Hi, I'm having a few issues in porting lwip 1.3.2 on BeRTOS (www.bertos.org). I have implemented my EMAC driver and the low_level_input() functions. I've used BeRTOS facilities to implement the EMAC driver; however, whenever I wait inside the driver timeouts are not processed and so TCP does not retransmit lost packets.
>From what I can understand, timeouts are handled only in sys_sem_wait() or sys_mbox_fetch() calls: when a process is going to block on a condition, it starts to process timeouts; if there are none, the process really blocks. Is it correct? Since I'd like to avoid using lwip semaphores inside the EMAC driver (which might be used without lwip), I'm looking for possible workarounds. I've thought to process timers by hand every once in a while with code mostly taken from sys_sem_wait. See attachment, functions lwip_process_timers() and ethernetif_loop() [lines 283 and 315]. Do you think this kind of approach could work or there are flaws in my reasoning? Another question: in my application I'm creating various threads using BeRTOS functions directly and not sys_thread_new(); all those threads use network functions (lwip_send(), lwip_recv(), lwip_select()). I have implemented the sys_arch_timeouts() function using the following logic: * if a thread has an enhanced TCB (ie. it's created with sys_thread_new), return it's own timeout list; * otherwise return a global timeout list. Do you think that this logic is flawed? Thanks. -- Luca Ottaviano - lottavi...@develer.com Develer S.r.l. - http://www.develer.com/ .hardware .software .innovation Tel.: +39 055 3986627 - ext.: 218
/** * \file * <!-- * This file is part of BeRTOS. * * Bertos is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * As a special exception, you may use this file as part of a free software * library without restriction. Specifically, if other files instantiate * templates or use macros or inline functions from this file, or you compile * this file and link it with other files to produce an executable, this * file does not by itself cause the resulting executable to be covered by * the GNU General Public License. This exception does not however * invalidate any other reasons why the executable file might be covered by * the GNU General Public License. * * Copyright 2010 Develer S.r.l. (http://www.develer.com/) * * --> * * \brief Ethernet driver glue for lwIP * * \author Andrea Righi <ari...@develer.com> */ /* * 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. 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 <a...@sics.se> * */ /* * This file is a skeleton for developing Ethernet network interface * drivers for lwIP. Add code to the low_level functions and do a * search-and-replace for the word "ethernetif" to replace it with * something that better describes your network interface. */ #include "cfg/cfg_lwip.h" #include <drv/eth.h> #include <drv/timer.h> #include <cpu/irq.h> #include <kern/proc.h> #include <lwip/def.h> #include <lwip/mem.h> #include <lwip/pbuf.h> #include <lwip/sys.h> #include <lwip/stats.h> #include <lwip/snmp.h> #include <netif/etharp.h> #include <netif/ppp_oe.h> #include <netif/ethernetif.h> /* Define those to better describe your network interface. */ #define IFNAME0 'e' #define IFNAME1 '0' /** * Helper struct to hold private data used to operate your ethernet interface. * Keeping the ethernet address of the MAC in this struct is not necessary * as it is already kept in the struct netif. * But this is only an example, anyway... */ struct ethernetif { struct eth_addr *ethaddr; /* Add whatever per-interface state that is needed here. */ }; /** * In this function, the hardware should be initialized. * Called from ethernetif_init(). * * @param netif the already initialized lwip network interface structure * for this ethernetif */ static void low_level_init(struct netif *netif) { /* set MAC hardware address length */ netif->hwaddr_len = ETHARP_HWADDR_LEN; /* set MAC hardware address */ netif->hwaddr[0] = mac_addr[0]; netif->hwaddr[1] = mac_addr[1]; netif->hwaddr[2] = mac_addr[2]; netif->hwaddr[3] = mac_addr[3]; netif->hwaddr[4] = mac_addr[4]; netif->hwaddr[5] = mac_addr[5]; /* maximum transfer unit */ netif->mtu = 1500; /* device capabilities */ /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */ netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP; eth_init(); } /** * This function should do the actual transmission of the packet. The packet is * contained in the pbuf that is passed to the function. This pbuf * might be chained. * * @param netif the lwip network interface structure for this ethernetif * @param p the MAC packet to send (e.g. IP packet including MAC addresses and type) * @return ERR_OK if the packet could be sent * an err_t value if the packet couldn't be sent * * @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to * strange results. You might consider waiting for space in the DMA queue * to become availale since the stack doesn't retry to send a packet * dropped because of memory failure (except for the TCP timers). */ static err_t low_level_output(UNUSED_ARG(struct netif *, netif), struct pbuf *p) { struct pbuf *q; #if ETH_PAD_SIZE pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */ #endif proc_forbid(); for (q = p; q != NULL; q = q->next) eth_putFrame(q->payload, q->len); eth_sendFrame(); #if ETH_PAD_SIZE pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */ #endif LINK_STATS_INC(link.xmit); proc_permit(); return ERR_OK; } /** * Should allocate a pbuf and transfer the bytes of the incoming * packet from the interface into the pbuf. * * @param netif the lwip network interface structure for this ethernetif * @return a pbuf filled with the received packet (including MAC header) * NULL on memory error */ static struct pbuf *low_level_input(UNUSED_ARG(struct netif *, netif)) { struct pbuf *p, *q; size_t len; len = eth_getFrameLen(); if (UNLIKELY(len <= 0)) return NULL; #if ETH_PAD_SIZE len += ETH_PAD_SIZE; /* allow room for Ethernet padding */ #endif proc_forbid(); /* We allocate a pbuf chain of pbufs from the pool. */ p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL); if (p != NULL) { #if ETH_PAD_SIZE pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */ #endif for (q = p; q != NULL; q = q->next) eth_getFrame(q->payload, q->len); #if ETH_PAD_SIZE pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */ #endif LINK_STATS_INC(link.recv); } else { LINK_STATS_INC(link.memerr); LINK_STATS_INC(link.drop); } proc_permit(); return p; } /** * This function should be called when a packet is ready to be read * from the interface. It uses the function low_level_input() that * should handle the actual reception of bytes from the network * interface. Then the type of the received packet is determined and * the appropriate input function is called. * * @param netif the lwip network interface structure for this ethernetif */ static void ethernetif_input(struct netif *netif) { struct ethernetif *ethernetif; struct eth_hdr *ethhdr; struct pbuf *p; ethernetif = netif->state; /* move received packet into a new pbuf */ p = low_level_input(netif); /* no packet could be read, silently ignore this */ if (p == NULL) return; ethhdr = p->payload; switch (htons(ethhdr->type)) { case ETHTYPE_ARP: etharp_arp_input(netif, ethernetif->ethaddr, p); break; case ETHTYPE_IP: #if DHCP_DOES_ARP_CHECK etharp_ip_input(netif, p); #endif pbuf_header(p, (int16_t) - sizeof(struct eth_hdr)); if (netif->input(p, netif) != ERR_OK) { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n")); pbuf_free(p); p = NULL; } break; default: pbuf_free(p); p = NULL; break; } } static void lwip_process_timers(u32_t delta) { struct sys_timeouts *timeouts; timeouts = sys_arch_timeouts(); if (!timeouts) return; struct sys_timeo *timeout = timeouts->next; while (timeout) { if (delta < timeout->time) { timeout->time -= delta; break; } else { delta -= timeout->time; // exec callback if (timeout->h) timeout->h(timeout->arg); // remove timer timeouts->next = timeout->next; memp_free(MEMP_SYS_TIMEOUT, timeout); timeout = timeouts->next; } } } static NORETURN void ethernetif_loop(void *arg) { struct netif *netif = (struct netif *)arg; ticks_t start = timer_clock(); while (1) { ethernetif_input(netif); ticks_t delta = timer_clock() - start; if (delta >= ms_to_ticks(50)) { lwip_process_timers(ticks_to_ms(delta)); start += delta; } } } /** * Should be called at the beginning of the program to set up the * network interface. It calls the function low_level_init() to do the * actual setup of the hardware. * * This function should be passed as a parameter to netif_add(). * * @param netif the lwip network interface structure for this ethernetif * @return ERR_OK if the loopif is initialized * ERR_MEM if private data couldn't be allocated * any other err_t on error */ err_t ethernetif_init(struct netif *netif) { struct ethernetif *ethernetif; LWIP_ASSERT("netif != NULL", (netif != NULL)); ethernetif = mem_malloc(sizeof(struct ethernetif)); if (ethernetif == NULL) { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: out of memory\n")); return ERR_MEM; } /* * Initialize the snmp variables and counters inside the struct netif. * The last argument should be replaced with your link speed, in units * of bits per second. */ NETIF_INIT_SNMP(netif, snmp_ifType_ethernet_csmacd, LINK_SPEED_OF_YOUR_NETIF_IN_BPS); netif->state = ethernetif; netif->hwaddr_len = 6; netif->name[0] = IFNAME0; netif->name[1] = IFNAME1; netif->mtu = 1500; /* We directly use etharp_output() here to save a function call. * You can instead declare your own function an call etharp_output() * from it if you have to do some checks before sending (e.g. if link * is available...) */ netif->output = etharp_output; netif->linkoutput = low_level_output; ethernetif->ethaddr = (struct eth_addr *)&(netif->hwaddr[0]); /* initialize the hardware */ low_level_init(netif); etharp_init(); if (!sys_thread_new((char *)"eth_thread", ethernetif_loop, netif, DEFAULT_THREAD_STACKSIZE, DEFAULT_THREAD_PRIO)) { LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_init: max number of threads exceeded\n")); mem_free(ethernetif); return ERR_MEM; } return ERR_OK; }
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