Adding upstream version 14.5.upstream/14.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 484 insertions, 0 deletions

diff --git a/src/backend/utils/misc/tzparser.c b/src/backend/utils/misc/tzparser.c
new file mode 100644
index 0000000..65e6673
--- /dev/null
+++ b/src/backend/utils/misc/tzparser.c
@@ -0,0 +1,484 @@
+/*-------------------------------------------------------------------------
+ *
+ * tzparser.c
+ *	  Functions for parsing timezone offset files
+ *
+ * Note: this code is invoked from the check_hook for the GUC variable
+ * timezone_abbreviations.  Therefore, it should report problems using
+ * GUC_check_errmsg() and related functions, and try to avoid throwing
+ * elog(ERROR).  This is not completely bulletproof at present --- in
+ * particular out-of-memory will throw an error.  Could probably fix with
+ * PG_TRY if necessary.
+ *
+ *
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *	  src/backend/utils/misc/tzparser.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include <ctype.h>
+
+#include "miscadmin.h"
+#include "storage/fd.h"
+#include "utils/guc.h"
+#include "utils/memutils.h"
+#include "utils/tzparser.h"
+
+
+#define WHITESPACE " \t\n\r"
+
+static bool validateTzEntry(tzEntry *tzentry);
+static bool splitTzLine(const char *filename, int lineno,
+						char *line, tzEntry *tzentry);
+static int	addToArray(tzEntry **base, int *arraysize, int n,
+					   tzEntry *entry, bool override);
+static int	ParseTzFile(const char *filename, int depth,
+						tzEntry **base, int *arraysize, int n);
+
+
+/*
+ * Apply additional validation checks to a tzEntry
+ *
+ * Returns true if OK, else false
+ */
+static bool
+validateTzEntry(tzEntry *tzentry)
+{
+	unsigned char *p;
+
+	/*
+	 * Check restrictions imposed by datetktbl storage format (see datetime.c)
+	 */
+	if (strlen(tzentry->abbrev) > TOKMAXLEN)
+	{
+		GUC_check_errmsg("time zone abbreviation \"%s\" is too long (maximum %d characters) in time zone file \"%s\", line %d",
+						 tzentry->abbrev, TOKMAXLEN,
+						 tzentry->filename, tzentry->lineno);
+		return false;
+	}
+
+	/*
+	 * Sanity-check the offset: shouldn't exceed 14 hours
+	 */
+	if (tzentry->offset > 14 * 60 * 60 ||
+		tzentry->offset < -14 * 60 * 60)
+	{
+		GUC_check_errmsg("time zone offset %d is out of range in time zone file \"%s\", line %d",
+						 tzentry->offset,
+						 tzentry->filename, tzentry->lineno);
+		return false;
+	}
+
+	/*
+	 * Convert abbrev to lowercase (must match datetime.c's conversion)
+	 */
+	for (p = (unsigned char *) tzentry->abbrev; *p; p++)
+		*p = pg_tolower(*p);
+
+	return true;
+}
+
+/*
+ * Attempt to parse the line as a timezone abbrev spec
+ *
+ * Valid formats are:
+ *	name  zone
+ *	name  offset  dst
+ *
+ * Returns true if OK, else false; data is stored in *tzentry
+ */
+static bool
+splitTzLine(const char *filename, int lineno, char *line, tzEntry *tzentry)
+{
+	char	   *abbrev;
+	char	   *offset;
+	char	   *offset_endptr;
+	char	   *remain;
+	char	   *is_dst;
+
+	tzentry->lineno = lineno;
+	tzentry->filename = filename;
+
+	abbrev = strtok(line, WHITESPACE);
+	if (!abbrev)
+	{
+		GUC_check_errmsg("missing time zone abbreviation in time zone file \"%s\", line %d",
+						 filename, lineno);
+		return false;
+	}
+	tzentry->abbrev = pstrdup(abbrev);
+
+	offset = strtok(NULL, WHITESPACE);
+	if (!offset)
+	{
+		GUC_check_errmsg("missing time zone offset in time zone file \"%s\", line %d",
+						 filename, lineno);
+		return false;
+	}
+
+	/* We assume zone names don't begin with a digit or sign */
+	if (isdigit((unsigned char) *offset) || *offset == '+' || *offset == '-')
+	{
+		tzentry->zone = NULL;
+		tzentry->offset = strtol(offset, &offset_endptr, 10);
+		if (offset_endptr == offset || *offset_endptr != '\0')
+		{
+			GUC_check_errmsg("invalid number for time zone offset in time zone file \"%s\", line %d",
+							 filename, lineno);
+			return false;
+		}
+
+		is_dst = strtok(NULL, WHITESPACE);
+		if (is_dst && pg_strcasecmp(is_dst, "D") == 0)
+		{
+			tzentry->is_dst = true;
+			remain = strtok(NULL, WHITESPACE);
+		}
+		else
+		{
+			/* there was no 'D' dst specifier */
+			tzentry->is_dst = false;
+			remain = is_dst;
+		}
+	}
+	else
+	{
+		/*
+		 * Assume entry is a zone name.  We do not try to validate it by
+		 * looking up the zone, because that would force loading of a lot of
+		 * zones that probably will never be used in the current session.
+		 */
+		tzentry->zone = pstrdup(offset);
+		tzentry->offset = 0;
+		tzentry->is_dst = false;
+		remain = strtok(NULL, WHITESPACE);
+	}
+
+	if (!remain)				/* no more non-whitespace chars */
+		return true;
+
+	if (remain[0] != '#')		/* must be a comment */
+	{
+		GUC_check_errmsg("invalid syntax in time zone file \"%s\", line %d",
+						 filename, lineno);
+		return false;
+	}
+	return true;
+}
+
+/*
+ * Insert entry into sorted array
+ *
+ * *base: base address of array (changeable if must enlarge array)
+ * *arraysize: allocated length of array (changeable if must enlarge array)
+ * n: current number of valid elements in array
+ * entry: new data to insert
+ * override: true if OK to override
+ *
+ * Returns the new array length (new value for n), or -1 if error
+ */
+static int
+addToArray(tzEntry **base, int *arraysize, int n,
+		   tzEntry *entry, bool override)
+{
+	tzEntry    *arrayptr;
+	int			low;
+	int			high;
+
+	/*
+	 * Search the array for a duplicate; as a useful side effect, the array is
+	 * maintained in sorted order.  We use strcmp() to ensure we match the
+	 * sort order datetime.c expects.
+	 */
+	arrayptr = *base;
+	low = 0;
+	high = n - 1;
+	while (low <= high)
+	{
+		int			mid = (low + high) >> 1;
+		tzEntry    *midptr = arrayptr + mid;
+		int			cmp;
+
+		cmp = strcmp(entry->abbrev, midptr->abbrev);
+		if (cmp < 0)
+			high = mid - 1;
+		else if (cmp > 0)
+			low = mid + 1;
+		else
+		{
+			/*
+			 * Found a duplicate entry; complain unless it's the same.
+			 */
+			if ((midptr->zone == NULL && entry->zone == NULL &&
+				 midptr->offset == entry->offset &&
+				 midptr->is_dst == entry->is_dst) ||
+				(midptr->zone != NULL && entry->zone != NULL &&
+				 strcmp(midptr->zone, entry->zone) == 0))
+			{
+				/* return unchanged array */
+				return n;
+			}
+			if (override)
+			{
+				/* same abbrev but something is different, override */
+				midptr->zone = entry->zone;
+				midptr->offset = entry->offset;
+				midptr->is_dst = entry->is_dst;
+				return n;
+			}
+			/* same abbrev but something is different, complain */
+			GUC_check_errmsg("time zone abbreviation \"%s\" is multiply defined",
+							 entry->abbrev);
+			GUC_check_errdetail("Entry in time zone file \"%s\", line %d, conflicts with entry in file \"%s\", line %d.",
+								midptr->filename, midptr->lineno,
+								entry->filename, entry->lineno);
+			return -1;
+		}
+	}
+
+	/*
+	 * No match, insert at position "low".
+	 */
+	if (n >= *arraysize)
+	{
+		*arraysize *= 2;
+		*base = (tzEntry *) repalloc(*base, *arraysize * sizeof(tzEntry));
+	}
+
+	arrayptr = *base + low;
+
+	memmove(arrayptr + 1, arrayptr, (n - low) * sizeof(tzEntry));
+
+	memcpy(arrayptr, entry, sizeof(tzEntry));
+
+	return n + 1;
+}
+
+/*
+ * Parse a single timezone abbrev file --- can recurse to handle @INCLUDE
+ *
+ * filename: user-specified file name (does not include path)
+ * depth: current recursion depth
+ * *base: array for results (changeable if must enlarge array)
+ * *arraysize: allocated length of array (changeable if must enlarge array)
+ * n: current number of valid elements in array
+ *
+ * Returns the new array length (new value for n), or -1 if error
+ */
+static int
+ParseTzFile(const char *filename, int depth,
+			tzEntry **base, int *arraysize, int n)
+{
+	char		share_path[MAXPGPATH];
+	char		file_path[MAXPGPATH];
+	FILE	   *tzFile;
+	char		tzbuf[1024];
+	char	   *line;
+	tzEntry		tzentry;
+	int			lineno = 0;
+	bool		override = false;
+	const char *p;
+
+	/*
+	 * We enforce that the filename is all alpha characters.  This may be
+	 * overly restrictive, but we don't want to allow access to anything
+	 * outside the timezonesets directory, so for instance '/' *must* be
+	 * rejected.
+	 */
+	for (p = filename; *p; p++)
+	{
+		if (!isalpha((unsigned char) *p))
+		{
+			/* at level 0, just use guc.c's regular "invalid value" message */
+			if (depth > 0)
+				GUC_check_errmsg("invalid time zone file name \"%s\"",
+								 filename);
+			return -1;
+		}
+	}
+
+	/*
+	 * The maximal recursion depth is a pretty arbitrary setting. It is hard
+	 * to imagine that someone needs more than 3 levels so stick with this
+	 * conservative setting until someone complains.
+	 */
+	if (depth > 3)
+	{
+		GUC_check_errmsg("time zone file recursion limit exceeded in file \"%s\"",
+						 filename);
+		return -1;
+	}
+
+	get_share_path(my_exec_path, share_path);
+	snprintf(file_path, sizeof(file_path), "%s/timezonesets/%s",
+			 share_path, filename);
+	tzFile = AllocateFile(file_path, "r");
+	if (!tzFile)
+	{
+		/*
+		 * Check to see if the problem is not the filename but the directory.
+		 * This is worth troubling over because if the installation share/
+		 * directory is missing or unreadable, this is likely to be the first
+		 * place we notice a problem during postmaster startup.
+		 */
+		int			save_errno = errno;
+		DIR		   *tzdir;
+
+		snprintf(file_path, sizeof(file_path), "%s/timezonesets",
+				 share_path);
+		tzdir = AllocateDir(file_path);
+		if (tzdir == NULL)
+		{
+			GUC_check_errmsg("could not open directory \"%s\": %m",
+							 file_path);
+			GUC_check_errhint("This may indicate an incomplete PostgreSQL installation, or that the file \"%s\" has been moved away from its proper location.",
+							  my_exec_path);
+			return -1;
+		}
+		FreeDir(tzdir);
+		errno = save_errno;
+
+		/*
+		 * otherwise, if file doesn't exist and it's level 0, guc.c's
+		 * complaint is enough
+		 */
+		if (errno != ENOENT || depth > 0)
+			GUC_check_errmsg("could not read time zone file \"%s\": %m",
+							 filename);
+
+		return -1;
+	}
+
+	while (!feof(tzFile))
+	{
+		lineno++;
+		if (fgets(tzbuf, sizeof(tzbuf), tzFile) == NULL)
+		{
+			if (ferror(tzFile))
+			{
+				GUC_check_errmsg("could not read time zone file \"%s\": %m",
+								 filename);
+				n = -1;
+				break;
+			}
+			/* else we're at EOF after all */
+			break;
+		}
+		if (strlen(tzbuf) == sizeof(tzbuf) - 1)
+		{
+			/* the line is too long for tzbuf */
+			GUC_check_errmsg("line is too long in time zone file \"%s\", line %d",
+							 filename, lineno);
+			n = -1;
+			break;
+		}
+
+		/* skip over whitespace */
+		line = tzbuf;
+		while (*line && isspace((unsigned char) *line))
+			line++;
+
+		if (*line == '\0')		/* empty line */
+			continue;
+		if (*line == '#')		/* comment line */
+			continue;
+
+		if (pg_strncasecmp(line, "@INCLUDE", strlen("@INCLUDE")) == 0)
+		{
+			/* pstrdup so we can use filename in result data structure */
+			char	   *includeFile = pstrdup(line + strlen("@INCLUDE"));
+
+			includeFile = strtok(includeFile, WHITESPACE);
+			if (!includeFile || !*includeFile)
+			{
+				GUC_check_errmsg("@INCLUDE without file name in time zone file \"%s\", line %d",
+								 filename, lineno);
+				n = -1;
+				break;
+			}
+			n = ParseTzFile(includeFile, depth + 1,
+							base, arraysize, n);
+			if (n < 0)
+				break;
+			continue;
+		}
+
+		if (pg_strncasecmp(line, "@OVERRIDE", strlen("@OVERRIDE")) == 0)
+		{
+			override = true;
+			continue;
+		}
+
+		if (!splitTzLine(filename, lineno, line, &tzentry))
+		{
+			n = -1;
+			break;
+		}
+		if (!validateTzEntry(&tzentry))
+		{
+			n = -1;
+			break;
+		}
+		n = addToArray(base, arraysize, n, &tzentry, override);
+		if (n < 0)
+			break;
+	}
+
+	FreeFile(tzFile);
+
+	return n;
+}
+
+/*
+ * load_tzoffsets --- read and parse the specified timezone offset file
+ *
+ * On success, return a filled-in TimeZoneAbbrevTable, which must have been
+ * malloc'd not palloc'd.  On failure, return NULL, using GUC_check_errmsg
+ * and friends to give details of the problem.
+ */
+TimeZoneAbbrevTable *
+load_tzoffsets(const char *filename)
+{
+	TimeZoneAbbrevTable *result = NULL;
+	MemoryContext tmpContext;
+	MemoryContext oldContext;
+	tzEntry    *array;
+	int			arraysize;
+	int			n;
+
+	/*
+	 * Create a temp memory context to work in.  This makes it easy to clean
+	 * up afterwards.
+	 */
+	tmpContext = AllocSetContextCreate(CurrentMemoryContext,
+									   "TZParserMemory",
+									   ALLOCSET_SMALL_SIZES);
+	oldContext = MemoryContextSwitchTo(tmpContext);
+
+	/* Initialize array at a reasonable size */
+	arraysize = 128;
+	array = (tzEntry *) palloc(arraysize * sizeof(tzEntry));
+
+	/* Parse the file(s) */
+	n = ParseTzFile(filename, 0, &array, &arraysize, 0);
+
+	/* If no errors so far, let datetime.c allocate memory & convert format */
+	if (n >= 0)
+	{
+		result = ConvertTimeZoneAbbrevs(array, n);
+		if (!result)
+			GUC_check_errmsg("out of memory");
+	}
+
+	/* Clean up */
+	MemoryContextSwitchTo(oldContext);
+	MemoryContextDelete(tmpContext);
+
+	return result;
+}