# License: MIT

# http://opensource.org/licenses/MIT

Add support for use of the system timezone database, rather

than embedding a copy.  Discussed upstream but was not desired.

History:

r22: retrieve tzdata version from /usr/share/zoneinfo/tzdata.zi

r21: adapt for timelib 2021.03 (in 8.1.0)

r20: adapt for timelib 2020.03 (in 8.0.10RC1)

r19: adapt for timelib 2020.02 (in 8.0.0beta2)

r18: adapt for autotool change in 7.3.3RC1

r17: adapt for timelib 2018.01 (in 7.3.2RC1)

r16: adapt for timelib 2017.06 (in 7.2.3RC1)

r15: adapt for timelib 2017.05beta7 (in 7.2.0RC1)

r14: improve check for valid tz file

r13: adapt for upstream changes to use PHP allocator

r12: adapt for upstream changes for new zic

r11: use canonical names to avoid more case sensitivity issues

     round lat/long from zone.tab towards zero per builtin db

r10: make timezone case insensitive

r9: fix another compile error without --with-system-tzdata configured (Michael Heimpold)

r8: fix compile error without --with-system-tzdata configured

r7: improve check for valid timezone id to exclude directories

r6: fix fd leak in r5, fix country code/BC flag use in

    timezone_identifiers_list() using system db,

    fix use of PECL timezonedb to override system db,

r5: reverts addition of "System/Localtime" fake tzname.

    updated for 5.3.0, parses zone.tab to pick up mapping between

    timezone name, country code and long/lat coords

r4: added "System/Localtime" tzname which uses /etc/localtime

r3: fix a crash if /usr/share/zoneinfo doesn't exist (Raphael Geissert)

r2: add filesystem trawl to set up name alias index

r1: initial revision

diff --git a/ext/date/config0.m4 b/ext/date/config0.m4

index 18b8106bd2..3d1f63c758 100644

--- a/ext/date/config0.m4

+++ b/ext/date/config0.m4

@@ -4,6 +4,19 @@ AC_CHECK_HEADERS([io.h])

 dnl Check for strtoll, atoll

 AC_CHECK_FUNCS(strtoll atoll)

+PHP_ARG_WITH(system-tzdata, for use of system timezone data,

+[  --with-system-tzdata[=DIR]      to specify use of system timezone data],

+no, no)

+

+if test "$PHP_SYSTEM_TZDATA" != "no"; then

+   AC_DEFINE(HAVE_SYSTEM_TZDATA, 1, [Define if system timezone data is used])

+

+   if test "$PHP_SYSTEM_TZDATA" != "yes"; then

+      AC_DEFINE_UNQUOTED(HAVE_SYSTEM_TZDATA_PREFIX, "$PHP_SYSTEM_TZDATA",

+                         [Define for location of system timezone data])

+   fi

+fi

+

 PHP_DATE_CFLAGS="-Wno-implicit-fallthrough -I@ext_builddir@/lib -DZEND_ENABLE_STATIC_TSRMLS_CACHE=1 -DHAVE_TIMELIB_CONFIG_H=1"

 timelib_sources="lib/astro.c lib/dow.c lib/parse_date.c lib/parse_tz.c lib/parse_posix.c

                  lib/timelib.c lib/tm2unixtime.c lib/unixtime2tm.c lib/parse_iso_intervals.c lib/interval.c"

diff --git a/ext/date/lib/parse_tz.c b/ext/date/lib/parse_tz.c

index e41315efdb..4b6547c0a3 100644

--- a/ext/date/lib/parse_tz.c

+++ b/ext/date/lib/parse_tz.c

@@ -26,9 +26,22 @@

 #include "timelib.h"

 #include "timelib_private.h"

+#ifdef HAVE_SYSTEM_TZDATA

+#include <sys/mman.h>

+#include <sys/stat.h>

+#include <limits.h>

+#include <fcntl.h>

+#include <unistd.h>

+

+#include "php_scandir.h"

+

+#else

 #define TIMELIB_SUPPORTS_V2DATA

 #define TIMELIB_SUPPORT_SLIM_FILE

 #include "timezonedb.h"

+#endif

+

+#include <ctype.h>

 #if (defined(__APPLE__) || defined(__APPLE_CC__)) && (defined(__BIG_ENDIAN__) || defined(__LITTLE_ENDIAN__))

 # if defined(__LITTLE_ENDIAN__)

@@ -95,6 +108,11 @@ static int read_php_preamble(const unsigned char **tzf, timelib_tzinfo *tz)

 {

 	uint32_t version;

+	if (memcmp(*tzf, "TZif", 4) == 0) {

+		*tzf += 20;

+		return 0;

+	}

+

 	/* read ID */

 	version = (*tzf)[3] - '0';

 	*tzf += 4;

@@ -577,7 +595,467 @@ void timelib_dump_tzinfo(timelib_tzinfo *tz)

 	}

 }

-static int seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)

+#ifdef HAVE_SYSTEM_TZDATA

+

+#ifdef HAVE_SYSTEM_TZDATA_PREFIX

+#define ZONEINFO_PREFIX HAVE_SYSTEM_TZDATA_PREFIX

+#else

+#define ZONEINFO_PREFIX "/usr/share/zoneinfo"

+#endif

+

+/* System timezone database pointer. */

+static const timelib_tzdb *timezonedb_system;

+

+/* Hash table entry for the cache of the zone.tab mapping table. */

+struct location_info {

+        char code[2];

+        double latitude, longitude;

+        char name[64];

+        char *comment;

+        struct location_info *next;

+};

+

+/* Cache of zone.tab. */

+static struct location_info **system_location_table;

+

+/* Size of the zone.tab hash table; a random-ish prime big enough to

+ * prevent too many collisions. */

+#define LOCINFO_HASH_SIZE (1021)

+

+/* Compute a case insensitive hash of str */

+static uint32_t tz_hash(const char *str)

+{

+    const unsigned char *p = (const unsigned char *)str;

+    uint32_t hash = 5381;

+    int c;

+

+    while ((c = tolower(*p++)) != '\0') {

+        hash = (hash << 5) ^ hash ^ c;

+    }

+

+    return hash % LOCINFO_HASH_SIZE;

+}

+

+/* Parse an ISO-6709 date as used in zone.tab. Returns end of the

+ * parsed string on success, or NULL on parse error.  On success,

+ * writes the parsed number to *result. */

+static char *parse_iso6709(char *p, double *result)

+{

+    double v, sign;

+    char *pend;

+    size_t len;

+

+    if (*p == '+')

+        sign = 1.0;

+    else if (*p == '-')

+        sign = -1.0;

+    else

+        return NULL;

+

+    p++;

+    for (pend = p; *pend >= '0' && *pend <= '9'; pend++)

+        ;;

+

+    /* Annoying encoding used by zone.tab has no decimal point, so use

+     * the length to determine the format:

+     * 

+     * 4 = DDMM

+     * 5 = DDDMM

+     * 6 = DDMMSS

+     * 7 = DDDMMSS

+     */

+    len = pend - p;

+    if (len < 4 || len > 7) {

+        return NULL;

+    }

+

+    /* p => [D]DD */

+    v = (p[0] - '0') * 10.0 + (p[1] - '0');

+    p += 2;

+    if (len == 5 || len == 7)

+        v = v * 10.0 + (*p++ - '0');

+    /* p => MM[SS] */

+    v += (10.0 * (p[0] - '0')

+          + p[1] - '0') / 60.0;

+    p += 2;

+    /* p => [SS] */

+    if (len > 5) {

+        v += (10.0 * (p[0] - '0')

+              + p[1] - '0') / 3600.0;

+        p += 2;

+    }

+

+    /* Round to five decimal place, not because it's a good idea,

+     * but, because the builtin data uses rounded data, so, match

+     * that. */

+    *result = trunc(v * sign * 100000.0) / 100000.0;

+

+    return p;

+}

+

+/* This function parses the zone.tab file to build up the mapping of

+ * timezone to country code and geographic location, and returns a

+ * hash table.  The hash table is indexed by the function:

+ *

+ *   tz_hash(timezone-name)

+ */

+static struct location_info **create_location_table(void)

+{

+    struct location_info **li, *i;

+    char zone_tab[PATH_MAX];

+    char line[512];

+    FILE *fp;

+

+    strncpy(zone_tab, ZONEINFO_PREFIX "/zone.tab", sizeof zone_tab);

+

+    fp = fopen(zone_tab, "r");

+    if (!fp) {

+        return NULL;

+    }

+

+    li = calloc(LOCINFO_HASH_SIZE, sizeof *li);

+

+    while (fgets(line, sizeof line, fp)) {

+        char *p = line, *code, *name, *comment;

+        uint32_t hash;

+        double latitude, longitude;

+

+        while (isspace(*p))

+            p++;

+

+        if (*p == '#' || *p == '\0' || *p == '\n')

+            continue;

+        

+        if (!isalpha(p[0]) || !isalpha(p[1]) || p[2] != '\t')

+            continue;

+        

+        /* code => AA */

+        code = p;

+        p[2] = 0;

+        p += 3;

+

+        /* coords => [+-][D]DDMM[SS][+-][D]DDMM[SS] */

+        p = parse_iso6709(p, &latitude);

+        if (!p) {

+            continue;

+        }

+        p = parse_iso6709(p, &longitude);

+        if (!p) {

+            continue;

+        }

+

+        if (!p || *p != '\t') {

+            continue;

+        }

+

+        /* name = string */

+        name = ++p;

+        while (*p != '\t' && *p && *p != '\n')

+            p++;

+

+        *p++ = '\0';

+

+        /* comment = string */

+        comment = p;

+        while (*p != '\t' && *p && *p != '\n')

+            p++;

+

+        if (*p == '\n' || *p == '\t')

+            *p = '\0';

+        

+        hash = tz_hash(name);

+        i = malloc(sizeof *i);

+        memcpy(i->code, code, 2);

+        strncpy(i->name, name, sizeof i->name);

+        i->comment = strdup(comment);

+        i->longitude = longitude;

+        i->latitude = latitude;

+        i->next = li[hash];

+        li[hash] = i;

+        /* printf("%s [%u, %f, %f]\n", name, hash, latitude, longitude); */

+    }

+

+    fclose(fp);

+

+    return li;

+}

+

+/* Return location info from hash table, using given timezone name.

+ * Returns NULL if the name could not be found. */

+const struct location_info *find_zone_info(struct location_info **li, 

+                                           const char *name)

+{

+    uint32_t hash = tz_hash(name);

+    const struct location_info *l;

+

+    if (!li) {

+        return NULL;

+    }

+

+    for (l = li[hash]; l; l = l->next) {

+        if (timelib_strcasecmp(l->name, name) == 0)

+            return l;

+    }

+

+    return NULL;

+}    

+

+/* Filter out some non-tzdata files and the posix/right databases, if

+ * present. */

+static int index_filter(const struct dirent *ent)

+{

+	return strcmp(ent->d_name, ".") != 0

+		&& strcmp(ent->d_name, "..") != 0

+		&& strcmp(ent->d_name, "posix") != 0

+		&& strcmp(ent->d_name, "posixrules") != 0

+		&& strcmp(ent->d_name, "right") != 0

+		&& strstr(ent->d_name, ".list") == NULL

+		&& strstr(ent->d_name, ".tab") == NULL;

+}

+

+static int sysdbcmp(const void *first, const void *second)

+{

+        const timelib_tzdb_index_entry *alpha = first, *beta = second;

+

+        return timelib_strcasecmp(alpha->id, beta->id);

+}

+

+/* Retrieve tzdata version. */

+static void retrieve_zone_version(timelib_tzdb *db)

+{

+    static char buf[30];

+    char path[PATH_MAX];

+    FILE *fp;

+

+    strncpy(path, ZONEINFO_PREFIX "/tzdata.zi", sizeof(path));

+

+    fp = fopen(path, "r");

+    if (fp) {

+		if (fgets(buf, sizeof(buf), fp)) {

+			if (!memcmp(buf, "# version ", 10) &&

+				isdigit(buf[10]) &&

+				isdigit(buf[11]) &&

+				isdigit(buf[12]) &&

+				isdigit(buf[13]) &&

+				islower(buf[14])) {

+				if (buf[14] >= 't') {        /* 2022t = 2022.20 */

+					buf[17] = 0;

+					buf[16] = buf[14] - 't' + '0';

+					buf[15] = '2';

+				} else if (buf[14] >= 'j') { /* 2022j = 2022.10 */

+					buf[17] = 0;

+					buf[16] = buf[14] - 'j' + '0';

+					buf[15] = '1';

+				} else {                     /* 2022a = 2022.1  */

+					buf[16] = 0;

+					buf[15] = buf[14] - 'a' + '1';

+				}

+				buf[14] = '.';

+				db->version = buf+10;

+			}

+		}

+		fclose(fp);

+    }

+}

+

+

+/* Create the zone identifier index by trawling the filesystem. */

+static void create_zone_index(timelib_tzdb *db)

+{

+	size_t dirstack_size,  dirstack_top;

+	size_t index_size, index_next;

+	timelib_tzdb_index_entry *db_index;

+	char **dirstack;

+

+	/* LIFO stack to hold directory entries to scan; each slot is a

+	 * directory name relative to the zoneinfo prefix. */

+	dirstack_size = 32;

+	dirstack = malloc(dirstack_size * sizeof *dirstack);

+	dirstack_top = 1;

+	dirstack[0] = strdup("");

+	

+	/* Index array. */

+	index_size = 64;

+	db_index = malloc(index_size * sizeof *db_index);

+	index_next = 0;

+

+	do {

+		struct dirent **ents;

+		char name[PATH_MAX], *top;

+		int count;

+

+		/* Pop the top stack entry, and iterate through its contents. */

+		top = dirstack[--dirstack_top];

+		snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s", top);

+

+		count = php_scandir(name, &ents, index_filter, php_alphasort);

+

+		while (count > 0) {

+			struct stat st;

+			const char *leaf = ents[count - 1]->d_name;

+

+			snprintf(name, sizeof name, ZONEINFO_PREFIX "/%s/%s", 

+				 top, leaf);

+			

+			if (strlen(name) && stat(name, &st) == 0) {

+				/* Name, relative to the zoneinfo prefix. */

+				const char *root = top;

+

+				if (root[0] == '/') root++;

+

+				snprintf(name, sizeof name, "%s%s%s", root, 

+					 *root ? "/": "", leaf);

+

+				if (S_ISDIR(st.st_mode)) {

+					if (dirstack_top == dirstack_size) {

+						dirstack_size *= 2;

+						dirstack = realloc(dirstack, 

+								   dirstack_size * sizeof *dirstack);

+					}

+					dirstack[dirstack_top++] = strdup(name);

+				}

+				else {

+					if (index_next == index_size) {

+						index_size *= 2;

+						db_index = realloc(db_index,

+								   index_size * sizeof *db_index);

+					}

+

+					db_index[index_next++].id = strdup(name);

+				}

+			}

+

+			free(ents[--count]);

+		}

+		

+		if (count != -1) free(ents);

+		free(top);

+	} while (dirstack_top);

+

+        qsort(db_index, index_next, sizeof *db_index, sysdbcmp);

+

+	db->index = db_index;

+	db->index_size = index_next;

+

+	free(dirstack);

+}

+

+#define FAKE_HEADER "1234\0??\1??"

+#define FAKE_UTC_POS (7 - 4)

+

+/* Create a fake data segment for database 'sysdb'. */

+static void fake_data_segment(timelib_tzdb *sysdb,

+                              struct location_info **info)

+{

+        size_t n;

+        char *data, *p;

+        

+        data = malloc(3 * sysdb->index_size + 7);

+

+        p = mempcpy(data, FAKE_HEADER, sizeof(FAKE_HEADER) - 1);

+

+        for (n = 0; n < sysdb->index_size; n++) {

+                const struct location_info *li;

+                timelib_tzdb_index_entry *ent;

+

+                ent = (timelib_tzdb_index_entry *)&sysdb->index[n];

+

+                /* Lookup the timezone name in the hash table. */

+                if (strcmp(ent->id, "UTC") == 0) {

+                        ent->pos = FAKE_UTC_POS;

+                        continue;

+                }

+

+                li = find_zone_info(info, ent->id);

+                if (li) {

+                        /* If found, append the BC byte and the

+                         * country code; set the position for this

+                         * section of timezone data.  */

+                        ent->pos = (p - data) - 4;

+                        *p++ = '\1';

+                        *p++ = li->code[0];

+                        *p++ = li->code[1];

+                }

+                else {

+                        /* If not found, the timezone data can

+                         * point at the header. */

+                        ent->pos = 0;

+                }

+        }

+        

+        sysdb->data = (unsigned char *)data;

+}

+

+/* Returns true if the passed-in stat structure describes a

+ * probably-valid timezone file. */

+static int is_valid_tzfile(const struct stat *st, int fd)

+{

+	if (fd) {

+		char buf[20];

+		if (read(fd, buf, 20)!=20) {

+			return 0;

+		}

+		lseek(fd, SEEK_SET, 0);

+		if (memcmp(buf, "TZif", 4)) {

+			return 0;

+		}

+	}

+	return S_ISREG(st->st_mode) && st->st_size > 20;

+}

+

+/* To allow timezone names to be used case-insensitively, find the

+ * canonical name for this timezone, if possible. */

+static const char *canonical_tzname(const char *timezone)

+{

+    if (timezonedb_system) {

+        timelib_tzdb_index_entry *ent, lookup;

+

+        lookup.id = (char *)timezone;

+

+        ent = bsearch(&lookup, timezonedb_system->index,

+                      timezonedb_system->index_size, sizeof lookup,

+                      sysdbcmp);

+        if (ent) {

+            return ent->id;

+        }

+    }

+

+    return timezone;

+}

+

+/* Return the mmap()ed tzfile if found, else NULL.  On success, the

+ * length of the mapped data is placed in *length. */

+static char *map_tzfile(const char *timezone, size_t *length)

+{

+	char fname[PATH_MAX];

+	struct stat st;

+	char *p;

+	int fd;

+	

+	if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {

+		return NULL;

+	}

+

+	snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));

+

+	fd = open(fname, O_RDONLY);

+	if (fd == -1) {

+		return NULL;

+	} else if (fstat(fd, &st) != 0 || !is_valid_tzfile(&st, fd)) {

+		close(fd);

+		return NULL;

+	}

+

+	*length = st.st_size;

+	p = mmap(NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);

+	close(fd);

+	

+	return p != MAP_FAILED ? p : NULL;

+}

+

+#endif

+

+static int inmem_seek_to_tz_position(const unsigned char **tzf, const char *timezone, const timelib_tzdb *tzdb)

 {

 	int left = 0, right = tzdb->index_size - 1;

@@ -603,9 +1081,49 @@ static int seek_to_tz_position(const unsigned char **tzf, const char *timezone,

 	return 0;

 }

+static int seek_to_tz_position(const unsigned char **tzf, const char *timezone,

+			       char **map, size_t *maplen,

+			       const timelib_tzdb *tzdb)

+{

+#ifdef HAVE_SYSTEM_TZDATA

+	if (tzdb == timezonedb_system) {

+		char *orig;

+

+		orig = map_tzfile(timezone, maplen);

+		if (orig == NULL) {

+			return 0;

+		}

+

+		(*tzf) = (unsigned char *)orig;

+		*map = orig;

+        return 1;

+	}

+	else

+#endif

+	{

+		return inmem_seek_to_tz_position(tzf, timezone, tzdb);

+	}

+}

+

 const timelib_tzdb *timelib_builtin_db(void)

 {

+#ifdef HAVE_SYSTEM_TZDATA

+	if (timezonedb_system == NULL) {

+		timelib_tzdb *tmp = malloc(sizeof *tmp);

+

+		tmp->version = "0.system";

+		tmp->data = NULL;

+		create_zone_index(tmp);

+		retrieve_zone_version(tmp);

+		system_location_table = create_location_table();

+		fake_data_segment(tmp, system_location_table);

+		timezonedb_system = tmp;

+	}

+

+	return timezonedb_system;

+#else

 	return &timezonedb_builtin;

+#endif

 }

 const timelib_tzdb_index_entry *timelib_timezone_identifiers_list(const timelib_tzdb *tzdb, int *count)

@@ -617,7 +1135,30 @@ const timelib_tzdb_index_entry *timelib_timezone_identifiers_list(const timelib_

 int timelib_timezone_id_is_valid(const char *timezone, const timelib_tzdb *tzdb)

 {

 	const unsigned char *tzf;

-	return (seek_to_tz_position(&tzf, timezone, tzdb));

+

+#ifdef HAVE_SYSTEM_TZDATA

+	if (tzdb == timezonedb_system) {

+		char fname[PATH_MAX];

+		struct stat st;

+

+		if (timezone[0] == '\0' || strstr(timezone, "..") != NULL) {

+			return 0;

+		}

+

+		if (system_location_table) {

+			if (find_zone_info(system_location_table, timezone) != NULL) {

+				/* found in cache */

+				return 1;

+			}

+		}

+

+		snprintf(fname, sizeof fname, ZONEINFO_PREFIX "/%s", canonical_tzname(timezone));

+

+		return stat(fname, &st) == 0 && is_valid_tzfile(&st, 0);

+	}

+#endif

+

+	return (inmem_seek_to_tz_position(&tzf, timezone, tzdb));

 }

 static int skip_64bit_preamble(const unsigned char **tzf, timelib_tzinfo *tz)

@@ -662,6 +1203,8 @@ static timelib_tzinfo* timelib_tzinfo_ctor(const char *name)

 timelib_tzinfo *timelib_parse_tzfile(const char *timezone, const timelib_tzdb *tzdb, int *error_code)

 {

 	const unsigned char *tzf;

+	char *memmap = NULL;

+	size_t maplen;

 	timelib_tzinfo *tmp;

 	int version;

 	int transitions_result, types_result;

@@ -669,7 +1212,7 @@ timelib_tzinfo *timelib_parse_tzfile(const char *timezone, const timelib_tzdb *t

 	*error_code = TIMELIB_ERROR_NO_ERROR;

-	if (seek_to_tz_position(&tzf, timezone, tzdb)) {

+	if (seek_to_tz_position(&tzf, timezone, &memmap, &maplen, tzdb)) {

 		tmp = timelib_tzinfo_ctor(timezone);

 		version = read_preamble(&tzf, tmp, &type);

@@ -712,11 +1255,36 @@ timelib_tzinfo *timelib_parse_tzfile(const char *timezone, const timelib_tzdb *t

 			return NULL;

 		}

+#ifdef HAVE_SYSTEM_TZDATA

+		if (memmap) {

+			const struct location_info *li;

+

+			/* TZif-style - grok the location info from the system database,

+			 * if possible. */

+

+			if ((li = find_zone_info(system_location_table, timezone)) != NULL) {

+				tmp->location.comments = timelib_strdup(li->comment);

+				strncpy(tmp->location.country_code, li->code, 2);

+				tmp->location.longitude = li->longitude;

+				tmp->location.latitude = li->latitude;

+				tmp->bc = 1;

+			}

+			else {

+				set_default_location_and_comments(&tzf, tmp);

+			}

+

+			/* Now done with the mmap segment - discard it. */

+			munmap(memmap, maplen);

+		} else {

+#endif

 		if (type == TIMELIB_TZINFO_PHP) {

 			read_location(&tzf, tmp);

 		} else {

 			set_default_location_and_comments(&tzf, tmp);

 		}

+#ifdef HAVE_SYSTEM_TZDATA

+		}

+#endif

 	} else {

 		*error_code = TIMELIB_ERROR_NO_SUCH_TIMEZONE;

 		tmp = NULL;

diff --git a/ext/date/php_date.c b/ext/date/php_date.c

index cf4a11b8a2..cd49abc78d 100644

--- a/ext/date/php_date.c

+++ b/ext/date/php_date.c

@@ -457,7 +457,11 @@ PHP_MINFO_FUNCTION(date)

 	php_info_print_table_row(2, "date/time support", "enabled");

 	php_info_print_table_row(2, "timelib version", TIMELIB_ASCII_VERSION);

 	php_info_print_table_row(2, "\"Olson\" Timezone Database Version", tzdb->version);

+#ifdef HAVE_SYSTEM_TZDATA

+	php_info_print_table_row(2, "Timezone Database", "system");

+#else

 	php_info_print_table_row(2, "Timezone Database", php_date_global_timezone_db_enabled ? "external" : "internal");

+#endif

 	php_info_print_table_row(2, "Default timezone", guess_timezone(tzdb));