| 1 | /* $Id: RTTimeZoneGetCurrent-posix.cpp 106061 2024-09-16 14:03:52Z vboxsync $ */
|
|---|
| 2 | /** @file
|
|---|
| 3 | * IPRT - RTTimeZoneGetCurrent, POSIX.
|
|---|
| 4 | */
|
|---|
| 5 |
|
|---|
| 6 | /*
|
|---|
| 7 | * Copyright (C) 2020-2024 Oracle and/or its affiliates.
|
|---|
| 8 | *
|
|---|
| 9 | * This file is part of VirtualBox base platform packages, as
|
|---|
| 10 | * available from https://www.virtualbox.org.
|
|---|
| 11 | *
|
|---|
| 12 | * This program is free software; you can redistribute it and/or
|
|---|
| 13 | * modify it under the terms of the GNU General Public License
|
|---|
| 14 | * as published by the Free Software Foundation, in version 3 of the
|
|---|
| 15 | * License.
|
|---|
| 16 | *
|
|---|
| 17 | * This program is distributed in the hope that it will be useful, but
|
|---|
| 18 | * WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|---|
| 20 | * General Public License for more details.
|
|---|
| 21 | *
|
|---|
| 22 | * You should have received a copy of the GNU General Public License
|
|---|
| 23 | * along with this program; if not, see <https://www.gnu.org/licenses>.
|
|---|
| 24 | *
|
|---|
| 25 | * The contents of this file may alternatively be used under the terms
|
|---|
| 26 | * of the Common Development and Distribution License Version 1.0
|
|---|
| 27 | * (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
|
|---|
| 28 | * in the VirtualBox distribution, in which case the provisions of the
|
|---|
| 29 | * CDDL are applicable instead of those of the GPL.
|
|---|
| 30 | *
|
|---|
| 31 | * You may elect to license modified versions of this file under the
|
|---|
| 32 | * terms and conditions of either the GPL or the CDDL or both.
|
|---|
| 33 | *
|
|---|
| 34 | * SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
|
|---|
| 35 | */
|
|---|
| 36 |
|
|---|
| 37 |
|
|---|
| 38 | /*********************************************************************************************************************************
|
|---|
| 39 | * Header Files *
|
|---|
| 40 | *********************************************************************************************************************************/
|
|---|
| 41 | #include <iprt/time.h>
|
|---|
| 42 | #include "internal/iprt.h"
|
|---|
| 43 |
|
|---|
| 44 | #include <iprt/env.h>
|
|---|
| 45 | #include <iprt/file.h>
|
|---|
| 46 | #include <iprt/path.h>
|
|---|
| 47 | #include <iprt/string.h>
|
|---|
| 48 | #include <iprt/err.h>
|
|---|
| 49 | #include <iprt/errcore.h>
|
|---|
| 50 | #include <iprt/types.h>
|
|---|
| 51 | #include <iprt/symlink.h>
|
|---|
| 52 | #include <iprt/stream.h>
|
|---|
| 53 |
|
|---|
| 54 | #if defined(RT_OS_DARWIN) || defined(RT_OS_SOLARIS)
|
|---|
| 55 | # include <tzfile.h>
|
|---|
| 56 | #else
|
|---|
| 57 | # define TZDIR "/usr/share/zoneinfo"
|
|---|
| 58 | # define TZ_MAGIC "TZif"
|
|---|
| 59 | #endif
|
|---|
| 60 |
|
|---|
| 61 |
|
|---|
| 62 | /*********************************************************************************************************************************
|
|---|
| 63 | * Defined Constants And Macros *
|
|---|
| 64 | *********************************************************************************************************************************/
|
|---|
| 65 | #define PATH_LOCALTIME "/etc/localtime"
|
|---|
| 66 | #if defined(RT_OS_FREEBSD)
|
|---|
| 67 | # define PATH_TIMEZONE "/var/db/zoneinfo"
|
|---|
| 68 | #else
|
|---|
| 69 | # define PATH_TIMEZONE "/etc/timezone"
|
|---|
| 70 | #endif
|
|---|
| 71 | #define PATH_SYSCONFIG_CLOCK "/etc/sysconfig/clock"
|
|---|
| 72 |
|
|---|
| 73 |
|
|---|
| 74 | /**
|
|---|
| 75 | * Checks if a time zone database file is valid by verifying it begins with
|
|---|
| 76 | * TZ_MAGIC.
|
|---|
| 77 | *
|
|---|
| 78 | * @returns IPRT status code.
|
|---|
| 79 | * @param pszTimezone The time zone database file relative to
|
|---|
| 80 | * <tzfile.h>:TZDIR (normally /usr/share/zoneinfo),
|
|---|
| 81 | * e.g. Europe/London, or Etc/UTC, or UTC, or etc.
|
|---|
| 82 | *
|
|---|
| 83 | * @note File format is documented in RFC-8536.
|
|---|
| 84 | */
|
|---|
| 85 | static int rtIsValidTimeZoneFile(const char *pszTimeZone)
|
|---|
| 86 | {
|
|---|
| 87 | if (pszTimeZone == NULL || *pszTimeZone == '\0' || *pszTimeZone == '/')
|
|---|
| 88 | return VERR_INVALID_PARAMETER;
|
|---|
| 89 |
|
|---|
| 90 | int rc = RTStrValidateEncoding(pszTimeZone);
|
|---|
| 91 | if (RT_SUCCESS(rc))
|
|---|
| 92 | {
|
|---|
| 93 | /* construct full pathname of the time zone file */
|
|---|
| 94 | char szTZPath[RTPATH_MAX];
|
|---|
| 95 | rc = RTPathJoin(szTZPath, sizeof(szTZPath), TZDIR, pszTimeZone);
|
|---|
| 96 | if (RT_SUCCESS(rc))
|
|---|
| 97 | {
|
|---|
| 98 | /* open the time zone file and check that it begins with the correct magic number */
|
|---|
| 99 | RTFILE hFile = NIL_RTFILE;
|
|---|
| 100 | rc = RTFileOpen(&hFile, szTZPath, RTFILE_O_READ | RTFILE_O_OPEN | RTFILE_O_DENY_WRITE);
|
|---|
| 101 | if (RT_SUCCESS(rc))
|
|---|
| 102 | {
|
|---|
| 103 | char achTZBuf[sizeof(TZ_MAGIC)];
|
|---|
| 104 | rc = RTFileRead(hFile, achTZBuf, sizeof(achTZBuf), NULL);
|
|---|
| 105 | RTFileClose(hFile);
|
|---|
| 106 | if (RT_SUCCESS(rc))
|
|---|
| 107 | {
|
|---|
| 108 | if (memcmp(achTZBuf, RT_STR_TUPLE(TZ_MAGIC)) == 0)
|
|---|
| 109 | rc = VINF_SUCCESS;
|
|---|
| 110 | else
|
|---|
| 111 | rc = VERR_INVALID_MAGIC;
|
|---|
| 112 | }
|
|---|
| 113 | }
|
|---|
| 114 | }
|
|---|
| 115 | }
|
|---|
| 116 |
|
|---|
| 117 | return rc;
|
|---|
| 118 | }
|
|---|
| 119 |
|
|---|
| 120 |
|
|---|
| 121 | /**
|
|---|
| 122 | * Return the system time zone.
|
|---|
| 123 | *
|
|---|
| 124 | * @returns IPRT status code.
|
|---|
| 125 | * @param pszName The buffer to return the time zone in.
|
|---|
| 126 | * @param cbName The size of the pszName buffer.
|
|---|
| 127 | */
|
|---|
| 128 | RTDECL(int) RTTimeZoneGetCurrent(char *pszName, size_t cbName)
|
|---|
| 129 | {
|
|---|
| 130 | int rc = RTEnvGetEx(RTENV_DEFAULT, "TZ", pszName, cbName, NULL);
|
|---|
| 131 | if (RT_SUCCESS(rc))
|
|---|
| 132 | {
|
|---|
| 133 | /*
|
|---|
| 134 | * $TZ can have two different formats and one of them doesn't specify
|
|---|
| 135 | * a time zone database file under <tzfile.h>:TZDIR but since all
|
|---|
| 136 | * current callers of this routine expect a time zone filename we do
|
|---|
| 137 | * the validation check here so that if it is invalid then we fall back
|
|---|
| 138 | * to the other mechanisms to return the system's current time zone.
|
|---|
| 139 | */
|
|---|
| 140 | if (*pszName == ':') /* POSIX allows $TZ to begin with a colon (:) so we allow for that here */
|
|---|
| 141 | memmove(pszName, pszName + 1, strlen(pszName));
|
|---|
| 142 | /** @todo this isn't perfect for absolute paths... Should probably try treat
|
|---|
| 143 | * it like /etc/localtime. */
|
|---|
| 144 | rc = rtIsValidTimeZoneFile(pszName);
|
|---|
| 145 | if (RT_SUCCESS(rc))
|
|---|
| 146 | return rc;
|
|---|
| 147 | }
|
|---|
| 148 | else if (rc != VERR_ENV_VAR_NOT_FOUND)
|
|---|
| 149 | return rc;
|
|---|
| 150 |
|
|---|
| 151 | /*
|
|---|
| 152 | * /etc/localtime is a symbolic link to the system time zone on many OSes
|
|---|
| 153 | * including Solaris, macOS, Ubuntu, RH/OEL 6 and later, Arch Linux, NetBSD,
|
|---|
| 154 | * and etc. We extract the time zone pathname relative to TZDIR defined in
|
|---|
| 155 | * <tzfile.h> which is normally /usr/share/zoneinfo.
|
|---|
| 156 | *
|
|---|
| 157 | * N.B. Some OSes have /etc/localtime as a regular file instead of a
|
|---|
| 158 | * symlink and while we could trawl through all the files under TZDIR
|
|---|
| 159 | * looking for a match we instead fallback to other popular mechanisms of
|
|---|
| 160 | * specifying the system-wide time zone for the sake of simplicity.
|
|---|
| 161 | */
|
|---|
| 162 | char szBuf[RTPATH_MAX];
|
|---|
| 163 | const char *pszPath = PATH_LOCALTIME;
|
|---|
| 164 | if (RTSymlinkExists(pszPath))
|
|---|
| 165 | {
|
|---|
| 166 | /* the contents of the symink may contain '..' or other links */
|
|---|
| 167 | char szLinkPathReal[RTPATH_MAX];
|
|---|
| 168 | rc = RTPathReal(pszPath, szLinkPathReal, sizeof(szLinkPathReal));
|
|---|
| 169 | if (RT_SUCCESS(rc))
|
|---|
| 170 | {
|
|---|
| 171 | rc = RTPathReal(TZDIR, szBuf, sizeof(szBuf));
|
|---|
| 172 | AssertRC(rc);
|
|---|
| 173 | if (RT_SUCCESS(rc))
|
|---|
| 174 | {
|
|---|
| 175 | Assert(RTPathStartsWith(szLinkPathReal, szBuf));
|
|---|
| 176 | if (RTPathStartsWith(szLinkPathReal, szBuf))
|
|---|
| 177 | {
|
|---|
| 178 | /* <tzfile.h>:TZDIR doesn't include a trailing slash */
|
|---|
| 179 | const char *pszTimeZone = &szLinkPathReal[strlen(szBuf) + 1];
|
|---|
| 180 | rc = rtIsValidTimeZoneFile(pszTimeZone);
|
|---|
| 181 | if (RT_SUCCESS(rc))
|
|---|
| 182 | return RTStrCopy(pszName, cbName, pszTimeZone);
|
|---|
| 183 | }
|
|---|
| 184 | }
|
|---|
| 185 | }
|
|---|
| 186 | }
|
|---|
| 187 |
|
|---|
| 188 | /*
|
|---|
| 189 | * /etc/timezone is a regular file consisting of a single line containing
|
|---|
| 190 | * the time zone (e.g. Europe/London or Etc/UTC or etc.) and is used by a
|
|---|
| 191 | * variety of Linux distros such as Ubuntu, Gentoo, Debian, and etc.
|
|---|
| 192 | * The equivalent on FreeBSD is /var/db/zoneinfo.
|
|---|
| 193 | */
|
|---|
| 194 | pszPath = PATH_TIMEZONE;
|
|---|
| 195 | if (RTFileExists(pszPath))
|
|---|
| 196 | {
|
|---|
| 197 | RTFILE hFile = NIL_RTFILE;
|
|---|
| 198 | rc = RTFileOpen(&hFile, PATH_TIMEZONE, RTFILE_O_READ | RTFILE_O_OPEN | RTFILE_O_DENY_WRITE);
|
|---|
| 199 | if (RT_SUCCESS(rc))
|
|---|
| 200 | {
|
|---|
| 201 | size_t cbRead = 0;
|
|---|
| 202 | rc = RTFileRead(hFile, szBuf, sizeof(szBuf), &cbRead);
|
|---|
| 203 | RTFileClose(hFile);
|
|---|
| 204 | if (RT_SUCCESS(rc) && cbRead > 0)
|
|---|
| 205 | {
|
|---|
| 206 | /* Get the first line and strip it. */
|
|---|
| 207 | szBuf[RT_MIN(sizeof(szBuf) - 1, cbRead)] = '\0';
|
|---|
| 208 | size_t const offNewLine = RTStrOffCharOrTerm(szBuf, '\n');
|
|---|
| 209 | szBuf[offNewLine] = '\0';
|
|---|
| 210 | const char *pszTimeZone = RTStrStrip(szBuf);
|
|---|
| 211 |
|
|---|
| 212 | rc = rtIsValidTimeZoneFile(pszTimeZone);
|
|---|
| 213 | if (RT_SUCCESS(rc))
|
|---|
| 214 | return RTStrCopy(pszName, cbName, pszTimeZone);
|
|---|
| 215 | }
|
|---|
| 216 | }
|
|---|
| 217 | }
|
|---|
| 218 |
|
|---|
| 219 | /*
|
|---|
| 220 | * Older versions of RedHat / OEL don't have /etc/localtime as a symlink or
|
|---|
| 221 | * /etc/timezone but instead have /etc/sysconfig/clock which contains a line
|
|---|
| 222 | * of the syntax ZONE=Europe/London or ZONE="Europe/London" amongst other entries.
|
|---|
| 223 | */
|
|---|
| 224 | pszPath = PATH_SYSCONFIG_CLOCK;
|
|---|
| 225 | if (RTFileExists(pszPath))
|
|---|
| 226 | {
|
|---|
| 227 | PRTSTREAM pStrm;
|
|---|
| 228 | rc = RTStrmOpen(pszPath, "r", &pStrm);
|
|---|
| 229 | if (RT_SUCCESS(rc))
|
|---|
| 230 | {
|
|---|
| 231 | while (RT_SUCCESS(rc = RTStrmGetLine(pStrm, szBuf, sizeof(szBuf))))
|
|---|
| 232 | {
|
|---|
| 233 | static char const s_szVarEq[] = "ZONE=";
|
|---|
| 234 | char *pszStart = RTStrStrip(szBuf);
|
|---|
| 235 | if (memcmp(pszStart, RT_STR_TUPLE(s_szVarEq)) == 0)
|
|---|
| 236 | {
|
|---|
| 237 | char *pszTimeZone = &pszStart[sizeof(s_szVarEq) - 1];
|
|---|
| 238 |
|
|---|
| 239 | /* Drop any quoting before using the value, assuming it is plain stuff: */
|
|---|
| 240 | if (*pszTimeZone == '\"' || *pszTimeZone == '\'')
|
|---|
| 241 | {
|
|---|
| 242 | pszTimeZone++;
|
|---|
| 243 | size_t const cchTimeZone = strlen(pszTimeZone);
|
|---|
| 244 | if (cchTimeZone && (pszTimeZone[cchTimeZone - 1] == '"' || pszTimeZone[cchTimeZone - 1] == '\''))
|
|---|
| 245 | pszTimeZone[cchTimeZone - 1] = '\0';
|
|---|
| 246 | }
|
|---|
| 247 |
|
|---|
| 248 | rc = rtIsValidTimeZoneFile(pszTimeZone);
|
|---|
| 249 | if (RT_SUCCESS(rc))
|
|---|
| 250 | {
|
|---|
| 251 | RTStrmClose(pStrm);
|
|---|
| 252 | return RTStrCopy(pszName, cbName, pszTimeZone);
|
|---|
| 253 | }
|
|---|
| 254 | }
|
|---|
| 255 | }
|
|---|
| 256 | RTStrmClose(pStrm);
|
|---|
| 257 | }
|
|---|
| 258 | }
|
|---|
| 259 |
|
|---|
| 260 | return rc;
|
|---|
| 261 | }
|
|---|
| 262 |
|
|---|
