[Bluetooth]: Implement RFCOMM remote port negotiation

This patch implements the remote port negotiation (RPN) of the RFCOMM
protocol for Bluetooth.

Signed-off-by: J. Suter <jsuter@hardwave.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 160 insertions, 37 deletions

diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 67d9dd6b0fac..bbc3a44a86f0 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -745,20 +745,143 @@ static int rfcomm_tty_ioctl(struct tty_struct *tty, struct file *filp, unsigned
         return -ENOIOCTLCMD;
 }
 
-#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
-
 static void rfcomm_tty_set_termios(struct tty_struct *tty, struct termios *old)
 {
-        BT_DBG("tty %p", tty);
+        struct termios *new = (struct termios *) tty->termios;
+        int old_baud_rate = tty_termios_baud_rate(old);
+        int new_baud_rate = tty_termios_baud_rate(new);
 
-        if ((tty->termios->c_cflag == old->c_cflag) &&
-                (RELEVANT_IFLAG(tty->termios->c_iflag) == RELEVANT_IFLAG(old->c_iflag)))
-                return;
+        u8 baud, data_bits, stop_bits, parity, x_on, x_off;
+        u16 changes = 0;
+
+        struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+
+        BT_DBG("tty %p termios %p", tty, old);
+
+        /* Handle turning off CRTSCTS */
+        if ((old->c_cflag & CRTSCTS) && !(new->c_cflag & CRTSCTS)) 
+                BT_DBG("Turning off CRTSCTS unsupported");
+
+        /* Parity on/off and when on, odd/even */
+        if (((old->c_cflag & PARENB) != (new->c_cflag & PARENB)) ||
+                        ((old->c_cflag & PARODD) != (new->c_cflag & PARODD)) ) {
+                changes |= RFCOMM_RPN_PM_PARITY;
+                BT_DBG("Parity change detected.");
+        }
+
+        /* Mark and space parity are not supported! */
+        if (new->c_cflag & PARENB) {
+                if (new->c_cflag & PARODD) {
+                        BT_DBG("Parity is ODD");
+                        parity = RFCOMM_RPN_PARITY_ODD;
+                } else {
+                        BT_DBG("Parity is EVEN");
+                        parity = RFCOMM_RPN_PARITY_EVEN;
+                }
+        } else {
+                BT_DBG("Parity is OFF");
+                parity = RFCOMM_RPN_PARITY_NONE;
+        }
+
+        /* Setting the x_on / x_off characters */
+        if (old->c_cc[VSTOP] != new->c_cc[VSTOP]) {
+                BT_DBG("XOFF custom");
+                x_on = new->c_cc[VSTOP];
+                changes |= RFCOMM_RPN_PM_XON;
+        } else {
+                BT_DBG("XOFF default");
+                x_on = RFCOMM_RPN_XON_CHAR;
+        }
+
+        if (old->c_cc[VSTART] != new->c_cc[VSTART]) {
+                BT_DBG("XON custom");
+                x_off = new->c_cc[VSTART];
+                changes |= RFCOMM_RPN_PM_XOFF;
+        } else {
+                BT_DBG("XON default");
+                x_off = RFCOMM_RPN_XOFF_CHAR;
+        }
+
+        /* Handle setting of stop bits */
+        if ((old->c_cflag & CSTOPB) != (new->c_cflag & CSTOPB))
+                changes |= RFCOMM_RPN_PM_STOP;
+
+        /* POSIX does not support 1.5 stop bits and RFCOMM does not
+         * support 2 stop bits. So a request for 2 stop bits gets
+         * translated to 1.5 stop bits */
+        if (new->c_cflag & CSTOPB) {
+                stop_bits = RFCOMM_RPN_STOP_15;
+        } else {
+                stop_bits = RFCOMM_RPN_STOP_1;
+        }
 
-        /* handle turning off CRTSCTS */
-        if ((old->c_cflag & CRTSCTS) && !(tty->termios->c_cflag & CRTSCTS)) {
-                BT_DBG("turning off CRTSCTS");
+        /* Handle number of data bits [5-8] */
+        if ((old->c_cflag & CSIZE) != (new->c_cflag & CSIZE)) 
+                changes |= RFCOMM_RPN_PM_DATA;
+
+        switch (new->c_cflag & CSIZE) {
+        case CS5:
+                data_bits = RFCOMM_RPN_DATA_5;
+                break;
+        case CS6:
+                data_bits = RFCOMM_RPN_DATA_6;
+                break;
+        case CS7:
+                data_bits = RFCOMM_RPN_DATA_7;
+                break;
+        case CS8:
+                data_bits = RFCOMM_RPN_DATA_8;
+                break;
+        default:
+                data_bits = RFCOMM_RPN_DATA_8;
+                break;
         }
+
+        /* Handle baudrate settings */
+        if (old_baud_rate != new_baud_rate)
+                changes |= RFCOMM_RPN_PM_BITRATE;
+
+        switch (new_baud_rate) {
+        case 2400:
+                baud = RFCOMM_RPN_BR_2400;
+                break;
+        case 4800:
+                baud = RFCOMM_RPN_BR_4800;
+                break;
+        case 7200:
+                baud = RFCOMM_RPN_BR_7200;
+                break;
+        case 9600:
+                baud = RFCOMM_RPN_BR_9600;
+                break;
+        case 19200: 
+                baud = RFCOMM_RPN_BR_19200;
+                break;
+        case 38400:
+                baud = RFCOMM_RPN_BR_38400;
+                break;
+        case 57600:
+                baud = RFCOMM_RPN_BR_57600;
+                break;
+        case 115200:
+                baud = RFCOMM_RPN_BR_115200;
+                break;
+        case 230400:
+                baud = RFCOMM_RPN_BR_230400;
+                break;
+        default:
+                /* 9600 is standard accordinag to the RFCOMM specification */
+                baud = RFCOMM_RPN_BR_9600;
+                break;
+        
+        }
+
+        if (changes)
+                rfcomm_send_rpn(dev->dlc->session, 1, dev->dlc->dlci, baud,
+                                data_bits, stop_bits, parity,
+                                RFCOMM_RPN_FLOW_NONE, x_on, x_off, changes);
+
+        return;
 }
 
 static void rfcomm_tty_throttle(struct tty_struct *tty)
@@ -766,7 +889,7 @@ static void rfcomm_tty_throttle(struct tty_struct *tty)
         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 
         BT_DBG("tty %p dev %p", tty, dev);
-        
+
         rfcomm_dlc_throttle(dev->dlc);
 }
 
@@ -775,7 +898,7 @@ static void rfcomm_tty_unthrottle(struct tty_struct *tty)
         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
 
         BT_DBG("tty %p dev %p", tty, dev);
-        
+
         rfcomm_dlc_unthrottle(dev->dlc);
 }
 
@@ -846,35 +969,35 @@ static int rfcomm_tty_tiocmget(struct tty_struct *tty, struct file *filp)
 
 static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsigned int set, unsigned int clear)
 {
-        struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
-        struct rfcomm_dlc *dlc = dev->dlc;
-        u8 v24_sig;
+        struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+        struct rfcomm_dlc *dlc = dev->dlc;
+        u8 v24_sig;
 
         BT_DBG("tty %p dev %p set 0x%02x clear 0x%02x", tty, dev, set, clear);
 
-        rfcomm_dlc_get_modem_status(dlc, &v24_sig);
-
-        if (set & TIOCM_DSR || set & TIOCM_DTR)
-                v24_sig |= RFCOMM_V24_RTC;
-        if (set & TIOCM_RTS || set & TIOCM_CTS)
-                v24_sig |= RFCOMM_V24_RTR;
-        if (set & TIOCM_RI)
-                v24_sig |= RFCOMM_V24_IC;
-        if (set & TIOCM_CD)
-                v24_sig |= RFCOMM_V24_DV;
-
-        if (clear & TIOCM_DSR || clear & TIOCM_DTR)
-                v24_sig &= ~RFCOMM_V24_RTC;
-        if (clear & TIOCM_RTS || clear & TIOCM_CTS)
-                v24_sig &= ~RFCOMM_V24_RTR;
-        if (clear & TIOCM_RI)
-                v24_sig &= ~RFCOMM_V24_IC;
-        if (clear & TIOCM_CD)
-                v24_sig &= ~RFCOMM_V24_DV;
-
-        rfcomm_dlc_set_modem_status(dlc, v24_sig);
-
-        return 0;
+        rfcomm_dlc_get_modem_status(dlc, &v24_sig);
+
+        if (set & TIOCM_DSR || set & TIOCM_DTR)
+                v24_sig |= RFCOMM_V24_RTC;
+        if (set & TIOCM_RTS || set & TIOCM_CTS)
+                v24_sig |= RFCOMM_V24_RTR;
+        if (set & TIOCM_RI)
+                v24_sig |= RFCOMM_V24_IC;
+        if (set & TIOCM_CD)
+                v24_sig |= RFCOMM_V24_DV;
+
+        if (clear & TIOCM_DSR || clear & TIOCM_DTR)
+                v24_sig &= ~RFCOMM_V24_RTC;
+        if (clear & TIOCM_RTS || clear & TIOCM_CTS)
+                v24_sig &= ~RFCOMM_V24_RTR;
+        if (clear & TIOCM_RI)
+                v24_sig &= ~RFCOMM_V24_IC;
+        if (clear & TIOCM_CD)
+                v24_sig &= ~RFCOMM_V24_DV;
+
+        rfcomm_dlc_set_modem_status(dlc, v24_sig);
+
+        return 0;
 }
 
 /* ---- TTY structure ---- */