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freebsd/sys/netipx/spx_reass.c

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/*-
* Copyright (c) 1984, 1985, 1986, 1987, 1993
* The Regents of the University of California.
* Copyright (c) 2004-2009 Robert N. M. Watson
* 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.
* 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.
*
* Copyright (c) 1995, Mike Mitchell
* 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.
*
* @(#)spx_usrreq.h
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <net/route.h>
#include <netinet/tcp_fsm.h>
#include <netipx/ipx.h>
#include <netipx/ipx_pcb.h>
#include <netipx/ipx_var.h>
#include <netipx/spx.h>
#include <netipx/spx_debug.h>
#include <netipx/spx_timer.h>
#include <netipx/spx_var.h>
static int spx_use_delack = 0;
static int spxrexmtthresh = 3;
static __inline void
spx_insque(struct spx_q *element, struct spx_q *head)
{
element->si_next = head->si_next;
element->si_prev = head;
head->si_next = element;
element->si_next->si_prev = element;
}
static void
spx_remque(struct spx_q *element)
{
element->si_next->si_prev = element->si_prev;
element->si_prev->si_next = element->si_next;
element->si_prev = NULL;
}
/*
* Flesh pending queued segments on SPX close.
*/
void
spx_reass_flush(struct spxpcb *cb)
{
struct spx_q *s;
struct mbuf *m;
s = cb->s_q.si_next;
while (s != &(cb->s_q)) {
s = s->si_next;
spx_remque(s);
m = dtom(s);
m_freem(m);
}
}
/*
* Initialize SPX segment reassembly queue on SPX socket open.
*/
void
spx_reass_init(struct spxpcb *cb)
{
cb->s_q.si_next = cb->s_q.si_prev = &cb->s_q;
}
/*
* This is structurally similar to the tcp reassembly routine but its
* function is somewhat different: it merely queues packets up, and
* suppresses duplicates.
*/
int
spx_reass(struct spxpcb *cb, struct spx *si)
{
struct spx_q *q;
struct mbuf *m;
struct socket *so = cb->s_ipxpcb->ipxp_socket;
char packetp = cb->s_flags & SF_HI;
int incr;
char wakeup = 0;
IPX_LOCK_ASSERT(cb->s_ipxpcb);
if (si == SI(0))
goto present;
/*
* Update our news from them.
*/
if (si->si_cc & SPX_SA)
cb->s_flags |= (spx_use_delack ? SF_DELACK : SF_ACKNOW);
if (SSEQ_GT(si->si_alo, cb->s_ralo))
cb->s_flags |= SF_WIN;
if (SSEQ_LEQ(si->si_ack, cb->s_rack)) {
if ((si->si_cc & SPX_SP) && cb->s_rack != (cb->s_smax + 1)) {
spxstat.spxs_rcvdupack++;
/*
* If this is a completely duplicate ack and other
* conditions hold, we assume a packet has been
* dropped and retransmit it exactly as in
* tcp_input().
*/
if (si->si_ack != cb->s_rack ||
si->si_alo != cb->s_ralo)
cb->s_dupacks = 0;
else if (++cb->s_dupacks == spxrexmtthresh) {
u_short onxt = cb->s_snxt;
int cwnd = cb->s_cwnd;
cb->s_snxt = si->si_ack;
cb->s_cwnd = CUNIT;
cb->s_force = 1 + SPXT_REXMT;
spx_output(cb, NULL);
cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
cb->s_rtt = 0;
if (cwnd >= 4 * CUNIT)
cb->s_cwnd = cwnd / 2;
if (SSEQ_GT(onxt, cb->s_snxt))
cb->s_snxt = onxt;
return (1);
}
} else
cb->s_dupacks = 0;
goto update_window;
}
cb->s_dupacks = 0;
/*
* If our correspondent acknowledges data we haven't sent TCP would
* drop the packet after acking. We'll be a little more permissive.
*/
if (SSEQ_GT(si->si_ack, (cb->s_smax + 1))) {
spxstat.spxs_rcvacktoomuch++;
si->si_ack = cb->s_smax + 1;
}
spxstat.spxs_rcvackpack++;
/*
* If transmit timer is running and timed sequence number was acked,
* update smoothed round trip time. See discussion of algorithm in
* tcp_input.c
*/
if (cb->s_rtt && SSEQ_GT(si->si_ack, cb->s_rtseq)) {
spxstat.spxs_rttupdated++;
if (cb->s_srtt != 0) {
short delta;
delta = cb->s_rtt - (cb->s_srtt >> 3);
if ((cb->s_srtt += delta) <= 0)
cb->s_srtt = 1;
if (delta < 0)
delta = -delta;
delta -= (cb->s_rttvar >> 2);
if ((cb->s_rttvar += delta) <= 0)
cb->s_rttvar = 1;
} else {
/*
* No rtt measurement yet.
*/
cb->s_srtt = cb->s_rtt << 3;
cb->s_rttvar = cb->s_rtt << 1;
}
cb->s_rtt = 0;
cb->s_rxtshift = 0;
SPXT_RANGESET(cb->s_rxtcur,
((cb->s_srtt >> 2) + cb->s_rttvar) >> 1,
SPXTV_MIN, SPXTV_REXMTMAX);
}
/*
* If all outstanding data is acked, stop retransmit timer and
* remember to restart (more output or persist). If there is more
* data to be acked, restart retransmit timer, using current
* (possibly backed-off) value;
*/
if (si->si_ack == cb->s_smax + 1) {
cb->s_timer[SPXT_REXMT] = 0;
cb->s_flags |= SF_RXT;
} else if (cb->s_timer[SPXT_PERSIST] == 0)
cb->s_timer[SPXT_REXMT] = cb->s_rxtcur;
/*
* When new data is acked, open the congestion window. If the window
* gives us less than ssthresh packets in flight, open exponentially
* (maxseg at a time). Otherwise open linearly (maxseg^2 / cwnd at a
* time).
*/
incr = CUNIT;
if (cb->s_cwnd > cb->s_ssthresh)
incr = max(incr * incr / cb->s_cwnd, 1);
cb->s_cwnd = min(cb->s_cwnd + incr, cb->s_cwmx);
/*
* Trim Acked data from output queue.
*/
SOCKBUF_LOCK(&so->so_snd);
while ((m = so->so_snd.sb_mb) != NULL) {
if (SSEQ_LT((mtod(m, struct spx *))->si_seq, si->si_ack))
sbdroprecord_locked(&so->so_snd);
else
break;
}
sowwakeup_locked(so);
cb->s_rack = si->si_ack;
update_window:
if (SSEQ_LT(cb->s_snxt, cb->s_rack))
cb->s_snxt = cb->s_rack;
if (SSEQ_LT(cb->s_swl1, si->si_seq) || ((cb->s_swl1 == si->si_seq &&
(SSEQ_LT(cb->s_swl2, si->si_ack))) ||
(cb->s_swl2 == si->si_ack && SSEQ_LT(cb->s_ralo, si->si_alo)))) {
/* keep track of pure window updates */
if ((si->si_cc & SPX_SP) && cb->s_swl2 == si->si_ack
&& SSEQ_LT(cb->s_ralo, si->si_alo)) {
spxstat.spxs_rcvwinupd++;
spxstat.spxs_rcvdupack--;
}
cb->s_ralo = si->si_alo;
cb->s_swl1 = si->si_seq;
cb->s_swl2 = si->si_ack;
cb->s_swnd = (1 + si->si_alo - si->si_ack);
if (cb->s_swnd > cb->s_smxw)
cb->s_smxw = cb->s_swnd;
cb->s_flags |= SF_WIN;
}
/*
* If this packet number is higher than that which we have allocated
* refuse it, unless urgent.
*/
if (SSEQ_GT(si->si_seq, cb->s_alo)) {
if (si->si_cc & SPX_SP) {
spxstat.spxs_rcvwinprobe++;
return (1);
} else
spxstat.spxs_rcvpackafterwin++;
if (si->si_cc & SPX_OB) {
if (SSEQ_GT(si->si_seq, cb->s_alo + 60))
return (1); /* else queue this packet; */
} else {
#ifdef BROKEN
/*
* XXXRW: This is broken on at least one count:
* spx_close() will free the ipxp and related parts,
* which are then touched by spx_input() after the
* return from spx_reass().
*/
/*struct socket *so = cb->s_ipxpcb->ipxp_socket;
if (so->so_state && SS_NOFDREF) {
spx_close(cb);
} else
would crash system*/
#endif
spx_istat.notyet++;
return (1);
}
}
/*
* If this is a system packet, we don't need to queue it up, and
* won't update acknowledge #.
*/
if (si->si_cc & SPX_SP)
return (1);
/*
* We have already seen this packet, so drop.
*/
if (SSEQ_LT(si->si_seq, cb->s_ack)) {
spx_istat.bdreas++;
spxstat.spxs_rcvduppack++;
if (si->si_seq == cb->s_ack - 1)
spx_istat.lstdup++;
return (1);
}
/*
* Loop through all packets queued up to insert in appropriate
* sequence.
*/
for (q = cb->s_q.si_next; q != &cb->s_q; q = q->si_next) {
if (si->si_seq == SI(q)->si_seq) {
spxstat.spxs_rcvduppack++;
return (1);
}
if (SSEQ_LT(si->si_seq, SI(q)->si_seq)) {
spxstat.spxs_rcvoopack++;
break;
}
}
spx_insque((struct spx_q *)si, q->si_prev);
/*
* If this packet is urgent, inform process
*/
if (si->si_cc & SPX_OB) {
cb->s_iobc = ((char *)si)[1 + sizeof(*si)];
sohasoutofband(so);
cb->s_oobflags |= SF_IOOB;
}
present:
#define SPINC sizeof(struct spxhdr)
SOCKBUF_LOCK(&so->so_rcv);
/*
* Loop through all packets queued up to update acknowledge number,
* and present all acknowledged data to user; if in packet interface
* mode, show packet headers.
*/
for (q = cb->s_q.si_next; q != &cb->s_q; q = q->si_next) {
if (SI(q)->si_seq == cb->s_ack) {
cb->s_ack++;
m = dtom(q);
if (SI(q)->si_cc & SPX_OB) {
cb->s_oobflags &= ~SF_IOOB;
if (so->so_rcv.sb_cc)
so->so_oobmark = so->so_rcv.sb_cc;
else
so->so_rcv.sb_state |= SBS_RCVATMARK;
}
q = q->si_prev;
spx_remque(q->si_next);
wakeup = 1;
spxstat.spxs_rcvpack++;
#ifdef SF_NEWCALL
if (cb->s_flags2 & SF_NEWCALL) {
struct spxhdr *sp = mtod(m, struct spxhdr *);
u_char dt = sp->spx_dt;
spx_newchecks[4]++;
if (dt != cb->s_rhdr.spx_dt) {
struct mbuf *mm =
m_getclr(M_DONTWAIT, MT_CONTROL);
spx_newchecks[0]++;
if (mm != NULL) {
u_short *s =
mtod(mm, u_short *);
cb->s_rhdr.spx_dt = dt;
mm->m_len = 5; /*XXX*/
s[0] = 5;
s[1] = 1;
*(u_char *)(&s[2]) = dt;
sbappend_locked(&so->so_rcv, mm);
}
}
if (sp->spx_cc & SPX_OB) {
MCHTYPE(m, MT_OOBDATA);
spx_newchecks[1]++;
so->so_oobmark = 0;
so->so_rcv.sb_state &= ~SBS_RCVATMARK;
}
if (packetp == 0) {
m->m_data += SPINC;
m->m_len -= SPINC;
m->m_pkthdr.len -= SPINC;
}
if ((sp->spx_cc & SPX_EM) || packetp) {
sbappendrecord_locked(&so->so_rcv, m);
spx_newchecks[9]++;
} else
sbappend_locked(&so->so_rcv, m);
} else
#endif
if (packetp)
sbappendrecord_locked(&so->so_rcv, m);
else {
cb->s_rhdr = *mtod(m, struct spxhdr *);
m->m_data += SPINC;
m->m_len -= SPINC;
m->m_pkthdr.len -= SPINC;
sbappend_locked(&so->so_rcv, m);
}
} else
break;
}
if (wakeup)
sorwakeup_locked(so);
else
SOCKBUF_UNLOCK(&so->so_rcv);
return (0);
}
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