// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright (c) 2017 Konsulko Group Inc. All rights reserved.

 *

 * Author:

 *	 Pantelis Antoniou <pantelis.antoniou@konsulko.com>

 */

#include <assert.h>

#include <ctype.h>

#include <getopt.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <inttypes.h>

#include <libfdt.h>

#include "util.h"

#define BUF_INCREMENT	65536

/* Usage related data. */

static const char usage_synopsis[] =

	"apply a number of overlays to a base blob\n"

	"	fdtoverlay <options> [<overlay.dtbo> [<overlay.dtbo>]]\n"

	"\n"

	USAGE_TYPE_MSG;

static const char usage_short_opts[] = "i:o:v" USAGE_COMMON_SHORT_OPTS;

static struct option const usage_long_opts[] = {

	{"input",            required_argument, NULL, 'i'},

	{"output",	     required_argument, NULL, 'o'},

	{"verbose",	           no_argument, NULL, 'v'},

	USAGE_COMMON_LONG_OPTS,

};

static const char * const usage_opts_help[] = {

	"Input base DT blob",

	"Output DT blob",

	"Verbose messages",

	USAGE_COMMON_OPTS_HELP

};

int verbose = 0;

static void *apply_one(char *base, const char *overlay, size_t *buf_len,

		       const char *name)

{

	char *tmp = NULL;

	char *tmpo;

	int ret;

	/*

	 * We take a copies first, because a a failed apply can trash

	 * both the base blob and the overlay

	 */

	tmpo = xmalloc(fdt_totalsize(overlay));

	do {

		tmp = xrealloc(tmp, *buf_len);

		ret = fdt_open_into(base, tmp, *buf_len);

		if (ret) {

			fprintf(stderr,

				"\nFailed to make temporary copy: %s\n",

				fdt_strerror(ret));

			goto fail;

		}

		memcpy(tmpo, overlay, fdt_totalsize(overlay));

		ret = fdt_overlay_apply(tmp, tmpo);

		if (ret == -FDT_ERR_NOSPACE) {

			*buf_len += BUF_INCREMENT;

		}

	} while (ret == -FDT_ERR_NOSPACE);

	if (ret) {

		fprintf(stderr, "\nFailed to apply '%s': %s\n",

			name, fdt_strerror(ret));

		goto fail;

	}

	free(base);

	free(tmpo);

	return tmp;

fail:

	free(tmpo);

	if (tmp)

		free(tmp);

	return NULL;

}

static int do_fdtoverlay(const char *input_filename,

			 const char *output_filename,

			 int argc, char *argv[])

{

	char *blob = NULL;

	char **ovblob = NULL;

	size_t buf_len;

	int i, ret = -1;

	blob = utilfdt_read(input_filename, &buf_len);

	if (!blob) {

		fprintf(stderr, "\nFailed to read '%s'\n", input_filename);

		goto out_err;

	}

	if (fdt_totalsize(blob) > buf_len) {

		fprintf(stderr,

 "\nBase blob is incomplete (%lu / %" PRIu32 " bytes read)\n",

			(unsigned long)buf_len, fdt_totalsize(blob));

		goto out_err;

	}

	/* allocate blob pointer array */

	ovblob = xmalloc(sizeof(*ovblob) * argc);

	memset(ovblob, 0, sizeof(*ovblob) * argc);

	/* read and keep track of the overlay blobs */

	for (i = 0; i < argc; i++) {

		size_t ov_len;

		ovblob[i] = utilfdt_read(argv[i], &ov_len);

		if (!ovblob[i]) {

			fprintf(stderr, "\nFailed to read '%s'\n", argv[i]);

			goto out_err;

		}

		if (fdt_totalsize(ovblob[i]) > ov_len) {

			fprintf(stderr,

"\nOverlay '%s' is incomplete (%lu / %" PRIu32 " bytes read)\n",

				argv[i], (unsigned long)ov_len,

				fdt_totalsize(ovblob[i]));

			goto out_err;

		}

	}

	buf_len = fdt_totalsize(blob);

	/* apply the overlays in sequence */

	for (i = 0; i < argc; i++) {

		blob = apply_one(blob, ovblob[i], &buf_len, argv[i]);

		if (!blob)

			goto out_err;

	}

	fdt_pack(blob);

	ret = utilfdt_write(output_filename, blob);

	if (ret)

		fprintf(stderr, "\nFailed to write '%s'\n",

			output_filename);

out_err:

	if (ovblob) {

		for (i = 0; i < argc; i++) {

			if (ovblob[i])

				free(ovblob[i]);

		}

		free(ovblob);

	}

	free(blob);

	return ret;

}

int main(int argc, char *argv[])

{

	int opt, i;

	char *input_filename = NULL;

	char *output_filename = NULL;

	while ((opt = util_getopt_long()) != EOF) {

		switch (opt) {

		case_USAGE_COMMON_FLAGS

		case 'i':

			input_filename = optarg;

			break;

		case 'o':

			output_filename = optarg;

			break;

		case 'v':

			verbose = 1;

			break;

		}

	}

	if (!input_filename)

		usage("missing input file");

	if (!output_filename)

		usage("missing output file");

	argv += optind;

	argc -= optind;

	if (argc <= 0)

		usage("missing overlay file(s)");

	if (verbose) {

		printf("input  = %s\n", input_filename);

		printf("output = %s\n", output_filename);

		for (i = 0; i < argc; i++)

			printf("overlay[%d] = %s\n", i, argv[i]);

	}

	if (do_fdtoverlay(input_filename, output_filename, argc, argv))

		return 1;

	return 0;

}