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 
hwtime(int flag,int request,struct rtc_time * tm)27 static 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 
rd_hwtime(struct rtc_time * tm)72 static int rd_hwtime(struct rtc_time *tm) {
73   return hwtime(O_RDONLY, RTC_RD_TIME, tm);
74 }
75 
set_hwtime(struct rtc_time * tm)76 static int set_hwtime(struct rtc_time *tm) {
77   return hwtime(O_WRONLY, RTC_SET_TIME, tm);
78 }
79 
rtc_rollover(int start,int end)80 static 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 
TEST(time,rtc_rollover_1970_1990)184 TEST(time, rtc_rollover_1970_1990) {
185   rtc_rollover(70, 90);
186 }
187 
TEST(time,rtc_rollover_1990_2010)188 TEST(time, rtc_rollover_1990_2010) {
189   rtc_rollover(90, 110);
190 }
191 
TEST(time,rtc_rollover_2010_2030)192 TEST(time, rtc_rollover_2010_2030) {
193   rtc_rollover(110, 130);
194 }
195 
TEST(time,rtc_rollover_2030_2037)196 TEST(time, rtc_rollover_2030_2037) {
197   rtc_rollover(130, 137);
198 }
199