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authorPaul Moore <pmoore@redhat.com>2012-06-01 05:54:56 +0000
committerDavid S. Miller <davem@davemloft.net>2012-06-01 14:18:29 -0400
commit20e2a86485967c385d7c7befc1646e4d1d39362e (patch)
treee08d5d8dd133a8548e9f5dd0f85e69241ec1e176
parentcc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc (diff)
downloadlinux-sh-20e2a86485967c385d7c7befc1646e4d1d39362e.tar.gz
cipso: handle CIPSO options correctly when NetLabel is disabled
When NetLabel is not enabled, e.g. CONFIG_NETLABEL=n, and the system receives a CIPSO tagged packet it is dropped (cipso_v4_validate() returns non-zero). In most cases this is the correct and desired behavior, however, in the case where we are simply forwarding the traffic, e.g. acting as a network bridge, this becomes a problem. This patch fixes the forwarding problem by providing the basic CIPSO validation code directly in ip_options_compile() without the need for the NetLabel or CIPSO code. The new validation code can not perform any of the CIPSO option label/value verification that cipso_v4_validate() does, but it can verify the basic CIPSO option format. The behavior when NetLabel is enabled is unchanged. Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/cipso_ipv4.h29
1 files changed, 28 insertions, 1 deletions
diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h
index 9808877c2ab9..a7a683e30b64 100644
--- a/include/net/cipso_ipv4.h
+++ b/include/net/cipso_ipv4.h
@@ -42,6 +42,7 @@
#include <net/netlabel.h>
#include <net/request_sock.h>
#include <linux/atomic.h>
+#include <asm/unaligned.h>
/* known doi values */
#define CIPSO_V4_DOI_UNKNOWN 0x00000000
@@ -285,7 +286,33 @@ static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
static inline int cipso_v4_validate(const struct sk_buff *skb,
unsigned char **option)
{
- return -ENOSYS;
+ unsigned char *opt = *option;
+ unsigned char err_offset = 0;
+ u8 opt_len = opt[1];
+ u8 opt_iter;
+
+ if (opt_len < 8) {
+ err_offset = 1;
+ goto out;
+ }
+
+ if (get_unaligned_be32(&opt[2]) == 0) {
+ err_offset = 2;
+ goto out;
+ }
+
+ for (opt_iter = 6; opt_iter < opt_len;) {
+ if (opt[opt_iter + 1] > (opt_len - opt_iter)) {
+ err_offset = opt_iter + 1;
+ goto out;
+ }
+ opt_iter += opt[opt_iter + 1];
+ }
+
+out:
+ *option = opt + err_offset;
+ return err_offset;
+
}
#endif /* CONFIG_NETLABEL */