strace/dirent.c

139 lines
3.1 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) 2014-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
#include DEF_MPERS_TYPE(kernel_dirent)
#include MPERS_DEFS
#define D_NAME_LEN_MAX 256
static void
print_old_dirent(struct tcb *const tcp, const kernel_ulong_t addr)
{
kernel_dirent d;
if (umove_or_printaddr(tcp, addr, &d))
return;
tprintf("{d_ino=%llu, d_off=%llu, d_reclen=%u, d_name=",
zero_extend_signed_to_ull(d.d_ino),
zero_extend_signed_to_ull(d.d_off), d.d_reclen);
if (d.d_reclen > D_NAME_LEN_MAX)
d.d_reclen = D_NAME_LEN_MAX;
printpathn(tcp, addr + offsetof(kernel_dirent, d_name), d.d_reclen);
tprints("}");
}
SYS_FUNC(readdir)
{
if (entering(tcp)) {
printfd(tcp, tcp->u_arg[0]);
tprints(", ");
} else {
if (tcp->u_rval == 0)
printaddr(tcp->u_arg[1]);
else
print_old_dirent(tcp, tcp->u_arg[1]);
/* Not much point in printing this out, it is always 1. */
if (tcp->u_arg[2] != 1)
tprintf(", %" PRI_klu, tcp->u_arg[2]);
}
return 0;
}
SYS_FUNC(getdents)
{
unsigned int i, len, dents = 0;
unsigned 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) sizeof(kernel_dirent))
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 - sizeof(kernel_dirent); ) {
kernel_dirent *d = (kernel_dirent *) &buf[i];
if (!abbrev(tcp)) {
int oob = d->d_reclen < sizeof(kernel_dirent) ||
i + d->d_reclen - 1 >= len;
int d_name_len = oob ? len - i : d->d_reclen;
d_name_len -= offsetof(kernel_dirent, d_name) + 1;
if (d_name_len > D_NAME_LEN_MAX)
d_name_len = D_NAME_LEN_MAX;
tprintf("%s{d_ino=%llu, d_off=%llu, d_reclen=%u"
", d_name=", i ? ", " : "",
zero_extend_signed_to_ull(d->d_ino),
zero_extend_signed_to_ull(d->d_off),
d->d_reclen);
print_quoted_cstring(d->d_name, d_name_len);
tprints(", d_type=");
if (oob)
tprints("?");
else
printxval(dirent_types, buf[i + d->d_reclen - 1], "DT_???");
tprints("}");
}
dents++;
if (d->d_reclen < sizeof(kernel_dirent)) {
tprints_comment("d_reclen < sizeof(struct dirent)");
break;
}
i += d->d_reclen;
}
if (!abbrev(tcp))
tprints("]");
else
tprintf_comment("%u entries", dents);
tprintf(", %u", count);
free(buf);
return 0;
}