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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/xdp2_kern.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/xdp2_kern.c')
-rw-r--r-- | samples/bpf/xdp2_kern.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/samples/bpf/xdp2_kern.c b/samples/bpf/xdp2_kern.c new file mode 100644 index 000000000..8bca67445 --- /dev/null +++ b/samples/bpf/xdp2_kern.c @@ -0,0 +1,125 @@ +/* Copyright (c) 2016 PLUMgrid + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ +#define KBUILD_MODNAME "foo" +#include <uapi/linux/bpf.h> +#include <linux/in.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/if_vlan.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <bpf/bpf_helpers.h> + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __type(key, u32); + __type(value, long); + __uint(max_entries, 256); +} rxcnt SEC(".maps"); + +static void swap_src_dst_mac(void *data) +{ + unsigned short *p = data; + unsigned short dst[3]; + + dst[0] = p[0]; + dst[1] = p[1]; + dst[2] = p[2]; + p[0] = p[3]; + p[1] = p[4]; + p[2] = p[5]; + p[3] = dst[0]; + p[4] = dst[1]; + p[5] = dst[2]; +} + +static int parse_ipv4(void *data, u64 nh_off, void *data_end) +{ + struct iphdr *iph = data + nh_off; + + if (iph + 1 > data_end) + return 0; + return iph->protocol; +} + +static int parse_ipv6(void *data, u64 nh_off, void *data_end) +{ + struct ipv6hdr *ip6h = data + nh_off; + + if (ip6h + 1 > data_end) + return 0; + return ip6h->nexthdr; +} + +#define XDPBUFSIZE 60 +SEC("xdp.frags") +int xdp_prog1(struct xdp_md *ctx) +{ + __u8 pkt[XDPBUFSIZE] = {}; + void *data_end = &pkt[XDPBUFSIZE-1]; + void *data = pkt; + struct ethhdr *eth = data; + int rc = XDP_DROP; + long *value; + u16 h_proto; + u64 nh_off; + u32 ipproto; + + if (bpf_xdp_load_bytes(ctx, 0, pkt, sizeof(pkt))) + return rc; + + nh_off = sizeof(*eth); + if (data + nh_off > data_end) + return rc; + + h_proto = eth->h_proto; + + /* Handle VLAN tagged packet */ + if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) { + struct vlan_hdr *vhdr; + + vhdr = data + nh_off; + nh_off += sizeof(struct vlan_hdr); + if (data + nh_off > data_end) + return rc; + h_proto = vhdr->h_vlan_encapsulated_proto; + } + /* Handle double VLAN tagged packet */ + if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) { + struct vlan_hdr *vhdr; + + vhdr = data + nh_off; + nh_off += sizeof(struct vlan_hdr); + if (data + nh_off > data_end) + return rc; + h_proto = vhdr->h_vlan_encapsulated_proto; + } + + if (h_proto == htons(ETH_P_IP)) + ipproto = parse_ipv4(data, nh_off, data_end); + else if (h_proto == htons(ETH_P_IPV6)) + ipproto = parse_ipv6(data, nh_off, data_end); + else + ipproto = 0; + + value = bpf_map_lookup_elem(&rxcnt, &ipproto); + if (value) + *value += 1; + + if (ipproto == IPPROTO_UDP) { + swap_src_dst_mac(data); + + if (bpf_xdp_store_bytes(ctx, 0, pkt, sizeof(pkt))) + return rc; + + rc = XDP_TX; + } + + return rc; +} + +char _license[] SEC("license") = "GPL"; |