1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <errno.h>
18#include <fcntl.h>
19#include <linux/rtc.h>
20#include <sys/ioctl.h>
21#include <sys/stat.h>
22#include <sys/types.h>
23#include <unistd.h>
24
25#include <gtest/gtest.h>
26
27static int hwtime(int flag, int request, struct rtc_time *tm) {
28  static const char rtc[] = "/dev/rtc0";
29
30  int ret = TEMP_FAILURE_RETRY(access(rtc, flag & O_WRONLY) ? W_OK : R_OK);
31  if (ret < 0) {
32    ret = -errno;
33  }
34  if (ret == -EACCES) {
35    return ret;
36  }
37
38  if (flag & O_WRONLY) {
39    struct stat st;
40    ret = TEMP_FAILURE_RETRY(stat(rtc, &st));
41    if (ret < 0) {
42      ret = -errno;
43    } else if (!(st.st_mode & (S_IWUSR|S_IWGRP|S_IWOTH))) {
44      ret = -EACCES;
45    }
46  }
47  if (ret == -EACCES) {
48    return ret;
49  }
50
51  do {
52    ret = TEMP_FAILURE_RETRY(open(rtc, flag));
53    if (ret < 0) {
54      ret = -errno;
55    }
56  } while (ret == -EBUSY);
57  if (ret < 0) {
58    return ret;
59  }
60
61  int fd = ret;
62  do {
63    ret = TEMP_FAILURE_RETRY(ioctl(fd, request, tm));
64    if (ret < 0) {
65      ret = -errno;
66    }
67  } while (ret == -EBUSY);
68  close(fd);
69  return ret;
70}
71
72static int rd_hwtime(struct rtc_time *tm) {
73  return hwtime(O_RDONLY, RTC_RD_TIME, tm);
74}
75
76static int set_hwtime(struct rtc_time *tm) {
77  return hwtime(O_WRONLY, RTC_SET_TIME, tm);
78}
79
80static void rtc_rollover(int start, int end) {
81  struct rtc_time roll;
82  memset(&roll, 0, sizeof(roll));
83  ASSERT_LE(0, rd_hwtime(&roll));
84  int mday[12] = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
85  mday[1] = (roll.tm_year % 4) ? 28 : 29;
86  ASSERT_LE(0, roll.tm_sec);
87  ASSERT_GT(60, roll.tm_sec);
88  ASSERT_LE(0, roll.tm_min);
89  ASSERT_GT(60, roll.tm_min);
90  ASSERT_LE(0, roll.tm_hour);
91  ASSERT_GT(24, roll.tm_hour);
92  ASSERT_LE(0, roll.tm_mday);
93  ASSERT_GE(mday[roll.tm_mon], roll.tm_mday);
94  ASSERT_LE(0, roll.tm_mon);
95  ASSERT_GT(12, roll.tm_mon);
96  ASSERT_LE(0, roll.tm_year);
97  ASSERT_GT(138, roll.tm_year);
98
99  // Wait for granular clock
100  struct rtc_time save = roll;
101  static const useconds_t timeout_sleep = 10000;
102  static const int timeout_num = 2000000 / timeout_sleep;
103  int timeout;
104  for (timeout = timeout_num; timeout && (roll.tm_year == save.tm_year); --timeout) {
105    ASSERT_LE(0, rd_hwtime(&save));
106    usleep(timeout_sleep);
107  }
108
109  memset(&roll, 0, sizeof(roll));
110  roll.tm_sec = 59;
111  roll.tm_min = 59;
112  roll.tm_hour = 23;
113  roll.tm_mday = 31;
114  roll.tm_mon = 11;
115  roll.tm_year = 70;
116  roll.tm_wday = 0;
117  roll.tm_yday = 0;
118  roll.tm_isdst = 0;
119
120  bool eacces = true;
121  for (roll.tm_year = start; roll.tm_year < end; ++roll.tm_year) {
122    struct rtc_time tm = roll;
123    int __set_hwtime = set_hwtime(&tm);
124    // Allowed to be 100% denied for writing
125    if ((__set_hwtime == -EACCES) && (eacces == true)) {
126      continue;
127    }
128    eacces = false;
129    // below 2016, permitted to error out.
130    if ((__set_hwtime == -EINVAL) && (roll.tm_year < 116)) {
131      continue;
132    }
133    ASSERT_LE(0, __set_hwtime);
134    ASSERT_LE(0, rd_hwtime(&tm));
135    ASSERT_EQ(roll.tm_sec, tm.tm_sec);
136    ASSERT_EQ(roll.tm_min, tm.tm_min);
137    ASSERT_EQ(roll.tm_hour, tm.tm_hour);
138    ASSERT_EQ(roll.tm_mday, tm.tm_mday);
139    ASSERT_EQ(roll.tm_mon, tm.tm_mon);
140    ASSERT_EQ(roll.tm_year, tm.tm_year);
141    for (timeout = timeout_num; timeout && (roll.tm_year == tm.tm_year); --timeout) {
142      ASSERT_LE(0, rd_hwtime(&tm));
143      usleep(timeout_sleep);
144    }
145    ASSERT_EQ(roll.tm_year + 1, tm.tm_year);
146    EXPECT_LT(timeout_num * 5 / 100, timeout);
147    EXPECT_GT(timeout_num * 95 / 100, timeout);
148
149    // correct saved time to compensate for rollover check
150    if (++save.tm_sec >= 60) {
151      save.tm_sec = 0;
152      if (++save.tm_min >= 60) {
153        save.tm_min = 0;
154        if (++save.tm_hour >= 24) {
155          save.tm_hour = 0;
156          mday[1] = (save.tm_year % 4) ? 28 : 29;
157          if (++save.tm_mday >= mday[save.tm_mon]) {
158            save.tm_mday = 1;
159            if (++save.tm_mon >= 12) {
160              save.tm_mon = 0;
161              ++save.tm_year;
162            }
163          }
164        }
165      }
166    }
167  }
168
169  if (!eacces) {
170    ASSERT_LE(0, set_hwtime(&save));
171  }
172  ASSERT_LE(0, rd_hwtime(&roll));
173
174  if (!eacces) {
175    ASSERT_EQ(save.tm_sec, roll.tm_sec);
176    ASSERT_EQ(save.tm_min, roll.tm_min);
177    ASSERT_EQ(save.tm_hour, roll.tm_hour);
178    ASSERT_EQ(save.tm_mday, roll.tm_mday);
179    ASSERT_EQ(save.tm_mon, roll.tm_mon);
180    ASSERT_EQ(save.tm_year, roll.tm_year);
181  }
182}
183
184TEST(time, rtc_rollover_1970_1990) {
185  rtc_rollover(70, 90);
186}
187
188TEST(time, rtc_rollover_1990_2010) {
189  rtc_rollover(90, 110);
190}
191
192TEST(time, rtc_rollover_2010_2030) {
193  rtc_rollover(110, 130);
194}
195
196TEST(time, rtc_rollover_2030_2037) {
197  rtc_rollover(130, 137);
198}
199