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/*
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* Copyright (c) 1982, 1986, 1988, 1990, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)tcp_output.c 8.3 (Berkeley) 12/30/93
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* tcp_output.c,v 1.3 1994/09/15 10:36:55 davidg Exp
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*/
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/*
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* Changes and additions relating to SLiRP
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* Copyright (c) 1995 Danny Gasparovski.
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*
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* Please read the file COPYRIGHT for the
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* terms and conditions of the copyright.
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*/
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#include <slirp.h> |
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/*
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* Since this is only used in "stats socket", we give meaning
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* names instead of the REAL names
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*/
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char *tcpstates[] = {
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/* "CLOSED", "LISTEN", "SYN_SENT", "SYN_RCVD", */
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"REDIRECT", "LISTEN", "SYN_SENT", "SYN_RCVD", |
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"ESTABLISHED", "CLOSE_WAIT", "FIN_WAIT_1", "CLOSING", |
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"LAST_ACK", "FIN_WAIT_2", "TIME_WAIT", |
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}; |
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u_char tcp_outflags[TCP_NSTATES] = { |
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TH_RST|TH_ACK, 0, TH_SYN, TH_SYN|TH_ACK,
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TH_ACK, TH_ACK, TH_FIN|TH_ACK, TH_FIN|TH_ACK, |
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TH_FIN|TH_ACK, TH_ACK, TH_ACK, |
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}; |
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#define MAX_TCPOPTLEN 32 /* max # bytes that go in options */ |
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/*
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* Tcp output routine: figure out what should be sent and send it.
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*/
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int
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tcp_output(tp) |
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register struct tcpcb *tp; |
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{ |
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register struct socket *so = tp->t_socket; |
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register long len, win; |
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int off, flags, error;
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register struct mbuf *m; |
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register struct tcpiphdr *ti; |
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u_char opt[MAX_TCPOPTLEN]; |
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unsigned optlen, hdrlen;
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int idle, sendalot;
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DEBUG_CALL("tcp_output");
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DEBUG_ARG("tp = %lx", (long )tp); |
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/*
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* Determine length of data that should be transmitted,
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* and flags that will be used.
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* If there is some data or critical controls (SYN, RST)
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* to send, then transmit; otherwise, investigate further.
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*/
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idle = (tp->snd_max == tp->snd_una); |
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if (idle && tp->t_idle >= tp->t_rxtcur)
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/*
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* We have been idle for "a while" and no acks are
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* expected to clock out any data we send --
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* slow start to get ack "clock" running again.
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*/
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tp->snd_cwnd = tp->t_maxseg; |
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again:
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sendalot = 0;
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off = tp->snd_nxt - tp->snd_una; |
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win = min(tp->snd_wnd, tp->snd_cwnd); |
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flags = tcp_outflags[tp->t_state]; |
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DEBUG_MISC((dfd, " --- tcp_output flags = 0x%x\n",flags));
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/*
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* If in persist timeout with window of 0, send 1 byte.
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* Otherwise, if window is small but nonzero
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* and timer expired, we will send what we can
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* and go to transmit state.
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*/
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if (tp->t_force) {
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if (win == 0) { |
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/*
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* If we still have some data to send, then
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* clear the FIN bit. Usually this would
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* happen below when it realizes that we
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* aren't sending all the data. However,
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* if we have exactly 1 byte of unset data,
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* then it won't clear the FIN bit below,
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* and if we are in persist state, we wind
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* up sending the packet without recording
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* that we sent the FIN bit.
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*
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* We can't just blindly clear the FIN bit,
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* because if we don't have any more data
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* to send then the probe will be the FIN
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* itself.
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*/
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if (off < so->so_snd.sb_cc)
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flags &= ~TH_FIN; |
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win = 1;
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} else {
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tp->t_timer[TCPT_PERSIST] = 0;
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tp->t_rxtshift = 0;
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} |
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} |
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len = min(so->so_snd.sb_cc, win) - off; |
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if (len < 0) { |
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/*
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* If FIN has been sent but not acked,
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* but we haven't been called to retransmit,
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* len will be -1. Otherwise, window shrank
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* after we sent into it. If window shrank to 0,
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* cancel pending retransmit and pull snd_nxt
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* back to (closed) window. We will enter persist
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* state below. If the window didn't close completely,
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* just wait for an ACK.
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*/
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len = 0;
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if (win == 0) { |
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tp->t_timer[TCPT_REXMT] = 0;
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tp->snd_nxt = tp->snd_una; |
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} |
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} |
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if (len > tp->t_maxseg) {
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len = tp->t_maxseg; |
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sendalot = 1;
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} |
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if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + so->so_snd.sb_cc))
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flags &= ~TH_FIN; |
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win = sbspace(&so->so_rcv); |
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/*
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* Sender silly window avoidance. If connection is idle
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* and can send all data, a maximum segment,
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* at least a maximum default-size segment do it,
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* or are forced, do it; otherwise don't bother.
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* If peer's buffer is tiny, then send
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* when window is at least half open.
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* If retransmitting (possibly after persist timer forced us
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* to send into a small window), then must resend.
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*/
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if (len) {
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if (len == tp->t_maxseg)
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goto send;
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if ((1 || idle || tp->t_flags & TF_NODELAY) && |
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len + off >= so->so_snd.sb_cc) |
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goto send;
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if (tp->t_force)
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goto send;
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if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) |
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goto send;
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if (SEQ_LT(tp->snd_nxt, tp->snd_max))
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goto send;
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} |
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/*
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* Compare available window to amount of window
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* known to peer (as advertised window less
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* next expected input). If the difference is at least two
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* max size segments, or at least 50% of the maximum possible
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* window, then want to send a window update to peer.
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*/
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if (win > 0) { |
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/*
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* "adv" is the amount we can increase the window,
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* taking into account that we are limited by
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* TCP_MAXWIN << tp->rcv_scale.
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*/
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long adv = min(win, (long)TCP_MAXWIN << tp->rcv_scale) - |
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(tp->rcv_adv - tp->rcv_nxt); |
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if (adv >= (long) (2 * tp->t_maxseg)) |
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goto send;
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if (2 * adv >= (long) so->so_rcv.sb_datalen) |
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goto send;
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} |
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/*
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* Send if we owe peer an ACK.
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*/
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if (tp->t_flags & TF_ACKNOW)
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goto send;
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if (flags & (TH_SYN|TH_RST))
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goto send;
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if (SEQ_GT(tp->snd_up, tp->snd_una))
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goto send;
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/*
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* If our state indicates that FIN should be sent
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* and we have not yet done so, or we're retransmitting the FIN,
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* then we need to send.
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*/
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if (flags & TH_FIN &&
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((tp->t_flags & TF_SENTFIN) == 0 || tp->snd_nxt == tp->snd_una))
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goto send;
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/*
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* TCP window updates are not reliable, rather a polling protocol
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* using ``persist'' packets is used to insure receipt of window
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* updates. The three ``states'' for the output side are:
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* idle not doing retransmits or persists
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* persisting to move a small or zero window
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* (re)transmitting and thereby not persisting
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*
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* tp->t_timer[TCPT_PERSIST]
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* is set when we are in persist state.
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* tp->t_force
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* is set when we are called to send a persist packet.
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* tp->t_timer[TCPT_REXMT]
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* is set when we are retransmitting
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* The output side is idle when both timers are zero.
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*
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* If send window is too small, there is data to transmit, and no
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* retransmit or persist is pending, then go to persist state.
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* If nothing happens soon, send when timer expires:
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* if window is nonzero, transmit what we can,
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* otherwise force out a byte.
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*/
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if (so->so_snd.sb_cc && tp->t_timer[TCPT_REXMT] == 0 && |
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tp->t_timer[TCPT_PERSIST] == 0) {
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tp->t_rxtshift = 0;
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tcp_setpersist(tp); |
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} |
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/*
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* No reason to send a segment, just return.
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*/
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tcpstat.tcps_didnuttin++; |
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return (0); |
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send:
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/*
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* Before ESTABLISHED, force sending of initial options
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* unless TCP set not to do any options.
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* NOTE: we assume that the IP/TCP header plus TCP options
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* always fit in a single mbuf, leaving room for a maximum
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* link header, i.e.
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* max_linkhdr + sizeof (struct tcpiphdr) + optlen <= MHLEN
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*/
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optlen = 0;
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hdrlen = sizeof (struct tcpiphdr); |
281 |
if (flags & TH_SYN) {
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tp->snd_nxt = tp->iss; |
283 |
if ((tp->t_flags & TF_NOOPT) == 0) { |
284 |
u_int16_t mss; |
285 |
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opt[0] = TCPOPT_MAXSEG;
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opt[1] = 4; |
288 |
mss = htons((u_int16_t) tcp_mss(tp, 0));
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memcpy((caddr_t)(opt + 2), (caddr_t)&mss, sizeof(mss)); |
290 |
optlen = 4;
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|
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/* if ((tp->t_flags & TF_REQ_SCALE) &&
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* ((flags & TH_ACK) == 0 ||
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* (tp->t_flags & TF_RCVD_SCALE))) {
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* *((u_int32_t *) (opt + optlen)) = htonl(
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* TCPOPT_NOP << 24 |
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* TCPOPT_WINDOW << 16 |
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* TCPOLEN_WINDOW << 8 |
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* tp->request_r_scale);
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* optlen += 4;
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* }
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*/
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303 |
} |
304 |
} |
305 |
|
306 |
/*
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307 |
* Send a timestamp and echo-reply if this is a SYN and our side
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308 |
* wants to use timestamps (TF_REQ_TSTMP is set) or both our side
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309 |
* and our peer have sent timestamps in our SYN's.
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310 |
*/
|
311 |
/* if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
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312 |
* (flags & TH_RST) == 0 &&
|
313 |
* ((flags & (TH_SYN|TH_ACK)) == TH_SYN ||
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314 |
* (tp->t_flags & TF_RCVD_TSTMP))) {
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315 |
* u_int32_t *lp = (u_int32_t *)(opt + optlen);
|
316 |
*
|
317 |
* / * Form timestamp option as shown in appendix A of RFC 1323. * /
|
318 |
* *lp++ = htonl(TCPOPT_TSTAMP_HDR);
|
319 |
* *lp++ = htonl(tcp_now);
|
320 |
* *lp = htonl(tp->ts_recent);
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321 |
* optlen += TCPOLEN_TSTAMP_APPA;
|
322 |
* }
|
323 |
*/
|
324 |
hdrlen += optlen; |
325 |
|
326 |
/*
|
327 |
* Adjust data length if insertion of options will
|
328 |
* bump the packet length beyond the t_maxseg length.
|
329 |
*/
|
330 |
if (len > tp->t_maxseg - optlen) {
|
331 |
len = tp->t_maxseg - optlen; |
332 |
sendalot = 1;
|
333 |
} |
334 |
|
335 |
/*
|
336 |
* Grab a header mbuf, attaching a copy of data to
|
337 |
* be transmitted, and initialize the header from
|
338 |
* the template for sends on this connection.
|
339 |
*/
|
340 |
if (len) {
|
341 |
if (tp->t_force && len == 1) |
342 |
tcpstat.tcps_sndprobe++; |
343 |
else if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { |
344 |
tcpstat.tcps_sndrexmitpack++; |
345 |
tcpstat.tcps_sndrexmitbyte += len; |
346 |
} else {
|
347 |
tcpstat.tcps_sndpack++; |
348 |
tcpstat.tcps_sndbyte += len; |
349 |
} |
350 |
|
351 |
m = m_get(); |
352 |
if (m == NULL) { |
353 |
/* error = ENOBUFS; */
|
354 |
error = 1;
|
355 |
goto out;
|
356 |
} |
357 |
m->m_data += if_maxlinkhdr; |
358 |
m->m_len = hdrlen; |
359 |
|
360 |
/*
|
361 |
* This will always succeed, since we make sure our mbufs
|
362 |
* are big enough to hold one MSS packet + header + ... etc.
|
363 |
*/
|
364 |
/* if (len <= MHLEN - hdrlen - max_linkhdr) { */
|
365 |
|
366 |
sbcopy(&so->so_snd, off, (int) len, mtod(m, caddr_t) + hdrlen);
|
367 |
m->m_len += len; |
368 |
|
369 |
/* } else {
|
370 |
* m->m_next = m_copy(so->so_snd.sb_mb, off, (int) len);
|
371 |
* if (m->m_next == 0)
|
372 |
* len = 0;
|
373 |
* }
|
374 |
*/
|
375 |
/*
|
376 |
* If we're sending everything we've got, set PUSH.
|
377 |
* (This will keep happy those implementations which only
|
378 |
* give data to the user when a buffer fills or
|
379 |
* a PUSH comes in.)
|
380 |
*/
|
381 |
if (off + len == so->so_snd.sb_cc)
|
382 |
flags |= TH_PUSH; |
383 |
} else {
|
384 |
if (tp->t_flags & TF_ACKNOW)
|
385 |
tcpstat.tcps_sndacks++; |
386 |
else if (flags & (TH_SYN|TH_FIN|TH_RST)) |
387 |
tcpstat.tcps_sndctrl++; |
388 |
else if (SEQ_GT(tp->snd_up, tp->snd_una)) |
389 |
tcpstat.tcps_sndurg++; |
390 |
else
|
391 |
tcpstat.tcps_sndwinup++; |
392 |
|
393 |
m = m_get(); |
394 |
if (m == NULL) { |
395 |
/* error = ENOBUFS; */
|
396 |
error = 1;
|
397 |
goto out;
|
398 |
} |
399 |
m->m_data += if_maxlinkhdr; |
400 |
m->m_len = hdrlen; |
401 |
} |
402 |
|
403 |
ti = mtod(m, struct tcpiphdr *);
|
404 |
|
405 |
memcpy((caddr_t)ti, &tp->t_template, sizeof (struct tcpiphdr)); |
406 |
|
407 |
/*
|
408 |
* Fill in fields, remembering maximum advertised
|
409 |
* window for use in delaying messages about window sizes.
|
410 |
* If resending a FIN, be sure not to use a new sequence number.
|
411 |
*/
|
412 |
if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
|
413 |
tp->snd_nxt == tp->snd_max) |
414 |
tp->snd_nxt--; |
415 |
/*
|
416 |
* If we are doing retransmissions, then snd_nxt will
|
417 |
* not reflect the first unsent octet. For ACK only
|
418 |
* packets, we do not want the sequence number of the
|
419 |
* retransmitted packet, we want the sequence number
|
420 |
* of the next unsent octet. So, if there is no data
|
421 |
* (and no SYN or FIN), use snd_max instead of snd_nxt
|
422 |
* when filling in ti_seq. But if we are in persist
|
423 |
* state, snd_max might reflect one byte beyond the
|
424 |
* right edge of the window, so use snd_nxt in that
|
425 |
* case, since we know we aren't doing a retransmission.
|
426 |
* (retransmit and persist are mutually exclusive...)
|
427 |
*/
|
428 |
if (len || (flags & (TH_SYN|TH_FIN)) || tp->t_timer[TCPT_PERSIST])
|
429 |
ti->ti_seq = htonl(tp->snd_nxt); |
430 |
else
|
431 |
ti->ti_seq = htonl(tp->snd_max); |
432 |
ti->ti_ack = htonl(tp->rcv_nxt); |
433 |
if (optlen) {
|
434 |
memcpy((caddr_t)(ti + 1), (caddr_t)opt, optlen);
|
435 |
ti->ti_off = (sizeof (struct tcphdr) + optlen) >> 2; |
436 |
} |
437 |
ti->ti_flags = flags; |
438 |
/*
|
439 |
* Calculate receive window. Don't shrink window,
|
440 |
* but avoid silly window syndrome.
|
441 |
*/
|
442 |
if (win < (long)(so->so_rcv.sb_datalen / 4) && win < (long)tp->t_maxseg) |
443 |
win = 0;
|
444 |
if (win > (long)TCP_MAXWIN << tp->rcv_scale) |
445 |
win = (long)TCP_MAXWIN << tp->rcv_scale;
|
446 |
if (win < (long)(tp->rcv_adv - tp->rcv_nxt)) |
447 |
win = (long)(tp->rcv_adv - tp->rcv_nxt);
|
448 |
ti->ti_win = htons((u_int16_t) (win>>tp->rcv_scale)); |
449 |
|
450 |
if (SEQ_GT(tp->snd_up, tp->snd_una)) {
|
451 |
ti->ti_urp = htons((u_int16_t)(tp->snd_up - ntohl(ti->ti_seq))); |
452 |
#ifdef notdef
|
453 |
if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
|
454 |
ti->ti_urp = htons((u_int16_t)(tp->snd_up - tp->snd_nxt)); |
455 |
#endif
|
456 |
ti->ti_flags |= TH_URG; |
457 |
} else
|
458 |
/*
|
459 |
* If no urgent pointer to send, then we pull
|
460 |
* the urgent pointer to the left edge of the send window
|
461 |
* so that it doesn't drift into the send window on sequence
|
462 |
* number wraparound.
|
463 |
*/
|
464 |
tp->snd_up = tp->snd_una; /* drag it along */
|
465 |
|
466 |
/*
|
467 |
* Put TCP length in extended header, and then
|
468 |
* checksum extended header and data.
|
469 |
*/
|
470 |
if (len + optlen)
|
471 |
ti->ti_len = htons((u_int16_t)(sizeof (struct tcphdr) + |
472 |
optlen + len)); |
473 |
ti->ti_sum = cksum(m, (int)(hdrlen + len));
|
474 |
|
475 |
/*
|
476 |
* In transmit state, time the transmission and arrange for
|
477 |
* the retransmit. In persist state, just set snd_max.
|
478 |
*/
|
479 |
if (tp->t_force == 0 || tp->t_timer[TCPT_PERSIST] == 0) { |
480 |
tcp_seq startseq = tp->snd_nxt; |
481 |
|
482 |
/*
|
483 |
* Advance snd_nxt over sequence space of this segment.
|
484 |
*/
|
485 |
if (flags & (TH_SYN|TH_FIN)) {
|
486 |
if (flags & TH_SYN)
|
487 |
tp->snd_nxt++; |
488 |
if (flags & TH_FIN) {
|
489 |
tp->snd_nxt++; |
490 |
tp->t_flags |= TF_SENTFIN; |
491 |
} |
492 |
} |
493 |
tp->snd_nxt += len; |
494 |
if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
|
495 |
tp->snd_max = tp->snd_nxt; |
496 |
/*
|
497 |
* Time this transmission if not a retransmission and
|
498 |
* not currently timing anything.
|
499 |
*/
|
500 |
if (tp->t_rtt == 0) { |
501 |
tp->t_rtt = 1;
|
502 |
tp->t_rtseq = startseq; |
503 |
tcpstat.tcps_segstimed++; |
504 |
} |
505 |
} |
506 |
|
507 |
/*
|
508 |
* Set retransmit timer if not currently set,
|
509 |
* and not doing an ack or a keep-alive probe.
|
510 |
* Initial value for retransmit timer is smoothed
|
511 |
* round-trip time + 2 * round-trip time variance.
|
512 |
* Initialize shift counter which is used for backoff
|
513 |
* of retransmit time.
|
514 |
*/
|
515 |
if (tp->t_timer[TCPT_REXMT] == 0 && |
516 |
tp->snd_nxt != tp->snd_una) { |
517 |
tp->t_timer[TCPT_REXMT] = tp->t_rxtcur; |
518 |
if (tp->t_timer[TCPT_PERSIST]) {
|
519 |
tp->t_timer[TCPT_PERSIST] = 0;
|
520 |
tp->t_rxtshift = 0;
|
521 |
} |
522 |
} |
523 |
} else
|
524 |
if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))
|
525 |
tp->snd_max = tp->snd_nxt + len; |
526 |
|
527 |
/*
|
528 |
* Fill in IP length and desired time to live and
|
529 |
* send to IP level. There should be a better way
|
530 |
* to handle ttl and tos; we could keep them in
|
531 |
* the template, but need a way to checksum without them.
|
532 |
*/
|
533 |
m->m_len = hdrlen + len; /* XXX Needed? m_len should be correct */
|
534 |
|
535 |
{ |
536 |
|
537 |
((struct ip *)ti)->ip_len = m->m_len;
|
538 |
|
539 |
((struct ip *)ti)->ip_ttl = ip_defttl;
|
540 |
((struct ip *)ti)->ip_tos = so->so_iptos;
|
541 |
|
542 |
/* #if BSD >= 43 */
|
543 |
/* Don't do IP options... */
|
544 |
/* error = ip_output(m, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
|
545 |
* so->so_options & SO_DONTROUTE, 0);
|
546 |
*/
|
547 |
error = ip_output(so, m); |
548 |
|
549 |
/* #else
|
550 |
* error = ip_output(m, (struct mbuf *)0, &tp->t_inpcb->inp_route,
|
551 |
* so->so_options & SO_DONTROUTE);
|
552 |
* #endif
|
553 |
*/
|
554 |
} |
555 |
if (error) {
|
556 |
out:
|
557 |
/* if (error == ENOBUFS) {
|
558 |
* tcp_quench(tp->t_inpcb, 0);
|
559 |
* return (0);
|
560 |
* }
|
561 |
*/
|
562 |
/* if ((error == EHOSTUNREACH || error == ENETDOWN)
|
563 |
* && TCPS_HAVERCVDSYN(tp->t_state)) {
|
564 |
* tp->t_softerror = error;
|
565 |
* return (0);
|
566 |
* }
|
567 |
*/
|
568 |
return (error);
|
569 |
} |
570 |
tcpstat.tcps_sndtotal++; |
571 |
|
572 |
/*
|
573 |
* Data sent (as far as we can tell).
|
574 |
* If this advertises a larger window than any other segment,
|
575 |
* then remember the size of the advertised window.
|
576 |
* Any pending ACK has now been sent.
|
577 |
*/
|
578 |
if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv)) |
579 |
tp->rcv_adv = tp->rcv_nxt + win; |
580 |
tp->last_ack_sent = tp->rcv_nxt; |
581 |
tp->t_flags &= ~(TF_ACKNOW|TF_DELACK); |
582 |
if (sendalot)
|
583 |
goto again;
|
584 |
|
585 |
return (0); |
586 |
} |
587 |
|
588 |
void
|
589 |
tcp_setpersist(tp) |
590 |
register struct tcpcb *tp; |
591 |
{ |
592 |
int t = ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1; |
593 |
|
594 |
/* if (tp->t_timer[TCPT_REXMT])
|
595 |
* panic("tcp_output REXMT");
|
596 |
*/
|
597 |
/*
|
598 |
* Start/restart persistence timer.
|
599 |
*/
|
600 |
TCPT_RANGESET(tp->t_timer[TCPT_PERSIST], |
601 |
t * tcp_backoff[tp->t_rxtshift], |
602 |
TCPTV_PERSMIN, TCPTV_PERSMAX); |
603 |
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
|
604 |
tp->t_rxtshift++; |
605 |
} |