/*
- * Copyright (c) 1987 Regents of the University of California.
+ * Copyright (c) 1987, 1989 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
- * @(#)if_sl.c 7.13 (Berkeley) %G%
+ * @(#)if_sl.c 7.16 (Berkeley) %G%
*/
/*
*
* Converted to 4.3BSD Beta by Chris Torek.
* Other changes made at Berkeley, based in part on code by Kirk Smith.
+ * W. Jolitz added slip abort.
+ *
+ * Hacked almost beyond recognition by Van Jacobson (van@helios.ee.lbl.gov).
+ * Added priority queuing for "interactive" traffic; hooks for TCP
+ * header compression; ICMP filtering (at 2400 baud, some cretin
+ * pinging you can use up all your bandwidth). Made low clist behavior
+ * more robust and slightly less likely to hang serial line.
+ * Sped up a bunch of things.
+ *
+ * Note that splimp() is used throughout to block both (tty) input
+ * interrupts and network activity; thus, splimp must be >= spltty.
*/
-/* $Header: if_sl.c,v 1.12 85/12/20 21:54:55 chris Exp $ */
+/* $Header: if_sl.c,v 1.7 89/05/31 02:24:52 van Exp $ */
/* from if_sl.c,v 1.11 84/10/04 12:54:47 rick Exp */
#include "sl.h"
#if NSL > 0
#include "param.h"
+#include "dir.h"
+#include "user.h"
#include "mbuf.h"
#include "buf.h"
#include "dk.h"
#include "ioctl.h"
#include "file.h"
#include "tty.h"
+#include "kernel.h"
+#include "conf.h"
#include "errno.h"
#include "if.h"
#include "machine/mtpr.h"
+#include "slcompress.h"
+#include "if_slvar.h"
+
+/*
+ * SLMTU is a hard limit on input packet size. To simplify the code
+ * and improve performance, we require that packets fit in an mbuf
+ * cluster, that there be enough extra room for the ifnet pointer that
+ * IP input requires and, if we get a compressed packet, there's
+ * enough extra room to expand the header into a max length tcp/ip
+ * header (128 bytes). So, SLMTU can be at most
+ * MCLBYTES - sizeof(struct ifnet *) - 128
+ *
+ * To insure we get good interactive response, the MTU wants to be
+ * the smallest size that amortizes the header cost. (Remember
+ * that even with type-of-service queuing, we have to wait for any
+ * in-progress packet to finish. I.e., we wait, on the average,
+ * 1/2 * mtu / cps, where cps is the line speed in characters per
+ * second. E.g., 533ms wait for a 1024 byte MTU on a 9600 baud
+ * line. The average compressed header size is 6-8 bytes so any
+ * MTU > 90 bytes will give us 90% of the line bandwidth. A 100ms
+ * wait is tolerable (500ms is not), so want an MTU around 256.
+ * (Since TCP will send 212 byte segments (to allow for 40 byte
+ * headers), the typical packet size on the wire will be around 220
+ * bytes). In 4.3tahoe+ systems, we can set an MTU in a route
+ * so we do that & leave the interface MTU relatively high (so we
+ * don't IP fragment when acting as a gateway to someone using a
+ * stupid MTU).
+ */
+#define SLMTU 576
+#define BUFOFFSET (128+sizeof(struct ifnet **))
+#define SLIP_HIWAT 1024 /* don't start a new packet if HIWAT on queue */
+#define CLISTRESERVE 1024 /* Can't let clists get too low */
+/*
+ * SLIP ABORT ESCAPE MECHANISM:
+ * (inspired by HAYES modem escape arrangement)
+ * 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
+ * signals a "soft" exit from slip mode by usermode process
+ */
+
+#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/
+#define ABT_WAIT 1 /* in seconds - idle before an escape & after */
+#define ABT_RECYCLE (5*2+2) /* in seconds - time window processing abort */
+
+#define ABT_SOFT 3 /* count of escapes */
+
/*
- * N.B.: SLMTU is now a hard limit on input packet size.
- * SLMTU must be <= MCLBYTES - sizeof(struct ifnet *).
+ * The following disgusting hack gets around the problem that IP TOS
+ * can't be set in BSD/Sun OS yet. We want to put "interactive"
+ * traffic on a high priority queue. To decide if traffic is
+ * interactive, we check that a) it is TCP and b) one of it's ports
+ * if telnet, rlogin or ftp control.
*/
-#define SLMTU 1006
-#define SLIP_HIWAT 1000 /* don't start a new packet if HIWAT on queue */
-#define CLISTRESERVE 1000 /* Can't let clists get too low */
-
-struct sl_softc {
- struct ifnet sc_if; /* network-visible interface */
- short sc_flags; /* see below */
- short sc_ilen; /* length of input-packet-so-far */
- struct tty *sc_ttyp; /* pointer to tty structure */
- char *sc_mp; /* pointer to next available buf char */
- char *sc_buf; /* input buffer */
-} sl_softc[NSL];
-
-/* flags */
-#define SC_ESCAPED 0x0001 /* saw a FRAME_ESCAPE */
-
-#define FRAME_END 0300 /* Frame End */
-#define FRAME_ESCAPE 0333 /* Frame Esc */
-#define TRANS_FRAME_END 0334 /* transposed frame end */
-#define TRANS_FRAME_ESCAPE 0335 /* transposed frame esc */
+static u_short interactive_ports[8] = {
+ 0, 513, 0, 0,
+ 0, 21, 0, 23,
+};
+#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))
+
+struct sl_softc sl_softc[NSL];
+
+#define FRAME_END 0xc0 /* Frame End */
+#define FRAME_ESCAPE 0xdb /* Frame Esc */
+#define TRANS_FRAME_END 0xdc /* transposed frame end */
+#define TRANS_FRAME_ESCAPE 0xdd /* transposed frame esc */
#define t_sc T_LINEP
sc->sc_if.if_flags = IFF_POINTOPOINT;
sc->sc_if.if_ioctl = slioctl;
sc->sc_if.if_output = sloutput;
- sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
+ sc->sc_if.if_snd.ifq_maxlen = 50;
+ sc->sc_fastq.ifq_maxlen = 32;
if_attach(&sc->sc_if);
}
}
+static int
+slinit(sc)
+ register struct sl_softc *sc;
+{
+ register caddr_t p;
+
+ if (sc->sc_ep == (u_char *) 0) {
+ MCLALLOC(p, M_WAIT);
+ if (p)
+ sc->sc_ep = (u_char *)p + (BUFOFFSET + SLMTU);
+ else {
+ printf("sl%d: can't allocate buffer\n", sc - sl_softc);
+ sc->sc_if.if_flags &= ~IFF_UP;
+ return (0);
+ }
+ }
+ sc->sc_buf = sc->sc_ep - SLMTU;
+ sc->sc_mp = sc->sc_buf;
+ sl_compress_init(&sc->sc_comp);
+ return (1);
+}
+
/*
* Line specific open routine.
* Attach the given tty to the first available sl unit.
if (error = suser(u.u_cred, &u.u_acflag))
return (error);
+
if (tp->t_line == SLIPDISC)
return (EBUSY);
- for (nsl = 0, sc = sl_softc; nsl < NSL; nsl++, sc++)
+ for (nsl = NSL, sc = sl_softc; --nsl >= 0; sc++)
if (sc->sc_ttyp == NULL) {
- sc->sc_flags = 0;
- sc->sc_ilen = 0;
if (slinit(sc) == 0)
return (ENOBUFS);
tp->t_sc = (caddr_t)sc;
ttyflush(tp, FREAD | FWRITE);
return (0);
}
-
return (ENXIO);
}
int s;
ttywflush(tp);
+ s = splimp(); /* actually, max(spltty, splnet) */
tp->t_line = 0;
- s = splimp(); /* paranoid; splnet probably ok */
sc = (struct sl_softc *)tp->t_sc;
if (sc != NULL) {
if_down(&sc->sc_if);
sc->sc_ttyp = NULL;
tp->t_sc = NULL;
- MCLFREE((struct mbuf *)sc->sc_buf);
+ MCLFREE((struct mbuf *)(sc->sc_ep - (SLMTU + BUFOFFSET)));
+ sc->sc_ep = 0;
+ sc->sc_mp = 0;
sc->sc_buf = 0;
}
splx(s);
struct tty *tp;
caddr_t data;
{
+ struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
+ int s;
- if (cmd == TIOCGETD) {
- *(int *)data = ((struct sl_softc *)tp->t_sc)->sc_if.if_unit;
- return (0);
+ switch (cmd) {
+ case TIOCGETD: /* XXX */
+ case SLIOGUNIT:
+ *(int *)data = sc->sc_if.if_unit;
+ break;
+
+ case SLIOCGFLAGS:
+ *(int *)data = sc->sc_flags;
+ break;
+
+ case SLIOCSFLAGS:
+#define SC_MASK (SC_COMPRESS|SC_NOICMP)
+ s = splimp();
+ sc->sc_flags =
+ (sc->sc_flags &~ SC_MASK) | ((*(int *)data) & SC_MASK);
+ splx(s);
+ break;
+
+ default:
+ return (-1);
}
- return (-1);
+ return (0);
}
/*
struct sockaddr *dst;
{
register struct sl_softc *sc;
+ register struct ip *ip;
+ register struct ifqueue *ifq;
int s;
/*
m_freem(m);
return (EHOSTUNREACH);
}
+ ifq = &ifp->if_snd;
+ if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
+ register int p = ((int *)ip)[ip->ip_hl];
+
+ if (INTERACTIVE(p & 0xffff) || INTERACTIVE(p >> 16))
+ ifq = &sc->sc_fastq;
+
+ if (sc->sc_flags & SC_COMPRESS) {
+ /* if two copies of sl_compress_tcp are running
+ * for the same line, the compression state can
+ * get screwed up. We're assuming that sloutput
+ * was invoked at splnet so this isn't possible
+ * (this assumption is correct for 4.xbsd, x<=4).
+ * In a multi-threaded kernel, a lockout might
+ * be needed here. */
+ p = sl_compress_tcp(m, ip, &sc->sc_comp);
+ *mtod(m, u_char *) |= p;
+ }
+ } else if (sc->sc_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
+ m_freem(m);
+ return (0);
+ }
s = splimp();
- if (IF_QFULL(&ifp->if_snd)) {
- IF_DROP(&ifp->if_snd);
- splx(s);
+ if (IF_QFULL(ifq)) {
+ IF_DROP(ifq);
m_freem(m);
+ splx(s);
sc->sc_if.if_oerrors++;
return (ENOBUFS);
}
- IF_ENQUEUE(&ifp->if_snd, m);
+ IF_ENQUEUE(ifq, m);
if (sc->sc_ttyp->t_outq.c_cc == 0) {
splx(s);
slstart(sc->sc_ttyp);
{
register struct sl_softc *sc = (struct sl_softc *)tp->t_sc;
register struct mbuf *m;
- register int len;
register u_char *cp;
- int nd, np, n, s;
+ int s;
struct mbuf *m2;
extern int cfreecount;
* We are being called in lieu of ttstart and must do what
* it would.
*/
- if (tp->t_outq.c_cc > 0)
- ttstart(tp);
- if (tp->t_outq.c_cc > SLIP_HIWAT)
- return;
-
+ if (tp->t_outq.c_cc != 0) {
+ (*tp->t_oproc)(tp);
+ if (tp->t_outq.c_cc > SLIP_HIWAT)
+ return;
+ }
/*
* This happens briefly when the line shuts down.
*/
if (sc == NULL)
return;
- /*
- * If system is getting low on clists
- * and we have something running already, stop here.
- */
- if (cfreecount < CLISTRESERVE + SLMTU && tp->t_outq.c_cc)
- return;
-
/*
* Get a packet and send it to the interface.
*/
s = splimp();
- IF_DEQUEUE(&sc->sc_if.if_snd, m);
+ IF_DEQUEUE(&sc->sc_fastq, m);
+ if (m == NULL)
+ IF_DEQUEUE(&sc->sc_if.if_snd, m);
splx(s);
if (m == NULL)
return;
+ /*
+ * If system is getting low on clists, just flush our
+ * output queue (if the stuff was important, it'll get
+ * retransmitted).
+ */
+ if (cfreecount < CLISTRESERVE + SLMTU) {
+ m_freem(m);
+ sc->sc_if.if_collisions++;
+ continue;
+ }
/*
* The extra FRAME_END will start up a new packet, and thus
* will flush any accumulated garbage. We do this whenever
* the line may have been idle for some time.
*/
- if (tp->t_outq.c_cc == 0)
+ if (tp->t_outq.c_cc == 0) {
+ ++sc->sc_bytessent;
(void) putc(FRAME_END, &tp->t_outq);
+ }
while (m) {
- cp = mtod(m, u_char *);
- len = m->m_len;
- while (len > 0) {
+ register u_char *ep;
+
+ cp = mtod(m, u_char *); ep = cp + m->m_len;
+ while (cp < ep) {
/*
* Find out how many bytes in the string we can
* handle without doing something special.
*/
- nd = locc(FRAME_ESCAPE, len, cp);
- np = locc(FRAME_END, len, cp);
- n = len - MAX(nd, np);
- if (n) {
+ register u_char *bp = cp;
+
+ while (cp < ep) {
+ switch (*cp++) {
+ case FRAME_ESCAPE:
+ case FRAME_END:
+ --cp;
+ goto out;
+ }
+ }
+ out:
+ if (cp > bp) {
/*
* Put n characters at once
* into the tty output queue.
*/
- if (b_to_q((char *)cp, n, &tp->t_outq))
+ if (b_to_q((char *)bp, cp - bp, &tp->t_outq))
break;
- len -= n;
- cp += n;
+ sc->sc_bytessent += cp - bp;
}
/*
* If there are characters left in the mbuf,
* the first one must be special..
* Put it out in a different form.
*/
- if (len) {
+ if (cp < ep) {
if (putc(FRAME_ESCAPE, &tp->t_outq))
break;
- if (putc(*cp == FRAME_ESCAPE ?
+ if (putc(*cp++ == FRAME_ESCAPE ?
TRANS_FRAME_ESCAPE : TRANS_FRAME_END,
&tp->t_outq)) {
(void) unputc(&tp->t_outq);
break;
}
- cp++;
- len--;
+ sc->sc_bytessent += 2;
}
}
MFREE(m, m2);
(void) unputc(&tp->t_outq);
(void) putc(FRAME_END, &tp->t_outq);
sc->sc_if.if_collisions++;
- } else
- sc->sc_if.if_opackets++;
- }
-}
-
-slinit(sc)
- register struct sl_softc *sc;
-{
- register caddr_t p;
-
- if (sc->sc_buf == (char *) 0) {
- MCLALLOC(p, M_WAIT);
- if (p) {
- sc->sc_buf = p;
- sc->sc_mp = p;
} else {
- printf("sl%d: can't allocate buffer\n", sc - sl_softc);
- sc->sc_if.if_flags &= ~IFF_UP;
- return (0);
+ ++sc->sc_bytessent;
+ sc->sc_if.if_opackets++;
}
}
- return (1);
}
/*
- * Copy data buffer to mbuf chain; add ifnet pointer ifp.
+ * Copy data buffer to mbuf chain; add ifnet pointer.
*/
-struct mbuf *
-sl_btom(sc, len, ifp)
- struct sl_softc *sc;
+static struct mbuf *
+sl_btom(sc, len)
+ register struct sl_softc *sc;
register int len;
- struct ifnet *ifp;
{
- register caddr_t cp;
- register struct mbuf *m, **mp;
- register unsigned count;
- struct mbuf *top = NULL;
-
- cp = sc->sc_buf + sizeof(struct ifnet *);
- mp = ⊤
- while (len > 0) {
- if (top == NULL) {
- MGETHDR(m, M_DONTWAIT, MT_DATA);
- } else {
- MGET(m, M_DONTWAIT, MT_DATA);
- }
- if ((*mp = m) == NULL) {
- m_freem(top);
+ register u_char *cp;
+ register struct mbuf *m;
+
+ MGETHDR(m, M_DONTWAIT, MT_DATA);
+ if (m == NULL)
+ return (NULL);
+
+ /*
+ * If we have more than MLEN bytes, it's cheaper to
+ * queue the cluster we just filled & allocate a new one
+ * for the input buffer. Otherwise, fill the mbuf we
+ * allocated above. Note that code in the input routine
+ * guarantees that packet will fit in a cluster.
+ */
+ cp = sc->sc_buf;
+ if (len >= MHLEN) {
+ MCLGET(m, M_DONTWAIT);
+ if ((m->m_flags & M_EXT) == 0) {
+ /* we couldn't get a cluster - if memory's this
+ * low, it's time to start dropping packets. */
+ m_freem(m);
return (NULL);
}
- if (top == NULL) {
- m->m_pkthdr.rcvif = ifp;
- m->m_pkthdr.len = len;
- m->m_len = MHLEN;
- } else
- m->m_len = MLEN;
- /*
- * If we have at least MINCLSIZE bytes,
- * allocate a new page. Swap the current
- * buffer page with the new one.
- */
- if (len >= MINCLSIZE) {
- MCLGET(m, M_DONTWAIT);
- if (m->m_flags & M_EXT) {
- cp = mtod(m, char *);
- m->m_data = sc->sc_buf;
- sc->sc_buf = cp;
- count = MIN(len, MCLBYTES);
- goto nocopy;
- }
- }
- count = MIN(len, m->m_len);
- bcopy(cp, mtod(m, caddr_t), count);
-nocopy:
- m->m_len = count;
- cp += count;
- len -= count;
- mp = &m->m_next;
- }
- return (top);
+ sc->sc_ep = mtod(m, u_char *) + (BUFOFFSET + SLMTU);
+ m->m_data = (caddr_t)cp;
+ } else
+ bcopy((caddr_t)cp, mtod(m, caddr_t), len);
+
+ m->m_len = len;
+ m->m_pkthdr.len = len;
+ m->m_pkthdr.rcvif = &sc->sc_if;
+ return (m);
}
/*
{
register struct sl_softc *sc;
register struct mbuf *m;
+ register int len;
int s;
tk_nin++;
sc = (struct sl_softc *)tp->t_sc;
if (sc == NULL)
return;
+ if (!(tp->t_state&TS_CARR_ON)) /* XXX */
+ return;
+
+ ++sc->sc_bytesrcvd;
+ c &= 0xff; /* XXX */
+
+#ifdef ABT_ESC
+ if (sc->sc_flags & SC_ABORT) {
+ /* if we see an abort after "idle" time, count it */
+ if (c == ABT_ESC && time.tv_sec >= sc->sc_lasttime + ABT_WAIT) {
+ sc->sc_abortcount++;
+ /* record when the first abort escape arrived */
+ if (sc->sc_abortcount == 1)
+ sc->sc_starttime = time.tv_sec;
+ }
+ /*
+ * if we have an abort, see that we have not run out of time,
+ * or that we have an "idle" time after the complete escape
+ * sequence
+ */
+ if (sc->sc_abortcount) {
+ if (time.tv_sec >= sc->sc_starttime + ABT_RECYCLE)
+ sc->sc_abortcount = 0;
+ if (sc->sc_abortcount >= ABT_SOFT &&
+ time.tv_sec >= sc->sc_lasttime + ABT_WAIT) {
+ slclose(tp);
+ return;
+ }
+ }
+ sc->sc_lasttime = time.tv_sec;
+ }
+#endif
- c &= 0xff;
- if (sc->sc_flags & SC_ESCAPED) {
- sc->sc_flags &= ~SC_ESCAPED;
- switch (c) {
+ switch (c) {
- case TRANS_FRAME_ESCAPE:
+ case TRANS_FRAME_ESCAPE:
+ if (sc->sc_escape)
c = FRAME_ESCAPE;
- break;
+ break;
- case TRANS_FRAME_END:
+ case TRANS_FRAME_END:
+ if (sc->sc_escape)
c = FRAME_END;
- break;
+ break;
- default:
- sc->sc_if.if_ierrors++;
- sc->sc_mp = sc->sc_buf + sizeof(struct ifnet *);
- sc->sc_ilen = 0;
- return;
- }
- } else {
- switch (c) {
+ case FRAME_ESCAPE:
+ sc->sc_escape = 1;
+ return;
- case FRAME_END:
- if (sc->sc_ilen == 0) /* ignore */
- return;
- m = sl_btom(sc, sc->sc_ilen, &sc->sc_if);
- if (m == NULL) {
- sc->sc_if.if_ierrors++;
- return;
- }
- sc->sc_mp = sc->sc_buf + sizeof(struct ifnet *);
- sc->sc_ilen = 0;
- sc->sc_if.if_ipackets++;
- s = splimp();
- if (IF_QFULL(&ipintrq)) {
- IF_DROP(&ipintrq);
- sc->sc_if.if_ierrors++;
- m_freem(m);
- } else {
- IF_ENQUEUE(&ipintrq, m);
- schednetisr(NETISR_IP);
- }
- splx(s);
- return;
+ case FRAME_END:
+ len = sc->sc_mp - sc->sc_buf;
+ if (len < 3)
+ /* less than min length packet - ignore */
+ goto newpack;
+
+ if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) {
+ if (c & 0x80)
+ c = TYPE_COMPRESSED_TCP;
+ else if (c == TYPE_UNCOMPRESSED_TCP)
+ *sc->sc_buf &= 0x4f; /* XXX */
+ len = sl_uncompress_tcp(&sc->sc_buf, len, (u_int)c,
+ &sc->sc_comp);
+ if (len <= 0)
+ goto error;
+ }
+ m = sl_btom(sc, len);
+ if (m == NULL)
+ goto error;
- case FRAME_ESCAPE:
- sc->sc_flags |= SC_ESCAPED;
- return;
+ sc->sc_if.if_ipackets++;
+ s = splimp();
+ if (IF_QFULL(&ipintrq)) {
+ IF_DROP(&ipintrq);
+ sc->sc_if.if_ierrors++;
+ m_freem(m);
+ } else {
+ IF_ENQUEUE(&ipintrq, m);
+ schednetisr(NETISR_IP);
}
+ splx(s);
+ goto newpack;
}
- if (++sc->sc_ilen > SLMTU) {
- sc->sc_if.if_ierrors++;
- sc->sc_mp = sc->sc_buf + sizeof(struct ifnet *);
- sc->sc_ilen = 0;
+ if (sc->sc_mp < sc->sc_ep) {
+ *sc->sc_mp++ = c;
+ sc->sc_escape = 0;
return;
}
- *sc->sc_mp++ = c;
+error:
+ sc->sc_if.if_ierrors++;
+newpack:
+ sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMTU;
+ sc->sc_escape = 0;
}
/*