Merge pull request #17 from kinvolk/nhlfr/remove-kernel-source-dep

Remove kernel source tree dependency

bpf/Makefile

@@ -1,7 +1,6 @@
 OUTDIR=out
 OUTFILE=$(OUTDIR)/cgnet.o
 
-LINUX_HEADERS="/usr/lib/modules/$(shell uname -r)/build"
 
 .PHONY: all build clean
 
@@ -11,8 +10,8 @@ $(OUTFILE):
 	mkdir -p $(OUTDIR)
 	clang -D__KERNEL__ -D__ASM_SYSREG_H \
 	-Wno-unused-value -Wno-pointer-sign -Wno-compare-distinct-pointer-types \
+			-fno-stack-protector \
 			-O2 -emit-llvm -c "src/cgnet.c" \
-			$(foreach path,$(LINUX_HEADERS), -I $(path)/arch/x86/include -I $(path)/arch/x86/include/generated -I $(path)/include -I $(path)/include/generated/uapi -I $(path)/arch/x86/include/uapi -I $(path)/include/uapi) \
 			-o - | llc -march=bpf -filetype=obj -o $(OUTFILE)
 
 bindata.go:

bpf/src/cgnet.c

@@ -12,11 +12,12 @@
  * limitations under the License.
  */
 
-#include <linux/kconfig.h>
 #include <linux/bpf.h>
-#include <uapi/linux/tcp.h>
-#include <uapi/linux/if_ether.h>
-#include <uapi/linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <arpa/inet.h>
+#include <stddef.h>
 #include "bpf_helpers.h"
 
 struct bpf_map_def SEC("maps/count") count_map = {
@@ -29,23 +30,23 @@ struct bpf_map_def SEC("maps/count") count_map = {
 SEC("cgroup/skb")
 int count_packets(struct __sk_buff *skb) {
     int packets_key = 0, bytes_key = 1;
-    u64 *packets = NULL;
-    u64 *bytes = NULL;
+    __u64 *packets = 0;
+    __u64 *bytes = 0;
 
     packets = bpf_map_lookup_elem(&count_map, &packets_key);
-    if (packets == NULL)
+    if (packets == 0)
         return 0;
 
     *packets += 1;
 
     bytes = bpf_map_lookup_elem(&count_map, &bytes_key);
-    if (bytes == NULL)
+    if (bytes == 0)
         return 0;
 
-    u16 dest = 0;
+    __u16 dest = 0;
     bpf_skb_load_bytes(skb, sizeof(struct iphdr) + offsetof(struct tcphdr, dest), &dest, sizeof(dest));
 
-    if (dest == ntohs(80))
+    if (dest == __constant_ntohs(80))
         *bytes += skb->len;
 
     return 1;