// XCom ULTRA (XCU) - Kernel Layer Logic (eBPF/Rust)
// This is how the "Muscle" handles the 101 modules at the kernel level.

#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>

/**
 * XCU KERNEL INTERCEPTOR (eBPF/XDP)
 * Modul: [xcu.feature.ebpf]
 * 
 * Fungsi: Mem-bypass Network Stack Linux untuk paket video QUIC.
 */

struct tenant_config {
    __u32 allow_av1;
    __u32 allow_moq;
    __u32 active_killswitch;
};

// Map untuk menyimpan konfigurasi tenant dari IAM (diperbarui via lib/quantum-orchestrator.ts)
struct {
    __uint(type, BPF_MAP_TYPE_HASH);
    __uint(max_entries, 1024);
    __type(key, __u32); // Tenant ID Hash
    __type(value, struct tenant_config);
} tenant_matrix_map SEC(".maps");

SEC("xdp_xcu")
int xcu_ingress_handler(struct xdp_md *ctx) {
    void *data_end = (void *)(long)ctx->data_end;
    void *data = (void *)(long)ctx->data;

    // 1. Ambil Tenant ID dari Packet Header (Custom XCU Header)
    __u32 tenant_id = extract_tenant_id(data, data_end);
    
    struct tenant_config *config = bpf_map_lookup_elem(&tenant_matrix_map, &tenant_id);
    if (!config) return XDP_PASS; // Tenant tidak dikenal, gunakan jalur lambat standar.

    // 2. MODUL: [xcu.security.killswitch]
    if (config->active_killswitch) {
        return XDP_DROP; // Paket dibuang langsung di hardware/kernel. Nol latensi, nol beban CPU aplikasi.
    }

    // 3. MODUL: [xcu.transport.moq]
    if (config->allow_moq) {
        // Alihkan paket langsung ke High-Priority Media Queue
        return XDP_REDIRECT; 
    }

    return XDP_PASS;
}

char _license[] SEC("license") = "GPL";