/* -----------------------------------------------------------------------------
Handle a CCP packet. `rcvd' is 1 if the packet was received,
0 if it is about to be transmitted.
mbuf points to the ccp payload (doesn't include FF03 and 80FD)
----------------------------------------------------------------------------- */
void ppp_comp_ccp(struct ppp_if *wan, mbuf_t m, int rcvd)
{
u_char *p = mbuf_data(m);
int slen;
slen = CCP_LENGTH(p);
if (slen > mbuf_pkthdr_len(m)) {
LOGDBG(wan->net, ("ppp_comp_ccp: not enough data in mbuf (expected = %d, got = %d)\n",
slen, mbuf_pkthdr_len(m)));
return;
}
switch (CCP_CODE(p)) {
case CCP_CONFREQ:
case CCP_TERMREQ:
case CCP_TERMACK:
/* CCP must be going down - disable compression */
wan->sc_flags &= ~(rcvd ? SC_COMP_RUN : SC_DECOMP_RUN);
break;
case CCP_CONFACK:
if (wan->sc_flags & SC_CCP_OPEN && !(wan->sc_flags & SC_CCP_UP)
&& slen >= CCP_HDRLEN + CCP_OPT_MINLEN
&& slen >= CCP_OPT_LENGTH(p + CCP_HDRLEN) + CCP_HDRLEN) {
if (rcvd) {
/* peer is agreeing to send compressed packets. */
if (wan->rc_state
&& (*wan->rcomp->decomp_init)
(wan->rc_state, p + CCP_HDRLEN, slen - CCP_HDRLEN,
ifnet_unit(wan->net), 0, wan->mru, ifnet_flags(wan->net) & IFF_DEBUG)) {
wan->sc_flags |= SC_DECOMP_RUN;
wan->sc_flags &= ~(SC_DC_ERROR | SC_DC_FERROR);
}
} else {
/* we're agreeing to send compressed packets. */
if (wan->xc_state
&& (*wan->xcomp->comp_init)
(wan->xc_state, p + CCP_HDRLEN, slen - CCP_HDRLEN,
ifnet_unit(wan->net), 0, ifnet_mtu(wan->net), ifnet_flags(wan->net) & IFF_DEBUG)) {
wan->sc_flags |= SC_COMP_RUN;
}
}
}
break;
case CCP_RESETACK:
if (wan->sc_flags & SC_CCP_UP) {
if (rcvd) {
if (wan->rc_state && (wan->sc_flags & SC_DECOMP_RUN)) {
(*wan->rcomp->decomp_reset)(wan->rc_state);
wan->sc_flags &= ~SC_DC_ERROR;
}
} else {
if (wan->xc_state && (wan->sc_flags & SC_COMP_RUN))
(*wan->xcomp->comp_reset)(wan->xc_state);
}
}
break;
}
}
void
handle_ccp(struct pkt *cp, u_char *dp, int len)
{
int clen;
struct compressor **comp;
if (len < CCP_HDRLEN)
return;
clen = CCP_LENGTH(dp);
if (clen > len)
return;
switch (CCP_CODE(dp)) {
case CCP_CONFACK:
cp->flags &= ~(CCP_DECOMP_RUN | CCP_ISUP);
if (clen < CCP_HDRLEN + CCP_OPT_MINLEN
|| clen < CCP_HDRLEN + CCP_OPT_LENGTH(dp + CCP_HDRLEN))
break;
dp += CCP_HDRLEN;
clen -= CCP_HDRLEN;
for (comp = compressors; *comp != NULL; ++comp) {
if ((*comp)->compress_proto == dp[0]) {
if (cp->state != NULL) {
(*cp->comp->decomp_free)(cp->state);
cp->state = NULL;
}
cp->comp = *comp;
cp->state = (*comp)->decomp_alloc(dp, CCP_OPT_LENGTH(dp));
cp->flags |= CCP_ISUP;
if (cp->state != NULL
&& (*cp->comp->decomp_init)
(cp->state, dp, clen, 0, 0, 8192, 1))
cp->flags = (cp->flags & ~CCP_ERR) | CCP_DECOMP_RUN;
break;
}
}
break;
case CCP_CONFNAK:
case CCP_CONFREJ:
cp->flags &= ~(CCP_DECOMP_RUN | CCP_ISUP);
break;
case CCP_RESETACK:
if (cp->flags & CCP_ISUP) {
if (cp->state && (cp->flags & CCP_DECOMP_RUN)) {
(*cp->comp->decomp_reset)(cp->state);
cp->flags &= ~CCP_ERROR;
}
}
break;
}
}