netfilter: nf_conntrack_sip: pass data offset to NAT functions
When using TCP multiple SIP messages might be present in a single packet.
A following patch will parse them by setting the dptr to the beginning of
each message. The NAT helper needs to reload the dptr value after mangling
the packet however, so it needs to know the offset of the message to the
beginning of the packet.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index 0ca2f2b..0ec37d6 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -50,12 +50,13 @@
MODULE_PARM_DESC(sip_direct_media, "Expect Media streams between signalling "
"endpoints only (default 1)");
-unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sip_hook)(struct sk_buff *skb, unsigned int dataoff,
const char **dptr,
unsigned int *datalen) __read_mostly;
EXPORT_SYMBOL_GPL(nf_nat_sip_hook);
unsigned int (*nf_nat_sip_expect_hook)(struct sk_buff *skb,
+ unsigned int dataoff,
const char **dptr,
unsigned int *datalen,
struct nf_conntrack_expect *exp,
@@ -63,17 +64,17 @@
unsigned int matchlen) __read_mostly;
EXPORT_SYMBOL_GPL(nf_nat_sip_expect_hook);
-unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_addr_hook)(struct sk_buff *skb, unsigned int dataoff,
const char **dptr,
- unsigned int dataoff,
unsigned int *datalen,
+ unsigned int sdpoff,
enum sdp_header_types type,
enum sdp_header_types term,
const union nf_inet_addr *addr)
__read_mostly;
EXPORT_SYMBOL_GPL(nf_nat_sdp_addr_hook);
-unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_port_hook)(struct sk_buff *skb, unsigned int dataoff,
const char **dptr,
unsigned int *datalen,
unsigned int matchoff,
@@ -82,14 +83,15 @@
EXPORT_SYMBOL_GPL(nf_nat_sdp_port_hook);
unsigned int (*nf_nat_sdp_session_hook)(struct sk_buff *skb,
- const char **dptr,
unsigned int dataoff,
+ const char **dptr,
unsigned int *datalen,
+ unsigned int sdpoff,
const union nf_inet_addr *addr)
__read_mostly;
EXPORT_SYMBOL_GPL(nf_nat_sdp_session_hook);
-unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb,
+unsigned int (*nf_nat_sdp_media_hook)(struct sk_buff *skb, unsigned int dataoff,
const char **dptr,
unsigned int *datalen,
struct nf_conntrack_expect *rtp_exp,
@@ -729,7 +731,7 @@
spin_unlock_bh(&nf_conntrack_lock);
}
-static int set_expected_rtp_rtcp(struct sk_buff *skb,
+static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
union nf_inet_addr *daddr, __be16 port,
enum sip_expectation_classes class,
@@ -806,7 +808,7 @@
if (direct_rtp) {
nf_nat_sdp_port = rcu_dereference(nf_nat_sdp_port_hook);
if (nf_nat_sdp_port &&
- !nf_nat_sdp_port(skb, dptr, datalen,
+ !nf_nat_sdp_port(skb, dataoff, dptr, datalen,
mediaoff, medialen, ntohs(rtp_port)))
goto err1;
}
@@ -828,7 +830,8 @@
nf_nat_sdp_media = rcu_dereference(nf_nat_sdp_media_hook);
if (nf_nat_sdp_media && ct->status & IPS_NAT_MASK && !direct_rtp)
- ret = nf_nat_sdp_media(skb, dptr, datalen, rtp_exp, rtcp_exp,
+ ret = nf_nat_sdp_media(skb, dataoff, dptr, datalen,
+ rtp_exp, rtcp_exp,
mediaoff, medialen, daddr);
else {
if (nf_ct_expect_related(rtp_exp) == 0) {
@@ -867,7 +870,7 @@
return NULL;
}
-static int process_sdp(struct sk_buff *skb,
+static int process_sdp(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq)
{
@@ -942,7 +945,7 @@
else
return NF_DROP;
- ret = set_expected_rtp_rtcp(skb, dptr, datalen,
+ ret = set_expected_rtp_rtcp(skb, dataoff, dptr, datalen,
&rtp_addr, htons(port), t->class,
mediaoff, medialen);
if (ret != NF_ACCEPT)
@@ -950,8 +953,9 @@
/* Update media connection address if present */
if (maddr_len && nf_nat_sdp_addr && ct->status & IPS_NAT_MASK) {
- ret = nf_nat_sdp_addr(skb, dptr, mediaoff, datalen,
- c_hdr, SDP_HDR_MEDIA, &rtp_addr);
+ ret = nf_nat_sdp_addr(skb, dataoff, dptr, datalen,
+ mediaoff, c_hdr, SDP_HDR_MEDIA,
+ &rtp_addr);
if (ret != NF_ACCEPT)
return ret;
}
@@ -961,14 +965,15 @@
/* Update session connection and owner addresses */
nf_nat_sdp_session = rcu_dereference(nf_nat_sdp_session_hook);
if (nf_nat_sdp_session && ct->status & IPS_NAT_MASK)
- ret = nf_nat_sdp_session(skb, dptr, sdpoff, datalen, &rtp_addr);
+ ret = nf_nat_sdp_session(skb, dataoff, dptr, datalen, sdpoff,
+ &rtp_addr);
if (ret == NF_ACCEPT && i > 0)
help->help.ct_sip_info.invite_cseq = cseq;
return ret;
}
-static int process_invite_response(struct sk_buff *skb,
+static int process_invite_response(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq, unsigned int code)
{
@@ -978,13 +983,13 @@
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
- return process_sdp(skb, dptr, datalen, cseq);
+ return process_sdp(skb, dataoff, dptr, datalen, cseq);
else if (help->help.ct_sip_info.invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
-static int process_update_response(struct sk_buff *skb,
+static int process_update_response(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq, unsigned int code)
{
@@ -994,13 +999,13 @@
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
- return process_sdp(skb, dptr, datalen, cseq);
+ return process_sdp(skb, dataoff, dptr, datalen, cseq);
else if (help->help.ct_sip_info.invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
-static int process_prack_response(struct sk_buff *skb,
+static int process_prack_response(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq, unsigned int code)
{
@@ -1010,13 +1015,13 @@
if ((code >= 100 && code <= 199) ||
(code >= 200 && code <= 299))
- return process_sdp(skb, dptr, datalen, cseq);
+ return process_sdp(skb, dataoff, dptr, datalen, cseq);
else if (help->help.ct_sip_info.invite_cseq == cseq)
flush_expectations(ct, true);
return NF_ACCEPT;
}
-static int process_bye_request(struct sk_buff *skb,
+static int process_bye_request(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq)
{
@@ -1031,7 +1036,7 @@
* signalling connections. The expectation is marked inactive and is activated
* when receiving a response indicating success from the registrar.
*/
-static int process_register_request(struct sk_buff *skb,
+static int process_register_request(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq)
{
@@ -1101,7 +1106,7 @@
nf_nat_sip_expect = rcu_dereference(nf_nat_sip_expect_hook);
if (nf_nat_sip_expect && ct->status & IPS_NAT_MASK)
- ret = nf_nat_sip_expect(skb, dptr, datalen, exp,
+ ret = nf_nat_sip_expect(skb, dataoff, dptr, datalen, exp,
matchoff, matchlen);
else {
if (nf_ct_expect_related(exp) != 0)
@@ -1117,7 +1122,7 @@
return ret;
}
-static int process_register_response(struct sk_buff *skb,
+static int process_register_response(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen,
unsigned int cseq, unsigned int code)
{
@@ -1127,7 +1132,7 @@
enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
union nf_inet_addr addr;
__be16 port;
- unsigned int matchoff, matchlen, dataoff = 0;
+ unsigned int matchoff, matchlen, coff = 0;
unsigned int expires = 0;
int in_contact = 0, ret;
@@ -1154,7 +1159,7 @@
while (1) {
unsigned int c_expires = expires;
- ret = ct_sip_parse_header_uri(ct, *dptr, &dataoff, *datalen,
+ ret = ct_sip_parse_header_uri(ct, *dptr, &coff, *datalen,
SIP_HDR_CONTACT, &in_contact,
&matchoff, &matchlen,
&addr, &port);
@@ -1193,13 +1198,13 @@
SIP_HANDLER("REGISTER", process_register_request, process_register_response),
};
-static int process_sip_response(struct sk_buff *skb,
+static int process_sip_response(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen)
{
enum ip_conntrack_info ctinfo;
struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
- unsigned int matchoff, matchlen;
- unsigned int code, cseq, dataoff, i;
+ unsigned int matchoff, matchlen, matchend;
+ unsigned int code, cseq, i;
if (*datalen < strlen("SIP/2.0 200"))
return NF_ACCEPT;
@@ -1213,7 +1218,7 @@
cseq = simple_strtoul(*dptr + matchoff, NULL, 10);
if (!cseq)
return NF_DROP;
- dataoff = matchoff + matchlen + 1;
+ matchend = matchoff + matchlen + 1;
for (i = 0; i < ARRAY_SIZE(sip_handlers); i++) {
const struct sip_handler *handler;
@@ -1221,15 +1226,16 @@
handler = &sip_handlers[i];
if (handler->response == NULL)
continue;
- if (*datalen < dataoff + handler->len ||
- strnicmp(*dptr + dataoff, handler->method, handler->len))
+ if (*datalen < matchend + handler->len ||
+ strnicmp(*dptr + matchend, handler->method, handler->len))
continue;
- return handler->response(skb, dptr, datalen, cseq, code);
+ return handler->response(skb, dataoff, dptr, datalen,
+ cseq, code);
}
return NF_ACCEPT;
}
-static int process_sip_request(struct sk_buff *skb,
+static int process_sip_request(struct sk_buff *skb, unsigned int dataoff,
const char **dptr, unsigned int *datalen)
{
enum ip_conntrack_info ctinfo;
@@ -1254,7 +1260,7 @@
if (!cseq)
return NF_DROP;
- return handler->request(skb, dptr, datalen, cseq);
+ return handler->request(skb, dataoff, dptr, datalen, cseq);
}
return NF_ACCEPT;
}
@@ -1288,13 +1294,13 @@
return NF_ACCEPT;
if (strnicmp(dptr, "SIP/2.0 ", strlen("SIP/2.0 ")) != 0)
- ret = process_sip_request(skb, &dptr, &datalen);
+ ret = process_sip_request(skb, dataoff, &dptr, &datalen);
else
- ret = process_sip_response(skb, &dptr, &datalen);
+ ret = process_sip_response(skb, dataoff, &dptr, &datalen);
if (ret == NF_ACCEPT && ct->status & IPS_NAT_MASK) {
nf_nat_sip = rcu_dereference(nf_nat_sip_hook);
- if (nf_nat_sip && !nf_nat_sip(skb, &dptr, &datalen))
+ if (nf_nat_sip && !nf_nat_sip(skb, dataoff, &dptr, &datalen))
ret = NF_DROP;
}