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Sync with if_sl.c,v 1.64:

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Make the buffer management in STRIP just a little less evil.
This commit is contained in:
thorpej 2001-01-11 22:23:11 +00:00
parent 4502c34907
commit a5ee0c0a19
2 changed files with 70 additions and 76 deletions
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139
sys/net/if_strip.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: if_strip.c,v 1.27 2001/01/08 23:43:34 thorpej Exp $ */
/* $NetBSD: if_strip.c,v 1.28 2001/01/11 22:23:11 thorpej Exp $ */
/* from: NetBSD: if_sl.c,v 1.38 1996/02/13 22:00:23 christos Exp $ */
/*
@ -188,11 +188,7 @@ typedef char ttychar_t;
* time. So, setting SLIP_HIWAT to ~100 guarantees that we'll lose
* at most 1% while maintaining good interactive response.
*/
#if NBPFILTER > 0
#define BUFOFFSET (128+sizeof(struct ifnet **)+SLIP_HDRLEN)
#else
#define BUFOFFSET (128+sizeof(struct ifnet **))
#endif
#define SLMAX (MCLBYTES - BUFOFFSET)
#define SLBUFSIZE (SLMAX + BUFOFFSET)
#define SLMTU 1100 /* XXX -- appromaximated. 1024 may be safer. */
@ -378,20 +374,14 @@ stripinit(sc)
{
u_char *p;
if (sc->sc_ep == NULL) {
/*
* XXX the trick this is used for is evil...
*/
sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_WAITOK);
if (sc->sc_xxx)
sc->sc_ep = sc->sc_xxx + SLBUFSIZE;
else {
printf("%s: can't allocate buffer\n",
sc->sc_if.if_xname);
sc->sc_if.if_flags &= ~IFF_UP;
return (0);
}
if (sc->sc_mbuf == NULL) {
MGETHDR(sc->sc_mbuf, M_WAIT, MT_DATA);
MCLGET(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) {
@ -420,8 +410,6 @@ stripinit(sc)
}
}
sc->sc_buf = sc->sc_ep - SLMAX;
sc->sc_mp = sc->sc_buf;
sl_compress_init(&sc->sc_comp);
/* Initialize radio probe/reset state machine */
@ -529,16 +517,18 @@ stripclose(tp)
if_down(&sc->sc_if);
sc->sc_ttyp = NULL;
tp->t_sc = NULL;
free((caddr_t)(sc->sc_ep - SLBUFSIZE), M_MBUF);
m_freem(sc->sc_mbuf);
sc->sc_mbuf = NULL;
sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
/* XXX */
free((caddr_t)(sc->sc_rxbuf - SLBUFSIZE + SLMAX), M_DEVBUF);
sc->sc_rxbuf = NULL;
/* XXX */
free((caddr_t)(sc->sc_txbuf - SLBUFSIZE + SLMAX), M_DEVBUF);
sc->sc_ep = 0;
sc->sc_mp = 0;
sc->sc_buf = 0;
sc->sc_rxbuf = 0;
sc->sc_txbuf = 0;
sc->sc_txbuf = NULL;
if (sc->sc_flags & SC_TIMEOUT) {
callout_stop(&sc->sc_timo_ch);
@ -1084,42 +1074,46 @@ strip_btom(sc, len)
int len;
{
struct mbuf *m;
u_char *p;
MGETHDR(m, M_DONTWAIT, MT_DATA);
if (m == NULL)
return (NULL);
/*
* If we have more than MHLEN 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.
* We always prepend enough space for the SLIP "header".
*/
if (len >= MHLEN) {
sc->sc_pktstart -= SLIP_HDRLEN;
len += SLIP_HDRLEN;
/*
* If the packet will fit into the header mbuf we allocated
* above, copy it there and re-use the input buffer we already
* have.
*/
if (len < MHLEN)
memcpy(mtod(m, caddr_t), sc->sc_pktstart, len);
else {
/*
* XXX this is that evil trick I mentioned...
* Allocate a new input buffer and swap.
*/
p = sc->sc_xxx;
sc->sc_xxx = (u_char *)malloc(MCLBYTES, M_MBUF, M_NOWAIT);
if (sc->sc_xxx == NULL) {
/*
* We couldn't allocate a new buffer - if
* memory's this low, it's time to start
* dropping packets.
*/
(void) m_free(m);
m = sc->sc_mbuf;
MGETHDR(sc->sc_mbuf, M_DONTWAIT, MT_DATA);
if (sc->sc_mbuf == NULL) {
sc->sc_mbuf = m;
return (NULL);
}
sc->sc_ep = sc->sc_xxx + SLBUFSIZE;
MEXTADD(m, p, MCLBYTES, M_MBUF, NULL, NULL);
m->m_data = (caddr_t)sc->sc_buf;
} else
bcopy((caddr_t)sc->sc_buf, mtod(m, caddr_t), len);
MCLGET(sc->sc_mbuf, M_DONTWAIT);
if ((sc->sc_mbuf->m_flags & M_EXT) == 0) {
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_len = len;
m->m_pkthdr.len = len;
m->m_data = sc->sc_pktstart;
}
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = &sc->sc_if;
return (m);
}
@ -1171,7 +1165,7 @@ stripinput(c, tp)
* 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_buf == 0)
if (sc->sc_mp - sc->sc_pktstart == 0)
break;
/* Fall through to */
@ -1195,7 +1189,7 @@ stripinput(c, tp)
*/
len = sc->sc_mp - sc->sc_buf;
len = sc->sc_mp - sc->sc_pktstart;
#ifdef XDEBUG
if (len < 15 || sc->sc_flags & SC_ERROR)
@ -1214,7 +1208,7 @@ stripinput(c, tp)
* Process an IP packet, ARP packet, AppleTalk packet,
* AT command resposne, or Starmode error.
*/
len = strip_newpacket(sc, sc->sc_buf, sc->sc_mp);
len = strip_newpacket(sc, sc->sc_pktstart, sc->sc_mp);
if (len <= 1)
/* less than min length packet - ignore */
goto newpack;
@ -1230,15 +1224,15 @@ stripinput(c, tp)
* where the buffer started so we can
* compute the new header length.
*/
bcopy(sc->sc_buf, chdr, CHDR_LEN);
bcopy(sc->sc_pktstart, chdr, CHDR_LEN);
}
#endif
if ((c = (*sc->sc_buf & 0xf0)) != (IPVERSION << 4)) {
if ((c = (*sc->sc_pktstart & 0xf0)) != (IPVERSION << 4)) {
if (c & 0x80)
c = TYPE_COMPRESSED_TCP;
else if (c == TYPE_UNCOMPRESSED_TCP)
*sc->sc_buf &= 0x4f; /* XXX */
*sc->sc_pktstart &= 0x4f; /* XXX */
/*
* We've got something that's not an IP packet.
* If compression is enabled, try to decompress it.
@ -1247,13 +1241,13 @@ stripinput(c, tp)
* enable compression. Otherwise, drop it.
*/
if (sc->sc_if.if_flags & SC_COMPRESS) {
len = sl_uncompress_tcp(&sc->sc_buf, len,
len = sl_uncompress_tcp(&sc->sc_pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0)
goto error;
} else if ((sc->sc_if.if_flags & SC_AUTOCOMP) &&
c == TYPE_UNCOMPRESSED_TCP && len >= 40) {
len = sl_uncompress_tcp(&sc->sc_buf, len,
len = sl_uncompress_tcp(&sc->sc_pktstart, len,
(u_int)c, &sc->sc_comp);
if (len <= 0)
goto error;
@ -1262,26 +1256,27 @@ stripinput(c, tp)
goto error;
}
m = strip_btom(sc, len);
if (m == NULL)
goto error;
#if NBPFILTER > 0
if (sc->sc_if.if_bpf) {
/*
* Put the SLIP pseudo-"link header" in place.
* We couldn't do this any earlier since
* decompression probably moved the buffer
* pointer. Then, invoke BPF.
* Note the space for it has already been
* allocated in strip_btom().
*/
u_char *hp = sc->sc_buf - SLIP_HDRLEN;
u_char *hp = mtod(m, u_char *);
hp[SLX_DIR] = SLIPDIR_IN;
bcopy(chdr, &hp[SLX_CHDR], CHDR_LEN);
bpf_tap(sc->sc_if.if_bpf, hp, len + SLIP_HDRLEN);
memcpy(&hp[SLX_CHDR], chdr, CHDR_LEN);
bpf_mtap(sc->sc_if.if_bpf, m);
}
#endif
m = strip_btom(sc, len);
if (m == NULL) {
goto error;
}
m_adj(m, SLIP_HDRLEN);
sc->sc_if.if_ipackets++;
sc->sc_if.if_lastchange = time;
s = splimp();
@ -1301,8 +1296,8 @@ error:
sc->sc_if.if_ierrors++;
newpack:
sc->sc_mp = sc->sc_buf = sc->sc_ep - SLMAX;
sc->sc_mp = sc->sc_pktstart = (u_char *) sc->sc_mbuf->m_ext.ext_buf +
BUFOFFSET;
}
/*
@ -1681,7 +1676,7 @@ strip_newpacket(sc, ptr, end)
}
/* XXX redundant copy */
bcopy(sc->sc_rxbuf, sc->sc_buf, packetlen );
bcopy(sc->sc_rxbuf, sc->sc_pktstart, packetlen );
return(packetlen);
}
@ -1943,7 +1938,7 @@ RecvErr(msg, sc)
struct strip_softc *sc;
{
static const int MAX_RecErr = 80;
u_char *ptr = sc->sc_buf;
u_char *ptr = sc->sc_pktstart;
u_char *end = sc->sc_mp;
u_char pkt_text[MAX_RecErr], *p = pkt_text;
*p++ = '\"';

7
sys/net/if_stripvar.h
View File

@ -1,11 +1,10 @@
/* $NetBSD: if_stripvar.h,v 1.8 2000/12/12 18:00:30 thorpej Exp $ */
/* $NetBSD: if_stripvar.h,v 1.9 2001/01/11 22:23:12 thorpej Exp $ */
#ifndef _NET_IF_STRIPVAR_H_
#define _NET_IF_STRIPVAR_H_
/*
* Definitions for STRIP interface data structures
*
*/
struct strip_softc {
struct ifnet sc_if; /* network-visible interface */
@ -15,10 +14,10 @@ struct strip_softc {
struct callout sc_timo_ch; /* timeout callout */
u_char *sc_mp; /* pointer to next available buf char */
u_char *sc_ep; /* pointer to last available buf char */
u_char *sc_buf; /* input buffer */
u_char *sc_pktstart; /* pointer to beginning of packet */
struct mbuf *sc_mbuf; /* input buffer */
u_char *sc_rxbuf; /* input destuffing buffer */
u_char *sc_txbuf; /* output stuffing buffer */
u_char *sc_xxx; /* XXX don't ask... */
u_int sc_flags; /* see below */
long sc_oqlen; /* previous output queue size */
long sc_otimeout; /* number of times output's stalled */