Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * tzparser.c
4 : * Functions for parsing timezone offset files
5 : *
6 : * Note: this code is invoked from the check_hook for the GUC variable
7 : * timezone_abbreviations. Therefore, it should report problems using
8 : * GUC_check_errmsg() and related functions, and try to avoid throwing
9 : * elog(ERROR). This is not completely bulletproof at present --- in
10 : * particular out-of-memory will throw an error. Could probably fix with
11 : * PG_TRY if necessary.
12 : *
13 : *
14 : * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
15 : * Portions Copyright (c) 1994, Regents of the University of California
16 : *
17 : * IDENTIFICATION
18 : * src/backend/utils/misc/tzparser.c
19 : *
20 : *-------------------------------------------------------------------------
21 : */
22 :
23 : #include "postgres.h"
24 :
25 : #include <ctype.h>
26 :
27 : #include "miscadmin.h"
28 : #include "storage/fd.h"
29 : #include "utils/guc.h"
30 : #include "utils/memutils.h"
31 : #include "utils/tzparser.h"
32 :
33 :
34 : #define WHITESPACE " \t\n\r"
35 :
36 : static bool validateTzEntry(tzEntry *tzentry);
37 : static bool splitTzLine(const char *filename, int lineno,
38 : char *line, tzEntry *tzentry);
39 : static int addToArray(tzEntry **base, int *arraysize, int n,
40 : tzEntry *entry, bool override);
41 : static int ParseTzFile(const char *filename, int depth,
42 : tzEntry **base, int *arraysize, int n);
43 :
44 :
45 : /*
46 : * Apply additional validation checks to a tzEntry
47 : *
48 : * Returns TRUE if OK, else false
49 : */
50 : static bool
51 88599 : validateTzEntry(tzEntry *tzentry)
52 : {
53 : unsigned char *p;
54 :
55 : /*
56 : * Check restrictions imposed by datetkntbl storage format (see
57 : * datetime.c)
58 : */
59 88599 : if (strlen(tzentry->abbrev) > TOKMAXLEN)
60 : {
61 0 : GUC_check_errmsg("time zone abbreviation \"%s\" is too long (maximum %d characters) in time zone file \"%s\", line %d",
62 : tzentry->abbrev, TOKMAXLEN,
63 : tzentry->filename, tzentry->lineno);
64 0 : return false;
65 : }
66 :
67 : /*
68 : * Sanity-check the offset: shouldn't exceed 14 hours
69 : */
70 177198 : if (tzentry->offset > 14 * 60 * 60 ||
71 88599 : tzentry->offset < -14 * 60 * 60)
72 : {
73 0 : GUC_check_errmsg("time zone offset %d is out of range in time zone file \"%s\", line %d",
74 : tzentry->offset,
75 : tzentry->filename, tzentry->lineno);
76 0 : return false;
77 : }
78 :
79 : /*
80 : * Convert abbrev to lowercase (must match datetime.c's conversion)
81 : */
82 410898 : for (p = (unsigned char *) tzentry->abbrev; *p; p++)
83 322299 : *p = pg_tolower(*p);
84 :
85 88599 : return true;
86 : }
87 :
88 : /*
89 : * Attempt to parse the line as a timezone abbrev spec
90 : *
91 : * Valid formats are:
92 : * name zone
93 : * name offset dst
94 : *
95 : * Returns TRUE if OK, else false; data is stored in *tzentry
96 : */
97 : static bool
98 88599 : splitTzLine(const char *filename, int lineno, char *line, tzEntry *tzentry)
99 : {
100 : char *abbrev;
101 : char *offset;
102 : char *offset_endptr;
103 : char *remain;
104 : char *is_dst;
105 :
106 88599 : tzentry->lineno = lineno;
107 88599 : tzentry->filename = filename;
108 :
109 88599 : abbrev = strtok(line, WHITESPACE);
110 88599 : if (!abbrev)
111 : {
112 0 : GUC_check_errmsg("missing time zone abbreviation in time zone file \"%s\", line %d",
113 : filename, lineno);
114 0 : return false;
115 : }
116 88599 : tzentry->abbrev = pstrdup(abbrev);
117 :
118 88599 : offset = strtok(NULL, WHITESPACE);
119 88599 : if (!offset)
120 : {
121 0 : GUC_check_errmsg("missing time zone offset in time zone file \"%s\", line %d",
122 : filename, lineno);
123 0 : return false;
124 : }
125 :
126 : /* We assume zone names don't begin with a digit or sign */
127 88599 : if (isdigit((unsigned char) *offset) || *offset == '+' || *offset == '-')
128 : {
129 65547 : tzentry->zone = NULL;
130 65547 : tzentry->offset = strtol(offset, &offset_endptr, 10);
131 65547 : if (offset_endptr == offset || *offset_endptr != '\0')
132 : {
133 0 : GUC_check_errmsg("invalid number for time zone offset in time zone file \"%s\", line %d",
134 : filename, lineno);
135 0 : return false;
136 : }
137 :
138 65547 : is_dst = strtok(NULL, WHITESPACE);
139 131094 : if (is_dst && pg_strcasecmp(is_dst, "D") == 0)
140 : {
141 21696 : tzentry->is_dst = true;
142 21696 : remain = strtok(NULL, WHITESPACE);
143 : }
144 : else
145 : {
146 : /* there was no 'D' dst specifier */
147 43851 : tzentry->is_dst = false;
148 43851 : remain = is_dst;
149 : }
150 : }
151 : else
152 : {
153 : /*
154 : * Assume entry is a zone name. We do not try to validate it by
155 : * looking up the zone, because that would force loading of a lot of
156 : * zones that probably will never be used in the current session.
157 : */
158 23052 : tzentry->zone = pstrdup(offset);
159 23052 : tzentry->offset = 0;
160 23052 : tzentry->is_dst = false;
161 23052 : remain = strtok(NULL, WHITESPACE);
162 : }
163 :
164 88599 : if (!remain) /* no more non-whitespace chars */
165 0 : return true;
166 :
167 88599 : if (remain[0] != '#') /* must be a comment */
168 : {
169 0 : GUC_check_errmsg("invalid syntax in time zone file \"%s\", line %d",
170 : filename, lineno);
171 0 : return false;
172 : }
173 88599 : return true;
174 : }
175 :
176 : /*
177 : * Insert entry into sorted array
178 : *
179 : * *base: base address of array (changeable if must enlarge array)
180 : * *arraysize: allocated length of array (changeable if must enlarge array)
181 : * n: current number of valid elements in array
182 : * entry: new data to insert
183 : * override: TRUE if OK to override
184 : *
185 : * Returns the new array length (new value for n), or -1 if error
186 : */
187 : static int
188 88599 : addToArray(tzEntry **base, int *arraysize, int n,
189 : tzEntry *entry, bool override)
190 : {
191 : tzEntry *arrayptr;
192 : int low;
193 : int high;
194 :
195 : /*
196 : * Search the array for a duplicate; as a useful side effect, the array is
197 : * maintained in sorted order. We use strcmp() to ensure we match the
198 : * sort order datetime.c expects.
199 : */
200 88599 : arrayptr = *base;
201 88599 : low = 0;
202 88599 : high = n - 1;
203 736820 : while (low <= high)
204 : {
205 559627 : int mid = (low + high) >> 1;
206 559627 : tzEntry *midptr = arrayptr + mid;
207 : int cmp;
208 :
209 559627 : cmp = strcmp(entry->abbrev, midptr->abbrev);
210 559627 : if (cmp < 0)
211 223310 : high = mid - 1;
212 336317 : else if (cmp > 0)
213 336312 : low = mid + 1;
214 : else
215 : {
216 : /*
217 : * Found a duplicate entry; complain unless it's the same.
218 : */
219 9 : if ((midptr->zone == NULL && entry->zone == NULL &&
220 4 : midptr->offset == entry->offset &&
221 5 : midptr->is_dst == entry->is_dst) ||
222 6 : (midptr->zone != NULL && entry->zone != NULL &&
223 0 : strcmp(midptr->zone, entry->zone) == 0))
224 : {
225 : /* return unchanged array */
226 0 : return n;
227 : }
228 5 : if (override)
229 : {
230 : /* same abbrev but something is different, override */
231 5 : midptr->zone = entry->zone;
232 5 : midptr->offset = entry->offset;
233 5 : midptr->is_dst = entry->is_dst;
234 5 : return n;
235 : }
236 : /* same abbrev but something is different, complain */
237 0 : GUC_check_errmsg("time zone abbreviation \"%s\" is multiply defined",
238 : entry->abbrev);
239 0 : GUC_check_errdetail("Entry in time zone file \"%s\", line %d, conflicts with entry in file \"%s\", line %d.",
240 : midptr->filename, midptr->lineno,
241 : entry->filename, entry->lineno);
242 0 : return -1;
243 : }
244 : }
245 :
246 : /*
247 : * No match, insert at position "low".
248 : */
249 88594 : if (n >= *arraysize)
250 : {
251 452 : *arraysize *= 2;
252 452 : *base = (tzEntry *) repalloc(*base, *arraysize * sizeof(tzEntry));
253 : }
254 :
255 88594 : arrayptr = *base + low;
256 :
257 88594 : memmove(arrayptr + 1, arrayptr, (n - low) * sizeof(tzEntry));
258 :
259 88594 : memcpy(arrayptr, entry, sizeof(tzEntry));
260 :
261 88594 : return n + 1;
262 : }
263 :
264 : /*
265 : * Parse a single timezone abbrev file --- can recurse to handle @INCLUDE
266 : *
267 : * filename: user-specified file name (does not include path)
268 : * depth: current recursion depth
269 : * *base: array for results (changeable if must enlarge array)
270 : * *arraysize: allocated length of array (changeable if must enlarge array)
271 : * n: current number of valid elements in array
272 : *
273 : * Returns the new array length (new value for n), or -1 if error
274 : */
275 : static int
276 454 : ParseTzFile(const char *filename, int depth,
277 : tzEntry **base, int *arraysize, int n)
278 : {
279 : char share_path[MAXPGPATH];
280 : char file_path[MAXPGPATH];
281 : FILE *tzFile;
282 : char tzbuf[1024];
283 : char *line;
284 : tzEntry tzentry;
285 454 : int lineno = 0;
286 454 : bool override = false;
287 : const char *p;
288 :
289 : /*
290 : * We enforce that the filename is all alpha characters. This may be
291 : * overly restrictive, but we don't want to allow access to anything
292 : * outside the timezonesets directory, so for instance '/' *must* be
293 : * rejected.
294 : */
295 3632 : for (p = filename; *p; p++)
296 : {
297 3178 : if (!isalpha((unsigned char) *p))
298 : {
299 : /* at level 0, just use guc.c's regular "invalid value" message */
300 0 : if (depth > 0)
301 0 : GUC_check_errmsg("invalid time zone file name \"%s\"",
302 : filename);
303 0 : return -1;
304 : }
305 : }
306 :
307 : /*
308 : * The maximal recursion depth is a pretty arbitrary setting. It is hard
309 : * to imagine that someone needs more than 3 levels so stick with this
310 : * conservative setting until someone complains.
311 : */
312 454 : if (depth > 3)
313 : {
314 0 : GUC_check_errmsg("time zone file recursion limit exceeded in file \"%s\"",
315 : filename);
316 0 : return -1;
317 : }
318 :
319 454 : get_share_path(my_exec_path, share_path);
320 454 : snprintf(file_path, sizeof(file_path), "%s/timezonesets/%s",
321 : share_path, filename);
322 454 : tzFile = AllocateFile(file_path, "r");
323 454 : if (!tzFile)
324 : {
325 : /*
326 : * Check to see if the problem is not the filename but the directory.
327 : * This is worth troubling over because if the installation share/
328 : * directory is missing or unreadable, this is likely to be the first
329 : * place we notice a problem during postmaster startup.
330 : */
331 0 : int save_errno = errno;
332 : DIR *tzdir;
333 :
334 0 : snprintf(file_path, sizeof(file_path), "%s/timezonesets",
335 : share_path);
336 0 : tzdir = AllocateDir(file_path);
337 0 : if (tzdir == NULL)
338 : {
339 0 : GUC_check_errmsg("could not open directory \"%s\": %m",
340 : file_path);
341 0 : GUC_check_errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
342 : my_exec_path);
343 0 : return -1;
344 : }
345 0 : FreeDir(tzdir);
346 0 : errno = save_errno;
347 :
348 : /*
349 : * otherwise, if file doesn't exist and it's level 0, guc.c's
350 : * complaint is enough
351 : */
352 0 : if (errno != ENOENT || depth > 0)
353 0 : GUC_check_errmsg("could not read time zone file \"%s\": %m",
354 : filename);
355 :
356 0 : return -1;
357 : }
358 :
359 285262 : while (!feof(tzFile))
360 : {
361 284808 : lineno++;
362 284808 : if (fgets(tzbuf, sizeof(tzbuf), tzFile) == NULL)
363 : {
364 454 : if (ferror(tzFile))
365 : {
366 0 : GUC_check_errmsg("could not read time zone file \"%s\": %m",
367 : filename);
368 0 : return -1;
369 : }
370 : /* else we're at EOF after all */
371 454 : break;
372 : }
373 284354 : if (strlen(tzbuf) == sizeof(tzbuf) - 1)
374 : {
375 : /* the line is too long for tzbuf */
376 0 : GUC_check_errmsg("line is too long in time zone file \"%s\", line %d",
377 : filename, lineno);
378 0 : return -1;
379 : }
380 :
381 : /* skip over whitespace */
382 284354 : line = tzbuf;
383 3314184 : while (*line && isspace((unsigned char) *line))
384 2745476 : line++;
385 :
386 284354 : if (*line == '\0') /* empty line */
387 9955 : continue;
388 274399 : if (*line == '#') /* comment line */
389 185796 : continue;
390 :
391 88603 : if (pg_strncasecmp(line, "@INCLUDE", strlen("@INCLUDE")) == 0)
392 : {
393 : /* pstrdup so we can use filename in result data structure */
394 2 : char *includeFile = pstrdup(line + strlen("@INCLUDE"));
395 :
396 2 : includeFile = strtok(includeFile, WHITESPACE);
397 2 : if (!includeFile || !*includeFile)
398 : {
399 0 : GUC_check_errmsg("@INCLUDE without file name in time zone file \"%s\", line %d",
400 : filename, lineno);
401 0 : return -1;
402 : }
403 2 : n = ParseTzFile(includeFile, depth + 1,
404 : base, arraysize, n);
405 2 : if (n < 0)
406 0 : return -1;
407 2 : continue;
408 : }
409 :
410 88601 : if (pg_strncasecmp(line, "@OVERRIDE", strlen("@OVERRIDE")) == 0)
411 : {
412 2 : override = true;
413 2 : continue;
414 : }
415 :
416 88599 : if (!splitTzLine(filename, lineno, line, &tzentry))
417 0 : return -1;
418 88599 : if (!validateTzEntry(&tzentry))
419 0 : return -1;
420 88599 : n = addToArray(base, arraysize, n, &tzentry, override);
421 88599 : if (n < 0)
422 0 : return -1;
423 : }
424 :
425 454 : FreeFile(tzFile);
426 :
427 454 : return n;
428 : }
429 :
430 : /*
431 : * load_tzoffsets --- read and parse the specified timezone offset file
432 : *
433 : * On success, return a filled-in TimeZoneAbbrevTable, which must have been
434 : * malloc'd not palloc'd. On failure, return NULL, using GUC_check_errmsg
435 : * and friends to give details of the problem.
436 : */
437 : TimeZoneAbbrevTable *
438 452 : load_tzoffsets(const char *filename)
439 : {
440 452 : TimeZoneAbbrevTable *result = NULL;
441 : MemoryContext tmpContext;
442 : MemoryContext oldContext;
443 : tzEntry *array;
444 : int arraysize;
445 : int n;
446 :
447 : /*
448 : * Create a temp memory context to work in. This makes it easy to clean
449 : * up afterwards.
450 : */
451 452 : tmpContext = AllocSetContextCreate(CurrentMemoryContext,
452 : "TZParserMemory",
453 : ALLOCSET_SMALL_SIZES);
454 452 : oldContext = MemoryContextSwitchTo(tmpContext);
455 :
456 : /* Initialize array at a reasonable size */
457 452 : arraysize = 128;
458 452 : array = (tzEntry *) palloc(arraysize * sizeof(tzEntry));
459 :
460 : /* Parse the file(s) */
461 452 : n = ParseTzFile(filename, 0, &array, &arraysize, 0);
462 :
463 : /* If no errors so far, let datetime.c allocate memory & convert format */
464 452 : if (n >= 0)
465 : {
466 452 : result = ConvertTimeZoneAbbrevs(array, n);
467 452 : if (!result)
468 0 : GUC_check_errmsg("out of memory");
469 : }
470 :
471 : /* Clean up */
472 452 : MemoryContextSwitchTo(oldContext);
473 452 : MemoryContextDelete(tmpContext);
474 :
475 452 : return result;
476 : }
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