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Commit 2f009a2a authored by Gregory Nutt's avatar Gregory Nutt
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Networking: SLIP interface improvements. From Macs N.

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with 92 additions and 57 deletions
drivers/net/slip.c
+ 92
− 57
View file @ 2f009a2a
/****************************************************************************
* drivers/net/slip.c
*
* Copyright (C) 2011-2012 Gregory Nutt. All rights reserved.
* Copyright (C) 2011-2012, 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Reference: RFC 1055
......@@ -56,6 +56,7 @@
#include <nuttx/irq.h>
#include <nuttx/net/net.h>
#include <nuttx/clock.h>
#include <nuttx/net/netdev.h>
#include <nuttx/net/ip.h>
#include <nuttx/net/slip.h>
......@@ -158,11 +159,12 @@ struct slip_statistics_s
struct slip_driver_s
{
volatile bool bifup; /* true:ifup false:ifdown */
int fd; /* TTY file descriptor */
bool txnodelay; /* True: usleep() not needed */
int16_t fd; /* TTY file descriptor */
uint16_t rxlen; /* The number of bytes in rxbuf */
pid_t rxpid; /* Receiver thread ID */
pid_t txpid; /* Transmitter thread ID */
sem_t waitsem; /* Mutually exclusive access to uIP */
uint16_t rxlen; /* The number of bytes in rxbuf */
/* Driver statistics */
......@@ -195,7 +197,8 @@ static void slip_semtake(FAR struct slip_driver_s *priv);
/* Common TX logic */
static void slip_write(FAR struct slip_driver_s *priv, const uint8_t *buffer, int len);
static void slip_write(FAR struct slip_driver_s *priv,
FAR const uint8_t *buffer, int len);
static void slip_putc(FAR struct slip_driver_s *priv, int ch);
static int slip_transmit(FAR struct slip_driver_s *priv);
static int slip_txpoll(FAR struct net_driver_s *dev);
......@@ -255,7 +258,7 @@ static void slip_semtake(FAR struct slip_driver_s *priv)
****************************************************************************/
static inline void slip_write(FAR struct slip_driver_s *priv,
const uint8_t *buffer, int len)
FAR const uint8_t *buffer, int len)
{
/* Handle the case where the write is awakened by a signal */
......@@ -390,6 +393,7 @@ static int slip_transmit(FAR struct slip_driver_s *priv)
/* And send the END token */
slip_putc(priv, SLIP_END);
priv->txnodelay = true;
return OK;
}
......@@ -454,6 +458,9 @@ static void slip_txtask(int argc, FAR char *argv[])
FAR struct slip_driver_s *priv;
unsigned int index = *(argv[1]) - '0';
net_lock_t flags;
unsigned int msec_start;
unsigned int msec_now;
unsigned int hsec;
ndbg("index: %d\n", index);
DEBUGASSERT(index < CONFIG_SLIP_NINTERFACES);
......@@ -467,11 +474,22 @@ static void slip_txtask(int argc, FAR char *argv[])
/* Loop forever */
msec_start = clock_systimer() * MSEC_PER_TICK;
for (;;)
{
/* Wait for the timeout to expire (or until we are signaled by by */
usleep(SLIP_WDDELAY);
slip_semtake(priv);
if (!priv->txnodelay)
{
slip_semgive(priv);
usleep(SLIP_WDDELAY);
}
else
{
priv->txnodelay = false;
slip_semgive(priv);
}
/* Is the interface up? */
......@@ -483,15 +501,23 @@ static void slip_txtask(int argc, FAR char *argv[])
slip_semtake(priv);
/* Poll uIP for new XMIT data. BUG: We really need to calculate
* the number of hsecs! When we are awakened by slip_txavail, the
* number will be smaller; when we have to wait for the semaphore
* (above), it may be larger.
*/
/* Poll the networking layer for new XMIT data. */
flags = net_lock();
priv->dev.d_buf = priv->txbuf;
(void)devif_timer(&priv->dev, slip_txpoll, SLIP_POLLHSEC);
msec_now = clock_systimer() * MSEC_PER_TICK;
hsec = (unsigned int)(msec_now - msec_start) / (MSEC_PER_SEC / 2);
if (hsec)
{
(void)devif_timer(&priv->dev, slip_txpoll, hsec);
msec_start += hsec * (MSEC_PER_SEC / 2);
}
else
{
(void)uip_poll(&priv->dev, slip_uiptxpoll);
}
net_unlock(flags);
slip_semgive(priv);
}
......@@ -563,19 +589,21 @@ static inline void slip_receive(FAR struct slip_driver_s *priv)
*/
case SLIP_END:
nvdbg("END\n");
/* A minor optimization: if there is no data in the packet, ignore
* it. This is meant to avoid bothering IP with all the empty
* packets generated by the duplicate END characters which are in
* turn sent to try to detect line noise.
*/
if (priv->rxlen > 0)
{
nvdbg("Received packet size %d\n", priv->rxlen);
return;
}
{
nvdbg("END\n");
/* A minor optimization: if there is no data in the packet,
* ignore it. This is meant to avoid bothering IP with all the
* empty packets generated by the duplicate END characters which
* are in turn sent to try to detect line noise.
*/
if (priv->rxlen > 0)
{
nvdbg("Received packet size %d\n", priv->rxlen);
return;
}
}
break;
/* if it's the same code as an ESC character, wait and get another
......@@ -584,38 +612,44 @@ static inline void slip_receive(FAR struct slip_driver_s *priv)
*/
case SLIP_ESC:
nvdbg("ESC\n");
ch = slip_getc(priv);
/* if "ch" is not one of these two, then we have a protocol
* violation. The best bet seems to be to leave the byte alone
* and just stuff it into the packet
*/
switch (ch)
{
case SLIP_ESC_END:
nvdbg("ESC-END\n");
ch = SLIP_END;
break;
case SLIP_ESC_ESC:
nvdbg("ESC-ESC\n");
ch = SLIP_ESC;
break;
default:
ndbg("ERROR: Protocol violation: %02x\n", ch);
break;
}
/* Here we fall into the default handler and let it store the
* character for us
*/
{
nvdbg("ESC\n");
ch = slip_getc(priv);
/* if "ch" is not one of these two, then we have a protocol
* violation. The best bet seems to be to leave the byte alone
* and just stuff it into the packet
*/
switch (ch)
{
case SLIP_ESC_END:
nvdbg("ESC-END\n");
ch = SLIP_END;
break;
case SLIP_ESC_ESC:
nvdbg("ESC-ESC\n");
ch = SLIP_ESC;
break;
default:
ndbg("ERROR: Protocol violation: %02x\n", ch);
break;
}
/* Here we fall into the default handler and let it store the
* character for us
*/
}
default:
if (priv->rxlen < CONFIG_NET_SLIP_MTU+2)
{
priv->rxbuf[priv->rxlen++] = ch;
}
{
if (priv->rxlen < CONFIG_NET_SLIP_MTU+2)
{
priv->rxbuf[priv->rxlen++] = ch;
}
}
break;
}
}
......@@ -724,6 +758,7 @@ static int slip_rxtask(int argc, FAR char *argv[])
if (priv->dev.d_len > 0)
{
slip_transmit(priv);
kill(priv->txpid, SIGALRM);
}
net_unlock(flags);
slip_semgive(priv);
......@@ -822,6 +857,7 @@ static int slip_txavail(FAR struct net_driver_s *dev)
{
/* Wake up the TX polling thread */
priv->txnodelay = true;
kill(priv->txpid, SIGALRM);
}
......@@ -912,7 +948,7 @@ int slip_initialize(int intf, FAR const char *devname)
{
FAR struct slip_driver_s *priv;
char buffer[8];
FAR const char *argv[2];
FAR char *argv[2];
/* Get the interface structure associated with this interface number. */
......@@ -1002,4 +1038,3 @@ int slip_initialize(int intf, FAR const char *devname)
}
#endif /* CONFIG_NET && CONFIG_NET_SLIP */
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