strace/ioctl.c
Dmitry V. Levin 204c2bc9cb Implement RVAL_DECODED flag
Implement a method for "on entering" parsers to return
"done with decoding" information to their callers.

If a syscall parser called from trace_syscall_entering returns a value
with RVAL_DECODED bit set, record this value in tcp->sys_func_rval
and use it in trace_syscall_exiting instead of calling the parser on
exiting syscall.

If an ioctl parser returned RVAL_DECODED, this would tell
SYS_FUNC(ioctl) that the decoding is finished but fallback printing of
the ioctl command argument is needed, while e.g. RVAL_DONE+1 would mean
that the decoding is finished and no fallback decoding is needed.

* defs.h (struct tcb): Add sys_func_rval.
(RVAL_DECODED): New macro.
* syscall.c (trace_syscall_entering): Initialize tcp->sys_func_rval
along with setting TCB_INSYSCALL flag.
(trace_syscall_exiting): Use tcp->sys_func_rval instead of calling
tcp->s_ent->sys_func when the former has RVAL_DECODED flag set.
Reset tcp->sys_func_rval along with clearing TCB_INSYSCALL flag.
* ioctl.c (sys_ioctl): Set RVAL_DECODED flag on exiting.
Print ioctl argument iff RVAL_DECODED is set and fallback decoding
is requested.
2015-07-09 01:08:01 +00:00

309 lines
7.3 KiB
C

/*
* 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) 1996-2001 Wichert Akkerman <wichert@cistron.nl>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include <linux/ioctl.h>
#include "xlat/ioctl_dirs.h"
#ifdef HAVE_LINUX_INPUT_H
# include <linux/input.h>
#endif
#include "xlat/evdev_abs.h"
#include "xlat/evdev_ev.h"
static int
compare(const void *a, const void *b)
{
const unsigned int code1 = (const unsigned long) a;
const unsigned int code2 = ((struct_ioctlent *) b)->code;
return (code1 > code2) ? 1 : (code1 < code2) ? -1 : 0;
}
static const struct_ioctlent *
ioctl_lookup(const unsigned int code)
{
struct_ioctlent *iop;
iop = bsearch((const void *) (const unsigned long) code, ioctlent,
nioctlents, sizeof(ioctlent[0]), compare);
while (iop > ioctlent) {
iop--;
if (iop->code != code) {
iop++;
break;
}
}
return iop;
}
static const struct_ioctlent *
ioctl_next_match(const struct_ioctlent *iop)
{
const unsigned int code = iop->code;
iop++;
if (iop < ioctlent + nioctlents && iop->code == code)
return iop;
return NULL;
}
static void
ioctl_print_code(const unsigned int code)
{
tprints("_IOC(");
printflags(ioctl_dirs, _IOC_DIR(code), "_IOC_???");
tprintf(", 0x%02x, 0x%02x, 0x%02x)",
_IOC_TYPE(code), _IOC_NR(code), _IOC_SIZE(code));
}
static int
evdev_decode_number(const unsigned int code)
{
const unsigned int nr = _IOC_NR(code);
if (_IOC_DIR(code) == _IOC_WRITE) {
if (nr >= 0xc0 && nr <= 0xc0 + 0x3f) {
tprints("EVIOCSABS(");
printxval(evdev_abs, nr - 0xc0, "EV_???");
tprints(")");
return 1;
}
}
if (_IOC_DIR(code) != _IOC_READ)
return 0;
if (nr >= 0x20 && nr <= 0x20 + 0x1f) {
tprints("EVIOCGBIT(");
printxval(evdev_ev, nr - 0x20, "EV_???");
tprintf(", %u)", _IOC_SIZE(code));
return 1;
} else if (nr >= 0x40 && nr <= 0x40 + 0x3f) {
tprints("EVIOCGABS(");
printxval(evdev_abs, nr - 0x40, "ABS_???");
tprints(")");
return 1;
}
switch (_IOC_NR(nr)) {
case 0x06:
tprintf("EVIOCGNAME(%u)", _IOC_SIZE(code));
return 1;
case 0x07:
tprintf("EVIOCGPHYS(%u)", _IOC_SIZE(code));
return 1;
case 0x08:
tprintf("EVIOCGUNIQ(%u)", _IOC_SIZE(code));
return 1;
case 0x09:
tprintf("EVIOCGPROP(%u)", _IOC_SIZE(code));
return 1;
case 0x0a:
tprintf("EVIOCGMTSLOTS(%u)", _IOC_SIZE(code));
return 1;
case 0x18:
tprintf("EVIOCGKEY(%u)", _IOC_SIZE(code));
return 1;
case 0x19:
tprintf("EVIOCGLED(%u)", _IOC_SIZE(code));
return 1;
case 0x1a:
tprintf("EVIOCGSND(%u)", _IOC_SIZE(code));
return 1;
case 0x1b:
tprintf("EVIOCGSW(%u)", _IOC_SIZE(code));
return 1;
default:
return 0;
}
}
static int
hiddev_decode_number(const unsigned int code)
{
if (_IOC_DIR(code) == _IOC_READ) {
switch (_IOC_NR(code)) {
case 0x04:
tprintf("HIDIOCGRAWNAME(%u)", _IOC_SIZE(code));
return 1;
case 0x05:
tprintf("HIDIOCGRAWPHYS(%u)", _IOC_SIZE(code));
return 1;
case 0x06:
tprintf("HIDIOCSFEATURE(%u)", _IOC_SIZE(code));
return 1;
case 0x12:
tprintf("HIDIOCGPHYS(%u)", _IOC_SIZE(code));
return 1;
default:
return 0;
}
} else if (_IOC_DIR(code) == (_IOC_READ | _IOC_WRITE)) {
switch (_IOC_NR(code)) {
case 0x06:
tprintf("HIDIOCSFEATURE(%u)", _IOC_SIZE(code));
return 1;
case 0x07:
tprintf("HIDIOCGFEATURE(%u)", _IOC_SIZE(code));
return 1;
default:
return 0;
}
}
return 0;
}
static int
ioctl_decode_command_number(struct tcb *tcp)
{
const unsigned int code = tcp->u_arg[1];
switch (_IOC_TYPE(code)) {
case 'E':
return evdev_decode_number(code);
case 'H':
return hiddev_decode_number(code);
case 'M':
if (_IOC_DIR(code) == _IOC_WRITE) {
tprintf("MIXER_WRITE(%u)", _IOC_NR(code));
return 1;
} else if (_IOC_DIR(code) == _IOC_READ) {
tprintf("MIXER_READ(%u)", _IOC_NR(code));
return 1;
}
return 0;
case 'U':
if (_IOC_DIR(code) == _IOC_READ && _IOC_NR(code) == 0x2c) {
tprintf("UI_GET_SYSNAME(%u)", _IOC_SIZE(code));
return 1;
}
return 0;
case 'j':
if (_IOC_DIR(code) == _IOC_READ && _IOC_NR(code) == 0x13) {
tprintf("JSIOCGNAME(%u)", _IOC_SIZE(code));
return 1;
}
return 0;
case 'k':
if (_IOC_DIR(code) == _IOC_WRITE && _IOC_NR(code) == 0) {
tprintf("SPI_IOC_MESSAGE(%u)", _IOC_SIZE(code));
return 1;
}
return 0;
default:
return 0;
}
}
static int
ioctl_decode(struct tcb *tcp)
{
const unsigned int code = tcp->u_arg[1];
const long arg = tcp->u_arg[2];
switch (_IOC_TYPE(code)) {
#if defined(ALPHA) || defined(POWERPC)
case 'f': case 't': case 'T':
#else /* !ALPHA */
case 0x54:
#endif /* !ALPHA */
return term_ioctl(tcp, code, arg);
case 0x89:
return sock_ioctl(tcp, code, arg);
case 'p':
return rtc_ioctl(tcp, code, arg);
case 0x03:
case 0x12:
case 'X':
return block_ioctl(tcp, code, arg);
#ifdef HAVE_SCSI_SG_H
case 0x22:
return scsi_ioctl(tcp, code, arg);
#endif
case 'L':
return loop_ioctl(tcp, code, arg);
case 'M':
return mtd_ioctl(tcp, code, arg);
case 'o':
case 'O':
return ubi_ioctl(tcp, code, arg);
case 'V':
return v4l2_ioctl(tcp, code, arg);
case '=':
return ptp_ioctl(tcp, code, arg);
#ifdef HAVE_LINUX_INPUT_H
case 'E':
return evdev_ioctl(tcp, code, arg);
#endif
default:
break;
}
return 0;
}
SYS_FUNC(ioctl)
{
const struct_ioctlent *iop;
int ret;
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
tprints(", ");
if (!ioctl_decode_command_number(tcp)) {
iop = ioctl_lookup(tcp->u_arg[1]);
if (iop) {
tprints(iop->symbol);
while ((iop = ioctl_next_match(iop)))
tprintf(" or %s", iop->symbol);
} else {
ioctl_print_code(tcp->u_arg[1]);
}
}
ret = ioctl_decode(tcp);
} else {
ret = ioctl_decode(tcp) | RVAL_DECODED;
}
if (ret & RVAL_DECODED) {
ret &= ~RVAL_DECODED;
if (ret)
--ret;
else
tprintf(", %#lx", tcp->u_arg[2]);
ret |= RVAL_DECODED;
} else {
if (ret)
--ret;
}
return ret;
}