/*-
 * Copyright (c) 2021 3mdeb Embedded Systems Consulting <contact@3mdeb.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/efi.h>
#include <sys/efiio.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include <uuid.h>
#include <libxo/xo.h>

#define TABLE_MAX_LEN 30
#define EFITABLE_XO_VERSION "1"

static void efi_table_print_esrt(const void *data);
static void efi_table_print_prop(const void *data);
static void efi_table_print_memory(const void *data);
static void usage(void) __dead2;

struct efi_table_op {
        char name[TABLE_MAX_LEN];
        void (*parse) (const void *);
        efi_guid_t guid;
};

static const struct efi_table_op efi_table_ops[] = {
        { .name = "esrt", .parse = efi_table_print_esrt,
            .guid = EFI_TABLE_ESRT },
        { .name = "prop", .parse = efi_table_print_prop,
            .guid = EFI_PROPERTIES_TABLE },
        { .name = "memory", .parse = efi_table_print_memory,
            .guid = EFI_MEMORY_ATTRIBUTES_TABLE }
};

int
main(int argc, char **argv)
{
        struct efi_get_table_ioc table = {
                .buf = NULL,
                .buf_len = 0,
                .table_len = 0
        };
        int efi_fd, ch, rc = 1, efi_idx = -1;
        bool got_table = false;
        bool table_set = false;
        bool uuid_set = false;
        struct option longopts[] = {
                { "uuid",  required_argument, NULL, 'u' },
                { "table", required_argument, NULL, 't' },
                { NULL,    0,                 NULL,  0  }
        };

        argc = xo_parse_args(argc, argv);
        if (argc < 0)
                exit(EXIT_FAILURE);

        while ((ch = getopt_long(argc, argv, "g:t:u:", longopts, NULL)) != -1) {
                switch (ch) {
                case 'g':
                case 'u':
                {
                        char *uuid_str = optarg;
                        struct uuid uuid;
                        uint32_t status;

                        /*
                         * Note: we use the uuid parsing routine to parse the
                         * guid strings. However, EFI defines a slightly
                         * different structure to access them. We unify on
                         * using a structure that's compatible with EDK2
                         * EFI_GUID structure.
                         */

                        uuid_set = 1;

                        uuid_from_string(uuid_str, &uuid, &status);
                        if (status != uuid_s_ok)
                                xo_errx(EX_DATAERR, "invalid UUID");

                        for (size_t n = 0; n < nitems(efi_table_ops); n++) {
                                if (!memcmp(&uuid, &efi_table_ops[n].guid,
                                    sizeof(uuid))) {
                                        efi_idx = n;
                                        got_table = true;
                                        break;
                                }
                        }
                        break;
                }
                case 't':
                {
                        char *table_name = optarg;

                        table_set = true;

                        for (size_t n = 0; n < nitems(efi_table_ops); n++) {
                                if (!strcmp(table_name,
                                    efi_table_ops[n].name)) {
                                        efi_idx = n;
                                        got_table = true;
                                        break;
                                }
                        }

                        if (!got_table)
                                xo_errx(EX_DATAERR, "unsupported efi table");

                        break;
                }
                default:
                        usage();
                }
        }

        if (!table_set && !uuid_set)
                xo_errx(EX_USAGE, "table is not set");

        if (!got_table)
                xo_errx(EX_DATAERR, "unsupported table");

        efi_fd = open("/dev/efi", O_RDWR);
        if (efi_fd < 0)
                xo_err(EX_OSFILE, "/dev/efi");

        memcpy(&table.uuid, &efi_table_ops[efi_idx].guid, sizeof(struct uuid));
        if (ioctl(efi_fd, EFIIOC_GET_TABLE, &table) == -1)
                xo_err(EX_OSERR, "EFIIOC_GET_TABLE (len == 0)");

        table.buf = malloc(table.table_len);
        table.buf_len = table.table_len;

        if (ioctl(efi_fd, EFIIOC_GET_TABLE, &table) == -1)
                xo_err(EX_OSERR, "EFIIOC_GET_TABLE");

        efi_table_ops[efi_idx].parse(table.buf);
        close(efi_fd);

        return (rc);
}

static void
efi_table_print_esrt(const void *data)
{
        const struct efi_esrt_entry_v1 *entries_v1;
        const struct efi_esrt_table *esrt;

        esrt = (const struct efi_esrt_table *)data;

        xo_set_version(EFITABLE_XO_VERSION);
        xo_open_container("esrt");
        xo_emit("{Lwc:FwResourceCount}{:fw_resource_count/%u}\n",
            esrt->fw_resource_count);
        xo_emit("{Lwc:FwResourceCountMax}{:fw_resource_count_max/%u}\n",
            esrt->fw_resource_count_max);
        xo_emit("{Lwc:FwResourceVersion}{:fw_resource_version/%u}\n",
            esrt->fw_resource_version);
        xo_open_list("entries");
        xo_emit("\nEntries:\n");

        entries_v1 = (const void *) esrt->entries;
        for (uint32_t i = 0; i < esrt->fw_resource_count; i++) {
                const struct efi_esrt_entry_v1 *e = &entries_v1[i];
                uint32_t status;
                char *uuid;

                uuid_to_string((const uuid_t *)&e->fw_class, &uuid, &status);
                if (status != uuid_s_ok) {
                        xo_errx(EX_DATAERR, "uuid_to_string error");
                }

                xo_open_instance("entries");
                xo_emit("\n");
                xo_emit("{P:  }{Lwc:FwClass}{:fw_class/%s}\n", uuid);
                xo_emit("{P:  }{Lwc:FwType}{:fw_type/%u}\n", e->fw_type);
                xo_emit("{P:  }{Lwc:FwVersion}{:fw_version/%u}\n",
                    e->fw_version);
                xo_emit("{P:  }{Lwc:LowestSupportedFwVersion}"
                    "{:lowest_supported_fw_version/%u}\n",
                    e->lowest_supported_fw_version);
                xo_emit("{P:  }{Lwc:CapsuleFlags}{:capsule_flags/%#x}\n",
                    e->capsule_flags);
                xo_emit("{P:  }{Lwc:LastAttemptVersion"
                    "}{:last_attempt_version/%u}\n", e->last_attempt_version);
                xo_emit("{P:  }{Lwc:LastAttemptStatus"
                    "}{:last_attempt_status/%u}\n", e->last_attempt_status);

                xo_close_instance("entries");
        }

        xo_close_list("entries");
        xo_close_container("esrt");
        if (xo_finish() < 0)
                xo_err(EX_IOERR, "stdout");
}

static void
efi_table_print_prop(const void *data)
{
        const struct efi_prop_table *prop;

        prop = (const struct efi_prop_table *)data;

        xo_set_version(EFITABLE_XO_VERSION);
        xo_open_container("prop");
        xo_emit("{Lwc:Version}{:version/%#x}\n", prop->version);
        xo_emit("{Lwc:Length}{:length/%u}\n", prop->length);
        xo_emit("{Lwc:MemoryProtectionAttribute}"
            "{:memory_protection_attribute/%#lx}\n",
            prop->memory_protection_attribute);
        xo_close_container("prop");
        if (xo_finish() < 0)
                xo_err(EX_IOERR, "stdout");
}

static void
efi_table_print_memory(const void *data)
{
        const struct efi_memory_attribute_table *attr =
            (const struct efi_memory_attribute_table *)data;
        const struct efi_memory_descriptor *desc;
        int i, nentries;

        nentries = attr->num_ents;
        desc = attr->tables;

        xo_set_version(EFITABLE_XO_VERSION);

        xo_open_container("memory");
        xo_emit("{Lwc:Version}{:version/%#x}\n", attr->version);
        xo_emit("{Lwc:Length}{:length/%u}\n", attr->descriptor_size);
        xo_emit("{Lwc:Entries}{:entries/%u}\n", attr->num_ents);

        xo_open_container("attributes");

        /*
         * According to https://forum.osdev.org/viewtopic.php?t=32953, the size
         * of records into the attribute table never equals to
         * sizeof(efi_memory_descriptor). The correct one for indexing the array
         * resides in the attributet table.
         */
        for (i = 0; i < nentries; i++) {
                xo_emit("{Lwc:ID}{:id/%#x}\n", i);
                xo_emit("{Lwc:Attributes}{:attributes/%#x}\n", desc->attrs);
                xo_emit("{Lwc:Type}{:type/%#x}\n", desc->type);
                xo_emit("{Lwc:Pages}{:pages/%#x}\n", desc->pages);
                xo_emit("{Lwc:Phyaddr}{:phyaddr/%#p}\n", desc->phy_addr);
                xo_emit("{Lwc:Virtaddr}{:virtaddr/%#p}\n", desc->virt_addr);
                desc = (const struct efi_memory_descriptor *)(const void *)
                    ((const char *)desc + attr->descriptor_size);
        }

        xo_close_container("attributes");

        xo_close_container("memory");

        if (xo_finish() < 0)
                xo_err(EX_IOERR, "stdout");
}

static void usage(void)
{
        xo_error("usage: efitable [-g guid | -t name] [--libxo]\n");
        exit(EX_USAGE);
}