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NetBSD/sys/net/if_strip.c

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/* $NetBSD: if_strip.c,v 1.85 2008/02/20 17:05:53 matt Exp $ */
/* from: NetBSD: if_sl.c,v 1.38 1996/02/13 22:00:23 christos Exp $ */
/*
* Copyright 1996 The Board of Trustees of The Leland Stanford
* Junior University. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies. Stanford University
* makes no representations about the suitability of this
* software for any purpose. It is provided "as is" without
* express or implied warranty.
*
*
* This driver was contributed by Jonathan Stone.
*
* Starmode Radio IP interface (STRIP) for Metricom wireless radio.
* This STRIP driver assumes address resolution of IP addresses to
* Metricom MAC addresses is done via local link-level routes.
* The link-level addresses are entered as an 8-digit packed BCD number.
* To add a route for a radio at IP address 10.1.2.3, with radio
* address '1234-5678', reachable via interface strip0, use the command
*
* route add -host 10.1.2.3 -link strip0:12:34:56:78
*/
/*
* Copyright (c) 1987, 1989, 1992, 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. 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.
*
* @(#)if_sl.c 8.6 (Berkeley) 2/1/94
*/
/*
* Derived from: Serial Line interface written by Rick Adams (rick@seismo.gov)
*
* Rick Adams
* Center for Seismic Studies
* 1300 N 17th Street, Suite 1450
* Arlington, Virginia 22209
* (703)276-7900
* rick@seismo.ARPA
* seismo!rick
*
* Pounded on heavily by Chris Torek (chris@mimsy.umd.edu, umcp-cs!chris).
* N.B.: this belongs in netinet, not net, the way it stands now.
* Should have a link-layer type designation, but wouldn't be
* backwards-compatible.
*
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: if_strip.c,v 1.85 2008/02/20 17:05:53 matt Exp $");
#include "opt_inet.h"
#include "bpfilter.h"
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/dkstat.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/tty.h>
#include <sys/kernel.h>
#if __NetBSD__
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/kauth.h>
#endif
#include <sys/syslog.h>
#include <sys/cpu.h>
#include <sys/intr.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#endif
#include <net/slcompress.h>
#include <net/if_stripvar.h>
#include <net/slip.h>
#ifdef __NetBSD__ /* XXX -- jrs */
typedef u_char ttychar_t;
#else
typedef char ttychar_t;
#endif
#if NBPFILTER > 0
#include <sys/time.h>
#include <net/bpf.h>
#endif
/*
* SLMAX is a hard limit on input packet size. To simplify the code
* and improve performance, we require that packets fit in an mbuf
* cluster, 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, SLMAX can be at most
* MCLBYTES - 128
*
* SLMTU is a hard limit on output packet size. To insure good
* interactive response, SLMTU 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 296. (Since TCP
* will send 256 byte segments (to allow for 40 byte headers), the
* typical packet size on the wire will be around 260 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).
*
* Similar considerations apply to SLIP_HIWAT: It's the amount of
* data that will be queued 'downstream' of us (i.e., in clists
* waiting to be picked up by the tty output interrupt). If we
* queue a lot of data downstream, it's immune to our t.o.s. queuing.
* E.g., if SLIP_HIWAT is 1024, the interactive traffic in mixed
* telnet/ftp will see a 1 sec wait, independent of the mtu (the
* wait is dependent on the ftp window size but that's typically
* 1k - 4k). So, we want SLIP_HIWAT just big enough to amortize
* the cost (in idle time on the wire) of the tty driver running
* off the end of its clists & having to call back slstart for a
* new packet. For a tty interface with any buffering at all, this
* cost will be zero. Even with a totally brain dead interface (like
* the one on a typical workstation), the cost will be <= 1 character
* time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
* at most 1% while maintaining good interactive response.
*/
#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
#define SLMAX (MCLBYTES - BUFOFFSET)
#define SLBUFSIZE (SLMAX + BUFOFFSET)
#define SLMTU 1100 /* XXX -- appromaximated. 1024 may be safer. */
#define STRIP_MTU_ONWIRE (SLMTU + 20 + STRIP_HDRLEN) /* (2*SLMTU+2 in sl.c */
#define SLIP_HIWAT roundup(50,CBSIZE)
/* This is a NetBSD-1.0 or later kernel. */
#define CCOUNT(q) ((q)->c_cc)
#ifndef __NetBSD__ /* XXX - cgd */
#define CLISTRESERVE 1024 /* Can't let clists get too low */
#endif /* !__NetBSD__ */
/*
* SLIP ABORT ESCAPE MECHANISM:
* (inspired by HAYES modem escape arrangement)
* 1sec escape 1sec escape 1sec escape { 1sec escape 1sec escape }
* within window time signals a "soft" exit from slip mode by remote end
* if the IFF_DEBUG flag is on.
*/
#define ABT_ESC '\033' /* can't be t_intr - distant host must know it*/
#define ABT_IDLE 1 /* in seconds - idle before an escape */
#define ABT_COUNT 3 /* count of escapes for abort */
#define ABT_WINDOW (ABT_COUNT*2+2) /* in seconds - time to count */
static int strip_clone_create(struct if_clone *, int);
static int strip_clone_destroy(struct ifnet *);
static LIST_HEAD(, strip_softc) strip_softc_list;
struct if_clone strip_cloner =
IF_CLONE_INITIALIZER("strip", strip_clone_create, strip_clone_destroy);
#define STRIP_FRAME_END 0x0D /* carriage return */
static void stripintr(void *);
static int stripinit(struct strip_softc *);
static struct mbuf *strip_btom(struct strip_softc *, int);
/*
* STRIP header: '*' + modem address (dddd-dddd) + '*' + mactype ('SIP0')
* A Metricom packet looks like this: *<address>*<key><payload><CR>
* eg. *0000-1164*SIP0<payload><CR>
*
*/
#define STRIP_ENCAP_SIZE(X) ((36) + (X)*65/64 + 2)
#define STRIP_HDRLEN 15
#define STRIP_MAC_ADDR_LEN 9
/*
* Star mode packet header.
* (may be used for encapsulations other than STRIP.)
*/
#define STARMODE_ADDR_LEN 11
struct st_header {
u_char starmode_addr[STARMODE_ADDR_LEN];
u_char starmode_type[4];
};
/*
* Forward declarations for Metricom-specific functions.
* Ideally, these would be in a library and shared across
* different STRIP implementations: *BSD, Linux, etc.
*
*/
static u_char* UnStuffData(u_char *src, u_char *end, u_char
*dest, u_long dest_length);
static u_char* StuffData(u_char *src, u_long length, u_char *dest,
u_char **code_ptr_ptr);
static void RecvErr(const char *msg, struct strip_softc *sc);
static void RecvErr_Message(struct strip_softc *strip_info,
u_char *sendername, const u_char *msg);
void strip_resetradio(struct strip_softc *sc, struct tty *tp);
void strip_proberadio(struct strip_softc *sc, struct tty *tp);
void strip_watchdog(struct ifnet *ifp);
void strip_sendbody(struct strip_softc *sc, struct mbuf *m);
int strip_newpacket(struct strip_softc *sc, u_char *ptr, u_char *end);
void strip_send(struct strip_softc *sc, struct mbuf *m0);
void strip_timeout(void *x);
#ifdef DEBUG
#define DPRINTF(x) printf x
#else
#define DPRINTF(x)
#endif
/*
* Radio reset macros.
* The Metricom radios are not particularly well-designed for
* use in packet mode (starmode). There's no easy way to tell
* when the radio is in starmode. Worse, when the radios are reset
* or power-cycled, they come back up in Hayes AT-emulation mode,
* and there's no good way for this driver to tell.
* We deal with this by peridically tickling the radio
* with an invalid starmode command. If the radio doesn't
* respond with an error, the driver knows to reset the radio.
*/
/* Radio-reset finite state machine (if_watchdog) callback rate, in seconds */
#define STRIP_WATCHDOG_INTERVAL 5
/* Period between intrusive radio probes, in seconds */
#define ST_PROBE_INTERVAL 10
/* Grace period for radio to answer probe, in seconds */
#define ST_PROBERESPONSE_INTERVAL 2
/* Be less agressive about repeated resetting. */
#define STRIP_RESET_INTERVAL 5
/*
* We received a response from the radio that indicates it's in
* star mode. Clear any pending probe or reset timer.
* Don't probe radio again for standard polling interval.
*/
#define CLEAR_RESET_TIMER(sc) \
do {\
(sc)->sc_state = ST_ALIVE; \
(sc)->sc_statetimo = time_second + ST_PROBE_INTERVAL; \
} while (/*CONSTCOND*/ 0)
/*
* we received a response from the radio that indicates it's crashed
* out of starmode into Hayse mode. Reset it ASAP.
*/
#define FORCE_RESET(sc) \
do {\
(sc)->sc_statetimo = time_second - 1; \
(sc)->sc_state = ST_DEAD; \
/*(sc)->sc_if.if_timer = 0;*/ \
} while (/*CONSTCOND*/ 0)
#define RADIO_PROBE_TIMEOUT(sc) \
((sc)-> sc_statetimo > time_second)
static int stripclose(struct tty *, int);
static int stripinput(int, struct tty *);
static int stripioctl(struct ifnet *, u_long, void *);
static int stripopen(dev_t, struct tty *);
static int stripoutput(struct ifnet *,
struct mbuf *, const struct sockaddr *, struct rtentry *);
static int stripstart(struct tty *);
static int striptioctl(struct tty *, u_long, void *, int, struct lwp *);
static struct linesw strip_disc = {
.l_name = "strip",
.l_open = stripopen,
.l_close = stripclose,
.l_read = ttyerrio,
.l_write = ttyerrio,
.l_ioctl = striptioctl,
.l_rint = stripinput,
.l_start = stripstart,
.l_modem = nullmodem,
.l_poll = ttyerrpoll
};
void
stripattach(void)
{
if (ttyldisc_attach(&strip_disc) != 0)
panic("stripattach");
LIST_INIT(&strip_softc_list);
if_clone_attach(&strip_cloner);
}
static int
strip_clone_create(struct if_clone *ifc, int unit)
{
struct strip_softc *sc;
MALLOC(sc, struct strip_softc *, sizeof(*sc), M_DEVBUF, M_WAIT|M_ZERO);
sc->sc_unit = unit;
(void)snprintf(sc->sc_if.if_xname, sizeof(sc->sc_if.if_xname),
"%s%d", ifc->ifc_name, unit);
callout_init(&sc->sc_timo_ch, 0);
sc->sc_if.if_softc = sc;
sc->sc_if.if_mtu = SLMTU;
sc->sc_if.if_flags = 0;
sc->sc_if.if_type = IFT_OTHER;
#if 0
sc->sc_if.if_flags |= SC_AUTOCOMP /* | IFF_POINTOPOINT | IFF_MULTICAST*/;
#endif
sc->sc_if.if_type = IFT_SLIP;
sc->sc_if.if_ioctl = stripioctl;
sc->sc_if.if_output = stripoutput;
sc->sc_if.if_dlt = DLT_SLIP;
sc->sc_fastq.ifq_maxlen = 32;
IFQ_SET_READY(&sc->sc_if.if_snd);
sc->sc_if.if_watchdog = strip_watchdog;
if_attach(&sc->sc_if);
if_alloc_sadl(&sc->sc_if);
#if NBPFILTER > 0
bpfattach(&sc->sc_if, DLT_SLIP, SLIP_HDRLEN);
#endif
LIST_INSERT_HEAD(&strip_softc_list, sc, sc_iflist);
return 0;
}
static int
strip_clone_destroy(struct ifnet *ifp)
{
struct strip_softc *sc = (struct strip_softc *)ifp->if_softc;
if (sc->sc_ttyp != NULL)
return EBUSY; /* Not removing it */
LIST_REMOVE(sc, sc_iflist);
#if NBPFILTER > 0
bpfdetach(ifp);
#endif
if_detach(ifp);
FREE(sc, M_DEVBUF);
return 0;
}
static int
stripinit(struct strip_softc *sc)
{
u_char *p;
if (sc->sc_mbuf == NULL) {
sc->sc_mbuf = m_get(M_WAIT, MT_DATA);
m_clget(sc->sc_mbuf, M_WAIT);
}
sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
sc->sc_mbuf->m_ext.ext_size;
sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
BUFOFFSET;
/* Get contiguous buffer in which to de-bytestuff/rll-decode input */
if (sc->sc_rxbuf == NULL) {
p = (u_char *)malloc(MCLBYTES, M_DEVBUF, M_WAITOK);
if (p)
sc->sc_rxbuf = p + SLBUFSIZE - SLMAX;
else {
printf("%s: can't allocate input buffer\n",
sc->sc_if.if_xname);
sc->sc_if.if_flags &= ~IFF_UP;
return (0);
}
}
/* Get contiguous buffer in which to bytestuff/rll-encode output */
if (sc->sc_txbuf == NULL) {
p = (u_char *)malloc(MCLBYTES, M_DEVBUF, M_WAITOK);
if (p)
sc->sc_txbuf = (u_char *)p + SLBUFSIZE - SLMAX;
else {
printf("%s: can't allocate buffer\n",
sc->sc_if.if_xname);
sc->sc_if.if_flags &= ~IFF_UP;
return (0);
}
}
#ifdef INET
sl_compress_init(&sc->sc_comp);
#endif
/* Initialize radio probe/reset state machine */
sc->sc_state = ST_DEAD; /* assumet the worst. */
sc->sc_statetimo = time_second; /* do reset immediately */
return (1);
}
/*
* Line specific open routine.
* Attach the given tty to the first available sl unit.
*/
/* ARGSUSED */
int
stripopen(dev_t dev, struct tty *tp)
{
struct lwp *l = curlwp; /* XXX */
struct strip_softc *sc;
int error;
if ((error = kauth_authorize_generic(l->l_cred,
KAUTH_GENERIC_ISSUSER, NULL)) != 0)
return (error);
if (tp->t_linesw == &strip_disc)
return (0);
LIST_FOREACH(sc, &strip_softc_list, sc_iflist) {
if (sc->sc_ttyp == NULL) {
sc->sc_si = softint_establish(SOFTINT_NET,
stripintr, sc);
if (stripinit(sc) == 0) {
softint_disestablish(sc->sc_si);
return (ENOBUFS);
}
mutex_spin_enter(&tty_lock);
tp->t_sc = (void *)sc;
sc->sc_ttyp = tp;
sc->sc_if.if_baudrate = tp->t_ospeed;
ttyflush(tp, FREAD | FWRITE);
/*
* Make sure tty output queue is large enough
* to hold a full-sized packet (including frame
* end, and a possible extra frame end).
* A full-sized of 65/64) *SLMTU bytes (because
* of escapes and clever RLL bytestuffing),
* plus frame header, and add two on for frame ends.
*/
if (tp->t_outq.c_cn < STRIP_MTU_ONWIRE) {
sc->sc_oldbufsize = tp->t_outq.c_cn;
sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
mutex_spin_exit(&tty_lock);
clfree(&tp->t_outq);
error = clalloc(&tp->t_outq, 3*SLMTU, 0);
if (error) {
softint_disestablish(sc->sc_si);
/*
* clalloc() might return -1 which
* is no good, so we need to return
* something else.
*/
return (ENOMEM);
}
mutex_spin_enter(&tty_lock);
} else
sc->sc_oldbufsize = sc->sc_oldbufquot = 0;
strip_resetradio(sc, tp);
mutex_spin_exit(&tty_lock);
/*
* Start the watchdog timer to get the radio
* "probe-for-death"/reset machine going.
*/
sc->sc_if.if_timer = STRIP_WATCHDOG_INTERVAL;
return (0);
}
}
return (ENXIO);
}
/*
* Line specific close routine.
* Detach the tty from the strip unit.
*/
static int
stripclose(struct tty *tp, int flag)
{
struct strip_softc *sc;
int s;
ttywflush(tp);
sc = tp->t_sc;
if (sc != NULL) {
softint_disestablish(sc->sc_si);
s = splnet();
/*
* Cancel watchdog timer, which stops the "probe-for-death"/
* reset machine.
*/
sc->sc_if.if_timer = 0;
if_down(&sc->sc_if);
IF_PURGE(&sc->sc_fastq);
splx(s);
s = spltty();
ttyldisc_release(tp->t_linesw);
tp->t_linesw = ttyldisc_default();
tp->t_state = 0;
sc->sc_ttyp = NULL;
tp->t_sc = NULL;
m_freem(sc->sc_mbuf);
sc->sc_mbuf = NULL;
sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
IF_PURGE(&sc->sc_inq);
/* XXX */
free((void *)(sc->sc_rxbuf - SLBUFSIZE + SLMAX), M_DEVBUF);
sc->sc_rxbuf = NULL;
/* XXX */
free((void *)(sc->sc_txbuf - SLBUFSIZE + SLMAX), M_DEVBUF);
sc->sc_txbuf = NULL;
if (sc->sc_flags & SC_TIMEOUT) {
callout_stop(&sc->sc_timo_ch);
sc->sc_flags &= ~SC_TIMEOUT;
}
/*
* If necessary, install a new outq buffer of the
* appropriate size.
*/
if (sc->sc_oldbufsize != 0) {
clfree(&tp->t_outq);
clalloc(&tp->t_outq, sc->sc_oldbufsize,
sc->sc_oldbufquot);
}
splx(s);
}
return (0);
}
/*
* Line specific (tty) ioctl routine.
* Provide a way to get the sl unit number.
*/
/* ARGSUSED */
int
striptioctl(struct tty *tp, u_long cmd, void *data, int flag,
struct lwp *l)
{
struct strip_softc *sc = (struct strip_softc *)tp->t_sc;
switch (cmd) {
case SLIOCGUNIT:
*(int *)data = sc->sc_unit;
break;
default:
return (EPASSTHROUGH);
}
return (0);
}
/*
* Take an mbuf chain containing a STRIP packet (no link-level header),
* byte-stuff (escape) it, and enqueue it on the tty send queue.
*/
void
strip_sendbody(struct strip_softc *sc, struct mbuf *m)
{
struct tty *tp = sc->sc_ttyp;
u_char *dp = sc->sc_txbuf;
struct mbuf *m2;
int len;
u_char *rllstate_ptr = NULL;
while (m) {
if (m->m_len != 0) {
/*
* Byte-stuff/run-length encode this mbuf's data
* into the output buffer.
* XXX Note that chained calls to stuffdata()
* require that the stuffed data be left in the
* output buffer until the entire packet is encoded.
*/
dp = StuffData(mtod(m, u_char *), m->m_len, dp,
&rllstate_ptr);
}
MFREE(m, m2);
m = m2;
}
/*
* Put the entire stuffed packet into the tty output queue.
*/
len = dp - sc->sc_txbuf;
if (b_to_q((ttychar_t *)sc->sc_txbuf, len, &tp->t_outq)) {
if (sc->sc_if.if_flags & IFF_DEBUG)
addlog("%s: tty output overflow\n",
sc->sc_if.if_xname);
return;
}
sc->sc_if.if_obytes += len;
}
/*
* Send a STRIP packet. Must be called at spltty().
*/
void
strip_send(struct strip_softc *sc, struct mbuf *m0)
{
struct tty *tp = sc->sc_ttyp;
struct st_header *hdr;
/*
* Send starmode header (unstuffed).
*/
hdr = mtod(m0, struct st_header *);
if (b_to_q((ttychar_t *)hdr, STRIP_HDRLEN, &tp->t_outq)) {
if (sc->sc_if.if_flags & IFF_DEBUG)
addlog("%s: outq overflow writing header\n",
sc->sc_if.if_xname);
m_freem(m0);
return;
}
m_adj(m0, sizeof(struct st_header));
/* Byte-stuff and run-length encode the remainder of the packet. */
strip_sendbody(sc, m0);
if (putc(STRIP_FRAME_END, &tp->t_outq)) {
/*
* Not enough room. Remove a char to make room
* and end the packet normally.
* If you get many collisions (more than one or two
* a day) you probably do not have enough clists
* and you should increase "nclist" in param.c.
*/
(void) unputc(&tp->t_outq);
(void) putc(STRIP_FRAME_END, &tp->t_outq);
sc->sc_if.if_collisions++;
} else {
++sc->sc_if.if_obytes;
sc->sc_if.if_opackets++;
}
/*
* If a radio probe is due now, append it to this packet rather
* than waiting until the watchdog routine next runs.
*/
if (time_second >= sc->sc_statetimo && sc->sc_state == ST_ALIVE)
strip_proberadio(sc, tp);
}
/*
* Queue a packet. Start transmission if not active.
* Compression happens in stripintr(); if we do it here, IP TOS
* will cause us to not compress "background" packets, because
* ordering gets trashed. It can be done for all packets in stripintr().
*/
int
stripoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
struct rtentry *rt)
{
struct strip_softc *sc = ifp->if_softc;
struct ip *ip;
struct st_header *shp;
const u_char *dldst; /* link-level next-hop */
struct ifqueue *ifq;
int s, error;
u_char dl_addrbuf[STARMODE_ADDR_LEN+1];
ALTQ_DECL(struct altq_pktattr pktattr;)
/*
* Verify tty line is up and alive.
*/
if (sc->sc_ttyp == NULL) {
m_freem(m);
return (ENETDOWN); /* sort of */
}
if ((sc->sc_ttyp->t_state & TS_CARR_ON) == 0 &&
(sc->sc_ttyp->t_cflag & CLOCAL) == 0) {
m_freem(m);
return (EHOSTUNREACH);
}
#ifdef DEBUG
if (rt) {
printf("stripout, rt: dst af%d gw af%d",
rt_getkey(rt)->sa_family, rt->rt_gateway->sa_family);
if (rt_getkey(rt)->sa_family == AF_INET)
printf(" dst %x",
satocsin(rt_getkey(rt))->sin_addr.s_addr);
printf("\n");
}
#endif
switch (dst->sa_family) {
case AF_INET:
if (rt != NULL && rt->rt_gwroute != NULL)
rt = rt->rt_gwroute;
/* assume rt is never NULL */
if (rt == NULL || rt->rt_gateway->sa_family != AF_LINK
|| satocsdl(rt->rt_gateway)->sdl_alen != ifp->if_addrlen) {
DPRINTF(("strip: could not arp starmode addr %x\n",
satocsin(dst)->sin_addr.s_addr));
m_freem(m);
return (EHOSTUNREACH);
}
dldst = CLLADDR(satocsdl(rt->rt_gateway));
break;
case AF_LINK:
dldst = CLLADDR(satocsdl(dst));
break;
default:
/*
* `Cannot happen' (see stripioctl). Someday we will extend
* the line protocol to support other address families.
*/
printf("%s: af %d not supported\n", sc->sc_if.if_xname,
dst->sa_family);
m_freem(m);
sc->sc_if.if_noproto++;
return (EAFNOSUPPORT);
}
ip = mtod(m, struct ip *);
#ifdef INET
if (sc->sc_if.if_flags & SC_NOICMP && ip->ip_p == IPPROTO_ICMP) {
m_freem(m);
return (ENETRESET); /* XXX ? */
}
if ((ip->ip_tos & IPTOS_LOWDELAY) != 0
#ifdef ALTQ
&& ALTQ_IS_ENABLED(&ifp->if_snd) == 0
#endif
)
ifq = &sc->sc_fastq;
else
#endif
ifq = NULL;
/*
* Add local net header. If no space in first mbuf,
* add another.
*/
M_PREPEND(m, sizeof(struct st_header), M_DONTWAIT);
if (m == 0) {
DPRINTF(("strip: could not prepend starmode header\n"));
return (ENOBUFS);
}
/*
* Unpack BCD route entry into an ASCII starmode address.
*/
dl_addrbuf[0] = '*';
dl_addrbuf[1] = ((dldst[0] >> 4) & 0x0f) + '0';
dl_addrbuf[2] = ((dldst[0] ) & 0x0f) + '0';
dl_addrbuf[3] = ((dldst[1] >> 4) & 0x0f) + '0';
dl_addrbuf[4] = ((dldst[1] ) & 0x0f) + '0';
dl_addrbuf[5] = '-';
dl_addrbuf[6] = ((dldst[2] >> 4) & 0x0f) + '0';
dl_addrbuf[7] = ((dldst[2] ) & 0x0f) + '0';
dl_addrbuf[8] = ((dldst[3] >> 4) & 0x0f) + '0';
dl_addrbuf[9] = ((dldst[3] ) & 0x0f) + '0';
dl_addrbuf[10] = '*';
dl_addrbuf[11] = 0;
dldst = dl_addrbuf;
shp = mtod(m, struct st_header *);
memcpy(&shp->starmode_type, "SIP0", sizeof(shp->starmode_type));
memcpy(shp->starmode_addr, dldst, sizeof(shp->starmode_addr));
s = spltty();
if (sc->sc_oqlen && sc->sc_ttyp->t_outq.c_cc == sc->sc_oqlen) {
struct bintime bt;
/* if output's been stalled for too long, and restart */
getbinuptime(&bt);
bintime_sub(&bt, &sc->sc_lastpacket);
if (bt.sec > 0) {
DPRINTF(("stripoutput: stalled, resetting\n"));
sc->sc_otimeout++;
stripstart(sc->sc_ttyp);
}
}
splx(s);
s = splnet();
if ((error = ifq_enqueue2(ifp, ifq, m ALTQ_COMMA
ALTQ_DECL(&pktattr))) != 0) {
splx(s);
return error;
}
getbinuptime(&sc->sc_lastpacket);
splx(s);
s = spltty();
stripstart(sc->sc_ttyp);
splx(s);
return (0);
}
/*
* Start output on interface. Get another datagram
* to send from the interface queue and map it to
* the interface before starting output.
*
*/
int
stripstart(struct tty *tp)
{
struct strip_softc *sc = tp->t_sc;
/*
* If there is more in the output queue, just send it now.
* We are being called in lieu of ttstart and must do what
* it would.
*/
if (tp->t_outq.c_cc != 0) {
(*tp->t_oproc)(tp);
if (tp->t_outq.c_cc > SLIP_HIWAT)
return (0);
}
/*
* This happens briefly when the line shuts down.
*/
if (sc == NULL)
return (0);
softint_schedule(sc->sc_si);
return (0);
}
/*
* Copy data buffer to mbuf chain; add ifnet pointer.
*/
static struct mbuf *
strip_btom(struct strip_softc *sc, int len)
{
struct mbuf *m;
/*
* Allocate a new input buffer and swap.
*/
m = sc->sc_mbuf;
MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
if (sc->sc_mbuf == NULL) {
sc->sc_mbuf = m;
return (NULL);
}
MCLGET(sc->sc_mbuf, M_DONTWAIT);
if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
m_freem(sc->sc_mbuf);
sc->sc_mbuf = m;
return (NULL);
}
sc->sc_ep = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
sc->sc_mbuf->m_ext.ext_size;
m->m_data = sc->sc_pktstart;
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = &sc->sc_if;
return (m);
}
/*
* tty interface receiver interrupt.
*
* Called with a single char from the tty receiver interrupt; put
* the char into the buffer containing a partial packet. If the
* char is a packet delimiter, decapsulate the packet, wrap it in
* an mbuf, and put it on the protocol input queue.
*/
int
stripinput(int c, struct tty *tp)
{
struct strip_softc *sc;
struct mbuf *m;
int len;
tk_nin++;
sc = (struct strip_softc *)tp->t_sc;
if (sc == NULL)
return (0);
if (c & TTY_ERRORMASK || ((tp->t_state & TS_CARR_ON) == 0 &&
(tp->t_cflag & CLOCAL) == 0)) {
sc->sc_flags |= SC_ERROR;
DPRINTF(("strip: input, error %x\n", c)); /* XXX */
return (0);
}
c &= TTY_CHARMASK;
++sc->sc_if.if_ibytes;
/*
* Accumulate characters until we see a frame terminator (\r).
*/
switch (c) {
case '\n':
/*
* Error message strings from the modem are terminated with
* \r\n. This driver interprets the \r as a packet terminator.
* If the first character in a packet is a \n, drop it.
* (it can never be the first char of a vaild frame).
*/
if (sc->sc_mp - sc->sc_pktstart == 0)
break;
/* Fall through to */
default:
if (sc->sc_mp < sc->sc_ep) {
*sc->sc_mp++ = c;
} else {
sc->sc_flags |= SC_ERROR;
goto error;
}
return (0);
case STRIP_FRAME_END:
break;
}
/*
* We only reach here if we see a CR delimiting a packet.
*/
len = sc->sc_mp - sc->sc_pktstart;
#ifdef XDEBUG
if (len < 15 || sc->sc_flags & SC_ERROR)
printf("stripinput: end of pkt, len %d, err %d\n",
len, sc->sc_flags & SC_ERROR); /*XXX*/
#endif
if(sc->sc_flags & SC_ERROR) {
sc->sc_flags &= ~SC_ERROR;
addlog("%s: sc error flag set. terminating packet\n",
sc->sc_if.if_xname);
goto newpack;
}
/*
* We have a frame.
* Process an IP packet, ARP packet, AppleTalk packet,
* AT command resposne, or Starmode error.
*/
len = strip_newpacket(sc, sc->sc_pktstart, sc->sc_mp);
if (len <= 1)
/* less than min length packet - ignore */
goto newpack;
m = strip_btom(sc, len);
if (m == NULL)
goto error;
IF_ENQUEUE(&sc->sc_inq, m);
softint_schedule(sc->sc_si);
goto newpack;
error:
sc->sc_if.if_ierrors++;
newpack:
sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
BUFOFFSET;
return (0);
}
static void
stripintr(void *arg)
{
struct strip_softc *sc = arg;
struct tty *tp = sc->sc_ttyp;
struct mbuf *m;
int s, len;
u_char *pktstart;
#ifdef INET
u_char c;
#endif
#if NBPFILTER > 0
u_char chdr[CHDR_LEN];
#endif
KASSERT(tp != NULL);
/*
* Output processing loop.
*/
for (;;) {
#ifdef INET
struct ip *ip;
#endif
#if NBPFILTER > 0
struct mbuf *bpf_m;
#endif
/*
* Do not remove the packet from the queue if it
* doesn't look like it will fit into the current
* serial output queue (STRIP_MTU_ONWIRE, or
* Starmode header + 20 bytes + 4 bytes in case we
* have to probe the radio).
*/
s = spltty();
if (tp->t_outq.c_cn - tp->t_outq.c_cc <
STRIP_MTU_ONWIRE + 4) {
splx(s);
break;
}
splx(s);
/*
* Get a packet and send it to the radio.
*/
s = splnet();
IF_DEQUEUE(&sc->sc_fastq, m);
if (m)
sc->sc_if.if_omcasts++; /* XXX */
else
IFQ_DEQUEUE(&sc->sc_if.if_snd, m);
splx(s);
if (m == NULL)
break;
/*
* We do the header compression here rather than in
* stripoutput() because the packets will be out of
* order if we are using TOS queueing, and the
* connection ID compression will get munged when
* this happens.
*/
#if NBPFILTER > 0
if (sc->sc_if.if_bpf) {
/*
* We need to save the TCP/IP header before
* it's compressed. To avoid complicated
* code, we just make a deep copy of the
* entire packet (since this is a serial
* line, packets should be short and/or the
* copy should be negligible cost compared
* to the packet transmission time).
*/
bpf_m = m_dup(m, 0, M_COPYALL, M_DONTWAIT);
} else
bpf_m = NULL;
#endif
#ifdef INET
if ((ip = mtod(m, struct ip *))->ip_p == IPPROTO_TCP) {
if (sc->sc_if.if_flags & SC_COMPRESS)
*mtod(m, u_char *) |=
sl_compress_tcp(m, ip,
&sc->sc_comp, 1);
}
#endif
#if NBPFILTER > 0
if (sc->sc_if.if_bpf && bpf_m != NULL)
bpf_mtap_sl_out(sc->sc_if.if_bpf, mtod(m, u_char *),
bpf_m);
#endif
getbinuptime(&sc->sc_lastpacket);
s = spltty();
strip_send(sc, m);
/*
* We now have characters in the output queue,
* kick the serial port.
*/
if (tp->t_outq.c_cc != 0)
(*tp->t_oproc)(tp);
splx(s);
}
/*
* Input processing loop.
*/
for (;;) {
s = spltty();
IF_DEQUEUE(&sc->sc_inq, m);
splx(s);
if (m == NULL)
break;
pktstart = mtod(m, u_char *);
len = m->m_pkthdr.len;
#if NBPFILTER > 0
if (sc->sc_if.if_bpf) {
/*
* Save the compressed header, so we
* can tack it on later. Note that we
* will end up copying garbage in come
* cases but this is okay. We remember
* where the buffer started so we can
* compute the new header length.
*/
memcpy(chdr, pktstart, CHDR_LEN);
}
#endif /* NBPFILTER > 0 */
#ifdef INET
if ((c = (*pktstart & 0xf0)) != (IPVERSION << 4)) {
if (c & 0x80)
c = TYPE_COMPRESSED_TCP;
else if (c == TYPE_UNCOMPRESSED_TCP)
*pktstart &= 0x4f; /* XXX */
/*
* We've got something that's not an IP
* packet. If compression is enabled,
* try to decompress it. Otherwise, if
* `auto-enable' compression is on and
* it's a reasonable packet, decompress
* it and then enable compression.
* Otherwise, drop it.
*/
if (sc->sc_if.if_flags & SC_COMPRESS) {
len = sl_uncompress_tcp(&pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0) {
m_freem(m);
continue;
}
} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
len = sl_uncompress_tcp(&pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0) {
m_freem(m);
continue;
}
sc->sc_if.if_flags |= SC_COMPRESS;
} else {
m_freem(m);
continue;
}
}
#endif
m->m_data = (void *) pktstart;
m->m_pkthdr.len = m->m_len = len;
#if NBPFILTER > 0
if (sc->sc_if.if_bpf) {
bpf_mtap_sl_in(sc->sc_if.if_bpf, chdr, &m);
if (m == NULL)
continue;
}
#endif
/*
* If the packet will fit into a single
* header mbuf, copy it into one, to save
* memory.
*/
if (m->m_pkthdr.len < MHLEN) {
struct mbuf *n;
int pktlen;
MGETHDR(n, M_DONTWAIT, MT_DATA);
pktlen = m->m_pkthdr.len;
M_MOVE_PKTHDR(n, m);
memcpy(mtod(n, void *), mtod(m, void *), pktlen);
n->m_len = m->m_len;
m_freem(m);
m = n;
}
sc->sc_if.if_ipackets++;
getbinuptime(&sc->sc_lastpacket);
#ifdef INET
s = splnet();
if (IF_QFULL(&ipintrq)) {
IF_DROP(&ipintrq);
sc->sc_if.if_ierrors++;
sc->sc_if.if_iqdrops++;
m_freem(m);
} else {
IF_ENQUEUE(&ipintrq, m);
schednetisr(NETISR_IP);
}
splx(s);
#endif
}
}
/*
* Process an ioctl request.
*/
int
stripioctl(struct ifnet *ifp, u_long cmd, void *data)
{
struct ifaddr *ifa = (struct ifaddr *)data;
struct ifreq *ifr;
int s, error = 0;
s = splnet();
switch (cmd) {
case SIOCSIFADDR:
if (ifa->ifa_addr->sa_family == AF_INET)
ifp->if_flags |= IFF_UP;
else
error = EAFNOSUPPORT;
break;
case SIOCSIFDSTADDR:
if (ifa->ifa_addr->sa_family != AF_INET)
error = EAFNOSUPPORT;
break;
case SIOCADDMULTI:
case SIOCDELMULTI:
ifr = (struct ifreq *)data;
if (ifr == 0) {
error = EAFNOSUPPORT; /* XXX */
break;
}
switch (ifreq_getaddr(cmd, ifr)->sa_family) {
#ifdef INET
case AF_INET:
break;
#endif
default:
error = EAFNOSUPPORT;
break;
}
break;
default:
error = EINVAL;
}
splx(s);
return (error);
}
/*
* Strip subroutines
*/
/*
* Set a radio into starmode.
* Must be called at spltty().
*/
void
strip_resetradio(struct strip_softc *sc, struct tty *tp)
{
#if 0
static ttychar_t InitString[] =
"\r\n\r\n\r\nat\r\n\r\n\r\nate0dt**starmode\r\n**\r\n";
#else
static ttychar_t InitString[] =
"\r\rat\r\r\rate0q1dt**starmode\r**\r";
#endif
int i;
/*
* XXX Perhaps flush tty output queue?
*/
if ((i = b_to_q(InitString, sizeof(InitString) - 1, &tp->t_outq))) {
printf("resetradio: %d chars didn't fit in tty queue\n", i);
return;
}
sc->sc_if.if_obytes += sizeof(InitString) - 1;
/*
* Assume the radio is still dead, so we can detect repeated
* resets (perhaps the radio is disconnected, powered off, or
* is so badlyhung it needs powercycling.
*/
sc->sc_state = ST_DEAD;
getbinuptime(&sc->sc_lastpacket);
sc->sc_statetimo = time_second + STRIP_RESET_INTERVAL;
/*
* XXX Does calling the tty output routine now help resets?
*/
(*sc->sc_ttyp->t_oproc)(tp);
}
/*
* Send an invalid starmode packet to the radio, to induce an error message
* indicating the radio is in starmode.
* Update the state machine to indicate a response is expected.
* Either the radio answers, which will be caught by the parser,
* or the watchdog will start resetting.
*
* NOTE: drops chars directly on the tty output queue.
* should be caled at spl >= spltty.
*/
void
strip_proberadio(struct strip_softc *sc, struct tty *tp)
{
int overflow;
const char *strip_probestr = "**";
if (sc->sc_if.if_flags & IFF_DEBUG)
addlog("%s: attempting to probe radio\n", sc->sc_if.if_xname);
overflow = b_to_q((const ttychar_t *)strip_probestr, 2, &tp->t_outq);
if (overflow == 0) {
if (sc->sc_if.if_flags & IFF_DEBUG)
addlog("%s:: sent probe to radio\n",
sc->sc_if.if_xname);
/* Go to probe-sent state, set timeout accordingly. */
sc->sc_state = ST_PROBE_SENT;
sc->sc_statetimo = time_second + ST_PROBERESPONSE_INTERVAL;
} else {
addlog("%s: incomplete probe, tty queue %d bytes overfull\n",
sc->sc_if.if_xname, overflow);
}
}
#ifdef DEBUG
static const char *strip_statenames[] = {
"Alive",
"Probe sent, awaiting answer",
"Probe not answered, resetting"
};
#endif
/*
* Timeout routine -- try to start more output.
* Will be needed to make strip work on ptys.
*/
void
strip_timeout(void *x)
{
struct strip_softc *sc = (struct strip_softc *) x;
struct tty *tp = sc->sc_ttyp;
int s;
s = spltty();
sc->sc_flags &= ~SC_TIMEOUT;
stripstart(tp);
splx(s);
}
/*
* Strip watchdog routine.
* The radio hardware is balky. When sent long packets or bursts of small
* packets, the radios crash and reboots into Hayes-emulation mode.
* The transmit-side machinery, the error parser, and strip_watchdog()
* implement a simple finite state machine.
*
* We attempt to send a probe to the radio every ST_PROBE seconds. There
* is no direct way to tell if the radio is in starmode, so we send it a
* malformed starmode packet -- a frame with no destination address --
* and expect to an "name missing" error response from the radio within
* 1 second. If we hear such a response, we assume the radio is alive
* for the next ST_PROBE seconds.
* If we don't hear a starmode-error response from the radio, we reset it.
*
* Probes, and parsing of error responses, are normally done inside the send
* and receive side respectively. This watchdog routine examines the
* state-machine variables. If there are no packets to send to the radio
* during an entire probe interval, strip_output will not be called,
* so we send a probe on its behalf.
*/
void
strip_watchdog(struct ifnet *ifp)
{
struct strip_softc *sc = ifp->if_softc;
struct tty *tp = sc->sc_ttyp;
/*
* Just punt if the line has been closed.
*/
if (tp == NULL)
return;
#ifdef DEBUG
if (ifp->if_flags & IFF_DEBUG)
addlog("\n%s: in watchdog, state %s timeout %ld\n",
ifp->if_xname,
((unsigned) sc->sc_state < 3) ?
strip_statenames[sc->sc_state] : "<<illegal state>>",
sc->sc_statetimo - time_second);
#endif
/*
* If time in this state hasn't yet expired, return.
*/
if ((ifp->if_flags & IFF_UP) == 0 || sc->sc_statetimo > time_second) {
goto done;
}
/*
* The time in the current state has expired.
* Take appropriate action and advance FSA to the next state.
*/
switch (sc->sc_state) {
case ST_ALIVE:
/*
* A probe is due but we haven't piggybacked one on a packet.
* Send a probe now.
*/
strip_proberadio(sc, sc->sc_ttyp);
(*tp->t_oproc)(tp);
break;
case ST_PROBE_SENT:
/*
* Probe sent but no response within timeout. Reset.
*/
addlog("%s: no answer to probe, resetting radio\n",
ifp->if_xname);
strip_resetradio(sc, sc->sc_ttyp);
ifp->if_oerrors++;
break;
case ST_DEAD:
/*
* The radio has been sent a reset but didn't respond.
* XXX warn user to remove AC adaptor and battery,
* wait 5 secs, and replace.
*/
addlog("%s: radio reset but not responding, Trying again\n",
ifp->if_xname);
strip_resetradio(sc, sc->sc_ttyp);
ifp->if_oerrors++;
break;
default:
/* Cannot happen. To be safe, do a reset. */
addlog("%s: %s %d, resetting\n",
sc->sc_if.if_xname,
"radio-reset finite-state machine in invalid state",
sc->sc_state);
strip_resetradio(sc, sc->sc_ttyp);
sc->sc_state = ST_DEAD;
break;
}
done:
ifp->if_timer = STRIP_WATCHDOG_INTERVAL;
return;
}
/*
* The following bytestuffing and run-length encoding/decoding
* functions are taken, with permission from Stuart Cheshire,
* from the MosquitonNet strip driver for Linux.
* XXX Linux style left intact, to ease folding in updates from
* the Mosquitonet group.
*/
/*
* Process a received packet.
*/
int
strip_newpacket(struct strip_softc *sc, u_char *ptr, u_char *end)
{
int len = ptr - end;
u_char *name, *name_end;
u_int packetlen;
/* Ignore empty lines */
if (len == 0) return 0;
/* Catch 'OK' responses which show radio has fallen out of starmode */
if (len >= 2 && ptr[0] == 'O' && ptr[1] == 'K') {
printf("%s: Radio is back in AT command mode: will reset\n",
sc->sc_if.if_xname);
FORCE_RESET(sc); /* Do reset ASAP */
return 0;
}
/* Check for start of address marker, and then skip over it */
if (*ptr != '*') {
/* Catch other error messages */
if (ptr[0] == 'E' && ptr[1] == 'R' && ptr[2] == 'R' && ptr[3] == '_')
RecvErr_Message(sc, NULL, ptr+4);
/* XXX what should the message above be? */
else {
RecvErr("No initial *", sc);
addlog("(len = %d)\n", len);
}
return 0;
}
/* skip the '*' */
ptr++;
/* Skip the return address */
name = ptr;
while (ptr < end && *ptr != '*')
ptr++;
/* Check for end of address marker, and skip over it */
if (ptr == end) {
RecvErr("No second *", sc);
return 0;
}
name_end = ptr++;
/* Check for SRIP key, and skip over it */
if (ptr[0] != 'S' || ptr[1] != 'I' || ptr[2] != 'P' || ptr[3] != '0') {
if (ptr[0] == 'E' && ptr[1] == 'R' && ptr[2] == 'R' &&
ptr[3] == '_') {
*name_end = 0;
RecvErr_Message(sc, name, ptr+4);
}
else RecvErr("No SRIP key", sc);
return 0;
}
ptr += 4;
/* Decode start of the IP packet header */
ptr = UnStuffData(ptr, end, sc->sc_rxbuf, 4);
if (ptr == 0) {
RecvErr("Runt packet (hdr)", sc);
return 0;
}
/*
* The STRIP bytestuff/RLL encoding has no explicit length
* of the decoded packet. Decode start of IP header, get the
* IP header length and decode that many bytes in total.
*/
packetlen = ((uint16_t)sc->sc_rxbuf[2] << 8) | sc->sc_rxbuf[3];
#ifdef DIAGNOSTIC
#if 0
printf("Packet %02x.%02x.%02x.%02x\n",
sc->sc_rxbuf[0], sc->sc_rxbuf[1],
sc->sc_rxbuf[2], sc->sc_rxbuf[3]);
printf("Got %d byte packet\n", packetlen);
#endif
#endif
/* Decode remainder of the IP packer */
ptr = UnStuffData(ptr, end, sc->sc_rxbuf+4, packetlen-4);
if (ptr == 0) {
RecvErr("Short packet", sc);
return 0;
}
/* XXX redundant copy */
bcopy(sc->sc_rxbuf, sc->sc_pktstart, packetlen );
return (packetlen);
}
/*
* Stuffing scheme:
* 00 Unused (reserved character)
* 01-3F Run of 2-64 different characters
* 40-7F Run of 1-64 different characters plus a single zero at the end
* 80-BF Run of 1-64 of the same character
* C0-FF Run of 1-64 zeroes (ASCII 0)
*/
typedef enum
{
Stuff_Diff = 0x00,
Stuff_DiffZero = 0x40,
Stuff_Same = 0x80,
Stuff_Zero = 0xC0,
Stuff_NoCode = 0xFF, /* Special code, meaning no code selected */
Stuff_CodeMask = 0xC0,
Stuff_CountMask = 0x3F,
Stuff_MaxCount = 0x3F,
Stuff_Magic = 0x0D /* The value we are eliminating */
} StuffingCode;
/*
* StuffData encodes the data starting at "src" for "length" bytes.
* It writes it to the buffer pointed to by "dest" (which must be at least
* as long as 1 + 65/64 of the input length). The output may be up to 1.6%
* larger than the input for pathological input, but will usually be smaller.
* StuffData returns the new value of the dest pointer as its result.
*
* "code_ptr_ptr" points to a "u_char *" which is used to hold
* encoding state between calls, allowing an encoded packet to be
* incrementally built up from small parts.
* On the first call, the "u_char *" pointed to should be initialized
* to NULL; between subsequent calls the calling routine should leave
* the value alone and simply pass it back unchanged so that the
* encoder can recover its current state.
*/
#define StuffData_FinishBlock(X) \
(*code_ptr = (X) ^ Stuff_Magic, code = Stuff_NoCode)
static u_char*
StuffData(u_char *src, u_long length, u_char *dest, u_char **code_ptr_ptr)
{
u_char *end = src + length;
u_char *code_ptr = *code_ptr_ptr;
u_char code = Stuff_NoCode, count = 0;
if (!length) return (dest);
if (code_ptr) { /* Recover state from last call, if applicable */
code = (*code_ptr ^ Stuff_Magic) & Stuff_CodeMask;
count = (*code_ptr ^ Stuff_Magic) & Stuff_CountMask;
}
while (src < end) {
switch (code) {
/*
* Stuff_NoCode: If no current code, select one
*/
case Stuff_NoCode:
code_ptr = dest++; /* Record where we're going to put this code */
count = 0; /* Reset the count (zero means one instance) */
/* Tentatively start a new block */
if (*src == 0) {
code = Stuff_Zero;
src++;
} else {
code = Stuff_Same;
*dest++ = *src++ ^ Stuff_Magic;
}
/* Note: We optimistically assume run of same -- which will be */
/* fixed later in Stuff_Same if it turns out not to be true. */
break;
/*
* Stuff_Zero: We already have at least one zero encoded
*/
case Stuff_Zero:
/* If another zero, count it, else finish this code block */
if (*src == 0) {
count++;
src++;
} else
StuffData_FinishBlock(Stuff_Zero + count);
break;
/*
* Stuff_Same: We already have at least one byte encoded
*/
case Stuff_Same:
/* If another one the same, count it */
if ((*src ^ Stuff_Magic) == code_ptr[1]) {
count++;
src++;
break;
}
/* else, this byte does not match this block. */
/* If we already have two or more bytes encoded, finish this code block */
if (count) {
StuffData_FinishBlock(Stuff_Same + count);
break;
}
/* else, we only have one so far, so switch to Stuff_Diff code */
code = Stuff_Diff; /* and fall through to Stuff_Diff case below */
case Stuff_Diff: /* Stuff_Diff: We have at least two *different* bytes encoded */
/* If this is a zero, must encode a Stuff_DiffZero, and begin a new block */
if (*src == 0)
StuffData_FinishBlock(Stuff_DiffZero + count);
/* else, if we have three in a row, it is worth starting a Stuff_Same block */
else if ((*src ^ Stuff_Magic) == dest[-1] && dest[-1] == dest[-2])
{
code += count-2;
if (code == Stuff_Diff)
code = Stuff_Same;
StuffData_FinishBlock(code);
code_ptr = dest-2;
/* dest[-1] already holds the correct value */
count = 2; /* 2 means three bytes encoded */
code = Stuff_Same;
}
/* else, another different byte, so add it to the block */
else {
*dest++ = *src ^ Stuff_Magic;
count++;
}
src++; /* Consume the byte */
break;
}
if (count == Stuff_MaxCount)
StuffData_FinishBlock(code + count);
}
if (code == Stuff_NoCode)
*code_ptr_ptr = NULL;
else {
*code_ptr_ptr = code_ptr;
StuffData_FinishBlock(code + count);
}
return (dest);
}
/*
* UnStuffData decodes the data at "src", up to (but not including)
* "end". It writes the decoded data into the buffer pointed to by
* "dst", up to a maximum of "dst_length", and returns the new
* value of "src" so that a follow-on call can read more data,
* continuing from where the first left off.
*
* There are three types of results:
* 1. The source data runs out before extracting "dst_length" bytes:
* UnStuffData returns NULL to indicate failure.
* 2. The source data produces exactly "dst_length" bytes:
* UnStuffData returns new_src = end to indicate that all bytes
* were consumed.
* 3. "dst_length" bytes are extracted, with more
* remaining. UnStuffData returns new_src < end to indicate that
* there are more bytes to be read.
*
* Note: The decoding may be dstructive, in that it may alter the
* source data in the process of decoding it (this is necessary to
* allow a follow-on call to resume correctly).
*/
static u_char*
UnStuffData(u_char *src, u_char *end, u_char *dst, u_long dst_length)
{
u_char *dst_end = dst + dst_length;
/* Sanity check */
if (!src || !end || !dst || !dst_length)
return (NULL);
while (src < end && dst < dst_end)
{
int count = (*src ^ Stuff_Magic) & Stuff_CountMask;
switch ((*src ^ Stuff_Magic) & Stuff_CodeMask)
{
case Stuff_Diff:
if (src+1+count >= end)
return (NULL);
do
{
*dst++ = *++src ^ Stuff_Magic;
}
while(--count >= 0 && dst < dst_end);
if (count < 0)
src += 1;
else
if (count == 0)
*src = Stuff_Same ^ Stuff_Magic;
else
*src = (Stuff_Diff + count) ^ Stuff_Magic;
break;
case Stuff_DiffZero:
if (src+1+count >= end)
return (NULL);
do
{
*dst++ = *++src ^ Stuff_Magic;
}
while(--count >= 0 && dst < dst_end);
if (count < 0)
*src = Stuff_Zero ^ Stuff_Magic;
else
*src = (Stuff_DiffZero + count) ^ Stuff_Magic;
break;
case Stuff_Same:
if (src+1 >= end)
return (NULL);
do
{
*dst++ = src[1] ^ Stuff_Magic;
}
while(--count >= 0 && dst < dst_end);
if (count < 0)
src += 2;
else
*src = (Stuff_Same + count) ^ Stuff_Magic;
break;
case Stuff_Zero:
do
{
*dst++ = 0;
}
while(--count >= 0 && dst < dst_end);
if (count < 0)
src += 1;
else
*src = (Stuff_Zero + count) ^ Stuff_Magic;
break;
}
}
if (dst < dst_end)
return (NULL);
else
return (src);
}
/*
* Log an error mesesage (for a packet received with errors?)
* from the STRIP driver.
*/
static void
RecvErr(const char *msg, struct strip_softc *sc)
{
#define MAX_RecErr 80
u_char *ptr = sc->sc_pktstart;
u_char *end = sc->sc_mp;
u_char pkt_text[MAX_RecErr], *p = pkt_text;
*p++ = '\"';
while (ptr < end && p < &pkt_text[MAX_RecErr-4]) {
if (*ptr == '\\') {
*p++ = '\\';
*p++ = '\\';
} else if (*ptr >= 32 && *ptr <= 126)
*p++ = *ptr;
else {
snprintf(p, sizeof(pkt_text) - (p - pkt_text),
"\\%02x", *ptr);
p += 3;
}
ptr++;
}
if (ptr == end) *p++ = '\"';
*p++ = 0;
addlog("%s: %13s : %s\n", sc->sc_if.if_xname, msg, pkt_text);
sc->sc_if.if_ierrors++;
}
/*
* Parse an error message from the radio.
*/
static void
RecvErr_Message(struct strip_softc *strip_info, u_char *sendername,
const u_char *msg)
{
static const char ERR_001[] = "001"; /* Not in StarMode! */
static const char ERR_002[] = "002"; /* Remap handle */
static const char ERR_003[] = "003"; /* Can't resolve name */
static const char ERR_004[] = "004"; /* Name too small or missing */
static const char ERR_005[] = "005"; /* Bad count specification */
static const char ERR_006[] = "006"; /* Header too big */
static const char ERR_007[] = "007"; /* Body too big */
static const char ERR_008[] = "008"; /* Bad character in name */
static const char ERR_009[] = "009"; /* No count or line terminator */
char * if_name;
if_name = strip_info->sc_if.if_xname;
if (!strncmp(msg, ERR_001, sizeof(ERR_001)-1))
{
RecvErr("radio error message:", strip_info);
addlog("%s: Radio %s is not in StarMode\n",
if_name, sendername);
}
else if (!strncmp(msg, ERR_002, sizeof(ERR_002)-1))
{
RecvErr("radio error message:", strip_info);
#ifdef notyet /*Kernel doesn't have scanf!*/
int handle;
u_char newname[64];
sscanf(msg, "ERR_002 Remap handle &%d to name %s", &handle, newname);
addlog("%s: Radio name %s is handle %d\n",
if_name, newname, handle);
#endif
}
else if (!strncmp(msg, ERR_003, sizeof(ERR_003)-1))
{
RecvErr("radio error message:", strip_info);
addlog("%s: Destination radio name is unknown\n", if_name);
}
else if (!strncmp(msg, ERR_004, sizeof(ERR_004)-1)) {
/*
* The radio reports it got a badly-framed starmode packet
* from us; so it must me in starmode.
*/
if (strip_info->sc_if.if_flags & IFF_DEBUG)
addlog("%s: radio responded to probe\n", if_name);
if (strip_info->sc_state == ST_DEAD) {
/* A successful reset... */
addlog("%s: Radio back in starmode\n", if_name);
}
CLEAR_RESET_TIMER(strip_info);
}
else if (!strncmp(msg, ERR_005, sizeof(ERR_005)-1))
RecvErr("radio error message:", strip_info);
else if (!strncmp(msg, ERR_006, sizeof(ERR_006)-1))
RecvErr("radio error message:", strip_info);
else if (!strncmp(msg, ERR_007, sizeof(ERR_007)-1))
{
/*
* Note: This error knocks the radio back into
* command mode.
*/
RecvErr("radio error message:", strip_info);
printf("%s: Error! Packet size too big for radio.",
if_name);
FORCE_RESET(strip_info);
}
else if (!strncmp(msg, ERR_008, sizeof(ERR_008)-1))
{
RecvErr("radio error message:", strip_info);
printf("%s: Radio name contains illegal character\n",
if_name);
}
else if (!strncmp(msg, ERR_009, sizeof(ERR_009)-1))
RecvErr("radio error message:", strip_info);
else {
addlog("failed to parse ]%3s[\n", msg);
RecvErr("unparsed radio error message:", strip_info);
}
}
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