Invoke the skb_flow_out LSM hook for outbound
traffic for secid reconciliation and flow control.
Signed-off-by: Venkat Yekkirala <[EMAIL PROTECTED]>
---
net/netfilter/xt_CONNSECMARK.c | 72 ++++++++++++++++++++++++-------
net/netfilter/xt_SECMARK.c | 45 ++++++++++++++++++-
2 files changed, 100 insertions(+), 17 deletions(-)
diff --git a/net/netfilter/xt_CONNSECMARK.c b/net/netfilter/xt_CONNSECMARK.c
index 4673862..cca4a0c 100644
--- a/net/netfilter/xt_CONNSECMARK.c
+++ b/net/netfilter/xt_CONNSECMARK.c
@@ -17,6 +17,8 @@
*/
#include <linux/module.h>
#include <linux/skbuff.h>
+#include <linux/security.h>
+#include <linux/netfilter_ipv6.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_CONNSECMARK.h>
#include <net/netfilter/nf_conntrack_compat.h>
@@ -29,38 +31,78 @@ MODULE_DESCRIPTION("ip[6]tables CONNSECM
MODULE_ALIAS("ipt_CONNSECMARK");
MODULE_ALIAS("ip6t_CONNSECMARK");
+static inline int outbound(unsigned short family, unsigned int hooknum)
+{
+ if ((family == AF_INET &&
+ (hooknum == NF_IP_POST_ROUTING ||
+ hooknum == NF_IP_LOCAL_OUT ||
+ hooknum == NF_IP_FORWARD)) ||
+ (family == AF_INET6 &&
+ (hooknum == NF_IP6_POST_ROUTING ||
+ hooknum == NF_IP6_LOCAL_OUT ||
+ hooknum == NF_IP6_FORWARD)))
+ return 1;
+ else
+ return 0;
+}
+
/*
* If the packet has a security mark and the connection does not, copy
* the security mark from the packet to the connection.
*/
-static void secmark_save(struct sk_buff *skb)
+static void secmark_save(struct sk_buff *skb, unsigned int hooknum)
{
if (skb->secmark) {
u32 *connsecmark;
enum ip_conntrack_info ctinfo;
connsecmark = nf_ct_get_secmark(skb, &ctinfo);
- if (connsecmark && !*connsecmark)
+ if (connsecmark)
if (*connsecmark != skb->secmark)
*connsecmark = skb->secmark;
}
}
/*
- * If packet has no security mark, and the connection does, restore the
- * security mark from the connection to the packet.
+ * On the inbound, restore the security mark from the connection to the packet.
+ * On the outbound, filter based on the current secmark.
*/
-static void secmark_restore(struct sk_buff *skb)
+static unsigned int secmark_restore(struct sk_buff *skb, unsigned int hooknum,
+ const struct net_device *in, unsigned short family)
{
- if (!skb->secmark) {
- u32 *connsecmark;
- enum ip_conntrack_info ctinfo;
-
- connsecmark = nf_ct_get_secmark(skb, &ctinfo);
- if (connsecmark && *connsecmark)
- if (skb->secmark != *connsecmark)
- skb->secmark = *connsecmark;
+ u32 *psecmark;
+ enum ip_conntrack_info ctinfo;
+
+ psecmark = nf_ct_get_secmark(skb, &ctinfo);
+
+ if (psecmark && *psecmark) {
+
+ /* Set secmark on inbound and filter it on outbound */
+ if (outbound(family, hooknum)) {
+ int err;
+
+ err = security_skb_flow_out(skb, *psecmark);
+ if (!err)
+ return NF_DROP;
+ } else
+ /*
+ * inbound:
+ * loopback traffic should already be labeled
+ * and any filtering on outbound should suffice
+ */
+ if (in == &loopback_dev)
+ goto out;
+
+ /*
+ * inbound or done with outbound check or no LSM hook
+ * for outbound
+ */
+ if (skb->secmark != *psecmark)
+ skb->secmark = *psecmark;
}
+
+out:
+ return XT_CONTINUE;
}
static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
@@ -73,11 +115,11 @@ static unsigned int target(struct sk_buf
switch (info->mode) {
case CONNSECMARK_SAVE:
- secmark_save(skb);
+ secmark_save(skb, hooknum);
break;
case CONNSECMARK_RESTORE:
- secmark_restore(skb);
+ return secmark_restore(skb, hooknum, in, target->family);
break;
default:
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index add7521..9ecce66 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -15,8 +15,10 @@
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/selinux.h>
+#include <linux/security.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_SECMARK.h>
+#include <linux/netfilter_ipv6.h>
MODULE_LICENSE("GPL");
MODULE_AUTHOR("James Morris <[EMAIL PROTECTED]>");
@@ -28,6 +30,21 @@ #define PFX "SECMARK: "
static u8 mode;
+static inline int outbound(unsigned short family, unsigned int hooknum)
+{
+ if ((family == AF_INET &&
+ (hooknum == NF_IP_POST_ROUTING ||
+ hooknum == NF_IP_LOCAL_OUT ||
+ hooknum == NF_IP_FORWARD)) ||
+ (family == AF_INET6 &&
+ (hooknum == NF_IP6_POST_ROUTING ||
+ hooknum == NF_IP6_LOCAL_OUT ||
+ hooknum == NF_IP6_FORWARD)))
+ return 1;
+ else
+ return 0;
+}
+
static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
const struct net_device *out, unsigned int hooknum,
const struct xt_target *target,
@@ -47,9 +64,33 @@ static unsigned int target(struct sk_buf
BUG();
}
- if ((*pskb)->secmark != secmark)
- (*pskb)->secmark = secmark;
+ if (secmark) {
+
+ /* Set secmark on inbound and filter it on outbound */
+ if (outbound(target->family, hooknum)) {
+ int err;
+
+ err = security_skb_flow_out(*pskb, secmark);
+ if (!err)
+ return NF_DROP;
+ } else
+ /*
+ * inbound:
+ * loopback traffic should already be labeled
+ * and any filtering on outbound should suffice
+ */
+ if (in == &loopback_dev)
+ goto out;
+
+ /*
+ * inbound or done with outbound check or no LSM hook
+ * for outbound
+ */
+ if ((*pskb)->secmark != secmark)
+ (*pskb)->secmark = secmark;
+ }
+out:
return XT_CONTINUE;
}
-
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