[lwip-devel] Fwd: Dead PCB-problem when PPP interface is removed

[Romeo]

in addition to

http://lists.gnu.org/archive/html/lwip-users/2003-03/msg00118.html

I've extended pcb remove code code to use it in netif_remove too. My edition solves problem when PPP connection is suddenly lost, netif is removed and there's some PCBs left in stack. When link goes up (with the same IP), these PCBs is sent out, even if the connection has been already closed.

patch to 1.4.1 is attached

#if LWIP_TCP

static void netif_remove_pcbs(struct netif *netif){

  struct tcp_pcb *pcb;

  pcb = tcp_active_pcbs;

  while (pcb != NULL) {

    /* PCB bound to current local interface address? */

    if (ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))

#if LWIP_AUTOIP

      /* connections to link-local addresses must persist (RFC3927 ch. 1.9) */

      && !ip_addr_islinklocal(&(pcb->local_ip))

#endif /* LWIP_AUTOIP */

      ) {

      /* this connection must be aborted */

      struct tcp_pcb *next = pcb->next;

      LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_remove_pcbs: aborting TCP pcb %p\n", (void *)pcb));

      tcp_abort(pcb);

      pcb = next;

    } else {

      pcb = pcb->next;

    }

  }

}

#endif

/**

 * Remove a network interface from the list of lwIP netifs.

 *

 * @param netif the network interface to remove

 */

void

netif_remove(struct netif *netif)

{

  if (netif == NULL) {

    return;

  }

#if LWIP_TCP

  netif_remove_pcbs(netif);

#endif

#if LWIP_IGMP

  /* stop IGMP processing */

  if (netif->flags & NETIF_FLAG_IGMP) {

    igmp_stop(netif);

  }

#endif /* LWIP_IGMP */

  if (netif_is_up(netif)) {

    /* set netif down before removing (call callback function) */

    netif_set_down(netif);

  }

  snmp_delete_ipaddridx_tree(netif);

  /*  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 */

  }

  snmp_dec_iflist();

  /* this netif is default? */

  if (netif_default == netif) {

    /* reset default netif */

    netif_set_default(NULL);

  }

#if LWIP_NETIF_REMOVE_CALLBACK

  if (netif->remove_callback) {

    netif->remove_callback(netif);

  }

#endif /* LWIP_NETIF_REMOVE_CALLBACK */

  LWIP_DEBUGF( NETIF_DEBUG, ("netif_remove: removed netif\n") );

}

void

netif_set_ipaddr(struct netif *netif, ip_addr_t *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_listen *lpcb;

  /* address is actually being changed? */

  if (ipaddr && (ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0) {

    /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */

    LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: netif address being changed\n"));

    netif_remove_pcbs(netif);

    for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {

      /* PCB bound to current local interface address? */

      if ((!(ip_addr_isany(&(lpcb->local_ip)))) &&

          (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

  snmp_delete_ipaddridx_tree(netif);

  snmp_delete_iprteidx_tree(0,netif);

  /* set new IP address to netif */

  ip_addr_set(&(netif->ip_addr), ipaddr);

  snmp_insert_ipaddridx_tree(netif);

  snmp_insert_iprteidx_tree(0,netif);

  LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("netif: IP address of interface %c%c set to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",

    netif->name[0], netif->name[1],

    ip4_addr1_16(&netif->ip_addr),

    ip4_addr2_16(&netif->ip_addr),

    ip4_addr3_16(&netif->ip_addr),

    ip4_addr4_16(&netif->ip_addr)));

}

--

Best Regards,

Roman Savrulin

Phone: +7 (921) 562 40 07

netif.c.patch
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