/*
 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
 * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
 * Copyright (c) 2005-2007 Roland McGrath <roland@redhat.com>
 * Copyright (c) 2006-2007 Ulrich Drepper <drepper@redhat.com>
 * Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
 * Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
 * Copyright (c) 2014-2020 The strace developers.
 * All rights reserved.
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#include "defs.h"
#include "xstring.h"

#include <asm/fcntl.h>

#include "print_fields.h"

#include "types/openat2.h"

/* some libcs are guilty of messing up with O_ACCMODE */
#undef O_ACCMODE
#define O_ACCMODE 03

#ifdef O_LARGEFILE
# if O_LARGEFILE == 0		/* biarch platforms in 64-bit mode */
#  undef O_LARGEFILE
# endif
#endif

#include "xlat/open_access_modes.h"
#include "xlat/open_mode_flags.h"
#include "xlat/open_resolve_flags.h"

#ifndef AT_FDCWD
# define AT_FDCWD	-100
#endif

/* The fd is an "int", so when decoding x86 on x86_64, we need to force sign
 * extension to get the right value.  We do this by declaring fd as int here.
 */
void
print_dirfd(struct tcb *tcp, int fd)
{
	if (fd == AT_FDCWD)
		print_xlat_d(AT_FDCWD);
	else
		printfd(tcp, fd);
}

/*
 * low bits of the open(2) flags define access mode,
 * other bits are real flags.
 */
static const char *
sprint_open_modes64(uint64_t flags)
{
	static char outstr[sizeof("flags O_ACCMODE")];
	char *p;
	char sep;
	const char *str;

	sep = ' ';
	p = stpcpy(outstr, "flags");
	str = xlookup(open_access_modes, flags & 3);
	if (str) {
		*p++ = sep;
		p = stpcpy(p, str);
		flags &= ~3;
		if (!flags)
			return outstr;
		sep = '|';
	}
	*p = '\0';

	return sprintflags_ex(outstr, open_mode_flags, flags, sep,
			      XLAT_STYLE_ABBREV) ?: outstr;
}

const char *
sprint_open_modes(unsigned int flags)
{
	return sprint_open_modes64(flags);
}

static void
tprint_open_modes64(uint64_t flags)
{
	print_xlat_ex(flags, sprint_open_modes64(flags) + sizeof("flags"),
		      XLAT_STYLE_DEFAULT);
}
void
tprint_open_modes(unsigned int flags)
{
	tprint_open_modes64(flags);
}

static int
decode_open(struct tcb *tcp, int offset)
{
	printpath(tcp, tcp->u_arg[offset]);
	tprints(", ");
	/* flags */
	tprint_open_modes(tcp->u_arg[offset + 1]);
	if (tcp->u_arg[offset + 1] & (O_CREAT | __O_TMPFILE)) {
		/* mode */
		tprints(", ");
		print_numeric_umode_t(tcp->u_arg[offset + 2]);
	}

	return RVAL_DECODED | RVAL_FD;
}

SYS_FUNC(open)
{
	return decode_open(tcp, 0);
}

static void
print_open_how(struct tcb *tcp, kernel_ulong_t addr, kernel_ulong_t size)
{
	enum { OPEN_HOW_MIN_SIZE = 24 };

	struct_open_how how;

	if (size < OPEN_HOW_MIN_SIZE) {
		printaddr(addr);
		return;
	}
	if (umoven_or_printaddr(tcp, addr, MIN(size, sizeof(how)), &how))
		return;

	tprints("{flags=");
	tprint_open_modes64(how.flags);
	if ((how.flags & (O_CREAT| __O_TMPFILE)) || how.mode)
		PRINT_FIELD_NUMERIC_UMODE_T(", ", how, mode);
	PRINT_FIELD_FLAGS(", ", how, resolve, open_resolve_flags,
			  "RESOLVE_???");

	if (size > sizeof(how)) {
		print_nonzero_bytes(tcp, ", ", addr, sizeof(how),
				    MIN(size, get_pagesize()), QUOTE_FORCE_HEX);
	}

	tprints("}");
}

SYS_FUNC(openat)
{
	print_dirfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	return decode_open(tcp, 1);
}

SYS_FUNC(openat2)
{
	print_dirfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printpath(tcp, tcp->u_arg[1]);
	tprints(", ");
	print_open_how(tcp, tcp->u_arg[2], tcp->u_arg[3]);
	tprintf(", %" PRI_klu, tcp->u_arg[3]);

	return RVAL_DECODED | RVAL_FD;
}

SYS_FUNC(creat)
{
	printpath(tcp, tcp->u_arg[0]);
	tprints(", ");
	print_numeric_umode_t(tcp->u_arg[1]);

	return RVAL_DECODED | RVAL_FD;
}