xref: /xnu-8792.81.2/libsyscall/wrappers/utimensat.c (revision 19c3b8c28c31cb8130e034cfb5df6bf9ba342d90)
1 /*
2  * Copyright (c) 2006, 2017 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. Please obtain a copy of the License at
10  * http://www.opensource.apple.com/apsl/ and read it before using this
11  * file.
12  *
13  * The Original Code and all software distributed under the License are
14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18  * Please see the License for the specific language governing rights and
19  * limitations under the License.
20  *
21  * @APPLE_LICENSE_HEADER_END@
22  */
23 
24 #include <sys/types.h>
25 #include <sys/stat.h>
26 #include <sys/attr.h>
27 #include <sys/time.h>
28 #include <sys/fcntl.h>
29 #include <unistd.h>
30 #include <strings.h>
31 
32 extern int __gettimeofday(struct timeval *, struct timezone *);
33 extern int __commpage_gettimeofday(struct timeval *);
34 
35 static struct timespec times_now[2] = {
36 	{ .tv_nsec = UTIME_NOW },
37 	{ .tv_nsec = UTIME_NOW }
38 };
39 
40 /*
41  * Resolve any UTIME_NOW or UTIME_OMIT and return the attributes buffer and
42  * attributes to pass.  Assumes times_in is writable.
43  */
44 static int
prepare_times_array_and_attrs(struct timespec times_in[2],struct timespec times_out[2],size_t * times_out_size,int * flags)45 prepare_times_array_and_attrs(struct timespec times_in[2],
46     struct timespec times_out[2], size_t *times_out_size, int *flags)
47 {
48 	if (times_in[0].tv_nsec == UTIME_OMIT &&
49 	    times_in[1].tv_nsec == UTIME_OMIT) {
50 		return 0;
51 	}
52 
53 	if (times_in[0].tv_nsec == UTIME_NOW ||
54 	    times_in[1].tv_nsec == UTIME_NOW) {
55 		*flags |= FSOPT_UTIMES_NULL;
56 		struct timespec now = {};
57 		{
58 			/*
59 			 * TODO: Replace with nanosecond time when available
60 			 */
61 			struct timeval tv;
62 			if (__commpage_gettimeofday(&tv) != 0) {
63 				__gettimeofday(&tv, NULL);
64 			}
65 			TIMEVAL_TO_TIMESPEC(&tv, &now);
66 		}
67 
68 		if (times_in[0].tv_nsec == UTIME_NOW) {
69 			times_in[0] = now;
70 		}
71 		if (times_in[1].tv_nsec == UTIME_NOW) {
72 			times_in[1] = now;
73 		}
74 	}
75 
76 	int attrs = 0;
77 	*times_out_size = 0;
78 	struct timespec *times_cursor = times_out;
79 	if (times_in[1].tv_nsec != UTIME_OMIT) {
80 		attrs |= ATTR_CMN_MODTIME;
81 		*times_cursor++ = times_in[1];
82 		*times_out_size += sizeof(struct timespec);
83 	}
84 	if (times_in[0].tv_nsec != UTIME_OMIT) {
85 		attrs |= ATTR_CMN_ACCTIME;
86 		*times_cursor = times_in[0];
87 		*times_out_size += sizeof(struct timespec);
88 	}
89 	return attrs;
90 }
91 
92 int
futimens(int fd,const struct timespec _times_in[2])93 futimens(int fd, const struct timespec _times_in[2])
94 {
95 	struct timespec times_in[2];
96 	int flags_out;
97 
98 	if (_times_in != NULL) {
99 		memcpy(&times_in, _times_in, sizeof(times_in));
100 	} else {
101 		memcpy(&times_in, times_now, sizeof(times_in));
102 	}
103 
104 	size_t attrbuf_size = 0;
105 	struct timespec times_out[2] = {};
106 	struct attrlist a = {
107 		.bitmapcount = ATTR_BIT_MAP_COUNT
108 	};
109 	a.commonattr = prepare_times_array_and_attrs(times_in, times_out, &attrbuf_size, &flags_out);
110 
111 	return fsetattrlist(fd, &a, &times_out, attrbuf_size, 0);
112 }
113 
114 int
utimensat(int fd,const char * path,const struct timespec _times_in[2],int flags)115 utimensat(int fd, const char *path, const struct timespec _times_in[2], int flags)
116 {
117 	struct timespec times_in[2];
118 	int flags_out = 0;
119 
120 	if (_times_in != NULL) {
121 		memcpy(&times_in, _times_in, sizeof(times_in));
122 	} else {
123 		memcpy(&times_in, times_now, sizeof(times_in));
124 	}
125 
126 	size_t attrbuf_size = 0;
127 	struct timespec times_out[2] = {};
128 	struct attrlist a = {
129 		.bitmapcount = ATTR_BIT_MAP_COUNT
130 	};
131 	a.commonattr = prepare_times_array_and_attrs(times_in, times_out, &attrbuf_size, &flags_out);
132 
133 	if (flags & AT_SYMLINK_NOFOLLOW) {
134 		flags_out |= FSOPT_NOFOLLOW;
135 	}
136 	if (flags & AT_SYMLINK_NOFOLLOW_ANY) {
137 		flags_out |= FSOPT_NOFOLLOW_ANY;
138 	}
139 
140 	return setattrlistat(fd, path, &a, &times_out, attrbuf_size, flags_out);
141 }
142