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