strace/dirent64.c

107 lines
2.4 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) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2015-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
#include <dirent.h>
#include "xlat/dirent_types.h"
#define D_NAME_LEN_MAX 256
SYS_FUNC(getdents64)
{
/* the minimum size of a valid dirent64 structure */
const unsigned int d_name_offset = offsetof(struct dirent64, d_name);
unsigned int i, len, dents = 0;
char *buf;
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
return 0;
}
const unsigned int count = tcp->u_arg[2];
if (syserror(tcp) || !verbose(tcp)) {
tprints(", ");
printaddr(tcp->u_arg[1]);
tprintf(", %u", count);
return 0;
}
/* Beware of insanely large or too small values in tcp->u_rval */
if (tcp->u_rval > 1024*1024)
len = 1024*1024;
else if (tcp->u_rval < (int) d_name_offset)
len = 0;
else
len = tcp->u_rval;
if (len) {
buf = malloc(len);
if (!buf || umoven(tcp, tcp->u_arg[1], len, buf) < 0) {
tprints(", ");
printaddr(tcp->u_arg[1]);
tprintf(", %u", count);
free(buf);
return 0;
}
} else {
buf = NULL;
}
tprints(",");
if (!abbrev(tcp))
tprints(" [");
for (i = 0; len && i <= len - d_name_offset; ) {
struct dirent64 *d = (struct dirent64 *) &buf[i];
if (!abbrev(tcp)) {
int d_name_len;
if (d->d_reclen >= d_name_offset
&& i + d->d_reclen <= len) {
d_name_len = d->d_reclen - d_name_offset;
} else {
d_name_len = len - i - d_name_offset;
}
if (d_name_len > D_NAME_LEN_MAX)
d_name_len = D_NAME_LEN_MAX;
tprintf("%s{d_ino=%" PRIu64 ", d_off=%" PRId64
", d_reclen=%u, d_type=",
i ? ", " : "",
d->d_ino,
d->d_off,
d->d_reclen);
printxval(dirent_types, d->d_type, "DT_???");
tprints(", d_name=");
print_quoted_cstring(d->d_name, d_name_len);
tprints("}");
}
if (d->d_reclen < d_name_offset) {
tprints_comment("d_reclen < offsetof(struct dirent64, d_name)");
break;
}
i += d->d_reclen;
dents++;
}
if (!abbrev(tcp))
tprints("]");
else
tprintf_comment("%u entries", dents);
tprintf(", %u", count);
free(buf);
return 0;
}