netfilter: x_tables: add xt_bpf match
Support arbitrary linux socket filter (BPF) programs as x_tables
match rules. This allows for very expressive filters, and on
platforms with BPF JIT appears competitive with traditional
hardcoded iptables rules using the u32 match.
The size of the filter has been artificially limited to 64
instructions maximum to avoid bloating the size of each rule
using this new match.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/xt_bpf.h b/include/uapi/linux/netfilter/xt_bpf.h
new file mode 100644
index 0000000..5dda450
--- /dev/null
+++ b/include/uapi/linux/netfilter/xt_bpf.h
@@ -0,0 +1,17 @@
+#ifndef _XT_BPF_H
+#define _XT_BPF_H
+
+#include <linux/filter.h>
+#include <linux/types.h>
+
+#define XT_BPF_MAX_NUM_INSTR 64
+
+struct xt_bpf_info {
+ __u16 bpf_program_num_elem;
+ struct sock_filter bpf_program[XT_BPF_MAX_NUM_INSTR];
+
+ /* only used in the kernel */
+ struct sk_filter *filter __attribute__((aligned(8)));
+};
+
+#endif /*_XT_BPF_H */