granicus.if.org Git - strace/blob - dirent64.c

   1 /*
   2  * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
   3  * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
   4  * Copyright (c) 1993, 1994, 1995, 1996 Rick Sladkey <jrs@world.std.com>
   5  * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
   6  * Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
   7  * Copyright (c) 2015-2018 The strace developers.
   8  * All rights reserved.
   9  *
  10  * SPDX-License-Identifier: LGPL-2.1-or-later
  11  */
  12
  13 #include "defs.h"
  14 #include <dirent.h>
  15
  16 #include "xlat/dirent_types.h"
  17
  18 #define D_NAME_LEN_MAX 256
  19
  20 SYS_FUNC(getdents64)
  21 {
  22         /* the minimum size of a valid dirent64 structure */
  23         const unsigned int d_name_offset = offsetof(struct dirent64, d_name);
  24
  25         unsigned int i, len, dents = 0;
  26         char *buf;
  27
  28         if (entering(tcp)) {
  29                 printfd(tcp, tcp->u_arg[0]);
  30                 return 0;
  31         }
  32
  33         const unsigned int count = tcp->u_arg[2];
  34
  35         if (syserror(tcp) || !verbose(tcp)) {
  36                 tprints(", ");
  37                 printaddr(tcp->u_arg[1]);
  38                 tprintf(", %u", count);
  39                 return 0;
  40         }
  41
  42         /* Beware of insanely large or too small values in tcp->u_rval */
  43         if (tcp->u_rval > 1024*1024)
  44                 len = 1024*1024;
  45         else if (tcp->u_rval < (int) d_name_offset)
  46                 len = 0;
  47         else
  48                 len = tcp->u_rval;
  49
  50         if (len) {
  51                 buf = malloc(len);
  52                 if (!buf || umoven(tcp, tcp->u_arg[1], len, buf) < 0) {
  53                         tprints(", ");
  54                         printaddr(tcp->u_arg[1]);
  55                         tprintf(", %u", count);
  56                         free(buf);
  57                         return 0;
  58                 }
  59         } else {
  60                 buf = NULL;
  61         }
  62
  63         tprints(",");
  64         if (!abbrev(tcp))
  65                 tprints(" [");
  66         for (i = 0; len && i <= len - d_name_offset; ) {
  67                 struct dirent64 *d = (struct dirent64 *) &buf[i];
  68                 if (!abbrev(tcp)) {
  69                         int d_name_len;
  70                         if (d->d_reclen >= d_name_offset
  71                             && i + d->d_reclen <= len) {
  72                                 d_name_len = d->d_reclen - d_name_offset;
  73                         } else {
  74                                 d_name_len = len - i - d_name_offset;
  75                         }
  76                         if (d_name_len > D_NAME_LEN_MAX)
  77                                 d_name_len = D_NAME_LEN_MAX;
  78
  79                         tprintf("%s{d_ino=%" PRIu64 ", d_off=%" PRId64
  80                                 ", d_reclen=%u, d_type=",
  81                                 i ? ", " : "",
  82                                 d->d_ino,
  83                                 d->d_off,
  84                                 d->d_reclen);
  85                         printxval(dirent_types, d->d_type, "DT_???");
  86
  87                         tprints(", d_name=");
  88                         print_quoted_cstring(d->d_name, d_name_len);
  89
  90                         tprints("}");
  91                 }
  92                 if (d->d_reclen < d_name_offset) {
  93                         tprints_comment("d_reclen < offsetof(struct dirent64, d_name)");
  94                         break;
  95                 }
  96                 i += d->d_reclen;
  97                 dents++;
  98         }
  99         if (!abbrev(tcp))
 100                 tprints("]");
 101         else
 102                 tprintf_comment("%u entries", dents);
 103         tprintf(", %u", count);
 104         free(buf);
 105         return 0;
 106 }