net/ping.c

   1 /*
   2  *      Copied from Linux Monitor (LiMon) - Networking.
   3  *
   4  *      Copyright 1994 - 2000 Neil Russell.
   5  *      (See License)
   6  *      Copyright 2000 Roland Borde
   7  *      Copyright 2000 Paolo Scaffardi
   8  *      Copyright 2000-2002 Wolfgang Denk, wd@denx.de
   9  */
  10
  11 #include "ping.h"
  12 #include "arp.h"
  13
  14 static ushort PingSeqNo;
  15
  16 /* The ip address to ping */
  17 IPaddr_t NetPingIP;
  18
  19 static void set_icmp_header(uchar *pkt, IPaddr_t dest)
  20 {
  21         /*
  22          *      Construct an IP and ICMP header.
  23          */
  24         struct ip_hdr *ip = (struct ip_hdr *)pkt;
  25         struct icmp_hdr *icmp = (struct icmp_hdr *)(pkt + IP_HDR_SIZE);
  26
  27         net_set_ip_header(pkt, dest, NetOurIP);
  28
  29         ip->ip_len   = htons(IP_ICMP_HDR_SIZE);
  30         ip->ip_p     = IPPROTO_ICMP;
  31         ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE >> 1);
  32
  33         icmp->type = ICMP_ECHO_REQUEST;
  34         icmp->code = 0;
  35         icmp->checksum = 0;
  36         icmp->un.echo.id = 0;
  37         icmp->un.echo.sequence = htons(PingSeqNo++);
  38         icmp->checksum = ~NetCksum((uchar *)icmp, ICMP_HDR_SIZE >> 1);
  39 }
  40
  41 static int ping_send(void)
  42 {
  43         static uchar mac[6];
  44         uchar *pkt;
  45         int eth_hdr_size;
  46
  47         /* XXX always send arp request */
  48
  49         memcpy(mac, NetEtherNullAddr, 6);
  50
  51         debug("sending ARP for %pI4\n", &NetPingIP);
  52
  53         NetArpWaitPacketIP = NetPingIP;
  54         NetArpWaitPacketMAC = mac;
  55
  56         pkt = NetArpWaitTxPacket;
  57         eth_hdr_size = NetSetEther(pkt, mac, PROT_IP);
  58         pkt += eth_hdr_size;
  59
  60         set_icmp_header(pkt, NetPingIP);
  61
  62         /* size of the waiting packet */
  63         NetArpWaitTxPacketSize = eth_hdr_size + IP_ICMP_HDR_SIZE;
  64
  65         /* and do the ARP request */
  66         NetArpWaitTry = 1;
  67         NetArpWaitTimerStart = get_timer(0);
  68         ArpRequest();
  69         return 1;       /* waiting */
  70 }
  71
  72 static void ping_timeout(void)
  73 {
  74         eth_halt();
  75         NetState = NETLOOP_FAIL;        /* we did not get the reply */
  76 }
  77
  78 void ping_start(void)
  79 {
  80         printf("Using %s device\n", eth_get_name());
  81         NetSetTimeout(10000UL, ping_timeout);
  82
  83         ping_send();
  84 }
  85
  86 void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
  87 {
  88         struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
  89         IPaddr_t src_ip;
  90
  91         switch (icmph->type) {
  92         case ICMP_ECHO_REPLY:
  93                 src_ip = NetReadIP((void *)&ip->ip_src);
  94                 if (src_ip == NetPingIP)
  95                         NetState = NETLOOP_SUCCESS;
  96                 return;
  97         case ICMP_ECHO_REQUEST:
  98                 debug("Got ICMP ECHO REQUEST, return "
  99                         "%d bytes\n", ETHER_HDR_SIZE + len);
 100
 101                 memcpy(&et->et_dest[0], &et->et_src[0], 6);
 102                 memcpy(&et->et_src[0], NetOurEther, 6);
 103
 104                 ip->ip_sum = 0;
 105                 ip->ip_off = 0;
 106                 NetCopyIP((void *)&ip->ip_dst, &ip->ip_src);
 107                 NetCopyIP((void *)&ip->ip_src, &NetOurIP);
 108                 ip->ip_sum = ~NetCksum((uchar *)ip,
 109                                        IP_HDR_SIZE >> 1);
 110
 111                 icmph->type = ICMP_ECHO_REPLY;
 112                 icmph->checksum = 0;
 113                 icmph->checksum = ~NetCksum((uchar *)icmph,
 114                         (len - IP_HDR_SIZE) >> 1);
 115                 NetSendPacket((uchar *)et, ETHER_HDR_SIZE + len);
 116                 return;
 117 /*      default:
 118                 return;*/
 119         }
 120 }