/* track caller id inside control connection, call expect_related */
static int
conntrack_pptp_help(struct sk_buff *skb, unsigned int protoff,
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
{
int dir = CTINFO2DIR(ctinfo);
const struct nf_ct_pptp_master *info = &nfct_help(ct)->help.ct_pptp_info;
const struct tcphdr *tcph;
struct tcphdr _tcph;
const struct pptp_pkt_hdr *pptph;
struct pptp_pkt_hdr _pptph;
struct PptpControlHeader _ctlh, *ctlh;
union pptp_ctrl_union _pptpReq, *pptpReq;
unsigned int tcplen = skb->len - protoff;
unsigned int datalen, reqlen, nexthdr_off;
int oldsstate, oldcstate;
int ret;
u_int16_t msg;
/* don't do any tracking before tcp handshake complete */
if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
return NF_ACCEPT;
nexthdr_off = protoff;
tcph = skb_header_pointer(skb, nexthdr_off, sizeof(_tcph), &_tcph);
BUG_ON(!tcph);
nexthdr_off += tcph->doff * 4;
datalen = tcplen - tcph->doff * 4;
pptph = skb_header_pointer(skb, nexthdr_off, sizeof(_pptph), &_pptph);
if (!pptph) {
pr_debug("no full PPTP header, can't track\n");
return NF_ACCEPT;
}
nexthdr_off += sizeof(_pptph);
datalen -= sizeof(_pptph);
/* if it's not a control message we can't do anything with it */
if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
pr_debug("not a control packet\n");
return NF_ACCEPT;
}
ctlh = skb_header_pointer(skb, nexthdr_off, sizeof(_ctlh), &_ctlh);
if (!ctlh)
return NF_ACCEPT;
nexthdr_off += sizeof(_ctlh);
datalen -= sizeof(_ctlh);
reqlen = datalen;
msg = ntohs(ctlh->messageType);
if (msg > 0 && msg <= PPTP_MSG_MAX && reqlen < pptp_msg_size[msg])
return NF_ACCEPT;
if (reqlen > sizeof(*pptpReq))
reqlen = sizeof(*pptpReq);
pptpReq = skb_header_pointer(skb, nexthdr_off, reqlen, &_pptpReq);
if (!pptpReq)
return NF_ACCEPT;
oldsstate = info->sstate;
oldcstate = info->cstate;
spin_lock_bh(&nf_pptp_lock);
/* FIXME: We just blindly assume that the control connection is always
* established from PNS->PAC. However, RFC makes no guarantee */
if (dir == IP_CT_DIR_ORIGINAL)
/* client -> server (PNS -> PAC) */
ret = pptp_outbound_pkt(skb, ctlh, pptpReq, reqlen, ct,
ctinfo);
else
/* server -> client (PAC -> PNS) */
ret = pptp_inbound_pkt(skb, ctlh, pptpReq, reqlen, ct,
ctinfo);
pr_debug("sstate: %d->%d, cstate: %d->%d\n",
oldsstate, info->sstate, oldcstate, info->cstate);
spin_unlock_bh(&nf_pptp_lock);
return ret;
}
/* track caller id inside control connection, call expect_related */
static int
conntrack_pptp_help(const struct iphdr *iph, size_t len,
struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
{
struct pptp_pkt_hdr *pptph;
struct tcphdr *tcph = (void *) iph + iph->ihl * 4;
u_int32_t tcplen = len - iph->ihl * 4;
u_int32_t datalen = tcplen - tcph->doff * 4;
void *datalimit;
int dir = CTINFO2DIR(ctinfo);
struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
int oldsstate, oldcstate;
int ret;
#ifdef CONFIG_IFX_ALG_QOS // chandrav
/*
* Mark the connection tracket with PPTP ALG Family type
* ( IFX_ALG_APP_PPTP) for PPTP traffic.
*/
ct->ifx_alg_qos_mark = IFX_ALG_APP_PPTP;
IFX_ALG_QOS_DBG("\nPPTP_ALG helper marked ct->ifx_alg_qos_mark to : %x ***\n",ct->ifx_alg_qos_mark );
#endif /* CONFIG_IFX_ALG_QOS */
/* don't do any tracking before tcp handshake complete */
if (ctinfo != IP_CT_ESTABLISHED
&& ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) {
DEBUGP("ctinfo = %u, skipping\n", ctinfo);
return NF_ACCEPT;
}
/* not a complete TCP header? */
if (tcplen < sizeof(struct tcphdr) || tcplen < tcph->doff * 4) {
DEBUGP("tcplen = %u\n", tcplen);
return NF_ACCEPT;
}
/* checksum invalid? */
if (tcp_v4_check(tcph, tcplen, iph->saddr, iph->daddr,
csum_partial((char *) tcph, tcplen, 0))) {
DEBUGP("TC Test0\n");
printk(KERN_NOTICE __FILE__ ": bad csum\n");
/* W2K PPTP server sends TCP packets with wrong checksum :(( */
//return NF_ACCEPT;
}
DEBUGP("TC Test1\n");
if (tcph->fin || tcph->rst) {
DEBUGP("RST/FIN received, timeouting GRE\n");
/* can't do this after real newnat */
info->cstate = PPTP_CALL_NONE;
/* untrack this call id, unexpect GRE packets */
pptp_timeout_related(ct);
}
DEBUGP("TC Test2\n");
pptph = (struct pptp_pkt_hdr *) ((void *) tcph + tcph->doff * 4);
datalimit = (void *) pptph + datalen;
/* not a full pptp packet header? */
if ((void *) pptph+sizeof(*pptph) >= datalimit) {
DEBUGP("no full PPTP header, can't track\n");
return NF_ACCEPT;
}
/* if it's not a control message we can't do anything with it */
if (ntohs(pptph->packetType) != PPTP_PACKET_CONTROL ||
ntohl(pptph->magicCookie) != PPTP_MAGIC_COOKIE) {
DEBUGP("not a control packet\n");
return NF_ACCEPT;
}
DEBUGP("TC Test3\n");
oldsstate = info->sstate;
oldcstate = info->cstate;
LOCK_BH(&ip_pptp_lock);
/* FIXME: We just blindly assume that the control connection is always
* established from PNS->PAC. However, RFC makes no guarantee */
if (dir == IP_CT_DIR_ORIGINAL)
/* client -> server (PNS -> PAC) */
ret = pptp_outbound_pkt(tcph, pptph, datalen, ct, ctinfo);
else
/* server -> client (PAC -> PNS) */
ret = pptp_inbound_pkt(tcph, pptph, datalen, ct, ctinfo);
DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
oldsstate, info->sstate, oldcstate, info->cstate);
UNLOCK_BH(&ip_pptp_lock);
return ret;
}