1 /* tzset tests with crafted time zone data.
2    Copyright (C) 2015-2022 Free Software Foundation, Inc.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #define _GNU_SOURCE 1
19 
20 #include <errno.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/resource.h>
25 #include <time.h>
26 #include <unistd.h>
27 #include <support/check.h>
28 #include <inttypes.h>
29 
30 static int do_test (void);
31 #define TEST_FUNCTION do_test ()
32 #include "../test-skeleton.c"
33 
34 /* Returns the name of a large TZ file.  */
35 static char *
create_tz_file(off64_t size)36 create_tz_file (off64_t size)
37 {
38   char *path;
39   int fd = create_temp_file ("tst-tzset-", &path);
40   if (fd < 0)
41     exit (1);
42   if (!support_descriptor_supports_holes (fd))
43     FAIL_UNSUPPORTED ("File %s does not support holes", path);
44 
45   // Reopen for large-file support.
46   close (fd);
47   fd = open64 (path, O_WRONLY);
48   if (fd < 0)
49     {
50       printf ("open64 (%s) failed: %m\n", path);
51       exit (1);
52     }
53 
54   static const char data[] = {
55     0x54, 0x5a, 0x69, 0x66, 0x32, 0x00, 0x00, 0x00,
56     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
57     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
58     0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
59     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
60     0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00,
61     0x00, 0x00, 0x58, 0x54, 0x47, 0x00, 0x00, 0x00,
62     0x54, 0x5a, 0x69, 0x66, 0x32, 0x00, 0x00, 0x00,
63     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
64     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
65     0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
66     0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
67     0x00, 0x00, 0x00, 0x04, 0xf8, 0x00, 0x00, 0x00,
68     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
69     0x00, 0x00, 0x00, 0x58, 0x54, 0x47, 0x00, 0x00,
70     0x00, 0x0a, 0x58, 0x54, 0x47, 0x30, 0x0a
71   };
72   ssize_t ret = write (fd, data, sizeof (data));
73   if (ret < 0)
74     {
75       printf ("write failed: %m\n");
76       exit (1);
77     }
78   if ((size_t) ret != sizeof (data))
79     {
80       printf ("Short write\n");
81       exit (1);
82     }
83   if (lseek64 (fd, size, SEEK_CUR) < 0)
84     {
85       printf ("lseek failed: %m\n");
86       close (fd);
87       return NULL;
88     }
89   if (write (fd, "", 1) != 1)
90     {
91       printf ("Single-byte write failed\n");
92       close (fd);
93       return NULL;
94     }
95   if (close (fd) != 0)
96     {
97       printf ("close failed: %m\n");
98       exit (1);
99     }
100   return path;
101 }
102 
103 static void
test_tz_file(off64_t size)104 test_tz_file (off64_t size)
105 {
106   char *path = create_tz_file (size);
107   if (path == NULL)
108    {
109      printf ("creating timezone file of size: %" PRId64 "MiB failed.\n",
110 	     size / (1024 * 1024));
111      exit (1);
112    }
113 
114   if (setenv ("TZ", path, 1) < 0)
115     {
116       printf ("setenv failed: %m\n");
117       exit (1);
118     }
119   tzset ();
120   free (path);
121 }
122 
123 static int
do_test(void)124 do_test (void)
125 {
126   /* Limit the size of the process.  Otherwise, some of the tests will
127      consume a lot of resources.  */
128   {
129     struct rlimit limit;
130     if (getrlimit (RLIMIT_AS, &limit) != 0)
131       {
132 	printf ("getrlimit (RLIMIT_AS) failed: %m\n");
133 	return 1;
134       }
135     long target = 512 * 1024 * 1024;
136     if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)
137       {
138 	limit.rlim_cur = 512 * 1024 * 1024;
139 	if (setrlimit (RLIMIT_AS, &limit) != 0)
140 	  {
141 	    printf ("setrlimit (RLIMIT_AS) failed: %m\n");
142 	    return 1;
143 	  }
144       }
145   }
146 
147   int errors = 0;
148   for (int i = 1; i <= 4; ++i)
149     {
150       char tz[16];
151       snprintf (tz, sizeof (tz), "XT%d", i);
152       if (setenv ("TZ", tz, 1) < 0)
153 	{
154 	  printf ("setenv failed: %m\n");
155 	  return 1;
156 	}
157       tzset ();
158       if (strcmp (tzname[0], tz) == 0)
159 	{
160 	  printf ("Unexpected success for %s\n", tz);
161 	  ++errors;
162 	}
163     }
164 
165   /* Large TZ files.  */
166 
167   /* This will succeed on 64-bit architectures, and fail on 32-bit
168      architectures.  It used to crash on 32-bit.  */
169   test_tz_file (64 * 1024 * 1024);
170 
171   /* This will fail on 64-bit and 32-bit architectures.  It used to
172      cause a test timeout on 64-bit and crash on 32-bit if the TZ file
173      open succeeded for some reason (it does not use O_LARGEFILE in
174      regular builds).  */
175   test_tz_file (4LL * 1024 * 1024 * 1024 - 6);
176 
177   /* Large TZ variables.  */
178   {
179     size_t length = 64 * 1024 * 1024;
180     char *value = malloc (length + 1);
181     if (value == NULL)
182       {
183 	puts ("malloc failed: %m");
184 	return 1;
185       }
186     value[length] = '\0';
187 
188     memset (value, ' ', length);
189     value[0] = 'U';
190     value[1] = 'T';
191     value[2] = 'C';
192     if (setenv ("TZ", value, 1) < 0)
193       {
194 	printf ("setenv failed: %m\n");
195 	return 1;
196       }
197     tzset ();
198 
199     memset (value, '0', length);
200     value[0] = '<';
201     value[length - 1] = '>';
202     if (setenv ("TZ", value, 1) < 0)
203       {
204 	printf ("setenv failed: %m\n");
205 	return 1;
206       }
207     tzset ();
208   }
209 
210   return errors > 0;
211 }
212