/*
* Copyright (c) Martin Schoeberl, martin@jopdesign.com
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Martin Schoeberl
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS 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 THE REGENTS OR 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.
*
*/
/*
* Changelog:
* 2002-11-11 use LinkLayer info to mix Slip and Ethernet packets
*/
package ejip_old;
import util.Dbg;
/**
* Packet buffer handling for a minimalistic TCP/IP stack.
*
*/
public class Packet {
public final static int MAX = 1500; // maximum Packet length in bytes
// public final static int MAX = StackParameters.PACKET_MTU_SIZE;
public final static int MAXW = 1500/4; // maximum Packet length in word
public final static int MAXLLH = 7; // 7 16 bit words for ethernet
private final static int CNT = 8; // size of packet pool
// private final static int CNT = StackParameters.PACKET_POOL_SIZE;
/** interface source/destination */
public LinkLayer interf;
/** place for link layer data */
public int[] llh;
/** Buffer for the ip datagram */
public int[] buf;
/** Packet length in bytes */
public int len;
/** Current status of the packet. */
private int status;
/** The packet is free to use. */
public final static int FREE = 0;
/** Allocated and either under interpretation or under construction. */
public final static int ALLOC = 1;
/** A datagram packet ready to be sent by the link layer. */
public final static int SND_DGRAM = 2;
/** Received packet ready to be processed by the network stack. */
public final static int RCV = 3;
/** A TCP packet ready to be sent. This will go to TCP_ONFLY after sending. */
public final static int SND_TCP = 4;
/** A sent and not acked TCP packet. Can be resent after a timeout. */
public final static int TCP_ONFLY = 5;
private static Object mutex;
// no direct construction
private Packet() {
llh = new int[MAXLLH];
buf = new int[MAXW];
len = 0;
status = FREE;
interf = null;
}
private static Packet[] packets;
static {
mutex = new Object();
packets = new Packet[CNT];
for (int i=0; i<CNT; ++i) { // @WCA loop=8
packets[i] = new Packet();
}
}
private static void dbg() {
synchronized (mutex) {
Dbg.wr('|');
for (int i=0; i<CNT; ++i) { // @WCA loop=8
Dbg.wr('0'+packets[i].status);
}
Dbg.wr('|');
}
}
/**
* Request a packet of a given type from the pool and set new type.
*/
public static Packet getPacket(int type, int newType) {
int i;
Packet p;
synchronized (mutex) {
for (i=0; i<CNT; ++i) { // @WCA loop=8
if (packets[i].status==type) {
break;
}
}
if (i==CNT) {
if (type==FREE) Dbg.wr('!');
return null;
}
packets[i].status = newType;
p = packets[i];
}
// dbg();
return p;
}
/**
* Request a packet of a given type from the pool and set new type and source.
*/
public static Packet getPacket(int type, int newType, LinkLayer s) {
int i;
Packet p;
synchronized (mutex) {
for (i=0; i<CNT; ++i) { // @WCA loop=8
if (packets[i].status==type) {
break;
}
}
if (i==CNT) {
if (type==FREE) Dbg.wr('!');
return null;
}
packets[i].status = newType;
packets[i].interf = s;
p = packets[i];
}
// dbg();
return p;
}
/**
* Request a packet of a given type and source from the pool and set new type.
*/
public static Packet getPacket(LinkLayer s, int type, int newType) {
int i;
Packet p = null;
synchronized (mutex) {
for (i=0; i<CNT; ++i) { // @WCA loop=8
p = packets[i];
if (p.status==type && packets[i].interf==s) {
p.status = newType;
break;
}
}
}
if (i==CNT) {
p = null;
}
return p;
}
/**
* Get a packet with either status SND or SND_TCP.
* Keep the status as it is needed in the link layer.
* @param s link layer for this packet.
* @return a Packet
*/
public static Packet getTxPacket(LinkLayer s) {
int i;
Packet p = null;
synchronized (mutex) {
for (i=0; i<CNT; ++i) { // @WCA loop=8
p = packets[i];
if ((p.status==SND_DGRAM || p.status==SND_TCP)
&& packets[i].interf==s) {
break;
}
}
}
if (i==CNT) {
p = null;
}
return p;
}
public void setStatus(int v) {
synchronized (mutex) {
status = v;
}
// dbg();
}
public int getStatus() {
return status;
}
public LinkLayer getLinkLayer() {
return interf;
}
/**
* Make a deep copy from Packet p. Used just for ARP requests
* with a TCP packet as the TCP packet is kept in the connection.
* @param p
*/
public void copy(Packet p) {
int i;
synchronized (mutex) {
this.len = p.len;
this.interf = p.interf;
for (i=0; i<MAXLLH; ++i) { // @WCA loop=7
this.llh[i] = p.llh[i];
}
for (i=0; i<MAXW; ++i) { // @WCA loop=375
this.buf[i] = p.buf[i];
}
}
}
}