granicus.if.org Git - strace/blob - dirent.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
  34 #include DEF_MPERS_TYPE(kernel_dirent)
  35
  36 #include <dirent.h>
  37
  38 typedef struct {
  39         unsigned long   d_ino;
  40         unsigned long   d_off;
  41         unsigned short  d_reclen;
  42         char            d_name[1];
  43 } kernel_dirent;
  44
  45 #include MPERS_DEFS
  46
  47 #define D_NAME_LEN_MAX 256
  48
  49 static void
  50 print_old_dirent(struct tcb *tcp, long addr)
  51 {
  52         kernel_dirent d;
  53
  54         if (umove_or_printaddr(tcp, addr, &d))
  55                 return;
  56
  57         tprintf("{d_ino=%lu, d_off=%lu, d_reclen=%u, d_name=",
  58                 (unsigned long) d.d_ino, (unsigned long) d.d_off, d.d_reclen);
  59         if (d.d_reclen > D_NAME_LEN_MAX)
  60                 d.d_reclen = D_NAME_LEN_MAX;
  61         printpathn(tcp, addr + offsetof(kernel_dirent, d_name), d.d_reclen);
  62         tprints("}");
  63 }
  64
  65 SYS_FUNC(readdir)
  66 {
  67         if (entering(tcp)) {
  68                 printfd(tcp, tcp->u_arg[0]);
  69                 tprints(", ");
  70         } else {
  71                 if (tcp->u_rval == 0)
  72                         printaddr(tcp->u_arg[1]);
  73                 else
  74                         print_old_dirent(tcp, tcp->u_arg[1]);
  75                 /* Not much point in printing this out, it is always 1. */
  76                 if (tcp->u_arg[2] != 1)
  77                         tprintf(", %lu", tcp->u_arg[2]);
  78         }
  79         return 0;
  80 }
  81
  82 SYS_FUNC(getdents)
  83 {
  84         unsigned int i, len, dents = 0;
  85         char *buf;
  86
  87         if (entering(tcp)) {
  88                 printfd(tcp, tcp->u_arg[0]);
  89                 tprints(", ");
  90                 return 0;
  91         }
  92         if (syserror(tcp) || !verbose(tcp)) {
  93                 printaddr(tcp->u_arg[1]);
  94                 tprintf(", %lu", tcp->u_arg[2]);
  95                 return 0;
  96         }
  97
  98         /* Beware of insanely large or too small values in tcp->u_rval */
  99         if (tcp->u_rval > 1024*1024)
 100                 len = 1024*1024;
 101         else if (tcp->u_rval < (int) sizeof(kernel_dirent))
 102                 len = 0;
 103         else
 104                 len = tcp->u_rval;
 105
 106         if (len) {
 107                 buf = malloc(len);
 108                 if (!buf || umoven(tcp, tcp->u_arg[1], len, buf) < 0) {
 109                         printaddr(tcp->u_arg[1]);
 110                         tprintf(", %lu", tcp->u_arg[2]);
 111                         free(buf);
 112                         return 0;
 113                 }
 114         } else {
 115                 buf = NULL;
 116         }
 117
 118         if (!abbrev(tcp))
 119                 tprints("[");
 120         for (i = 0; len && i <= len - sizeof(kernel_dirent); ) {
 121                 kernel_dirent *d = (kernel_dirent *) &buf[i];
 122
 123                 if (!abbrev(tcp)) {
 124                         int oob = d->d_reclen < sizeof(kernel_dirent) ||
 125                                   i + d->d_reclen - 1 >= len;
 126                         int d_name_len = oob ? len - i : d->d_reclen;
 127                         d_name_len -= offsetof(kernel_dirent, d_name) + 1;
 128                         if (d_name_len > D_NAME_LEN_MAX)
 129                                 d_name_len = D_NAME_LEN_MAX;
 130
 131                         tprintf("%s{d_ino=%lu, d_off=%lu, d_reclen=%u, d_name=",
 132                                 i ? ", " : "", (unsigned long) d->d_ino,
 133                                 (unsigned long) d->d_off, d->d_reclen);
 134
 135                         if (print_quoted_string(d->d_name, d_name_len,
 136                                                 QUOTE_0_TERMINATED) > 0) {
 137                                 tprints("...");
 138                         }
 139
 140                         tprints(", d_type=");
 141                         if (oob)
 142                                 tprints("?");
 143                         else
 144                                 printxval(dirent_types, buf[i + d->d_reclen - 1], "DT_???");
 145                         tprints("}");
 146                 }
 147                 dents++;
 148                 if (d->d_reclen < sizeof(kernel_dirent)) {
 149                         tprints("/* d_reclen < sizeof(kernel_dirent) */");
 150                         break;
 151                 }
 152                 i += d->d_reclen;
 153         }
 154         if (!abbrev(tcp))
 155                 tprints("]");
 156         else
 157                 tprintf("/* %u entries */", dents);
 158         tprintf(", %lu", tcp->u_arg[2]);
 159         free(buf);
 160         return 0;
 161 }