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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) 2015-2017 The strace developers.
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include "defs.h"
34 #include <dirent.h>
35 
36 #include "xlat/dirent_types.h"
37 
38 #define D_NAME_LEN_MAX 256
39 
SYS_FUNC(getdents64)40 SYS_FUNC(getdents64)
41 {
42 	/* the minimum size of a valid dirent64 structure */
43 	const unsigned int d_name_offset = offsetof(struct dirent64, d_name);
44 
45 	unsigned int i, len, dents = 0;
46 	char *buf;
47 
48 	if (entering(tcp)) {
49 		printfd(tcp, tcp->u_arg[0]);
50 		return 0;
51 	}
52 
53 	const unsigned int count = tcp->u_arg[2];
54 
55 	if (syserror(tcp) || !verbose(tcp)) {
56 		tprints(", ");
57 		printaddr(tcp->u_arg[1]);
58 		tprintf(", %u", count);
59 		return 0;
60 	}
61 
62 	/* Beware of insanely large or too small values in tcp->u_rval */
63 	if (tcp->u_rval > 1024*1024)
64 		len = 1024*1024;
65 	else if (tcp->u_rval < (int) d_name_offset)
66 		len = 0;
67 	else
68 		len = tcp->u_rval;
69 
70 	if (len) {
71 		buf = malloc(len);
72 		if (!buf || umoven(tcp, tcp->u_arg[1], len, buf) < 0) {
73 			tprints(", ");
74 			printaddr(tcp->u_arg[1]);
75 			tprintf(", %u", count);
76 			free(buf);
77 			return 0;
78 		}
79 	} else {
80 		buf = NULL;
81 	}
82 
83 	tprints(",");
84 	if (!abbrev(tcp))
85 		tprints(" [");
86 	for (i = 0; len && i <= len - d_name_offset; ) {
87 		struct dirent64 *d = (struct dirent64 *) &buf[i];
88 		if (!abbrev(tcp)) {
89 			int d_name_len;
90 			if (d->d_reclen >= d_name_offset
91 			    && i + d->d_reclen <= len) {
92 				d_name_len = d->d_reclen - d_name_offset;
93 			} else {
94 				d_name_len = len - i - d_name_offset;
95 			}
96 			if (d_name_len > D_NAME_LEN_MAX)
97 				d_name_len = D_NAME_LEN_MAX;
98 
99 			tprintf("%s{d_ino=%" PRIu64 ", d_off=%" PRId64
100 				", d_reclen=%u, d_type=",
101 				i ? ", " : "",
102 				d->d_ino,
103 				d->d_off,
104 				d->d_reclen);
105 			printxval(dirent_types, d->d_type, "DT_???");
106 
107 			tprints(", d_name=");
108 			print_quoted_cstring(d->d_name, d_name_len);
109 
110 			tprints("}");
111 		}
112 		if (d->d_reclen < d_name_offset) {
113 			tprints_comment("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_comment("%u entries", dents);
123 	tprintf(", %u", count);
124 	free(buf);
125 	return 0;
126 }
127