diff options
Diffstat (limited to 'FreeRTOS/Demo/uIP_Demo_Rowley_ARM7/uip/uip.c')
| -rw-r--r-- | FreeRTOS/Demo/uIP_Demo_Rowley_ARM7/uip/uip.c | 1509 |
1 files changed, 0 insertions, 1509 deletions
diff --git a/FreeRTOS/Demo/uIP_Demo_Rowley_ARM7/uip/uip.c b/FreeRTOS/Demo/uIP_Demo_Rowley_ARM7/uip/uip.c deleted file mode 100644 index 3ef7e8d6c..000000000 --- a/FreeRTOS/Demo/uIP_Demo_Rowley_ARM7/uip/uip.c +++ /dev/null @@ -1,1509 +0,0 @@ -/**
- * \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"
-
-/*-----------------------------------------------------------------------------------*/
-/* 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 u16_t uip_hostaddr[2] =
- {HTONS((UIP_IPADDR0 << 8) | UIP_IPADDR1),
- HTONS((UIP_IPADDR2 << 8) | UIP_IPADDR3)};
-const u16_t uip_arp_draddr[2] =
- {HTONS((UIP_DRIPADDR0 << 8) | UIP_DRIPADDR1),
- HTONS((UIP_DRIPADDR2 << 8) | UIP_DRIPADDR3)};
-const u16_t uip_arp_netmask[2] =
- {HTONS((UIP_NETMASK0 << 8) | UIP_NETMASK1),
- HTONS((UIP_NETMASK2 << 8) | UIP_NETMASK3)};
-#else
-u16_t uip_hostaddr[2];
-u16_t uip_arp_draddr[2], uip_arp_netmask[2];
-#endif /* UIP_FIXEDADDR */
-
-u8_t uip_buf[UIP_BUFSIZE+2]; /* The packet buffer that contains
- incoming packets. */
-volatile u8_t *uip_appdata; /* The uip_appdata pointer points to
- application data. */
-volatile u8_t *uip_sappdata; /* The uip_appdata pointer points to the
- application data which is to be sent. */
-#if UIP_URGDATA > 0
-volatile u8_t *uip_urgdata; /* The uip_urgdata pointer points to
- urgent data (out-of-band data), if
- present. */
-volatile u8_t uip_urglen, uip_surglen;
-#endif /* UIP_URGDATA > 0 */
-
-volatile u16_t uip_len, uip_slen;
- /* The uip_len is either 8 or 16 bits,
- depending on the maximum packet
- size. */
-
-volatile u8_t 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. */
-u16_t 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 u16_t ipid; /* Ths ipid variable is an increasing
- number that is used for the IP ID
- field. */
-
-static u8_t iss[4]; /* The iss variable is used for the TCP
- initial sequence number. */
-
-#if UIP_ACTIVE_OPEN
-static u16_t lastport; /* Keeps track of the last port used for
- a new connection. */
-#endif /* UIP_ACTIVE_OPEN */
-
-/* Temporary variables. */
-volatile u8_t uip_acc32[4];
-static u8_t c, opt;
-static u16_t 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(u16_t *ripaddr, u16_t 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(lastport);
- conn->rport = rport;
- conn->ripaddr[0] = ripaddr[0];
- conn->ripaddr[1] = ripaddr[1];
-
- return conn;
-}
-#endif /* UIP_ACTIVE_OPEN */
-/*-----------------------------------------------------------------------------------*/
-#if UIP_UDP
-struct uip_udp_conn *
-uip_udp_new(u16_t *ripaddr, u16_t rport)
-{
- register struct uip_udp_conn *conn;
-
- /* Find an unused local port. */
- again:
- ++lastport;
-
- if(lastport >= 32000) {
- lastport = 4096;
- }
-
- for(c = 0; c < UIP_UDP_CONNS; ++c) {
- if(uip_udp_conns[c].lport == lastport) {
- goto again;
- }
- }
-
-
- conn = 0;
- for(c = 0; c < UIP_UDP_CONNS; ++c) {
- if(uip_udp_conns[c].lport == 0) {
- conn = &uip_udp_conns[c];
- break;
- }
- }
-
- if(conn == 0) {
- return 0;
- }
-
- conn->lport = HTONS(lastport);
- conn->rport = HTONS(rport);
- conn->ripaddr[0] = ripaddr[0];
- conn->ripaddr[1] = ripaddr[1];
-
- return conn;
-}
-#endif /* UIP_UDP */
-/*-----------------------------------------------------------------------------------*/
-void
-uip_unlisten(u16_t port)
-{
- for(c = 0; c < UIP_LISTENPORTS; ++c) {
- if(uip_listenports[c] == port) {
- uip_listenports[c] = 0;
- return;
- }
- }
-}
-/*-----------------------------------------------------------------------------------*/
-void
-uip_listen(u16_t port)
-{
- for(c = 0; c < UIP_LISTENPORTS; ++c) {
- if(uip_listenports[c] == 0) {
- uip_listenports[c] = port;
- return;
- }
- }
-}
-/*-----------------------------------------------------------------------------------*/
-/* XXX: IP fragment reassembly: not well-tested. */
-
-#if UIP_REASSEMBLY
-#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
-static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
-static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
-static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
- 0x0f, 0x07, 0x03, 0x01};
-static u16_t uip_reasslen;
-static u8_t uip_reassflags;
-#define UIP_REASS_FLAG_LASTFRAG 0x01
-static u8_t uip_reasstmr;
-
-#define IP_HLEN 20
-#define IP_MF 0x20
-
-static u8_t
-uip_reass(void)
-{
- u16_t offset, len;
- u16_t i;
-
- /* If ip_reasstmr is zero, no packet is present in the buffer, so we
- write the IP header of the fragment into the reassembly
- buffer. The timer is updated with the maximum age. */
- if(uip_reasstmr == 0) {
- memcpy(uip_reassbuf, &BUF->vhl, IP_HLEN);
- uip_reasstmr = UIP_REASS_MAXAGE;
- uip_reassflags = 0;
- /* Clear the bitmap. */
- memset(uip_reassbitmap, sizeof(uip_reassbitmap), 0);
- }
-
- /* Check if the incoming fragment matches the one currently present
- in the reasembly buffer. If so, we proceed with copying the
- fragment into the buffer. */
- if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
- BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
- BUF->destipaddr[0] == FBUF->destipaddr[0] &&
- BUF->destipaddr[1] == FBUF->destipaddr[1] &&
- BUF->ipid[0] == FBUF->ipid[0] &&
- BUF->ipid[1] == FBUF->ipid[1]) {
-
- len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
- offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
-
- /* If the offset or the offset + fragment length overflows the
- reassembly buffer, we discard the entire packet. */
- if(offset > UIP_REASS_BUFSIZE ||
- offset + len > UIP_REASS_BUFSIZE) {
- uip_reasstmr = 0;
- goto nullreturn;
- }
-
- /* Copy the fragment into the reassembly buffer, at the right
- offset. */
- memcpy(&uip_reassbuf[IP_HLEN + offset],
- (char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
- len);
-
- /* Update the bitmap. */
- if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
- /* If the two endpoints are in the same byte, we only update
- that byte. */
-
- uip_reassbitmap[offset / (8 * 8)] |=
- bitmap_bits[(offset / 8 ) & 7] &
- ~bitmap_bits[((offset + len) / 8 ) & 7];
- } else {
- /* If the two endpoints are in different bytes, we update the
- bytes in the endpoints and fill the stuff inbetween with
- 0xff. */
- uip_reassbitmap[offset / (8 * 8)] |=
- bitmap_bits[(offset / 8 ) & 7];
- for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
- uip_reassbitmap[i] = 0xff;
- }
- uip_reassbitmap[(offset + len) / (8 * 8)] |=
- ~bitmap_bits[((offset + len) / 8 ) & 7];
- }
-
- /* If this fragment has the More Fragments flag set to zero, we
- know that this is the last fragment, so we can calculate the
- size of the entire packet. We also set the
- IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
- the final fragment. */
-
- if((BUF->ipoffset[0] & IP_MF) == 0) {
- uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
- uip_reasslen = offset + len;
- }
-
- /* Finally, we check if we have a full packet in the buffer. We do
- this by checking if we have the last fragment and if all bits
- in the bitmap are set. */
- if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
- /* Check all bytes up to and including all but the last byte in
- the bitmap. */
- for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
- if(uip_reassbitmap[i] != 0xff) {
- goto nullreturn;
- }
- }
- /* Check the last byte in the bitmap. It should contain just the
- right amount of bits. */
- if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
- (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
- goto nullreturn;
- }
-
- /* If we have come this far, we have a full packet in the
- buffer, so we allocate a pbuf and copy the packet into it. We
- also reset the timer. */
- uip_reasstmr = 0;
- memcpy(BUF, FBUF, uip_reasslen);
-
- /* Pretend to be a "normal" (i.e., not fragmented) IP packet
- from now on. */
- BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
- BUF->len[0] = uip_reasslen >> 8;
- BUF->len[1] = uip_reasslen & 0xff;
- BUF->ipchksum = 0;
- BUF->ipchksum = ~(uip_ipchksum());
-
- return uip_reasslen;
- }
- }
-
- nullreturn:
- return 0;
-}
-#endif /* UIP_REASSEMBL */
-/*-----------------------------------------------------------------------------------*/
-static void
-uip_add_rcv_nxt(u16_t n)
-{
- uip_add32(uip_conn->rcv_nxt, n);
- uip_conn->rcv_nxt[0] = uip_acc32[0];
- uip_conn->rcv_nxt[1] = uip_acc32[1];
- uip_conn->rcv_nxt[2] = uip_acc32[2];
- uip_conn->rcv_nxt[3] = uip_acc32[3];
-}
-/*-----------------------------------------------------------------------------------*/
-void
-uip_process(u8_t flag)
-{
- register struct uip_conn *uip_connr = uip_conn;
-
- uip_appdata = &uip_buf[40 + UIP_LLH_LEN];
-
-
- /* Check if we were invoked because of the perodic timer fireing. */
- if(flag == UIP_TIMER) {
-#if UIP_REASSEMBLY
- if(uip_reasstmr != 0) {
- --uip_reasstmr;
- }
-#endif /* UIP_REASSEMBLY */
- /* Increase the initial sequence number. */
- if(++iss[3] == 0) {
- if(++iss[2] == 0) {
- if(++iss[1] == 0) {
- ++iss[0];
- }
- }
- }
- uip_len = 0;
- if(uip_connr->tcpstateflags == TIME_WAIT ||
- uip_connr->tcpstateflags == FIN_WAIT_2) {
- ++(uip_connr->timer);
- if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
- uip_connr->tcpstateflags = CLOSED;
- }
- } else if(uip_connr->tcpstateflags != CLOSED) {
- /* If the connection has outstanding data, we increase the
- connection's timer and see if it has reached the RTO value
- in which case we retransmit. */
- if(uip_outstanding(uip_connr)) {
- if(uip_connr->timer-- == 0) {
- if(uip_connr->nrtx == UIP_MAXRTX ||
- ((uip_connr->tcpstateflags == SYN_SENT ||
- uip_connr->tcpstateflags == SYN_RCVD) &&
- uip_connr->nrtx == UIP_MAXSYNRTX)) {
- uip_connr->tcpstateflags = CLOSED;
-
- /* We call UIP_APPCALL() with uip_flags set to
- UIP_TIMEDOUT to inform the application that the
- connection has timed out. */
- uip_flags = UIP_TIMEDOUT;
- UIP_APPCALL();
-
- /* We also send a reset packet to the remote host. */
- BUF->flags = TCP_RST | TCP_ACK;
- goto tcp_send_nodata;
- }
-
- /* Exponential backoff. */
- uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
- 4:
- uip_connr->nrtx);
- ++(uip_connr->nrtx);
-
- /* Ok, so we need to retransmit. We do this differently
- depending on which state we are in. In ESTABLISHED, we
- call upon the application so that it may prepare the
- data for the retransmit. In SYN_RCVD, we resend the
- SYNACK that we sent earlier and in LAST_ACK we have to
- retransmit our FINACK. */
- UIP_STAT(++uip_stat.tcp.rexmit);
- switch(uip_connr->tcpstateflags & TS_MASK) {
- case SYN_RCVD:
- /* In the SYN_RCVD state, we should retransmit our
- SYNACK. */
- goto tcp_send_synack;
-
-#if UIP_ACTIVE_OPEN
- case SYN_SENT:
- /* In the SYN_SENT state, we retransmit out SYN. */
- BUF->flags = 0;
- goto tcp_send_syn;
-#endif /* UIP_ACTIVE_OPEN */
-
- case ESTABLISHED:
- /* In the ESTABLISHED state, we call upon the application
- to do the actual retransmit after which we jump into
- the code for sending out the packet (the apprexmit
- label). */
- uip_len = 0;
- uip_slen = 0;
- uip_flags = UIP_REXMIT;
- UIP_APPCALL();
- goto apprexmit;
-
- case FIN_WAIT_1:
- case CLOSING:
- case LAST_ACK:
- /* In all these states we should retransmit a FINACK. */
- goto tcp_send_finack;
-
- }
- }
- } else if((uip_connr->tcpstateflags & TS_MASK) == ESTABLISHED) {
- /* If there was no need for a retransmission, we poll the
- application for new data. */
- uip_len = 0;
- uip_slen = 0;
- uip_flags = UIP_POLL;
- UIP_APPCALL();
- goto appsend;
- }
- }
- goto drop;
- }
-#if UIP_UDP
- if(flag == UIP_UDP_TIMER) {
- if(uip_udp_conn->lport != 0) {
- uip_appdata = &uip_buf[UIP_LLH_LEN + 28];
- uip_len = uip_slen = 0;
- uip_flags = UIP_POLL;
- UIP_UDP_APPCALL();
- goto udp_send;
- } else {
- goto drop;
- }
- }
-#endif
-
- /* This is where the input processing starts. */
- UIP_STAT(++uip_stat.ip.recv);
-
-
- /* Start of IPv4 input header processing code. */
-
- /* Check validity of the IP header. */
- if(BUF->vhl != 0x45) { /* IP version and header length. */
- UIP_STAT(++uip_stat.ip.drop);
- UIP_STAT(++uip_stat.ip.vhlerr);
- UIP_LOG("ip: invalid version or header length.");
- goto drop;
- }
-
- /* Check the size of the packet. If the size reported to us in
- uip_len doesn't match the size reported in the IP header, there
- has been a transmission error and we drop the packet. */
-
- if(BUF->len[0] != (uip_len >> 8)) { /* IP length, high byte. */
- uip_len = (uip_len & 0xff) | (BUF->len[0] << 8);
- }
- if(BUF->len[1] != (uip_len & 0xff)) { /* IP length, low byte. */
- uip_len = (uip_len & 0xff00) | BUF->len[1];
- }
-
- /* Check the fragment flag. */
- if((BUF->ipoffset[0] & 0x3f) != 0 ||
- BUF->ipoffset[1] != 0) {
-#if UIP_REASSEMBLY
- uip_len = uip_reass();
- if(uip_len == 0) {
- goto drop;
- }
-#else
- UIP_STAT(++uip_stat.ip.drop);
- UIP_STAT(++uip_stat.ip.fragerr);
- UIP_LOG("ip: fragment dropped.");
- goto drop;
-#endif /* UIP_REASSEMBLY */
- }
-
- /* If we are configured to use ping IP address configuration and
- hasn't been assigned an IP address yet, we accept all ICMP
- packets. */
-#if UIP_PINGADDRCONF
- if((uip_hostaddr[0] | uip_hostaddr[1]) == 0) {
- if(BUF->proto == UIP_PROTO_ICMP) {
- UIP_LOG("ip: possible ping config packet received.");
- goto icmp_input;
- } else {
- UIP_LOG("ip: packet dropped since no address assigned.");
- goto drop;
- }
- }
-#endif /* UIP_PINGADDRCONF */
-
- /* Check if the packet is destined for our IP address. */
- if(BUF->destipaddr[0] != uip_hostaddr[0]) {
- UIP_STAT(++uip_stat.ip.drop);
- UIP_LOG("ip: packet not for us.");
- goto drop;
- }
- if(BUF->destipaddr[1] != uip_hostaddr[1]) {
- UIP_STAT(++uip_stat.ip.drop);
- UIP_LOG("ip: packet not for us.");
- goto drop;
- }
-
-#if 0
- // IP checksum is wrong through Netgear DSL router
- if (uip_ipchksum() != 0xffff) { /* Compute and check the IP header
- checksum. */
- UIP_STAT(++uip_stat.ip.drop);
- UIP_STAT(++uip_stat.ip.chkerr);
- UIP_LOG("ip: bad checksum.");
- goto drop;
- }
-#endif
-
- if(BUF->proto == UIP_PROTO_TCP) /* Check for TCP packet. If so, jump
- to the tcp_input label. */
- goto tcp_input;
-
-#if UIP_UDP
- if(BUF->proto == UIP_PROTO_UDP)
- goto udp_input;
-#endif /* UIP_UDP */
-
- if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
- here. */
- UIP_STAT(++uip_stat.ip.drop);
- UIP_STAT(++uip_stat.ip.protoerr);
- UIP_LOG("ip: neither tcp nor icmp.");
- goto drop;
- }
-
- icmp_input:
- UIP_STAT(++uip_stat.icmp.recv);
-
- /* ICMP echo (i.e., ping) processing. This is simple, we only change
- the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
- checksum before we return the packet. */
- if(ICMPBUF->type != ICMP_ECHO) {
- UIP_STAT(++uip_stat.icmp.drop);
- UIP_STAT(++uip_stat.icmp.typeerr);
- UIP_LOG("icmp: not icmp echo.");
- goto drop;
- }
-
- /* If we are configured to use ping IP address assignment, we use
- the destination IP address of this ping packet and assign it to
- ourself. */
-#if UIP_PINGADDRCONF
- if((uip_hostaddr[0] | uip_hostaddr[1]) == 0) {
- uip_hostaddr[0] = BUF->destipaddr[0];
- uip_hostaddr[1] = BUF->destipaddr[1];
- }
-#endif /* UIP_PINGADDRCONF */
-
- ICMPBUF->type = ICMP_ECHO_REPLY;
-
- if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
- ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
- } else {
- ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
- }
-
- /* Swap IP addresses. */
- tmp16 = BUF->destipaddr[0];
- BUF->destipaddr[0] = BUF->srcipaddr[0];
- BUF->srcipaddr[0] = tmp16;
- tmp16 = BUF->destipaddr[1];
- BUF->destipaddr[1] = BUF->srcipaddr[1];
- BUF->srcipaddr[1] = tmp16;
-
- UIP_STAT(++uip_stat.icmp.sent);
- goto send;
-
- /* End of IPv4 input header processing code. */
-
-
-#if UIP_UDP
- /* UDP input processing. */
- udp_input:
- /* UDP processing is really just a hack. We don't do anything to the
- UDP/IP headers, but let the UDP application do all the hard
- work. If the application sets uip_slen, it has a packet to
- send. */
-#if UIP_UDP_CHECKSUMS
- if(uip_udpchksum() != 0xffff) {
- UIP_STAT(++uip_stat.udp.drop);
- UIP_STAT(++uip_stat.udp.chkerr);
- UIP_LOG("udp: bad checksum.");
- goto drop;
- }
-#endif /* UIP_UDP_CHECKSUMS */
-
- /* Demultiplex this UDP packet between the UDP "connections". */
- for(uip_udp_conn = &uip_udp_conns[0];
- uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS];
- ++uip_udp_conn) {
- if(uip_udp_conn->lport != 0 &&
- UDPBUF->destport == uip_udp_conn->lport &&
- (uip_udp_conn->rport == 0 ||
- UDPBUF->srcport == uip_udp_conn->rport) &&
- BUF->srcipaddr[0] == uip_udp_conn->ripaddr[0] &&
- BUF->srcipaddr[1] == uip_udp_conn->ripaddr[1]) {
- goto udp_found;
- }
- }
- goto drop;
-
- udp_found:
- uip_len = uip_len - 28;
- uip_appdata = &uip_buf[UIP_LLH_LEN + 28];
- uip_flags = UIP_NEWDATA;
- uip_slen = 0;
- UIP_UDP_APPCALL();
- udp_send:
- if(uip_slen == 0) {
- goto drop;
- }
- uip_len = uip_slen + 28;
-
- BUF->len[0] = (uip_len >> 8);
- BUF->len[1] = (uip_len & 0xff);
-
- BUF->proto = UIP_PROTO_UDP;
-
- UDPBUF->udplen = HTONS(uip_slen + 8);
- UDPBUF->udpchksum = 0;
-#if UIP_UDP_CHECKSUMS
- /* Calculate UDP checksum. */
- UDPBUF->udpchksum = ~(uip_udpchksum());
- if(UDPBUF->udpchksum == 0) {
- UDPBUF->udpchksum = 0xffff;
- }
-#endif /* UIP_UDP_CHECKSUMS */
-
- BUF->srcport = uip_udp_conn->lport;
- BUF->destport = uip_udp_conn->rport;
-
- BUF->srcipaddr[0] = uip_hostaddr[0];
- BUF->srcipaddr[1] = uip_hostaddr[1];
- BUF->destipaddr[0] = uip_udp_conn->ripaddr[0];
- BUF->destipaddr[1] = uip_udp_conn->ripaddr[1];
-
- uip_appdata = &uip_buf[UIP_LLH_LEN + 40];
- goto ip_send_nolen;
-#endif /* UIP_UDP */
-
- /* TCP input processing. */
- tcp_input:
- UIP_STAT(++uip_stat.tcp.recv);
-
- /* Start of TCP input header processing code. */
-
-#if 1 // FIXME
- if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP
- checksum. */
- UIP_STAT(++uip_stat.tcp.drop);
- UIP_STAT(++uip_stat.tcp.chkerr);
- UIP_LOG("tcp: bad checksum.");
- goto drop;
- }
-#endif
-
- /* Demultiplex this segment. */
- /* First check any active connections. */
- for(uip_connr = &uip_conns[0]; uip_connr < &uip_conns[UIP_CONNS]; ++uip_connr) {
- if(uip_connr->tcpstateflags != CLOSED &&
- BUF->destport == uip_connr->lport &&
- BUF->srcport == uip_connr->rport &&
- BUF->srcipaddr[0] == uip_connr->ripaddr[0] &&
- BUF->srcipaddr[1] == uip_connr->ripaddr[1]) {
- goto found;
- }
- }
-
- /* If we didn't find and active connection that expected the packet,
- either this packet is an old duplicate, or this is a SYN packet
- destined for a connection in LISTEN. If the SYN flag isn't set,
- it is an old packet and we send a RST. */
- if((BUF->flags & TCP_CTL) != TCP_SYN)
- goto reset;
-
- tmp16 = BUF->destport;
- /* Next, check listening connections. */
- for(c = 0; c < UIP_LISTENPORTS; ++c) {
- if(tmp16 == uip_listenports[c])
- goto found_listen;
- }
-
- /* No matching connection found, so we send a RST packet. */
- UIP_STAT(++uip_stat.tcp.synrst);
- reset:
-
- /* We do not send resets in response to resets. */
- if(BUF->flags & TCP_RST)
- goto drop;
-
- UIP_STAT(++uip_stat.tcp.rst);
-
- BUF->flags = TCP_RST | TCP_ACK;
- uip_len = 40;
- BUF->tcpoffset = 5 << 4;
-
- /* Flip the seqno and ackno fields in the TCP header. */
- c = BUF->seqno[3];
- BUF->seqno[3] = BUF->ackno[3];
- BUF->ackno[3] = c;
-
- c = BUF->seqno[2];
- BUF->seqno[2] = BUF->ackno[2];
- BUF->ackno[2] = c;
-
- c = BUF->seqno[1];
- BUF->seqno[1] = BUF->ackno[1];
- BUF->ackno[1] = c;
-
- c = BUF->seqno[0];
- BUF->seqno[0] = BUF->ackno[0];
- BUF->ackno[0] = c;
-
- /* We also have to increase the sequence number we are
- acknowledging. If the least significant byte overflowed, we need
- to propagate the carry to the other bytes as well. */
- if(++BUF->ackno[3] == 0) {
- if(++BUF->ackno[2] == 0) {
- if(++BUF->ackno[1] == 0) {
- ++BUF->ackno[0];
- }
- }
- }
-
- /* Swap port numbers. */
- tmp16 = BUF->srcport;
- BUF->srcport = BUF->destport;
- BUF->destport = tmp16;
-
- /* Swap IP addresses. */
- tmp16 = BUF->destipaddr[0];
- BUF->destipaddr[0] = BUF->srcipaddr[0];
- BUF->srcipaddr[0] = tmp16;
- tmp16 = BUF->destipaddr[1];
- BUF->destipaddr[1] = BUF->srcipaddr[1];
- BUF->srcipaddr[1] = tmp16;
-
-
- /* And send out the RST packet! */
- goto tcp_send_noconn;
-
- /* This label will be jumped to if we matched the incoming packet
- with a connection in LISTEN. In that case, we should create a new
- connection and send a SYNACK in return. */
- found_listen:
- /* First we check if there are any connections avaliable. Unused
- connections are kept in the same table as used connections, but
- unused ones have the tcpstate set to CLOSED. Also, connections in
- TIME_WAIT are kept track of and we'll use the oldest one if no
- CLOSED connections are found. Thanks to Eddie C. Dost for a very
- nice algorithm for the TIME_WAIT search. */
- uip_connr = 0;
- for(c = 0; c < UIP_CONNS; ++c) {
- if(uip_conns[c].tcpstateflags == CLOSED) {
- uip_connr = &uip_conns[c];
- break;
- }
- if(uip_conns[c].tcpstateflags == TIME_WAIT) {
- if(uip_connr == 0 ||
- uip_conns[c].timer > uip_connr->timer) {
- uip_connr = &uip_conns[c];
- }
- }
- }
-
- if(uip_connr == 0) {
- /* All connections are used already, we drop packet and hope that
- the remote end will retransmit the packet at a time when we
- have more spare connections. */
- UIP_STAT(++uip_stat.tcp.syndrop);
- UIP_LOG("tcp: found no unused connections.");
- goto drop;
- }
- uip_conn = uip_connr;
-
- /* Fill in the necessary fields for the new connection. */
- uip_connr->rto = uip_connr->timer = UIP_RTO;
- uip_connr->sa = 0;
- uip_connr->sv = 4;
- uip_connr->nrtx = 0;
- uip_connr->lport = BUF->destport;
- uip_connr->rport = BUF->srcport;
- uip_connr->ripaddr[0] = BUF->srcipaddr[0];
- uip_connr->ripaddr[1] = BUF->srcipaddr[1];
- uip_connr->tcpstateflags = SYN_RCVD;
-
- uip_connr->snd_nxt[0] = iss[0];
- uip_connr->snd_nxt[1] = iss[1];
- uip_connr->snd_nxt[2] = iss[2];
- uip_connr->snd_nxt[3] = iss[3];
- uip_connr->len = 1;
-
- /* rcv_nxt should be the seqno from the incoming packet + 1. */
- uip_connr->rcv_nxt[3] = BUF->seqno[3];
- uip_connr->rcv_nxt[2] = BUF->seqno[2];
- uip_connr->rcv_nxt[1] = BUF->seqno[1];
- uip_connr->rcv_nxt[0] = BUF->seqno[0];
- uip_add_rcv_nxt(1);
-
- /* Parse the TCP MSS option, if present. */
- if((BUF->tcpoffset & 0xf0) > 0x50) {
- for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
- opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
- if(opt == 0x00) {
- /* End of options. */
- break;
- } else if(opt == 0x01) {
- ++c;
- /* NOP option. */
- } else if(opt == 0x02 &&
- uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0x04) {
- /* An MSS option with the right option length. */
- tmp16 = ((u16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
- (u16_t)uip_buf[40 + UIP_LLH_LEN + 3 + c];
- uip_connr->initialmss = uip_connr->mss =
- tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
-
- /* And we are done processing options. */
- break;
- } else {
- /* All other options have a length field, so that we easily
- can skip past them. */
- if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
- /* If the length field is zero, the options are malformed
- and we don't process them further. */
- break;
- }
- c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
- }
- }
- }
-
- /* Our response will be a SYNACK. */
-#if UIP_ACTIVE_OPEN
- tcp_send_synack:
- BUF->flags = TCP_ACK;
-
- tcp_send_syn:
- BUF->flags |= TCP_SYN;
-#else /* UIP_ACTIVE_OPEN */
- tcp_send_synack:
- BUF->flags = TCP_SYN | TCP_ACK;
-#endif /* UIP_ACTIVE_OPEN */
-
- /* We send out the TCP Maximum Segment Size option with our
- SYNACK. */
- BUF->optdata[0] = 2;
- BUF->optdata[1] = 4;
- BUF->optdata[2] = (UIP_TCP_MSS) / 256;
- BUF->optdata[3] = (UIP_TCP_MSS) & 255;
- uip_len = 44;
- BUF->tcpoffset = 6 << 4;
- goto tcp_send;
-
- /* This label will be jumped to if we found an active connection. */
- found:
- uip_conn = uip_connr;
- uip_flags = 0;
-
- /* We do a very naive form of TCP reset processing; we just accept
- any RST and kill our connection. We should in fact check if the
- sequence number of this reset is wihtin our advertised window
- before we accept the reset. */
- if(BUF->flags & TCP_RST) {
- uip_connr->tcpstateflags = CLOSED;
- UIP_LOG("tcp: got reset, aborting connection.");
- uip_flags = UIP_ABORT;
- UIP_APPCALL();
- goto drop;
- }
- /* Calculated the length of the data, if the application has sent
- any data to us. */
- c = (BUF->tcpoffset >> 4) << 2;
- /* uip_len will contain the length of the actual TCP data. This is
- calculated by subtracing the length of the TCP header (in
- c) and the length of the IP header (20 bytes). */
- uip_len = uip_len - c - 20;
-
- /* First, check if the sequence number of the incoming packet is
- what we're expecting next. If not, we send out an ACK with the
- correct numbers in. */
- if(uip_len > 0 &&
- (BUF->seqno[0] != uip_connr->rcv_nxt[0] ||
- BUF->seqno[1] != uip_connr->rcv_nxt[1] ||
- BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
- BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
- goto tcp_send_ack;
- }
-
- /* Next, check if the incoming segment acknowledges any outstanding
- data. If so, we update the sequence number, reset the length of
- the outstanding data, calculate RTT estimations, and reset the
- retransmission timer. */
- if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
- uip_add32(uip_connr->snd_nxt, uip_connr->len);
- if(BUF->ackno[0] == uip_acc32[0] &&
- BUF->ackno[1] == uip_acc32[1] &&
- BUF->ackno[2] == uip_acc32[2] &&
- BUF->ackno[3] == uip_acc32[3]) {
- /* Update sequence number. */
- uip_connr->snd_nxt[0] = uip_acc32[0];
- uip_connr->snd_nxt[1] = uip_acc32[1];
- uip_connr->snd_nxt[2] = uip_acc32[2];
- uip_connr->snd_nxt[3] = uip_acc32[3];
-
-
- /* Do RTT estimation, unless we have done retransmissions. */
- if(uip_connr->nrtx == 0) {
- signed char m;
- m = uip_connr->rto - uip_connr->timer;
- /* This is taken directly from VJs original code in his paper */
- m = m - (uip_connr->sa >> 3);
- uip_connr->sa += m;
- if(m < 0) {
- m = -m;
- }
- m = m - (uip_connr->sv >> 2);
- uip_connr->sv += m;
- uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
-
- }
- /* Set the acknowledged flag. */
- uip_flags = UIP_ACKDATA;
- /* Reset the retransmission timer. */
- uip_connr->timer = uip_connr->rto;
- }
-
- }
-
- /* Do different things depending on in what state the connection is. */
- switch(uip_connr->tcpstateflags & TS_MASK) {
- /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
- implemented, since we force the application to close when the
- peer sends a FIN (hence the application goes directly from
- ESTABLISHED to LAST_ACK). */
- case SYN_RCVD:
- /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
- we are waiting for an ACK that acknowledges the data we sent
- out the last time. Therefore, we want to have the UIP_ACKDATA
- flag set. If so, we enter the ESTABLISHED state. */
- if(uip_flags & UIP_ACKDATA) {
- uip_connr->tcpstateflags = ESTABLISHED;
- uip_flags = UIP_CONNECTED;
- uip_connr->len = 0;
- if(uip_len > 0) {
- uip_flags |= UIP_NEWDATA;
- uip_add_rcv_nxt(uip_len);
- }
- uip_slen = 0;
- UIP_APPCALL();
- goto appsend;
- }
- goto drop;
-#if UIP_ACTIVE_OPEN
- case SYN_SENT:
- /* In SYN_SENT, we wait for a SYNACK that is sent in response to
- our SYN. The rcv_nxt is set to sequence number in the SYNACK
- plus one, and we send an ACK. We move into the ESTABLISHED
- state. */
- if((uip_flags & UIP_ACKDATA) &&
- BUF->flags == (TCP_SYN | TCP_ACK)) {
-
- /* Parse the TCP MSS option, if present. */
- if((BUF->tcpoffset & 0xf0) > 0x50) {
- for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
- opt = uip_buf[40 + UIP_LLH_LEN + c];
- if(opt == 0x00) {
- /* End of options. */
- break;
- } else if(opt == 0x01) {
- ++c;
- /* NOP option. */
- } else if(opt == 0x02 &&
- uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0x04) {
- /* An MSS option with the right option length. */
- tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
- uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
- uip_connr->initialmss =
- uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
-
- /* And we are done processing options. */
- break;
- } else {
- /* All other options have a length field, so that we easily
- can skip past them. */
- if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
- /* If the length field is zero, the options are malformed
- and we don't process them further. */
- break;
- }
- c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
- }
- }
- }
- uip_connr->tcpstateflags = ESTABLISHED;
- uip_connr->rcv_nxt[0] = BUF->seqno[0];
- uip_connr->rcv_nxt[1] = BUF->seqno[1];
- uip_connr->rcv_nxt[2] = BUF->seqno[2];
- uip_connr->rcv_nxt[3] = BUF->seqno[3];
- uip_add_rcv_nxt(1);
- uip_flags = UIP_CONNECTED | UIP_NEWDATA;
- uip_connr->len = 0;
- uip_len = 0;
- uip_slen = 0;
- UIP_APPCALL();
- goto appsend;
- }
- goto reset;
-#endif /* UIP_ACTIVE_OPEN */
-
- case ESTABLISHED:
- /* In the ESTABLISHED state, we call upon the application to feed
- data into the uip_buf. If the UIP_ACKDATA flag is set, the
- application should put new data into the buffer, otherwise we are
- retransmitting an old segment, and the application should put that
- data into the buffer.
-
- If the incoming packet is a FIN, we should close the connection on
- this side as well, and we send out a FIN and enter the LAST_ACK
- state. We require that there is no outstanding data; otherwise the
- sequence numbers will be screwed up. */
-
- if(BUF->flags & TCP_FIN) {
- if(uip_outstanding(uip_connr)) {
- goto drop;
- }
- uip_add_rcv_nxt(1 + uip_len);
- uip_flags = UIP_CLOSE;
- if(uip_len > 0) {
- uip_flags |= UIP_NEWDATA;
- }
- UIP_APPCALL();
- uip_connr->len = 1;
- uip_connr->tcpstateflags = LAST_ACK;
- uip_connr->nrtx = 0;
- tcp_send_finack:
- BUF->flags = TCP_FIN | TCP_ACK;
- goto tcp_send_nodata;
- }
-
- /* Check the URG flag. If this is set, the segment carries urgent
- data that we must pass to the application. */
- if(BUF->flags & TCP_URG) {
-#if UIP_URGDATA > 0
- uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
- if(uip_urglen > uip_len) {
- /* There is more urgent data in the next segment to come. */
- uip_urglen = uip_len;
- }
- uip_add_rcv_nxt(uip_urglen);
- uip_len -= uip_urglen;
- uip_urgdata = uip_appdata;
- uip_appdata += uip_urglen;
- } else {
- uip_urglen = 0;
-#endif /* UIP_URGDATA > 0 */
- uip_appdata += (BUF->urgp[0] << 8) | BUF->urgp[1];
- uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1];
- }
-
-
- /* If uip_len > 0 we have TCP data in the packet, and we flag this
- by setting the UIP_NEWDATA flag and update the sequence number
- we acknowledge. If the application has stopped the dataflow
- using uip_stop(), we must not accept any data packets from the
- remote host. */
- if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
- uip_flags |= UIP_NEWDATA;
- uip_add_rcv_nxt(uip_len);
- }
-
- /* Check if the available buffer space advertised by the other end
- is smaller than the initial MSS for this connection. If so, we
- set the current MSS to the window size to ensure that the
- application does not send more data than the other end can
- handle.
-
- If the remote host advertises a zero window, we set the MSS to
- the initial MSS so that the application will send an entire MSS
- of data. This data will not be acknowledged by the receiver,
- and the application will retransmit it. This is called the
- "persistent timer" and uses the retransmission mechanim.
- */
- tmp16 = ((u16_t)BUF->wnd[0] << 8) + (u16_t)BUF->wnd[1];
- if(tmp16 > uip_connr->initialmss ||
- tmp16 == 0) {
- tmp16 = uip_connr->initialmss;
- }
- uip_connr->mss = tmp16;
-
- /* If this packet constitutes an ACK for outstanding data (flagged
- by the UIP_ACKDATA flag, we should call the application since it
- might want to send more data. If the incoming packet had data
- from the peer (as flagged by the UIP_NEWDATA flag), the
- application must also be notified.
-
- When the application is called, the global variable uip_len
- contains the length of the incoming data. The application can
- access the incoming data through the global pointer
- uip_appdata, which usually points 40 bytes into the uip_buf
- array.
-
- If the application wishes to send any data, this data should be
- put into the uip_appdata and the length of the data should be
- put into uip_len. If the application don't have any data to
- send, uip_len must be set to 0. */
- if(uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) {
- uip_slen = 0;
- UIP_APPCALL();
-
- appsend:
-
- if(uip_flags & UIP_ABORT) {
- uip_slen = 0;
- uip_connr->tcpstateflags = CLOSED;
- BUF->flags = TCP_RST | TCP_ACK;
- goto tcp_send_nodata;
- }
-
- if(uip_flags & UIP_CLOSE) {
- uip_slen = 0;
- uip_connr->len = 1;
- uip_connr->tcpstateflags = FIN_WAIT_1;
- uip_connr->nrtx = 0;
- BUF->flags = TCP_FIN | TCP_ACK;
- goto tcp_send_nodata;
- }
-
- /* If uip_slen > 0, the application has data to be sent. */
- if(uip_slen > 0) {
-
- /* If the connection has acknowledged data, the contents of
- the ->len variable should be discarded. */
- if((uip_flags & UIP_ACKDATA) != 0) {
- uip_connr->len = 0;
- }
-
- /* If the ->len variable is non-zero the connection has
- already data in transit and cannot send anymore right
- now. */
- if(uip_connr->len == 0) {
-
- /* The application cannot send more than what is allowed by
- the mss (the minumum of the MSS and the available
- window). */
- if(uip_slen > uip_connr->mss) {
- uip_slen = uip_connr->mss;
- }
-
- /* Remember how much data we send out now so that we know
- when everything has been acknowledged. */
- uip_connr->len = uip_slen;
- } else {
-
- /* If the application already had unacknowledged data, we
- make sure that the application does not send (i.e.,
- retransmit) out more than it previously sent out. */
- uip_slen = uip_connr->len;
- }
- } else {
- uip_connr->len = 0;
- }
- uip_connr->nrtx = 0;
- apprexmit:
- uip_appdata = uip_sappdata;
-
- /* If the application has data to be sent, or if the incoming
- packet had new data in it, we must send out a packet. */
- if(uip_slen > 0 && uip_connr->len > 0) {
- /* Add the length of the IP and TCP headers. */
- uip_len = uip_connr->len + UIP_TCPIP_HLEN;
- /* We always set the ACK flag in response packets. */
- BUF->flags = TCP_ACK | TCP_PSH;
- /* Send the packet. */
- goto tcp_send_noopts;
- }
- /* If there is no data to send, just send out a pure ACK if
- there is newdata. */
- if(uip_flags & UIP_NEWDATA) {
- uip_len = UIP_TCPIP_HLEN;
- BUF->flags = TCP_ACK;
- goto tcp_send_noopts;
- }
- }
- goto drop;
- case LAST_ACK:
- /* We can close this connection if the peer has acknowledged our
- FIN. This is indicated by the UIP_ACKDATA flag. */
- if(uip_flags & UIP_ACKDATA) {
- uip_connr->tcpstateflags = CLOSED;
- uip_flags = UIP_CLOSE;
- UIP_APPCALL();
- }
- break;
-
- case FIN_WAIT_1:
- /* The application has closed the connection, but the remote host
- hasn't closed its end yet. Thus we do nothing but wait for a
- FIN from the other side. */
- if(uip_len > 0) {
- uip_add_rcv_nxt(uip_len);
- }
- if(BUF->flags & TCP_FIN) {
- if(uip_flags & UIP_ACKDATA) {
- uip_connr->tcpstateflags = TIME_WAIT;
- uip_connr->timer = 0;
- uip_connr->len = 0;
- } else {
- uip_connr->tcpstateflags = CLOSING;
- }
- uip_add_rcv_nxt(1);
- uip_flags = UIP_CLOSE;
- UIP_APPCALL();
- goto tcp_send_ack;
- } else if(uip_flags & UIP_ACKDATA) {
- uip_connr->tcpstateflags = FIN_WAIT_2;
- uip_connr->len = 0;
- goto drop;
- }
- if(uip_len > 0) {
- goto tcp_send_ack;
- }
- goto drop;
-
- case FIN_WAIT_2:
- if(uip_len > 0) {
- uip_add_rcv_nxt(uip_len);
- }
- if(BUF->flags & TCP_FIN) {
- uip_connr->tcpstateflags = TIME_WAIT;
- uip_connr->timer = 0;
- uip_add_rcv_nxt(1);
- uip_flags = UIP_CLOSE;
- UIP_APPCALL();
- goto tcp_send_ack;
- }
- if(uip_len > 0) {
- goto tcp_send_ack;
- }
- goto drop;
-
- case TIME_WAIT:
- goto tcp_send_ack;
-
- case CLOSING:
- if(uip_flags & UIP_ACKDATA) {
- uip_connr->tcpstateflags = TIME_WAIT;
- uip_connr->timer = 0;
- }
- }
- goto drop;
-
-
- /* We jump here when we are ready to send the packet, and just want
- to set the appropriate TCP sequence numbers in the TCP header. */
- tcp_send_ack:
- BUF->flags = TCP_ACK;
- tcp_send_nodata:
- uip_len = 40;
- tcp_send_noopts:
- BUF->tcpoffset = 5 << 4;
- tcp_send:
- /* We're done with the input processing. We are now ready to send a
- reply. Our job is to fill in all the fields of the TCP and IP
- headers before calculating the checksum and finally send the
- packet. */
- BUF->ackno[0] = uip_connr->rcv_nxt[0];
- BUF->ackno[1] = uip_connr->rcv_nxt[1];
- BUF->ackno[2] = uip_connr->rcv_nxt[2];
- BUF->ackno[3] = uip_connr->rcv_nxt[3];
-
- BUF->seqno[0] = uip_connr->snd_nxt[0];
- BUF->seqno[1] = uip_connr->snd_nxt[1];
- BUF->seqno[2] = uip_connr->snd_nxt[2];
- BUF->seqno[3] = uip_connr->snd_nxt[3];
-
- BUF->proto = UIP_PROTO_TCP;
-
- BUF->srcport = uip_connr->lport;
- BUF->destport = uip_connr->rport;
-
- BUF->srcipaddr[0] = uip_hostaddr[0];
- BUF->srcipaddr[1] = uip_hostaddr[1];
- BUF->destipaddr[0] = uip_connr->ripaddr[0];
- BUF->destipaddr[1] = uip_connr->ripaddr[1];
-
-
- if(uip_connr->tcpstateflags & UIP_STOPPED) {
- /* If the connection has issued uip_stop(), we advertise a zero
- window so that the remote host will stop sending data. */
- BUF->wnd[0] = BUF->wnd[1] = 0;
- } else {
- BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
- BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
- }
-
- tcp_send_noconn:
-
- BUF->len[0] = (uip_len >> 8);
- BUF->len[1] = (uip_len & 0xff);
-
- /* Calculate TCP checksum. */
- BUF->tcpchksum = 0;
- BUF->tcpchksum = ~(uip_tcpchksum());
-
- ip_send_nolen:
-
- BUF->vhl = 0x45;
- BUF->tos = 0;
- BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
- BUF->ttl = UIP_TTL;
- ++ipid;
- BUF->ipid[0] = ipid >> 8;
- BUF->ipid[1] = ipid & 0xff;
-
- /* Calculate IP checksum. */
- BUF->ipchksum = 0;
- BUF->ipchksum = ~(uip_ipchksum());
-
- UIP_STAT(++uip_stat.tcp.sent);
- send:
- UIP_STAT(++uip_stat.ip.sent);
- /* Return and let the caller do the actual transmission. */
- return;
- drop:
- uip_len = 0;
- return;
-}
-/*-----------------------------------------------------------------------------------*/
-u16_t
-htons(u16_t val)
-{
- return HTONS(val);
-}
-/*-----------------------------------------------------------------------------------*/
-/** @} */
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