Modules/IPStack/icmp.c

   1 /*
   2  * Acess2 IP Stack
   3  * - ICMP Handling
   4  */
   5 #include "ipstack.h"
   6 #include "ipv4.h"
   7 #include "icmp.h"
   8
   9 // === CONSTANTS ===
  10 #define PING_SLOTS      64
  11
  12 // === PROTOTYPES ===
  13 void    ICMP_Initialise();
  14 void    ICMP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer);
  15
  16 // === GLOBALS ===
  17 struct {
  18         tInterface      *Interface;
  19          int    bArrived;
  20 }       gICMP_PingSlots[PING_SLOTS];
  21
  22 // === CODE ===
  23 /**
  24  * \fn void ICMP_Initialise()
  25  * \brief Initialise the ICMP Layer
  26  */
  27 void ICMP_Initialise()
  28 {
  29         IPv4_RegisterCallback(IP4PROT_ICMP, ICMP_GetPacket);
  30 }
  31
  32 /**
  33  * \fn void ICMP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
  34  * \brief Handles a packet from the IP Layer
  35  */
  36 void ICMP_GetPacket(tInterface *Interface, void *Address, int Length, void *Buffer)
  37 {
  38         tICMPHeader     *hdr = Buffer;
  39
  40         Log("[ICMP ] hdr->Type = %i", hdr->Type);
  41         Log("[ICMP ] hdr->Code = %i", hdr->Code);
  42         Log("[ICMP ] hdr->Checksum = 0x%x", ntohs(hdr->Checksum));
  43         Log("[ICMP ] hdr->ID = 0x%x", ntohs(hdr->ID));
  44         Log("[ICMP ] hdr->Sequence = 0x%x", ntohs(hdr->Sequence));
  45
  46         switch(hdr->Type)
  47         {
  48         case ICMP_ECHOREPLY:
  49                 if(hdr->Code != 0) {
  50                         Warning("[ICMP ] Code == %i for ICMP Echo Reply, should be 0", hdr->Code);
  51                         return ;
  52                 }
  53                 if(hdr->ID != ~hdr->Sequence) {
  54                         Warning("[ICMP ] ID and Sequence values do not match");
  55                         return ;
  56                 }
  57                 gICMP_PingSlots[hdr->ID].bArrived = 1;
  58                 break;
  59         }
  60
  61 }
  62
  63 /**
  64  * \brief Sends ICMP Echo and waits for the reply
  65  * \note Times out after \a Interface->TimeoutDelay has elapsed
  66  */
  67 int ICMP_Ping(tInterface *Interface, tIPv4 Addr)
  68 {
  69         //Sint64        ts;
  70         char    buf[32] = "\x8\0\0\0\0\0\0\0Acess2 I"
  71                       "P/TCP Stack 1.0\0";
  72         tICMPHeader     *hdr = (void*)buf;
  73          int    i;
  74
  75         for(;;)
  76         {
  77                 for(i=0;i<PING_SLOTS;i++)
  78                 {
  79                         if(gICMP_PingSlots[i].Interface == NULL)        break;
  80                 }
  81                 if(gICMP_PingSlots[i].Interface == NULL)        break;
  82                 Threads_Yield();
  83         }
  84         gICMP_PingSlots[i].Interface = Interface;
  85         gICMP_PingSlots[i].bArrived = 0;
  86         hdr->ID = i;
  87         hdr->Sequence = ~i;
  88         hdr->Checksum = htons( IPv4_Checksum(hdr, sizeof(buf)) );
  89         IPv4_SendPacket(Interface, Addr, 1, i, 32, buf);
  90
  91         return -1;
  92 }