/****************************************************************/

/*  mdso: midipix dso scavenger                                 */

/*  Copyright (C) 2015--2024  SysDeer Technologies, LLC         */

/*  Released under GPLv2 and GPLv3; see COPYING.MDSO.           */

/****************************************************************/

#include <stdint.h>

#include <unistd.h>

#include <fcntl.h>

#include <stdbool.h>

#include <string.h>

#include <sys/stat.h>

#define ARGV_DRIVER

#include <mdso/mdso.h>

#include <mdso/mdso_output.h>

#include <mdso/mdso_specs.h>

#include "mdso_version.h"

#include "mdso_driver_impl.h"

#include "argv/argv.h"

#define MDSO_LOADER_FLAGS_MASK	(MDSO_FLAG_LOADER_PATH \

				| MDSO_FLAG_LDSO_LIB   \

				| MDSO_FLAG_PEB_PATH   \

				| MDSO_FLAG_SYSTEM32)

/* package info */

static const struct mdso_source_version mdso_src_version = {

	MDSO_TAG_VER_MAJOR,

	MDSO_TAG_VER_MINOR,

	MDSO_TAG_VER_PATCH,

	MDSO_GIT_VERSION

};

/* default fd context */

static const struct mdso_fd_ctx mdso_default_fdctx = {

	.fdin  = STDIN_FILENO,

	.fdout = STDOUT_FILENO,

	.fderr = STDERR_FILENO,

	.fdcwd = AT_FDCWD,

	.fddst = AT_FDCWD,

	.fdlog = (-1),

};

struct mdso_driver_ctx_alloc {

	struct argv_meta *		meta;

	struct mdso_driver_ctx_impl	ctx;

	uint64_t			guard;

	const char *			units[];

};

static uint32_t mdso_argv_flags(uint32_t flags)

{

	uint32_t ret = ARGV_CLONE_VECTOR;

	if (flags & MDSO_DRIVER_VERBOSITY_NONE)

		ret |= ARGV_VERBOSITY_NONE;

	if (flags & MDSO_DRIVER_VERBOSITY_ERRORS)

		ret |= ARGV_VERBOSITY_ERRORS;

	if (flags & MDSO_DRIVER_VERBOSITY_STATUS)

		ret |= ARGV_VERBOSITY_STATUS;

	return ret;

}

static int mdso_driver_usage(

	int				fdout,

	const char *			program,

	const char *			arg,

	const struct argv_option **	optv,

	struct argv_meta *		meta)

{

	char header[512];

	snprintf(header,sizeof(header),

		"Usage: %s [options] <file>...\n" "Options:\n",

		program);

	argv_usage(fdout,header,optv,arg);

	argv_free(meta);

	return MDSO_USAGE;

}

static struct mdso_driver_ctx_impl * mdso_driver_ctx_alloc(

	struct argv_meta *		meta,

	const struct mdso_fd_ctx *	fdctx,

	const struct mdso_common_ctx *	cctx,

	size_t				nunits)

{

	struct mdso_driver_ctx_alloc *	ictx;

	size_t				size;

	struct argv_entry *		entry;

	const char **			units;

	int				elements;

	size =  sizeof(struct mdso_driver_ctx_alloc);

	size += (nunits+1)*sizeof(const char *);

	if (!(ictx = calloc(1,size)))

		return 0;

	memcpy(&ictx->ctx.fdctx,fdctx,sizeof(*fdctx));

	memcpy(&ictx->ctx.cctx,cctx,sizeof(*cctx));

	for (entry=meta->entries,units=ictx->units; entry->fopt || entry->arg; entry++)

		if (!entry->fopt)

			*units++ = entry->arg;

	elements = sizeof(ictx->ctx.erribuf) / sizeof(*ictx->ctx.erribuf);

	ictx->ctx.errinfp  = &ictx->ctx.erriptr[0];

	ictx->ctx.erricap  = &ictx->ctx.erriptr[--elements];

	ictx->meta = meta;

	ictx->ctx.fdtmpin = -1;

	ictx->ctx.ctx.units = ictx->units;

	ictx->ctx.ctx.errv  = ictx->ctx.errinfp;

	return &ictx->ctx;

}

static int mdso_dstdir_open(int fdcwd, const char * dstdir, const char * asmbase)

{

	int fdtop;

	int fddst;

	int dirmode = S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;

	if (!dstdir)

		fdtop = fdcwd;

	else if ((fdtop = openat(fdcwd,dstdir,O_DIRECTORY)) >= 0)

		(void)0;

	else if (mkdirat(fdcwd,dstdir,dirmode) < 0)

			return -1;

	else if ((fdtop = openat(fdcwd,dstdir,O_DIRECTORY)) < 0)

		return -1;

	if ((fddst = openat(fdtop,asmbase,O_DIRECTORY)) >= 0)

		(void)0;

	else if (mkdirat(fdtop,asmbase,dirmode))

		fddst = AT_FDCWD;

	else if ((fddst = openat(fdtop,asmbase,O_DIRECTORY)) < 0)

		fddst = AT_FDCWD;

	close(fdtop);

	return fddst;

}

static int mdso_get_driver_ctx_fail(

	struct argv_meta *	meta,

	char *			implib,

	char *			asmbase,

	int			fddst)

{

	if (fddst != AT_FDCWD)

		close(fddst);

	if (implib)

		free(implib);

	if (asmbase)

		free(asmbase);

	argv_free(meta);

	return -1;

}

int mdso_get_driver_ctx(

	char **				argv,

	char **				envp,

	uint32_t			flags,

	const struct mdso_fd_ctx *	fdctx,

	struct mdso_driver_ctx **	pctx)

{

	struct mdso_driver_ctx_impl *	ctx;

	struct mdso_common_ctx		cctx;

	const struct argv_option *	optv[MDSO_OPTV_ELEMENTS];

	struct argv_meta *		meta;

	struct argv_entry *		entry;

	struct argv_entry *		machine;

	size_t				nunits;

	const char *			program;

	const char *			pretty;

	char *				implib;

	char *				asmbase;

	char *				dot;

	int				fddst;

	(void)envp;

	if (!fdctx)

		fdctx = &mdso_default_fdctx;

	argv_optv_init(mdso_default_options,optv);

	if (!(meta = argv_get(

			argv,optv,

			mdso_argv_flags(flags),

			fdctx->fderr)))

		return -1;

	/* cctx init, option defaults */

	memset(&cctx,0,sizeof(cctx));

	machine = 0;

	nunits	= 0;

	pretty	= 0;

	implib  = 0;

	asmbase = 0;

	program = argv_program_name(argv[0]);

	cctx.drvflags = flags;

	cctx.dsoflags = MDSO_FLAG_LOADER_PATH;

	if (!argv[1] && (flags & MDSO_DRIVER_VERBOSITY_USAGE))

		return mdso_driver_usage(

			fdctx->fderr,

			program,0,

			optv,meta);

	/* get options, count units */

	for (entry=meta->entries; entry->fopt || entry->arg; entry++) {

		if (entry->fopt) {

			switch (entry->tag) {

				case TAG_HELP:

					if (flags & MDSO_DRIVER_VERBOSITY_USAGE)

						return mdso_driver_usage(

							fdctx->fdout,

							program,

							entry->arg,

							optv,meta);

					break;

				case TAG_VERSION:

					cctx.drvflags |= MDSO_DRIVER_VERSION;

					break;

				case TAG_ASM:

					cctx.drvflags |= MDSO_DRIVER_GENERATE_ASM;

					break;

				case TAG_OBJ:

					cctx.drvflags |= MDSO_DRIVER_GENERATE_OBJECTS;

					break;

				case TAG_CRC:

					if (!(strcmp(entry->arg,"64"))) {

						cctx.drvflags &= ~(uint64_t)MDSO_DRIVER_COMPUTE_CRC32;

						cctx.drvflags |= MDSO_DRIVER_COMPUTE_CRC64;

					} else {

						cctx.drvflags &= ~(uint64_t)MDSO_DRIVER_COMPUTE_CRC64;

						cctx.drvflags |= MDSO_DRIVER_COMPUTE_CRC32;

					}

					break;

				case TAG_QUAD_PTR:

					machine = entry;

					if (!(strcmp(entry->arg,"64")))

						cctx.drvflags |= MDSO_DRIVER_QUAD_PTR;

					else

						cctx.drvflags &= ~(uint64_t)MDSO_DRIVER_QUAD_PTR;

					break;

				case TAG_IMPLIB:

					cctx.implib = entry->arg;

					break;

				case TAG_LIBPATH:

					cctx.dsoflags &= ~(uint64_t)MDSO_LOADER_FLAGS_MASK;

					if (!(strcmp(entry->arg,"loader")))

						cctx.dsoflags |= MDSO_FLAG_LOADER_PATH;

					else if (!(strcmp(entry->arg,"ldso")))

						cctx.dsoflags |= MDSO_FLAG_LDSO_LIB;

					else if (!(strcmp(entry->arg,"peb")))

						cctx.dsoflags |= MDSO_FLAG_PEB_PATH;

					else if (!(strcmp(entry->arg,"system32")))

						cctx.dsoflags |= MDSO_FLAG_SYSTEM32;

					break;

				case TAG_LIBNAME:

					cctx.libname = entry->arg;

					break;

				case TAG_DSTDIR:

					cctx.dstdir = entry->arg;

					break;

				case TAG_PRETTY:

					pretty = entry->arg;

					break;

				case TAG_EXPSYMS:

					cctx.fmtflags |= MDSO_OUTPUT_EXPORT_SYMS;

					break;

			}

		} else

			nunits++;

	}

	if (!machine && MDSO_DRIVER_PE_HOST && (sizeof(size_t) == 8))

		cctx.drvflags |= MDSO_DRIVER_QUAD_PTR;

	else if (!machine && MDSO_DRIVER_WINNT_HOST && (sizeof(size_t) == 8))

		cctx.drvflags |= MDSO_DRIVER_QUAD_PTR;

	else if (!machine && strstr(program,"64"))

		cctx.drvflags |= MDSO_DRIVER_QUAD_PTR;

	if (cctx.drvflags & MDSO_DRIVER_VERBOSITY_USAGE)

		if (!nunits && !(cctx.drvflags & MDSO_DRIVER_VERSION))

			return mdso_driver_usage(

				fdctx->fderr,

				program,0,

				optv,meta);

	if (pretty && !strcmp(pretty,"yaml"))

		cctx.fmtflags |= MDSO_PRETTY_YAML;

	if (!cctx.libname)

		cctx.libname = "win32any";

	if (cctx.implib && !(implib = strdup(cctx.implib)))

		return mdso_get_driver_ctx_fail(meta,0,0,AT_FDCWD);

	if (!(asmbase = strdup(cctx.libname)))

		return mdso_get_driver_ctx_fail(meta,implib,0,AT_FDCWD);

	if ((dot = strchr(asmbase,'.')))

		*dot = '\0';

	if (!cctx.dstdir && !(cctx.drvflags & MDSO_DRIVER_GENERATE_OBJECTS))

		fddst = AT_FDCWD;

	else if ((fddst = mdso_dstdir_open(fdctx->fdcwd,cctx.dstdir,asmbase)) < 0)

		return mdso_get_driver_ctx_fail(meta,implib,asmbase,AT_FDCWD);

	if (!(ctx = mdso_driver_ctx_alloc(meta,fdctx,&cctx,nunits)))

		return mdso_get_driver_ctx_fail(meta,implib,asmbase,fddst);

	ctx->implib		= implib;

	ctx->asmbase		= asmbase;

	ctx->cctx.asmbase	= asmbase;

	ctx->fddst		= fddst;

	ctx->ctx.program	= program;

	ctx->ctx.cctx		= &ctx->cctx;

	ctx->fdctx.fddst	= fddst;

	*pctx = &ctx->ctx;

	return MDSO_OK;

}

static void mdso_free_driver_ctx_impl(struct mdso_driver_ctx_alloc * ictx)

{

	if (ictx->ctx.fddst != AT_FDCWD)

		close(ictx->ctx.fddst);

	if (ictx->ctx.fdtmpin >= 0)

		unlink(ictx->ctx.tmpname);

	if (ictx->ctx.fdtmpin >= 0)

		close(ictx->ctx.fdtmpin);

	if (ictx->ctx.asmbase)

		free(ictx->ctx.asmbase);

	if (ictx->ctx.implib)

		free(ictx->ctx.implib);

	argv_free(ictx->meta);

	free(ictx);

}

void mdso_free_driver_ctx(struct mdso_driver_ctx * ctx)

{

	struct mdso_driver_ctx_alloc *	ictx;

	uintptr_t			addr;

	if (ctx) {

		addr = (uintptr_t)ctx - offsetof(struct mdso_driver_ctx_impl,ctx);

		addr = addr - offsetof(struct mdso_driver_ctx_alloc,ctx);

		ictx = (struct mdso_driver_ctx_alloc *)addr;

		mdso_free_driver_ctx_impl(ictx);

	}

}

const struct mdso_source_version * mdso_source_version(void)

{

	return &mdso_src_version;

}

int mdso_get_driver_fdctx(

	const struct mdso_driver_ctx *	dctx,

	struct mdso_fd_ctx *		fdctx)

{

	struct mdso_driver_ctx_impl *	ictx;

	ictx = mdso_get_driver_ictx(dctx);

	fdctx->fdin  = ictx->fdctx.fdin;

	fdctx->fdout = ictx->fdctx.fdout;

	fdctx->fderr = ictx->fdctx.fderr;

	fdctx->fdlog = ictx->fdctx.fdlog;

	fdctx->fdcwd = ictx->fdctx.fdcwd;

	fdctx->fddst = ictx->fdctx.fddst;

	return 0;

}

int mdso_set_driver_fdctx(

	struct mdso_driver_ctx *	dctx,

	const struct mdso_fd_ctx *	fdctx)

{

	struct mdso_driver_ctx_impl *	ictx;

	ictx = mdso_get_driver_ictx(dctx);

	ictx->fdctx.fdin  = fdctx->fdin;

	ictx->fdctx.fdout = fdctx->fdout;

	ictx->fdctx.fderr = fdctx->fderr;

	ictx->fdctx.fdlog = fdctx->fdlog;

	ictx->fdctx.fdcwd = fdctx->fdcwd;

	if (ictx->fdctx.fddst == fdctx->fddst) {

		(void)0;

	} else if (ictx->fddst == AT_FDCWD) {

		ictx->fdctx.fddst = fdctx->fddst;

	} else {

		close(ictx->fddst);

		ictx->fddst       = AT_FDCWD;

		ictx->fdctx.fddst = fdctx->fddst;

	}

	return 0;

}