/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>

#include "alloc-util.h"
#include "cryptsetup-util.h"
#include "fileio.h"
#include "hexdecoct.h"
#include "integrity-util.h"
#include "log.h"
#include "main-func.h"
#include "memory-util.h"
#include "path-util.h"
#include "parse-util.h"
#include "pretty-print.h"
#include "string-util.h"
#include "terminal-util.h"

static uint32_t arg_activate_flags;
static int arg_percent;
static usec_t arg_commit_time;
static char *arg_existing_data_device;
static char *arg_integrity_algorithm;

STATIC_DESTRUCTOR_REGISTER(arg_existing_data_device, freep);
STATIC_DESTRUCTOR_REGISTER(arg_integrity_algorithm, freep);

static int help(void) {
        _cleanup_free_ char *link = NULL;
        int r;

        r = terminal_urlify_man("systemd-integritysetup@.service", "8", &link);
        if (r < 0)
                return log_oom();

        printf("%s attach VOLUME DEVICE [HMAC_KEY_FILE|-] [OPTIONS]\n"
               "%s detach VOLUME\n\n"
               "Attach or detach an integrity protected block device.\n"
               "\nSee the %s for details.\n",
               program_invocation_short_name,
               program_invocation_short_name,
               link);

        return 0;
}

static int load_key_file(
                const char *key_file,
                void **ret_key_file_contents,
                size_t *ret_key_file_size) {
        int r;
        _cleanup_(erase_and_freep) char *tmp_key_file_contents = NULL;
        size_t tmp_key_file_size;

        if (!path_is_absolute(key_file))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "key file not absolute path: %s", key_file);

        r = read_full_file_full(
                        AT_FDCWD, key_file, UINT64_MAX, DM_MAX_KEY_SIZE,
                        READ_FULL_FILE_SECURE|READ_FULL_FILE_WARN_WORLD_READABLE|READ_FULL_FILE_CONNECT_SOCKET|READ_FULL_FILE_FAIL_WHEN_LARGER,
                        NULL,
                        &tmp_key_file_contents, &tmp_key_file_size);
        if (r < 0)
                return log_error_errno(r, "Failed to process key file: %m");

        if (ret_key_file_contents && ret_key_file_size) {
                *ret_key_file_contents = TAKE_PTR(tmp_key_file_contents);
                *ret_key_file_size = tmp_key_file_size;
        }

        return 0;
}

static const char *integrity_algorithm_select(const void *key_file_buf) {
        /*  To keep a bit of sanity for end users, the subset of integrity
            algorithms we support will match what is used in integritysetup */
        if (arg_integrity_algorithm) {
                if (streq("hmac-sha256", arg_integrity_algorithm))
                        return DM_HMAC_256;
                return arg_integrity_algorithm;
        } else if (key_file_buf)
                return DM_HMAC_256;
        return "crc32c";
}

static int run(int argc, char *argv[]) {
        _cleanup_(crypt_freep) struct crypt_device *cd = NULL;
        int r;
        char *action, *volume;

        if (argc <= 1 ||
            strv_contains(strv_skip(argv, 1), "--help") ||
            strv_contains(strv_skip(argv, 1), "-h") ||
            streq(argv[1], "help"))
                return help();

        if (argc < 3)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "This program requires at least two arguments.");

        action = argv[1];
        volume = argv[2];

        log_setup();

        cryptsetup_enable_logging(NULL);

        umask(0022);

        if (streq(action, "attach")) {
                /* attach name device optional_key_file optional_options */

                crypt_status_info status;
                _cleanup_(erase_and_freep) void *key_buf = NULL;
                const char *device, *key_file, *options;
                size_t key_buf_size = 0;

                if (argc < 4)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "attach requires at least three arguments.");

                if (argc > 6)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "attach has a maximum of five arguments.");

                device = argv[3];
                key_file = (argc > 4) ? empty_or_dash_to_null(argv[4]) : NULL;
                options = (argc > 5) ? empty_or_dash_to_null(argv[5]) : NULL;

                if (key_file) {
                        r = load_key_file(key_file, &key_buf, &key_buf_size);
                        if (r < 0)
                                return r;
                }

                if (options) {
                        r = parse_integrity_options(options, &arg_activate_flags, &arg_percent,
                                                    &arg_commit_time, &arg_existing_data_device, &arg_integrity_algorithm);
                        if (r < 0)
                                return r;
                }

                r = crypt_init(&cd, device);
                if (r < 0)
                        return log_error_errno(r, "Failed to open integrity device %s: %m", device);

                cryptsetup_enable_logging(cd);

                status = crypt_status(cd, volume);
                if (IN_SET(status, CRYPT_ACTIVE, CRYPT_BUSY)) {
                        log_info("Volume %s already active.", volume);
                        return 0;
                }

                if (!isempty(arg_existing_data_device)) {
                        r = crypt_init_data_device(&cd, device, arg_existing_data_device);
                        if (r < 0)
                                return log_error_errno(r, "Failed to add separate data device: %m");
                }

                r = crypt_load(cd,
                        CRYPT_INTEGRITY,
                        &(struct crypt_params_integrity) {
                                .journal_watermark = arg_percent,
                                .journal_commit_time = DIV_ROUND_UP(arg_commit_time, USEC_PER_SEC),
                                .integrity = integrity_algorithm_select(key_buf),
                        });
                if (r < 0)
                        return log_error_errno(r, "Failed to load integrity superblock: %m");

                r = crypt_activate_by_volume_key(cd, volume, key_buf, key_buf_size, arg_activate_flags);
                if (r < 0)
                        return log_error_errno(r, "Failed to set up integrity device: %m");

        } else if (streq(action, "detach")) {

                if (argc > 3)
                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "detach has a maximum of two arguments.");

                r = crypt_init_by_name(&cd, volume);
                if (r == -ENODEV)
                        return 0;
                if (r < 0)
                        return log_error_errno(r, "crypt_init_by_name() failed: %m");

                cryptsetup_enable_logging(cd);

                r = crypt_deactivate(cd, volume);
                if (r < 0)
                        return log_error_errno(r, "Failed to deactivate: %m");

        } else
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb %s.", action);

        return 0;
}

DEFINE_MAIN_FUNCTION(run);