/**
* \addtogroup uIP
* @{
*/
/**
* \file
* The uIP TCP/IP stack code.
* \author Adam Dunkels <adam@dunkels.com>
*/
/*
* Copyright (c) 2001-2003, Adam Dunkels.
* 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 name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* This file is part of the uIP TCP/IP stack.
*
* $Id: uip.c,v 1.62.2.10 2003/10/07 13:23:01 adam Exp $
*
*/
/*
This is a small implementation of the IP and TCP protocols (as well as
some basic ICMP stuff). The implementation couples the IP, TCP and the
application layers very tightly. To keep the size of the compiled code
down, this code also features heavy usage of the goto statement.
The principle is that we have a small buffer, called the uip_buf, in
which the device driver puts an incoming packet. The TCP/IP stack
parses the headers in the packet, and calls upon the application. If
the remote host has sent data to the application, this data is present
in the uip_buf and the application read the data from there. It is up
to the application to put this data into a byte stream if needed. The
application will not be fed with data that is out of sequence.
If the application whishes to send data to the peer, it should put its
data into the uip_buf, 40 bytes from the start of the buffer. The
TCP/IP stack will calculate the checksums, and fill in the necessary
header fields and finally send the packet back to the peer.
*/
#include "uip.h"
#include "uipopt.h"
#include "uip_arch.h"
#include <stdio.h>
/*-----------------------------------------------------------------------------------*/
/* Variable definitions. */
/* The IP address of this host. If it is defined to be fixed (by setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set here. Otherwise, the address */
#if UIP_FIXEDADDR > 0
const WORD uip_hostaddr[2] =
{HTONS((UIP_IPADDR0 << 8) | UIP_IPADDR1),
HTONS((UIP_IPADDR2 << 8) | UIP_IPADDR3)};
const WORD uip_arp_draddr[2] =
{HTONS((UIP_DRIPADDR0 << 8) | UIP_DRIPADDR1),
HTONS((UIP_DRIPADDR2 << 8) | UIP_DRIPADDR3)};
const WORD uip_arp_netmask[2] =
{HTONS((UIP_NETMASK0 << 8) | UIP_NETMASK1),
HTONS((UIP_NETMASK2 << 8) | UIP_NETMASK3)};
#else
WORD uip_hostaddr[2];
WORD uip_arp_draddr[2], uip_arp_netmask[2];
#endif /* UIP_FIXEDADDR */
BYTE uip_buf[UIP_BUFSIZE+2]={0}; /* The packet buffer that contains
incoming packets. */
volatile BYTE *uip_appdata; /* The uip_appdata pointer points to
application data. */
volatile BYTE *uip_sappdata; /* The uip_appdata pointer points to the
application data which is to be sent. */
#if UIP_URGDATA > 0
volatile BYTE *uip_urgdata; /* The uip_urgdata pointer points to
urgent data (out-of-band data), if
present. */
volatile BYTE uip_urglen, uip_surglen;
#endif /* UIP_URGDATA > 0 */
volatile WORD uip_len, uip_slen;
/* The uip_len is either 8 or 16 bits,
depending on the maximum packet
size. */
volatile BYTE uip_flags; /* The uip_flags variable is used for
communication between the TCP/IP stack
and the application program. */
struct uip_conn *uip_conn; /* uip_conn always points to the current
connection. */
struct uip_conn uip_conns[UIP_CONNS];
/* The uip_conns array holds all TCP
connections. */
WORD uip_listenports[UIP_LISTENPORTS];
/* The uip_listenports list all currently
listning ports. */
#if UIP_UDP
struct uip_udp_conn *uip_udp_conn;
struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
#endif /* UIP_UDP */
static WORD ipid; /* Ths ipid variable is an increasing
number that is used for the IP ID
field. */
static BYTE iss[4]; /* The iss variable is used for the TCP
initial sequence number. */
#if UIP_ACTIVE_OPEN
static WORD lastport; /* Keeps track of the last port used for
a new connection. */
#endif /* UIP_ACTIVE_OPEN */
/* Temporary variables. */
volatile BYTE uip_acc32[4];
static BYTE c, opt;
static WORD tmp16;
/* Structures and definitions. */
#define TCP_FIN 0x01
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define TCP_PSH 0x08
#define TCP_ACK 0x10
#define TCP_URG 0x20
#define TCP_CTL 0x3f
#define ICMP_ECHO_REPLY 0
#define ICMP_ECHO 8
/* Macros. */
#define BUF ((uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define FBUF ((uip_tcpip_hdr *)&uip_reassbuf[0])
#define ICMPBUF ((uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UDPBUF ((uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
#if UIP_STATISTICS == 1
struct uip_stats uip_stat;
#define UIP_STAT(s) s
#else
#define UIP_STAT(s)
#endif /* UIP_STATISTICS == 1 */
#if UIP_LOGGING == 1
#include <stdio.h>
void uip_log(char *msg);
#define UIP_LOG(m) uip_log(m)
#else
#define UIP_LOG(m)
#endif /* UIP_LOGGING == 1 */
/*-----------------------------------------------------------------------------------*/
void
uip_init(void)
{
for(c = 0; c < UIP_LISTENPORTS; ++c) {
uip_listenports[c] = 0;
}
for(c = 0; c < UIP_CONNS; ++c) {
uip_conns[c].tcpstateflags = CLOSED;
}
#if UIP_ACTIVE_OPEN
lastport = 1024;
#endif /* UIP_ACTIVE_OPEN */
#if UIP_UDP
for(c = 0; c < UIP_UDP_CONNS; ++c) {
uip_udp_conns[c].lport = 0;
}
#endif /* UIP_UDP */
/* IPv4 initialization. */
#if UIP_FIXEDADDR == 0
uip_hostaddr[0] = uip_hostaddr[1] = 0;
#endif /* UIP_FIXEDADDR */
}
/*-----------------------------------------------------------------------------------*/
#if UIP_ACTIVE_OPEN
struct uip_conn *
uip_connect(WORD *ripaddr, WORD rport)
{
register struct uip_conn *conn, *cconn;
/* Find an unused local port. */
again:
++lastport;
if(lastport >= 32000) {
lastport = 4096;
}
/* Check if this port is already in use, and if so try to find
another one. */
for(c = 0; c < UIP_CONNS; ++c) {
conn = &uip_conns[c];
if(conn->tcpstateflags != CLOSED &&
conn->lport == htons(lastport)) {
goto again;
}
}
conn = 0;
for(c = 0; c < UIP_CONNS; ++c) {
cconn = &uip_conns[c];
if(cconn->tcpstateflags == CLOSED) {
conn = cconn;
break;
}
if(cconn->tcpstateflags == TIME_WAIT) {
if(conn == 0 ||
cconn->timer > uip_conn->timer) {
conn = cconn;
}
}
}
if(conn == 0) {
return 0;
}
conn->tcpstateflags = SYN_SENT;
conn->snd_nxt[0] = iss[0];
conn->snd_nxt[1] = iss[1];
conn->snd_nxt[2] = iss[2];
conn->snd_nxt[3] = iss[3];
conn->initialmss = conn->mss = UIP_TCP_MSS;
conn->len = 1; /* TCP length of the SYN is one. */
conn->nrtx = 0;
conn->timer = 1; /* Send the SYN next time around. */
conn->rto = UIP_RTO;
conn->sa = 0;
conn->sv = 16;
conn->lport = htons(lastpo