/*
* This version is for use with STREAMS under SunOS 4.x.
*
- * $Id: bsd-comp.c,v 1.5 1994/10/21 06:30:15 paulus Exp $
+ * $Id: bsd-comp.c,v 1.7 1994/11/30 05:29:36 paulus Exp $
*/
#include <sys/param.h>
u_char maxbits;
u_char debug;
u_char unit;
- u_short mru;
u_short seqno; /* sequence number of next packet */
+ u_int hdrlen; /* header length to preallocate */
+ u_int mru;
u_int maxmaxcode; /* largest valid code */
u_int max_ent; /* largest code in use */
u_int in_count; /* uncompressed bytes, aged */
static int bsd_comp_init __P((void *state, u_char *options, int opt_len,
int unit, int debug));
static int bsd_decomp_init __P((void *state, u_char *options, int opt_len,
- int unit, int mru, int debug));
+ int unit, int hdrlen, int mru, int debug));
static int bsd_compress __P((void *state, mblk_t **mret,
mblk_t *mp, int slen, int maxolen));
static void bsd_incomp __P((void *state, mblk_t *dmsg));
struct compstat *stats;
{
struct bsd_db *db = (struct bsd_db *) state;
+ u_int out;
stats->unc_bytes = db->uncomp_bytes;
stats->unc_packets = db->uncomp_count;
stats->comp_packets = db->comp_count;
stats->inc_bytes = db->incomp_bytes;
stats->inc_packets = db->incomp_count;
- stats->ratio = (double) db->in_count;
- if (db->bytes_out != 0)
- stats->ratio /= db->bytes_out;
+ stats->ratio = db->in_count;
+ out = db->bytes_out;
+ if (stats->ratio <= 0x7fffff)
+ stats->ratio <<= 8;
+ else
+ out >>= 8;
+ if (out != 0)
+ stats->ratio /= out;
}
/*
* Initialize the database.
*/
static int
-bsd_init(db, options, opt_len, unit, mru, debug, decomp)
+bsd_init(db, options, opt_len, unit, hdrlen, mru, debug, decomp)
struct bsd_db *db;
u_char *options;
- int opt_len, unit, mru, debug, decomp;
+ int opt_len, unit, hdrlen, mru, debug, decomp;
{
int i;
}
db->unit = unit;
+ db->hdrlen = hdrlen;
db->mru = mru;
- db->clear_count = -1;
if (debug)
db->debug = 1;
- bsd_clear(db);
+ bsd_reset(db);
return 1;
}
int opt_len, unit, debug;
{
return bsd_init((struct bsd_db *) state, options, opt_len,
- unit, 0, debug, 0);
+ unit, 0, 0, debug, 0);
}
static int
-bsd_decomp_init(state, options, opt_len, unit, mru, debug)
+bsd_decomp_init(state, options, opt_len, unit, hdrlen, mru, debug)
void *state;
u_char *options;
- int opt_len, unit, mru, debug;
+ int opt_len, unit, hdrlen, mru, debug;
{
return bsd_init((struct bsd_db *) state, options, opt_len,
- unit, mru, debug, 1);
+ unit, hdrlen, mru, debug, 1);
}
-
/*
* compress a packet
* One change from the BSD compress command is that when the
if (dictp->codem1 >= max_ent)
goto nomatch;
} while (dictp->f.fcode != fcode);
- ent = dictp->codem1+1; /* finally found (prefix,suffix) */
+ ent = dictp->codem1 + 1; /* finally found (prefix,suffix) */
continue;
nomatch:
}
ent = c;
}
- OUTPUT(ent); /* output the last code */
+ OUTPUT(ent); /* output the last code */
db->bytes_out += olen;
db->in_count += ilen;
+ if (bitno < 32)
+ ++db->bytes_out; /* count complete bytes */
+
if (bsd_check(db))
- OUTPUT(CLEAR); /* do not count the CLEAR */
+ OUTPUT(CLEAR); /* do not count the CLEAR */
/*
* Pad dribble bits of last code with ones.
db->in_count += ilen;
(void)bsd_check(db);
- ++db->comp_count;
- db->comp_bytes += bitno / 8;
++db->incomp_count;
db->incomp_bytes += ilen;
+ ++db->uncomp_count;
+ db->uncomp_bytes += ilen;
/* Increase code size if we would have without the packet
* boundary and as the decompressor will.
/*
* Decompress "BSD Compress"
+ *
+ * Because of patent problems, we return DECOMP_ERROR for errors
+ * found by inspecting the input data and for system problems, but
+ * DECOMP_FATALERROR for any errors which could possibly be said to
+ * be being detected "after" decompression. For DECOMP_ERROR,
+ * we can issue a CCP reset-request; for DECOMP_FATALERROR, we may be
+ * infringing a patent of Motorola's if we do, so we take CCP down
+ * instead.
+ *
+ * Given that the frame has the correct sequence number and a good FCS,
+ * errors such as invalid codes in the input most likely indicate a
+ * bug, so we return DECOMP_FATALERROR for them in order to turn off
+ * compression, even though they are detected by inspecting the input.
*/
static int
bsd_decompress(state, cmsg, dmpp)
/*
* Allocate one message block to start with.
*/
- if ((dmsg = allocb(DECOMP_CHUNK, BPRI_MED)) == NULL)
+ if ((dmsg = allocb(DECOMP_CHUNK + db->hdrlen, BPRI_MED)) == NULL)
return DECOMP_ERROR;
mret = dmsg;
+ dmsg->b_wptr += db->hdrlen;
dmsg->b_rptr = wptr = dmsg->b_wptr;
/* Fill in the ppp header, but not the last byte of the protocol
break;
rptr = cmsg->b_rptr;
len = cmsg->b_wptr - rptr;
+ ilen += len;
continue; /* handle 0-length buffers */
}
}
}
bsd_clear(db);
- explen = 0;
+ explen = ilen = 0;
break;
}
- if (incode > max_ent+2 || incode > db->maxmaxcode
+ if (incode > max_ent + 2 || incode > db->maxmaxcode
|| incode > max_ent && oldcode == CLEAR) {
freemsg(dmsg);
if (db->debug) {
printf("max_ent=0x%x dlen=%d seqno=%d\n",
max_ent, dlen, db->seqno);
}
- return DECOMP_FATALERROR;
+ return DECOMP_FATALERROR; /* probably a bug */
}
/* Special case for KwKwK string. */
projects / ppp.git / blobdiff