📄 ip.c
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/** \file ip.c
* \brief OpenTCP IP protocol implementation
* \author
* \li Jari Lahti (jari.lahti@violasystems.com)
* \li Vladan Jovanovic (vladan.jovanovic@violasystems.com)
* \version 1.0
* \date 11.6.2002
* \bug
* \warning
* \todo
* \li Implement stub handler for supporting fragmented datagrams (
* may be usefull on MCUs with lots of available RAM)
*
* OpenTCP IP protocol implementation functions. For declaration,
* constants and data structures refer to ip.h.
*/
/*
*Copyright (c) 2000-2002 Viola Systems Ltd.
*All rights reserved.
*
*Redistribution and use in source and binary forms, with or without
*modification, are permitted provided that the following conditions
*are met:
*
*1. Redistributions of source code must retain the above copyright
*notice, this list of conditions and the following disclaimer.
*
*2. Redistributions in binary form must reproduce the above copyright
*notice, this list of conditions and the following disclaimer in the
*documentation and/or other materials provided with the distribution.
*
*3. The end-user documentation included with the redistribution, if
*any, must include the following acknowledgment:
* "This product includes software developed by Viola
* Systems (http://www.violasystems.com/)."
*
*Alternately, this acknowledgment may appear in the software itself,
*if and wherever such third-party acknowledgments normally appear.
*
*4. The names "OpenTCP" and "Viola Systems" must not be used to
*endorse or promote products derived from this software without prior
*written permission. For written permission, please contact
*opentcp@opentcp.org.
*
*5. Products derived from this software may not be called "OpenTCP",
*nor may "OpenTCP" appear in their name, without prior written
*permission of the Viola Systems Ltd.
*
*THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
*WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
*MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
*IN NO EVENT SHALL VIOLA SYSTEMS LTD. OR ITS CONTRIBUTORS BE LIABLE
*FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
*CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
*SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
*BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
*WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
*OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
*EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*====================================================================
*
*OpenTCP is the unified open source TCP/IP stack available on a series
*of 8/16-bit microcontrollers, please see <http://www.opentcp.org>.
*
*For more information on how to network-enable your devices, or how to
*obtain commercial technical support for OpenTCP, please see
*<http://www.violasystems.com/>.
*/
#include <debug.h>
#include <datatypes.h>
#include <ethernet.h>
#include <arp.h>
#include <ip.h>
#include <system.h>
/** \brief Used for storing various information about the incoming IP packet
*
* Various fields from the IP packet are stored in this structure. These
* values are later used from other upper layer protocols (ICMP, UDP, TCP
* and possibly others) to extract needed information about the received
* packet. See ip_frame definition for struct information.
*/
struct ip_frame received_ip_packet;
/** \brief Used for storing various information about the outgoing IP packet
*
* Various fields from the IP packet are stored in this structure. These
* values are filled based on the information supplied by the upper
* layer protocols (ICMP, UDP, TCP and possibly others) and used to form
* a correct IP packet (correct filed values, checksum,..). See ip_frame
* definition for struct information.
*/
struct ip_frame send_ip_packet;
UINT16 ip_id; /**< ID field in the next IP packet that will be sent */
/** \brief Process received IP frame
* \ingroup periodic_functions
* \author
* \li Jari Lahti
* \date 11.06.2002
* \param frame pointer to ethernet_frame structure holding information
* about the received frame that carries IP datagram.
* \return
* \li -1 - IP packet not OK
* \li >0 - Length of next layer data (IP packet OK)
*
* Process received IP packet by checking necessary header information
* and storing it accordingly to received_ip_packet variable. If everything
* checks out, return length of the data carried in the IP datagram (for
* higher-level protocols), otherwise return -1.
*/
INT16 process_ip_in (struct ethernet_frame* frame)
{
UINT8 olen;
UINT8 i;
/* Check for Protocol */
IP_DEBUGOUT("Checking if IP Protocol\n\r");
if( frame->protocol != PROTOCOL_IP )
return(-1);
IP_DEBUGOUT("It's IP\n\r");
if( frame->frame_size < ETH_HEADER_LEN )
return(-1);
if( (frame->frame_size - ETH_HEADER_LEN) < IP_HLEN )
return(-1);
/* Get IP Header Information */
NETWORK_RECEIVE_INITIALIZE(frame->buf_index);
received_ip_packet.vihl = RECEIVE_NETWORK_B();
/* Is it IPv4? */
if( (received_ip_packet.vihl & 0xF0) != 0x40 ) {
IP_DEBUGOUT("ERROR: IP is not version 4!\n\r");
return(-1);
}
IP_DEBUGOUT("IP Version 4 OK!\n\r");
received_ip_packet.tos = RECEIVE_NETWORK_B();
received_ip_packet.tlen = RECEIVE_NETWORK_W();
received_ip_packet.id = RECEIVE_NETWORK_W();
received_ip_packet.frags = RECEIVE_NETWORK_W();
received_ip_packet.ttl = RECEIVE_NETWORK_B();
received_ip_packet.protocol = RECEIVE_NETWORK_B();
received_ip_packet.checksum = RECEIVE_NETWORK_W();
received_ip_packet.sip = (((UINT32)RECEIVE_NETWORK_B()) << 24);
received_ip_packet.sip |= (((UINT32)RECEIVE_NETWORK_B()) << 16);
received_ip_packet.sip |= (((UINT32)RECEIVE_NETWORK_B()) << 8);
received_ip_packet.sip |= RECEIVE_NETWORK_B();
received_ip_packet.dip = (((UINT32)RECEIVE_NETWORK_B()) << 24);
received_ip_packet.dip |= (((UINT32)RECEIVE_NETWORK_B()) << 16);
received_ip_packet.dip |= (((UINT32)RECEIVE_NETWORK_B()) << 8);
received_ip_packet.dip |= RECEIVE_NETWORK_B();
/* Is that packet for us? */
if((received_ip_packet.dip != localmachine.localip )&&
(received_ip_packet.dip != IP_BROADCAST_ADDRESS))
{
/* It's not for us. Check still if ICMP with rigth physical */
/* address that migth be used to set temporary IP */
IP_DEBUGOUT("IP address does not match!\n\r");
if( received_ip_packet.protocol != IP_ICMP)
return(-1);
/* Check physical address */
for(i=0; i<PHY_ADR_LEN; i++)
{
if(frame->destination[i] != localmachine.localHW[i])
return(-1);
}
}
/* Is there options to copy? */
olen = ((received_ip_packet.vihl & 0x0F) << 2) - IP_MIN_HLEN;
/* Somebody bluffing with too long option field? */
if(olen > MAX_IP_OPTLEN) {
IP_DEBUGOUT("ERROR:Size of maximum allowed IP option lengt exceeded!\n\r");
return(-1);
}
if( olen > (frame->frame_size - ETH_HEADER_LEN - IP_HLEN) ) {
IP_DEBUGOUT("ERROR:IP option field too long!\n\r");
return(-1);
}
for( i=0; i < olen; i++ ) {
received_ip_packet.opt[i] = RECEIVE_NETWORK_B();
IP_DEBUGOUT("IP Options..\n\r");
}
if(received_ip_packet.tlen > (frame->frame_size - ETH_HEADER_LEN) ) {
IP_DEBUGOUT("ERROR: Total len too long\r\n");
return(-1);
}
/* Is the checksum OK? */
IP_DEBUGOUT("Validating the IP checksum..\n\r");
if ( ip_check_cs(&received_ip_packet) != TRUE ) {
IP_DEBUGOUT("IP Checksum Corrupted..\n\r");
return(-1);
}
IP_DEBUGOUT("..Checksum OK!\n\r");
/* Add the address to ARP cache */
if( received_ip_packet.sip != IP_BROADCAST_ADDRESS)
arp_add( received_ip_packet.sip, &frame->source[0], ARP_TEMP_IP);
/* Calculate the start of next layer data */
received_ip_packet.buf_index = frame->buf_index + IP_HLEN + olen;
/* Is this packet fragmented? */
/* We don't deal with those */
/* TODO: Implement Stub handler for more mem. uP's */
if( received_ip_packet.frags & (IP_MOREFRAGS | IP_FRAGOFF) )
{
IP_DEBUGOUT("Fragmented IP packet\r\n");
return(-1);
}
/* checking moved upwards!
if( received_ip_packet.frags & IP_FRAGOFF ) {
IP_DEBUGOUT("Fragmented IP packet\r\n");
return(-1);
}
*/
IP_DEBUGOUT("Leaving IP succesfully..\n\r");
return(received_ip_packet.tlen - IP_HLEN - olen);
}
/** \brief Try to send out IP frame
* \author
* \li Jari Lahti
* \date 11.06.2002
* \param ipadr remote IP address
* \param pcol protocol over IP used. Can be one of the
* following:
* \li #IP_ICMP
* \li #IP_UDP
* \li #IP_TCP
* \param tos type of service required
* \param ttl time to live header field of IP packet
* \param dat pointer to data buffer
* \param len length of data to be sent in IP datagram
* \return
* \li -1 - general error
* \li -2 - ARP cache not ready
* \li >0 - number of data bytes sent (packet OK)
*
* Invoke this function to perform all of the necessary preparation in
* order to send out an IP packet. These include:
* \li Consulting ARP cache for HW address to send the packet to
* \li Filling send_ip_packet variable with correct values
* \li Calculating checksum for the IP packet
* \li Adding datalink header information
* \li Sending IP header and data
* \li Instructing NIC to send the data
*/
INT16 process_ip_out (UINT32 ipadr, UINT8 pcol, UINT8 tos, UINT8 ttl, UINT8* dat, UINT16 len)
{
struct arp_entry *qstruct;
UINT16 i;
/* Try to get MAC address from ARP cache */
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