +1068,7 @@ 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;
 
@@ -1023,18 +1093,19 @@ ttynvt_poll(fuse_req_t req, struct fuse_file_info *info,
             struct fuse_pollhandle *ph)
 {
     ttynvt_t       *tty = (ttynvt_t *) (uintptr_t) info->fh;
-    int             revents;
+    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);
 
-    revents = POLLOUT;
-
+    if (tty->pollout)
+    {
+        revents = POLLOUT;
+    }
     if (tty->pollin)
     {
-        tty->pollin = 0;
         revents |= POLLIN;
     }
     if (tty->error)
@@ -1082,6 +1153,8 @@ 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"
@@ -1122,6 +1195,9 @@ 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";
 
@@ -1164,14 +1240,14 @@ int main(int argc, char *argv[])
     switch (cpid)
     {
     case -1:
-        _log(LOG_ERR, "fork(): %m\n");
+        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\n", 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 */