/*
 * Based on mkimage.c.
 *
 * Written by Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include "dumpimage.h"
#include <image.h>
#include <version.h>

static void usage(void);

/* image_type_params linked list to maintain registered image types supports */
static struct image_type_params *dumpimage_tparams;

/* parameters initialized by core will be used by the image type code */
static struct image_tool_params params = {
        .type = IH_TYPE_KERNEL,
};

/**
 * dumpimage_register() - register respective image generation/list support
 *
 * the input struct image_type_params is checked and appended to the link
 * list, if the input structure is already registered, issue an error
 *
 * @tparams: Image type parameters
 */
static void dumpimage_register(struct image_type_params *tparams)
{
        struct image_type_params **tp;

        if (!tparams) {
                fprintf(stderr, "%s: %s: Null input\n", params.cmdname,
                        __func__);
                exit(EXIT_FAILURE);
        }

        /* scan the linked list, check for registry and point the last one */
        for (tp = &dumpimage_tparams; *tp != NULL; tp = &(*tp)->next) {
                if (!strcmp((*tp)->name, tparams->name)) {
                        fprintf(stderr, "%s: %s already registered\n",
                                params.cmdname, tparams->name);
                        return;
                }
        }

        /* add input struct entry at the end of link list */
        *tp = tparams;
        /* mark input entry as last entry in the link list */
        tparams->next = NULL;

        debug("Registered %s\n", tparams->name);
}

/**
 * dumpimage_get_type() - find the image type params for a given image type
 *
 * Scan all registered image types and check the input type_id for each
 * supported image type
 *
 * @return respective image_type_params pointer. If the input type is not
 * supported by any of registered image types, returns NULL
 */
static struct image_type_params *dumpimage_get_type(int type)
{
        struct image_type_params *curr;

        for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
                if (curr->check_image_type) {
                        if (!curr->check_image_type(type))
                                return curr;
                }
        }
        return NULL;
}

/*
 * dumpimage_verify_print_header() - verifies the image header
 *
 * Scan registered image types and verify the image_header for each
 * supported image type. If verification is successful, this prints
 * the respective header.
 *
 * @return 0 on success, negative if input image format does not match with
 * any of supported image types
 */
static int dumpimage_verify_print_header(void *ptr, struct stat *sbuf)
{
        int retval = -1;
        struct image_type_params *curr;

        for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
                if (curr->verify_header) {
                        retval = curr->verify_header((unsigned char *)ptr,
                                                     sbuf->st_size, &params);
                        if (retval != 0)
                                continue;
                        /*
                         * Print the image information  if verify is
                         * successful
                         */
                        if (curr->print_header) {
                                curr->print_header(ptr);
                        } else {
                                fprintf(stderr,
                                        "%s: print_header undefined for %s\n",
                                        params.cmdname, curr->name);
                        }
                        break;
                }
        }

        return retval;
}

/*
 * dumpimage_extract_datafile -
 *
 * It scans all registered image types,
 * verifies image_header for each supported image type
 * if verification is successful, it extracts the desired file,
 * indexed by pflag, from the image
 *
 * returns negative if input image format does not match with any of
 * supported image types
 */
static int dumpimage_extract_datafile(void *ptr, struct stat *sbuf)
{
        int retval = -1;
        struct image_type_params *curr;

        for (curr = dumpimage_tparams; curr != NULL; curr = curr->next) {
                if (curr->verify_header) {
                        retval = curr->verify_header((unsigned char *)ptr,
                                                     sbuf->st_size, &params);
                        if (retval != 0)
                                continue;
                        /*
                         * Extract the file from the image
                         * if verify is successful
                         */
                        if (curr->extract_datafile) {
                                curr->extract_datafile(ptr, &params);
                        } else {
                                fprintf(stderr,
                                        "%s: extract_datafile undefined for %s\n",
                                        params.cmdname, curr->name);
                        break;
                        }
                }
        }

        return retval;
}

int main(int argc, char **argv)
{
        int opt;
        int ifd = -1;
        struct stat sbuf;
        char *ptr;
        int retval = 0;
        struct image_type_params *tparams = NULL;

        /* Init all image generation/list support */
        register_image_tool(dumpimage_register);

        params.cmdname = *argv;

        while ((opt = getopt(argc, argv, "li:o:p:V")) != -1) {
                switch (opt) {
                case 'l':
                        params.lflag = 1;
                        break;
                case 'i':
                        params.imagefile = optarg;
                        params.iflag = 1;
                        break;
                case 'o':
                        params.outfile = optarg;
                        break;
                case 'p':
                        params.pflag = strtoul(optarg, &ptr, 10);
                        if (*ptr) {
                                fprintf(stderr,
                                        "%s: invalid file position %s\n",
                                        params.cmdname, *argv);
                                exit(EXIT_FAILURE);
                        }
                        break;
                case 'V':
                        printf("dumpimage version %s\n", PLAIN_VERSION);
                        exit(EXIT_SUCCESS);
                default:
                        usage();
                }
        }

        if (optind >= argc)
                usage();

        /* set tparams as per input type_id */
        tparams = dumpimage_get_type(params.type);
        if (tparams == NULL) {
                fprintf(stderr, "%s: unsupported type %s\n",
                        params.cmdname, genimg_get_type_name(params.type));
                exit(EXIT_FAILURE);
        }

        /*
         * check the passed arguments parameters meets the requirements
         * as per image type to be generated/listed
         */
        if (tparams->check_params) {
                if (tparams->check_params(&params))
                        usage();
        }

        if (params.iflag)
                params.datafile = argv[optind];
        else
                params.imagefile = argv[optind];
        if (!params.outfile)
                params.outfile = params.datafile;

        ifd = open(params.imagefile, O_RDONLY|O_BINARY);
        if (ifd < 0) {
                fprintf(stderr, "%s: Can't open \"%s\": %s\n",
                        params.cmdname, params.imagefile,
                        strerror(errno));
                exit(EXIT_FAILURE);
        }

        if (params.lflag || params.iflag) {
                if (fstat(ifd, &sbuf) < 0) {
                        fprintf(stderr, "%s: Can't stat \"%s\": %s\n",
                                params.cmdname, params.imagefile,
                                strerror(errno));
                        exit(EXIT_FAILURE);
                }

                if ((unsigned)sbuf.st_size < tparams->header_size) {
                        fprintf(stderr,
                                "%s: Bad size: \"%s\" is not valid image\n",
                                params.cmdname, params.imagefile);
                        exit(EXIT_FAILURE);
                }

                ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, ifd, 0);
                if (ptr == MAP_FAILED) {
                        fprintf(stderr, "%s: Can't read \"%s\": %s\n",
                                params.cmdname, params.imagefile,
                                strerror(errno));
                        exit(EXIT_FAILURE);
                }

                /*
                 * Both calls bellow scan through dumpimage registry for all
                 * supported image types and verify the input image file
                 * header for match
                 */
                if (params.iflag) {
                        /*
                         * Extract the data files from within the matched
                         * image type. Returns the error code if not matched
                         */
                        retval = dumpimage_extract_datafile(ptr, &sbuf);
                } else {
                        /*
                         * Print the image information for matched image type
                         * Returns the error code if not matched
                         */
                        retval = dumpimage_verify_print_header(ptr, &sbuf);
                }

                (void)munmap((void *)ptr, sbuf.st_size);
                (void)close(ifd);

                return retval;
        }

        (void)close(ifd);

        return EXIT_SUCCESS;
}

static void usage(void)
{
        fprintf(stderr, "Usage: %s -l image\n"
                "          -l ==> list image header information\n",
                params.cmdname);
        fprintf(stderr,
                "       %s -i image [-p position] [-o outfile] data_file\n"
                "          -i ==> extract from the 'image' a specific 'data_file'"
                ", indexed by 'position' (starting at 0)\n",
                params.cmdname);
        fprintf(stderr,
                "       %s -V ==> print version information and exit\n",
                params.cmdname);

        exit(EXIT_FAILURE);
}