Add support for setting non-standard baudrates

Support for non-standard baudrate settings will be automatically enabled
if the termios2 interface is detected available. However, to play it
safe, the old and widely supported termios interface will still be used
when setting standard baudrates.

configure.ac

@@ -84,6 +84,10 @@ TIO_CHECK_BAUDRATES(
 
 AC_DEFINE_UNQUOTED([AUTOCONF_BAUDRATE_CASES],[$BAUDRATE_CASES],[Switch cases for detected baud rates])
 
+# Check for interface for setting arbitrary I/O speeds
+AC_CHECK_DECL([TCGETS2], [AC_DEFINE([HAVE_TERMIOS2],[1],[Define if termios2 exists.]) have_termios2=yes], , [[#include <asm/termios.h>]])
+AM_CONDITIONAL([ADD_SETSPEED2],[test "x$have_termios2" == "xyes"])
+
 AC_CONFIG_FILES([Makefile])
 AC_CONFIG_FILES([src/Makefile])
 AC_CONFIG_FILES([src/bash-completion/tio])

src/Makefile.am

@@ -13,6 +13,10 @@ tio_SOURCES = tty.c \
               include/tio/log.h \
               include/tio/error.h
 
+if ADD_SETSPEED2
+tio_SOURCES += setspeed2.c
+endif
+
 if ENABLE_BASH_COMPLETION
 bashcompletiondir=@BASH_COMPLETION_DIR@
 bashcompletion_DATA=bash-completion/tio

src/setspeed2.c

@@ -0,0 +1,20 @@
+#include <sys/ioctl.h>
+#include <asm/termbits.h>
+
+int setspeed2(int fd, int baudrate)
+{
+    struct termios2 tio;
+    int status;
+
+    status = ioctl(fd, TCGETS2, &tio);
+
+    // Set baudrate speed using termios2 interface
+    tio.c_cflag &= ~CBAUD;
+    tio.c_cflag |= BOTHER;
+    tio.c_ispeed = baudrate;
+    tio.c_ospeed = baudrate;
+
+    status = ioctl(fd, TCSETS2, &tio);
+
+    return status;
+}

src/tty.c

@@ -42,13 +42,18 @@
 #include "tio/log.h"
 #include "tio/error.h"
 
+#ifdef HAVE_TERMIOS2
+extern int setspeed2(int fd, int baudrate);
+#endif
+
 static struct termios tio, tio_old, stdout_new, stdout_old, stdin_new, stdin_old;
 static unsigned long rx_total = 0, tx_total = 0;
 static bool connected = false;
 static bool tainted = false;
-static int fd;
 static bool print_mode = NORMAL;
+static bool standard_baudrate = true;
 static void (*print)(char c);
+static int fd;
 
 #define tio_printf(format, args...) \
 { \
@@ -276,24 +281,32 @@ void tty_configure(void)
         AUTOCONF_BAUDRATE_CASES
 
         default:
+#ifdef HAVE_TERMIOS2
+            standard_baudrate = false;
+            break;
+#else
             error_printf("Invalid baud rate");
             exit(EXIT_FAILURE);
+#endif
     }
 
-    // Set input speed
+    if (standard_baudrate)
-    status = cfsetispeed(&tio, baudrate);
-    if (status == -1)
     {
-        error_printf("Could not configure input speed (%s)", strerror(errno));
+        // Set input speed
-        exit(EXIT_FAILURE);
+        status = cfsetispeed(&tio, baudrate);
-    }
+        if (status == -1)
+        {
+            error_printf("Could not configure input speed (%s)", strerror(errno));
+            exit(EXIT_FAILURE);
+        }
 
-    // Set output speed
+        // Set output speed
-    cfsetospeed(&tio, baudrate);
+        cfsetospeed(&tio, baudrate);
-    if (status == -1)
+        if (status == -1)
-    {
+        {
-        error_printf("Could not configure output speed (%s)", strerror(errno));
+            error_printf("Could not configure output speed (%s)", strerror(errno));
-        exit(EXIT_FAILURE);
+            exit(EXIT_FAILURE);
+        }
     }
 
     /* Set databits */
@@ -551,6 +564,17 @@ int tty_connect(void)
         goto error_tcsetattr;
     }
 
+#ifdef HAVE_TERMIOS2
+    if (!standard_baudrate)
+    {
+        if (setspeed2(fd, option.baudrate) != 0)
+        {
+            error_printf_silent("Could not set baudrate speed (%s)", strerror(errno));
+            goto error_setspeed2;
+        }
+    }
+#endif
+
     maxfd = MAX(fd, STDIN_FILENO) + 1;  /* Maximum bit entry (fd) to test */
 
     /* Input loop */
@@ -636,6 +660,9 @@ int tty_connect(void)
 
     return TIO_SUCCESS;
 
+#ifdef HAVE_TERMIOS2
+error_setspeed2:
+#endif
 error_tcsetattr:
 error_tcgetattr:
 error_read: