static inline int
pptp_inbound_pkt(struct sk_buff *skb,
struct PptpControlHeader *ctlh,
union pptp_ctrl_union *pptpReq,
unsigned int reqlen,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
struct nf_ct_pptp_master *info = &nfct_help(ct)->help.ct_pptp_info;
u_int16_t msg;
__be16 cid = 0, pcid = 0;
typeof(nf_nat_pptp_hook_inbound) nf_nat_pptp_inbound;
msg = ntohs(ctlh->messageType);
pr_debug("inbound control message %s\n", pptp_msg_name[msg]);
switch (msg) {
case PPTP_START_SESSION_REPLY:
/* server confirms new control session */
if (info->sstate < PPTP_SESSION_REQUESTED)
goto invalid;
if (pptpReq->srep.resultCode == PPTP_START_OK)
info->sstate = PPTP_SESSION_CONFIRMED;
else
info->sstate = PPTP_SESSION_ERROR;
break;
case PPTP_STOP_SESSION_REPLY:
/* server confirms end of control session */
if (info->sstate > PPTP_SESSION_STOPREQ)
goto invalid;
if (pptpReq->strep.resultCode == PPTP_STOP_OK)
info->sstate = PPTP_SESSION_NONE;
else
info->sstate = PPTP_SESSION_ERROR;
break;
case PPTP_OUT_CALL_REPLY:
/* server accepted call, we now expect GRE frames */
if (info->sstate != PPTP_SESSION_CONFIRMED)
goto invalid;
if (info->cstate != PPTP_CALL_OUT_REQ &&
info->cstate != PPTP_CALL_OUT_CONF)
goto invalid;
cid = pptpReq->ocack.callID;
pcid = pptpReq->ocack.peersCallID;
if (info->pns_call_id != pcid)
goto invalid;
pr_debug("%s, CID=%X, PCID=%X\n", pptp_msg_name[msg],
ntohs(cid), ntohs(pcid));
if (pptpReq->ocack.resultCode == PPTP_OUTCALL_CONNECT) {
info->cstate = PPTP_CALL_OUT_CONF;
info->pac_call_id = cid;
exp_gre(ct, cid, pcid);
} else
info->cstate = PPTP_CALL_NONE;
break;
case PPTP_IN_CALL_REQUEST:
/* server tells us about incoming call request */
if (info->sstate != PPTP_SESSION_CONFIRMED)
goto invalid;
cid = pptpReq->icreq.callID;
pr_debug("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid));
info->cstate = PPTP_CALL_IN_REQ;
info->pac_call_id = cid;
break;
case PPTP_IN_CALL_CONNECT:
/* server tells us about incoming call established */
if (info->sstate != PPTP_SESSION_CONFIRMED)
goto invalid;
if (info->cstate != PPTP_CALL_IN_REP &&
info->cstate != PPTP_CALL_IN_CONF)
goto invalid;
pcid = pptpReq->iccon.peersCallID;
cid = info->pac_call_id;
if (info->pns_call_id != pcid)
goto invalid;
pr_debug("%s, PCID=%X\n", pptp_msg_name[msg], ntohs(pcid));
info->cstate = PPTP_CALL_IN_CONF;
/* we expect a GRE connection from PAC to PNS */
exp_gre(ct, cid, pcid);
break;
case PPTP_CALL_DISCONNECT_NOTIFY:
/* server confirms disconnect */
cid = pptpReq->disc.callID;
pr_debug("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid));
info->cstate = PPTP_CALL_NONE;
/* untrack this call id, unexpect GRE packets */
pptp_destroy_siblings(ct);
break;
case PPTP_WAN_ERROR_NOTIFY:
case PPTP_ECHO_REQUEST:
case PPTP_ECHO_REPLY:
/* I don't have to explain these ;) */
break;
default:
goto invalid;
}
nf_nat_pptp_inbound = rcu_dereference(nf_nat_pptp_hook_inbound);
if (nf_nat_pptp_inbound && ct->status & IPS_NAT_MASK)
return nf_nat_pptp_inbound(skb, ct, ctinfo, ctlh, pptpReq);
return NF_ACCEPT;
invalid:
pr_debug("invalid %s: type=%d cid=%u pcid=%u "
"cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n",
msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : pptp_msg_name[0],
msg, ntohs(cid), ntohs(pcid), info->cstate, info->sstate,
ntohs(info->pns_call_id), ntohs(info->pac_call_id));
return NF_ACCEPT;
}
static inline int
pptp_inbound_pkt(struct tcphdr *tcph,
struct pptp_pkt_hdr *pptph,
size_t datalen,
struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo)
{
struct PptpControlHeader *ctlh;
union pptp_ctrl_union pptpReq;
struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
u_int16_t msg, *cid, *pcid;
u_int32_t seq;
ctlh = (struct PptpControlHeader *)
((char *) pptph + sizeof(struct pptp_pkt_hdr));
pptpReq.rawreq = (void *)
((char *) ctlh + sizeof(struct PptpControlHeader));
msg = ntohs(ctlh->messageType);
DEBUGP("inbound control message %s\n", strMName[msg]);
switch (msg) {
case PPTP_START_SESSION_REPLY:
/* server confirms new control session */
if (info->sstate < PPTP_SESSION_REQUESTED) {
DEBUGP("%s without START_SESS_REQUEST\n",
strMName[msg]);
break;
}
if (pptpReq.srep->resultCode == PPTP_START_OK)
info->sstate = PPTP_SESSION_CONFIRMED;
else
info->sstate = PPTP_SESSION_ERROR;
break;
case PPTP_STOP_SESSION_REPLY:
/* server confirms end of control session */
if (info->sstate > PPTP_SESSION_STOPREQ) {
DEBUGP("%s without STOP_SESS_REQUEST\n",
strMName[msg]);
break;
}
if (pptpReq.strep->resultCode == PPTP_STOP_OK)
info->sstate = PPTP_SESSION_NONE;
else
info->sstate = PPTP_SESSION_ERROR;
break;
case PPTP_OUT_CALL_REPLY:
/* server accepted call, we now expect GRE frames */
if (info->sstate != PPTP_SESSION_CONFIRMED) {
DEBUGP("%s but no session\n", strMName[msg]);
break;
}
if (info->cstate != PPTP_CALL_OUT_REQ &&
info->cstate != PPTP_CALL_OUT_CONF) {
DEBUGP("%s without OUTCALL_REQ\n", strMName[msg]);
break;
}
if (pptpReq.ocack->resultCode != PPTP_OUTCALL_CONNECT) {
info->cstate = PPTP_CALL_NONE;
break;
}
cid = &pptpReq.ocack->callID;
pcid = &pptpReq.ocack->peersCallID;
info->pac_call_id = ntohs(*cid);
if (htons(info->pns_call_id) != *pcid) {
DEBUGP("%s for unknown callid %u\n",
strMName[msg], ntohs(*pcid));
break;
}
DEBUGP("%s, CID=%X, PCID=%X\n", strMName[msg],
ntohs(*cid), ntohs(*pcid));
info->cstate = PPTP_CALL_OUT_CONF;
seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
if (exp_gre(ct, seq, *cid, *pcid) != 0)
printk("ip_conntrack_pptp: error during exp_gre\n");
break;
case PPTP_IN_CALL_REQUEST:
/* server tells us about incoming call request */
if (info->sstate != PPTP_SESSION_CONFIRMED) {
DEBUGP("%s but no session\n", strMName[msg]);
break;
}
pcid = &pptpReq.icack->peersCallID;
DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
info->cstate = PPTP_CALL_IN_REQ;
info->pac_call_id= ntohs(*pcid);
break;
case PPTP_IN_CALL_CONNECT:
/* server tells us about incoming call established */
if (info->sstate != PPTP_SESSION_CONFIRMED) {
DEBUGP("%s but no session\n", strMName[msg]);
break;
}
if (info->sstate != PPTP_CALL_IN_REP
&& info->sstate != PPTP_CALL_IN_CONF) {
DEBUGP("%s but never sent IN_CALL_REPLY\n",
strMName[msg]);
break;
}
pcid = &pptpReq.iccon->peersCallID;
cid = &info->pac_call_id;
if (info->pns_call_id != ntohs(*pcid)) {
DEBUGP("%s for unknown CallID %u\n",
strMName[msg], ntohs(*cid));
break;
}
DEBUGP("%s, PCID=%X\n", strMName[msg], ntohs(*pcid));
info->cstate = PPTP_CALL_IN_CONF;
/* we expect a GRE connection from PAC to PNS */
seq = ntohl(tcph->seq) + ((void *)pcid - (void *)pptph);
if (exp_gre(ct, seq, *cid, *pcid) != 0)
printk("ip_conntrack_pptp: error during exp_gre\n");
break;
case PPTP_CALL_DISCONNECT_NOTIFY:
/* server confirms disconnect */
cid = &pptpReq.disc->callID;
DEBUGP("%s, CID=%X\n", strMName[msg], ntohs(*cid));
info->cstate = PPTP_CALL_NONE;
/* untrack this call id, unexpect GRE packets */
pptp_timeout_related(ct);
break;
case PPTP_WAN_ERROR_NOTIFY:
break;
case PPTP_ECHO_REQUEST:
case PPTP_ECHO_REPLY:
/* I don't have to explain these ;) */
break;
default:
DEBUGP("invalid %s (TY=%d)\n", (msg <= PPTP_MSG_MAX)
? strMName[msg]:strMName[0], msg);
break;
}
return NF_ACCEPT;
}
