* 2005-06-10 - Version 3.0
* - kernel >= 2.6.11 version,
* funded by Oxcoda NetBox Blue (http://www.netboxblue.com/)
- *
+ *
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#define IP_NAT_PPTP_VERSION "3.0"
+#define REQ_CID(req, off) (*(u_int16_t *)((char *)(req) + (off)))
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
MODULE_DESCRIPTION("Netfilter NAT helper module for PPTP");
DEBUGP("we are PNS->PAC\n");
/* therefore, build tuple for PAC->PNS */
t.src.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
- t.src.u.gre.key = htons(master->help.ct_pptp_info.pac_call_id);
+ t.src.u.gre.key = master->help.ct_pptp_info.pac_call_id;
t.dst.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
- t.dst.u.gre.key = htons(master->help.ct_pptp_info.pns_call_id);
+ t.dst.u.gre.key = master->help.ct_pptp_info.pns_call_id;
t.dst.protonum = IPPROTO_GRE;
} else {
DEBUGP("we are PAC->PNS\n");
/* build tuple for PNS->PAC */
t.src.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
- t.src.u.gre.key =
- htons(master->nat.help.nat_pptp_info.pns_call_id);
+ t.src.u.gre.key = master->nat.help.nat_pptp_info.pns_call_id;
t.dst.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
- t.dst.u.gre.key =
- htons(master->nat.help.nat_pptp_info.pac_call_id);
+ t.dst.u.gre.key = master->nat.help.nat_pptp_info.pac_call_id;
t.dst.protonum = IPPROTO_GRE;
}
{
struct ip_ct_pptp_master *ct_pptp_info = &ct->help.ct_pptp_info;
struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
+ u_int16_t msg;
+ __be16 new_callid;
+ unsigned int cid_off;
- u_int16_t msg, *cid = NULL, new_callid;
+ new_callid = ct_pptp_info->pns_call_id;
- new_callid = htons(ct_pptp_info->pns_call_id);
-
switch (msg = ntohs(ctlh->messageType)) {
- case PPTP_OUT_CALL_REQUEST:
- cid = &pptpReq->ocreq.callID;
- /* FIXME: ideally we would want to reserve a call ID
- * here. current netfilter NAT core is not able to do
- * this :( For now we use TCP source port. This breaks
- * multiple calls within one control session */
-
- /* save original call ID in nat_info */
- nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
-
- /* don't use tcph->source since we are at a DSTmanip
- * hook (e.g. PREROUTING) and pkt is not mangled yet */
- new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
-
- /* save new call ID in ct info */
- ct_pptp_info->pns_call_id = ntohs(new_callid);
- break;
- case PPTP_IN_CALL_REPLY:
- cid = &pptpReq->icreq.callID;
- break;
- case PPTP_CALL_CLEAR_REQUEST:
- cid = &pptpReq->clrreq.callID;
- break;
- default:
- DEBUGP("unknown outbound packet 0x%04x:%s\n", msg,
- (msg <= PPTP_MSG_MAX)?
- pptp_msg_name[msg]:pptp_msg_name[0]);
- /* fall through */
-
- case PPTP_SET_LINK_INFO:
- /* only need to NAT in case PAC is behind NAT box */
- case PPTP_START_SESSION_REQUEST:
- case PPTP_START_SESSION_REPLY:
- case PPTP_STOP_SESSION_REQUEST:
- case PPTP_STOP_SESSION_REPLY:
- case PPTP_ECHO_REQUEST:
- case PPTP_ECHO_REPLY:
- /* no need to alter packet */
- return NF_ACCEPT;
+ case PPTP_OUT_CALL_REQUEST:
+ cid_off = offsetof(union pptp_ctrl_union, ocreq.callID);
+ /* FIXME: ideally we would want to reserve a call ID
+ * here. current netfilter NAT core is not able to do
+ * this :( For now we use TCP source port. This breaks
+ * multiple calls within one control session */
+
+ /* save original call ID in nat_info */
+ nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
+
+ /* don't use tcph->source since we are at a DSTmanip
+ * hook (e.g. PREROUTING) and pkt is not mangled yet */
+ new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
+
+ /* save new call ID in ct info */
+ ct_pptp_info->pns_call_id = new_callid;
+ break;
+ case PPTP_IN_CALL_REPLY:
+ cid_off = offsetof(union pptp_ctrl_union, icreq.callID);
+ break;
+ case PPTP_CALL_CLEAR_REQUEST:
+ cid_off = offsetof(union pptp_ctrl_union, clrreq.callID);
+ break;
+ default:
+ DEBUGP("unknown outbound packet 0x%04x:%s\n", msg,
+ (msg <= PPTP_MSG_MAX)?
+ pptp_msg_name[msg]:pptp_msg_name[0]);
+ /* fall through */
+
+ case PPTP_SET_LINK_INFO:
+ /* only need to NAT in case PAC is behind NAT box */
+ case PPTP_START_SESSION_REQUEST:
+ case PPTP_START_SESSION_REPLY:
+ case PPTP_STOP_SESSION_REQUEST:
+ case PPTP_STOP_SESSION_REPLY:
+ case PPTP_ECHO_REQUEST:
+ case PPTP_ECHO_REPLY:
+ /* no need to alter packet */
+ return NF_ACCEPT;
}
/* only OUT_CALL_REQUEST, IN_CALL_REPLY, CALL_CLEAR_REQUEST pass
* down to here */
-
- IP_NF_ASSERT(cid);
-
DEBUGP("altering call id from 0x%04x to 0x%04x\n",
- ntohs(*cid), ntohs(new_callid));
+ ntohs(REQ_CID(pptpReq, cid_off)), ntohs(new_callid));
/* mangle packet */
if (ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
- (void *)cid - ((void *)ctlh - sizeof(struct pptp_pkt_hdr)),
- sizeof(new_callid),
- (char *)&new_callid,
- sizeof(new_callid)) == 0)
+ cid_off + sizeof(struct pptp_pkt_hdr) +
+ sizeof(struct PptpControlHeader),
+ sizeof(new_callid), (char *)&new_callid,
+ sizeof(new_callid)) == 0)
return NF_DROP;
return NF_ACCEPT;
pptp_exp_gre(struct ip_conntrack_expect *expect_orig,
struct ip_conntrack_expect *expect_reply)
{
- struct ip_ct_pptp_master *ct_pptp_info =
+ struct ip_ct_pptp_master *ct_pptp_info =
&expect_orig->master->help.ct_pptp_info;
- struct ip_nat_pptp *nat_pptp_info =
+ struct ip_nat_pptp *nat_pptp_info =
&expect_orig->master->nat.help.nat_pptp_info;
struct ip_conntrack *ct = expect_orig->master;
/* alter expectation for PNS->PAC direction */
invert_tuplepr(&inv_t, &expect_orig->tuple);
- expect_orig->saved_proto.gre.key = htons(ct_pptp_info->pns_call_id);
- expect_orig->tuple.src.u.gre.key = htons(nat_pptp_info->pns_call_id);
- expect_orig->tuple.dst.u.gre.key = htons(ct_pptp_info->pac_call_id);
+ expect_orig->saved_proto.gre.key = ct_pptp_info->pns_call_id;
+ expect_orig->tuple.src.u.gre.key = nat_pptp_info->pns_call_id;
+ expect_orig->tuple.dst.u.gre.key = ct_pptp_info->pac_call_id;
expect_orig->dir = IP_CT_DIR_ORIGINAL;
inv_t.src.ip = reply_t->src.ip;
inv_t.dst.ip = reply_t->dst.ip;
- inv_t.src.u.gre.key = htons(nat_pptp_info->pac_call_id);
- inv_t.dst.u.gre.key = htons(ct_pptp_info->pns_call_id);
+ inv_t.src.u.gre.key = nat_pptp_info->pac_call_id;
+ inv_t.dst.u.gre.key = ct_pptp_info->pns_call_id;
if (!ip_conntrack_expect_related(expect_orig)) {
DEBUGP("successfully registered expect\n");
/* alter expectation for PAC->PNS direction */
invert_tuplepr(&inv_t, &expect_reply->tuple);
- expect_reply->saved_proto.gre.key = htons(nat_pptp_info->pns_call_id);
- expect_reply->tuple.src.u.gre.key = htons(nat_pptp_info->pac_call_id);
- expect_reply->tuple.dst.u.gre.key = htons(ct_pptp_info->pns_call_id);
+ expect_reply->saved_proto.gre.key = nat_pptp_info->pns_call_id;
+ expect_reply->tuple.src.u.gre.key = nat_pptp_info->pac_call_id;
+ expect_reply->tuple.dst.u.gre.key = ct_pptp_info->pns_call_id;
expect_reply->dir = IP_CT_DIR_REPLY;
inv_t.src.ip = orig_t->src.ip;
inv_t.dst.ip = orig_t->dst.ip;
- inv_t.src.u.gre.key = htons(nat_pptp_info->pns_call_id);
- inv_t.dst.u.gre.key = htons(ct_pptp_info->pac_call_id);
+ inv_t.src.u.gre.key = nat_pptp_info->pns_call_id;
+ inv_t.dst.u.gre.key = ct_pptp_info->pac_call_id;
if (!ip_conntrack_expect_related(expect_reply)) {
DEBUGP("successfully registered expect\n");
union pptp_ctrl_union *pptpReq)
{
struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
- u_int16_t msg, new_cid = 0, new_pcid, *pcid = NULL, *cid = NULL;
-
- int ret = NF_ACCEPT, rv;
+ u_int16_t msg;
+ __be16 new_pcid;
+ unsigned int pcid_off;
- new_pcid = htons(nat_pptp_info->pns_call_id);
+ new_pcid = nat_pptp_info->pns_call_id;
switch (msg = ntohs(ctlh->messageType)) {
case PPTP_OUT_CALL_REPLY:
- pcid = &pptpReq->ocack.peersCallID;
- cid = &pptpReq->ocack.callID;
+ pcid_off = offsetof(union pptp_ctrl_union, ocack.peersCallID);
break;
case PPTP_IN_CALL_CONNECT:
- pcid = &pptpReq->iccon.peersCallID;
+ pcid_off = offsetof(union pptp_ctrl_union, iccon.peersCallID);
break;
case PPTP_IN_CALL_REQUEST:
/* only need to nat in case PAC is behind NAT box */
- break;
+ return NF_ACCEPT;
case PPTP_WAN_ERROR_NOTIFY:
- pcid = &pptpReq->wanerr.peersCallID;
+ pcid_off = offsetof(union pptp_ctrl_union, wanerr.peersCallID);
break;
case PPTP_CALL_DISCONNECT_NOTIFY:
- pcid = &pptpReq->disc.callID;
+ pcid_off = offsetof(union pptp_ctrl_union, disc.callID);
break;
case PPTP_SET_LINK_INFO:
- pcid = &pptpReq->setlink.peersCallID;
+ pcid_off = offsetof(union pptp_ctrl_union, setlink.peersCallID);
break;
default:
- DEBUGP("unknown inbound packet %s\n", (msg <= PPTP_MSG_MAX)?
+ DEBUGP("unknown inbound packet %s\n", (msg <= PPTP_MSG_MAX)?
pptp_msg_name[msg]:pptp_msg_name[0]);
/* fall through */
* WAN_ERROR_NOTIFY, CALL_DISCONNECT_NOTIFY pass down here */
/* mangle packet */
- IP_NF_ASSERT(pcid);
DEBUGP("altering peer call id from 0x%04x to 0x%04x\n",
- ntohs(*pcid), ntohs(new_pcid));
-
- rv = ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
- (void *)pcid - ((void *)ctlh - sizeof(struct pptp_pkt_hdr)),
- sizeof(new_pcid), (char *)&new_pcid,
- sizeof(new_pcid));
- if (rv != NF_ACCEPT)
- return rv;
-
- if (new_cid) {
- IP_NF_ASSERT(cid);
- DEBUGP("altering call id from 0x%04x to 0x%04x\n",
- ntohs(*cid), ntohs(new_cid));
- rv = ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
- (void *)cid - ((void *)ctlh - sizeof(struct pptp_pkt_hdr)),
- sizeof(new_cid),
- (char *)&new_cid,
- sizeof(new_cid));
- if (rv != NF_ACCEPT)
- return rv;
- }
-
- /* check for earlier return value of 'switch' above */
- if (ret != NF_ACCEPT)
- return ret;
+ ntohs(REQ_CID(pptpReq, pcid_off)), ntohs(new_pcid));
- /* great, at least we don't need to resize packets */
+ if (ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
+ pcid_off + sizeof(struct pptp_pkt_hdr) +
+ sizeof(struct PptpControlHeader),
+ sizeof(new_pcid), (char *)&new_pcid,
+ sizeof(new_pcid)) == 0)
+ return NF_DROP;
return NF_ACCEPT;
}
extern int __init ip_nat_proto_gre_init(void);
extern void __exit ip_nat_proto_gre_fini(void);
-static int __init init(void)
+static int __init ip_nat_helper_pptp_init(void)
{
int ret;
return 0;
}
-static void __exit fini(void)
+static void __exit ip_nat_helper_pptp_fini(void)
{
DEBUGP("cleanup_module\n" );
printk("ip_nat_pptp version %s unloaded\n", IP_NAT_PPTP_VERSION);
}
-module_init(init);
-module_exit(fini);
+module_init(ip_nat_helper_pptp_init);
+module_exit(ip_nat_helper_pptp_fini);
git.openpandora.org / pandora-kernel.git / blobdiff