first commit

xdp/bridge_xdp.c

@@ -0,0 +1,77 @@
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include "bridge_xdp.h"
+
+// Definição local para struct vlan_hdr (caso não esteja disponível)
+#ifndef VLAN_HLEN
+#define VLAN_HLEN 4
+#endif
+
+struct vlan_hdr {
+    __be16 h_vlan_TCI;
+    __be16 h_vlan_encapsulated_proto;
+};
+
+struct {
+    __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+    __uint(max_entries, 1);
+    __type(key, __u32);
+    __type(value, struct packet_stats);
+} stats_map SEC(".maps");
+
+SEC("xdp")
+int bridge_filter(struct xdp_md *ctx)
+{
+    void *data_end = (void *)(long)ctx->data_end;
+    void *data = (void *)(long)ctx->data;
+    struct ethhdr *eth = data;
+    __u16 h_proto;
+    struct iphdr *iph;
+    int action = XDP_PASS;
+    __u32 key = 0;
+    struct packet_stats *stats;
+
+    if ((void*)(eth + 1) > data_end)
+        return XDP_ABORTED;
+
+    h_proto = eth->h_proto;
+
+    // Tráfego broadcast/multicast: libera imediatamente
+    if (eth->h_dest[0] & 1)
+        goto stats;
+
+    // VLAN
+    if (h_proto == bpf_htons(ETH_P_8021Q) || h_proto == bpf_htons(ETH_P_8021AD)) {
+        struct vlan_hdr *vhdr = (void *)(eth + 1);
+        if ((void *)(vhdr + 1) > data_end)
+            return XDP_ABORTED;
+        h_proto = vhdr->h_vlan_encapsulated_proto;
+        iph = (void *)(vhdr + 1);
+    } else {
+        iph = (void *)(eth + 1);
+    }
+
+    // IPv4 local: libera imediatamente
+    if (h_proto == bpf_htons(ETH_P_IP)) {
+        if ((void*)(iph + 1) > data_end)
+            goto stats;
+        if ((iph->daddr & bpf_htonl(0xffff0000)) == bpf_htonl(0x0a0f0000))
+            goto stats;
+    }
+
+    // ...outros filtros podem ser adicionados aqui...
+
+stats:
+    // Atualizar estatísticas apenas uma vez
+    stats = bpf_map_lookup_elem(&stats_map, &key);
+    if (stats) {
+        stats->packets++;
+        stats->bytes += (data_end - data);
+    }
+    return action;
+}
+
+char _license[] SEC("license") = "GPL";