natpptpptalg.c

vxworks下ppp的实现源码

				(sptr_pptp_translation_entry->remote_address == remote_address))
				{
				nat_printf (NAT_PRINTF_TRACE, 
					"Found match for local addr = %08lx, remote addr = %08lx\n\t peers_call_id = %04x in PPTP list\n",
					local_address, remote_address, call_id);

				semGive (pptpListLock);

				return (sptr_pptp_translation_entry);
				}
		}

	nat_printf (NAT_PRINTF_TRACE, 
				"No match for local addr = %08lx, remote addr = %08lx\n\t peers_call_id = %04x in PPTP list\n",
				local_address, remote_address, call_id);

	semGive (pptpListLock);

	return (NULL);
}

/*****************************************************************************
Function:	find_outbound_pptp_entry

Description:
Look for PPTP entry with matching call_id, local address and remote address.
*****************************************************************************/
LOCAL PPTP_TRANSLATION_ENTRY *find_outbound_pptp_entry (
	IP_ADDRESS local_address, IP_ADDRESS remote_address, USHORT call_id,
    PPTP_TRANSLATION_HEADER *sptr_pptp_translation_list)
{
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry;

	semTake (pptpListLock, WAIT_FOREVER);

	for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
		DLL_FIRST ((DL_LIST *) sptr_pptp_translation_list);
		sptr_pptp_translation_entry != NULL;
		sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
			DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry))
		{
			if ((sptr_pptp_translation_entry->call_id == call_id) &&
				(sptr_pptp_translation_entry->local_address == local_address) &&
				(sptr_pptp_translation_entry->remote_address == remote_address))
				{
				nat_printf (NAT_PRINTF_TRACE, 
					"Found match for local addr = %08lx, remote addr = %08lx\n\t call_id = %04x in PPTP list\n",
					local_address, remote_address, call_id);

				semGive (pptpListLock);

				return (sptr_pptp_translation_entry);
				}
		}

	nat_printf (NAT_PRINTF_TRACE, 
				"No match for local addr = %08lx, remote addr = %08lx\n\t call_id = %04x in PPTP list\n",
				local_address, remote_address, call_id);

	semGive (pptpListLock);

	return (NULL);
}

/*****************************************************************************
Function:	find_inbound_pptp_entry

Description:
Look for PPTP entry with call_id, local address and remote address.
*****************************************************************************/
LOCAL PPTP_TRANSLATION_ENTRY *find_inbound_pptp_entry (
	IP_ADDRESS remote_address, USHORT call_id,
    PPTP_TRANSLATION_HEADER *sptr_pptp_translation_list)
{
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry;

	semTake (pptpListLock, WAIT_FOREVER);
    
    /* Look up by spoofed call ID and remote address (NAT'ed client) */
	for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
		DLL_FIRST ((DL_LIST *) sptr_pptp_translation_list);
		sptr_pptp_translation_entry != NULL;
		sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
			DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry))
		{
			if ((sptr_pptp_translation_entry->spoofed_call_id == call_id) &&
				(sptr_pptp_translation_entry->remote_address == remote_address))
				{
				nat_printf (NAT_PRINTF_TRACE, 
					"Found match for remote addr = %08lx\n\t call_id = %04x in PPTP list\n",
					remote_address, call_id);

				semGive (pptpListLock);

				return (sptr_pptp_translation_entry);
				}
		}

    /* Look up by remote address and faked spoofed call ID (NAT'ed server) */
	for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
		DLL_FIRST ((DL_LIST *) sptr_pptp_translation_list);
		sptr_pptp_translation_entry != NULL;
		sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) 
			DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry))
		{
			if ((sptr_pptp_translation_entry->spoofed_call_id == 
                    (remote_address & FAKE_SPOOFED_CALL_ID_MASK)) &&
				(!sptr_pptp_translation_entry->nated_client) &&
				(sptr_pptp_translation_entry->remote_address == remote_address))
				{
				nat_printf (NAT_PRINTF_TRACE, 
					"Found match for remote addr = %08lx\n\t call_id = %04x in PPTP list\n",
					remote_address, call_id);

				semGive (pptpListLock);

				return (sptr_pptp_translation_entry);
				}
		}

	nat_printf (NAT_PRINTF_TRACE, 
				"No match for remote addr = %08lx\n\t call_id = %04x in PPTP list\n",
				remote_address, call_id);

	semGive (pptpListLock);

	return (NULL);
}

/************************************************************************/
LOCAL void nat_pptp_timer (void)
{
    if (nat.single_global_address_enabled == TRUE)
        {
        check_pptp_translation_entry_timer (&pptp_translation_list);
        }
}


/************************************************************************/
static void check_pptp_translation_entry_timer (PPTP_TRANSLATION_HEADER *sptr_pptp_translation_list)
{
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry;
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry_next;
	char addr_str[32];

	semTake (pptpListLock, WAIT_FOREVER);
	for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) DLL_FIRST ((DL_LIST *) sptr_pptp_translation_list);
		sptr_pptp_translation_entry != NULL;
		sptr_pptp_translation_entry = sptr_pptp_translation_entry_next)
		{
		sptr_pptp_translation_entry_next = (PPTP_TRANSLATION_ENTRY *) DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry);

		if (sptr_pptp_translation_entry->pptp_translation_entry_timer > 0x00000000L)
			{
			--sptr_pptp_translation_entry->pptp_translation_entry_timer;
			}
		else
			{
			if (nat.printing_enabled == true || nat.logging_enabled == true)
			    {
			    struct in_addr iaddr;

			    iaddr.s_addr = sptr_pptp_translation_entry->local_address;
			    iaddr.s_addr = htonl(iaddr.s_addr);
			    inet_ntoa_b(iaddr,addr_str);

			    nat_printf (NAT_PRINTF_TRACE, "PPTP translation entry expired, addr: %s\n",addr_str);
                            }

			dllRemove ((DL_LIST *) sptr_pptp_translation_list, 
				(DL_NODE *) sptr_pptp_translation_entry);

			free (sptr_pptp_translation_entry);
			}
		}
	semGive (pptpListLock);
}

/************************************************************************/
static void clear_pptp_translation_entry_list (PPTP_TRANSLATION_HEADER *sptr_pptp_translation_list)
{
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry;
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry_next;

	semTake (pptpListLock, WAIT_FOREVER);
	for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) DLL_FIRST ((DL_LIST *) sptr_pptp_translation_list);
		sptr_pptp_translation_entry != NULL;
		sptr_pptp_translation_entry = sptr_pptp_translation_entry_next)
		{
		sptr_pptp_translation_entry_next = (PPTP_TRANSLATION_ENTRY *) DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry);

		dllRemove ((DL_LIST *) sptr_pptp_translation_list, 
				(DL_NODE *) sptr_pptp_translation_entry);

		free (sptr_pptp_translation_entry);
		}
	semGive (pptpListLock);
}

/************************************************************************/
LOCAL USHORT new_spoofed_call_id(void)
{
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry_next;
	PPTP_TRANSLATION_ENTRY *sptr_pptp_translation_entry;
    BOOL conflict;
	BOOL first_pass;

	first_pass = FALSE;

	for (next_pptp_spoofed_call_id = next_pptp_spoofed_call_id + 1; 
		; next_pptp_spoofed_call_id = next_pptp_spoofed_call_id +1)
		{
		if (next_pptp_spoofed_call_id > UPPER_SPOOFED_CALL_ID_VALUE)
			{
			next_pptp_spoofed_call_id = LOWER_SPOOFED_CALL_ID_VALUE;

			if (first_pass == FALSE)
				first_pass = TRUE;
			else
				return (UPPER_SPOOFED_CALL_ID_VALUE+1);
			}

        conflict = FALSE;

        semTake (pptpListLock, WAIT_FOREVER);
        for (sptr_pptp_translation_entry = (PPTP_TRANSLATION_ENTRY *) DLL_FIRST ((DL_LIST *)&pptp_translation_list);
            sptr_pptp_translation_entry != NULL;
            sptr_pptp_translation_entry = sptr_pptp_translation_entry_next)
            {
            if (sptr_pptp_translation_entry->spoofed_call_id == next_pptp_spoofed_call_id)
                {
                conflict = TRUE;

				break;
                }
            sptr_pptp_translation_entry_next = (PPTP_TRANSLATION_ENTRY *) DLL_NEXT ((DL_NODE *) sptr_pptp_translation_entry);
            }
        semGive (pptpListLock);

   
		if (conflict == TRUE)
			{
			continue;
			}

        return(next_pptp_spoofed_call_id);
        }
}

/**********************************************************************************/
void natPPTPXlatShow()
{
	char					local_addr[INET_ADDR_LEN];
	char					remote_addr[INET_ADDR_LEN];
    char                    type[10];
	int						entry_num;
	PPTP_TRANSLATION_ENTRY*	pptp_entry;
	struct in_addr			iaddr;

	entry_num = 0;
	pptp_entry = (PPTP_TRANSLATION_ENTRY *) DLL_FIRST(
			(DL_LIST *) &pptp_translation_list);

	while (pptp_entry != NULL) 
		{

		if(entry_num==0)
			{
			printf("\n");
			printf("NAT PPTP Client Translation List\n");
			printf("-------------------------------\n");
			printf("#    %-*s CallID   SpoofedCallID   PeersCallID"
					  "  %-*s  Type     Timer\n"
				,15,"Local Address"
				,15,"Remote Address");
			}

			entry_num++;

			iaddr.s_addr = htonl(pptp_entry->local_address);
			inet_ntoa_b(iaddr, local_addr);

			iaddr.s_addr = htonl(pptp_entry->remote_address);
			inet_ntoa_b(iaddr, remote_addr);

            if (pptp_entry->nated_client)
                strcpy(type,"Client");
            else
                strcpy(type,"Server");

			
			printf("%-3d  %-*s %04x        %04x           %04x    " 
					 "   %-*s  %-*s   %5lu\n",
				entry_num, 
				15,local_addr, 
				pptp_entry->call_id,
                pptp_entry->spoofed_call_id,
                pptp_entry->peers_call_id,
				15,remote_addr,
                6,type,
				pptp_entry->pptp_translation_entry_timer
				);
				
			pptp_entry = (PPTP_TRANSLATION_ENTRY *) DLL_NEXT(
				(DL_NODE *) pptp_entry);
			}
}