libsyscall/wrappers/utimensat.c

   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
  45 prepare_times_array_and_attrs(struct timespec times_in[2],
  46     struct timespec times_out[2], size_t *times_out_size)
  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                 struct timespec now = {};
  56                 {
  57                         /*
  58                          * TODO: Replace with nanosecond time when available
  59                          */
  60                         struct timeval tv;
  61                         if (__commpage_gettimeofday(&tv) != 0) {
  62                                 __gettimeofday(&tv, NULL);
  63                         }
  64                         TIMEVAL_TO_TIMESPEC(&tv, &now);
  65                 }
  66
  67                 if (times_in[0].tv_nsec == UTIME_NOW) {
  68                         times_in[0] = now;
  69                 }
  70                 if (times_in[1].tv_nsec == UTIME_NOW) {
  71                         times_in[1] = now;
  72                 }
  73         }
  74
  75         int attrs = 0;
  76         *times_out_size = 0;
  77         struct timespec *times_cursor = times_out;
  78         if (times_in[1].tv_nsec != UTIME_OMIT) {
  79                 attrs |= ATTR_CMN_MODTIME;
  80                 *times_cursor++ = times_in[1];
  81                 *times_out_size += sizeof(struct timespec);
  82         }
  83         if (times_in[0].tv_nsec != UTIME_OMIT) {
  84                 attrs |= ATTR_CMN_ACCTIME;
  85                 *times_cursor = times_in[0];
  86                 *times_out_size += sizeof(struct timespec);
  87         }
  88         return attrs;
  89 }
  90
  91 int
  92 futimens(int fd, const struct timespec _times_in[2])
  93 {
  94         struct timespec times_in[2];
  95         if (_times_in != NULL) {
  96                 memcpy(&times_in, _times_in, sizeof(times_in));
  97         } else {
  98                 memcpy(&times_in, times_now, sizeof(times_in));
  99         }
 100
 101         size_t attrbuf_size = 0;
 102         struct timespec times_out[2] = {};
 103         struct attrlist a = {
 104                 .bitmapcount = ATTR_BIT_MAP_COUNT
 105         };
 106         a.commonattr = prepare_times_array_and_attrs(times_in, times_out, &attrbuf_size);
 107
 108         return fsetattrlist(fd, &a, &times_out, attrbuf_size, 0);
 109 }
 110
 111 int
 112 utimensat(int fd, const char *path, const struct timespec _times_in[2], int flags)
 113 {
 114         struct timespec times_in[2];
 115         if (_times_in != NULL) {
 116                 memcpy(&times_in, _times_in, sizeof(times_in));
 117         } else {
 118                 memcpy(&times_in, times_now, sizeof(times_in));
 119         }
 120
 121         size_t attrbuf_size = 0;
 122         struct timespec times_out[2] = {};
 123         struct attrlist a = {
 124                 .bitmapcount = ATTR_BIT_MAP_COUNT
 125         };
 126         a.commonattr = prepare_times_array_and_attrs(times_in, times_out, &attrbuf_size);
 127
 128         int flags_out = 0;
 129         if (flags & AT_SYMLINK_NOFOLLOW) {
 130                 flags_out |= FSOPT_NOFOLLOW;
 131         }
 132
 133         return setattrlistat(fd, path, &a, &times_out, attrbuf_size, flags_out);
 134 }