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         uchar *pkt;
  44         int eth_hdr_size;
  45
  46         /* XXX always send arp request */
  47
  48         debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &NetPingIP);
  49
  50         NetArpWaitPacketIP = NetPingIP;
  51
  52         eth_hdr_size = NetSetEther(NetTxPacket, NetEtherNullAddr, PROT_IP);
  53         pkt = (uchar *)NetTxPacket + eth_hdr_size;
  54
  55         set_icmp_header(pkt, NetPingIP);
  56
  57         /* size of the waiting packet */
  58         NetArpWaitTxPacketSize = eth_hdr_size + IP_ICMP_HDR_SIZE;
  59
  60         /* and do the ARP request */
  61         NetArpWaitTry = 1;
  62         NetArpWaitTimerStart = get_timer(0);
  63         ArpRequest();
  64         return 1;       /* waiting */
  65 }
  66
  67 static void ping_timeout(void)
  68 {
  69         eth_halt();
  70         net_set_state(NETLOOP_FAIL);    /* we did not get the reply */
  71 }
  72
  73 void ping_start(void)
  74 {
  75         printf("Using %s device\n", eth_get_name());
  76         NetSetTimeout(10000UL, ping_timeout);
  77
  78         ping_send();
  79 }
  80
  81 void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
  82 {
  83         struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
  84         IPaddr_t src_ip;
  85         int eth_hdr_size;
  86
  87         switch (icmph->type) {
  88         case ICMP_ECHO_REPLY:
  89                 src_ip = NetReadIP((void *)&ip->ip_src);
  90                 if (src_ip == NetPingIP)
  91                         net_set_state(NETLOOP_SUCCESS);
  92                 return;
  93         case ICMP_ECHO_REQUEST:
  94                 eth_hdr_size = net_update_ether(et, et->et_src, PROT_IP);
  95
  96                 debug_cond(DEBUG_DEV_PKT, "Got ICMP ECHO REQUEST, return "
  97                         "%d bytes\n", eth_hdr_size + len);
  98
  99                 ip->ip_sum = 0;
 100                 ip->ip_off = 0;
 101                 NetCopyIP((void *)&ip->ip_dst, &ip->ip_src);
 102                 NetCopyIP((void *)&ip->ip_src, &NetOurIP);
 103                 ip->ip_sum = ~NetCksum((uchar *)ip,
 104                                        IP_HDR_SIZE >> 1);
 105
 106                 icmph->type = ICMP_ECHO_REPLY;
 107                 icmph->checksum = 0;
 108                 icmph->checksum = ~NetCksum((uchar *)icmph,
 109                         (len - IP_HDR_SIZE) >> 1);
 110                 NetSendPacket((uchar *)et, eth_hdr_size + len);
 111                 return;
 112 /*      default:
 113                 return;*/
 114         }
 115 }