working on lwip

CMakeLists.txt

@@ -34,9 +34,7 @@ endif()
 add_executable(${OBSW_NAME})
 
 # export lwip path, so the bsp can find it
-if(${CMAKE_CROSSCOMPILING})
 set (LWIP_DIR ${CMAKE_CURRENT_SOURCE_DIR}/contrib/lwip)
-endif()
 
 # Platform dependend configuration
 # Includes setting the FreeRTOS port, compiler options and

bsp_linux/CMakeLists.txt

@@ -1,8 +1,12 @@
 add_library(bsp STATIC)
 
 add_subdirectory(hardware)
+add_subdirectory(lwip)
 
 target_sources(bsp PRIVATE main.c)
 
 # bsp depends on FreeRTOS
 target_link_libraries(bsp PUBLIC freertos_kernel)
+
+# export lwip as part of bsp
+target_link_libraries(bsp INTERFACE lwip)

bsp_linux/lwip/CMakeLists.txt

@@ -0,0 +1,22 @@
+# LWIP_DIR should point to the lwip source, to be set in main CMakeLists.txt
+include(${LWIP_DIR}/src/Filelists.cmake)
+
+set (LWIP_INCLUDE_DIRS
+    "${LWIP_DIR}/src/include"
+    "${LWIP_DIR}/src/include/compat/posix"
+    "include"
+)
+
+set(lwip_SRCS
+    ${lwipcore_SRCS}
+    ${lwipcore4_SRCS}
+    ${lwipcore6_SRCS}
+    ${lwipnetif_SRCS}
+    ${lwipapi_SRCS}
+    #${LWIP_DIR}/contrib/ports/freertos/sys_arch.c
+    #${LWIP_DIR}/src/netif/slipif.c
+    #${LWIP_DIR}/src/apps/tftp/tftp.c
+)
+
+add_library(lwip ${lwip_SRCS})
+target_include_directories(lwip PUBLIC ${LWIP_INCLUDE_DIRS})

bsp_linux/lwip/include/arch/cc.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "lwipopts.h"
+
+/** if you want to use the struct timeval provided
+ * by your system, set this to 0 and include <sys/time.h> in cc.h */
+#define LWIP_TIMEVAL_PRIVATE 0
+#include <sys/time.h>
+
+// errno is a macro. If we define LWIP_ERRNO_INCLUDE to errno.h the preprocessor will replace it,
+// breaking the include. Instead we supply a helper include which in turn includes errno.h
+#define LWIP_ERRNO_INCLUDE <onrre.h>
+
+#define LWIP_RAND rand
+
+#define PACK_STRUCT_FIELD(x) x
+#define PACK_STRUCT_STRUCT __attribute__((packed))
+#define PACK_STRUCT_BEGIN
+#define PACK_STRUCT_END
+
+#define LWIP_PLATFORM_ASSERT(x)
+#define LWIP_PLATFORM_DIAG(x) do { printf x; } while(0)

bsp_linux/lwip/include/lwipopts.h

@@ -0,0 +1,336 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+#ifndef LWIP_LWIPOPTS_H
+#define LWIP_LWIPOPTS_H
+
+#define LWIP_IPV4                  1
+#define LWIP_IPV6                  0
+
+#define NO_SYS                     1
+#define LWIP_SOCKET                0
+#define LWIP_NETCONN               0
+#define LWIP_NETIF_API             0
+
+#define LWIP_IGMP                  0
+#define LWIP_ICMP                  LWIP_IPV4
+
+#define LWIP_SNMP                  0
+//#define MIB2_STATS                 LWIP_SNMP
+#ifdef LWIP_HAVE_MBEDTLS
+#define LWIP_SNMP_V3               (LWIP_SNMP)
+#endif
+
+#define LWIP_DNS                   0
+#define LWIP_MDNS_RESPONDER        0
+
+#define LWIP_NUM_NETIF_CLIENT_DATA (LWIP_MDNS_RESPONDER)
+
+#define LWIP_HAVE_LOOPIF           0
+#define LWIP_NETIF_LOOPBACK        0
+#define LWIP_LOOPBACK_MAX_PBUFS    0
+
+#define TCP_LISTEN_BACKLOG         0
+
+#define LWIP_COMPAT_SOCKETS         0
+//TODO put this into the OS
+#define LWIP_POSIX_SOCKETS_IO_NAMES 0
+#define LWIP_SO_RCVTIMEO            0
+#define LWIP_SO_RCVBUF              0
+//TODO use this with LWIP_POSIX_SOCKETS_IO_NAMES
+// TODO why is 100 not working...
+#define LWIP_SOCKET_OFFSET          10
+
+#define LWIP_SOCKET_SELECT          0
+#define LWIP_SOCKET_POLL            0
+
+#define LWIP_TCPIP_CORE_LOCKING    0
+
+#define LWIP_NETIF_LINK_CALLBACK        1
+#define LWIP_NETIF_STATUS_CALLBACK      1
+#define LWIP_NETIF_EXT_STATUS_CALLBACK  1
+
+//#define LWIP_DEBUG
+
+#ifdef LWIP_DEBUG
+
+#define LWIP_DBG_MIN_LEVEL         LWIP_DBG_LEVEL_ALL
+#define PPP_DEBUG                  LWIP_DBG_OFF
+#define MEM_DEBUG                  LWIP_DBG_OFF
+#define MEMP_DEBUG                 LWIP_DBG_OFF
+#define PBUF_DEBUG                 LWIP_DBG_ON
+#define API_LIB_DEBUG              LWIP_DBG_ON
+#define API_MSG_DEBUG              LWIP_DBG_ON
+#define TCPIP_DEBUG                LWIP_DBG_ON
+#define NETIF_DEBUG                LWIP_DBG_ON
+#define SOCKETS_DEBUG              LWIP_DBG_ON
+#define DNS_DEBUG                  LWIP_DBG_ON
+#define AUTOIP_DEBUG               LWIP_DBG_ON
+#define DHCP_DEBUG                 LWIP_DBG_ON
+#define IP_DEBUG                   LWIP_DBG_ON
+#define IP_REASS_DEBUG             LWIP_DBG_ON
+#define ICMP_DEBUG                 LWIP_DBG_ON
+#define IGMP_DEBUG                 LWIP_DBG_ON
+#define UDP_DEBUG                  LWIP_DBG_ON
+#define TCP_DEBUG                  LWIP_DBG_OFF
+#define TCP_INPUT_DEBUG            LWIP_DBG_OFF
+#define TCP_OUTPUT_DEBUG           LWIP_DBG_OFF
+#define TCP_RTO_DEBUG              LWIP_DBG_OFF
+#define TCP_CWND_DEBUG             LWIP_DBG_OFF
+#define TCP_WND_DEBUG              LWIP_DBG_OFF
+#define TCP_FR_DEBUG               LWIP_DBG_OFF
+#define TCP_QLEN_DEBUG             LWIP_DBG_OFF
+#define TCP_RST_DEBUG              LWIP_DBG_OFF
+#define TIMERS_DEBUG               LWIP_DBG_OFF
+#define LWIP_DEBUG_TIMERNAMES      LWIP_DBG_OFF
+#endif
+
+#define LWIP_DBG_TYPES_ON         (LWIP_DBG_ON|LWIP_DBG_TRACE|LWIP_DBG_STATE|LWIP_DBG_FRESH|LWIP_DBG_HALT)
+
+
+/* ---------- Memory options ---------- */
+/* MEM_ALIGNMENT: should be set to the alignment of the CPU for which
+   lwIP is compiled. 4 byte alignment -> define MEM_ALIGNMENT to 4, 2
+   byte alignment -> define MEM_ALIGNMENT to 2. */
+/* MSVC port: intel processors don't need 4-byte alignment,
+   but are faster that way! */
+   //TODO documentation
+   //Zynq needs 32 for DMA to work (something about cache I guess...)
+#define MEM_ALIGNMENT           32U
+
+#define MEM_USE_POOLS 1
+#define MEMP_USE_CUSTOM_POOLS MEM_USE_POOLS
+
+/* MEM_SIZE: the size of the heap memory. If the application will send
+a lot of data that needs to be copied, this should be set high. */
+#define MEM_SIZE               102400
+
+/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
+   sends a lot of data out of ROM (or other static memory), this
+   should be set high. */
+#define MEMP_NUM_PBUF           16
+/* MEMP_NUM_RAW_PCB: the number of UDP protocol control blocks. One
+   per active RAW "connection". */
+#define MEMP_NUM_RAW_PCB        0
+/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
+   per active UDP "connection". */
+#define MEMP_NUM_UDP_PCB        8
+/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
+   connections. */
+#define MEMP_NUM_TCP_PCB        0
+/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
+   connections. */
+#define MEMP_NUM_TCP_PCB_LISTEN 0
+/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
+   segments. */
+#define MEMP_NUM_TCP_SEG        0
+/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
+   timeouts. */
+#define MEMP_NUM_SYS_TIMEOUT    17
+
+/* The following four are used only with the sequential API and can be
+   set to 0 if the application only will use the raw API. */
+/* MEMP_NUM_NETBUF: the number of struct netbufs. */
+#define MEMP_NUM_NETBUF         0
+/* MEMP_NUM_NETCONN: the number of struct netconns. */
+#define MEMP_NUM_NETCONN        0
+/* MEMP_NUM_TCPIP_MSG_*: the number of struct tcpip_msg, which is used
+   for sequential API communication and incoming packets. Used in
+   src/api/tcpip.c. */
+#define MEMP_NUM_TCPIP_MSG_API   0
+#define MEMP_NUM_TCPIP_MSG_INPKT 0
+
+#define TCPIP_THREAD_STACKSIZE          10240
+
+
+/* ---------- Pbuf options ---------- */
+/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */
+#define PBUF_POOL_SIZE          120
+
+/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */
+/* Needs to be large enough to fit eth MTU to be able to use DMA for xemacps rx*/
+#define PBUF_POOL_BUFSIZE       1600
+
+/** SYS_LIGHTWEIGHT_PROT
+ * define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection
+ * for certain critical regions during buffer allocation, deallocation and memory
+ * allocation and deallocation.
+ */
+#define SYS_LIGHTWEIGHT_PROT    0
+
+
+/* ---------- TCP options ---------- */
+#define LWIP_TCP                0
+#define TCP_TTL                 255
+
+#define LWIP_ALTCP              (LWIP_TCP)
+#ifdef LWIP_HAVE_MBEDTLS
+#define LWIP_ALTCP_TLS          (LWIP_TCP)
+#define LWIP_ALTCP_TLS_MBEDTLS  (LWIP_TCP)
+#endif
+
+
+/* Controls if TCP should queue segments that arrive out of
+   order. Define to 0 if your device is low on memory. */
+#define TCP_QUEUE_OOSEQ         1
+
+/* TCP Maximum segment size. */
+#define TCP_MSS                 1024
+
+/* TCP sender buffer space (bytes). */
+#define TCP_SND_BUF             2048
+
+/* TCP sender buffer space (pbufs). This must be at least = 2 *
+   TCP_SND_BUF/TCP_MSS for things to work. */
+#define TCP_SND_QUEUELEN       (4 * TCP_SND_BUF/TCP_MSS)
+
+/* TCP writable space (bytes). This must be less than or equal
+   to TCP_SND_BUF. It is the amount of space which must be
+   available in the tcp snd_buf for select to return writable */
+#define TCP_SNDLOWAT           (TCP_SND_BUF/2)
+
+/* TCP receive window. */
+#define TCP_WND                 (20 * 1024)
+
+/* Maximum number of retransmissions of data segments. */
+#define TCP_MAXRTX              12
+
+/* Maximum number of retransmissions of SYN segments. */
+#define TCP_SYNMAXRTX           4
+
+
+#define TCPIP_MBOX_SIZE                 5
+
+/* ---------- ARP options ---------- */
+#define LWIP_ARP                1
+#define ARP_TABLE_SIZE          10
+#define ARP_QUEUEING            1
+#define ARP_QUEUE_LEN         10
+
+
+/* ---------- IP options ---------- */
+/* Define IP_FORWARD to 1 if you wish to have the ability to forward
+   IP packets across network interfaces. If you are going to run lwIP
+   on a device with only one network interface, define this to 0. */
+#define IP_FORWARD              1
+
+/* IP reassembly and segmentation.These are orthogonal even
+ * if they both deal with IP fragments */
+#define IP_REASSEMBLY           1
+#define IP_REASS_MAX_PBUFS      (10 * ((1500 + PBUF_POOL_BUFSIZE - 1) / PBUF_POOL_BUFSIZE))
+#define MEMP_NUM_REASSDATA      IP_REASS_MAX_PBUFS
+#define IP_FRAG                 1
+#define IPV6_FRAG_COPYHEADER    1
+
+/* ---------- ICMP options ---------- */
+#define ICMP_TTL                255
+
+
+/* ---------- DHCP options ---------- */
+/* Define LWIP_DHCP to 1 if you want DHCP configuration of
+   interfaces. */
+#define LWIP_DHCP               0
+
+/* 1 if you want to do an ARP check on the offered address
+   (recommended). */
+#define DHCP_DOES_ARP_CHECK    (LWIP_DHCP)
+
+
+/* ---------- AUTOIP options ------- */
+#define LWIP_AUTOIP            (LWIP_DHCP)
+#define LWIP_DHCP_AUTOIP_COOP  (LWIP_DHCP && LWIP_AUTOIP)
+
+
+/* ---------- UDP options ---------- */
+#define LWIP_UDP                1
+#define LWIP_UDPLITE            0
+#define UDP_TTL                 255
+#define DEFAULT_UDP_RECVMBOX_SIZE       4
+
+/* ---------- RAW options ---------- */
+#define LWIP_RAW                0
+#define DEFAULT_TCP_RECVMBOX_SIZE       2
+
+/* ---------- Statistics options ---------- */
+
+#define LWIP_STATS              0
+#define LWIP_STATS_DISPLAY      0
+
+#if LWIP_STATS
+#define LINK_STATS              1
+#define IP_STATS                1
+#define ICMP_STATS              1
+#define IGMP_STATS              1
+#define IPFRAG_STATS            1
+#define UDP_STATS               1
+#define TCP_STATS               1
+#define MEM_STATS               1
+#define MEMP_STATS              1
+#define PBUF_STATS              1
+#define SYS_STATS               1
+#endif /* LWIP_STATS */
+
+/* ---------- NETBIOS options ---------- */
+#define LWIP_NETBIOS_RESPOND_NAME_QUERY 0
+
+/* ---------- PPP options ---------- */
+
+#define PPP_SUPPORT             0      /* Set > 0 for PPP */
+
+#if PPP_SUPPORT
+
+#define NUM_PPP                 1      /* Max PPP sessions. */
+
+
+/* Select modules to enable.  Ideally these would be set in the makefile but
+ * we're limited by the command line length so you need to modify the settings
+ * in this file.
+ */
+#define PPPOE_SUPPORT           1
+#define PPPOS_SUPPORT           1
+
+#define PAP_SUPPORT             1      /* Set > 0 for PAP. */
+#define CHAP_SUPPORT            1      /* Set > 0 for CHAP. */
+#define MSCHAP_SUPPORT          0      /* Set > 0 for MSCHAP */
+#define CBCP_SUPPORT            0      /* Set > 0 for CBCP (NOT FUNCTIONAL!) */
+#define CCP_SUPPORT             0      /* Set > 0 for CCP */
+#define VJ_SUPPORT              0      /* Set > 0 for VJ header compression. */
+#define MD5_SUPPORT             1      /* Set > 0 for MD5 (see also CHAP) */
+
+#endif /* PPP_SUPPORT */
+
+
+// Disable slip task
+#define SLIP_USE_RX_THREAD 0
+
+
+
+#endif /* LWIP_LWIPOPTS_H */

bsp_linux/lwip/include/lwippools.h

@@ -0,0 +1,5 @@
+LWIP_MALLOC_MEMPOOL_START
+LWIP_MALLOC_MEMPOOL(50, 256)
+LWIP_MALLOC_MEMPOOL(50, 512)
+LWIP_MALLOC_MEMPOOL(50, 1550)
+LWIP_MALLOC_MEMPOOL_END

bsp_linux/lwip/include/onrre.h

@@ -0,0 +1,2 @@
+#pragma once
+#include <errno.h>

bsp_z7/lwip/bare/include/lwipopts.h

@@ -139,19 +139,19 @@ a lot of data that needs to be copied, this should be set high. */
 #define MEMP_NUM_PBUF           16
 /* MEMP_NUM_RAW_PCB: the number of UDP protocol control blocks. One
    per active RAW "connection". */
-#define MEMP_NUM_RAW_PCB        3
+#define MEMP_NUM_RAW_PCB        0
 /* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
    per active UDP "connection". */
 #define MEMP_NUM_UDP_PCB        8
 /* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
    connections. */
-#define MEMP_NUM_TCP_PCB        5
+#define MEMP_NUM_TCP_PCB        0
 /* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
    connections. */
-#define MEMP_NUM_TCP_PCB_LISTEN 8
+#define MEMP_NUM_TCP_PCB_LISTEN 0
 /* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
    segments. */
-#define MEMP_NUM_TCP_SEG        16
+#define MEMP_NUM_TCP_SEG        0
 /* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
    timeouts. */
 #define MEMP_NUM_SYS_TIMEOUT    17
@@ -159,14 +159,14 @@ a lot of data that needs to be copied, this should be set high. */
 /* The following four are used only with the sequential API and can be
    set to 0 if the application only will use the raw API. */
 /* MEMP_NUM_NETBUF: the number of struct netbufs. */
-#define MEMP_NUM_NETBUF         2
+#define MEMP_NUM_NETBUF         0
 /* MEMP_NUM_NETCONN: the number of struct netconns. */
-#define MEMP_NUM_NETCONN        12
+#define MEMP_NUM_NETCONN        0
 /* MEMP_NUM_TCPIP_MSG_*: the number of struct tcpip_msg, which is used
    for sequential API communication and incoming packets. Used in
    src/api/tcpip.c. */
-#define MEMP_NUM_TCPIP_MSG_API   16
+#define MEMP_NUM_TCPIP_MSG_API   0
-#define MEMP_NUM_TCPIP_MSG_INPKT 16
+#define MEMP_NUM_TCPIP_MSG_INPKT 0
 
 #define TCPIP_THREAD_STACKSIZE          10240
 

mission/CMakeLists.txt

@@ -3,4 +3,6 @@
 # adds directly to the OBSW target
 ################################################
 
+add_subdirectory(netif)
+
 target_sources(${OBSW_NAME} PRIVATE mission.c freeRTOS_rust_helper.c)

mission/mission.c

@@ -7,6 +7,13 @@
 #include "semphr.h"
 #include "task.h"
 
+#include "lwip/init.h"
+#include "lwip/timeouts.h"
+#include "lwip/udp.h"
+#include <lwip/ip_addr.h>
+#include <lwip/netif.h>
+#include "netif/slipif.h"
+
 void rust_main();
 
 #include <hardware/interfaces.h>
@@ -39,15 +46,62 @@ void test_hardware() {
   write(1, buffer, read_bytes);
 }
 
+
+struct netif netif;
+struct slipif_priv slipif_config;
+static struct udp_pcb *udpecho_raw_pcb;
+
+u32_t sys_now(void) { return xTaskGetTickCount() * portTICK_PERIOD_MS; }
+
+void test_lwip() {
+  lwip_init();
+
+  ip4_addr_t slip_addr = {PP_HTONL(LWIP_MAKEU32(10, 13, 80, 10))},
+             slip_mask = {PP_HTONL(LWIP_MAKEU32(255, 255, 255, 0))},
+             slip_gw = {PP_HTONL(LWIP_MAKEU32(10, 13, 80, 1))};
+
+  slipif_config.fd = hw_device_open("uart1", 5);
+
+  netif_add(&netif, &slip_addr, &slip_mask, &slip_gw, &slipif_config, slipif_init,
+            netif_input);
+
+  netif_set_default(&netif);
+  // should be done by driver, which does not do it, so we do it here
+  netif_set_link_up(&netif);
+  netif_set_up(&netif);
+
+  udpecho_raw_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
+  if (udpecho_raw_pcb != NULL) {
+    err_t err;
+
+    err = udp_bind(udpecho_raw_pcb, IP_ANY_TYPE, 7);
+    if (err != ERR_OK) {
+      return;
+    }
+
+    ip_addr_t addr  = IPADDR4_INIT_BYTES(10,13,80,1);
+
+    uint8_t data[] = {'1','2','3','4'};
+
+    struct pbuf* tx = pbuf_alloc_reference(data, sizeof(data), PBUF_REF);
+
+    udp_sendto(udpecho_raw_pcb,tx,&addr,1234);
+  }
+}
+
 // called to stop execution (either a panic or program ended)
 // to be implemented by bsp (do not return from it!)
 void done();
 
+
+
 void init_task(void * _) {
   (void )_;
   // printf("Starting Mission\n");
 
-  test_hardware();
+  //test_hardware();
+
+  test_lwip();
 
   rust_main();
 

mission/netif/CMakeLists.txt

@@ -0,0 +1 @@
+target_sources(${OBSW_NAME} PRIVATE slipif.c)

mission/netif/slipif.c

@@ -0,0 +1,409 @@
+/**
+ * @file
+ * SLIP Interface
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is built upon the file: src/arch/rtxc/netif/sioslip.c
+ *
+ * Author: Magnus Ivarsson <magnus.ivarsson(at)volvo.com>
+ *         Simon Goldschmidt
+ */
+
+
+/**
+ * @defgroup slipif SLIP
+ * @ingroup netifs
+ *
+ * This is an arch independent SLIP netif. The specific serial hooks must be
+ * provided by another file. They are sio_open, sio_read/sio_tryread and sio_send
+ *
+ * Usage: This netif can be used in three ways:
+ *        1. For NO_SYS==0, an RX thread can be used which blocks on sio_read()
+ *           until data is received.
+ *        2. In your main loop, call slipif_poll() to check for new RX bytes,
+ *           completed packets are fed into netif->input().
+ *        3. Call slipif_received_byte[s]() from your serial RX ISR and
+ *           slipif_process_rxqueue() from your main loop. ISR level decodes
+ *           packets and puts completed packets on a queue which is fed into
+ *           the stack from the main loop (needs SYS_LIGHTWEIGHT_PROT for
+ *           pbuf_alloc to work on ISR level!).
+ *
+ */
+
+#include "slipif.h"
+#include "lwip/opt.h"
+
+#include "lwip/def.h"
+#include "lwip/pbuf.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "lwip/sys.h"
+
+#define SLIP_END     0xC0 /* 0300: start and end of every packet */
+#define SLIP_ESC     0xDB /* 0333: escape start (one byte escaped data follows) */
+#define SLIP_ESC_END 0xDC /* 0334: following escape: original byte is 0xC0 (END) */
+#define SLIP_ESC_ESC 0xDD /* 0335: following escape: original byte is 0xDB (ESC) */
+
+/** Maximum packet size that is received by this netif */
+#ifndef SLIP_MAX_SIZE
+#define SLIP_MAX_SIZE 1500
+#endif
+
+#ifndef SLIP_CHUNK_SIZE
+#define SLIP_CHUNK_SIZE 120
+#endif
+
+enum slipif_recv_state {
+  SLIP_RECV_NORMAL,
+  SLIP_RECV_ESCAPE
+};
+
+
+
+static void 
+slipif_send_chunk(uint8_t c, int fd, uint8_t *chunk, size_t *current_index, size_t chunksize, int flush){
+    if (*current_index >= chunksize) {
+      write(0,"stra", 5);
+        //chunk is already full, send it and reset
+        write(fd, chunk, chunksize);
+        *current_index = 0;
+    }
+    // add byte to chunk, (can not be full, we checked)
+    if (*current_index < chunksize) {
+        chunk[*current_index] = c;
+        (*current_index)++;
+    }
+    // if either chunk is full or we shall flush, send it
+    if ((*current_index >= chunksize) || ( flush != 0)) {
+      write(0,"full", 5);
+       write(fd, chunk, *current_index);
+        *current_index = 0;
+    }
+}
+
+
+/**
+ * Send a pbuf doing the necessary SLIP encapsulation
+ *
+ * Uses the serial layer's sio_send()
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param p the pbuf chain packet to send
+ * @return always returns ERR_OK since the serial layer does not provide return values
+ */
+static err_t
+slipif_output(struct netif *netif, struct pbuf *p)
+{
+  struct slipif_priv *priv;
+  struct pbuf *q;
+  u16_t i;
+  u8_t c;
+
+  uint8_t chunk[SLIP_CHUNK_SIZE];
+  size_t current_index = 0;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+  LWIP_ASSERT("p != NULL", (p != NULL));
+
+  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_output: sending %"U16_F" bytes\n", p->tot_len));
+  priv = (struct slipif_priv *)netif->state;
+
+  /* Send pbuf out on the serial I/O device. */
+  /* Start with packet delimiter. */
+  slipif_send_chunk(SLIP_END, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+
+  for (q = p; q != NULL; q = q->next) {
+    for (i = 0; i < q->len; i++) {
+      c = ((u8_t *)q->payload)[i];
+      switch (c) {
+        case SLIP_END:
+          /* need to escape this byte (0xC0 -> 0xDB, 0xDC) */
+          slipif_send_chunk(SLIP_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          slipif_send_chunk(SLIP_ESC_END, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+        case SLIP_ESC:
+          /* need to escape this byte (0xDB -> 0xDB, 0xDD) */
+          slipif_send_chunk(SLIP_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          slipif_send_chunk(SLIP_ESC_ESC, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+        default:
+          /* normal byte - no need for escaping */
+          slipif_send_chunk(c, priv->fd, chunk, &current_index, sizeof(chunk), 0);
+          break;
+      }
+    }
+  }
+  /* End with packet delimiter, flush the chunk */
+  slipif_send_chunk(SLIP_END, priv->fd, chunk, &current_index, sizeof(chunk), 1);
+  return ERR_OK;
+}
+
+#if LWIP_IPV4
+/**
+ * Send a pbuf doing the necessary SLIP encapsulation
+ *
+ * Uses the serial layer's sio_send()
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param p the pbuf chain packet to send
+ * @param ipaddr the ip address to send the packet to (not used for slipif)
+ * @return always returns ERR_OK since the serial layer does not provide return values
+ */
+static err_t
+slipif_output_v4(struct netif *netif, struct pbuf *p, const ip4_addr_t *ipaddr)
+{
+  LWIP_UNUSED_ARG(ipaddr);
+  return slipif_output(netif, p);
+}
+#endif /* LWIP_IPV4 */
+
+#if LWIP_IPV6
+/**
+ * Send a pbuf doing the necessary SLIP encapsulation
+ *
+ * Uses the serial layer's sio_send()
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param p the pbuf chain packet to send
+ * @param ipaddr the ip address to send the packet to (not used for slipif)
+ * @return always returns ERR_OK since the serial layer does not provide return values
+ */
+static err_t
+slipif_output_v6(struct netif *netif, struct pbuf *p, const ip6_addr_t *ipaddr)
+{
+  LWIP_UNUSED_ARG(ipaddr);
+  return slipif_output(netif, p);
+}
+#endif /* LWIP_IPV6 */
+
+/**
+ * Handle the incoming SLIP stream character by character
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @param c received character (multiple calls to this function will
+ *        return a complete packet, NULL is returned before - used for polling)
+ * @return The IP packet when SLIP_END is received
+ */
+static struct pbuf *
+slipif_rxbyte(struct netif *netif, u8_t c)
+{
+  struct slipif_priv *priv;
+  struct pbuf *t;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+  priv = (struct slipif_priv *)netif->state;
+
+  switch (priv->state) {
+    case SLIP_RECV_NORMAL:
+      switch (c) {
+        case SLIP_END:
+          if (priv->recved > 0) {
+            /* Received whole packet. */
+            /* Trim the pbuf to the size of the received packet. */
+            pbuf_realloc(priv->q, priv->recved);
+
+            LINK_STATS_INC(link.recv);
+
+            LWIP_DEBUGF(SLIP_DEBUG, ("slipif: Got packet (%"U16_F" bytes)\n", priv->recved));
+            t = priv->q;
+            priv->p = priv->q = NULL;
+            priv->i = priv->recved = 0;
+            return t;
+          }
+          return NULL;
+        case SLIP_ESC:
+          priv->state = SLIP_RECV_ESCAPE;
+          return NULL;
+        default:
+          break;
+      } /* end switch (c) */
+      break;
+    case SLIP_RECV_ESCAPE:
+      /* un-escape END or ESC bytes, leave other bytes
+         (although that would be a protocol error) */
+      switch (c) {
+        case SLIP_ESC_END:
+          c = SLIP_END;
+          break;
+        case SLIP_ESC_ESC:
+          c = SLIP_ESC;
+          break;
+        default:
+          break;
+      }
+      priv->state = SLIP_RECV_NORMAL;
+      break;
+    default:
+      break;
+  } /* end switch (priv->state) */
+
+  /* byte received, packet not yet completely received */
+  if (priv->p == NULL) {
+    /* allocate a new pbuf */
+    LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: alloc\n"));
+    priv->p = pbuf_alloc(PBUF_LINK, (PBUF_POOL_BUFSIZE - PBUF_LINK_HLEN - PBUF_LINK_ENCAPSULATION_HLEN), PBUF_POOL);
+
+    if (priv->p == NULL) {
+      LINK_STATS_INC(link.drop);
+      LWIP_DEBUGF(SLIP_DEBUG, ("slipif_input: no new pbuf! (DROP)\n"));
+      /* don't process any further since we got no pbuf to receive to */
+      return NULL;
+    }
+
+    if (priv->q != NULL) {
+      /* 'chain' the pbuf to the existing chain */
+      pbuf_cat(priv->q, priv->p);
+    } else {
+      /* p is the first pbuf in the chain */
+      priv->q = priv->p;
+    }
+  }
+
+  /* this automatically drops bytes if > SLIP_MAX_SIZE */
+  if ((priv->p != NULL) && (priv->recved <= SLIP_MAX_SIZE)) {
+    ((u8_t *)priv->p->payload)[priv->i] = c;
+    priv->recved++;
+    priv->i++;
+    if (priv->i >= priv->p->len) {
+      /* on to the next pbuf */
+      priv->i = 0;
+      if (priv->p->next != NULL && priv->p->next->len > 0) {
+        /* p is a chain, on to the next in the chain */
+        priv->p = priv->p->next;
+      } else {
+        /* p is a single pbuf, set it to NULL so next time a new
+         * pbuf is allocated */
+        priv->p = NULL;
+      }
+    }
+  }
+  return NULL;
+}
+
+/** Like slipif_rxbyte, but passes completed packets to netif->input
+ *
+ * @param netif The lwip network interface structure for this slipif
+ * @param c received character
+ */
+static void
+slipif_rxbyte_input(struct netif *netif, u8_t c)
+{
+  struct pbuf *p;
+  p = slipif_rxbyte(netif, c);
+  if (p != NULL) {
+    if (netif->input(p, netif) != ERR_OK) {
+      pbuf_free(p);
+    }
+  }
+}
+
+
+/**
+ * @ingroup slipif
+ * SLIP netif initialization
+ *
+ * Call the arch specific sio_open and remember
+ * the opened device in the state field of the netif.
+ *
+ * @param netif the lwip network interface structure for this slipif
+ * @return ERR_OK if serial line could be opened,
+ *         ERR_MEM if no memory could be allocated,
+ *         ERR_IF is serial line couldn't be opened
+ *
+ * @note If netif->state is interpreted as an u8_t serial port number.
+ *
+ */
+err_t
+slipif_init(struct netif *netif)
+{
+  struct slipif_priv *priv;
+
+  LWIP_ASSERT("slipif needs an input callback", netif->input != NULL);
+
+  LWIP_DEBUGF(SLIP_DEBUG, ("slipif_init: netif->num=%"U16_F"\n", (u16_t)sio_num));
+
+
+  netif->name[0] = 's';
+  netif->name[1] = 'l';
+#if LWIP_IPV4
+  netif->output = slipif_output_v4;
+#endif /* LWIP_IPV4 */
+#if LWIP_IPV6
+  netif->output_ip6 = slipif_output_v6;
+#endif /* LWIP_IPV6 */
+  netif->mtu = SLIP_MAX_SIZE;
+
+  /* private data needs to be allocated by user and passed via state (see netif_add()) */
+  priv = netif->state;
+  /* Initialize private data */
+  priv->p = NULL;
+  priv->q = NULL;
+  priv->state = SLIP_RECV_NORMAL;
+  priv->i = 0;
+  priv->recved = 0;
+  
+  LWIP_ASSERT("slipif private data fd needs to be initialized before calling netif_add()", priv->fd != 0);
+
+  
+
+  /* initialize the snmp variables and counters inside the struct netif */
+  MIB2_INIT_NETIF(netif, snmp_ifType_slip, SLIP_SIO_SPEED(priv->sd));
+
+  return ERR_OK;
+}
+
+/**
+ * @ingroup slipif
+ * Polls the serial device and feeds the IP layer with incoming packets.
+ *
+ * @param netif The lwip network interface structure for this slipif
+ */
+void
+slipif_poll(struct netif *netif)
+{
+  struct slipif_priv *priv;
+
+  LWIP_ASSERT("netif != NULL", (netif != NULL));
+  LWIP_ASSERT("netif->state != NULL", (netif->state != NULL));
+
+  priv = (struct slipif_priv *)netif->state;
+
+  uint8_t chunk[SLIP_CHUNK_SIZE];
+  int read_bytes = read(priv->fd, chunk, sizeof(chunk));
+
+  for (int i = 0; i < read_bytes; i++){
+    slipif_rxbyte_input(netif, chunk[i]);
+  }
+}

mission/netif/slipif.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include "lwip/opt.h"
+#include "lwip/netif.h"
+
+struct slipif_priv {
+  int fd;
+  /* q is the whole pbuf chain for a packet, p is the current pbuf in the chain */
+  struct pbuf *p, *q;
+  u8_t state;
+  u16_t i, recved;
+};
+
+err_t slipif_init(struct netif * netif);
+void slipif_poll(struct netif *netif);