Source-Changes-HG archive
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
[src/trunk]: src/sys/net Make the buffer management in SLIP just a little les...
details: https://anonhg.NetBSD.org/src/rev/36cea87eb146
branches: trunk
changeset: 501909:36cea87eb146
user: thorpej <thorpej%NetBSD.org@localhost>
date: Tue Jan 09 04:42:48 2001 +0000
description:
Make the buffer management in SLIP just a little less evil.
diffstat:
sys/net/if_sl.c | 124 ++++++++++++++++++++++++++--------------------------
sys/net/if_slvar.h | 6 +-
2 files changed, 64 insertions(+), 66 deletions(-)
diffs (250 lines):
diff -r 766c18bf8fd6 -r 36cea87eb146 sys/net/if_sl.c
--- a/sys/net/if_sl.c Tue Jan 09 04:31:18 2001 +0000
+++ b/sys/net/if_sl.c Tue Jan 09 04:42:48 2001 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_sl.c,v 1.63 2000/12/18 20:41:44 thorpej Exp $ */
+/* $NetBSD: if_sl.c,v 1.64 2001/01/09 04:42:48 thorpej Exp $ */
/*
* Copyright (c) 1987, 1989, 1992, 1993
@@ -153,11 +153,7 @@
* 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)
#ifndef SLMTU
@@ -227,22 +223,17 @@
struct sl_softc *sc;
{
- 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("sl%d: can't allocate buffer\n", sc->sc_unit);
- 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_buf = sc->sc_ep - SLMAX;
- sc->sc_mp = sc->sc_buf;
+ 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;
+
sl_compress_init(&sc->sc_comp);
+
return (1);
}
@@ -328,10 +319,9 @@
if_down(&sc->sc_if);
sc->sc_ttyp = NULL;
tp->t_sc = NULL;
- free((caddr_t)(sc->sc_ep - SLBUFSIZE), M_MBUF);
- sc->sc_ep = 0;
- sc->sc_mp = 0;
- sc->sc_buf = 0;
+ m_freem(sc->sc_mbuf);
+ sc->sc_mbuf = NULL;
+ sc->sc_ep = sc->sc_mp = sc->sc_pktstart = NULL;
}
#ifdef __NetBSD__
/* if necessary, install a new outq buffer of the appropriate size */
@@ -688,42 +678,46 @@
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);
}
@@ -804,7 +798,7 @@
sc->sc_flags &= ~SC_ERROR;
goto newpack;
}
- len = sc->sc_mp - sc->sc_buf;
+ len = sc->sc_mp - sc->sc_pktstart;
if (len < 3)
/* less than min length packet - ignore */
goto newpack;
@@ -819,15 +813,15 @@
* 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.
@@ -836,13 +830,13 @@
* 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;
@@ -850,25 +844,28 @@
} else
goto error;
}
+
+ m = sl_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 sl_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 = sl_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();
@@ -896,7 +893,8 @@
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;
sc->sc_escape = 0;
}
diff -r 766c18bf8fd6 -r 36cea87eb146 sys/net/if_slvar.h
--- a/sys/net/if_slvar.h Tue Jan 09 04:31:18 2001 +0000
+++ b/sys/net/if_slvar.h Tue Jan 09 04:42:48 2001 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_slvar.h,v 1.20 2000/07/12 23:02:38 thorpej Exp $ */
+/* $NetBSD: if_slvar.h,v 1.21 2001/01/09 04:42:49 thorpej Exp $ */
/*-
* Copyright (c) 1991, 1993
@@ -51,8 +51,8 @@
struct tty *sc_ttyp; /* pointer to tty structure */
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_xxx; /* XXX don't ask... */
+ u_char *sc_pktstart; /* pointer to beginning of packet */
+ struct mbuf *sc_mbuf; /* input buffer */
u_int sc_flags; /* see below */
u_int sc_escape; /* =1 if last char input was FRAME_ESCAPE */
long sc_lasttime; /* last time a char arrived */
Home |
Main Index |
Thread Index |
Old Index