#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <net/ppp_defs.h>
#define PACKETPTR struct mbuf *
#include <net/ppp_comp.h>
#if DO_BSD_COMPRESS
struct bsd_db {
int totlen;
u_int hsize;
u_char hshift;
u_char n_bits;
u_char maxbits;
u_char debug;
u_char unit;
u_int16_t seqno;
u_int hdrlen;
u_int mru;
u_int maxmaxcode;
u_int max_ent;
u_int in_count;
u_int bytes_out;
u_int ratio;
u_int checkpoint;
u_int clear_count;
u_int incomp_count;
u_int incomp_bytes;
u_int uncomp_count;
u_int uncomp_bytes;
u_int comp_count;
u_int comp_bytes;
u_int16_t *lens;
struct bsd_dict {
union {
u_int32_t fcode;
struct {
#if BYTE_ORDER == LITTLE_ENDIAN
u_int16_t prefix;
u_char suffix;
u_char pad;
#else
u_char pad;
u_char suffix;
u_int16_t prefix;
#endif
} hs;
} f;
u_int16_t codem1;
u_int16_t cptr;
} dict[1];
};
#define BSD_OVHD 2
#define BSD_INIT_BITS BSD_MIN_BITS
static void bsd_clear __P((struct bsd_db *db));
static int bsd_check __P((struct bsd_db *db));
static void *bsd_alloc __P((u_char *options, int opt_len, int decomp));
static int bsd_init_comp_db __P((struct bsd_db *db, u_char *options, int opt_len,
int unit, int hdrlen, int mru, int debug,
int decomp));
static void *bsd_comp_alloc __P((u_char *options, int opt_len));
static void *bsd_decomp_alloc __P((u_char *options, int opt_len));
static void bsd_free __P((void *state));
static int bsd_comp_init __P((void *state, u_char *options, int opt_len,
int unit, int hdrlen, int debug));
static int bsd_decomp_init __P((void *state, u_char *options, int opt_len,
int unit, int hdrlen, int mru, int debug));
static int bsd_compress __P((void *state, struct mbuf **mret,
struct mbuf *mp, int slen, int maxolen));
static void bsd_incomp __P((void *state, struct mbuf *dmsg));
static int bsd_decompress __P((void *state, struct mbuf *cmp,
struct mbuf **dmpp));
static void bsd_reset __P((void *state));
static void bsd_comp_stats __P((void *state, struct compstat *stats));
struct compressor ppp_bsd_compress = {
CI_BSD_COMPRESS,
bsd_comp_alloc,
bsd_free,
bsd_comp_init,
bsd_reset,
bsd_compress,
bsd_comp_stats,
bsd_decomp_alloc,
bsd_free,
bsd_decomp_init,
bsd_reset,
bsd_decompress,
bsd_incomp,
bsd_comp_stats,
};
#define CLEAR 256
#define FIRST 257
#define LAST 255
#define MAXCODE(b) ((1 << (b)) - 1)
#define BADCODEM1 MAXCODE(BSD_MAX_BITS)
#define BSD_HASH(prefix,suffix,hshift) ((((u_int32_t)(suffix)) << (hshift)) \
^ (u_int32_t)(prefix))
#define BSD_KEY(prefix,suffix) ((((u_int32_t)(suffix)) << 16) \
+ (u_int32_t)(prefix))
#define CHECK_GAP 10000
#define RATIO_SCALE_LOG 8
#define RATIO_SCALE (1<<RATIO_SCALE_LOG)
#define RATIO_MAX (0x7fffffff>>RATIO_SCALE_LOG)
static void
bsd_clear(db)
struct bsd_db *db;
{
db->clear_count++;
db->max_ent = FIRST-1;
db->n_bits = BSD_INIT_BITS;
db->ratio = 0;
db->bytes_out = 0;
db->in_count = 0;
db->checkpoint = CHECK_GAP;
}
static int
bsd_check(db)
struct bsd_db *db;
{
u_int new_ratio;
if (db->in_count >= db->checkpoint) {
if (db->in_count >= RATIO_MAX
|| db->bytes_out >= RATIO_MAX) {
db->in_count -= db->in_count/4;
db->bytes_out -= db->bytes_out/4;
}
db->checkpoint = db->in_count + CHECK_GAP;
if (db->max_ent >= db->maxmaxcode) {
new_ratio = db->in_count << RATIO_SCALE_LOG;
if (db->bytes_out != 0)
new_ratio /= db->bytes_out;
if (new_ratio < db->ratio || new_ratio < 1 * RATIO_SCALE) {
bsd_clear(db);
return 1;
}
db->ratio = new_ratio;
}
}
return 0;
}
static void
bsd_comp_stats(state, stats)
void *state;
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_bytes = db->comp_bytes;
stats->comp_packets = db->comp_count;
stats->inc_bytes = db->incomp_bytes;
stats->inc_packets = db->incomp_count;
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;
}
static void
bsd_reset(state)
void *state;
{
struct bsd_db *db = (struct bsd_db *) state;
db->seqno = 0;
bsd_clear(db);
db->clear_count = 0;
}
static void *
bsd_alloc(options, opt_len, decomp)
u_char *options;
int opt_len, decomp;
{
int bits;
u_int newlen, hsize, hshift, maxmaxcode;
struct bsd_db *db;
if (opt_len < CILEN_BSD_COMPRESS || options[0] != CI_BSD_COMPRESS
|| options[1] != CILEN_BSD_COMPRESS
|| BSD_VERSION(options[2]) != BSD_CURRENT_VERSION)
return NULL;
bits = BSD_NBITS(options[2]);
switch (bits) {
case 9:
case 10:
case 11:
case 12:
hsize = 5003;
hshift = 4;
break;
case 13:
hsize = 9001;
hshift = 5;
break;
case 14:
hsize = 18013;
hshift = 6;
break;
case 15:
hsize = 35023;
hshift = 7;
break;
case 16:
default:
return NULL;
}
maxmaxcode = MAXCODE(bits);
newlen = sizeof(*db) + (hsize-1) * (sizeof(db->dict[0]));
MALLOC(db, struct bsd_db *, newlen, M_DEVBUF, M_NOWAIT);
if (!db)
return NULL;
bzero(db, sizeof(*db) - sizeof(db->dict));
if (!decomp) {
db->lens = NULL;
} else {
MALLOC(db->lens, u_int16_t *, (maxmaxcode+1) * sizeof(db->lens[0]),
M_DEVBUF, M_NOWAIT);
if (!db->lens) {
FREE(db, M_DEVBUF);
return NULL;
}
}
db->totlen = newlen;
db->hsize = hsize;
db->hshift = hshift;
db->maxmaxcode = maxmaxcode;
db->maxbits = bits;
return (void *) db;
}
static void
bsd_free(state)
void *state;
{
struct bsd_db *db = (struct bsd_db *) state;
if (db->lens)
FREE(db->lens, M_DEVBUF);
FREE(db, M_DEVBUF);
}
static void *
bsd_comp_alloc(options, opt_len)
u_char *options;
int opt_len;
{
return bsd_alloc(options, opt_len, 0);
}
static void *
bsd_decomp_alloc(options, opt_len)
u_char *options;
int opt_len;
{
return bsd_alloc(options, opt_len, 1);
}
static int
bsd_init_comp_db(db, options, opt_len, unit, hdrlen, mru, debug, decomp)
struct bsd_db *db;
u_char *options;
int opt_len, unit, hdrlen, mru, debug, decomp;
{
int i;
if (opt_len < CILEN_BSD_COMPRESS || options[0] != CI_BSD_COMPRESS
|| options[1] != CILEN_BSD_COMPRESS
|| BSD_VERSION(options[2]) != BSD_CURRENT_VERSION
|| BSD_NBITS(options[2]) != db->maxbits
|| (decomp && db->lens == NULL))
return 0;
if (decomp) {
i = LAST+1;
while (i != 0)
db->lens[--i] = 1;
}
i = db->hsize;
while (i != 0) {
db->dict[--i].codem1 = BADCODEM1;
db->dict[i].cptr = 0;
}
db->unit = unit;
db->hdrlen = hdrlen;
db->mru = mru;
#ifndef DEBUG
if (debug)
#endif
db->debug = 1;
bsd_reset(db);
return 1;
}
static int
bsd_comp_init(state, options, opt_len, unit, hdrlen, debug)
void *state;
u_char *options;
int opt_len, unit, hdrlen, debug;
{
return bsd_init_comp_db((struct bsd_db *) state, options, opt_len,
unit, hdrlen, 0, debug, 0);
}
static int
bsd_decomp_init(state, options, opt_len, unit, hdrlen, mru, debug)
void *state;
u_char *options;
int opt_len, unit, hdrlen, mru, debug;
{
return bsd_init_comp_db((struct bsd_db *) state, options, opt_len,
unit, hdrlen, mru, debug, 1);
}
int
bsd_compress(state, mret, mp, slen, maxolen)
void *state;
struct mbuf **mret;
struct mbuf *mp;
int slen;
int maxolen;
{
struct bsd_db *db = (struct bsd_db *) state;
int hshift = db->hshift;
u_int max_ent = db->max_ent;
u_int n_bits = db->n_bits;
u_int bitno = 32;
u_int32_t accm = 0, fcode;
struct bsd_dict *dictp;
u_char c;
int hval, disp, ent, ilen;
u_char *rptr, *wptr;
u_char *cp_end;
int olen;
struct mbuf *m;
#define PUTBYTE(v) { \
++olen; \
if (wptr) { \
*wptr++ = (v); \
if (wptr >= cp_end) { \
m->m_len = wptr - mtod(m, u_char *); \
MGET(m->m_next, M_DONTWAIT, MT_DATA); \
m = m->m_next; \
if (m) { \
m->m_len = 0; \
if (maxolen - olen > MLEN) \
MCLGET(m, M_DONTWAIT); \
wptr = mtod(m, u_char *); \
cp_end = wptr + M_TRAILINGSPACE(m); \
} else \
wptr = NULL; \
} \
} \
}
#define OUTPUT(ent) { \
bitno -= n_bits; \
accm |= ((ent) << bitno); \
do { \
PUTBYTE(accm >> 24); \
accm <<= 8; \
bitno += 8; \
} while (bitno <= 24); \
}
rptr = mtod(mp, u_char *);
ent = PPP_PROTOCOL(rptr);
if (ent < 0x21 || ent > 0xf9) {
*mret = NULL;
return slen;
}
if (maxolen > slen)
maxolen = slen;
MGET(m, M_DONTWAIT, MT_DATA);
*mret = m;
if (m != NULL) {
m->m_len = 0;
if (maxolen + db->hdrlen > MLEN)
MCLGET(m, M_DONTWAIT);
m->m_data += db->hdrlen;
wptr = mtod(m, u_char *);
cp_end = wptr + M_TRAILINGSPACE(m);
} else
wptr = cp_end = NULL;
if (wptr) {
*wptr++ = PPP_ADDRESS(rptr);
*wptr++ = PPP_CONTROL(rptr);
*wptr++ = 0;
*wptr++ = PPP_COMP;
*wptr++ = db->seqno >> 8;
*wptr++ = db->seqno;
}
++db->seqno;
olen = 0;
rptr += PPP_HDRLEN;
slen = mp->m_len - PPP_HDRLEN;
ilen = slen + 1;
for (;;) {
if (slen <= 0) {
mp = mp->m_next;
if (!mp)
break;
rptr = mtod(mp, u_char *);
slen = mp->m_len;
if (!slen)
continue;
ilen += slen;
}
slen--;
c = *rptr++;
fcode = BSD_KEY(ent, c);
hval = BSD_HASH(ent, c, hshift);
dictp = &db->dict[hval];
if (dictp->codem1 >= max_ent)
goto nomatch;
if (dictp->f.fcode == fcode) {
ent = dictp->codem1+1;
continue;
}
disp = (hval == 0) ? 1 : hval;
do {
hval += disp;
if (hval >= db->hsize)
hval -= db->hsize;
dictp = &db->dict[hval];
if (dictp->codem1 >= max_ent)
goto nomatch;
} while (dictp->f.fcode != fcode);
ent = dictp->codem1 + 1;
continue;
nomatch:
OUTPUT(ent);
if (max_ent < db->maxmaxcode) {
struct bsd_dict *dictp2;
if (max_ent >= MAXCODE(n_bits))
db->n_bits = ++n_bits;
dictp2 = &db->dict[max_ent+1];
if (db->dict[dictp2->cptr].codem1 == max_ent)
db->dict[dictp2->cptr].codem1 = BADCODEM1;
dictp2->cptr = hval;
dictp->codem1 = max_ent;
dictp->f.fcode = fcode;
db->max_ent = ++max_ent;
}
ent = c;
}
OUTPUT(ent);
db->bytes_out += olen;
db->in_count += ilen;
if (bitno < 32)
++db->bytes_out;
if (bsd_check(db))
OUTPUT(CLEAR);
if (bitno != 32)
PUTBYTE((accm | (0xff << (bitno-8))) >> 24);
if (m != NULL) {
m->m_len = wptr - mtod(m, u_char *);
m->m_next = NULL;
}
if (max_ent >= MAXCODE(n_bits) && max_ent < db->maxmaxcode)
db->n_bits++;
db->uncomp_bytes += ilen;
++db->uncomp_count;
if (olen + PPP_HDRLEN + BSD_OVHD > maxolen) {
if (*mret != NULL) {
m_freem(*mret);
*mret = NULL;
}
++db->incomp_count;
db->incomp_bytes += ilen;
} else {
++db->comp_count;
db->comp_bytes += olen + BSD_OVHD;
}
return olen + PPP_HDRLEN + BSD_OVHD;
#undef OUTPUT
#undef PUTBYTE
}
static void
bsd_incomp(state, dmsg)
void *state;
struct mbuf *dmsg;
{
struct bsd_db *db = (struct bsd_db *) state;
u_int hshift = db->hshift;
u_int max_ent = db->max_ent;
u_int n_bits = db->n_bits;
struct bsd_dict *dictp;
u_int32_t fcode;
u_char c;
u_int32_t hval, disp;
int slen, ilen;
u_int bitno = 7;
u_char *rptr;
u_int ent;
rptr = mtod(dmsg, u_char *);
ent = PPP_PROTOCOL(rptr);
if (ent < 0x21 || ent > 0xf9)
return;
db->seqno++;
ilen = 1;
rptr += PPP_HDRLEN;
slen = dmsg->m_len - PPP_HDRLEN;
for (;;) {
if (slen <= 0) {
dmsg = dmsg->m_next;
if (!dmsg)
break;
rptr = mtod(dmsg, u_char *);
slen = dmsg->m_len;
continue;
}
ilen += slen;
do {
c = *rptr++;
fcode = BSD_KEY(ent, c);
hval = BSD_HASH(ent, c, hshift);
dictp = &db->dict[hval];
if (dictp->codem1 >= max_ent)
goto nomatch;
if (dictp->f.fcode == fcode) {
ent = dictp->codem1+1;
continue;
}
disp = (hval == 0) ? 1 : hval;
do {
hval += disp;
if (hval >= db->hsize)
hval -= db->hsize;
dictp = &db->dict[hval];
if (dictp->codem1 >= max_ent)
goto nomatch;
} while (dictp->f.fcode != fcode);
ent = dictp->codem1+1;
continue;
nomatch:
bitno += n_bits;
if (max_ent < db->maxmaxcode) {
struct bsd_dict *dictp2;
if (max_ent >= MAXCODE(n_bits))
db->n_bits = ++n_bits;
dictp2 = &db->dict[max_ent+1];
if (db->dict[dictp2->cptr].codem1 == max_ent)
db->dict[dictp2->cptr].codem1 = BADCODEM1;
dictp2->cptr = hval;
dictp->codem1 = max_ent;
dictp->f.fcode = fcode;
db->max_ent = ++max_ent;
db->lens[max_ent] = db->lens[ent]+1;
}
ent = c;
} while (--slen != 0);
}
bitno += n_bits;
db->bytes_out += bitno/8;
db->in_count += ilen;
(void)bsd_check(db);
++db->incomp_count;
db->incomp_bytes += ilen;
++db->uncomp_count;
db->uncomp_bytes += ilen;
if (max_ent >= MAXCODE(n_bits) && max_ent < db->maxmaxcode)
db->n_bits++;
}
int
bsd_decompress(state, cmp, dmpp)
void *state;
struct mbuf *cmp, **dmpp;
{
struct bsd_db *db = (struct bsd_db *) state;
u_int max_ent = db->max_ent;
u_int32_t accm = 0;
u_int bitno = 32;
u_int n_bits = db->n_bits;
u_int tgtbitno = 32-n_bits;
struct bsd_dict *dictp;
int explen, i, seq, len;
u_int incode, oldcode, finchar;
u_char *p, *rptr, *wptr;
struct mbuf *m, *dmp, *mret;
int adrs, ctrl, ilen;
int space, codelen, extra;
*dmpp = NULL;
rptr = mtod(cmp, u_char *);
adrs = PPP_ADDRESS(rptr);
ctrl = PPP_CONTROL(rptr);
rptr += PPP_HDRLEN;
len = cmp->m_len - PPP_HDRLEN;
seq = 0;
for (i = 0; i < 2; ++i) {
while (len <= 0) {
cmp = cmp->m_next;
if (cmp == NULL)
return DECOMP_ERROR;
rptr = mtod(cmp, u_char *);
len = cmp->m_len;
}
seq = (seq << 8) + *rptr++;
--len;
}
if (seq != db->seqno) {
if (db->debug)
printf("bsd_decomp%d: bad sequence # %d, expected %d\n",
db->unit, seq, db->seqno - 1);
return DECOMP_ERROR;
}
++db->seqno;
MGETHDR(dmp, M_DONTWAIT, MT_DATA);
if (dmp == NULL)
return DECOMP_ERROR;
mret = dmp;
dmp->m_len = 0;
dmp->m_next = NULL;
MCLGET(dmp, M_DONTWAIT);
dmp->m_data += db->hdrlen;
wptr = mtod(dmp, u_char *);
space = M_TRAILINGSPACE(dmp) - PPP_HDRLEN + 1;
wptr[0] = adrs;
wptr[1] = ctrl;
wptr[2] = 0;
wptr += PPP_HDRLEN - 1;
ilen = len;
oldcode = CLEAR;
explen = 0;
for (;;) {
if (len == 0) {
cmp = cmp->m_next;
if (!cmp)
break;
rptr = mtod(cmp, u_char *);
len = cmp->m_len;
ilen += len;
continue;
}
bitno -= 8;
accm |= *rptr++ << bitno;
--len;
if (tgtbitno < bitno)
continue;
incode = accm >> tgtbitno;
accm <<= n_bits;
bitno += n_bits;
if (incode == CLEAR) {
if (len > 0 || cmp->m_next != NULL) {
while ((cmp = cmp->m_next) != NULL)
len += cmp->m_len;
if (len > 0) {
m_freem(mret);
if (db->debug)
printf("bsd_decomp%d: bad CLEAR\n", db->unit);
return DECOMP_FATALERROR;
}
}
bsd_clear(db);
explen = ilen = 0;
break;
}
if (incode > max_ent + 2 || incode > db->maxmaxcode
|| (incode > max_ent && oldcode == CLEAR)) {
m_freem(mret);
if (db->debug) {
printf("bsd_decomp%d: bad code 0x%x oldcode=0x%x ",
db->unit, incode, oldcode);
printf("max_ent=0x%x explen=%d seqno=%d\n",
max_ent, explen, db->seqno);
}
return DECOMP_FATALERROR;
}
if (incode > max_ent) {
finchar = oldcode;
extra = 1;
} else {
finchar = incode;
extra = 0;
}
codelen = db->lens[finchar];
explen += codelen + extra;
if (explen > db->mru + 1) {
m_freem(mret);
if (db->debug) {
printf("bsd_decomp%d: ran out of mru\n", db->unit);
#ifdef DEBUG
while ((cmp = cmp->m_next) != NULL)
len += cmp->m_len;
printf(" len=%d, finchar=0x%x, codelen=%d, explen=%d\n",
len, finchar, codelen, explen);
#endif
}
return DECOMP_FATALERROR;
}
if ((space -= codelen + extra) < 0) {
dmp->m_len = wptr - mtod(dmp, u_char *);
MGET(m, M_DONTWAIT, MT_DATA);
if (m == NULL) {
m_freem(mret);
return DECOMP_ERROR;
}
m->m_len = 0;
m->m_next = NULL;
dmp->m_next = m;
MCLGET(m, M_DONTWAIT);
space = M_TRAILINGSPACE(m) - (codelen + extra);
if (space < 0) {
m_freem(mret);
return DECOMP_ERROR;
}
dmp = m;
wptr = mtod(dmp, u_char *);
}
p = (wptr += codelen);
while (finchar > LAST) {
dictp = &db->dict[db->dict[finchar].cptr];
#ifdef DEBUG
if (--codelen <= 0 || dictp->codem1 != finchar-1)
goto bad;
#endif
*--p = dictp->f.hs.suffix;
finchar = dictp->f.hs.prefix;
}
*--p = finchar;
#ifdef DEBUG
if (--codelen != 0)
printf("bsd_decomp%d: short by %d after code 0x%x, max_ent=0x%x\n",
db->unit, codelen, incode, max_ent);
#endif
if (extra)
*wptr++ = finchar;
if (oldcode != CLEAR && max_ent < db->maxmaxcode) {
struct bsd_dict *dictp2;
u_int32_t fcode;
u_int32_t hval, disp;
fcode = BSD_KEY(oldcode,finchar);
hval = BSD_HASH(oldcode,finchar,db->hshift);
dictp = &db->dict[hval];
if (dictp->codem1 < max_ent) {
disp = (hval == 0) ? 1 : hval;
do {
hval += disp;
if (hval >= db->hsize)
hval -= db->hsize;
dictp = &db->dict[hval];
} while (dictp->codem1 < max_ent);
}
dictp2 = &db->dict[max_ent+1];
if (db->dict[dictp2->cptr].codem1 == max_ent) {
db->dict[dictp2->cptr].codem1 = BADCODEM1;
}
dictp2->cptr = hval;
dictp->codem1 = max_ent;
dictp->f.fcode = fcode;
db->max_ent = ++max_ent;
db->lens[max_ent] = db->lens[oldcode]+1;
if (max_ent >= MAXCODE(n_bits) && max_ent < db->maxmaxcode) {
db->n_bits = ++n_bits;
tgtbitno = 32-n_bits;
}
}
oldcode = incode;
}
dmp->m_len = wptr - mtod(dmp, u_char *);
db->bytes_out += ilen;
db->in_count += explen;
if (bsd_check(db) && db->debug) {
printf("bsd_decomp%d: peer should have cleared dictionary\n",
db->unit);
}
++db->comp_count;
db->comp_bytes += ilen + BSD_OVHD;
++db->uncomp_count;
db->uncomp_bytes += explen;
*dmpp = mret;
return DECOMP_OK;
#ifdef DEBUG
bad:
if (codelen <= 0) {
printf("bsd_decomp%d: fell off end of chain ", db->unit);
printf("0x%x at 0x%x by 0x%x, max_ent=0x%x\n",
incode, finchar, db->dict[finchar].cptr, max_ent);
} else if (dictp->codem1 != finchar-1) {
printf("bsd_decomp%d: bad code chain 0x%x finchar=0x%x ",
db->unit, incode, finchar);
printf("oldcode=0x%x cptr=0x%x codem1=0x%x\n", oldcode,
db->dict[finchar].cptr, dictp->codem1);
}
m_freem(mret);
return DECOMP_FATALERROR;
#endif
}
#endif