// SPDX-License-Identifier: GPL-2.0-only
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include <asm/papr-vpd.h>

#include "utils.h"

#define DEVPATH "/dev/papr-vpd"

static int dev_papr_vpd_open_close(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);
        FAIL_IF(close(devfd) != 0);

        return 0;
}

static int dev_papr_vpd_get_handle_all(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        struct papr_location_code lc = { .str = "", };
        off_t size;
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(errno != 0);
        FAIL_IF(fd < 0);

        FAIL_IF(close(devfd) != 0);

        size = lseek(fd, 0, SEEK_END);
        FAIL_IF(size <= 0);

        void *buf = malloc((size_t)size);
        FAIL_IF(!buf);

        ssize_t consumed = pread(fd, buf, size, 0);
        FAIL_IF(consumed != size);

        /* Ensure EOF */
        FAIL_IF(read(fd, buf, size) != 0);
        FAIL_IF(close(fd));

        /* Verify that the buffer looks like VPD */
        static const char needle[] = "System VPD";
        FAIL_IF(!memmem(buf, size, needle, strlen(needle)));

        return 0;
}

static int dev_papr_vpd_get_handle_byte_at_a_time(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        struct papr_location_code lc = { .str = "", };
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(errno != 0);
        FAIL_IF(fd < 0);

        FAIL_IF(close(devfd) != 0);

        size_t consumed = 0;
        while (1) {
                ssize_t res;
                char c;

                errno = 0;
                res = read(fd, &c, sizeof(c));
                FAIL_IF(res > sizeof(c));
                FAIL_IF(res < 0);
                FAIL_IF(errno != 0);
                consumed += res;
                if (res == 0)
                        break;
        }

        FAIL_IF(consumed != lseek(fd, 0, SEEK_END));

        FAIL_IF(close(fd));

        return 0;
}


static int dev_papr_vpd_unterm_loc_code(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        struct papr_location_code lc = {};
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        /*
         * Place a non-null byte in every element of loc_code; the
         * driver should reject this input.
         */
        memset(lc.str, 'x', ARRAY_SIZE(lc.str));

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(fd != -1);
        FAIL_IF(errno != EINVAL);

        FAIL_IF(close(devfd) != 0);
        return 0;
}

static int dev_papr_vpd_null_handle(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        int rc;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        errno = 0;
        rc = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, NULL);
        FAIL_IF(rc != -1);
        FAIL_IF(errno != EFAULT);

        FAIL_IF(close(devfd) != 0);
        return 0;
}

static int papr_vpd_close_handle_without_reading(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        struct papr_location_code lc = { .str = "", };
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(errno != 0);
        FAIL_IF(fd < 0);

        /* close the handle without reading it */
        FAIL_IF(close(fd) != 0);

        FAIL_IF(close(devfd) != 0);
        return 0;
}

static int papr_vpd_reread(void)
{
        const int devfd = open(DEVPATH, O_RDONLY);
        struct papr_location_code lc = { .str = "", };
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");

        FAIL_IF(devfd < 0);

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(errno != 0);
        FAIL_IF(fd < 0);

        FAIL_IF(close(devfd) != 0);

        const off_t size = lseek(fd, 0, SEEK_END);
        FAIL_IF(size <= 0);

        char *bufs[2];

        for (size_t i = 0; i < ARRAY_SIZE(bufs); ++i) {
                bufs[i] = malloc(size);
                FAIL_IF(!bufs[i]);
                ssize_t consumed = pread(fd, bufs[i], size, 0);
                FAIL_IF(consumed != size);
        }

        FAIL_IF(memcmp(bufs[0], bufs[1], size));

        FAIL_IF(close(fd) != 0);

        return 0;
}

static int get_system_loc_code(struct papr_location_code *lc)
{
        static const char system_id_path[] = "/sys/firmware/devicetree/base/system-id";
        static const char model_path[] = "/sys/firmware/devicetree/base/model";
        char *system_id;
        char *model;
        int err = -1;

        if (read_file_alloc(model_path, &model, NULL))
                return err;

        if (read_file_alloc(system_id_path, &system_id, NULL))
                goto free_model;

        char *mtm;
        int sscanf_ret = sscanf(model, "IBM,%ms", &mtm);
        if (sscanf_ret != 1)
                goto free_system_id;

        char *plant_and_seq;
        if (sscanf(system_id, "IBM,%*c%*c%ms", &plant_and_seq) != 1)
                goto free_mtm;
        /*
         * Replace - with . to build location code.
         */
        char *sep = strchr(mtm, '-');
        if (!sep)
                goto free_mtm;
        else
                *sep = '.';

        snprintf(lc->str, sizeof(lc->str),
                 "U%s.%s", mtm, plant_and_seq);
        err = 0;

        free(plant_and_seq);
free_mtm:
        free(mtm);
free_system_id:
        free(system_id);
free_model:
        free(model);
        return err;
}

static int papr_vpd_system_loc_code(void)
{
        struct papr_location_code lc;
        const int devfd = open(DEVPATH, O_RDONLY);
        off_t size;
        int fd;

        SKIP_IF_MSG(devfd < 0 && errno == ENOENT,
                    DEVPATH " not present");
        SKIP_IF_MSG(get_system_loc_code(&lc),
                    "Cannot determine system location code");

        FAIL_IF(devfd < 0);

        errno = 0;
        fd = ioctl(devfd, PAPR_VPD_IOC_CREATE_HANDLE, &lc);
        FAIL_IF(errno != 0);
        FAIL_IF(fd < 0);

        FAIL_IF(close(devfd) != 0);

        size = lseek(fd, 0, SEEK_END);
        FAIL_IF(size <= 0);

        void *buf = malloc((size_t)size);
        FAIL_IF(!buf);

        ssize_t consumed = pread(fd, buf, size, 0);
        FAIL_IF(consumed != size);

        /* Ensure EOF */
        FAIL_IF(read(fd, buf, size) != 0);
        FAIL_IF(close(fd));

        /* Verify that the buffer looks like VPD */
        static const char needle[] = "System VPD";
        FAIL_IF(!memmem(buf, size, needle, strlen(needle)));

        return 0;
}

struct vpd_test {
        int (*function)(void);
        const char *description;
};

static const struct vpd_test vpd_tests[] = {
        {
                .function = dev_papr_vpd_open_close,
                .description = "open/close " DEVPATH,
        },
        {
                .function = dev_papr_vpd_unterm_loc_code,
                .description = "ensure EINVAL on unterminated location code",
        },
        {
                .function = dev_papr_vpd_null_handle,
                .description = "ensure EFAULT on bad handle addr",
        },
        {
                .function = dev_papr_vpd_get_handle_all,
                .description = "get handle for all VPD"
        },
        {
                .function = papr_vpd_close_handle_without_reading,
                .description = "close handle without consuming VPD"
        },
        {
                .function = dev_papr_vpd_get_handle_byte_at_a_time,
                .description = "read all VPD one byte at a time"
        },
        {
                .function = papr_vpd_reread,
                .description = "ensure re-read yields same results"
        },
        {
                .function = papr_vpd_system_loc_code,
                .description = "get handle for system VPD"
        },
};

int main(void)
{
        size_t fails = 0;

        for (size_t i = 0; i < ARRAY_SIZE(vpd_tests); ++i) {
                const struct vpd_test *t = &vpd_tests[i];

                if (test_harness(t->function, t->description))
                        ++fails;
        }

        return fails == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}