1 files changed, 43 insertions, 0 deletions
diff --git a/bpf_comp.c b/bpf_comp.c
new file mode 100644
index 0000000..27f7a00
--- /dev/null
+++ b/bpf_comp.c
@@ -0,0 +1,43 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2013 Daniel Borkmann.
+ * Subject to the GPL, version 2.
+ */
+
+#include <pcap.h>
+#include <linux/filter.h>
+
+#include "xmalloc.h"
+#include "bpf.h"
+#include "die.h"
+
+void bpf_try_compile(const char *rulefile, struct sock_fprog *bpf, uint32_t link_type)
+{
+	int i, ret;
+	const struct bpf_insn *ins;
+	struct sock_filter *out;
+	struct bpf_program _bpf;
+
+	ret = pcap_compile_nopcap(65535, link_type, &_bpf, rulefile, 1, 0xffffffff);
+	if (ret < 0)
+		panic("Cannot compile filter %s\n", rulefile);
+
+	bpf->len = _bpf.bf_len;
+	bpf->filter = xrealloc(bpf->filter, 1, bpf->len * sizeof(*out));
+
+	for (i = 0, ins = _bpf.bf_insns, out = bpf->filter; i < bpf->len; ++i, ++ins, ++out) {
+
+		out->code = ins->code;
+		out->jt = ins->jt;
+		out->jf = ins->jf;
+		out->k = ins->k;
+
+		if (out->code == 0x06 && out->k > 0)
+			out->k = 0xFFFFFFFF;
+	}
+
+	pcap_freecode(&_bpf);
+
+	if (__bpf_validate(bpf) == 0)
+		panic("This is not a valid BPF program!\n");
+}