/**************************************************************************** * net/uip/uip-tcpsend.c * * Copyright (C) 2007 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Adapted for NuttX from logic in uIP which also has a BSD-like license: * * Original author Adam Dunkels * Copyright () 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. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #if defined(CONFIG_NET) && defined(CONFIG_NET_TCP) #include #include #include #include #include #include "uip-internal.h" /**************************************************************************** * Definitions ****************************************************************************/ #define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN]) /**************************************************************************** * Public Variables ****************************************************************************/ /**************************************************************************** * Private Variables ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: uip_tcpsendcomplete * * Description: * Complete the final portions of the send operation. This function sets * up IP header and computes the TCP checksum * * Parameters: * dev - The device driver structure to use in the send operation * * Return: * None * * Assumptions: * Called from the interrupt level or with interrupts disabled. * ****************************************************************************/ static void uip_tcpsendcomplete(struct uip_driver_s *dev) { BUF->ttl = UIP_TTL; #ifdef CONFIG_NET_IPv6 /* For IPv6, the IP length field does not include the IPv6 IP header * length. */ BUF->len[0] = ((dev->d_len - UIP_IPH_LEN) >> 8); BUF->len[1] = ((dev->d_len - UIP_IPH_LEN) & 0xff); #else /* CONFIG_NET_IPv6 */ BUF->len[0] = (dev->d_len >> 8); BUF->len[1] = (dev->d_len & 0xff); #endif /* CONFIG_NET_IPv6 */ BUF->urgp[0] = BUF->urgp[1] = 0; /* Calculate TCP checksum. */ BUF->tcpchksum = 0; BUF->tcpchksum = ~(uip_tcpchksum(dev)); #ifdef CONFIG_NET_IPv6 BUF->vtc = 0x60; BUF->tcf = 0x00; BUF->flow = 0x00; #else /* CONFIG_NET_IPv6 */ BUF->vhl = 0x45; BUF->tos = 0; BUF->ipoffset[0] = 0; BUF->ipoffset[1] = 0; ++g_ipid; BUF->ipid[0] = g_ipid >> 8; BUF->ipid[1] = g_ipid & 0xff; /* Calculate IP checksum. */ BUF->ipchksum = 0; BUF->ipchksum = ~(uip_ipchksum(dev)); #endif /* CONFIG_NET_IPv6 */ nvdbg("Outgoing TCP packet length: %d (%d)\n", dev->d_len, (BUF->len[0] << 8) | BUF->len[1]); #ifdef CONFIG_NET_STATISTICS uip_stat.tcp.sent++; uip_stat.ip.sent++; #endif } /**************************************************************************** * Name: uip_tcpsendcommon * * Description: * 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. * * Parameters: * dev - The device driver structure to use in the send operation * conn - The TCP connection structure holding connection information * * Return: * None * * Assumptions: * Called from the interrupt level or with interrupts disabled. * ****************************************************************************/ static void uip_tcpsendcommon(struct uip_driver_s *dev, struct uip_conn *conn) { memcpy(BUF->ackno, conn->rcv_nxt, 4); memcpy(BUF->seqno, conn->snd_nxt, 4); BUF->proto = UIP_PROTO_TCP; BUF->srcport = conn->lport; BUF->destport = conn->rport; uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr); uiphdr_ipaddr_copy(BUF->destipaddr, &conn->ripaddr); if (conn->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] = 0; BUF->wnd[1] = 0; } else { BUF->wnd[0] = ((CONFIG_NET_RECEIVE_WINDOW) >> 8); BUF->wnd[1] = ((CONFIG_NET_RECEIVE_WINDOW) & 0xff); } /* Finish the IP portion of the message, calculate checksums and send * the message. */ uip_tcpsendcomplete(dev); } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: uip_tcpsend * * Description: * Setup to send a TCP packet * * Parameters: * dev - The device driver structure to use in the send operation * conn - The TCP connection structure holding connection information * flags - flags to apply to the TCP header * len - length of the message * * Return: * None * * Assumptions: * Called from the interrupt level or with interrupts disabled. * ****************************************************************************/ void uip_tcpsend(struct uip_driver_s *dev, struct uip_conn *conn, uint8 flags, uint16 len) { BUF->flags = flags; dev->d_len = len; BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4; uip_tcpsendcommon(dev, conn); } /**************************************************************************** * Name: uip_tcpreset * * Description: * Send a TCP reset (no-data) message * * Parameters: * dev - The device driver structure to use in the send operation * * Return: * None * * Assumptions: * Called from the interrupt level or with interrupts disabled. * ****************************************************************************/ void uip_tcpreset(struct uip_driver_s *dev) { uint16 tmp16; uint8 seqbyte; #ifdef CONFIG_NET_STATISTICS uip_stat.tcp.rst++; #endif BUF->flags = TCP_RST | TCP_ACK; dev->d_len = UIP_IPTCPH_LEN; BUF->tcpoffset = 5 << 4; /* Flip the seqno and ackno fields in the TCP header. */ seqbyte = BUF->seqno[3]; BUF->seqno[3] = BUF->ackno[3]; BUF->ackno[3] = seqbyte; seqbyte = BUF->seqno[2]; BUF->seqno[2] = BUF->ackno[2]; BUF->ackno[2] = seqbyte; seqbyte = BUF->seqno[1]; BUF->seqno[1] = BUF->ackno[1]; BUF->ackno[1] = seqbyte; seqbyte = BUF->seqno[0]; BUF->seqno[0] = BUF->ackno[0]; BUF->ackno[0] = seqbyte; /* 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. */ uiphdr_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr); uiphdr_ipaddr_copy(BUF->srcipaddr, &dev->d_ipaddr); /* And send out the RST packet */ uip_tcpsendcomplete(dev); } /**************************************************************************** * Name: uip_tcpack * * Description: * Send the SYN or SYNACK response. * * Parameters: * dev - The device driver structure to use in the send operation * conn - The TCP connection structure holding connection information * ack - The ACK response to send * * Return: * None * * Assumptions: * Called from the interrupt level or with interrupts disabled. * ****************************************************************************/ void uip_tcpack(struct uip_driver_s *dev, struct uip_conn *conn, uint8 ack) { /* Save the ACK bits */ BUF->flags = ack; /* We send out the TCP Maximum Segment Size option with our ack. */ BUF->optdata[0] = TCP_OPT_MSS; BUF->optdata[1] = TCP_OPT_MSS_LEN; BUF->optdata[2] = (UIP_TCP_MSS) / 256; BUF->optdata[3] = (UIP_TCP_MSS) & 255; dev->d_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN; BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4; /* Complete the common portions of the TCP message */ uip_tcpsendcommon(dev, conn); } #endif /* CONFIG_NET && CONFIG_NET_TCP */