// SPDX-FileCopyrightText: 2009-2019 nibble <nibble.ds@gmail.com>
// SPDX-FileCopyrightText: 2009-2019 pancake <pancake@nopcode.org>
// SPDX-License-Identifier: LGPL-3.0-only

#include <rz_types.h>
#include <rz_util.h>
#include <rz_lib.h>
#include <rz_bin.h>

#define RZ_BIN_MACH064 1
#include "../format/mach0/mach0.h"
#include "../format/mach0/mach0_defines.h"

/* at offset 0x10f8 (pointer to it stored right after "legion2") */
typedef struct _RSepHdr64 {
	ut8 kernel_uuid[16];
	ut64 unknown0;
	ut64 kernel_base_paddr;
	ut64 kernel_max_paddr;
	ut64 app_images_base_paddr;
	ut64 app_images_max_paddr;
	ut64 paddr_max; /* size of SEP firmware image */
	ut64 unknown1;
	ut64 unknown2;
	ut64 unknown3;
	ut64 init_base_paddr;
	ut64 unknown4;
	ut64 unknown5;
	ut64 unknown6;
	ut64 unknown7;
	ut64 unknown8;
	ut64 unknown9;
	char init_name[16];
	ut8 init_uuid[16];
	ut64 unknown10;
	ut64 unknown11;
	ut64 n_apps;
} RSepHdr64;

/* right after the above, from offset 0x11c0 */
typedef struct _RSepApp64 {
	ut64 phys_text;
	ut64 size_text;
	ut64 phys_data;
	ut64 size_data;
	ut64 virt;
	ut64 entry;
	ut64 unknown4;
	ut64 unknown5;
	ut64 unknown6;
	ut32 minus_one;
	ut32 unknown7;
	char app_name[16];
	ut8 app_uuid[16];
	ut64 unknown8;
} RSepApp64;

typedef struct _RSepMachoInfo {
	struct MACH0_(mach_header) * hdr;
	ut64 total_size;
	ut64 text_size;
	ut64 data_offset;
	ut64 data_size;
	ut64 text_offset_in_whole;
	ut64 data_offset_in_whole;
} RSepMachoInfo;

typedef struct _RSepSlice64 {
	RzBuffer *buf;
	RzBinXtrMetadata *meta;
	ut64 nominal_offset;
	ut64 total_size;
} RSepSlice64;

typedef struct _RSepXtr64Ctx {
	RSepHdr64 *hdr;
	RSepApp64 *apps;
} RSepXtr64Ctx;

static RSepXtr64Ctx *sep64_xtr_ctx_new(RzBuffer *buf);
static void sep64_xtr_ctx_free(void *p);
static RSepSlice64 *sep64_xtr_ctx_get_slice(RSepXtr64Ctx *ctx, RzBuffer *whole, int idx);

static RSepMachoInfo *mach0_info_new(RzBuffer *buf, ut64 at, ut64 max_size);
static void mach0_info_free(RSepMachoInfo *info);

static bool read_arm64_ins(RzBuffer *b, int idx, ut64 *result);
static char *get_proper_name(const char *app_name);
static RzBuffer *extract_slice(RzBuffer *whole, RSepMachoInfo *info);
static inline void fill_metadata_info_from_hdr(RzBinXtrMetadata *meta, struct MACH0_(mach_header) * hdr);

#define BTW(val, min, max) ((val) > min && (val) < max)

static bool check_buffer(RzBuffer *b) {
	rz_return_val_if_fail(b, false);

	const ut64 sz = rz_buf_size(b);
	if (sz < 0x11c0) {
		return false;
	}

	ut64 msr_vbar_el1;
	if (!read_arm64_ins(b, 2, &msr_vbar_el1)) {
		return false;
	}

	if (msr_vbar_el1 != 0xd518c002) {
		return false;
	}

	ut64 adr;
	if (!read_arm64_ins(b, 1, &adr)) {
		return false;
	}

	if (adr != 0x10003fe2) {
		return false;
	}

	ut64 tmp;
	if (!read_arm64_ins(b, 512, &tmp)) {
		return false;
	}

	/* check exception vector */
	if (tmp != 0x14000000) {
		return false;
	}

	if (!read_arm64_ins(b, 1023, &tmp)) {
		return false;
	}

	if (tmp != 0x14000000) {
		return false;
	}

	if (!read_arm64_ins(b, 1028, &tmp)) {
		return false;
	}

	/* legion2 */
	if (tmp != 0x326e6f69) {
		return false;
	}

	/* data header start */
	ut64 hdr_offset;
	if (!read_arm64_ins(b, 1029, &hdr_offset)) {
		return false;
	};

	if (hdr_offset >= sz) {
		return false;
	}

	ut64 size;
	if (!rz_buf_read_le64_at(b, hdr_offset + 56, &size)) {
		return false;
	}

	/* check size */
	if (size != sz) {
		return false;
	}

	return true;
}

static bool load(RzBin *bin) {
	return ((bin->cur->xtr_obj = sep64_xtr_ctx_new(bin->cur->buf)) != NULL);
}

static void destroy(RzBin *bin) {
	sep64_xtr_ctx_free(bin->cur->xtr_obj);
}

static int size(RzBin *bin) {
	// TODO
	return 0;
}

static RzBinXtrData *oneshot_buffer(RzBin *bin, RzBuffer *b, int idx) {
	rz_return_val_if_fail(bin && bin->cur, NULL);

	if (!bin->cur->xtr_obj) {
		bin->cur->xtr_obj = sep64_xtr_ctx_new(b);
	}
	RSepXtr64Ctx *ctx = bin->cur->xtr_obj;

	RSepSlice64 *slice = sep64_xtr_ctx_get_slice(ctx, b, idx);
	RzBinXtrData *res = rz_bin_xtrdata_new(slice->buf, slice->nominal_offset, slice->total_size, 3 + ctx->hdr->n_apps, slice->meta);

	rz_buf_free(slice->buf);
	free(slice);
	return res;
}

static RzList *oneshotall_buffer(RzBin *bin, RzBuffer *b) {
	RzBinXtrData *data = oneshot_buffer(bin, b, 0);
	if (data) {
		int narch = data->file_count;
		RzList *res = rz_list_newf(rz_bin_xtrdata_free);
		if (!res) {
			rz_bin_xtrdata_free(data);
			return NULL;
		}
		rz_list_append(res, data);
		int i;
		for (i = 1; data && i < narch; i++) {
			data = oneshot_buffer(bin, b, i);
			rz_list_append(res, data);
		}
		return res;
	}
	return NULL;
}

static RSepXtr64Ctx *sep64_xtr_ctx_new(RzBuffer *buf) {
	RSepHdr64 *hdr = NULL;
	RSepApp64 *apps = NULL;
	RSepXtr64Ctx *ctx = NULL;

	ut64 hdr_offset;
	if (!rz_buf_read_le64_at(buf, 0x1014, &hdr_offset)) {
		goto beach;
	}

	if (hdr_offset == UT64_MAX) {
		goto beach;
	}

	hdr = RZ_NEW0(RSepHdr64);
	if (!hdr) {
		goto beach;
	}
	if (rz_buf_fread_at(buf, hdr_offset, (ut8 *)hdr, "16c16l16c16c3l", 1) != sizeof(RSepHdr64)) {
		goto beach;
	}

	if (!hdr->n_apps) {
		goto beach;
	}

	ut64 apps_at = hdr_offset + sizeof(RSepHdr64);
	apps = RZ_NEWS0(RSepApp64, hdr->n_apps);
	if (!apps) {
		goto beach;
	}
	if (rz_buf_fread_at(buf, apps_at, (ut8 *)apps, "9l2i16c16cl", hdr->n_apps) != (sizeof(RSepApp64) * hdr->n_apps)) {
		goto beach;
	}

	ctx = RZ_NEW0(RSepXtr64Ctx);
	if (!ctx) {
		goto beach;
	}

	ctx->hdr = hdr;
	ctx->apps = apps;

	return ctx;
beach:
	free(hdr);
	free(apps);
	free(ctx);

	return NULL;
}

static void sep64_xtr_ctx_free(void *p) {
	if (!p) {
		return;
	}

	RSepXtr64Ctx *ctx = p;

	RZ_FREE(ctx->hdr);
	RZ_FREE(ctx->apps);

	free(ctx);
}

static RSepSlice64 *sep64_xtr_ctx_get_slice(RSepXtr64Ctx *ctx, RzBuffer *whole, int idx) {
	if (idx >= ctx->hdr->n_apps + 3) {
		return NULL;
	}

	ut64 whole_size = rz_buf_size(whole);
	RzBuffer *slice_buf = NULL;
	char *name = NULL;
	RSepSlice64 *slice = NULL;
	RSepMachoInfo *info = NULL;
	RzBinXtrMetadata *meta = NULL;
	ut64 nominal_offset = 0;
	ut64 total_size = 0;

	if (idx == 0) {
		name = strdup("boot");
		slice_buf = rz_buf_new_slice(whole, 0, ctx->hdr->kernel_base_paddr);
		total_size = ctx->hdr->kernel_base_paddr;
	} else if (idx == 1) {
		name = strdup("kernel");
		info = mach0_info_new(whole, ctx->hdr->kernel_base_paddr, whole_size - ctx->hdr->kernel_base_paddr);
		if (!info) {
			goto beach;
		}
		slice_buf = rz_buf_new_slice(whole, ctx->hdr->kernel_base_paddr, info->total_size);
		nominal_offset = ctx->hdr->kernel_base_paddr;
		total_size = info->total_size;
	} else if (idx == 2) {
		name = get_proper_name(ctx->hdr->init_name);
		info = mach0_info_new(whole, ctx->hdr->init_base_paddr, whole_size - ctx->hdr->init_base_paddr);
		if (!info) {
			goto beach;
		}
		slice_buf = extract_slice(whole, info);
		nominal_offset = ctx->hdr->init_base_paddr;
		total_size = info->total_size;
	} else {
		int app_idx = idx - 3;
		name = get_proper_name(ctx->apps[app_idx].app_name);
		info = mach0_info_new(whole, ctx->apps[app_idx].phys_text, whole_size - ctx->apps[app_idx].phys_text);
		if (!info) {
			goto beach;
		}
		info->data_offset_in_whole = ctx->apps[app_idx].phys_data;
		slice_buf = extract_slice(whole, info);
		nominal_offset = ctx->apps[app_idx].phys_text;
		total_size = info->total_size;
	}

	if (!name || !slice_buf) {
		goto beach;
	}

	meta = RZ_NEW0(RzBinXtrMetadata);
	if (!meta) {
		goto beach;
	}

	if (info) {
		fill_metadata_info_from_hdr(meta, info->hdr);
	} else {
		meta->arch = strdup("arm");
		meta->bits = 64;
		meta->machine = strdup("arm64e");
		meta->type = strdup("Executable file");
	}

	meta->xtr_type = "SEP";
	meta->libname = name;

	slice = RZ_NEW0(RSepSlice64);
	if (!slice) {
		goto beach;
	}

	slice->buf = slice_buf;
	slice->nominal_offset = nominal_offset;
	slice->total_size = total_size;
	slice->meta = meta;

	mach0_info_free(info);

	return slice;
beach:
	rz_buf_free(slice_buf);
	free(name);
	free(slice);
	free(meta);
	mach0_info_free(info);
	return NULL;
}

static RSepMachoInfo *mach0_info_new(RzBuffer *buf, ut64 at, ut64 max_size) {
	rz_return_val_if_fail(max_size >= 1024, NULL);

	RSepMachoInfo *result = NULL;
	struct MACH0_(mach_header) *hdr = NULL;
	ut8 *commands = NULL;
	ut64 total_size = 0, text_size = 0, data_offset = 0, data_size = 0;

	ut32 hdr_size = sizeof(struct MACH0_(mach_header));
	hdr = malloc(hdr_size);
	if (!hdr) {
		goto beach;
	}
	if (rz_buf_read_at(buf, at, (ut8 *)hdr, hdr_size) != hdr_size) {
		goto beach;
	}
	if (hdr->magic != MH_MAGIC_64 || !BTW(hdr->sizeofcmds, 0, max_size)) {
		goto beach;
	}

	commands = malloc(hdr->sizeofcmds);
	if (!commands) {
		goto beach;
	}
	if (rz_buf_read_at(buf, at + hdr_size, commands, hdr->sizeofcmds) != hdr->sizeofcmds) {
		goto beach;
	}

	ut32 i;
	ut8 *cursor = commands;
	for (i = 0; i < hdr->ncmds; i++) {
		const struct load_command *cmd = (struct load_command *)cursor;
		if (cmd->cmd == LC_SEGMENT_64) {
			const struct MACH0_(segment_command) *seg = (struct MACH0_(segment_command) *)cursor;
			ut64 end = seg->fileoff + seg->filesize;
			if (total_size < end) {
				total_size = end;
			}
			if (!strcmp(seg->segname, "__TEXT")) {
				text_size = seg->filesize;
			} else if (!strcmp(seg->segname, "__DATA")) {
				data_offset = seg->fileoff;
				data_size = seg->filesize;
			}
		}
		cursor = cursor + cmd->cmdsize;
	}

	if (total_size == 0 || text_size == 0 || data_offset == 0 || data_size == 0) {
		goto beach;
	}

	result = RZ_NEW0(RSepMachoInfo);
	if (!result) {
		goto beach;
	}

	result->hdr = hdr;
	result->total_size = total_size;
	result->text_size = text_size;
	result->data_offset = data_offset;
	result->data_size = data_size;
	result->text_offset_in_whole = at;

	free(commands);

	return result;
beach:

	free(result);
	free(hdr);
	free(commands);

	return NULL;
}

static void mach0_info_free(RSepMachoInfo *info) {
	if (!info) {
		return;
	}

	free(info->hdr);
	free(info);
}

static RzBuffer *extract_slice(RzBuffer *whole, RSepMachoInfo *info) {
	ut8 *content = NULL;

	content = (ut8 *)malloc(info->total_size);
	if (!content) {
		goto beach;
	}
	if (rz_buf_read_at(whole, info->text_offset_in_whole, content, info->text_size) != info->text_size) {
		goto beach;
	}
	ut64 data_offset = info->data_offset_in_whole ? info->data_offset_in_whole : info->text_offset_in_whole + info->data_offset;
	if (rz_buf_read_at(whole, data_offset, content + info->data_offset, info->data_size) != info->data_size) {
		goto beach;
	}

	return rz_buf_new_with_pointers(content, info->total_size, true);
beach:
	free(content);

	return NULL;
}

static inline void fill_metadata_info_from_hdr(RzBinXtrMetadata *meta, struct MACH0_(mach_header) * hdr) {
	meta->arch = strdup(MACH0_(get_cputype_from_hdr)(hdr));
	meta->bits = MACH0_(get_bits_from_hdr)(hdr);
	meta->machine = MACH0_(get_cpusubtype_from_hdr)(hdr);
	meta->type = MACH0_(get_filetype_from_hdr)(hdr);
}

static char *get_proper_name(const char *app_name) {
	char *proper_name = calloc(13, 1);
	if (!proper_name) {
		return NULL;
	}
	int i;

	for (i = 12; i != -1; i--) {
		if (app_name[i] == ' ') {
			proper_name[i] = 0;
		} else {
			proper_name[i] = app_name[i];
		}
	}

	return proper_name;
}

static bool read_arm64_ins(RzBuffer *b, int idx, ut64 *result) {
	ut32 tmp;

	bool res = rz_buf_read_le32_at(b, idx * 4, &tmp);
	if (!res) {
		return false;
	}

	*result = tmp;
	return res;
}

RzBinXtrPlugin rz_bin_xtr_plugin_xtr_sep64 = {
	.name = "xtr.sep64",
	.desc = "64-bit SEP bin extractor plugin",
	.license = "LGPL3",
	.check_buffer = check_buffer,
	.load = &load,
	.destroy = &destroy,
	.size = &size,
	.extract_from_buffer = &oneshot_buffer,
	.extractall_from_buffer = &oneshotall_buffer,
	.free_xtr = &sep64_xtr_ctx_free,
};

#ifndef RZ_PLUGIN_INCORE
RZ_API RzLibStruct rizin_plugin = {
	.type = RZ_LIB_TYPE_BIN_XTR,
	.data = &rz_bin_xtr_plugin_xtr_sep64,
	.version = RZ_VERSION
};
#endif
