Modifications as per feedback

Signed-off-by: David-VTUK <david.holder@gmail.com>

Author: David-VTUK

xdp-bpf2go-example/.gitignore

@@ -1 +1,3 @@
-xdp-bpf2go-example
+xdp-bpf2go-example
+**bpfeb.go
+**bpfel.go

xdp-bpf2go-example/main.go

@@ -14,6 +14,11 @@ import (
 )
 
 func main() {
+	// Check if running as root
+	if os.Geteuid() != 0 {
+		log.Fatal("This program must be run as root!")
+	}
+
 	// Remove resource limits for kernels <5.11.
 	if err := rlimit.RemoveMemlock(); err != nil {
 		log.Fatal("Removing memlock:", err)
@@ -26,7 +31,12 @@ func main() {
 	}
 	defer objs.Close()
 
-	ifname := "eno2" // Change this to an interface on your machine.
+	// Capture user input from command-line arguments
+	if len(os.Args) < 2 {
+		log.Fatal("Please provide a network interface name as an argument")
+	}
+	ifname := os.Args[1] // Get the interface name from the first argument
+
 	iface, err := net.InterfaceByName(ifname)
 	if err != nil {
 		log.Fatalf("Getting interface %s: %s", ifname, err)
@@ -50,7 +60,6 @@ func main() {
 	for {
 		select {
 		case <-tick:
-			//    log.Print(objs.ProtocolCount)
 			printMap(objs.ProtocolCount)
 			if err != nil {
 				log.Fatal("Map lookup:", err)

xdp-bpf2go-example/packetProtocol.c

@@ -4,6 +4,7 @@
 #include <bpf/bpf_helpers.h>
 #include <linux/if_ether.h>
 #include <linux/ip.h>
+#include <bpf/bpf_endian.h>
 
 struct{
   __uint(type, BPF_MAP_TYPE_ARRAY);
@@ -17,30 +18,28 @@ int get_packet_protocol(struct xdp_md *ctx) {
 
   void *data_end = (void *)(long)ctx->data_end;
   void *data = (void *)(long)ctx->data;
+  struct ethhdr *eth = data;
+  struct iphdr *ip = data + sizeof(struct ethhdr);
+  __u32 key = ip->protocol; // Using IP protocol as the key
+  __u64 *count = bpf_map_lookup_elem(&protocol_count, &key);
 
   // Parse Ethernet header
-  struct ethhdr *eth = data;
-  if ((void *)(eth + 1) > data_end) {
+  if ((void *)(eth + 1) > data_end) 
     return XDP_PASS;
-  }
 
   // Check if the packet is an IP packet
-  if (eth->h_proto != __constant_htons(ETH_P_IP)) {
+  if (eth->h_proto != bpf_htons(ETH_P_IP)) {
     return XDP_PASS;
   }
 
   // Parse IP header
-  struct iphdr *ip = data + sizeof(struct ethhdr);
   if ((void *)(ip + 1) > data_end) {
     return XDP_PASS;
   }
 
-  __u32 key = ip->protocol; // Using IP protocol as the key
-  __u64 *count = bpf_map_lookup_elem(&protocol_count, &key);
-  if (count) {
+  if (count) 
     __sync_fetch_and_add(count, 1);
-  }
-
+  
   return XDP_PASS;
 }