// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <test_progs.h>
#include <network_helpers.h>
#include "kfree_skb.skel.h"

struct meta {
        int ifindex;
        __u32 cb32_0;
        __u8 cb8_0;
};

static union {
        __u32 cb32[5];
        __u8 cb8[20];
} cb = {
        .cb32[0] = 0x81828384,
};

static void on_sample(void *ctx, int cpu, void *data, __u32 size)
{
        struct meta *meta = (struct meta *)data;
        struct ipv6_packet *pkt_v6 = data + sizeof(*meta);
        int duration = 0;

        if (CHECK(size != 72 + sizeof(*meta), "check_size", "size %u != %zu\n",
                  size, 72 + sizeof(*meta)))
                return;
        if (CHECK(meta->ifindex != 1, "check_meta_ifindex",
                  "meta->ifindex = %d\n", meta->ifindex))
                /* spurious kfree_skb not on loopback device */
                return;
        if (CHECK(meta->cb8_0 != cb.cb8[0], "check_cb8_0", "cb8_0 %x != %x\n",
                  meta->cb8_0, cb.cb8[0]))
                return;
        if (CHECK(meta->cb32_0 != cb.cb32[0], "check_cb32_0",
                  "cb32_0 %x != %x\n",
                  meta->cb32_0, cb.cb32[0]))
                return;
        if (CHECK(pkt_v6->eth.h_proto != htons(ETH_P_IPV6), "check_eth",
                  "h_proto %x\n", pkt_v6->eth.h_proto))
                return;
        if (CHECK(pkt_v6->iph.nexthdr != 6, "check_ip",
                  "iph.nexthdr %x\n", pkt_v6->iph.nexthdr))
                return;
        if (CHECK(pkt_v6->tcp.doff != 5, "check_tcp",
                  "tcp.doff %x\n", pkt_v6->tcp.doff))
                return;

        *(bool *)ctx = true;
}

/* TODO: fix kernel panic caused by this test in parallel mode */
void serial_test_kfree_skb(void)
{
        struct __sk_buff skb = {};
        LIBBPF_OPTS(bpf_test_run_opts, topts,
                .data_in = &pkt_v6,
                .data_size_in = sizeof(pkt_v6),
                .ctx_in = &skb,
                .ctx_size_in = sizeof(skb),
        );
        struct kfree_skb *skel = NULL;
        struct bpf_link *link;
        struct bpf_object *obj;
        struct perf_buffer *pb = NULL;
        int err, prog_fd;
        bool passed = false;
        __u32 duration = 0;
        const int zero = 0;
        bool test_ok[2];

        err = bpf_prog_test_load("./test_pkt_access.bpf.o", BPF_PROG_TYPE_SCHED_CLS,
                                 &obj, &prog_fd);
        if (CHECK(err, "prog_load sched cls", "err %d errno %d\n", err, errno))
                return;

        skel = kfree_skb__open_and_load();
        if (!ASSERT_OK_PTR(skel, "kfree_skb_skel"))
                goto close_prog;

        link = bpf_program__attach_raw_tracepoint(skel->progs.trace_kfree_skb, NULL);
        if (!ASSERT_OK_PTR(link, "attach_raw_tp"))
                goto close_prog;
        skel->links.trace_kfree_skb = link;

        link = bpf_program__attach_trace(skel->progs.fentry_eth_type_trans);
        if (!ASSERT_OK_PTR(link, "attach fentry"))
                goto close_prog;
        skel->links.fentry_eth_type_trans = link;

        link = bpf_program__attach_trace(skel->progs.fexit_eth_type_trans);
        if (!ASSERT_OK_PTR(link, "attach fexit"))
                goto close_prog;
        skel->links.fexit_eth_type_trans = link;

        /* set up perf buffer */
        pb = perf_buffer__new(bpf_map__fd(skel->maps.perf_buf_map), 1,
                              on_sample, NULL, &passed, NULL);
        if (!ASSERT_OK_PTR(pb, "perf_buf__new"))
                goto close_prog;

        memcpy(skb.cb, &cb, sizeof(cb));
        err = bpf_prog_test_run_opts(prog_fd, &topts);
        ASSERT_OK(err, "ipv6 test_run");
        ASSERT_OK(topts.retval, "ipv6 test_run retval");

        /* read perf buffer */
        err = perf_buffer__poll(pb, 100);
        if (CHECK(err < 0, "perf_buffer__poll", "err %d\n", err))
                goto close_prog;

        /* make sure kfree_skb program was triggered
         * and it sent expected skb into ring buffer
         */
        ASSERT_TRUE(passed, "passed");

        err = bpf_map_lookup_elem(bpf_map__fd(skel->maps.bss), &zero, test_ok);
        if (CHECK(err, "get_result",
                  "failed to get output data: %d\n", err))
                goto close_prog;

        CHECK_FAIL(!test_ok[0] || !test_ok[1]);
close_prog:
        perf_buffer__free(pb);
        bpf_object__close(obj);
        kfree_skb__destroy(skel);
}