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-rw-r--r--sys/net/if_sl.c4
-rw-r--r--sys/net/slcompress.c114
-rw-r--r--sys/net/slcompress.h8
3 files changed, 88 insertions, 38 deletions
diff --git a/sys/net/if_sl.c b/sys/net/if_sl.c
index 0fe601b..67bf528 100644
--- a/sys/net/if_sl.c
+++ b/sys/net/if_sl.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)if_sl.c 8.6 (Berkeley) 2/1/94
- * $Id: if_sl.c,v 1.31 1995/09/10 12:22:59 bde Exp $
+ * $Id: if_sl.c,v 1.32 1995/09/17 23:38:29 ache Exp $
*/
/*
@@ -243,7 +243,7 @@ slinit(sc)
}
sc->sc_buf = sc->sc_ep - SLRMAX;
sc->sc_mp = sc->sc_buf;
- sl_compress_init(&sc->sc_comp);
+ sl_compress_init(&sc->sc_comp, -1);
return (1);
}
diff --git a/sys/net/slcompress.c b/sys/net/slcompress.c
index 5630b51..9aadd4b 100644
--- a/sys/net/slcompress.c
+++ b/sys/net/slcompress.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)slcompress.c 8.2 (Berkeley) 4/16/94
- * $Id: slcompress.c,v 1.4 1994/10/08 22:38:27 phk Exp $
+ * $Id: slcompress.c,v 1.5 1995/05/30 08:08:33 rgrimes Exp $
*/
/*
@@ -67,18 +67,21 @@
#endif
void
-sl_compress_init(comp)
+sl_compress_init(comp, max_state)
struct slcompress *comp;
+ int max_state;
{
register u_int i;
register struct cstate *tstate = comp->tstate;
+ if (max_state == -1)
+ max_state = MAX_STATES - 1;
bzero((char *)comp, sizeof(*comp));
- for (i = MAX_STATES - 1; i > 0; --i) {
+ for (i = max_state; i > 0; --i) {
tstate[i].cs_id = i;
tstate[i].cs_next = &tstate[i - 1];
}
- tstate[0].cs_next = &tstate[MAX_STATES - 1];
+ tstate[0].cs_next = &tstate[max_state];
tstate[0].cs_id = 0;
comp->last_cs = &tstate[0];
comp->last_recv = 255;
@@ -401,16 +404,68 @@ sl_uncompress_tcp(bufp, len, type, comp)
u_int type;
struct slcompress *comp;
{
+ u_char *hdr, *cp;
+ int hlen, vjlen;
+
+ cp = bufp? *bufp: NULL;
+ vjlen = sl_uncompress_tcp_core(cp, len, len, type, comp, &hdr, &hlen);
+ if (vjlen < 0)
+ return (0); /* error */
+ if (vjlen == 0)
+ return (len); /* was uncompressed already */
+
+ cp += vjlen;
+ len -= vjlen;
+
+ /*
+ * At this point, cp points to the first byte of data in the
+ * packet. If we're not aligned on a 4-byte boundary, copy the
+ * data down so the ip & tcp headers will be aligned. Then back up
+ * cp by the tcp/ip header length to make room for the reconstructed
+ * header (we assume the packet we were handed has enough space to
+ * prepend 128 bytes of header).
+ */
+ if ((int)cp & 3) {
+ if (len > 0)
+ (void) ovbcopy(cp, (caddr_t)((int)cp &~ 3), len);
+ cp = (u_char *)((int)cp &~ 3);
+ }
+ cp -= hlen;
+ len += hlen;
+ BCOPY(hdr, cp, hlen);
+
+ *bufp = cp;
+ return (len);
+}
+
+/*
+ * Uncompress a packet of total length total_len. The first buflen
+ * bytes are at buf; this must include the entire (compressed or
+ * uncompressed) TCP/IP header. This procedure returns the length
+ * of the VJ header, with a pointer to the uncompressed IP header
+ * in *hdrp and its length in *hlenp.
+ */
+int
+sl_uncompress_tcp_core(buf, buflen, total_len, type, comp, hdrp, hlenp)
+ u_char *buf;
+ int buflen, total_len;
+ u_int type;
+ struct slcompress *comp;
+ u_char **hdrp;
+ u_int *hlenp;
+{
register u_char *cp;
register u_int hlen, changes;
register struct tcphdr *th;
register struct cstate *cs;
register struct ip *ip;
+ register u_short *bp;
+ register u_int vjlen;
switch (type) {
case TYPE_UNCOMPRESSED_TCP:
- ip = (struct ip *) *bufp;
+ ip = (struct ip *) buf;
if (ip->ip_p >= MAX_STATES)
goto bad;
cs = &comp->rstate[comp->last_recv = ip->ip_p];
@@ -420,10 +475,11 @@ sl_uncompress_tcp(bufp, len, type, comp)
hlen += ((struct tcphdr *)&((int *)ip)[hlen])->th_off;
hlen <<= 2;
BCOPY(ip, &cs->cs_ip, hlen);
- cs->cs_ip.ip_sum = 0;
cs->cs_hlen = hlen;
INCR(sls_uncompressedin)
- return (len);
+ *hdrp = (u_char *) &cs->cs_ip;
+ *hlenp = hlen;
+ return (0);
default:
goto bad;
@@ -433,7 +489,7 @@ sl_uncompress_tcp(bufp, len, type, comp)
}
/* We've got a compressed packet. */
INCR(sls_compressedin)
- cp = *bufp;
+ cp = buf;
changes = *cp++;
if (changes & NEW_C) {
/* Make sure the state index is in range, then grab the state.
@@ -449,7 +505,7 @@ sl_uncompress_tcp(bufp, len, type, comp)
* explicit state index, we have to toss the packet. */
if (comp->flags & SLF_TOSS) {
INCR(sls_tossed)
- return (0);
+ return (-1);
}
}
cs = &comp->rstate[comp->last_recv];
@@ -497,42 +553,34 @@ sl_uncompress_tcp(bufp, len, type, comp)
/*
* At this point, cp points to the first byte of data in the
- * packet. If we're not aligned on a 4-byte boundary, copy the
- * data down so the ip & tcp headers will be aligned. Then back up
- * cp by the tcp/ip header length to make room for the reconstructed
- * header (we assume the packet we were handed has enough space to
- * prepend 128 bytes of header). Adjust the length to account for
- * the new header & fill in the IP total length.
+ * packet. Fill in the IP total length and update the IP
+ * header checksum.
*/
- len -= (cp - *bufp);
- if (len < 0)
+ vjlen = cp - buf;
+ buflen -= vjlen;
+ if (buflen < 0)
/* we must have dropped some characters (crc should detect
* this but the old slip framing won't) */
goto bad;
- if ((int)cp & 3) {
- if (len > 0)
- (void) ovbcopy(cp, (caddr_t)((int)cp &~ 3), len);
- cp = (u_char *)((int)cp &~ 3);
- }
- cp -= cs->cs_hlen;
- len += cs->cs_hlen;
- cs->cs_ip.ip_len = htons(len);
- BCOPY(&cs->cs_ip, cp, cs->cs_hlen);
- *bufp = cp;
+ total_len += cs->cs_hlen - vjlen;
+ cs->cs_ip.ip_len = htons(total_len);
/* recompute the ip header checksum */
- {
- register u_short *bp = (u_short *)cp;
+ bp = (u_short *) &cs->cs_ip;
+ cs->cs_ip.ip_sum = 0;
for (changes = 0; hlen > 0; hlen -= 2)
changes += *bp++;
changes = (changes & 0xffff) + (changes >> 16);
changes = (changes & 0xffff) + (changes >> 16);
- ((struct ip *)cp)->ip_sum = ~ changes;
- }
- return (len);
+ cs->cs_ip.ip_sum = ~ changes;
+
+ *hdrp = (u_char *) &cs->cs_ip;
+ *hlenp = cs->cs_hlen;
+ return vjlen;
+
bad:
comp->flags |= SLF_TOSS;
INCR(sls_errorin)
- return (0);
+ return (-1);
}
diff --git a/sys/net/slcompress.h b/sys/net/slcompress.h
index 239f633..90a2c01 100644
--- a/sys/net/slcompress.h
+++ b/sys/net/slcompress.h
@@ -35,7 +35,7 @@
*
* Van Jacobson (van@helios.ee.lbl.gov), Dec 31, 1989:
* - Initial distribution.
- * $Id: slcompress.h,v 1.5 1994/08/22 14:16:36 bde Exp $
+ * $Id: slcompress.h,v 1.6 1995/05/30 08:08:34 rgrimes Exp $
*/
#ifndef _NET_SLCOMPRESS_H_
@@ -153,9 +153,11 @@ struct slcompress {
/* flag values */
#define SLF_TOSS 1 /* tossing rcvd frames because of input err */
-void sl_compress_init __P((struct slcompress *));
+void sl_compress_init __P((struct slcompress *, int));
u_int sl_compress_tcp __P((struct mbuf *,
struct ip *, struct slcompress *, int));
int sl_uncompress_tcp __P((u_char **, int, u_int, struct slcompress *));
+int sl_uncompress_tcp_core __P((u_char *, int, int, u_int,
+ struct slcompress *, u_char **, u_int *));
-#endif /* !_NET_SLCOMPRESS_H_ */
+#endif /* _NET_SLCOMPRESS_H_ */
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