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  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. The name of the author may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "defs.h"
  33 #include <dirent.h>
  34
  35 #include "xlat/dirent_types.h"
  36
  37 #define D_NAME_LEN_MAX 256
  38
  39 SYS_FUNC(getdents64)
  40 {
  41         /* the minimum size of a valid dirent64 structure */
  42         const unsigned int d_name_offset = offsetof(struct dirent64, d_name);
  43
  44         unsigned int i, len, dents = 0;
  45         char *buf;
  46
  47         if (entering(tcp)) {
  48                 printfd(tcp, tcp->u_arg[0]);
  49                 tprints(", ");
  50                 return 0;
  51         }
  52
  53         const unsigned int count = tcp->u_arg[2];
  54
  55         if (syserror(tcp) || !verbose(tcp)) {
  56                 printaddr(tcp->u_arg[1]);
  57                 tprintf(", %u", count);
  58                 return 0;
  59         }
  60
  61         /* Beware of insanely large or too small values in tcp->u_rval */
  62         if (tcp->u_rval > 1024*1024)
  63                 len = 1024*1024;
  64         else if (tcp->u_rval < (int) d_name_offset)
  65                 len = 0;
  66         else
  67                 len = tcp->u_rval;
  68
  69         if (len) {
  70                 buf = malloc(len);
  71                 if (!buf || umoven(tcp, tcp->u_arg[1], len, buf) < 0) {
  72                         printaddr(tcp->u_arg[1]);
  73                         tprintf(", %u", count);
  74                         free(buf);
  75                         return 0;
  76                 }
  77         } else {
  78                 buf = NULL;
  79         }
  80
  81         if (!abbrev(tcp))
  82                 tprints("[");
  83         for (i = 0; len && i <= len - d_name_offset; ) {
  84                 struct dirent64 *d = (struct dirent64 *) &buf[i];
  85                 if (!abbrev(tcp)) {
  86                         int d_name_len;
  87                         if (d->d_reclen >= d_name_offset
  88                             && i + d->d_reclen <= len) {
  89                                 d_name_len = d->d_reclen - d_name_offset;
  90                         } else {
  91                                 d_name_len = len - i - d_name_offset;
  92                         }
  93                         if (d_name_len > D_NAME_LEN_MAX)
  94                                 d_name_len = D_NAME_LEN_MAX;
  95
  96                         tprintf("%s{d_ino=%" PRIu64 ", d_off=%" PRId64
  97                                 ", d_reclen=%u, d_type=",
  98                                 i ? ", " : "",
  99                                 d->d_ino,
 100                                 d->d_off,
 101                                 d->d_reclen);
 102                         printxval(dirent_types, d->d_type, "DT_???");
 103
 104                         tprints(", d_name=");
 105                         if (print_quoted_string(d->d_name, d_name_len,
 106                                                 QUOTE_0_TERMINATED) > 0) {
 107                                 tprints("...");
 108                         }
 109
 110                         tprints("}");
 111                 }
 112                 if (d->d_reclen < d_name_offset) {
 113                         tprints("/* d_reclen < offsetof(struct dirent64, d_name) */");
 114                         break;
 115                 }
 116                 i += d->d_reclen;
 117                 dents++;
 118         }
 119         if (!abbrev(tcp))
 120                 tprints("]");
 121         else
 122                 tprintf("/* %u entries */", dents);
 123         tprintf(", %u", count);
 124         free(buf);
 125         return 0;
 126 }