[remove] the doc folder of lwIP 2.1.2

Signed-off-by: liuxianliang <liuxianliang@rt-thread.com>
2026-09-27 15:24:11 +08:00 · 2020-06-23 10:00:58 +08:00
parent be64fcba86
commit 0d8f90788f
15 changed files with 0 additions and 6636 deletions
@@ -1,9 +0,0 @@
 doxygen/       - Configuration files and scripts to create the lwIP doxygen source
                 documentation (found at http://www.nongnu.org/lwip/)
 savannah.txt   - How to obtain the current development source code.
 contrib.txt    - How to contribute to lwIP as a developer.
 rawapi.txt     - The documentation for the core API of lwIP.
                 Also provides an overview about the other APIs and multithreading.
 sys_arch.txt   - The documentation for a system abstraction layer of lwIP.
 ppp.txt        - Documentation of the PPP interface for lwIP.
@@ -1,122 +0,0 @@
 void
 eth_mac_irq()
 {
  /* Service MAC IRQ here */
  /* Allocate pbuf from pool (avoid using heap in interrupts) */
  struct pbuf* p = pbuf_alloc(PBUF_RAW, eth_data_count, PBUF_POOL);
  if(p != NULL) {
    /* Copy ethernet frame into pbuf */
    pbuf_take(p, eth_data, eth_data_count);
    /* Put in a queue which is processed in main loop */
    if(!queue_try_put(&queue, p)) {
      /* queue is full -> packet loss */
      pbuf_free(p);
    }
  }
 }
 static err_t 
 netif_output(struct netif *netif, struct pbuf *p)
 {
  LINK_STATS_INC(link.xmit);
  /* Update SNMP stats (only if you use SNMP) */
  MIB2_STATS_NETIF_ADD(netif, ifoutoctets, p->tot_len);
  int unicast = ((p->payload[0] & 0x01) == 0);
  if (unicast) {
    MIB2_STATS_NETIF_INC(netif, ifoutucastpkts);
  } else {
    MIB2_STATS_NETIF_INC(netif, ifoutnucastpkts);
  }
  lock_interrupts();
  pbuf_copy_partial(p, mac_send_buffer, p->tot_len, 0);
  /* Start MAC transmit here */
  unlock_interrupts();
  return ERR_OK;
 }
 static void 
 netif_status_callback(struct netif *netif)
 {
  printf("netif status changed %s\n", ip4addr_ntoa(netif_ip4_addr(netif)));
 }
 static err_t 
 netif_init(struct netif *netif)
 {
  netif->linkoutput = netif_output;
  netif->output     = etharp_output;
  netif->output_ip6 = ethip6_output;
  netif->mtu        = ETHERNET_MTU;
  netif->flags      = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET | NETIF_FLAG_IGMP | NETIF_FLAG_MLD6;
  MIB2_INIT_NETIF(netif, snmp_ifType_ethernet_csmacd, 100000000);
  SMEMCPY(netif->hwaddr, your_mac_address_goes_here, ETH_HWADDR_LEN);
  netif->hwaddr_len = ETH_HWADDR_LEN;
  return ERR_OK;
 }
 void 
 main(void)
 {
  struct netif netif;
  lwip_init();
  netif_add(&netif, IP4_ADDR_ANY, IP4_ADDR_ANY, IP4_ADDR_ANY, NULL, netif_init, netif_input);
  netif.name[0] = 'e';
  netif.name[1] = '0';
  netif_create_ip6_linklocal_address(&netif, 1);
  netif.ip6_autoconfig_enabled = 1;
  netif_set_status_callback(&netif, netif_status_callback);
  netif_set_default(&netif);
  netif_set_up(&netif);
  /* Start DHCP and HTTPD */
  dhcp_start(&netif );
  httpd_init();
  while(1) {
    /* Check link state, e.g. via MDIO communication with PHY */
    if(link_state_changed()) {
      if(link_is_up()) {
        netif_set_link_up(&netif);
      } else {
        netif_set_link_down(&netif);
      }
    }
    /* Check for received frames, feed them to lwIP */
    lock_interrupts();
    struct pbuf* p = queue_try_get(&queue);
    unlock_interrupts();
    if(p != NULL) {
      LINK_STATS_INC(link.recv);
      /* Update SNMP stats (only if you use SNMP) */
      MIB2_STATS_NETIF_ADD(netif, ifinoctets, p->tot_len);
      int unicast = ((p->payload[0] & 0x01) == 0);
      if (unicast) {
        MIB2_STATS_NETIF_INC(netif, ifinucastpkts);
      } else {
        MIB2_STATS_NETIF_INC(netif, ifinnucastpkts);
      }
      if(netif.input(p, &netif) != ERR_OK) {
        pbuf_free(p);
      }
    }
    /* Cyclic lwIP timers check */
    sys_check_timeouts();
    /* your application goes here */
  }
 }
@@ -1,45 +0,0 @@
 typedef struct my_custom_pbuf
 {
   struct pbuf_custom p;
   void* dma_descriptor;
 } my_custom_pbuf_t;
 LWIP_MEMPOOL_DECLARE(RX_POOL, 10, sizeof(my_custom_pbuf_t), "Zero-copy RX PBUF pool");
 void my_pbuf_free_custom(void* p)
 {
  SYS_ARCH_DECL_PROTECT(old_level);
  my_custom_pbuf_t* my_puf = (my_custom_pbuf_t*)p;
  // invalidate data cache here - lwIP and/or application may have written into buffer!
  // (invalidate is faster than flushing, and noone needs the correct data in the buffer)
  invalidate_cpu_cache(p->payload, p->tot_len);
  SYS_ARCH_PROTECT(old_level);
  free_rx_dma_descriptor(my_pbuf->dma_descriptor);
  LWIP_MEMPOOL_FREE(RX_POOL, my_pbuf);
  SYS_ARCH_UNPROTECT(old_level);
 }
 void eth_rx_irq()
 {
  dma_descriptor*   dma_desc = get_RX_DMA_descriptor_from_ethernet();
  my_custom_pbuf_t* my_pbuf  = (my_custom_pbuf_t*)LWIP_MEMPOOL_ALLOC(RX_POOL);
  my_pbuf->p.custom_free_function = my_pbuf_free_custom;
  my_pbuf->dma_descriptor         = dma_desc;
  invalidate_cpu_cache(dma_desc->rx_data, dma_desc->rx_length);
  struct pbuf* p = pbuf_alloced_custom(PBUF_RAW,
     dma_desc->rx_length,
     PBUF_REF,
     &my_pbuf->p,
     dma_desc->rx_data,
     dma_desc->max_buffer_size);
  if(netif->input(p, netif) != ERR_OK) {
    pbuf_free(p);
  }
 }
@@ -1,58 +0,0 @@
 1 Introduction
 This document describes some guidelines for people participating
 in lwIP development.
 2 How to contribute to lwIP
 Here is a short list of suggestions to anybody working with lwIP and 
 trying to contribute bug reports, fixes, enhancements, platform ports etc.
 First of all as you may already know lwIP is a volunteer project so feedback
 to fixes or questions might often come late. Hopefully the bug and patch tracking 
 features of Savannah help us not lose users' input.
 2.1 Source code style:
 1. do not use tabs.
 2. indentation is two spaces per level (i.e. per tab).
 3. end debug messages with a trailing newline (\n).
 4. one space between keyword and opening bracket.
 5. no space between function and opening bracket.
 6. one space and no newline before opening curly braces of a block.
 7. closing curly brace on a single line.
 8. spaces surrounding assignment and comparisons.
 9. don't initialize static and/or global variables to zero, the compiler takes care of that.
 10. use current source code style as further reference.
 2.2 Source code documentation style:
 1. JavaDoc compliant and Doxygen compatible.
 2. Function documentation above functions in .c files, not .h files.
   (This forces you to synchronize documentation and implementation.)
 3. Use current documentation style as further reference.
 2.3 Bug reports and patches:
 1. Make sure you are reporting bugs or send patches against the latest
   sources. (From the latest release and/or the current Git sources.)
 2. If you think you found a bug make sure it's not already filed in the
   bugtracker at Savannah.
 3. If you have a fix put the patch on Savannah. If it is a patch that affects
   both core and arch specific stuff please separate them so that the core can
   be applied separately while leaving the other patch 'open'. The preferred way
   is to NOT touch archs you can't test and let maintainers take care of them.
   This is a good way to see if they are used at all - the same goes for unix
   netifs except tapif.
 4. Do not file a bug and post a fix to it to the patch area. Either a bug report
   or a patch will be enough.
   If you correct an existing bug then attach the patch to the bug rather than creating a new entry in the patch area.
 5. Patches should be specific to a single change or to related changes. Do not mix bugfixes with spelling and other
   trivial fixes unless the bugfix is trivial too. Do not reorganize code and rename identifiers in the same patch you
   change behaviour if not necessary. A patch is easier to read and understand if it's to the point and short than
   if it's not to the point and long :) so the chances for it to be applied are greater. 
 2.4 Platform porters:
 1. If you have ported lwIP to a platform (an OS, a uC/processor or a combination of these) and
   you think it could benefit others[1] you might want discuss this on the mailing list. You
   can also ask for Git access to submit and maintain your port in the contrib Git module.
@@ -1 +0,0 @@
 doxygen lwip.Doxyfile
@@ -1,3 +0,0 @@
 #!/bin/sh
 doxygen lwip.Doxyfile
@@ -1,403 +0,0 @@
 /**
 * @defgroup lwip lwIP
 *
 * @defgroup infrastructure Infrastructure
 * 
 * @defgroup api APIs
 * lwIP provides three Application Program's Interfaces (APIs) for programs
 * to use for communication with the TCP/IP code:
 * - low-level "core" / "callback" or @ref callbackstyle_api.
 * - higher-level @ref sequential_api.
 * - BSD-style @ref socket.
 * 
 * The raw TCP/IP interface allows the application program to integrate
 * better with the TCP/IP code. Program execution is event based by
 * having callback functions being called from within the TCP/IP
 * code. The TCP/IP code and the application program both run in the same
 * thread. The sequential API has a much higher overhead and is not very
 * well suited for small systems since it forces a multithreaded paradigm
 * on the application.
 * 
 * The raw TCP/IP interface is not only faster in terms of code execution
 * time but is also less memory intensive. The drawback is that program
 * development is somewhat harder and application programs written for
 * the raw TCP/IP interface are more difficult to understand. Still, this
 * is the preferred way of writing applications that should be small in
 * code size and memory usage.
 * 
 * All APIs can be used simultaneously by different application
 * programs. In fact, the sequential API is implemented as an application
 * program using the raw TCP/IP interface.
 * 
 * Do not confuse the lwIP raw API with raw Ethernet or IP sockets.
 * The former is a way of interfacing the lwIP network stack (including
 * TCP and UDP), the latter refers to processing raw Ethernet or IP data
 * instead of TCP connections or UDP packets.
 * 
 * Raw API applications may never block since all packet processing
 * (input and output) as well as timer processing (TCP mainly) is done
 * in a single execution context.
 *
 * @defgroup callbackstyle_api "raw" APIs
 * @ingroup api
 * Non thread-safe APIs, callback style for maximum performance and minimum
 * memory footprint.
 * Program execution is driven by callbacks functions, which are then
 * invoked by the lwIP core when activity related to that application
 * occurs. A particular application may register to be notified via a
 * callback function for events such as incoming data available, outgoing
 * data sent, error notifications, poll timer expiration, connection
 * closed, etc. An application can provide a callback function to perform
 * processing for any or all of these events. Each callback is an ordinary
 * C function that is called from within the TCP/IP code. Every callback
 * function is passed the current TCP or UDP connection state as an
 * argument. Also, in order to be able to keep program specific state,
 * the callback functions are called with a program specified argument
 * that is independent of the TCP/IP state.
 * The raw API (sometimes called native API) is an event-driven API designed
 * to be used without an operating system that implements zero-copy send and
 * receive. This API is also used by the core stack for interaction between
 * the various protocols. It is the only API available when running lwIP
 * without an operating system.
 * 
 * @defgroup sequential_api Sequential-style APIs
 * @ingroup api
 * Sequential-style APIs, blocking functions. More overhead, but can be called
 * from any thread except TCPIP thread.
 * The sequential API provides a way for ordinary, sequential, programs
 * to use the lwIP stack. It is quite similar to the BSD socket API. The
 * model of execution is based on the blocking open-read-write-close
 * paradigm. Since the TCP/IP stack is event based by nature, the TCP/IP
 * code and the application program must reside in different execution
 * contexts (threads).
 * 
 * @defgroup socket Socket API
 * @ingroup api
 * BSD-style socket API.\n
 * Thread-safe, to be called from non-TCPIP threads only.\n
 * Can be activated by defining @ref LWIP_SOCKET to 1.\n
 * Header is in posix/sys/socket.h\n
 * The socket API is a compatibility API for existing applications,
 * currently it is built on top of the sequential API. It is meant to
 * provide all functions needed to run socket API applications running
 * on other platforms (e.g. unix / windows etc.). However, due to limitations
 * in the specification of this API, there might be incompatibilities
 * that require small modifications of existing programs.
 * 
 * @defgroup netifs NETIFs
 * 
 * @defgroup apps Applications
 */
 /**
 * @mainpage Overview
 * @verbinclude "README"
 */
 /**
 * @page upgrading Upgrading
 * @verbinclude "UPGRADING"
 */
 /**
 * @page changelog Changelog
 *
 * 2.1.0
 * -----
 * * Support TLS via new @ref altcp_api connection API (https, smtps, mqtt over TLS)
 * * Switch to cmake as the main build system (Makefile file lists are still
 *   maintained for now)
 * * Improve IPv6 support: support address scopes, support stateless DHCPv6, bugfixes
 * * Add debug helper asserts to ensure threading/locking requirements are met
 * * Add sys_mbox_trypost_fromisr() and tcpip_callbackmsg_trycallback_fromisr()
 *   (for FreeRTOS, mainly)
 * * socket API: support poll(), sendmsg() and recvmsg(); fix problems on close
 * 
 * Detailed Changelog
 * ------------------
 * @verbinclude "CHANGELOG"
 */
 /**
 * @page contrib How to contribute to lwIP
 * @verbinclude "contrib.txt"
 */
 /**
 * @page pitfalls Common pitfalls
 *
 * Multiple Execution Contexts in lwIP code
 * ========================================
 *
 * The most common source of lwIP problems is to have multiple execution contexts
 * inside the lwIP code.
 * 
 * lwIP can be used in two basic modes: @ref lwip_nosys (no OS/RTOS 
 * running on target system) or @ref lwip_os (there is an OS running
 * on the target system).
 * 
 * See also: @ref multithreading (especially the part about @ref LWIP_ASSERT_CORE_LOCKED()!)
 *
 * Mainloop Mode
 * -------------
 * In mainloop mode, only @ref callbackstyle_api can be used.
 * The user has two possibilities to ensure there is only one 
 * exection context at a time in lwIP:
 *
 * 1) Deliver RX ethernet packets directly in interrupt context to lwIP
 *    by calling netif->input directly in interrupt. This implies all lwIP 
 *    callback functions are called in IRQ context, which may cause further
 *    problems in application code: IRQ is blocked for a long time, multiple
 *    execution contexts in application code etc. When the application wants
 *    to call lwIP, it only needs to disable interrupts during the call.
 *    If timers are involved, even more locking code is needed to lock out
 *    timer IRQ and ethernet IRQ from each other, assuming these may be nested.
 *
 * 2) Run lwIP in a mainloop. There is example code here: @ref lwip_nosys.
 *    lwIP is _ONLY_ called from mainloop callstacks here. The ethernet IRQ
 *    has to put received telegrams into a queue which is polled in the
 *    mainloop. Ensure lwIP is _NEVER_ called from an interrupt, e.g.
 *    some SPI IRQ wants to forward data to udp_send() or tcp_write()!
 *
 * OS Mode
 * -------
 * In OS mode, @ref callbackstyle_api AND @ref sequential_api can be used.
 * @ref sequential_api are designed to be called from threads other than
 * the TCPIP thread, so there is nothing to consider here.
 * But @ref callbackstyle_api functions must _ONLY_ be called from
 * TCPIP thread. It is a common error to call these from other threads
 * or from IRQ contexts. Ethernet RX needs to deliver incoming packets
 * in the correct way by sending a message to TCPIP thread, this is
 * implemented in tcpip_input().
 * Again, ensure lwIP is _NEVER_ called from an interrupt, e.g.
 * some SPI IRQ wants to forward data to udp_send() or tcp_write()!
 * 
 * 1) tcpip_callback() can be used get called back from TCPIP thread,
 *    it is safe to call any @ref callbackstyle_api from there.
 *
 * 2) Use @ref LWIP_TCPIP_CORE_LOCKING. All @ref callbackstyle_api
 *    functions can be called when lwIP core lock is aquired, see
 *    @ref LOCK_TCPIP_CORE() and @ref UNLOCK_TCPIP_CORE().
 *    These macros cannot be used in an interrupt context!
 *    Note the OS must correctly handle priority inversion for this.
 *
 * Cache / DMA issues
 * ==================
 *
 * DMA-capable ethernet hardware and zero-copy RX
 * ----------------------------------------------
 * 
 * lwIP changes the content of RECEIVED pbufs in the TCP code path.
 * This implies one or more cacheline(s) of the RX pbuf become dirty
 * and need to be flushed before the memory is handed over to the
 * DMA ethernet hardware for the next telegram to be received.
 * See http://lists.nongnu.org/archive/html/lwip-devel/2017-12/msg00070.html
 * for a more detailed explanation.
 * Also keep in mind the user application may also write into pbufs,
 * so it is generally a bug not to flush the data cache before handing
 * a buffer to DMA hardware.
 *
 * DMA-capable ethernet hardware and cacheline alignment
 * -----------------------------------------------------
 * Nice description about DMA capable hardware and buffer handling:
 * http://www.pebblebay.com/a-guide-to-using-direct-memory-access-in-embedded-systems-part-two/
 * Read especially sections "Cache coherency" and "Buffer alignment".
 */
 /**
 * @page bugs Reporting bugs
 * Please report bugs in the lwIP bug tracker at savannah.\n
 * BEFORE submitting, please check if the bug has already been reported!\n
 * https://savannah.nongnu.org/bugs/?group=lwip
 */
 /**
 * @page zerocopyrx Zero-copy RX
 * The following code is an example for zero-copy RX ethernet driver:
 * @include ZeroCopyRx.c
 */
 /**
 * @defgroup lwip_nosys Mainloop mode ("NO_SYS")
 * @ingroup lwip
 * Use this mode if you do not run an OS on your system. \#define NO_SYS to 1.
 * Feed incoming packets to netif->input(pbuf, netif) function from mainloop,
 * *not* *from* *interrupt* *context*. You can allocate a @ref pbuf in interrupt
 * context and put them into a queue which is processed from mainloop.\n
 * Call sys_check_timeouts() periodically in the mainloop.\n
 * Porting: implement all functions in @ref sys_time, @ref sys_prot and 
 * @ref compiler_abstraction.\n
 * You can only use @ref callbackstyle_api in this mode.\n
 * Sample code:\n
 * @include NO_SYS_SampleCode.c
 */
 /**
 * @defgroup lwip_os OS mode (TCPIP thread)
 * @ingroup lwip
 * Use this mode if you run an OS on your system. It is recommended to
 * use an RTOS that correctly handles priority inversion and
 * to use @ref LWIP_TCPIP_CORE_LOCKING.\n
 * Porting: implement all functions in @ref sys_layer.\n
 * You can use @ref callbackstyle_api together with @ref tcpip_callback,
 * and all @ref sequential_api.
 */
 /**
 * @page sys_init System initalization
 A truly complete and generic sequence for initializing the lwIP stack
 cannot be given because it depends on additional initializations for
 your runtime environment (e.g. timers).
 We can give you some idea on how to proceed when using the raw API.
 We assume a configuration using a single Ethernet netif and the
 UDP and TCP transport layers, IPv4 and the DHCP client.
 Call these functions in the order of appearance:
 - lwip_init(): Initialize the lwIP stack and all of its subsystems.
 - netif_add(struct netif *netif, ...):
  Adds your network interface to the netif_list. Allocate a struct
  netif and pass a pointer to this structure as the first argument.
  Give pointers to cleared ip_addr structures when using DHCP,
  or fill them with sane numbers otherwise. The state pointer may be NULL.
  The init function pointer must point to a initialization function for
  your Ethernet netif interface. The following code illustrates its use.
@code{.c}
  err_t netif_if_init(struct netif *netif)
  {
    u8_t i;
    for (i = 0; i < ETHARP_HWADDR_LEN; i++) {
      netif->hwaddr[i] = some_eth_addr[i];
    }
    init_my_eth_device();
    return ERR_OK;
  }
@endcode
  For Ethernet drivers, the input function pointer must point to the lwIP
  function ethernet_input() declared in "netif/etharp.h". Other drivers
  must use ip_input() declared in "lwip/ip.h".
 - netif_set_default(struct netif *netif)
  Registers the default network interface.
 - netif_set_link_up(struct netif *netif)
  This is the hardware link state; e.g. whether cable is plugged for wired
  Ethernet interface. This function must be called even if you don't know
  the current state. Having link up and link down events is optional but
  DHCP and IPv6 discover benefit well from those events.
 - netif_set_up(struct netif *netif)
  This is the administrative (= software) state of the netif, when the
  netif is fully configured this function must be called.
 - dhcp_start(struct netif *netif)
  Creates a new DHCP client for this interface on the first call.
  You can peek in the netif->dhcp struct for the actual DHCP status.
 - sys_check_timeouts()
  When the system is running, you have to periodically call
  sys_check_timeouts() which will handle all timers for all protocols in
  the stack; add this to your main loop or equivalent.
 */
 /**
 * @page multithreading Multithreading
 * lwIP started targeting single-threaded environments. When adding multi-
 * threading support, instead of making the core thread-safe, another
 * approach was chosen: there is one main thread running the lwIP core
 * (also known as the "tcpip_thread"). When running in a multithreaded
 * environment, raw API functions MUST only be called from the core thread
 * since raw API functions are not protected from concurrent access (aside
 * from pbuf- and memory management functions). Application threads using
 * the sequential- or socket API communicate with this main thread through
 * message passing.
 * 
 * As such, the list of functions that may be called from
 * other threads or an ISR is very limited! Only functions
 * from these API header files are thread-safe:
 * - api.h
 * - netbuf.h
 * - netdb.h
 * - netifapi.h
 * - pppapi.h
 * - sockets.h
 * - sys.h
 * 
 * Additionaly, memory (de-)allocation functions may be
 * called from multiple threads (not ISR!) with NO_SYS=0
 * since they are protected by @ref SYS_LIGHTWEIGHT_PROT and/or
 * semaphores.
 * 
 * Netconn or Socket API functions are thread safe against the
 * core thread but they are not reentrant at the control block
 * granularity level. That is, a UDP or TCP control block must
 * not be shared among multiple threads without proper locking.
 * 
 * If @ref SYS_LIGHTWEIGHT_PROT is set to 1 and
 * @ref LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT is set to 1,
 * pbuf_free() may also be called from another thread or
 * an ISR (since only then, mem_free - for PBUF_RAM - may
 * be called from an ISR: otherwise, the HEAP is only
 * protected by semaphores).
 * 
 * How to get threading done right
 * -------------------------------
 * 
 * It is strongly recommended to implement the LWIP_ASSERT_CORE_LOCKED()
 * macro in an application that uses multithreading. lwIP code has
 * several places where a check for a correct thread context is
 * implemented which greatly helps the user to get threading done right.
 * See the example sys_arch.c files in unix and Win32 port 
 * in the contrib repository.
 * 
 * In short: Copy the functions sys_mark_tcpip_thread() and 
 * sys_check_core_locking() to your port and modify them to work with your OS.
 * Then let @ref LWIP_ASSERT_CORE_LOCKED() and @ref LWIP_MARK_TCPIP_THREAD()
 * point to these functions.
 * 
 * If you use @ref LWIP_TCPIP_CORE_LOCKING, you also need to copy and adapt
 * the functions sys_lock_tcpip_core() and sys_unlock_tcpip_core().
 * Let @ref LOCK_TCPIP_CORE() and @ref UNLOCK_TCPIP_CORE() point 
 * to these functions. 
 */
 /**
 * @page optimization Optimization hints
 The first thing you want to optimize is the lwip_standard_checksum()
 routine from src/core/inet.c. You can override this standard
 function with the \#define LWIP_CHKSUM your_checksum_routine().
 There are C examples given in inet.c or you might want to
 craft an assembly function for this. RFC1071 is a good
 introduction to this subject.
 Other significant improvements can be made by supplying
 assembly or inline replacements for htons() and htonl()
 if you're using a little-endian architecture.
 \#define lwip_htons(x) your_htons()
 \#define lwip_htonl(x) your_htonl()
 If you \#define them to htons() and htonl(), you should
 \#define LWIP_DONT_PROVIDE_BYTEORDER_FUNCTIONS to prevent lwIP from
 defining htonx / ntohx compatibility macros.
 Check your network interface driver if it reads at
 a higher speed than the maximum wire-speed. If the
 hardware isn't serviced frequently and fast enough
 buffer overflows are likely to occur.
 E.g. when using the cs8900 driver, call cs8900if_service(ethif)
 as frequently as possible. When using an RTOS let the cs8900 interrupt
 wake a high priority task that services your driver using a binary
 semaphore or event flag. Some drivers might allow additional tuning
 to match your application and network.
 For a production release it is recommended to set LWIP_STATS to 0.
 Note that speed performance isn't influenced much by simply setting
 high values to the memory options.
 */
@@ -1,10 +0,0 @@
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>Redirection</title>
  <meta http-equiv="refresh" content="0; url=html/index.html" />
 </head>
 <body>
  <a href="html/index.html">index.html</a>
 </body>
 </html>
@@ -1,112 +0,0 @@
 Multicast DNS for lwIP
 Author: Erik Ekman
 Note! The MDNS responder does not have all features required by the standards.
 See notes in src/apps/mdns/mdns.c for what is left. It is however usable in normal
 cases - but watch out if many devices on the same network try to use the same
 host/service instance names.
 How to enable:
 ==============
 MDNS support does not depend on DNS.
 MDNS supports using IPv4 only, v6 only, or v4+v6.
 To enable MDNS responder, set
  LWIP_MDNS_RESPONDER = 1
 in lwipopts.h and add src/apps/mdns/mdns.c to your list of files to build.
 The max number of services supported per netif is defined by MDNS_MAX_SERVICES,
 default is 1.
 Increase MEMP_NUM_UDP_PCB by 1. MDNS needs one PCB.
 Increase LWIP_NUM_NETIF_CLIENT_DATA by 1 (MDNS needs one entry on netif).
 MDNS with IPv4 requires LWIP_IGMP = 1, and preferably LWIP_AUTOIP = 1.
 MDNS with IPv6 requires LWIP_IPV6_MLD = 1, and that a link-local address is
 generated.
 The MDNS code puts its structs on the stack where suitable to reduce dynamic
 memory allocation. It may use up to 1kB of stack.
 MDNS (like other apps) needs a strncasecmp() implementation. If you have one, define
 'lwip_strnicmp' to it. Otherwise the code will provide an implementation
 for you.
 How to use:
 ===========
 Call mdns_resp_init() during system initialization.
 This opens UDP sockets on port 5353 for IPv4 and IPv6.
 To start responding on a netif, run
  mdns_resp_add_netif(struct netif *netif, char *hostname, u32_t dns_ttl)
 The hostname will be copied. If this returns successfully, the netif will join
 the multicast groups and any MDNS/legacy DNS requests sent unicast or multicast
 to port 5353 will be handled:
 - <hostname>.local type A, AAAA or ANY returns relevant IP addresses
 - Reverse lookups (PTR in-addr.arpa, ip6.arpa) of netif addresses
  returns <hostname>.local
 Answers will use the supplied TTL (in seconds)
 MDNS allows UTF-8 names, but it is recommended to stay within ASCII,
 since the default case-insensitive comparison assumes this.
 Call mdns_resp_announce() every time the IP address on the netif has changed.
 Call mdns_resp_restart() every time the network interface comes up after being
 down, for example cable connected after being disconnected, administrative 
 interface comes up after being down, or the device wakes up from sleep.
 To stop responding on a netif, run
  mdns_resp_remove_netif(struct netif *netif)
 Adding services:
 ================
 The netif first needs to be registered. Then run
  mdns_resp_add_service(struct netif *netif, char *name, char *service,
      u16_t proto, u16_t port, u32_t dns_ttl,
      service_get_txt_fn_t txt_fn, void *txt_userdata);
 The name and service pointers will be copied. Name refers to the name of the
 service instance, and service is the type of service, like _http
 proto can be DNSSD_PROTO_UDP or DNSSD_PROTO_TCP which represent _udp and _tcp.
 If this call returns successfully, the following queries will be answered:
 - _services._dns-sd._udp.local type PTR returns <service>.<proto>.local
 - <service>.<proto>.local type PTR returns <name>.<service>.<proto>.local
 - <name>.<service>.<proto>.local type SRV returns hostname and port of service
 - <name>.<service>.<proto>.local type TXT builds text strings by calling txt_fn
  with the supplied userdata. The callback adds strings to the reply by calling
  mdns_resp_add_service_txtitem(struct mdns_service *service, char *txt,
   int txt_len). Example callback method:
   static void srv_txt(struct mdns_service *service, void *txt_userdata)
   {
     res = mdns_resp_add_service_txtitem(service, "path=/", 6);
     LWIP_ERROR("mdns add service txt failed\n", (res == ERR_OK), return);
   }
  Since a hostname struct is used for TXT storage each single item can be max
  63 bytes long, and  the total max length (including length bytes for each
  item) is 255 bytes.
 If your device runs a webserver on port 80, an example call might be:
  mdns_resp_add_service(netif, "myweb", "_http"
      DNSSD_PROTO_TCP, 80, 3600, srv_txt, NULL);
 which will publish myweb._http._tcp.local for any hosts looking for web servers,
 and point them to <hostname>.local:80
 Relevant information will be sent as additional records to reduce number of
 requests required from a client.
 To remove a service from a netif, run
  mdns_resp_del_service(struct netif *netif, s8_t slot)
@@ -1,162 +0,0 @@
 MQTT client for lwIP
 Author: Erik Andersson
 Details of the MQTT protocol can be found at:
 http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html 
 -----------------------------------------------------------------
 1. Initial steps, reserve memory and make connection to server:
 1.1: Provide storage
 Static allocation:
  mqtt_client_t static_client;
  example_do_connect(&static_client);
 Dynamic allocation:
  mqtt_client_t *client = mqtt_client_new();
  if(client != NULL) {
    example_do_connect(&client);
  }
 1.2: Establish Connection with server
 void example_do_connect(mqtt_client_t *client)
 {
  struct mqtt_connect_client_info_t ci;
  err_t err;
  /* Setup an empty client info structure */
  memset(&ci, 0, sizeof(ci));
  /* Minimal amount of information required is client identifier, so set it here */ 
  ci.client_id = "lwip_test";
  /* Initiate client and connect to server, if this fails immediately an error code is returned
     otherwise mqtt_connection_cb will be called with connection result after attempting 
     to establish a connection with the server. 
     For now MQTT version 3.1.1 is always used */
  err = mqtt_client_connect(client, ip_addr, MQTT_PORT, mqtt_connection_cb, 0, &ci);
  /* For now just print the result code if something goes wrong */
  if(err != ERR_OK) {
    printf("mqtt_connect return %d\n", err);
  }
 }
 Connection to server can also be probed by calling mqtt_client_is_connected(client) 
 -----------------------------------------------------------------
 2. Implementing the connection status callback
 static void mqtt_connection_cb(mqtt_client_t *client, void *arg, mqtt_connection_status_t status)
 {
  err_t err;
  if(status == MQTT_CONNECT_ACCEPTED) {
    printf("mqtt_connection_cb: Successfully connected\n");
    /* Setup callback for incoming publish requests */
    mqtt_set_inpub_callback(client, mqtt_incoming_publish_cb, mqtt_incoming_data_cb, arg);
    /* Subscribe to a topic named "subtopic" with QoS level 1, call mqtt_sub_request_cb with result */ 
    err = mqtt_subscribe(client, "subtopic", 1, mqtt_sub_request_cb, arg);
    if(err != ERR_OK) {
      printf("mqtt_subscribe return: %d\n", err);
    }
  } else {
    printf("mqtt_connection_cb: Disconnected, reason: %d\n", status);
    /* Its more nice to be connected, so try to reconnect */
    example_do_connect(client);
  }  
 }
 static void mqtt_sub_request_cb(void *arg, err_t result)
 {
  /* Just print the result code here for simplicity, 
     normal behaviour would be to take some action if subscribe fails like 
     notifying user, retry subscribe or disconnect from server */
  printf("Subscribe result: %d\n", result);
 }
 -----------------------------------------------------------------
 3. Implementing callbacks for incoming publish and data
 /* The idea is to demultiplex topic and create some reference to be used in data callbacks
   Example here uses a global variable, better would be to use a member in arg
   If RAM and CPU budget allows it, the easiest implementation might be to just take a copy of
   the topic string and use it in mqtt_incoming_data_cb
 */
 static int inpub_id;
 static void mqtt_incoming_publish_cb(void *arg, const char *topic, u32_t tot_len)
 {
  printf("Incoming publish at topic %s with total length %u\n", topic, (unsigned int)tot_len);
  /* Decode topic string into a user defined reference */
  if(strcmp(topic, "print_payload") == 0) {
    inpub_id = 0;
  } else if(topic[0] == 'A') {
    /* All topics starting with 'A' might be handled at the same way */
    inpub_id = 1;
  } else {
    /* For all other topics */
    inpub_id = 2;
  }
 }
 static void mqtt_incoming_data_cb(void *arg, const u8_t *data, u16_t len, u8_t flags)
 {
  printf("Incoming publish payload with length %d, flags %u\n", len, (unsigned int)flags);
  if(flags & MQTT_DATA_FLAG_LAST) {
    /* Last fragment of payload received (or whole part if payload fits receive buffer
       See MQTT_VAR_HEADER_BUFFER_LEN)  */
    /* Call function or do action depending on reference, in this case inpub_id */
    if(inpub_id == 0) {
      /* Don't trust the publisher, check zero termination */
      if(data[len-1] == 0) {
        printf("mqtt_incoming_data_cb: %s\n", (const char *)data);
      }
    } else if(inpub_id == 1) {
      /* Call an 'A' function... */
    } else {
      printf("mqtt_incoming_data_cb: Ignoring payload...\n");
    }
  } else {
    /* Handle fragmented payload, store in buffer, write to file or whatever */
  }
 }
 -----------------------------------------------------------------
 4. Using outgoing publish
 void example_publish(mqtt_client_t *client, void *arg)
 {
  const char *pub_payload= "PubSubHubLubJub";
  err_t err;
  u8_t qos = 2; /* 0 1 or 2, see MQTT specification */
  u8_t retain = 0; /* No don't retain such crappy payload... */
  err = mqtt_publish(client, "pub_topic", pub_payload, strlen(pub_payload), qos, retain, mqtt_pub_request_cb, arg);
  if(err != ERR_OK) {
    printf("Publish err: %d\n", err);
  }
 }
 /* Called when publish is complete either with sucess or failure */
 static void mqtt_pub_request_cb(void *arg, err_t result)
 {
  if(result != ERR_OK) {
    printf("Publish result: %d\n", result);
  }
 }
 -----------------------------------------------------------------
 5. Disconnecting
 Simply call mqtt_disconnect(client)
@@ -1,120 +0,0 @@
 Daily Use Guide for using Savannah for lwIP
 Table of Contents:
 1 - Obtaining lwIP from the Git repository
 2 - Committers/developers Git access using SSH
 3 - Merging a development branch to master branch
 4 - How to release lwIP
 1 Obtaining lwIP from the Git repository
 ----------------------------------------
 To perform an anonymous Git clone of the master branch (this is where
 bug fixes and incremental enhancements occur), do this:
 git clone git://git.savannah.nongnu.org/lwip.git
 Or, obtain a stable branch (updated with bug fixes only) as follows:
 git clone --branch DEVEL-1_4_1 git://git.savannah.nongnu.org/lwip.git
 Or, obtain a specific (fixed) release as follows:
 git clone --branch STABLE-1_4_1 git://git.savannah.nongnu.org/lwip.git
 2 Committers/developers Git access using SSH
 --------------------------------------------
 The Savannah server uses SSH (Secure Shell) protocol 2 authentication and encryption.
 As such, Git commits to the server occur through a SSH tunnel for project members.
 To create a SSH2 key pair in UNIX-like environments, do this:
 ssh-keygen
 Under Windows, a recommended SSH client is "PuTTY", freely available with good
 documentation and a graphic user interface. Use its key generator.
 Now paste the id_rsa.pub contents into your Savannah account public key list. Wait
 a while so that Savannah can update its configuration (This can take minutes).
 Try to login using SSH:
 ssh -v your_login@git.sv.gnu.org
 If it tells you:
 Linux vcs.savannah.gnu.org 2.6.32-5-xen-686 #1 SMP Wed Jun 17 17:10:03 UTC 2015 i686
 Interactive shell login is not possible for security reasons.
 VCS commands are allowed.
 Last login: Tue May 15 23:10:12 2012 from 82.245.102.129
 You tried to execute:
 Sorry, you are not allowed to execute that command.
 Shared connection to git.sv.gnu.org closed.
 then you could login; Savannah refuses to give you a shell - which is OK, as we
 are allowed to use SSH for Git only. Now, you should be able to do this:
 git clone your_login@git.sv.gnu.org:/srv/git/lwip.git
 After which you can edit your local files with bug fixes or new features and
 commit them. Make sure you know what you are doing when using Git to make
 changes on the repository. If in doubt, ask on the lwip-members mailing list.
 (If SSH asks about authenticity of the host, you can check the key
 fingerprint against https://savannah.nongnu.org/git/?group=lwip
 3 - Merging a development branch to master branch
 -------------------------------------------------
 Merging is a straightforward process in Git. How to merge all changes in a
 development branch since our last merge from main:
 Checkout the master branch:
 git checkout master
 Merge the development branch to master:
 git merge your-development-branch
 Resolve any conflict.
 Commit the merge result.
 git commit -a
 Push your commits:
 git push
 4 How to release lwIP
 ---------------------
 First, tag the release using Git: (I use release number 1.4.1 throughout
 this example).
 git tag -a STABLE-1_4_1
 Share the tag reference by pushing it to remote:
 git push origin STABLE-1_4_1
 Prepare the release:
 cp -r lwip lwip-1.4.1
 rm -rf lwip-1.4.1/.git lwip-1.4.1/.gitattributes
 Archive the current directory using tar, gzip'd, bzip2'd and zip'd.
 tar czvf lwip-1.4.1.tar.gz lwip-1.4.1
 tar cjvf lwip-1.4.1.tar.bz2 lwip-1.4.1
 zip -r lwip-1.4.1.zip lwip-1.4.1
 Now, sign the archives with a detached GPG binary signature as follows:
 gpg -b lwip-1.4.1.tar.gz
 gpg -b lwip-1.4.1.tar.bz2
 gpg -b lwip-1.4.1.zip
 Upload these files using anonymous FTP:
 ncftp ftp://savannah.gnu.org/incoming/savannah/lwip
 ncftp> mput *1.4.1.*
 Additionally, you may post a news item on Savannah, like this:
 A new 1.4.1 release is now available here:
 http://savannah.nongnu.org/files/?group=lwip&highlight=1.4.1
 You will have to submit this via the user News interface, then approve
 this via the Administrator News interface.