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diff --git a/legacy-networking/using_networking_rtems_app.rst b/legacy-networking/using_networking_rtems_app.rst new file mode 100644 index 0000000..0d3e245 --- /dev/null +++ b/legacy-networking/using_networking_rtems_app.rst @@ -0,0 +1,851 @@ +.. SPDX-License-Identifier: CC-BY-SA-4.0 + +.. COMMENT: Written by Eric Norum +.. Copyright (C) 1988, 2002 On-Line Applications Research Corporation (OAR) + +Using Networking in an RTEMS Application +######################################## + +Makefile changes +================ + +Including the required managers +------------------------------- + +The FreeBSD networking code requires several RTEMS managers in the application: + +.. code-block:: makefile + + 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-block:: makefile + + 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-block:: c + + #include <rtems/rtems_bsdnet.h> + +Network Configuration +--------------------- + +The network configuration is specified by declaring and initializing the +``rtems_bsdnet_config`` structure. + +.. code-block:: 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. See + http://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-block:: 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-block:: 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-block:: 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-block:: 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-block:: 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-block:: 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-block:: 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-block:: 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. |