| /**************************************************************************** |
| * net/uip/uip-tcpinput.c |
| * Handling incoming TCP input |
| * |
| * Copyright (C) 2007 Gregory Nutt. All rights reserved. |
| * Author: Gregory Nutt <spudmonkey@racsa.co.cr> |
| * |
| * Adapted for NuttX from logic in uIP which also has a BSD-like license: |
| * |
| * Original author Adam Dunkels <adam@dunkels.com> |
| * 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 <nuttx/config.h> |
| #ifdef CONFIG_NET |
| |
| #include <sys/types.h> |
| #include <debug.h> |
| |
| #include <net/uip/uipopt.h> |
| #include <net/uip/uip.h> |
| #include <net/uip/uip-arch.h> |
| |
| #include "uip-internal.h" |
| |
| /**************************************************************************** |
| * Definitions |
| ****************************************************************************/ |
| |
| #define BUF ((struct uip_tcpip_hdr *)&dev->d_buf[UIP_LLH_LEN]) |
| |
| /**************************************************************************** |
| * Public Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Variables |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Private Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Name: uip_tcpinput |
| * |
| * Description: |
| * Handle incoming TCP input |
| * |
| * Parameters: |
| * dev - The device driver structure containing the received TCP packet. |
| * |
| * Return: |
| * None |
| * |
| * Assumptions: |
| * Called from the interrupt level or with interrupts disabled. |
| * |
| ****************************************************************************/ |
| |
| void uip_tcpinput(struct uip_driver_s *dev) |
| { |
| struct uip_conn *conn = NULL; |
| uint16 tmp16; |
| uint8 opt; |
| uint8 flags; |
| uint8 result; |
| int len; |
| int i; |
| |
| #ifdef CONFIG_NET_STATISTICS |
| uip_stat.tcp.recv++; |
| #endif |
| |
| /* Start of TCP input header processing code. */ |
| |
| if (uip_tcpchksum(dev) != 0xffff) |
| { |
| /* Compute and check the TCP checksum. */ |
| |
| #ifdef CONFIG_NET_STATISTICS |
| uip_stat.tcp.drop++; |
| uip_stat.tcp.chkerr++; |
| #endif |
| dbg("Bad TCP checksum\n"); |
| goto drop; |
| } |
| |
| /* Demultiplex this segment. First check any active connections. */ |
| |
| conn = uip_tcpactive(BUF); |
| if (conn) |
| { |
| goto found; |
| } |
| |
| /* If we didn't find and active connection that expected the packet, |
| * either (1) this packet is an old duplicate, or (2) 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) |
| { |
| /* This is a SYN packet for a connection. Find the connection |
| * listening on this port. |
| */ |
| |
| tmp16 = BUF->destport; |
| if (uip_islistener(tmp16)) |
| { |
| /* We matched the incoming packet with a connection in LISTEN. |
| * We now need to create a new connection and send a SYNACK in |
| * response. |
| */ |
| |
| /* First allocate a new connection structure and see if there is any |
| * user application to accept it. |
| */ |
| |
| conn = uip_tcpaccept(BUF); |
| if (conn) |
| { |
| /* The connection structure was successfully allocated. Now see |
| * there is an application waiting to accept the connection (or at |
| * least queue it it for acceptance). |
| */ |
| |
| if (uip_accept(conn, tmp16) != OK) |
| { |
| /* No, then we have to give the connection back */ |
| |
| uip_tcpfree(conn); |
| conn = NULL; |
| } |
| } |
| |
| if (!conn) |
| { |
| /* Either (1) all available connections are in use, or (2) there is no |
| * application in place to accept the connection. We drop packet and hope that |
| * the remote end will retransmit the packet at a time when we |
| * have more spare connections or someone waiting to accept the connection. |
| */ |
| |
| #ifdef CONFIG_NET_STATISTICS |
| uip_stat.tcp.syndrop++; |
| #endif |
| dbg("No free TCP connections\n"); |
| goto drop; |
| } |
| |
| uip_incr32(conn->rcv_nxt, 1); |
| |
| /* Parse the TCP MSS option, if present. */ |
| |
| if ((BUF->tcpoffset & 0xf0) > 0x50) |
| { |
| for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;) |
| { |
| opt = dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + i]; |
| if (opt == TCP_OPT_END) |
| { |
| /* End of options. */ |
| |
| break; |
| } |
| else if (opt == TCP_OPT_NOOP) |
| { |
| /* NOP option. */ |
| |
| ++i; |
| } |
| else if (opt == TCP_OPT_MSS && |
| dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN) |
| { |
| /* An MSS option with the right option length. */ |
| |
| tmp16 = ((uint16)dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) | |
| (uint16)dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + i]; |
| conn->initialmss = conn->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 (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0) |
| { |
| /* If the length field is zero, the options are malformed |
| * and we don't process them further. |
| */ |
| |
| break; |
| } |
| i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i]; |
| } |
| } |
| } |
| |
| /* Our response will be a SYNACK. */ |
| |
| uip_tcpack(dev, conn, TCP_ACK | TCP_SYN); |
| return; |
| } |
| } |
| |
| /* This is (1) an old duplicate packet or (2) a SYN packet but with |
| * no matching listener found. Send RST packet in either case. |
| */ |
| |
| /* We do not send resets in response to resets. */ |
| |
| if (BUF->flags & TCP_RST) |
| { |
| goto drop; |
| } |
| |
| #ifdef CONFIG_NET_STATISTICS |
| uip_stat.tcp.synrst++; |
| #endif |
| uip_tcpreset(dev); |
| return; |
| |
| found: |
| |
| 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) |
| { |
| conn->tcpstateflags = UIP_CLOSED; |
| dbg("RESET - TCP state: UIP_CLOSED\n"); |
| |
| (void)uip_tcpcallback(dev, conn, UIP_ABORT); |
| goto drop; |
| } |
| |
| /* Calculated the length of the data, if the application has sent |
| * any data to us. |
| */ |
| |
| len = (BUF->tcpoffset >> 4) << 2; |
| |
| /* d_len will contain the length of the actual TCP data. This is |
| * calculated by subtracing the length of the TCP header (in |
| * len) and the length of the IP header (20 bytes). |
| */ |
| |
| dev->d_len -= (len + UIP_IPH_LEN); |
| |
| /* 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 (!(((conn->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) && |
| ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) |
| { |
| if ((dev->d_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) && |
| (BUF->seqno[0] != conn->rcv_nxt[0] || |
| BUF->seqno[1] != conn->rcv_nxt[1] || |
| BUF->seqno[2] != conn->rcv_nxt[2] || |
| BUF->seqno[3] != conn->rcv_nxt[3])) |
| { |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| } |
| |
| /* 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(conn)) |
| { |
| /* Temporary variables. */ |
| |
| uint8 acc32[4]; |
| uip_add32(conn->snd_nxt, conn->len, acc32); |
| |
| if (BUF->ackno[0] == acc32[0] && BUF->ackno[1] == acc32[1] && |
| BUF->ackno[2] == acc32[2] && BUF->ackno[3] == acc32[3]) |
| { |
| /* Update sequence number. */ |
| |
| conn->snd_nxt[0] = acc32[0]; |
| conn->snd_nxt[1] = acc32[1]; |
| conn->snd_nxt[2] = acc32[2]; |
| conn->snd_nxt[3] = acc32[3]; |
| |
| /* Do RTT estimation, unless we have done retransmissions. */ |
| |
| if (conn->nrtx == 0) |
| { |
| signed char m; |
| m = conn->rto - conn->timer; |
| |
| /* This is taken directly from VJs original code in his paper */ |
| |
| m = m - (conn->sa >> 3); |
| conn->sa += m; |
| if (m < 0) |
| { |
| m = -m; |
| } |
| |
| m = m - (conn->sv >> 2); |
| conn->sv += m; |
| conn->rto = (conn->sa >> 3) + conn->sv; |
| } |
| |
| /* Set the acknowledged flag. */ |
| |
| flags = UIP_ACKDATA; |
| |
| /* Reset the retransmission timer. */ |
| |
| conn->timer = conn->rto; |
| |
| /* Reset length of outstanding data. */ |
| |
| conn->len = 0; |
| } |
| } |
| |
| /* Do different things depending on in what state the connection is. */ |
| |
| switch (conn->tcpstateflags & UIP_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 UIP_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 (flags & UIP_ACKDATA) |
| { |
| conn->tcpstateflags = UIP_ESTABLISHED; |
| conn->len = 0; |
| vdbg("TCP state: UIP_ESTABLISHED\n"); |
| |
| flags = UIP_CONNECTED; |
| |
| if (dev->d_len > 0) |
| { |
| flags |= UIP_NEWDATA; |
| uip_incr32(conn->rcv_nxt, dev->d_len); |
| } |
| |
| dev->d_sndlen = 0; |
| result = uip_tcpcallback(dev, conn, flags); |
| uip_tcpappsend(dev, conn, result); |
| return; |
| } |
| goto drop; |
| |
| case UIP_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 ((flags & UIP_ACKDATA) && (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) |
| { |
| /* Parse the TCP MSS option, if present. */ |
| |
| if ((BUF->tcpoffset & 0xf0) > 0x50) |
| { |
| for (i = 0; i < ((BUF->tcpoffset >> 4) - 5) << 2 ;) |
| { |
| opt = dev->d_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + i]; |
| if (opt == TCP_OPT_END) |
| { |
| /* End of options. */ |
| |
| break; |
| } |
| else if (opt == TCP_OPT_NOOP) |
| { |
| /* NOP option. */ |
| |
| ++i; |
| } |
| else if (opt == TCP_OPT_MSS && |
| dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == TCP_OPT_MSS_LEN) |
| { |
| /* An MSS option with the right option length. */ |
| |
| tmp16 = |
| (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + i] << 8) | |
| dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + i]; |
| conn->initialmss = |
| conn->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 (dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i] == 0) |
| { |
| /* If the length field is zero, the options are |
| * malformed and we don't process them further. |
| */ |
| |
| break; |
| } |
| i += dev->d_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + i]; |
| } |
| } |
| } |
| |
| conn->tcpstateflags = UIP_ESTABLISHED; |
| conn->rcv_nxt[0] = BUF->seqno[0]; |
| conn->rcv_nxt[1] = BUF->seqno[1]; |
| conn->rcv_nxt[2] = BUF->seqno[2]; |
| conn->rcv_nxt[3] = BUF->seqno[3]; |
| vdbg("TCP state: UIP_ESTABLISHED\n"); |
| |
| uip_incr32(conn->rcv_nxt, 1); |
| conn->len = 0; |
| dev->d_len = 0; |
| dev->d_sndlen = 0; |
| result = uip_tcpcallback(dev, conn, UIP_CONNECTED | UIP_NEWDATA); |
| uip_tcpappsend(dev, conn, result); |
| return; |
| } |
| |
| /* Inform the application that the connection failed */ |
| |
| (void)uip_tcpcallback(dev, conn, UIP_ABORT); |
| |
| /* The connection is closed after we send the RST */ |
| |
| conn->tcpstateflags = UIP_CLOSED; |
| vdbg("Connection failed - TCP state: UIP_CLOSED\n"); |
| |
| /* We do not send resets in response to resets. */ |
| |
| if (BUF->flags & TCP_RST) |
| { |
| goto drop; |
| } |
| uip_tcpreset(dev); |
| return; |
| |
| case UIP_ESTABLISHED: |
| /* In the ESTABLISHED state, we call upon the application to feed |
| * data into the d_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 && !(conn->tcpstateflags & UIP_STOPPED)) |
| { |
| if (uip_outstanding(conn)) |
| { |
| goto drop; |
| } |
| |
| uip_incr32(conn->rcv_nxt, dev->d_len + 1); |
| flags |= UIP_CLOSE; |
| |
| if (dev->d_len > 0) |
| { |
| flags |= UIP_NEWDATA; |
| } |
| |
| (void)uip_tcpcallback(dev, conn, flags); |
| |
| conn->tcpstateflags = UIP_LAST_ACK; |
| conn->len = 1; |
| conn->nrtx = 0; |
| vdbg("TCP state: UIP_LAST_ACK\n"); |
| |
| uip_tcpsend(dev, conn, TCP_FIN | TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| |
| /* 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) != 0) |
| { |
| #if UIP_URGDATA > 0 |
| uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1]; |
| if (uip_urglen > dev->d_len) |
| { |
| /* There is more urgent data in the next segment to come. */ |
| |
| uip_urglen = dev->d_len; |
| } |
| |
| uip_incr32(conn->rcv_nxt, uip_urglen); |
| dev->d_len -= uip_urglen; |
| uip_urgdata = dev->d_appdata; |
| dev->d_appdata += uip_urglen; |
| } |
| else |
| { |
| uip_urglen = 0; |
| #else /* UIP_URGDATA > 0 */ |
| dev->d_appdata = |
| ((uint8*)dev->d_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]); |
| dev->d_len -= |
| (BUF->urgp[0] << 8) | BUF->urgp[1]; |
| #endif /* UIP_URGDATA > 0 */ |
| } |
| |
| /* If d_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 (dev->d_len > 0 && !(conn->tcpstateflags & UIP_STOPPED)) |
| { |
| flags |= UIP_NEWDATA; |
| uip_incr32(conn->rcv_nxt, dev->d_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 = ((uint16)BUF->wnd[0] << 8) + (uint16)BUF->wnd[1]; |
| if (tmp16 > conn->initialmss || tmp16 == 0) |
| { |
| tmp16 = conn->initialmss; |
| } |
| conn->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 d_len field |
| * contains the length of the incoming data. The application can |
| * access the incoming data through the global pointer |
| * d_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN |
| * bytes into the d_buf array. |
| * |
| * If the application wishes to send any data, this data should be |
| * put into the d_appdata and the length of the data should be |
| * put into d_len. If the application don't have any data to |
| * send, d_len must be set to 0. |
| */ |
| |
| if (flags & (UIP_NEWDATA | UIP_ACKDATA)) |
| { |
| dev->d_sndlen = 0; |
| result = uip_tcpcallback(dev, conn, flags); |
| uip_tcpappsend(dev, conn, result); |
| return; |
| } |
| goto drop; |
| |
| case UIP_LAST_ACK: |
| /* We can close this connection if the peer has acknowledged our |
| * FIN. This is indicated by the UIP_ACKDATA flag. |
| */ |
| |
| if (flags & UIP_ACKDATA) |
| { |
| conn->tcpstateflags = UIP_CLOSED; |
| vdbg("UIP_LAST_ACK TCP state: UIP_CLOSED\n"); |
| |
| (void)uip_tcpcallback(dev, conn, UIP_CLOSE); |
| } |
| break; |
| |
| case UIP_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 (dev->d_len > 0) |
| { |
| uip_incr32(conn->rcv_nxt, dev->d_len); |
| } |
| if (BUF->flags & TCP_FIN) |
| { |
| if (flags & UIP_ACKDATA) |
| { |
| conn->tcpstateflags = UIP_TIME_WAIT; |
| conn->timer = 0; |
| conn->len = 0; |
| vdbg("TCP state: UIP_TIME_WAIT\n"); |
| } |
| else |
| { |
| conn->tcpstateflags = UIP_CLOSING; |
| vdbg("TCP state: UIP_CLOSING\n"); |
| } |
| |
| uip_incr32(conn->rcv_nxt, 1); |
| (void)uip_tcpcallback(dev, conn, UIP_CLOSE); |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| else if (flags & UIP_ACKDATA) |
| { |
| conn->tcpstateflags = UIP_FIN_WAIT_2; |
| conn->len = 0; |
| vdbg("TCP state: UIP_FIN_WAIT_2\n"); |
| goto drop; |
| } |
| |
| if (dev->d_len > 0) |
| { |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| goto drop; |
| |
| case UIP_FIN_WAIT_2: |
| if (dev->d_len > 0) |
| { |
| uip_incr32(conn->rcv_nxt, dev->d_len); |
| } |
| |
| if (BUF->flags & TCP_FIN) |
| { |
| conn->tcpstateflags = UIP_TIME_WAIT; |
| conn->timer = 0; |
| vdbg("TCP state: UIP_TIME_WAIT\n"); |
| |
| uip_incr32(conn->rcv_nxt, 1); |
| (void)uip_tcpcallback(dev, conn, UIP_CLOSE); |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| |
| if (dev->d_len > 0) |
| { |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| } |
| goto drop; |
| |
| case UIP_TIME_WAIT: |
| uip_tcpsend(dev, conn, TCP_ACK, UIP_IPTCPH_LEN); |
| return; |
| |
| case UIP_CLOSING: |
| if (flags & UIP_ACKDATA) |
| { |
| conn->tcpstateflags = UIP_TIME_WAIT; |
| conn->timer = 0; |
| vdbg("TCP state: UIP_TIME_WAIT\n"); |
| } |
| |
| default: |
| break; |
| } |
| |
| drop: |
| dev->d_len = 0; |
| } |
| |
| #endif /* CONFIG_NET */ |