xdp: Fix wrong UDP checksum in proxied GTPv1U packets

For now mark checksum as 0 to avoid transmitting with a wrong checksum, which would drop the packets at the receiver.
edgecomllc · Nov 14, 2024 · d5cf5ba · d5cf5ba
1 parent 0b596a2
commit d5cf5ba
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/cmd/ebpf/xdp/utils/gtp_utils.h b/cmd/ebpf/xdp/utils/gtp_utils.h
@@ -253,4 +253,10 @@ static __always_inline void update_gtp_tunnel(struct packet_context *ctx, int sr
     ctx->ip4->daddr = dstip;
     ctx->ip4->check = 0;
     ctx->ip4->check = ipv4_csum(ctx->ip4, sizeof(*ctx->ip4));
+    ctx->udp->check = 0;
+    /* TODO: Implement UDP csum:
+     * cs = 0;
+     * ipv4_l4_csum(udp, sizeof(*udp), &cs, iph);
+     * udp->check = cs;
+     */
 }