incubator-nuttx/include/nuttx/net/slip.h

129 lines
4.9 KiB
C

/****************************************************************************
* include/nuttx/net/slip.h
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author : Gregory Nutt <gnutt@nuttx.org>
*
* Includes some definitions that a compatible with the LGPL GNU C Library
* header file of the same name.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_NUTTX_NET_SLIP_H
#define __INCLUDE_NUTTX_NET_SLIP_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#ifdef CONFIG_NET_SLIP
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ***********************************************************/
/* Dependencies:
*
* CONFIG_NET_NOINTS - Required.
* CONFIG_NET_MULTIBUFFER - Required.
*
* SLIP Configuration:
*
* CONFIG_NET_SLIP - Enables building of the SLIP driver
* CONFIG_NET_SLIP_STACKSIZE - Provides the stack size for SLIP RX and TX
* threads. Default: 2048
* CONFIG_NET_SLIP_DEFPRIO - Provides the priority for SLIP RX and TX
* threads. Default 128.
* CONFIG_NET_NET_SLIP_MTU - Provides the size of the SLIP packet buffers.
* Default 296
*
* The Linux slip module hard-codes its MTU size to 296 (40 bytes for the
* IP+TPC headers plus 256 bytes of data). So you might as well set
* CONFIG_NET_SLIP_MTU to 296 as well.
*
* There may be an issue with this setting, however. I see that Linux
* uses a MTU of 296 and window of 256, but actually only sends 168 bytes
* of data: 40 + 128. I believe that is to allow for the 2x worst cast
* packet expansion. Ideally we would like to advertise the 256 MSS,
* but restrict transfers to 128 bytes (possibly by modifying the
* tcp_mss() macro).
*
* CONFIG_NET_SLIP_NINTERFACES determines the number of physical interfaces
* that will be supported.
*/
/****************************************************************************
* Public Data
****************************************************************************/
#ifdef __cplusplus
#define EXTERN extern "C"
extern "C"
{
#else
#define EXTERN extern
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Function: slip_initialize
*
* Description:
* Instantiate a SLIP network interface.
*
* Input Parameters:
* intf - In the case where there are multiple SLIP interfaces, this
* value identifies which is to be initialized. The number of
* possible SLIP interfaces is determined by
* devname - This is the path to the serial device that will support SLIP.
* For example, this might be "/dev/ttyS1"
*
* Returned Value:
* OK on success; Negated errno on failure.
*
* Assumptions:
*
****************************************************************************/
int slip_initialize(int intf, FAR const char *devname);
#undef EXTERN
#ifdef __cplusplus
}
#endif
#endif /* CONFIG_NET_SLIP */
#endif /* __INCLUDE_NUTTX_NET_SLIP_H */