// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */

#define _GNU_SOURCE
#include <test_progs.h>
#include "test_ns_current_pid_tgid.skel.h"
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <sched.h>
#include <sys/wait.h>
#include <sys/mount.h>
#include <fcntl.h>
#include "network_helpers.h"

#define STACK_SIZE (1024 * 1024)
static char child_stack[STACK_SIZE];

static int get_pid_tgid(pid_t *pid, pid_t *tgid,
                        struct test_ns_current_pid_tgid__bss *bss)
{
        struct stat st;
        int err;

        *pid = sys_gettid();
        *tgid = getpid();

        err = stat("/proc/self/ns/pid", &st);
        if (!ASSERT_OK(err, "stat /proc/self/ns/pid"))
                return err;

        bss->dev = st.st_dev;
        bss->ino = st.st_ino;
        bss->user_pid = 0;
        bss->user_tgid = 0;
        return 0;
}

static int test_current_pid_tgid_tp(void *args)
{
        struct test_ns_current_pid_tgid__bss  *bss;
        struct test_ns_current_pid_tgid *skel;
        int ret = -1, err;
        pid_t tgid, pid;

        skel = test_ns_current_pid_tgid__open();
        if (!ASSERT_OK_PTR(skel, "test_ns_current_pid_tgid__open"))
                return ret;

        bpf_program__set_autoload(skel->progs.tp_handler, true);

        err = test_ns_current_pid_tgid__load(skel);
        if (!ASSERT_OK(err, "test_ns_current_pid_tgid__load"))
                goto cleanup;

        bss = skel->bss;
        if (get_pid_tgid(&pid, &tgid, bss))
                goto cleanup;

        err = test_ns_current_pid_tgid__attach(skel);
        if (!ASSERT_OK(err, "test_ns_current_pid_tgid__attach"))
                goto cleanup;

        /* trigger tracepoint */
        usleep(1);
        if (!ASSERT_EQ(bss->user_pid, pid, "pid"))
                goto cleanup;
        if (!ASSERT_EQ(bss->user_tgid, tgid, "tgid"))
                goto cleanup;
        ret = 0;

cleanup:
        test_ns_current_pid_tgid__destroy(skel);
        return ret;
}

static int test_current_pid_tgid_cgrp(void *args)
{
        struct test_ns_current_pid_tgid__bss *bss;
        struct test_ns_current_pid_tgid *skel;
        int server_fd = -1, ret = -1, err;
        int cgroup_fd = *(int *)args;
        pid_t tgid, pid;

        skel = test_ns_current_pid_tgid__open();
        if (!ASSERT_OK_PTR(skel, "test_ns_current_pid_tgid__open"))
                return ret;

        bpf_program__set_autoload(skel->progs.cgroup_bind4, true);

        err = test_ns_current_pid_tgid__load(skel);
        if (!ASSERT_OK(err, "test_ns_current_pid_tgid__load"))
                goto cleanup;

        bss = skel->bss;
        if (get_pid_tgid(&pid, &tgid, bss))
                goto cleanup;

        skel->links.cgroup_bind4 = bpf_program__attach_cgroup(
                skel->progs.cgroup_bind4, cgroup_fd);
        if (!ASSERT_OK_PTR(skel->links.cgroup_bind4, "bpf_program__attach_cgroup"))
                goto cleanup;

        server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
        if (!ASSERT_GE(server_fd, 0, "start_server"))
                goto cleanup;

        if (!ASSERT_EQ(bss->user_pid, pid, "pid"))
                goto cleanup;
        if (!ASSERT_EQ(bss->user_tgid, tgid, "tgid"))
                goto cleanup;
        ret = 0;

cleanup:
        if (server_fd >= 0)
                close(server_fd);
        test_ns_current_pid_tgid__destroy(skel);
        return ret;
}

static int test_current_pid_tgid_sk_msg(void *args)
{
        int verdict, map, server_fd = -1, client_fd = -1;
        struct test_ns_current_pid_tgid__bss *bss;
        static const char send_msg[] = "message";
        struct test_ns_current_pid_tgid *skel;
        int ret = -1, err, key = 0;
        pid_t tgid, pid;

        skel = test_ns_current_pid_tgid__open();
        if (!ASSERT_OK_PTR(skel, "test_ns_current_pid_tgid__open"))
                return ret;

        bpf_program__set_autoload(skel->progs.sk_msg, true);

        err = test_ns_current_pid_tgid__load(skel);
        if (!ASSERT_OK(err, "test_ns_current_pid_tgid__load"))
                goto cleanup;

        bss = skel->bss;
        if (get_pid_tgid(&pid, &tgid, skel->bss))
                goto cleanup;

        verdict = bpf_program__fd(skel->progs.sk_msg);
        map = bpf_map__fd(skel->maps.sock_map);
        err = bpf_prog_attach(verdict, map, BPF_SK_MSG_VERDICT, 0);
        if (!ASSERT_OK(err, "prog_attach"))
                goto cleanup;

        server_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
        if (!ASSERT_GE(server_fd, 0, "start_server"))
                goto cleanup;

        client_fd = connect_to_fd(server_fd, 0);
        if (!ASSERT_GE(client_fd, 0, "connect_to_fd"))
                goto cleanup;

        err = bpf_map_update_elem(map, &key, &client_fd, BPF_ANY);
        if (!ASSERT_OK(err, "bpf_map_update_elem"))
                goto cleanup;

        err = send(client_fd, send_msg, sizeof(send_msg), 0);
        if (!ASSERT_EQ(err, sizeof(send_msg), "send(msg)"))
                goto cleanup;

        if (!ASSERT_EQ(bss->user_pid, pid, "pid"))
                goto cleanup;
        if (!ASSERT_EQ(bss->user_tgid, tgid, "tgid"))
                goto cleanup;
        ret = 0;

cleanup:
        if (server_fd >= 0)
                close(server_fd);
        if (client_fd >= 0)
                close(client_fd);
        test_ns_current_pid_tgid__destroy(skel);
        return ret;
}

static void test_ns_current_pid_tgid_new_ns(int (*fn)(void *), void *arg)
{
        int wstatus;
        pid_t cpid;

        /* Create a process in a new namespace, this process
         * will be the init process of this new namespace hence will be pid 1.
         */
        cpid = clone(fn, child_stack + STACK_SIZE,
                     CLONE_NEWPID | SIGCHLD, arg);

        if (!ASSERT_NEQ(cpid, -1, "clone"))
                return;

        if (!ASSERT_NEQ(waitpid(cpid, &wstatus, 0), -1, "waitpid"))
                return;

        if (!ASSERT_OK(WEXITSTATUS(wstatus), "newns_pidtgid"))
                return;
}

/* TODO: use a different tracepoint */
void serial_test_current_pid_tgid(void)
{
        if (test__start_subtest("root_ns_tp"))
                test_current_pid_tgid_tp(NULL);
        if (test__start_subtest("new_ns_tp"))
                test_ns_current_pid_tgid_new_ns(test_current_pid_tgid_tp, NULL);
}

void test_ns_current_pid_tgid_cgrp(void)
{
        int cgroup_fd = test__join_cgroup("/sock_addr");

        if (ASSERT_OK_FD(cgroup_fd, "join_cgroup")) {
                test_ns_current_pid_tgid_new_ns(test_current_pid_tgid_cgrp, &cgroup_fd);
                close(cgroup_fd);
        }
}

void test_ns_current_pid_tgid_sk_msg(void)
{
        test_ns_current_pid_tgid_new_ns(test_current_pid_tgid_sk_msg, NULL);
}