// SPDX-License-Identifier: GPL-2.0

#include <test_progs.h>
#include <network_helpers.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>

#include "test_tc_qevent.skel.h"

#define NS_TX           "tc_qevent_tx"
#define NS_RX           "tc_qevent_rx"
#define IP_TX           "10.255.0.1"
#define IP_RX           "10.255.0.2"
#define PIN_PATH        "/sys/fs/bpf/tc_qevent_redirect"

static void blast_udp(void)
{
        struct sockaddr_in dst = {};
        char buf[1400] = {};
        int fd, i;

        fd = socket(AF_INET, SOCK_DGRAM, 0);
        if (!ASSERT_GE(fd, 0, "udp socket"))
                return;

        dst.sin_family = AF_INET;
        dst.sin_port = htons(12345);
        inet_pton(AF_INET, IP_RX, &dst.sin_addr);

        /*
         * Push far more than the RED queue can hold. Once qavg crosses qth_min
         * every further packet hits the congestion_drop / early_drop qevent.
         */
        for (i = 0; i < 50000; i++)
                sendto(fd, buf, sizeof(buf), MSG_DONTWAIT,
                       (struct sockaddr *)&dst, sizeof(dst));

        close(fd);
}

static void run_qevent_redirect(struct bpf_program *prog, __u64 *counter)
{
        struct nstoken *tok = NULL;
        int err;

        SYS_NOFAIL("ip netns del %s", NS_TX);
        SYS_NOFAIL("ip netns del %s", NS_RX);
        unlink(PIN_PATH);

        err = bpf_program__pin(prog, PIN_PATH);
        if (!ASSERT_OK(err, "pin prog"))
                return;

        SYS(unpin,  "ip netns add %s", NS_TX);
        SYS(del_tx, "ip netns add %s", NS_RX);
        SYS(del_rx, "ip -n %s link add veth0 type veth peer name veth1 netns %s", NS_TX, NS_RX);
        SYS(del_rx, "ip -n %s addr add %s/24 dev veth0", NS_TX, IP_TX);
        SYS(del_rx, "ip -n %s link set veth0 up", NS_TX);
        SYS(del_rx, "ip -n %s addr add %s/24 dev veth1", NS_RX, IP_RX);
        SYS(del_rx, "ip -n %s link set veth1 up", NS_RX);

        tok = open_netns(NS_TX);
        if (!ASSERT_OK_PTR(tok, "open_netns"))
                goto del_rx;

        SYS(close_ns, "tc qdisc add dev veth0 root handle 1: htb default 1");
        SYS(close_ns, "tc class add dev veth0 parent 1: classid 1:1 htb rate 1mbit ceil 1mbit");

        if (system("tc qdisc add dev veth0 parent 1:1 handle 11: red "
                   "limit 500000 avpkt 1000 probability 1 min 5000 max 6000 "
                   "burst 6 qevent early_drop block 10 2>/dev/null")) {
                test__skip();
                goto close_ns;
        }

        if (system("tc filter add block 10 bpf da object-pinned "
                   PIN_PATH " 2>/dev/null")) {
                test__skip();
                goto close_ns;
        }

        blast_udp();
        ASSERT_GT(*counter, 0, "qevent classifier ran");
close_ns:
        close_netns(tok);
del_rx:
        SYS_NOFAIL("ip netns del %s", NS_RX);
del_tx:
        SYS_NOFAIL("ip netns del %s", NS_TX);
unpin:
        bpf_program__unpin(prog, PIN_PATH);
}

void test_tc_qevent(void)
{
        struct test_tc_qevent *skel;

        skel = test_tc_qevent__open_and_load();
        if (!ASSERT_OK_PTR(skel, "open_and_load"))
                return;

        if (test__start_subtest("redirect_verdict"))
                run_qevent_redirect(skel->progs.qevent_redirect_verdict,
                                    &skel->bss->verdict_calls);
        if (test__start_subtest("redirect_helper"))
                run_qevent_redirect(skel->progs.qevent_redirect_helper,
                                    &skel->bss->helper_calls);

        test_tc_qevent__destroy(skel);
}