Bpf refactoring

.clang-format

@@ -1,4 +1,7 @@
 ---
+Language: Cpp
+BasedOnStyle: LLVM
+
 # Use tabs for indentation
 UseTab: Always
 TabWidth: 4

src/main.c → bpf/bpf_dns.c

@@ -11,8 +11,9 @@
 #include <bpf/bpf_endian.h>
 #include <bpf/bpf_helpers.h>
 
-#include "dns.h"
-#include "xdp_map.h"
+#include "lib/dns.h"
+#include "lib/consts.h"
+#include "lib/maps.h"
 
 #define memcpy __builtin_memcpy
 
@@ -167,14 +168,14 @@ static int parse_dns_query(struct xdp_md *ctx, void *query_start,
 	// Fill dns_query.name with zero bytes
 	// Not doing so will make the verifier complain when dns_query is used as a
 	// key in bpf_map_lookup
-	for (i = 0; i < MAX_DNS_NAME_LENGTH; i++) {
+	for (i = 0; i < MAX_DNS_NAME_LEN; i++) {
 		q->name[i] = 0;
 	}
 	// Fill record_type and class with default values to satisfy verifier
 	q->record_type = 0;
 	q->record_class = 0;
 
-	for (i = 0; i < MAX_DNS_NAME_LENGTH; i++) {
+	for (i = 0; i < MAX_DNS_NAME_LEN; i++) {
 		// Boundary check of cursor. Verifier requires a +1 here.
 		// Probably because we are advancing the pointer at the end of the loop
 		if (cursor + 1 > data_end) {

src/xdp_struct.h → bpf/lib/client.h

@@ -1,5 +1,5 @@
-#ifndef __XDP_STRUCTS_H
-#define __XDP_STRUCTS_H
+#ifndef __LIB_CLIENT_H
+#define __LIB_CLIENT_H
 
 #include <linux/in6.h>
 #include <linux/types.h>

src/xdp_consts.h → bpf/lib/consts.h

@@ -1,9 +1,9 @@
-#ifndef __XDP_CONSTS_H
-#define __XDP_CONSTS_H
+#ifndef __LIB_CONSTS_H
+#define __LIB_CONSTS_H
 
 #define MAX_MAP_ENTRIES 1024
 #define MAX_SEGMENTLIST_ENTRIES 10
-#define MAX_DOMAIN_NAME_LEN 256
+#define MAX_DNS_NAME_LEN 256
 
 #define UDP_P_DNS 53
 

src/dns.h → bpf/lib/dns.h

@@ -1,9 +1,9 @@
-#ifndef __DNS_H
-#define __DNS_H
+#ifndef __LIB_DNS_H
+#define __LIB_DNS_H
 
 #include <linux/in6.h>
 
-#define MAX_DNS_NAME_LENGTH 256
+#include "consts.h"
 
 struct dns_hdr {
 	__u16 transaction_id;
@@ -26,7 +26,7 @@ struct dns_hdr {
 struct dns_query {
 	__u16 record_type;
 	__u16 record_class;
-	char name[MAX_DNS_NAME_LENGTH];
+	char name[MAX_DNS_NAME_LEN];
 } __attribute__((packed));
 
 struct dns_answer {

src/xdp_map.h → bpf/lib/maps.h

@@ -1,7 +1,7 @@
-#ifndef __XDP_MAPS_H
-#define __XDP_MAPS_H
-#include "xdp_consts.h"
-#include "xdp_struct.h"
+#ifndef __LIB_MAPS_H
+#define __LIB_MAPS_H
+#include "client.h"
+#include "consts.h"
 #include <bpf/bpf_endian.h>
 #include <bpf/bpf_helpers.h>
 #include <linux/bpf.h>
@@ -10,7 +10,7 @@
 struct {
 	__uint(type, BPF_MAP_TYPE_LRU_HASH);
 	__uint(max_entries, MAX_MAP_ENTRIES);
-	__type(key, char[MAX_DOMAIN_NAME_LEN]);
+	__type(key, char[MAX_DNS_NAME_LEN]);
 	__type(value, struct client_data);
 } client_map SEC(".maps");
 

pkg/bpf/bpf.go

@@ -8,7 +8,7 @@ import (
 	"github.com/cilium/ebpf"
 )
 
-//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -no-global-types -cc $BPF_CLANG -cflags $BPF_CFLAGS bpf ../../src/main.c -- -I../../src
+//go:generate go run github.com/cilium/ebpf/cmd/bpf2go -no-global-types -cc $BPF_CLANG -cflags $BPF_CFLAGS bpf ../../bpf/bpf_dns.c -- -I../../bpf
 
 type ClientData struct {
 	DstPort  uint16