//==========================================================================////      net/arp.c////      Stand-alone ARP support for RedBoot////==========================================================================//####COPYRIGHTBEGIN####//                                                                          // -------------------------------------------                              // The contents of this file are subject to the Red Hat eCos Public License // Version 1.1 (the "License"); you may not use this file except in         // compliance with the License.  You may obtain a copy of the License at    // http://www.redhat.com/                                                   //                                                                          // Software distributed under the License is distributed on an "AS IS"      // basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the // License for the specific language governing rights and limitations under // the License.                                                             //                                                                          // The Original Code is eCos - Embedded Configurable Operating System,      // released September 30, 1998.                                             //                                                                          // The Initial Developer of the Original Code is Red Hat.                   // Portions created by Red Hat are                                          // Copyright (C) 1998, 1999, 2000 Red Hat, Inc.                             // All Rights Reserved.                                                     // -------------------------------------------                              //                                                                          //####COPYRIGHTEND####//==========================================================================//#####DESCRIPTIONBEGIN####//// Author(s):    gthomas// Contributors: gthomas// Date:         2000-07-14// Purpose:      // Description:  //              // This code is part of RedBoot (tm).////####DESCRIPTIONEND####////==========================================================================#include <net/net.h>static struct {    int      waiting;    char     *eth;    char     *ip;} arp_req;/* * Handle incoming ARP packets. */void__arp_handler(pktbuf_t *pkt){    arp_header_t *arp = pkt->arp_hdr;    int hw_type, protocol;    /*     * Only handle ethernet hardware and IP protocol.     */    protocol = ntohs(arp->protocol);    hw_type = ntohs(arp->hw_type);    if ((hw_type == ARP_HW_ETHER) && (protocol == ETH_TYPE_IP)) {	/*	 * Handle requests for our ethernet address.	 */	if (!memcmp(arp->target_ip, __local_ip_addr, 4)) {	    if (ntohs(arp->opcode) == ARP_REQUEST) {		/* format response. */		arp->opcode = htons(ARP_REPLY);		memcpy(arp->target_ip, arp->sender_ip,		       sizeof(ip_addr_t));		memcpy(arp->target_enet, arp->sender_enet,		       sizeof(enet_addr_t));		memcpy(arp->sender_ip, __local_ip_addr,		       sizeof(ip_addr_t));		memcpy(arp->sender_enet, __local_enet_addr,		       sizeof(enet_addr_t));		pkt->pkt_bytes = sizeof(arp_header_t);		__enet_send(pkt, &arp->target_enet, ETH_TYPE_ARP);	    } else if (ntohs(arp->opcode) == ARP_REPLY && arp_req.waiting) {		if (!memcmp(arp_req.ip, arp->sender_ip, sizeof(ip_addr_t))) {                    memcpy(arp_req.eth, arp->sender_enet, sizeof(enet_addr_t));		    arp_req.waiting = 0;		}	    }	}    }    __pktbuf_free(pkt);}/*  * Find the ethernet address of the machine with the given * ip address. * Return 0 and fills in 'eth_addr' if successful, *       -1 if unsuccessful. */int__arp_request(ip_addr_t *ip_addr, enet_addr_t *eth_addr){    pktbuf_t *pkt;    arp_header_t *arp;    unsigned long retry_start;    enet_addr_t   bcast_addr;    int           retry;    /* just fail if can't get a buffer */    if ((pkt = __pktbuf_alloc(ARP_PKT_SIZE)) == NULL)	return -1;    arp = pkt->arp_hdr;    arp->opcode = htons(ARP_REQUEST);    arp->hw_type = htons(ARP_HW_ETHER);    arp->protocol = htons(0x800);    arp->hw_len = sizeof(enet_addr_t);    arp->proto_len = sizeof(ip_addr_t);    memcpy(arp->sender_ip, __local_ip_addr, sizeof(ip_addr_t));    memcpy(arp->sender_enet, __local_enet_addr, sizeof(enet_addr_t));    memcpy(arp->target_ip, ip_addr, sizeof(ip_addr_t));    bcast_addr[0] = 255;    bcast_addr[1] = 255;    bcast_addr[2] = 255;    bcast_addr[3] = 255;    bcast_addr[4] = 255;    bcast_addr[5] = 255;    arp_req.eth = (char *)eth_addr;    arp_req.ip = (char *)ip_addr;    arp_req.waiting = 1;    retry = 8;    while (retry-- > 0) {        /* send the packet */	pkt->pkt_bytes = sizeof(arp_header_t);        __enet_send(pkt, &bcast_addr, ETH_TYPE_ARP);        retry_start = MS_TICKS();	while ((MS_TICKS() - retry_start) < 250) {	    __enet_poll();	    if (!arp_req.waiting) {		__pktbuf_free(pkt);		return 0;	    }	}    }    __pktbuf_free(pkt);    return -1;}#define NUM_ARP 16static ip_route_t routes[NUM_ARP];int__arp_lookup(ip_addr_t *host, ip_route_t *rt){    int i;    static int next_arp = 0;    for (i = 0;  i < NUM_ARP;  i++) {        if (memcmp(host, &routes[i].ip_addr, sizeof(*host)) == 0) {            // This is a known host            memcpy(rt, &routes[i], sizeof(*rt));            return 0;        }    }    memcpy(&rt->ip_addr, host, sizeof(*host));    if (__arp_request(host, &rt->enet_addr) < 0) {        return -1;    } else {        memcpy(&routes[next_arp], rt, sizeof(*rt));        if (++next_arp == NUM_ARP) next_arp = 0;        return 0;    }}