ebpf do not allow to read a static array with a variable

ubuntu_intermediate/inter_op_ebpf.c

@@ -6,7 +6,7 @@
 
 #define SUBNET_BASE __constant_htonl(0xAC103C00)
 #define REPLACE_PROBABILITY 90
-const __be32 ALTERNATE_IPS[] = {__constant_htonl(0x7B640202)};
+const __be32 ALTERNATE_IPS[] = {__constant_htonl(0x7B640202), __constant_htonl(0x7B640303)};
 
 #define NUM_ALTERNATE_IPS (sizeof(ALTERNATE_IPS) / sizeof(ALTERNATE_IPS[0]))
 BPF_ARRAY(alt_ip_index, __u32, 1); // Single-element array to store index
@@ -295,7 +295,14 @@ int inter_op_ebpf(struct xdp_md *ctx)
             {
                 // Replace destination IP
                 __u32 original_ip = ip->daddr;
-                __u32 new_ip = ALTERNATE_IPS[current_index];
+                __u32 new_ip;
+                
+                for (int i = 0; i < NUM_ALTERNATE_IPS; i++) {
+                    if (i == current_index) {
+                        new_ip = ALTERNATE_IPS[i];  // Verifier allows (unrolled)
+                    }
+                }
+
                 ip->daddr = new_ip;
 
                 // Optional: log the replacement