/** * @file * * lwIP network interface abstraction *//* * 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 <adam@sics.se> * */#include "lwip/opt.h"#include "lwip/def.h"#include "lwip/ip_addr.h"#include "lwip/netif.h"#include "lwip/tcp.h"struct netif *netif_list = NULL;struct netif *netif_default = NULL;/** * Add a network interface to the list of lwIP netifs. * * @param netif a pre-allocated netif structure * @param ipaddr IP address for the new netif * @param netmask network mask for the new netif * @param gw default gateway IP address for the new netif * @param state opaque data passed to the new netif * @param init callback function that initializes the interface * @param input callback function that is called to pass * ingress packets up in the protocol layer stack. * * @return netif, or NULL if failed. */struct netif *netif_add(struct netif *netif, struct ip_addr *ipaddr, struct ip_addr *netmask,  struct ip_addr *gw,  void *state,  err_t (* init)(struct netif *netif),  err_t (* input)(struct pbuf *p, struct netif *netif)){  static int netifnum = 0;  #if LWIP_DHCP  /* netif not under DHCP control by default */  netif->dhcp = NULL;#endif  /* remember netif specific state information data */  netif->state = state;  netif->num = netifnum++;  netif->input = input;  netif_set_addr(netif, ipaddr, netmask, gw);  /* call user specified initialization function for netif */  if (init(netif) != ERR_OK) {    return NULL;  }  /* add this netif to the list */  netif->next = netif_list;  netif_list = netif;  LWIP_DEBUGF(NETIF_DEBUG, ("netif: added interface %c%c IP addr ",    netif->name[0], netif->name[1]));  ip_addr_debug_print(NETIF_DEBUG, ipaddr);  LWIP_DEBUGF(NETIF_DEBUG, (" netmask "));  ip_addr_debug_print(NETIF_DEBUG, netmask);  LWIP_DEBUGF(NETIF_DEBUG, (" gw "));  ip_addr_debug_print(NETIF_DEBUG, gw);  LWIP_DEBUGF(NETIF_DEBUG, ("\n"));  return netif;}voidnetif_set_addr(struct netif *netif,struct ip_addr *ipaddr, struct ip_addr *netmask,    struct ip_addr *gw){  netif_set_ipaddr(netif, ipaddr);  netif_set_netmask(netif, netmask);  netif_set_gw(netif, gw);}void netif_remove(struct netif * netif){  if ( netif == NULL ) return;  /*  is it the first netif? */  if (netif_list == netif) {    netif_list = netif->next;  }  else {    /*  look for netif further down the list */    struct netif * tmpNetif;    for (tmpNetif = netif_list; tmpNetif != NULL; tmpNetif = tmpNetif->next) {      if (tmpNetif->next == netif) {        tmpNetif->next = netif->next;        break;        }    }    if (tmpNetif == NULL)      return; /*  we didn't find any netif today */  }  /* this netif is default? */  if (netif_default == netif)    /* reset default netif */    netif_default = NULL;  LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );}struct netif *netif_find(char *name){  struct netif *netif;  u8_t num;  if (name == NULL) {    return NULL;  }  num = name[2] - '0';  for(netif = netif_list; netif != NULL; netif = netif->next) {    if (num == netif->num &&       name[0] == netif->name[0] &&       name[1] == netif->name[1]) {      LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: found %c%c\n", name[0], name[1]));      return netif;    }  }  LWIP_DEBUGF(NETIF_DEBUG, ("netif_find: didn't find %c%c\n", name[0], name[1]));  return NULL;}voidnetif_set_ipaddr(struct netif *netif, struct ip_addr *ipaddr){  /* TODO: Handling of obsolete pcbs */  /* See:  http://mail.gnu.org/archive/html/lwip-users/2003-03/msg00118.html */#if LWIP_TCP  struct tcp_pcb *pcb;  struct tcp_pcb_listen *lpcb;  /* address is actually being changed? */  if ((ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0)  {    /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */    LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: netif address being changed\n"));    pcb = tcp_active_pcbs;    while (pcb != NULL) {      /* PCB bound to current local interface address? */      if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {        /* this connection must be aborted */        struct tcp_pcb *next = pcb->next;        LWIP_DEBUGF(NETIF_DEBUG | 1, ("netif_set_ipaddr: aborting TCP pcb %p\n", (void *)pcb));        tcp_abort(pcb);        pcb = next;      } else {        pcb = pcb->next;      }    }    for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {      /* PCB bound to current local interface address? */      if (ip_addr_cmp(&(lpcb->local_ip), &(netif->ip_addr))) {        /* The PCB is listening to the old ipaddr and         * is set to listen to the new one instead */        ip_addr_set(&(lpcb->local_ip), ipaddr);      }    }  }#endif  ip_addr_set(&(netif->ip_addr), ipaddr);#if 0 /* only allowed for Ethernet interfaces TODO: how can we check? */  /** For Ethernet network interfaces, we would like to send a   *  "gratuitous ARP"; this is an ARP packet sent by a node in order   *  to spontaneously cause other nodes to update an entry in their   *  ARP cache. From RFC 3220 "IP Mobility Support for IPv4" section 4.6.   */   etharp_query(netif, ipaddr, NULL);#endif  LWIP_DEBUGF(NETIF_DEBUG | DBG_TRACE | DBG_STATE | 3, ("netif: IP address of interface %c%c set to %u.%u.%u.%u\n",    netif->name[0], netif->name[1],    ip4_addr1(&netif->ip_addr),    ip4_addr2(&netif->ip_addr),    ip4_addr3(&netif->ip_addr),    ip4_addr4(&netif->ip_addr)));}voidnetif_set_gw(struct netif *netif, struct ip_addr *gw){  ip_addr_set(&(netif->gw), gw);  LWIP_DEBUGF(NETIF_DEBUG | DBG_TRACE | DBG_STATE | 3, ("netif: GW address of interface %c%c set to %u.%u.%u.%u\n",    netif->name[0], netif->name[1],    ip4_addr1(&netif->gw),    ip4_addr2(&netif->gw),    ip4_addr3(&netif->gw),    ip4_addr4(&netif->gw)));}voidnetif_set_netmask(struct netif *netif, struct ip_addr *netmask){  ip_addr_set(&(netif->netmask), netmask);  LWIP_DEBUGF(NETIF_DEBUG | DBG_TRACE | DBG_STATE | 3, ("netif: netmask of interface %c%c set to %u.%u.%u.%u\n",    netif->name[0], netif->name[1],    ip4_addr1(&netif->netmask),    ip4_addr2(&netif->netmask),    ip4_addr3(&netif->netmask),    ip4_addr4(&netif->netmask)));}voidnetif_set_default(struct netif *netif){  netif_default = netif;  LWIP_DEBUGF(NETIF_DEBUG, ("netif: setting default interface %c%c\n",           netif ? netif->name[0] : '\'', netif ? netif->name[1] : '\''));}/** * Bring an interface up, available for processing * traffic. *  * @note: Enabling DHCP on a down interface will make it come * up once configured. *  * @see dhcp_start() */ void netif_set_up(struct netif *netif){  netif->flags |= NETIF_FLAG_UP;}/** * Ask if an interface is up */ u8_t netif_is_up(struct netif *netif){  return (netif->flags & NETIF_FLAG_UP)?1:0;}/** * Bring an interface down, disabling any traffic processing. * * @note: Enabling DHCP on a down interface will make it come * up once configured. *  * @see dhcp_start() */ void netif_set_down(struct netif *netif){  netif->flags &= ~NETIF_FLAG_UP;}voidnetif_init(void){  netif_list = netif_default = NULL;}