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
  46         /* XXX always send arp request */
  47
  48         memcpy(mac, NetEtherNullAddr, 6);
  49
  50         debug("sending ARP for %pI4\n", &NetPingIP);
  51
  52         NetArpWaitPacketIP = NetPingIP;
  53         NetArpWaitPacketMAC = mac;
  54
  55         pkt = NetArpWaitTxPacket;
  56         pkt += NetSetEther(pkt, mac, PROT_IP);
  57
  58         set_icmp_header(pkt, NetPingIP);
  59
  60         /* size of the waiting packet */
  61         NetArpWaitTxPacketSize =
  62                 (pkt - NetArpWaitTxPacket) + IP_HDR_SIZE + 8;
  63
  64         /* and do the ARP request */
  65         NetArpWaitTry = 1;
  66         NetArpWaitTimerStart = get_timer(0);
  67         ArpRequest();
  68         return 1;       /* waiting */
  69 }
  70
  71 static void ping_timeout(void)
  72 {
  73         eth_halt();
  74         NetState = NETLOOP_FAIL;        /* we did not get the reply */
  75 }
  76
  77 static void ping_handler(uchar *pkt, unsigned dest, IPaddr_t sip,
  78             unsigned src, unsigned len)
  79 {
  80         if (sip != NetPingIP)
  81                 return;
  82
  83         NetState = NETLOOP_SUCCESS;
  84 }
  85
  86 void ping_start(void)
  87 {
  88         printf("Using %s device\n", eth_get_name());
  89         NetSetTimeout(10000UL, ping_timeout);
  90         NetSetHandler(ping_handler);
  91
  92         ping_send();
  93 }
  94
  95 void ping_receive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
  96 {
  97         struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
  98         IPaddr_t src_ip;
  99
 100         switch (icmph->type) {
 101         case ICMP_ECHO_REPLY:
 102                 /*
 103                  * IP header OK.  Pass the packet to the
 104                  * current handler.
 105                  */
 106                 /* XXX point to ip packet */
 107                 src_ip = NetReadIP((void *)&ip->ip_src);
 108                 NetGetHandler()((uchar *)ip, 0, src_ip, 0, 0);
 109                 return;
 110         case ICMP_ECHO_REQUEST:
 111                 debug("Got ICMP ECHO REQUEST, return "
 112                         "%d bytes\n", ETHER_HDR_SIZE + len);
 113
 114                 memcpy(&et->et_dest[0], &et->et_src[0], 6);
 115                 memcpy(&et->et_src[0], NetOurEther, 6);
 116
 117                 ip->ip_sum = 0;
 118                 ip->ip_off = 0;
 119                 NetCopyIP((void *)&ip->ip_dst, &ip->ip_src);
 120                 NetCopyIP((void *)&ip->ip_src, &NetOurIP);
 121                 ip->ip_sum = ~NetCksum((uchar *)ip,
 122                                        IP_HDR_SIZE >> 1);
 123
 124                 icmph->type = ICMP_ECHO_REPLY;
 125                 icmph->checksum = 0;
 126                 icmph->checksum = ~NetCksum((uchar *)icmph,
 127                         (len - IP_HDR_SIZE) >> 1);
 128                 (void) eth_send((uchar *)et,
 129                                 ETHER_HDR_SIZE + len);
 130                 return;
 131 /*      default:
 132                 return;*/
 133         }
 134 }