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-rw-r--r--slirp2/tcp_output.c605
1 files changed, 0 insertions, 605 deletions
diff --git a/slirp2/tcp_output.c b/slirp2/tcp_output.c
deleted file mode 100644
index 95246aa..0000000
--- a/slirp2/tcp_output.c
+++ /dev/null
@@ -1,605 +0,0 @@
-/*
- * Copyright (c) 1982, 1986, 1988, 1990, 1993
- * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
- *
- * @(#)tcp_output.c 8.3 (Berkeley) 12/30/93
- * tcp_output.c,v 1.3 1994/09/15 10:36:55 davidg Exp
- */
-
-/*
- * Changes and additions relating to SLiRP
- * Copyright (c) 1995 Danny Gasparovski.
- *
- * Please read the file COPYRIGHT for the
- * terms and conditions of the copyright.
- */
-
-#include <slirp.h>
-
-/*
- * Since this is only used in "stats socket", we give meaning
- * names instead of the REAL names
- */
-char *tcpstates[] = {
-/* "CLOSED", "LISTEN", "SYN_SENT", "SYN_RCVD", */
- "REDIRECT", "LISTEN", "SYN_SENT", "SYN_RCVD",
- "ESTABLISHED", "CLOSE_WAIT", "FIN_WAIT_1", "CLOSING",
- "LAST_ACK", "FIN_WAIT_2", "TIME_WAIT",
-};
-
-u_char tcp_outflags[TCP_NSTATES] = {
- TH_RST|TH_ACK, 0, TH_SYN, TH_SYN|TH_ACK,
- TH_ACK, TH_ACK, TH_FIN|TH_ACK, TH_FIN|TH_ACK,
- TH_FIN|TH_ACK, TH_ACK, TH_ACK,
-};
-
-
-#define MAX_TCPOPTLEN 32 /* max # bytes that go in options */
-
-/*
- * Tcp output routine: figure out what should be sent and send it.
- */
-int
-tcp_output(tp)
- register struct tcpcb *tp;
-{
- register struct socket *so = tp->t_socket;
- register long len, win;
- int off, flags, error;
- register MBuf m;
- register struct tcpiphdr *ti;
- u_char opt[MAX_TCPOPTLEN];
- unsigned optlen, hdrlen;
- int idle, sendalot;
-
- DEBUG_CALL("tcp_output");
- DEBUG_ARG("tp = %lx", (long )tp);
-
- /*
- * Determine length of data that should be transmitted,
- * and flags that will be used.
- * If there is some data or critical controls (SYN, RST)
- * to send, then transmit; otherwise, investigate further.
- */
- idle = (tp->snd_max == tp->snd_una);
- if (idle && tp->t_idle >= tp->t_rxtcur)
- /*
- * We have been idle for "a while" and no acks are
- * expected to clock out any data we send --
- * slow start to get ack "clock" running again.
- */
- tp->snd_cwnd = tp->t_maxseg;
-again:
- sendalot = 0;
- off = tp->snd_nxt - tp->snd_una;
- win = min(tp->snd_wnd, tp->snd_cwnd);
-
- flags = tcp_outflags[tp->t_state];
-
- DEBUG_MISC((dfd, " --- tcp_output flags = 0x%x\n",flags));
-
- /*
- * If in persist timeout with window of 0, send 1 byte.
- * Otherwise, if window is small but nonzero
- * and timer expired, we will send what we can
- * and go to transmit state.
- */
- if (tp->t_force) {
- if (win == 0) {
- /*
- * If we still have some data to send, then
- * clear the FIN bit. Usually this would
- * happen below when it realizes that we
- * aren't sending all the data. However,
- * if we have exactly 1 byte of unset data,
- * then it won't clear the FIN bit below,
- * and if we are in persist state, we wind
- * up sending the packet without recording
- * that we sent the FIN bit.
- *
- * We can't just blindly clear the FIN bit,
- * because if we don't have any more data
- * to send then the probe will be the FIN
- * itself.
- */
- if (off < so->so_snd.sb_cc)
- flags &= ~TH_FIN;
- win = 1;
- } else {
- tp->t_timer[TCPT_PERSIST] = 0;
- tp->t_rxtshift = 0;
- }
- }
-
- len = min(so->so_snd.sb_cc, win) - off;
-
- if (len < 0) {
- /*
- * If FIN has been sent but not acked,
- * but we haven't been called to retransmit,
- * len will be -1. Otherwise, window shrank
- * after we sent into it. If window shrank to 0,
- * cancel pending retransmit and pull snd_nxt
- * back to (closed) window. We will enter persist
- * state below. If the window didn't close completely,
- * just wait for an ACK.
- */
- len = 0;
- if (win == 0) {
- tp->t_timer[TCPT_REXMT] = 0;
- tp->snd_nxt = tp->snd_una;
- }
- }
-
- if (len > tp->t_maxseg) {
- len = tp->t_maxseg;
- sendalot = 1;
- }
- if (SEQ_LT(tp->snd_nxt + len, tp->snd_una + so->so_snd.sb_cc))
- flags &= ~TH_FIN;
-
- win = sbuf_space(&so->so_rcv);
-
- /*
- * Sender silly window avoidance. If connection is idle
- * and can send all data, a maximum segment,
- * at least a maximum default-size segment do it,
- * or are forced, do it; otherwise don't bother.
- * If peer's buffer is tiny, then send
- * when window is at least half open.
- * If retransmitting (possibly after persist timer forced us
- * to send into a small window), then must resend.
- */
- if (len) {
- if (len == tp->t_maxseg)
- goto send;
- if ((1 || idle || tp->t_flags & TF_NODELAY) &&
- len + off >= so->so_snd.sb_cc)
- goto send;
- if (tp->t_force)
- goto send;
- if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0)
- goto send;
- if (SEQ_LT(tp->snd_nxt, tp->snd_max))
- goto send;
- }
-
- /*
- * Compare available window to amount of window
- * known to peer (as advertised window less
- * next expected input). If the difference is at least two
- * max size segments, or at least 50% of the maximum possible
- * window, then want to send a window update to peer.
- */
- if (win > 0) {
- /*
- * "adv" is the amount we can increase the window,
- * taking into account that we are limited by
- * TCP_MAXWIN << tp->rcv_scale.
- */
- long adv = min(win, (long)TCP_MAXWIN << tp->rcv_scale) -
- (tp->rcv_adv - tp->rcv_nxt);
-
- if (adv >= (long) (2 * tp->t_maxseg))
- goto send;
- if (2 * adv >= (long) so->so_rcv.sb_datalen)
- goto send;
- }
-
- /*
- * Send if we owe peer an ACK.
- */
- if (tp->t_flags & TF_ACKNOW)
- goto send;
- if (flags & (TH_SYN|TH_RST))
- goto send;
- if (SEQ_GT(tp->snd_up, tp->snd_una))
- goto send;
- /*
- * If our state indicates that FIN should be sent
- * and we have not yet done so, or we're retransmitting the FIN,
- * then we need to send.
- */
- if (flags & TH_FIN &&
- ((tp->t_flags & TF_SENTFIN) == 0 || tp->snd_nxt == tp->snd_una))
- goto send;
-
- /*
- * TCP window updates are not reliable, rather a polling protocol
- * using ``persist'' packets is used to insure receipt of window
- * updates. The three ``states'' for the output side are:
- * idle not doing retransmits or persists
- * persisting to move a small or zero window
- * (re)transmitting and thereby not persisting
- *
- * tp->t_timer[TCPT_PERSIST]
- * is set when we are in persist state.
- * tp->t_force
- * is set when we are called to send a persist packet.
- * tp->t_timer[TCPT_REXMT]
- * is set when we are retransmitting
- * The output side is idle when both timers are zero.
- *
- * If send window is too small, there is data to transmit, and no
- * retransmit or persist is pending, then go to persist state.
- * If nothing happens soon, send when timer expires:
- * if window is nonzero, transmit what we can,
- * otherwise force out a byte.
- */
- if (so->so_snd.sb_cc && tp->t_timer[TCPT_REXMT] == 0 &&
- tp->t_timer[TCPT_PERSIST] == 0) {
- tp->t_rxtshift = 0;
- tcp_setpersist(tp);
- }
-
- /*
- * No reason to send a segment, just return.
- */
- tcpstat.tcps_didnuttin++;
-
- return (0);
-
-send:
- /*
- * Before ESTABLISHED, force sending of initial options
- * unless TCP set not to do any options.
- * NOTE: we assume that the IP/TCP header plus TCP options
- * always fit in a single mbuf, leaving room for a maximum
- * link header, i.e.
- * max_linkhdr + sizeof (struct tcpiphdr) + optlen <= MHLEN
- */
- optlen = 0;
- hdrlen = sizeof (struct tcpiphdr);
- if (flags & TH_SYN) {
- tp->snd_nxt = tp->iss;
- if ((tp->t_flags & TF_NOOPT) == 0) {
- u_int16_t mss;
-
- opt[0] = TCPOPT_MAXSEG;
- opt[1] = 4;
- mss = htons((u_int16_t) tcp_mss(tp, 0));
- memcpy((caddr_t)(opt + 2), (caddr_t)&mss, sizeof(mss));
- optlen = 4;
-
-/* if ((tp->t_flags & TF_REQ_SCALE) &&
- * ((flags & TH_ACK) == 0 ||
- * (tp->t_flags & TF_RCVD_SCALE))) {
- * *((u_int32_t *) (opt + optlen)) = htonl(
- * TCPOPT_NOP << 24 |
- * TCPOPT_WINDOW << 16 |
- * TCPOLEN_WINDOW << 8 |
- * tp->request_r_scale);
- * optlen += 4;
- * }
- */
- }
- }
-
- /*
- * Send a timestamp and echo-reply if this is a SYN and our side
- * wants to use timestamps (TF_REQ_TSTMP is set) or both our side
- * and our peer have sent timestamps in our SYN's.
- */
-/* if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
- * (flags & TH_RST) == 0 &&
- * ((flags & (TH_SYN|TH_ACK)) == TH_SYN ||
- * (tp->t_flags & TF_RCVD_TSTMP))) {
- * u_int32_t *lp = (u_int32_t *)(opt + optlen);
- *
- * / * Form timestamp option as shown in appendix A of RFC 1323. * /
- * *lp++ = htonl(TCPOPT_TSTAMP_HDR);
- * *lp++ = htonl(tcp_now);
- * *lp = htonl(tp->ts_recent);
- * optlen += TCPOLEN_TSTAMP_APPA;
- * }
- */
- hdrlen += optlen;
-
- /*
- * Adjust data length if insertion of options will
- * bump the packet length beyond the t_maxseg length.
- */
- if (len > tp->t_maxseg - optlen) {
- len = tp->t_maxseg - optlen;
- sendalot = 1;
- }
-
- /*
- * Grab a header mbuf, attaching a copy of data to
- * be transmitted, and initialize the header from
- * the template for sends on this connection.
- */
- if (len) {
- if (tp->t_force && len == 1)
- tcpstat.tcps_sndprobe++;
- else if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
- tcpstat.tcps_sndrexmitpack++;
- tcpstat.tcps_sndrexmitbyte += len;
- } else {
- tcpstat.tcps_sndpack++;
- tcpstat.tcps_sndbyte += len;
- }
-
- m = mbuf_alloc();
- if (m == NULL) {
-/* error = ENOBUFS; */
- error = 1;
- goto out;
- }
- m->m_data += if_maxlinkhdr;
- m->m_len = hdrlen;
-
- /*
- * This will always succeed, since we make sure our mbufs
- * are big enough to hold one MSS packet + header + ... etc.
- */
-/* if (len <= MHLEN - hdrlen - max_linkhdr) { */
-
- sbuf_copy(&so->so_snd, off, (int) len, MBUF_TO(m, caddr_t) + hdrlen);
- m->m_len += len;
-
-/* } else {
- * m->m_next = mbuf_copy(so->so_snd.sb_mb, off, (int) len);
- * if (m->m_next == 0)
- * len = 0;
- * }
- */
- /*
- * If we're sending everything we've got, set PUSH.
- * (This will keep happy those implementations which only
- * give data to the user when a buffer fills or
- * a PUSH comes in.)
- */
- if (off + len == so->so_snd.sb_cc)
- flags |= TH_PUSH;
- } else {
- if (tp->t_flags & TF_ACKNOW)
- tcpstat.tcps_sndacks++;
- else if (flags & (TH_SYN|TH_FIN|TH_RST))
- tcpstat.tcps_sndctrl++;
- else if (SEQ_GT(tp->snd_up, tp->snd_una))
- tcpstat.tcps_sndurg++;
- else
- tcpstat.tcps_sndwinup++;
-
- m = mbuf_alloc();
- if (m == NULL) {
-/* error = ENOBUFS; */
- error = 1;
- goto out;
- }
- m->m_data += if_maxlinkhdr;
- m->m_len = hdrlen;
- }
-
- ti = MBUF_TO(m, struct tcpiphdr *);
-
- memcpy((caddr_t)ti, &tp->t_template, sizeof (struct tcpiphdr));
-
- /*
- * Fill in fields, remembering maximum advertised
- * window for use in delaying messages about window sizes.
- * If resending a FIN, be sure not to use a new sequence number.
- */
- if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
- tp->snd_nxt == tp->snd_max)
- tp->snd_nxt--;
- /*
- * If we are doing retransmissions, then snd_nxt will
- * not reflect the first unsent octet. For ACK only
- * packets, we do not want the sequence number of the
- * retransmitted packet, we want the sequence number
- * of the next unsent octet. So, if there is no data
- * (and no SYN or FIN), use snd_max instead of snd_nxt
- * when filling in ti_seq. But if we are in persist
- * state, snd_max might reflect one byte beyond the
- * right edge of the window, so use snd_nxt in that
- * case, since we know we aren't doing a retransmission.
- * (retransmit and persist are mutually exclusive...)
- */
- if (len || (flags & (TH_SYN|TH_FIN)) || tp->t_timer[TCPT_PERSIST])
- ti->ti_seq = htonl(tp->snd_nxt);
- else
- ti->ti_seq = htonl(tp->snd_max);
- ti->ti_ack = htonl(tp->rcv_nxt);
- if (optlen) {
- memcpy((caddr_t)(ti + 1), (caddr_t)opt, optlen);
- ti->ti_off = (sizeof (struct tcphdr) + optlen) >> 2;
- }
- ti->ti_flags = flags;
- /*
- * Calculate receive window. Don't shrink window,
- * but avoid silly window syndrome.
- */
- if (win < (long)(so->so_rcv.sb_datalen / 4) && win < (long)tp->t_maxseg)
- win = 0;
- if (win > (long)TCP_MAXWIN << tp->rcv_scale)
- win = (long)TCP_MAXWIN << tp->rcv_scale;
- if (win < (long)(tp->rcv_adv - tp->rcv_nxt))
- win = (long)(tp->rcv_adv - tp->rcv_nxt);
- ti->ti_win = htons((u_int16_t) (win>>tp->rcv_scale));
-
- if (SEQ_GT(tp->snd_up, tp->snd_una)) {
- ti->ti_urp = htons((u_int16_t)(tp->snd_up - ntohl(ti->ti_seq)));
-#ifdef notdef
- if (SEQ_GT(tp->snd_up, tp->snd_nxt)) {
- ti->ti_urp = htons((u_int16_t)(tp->snd_up - tp->snd_nxt));
-#endif
- ti->ti_flags |= TH_URG;
- } else
- /*
- * If no urgent pointer to send, then we pull
- * the urgent pointer to the left edge of the send window
- * so that it doesn't drift into the send window on sequence
- * number wraparound.
- */
- tp->snd_up = tp->snd_una; /* drag it along */
-
- /*
- * Put TCP length in extended header, and then
- * checksum extended header and data.
- */
- if (len + optlen)
- ti->ti_len = htons((u_int16_t)(sizeof (struct tcphdr) +
- optlen + len));
- ti->ti_sum = cksum(m, (int)(hdrlen + len));
-
- /*
- * In transmit state, time the transmission and arrange for
- * the retransmit. In persist state, just set snd_max.
- */
- if (tp->t_force == 0 || tp->t_timer[TCPT_PERSIST] == 0) {
- tcp_seq startseq = tp->snd_nxt;
-
- /*
- * Advance snd_nxt over sequence space of this segment.
- */
- if (flags & (TH_SYN|TH_FIN)) {
- if (flags & TH_SYN)
- tp->snd_nxt++;
- if (flags & TH_FIN) {
- tp->snd_nxt++;
- tp->t_flags |= TF_SENTFIN;
- }
- }
- tp->snd_nxt += len;
- if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
- tp->snd_max = tp->snd_nxt;
- /*
- * Time this transmission if not a retransmission and
- * not currently timing anything.
- */
- if (tp->t_rtt == 0) {
- tp->t_rtt = 1;
- tp->t_rtseq = startseq;
- tcpstat.tcps_segstimed++;
- }
- }
-
- /*
- * Set retransmit timer if not currently set,
- * and not doing an ack or a keep-alive probe.
- * Initial value for retransmit timer is smoothed
- * round-trip time + 2 * round-trip time variance.
- * Initialize shift counter which is used for backoff
- * of retransmit time.
- */
- if (tp->t_timer[TCPT_REXMT] == 0 &&
- tp->snd_nxt != tp->snd_una) {
- tp->t_timer[TCPT_REXMT] = tp->t_rxtcur;
- if (tp->t_timer[TCPT_PERSIST]) {
- tp->t_timer[TCPT_PERSIST] = 0;
- tp->t_rxtshift = 0;
- }
- }
- } else
- if (SEQ_GT(tp->snd_nxt + len, tp->snd_max))
- tp->snd_max = tp->snd_nxt + len;
-
- /*
- * Fill in IP length and desired time to live and
- * send to IP level. There should be a better way
- * to handle ttl and tos; we could keep them in
- * the template, but need a way to checksum without them.
- */
- m->m_len = hdrlen + len; /* XXX Needed? m_len should be correct */
-
- {
-
- ((struct ip *)ti)->ip_len = m->m_len;
-
- ((struct ip *)ti)->ip_ttl = ip_defttl;
- ((struct ip *)ti)->ip_tos = so->so_iptos;
-
-/* #if BSD >= 43 */
- /* Don't do IP options... */
-/* error = ip_output(m, tp->t_inpcb->inp_options, &tp->t_inpcb->inp_route,
- * so->so_options & SO_DONTROUTE, 0);
- */
- error = ip_output(so, m);
-
-/* #else
- * error = ip_output(m, (MBuf )0, &tp->t_inpcb->inp_route,
- * so->so_options & SO_DONTROUTE);
- * #endif
- */
- }
- if (error) {
-out:
-/* if (error == ENOBUFS) {
- * tcp_quench(tp->t_inpcb, 0);
- * return (0);
- * }
- */
-/* if ((error == EHOSTUNREACH || error == ENETDOWN)
- * && TCPS_HAVERCVDSYN(tp->t_state)) {
- * tp->t_softerror = error;
- * return (0);
- * }
- */
- return (error);
- }
- tcpstat.tcps_sndtotal++;
-
- /*
- * Data sent (as far as we can tell).
- * If this advertises a larger window than any other segment,
- * then remember the size of the advertised window.
- * Any pending ACK has now been sent.
- */
- if (win > 0 && SEQ_GT(tp->rcv_nxt+win, tp->rcv_adv))
- tp->rcv_adv = tp->rcv_nxt + win;
- tp->last_ack_sent = tp->rcv_nxt;
- tp->t_flags &= ~(TF_ACKNOW|TF_DELACK);
- if (sendalot)
- goto again;
-
- return (0);
-}
-
-void
-tcp_setpersist(tp)
- register struct tcpcb *tp;
-{
- int t = ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1;
-
-/* if (tp->t_timer[TCPT_REXMT])
- * panic("tcp_output REXMT");
- */
- /*
- * Start/restart persistence timer.
- */
- TCPT_RANGESET(tp->t_timer[TCPT_PERSIST],
- t * tcp_backoff[tp->t_rxtshift],
- TCPTV_PERSMIN, TCPTV_PERSMAX);
- if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
- tp->t_rxtshift++;
-}
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