// SPDX-License-Identifier: GPL-2.0
#include <fcntl.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include "aolib.h"

/*
 * Can't be included in the header: it defines static variables which
 * will be unique to every object. Let's include it only once here.
 */
#include "kselftest.h"

/* Prevent overriding of one thread's output by another */
static pthread_mutex_t ksft_print_lock = PTHREAD_MUTEX_INITIALIZER;

void __test_msg(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_print_msg("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}
void __test_ok(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_test_result_pass("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}
void __test_fail(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_test_result_fail("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}
void __test_xfail(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_test_result_xfail("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}
void __test_error(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_test_result_error("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}
void __test_skip(const char *buf)
{
        pthread_mutex_lock(&ksft_print_lock);
        ksft_test_result_skip("%s", buf);
        pthread_mutex_unlock(&ksft_print_lock);
}

static volatile int failed;
static volatile int skipped;

void test_failed(void)
{
        failed = 1;
}

static void test_exit(void)
{
        if (failed) {
                ksft_exit_fail();
        } else if (skipped) {
                /* ksft_exit_skip() is different from ksft_exit_*() */
                ksft_print_cnts();
                exit(KSFT_SKIP);
        } else {
                ksft_exit_pass();
        }
}

struct dlist_t {
        void (*destruct)(void);
        struct dlist_t *next;
};
static struct dlist_t *destructors_list;

void test_add_destructor(void (*d)(void))
{
        struct dlist_t *p;

        p = malloc(sizeof(struct dlist_t));
        if (p == NULL)
                test_error("malloc() failed");

        p->next = destructors_list;
        p->destruct = d;
        destructors_list = p;
}

static void test_destructor(void) __attribute__((destructor));
static void test_destructor(void)
{
        while (destructors_list) {
                struct dlist_t *p = destructors_list->next;

                destructors_list->destruct();
                free(destructors_list);
                destructors_list = p;
        }
        test_exit();
}

static void sig_int(int signo)
{
        test_error("Caught SIGINT - exiting");
}

int open_netns(void)
{
        const char *netns_path = "/proc/thread-self/ns/net";
        int fd;

        fd = open(netns_path, O_RDONLY);
        if (fd < 0)
                test_error("open(%s)", netns_path);
        return fd;
}

int unshare_open_netns(void)
{
        if (unshare(CLONE_NEWNET) != 0)
                test_error("unshare()");

        return open_netns();
}

void switch_ns(int fd)
{
        if (setns(fd, CLONE_NEWNET))
                test_error("setns()");
}

int switch_save_ns(int new_ns)
{
        int ret = open_netns();

        switch_ns(new_ns);
        return ret;
}

void switch_close_ns(int fd)
{
        if (setns(fd, CLONE_NEWNET))
                test_error("setns()");
        close(fd);
}

static int nsfd_outside = -1;
static int nsfd_parent  = -1;
static int nsfd_child   = -1;
const char veth_name[]  = "ktst-veth";

static void init_namespaces(void)
{
        nsfd_outside = open_netns();
        nsfd_parent = unshare_open_netns();
        nsfd_child = unshare_open_netns();
}

static void link_init(const char *veth, int family, uint8_t prefix,
                      union tcp_addr addr, union tcp_addr dest)
{
        if (link_set_up(veth))
                test_error("Failed to set link up");
        if (ip_addr_add(veth, family, addr, prefix))
                test_error("Failed to add ip address");
        if (ip_route_add(veth, family, addr, dest))
                test_error("Failed to add route");
}

static unsigned int nr_threads = 1;

static pthread_mutex_t sync_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t sync_cond = PTHREAD_COND_INITIALIZER;
static volatile unsigned int stage_threads[2];
static volatile unsigned int stage_nr;

/* synchronize all threads in the same stage */
void synchronize_threads(void)
{
        unsigned int q = stage_nr;

        pthread_mutex_lock(&sync_lock);
        stage_threads[q]++;
        if (stage_threads[q] == nr_threads) {
                stage_nr ^= 1;
                stage_threads[stage_nr] = 0;
                pthread_cond_signal(&sync_cond);
        }
        while (stage_threads[q] < nr_threads)
                pthread_cond_wait(&sync_cond, &sync_lock);
        pthread_mutex_unlock(&sync_lock);
}

__thread union tcp_addr this_ip_addr;
__thread union tcp_addr this_ip_dest;
int test_family;

struct new_pthread_arg {
        thread_fn       func;
        union tcp_addr  my_ip;
        union tcp_addr  dest_ip;
};
static void *new_pthread_entry(void *arg)
{
        struct new_pthread_arg *p = arg;

        this_ip_addr = p->my_ip;
        this_ip_dest = p->dest_ip;
        p->func(NULL); /* shouldn't return */
        exit(KSFT_FAIL);
}

static void __test_skip_all(const char *msg)
{
        ksft_set_plan(1);
        ksft_print_header();
        skipped = 1;
        test_skip("%s", msg);
        exit(KSFT_SKIP);
}

void __test_init(unsigned int ntests, int family, unsigned int prefix,
                 union tcp_addr addr1, union tcp_addr addr2,
                 thread_fn peer1, thread_fn peer2)
{
        struct sigaction sa = {
                .sa_handler = sig_int,
                .sa_flags = SA_RESTART,
        };
        time_t seed = time(NULL);

        sigemptyset(&sa.sa_mask);
        if (sigaction(SIGINT, &sa, NULL))
                test_error("Can't set SIGINT handler");

        test_family = family;
        if (!kernel_config_has(KCONFIG_NET_NS))
                __test_skip_all(tests_skip_reason[KCONFIG_NET_NS]);
        if (!kernel_config_has(KCONFIG_VETH))
                __test_skip_all(tests_skip_reason[KCONFIG_VETH]);
        if (!kernel_config_has(KCONFIG_TCP_AO))
                __test_skip_all(tests_skip_reason[KCONFIG_TCP_AO]);

        ksft_set_plan(ntests);
        test_print("rand seed %u", (unsigned int)seed);
        srand(seed);

        ksft_print_header();
        init_namespaces();
        test_init_ftrace(nsfd_parent, nsfd_child);

        if (add_veth(veth_name, nsfd_parent, nsfd_child))
                test_error("Failed to add veth");

        switch_ns(nsfd_child);
        link_init(veth_name, family, prefix, addr2, addr1);
        if (peer2) {
                struct new_pthread_arg targ;
                pthread_t t;

                targ.my_ip = addr2;
                targ.dest_ip = addr1;
                targ.func = peer2;
                nr_threads++;
                if (pthread_create(&t, NULL, new_pthread_entry, &targ))
                        test_error("Failed to create pthread");
        }
        switch_ns(nsfd_parent);
        link_init(veth_name, family, prefix, addr1, addr2);

        this_ip_addr = addr1;
        this_ip_dest = addr2;
        peer1(NULL);
        if (failed)
                exit(KSFT_FAIL);
        else
                exit(KSFT_PASS);
}

/* /proc/sys/net/core/optmem_max artifically limits the amount of memory
 * that can be allocated with sock_kmalloc() on each socket in the system.
 * It is not virtualized in v6.7, so it has to written outside test
 * namespaces. To be nice a test will revert optmem back to the old value.
 * Keeping it simple without any file lock, which means the tests that
 * need to set/increase optmem value shouldn't run in parallel.
 * Also, not re-entrant.
 * Since commit f5769faeec36 ("net: Namespace-ify sysctl_optmem_max")
 * it is per-namespace, keeping logic for non-virtualized optmem_max
 * for v6.7, which supports TCP-AO.
 */
static const char *optmem_file = "/proc/sys/net/core/optmem_max";
static size_t saved_optmem;
static int optmem_ns = -1;

static bool is_optmem_namespaced(void)
{
        if (optmem_ns == -1) {
                int old_ns = switch_save_ns(nsfd_child);

                optmem_ns = !access(optmem_file, F_OK);
                switch_close_ns(old_ns);
        }
        return !!optmem_ns;
}

size_t test_get_optmem(void)
{
        int old_ns = 0;
        FILE *foptmem;
        size_t ret;

        if (!is_optmem_namespaced())
                old_ns = switch_save_ns(nsfd_outside);
        foptmem = fopen(optmem_file, "r");
        if (!foptmem)
                test_error("failed to open %s", optmem_file);

        if (fscanf(foptmem, "%zu", &ret) != 1)
                test_error("can't read from %s", optmem_file);
        fclose(foptmem);
        if (!is_optmem_namespaced())
                switch_close_ns(old_ns);
        return ret;
}

static void __test_set_optmem(size_t new, size_t *old)
{
        int old_ns = 0;
        FILE *foptmem;

        if (old != NULL)
                *old = test_get_optmem();

        if (!is_optmem_namespaced())
                old_ns = switch_save_ns(nsfd_outside);
        foptmem = fopen(optmem_file, "w");
        if (!foptmem)
                test_error("failed to open %s", optmem_file);

        if (fprintf(foptmem, "%zu", new) <= 0)
                test_error("can't write %zu to %s", new, optmem_file);
        fclose(foptmem);
        if (!is_optmem_namespaced())
                switch_close_ns(old_ns);
}

static void test_revert_optmem(void)
{
        if (saved_optmem == 0)
                return;

        __test_set_optmem(saved_optmem, NULL);
}

void test_set_optmem(size_t value)
{
        if (saved_optmem == 0) {
                __test_set_optmem(value, &saved_optmem);
                test_add_destructor(test_revert_optmem);
        } else {
                __test_set_optmem(value, NULL);
        }
}