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authorChris Johns <chrisj@rtems.org>2016-10-29 05:09:35 +1100
committerChris Johns <chrisj@rtems.org>2016-10-29 05:09:35 +1100
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tree6510c434a004fb3dabfab5c290bd2f520dd5f45c /networking/networking_old_reference_only.rst
parentshell: Fix code-block warnings. (diff)
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-.. comment SPDX-License-Identifier: CC-BY-SA-4.0
-
-:orphan:
-
-
-
-.. COMMENT: %**end of header
-
-.. COMMENT: COPYRIGHT (c) 1989-2013.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-.. COMMENT: Master file for the network Supplement
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-.. COMMENT: The following determines which set of the tables and figures we will use.
-
-.. COMMENT: We default to ASCII but if available TeX or HTML versions will
-
-.. COMMENT: be used instead.
-
-.. COMMENT: @clear use-html
-
-.. COMMENT: @clear use-tex
-
-.. COMMENT: The following variable says to use texinfo or html for the two column
-
-.. COMMENT: texinfo tables. For somethings the format does not look good in html.
-
-.. COMMENT: With our adjustment to the left column in TeX, it nearly always looks
-
-.. COMMENT: good printed.
-
-.. COMMENT: Custom whitespace adjustments. We could fiddle a bit more.
-
-.. COMMENT: Title Page Stuff
-
-.. COMMENT: I don't really like having a short title page. -joel
-
-.. COMMENT: @shorttitlepage RTEMS Network Supplement
-
-========================
-RTEMS Network Supplement
-========================
-
-.. COMMENT: COPYRIGHT (c) 1988-2015.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-.. COMMENT: The following puts a space somewhere on an otherwise empty page so we
-
-.. COMMENT: can force the copyright description onto a left hand page.
-
-COPYRIGHT © 1988 - 2015.
-
-On-Line Applications Research Corporation (OAR).
-
-The authors have used their best efforts in preparing
-this material. These efforts include the development, research,
-and testing of the theories and programs to determine their
-effectiveness. No warranty of any kind, expressed or implied,
-with regard to the software or the material contained in this
-document is provided. No liability arising out of the
-application or use of any product described in this document is
-assumed. The authors reserve the right to revise this material
-and to make changes from time to time in the content hereof
-without obligation to notify anyone of such revision or changes.
-
-The RTEMS Project is hosted at http://www.rtems.org. Any
-inquiries concerning RTEMS, its related support components, or its
-documentation should be directed to the Community Project hosted athttp://www.rtems.org.
-
-Any inquiries for commercial services including training, support, custom
-development, application development assistance should be directed tohttp://www.rtems.com.
-
-.. COMMENT: This prevents a black box from being printed on "overflow" lines.
-
-.. COMMENT: The alternative is to rework a sentence to avoid this problem.
-
-RTEMS TCP/IP Networking Supplement
-##################################
-
-.. COMMENT: COPYRIGHT (c) 1989-2011.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Preface
-#######
-
-This document describes the RTEMS specific parts of the FreeBSD TCP/IP
-stack. Much of this documentation was written by Eric Norum
-(eric@skatter.usask.ca)
-of the Saskatchewan Accelerator Laboratory
-who also ported the FreeBSD TCP/IP stack to RTEMS.
-
-The following is a list of resources which should be useful in trying
-to understand Ethernet:
-
-- *Charles Spurgeon’s Ethernet Web Site*
- "This site provides extensive information about Ethernet
- (IEEE 802.3) local area network (LAN) technology. Including
- the original 10 Megabit per second (Mbps) system, the 100 Mbps
- Fast Ethernet system (802.3u), and the Gigabit Ethernet system (802.3z)."
- The URL is:
- (http://www.ethermanage.com/ethernet/ethernet.html)
-
-- *TCP/IP Illustrated, Volume 1 : The Protocols* by
- by W. Richard Stevens (ISBN: 0201633469)
- This book provides detailed introduction to TCP/IP and includes diagnostic
- programs which are publicly available.
-
-- *TCP/IP Illustrated, Volume 2 : The Implementation* by W. Richard
- Stevens and Gary Wright (ISBN: 020163354X)
- This book focuses on implementation issues regarding TCP/IP. The
- treat for RTEMS users is that the implementation covered is the BSD
- stack with most of the source code described in detail.
-
-- *UNIX Network Programming, Volume 1 : 2nd Edition* by W. Richard
- Stevens (ISBN: 0-13-490012-X)
- This book describes how to write basic TCP/IP applications, again with primary
- focus on the BSD stack.
-
-.. COMMENT: Written by Eric Norum
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Network Task Structure and Data Flow
-####################################
-
-A schematic diagram of the tasks and message *mbuf* queues in a
-simple RTEMS networking application is shown in the following
-figure:
-
-.. image:: images/networkflow.jpg
-
-
-The transmit task for each network interface is normally blocked waiting
-for a packet to arrive in the transmit queue. Once a packet arrives, the
-transmit task may block waiting for an event from the transmit interrupt
-handler. The transmit interrupt handler sends an RTEMS event to the transmit
-task to indicate that transmit hardware resources have become available.
-
-The receive task for each network interface is normally blocked waiting
-for an event from the receive interrupt handler. When this event is received
-the receive task reads the packet and forwards it to the network stack
-for subsequent processing by the network task.
-
-The network task processes incoming packets and takes care of
-timed operations such as handling TCP timeouts and
-aging and removing routing table entries.
-
-The ‘Network code’ contains routines which may run in the context of
-the user application tasks, the interface receive task or the network task.
-A network semaphore ensures that
-the data structures manipulated by the network code remain consistent.
-
-.. COMMENT: Written by Eric Norum
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Networking Driver
-#################
-
-Introduction
-============
-
-This chapter is intended to provide an introduction to the
-procedure for writing RTEMS network device drivers.
-The example code is taken from the ‘Generic 68360’ network device
-driver. The source code for this driver is located in the``c/src/lib/libbsp/m68k/gen68360/network`` directory in the RTEMS
-source code distribution. Having a copy of this driver at
-hand when reading the following notes will help significantly.
-
-Learn about the network device
-==============================
-
-Before starting to write the network driver become completely
-familiar with the programmer’s view of the device.
-The following points list some of the details of the
-device that must be understood before a driver can be written.
-
-- Does the device use DMA to transfer packets to and from
- memory or does the processor have to
- copy packets to and from memory on the device?
-
-- If the device uses DMA, is it capable of forming a single
- outgoing packet from multiple fragments scattered in separate
- memory buffers?
-
-- If the device uses DMA, is it capable of chaining multiple
- outgoing packets, or does each outgoing packet require
- intervention by the driver?
-
-- Does the device automatically pad short frames to the minimum
- 64 bytes or does the driver have to supply the padding?
-
-- Does the device automatically retry a transmission on detection
- of a collision?
-
-- If the device uses DMA, is it capable of buffering multiple
- packets to memory, or does the receiver have to be restarted
- after the arrival of each packet?
-
-- How are packets that are too short, too long, or received with
- CRC errors handled? Does the device automatically continue
- reception or does the driver have to intervene?
-
-- How is the device Ethernet address set? How is the device
- programmed to accept or reject broadcast and multicast packets?
-
-- What interrupts does the device generate? Does it generate an
- interrupt for each incoming packet, or only for packets received
- without error? Does it generate an interrupt for each packet
- transmitted, or only when the transmit queue is empty? What
- happens when a transmit error is detected?
-
-In addition, some controllers have specific questions regarding
-board specific configuration. For example, the SONIC Ethernet
-controller has a very configurable data bus interface. It can
-even be configured for sixteen and thirty-two bit data buses. This
-type of information should be obtained from the board vendor.
-
-Understand the network scheduling conventions
-=============================================
-
-When writing code for the driver transmit and receive tasks,
-take care to follow the network scheduling conventions. All tasks
-which are associated with networking share various
-data structures and resources. To ensure the consistency
-of these structures the tasks
-execute only when they hold the network semaphore (``rtems_bsdnet_semaphore``).
-The transmit and receive tasks must abide by this protocol. Be very
-careful to avoid ‘deadly embraces’ with the other network tasks.
-A number of routines are provided to make it easier for the network
-driver code to conform to the network task scheduling conventions.
-
-- ``void rtems_bsdnet_semaphore_release(void)``
- This function releases the network semaphore.
- The network driver tasks must call this function immediately before
- making any blocking RTEMS request.
-
-- ``void rtems_bsdnet_semaphore_obtain(void)``
- This function obtains the network semaphore.
- If a network driver task has released the network semaphore to allow other
- network-related tasks to run while the task blocks, then this function must
- be called to reobtain the semaphore immediately after the return from the
- blocking RTEMS request.
-
-- ``rtems_bsdnet_event_receive(rtems_event_set, rtems_option, rtems_interval, rtems_event_set \*)``
- The network driver task should call this function when it wishes to wait
- for an event. This function releases the network semaphore,
- calls ``rtems_event_receive`` to wait for the specified event
- or events and reobtains the semaphore.
- The value returned is the value returned by the ``rtems_event_receive``.
-
-Network Driver Makefile
-=======================
-
-Network drivers are considered part of the BSD network package and as such
-are to be compiled with the appropriate flags. This can be accomplished by
-adding ``-D__INSIDE_RTEMS_BSD_TCPIP_STACK__`` to the ``command line``.
-If the driver is inside the RTEMS source tree or is built using the
-RTEMS application Makefiles, then adding the following line accomplishes
-this:
-.. code:: c
-
- DEFINES += -D__INSIDE_RTEMS_BSD_TCPIP_STACK__
-
-This is equivalent to the following list of definitions. Early versions
-of the RTEMS BSD network stack required that all of these be defined.
-
-.. code:: c
-
- -D_COMPILING_BSD_KERNEL_ -DKERNEL -DINET -DNFS \\
- -DDIAGNOSTIC -DBOOTP_COMPAT
-
-Defining these macros tells the network header files that the driver
-is to be compiled with extended visibility into the network stack. This
-is in sharp contrast to applications that simply use the network stack.
-Applications do not require this level of visibility and should stick
-to the portable application level API.
-
-As a direct result of being logically internal to the network stack,
-network drivers use the BSD memory allocation routines This means,
-for example, that malloc takes three arguments. See the SONIC
-device driver (``c/src/lib/libchip/network/sonic.c``) for an example
-of this. Because of this, network drivers should not include``<stdlib.h>``. Doing so will result in conflicting definitions
-of ``malloc()``.
-
-*Application level* code including network servers such as the FTP
-daemon are *not* part of the BSD kernel network code and should not be
-compiled with the BSD network flags. They should include``<stdlib.h>`` and not define the network stack visibility
-macros.
-
-Write the Driver Attach Function
-================================
-
-The driver attach function is responsible for configuring the driver
-and making the connection between the network stack
-and the driver.
-
-Driver attach functions take a pointer to an``rtems_bsdnet_ifconfig`` structure as their only argument.
-and set the driver parameters based on the
-values in this structure. If an entry in the configuration
-structure is zero the attach function chooses an
-appropriate default value for that parameter.
-
-The driver should then set up several fields in the ifnet structure
-in the device-dependent data structure supplied and maintained by the driver:
-
-``ifp->if_softc``
- Pointer to the device-dependent data. The first entry
- in the device-dependent data structure must be an ``arpcom``
- structure.
-
-``ifp->if_name``
- The name of the device. The network stack uses this string
- and the device number for device name lookups. The device name should
- be obtained from the ``name`` entry in the configuration structure.
-
-``ifp->if_unit``
- The device number. The network stack uses this number and the
- device name for device name lookups. For example, if``ifp->if_name`` is ‘``scc``’ and ``ifp->if_unit`` is ‘``1``’,
- the full device name would be ‘``scc1``’. The unit number should be
- obtained from the ‘name’ entry in the configuration structure.
-
-``ifp->if_mtu``
- The maximum transmission unit for the device. For Ethernet
- devices this value should almost always be 1500.
-
-``ifp->if_flags``
- The device flags. Ethernet devices should set the flags
- to ``IFF_BROADCAST|IFF_SIMPLEX``, indicating that the
- device can broadcast packets to multiple destinations
- and does not receive and transmit at the same time.
-
-``ifp->if_snd.ifq_maxlen``
- The maximum length of the queue of packets waiting to be
- sent to the driver. This is normally set to ``ifqmaxlen``.
-
-``ifp->if_init``
- The address of the driver initialization function.
-
-``ifp->if_start``
- The address of the driver start function.
-
-``ifp->if_ioctl``
- The address of the driver ioctl function.
-
-``ifp->if_output``
- The address of the output function. Ethernet devices
- should set this to ``ether_output``.
-
-RTEMS provides a function to parse the driver name in the
-configuration structure into a device name and unit number.
-.. code:: c
-
- int rtems_bsdnet_parse_driver_name (
- const struct rtems_bsdnet_ifconfig \*config,
- char \**namep
- );
-
-The function takes two arguments; a pointer to the configuration
-structure and a pointer to a pointer to a character. The function
-parses the configuration name entry, allocates memory for the driver
-name, places the driver name in this memory, sets the second argument
-to point to the name and returns the unit number.
-On error, a message is printed and -1 is returned.
-
-Once the attach function has set up the above entries it must link the
-driver data structure onto the list of devices by
-calling ``if_attach``. Ethernet devices should then
-call ``ether_ifattach``. Both functions take a pointer to the
-device’s ``ifnet`` structure as their only argument.
-
-The attach function should return a non-zero value to indicate that
-the driver has been successfully configured and attached.
-
-Write the Driver Start Function.
-================================
-
-This function is called each time the network stack wants to start the
-transmitter. This occures whenever the network stack adds a packet
-to a device’s send queue and the ``IFF_OACTIVE`` bit in the
-device’s ``if_flags`` is not set.
-
-For many devices this function need only set the ``IFF_OACTIVE`` bit in the``if_flags`` and send an event to the transmit task
-indicating that a packet is in the driver transmit queue.
-
-Write the Driver Initialization Function.
-=========================================
-
-This function should initialize the device, attach to interrupt handler,
-and start the driver transmit and receive tasks. The function
-.. code:: c
-
- rtems_id
- rtems_bsdnet_newproc (char \*name,
- int stacksize,
- void(\*entry)(void \*),
- void \*arg);
-
-should be used to start the driver tasks.
-
-Note that the network stack may call the driver initialization function more
-than once.
-Make sure multiple versions of the receive and transmit tasks are not accidentally
-started.
-
-Write the Driver Transmit Task
-==============================
-
-This task is reponsible for removing packets from the driver send queue and sending them to the device. The task should block waiting for an event from the
-driver start function indicating that packets are waiting to be transmitted.
-When the transmit task has drained the driver send queue the task should clear
-the ``IFF_OACTIVE`` bit in ``if_flags`` and block until another outgoing
-packet is queued.
-
-Write the Driver Receive Task
-=============================
-
-This task should block until a packet arrives from the device. If the
-device is an Ethernet interface the function ``ether_input`` should be called
-to forward the packet to the network stack. The arguments to ``ether_input``
-are a pointer to the interface data structure, a pointer to the ethernet
-header and a pointer to an mbuf containing the packet itself.
-
-Write the Driver Interrupt Handler
-==================================
-
-A typical interrupt handler will do nothing more than the hardware
-manipulation required to acknowledge the interrupt and send an RTEMS event
-to wake up the driver receive or transmit task waiting for the event.
-Network interface interrupt handlers must not make any calls to other
-network routines.
-
-Write the Driver IOCTL Function
-===============================
-
-This function handles ioctl requests directed at the device. The ioctl
-commands which must be handled are:
-
-``SIOCGIFADDR``
-
-``SIOCSIFADDR``
-
- If the device is an Ethernet interface these
- commands should be passed on to ``ether_ioctl``.
-
-``SIOCSIFFLAGS``
-
- This command should be used to start or stop the device,
- depending on the state of the interface ``IFF_UP`` and``IFF_RUNNING`` bits in ``if_flags``:
-
- ``IFF_RUNNING``
-
- Stop the device.
-
- ``IFF_UP``
-
- Start the device.
-
- ``IFF_UP|IFF_RUNNING``
-
- Stop then start the device.
-
- ``0``
-
- Do nothing.
-
-Write the Driver Statistic-Printing Function
-============================================
-
-This function should print the values of any statistic/diagnostic
-counters the network driver may use. The driver ioctl function should call
-the statistic-printing function when the ioctl command is``SIO_RTEMS_SHOW_STATS``.
-
-.. COMMENT: Written by Eric Norum
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Using Networking in an RTEMS Application
-########################################
-
-Makefile changes
-================
-
-Including the required managers
--------------------------------
-
-The FreeBSD networking code requires several RTEMS managers
-in the application:
-.. code:: c
-
- MANAGERS = io event semaphore
-
-Increasing the size of the heap
--------------------------------
-
-The networking tasks allocate a lot of memory. For most applications
-the heap should be at least 256 kbytes.
-The amount of memory set aside for the heap can be adjusted by setting
-the ``CFLAGS_LD`` definition as shown below:
-.. code:: c
-
- CFLAGS_LD += -Wl,--defsym -Wl,HeapSize=0x80000
-
-This sets aside 512 kbytes of memory for the heap.
-
-System Configuration
-====================
-
-The networking tasks allocate some RTEMS objects. These
-must be accounted for in the application configuration table. The following
-lists the requirements.
-
-*TASKS*
- One network task plus a receive and transmit task for each device.
-
-*SEMAPHORES*
- One network semaphore plus one syslog mutex semaphore if the application uses
- openlog/syslog.
-
-*EVENTS*
- The network stack uses ``RTEMS_EVENT_24`` and ``RTEMS_EVENT_25``.
- This has no effect on the application configuration, but
- application tasks which call the network functions should not
- use these events for other purposes.
-
-Initialization
-==============
-
-Additional include files
-------------------------
-
-The source file which declares the network configuration
-structures and calls the network initialization function must include
-.. code:: c
-
- #include <rtems/rtems_bsdnet.h>
-
-Network Configuration
----------------------
-
-The network configuration is specified by declaring
-and initializing the ``rtems_bsdnet_config``
-structure.
-.. code:: c
-
- struct rtems_bsdnet_config {
- /*
- * This entry points to the head of the ifconfig chain.
- \*/
- struct rtems_bsdnet_ifconfig \*ifconfig;
- /*
- * This entry should be rtems_bsdnet_do_bootp if BOOTP
- * is being used to configure the network, and NULL
- * if BOOTP is not being used.
- \*/
- void (\*bootp)(void);
- /*
- * The remaining items can be initialized to 0, in
- * which case the default value will be used.
- \*/
- rtems_task_priority network_task_priority; /* 100 \*/
- unsigned long mbuf_bytecount; /* 64 kbytes \*/
- unsigned long mbuf_cluster_bytecount; /* 128 kbytes \*/
- char \*hostname; /* BOOTP \*/
- char \*domainname; /* BOOTP \*/
- char \*gateway; /* BOOTP \*/
- char \*log_host; /* BOOTP \*/
- char \*name_server[3]; /* BOOTP \*/
- char \*ntp_server[3]; /* BOOTP \*/
- unsigned long sb_efficiency; /* 2 \*/
- /* UDP TX: 9216 bytes \*/
- unsigned long udp_tx_buf_size;
- /* UDP RX: 40 * (1024 + sizeof(struct sockaddr_in)) \*/
- unsigned long udp_rx_buf_size;
- /* TCP TX: 16 * 1024 bytes \*/
- unsigned long tcp_tx_buf_size;
- /* TCP TX: 16 * 1024 bytes \*/
- unsigned long tcp_rx_buf_size;
- /* Default Network Tasks CPU Affinity \*/
- #ifdef RTEMS_SMP
- const cpu_set_t \*network_task_cpuset;
- size_t network_task_cpuset_size;
- #endif
- };
-
-The structure entries are described in the following table.
-If your application uses BOOTP/DHCP to obtain network configuration
-information and if you are happy with the default values described
-below, you need to provide only the first two entries in this structure.
-
-``struct rtems_bsdnet_ifconfig \*ifconfig``
-
- A pointer to the first configuration structure of the first network
- device. This structure is described in the following section.
- You must provide a value for this entry since there is no default value for it.
-
-``void (\*bootp)(void)``
-
- This entry should be set to ``rtems_bsdnet_do_bootp`` if your
- application by default uses the BOOTP/DHCP client protocol to obtain
- network configuration information. It should be set to ``NULL`` if
- your application does not use BOOTP/DHCP.
- You can also use ``rtems_bsdnet_do_bootp_rootfs`` to have a set of
- standard files created with the information return by the BOOTP/DHCP
- protocol. The IP address is added to :file:`/etc/hosts` with the host
- name and domain returned. If no host name or domain is returned``me.mydomain`` is used. The BOOTP/DHCP server’s address is also
- added to :file:`/etc/hosts`. The domain name server listed in the
- BOOTP/DHCP information are added to :file:`/etc/resolv.conf`. A``search`` record is also added if a domain is returned. The files
- are created if they do not exist.
- The default ``rtems_bsdnet_do_bootp`` and``rtems_bsdnet_do_bootp_rootfs`` handlers will loop for-ever
- waiting for a BOOTP/DHCP server to respond. If an error is detected
- such as not valid interface or valid hardware address the target will
- reboot allowing any hardware reset to correct itself.
- You can provide your own custom handler which allows you to perform
- an initialization that meets your specific system requirements. For
- example you could try BOOTP/DHCP then enter a configuration tool if no
- server is found allowing the user to switch to a static configuration.
-
-``int network_task_priority``
- The priority at which the network task and network device
- receive and transmit tasks will run.
- If a value of 0 is specified the tasks will run at priority 100.
-
-``unsigned long mbuf_bytecount``
- The number of bytes to allocate from the heap for use as mbufs.
- If a value of 0 is specified, 64 kbytes will be allocated.
-
-``unsigned long mbuf_cluster_bytecount``
- The number of bytes to allocate from the heap for use as mbuf clusters.
- If a value of 0 is specified, 128 kbytes will be allocated.
-
-``char \*hostname``
- The host name of the system.
- If this, or any of the following, entries are ``NULL`` the value
- may be obtained from a BOOTP/DHCP server.
-
-``char \*domainname``
- The name of the Internet domain to which the system belongs.
-
-``char \*gateway``
- The Internet host number of the network gateway machine,
- specified in ’dotted decimal’ (``129.128.4.1``) form.
-
-``char \*log_host``
- The Internet host number of the machine to which ``syslog`` messages
- will be sent.
-
-``char \*name_server[3]``
- The Internet host numbers of up to three machines to be used as
- Internet Domain Name Servers.
-
-``char \*ntp_server[3]``
- The Internet host numbers of up to three machines to be used as
- Network Time Protocol (NTP) Servers.
-
-``unsigned long sb_efficiency``
- This is the first of five configuration parameters related to
- the amount of memory each socket may consume for buffers. The
- TCP/IP stack reserves buffers (e.g. mbufs) for each open socket. The
- TCP/IP stack has different limits for the transmit and receive
- buffers associated with each TCP and UDP socket. By tuning these
- parameters, the application developer can make trade-offs between
- memory consumption and performance. The default parameters favor
- performance over memory consumption. Seehttp://www.rtems.org/ml/rtems-users/2004/february/msg00200.html
- for more details but note that after the RTEMS 4.8 release series,
- the sb_efficiency default was changed from ``8`` to ``2``.
- The user should also be aware of the ``SO_SNDBUF`` and ``SO_RCVBUF``
- IO control operations. These can be used to specify the
- send and receive buffer sizes for a specific socket. There
- is no standard IO control to change the ``sb_efficiency`` factor.
- The ``sb_efficiency`` parameter is a buffering factor used
- in the implementation of the TCP/IP stack. The default is ``2``
- which indicates double buffering. When allocating memory for each
- socket, this number is multiplied by the buffer sizes for that socket.
-
-``unsigned long udp_tx_buf_size``
-
- This configuration parameter specifies the maximum amount of
- buffer memory which may be used for UDP sockets to transmit
- with. The default size is 9216 bytes which corresponds to
- the maximum datagram size.
-
-``unsigned long udp_rx_buf_size``
-
- This configuration parameter specifies the maximum amount of
- buffer memory which may be used for UDP sockets to receive
- into. The default size is the following length in bytes:
-
- .. code:: c
-
- 40 * (1024 + sizeof(struct sockaddr_in)
-
-``unsigned long tcp_tx_buf_size``
-
- This configuration parameter specifies the maximum amount of
- buffer memory which may be used for TCP sockets to transmit
- with. The default size is sixteen kilobytes.
-
-``unsigned long tcp_rx_buf_size``
-
- This configuration parameter specifies the maximum amount of
- buffer memory which may be used for TCP sockets to receive
- into. The default size is sixteen kilobytes.
-
-``const cpu_set_t \*network_task_cpuset``
-
- This configuration parameter specifies the CPU affinity of the
- network task. If set to ``0`` the network task can be scheduled on
- any CPU. Only available in SMP configurations.
-
-``size_t network_task_cpuset_size``
-
- This configuration parameter specifies the size of the``network_task_cpuset`` used. Only available in SMP configurations.
-
-In addition, the following fields in the ``rtems_bsdnet_ifconfig``
-are of interest.
-
-*int port*
- The I/O port number (ex: 0x240) on which the external Ethernet
- can be accessed.
-
-*int irno*
- The interrupt number of the external Ethernet controller.
-
-*int bpar*
- The address of the shared memory on the external Ethernet controller.
-
-Network device configuration
-----------------------------
-
-Network devices are specified and configured by declaring and initializing a``struct rtems_bsdnet_ifconfig`` structure for each network device.
-
-The structure entries are described in the following table. An application
-which uses a single network interface, gets network configuration information
-from a BOOTP/DHCP server, and uses the default values for all driver
-parameters needs to initialize only the first two entries in the
-structure.
-
-``char \*name``
- The full name of the network device. This name consists of the
- driver name and the unit number (e.g. ``"scc1"``).
- The ``bsp.h`` include file usually defines RTEMS_BSP_NETWORK_DRIVER_NAME as
- the name of the primary (or only) network driver.
-
-``int (\*attach)(struct rtems_bsdnet_ifconfig \*conf)``
- The address of the driver ``attach`` function. The network
- initialization function calls this function to configure the driver and
- attach it to the network stack.
- The ``bsp.h`` include file usually defines RTEMS_BSP_NETWORK_DRIVER_ATTACH as
- the name of the attach function of the primary (or only) network driver.
-
-``struct rtems_bsdnet_ifconfig \*next``
- A pointer to the network device configuration structure for the next network
- interface, or ``NULL`` if this is the configuration structure of the
- last network interface.
-
-``char \*ip_address``
- The Internet address of the device,
- specified in ‘dotted decimal’ (``129.128.4.2``) form, or ``NULL``
- if the device configuration information is being obtained from a
- BOOTP/DHCP server.
-
-``char \*ip_netmask``
- The Internet inetwork mask of the device,
- specified in ‘dotted decimal’ (``255.255.255.0``) form, or ``NULL``
- if the device configuration information is being obtained from a
- BOOTP/DHCP server.
-
-``void \*hardware_address``
- The hardware address of the device, or ``NULL`` if the driver is
- to obtain the hardware address in some other way (usually by reading
- it from the device or from the bootstrap ROM).
-
-``int ignore_broadcast``
- Zero if the device is to accept broadcast packets, non-zero if the device
- is to ignore broadcast packets.
-
-``int mtu``
- The maximum transmission unit of the device, or zero if the driver
- is to choose a default value (typically 1500 for Ethernet devices).
-
-``int rbuf_count``
- The number of receive buffers to use, or zero if the driver is to
- choose a default value
-
-``int xbuf_count``
- The number of transmit buffers to use, or zero if the driver is to
- choose a default value
- Keep in mind that some network devices may use 4 or more
- transmit descriptors for a single transmit buffer.
-
-A complete network configuration specification can be as simple as the one
-shown in the following example.
-This configuration uses a single network interface, gets
-network configuration information
-from a BOOTP/DHCP server, and uses the default values for all driver
-parameters.
-.. code:: c
-
- static struct rtems_bsdnet_ifconfig netdriver_config = {
- RTEMS_BSP_NETWORK_DRIVER_NAME,
- RTEMS_BSP_NETWORK_DRIVER_ATTACH
- };
- struct rtems_bsdnet_config rtems_bsdnet_config = {
- &netdriver_config,
- rtems_bsdnet_do_bootp,
- };
-
-Network initialization
-----------------------
-
-The networking tasks must be started before any network I/O operations
-can be performed. This is done by calling:
-
-.. code:: c
-
- rtems_bsdnet_initialize_network ();
-
-This function is declared in ``rtems/rtems_bsdnet.h``.
-t returns 0 on success and -1 on failure with an error code
-in ``errno``. It is not possible to undo the effects of
-a partial initialization, though, so the function can be
-called only once irregardless of the return code. Consequently,
-if the condition for the failure can be corrected, the
-system must be reset to permit another network initialization
-attempt.
-
-Application Programming Interface
-=================================
-
-The RTEMS network package provides almost a complete set of BSD network
-services. The network functions work like their BSD counterparts
-with the following exceptions:
-
-- A given socket can be read or written by only one task at a time.
-
-- The ``select`` function only works for file descriptors associated
- with sockets.
-
-- You must call ``openlog`` before calling any of the ``syslog`` functions.
-
-- *Some of the network functions are not thread-safe.*
- For example the following functions return a pointer to a static
- buffer which remains valid only until the next call:
-
- ``gethostbyaddr``
-
- ``gethostbyname``
-
- ``inet_ntoa``
-
- (``inet_ntop`` is thread-safe, though).
-
-- The RTEMS network package gathers statistics.
-
-- Addition of a mechanism to "tap onto" an interface
- and monitor every packet received and transmitted.
-
-- Addition of ``SO_SNDWAKEUP`` and ``SO_RCVWAKEUP`` socket options.
-
-Some of the new features are discussed in more detail in the following
-sections.
-
-Network Statistics
-------------------
-
-There are a number of functions to print statistics gathered by
-the network stack.
-These function are declared in ``rtems/rtems_bsdnet.h``.
-
-``rtems_bsdnet_show_if_stats``
- Display statistics gathered by network interfaces.
-
-``rtems_bsdnet_show_ip_stats``
- Display IP packet statistics.
-
-``rtems_bsdnet_show_icmp_stats``
- Display ICMP packet statistics.
-
-``rtems_bsdnet_show_tcp_stats``
- Display TCP packet statistics.
-
-``rtems_bsdnet_show_udp_stats``
- Display UDP packet statistics.
-
-``rtems_bsdnet_show_mbuf_stats``
- Display mbuf statistics.
-
-``rtems_bsdnet_show_inet_routes``
- Display the routing table.
-
-Tapping Into an Interface
--------------------------
-
-RTEMS add two new ioctls to the BSD networking code:
-SIOCSIFTAP and SIOCGIFTAP. These may be used to set and get a*tap function*. The tap function will be called for every
-Ethernet packet received by the interface.
-
-These are called like other interface ioctls, such as SIOCSIFADDR.
-When setting the tap function with SIOCSIFTAP, set the ifr_tap field
-of the ifreq struct to the tap function. When retrieving the tap
-function with SIOCGIFTAP, the current tap function will be returned in
-the ifr_tap field. To stop tapping packets, call SIOCSIFTAP with a
-ifr_tap field of 0.
-
-The tap function is called like this:
-.. code:: c
-
- int tap (struct ifnet \*, struct ether_header \*, struct mbuf \*)
-
-The tap function should return 1 if the packet was fully handled, in
-which case the caller will simply discard the mbuf. The tap function
-should return 0 if the packet should be passed up to the higher
-networking layers.
-
-The tap function is called with the network semaphore locked. It must
-not make any calls on the application levels of the networking level
-itself. It is safe to call other non-networking RTEMS functions.
-
-Socket Options
---------------
-
-RTEMS adds two new ``SOL_SOCKET`` level options for ``setsockopt`` and``getsockopt``: ``SO_SNDWAKEUP`` and ``SO_RCVWAKEUP``. For both, the
-option value should point to a sockwakeup structure. The sockwakeup
-structure has the following fields:
-.. code:: c
-
- void (\*sw_pfn) (struct socket \*, caddr_t);
- caddr_t sw_arg;
-
-These options are used to set a callback function to be called when, for
-example, there is
-data available from the socket (``SO_RCVWAKEUP``) and when there is space
-available to accept data written to the socket (``SO_SNDWAKEUP``).
-
-If ``setsockopt`` is called with the ``SO_RCVWAKEUP`` option, and the``sw_pfn`` field is not zero, then when there is data
-available to be read from
-the socket, the function pointed to by the ``sw_pfn`` field will be
-called. A pointer to the socket structure will be passed as the first
-argument to the function. The ``sw_arg`` field set by the``SO_RCVWAKEUP`` call will be passed as the second argument to the function.
-
-If ``setsockopt`` is called with the ``SO_SNDWAKEUP``
-function, and the ``sw_pfn`` field is not zero, then when
-there is space available to accept data written to the socket,
-the function pointed to by the ``sw_pfn`` field
-will be called. The arguments passed to the function will be as with``SO_SNDWAKEUP``.
-
-When the function is called, the network semaphore will be locked and
-the callback function runs in the context of the networking task.
-The function must be careful not to call any networking functions. It
-is OK to call an RTEMS function; for example, it is OK to send an
-RTEMS event.
-
-The purpose of these callback functions is to permit a more efficient
-alternative to the select call when dealing with a large number of
-sockets.
-
-The callbacks are called by the same criteria that the select
-function uses for indicating "ready" sockets. In Stevens *Unix
-Network Programming* on page 153-154 in the section "Under what Conditions
-Is a Descriptor Ready?" you will find the definitive list of conditions
-for readable and writable that also determine when the functions are
-called.
-
-When the number of received bytes equals or exceeds the socket receive
-buffer "low water mark" (default 1 byte) you get a readable callback. If
-there are 100 bytes in the receive buffer and you only read 1, you will
-not immediately get another callback. However, you will get another
-callback after you read the remaining 99 bytes and at least 1 more byte
-arrives. Using a non-blocking socket you should probably read until it
-produces error EWOULDBLOCK and then allow the readable callback to tell
-you when more data has arrived. (Condition 1.a.)
-
-For sending, when the socket is connected and the free space becomes at
-or above the "low water mark" for the send buffer (default 4096 bytes)
-you will receive a writable callback. You don’t get continuous callbacks
-if you don’t write anything. Using a non-blocking write socket, you can
-then call write until it returns a value less than the amount of data
-requested to be sent or it produces error EWOULDBLOCK (indicating buffer
-full and no longer writable). When this happens you can
-try the write again, but it is often better to go do other things and
-let the writable callback tell you when space is available to send
-again. You only get a writable callback when the free space transitions
-to above the "low water mark" and not every time you
-write to a non-full send buffer. (Condition 2.a.)
-
-The remaining conditions enumerated by Stevens handle the fact that
-sockets become readable and/or writable when connects, disconnects and
-errors occur, not just when data is received or sent. For example, when
-a server "listening" socket becomes readable it indicates that a client
-has connected and accept can be called without blocking, not that
-network data was received (Condition 1.c).
-
-Adding an IP Alias
-------------------
-
-The following code snippet adds an IP alias:
-.. code:: c
-
- void addAlias(const char \*pName, const char \*pAddr, const char \*pMask)
- {
- struct ifaliasreq aliasreq;
- struct sockaddr_in \*in;
- /* initialize alias request \*/
- memset(&aliasreq, 0, sizeof(aliasreq));
- sprintf(aliasreq.ifra_name, pName);
- /* initialize alias address \*/
- in = (struct sockaddr_in \*)&aliasreq.ifra_addr;
- in->sin_family = AF_INET;
- in->sin_len = sizeof(aliasreq.ifra_addr);
- in->sin_addr.s_addr = inet_addr(pAddr);
- /* initialize alias mask \*/
- in = (struct sockaddr_in \*)&aliasreq.ifra_mask;
- in->sin_family = AF_INET;
- in->sin_len = sizeof(aliasreq.ifra_mask);
- in->sin_addr.s_addr = inet_addr(pMask);
- /* call to setup the alias \*/
- rtems_bsdnet_ifconfig(pName, SIOCAIFADDR, &aliasreq);
- }
-
-Thanks to `Mike Seirs <mailto:mikes@poliac.com>`_ for this example
-code.
-
-Adding a Default Route
-----------------------
-
-The function provided in this section is functionally equivalent to
-the command ``route add default gw yyy.yyy.yyy.yyy``:
-.. code:: c
-
- void mon_ifconfig(int argc, char \*argv[], unsigned32 command_arg,
- bool verbose)
- {
- struct sockaddr_in ipaddr;
- struct sockaddr_in dstaddr;
- struct sockaddr_in netmask;
- struct sockaddr_in broadcast;
- char \*iface;
- int f_ip = 0;
- int f_ptp = 0;
- int f_netmask = 0;
- int f_up = 0;
- int f_down = 0;
- int f_bcast = 0;
- int cur_idx;
- int rc;
- int flags;
- bzero((void*) &ipaddr, sizeof(ipaddr));
- bzero((void*) &dstaddr, sizeof(dstaddr));
- bzero((void*) &netmask, sizeof(netmask));
- bzero((void*) &broadcast, sizeof(broadcast));
- ipaddr.sin_len = sizeof(ipaddr);
- ipaddr.sin_family = AF_INET;
- dstaddr.sin_len = sizeof(dstaddr);
- dstaddr.sin_family = AF_INET;
- netmask.sin_len = sizeof(netmask);
- netmask.sin_family = AF_INET;
- broadcast.sin_len = sizeof(broadcast);
- broadcast.sin_family = AF_INET;
- cur_idx = 0;
- if (argc <= 1) {
- /* display all interfaces \*/
- iface = NULL;
- cur_idx += 1;
- } else {
- iface = argv[1];
- if (isdigit(\*argv[2])) {
- if (inet_pton(AF_INET, argv[2], &ipaddr.sin_addr) < 0) {
- printf("bad ip address: %s\\n", argv[2]);
- return;
- }
- f_ip = 1;
- cur_idx += 3;
- } else {
- cur_idx += 2;
- }
- }
- if ((f_down !=0) && (f_ip != 0)) {
- f_up = 1;
- }
- while(argc > cur_idx) {
- if (strcmp(argv[cur_idx], "up") == 0) {
- f_up = 1;
- if (f_down != 0) {
- printf("Can't make interface up and down\\n");
- }
- } else if(strcmp(argv[cur_idx], "down") == 0) {
- f_down = 1;
- if (f_up != 0) {
- printf("Can't make interface up and down\\n");
- }
- } else if(strcmp(argv[cur_idx], "netmask") == 0) {
- if ((cur_idx + 1) >= argc) {
- printf("No netmask address\\n");
- return;
- }
- if (inet_pton(AF_INET, argv[cur_idx+1], &netmask.sin_addr) < 0) {
- printf("bad netmask: %s\\n", argv[cur_idx]);
- return;
- }
- f_netmask = 1;
- cur_idx += 1;
- } else if(strcmp(argv[cur_idx], "broadcast") == 0) {
- if ((cur_idx + 1) >= argc) {
- printf("No broadcast address\\n");
- return;
- }
- if (inet_pton(AF_INET, argv[cur_idx+1], &broadcast.sin_addr) < 0) {
- printf("bad broadcast: %s\\n", argv[cur_idx]);
- return;
- }
- f_bcast = 1;
- cur_idx += 1;
- } else if(strcmp(argv[cur_idx], "pointopoint") == 0) {
- if ((cur_idx + 1) >= argc) {
- printf("No pointopoint address\\n");
- return;
- }
- if (inet_pton(AF_INET, argv[cur_idx+1], &dstaddr.sin_addr) < 0) {
- printf("bad pointopoint: %s\\n", argv[cur_idx]);
- return;
- }
- f_ptp = 1;
- cur_idx += 1;
- } else {
- printf("Bad parameter: %s\\n", argv[cur_idx]);
- return;
- }
- cur_idx += 1;
- }
- printf("ifconfig ");
- if (iface != NULL) {
- printf("%s ", iface);
- if (f_ip != 0) {
- char str[256];
- inet_ntop(AF_INET, &ipaddr.sin_addr, str, 256);
- printf("%s ", str);
- }
- if (f_netmask != 0) {
- char str[256];
- inet_ntop(AF_INET, &netmask.sin_addr, str, 256);
- printf("netmask %s ", str);
- }
- if (f_bcast != 0) {
- char str[256];
- inet_ntop(AF_INET, &broadcast.sin_addr, str, 256);
- printf("broadcast %s ", str);
- }
- if (f_ptp != 0) {
- char str[256];
- inet_ntop(AF_INET, &dstaddr.sin_addr, str, 256);
- printf("pointopoint %s ", str);
- }
- if (f_up != 0) {
- printf("up\\n");
- } else if (f_down != 0) {
- printf("down\\n");
- } else {
- printf("\\n");
- }
- }
- if ((iface == NULL) \|| ((f_ip == 0) && (f_down == 0) && (f_up == 0))) {
- rtems_bsdnet_show_if_stats();
- return;
- }
- flags = 0;
- if (f_netmask) {
- rc = rtems_bsdnet_ifconfig(iface, SIOCSIFNETMASK, &netmask);
- if (rc < 0) {
- printf("Could not set netmask: %s\\n", strerror(errno));
- return;
- }
- }
- if (f_bcast) {
- rc = rtems_bsdnet_ifconfig(iface, SIOCSIFBRDADDR, &broadcast);
- if (rc < 0) {
- printf("Could not set broadcast: %s\\n", strerror(errno));
- return;
- }
- }
- if (f_ptp) {
- rc = rtems_bsdnet_ifconfig(iface, SIOCSIFDSTADDR, &dstaddr);
- if (rc < 0) {
- printf("Could not set destination address: %s\\n", strerror(errno));
- return;
- }
- flags \|= IFF_POINTOPOINT;
- }
- /* This must come _after_ setting the netmask, broadcast addresses \*/
- if (f_ip) {
- rc = rtems_bsdnet_ifconfig(iface, SIOCSIFADDR, &ipaddr);
- if (rc < 0) {
- printf("Could not set IP address: %s\\n", strerror(errno));
- return;
- }
- }
- if (f_up != 0) {
- flags \|= IFF_UP;
- }
- if (f_down != 0) {
- printf("Warning: taking interfaces down is not supported\\n");
- }
- rc = rtems_bsdnet_ifconfig(iface, SIOCSIFFLAGS, &flags);
- if (rc < 0) {
- printf("Could not set interface flags: %s\\n", strerror(errno));
- return;
- }
- }
- void mon_route(int argc, char \*argv[], unsigned32 command_arg,
- bool verbose)
- {
- int cmd;
- struct sockaddr_in dst;
- struct sockaddr_in gw;
- struct sockaddr_in netmask;
- int f_host;
- int f_gw = 0;
- int cur_idx;
- int flags;
- int rc;
- memset(&dst, 0, sizeof(dst));
- memset(&gw, 0, sizeof(gw));
- memset(&netmask, 0, sizeof(netmask));
- dst.sin_len = sizeof(dst);
- dst.sin_family = AF_INET;
- dst.sin_addr.s_addr = inet_addr("0.0.0.0");
- gw.sin_len = sizeof(gw);
- gw.sin_family = AF_INET;
- gw.sin_addr.s_addr = inet_addr("0.0.0.0");
- netmask.sin_len = sizeof(netmask);
- netmask.sin_family = AF_INET;
- netmask.sin_addr.s_addr = inet_addr("255.255.255.0");
- if (argc < 2) {
- rtems_bsdnet_show_inet_routes();
- return;
- }
- if (strcmp(argv[1], "add") == 0) {
- cmd = RTM_ADD;
- } else if (strcmp(argv[1], "del") == 0) {
- cmd = RTM_DELETE;
- } else {
- printf("invalid command: %s\\n", argv[1]);
- printf("\\tit should be 'add' or 'del'\\n");
- return;
- }
- if (argc < 3) {
- printf("not enough arguments\\n");
- return;
- }
- if (strcmp(argv[2], "-host") == 0) {
- f_host = 1;
- } else if (strcmp(argv[2], "-net") == 0) {
- f_host = 0;
- } else {
- printf("Invalid type: %s\\n", argv[1]);
- printf("\\tit should be '-host' or '-net'\\n");
- return;
- }
- if (argc < 4) {
- printf("not enough arguments\\n");
- return;
- }
- inet_pton(AF_INET, argv[3], &dst.sin_addr);
- cur_idx = 4;
- while(cur_idx < argc) {
- if (strcmp(argv[cur_idx], "gw") == 0) {
- if ((cur_idx +1) >= argc) {
- printf("no gateway address\\n");
- return;
- }
- f_gw = 1;
- inet_pton(AF_INET, argv[cur_idx + 1], &gw.sin_addr);
- cur_idx += 1;
- } else if(strcmp(argv[cur_idx], "netmask") == 0) {
- if ((cur_idx +1) >= argc) {
- printf("no netmask address\\n");
- return;
- }
- f_gw = 1;
- inet_pton(AF_INET, argv[cur_idx + 1], &netmask.sin_addr);
- cur_idx += 1;
- } else {
- printf("Unknown argument\\n");
- return;
- }
- cur_idx += 1;
- }
- flags = RTF_STATIC;
- if (f_gw != 0) {
- flags \|= RTF_GATEWAY;
- }
- if (f_host != 0) {
- flags \|= RTF_HOST;
- }
- rc = rtems_bsdnet_rtrequest(cmd, &dst, &gw, &netmask, flags, NULL);
- if (rc < 0) {
- printf("Error adding route\\n");
- }
- }
-
-Thanks to `Jay Monkman <mailto:jtm@smoothmsmoothie.com>`_ for this example
-code.
-
-Time Synchronization Using NTP
-------------------------------
-
-.. code:: c
-
- int rtems_bsdnet_synchronize_ntp (int interval, rtems_task_priority priority);
-
-If the interval argument is 0 the routine synchronizes the RTEMS time-of-day
-clock with the first NTP server in the rtems_bsdnet_ntpserve array and
-returns. The priority argument is ignored.
-
-If the interval argument is greater than 0, the routine also starts an
-RTEMS task at the specified priority and polls the NTP server every
-‘interval’ seconds. NOTE: This mode of operation has not yet been
-implemented.
-
-On successful synchronization of the RTEMS time-of-day clock the routine
-returns 0. If an error occurs a message is printed and the routine returns -1
-with an error code in errno.
-There is no timeout – if there is no response from an NTP server the
-routine will wait forever.
-
-.. COMMENT: Written by Eric Norum
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Testing the Driver
-##################
-
-Preliminary Setup
-=================
-
-The network used to test the driver should include at least:
-
-- The hardware on which the driver is to run.
- It makes testing much easier if you can run a debugger to control
- the operation of the target machine.
-
-- An Ethernet network analyzer or a workstation with an
- ‘Ethernet snoop’ program such as ``ethersnoop`` or``tcpdump``.
-
-- A workstation.
-
-During early debug, you should consider putting the target, workstation,
-and snooper on a small network by themselves. This offers a few
-advantages:
-
-- There is less traffic to look at on the snooper and for the target
- to process while bringing the driver up.
-
-- Any serious errors will impact only your small network not a building
- or campus network. You want to avoid causing any unnecessary problems.
-
-- Test traffic is easier to repeatably generate.
-
-- Performance measurements are not impacted by other systems on
- the network.
-
-Debug Output
-============
-
-There are a number of sources of debug output that can be enabled
-to aid in tracing the behavior of the network stack. The following
-is a list of them:
-
-- mbuf activity
- There are commented out calls to ``printf`` in the file``sys/mbuf.h`` in the network stack code. Uncommenting
- these lines results in output when mbuf’s are allocated
- and freed. This is very useful for finding memory leaks.
-
-- TX and RX queuing
- There are commented out calls to ``printf`` in the file``net/if.h`` in the network stack code. Uncommenting
- these lines results in output when packets are placed
- on or removed from one of the transmit or receive packet
- queues. These queues can be viewed as the boundary line
- between a device driver and the network stack. If the
- network stack is enqueuing packets to be transmitted that
- the device driver is not dequeuing, then that is indicative
- of a problem in the transmit side of the device driver.
- Conversely, if the device driver is enqueueing packets
- as it receives them (via a call to ``ether_input``) and
- they are not being dequeued by the network stack,
- then there is a problem. This situation would likely indicate
- that the network server task is not running.
-
-- TCP state transitions
- In the unlikely event that one would actually want to see
- TCP state transitions, the ``TCPDEBUG`` macro can be defined
- in the file ``opt_tcpdebug.h``. This results in the routine``tcp_trace()`` being called by the network stack and
- the state transitions logged into the ``tcp_debug`` data
- structure. If the variable ``tcpconsdebug`` in the file``netinet/tcp_debug.c`` is set to 1, then the state transitions
- will also be printed to the console.
-
-Monitor Commands
-================
-
-There are a number of command available in the shell / monitor
-to aid in tracing the behavior of the network stack. The following
-is a list of them:
-
-- ``inet``
- This command shows the current routing information for the TCP/IP stack. Following is an
- example showing the output of this command.
-
- .. code:: c
-
- Destination Gateway/Mask/Hw Flags Refs Use Expire Interface
- 10.0.0.0 255.0.0.0 U 0 0 17 smc1
- 127.0.0.1 127.0.0.1 UH 0 0 0 lo0
-
- In this example, there is only one network interface with an IP address of 10.8.1.1. This
- link is currently not up.
- Two routes that are shown are the default routes for the Ethernet interface (10.0.0.0) and the
- loopback interface (127.0.0.1).
- Since the stack comes from BSD, this command is very similar to the netstat command. For more
- details on the network routing please look the following
- URL: (http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/network-routing.html)
- For a quick reference to the flags, see the table below:
-
- ‘``U``’
- Up: The route is active.
-
- ‘``H``’
- Host: The route destination is a single host.
-
- ‘``G``’
- Gateway: Send anything for this destination on to this remote system, which
- will figure out from there where to send it.
-
- ‘``S``’
- Static: This route was configured manually, not automatically generated by the
- system.
-
- ‘``C``’
- Clone: Generates a new route based upon this route for machines we connect
- to. This type of route is normally used for local networks.
-
- ‘``W``’
- WasCloned: Indicated a route that was auto-configured based upon a local area
- network (Clone) route.
-
- ‘``L``’
- Link: Route involves references to Ethernet hardware.
-
-- ``mbuf``
-
- This command shows the current MBUF statistics. An example of the command is shown below:
-
- .. code:: c
-
- ************ MBUF STATISTICS \************
- mbufs:4096 clusters: 256 free: 241
- drops: 0 waits: 0 drains: 0
- free:4080 data:16 header:0 socket:0
- pcb:0 rtable:0 htable:0 atable:0
- soname:0 soopts:0 ftable:0 rights:0
- ifaddr:0 control:0 oobdata:0
-
-- ``if``
-
- This command shows the current statistics for your Ethernet driver as long as the ioctl hook``SIO_RTEMS_SHOW_STATS`` has been implemented. Below is an example:
-
- .. code:: c
-
- ************ INTERFACE STATISTICS \************
- \***** smc1 \*****
- Ethernet Address: 00:12:76:43:34:25
- Address:10.8.1.1 Broadcast Address:10.255.255.255 Net mask:255.0.0.0
- Flags: Up Broadcast Running Simplex
- Send queue limit:50 length:0 Dropped:0
- SMC91C111 RTEMS driver A0.01 11/03/2002 Ian Caddy (ianc@microsol.iinet.net.au)
- Rx Interrupts:0 Not First:0 Not Last:0
- Giant:0 Runt:0 Non-octet:0
- Bad CRC:0 Overrun:0 Collision:0
- Tx Interrupts:2 Deferred:0 Missed Hearbeat:0
- No Carrier:0 Retransmit Limit:0 Late Collision:0
- Underrun:0 Raw output wait:0 Coalesced:0
- Coalesce failed:0 Retries:0
- \***** lo0 \*****
- Address:127.0.0.1 Net mask:255.0.0.0
- Flags: Up Loopback Running Multicast
- Send queue limit:50 length:0 Dropped:0
-
-- ``ip``
- This command show the IP statistics for the currently configured interfaces.
-
-- ``icmp``
- This command show the ICMP statistics for the currently configured interfaces.
-
-- ``tcp``
- This command show the TCP statistics for the currently configured interfaces.
-
-- ``udp``
- This command show the UDP statistics for the currently configured interfaces.
-
-Driver basic operation
-======================
-
-The network demonstration program ``netdemo`` may be used for these tests.
-
-- Edit ``networkconfig.h`` to reflect the values for your network.
-
-- Start with ``RTEMS_USE_BOOTP`` not defined.
-
-- Edit ``networkconfig.h`` to configure the driver
- with an
- explicit Ethernet and Internet address and with reception of
- broadcast packets disabled:
- Verify that the program continues to run once the driver has been attached.
-
-- Issue a ‘``u``’ command to send UDP
- packets to the ‘discard’ port.
- Verify that the packets appear on the network.
-
-- Issue a ‘``s``’ command to print the network and driver statistics.
-
-- On a workstation, add a static route to the target system.
-
-- On that same workstation try to ‘ping’ the target system.
- Verify that the ICMP echo request and reply packets appear on the net.
-
-- Remove the static route to the target system.
- Modify ``networkconfig.h`` to attach the driver
- with reception of broadcast packets enabled.
- Try to ‘ping’ the target system again.
- Verify that ARP request/reply and ICMP echo request/reply packets appear
- on the net.
-
-- Issue a ‘``t``’ command to send TCP
- packets to the ‘discard’ port.
- Verify that the packets appear on the network.
-
-- Issue a ‘``s``’ command to print the network and driver statistics.
-
-- Verify that you can telnet to ports 24742
- and 24743 on the target system from one or more
- workstations on your network.
-
-BOOTP/DHCP operation
-====================
-
-Set up a BOOTP/DHCP server on the network.
-Set define ``RTEMS USE_BOOT`` in ``networkconfig.h``.
-Run the ``netdemo`` test program.
-Verify that the target system configures itself from the BOOTP/DHCP server and
-that all the above tests succeed.
-
-Stress Tests
-============
-
-Once the driver passes the tests described in the previous section it should
-be subjected to conditions which exercise it more
-thoroughly and which test its error handling routines.
-
-Giant packets
--------------
-
-- Recompile the driver with ``MAXIMUM_FRAME_SIZE`` set to
- a smaller value, say 514.
-
-- ‘Ping’ the driver from another workstation and verify
- that frames larger than 514 bytes are correctly rejected.
-
-- Recompile the driver with ``MAXIMUM_FRAME_SIZE`` restored to 1518.
-
-Resource Exhaustion
--------------------
-
-- Edit ``networkconfig.h``
- so that the driver is configured with just two receive and transmit descriptors.
-
-- Compile and run the ``netdemo`` program.
-
-- Verify that the program operates properly and that you can
- still telnet to both the ports.
-
-- Display the driver statistics (Console ‘``s``’ command or telnet
- ‘control-G’ character) and verify that:
-
- # The number of transmit interrupts is non-zero.
- This indicates that all transmit descriptors have been in use at some time.
-
- # The number of missed packets is non-zero.
- This indicates that all receive descriptors have been in use at some time.
-
-Cable Faults
-------------
-
-- Run the ``netdemo`` program.
-
-- Issue a ‘``u``’ console command to make the target machine transmit
- a bunch of UDP packets.
-
-- While the packets are being transmitted, disconnect and reconnect the
- network cable.
-
-- Display the network statistics and verify that the driver has
- detected the loss of carrier.
-
-- Verify that you can still telnet to both ports on the target machine.
-
-Throughput
-----------
-
-Run the ``ttcp`` network benchmark program.
-Transfer large amounts of data (100’s of megabytes) to and from the target
-system.
-
-The procedure for testing throughput from a host to an RTEMS target
-is as follows:
-
-# Download and start the ttcp program on the Target.
-
-# In response to the ``ttcp`` prompt, enter ``-s -r``. The
- meaning of these flags is described in the ``ttcp.1`` manual page
- found in the ``ttcp_orig`` subdirectory.
-
-# On the host run ``ttcp -s -t <<insert the hostname or IP address of the Target here>>``
-
-The procedure for testing throughput from an RTEMS target
-to a Host is as follows:
-
-# On the host run ``ttcp -s -r``.
-
-# Download and start the ttcp program on the Target.
-
-# In response to the ``ttcp`` prompt, enter ``-s -t <<insert the hostname or IP address of the Target here>>``. You need to type the
- IP address of the host unless your Target is talking to your Domain Name
- Server.
-
-To change the number of buffers, the buffer size, etc. you just add the
-extra flags to the ``-t`` machine as specified in the ``ttcp.1``
-manual page found in the ``ttcp_orig`` subdirectory.
-
-.. COMMENT: Text Written by Jake Janovetz
-
-.. COMMENT: COPYRIGHT (c) 1988-2002.
-
-.. COMMENT: On-Line Applications Research Corporation (OAR).
-
-.. COMMENT: All rights reserved.
-
-Network Servers
-###############
-
-RTEMS FTP Daemon
-================
-
-The RTEMS FTPD is a complete file transfer protocol (FTP) daemon
-which can store, retrieve, and manipulate files on the local
-filesystem. In addition, the RTEMS FTPD provides “hooks”
-which are actions performed on received data. Hooks are useful
-in situations where a destination file is not necessarily
-appropriate or in cases when a formal device driver has not yet
-been implemented.
-
-This server was implemented and documented by Jake Janovetz
-(janovetz@tempest.ece.uiuc.edu).
-
-Configuration Parameters
-------------------------
-
-The configuration structure for FTPD is as follows:
-.. code:: c
-
- struct rtems_ftpd_configuration
- {
- rtems_task_priority priority; /* FTPD task priority \*/
- unsigned long max_hook_filesize; /* Maximum buffersize \*/
- /* for hooks \*/
- int port; /* Well-known port \*/
- struct rtems_ftpd_hook \*hooks; /* List of hooks \*/
- };
-
-The FTPD task priority is specified with ``priority``. Because
-hooks are not saved as files, the received data is placed in an
-allocated buffer. ``max_hook_filesize`` specifies the maximum
-size of this buffer. Finally, ``hooks`` is a pointer to the
-configured hooks structure.
-
-Initializing FTPD (Starting the daemon)
----------------------------------------
-
-Starting FTPD is done with a call to ``rtems_initialize_ftpd()``.
-The configuration structure must be provided in the application
-source code. Example hooks structure and configuration structure
-folllow.
-.. code:: c
-
- struct rtems_ftpd_hook ftp_hooks[] =
- {
- {"untar", Untar_FromMemory},
- {NULL, NULL}
- };
- struct rtems_ftpd_configuration rtems_ftpd_configuration =
- {
- 40, /* FTPD task priority \*/
- 512*1024, /* Maximum hook 'file' size \*/
- 0, /* Use default port \*/
- ftp_hooks /* Local ftp hooks \*/
- };
-
-Specifying 0 for the well-known port causes FTPD to use the
-UNIX standard FTPD port (21).
-
-Using Hooks
------------
-
-In the example above, one hook was installed. The hook causes
-FTPD to call the function ``Untar_FromMemory`` when the
-user sends data to the file ``untar``. The prototype for
-the ``untar`` hook (and hooks, in general) is:
-.. code:: c
-
- int Untar_FromMemory(unsigned char \*tar_buf, unsigned long size);
-
-An example FTP transcript which exercises this hook is:
-.. code:: c
-
- 220 RTEMS FTP server (Version 1.0-JWJ) ready.
- Name (dcomm0:janovetz): John Galt
- 230 User logged in.
- Remote system type is RTEMS.
- ftp> bin
- 200 Type set to I.
- ftp> dir
- 200 PORT command successful.
- 150 ASCII data connection for LIST.
- drwxrwx--x 0 0 268 dev
- drwxrwx--x 0 0 0 TFTP
- 226 Transfer complete.
- ftp> put html.tar untar
- local: html.tar remote: untar
- 200 PORT command successful.
- 150 BINARY data connection.
- 210 File transferred successfully.
- 471040 bytes sent in 0.48 secs (9.6e+02 Kbytes/sec)
- ftp> dir
- 200 PORT command successful.
- 150 ASCII data connection for LIST.
- drwxrwx--x 0 0 268 dev
- drwxrwx--x 0 0 0 TFTP
- drwxrwx--x 0 0 3484 public_html
- 226 Transfer complete.
- ftp> quit
- 221 Goodbye.
-
-.. COMMENT: RTEMS Remote Debugger Server Specifications
-
-.. COMMENT: Written by: Emmanuel Raguet <raguet@crf.canon.fr>
-
-DEC 21140 Driver
-################
-
-DEC 21240 Driver Introduction
-=============================
-
-.. COMMENT: XXX add back in cross reference to list of boards.
-
-One aim of our project is to port RTEMS on a standard PowerPC platform.
-To achieve it, we have chosen a Motorola MCP750 board. This board includes
-an Ethernet controller based on a DEC21140 chip. Because RTEMS has a
-TCP/IP stack, we will
-have to develop the DEC21140 related ethernet driver for the PowerPC port of
-RTEMS. As this controller is able to support 100Mbps network and as there is
-a lot of PCI card using this DEC chip, we have decided to first
-implement this driver on an Intel PC386 target to provide a solution for using
-RTEMS on PC with the 100Mbps network and then to port this code on PowerPC in
-a second phase.
-
-The aim of this document is to give some PCI board generalities and
-to explain the software architecture of the RTEMS driver. Finally, we will see
-what will be done for ChorusOs and Netboot environment .
-
-Document Revision History
-=========================
-
-*Current release*:
-
-- Current applicable release is 1.0.
-
-*Existing releases*:
-
-- 1.0 : Released the 10/02/98. First version of this document.
-
-- 0.1 : First draft of this document
-
-*Planned releases*:
-
-- None planned today.
-
-DEC21140 PCI Board Generalities
-===============================
-
-.. COMMENT: XXX add crossreference to PCI Register Figure
-
-This chapter describes rapidely the PCI interface of this Ethernet controller.
-The board we have chosen for our PC386 implementation is a D-Link DFE-500TX.
-This is a dual-speed 10/100Mbps Ethernet PCI adapter with a DEC21140AF chip.
-Like other PCI devices, this board has a PCI device’s header containing some
-required configuration registers, as shown in the PCI Register Figure.
-By reading
-or writing these registers, a driver can obtain information about the type of
-the board, the interrupt it uses, the mapping of the chip specific registers, ...
-
-On Intel target, the chip specific registers can be accessed via 2
-methods : I/O port access or PCI address mapped access. We have chosen to implement
-the PCI address access to obtain compatible source code to the port the driver
-on a PowerPC target.
-
-.. COMMENT: PCI Device's Configuration Header Space Format
-
-
-.. image:: images/PCIreg.jpg
-
-
-.. COMMENT: XXX add crossreference to PCI Register Figure
-
-On RTEMS, a PCI API exists. We have used it to configure the board. After initializing
-this PCI module via the ``pci_initialize()`` function, we try to detect
-the DEC21140 based ethernet board. This board is characterized by its Vendor
-ID (0x1011) and its Device ID (0x0009). We give these arguments to the``pcib_find_by_deviceid``
-function which returns , if the device is present, a pointer to the configuration
-header space (see PCI Registers Fgure). Once this operation performed,
-the driver
-is able to extract the information it needs to configure the board internal
-registers, like the interrupt line, the base address,... The board internal
-registers will not be detailled here. You can find them in *DIGITAL
-Semiconductor 21140A PCI Fast Ethernet LAN Controller
-- Hardware Reference Manual*.
-
-.. COMMENT: fix citation
-
-RTEMS Driver Software Architecture
-==================================
-
-In this chapter will see the initialization phase, how the controller uses the
-host memory and the 2 threads launched at the initialization time.
-
-Initialization phase
---------------------
-
-The DEC21140 Ethernet driver keeps the same software architecture than the other
-RTEMS ethernet drivers. The only API the programmer can use is the ``rtems_dec21140_driver_attach````(struct rtems_bsdnet_ifconfig \*config)`` function which
-detects the board and initializes the associated data structure (with registers
-base address, entry points to low-level initialization function,...), if the
-board is found.
-
-Once the attach function executed, the driver initializes the DEC
-chip. Then the driver connects an interrupt handler to the interrupt line driven
-by the Ethernet controller (the only interrupt which will be treated is the
-receive interrupt) and launches 2 threads : a receiver thread and a transmitter
-thread. Then the driver waits for incoming frame to give to the protocol stack
-or outcoming frame to send on the physical link.
-
-Memory Buffer
--------------
-
-.. COMMENT: XXX add cross reference to Problem
-
-This DEC chip uses the host memory to store the incoming Ethernet frames and
-the descriptor of these frames. We have chosen to use 7 receive buffers and
-1 transmit buffer to optimize memory allocation due to cache and paging problem
-that will be explained in the section *Encountered Problems*.
-
-To reference these buffers to the DEC chip we use a buffer descriptors
-ring. The descriptor structure is defined in the Buffer Descriptor Figure.
-Each descriptor
-can reference one or two memory buffers. We choose to use only one buffer of
-1520 bytes per descriptor.
-
-The difference between a receive and a transmit buffer descriptor
-is located in the status and control bits fields. We do not give details here,
-please refer to the \[DEC21140 Hardware Manual].
-
-.. COMMENT: Buffer Descriptor
-
-
-.. image:: images/recvbd.jpg
-
-
-Receiver Thread
----------------
-
-This thread is event driven. Each time a DEC PCI board interrupt occurs, the
-handler checks if this is a receive interrupt and send an event “reception”
-to the receiver thread which looks into the entire buffer descriptors ring the
-ones that contain a valid incoming frame (bit OWN=0 means descriptor belongs
-to host processor). Each valid incoming ethernet frame is sent to the protocol
-stack and the buffer descriptor is given back to the DEC board (the host processor
-reset bit OWN, which means descriptor belongs to 21140).
-
-Transmitter Thread
-------------------
-
-This thread is also event driven. Each time an Ethernet frame is put in the
-transmit queue, an event is sent to the transmit thread, which empty the queue
-by sending each outcoming frame. Because we use only one transmit buffer, we
-are sure that the frame is well-sent before sending the next.
-
-Encountered Problems
-====================
-
-On Intel PC386 target, we were faced with a problem of memory cache management.
-Because the DEC chip uses the host memory to store the incoming frame and because
-the DEC21140 configuration registers are mapped into the PCI address space,
-we must ensure that the data read (or written) by the host processor are the
-ones written (or read) by the DEC21140 device in the host memory and not old
-data stored in the cache memory. Therefore, we had to provide a way to manage
-the cache. This module is described in the document *RTEMS
-Cache Management For Intel*. On Intel, the
-memory region cache management is available only if the paging unit is enabled.
-We have used this paging mechanism, with 4Kb page. All the buffers allocated
-to store the incoming or outcoming frames, buffer descriptor and also the PCI
-address space of the DEC board are located in a memory space with cache disable.
-
-Concerning the buffers and their descriptors, we have tried to optimize
-the memory space in term of allocated page. One buffer has 1520 bytes, one descriptor
-has 16 bytes. We have 7 receive buffers and 1 transmit buffer, and for each,
-1 descriptor : (7+1)*(1520+16) = 12288 bytes = 12Kb = 3 entire pages. This
-allows not to lose too much memory or not to disable cache memory for a page
-which contains other data than buffer, which could decrease performance.
-
-ChorusOs DEC Driver
-===================
-
-Because ChorusOs is used in several Canon CRF projects, we must provide such
-a driver on this OS to ensure compatibility between the RTEMS and ChorusOs developments.
-On ChorusOs, a DEC driver source code already exists but only for a PowerPC
-target. We plan to port this code (which uses ChorusOs API) on Intel target.
-This will allow us to have homogeneous developments. Moreover, the port of the
-development performed with ChorusOs environment to RTEMS environment will be
-easier for the developers.
-
-Netboot DEC driver
-==================
-
-We use Netboot tool to load our development from a server to the target via
-an ethernet network. Currently, this tool does not support the DEC board. We
-plan to port the DEC driver for the Netboot tool.
-
-But concerning the port of the DEC driver into Netboot, we are faced
-with a problem : in RTEMS environment, the DEC driver is interrupt or event
-driven, in Netboot environment, it must be used in polling mode. It means that
-we will have to re-write some mechanisms of this driver.
-
-List of Ethernet cards using the DEC chip
-=========================================
-
-Many Ethernet adapter cards use the Tulip chip. Here is a non exhaustive list
-of adapters which support this driver :
-
-- Accton EtherDuo PCI.
-
-- Accton EN1207 All three media types supported.
-
-- Adaptec ANA6911/TX 21140-AC.
-
-- Cogent EM110 21140-A with DP83840 N-Way MII transceiver.
-
-- Cogent EM400 EM100 with 4 21140 100mbps-only ports + PCI Bridge.
-
-- Danpex EN-9400P3.
-
-- D-Link DFE500-Tx 21140-A with DP83840 transceiver.
-
-- Kingston EtherX KNE100TX 21140AE.
-
-- Netgear FX310 TX 10/100 21140AE.
-
-- SMC EtherPower10/100 With DEC21140 and 68836 SYM transceiver.
-
-- SMC EtherPower10/100 With DEC21140-AC and DP83840 MII transceiver.
- Note: The EtherPower II uses the EPIC chip, which requires a different driver.
-
-- Surecom EP-320X DEC 21140.
-
-- Thomas Conrad TC5048.
-
-- Znyx ZX345 21140-A, usually with the DP83840 N-Way MII transciever. Some ZX345
- cards made in 1996 have an ICS 1890 transciver instead.
-
-- ZNYX ZX348 Two 21140-A chips using ICS 1890 transcievers and either a 21052
- or 21152 bridge. Early versions used National 83840 transcievers, but later
- versions are depopulated ZX346 boards.
-
-- ZNYX ZX351 21140 chip with a Broadcom 100BaseT4 transciever.
-
-Our DEC driver has not been tested with all these cards, only with the D-Link
-DFE500-TX.
-
-- *[DEC21140 Hardware Manual] DIGITAL, *DIGITAL
- Semiconductor 21140A PCI Fast Ethernet LAN Controller - Hardware
- Reference Manual**.
-
-- *[99.TA.0021.M.ER]Emmanuel Raguet,*RTEMS Cache Management For Intel**.
-
-Command and Variable Index
-##########################
-
-There are currently no Command and Variable Index entries.
-
-.. COMMENT: @printindex fn
-
-Concept Index
-#############
-
-There are currently no Concept Index entries.
-
-.. COMMENT: @printindex cp