precompile ppp active filter (reduces libpcap overhead to only a few k), enable by default to support proper demand dialling, fixes #307

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@3401 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 51 insertions, 0 deletions

diff --git a/package/ppp/utils/pfc.c b/package/ppp/utils/pfc.c
new file mode 100644
index 000000000..5476be170
--- /dev/null
+++ b/package/ppp/utils/pfc.c
@@ -0,0 +1,51 @@
+/* 
+ * Taken from fli4l 3.0
+ * Make sure you compile it against the same libpcap version used in OpenWrt
+ */
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <string.h>
+
+#include <linux/types.h>
+#include <linux/ppp_defs.h>
+
+#include <pcap.h>
+#include <pcap-bpf.h>
+
+int main (int argc, char ** argv)
+{
+    pcap_t  *pc; /* Fake struct pcap so we can compile expr */
+    struct  bpf_program filter; /* Filter program for link-active pkts */
+    u_int32_t netmask=0;
+
+    int dflag = 3;
+    if (argc == 4)
+    {
+	if (!strcmp (argv[1], "-d"))
+	{
+	    dflag = atoi (argv[2]);
+	    argv += 2;
+	    argc -=2;
+	}
+    }
+    if (argc != 2)
+    {
+	printf ("usage; %s [ -d <debug_level> ] expression\n", argv[0]);
+	return 1;
+    }
+
+    pc = pcap_open_dead(DLT_PPP_PPPD, PPP_HDRLEN);
+    if (pcap_compile(pc, &filter, argv[1], 1, netmask) == 0)
+    {
+	printf ("#\n# Expression: %s\n#\n", argv[1]);
+	bpf_dump (&filter, dflag);
+	return 0;
+    }
+    else
+    {
+	printf("error in active-filter expression: %s\n", pcap_geterr(pc));
+    }
+    return 1;
+}