diff options
Diffstat (limited to 'net/arp.c')
| -rw-r--r-- | net/arp.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/net/arp.c b/net/arp.c new file mode 100644 index 0000000..f75217c --- /dev/null +++ b/net/arp.c @@ -0,0 +1,213 @@ +/* + * Copied from Linux Monitor (LiMon) - Networking. + * + * Copyright 1994 - 2000 Neil Russell. + * (See License) + * Copyright 2000 Roland Borde + * Copyright 2000 Paolo Scaffardi + * Copyright 2000-2002 Wolfgang Denk, wd@denx.de + */ + +#include <common.h> + +#include "arp.h" + +#ifndef CONFIG_ARP_TIMEOUT +/* Milliseconds before trying ARP again */ +# define ARP_TIMEOUT 5000UL +#else +# define ARP_TIMEOUT CONFIG_ARP_TIMEOUT +#endif + + +#ifndef CONFIG_NET_RETRY_COUNT +# define ARP_TIMEOUT_COUNT 5 /* # of timeouts before giving up */ +#else +# define ARP_TIMEOUT_COUNT CONFIG_NET_RETRY_COUNT +#endif + +IPaddr_t NetArpWaitPacketIP; +IPaddr_t NetArpWaitReplyIP; +/* MAC address of waiting packet's destination */ +uchar *NetArpWaitPacketMAC; +/* THE transmit packet */ +uchar *NetArpWaitTxPacket; +int NetArpWaitTxPacketSize; +uchar NetArpWaitPacketBuf[PKTSIZE_ALIGN + PKTALIGN]; +ulong NetArpWaitTimerStart; +int NetArpWaitTry; + +void ArpInit(void) +{ + /* XXX problem with bss workaround */ + NetArpWaitPacketMAC = NULL; + NetArpWaitPacketIP = 0; + NetArpWaitReplyIP = 0; + NetArpWaitTxPacket = &NetArpWaitPacketBuf[0] + (PKTALIGN - 1); + NetArpWaitTxPacket -= (ulong)NetArpWaitTxPacket % PKTALIGN; + NetArpWaitTxPacketSize = 0; +} + +void ArpRequest(void) +{ + uchar *pkt; + ARP_t *arp; + + debug("ARP broadcast %d\n", NetArpWaitTry); + + pkt = NetTxPacket; + + pkt += NetSetEther(pkt, NetBcastAddr, PROT_ARP); + + arp = (ARP_t *) pkt; + + arp->ar_hrd = htons(ARP_ETHER); + arp->ar_pro = htons(PROT_IP); + arp->ar_hln = 6; + arp->ar_pln = 4; + arp->ar_op = htons(ARPOP_REQUEST); + + /* source ET addr */ + memcpy(&arp->ar_data[0], NetOurEther, 6); + /* source IP addr */ + NetWriteIP((uchar *) &arp->ar_data[6], NetOurIP); + /* dest ET addr = 0 */ + memset(&arp->ar_data[10], '\0', 6); + if ((NetArpWaitPacketIP & NetOurSubnetMask) != + (NetOurIP & NetOurSubnetMask)) { + if (NetOurGatewayIP == 0) { + puts("## Warning: gatewayip needed but not set\n"); + NetArpWaitReplyIP = NetArpWaitPacketIP; + } else { + NetArpWaitReplyIP = NetOurGatewayIP; + } + } else { + NetArpWaitReplyIP = NetArpWaitPacketIP; + } + + NetWriteIP((uchar *) &arp->ar_data[16], NetArpWaitReplyIP); + (void) eth_send(NetTxPacket, (pkt - NetTxPacket) + ARP_HDR_SIZE); +} + +void ArpTimeoutCheck(void) +{ + ulong t; + + if (!NetArpWaitPacketIP) + return; + + t = get_timer(0); + + /* check for arp timeout */ + if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT) { + NetArpWaitTry++; + + if (NetArpWaitTry >= ARP_TIMEOUT_COUNT) { + puts("\nARP Retry count exceeded; starting again\n"); + NetArpWaitTry = 0; + NetStartAgain(); + } else { + NetArpWaitTimerStart = t; + ArpRequest(); + } + } +} + +void ArpReceive(Ethernet_t *et, IP_t *ip, int len) +{ + ARP_t *arp; + IPaddr_t tmp; + uchar *pkt; + + /* + * We have to deal with two types of ARP packets: + * - REQUEST packets will be answered by sending our + * IP address - if we know it. + * - REPLY packates are expected only after we asked + * for the TFTP server's or the gateway's ethernet + * address; so if we receive such a packet, we set + * the server ethernet address + */ + debug("Got ARP\n"); + + arp = (ARP_t *)ip; + if (len < ARP_HDR_SIZE) { + printf("bad length %d < %d\n", len, ARP_HDR_SIZE); + return; + } + if (ntohs(arp->ar_hrd) != ARP_ETHER) + return; + if (ntohs(arp->ar_pro) != PROT_IP) + return; + if (arp->ar_hln != 6) + return; + if (arp->ar_pln != 4) + return; + + if (NetOurIP == 0) + return; + + if (NetReadIP(&arp->ar_data[16]) != NetOurIP) + return; + + switch (ntohs(arp->ar_op)) { + case ARPOP_REQUEST: + /* reply with our IP address */ + debug("Got ARP REQUEST, return our IP\n"); + pkt = (uchar *)et; + pkt += NetSetEther(pkt, et->et_src, PROT_ARP); + arp->ar_op = htons(ARPOP_REPLY); + memcpy(&arp->ar_data[10], &arp->ar_data[0], 6); + NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]); + memcpy(&arp->ar_data[0], NetOurEther, 6); + NetCopyIP(&arp->ar_data[6], &NetOurIP); + (void) eth_send((uchar *)et, + (pkt - (uchar *)et) + ARP_HDR_SIZE); + return; + + case ARPOP_REPLY: /* arp reply */ + /* are we waiting for a reply */ + if (!NetArpWaitPacketIP || !NetArpWaitPacketMAC) + break; + +#ifdef CONFIG_KEEP_SERVERADDR + if (NetServerIP == NetArpWaitPacketIP) { + char buf[20]; + sprintf(buf, "%pM", arp->ar_data); + setenv("serveraddr", buf); + } +#endif + + tmp = NetReadIP(&arp->ar_data[6]); + + /* matched waiting packet's address */ + if (tmp == NetArpWaitReplyIP) { + debug("Got ARP REPLY, set eth addr (%pM)\n", + arp->ar_data); + + /* save address for later use */ + memcpy(NetArpWaitPacketMAC, + &arp->ar_data[0], 6); + +#ifdef CONFIG_NETCONSOLE + NetGetHandler()(0, 0, 0, 0, 0); +#endif + /* modify header, and transmit it */ + memcpy(((Ethernet_t *)NetArpWaitTxPacket)-> + et_dest, NetArpWaitPacketMAC, 6); + (void) eth_send(NetArpWaitTxPacket, + NetArpWaitTxPacketSize); + + /* no arp request pending now */ + NetArpWaitPacketIP = 0; + NetArpWaitTxPacketSize = 0; + NetArpWaitPacketMAC = NULL; + + } + return; + default: + debug("Unexpected ARP opcode 0x%x\n", + ntohs(arp->ar_op)); + return; + } +} |