// SPDX-License-Identifier: GPL-2.0
#include <dirent.h>
#include <stdlib.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <api/fs/fs.h>
#include "dso.h"
#include "dsos.h"
#include "machine.h"
#include "symbol.h"
#include "tests.h"
#include "debug.h"

static char *test_file(int size)
{
#define TEMPL "/tmp/perf-test-XXXXXX"
        static char buf_templ[sizeof(TEMPL)];
        char *templ = buf_templ;
        int fd, i;
        unsigned char *buf;

        strcpy(buf_templ, TEMPL);
#undef TEMPL

        fd = mkstemp(templ);
        if (fd < 0) {
                perror("mkstemp failed");
                return NULL;
        }

        buf = malloc(size);
        if (!buf) {
                close(fd);
                return NULL;
        }

        for (i = 0; i < size; i++)
                buf[i] = (unsigned char) ((int) i % 10);

        if (size != write(fd, buf, size))
                templ = NULL;

        free(buf);
        close(fd);
        return templ;
}

#define TEST_FILE_SIZE (DSO__DATA_CACHE_SIZE * 20)

struct test_data_offset {
        off_t offset;
        u8 data[10];
        int size;
};

struct test_data_offset offsets[] = {
        /* Fill first cache page. */
        {
                .offset = 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Read first cache page. */
        {
                .offset = 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Fill cache boundary pages. */
        {
                .offset = DSO__DATA_CACHE_SIZE - DSO__DATA_CACHE_SIZE % 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Read cache boundary pages. */
        {
                .offset = DSO__DATA_CACHE_SIZE - DSO__DATA_CACHE_SIZE % 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Fill final cache page. */
        {
                .offset = TEST_FILE_SIZE - 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Read final cache page. */
        {
                .offset = TEST_FILE_SIZE - 10,
                .data   = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 },
                .size   = 10,
        },
        /* Read final cache page. */
        {
                .offset = TEST_FILE_SIZE - 3,
                .data   = { 7, 8, 9, 0, 0, 0, 0, 0, 0, 0 },
                .size   = 3,
        },
};

/* move it from util/dso.c for compatibility */
static int dso__data_fd(struct dso *dso, struct machine *machine)
{
        int fd = -1;

        if (dso__data_get_fd(dso, machine, &fd))
                dso__data_put_fd(dso);

        return fd;
}

static void dsos__delete(struct dsos *dsos)
{
        for (unsigned int i = 0; i < dsos->cnt; i++) {
                struct dso *dso = dsos->dsos[i];

                dso__data_close(dso);
                unlink(dso__name(dso));
        }
        dsos__exit(dsos);
}

static int test__dso_data(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
        struct machine machine;
        struct dso *dso;
        char *file = test_file(TEST_FILE_SIZE);
        size_t i;

        TEST_ASSERT_VAL("No test file", file);

        memset(&machine, 0, sizeof(machine));
        dsos__init(&machine.dsos);

        dso = dso__new(file);
        TEST_ASSERT_VAL("Failed to add dso", !dsos__add(&machine.dsos, dso));
        TEST_ASSERT_VAL("Failed to access to dso",
                        dso__data_fd(dso, &machine) >= 0);

        /* Basic 10 bytes tests. */
        for (i = 0; i < ARRAY_SIZE(offsets); i++) {
                struct test_data_offset *data = &offsets[i];
                ssize_t size;
                u8 buf[10];

                memset(buf, 0, 10);
                size = dso__data_read_offset(dso, &machine, data->offset,
                                     buf, 10);

                TEST_ASSERT_VAL("Wrong size", size == data->size);
                TEST_ASSERT_VAL("Wrong data", !memcmp(buf, data->data, 10));
        }

        /* Read cross multiple cache pages. */
        {
                ssize_t size;
                int c;
                u8 *buf;

                buf = malloc(TEST_FILE_SIZE);
                TEST_ASSERT_VAL("ENOMEM\n", buf);

                /* First iteration to fill caches, second one to read them. */
                for (c = 0; c < 2; c++) {
                        memset(buf, 0, TEST_FILE_SIZE);
                        size = dso__data_read_offset(dso, &machine, 10,
                                                     buf, TEST_FILE_SIZE);

                        TEST_ASSERT_VAL("Wrong size",
                                size == (TEST_FILE_SIZE - 10));

                        for (i = 0; i < (size_t)size; i++)
                                TEST_ASSERT_VAL("Wrong data",
                                        buf[i] == (i % 10));
                }

                free(buf);
        }

        dso__put(dso);
        dsos__delete(&machine.dsos);
        unlink(file);
        return 0;
}

static long open_files_cnt(void)
{
        char path[PATH_MAX];
        struct dirent *dent;
        DIR *dir;
        long nr = 0;

        scnprintf(path, PATH_MAX, "%s/self/fd", procfs__mountpoint());
        pr_debug("fd path: %s\n", path);

        dir = opendir(path);
        TEST_ASSERT_VAL("failed to open fd directory", dir);

        while ((dent = readdir(dir)) != NULL) {
                if (!strcmp(dent->d_name, ".") ||
                    !strcmp(dent->d_name, ".."))
                        continue;

                nr++;
        }

        closedir(dir);
        return nr - 1;
}

static int dsos__create(int cnt, int size, struct dsos *dsos)
{
        int i;

        dsos__init(dsos);

        for (i = 0; i < cnt; i++) {
                struct dso *dso;
                char *file = test_file(size);

                TEST_ASSERT_VAL("failed to get dso file", file);
                dso = dso__new(file);
                TEST_ASSERT_VAL("failed to get dso", dso);
                TEST_ASSERT_VAL("failed to add dso", !dsos__add(dsos, dso));
                dso__put(dso);
        }

        return 0;
}

static int set_fd_limit(int n)
{
        struct rlimit rlim;

        if (getrlimit(RLIMIT_NOFILE, &rlim))
                return -1;

        pr_debug("file limit %ld, new %d\n", (long) rlim.rlim_cur, n);

        rlim.rlim_cur = n;
        return setrlimit(RLIMIT_NOFILE, &rlim);
}

static int test__dso_data_cache(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
        struct machine machine;
        long nr_end, nr = open_files_cnt();
        int dso_cnt, limit, i, fd;

        /* Rest the internal dso open counter limit. */
        reset_fd_limit();

        memset(&machine, 0, sizeof(machine));

        /* set as system limit */
        limit = nr * 4;
        TEST_ASSERT_VAL("failed to set file limit", !set_fd_limit(limit));

        /* and this is now our dso open FDs limit */
        dso_cnt = limit / 2;
        TEST_ASSERT_VAL("failed to create dsos\n",
                        !dsos__create(dso_cnt, TEST_FILE_SIZE, &machine.dsos));

        for (i = 0; i < (dso_cnt - 1); i++) {
                struct dso *dso = machine.dsos.dsos[i];

                /*
                 * Open dsos via dso__data_fd(), it opens the data
                 * file and keep it open (unless open file limit).
                 */
                fd = dso__data_fd(dso, &machine);
                TEST_ASSERT_VAL("failed to get fd", fd > 0);

                if (i % 2) {
                        #define BUFSIZE 10
                        u8 buf[BUFSIZE];
                        ssize_t n;

                        n = dso__data_read_offset(dso, &machine, 0, buf, BUFSIZE);
                        TEST_ASSERT_VAL("failed to read dso", n == BUFSIZE);
                }
        }

        /* verify the first one is already open */
        TEST_ASSERT_VAL("dsos[0] is not open", dso__data(machine.dsos.dsos[0])->fd != -1);

        /* open +1 dso to reach the allowed limit */
        fd = dso__data_fd(machine.dsos.dsos[i], &machine);
        TEST_ASSERT_VAL("failed to get fd", fd > 0);

        /* should force the first one to be closed */
        TEST_ASSERT_VAL("failed to close dsos[0]", dso__data(machine.dsos.dsos[0])->fd == -1);

        /* cleanup everything */
        dsos__delete(&machine.dsos);

        /* Make sure we did not leak any file descriptor. */
        nr_end = open_files_cnt();
        pr_debug("nr start %ld, nr stop %ld\n", nr, nr_end);
        TEST_ASSERT_VAL("failed leaking files", nr == nr_end);
        return 0;
}

static long new_limit(int count)
{
        int fd = open("/dev/null", O_RDONLY);
        long ret = fd;
        if (count > 0)
                ret = new_limit(--count);
        close(fd);
        return ret;
}

static int test__dso_data_reopen(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
        struct machine machine;
        long nr_end, nr = open_files_cnt(), lim = new_limit(3);
        int fd, fd_extra;

#define dso_0 (machine.dsos.dsos[0])
#define dso_1 (machine.dsos.dsos[1])
#define dso_2 (machine.dsos.dsos[2])

        /* Rest the internal dso open counter limit. */
        reset_fd_limit();

        memset(&machine, 0, sizeof(machine));

        /*
         * Test scenario:
         * - create 3 dso objects
         * - set process file descriptor limit to current
         *   files count + 3
         * - test that the first dso gets closed when we
         *   reach the files count limit
         */

        /* Make sure we are able to open 3 fds anyway */
        TEST_ASSERT_VAL("failed to set file limit",
                        !set_fd_limit((lim)));

        TEST_ASSERT_VAL("failed to create dsos\n",
                        !dsos__create(3, TEST_FILE_SIZE, &machine.dsos));

        /* open dso_0 */
        fd = dso__data_fd(dso_0, &machine);
        TEST_ASSERT_VAL("failed to get fd", fd > 0);

        /* open dso_1 */
        fd = dso__data_fd(dso_1, &machine);
        TEST_ASSERT_VAL("failed to get fd", fd > 0);

        /*
         * open extra file descriptor and we just
         * reached the files count limit
         */
        fd_extra = open("/dev/null", O_RDONLY);
        TEST_ASSERT_VAL("failed to open extra fd", fd_extra > 0);

        /* open dso_2 */
        fd = dso__data_fd(dso_2, &machine);
        TEST_ASSERT_VAL("failed to get fd", fd > 0);

        /*
         * dso_0 should get closed, because we reached
         * the file descriptor limit
         */
        TEST_ASSERT_VAL("failed to close dso_0", dso__data(dso_0)->fd == -1);

        /* open dso_0 */
        fd = dso__data_fd(dso_0, &machine);
        TEST_ASSERT_VAL("failed to get fd", fd > 0);

        /*
         * dso_1 should get closed, because we reached
         * the file descriptor limit
         */
        TEST_ASSERT_VAL("failed to close dso_1", dso__data(dso_1)->fd == -1);

        /* cleanup everything */
        close(fd_extra);
        dsos__delete(&machine.dsos);

        /* Make sure we did not leak any file descriptor. */
        nr_end = open_files_cnt();
        pr_debug("nr start %ld, nr stop %ld\n", nr, nr_end);
        TEST_ASSERT_VAL("failed leaking files", nr == nr_end);
        return 0;
}


static struct test_case tests__dso_data[] = {
        TEST_CASE("read", dso_data),
        TEST_CASE("cache", dso_data_cache),
        TEST_CASE("reopen", dso_data_reopen),
        {       .name = NULL, }
};

struct test_suite suite__dso_data = {
        .desc = "DSO data tests",
        .test_cases = tests__dso_data,
};