root/tools/testing/selftests/bpf/progs/xdp_features.c
// SPDX-License-Identifier: GPL-2.0

#include <stdbool.h>
#include <linux/bpf.h>
#include <linux/netdev.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
#include <bpf/bpf_tracing.h>
#include <linux/if_ether.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/udp.h>
#include <asm-generic/errno-base.h>

#include "xdp_features.h"

#define ipv6_addr_equal(a, b)   ((a).s6_addr32[0] == (b).s6_addr32[0] &&        \
                                 (a).s6_addr32[1] == (b).s6_addr32[1] &&        \
                                 (a).s6_addr32[2] == (b).s6_addr32[2] &&        \
                                 (a).s6_addr32[3] == (b).s6_addr32[3])

struct net_device;
struct bpf_prog;

struct xdp_cpumap_stats {
        unsigned int redirect;
        unsigned int pass;
        unsigned int drop;
};

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __type(key, __u32);
        __type(value, __u32);
        __uint(max_entries, 1);
} stats SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_ARRAY);
        __type(key, __u32);
        __type(value, __u32);
        __uint(max_entries, 1);
} dut_stats SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_CPUMAP);
        __uint(key_size, sizeof(__u32));
        __uint(value_size, sizeof(struct bpf_cpumap_val));
        __uint(max_entries, 1);
} cpu_map SEC(".maps");

struct {
        __uint(type, BPF_MAP_TYPE_DEVMAP);
        __uint(key_size, sizeof(__u32));
        __uint(value_size, sizeof(struct bpf_devmap_val));
        __uint(max_entries, 1);
} dev_map SEC(".maps");

const volatile struct in6_addr tester_addr;
const volatile struct in6_addr dut_addr;

static __always_inline int
xdp_process_echo_packet(struct xdp_md *xdp, bool dut)
{
        void *data_end = (void *)(long)xdp->data_end;
        void *data = (void *)(long)xdp->data;
        struct ethhdr *eh = data;
        struct tlv_hdr *tlv;
        struct udphdr *uh;
        __be16 port;

        if (eh + 1 > (struct ethhdr *)data_end)
                return -EINVAL;

        if (eh->h_proto == bpf_htons(ETH_P_IP)) {
                struct iphdr *ih = (struct iphdr *)(eh + 1);
                __be32 saddr = dut ? tester_addr.s6_addr32[3]
                                   : dut_addr.s6_addr32[3];
                __be32 daddr = dut ? dut_addr.s6_addr32[3]
                                   : tester_addr.s6_addr32[3];

                ih = (struct iphdr *)(eh + 1);
                if (ih + 1 > (struct iphdr *)data_end)
                        return -EINVAL;

                if (saddr != ih->saddr)
                        return -EINVAL;

                if (daddr != ih->daddr)
                        return -EINVAL;

                if (ih->protocol != IPPROTO_UDP)
                        return -EINVAL;

                uh = (struct udphdr *)(ih + 1);
        } else if (eh->h_proto == bpf_htons(ETH_P_IPV6)) {
                struct in6_addr saddr = dut ? tester_addr : dut_addr;
                struct in6_addr daddr = dut ? dut_addr : tester_addr;
                struct ipv6hdr *ih6 = (struct ipv6hdr *)(eh + 1);

                if (ih6 + 1 > (struct ipv6hdr *)data_end)
                        return -EINVAL;

                if (!ipv6_addr_equal(saddr, ih6->saddr))
                        return -EINVAL;

                if (!ipv6_addr_equal(daddr, ih6->daddr))
                        return -EINVAL;

                if (ih6->nexthdr != IPPROTO_UDP)
                        return -EINVAL;

                uh = (struct udphdr *)(ih6 + 1);
        } else {
                return -EINVAL;
        }

        if (uh + 1 > (struct udphdr *)data_end)
                return -EINVAL;

        port = dut ? uh->dest : uh->source;
        if (port != bpf_htons(DUT_ECHO_PORT))
                return -EINVAL;

        tlv = (struct tlv_hdr *)(uh + 1);
        if (tlv + 1 > data_end)
                return -EINVAL;

        return bpf_htons(tlv->type) == CMD_ECHO ? 0 : -EINVAL;
}

static __always_inline int
xdp_update_stats(struct xdp_md *xdp, bool tx, bool dut)
{
        __u32 *val, key = 0;

        if (xdp_process_echo_packet(xdp, tx))
                return -EINVAL;

        if (dut)
                val = bpf_map_lookup_elem(&dut_stats, &key);
        else
                val = bpf_map_lookup_elem(&stats, &key);

        if (val)
                __sync_add_and_fetch(val, 1);

        return 0;
}

/* Tester */

SEC("xdp")
int xdp_tester_check_tx(struct xdp_md *xdp)
{
        xdp_update_stats(xdp, true, false);

        return XDP_PASS;
}

SEC("xdp")
int xdp_tester_check_rx(struct xdp_md *xdp)
{
        xdp_update_stats(xdp, false, false);

        return XDP_PASS;
}

/* DUT */

SEC("xdp")
int xdp_do_pass(struct xdp_md *xdp)
{
        xdp_update_stats(xdp, true, true);

        return XDP_PASS;
}

SEC("xdp")
int xdp_do_drop(struct xdp_md *xdp)
{
        if (xdp_update_stats(xdp, true, true))
                return XDP_PASS;

        return XDP_DROP;
}

SEC("xdp")
int xdp_do_aborted(struct xdp_md *xdp)
{
        if (xdp_process_echo_packet(xdp, true))
                return XDP_PASS;

        return XDP_ABORTED;
}

SEC("xdp")
int xdp_do_tx(struct xdp_md *xdp)
{
        void *data = (void *)(long)xdp->data;
        struct ethhdr *eh = data;
        __u8 tmp_mac[ETH_ALEN];

        if (xdp_update_stats(xdp, true, true))
                return XDP_PASS;

        __builtin_memcpy(tmp_mac, eh->h_source, ETH_ALEN);
        __builtin_memcpy(eh->h_source, eh->h_dest, ETH_ALEN);
        __builtin_memcpy(eh->h_dest, tmp_mac, ETH_ALEN);

        return XDP_TX;
}

SEC("xdp")
int xdp_do_redirect(struct xdp_md *xdp)
{
        if (xdp_process_echo_packet(xdp, true))
                return XDP_PASS;

        return bpf_redirect_map(&cpu_map, 0, 0);
}

SEC("tp_btf/xdp_exception")
int BPF_PROG(xdp_exception, const struct net_device *dev,
             const struct bpf_prog *xdp, __u32 act)
{
        __u32 *val, key = 0;

        val = bpf_map_lookup_elem(&dut_stats, &key);
        if (val)
                __sync_add_and_fetch(val, 1);

        return 0;
}

SEC("tp_btf/xdp_cpumap_kthread")
int BPF_PROG(tp_xdp_cpumap_kthread, int map_id, unsigned int processed,
             unsigned int drops, int sched, struct xdp_cpumap_stats *xdp_stats)
{
        __u32 *val, key = 0;

        val = bpf_map_lookup_elem(&dut_stats, &key);
        if (val)
                __sync_add_and_fetch(val, 1);

        return 0;
}

SEC("xdp/cpumap")
int xdp_do_redirect_cpumap(struct xdp_md *xdp)
{
        void *data = (void *)(long)xdp->data;
        struct ethhdr *eh = data;
        __u8 tmp_mac[ETH_ALEN];

        if (xdp_process_echo_packet(xdp, true))
                return XDP_PASS;

        __builtin_memcpy(tmp_mac, eh->h_source, ETH_ALEN);
        __builtin_memcpy(eh->h_source, eh->h_dest, ETH_ALEN);
        __builtin_memcpy(eh->h_dest, tmp_mac, ETH_ALEN);

        return bpf_redirect_map(&dev_map, 0, 0);
}

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