[NETFILTER]: PPTP conntrack: consolidate header parsing
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
index 3b5464f..9a98a6c 100644
--- a/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
+++ b/net/ipv4/netfilter/ip_conntrack_helper_pptp.c
@@ -291,60 +291,21 @@
goto out_put_both;
}
-static const unsigned int pptp_msg_size[] = {
- [PPTP_START_SESSION_REQUEST] = sizeof(struct PptpStartSessionRequest),
- [PPTP_START_SESSION_REPLY] = sizeof(struct PptpStartSessionReply),
- [PPTP_STOP_SESSION_REQUEST] = sizeof(struct PptpStopSessionRequest),
- [PPTP_STOP_SESSION_REPLY] = sizeof(struct PptpStopSessionReply),
- [PPTP_OUT_CALL_REQUEST] = sizeof(struct PptpOutCallRequest),
- [PPTP_OUT_CALL_REPLY] = sizeof(struct PptpOutCallReply),
- [PPTP_IN_CALL_REQUEST] = sizeof(struct PptpInCallRequest),
- [PPTP_IN_CALL_REPLY] = sizeof(struct PptpInCallReply),
- [PPTP_IN_CALL_CONNECT] = sizeof(struct PptpInCallConnected),
- [PPTP_CALL_CLEAR_REQUEST] = sizeof(struct PptpClearCallRequest),
- [PPTP_CALL_DISCONNECT_NOTIFY] = sizeof(struct PptpCallDisconnectNotify),
- [PPTP_WAN_ERROR_NOTIFY] = sizeof(struct PptpWanErrorNotify),
- [PPTP_SET_LINK_INFO] = sizeof(struct PptpSetLinkInfo),
-};
-
static inline int
pptp_inbound_pkt(struct sk_buff **pskb,
- struct tcphdr *tcph,
- unsigned int nexthdr_off,
- unsigned int datalen,
+ struct PptpControlHeader *ctlh,
+ union pptp_ctrl_union *pptpReq,
+ unsigned int reqlen,
struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo)
{
- struct PptpControlHeader _ctlh, *ctlh;
- unsigned int reqlen;
- union pptp_ctrl_union _pptpReq, *pptpReq;
struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
u_int16_t msg;
__be16 cid, pcid;
- ctlh = skb_header_pointer(*pskb, nexthdr_off, sizeof(_ctlh), &_ctlh);
- if (!ctlh) {
- DEBUGP("error during skb_header_pointer\n");
- return NF_ACCEPT;
- }
- nexthdr_off += sizeof(_ctlh);
- datalen -= sizeof(_ctlh);
-
- reqlen = datalen;
- if (reqlen > sizeof(*pptpReq))
- reqlen = sizeof(*pptpReq);
- pptpReq = skb_header_pointer(*pskb, nexthdr_off, reqlen, &_pptpReq);
- if (!pptpReq) {
- DEBUGP("error during skb_header_pointer\n");
- return NF_ACCEPT;
- }
-
msg = ntohs(ctlh->messageType);
DEBUGP("inbound control message %s\n", pptp_msg_name[msg]);
- if (msg > 0 && msg <= PPTP_MSG_MAX && reqlen < pptp_msg_size[msg])
- return NF_ACCEPT;
-
switch (msg) {
case PPTP_START_SESSION_REPLY:
/* server confirms new control session */
@@ -480,38 +441,19 @@
static inline int
pptp_outbound_pkt(struct sk_buff **pskb,
- struct tcphdr *tcph,
- unsigned int nexthdr_off,
- unsigned int datalen,
+ struct PptpControlHeader *ctlh,
+ union pptp_ctrl_union *pptpReq,
+ unsigned int reqlen,
struct ip_conntrack *ct,
enum ip_conntrack_info ctinfo)
{
- struct PptpControlHeader _ctlh, *ctlh;
- unsigned int reqlen;
- union pptp_ctrl_union _pptpReq, *pptpReq;
struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
u_int16_t msg;
__be16 cid, pcid;
- ctlh = skb_header_pointer(*pskb, nexthdr_off, sizeof(_ctlh), &_ctlh);
- if (!ctlh)
- return NF_ACCEPT;
- nexthdr_off += sizeof(_ctlh);
- datalen -= sizeof(_ctlh);
-
- reqlen = datalen;
- if (reqlen > sizeof(*pptpReq))
- reqlen = sizeof(*pptpReq);
- pptpReq = skb_header_pointer(*pskb, nexthdr_off, reqlen, &_pptpReq);
- if (!pptpReq)
- return NF_ACCEPT;
-
msg = ntohs(ctlh->messageType);
DEBUGP("outbound control message %s\n", pptp_msg_name[msg]);
- if (msg > 0 && msg <= PPTP_MSG_MAX && reqlen < pptp_msg_size[msg])
- return NF_ACCEPT;
-
switch (msg) {
case PPTP_START_SESSION_REQUEST:
/* client requests for new control session */
@@ -593,6 +535,21 @@
return NF_ACCEPT;
}
+static const unsigned int pptp_msg_size[] = {
+ [PPTP_START_SESSION_REQUEST] = sizeof(struct PptpStartSessionRequest),
+ [PPTP_START_SESSION_REPLY] = sizeof(struct PptpStartSessionReply),
+ [PPTP_STOP_SESSION_REQUEST] = sizeof(struct PptpStopSessionRequest),
+ [PPTP_STOP_SESSION_REPLY] = sizeof(struct PptpStopSessionReply),
+ [PPTP_OUT_CALL_REQUEST] = sizeof(struct PptpOutCallRequest),
+ [PPTP_OUT_CALL_REPLY] = sizeof(struct PptpOutCallReply),
+ [PPTP_IN_CALL_REQUEST] = sizeof(struct PptpInCallRequest),
+ [PPTP_IN_CALL_REPLY] = sizeof(struct PptpInCallReply),
+ [PPTP_IN_CALL_CONNECT] = sizeof(struct PptpInCallConnected),
+ [PPTP_CALL_CLEAR_REQUEST] = sizeof(struct PptpClearCallRequest),
+ [PPTP_CALL_DISCONNECT_NOTIFY] = sizeof(struct PptpCallDisconnectNotify),
+ [PPTP_WAN_ERROR_NOTIFY] = sizeof(struct PptpWanErrorNotify),
+ [PPTP_SET_LINK_INFO] = sizeof(struct PptpSetLinkInfo),
+};
/* track caller id inside control connection, call expect_related */
static int
@@ -600,16 +557,17 @@
struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
{
- struct pptp_pkt_hdr _pptph, *pptph;
- struct tcphdr _tcph, *tcph;
- u_int32_t tcplen = (*pskb)->len - (*pskb)->nh.iph->ihl * 4;
- u_int32_t datalen;
int dir = CTINFO2DIR(ctinfo);
struct ip_ct_pptp_master *info = &ct->help.ct_pptp_info;
- unsigned int nexthdr_off;
-
+ struct tcphdr _tcph, *tcph;
+ struct pptp_pkt_hdr _pptph, *pptph;
+ struct PptpControlHeader _ctlh, *ctlh;
+ union pptp_ctrl_union _pptpReq, *pptpReq;
+ unsigned int tcplen = (*pskb)->len - (*pskb)->nh.iph->ihl * 4;
+ 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
@@ -648,6 +606,23 @@
return NF_ACCEPT;
}
+ ctlh = skb_header_pointer(*pskb, 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(*pskb, nexthdr_off, reqlen, &_pptpReq);
+ if (!pptpReq)
+ return NF_ACCEPT;
+
oldsstate = info->sstate;
oldcstate = info->cstate;
@@ -657,11 +632,11 @@
* established from PNS->PAC. However, RFC makes no guarantee */
if (dir == IP_CT_DIR_ORIGINAL)
/* client -> server (PNS -> PAC) */
- ret = pptp_outbound_pkt(pskb, tcph, nexthdr_off, datalen, ct,
+ ret = pptp_outbound_pkt(pskb, ctlh, pptpReq, reqlen, ct,
ctinfo);
else
/* server -> client (PAC -> PNS) */
- ret = pptp_inbound_pkt(pskb, tcph, nexthdr_off, datalen, ct,
+ ret = pptp_inbound_pkt(pskb, ctlh, pptpReq, reqlen, ct,
ctinfo);
DEBUGP("sstate: %d->%d, cstate: %d->%d\n",
oldsstate, info->sstate, oldcstate, info->cstate);