1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2022 Intel */ 3 4 #include <linux/bpf.h> 5 #include <bpf/bpf_helpers.h> 6 #include <linux/if_ether.h> 7 #include "xsk_xdp_common.h" 8 9 struct { 10 __uint(type, BPF_MAP_TYPE_XSKMAP); 11 __uint(max_entries, 2); 12 __uint(key_size, sizeof(int)); 13 __uint(value_size, sizeof(int)); 14 } xsk SEC(".maps"); 15 16 static unsigned int idx; 17 int count = 0; 18 xsk_def_prog(struct xdp_md * xdp)19 SEC("xdp.frags") int xsk_def_prog(struct xdp_md *xdp) 20 { 21 return bpf_redirect_map(&xsk, 0, XDP_DROP); 22 } 23 xsk_xdp_drop(struct xdp_md * xdp)24 SEC("xdp.frags") int xsk_xdp_drop(struct xdp_md *xdp) 25 { 26 /* Drop every other packet */ 27 if (idx++ % 2) 28 return XDP_DROP; 29 30 return bpf_redirect_map(&xsk, 0, XDP_DROP); 31 } 32 xsk_xdp_populate_metadata(struct xdp_md * xdp)33 SEC("xdp.frags") int xsk_xdp_populate_metadata(struct xdp_md *xdp) 34 { 35 void *data, *data_meta; 36 struct xdp_info *meta; 37 int err; 38 39 /* Reserve enough for all custom metadata. */ 40 err = bpf_xdp_adjust_meta(xdp, -(int)sizeof(struct xdp_info)); 41 if (err) 42 return XDP_DROP; 43 44 data = (void *)(long)xdp->data; 45 data_meta = (void *)(long)xdp->data_meta; 46 47 if (data_meta + sizeof(struct xdp_info) > data) 48 return XDP_DROP; 49 50 meta = data_meta; 51 meta->count = count++; 52 53 return bpf_redirect_map(&xsk, 0, XDP_DROP); 54 } 55 xsk_xdp_shared_umem(struct xdp_md * xdp)56 SEC("xdp") int xsk_xdp_shared_umem(struct xdp_md *xdp) 57 { 58 void *data = (void *)(long)xdp->data; 59 void *data_end = (void *)(long)xdp->data_end; 60 struct ethhdr *eth = data; 61 62 if (eth + 1 > data_end) 63 return XDP_DROP; 64 65 /* Redirecting packets based on the destination MAC address */ 66 idx = ((unsigned int)(eth->h_dest[5])) / 2; 67 if (idx > MAX_SOCKETS) 68 return XDP_DROP; 69 70 return bpf_redirect_map(&xsk, idx, XDP_DROP); 71 } 72 73 char _license[] SEC("license") = "GPL"; 74