PostgreSQL Source Code  git master
pgtz.c File Reference
#include "postgres.h"
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <time.h>
#include "datatype/timestamp.h"
#include "miscadmin.h"
#include "pgtz.h"
#include "storage/fd.h"
#include "utils/hsearch.h"
Include dependency graph for pgtz.c:

Go to the source code of this file.

Data Structures

struct  pg_tz_cache
 
struct  pg_tzenum
 

Macros

#define MAX_TZDIR_DEPTH   10
 

Functions

static bool scan_directory_ci (const char *dirname, const char *fname, int fnamelen, char *canonname, int canonnamelen)
 
static const char * pg_TZDIR (void)
 
int pg_open_tzfile (const char *name, char *canonname)
 
static bool init_timezone_hashtable (void)
 
pg_tzpg_tzset (const char *name)
 
pg_tzpg_tzset_offset (long gmtoffset)
 
void pg_timezone_initialize (void)
 
pg_tzenumpg_tzenumerate_start (void)
 
void pg_tzenumerate_end (pg_tzenum *dir)
 
pg_tzpg_tzenumerate_next (pg_tzenum *dir)
 

Variables

pg_tzsession_timezone = NULL
 
pg_tzlog_timezone = NULL
 
static HTABtimezone_cache = NULL
 

Macro Definition Documentation

◆ MAX_TZDIR_DEPTH

#define MAX_TZDIR_DEPTH   10

Definition at line 383 of file pgtz.c.

Referenced by pg_tzenumerate_next().

Function Documentation

◆ init_timezone_hashtable()

static bool init_timezone_hashtable ( void  )
static

Definition at line 202 of file pgtz.c.

References HASHCTL::entrysize, hash_create(), HASH_ELEM, HASH_STRINGS, HASHCTL::keysize, and TZ_STRLEN_MAX.

Referenced by pg_tzset().

203 {
204  HASHCTL hash_ctl;
205 
206  hash_ctl.keysize = TZ_STRLEN_MAX + 1;
207  hash_ctl.entrysize = sizeof(pg_tz_cache);
208 
209  timezone_cache = hash_create("Timezones",
210  4,
211  &hash_ctl,
213  if (!timezone_cache)
214  return false;
215 
216  return true;
217 }
#define HASH_ELEM
Definition: hsearch.h:95
Size entrysize
Definition: hsearch.h:76
#define TZ_STRLEN_MAX
Definition: pgtime.h:51
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:349
Size keysize
Definition: hsearch.h:75
static HTAB * timezone_cache
Definition: pgtz.c:198
#define HASH_STRINGS
Definition: hsearch.h:96

◆ pg_open_tzfile()

int pg_open_tzfile ( const char *  name,
char *  canonname 
)

Definition at line 76 of file pgtz.c.

References MAXPGPATH, name, PG_BINARY, pg_TZDIR(), scan_directory_ci(), strlcpy(), and TZ_STRLEN_MAX.

77 {
78  const char *fname;
79  char fullname[MAXPGPATH];
80  int fullnamelen;
81  int orignamelen;
82 
83  /* Initialize fullname with base name of tzdata directory */
84  strlcpy(fullname, pg_TZDIR(), sizeof(fullname));
85  orignamelen = fullnamelen = strlen(fullname);
86 
87  if (fullnamelen + 1 + strlen(name) >= MAXPGPATH)
88  return -1; /* not gonna fit */
89 
90  /*
91  * If the caller doesn't need the canonical spelling, first just try to
92  * open the name as-is. This can be expected to succeed if the given name
93  * is already case-correct, or if the filesystem is case-insensitive; and
94  * we don't need to distinguish those situations if we aren't tasked with
95  * reporting the canonical spelling.
96  */
97  if (canonname == NULL)
98  {
99  int result;
100 
101  fullname[fullnamelen] = '/';
102  /* test above ensured this will fit: */
103  strcpy(fullname + fullnamelen + 1, name);
104  result = open(fullname, O_RDONLY | PG_BINARY, 0);
105  if (result >= 0)
106  return result;
107  /* If that didn't work, fall through to do it the hard way */
108  fullname[fullnamelen] = '\0';
109  }
110 
111  /*
112  * Loop to split the given name into directory levels; for each level,
113  * search using scan_directory_ci().
114  */
115  fname = name;
116  for (;;)
117  {
118  const char *slashptr;
119  int fnamelen;
120 
121  slashptr = strchr(fname, '/');
122  if (slashptr)
123  fnamelen = slashptr - fname;
124  else
125  fnamelen = strlen(fname);
126  if (!scan_directory_ci(fullname, fname, fnamelen,
127  fullname + fullnamelen + 1,
128  MAXPGPATH - fullnamelen - 1))
129  return -1;
130  fullname[fullnamelen++] = '/';
131  fullnamelen += strlen(fullname + fullnamelen);
132  if (slashptr)
133  fname = slashptr + 1;
134  else
135  break;
136  }
137 
138  if (canonname)
139  strlcpy(canonname, fullname + orignamelen + 1, TZ_STRLEN_MAX + 1);
140 
141  return open(fullname, O_RDONLY | PG_BINARY, 0);
142 }
static const char * pg_TZDIR(void)
Definition: pgtz.c:43
#define PG_BINARY
Definition: c.h:1271
#define TZ_STRLEN_MAX
Definition: pgtime.h:51
#define MAXPGPATH
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
static bool scan_directory_ci(const char *dirname, const char *fname, int fnamelen, char *canonname, int canonnamelen)
Definition: pgtz.c:151
const char * name
Definition: encode.c:561

◆ pg_timezone_initialize()

void pg_timezone_initialize ( void  )

Definition at line 361 of file pgtz.c.

References pg_tzset(), and session_timezone.

Referenced by InitializeGUCOptions().

362 {
363  /*
364  * We may not yet know where PGSHAREDIR is (in particular this is true in
365  * an EXEC_BACKEND subprocess). So use "GMT", which pg_tzset forces to be
366  * interpreted without reference to the filesystem. This corresponds to
367  * the bootstrap default for these variables in guc.c, although in
368  * principle it could be different.
369  */
370  session_timezone = pg_tzset("GMT");
372 }
pg_tz * log_timezone
Definition: pgtz.c:31
pg_tz * pg_tzset(const char *name)
Definition: pgtz.c:234
pg_tz * session_timezone
Definition: pgtz.c:28

◆ pg_TZDIR()

static const char* pg_TZDIR ( void  )
static

Definition at line 43 of file pgtz.c.

References get_share_path(), MAXPGPATH, my_exec_path, and strlcpy().

Referenced by pg_open_tzfile(), and pg_tzenumerate_start().

44 {
45 #ifndef SYSTEMTZDIR
46  /* normal case: timezone stuff is under our share dir */
47  static bool done_tzdir = false;
48  static char tzdir[MAXPGPATH];
49 
50  if (done_tzdir)
51  return tzdir;
52 
54  strlcpy(tzdir + strlen(tzdir), "/timezone", MAXPGPATH - strlen(tzdir));
55 
56  done_tzdir = true;
57  return tzdir;
58 #else
59  /* we're configured to use system's timezone database */
60  return SYSTEMTZDIR;
61 #endif
62 }
#define MAXPGPATH
char my_exec_path[MAXPGPATH]
Definition: globals.c:75
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
void get_share_path(const char *my_exec_path, char *ret_path)
Definition: path.c:704

◆ pg_tzenumerate_end()

void pg_tzenumerate_end ( pg_tzenum dir)

Definition at line 414 of file pgtz.c.

References pg_tzenum::depth, pg_tzenum::dirdesc, pg_tzenum::dirname, FreeDir(), and pfree().

Referenced by pg_timezone_names().

415 {
416  while (dir->depth >= 0)
417  {
418  FreeDir(dir->dirdesc[dir->depth]);
419  pfree(dir->dirname[dir->depth]);
420  dir->depth--;
421  }
422  pfree(dir);
423 }
DIR * dirdesc[MAX_TZDIR_DEPTH]
Definition: pgtz.c:389
void pfree(void *pointer)
Definition: mcxt.c:1169
char * dirname[MAX_TZDIR_DEPTH]
Definition: pgtz.c:390
int depth
Definition: pgtz.c:388
int FreeDir(DIR *dir)
Definition: fd.c:2839

◆ pg_tzenumerate_next()

pg_tz* pg_tzenumerate_next ( pg_tzenum dir)

Definition at line 426 of file pgtz.c.

References AllocateDir(), pg_tzenum::baselen, pg_tzenum::depth, pg_tzenum::dirdesc, pg_tzenum::dirname, ereport, errcode_for_file_access(), errmsg(), errmsg_internal(), ERROR, FreeDir(), MAX_TZDIR_DEPTH, MAXPGPATH, pfree(), pg_tz_acceptable(), pstrdup(), ReadDir(), S_ISDIR, snprintf, stat::st_mode, stat, pg_tz::state, strlcpy(), pg_tzenum::tz, tzload(), and pg_tz::TZname.

Referenced by pg_timezone_names().

427 {
428  while (dir->depth >= 0)
429  {
430  struct dirent *direntry;
431  char fullname[MAXPGPATH * 2];
432  struct stat statbuf;
433 
434  direntry = ReadDir(dir->dirdesc[dir->depth], dir->dirname[dir->depth]);
435 
436  if (!direntry)
437  {
438  /* End of this directory */
439  FreeDir(dir->dirdesc[dir->depth]);
440  pfree(dir->dirname[dir->depth]);
441  dir->depth--;
442  continue;
443  }
444 
445  if (direntry->d_name[0] == '.')
446  continue;
447 
448  snprintf(fullname, sizeof(fullname), "%s/%s",
449  dir->dirname[dir->depth], direntry->d_name);
450  if (stat(fullname, &statbuf) != 0)
451  ereport(ERROR,
453  errmsg("could not stat \"%s\": %m", fullname)));
454 
455  if (S_ISDIR(statbuf.st_mode))
456  {
457  /* Step into the subdirectory */
458  if (dir->depth >= MAX_TZDIR_DEPTH - 1)
459  ereport(ERROR,
460  (errmsg_internal("timezone directory stack overflow")));
461  dir->depth++;
462  dir->dirname[dir->depth] = pstrdup(fullname);
463  dir->dirdesc[dir->depth] = AllocateDir(fullname);
464  if (!dir->dirdesc[dir->depth])
465  ereport(ERROR,
467  errmsg("could not open directory \"%s\": %m",
468  fullname)));
469 
470  /* Start over reading in the new directory */
471  continue;
472  }
473 
474  /*
475  * Load this timezone using tzload() not pg_tzset(), so we don't fill
476  * the cache. Also, don't ask for the canonical spelling: we already
477  * know it, and pg_open_tzfile's way of finding it out is pretty
478  * inefficient.
479  */
480  if (tzload(fullname + dir->baselen, NULL, &dir->tz.state, true) != 0)
481  {
482  /* Zone could not be loaded, ignore it */
483  continue;
484  }
485 
486  if (!pg_tz_acceptable(&dir->tz))
487  {
488  /* Ignore leap-second zones */
489  continue;
490  }
491 
492  /* OK, return the canonical zone name spelling. */
493  strlcpy(dir->tz.TZname, fullname + dir->baselen,
494  sizeof(dir->tz.TZname));
495 
496  /* Timezone loaded OK. */
497  return &dir->tz;
498  }
499 
500  /* Nothing more found */
501  return NULL;
502 }
struct pg_tz tz
Definition: pgtz.c:391
int tzload(const char *name, char *canonname, struct state *sp, bool doextend)
Definition: localtime.c:584
char * pstrdup(const char *in)
Definition: mcxt.c:1299
Definition: dirent.h:9
DIR * dirdesc[MAX_TZDIR_DEPTH]
Definition: pgtz.c:389
void pfree(void *pointer)
Definition: mcxt.c:1169
char * dirname[MAX_TZDIR_DEPTH]
Definition: pgtz.c:390
#define ERROR
Definition: elog.h:46
#define MAXPGPATH
#define MAX_TZDIR_DEPTH
Definition: pgtz.c:383
int errcode_for_file_access(void)
Definition: elog.c:721
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2721
bool pg_tz_acceptable(pg_tz *tz)
Definition: localtime.c:1888
struct state state
Definition: pgtz.h:69
#define ereport(elevel,...)
Definition: elog.h:157
int baselen
Definition: pgtz.c:387
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
int errmsg_internal(const char *fmt,...)
Definition: elog.c:996
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2787
char TZname[TZ_STRLEN_MAX+1]
Definition: pgtz.h:68
#define S_ISDIR(m)
Definition: win32_port.h:324
int errmsg(const char *fmt,...)
Definition: elog.c:909
int depth
Definition: pgtz.c:388
#define snprintf
Definition: port.h:217
int FreeDir(DIR *dir)
Definition: fd.c:2839
#define stat
Definition: win32_port.h:283

◆ pg_tzenumerate_start()

pg_tzenum* pg_tzenumerate_start ( void  )

Definition at line 397 of file pgtz.c.

References AllocateDir(), pg_tzenum::baselen, pg_tzenum::depth, pg_tzenum::dirdesc, pg_tzenum::dirname, ereport, errcode_for_file_access(), errmsg(), ERROR, palloc0(), pg_TZDIR(), and pstrdup().

Referenced by pg_timezone_names().

398 {
399  pg_tzenum *ret = (pg_tzenum *) palloc0(sizeof(pg_tzenum));
400  char *startdir = pstrdup(pg_TZDIR());
401 
402  ret->baselen = strlen(startdir) + 1;
403  ret->depth = 0;
404  ret->dirname[0] = startdir;
405  ret->dirdesc[0] = AllocateDir(startdir);
406  if (!ret->dirdesc[0])
407  ereport(ERROR,
409  errmsg("could not open directory \"%s\": %m", startdir)));
410  return ret;
411 }
char * pstrdup(const char *in)
Definition: mcxt.c:1299
DIR * dirdesc[MAX_TZDIR_DEPTH]
Definition: pgtz.c:389
static const char * pg_TZDIR(void)
Definition: pgtz.c:43
char * dirname[MAX_TZDIR_DEPTH]
Definition: pgtz.c:390
#define ERROR
Definition: elog.h:46
int errcode_for_file_access(void)
Definition: elog.c:721
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2721
void * palloc0(Size size)
Definition: mcxt.c:1093
#define ereport(elevel,...)
Definition: elog.h:157
int baselen
Definition: pgtz.c:387
int errmsg(const char *fmt,...)
Definition: elog.c:909
int depth
Definition: pgtz.c:388

◆ pg_tzset()

pg_tz* pg_tzset ( const char *  name)

Definition at line 234 of file pgtz.c.

References elog, ERROR, HASH_ENTER, HASH_FIND, hash_search(), init_timezone_hashtable(), pg_toupper(), pg_tz::state, pg_tz_cache::tz, TZ_STRLEN_MAX, tzload(), pg_tz::TZname, and tzparse().

Referenced by check_log_timezone(), check_timezone(), DecodeDateTime(), DecodeTimeOnly(), FetchDynamicTimeZone(), parse_sane_timezone(), pg_timezone_initialize(), pg_tzset_offset(), timestamp_zone(), timestamptz_trunc_zone(), timestamptz_zone(), and timetz_zone().

235 {
236  pg_tz_cache *tzp;
237  struct state tzstate;
238  char uppername[TZ_STRLEN_MAX + 1];
239  char canonname[TZ_STRLEN_MAX + 1];
240  char *p;
241 
242  if (strlen(name) > TZ_STRLEN_MAX)
243  return NULL; /* not going to fit */
244 
245  if (!timezone_cache)
247  return NULL;
248 
249  /*
250  * Upcase the given name to perform a case-insensitive hashtable search.
251  * (We could alternatively downcase it, but we prefer upcase so that we
252  * can get consistently upcased results from tzparse() in case the name is
253  * a POSIX-style timezone spec.)
254  */
255  p = uppername;
256  while (*name)
257  *p++ = pg_toupper((unsigned char) *name++);
258  *p = '\0';
259 
261  uppername,
262  HASH_FIND,
263  NULL);
264  if (tzp)
265  {
266  /* Timezone found in cache, nothing more to do */
267  return &tzp->tz;
268  }
269 
270  /*
271  * "GMT" is always sent to tzparse(), as per discussion above.
272  */
273  if (strcmp(uppername, "GMT") == 0)
274  {
275  if (!tzparse(uppername, &tzstate, true))
276  {
277  /* This really, really should not happen ... */
278  elog(ERROR, "could not initialize GMT time zone");
279  }
280  /* Use uppercase name as canonical */
281  strcpy(canonname, uppername);
282  }
283  else if (tzload(uppername, canonname, &tzstate, true) != 0)
284  {
285  if (uppername[0] == ':' || !tzparse(uppername, &tzstate, false))
286  {
287  /* Unknown timezone. Fail our call instead of loading GMT! */
288  return NULL;
289  }
290  /* For POSIX timezone specs, use uppercase name as canonical */
291  strcpy(canonname, uppername);
292  }
293 
294  /* Save timezone in the cache */
296  uppername,
297  HASH_ENTER,
298  NULL);
299 
300  /* hash_search already copied uppername into the hash key */
301  strcpy(tzp->tz.TZname, canonname);
302  memcpy(&tzp->tz.state, &tzstate, sizeof(tzstate));
303 
304  return &tzp->tz;
305 }
int tzload(const char *name, char *canonname, struct state *sp, bool doextend)
Definition: localtime.c:584
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:954
#define TZ_STRLEN_MAX
Definition: pgtime.h:51
#define ERROR
Definition: elog.h:46
static bool init_timezone_hashtable(void)
Definition: pgtz.c:202
bool tzparse(const char *name, struct state *sp, bool lastditch)
Definition: localtime.c:934
pg_tz tz
Definition: pgtz.c:195
struct state state
Definition: pgtz.h:69
static HTAB * timezone_cache
Definition: pgtz.c:198
Definition: regguts.h:317
char TZname[TZ_STRLEN_MAX+1]
Definition: pgtz.h:68
const char * name
Definition: encode.c:561
#define elog(elevel,...)
Definition: elog.h:232
unsigned char pg_toupper(unsigned char ch)
Definition: pgstrcasecmp.c:105

◆ pg_tzset_offset()

pg_tz* pg_tzset_offset ( long  gmtoffset)

Definition at line 320 of file pgtz.c.

References pg_tzset(), SECS_PER_HOUR, SECS_PER_MINUTE, and snprintf.

Referenced by check_timezone(), and timestamptz_trunc_zone().

321 {
322  long absoffset = (gmtoffset < 0) ? -gmtoffset : gmtoffset;
323  char offsetstr[64];
324  char tzname[128];
325 
326  snprintf(offsetstr, sizeof(offsetstr),
327  "%02ld", absoffset / SECS_PER_HOUR);
328  absoffset %= SECS_PER_HOUR;
329  if (absoffset != 0)
330  {
331  snprintf(offsetstr + strlen(offsetstr),
332  sizeof(offsetstr) - strlen(offsetstr),
333  ":%02ld", absoffset / SECS_PER_MINUTE);
334  absoffset %= SECS_PER_MINUTE;
335  if (absoffset != 0)
336  snprintf(offsetstr + strlen(offsetstr),
337  sizeof(offsetstr) - strlen(offsetstr),
338  ":%02ld", absoffset);
339  }
340  if (gmtoffset > 0)
341  snprintf(tzname, sizeof(tzname), "<-%s>+%s",
342  offsetstr, offsetstr);
343  else
344  snprintf(tzname, sizeof(tzname), "<+%s>-%s",
345  offsetstr, offsetstr);
346 
347  return pg_tzset(tzname);
348 }
#define SECS_PER_MINUTE
Definition: timestamp.h:88
pg_tz * pg_tzset(const char *name)
Definition: pgtz.c:234
#define SECS_PER_HOUR
Definition: timestamp.h:87
#define snprintf
Definition: port.h:217

◆ scan_directory_ci()

static bool scan_directory_ci ( const char *  dirname,
const char *  fname,
int  fnamelen,
char *  canonname,
int  canonnamelen 
)
static

Definition at line 151 of file pgtz.c.

References AllocateDir(), dirent::d_name, FreeDir(), LOG, pg_strncasecmp(), ReadDirExtended(), and strlcpy().

Referenced by pg_open_tzfile().

153 {
154  bool found = false;
155  DIR *dirdesc;
156  struct dirent *direntry;
157 
158  dirdesc = AllocateDir(dirname);
159 
160  while ((direntry = ReadDirExtended(dirdesc, dirname, LOG)) != NULL)
161  {
162  /*
163  * Ignore . and .., plus any other "hidden" files. This is a security
164  * measure to prevent access to files outside the timezone directory.
165  */
166  if (direntry->d_name[0] == '.')
167  continue;
168 
169  if (strlen(direntry->d_name) == fnamelen &&
170  pg_strncasecmp(direntry->d_name, fname, fnamelen) == 0)
171  {
172  /* Found our match */
173  strlcpy(canonname, direntry->d_name, canonnamelen);
174  found = true;
175  break;
176  }
177  }
178 
179  FreeDir(dirdesc);
180 
181  return found;
182 }
struct dirent * ReadDirExtended(DIR *dir, const char *dirname, int elevel)
Definition: fd.c:2802
#define LOG
Definition: elog.h:26
Definition: dirent.h:9
int pg_strncasecmp(const char *s1, const char *s2, size_t n)
Definition: pgstrcasecmp.c:69
Definition: dirent.c:25
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2721
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
char d_name[MAX_PATH]
Definition: dirent.h:15
int FreeDir(DIR *dir)
Definition: fd.c:2839

Variable Documentation

◆ log_timezone

◆ session_timezone

◆ timezone_cache

HTAB* timezone_cache = NULL
static

Definition at line 198 of file pgtz.c.