desc.c - platform/external/strace - Gitiles

 /*
  * 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) 1999-2018 The strace developers.
  * 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 "xstring.h"

 SYS_FUNC(close)
 {
 	printfd(tcp, tcp->u_arg[0]);

 	return RVAL_DECODED;
 }

 SYS_FUNC(dup)
 {
 	printfd(tcp, tcp->u_arg[0]);

 	return RVAL_DECODED | RVAL_FD;
 }

 static int
 do_dup2(struct tcb *tcp, int flags_arg)
 {
 	printfd(tcp, tcp->u_arg[0]);
 	tprints(", ");
 	printfd(tcp, tcp->u_arg[1]);
 	if (flags_arg >= 0) {
 		tprints(", ");
 		printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
 	}

 	return RVAL_DECODED | RVAL_FD;
 }

 SYS_FUNC(dup2)
 {
 	return do_dup2(tcp, -1);
 }

 SYS_FUNC(dup3)
 {
 	return do_dup2(tcp, 2);
 }

 static int
 decode_select(struct tcb *const tcp, const kernel_ulong_t *const args,
 	      void (*const print_tv_ts) (struct tcb *, kernel_ulong_t),
 	      const char * (*const sprint_tv_ts) (struct tcb *, kernel_ulong_t))
 {
 	int i, j;
 	int nfds, fdsize;
 	fd_set *fds = NULL;
 	const char *sep;
 	kernel_ulong_t addr;

 	/* Kernel truncates args[0] to int, we do the same. */
 	nfds = (int) args[0];

 	/* Kernel rejects negative nfds, so we don't parse it either. */
 	if (nfds < 0)
 		nfds = 0;

 	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
 	if (nfds > 1024*1024)
 		nfds = 1024*1024;

 	/*
 	 * We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
 	 * Instead of args[0], use nfds for fd count, fdsize for array lengths.
 	 */
 	fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;

 	if (entering(tcp)) {
 		tprintf("%d", (int) args[0]);

 		if (verbose(tcp) && fdsize > 0)
 			fds = malloc(fdsize);
 		for (i = 0; i < 3; i++) {
 			addr = args[i+1];
 			tprints(", ");
 			if (!fds) {
 				printaddr(addr);
 				continue;
 			}
 			if (umoven_or_printaddr(tcp, addr, fdsize, fds))
 				continue;
 			tprints("[");
 			for (j = 0, sep = "";; j++) {
 				j = next_set_bit(fds, j, nfds);
 				if (j < 0)
 					break;
 				tprints(sep);
 				printfd(tcp, j);
 				sep = " ";
 			}
 			tprints("]");
 		}
 		free(fds);
 		tprints(", ");
 		print_tv_ts(tcp, args[4]);
 	} else {
 		static char outstr[1024];
 		char *outptr;
 #define end_outstr (outstr + sizeof(outstr))
 		int ready_fds;

 		if (syserror(tcp))
 			return 0;

 		ready_fds = tcp->u_rval;
 		if (ready_fds == 0) {
 			tcp->auxstr = "Timeout";
 			return RVAL_STR;
 		}

 		fds = malloc(fdsize);

 		outptr = outstr;
 		sep = "";
 		for (i = 0; i < 3 && ready_fds > 0; i++) {
 			int first = 1;

 			addr = args[i+1];
 			if (!addr || !fds || umoven(tcp, addr, fdsize, fds) < 0)
 				continue;
 			for (j = 0;; j++) {
 				j = next_set_bit(fds, j, nfds);
 				if (j < 0)
 					break;
 				/* +2 chars needed at the end: ']',NUL */
 				if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
 					if (first) {
 						outptr = xappendstr(outstr,
 							outptr,
 							"%s%s [%u",
 							sep,
 							i == 0 ? "in" : i == 1 ? "out" : "except",
 							j
 						);
 						first = 0;
 						sep = ", ";
 					} else {
 						outptr = xappendstr(outstr,
 							outptr,
 							" %u", j);
 					}
 				}
 				if (--ready_fds == 0)
 					break;
 			}
 			if (outptr != outstr)
 				*outptr++ = ']';
 		}
 		free(fds);
 		/* This contains no useful information on SunOS.  */
 		if (args[4]) {
 			const char *str = sprint_tv_ts(tcp, args[4]);
 			if (outptr + sizeof("left ") + strlen(sep) + strlen(str) < end_outstr) {
 				outptr = xappendstr(outstr, outptr,
 						    "%sleft %s", sep, str);
 			}
 		}
 		*outptr = '\0';
 		tcp->auxstr = outstr;
 		return RVAL_STR;
 #undef end_outstr
 	}
 	return 0;
 }

 #if HAVE_ARCH_OLD_SELECT
 SYS_FUNC(oldselect)
 {
 	kernel_ulong_t *args =
 		fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 5);

 	if (args) {
 		return decode_select(tcp, args, print_timeval, sprint_timeval);
 	} else {
 		if (entering(tcp))
 			printaddr(tcp->u_arg[0]);
 		return RVAL_DECODED;
 	}
 }
 #endif /* HAVE_ARCH_OLD_SELECT */

 #ifdef ALPHA
 SYS_FUNC(osf_select)
 {
 	return decode_select(tcp, tcp->u_arg, print_timeval32, sprint_timeval32);
 }
 #endif

 SYS_FUNC(select)
 {
 	return decode_select(tcp, tcp->u_arg, print_timeval, sprint_timeval);
 }

 static int
 umove_kulong_array_or_printaddr(struct tcb *const tcp, const kernel_ulong_t addr,
 				kernel_ulong_t *const ptr, const size_t n)
 {
 #ifndef current_klongsize
 	if (current_klongsize < sizeof(*ptr)) {
 		uint32_t ptr32[n];
 		int r = umove_or_printaddr(tcp, addr, &ptr32);
 		if (!r) {
 			size_t i;

 			for (i = 0; i < n; ++i)
 				ptr[i] = ptr32[i];
 		}
 		return r;
 	}
 #endif /* !current_klongsize */
 	return umoven_or_printaddr(tcp, addr, n * sizeof(*ptr), ptr);
 }

 SYS_FUNC(pselect6)
 {
 	int rc = decode_select(tcp, tcp->u_arg, print_timespec, sprint_timespec);
 	if (entering(tcp)) {
 		kernel_ulong_t data[2];

 		tprints(", ");
 		if (!umove_kulong_array_or_printaddr(tcp, tcp->u_arg[5],
 						     data, ARRAY_SIZE(data))) {
 			tprints("{");
 			/* NB: kernel requires data[1] == NSIG_BYTES */
 			print_sigset_addr_len(tcp, data[0], data[1]);
 			tprintf(", %" PRI_klu "}", data[1]);
 		}
 	}

 	return rc;
 }
	/*
	* 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) 1999-2018 The strace developers.
	* 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 "xstring.h"

	SYS_FUNC(close)
	{
	printfd(tcp, tcp->u_arg[0]);

	return RVAL_DECODED;
	}

	SYS_FUNC(dup)
	{
	printfd(tcp, tcp->u_arg[0]);

	return RVAL_DECODED \| RVAL_FD;
	}

	static int
	do_dup2(struct tcb *tcp, int flags_arg)
	{
	printfd(tcp, tcp->u_arg[0]);
	tprints(", ");
	printfd(tcp, tcp->u_arg[1]);
	if (flags_arg >= 0) {
	tprints(", ");
	printflags(open_mode_flags, tcp->u_arg[flags_arg], "O_???");
	}

	return RVAL_DECODED \| RVAL_FD;
	}

	SYS_FUNC(dup2)
	{
	return do_dup2(tcp, -1);
	}

	SYS_FUNC(dup3)
	{
	return do_dup2(tcp, 2);
	}

	static int
	decode_select(struct tcb const tcp, const kernel_ulong_t const args,
	void (const print_tv_ts) (struct tcb , kernel_ulong_t),
	const char * (const sprint_tv_ts) (struct tcb , kernel_ulong_t))
	{
	int i, j;
	int nfds, fdsize;
	fd_set *fds = NULL;
	const char *sep;
	kernel_ulong_t addr;

	/* Kernel truncates args[0] to int, we do the same. */
	nfds = (int) args[0];

	/* Kernel rejects negative nfds, so we don't parse it either. */
	if (nfds < 0)
	nfds = 0;

	/* Beware of select(2^31-1, NULL, NULL, NULL) and similar... */
	if (nfds > 1024*1024)
	nfds = 1024*1024;

	/*
	* We had bugs a-la "while (j < args[0])" and "umoven(args[0])" below.
	* Instead of args[0], use nfds for fd count, fdsize for array lengths.
	*/
	fdsize = (((nfds + 7) / 8) + current_wordsize-1) & -current_wordsize;

	if (entering(tcp)) {
	tprintf("%d", (int) args[0]);

	if (verbose(tcp) && fdsize > 0)
	fds = malloc(fdsize);
	for (i = 0; i < 3; i++) {
	addr = args[i+1];
	tprints(", ");
	if (!fds) {
	printaddr(addr);
	continue;
	}
	if (umoven_or_printaddr(tcp, addr, fdsize, fds))
	continue;
	tprints("[");
	for (j = 0, sep = "";; j++) {
	j = next_set_bit(fds, j, nfds);
	if (j < 0)
	break;
	tprints(sep);
	printfd(tcp, j);
	sep = " ";
	}
	tprints("]");
	}
	free(fds);
	tprints(", ");
	print_tv_ts(tcp, args[4]);
	} else {
	static char outstr[1024];
	char *outptr;
	#define end_outstr (outstr + sizeof(outstr))
	int ready_fds;

	if (syserror(tcp))
	return 0;

	ready_fds = tcp->u_rval;
	if (ready_fds == 0) {
	tcp->auxstr = "Timeout";
	return RVAL_STR;
	}

	fds = malloc(fdsize);

	outptr = outstr;
	sep = "";
	for (i = 0; i < 3 && ready_fds > 0; i++) {
	int first = 1;

	addr = args[i+1];
	if (!addr \|\| !fds \|\| umoven(tcp, addr, fdsize, fds) < 0)
	continue;
	for (j = 0;; j++) {
	j = next_set_bit(fds, j, nfds);
	if (j < 0)
	break;
	/* +2 chars needed at the end: ']',NUL */
	if (outptr < end_outstr - (sizeof(", except [") + sizeof(int)*3 + 2)) {
	if (first) {
	outptr = xappendstr(outstr,
	outptr,
	"%s%s [%u",
	sep,
	i == 0 ? "in" : i == 1 ? "out" : "except",
	j
	);
	first = 0;
	sep = ", ";
	} else {
	outptr = xappendstr(outstr,
	outptr,
	" %u", j);
	}
	}
	if (--ready_fds == 0)
	break;
	}
	if (outptr != outstr)
	*outptr++ = ']';
	}
	free(fds);
	/* This contains no useful information on SunOS. */
	if (args[4]) {
	const char *str = sprint_tv_ts(tcp, args[4]);
	if (outptr + sizeof("left ") + strlen(sep) + strlen(str) < end_outstr) {
	outptr = xappendstr(outstr, outptr,
	"%sleft %s", sep, str);
	}
	}
	*outptr = '\0';
	tcp->auxstr = outstr;
	return RVAL_STR;
	#undef end_outstr
	}
	return 0;
	}

	#if HAVE_ARCH_OLD_SELECT
	SYS_FUNC(oldselect)
	{
	kernel_ulong_t *args =
	fetch_indirect_syscall_args(tcp, tcp->u_arg[0], 5);

	if (args) {
	return decode_select(tcp, args, print_timeval, sprint_timeval);
	} else {
	if (entering(tcp))
	printaddr(tcp->u_arg[0]);
	return RVAL_DECODED;
	}
	}
	#endif /* HAVE_ARCH_OLD_SELECT */

	#ifdef ALPHA
	SYS_FUNC(osf_select)
	{
	return decode_select(tcp, tcp->u_arg, print_timeval32, sprint_timeval32);
	}
	#endif

	SYS_FUNC(select)
	{
	return decode_select(tcp, tcp->u_arg, print_timeval, sprint_timeval);
	}

	static int
	umove_kulong_array_or_printaddr(struct tcb *const tcp, const kernel_ulong_t addr,
	kernel_ulong_t *const ptr, const size_t n)
	{
	#ifndef current_klongsize
	if (current_klongsize < sizeof(*ptr)) {
	uint32_t ptr32[n];
	int r = umove_or_printaddr(tcp, addr, &ptr32);
	if (!r) {
	size_t i;

	for (i = 0; i < n; ++i)
	ptr[i] = ptr32[i];
	}
	return r;
	}
	#endif /* !current_klongsize */
	return umoven_or_printaddr(tcp, addr, n * sizeof(*ptr), ptr);
	}

	SYS_FUNC(pselect6)
	{
	int rc = decode_select(tcp, tcp->u_arg, print_timespec, sprint_timespec);
	if (entering(tcp)) {
	kernel_ulong_t data[2];

	tprints(", ");
	if (!umove_kulong_array_or_printaddr(tcp, tcp->u_arg[5],
	data, ARRAY_SIZE(data))) {
	tprints("{");
	/* NB: kernel requires data[1] == NSIG_BYTES */
	print_sigset_addr_len(tcp, data[0], data[1]);
	tprintf(", %" PRI_klu "}", data[1]);
	}
	}

	return rc;
	}