示例#1
0
/**
 * Handles every incoming ARP Packet, called by etharp_arp_input.
 *
 * @param netif network interface to use for autoip processing
 * @param hdr Incoming ARP packet
 */
void
autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
{
  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
  if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
   /* when ip.src == llipaddr && hw.src != netif->hwaddr
    *
    * when probing  ip.dst == llipaddr && hw.src != netif->hwaddr
    * we have a conflict and must solve it
    */
    ip_addr_t sipaddr, dipaddr;
    struct eth_addr netifaddr;
    ETHADDR16_COPY(netifaddr.addr, netif->hwaddr);

    /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
     * structure packing (not using structure copy which breaks strict-aliasing rules).
     */
    IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
    IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
      
    if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
        ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
         (netif->autoip->sent_num == 0))) {
     /* RFC 3927 Section 2.2.1:
      * from beginning to after ANNOUNCE_WAIT
      * seconds we have a conflict if
      * ip.src == llipaddr OR
      * ip.dst == llipaddr && hw.src != own hwaddr
      */
      if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
          (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
           !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
        LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
          ("autoip_arp_reply(): Probe Conflict detected\n"));
	/* Clear stored lladdr in case of conflict. As device should now
	 * re-probe conflicted address. */
	memset(&prev_llipaddr, 0, sizeof(ip_addr_t));
        autoip_restart(netif);
      }
    } else {
     /* RFC 3927 Section 2.5:
      * in any state we have a conflict if
      * ip.src == llipaddr && hw.src != own hwaddr
      */
      if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
          !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
        LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
          ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
	/* Clear stored lladdr in case of conflict. As device should now
	 * re-probe conflicted address.
	 * Clear stored address only if it was not announced */
		if (netif->autoip->state != AUTOIP_STATE_BOUND)
			memset(&prev_llipaddr, 0, sizeof(ip_addr_t));
        autoip_handle_arp_conflict(netif);
      }
    }
  }
}
示例#2
0
/**
 * Handles every incoming ARP Packet, called by etharp_arp_input.
 *
 * @param netif network interface to use for autoip processing
 * @param hdr Incoming ARP packet
 */
void
autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
{
    LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
    if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
        /* when ip.src == llipaddr && hw.src != netif->hwaddr
         *
         * when probing  ip.dst == llipaddr && hw.src != netif->hwaddr
         * we have a conflict and must solve it
         */
        struct ip_addr sipaddr, dipaddr;
        struct eth_addr netifaddr;
        netifaddr.addr[0] = netif->hwaddr[0];
        netifaddr.addr[1] = netif->hwaddr[1];
        netifaddr.addr[2] = netif->hwaddr[2];
        netifaddr.addr[3] = netif->hwaddr[3];
        netifaddr.addr[4] = netif->hwaddr[4];
        netifaddr.addr[5] = netif->hwaddr[5];

        /* Copy struct ip_addr2 to aligned ip_addr, to support compilers without
         * structure packing (not using structure copy which breaks strict-aliasing rules).
         */
        SMEMCPY(&sipaddr, &hdr->sipaddr, sizeof(sipaddr));
        SMEMCPY(&dipaddr, &hdr->dipaddr, sizeof(dipaddr));

        if ((netif->autoip->state == AUTOIP_STATE_PROBING) ||
                ((netif->autoip->state == AUTOIP_STATE_ANNOUNCING) &&
                 (netif->autoip->sent_num == 0))) {
            /* RFC 3927 Section 2.2.1:
             * from beginning to after ANNOUNCE_WAIT
             * seconds we have a conflict if
             * ip.src == llipaddr OR
             * ip.dst == llipaddr && hw.src != own hwaddr
             */
            if ((ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
                    (ip_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
                     !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
                LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
                            ("autoip_arp_reply(): Probe Conflict detected\n"));
                autoip_start(netif);
            }
        } else {
            /* RFC 3927 Section 2.5:
             * in any state we have a conflict if
             * ip.src == llipaddr && hw.src != own hwaddr
             */
            if (ip_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
                    !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
                LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
                            ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
                autoip_handle_arp_conflict(netif);
            }
        }
    }
}