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util.h (29420B)


      1 /*
      2 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
      3 *
      4 * Redistribution and use in source and binary forms, with or without
      5 * modification, are permitted provided that the following conditions
      6 * are met:
      7 * 1. Redistributions of source code must retain the above copyright
      8 *    notice, this list of conditions and the following disclaimer.
      9 * 2. Redistributions in binary form must reproduce the above copyright
     10 *    notice, this list of conditions and the following disclaimer in the
     11 *    documentation and/or other materials provided with the distribution.
     12 * 3. The name of the author may not be used to endorse or promote products
     13 *    derived from this software without specific prior written permission.
     14 *
     15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25 */
     26 #ifndef EVENT2_UTIL_H_INCLUDED_
     27 #define EVENT2_UTIL_H_INCLUDED_
     28 
     29 /** @file event2/util.h
     30 
     31  Common convenience functions for cross-platform portability and
     32  related socket manipulations.
     33 
     34 */
     35 #include <event2/visibility.h>
     36 
     37 #ifdef __cplusplus
     38 extern "C" {
     39 #endif
     40 
     41 #include <event2/event-config.h>
     42 #ifdef EVENT__HAVE_SYS_TIME_H
     43 #include <sys/time.h>
     44 #endif
     45 #ifdef EVENT__HAVE_STDINT_H
     46 #include <stdint.h>
     47 #elif defined(EVENT__HAVE_INTTYPES_H)
     48 #include <inttypes.h>
     49 #endif
     50 #ifdef EVENT__HAVE_SYS_TYPES_H
     51 #include <sys/types.h>
     52 #endif
     53 #ifdef EVENT__HAVE_STDDEF_H
     54 #include <stddef.h>
     55 #endif
     56 #ifdef _MSC_VER
     57 #include <BaseTsd.h>
     58 #endif
     59 #include <stdarg.h>
     60 #ifdef EVENT__HAVE_NETDB_H
     61 #include <netdb.h>
     62 #endif
     63 
     64 #ifdef _WIN32
     65 #include <winsock2.h>
     66 #ifdef EVENT__HAVE_GETADDRINFO
     67 /* for EAI_* definitions. */
     68 #include <ws2tcpip.h>
     69 #endif
     70 #else
     71 #ifdef EVENT__HAVE_ERRNO_H
     72 #include <errno.h>
     73 #endif
     74 #include <sys/socket.h>
     75 #endif
     76 
     77 #include <time.h>
     78 
     79 /* Some openbsd autoconf versions get the name of this macro wrong. */
     80 #if defined(EVENT__SIZEOF_VOID__) && !defined(EVENT__SIZEOF_VOID_P)
     81 #define EVENT__SIZEOF_VOID_P EVENT__SIZEOF_VOID__
     82 #endif
     83 
     84 /**
     85 * @name Standard integer types.
     86 *
     87 * Integer type definitions for types that are supposed to be defined in the
     88 * C99-specified stdint.h.  Shamefully, some platforms do not include
     89 * stdint.h, so we need to replace it.  (If you are on a platform like this,
     90 * your C headers are now over 10 years out of date.  You should bug them to
     91 * do something about this.)
     92 *
     93 * We define:
     94 *
     95 * <dl>
     96 *   <dt>ev_uint64_t, ev_uint32_t, ev_uint16_t, ev_uint8_t</dt>
     97 *      <dd>unsigned integer types of exactly 64, 32, 16, and 8 bits
     98 *          respectively.</dd>
     99 *    <dt>ev_int64_t, ev_int32_t, ev_int16_t, ev_int8_t</dt>
    100 *      <dd>signed integer types of exactly 64, 32, 16, and 8 bits
    101 *          respectively.</dd>
    102 *    <dt>ev_uintptr_t, ev_intptr_t</dt>
    103 *      <dd>unsigned/signed integers large enough
    104 *      to hold a pointer without loss of bits.</dd>
    105 *    <dt>ev_ssize_t</dt>
    106 *      <dd>A signed type of the same size as size_t</dd>
    107 *    <dt>ev_off_t</dt>
    108 *      <dd>A signed type typically used to represent offsets within a
    109 *      (potentially large) file</dd>
    110 *
    111 * @{
    112 */
    113 #ifdef EVENT__HAVE_UINT64_T
    114 #define ev_uint64_t uint64_t
    115 #define ev_int64_t int64_t
    116 #elif defined(_WIN32)
    117 #define ev_uint64_t unsigned __int64
    118 #define ev_int64_t signed __int64
    119 #elif EVENT__SIZEOF_LONG_LONG == 8
    120 #define ev_uint64_t unsigned long long
    121 #define ev_int64_t long long
    122 #elif EVENT__SIZEOF_LONG == 8
    123 #define ev_uint64_t unsigned long
    124 #define ev_int64_t long
    125 #elif defined(EVENT_IN_DOXYGEN_)
    126 #define ev_uint64_t ...
    127 #define ev_int64_t ...
    128 #else
    129 #error "No way to define ev_uint64_t"
    130 #endif
    131 
    132 #ifdef EVENT__HAVE_UINT32_T
    133 #define ev_uint32_t uint32_t
    134 #define ev_int32_t int32_t
    135 #elif defined(_WIN32)
    136 #define ev_uint32_t unsigned int
    137 #define ev_int32_t signed int
    138 #elif EVENT__SIZEOF_LONG == 4
    139 #define ev_uint32_t unsigned long
    140 #define ev_int32_t signed long
    141 #elif EVENT__SIZEOF_INT == 4
    142 #define ev_uint32_t unsigned int
    143 #define ev_int32_t signed int
    144 #elif defined(EVENT_IN_DOXYGEN_)
    145 #define ev_uint32_t ...
    146 #define ev_int32_t ...
    147 #else
    148 #error "No way to define ev_uint32_t"
    149 #endif
    150 
    151 #ifdef EVENT__HAVE_UINT16_T
    152 #define ev_uint16_t uint16_t
    153 #define ev_int16_t  int16_t
    154 #elif defined(_WIN32)
    155 #define ev_uint16_t unsigned short
    156 #define ev_int16_t  signed short
    157 #elif EVENT__SIZEOF_INT == 2
    158 #define ev_uint16_t unsigned int
    159 #define ev_int16_t  signed int
    160 #elif EVENT__SIZEOF_SHORT == 2
    161 #define ev_uint16_t unsigned short
    162 #define ev_int16_t  signed short
    163 #elif defined(EVENT_IN_DOXYGEN_)
    164 #define ev_uint16_t ...
    165 #define ev_int16_t ...
    166 #else
    167 #error "No way to define ev_uint16_t"
    168 #endif
    169 
    170 #ifdef EVENT__HAVE_UINT8_T
    171 #define ev_uint8_t uint8_t
    172 #define ev_int8_t int8_t
    173 #elif defined(EVENT_IN_DOXYGEN_)
    174 #define ev_uint8_t ...
    175 #define ev_int8_t ...
    176 #else
    177 #define ev_uint8_t unsigned char
    178 #define ev_int8_t signed char
    179 #endif
    180 
    181 #ifdef EVENT__HAVE_UINTPTR_T
    182 #define ev_uintptr_t uintptr_t
    183 #define ev_intptr_t intptr_t
    184 #elif EVENT__SIZEOF_VOID_P <= 4
    185 #define ev_uintptr_t ev_uint32_t
    186 #define ev_intptr_t ev_int32_t
    187 #elif EVENT__SIZEOF_VOID_P <= 8
    188 #define ev_uintptr_t ev_uint64_t
    189 #define ev_intptr_t ev_int64_t
    190 #elif defined(EVENT_IN_DOXYGEN_)
    191 #define ev_uintptr_t ...
    192 #define ev_intptr_t ...
    193 #else
    194 #error "No way to define ev_uintptr_t"
    195 #endif
    196 
    197 #ifdef EVENT__ssize_t
    198 #define ev_ssize_t EVENT__ssize_t
    199 #else
    200 #define ev_ssize_t ssize_t
    201 #endif
    202 
    203 /* Note that we define ev_off_t based on the compile-time size of off_t that
    204 * we used to build Libevent, and not based on the current size of off_t.
    205 * (For example, we don't define ev_off_t to off_t.).  We do this because
    206 * some systems let you build your software with different off_t sizes
    207 * at runtime, and so putting in any dependency on off_t would risk API
    208 * mismatch.
    209 */
    210 #ifdef _WIN32
    211 #define ev_off_t ev_int64_t
    212 #elif EVENT__SIZEOF_OFF_T == 8
    213 #define ev_off_t ev_int64_t
    214 #elif EVENT__SIZEOF_OFF_T == 4
    215 #define ev_off_t ev_int32_t
    216 #elif defined(EVENT_IN_DOXYGEN_)
    217 #define ev_off_t ...
    218 #else
    219 #define ev_off_t off_t
    220 #endif
    221 /**@}*/
    222 
    223 /* Limits for integer types.
    224 
    225   We're making two assumptions here:
    226     - The compiler does constant folding properly.
    227     - The platform does signed arithmetic in two's complement.
    228 */
    229 
    230 /**
    231   @name Limits for integer types
    232 
    233   These macros hold the largest or smallest values possible for the
    234   ev_[u]int*_t types.
    235 
    236   @{
    237 */
    238 #ifndef EVENT__HAVE_STDINT_H
    239 #define EV_UINT64_MAX ((((ev_uint64_t)0xffffffffUL) << 32) | 0xffffffffUL)
    240 #define EV_INT64_MAX  ((((ev_int64_t) 0x7fffffffL) << 32) | 0xffffffffL)
    241 #define EV_INT64_MIN  ((-EV_INT64_MAX) - 1)
    242 #define EV_UINT32_MAX ((ev_uint32_t)0xffffffffUL)
    243 #define EV_INT32_MAX  ((ev_int32_t) 0x7fffffffL)
    244 #define EV_INT32_MIN  ((-EV_INT32_MAX) - 1)
    245 #define EV_UINT16_MAX ((ev_uint16_t)0xffffUL)
    246 #define EV_INT16_MAX  ((ev_int16_t) 0x7fffL)
    247 #define EV_INT16_MIN  ((-EV_INT16_MAX) - 1)
    248 #define EV_UINT8_MAX  255
    249 #define EV_INT8_MAX   127
    250 #define EV_INT8_MIN   ((-EV_INT8_MAX) - 1)
    251 #else
    252 #define EV_UINT64_MAX UINT64_MAX
    253 #define EV_INT64_MAX  INT64_MAX
    254 #define EV_INT64_MIN  INT64_MIN
    255 #define EV_UINT32_MAX UINT32_MAX
    256 #define EV_INT32_MAX  INT32_MAX
    257 #define EV_INT32_MIN  INT32_MIN
    258 #define EV_UINT16_MAX UINT16_MAX
    259 #define EV_INT16_MIN  INT16_MIN
    260 #define EV_INT16_MAX  INT16_MAX
    261 #define EV_UINT8_MAX  UINT8_MAX
    262 #define EV_INT8_MAX   INT8_MAX
    263 #define EV_INT8_MIN   INT8_MIN
    264 /** @} */
    265 #endif
    266 
    267 
    268 /**
    269   @name Limits for SIZE_T and SSIZE_T
    270 
    271   @{
    272 */
    273 #if EVENT__SIZEOF_SIZE_T == 8
    274 #define EV_SIZE_MAX EV_UINT64_MAX
    275 #define EV_SSIZE_MAX EV_INT64_MAX
    276 #elif EVENT__SIZEOF_SIZE_T == 4
    277 #define EV_SIZE_MAX EV_UINT32_MAX
    278 #define EV_SSIZE_MAX EV_INT32_MAX
    279 #elif defined(EVENT_IN_DOXYGEN_)
    280 #define EV_SIZE_MAX ...
    281 #define EV_SSIZE_MAX ...
    282 #else
    283 #error "No way to define SIZE_MAX"
    284 #endif
    285 
    286 #define EV_SSIZE_MIN ((-EV_SSIZE_MAX) - 1)
    287 /**@}*/
    288 
    289 #ifdef _WIN32
    290 #define ev_socklen_t int
    291 #elif defined(EVENT__socklen_t)
    292 #define ev_socklen_t EVENT__socklen_t
    293 #else
    294 #define ev_socklen_t socklen_t
    295 #endif
    296 
    297 #ifdef EVENT__HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY
    298 #if !defined(EVENT__HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY) \
    299 && !defined(ss_family)
    300 #define ss_family __ss_family
    301 #endif
    302 #endif
    303 
    304 /**
    305 * A type wide enough to hold the output of "socket()" or "accept()".  On
    306 * Windows, this is an intptr_t; elsewhere, it is an int. */
    307 #ifdef _WIN32
    308 #define evutil_socket_t intptr_t
    309 #else
    310 #define evutil_socket_t int
    311 #endif
    312 
    313 /**
    314 * Structure to hold information about a monotonic timer
    315 *
    316 * Use this with evutil_configure_monotonic_time() and
    317 * evutil_gettime_monotonic().
    318 *
    319 * This is an opaque structure; you can allocate one using
    320 * evutil_monotonic_timer_new().
    321 *
    322 * @see evutil_monotonic_timer_new(), evutil_monotonic_timer_free(),
    323 * evutil_configure_monotonic_time(), evutil_gettime_monotonic()
    324 */
    325 struct evutil_monotonic_timer
    326 #ifdef EVENT_IN_DOXYGEN_
    327 {/*Empty body so that doxygen will generate documentation here.*/}
    328 #endif
    329 ;
    330 
    331 #define EV_MONOT_PRECISE  1
    332 #define EV_MONOT_FALLBACK 2
    333 
    334 /** Format a date string using RFC 1123 format (used in HTTP).
    335 * If `tm` is NULL, current system's time will be used.
    336 * The number of characters written will be returned.
    337 * One should check if the return value is smaller than `datelen` to check if
    338 * the result is truncated or not.
    339 */
    340 EVENT2_EXPORT_SYMBOL int
    341 evutil_date_rfc1123(char *date, const size_t datelen, const struct tm *tm);
    342 
    343 /** Allocate a new struct evutil_monotonic_timer for use with the
    344 * evutil_configure_monotonic_time() and evutil_gettime_monotonic()
    345 * functions.  You must configure the timer with
    346 * evutil_configure_monotonic_time() before using it.
    347 */
    348 EVENT2_EXPORT_SYMBOL
    349 struct evutil_monotonic_timer * evutil_monotonic_timer_new(void);
    350 
    351 /** Free a struct evutil_monotonic_timer that was allocated using
    352 * evutil_monotonic_timer_new().
    353 */
    354 EVENT2_EXPORT_SYMBOL
    355 void evutil_monotonic_timer_free(struct evutil_monotonic_timer *timer);
    356 
    357 /** Set up a struct evutil_monotonic_timer; flags can include
    358 * EV_MONOT_PRECISE and EV_MONOT_FALLBACK.
    359 */
    360 EVENT2_EXPORT_SYMBOL
    361 int evutil_configure_monotonic_time(struct evutil_monotonic_timer *timer,
    362                                    int flags);
    363 
    364 /** Query the current monotonic time from a struct evutil_monotonic_timer
    365 * previously configured with evutil_configure_monotonic_time().  Monotonic
    366 * time is guaranteed never to run in reverse, but is not necessarily epoch-
    367 * based, or relative to any other definite point.  Use it to make reliable
    368 * measurements of elapsed time between events even when the system time
    369 * may be changed.
    370 *
    371 * It is not safe to use this funtion on the same timer from multiple
    372 * threads.
    373 */
    374 EVENT2_EXPORT_SYMBOL
    375 int evutil_gettime_monotonic(struct evutil_monotonic_timer *timer,
    376                             struct timeval *tp);
    377 
    378 /** Create two new sockets that are connected to each other.
    379 
    380    On Unix, this simply calls socketpair().  On Windows, it uses the
    381    loopback network interface on 127.0.0.1, and only
    382    AF_INET,SOCK_STREAM are supported.
    383 
    384    (This may fail on some Windows hosts where firewall software has cleverly
    385    decided to keep 127.0.0.1 from talking to itself.)
    386 
    387    Parameters and return values are as for socketpair()
    388 */
    389 EVENT2_EXPORT_SYMBOL
    390 int evutil_socketpair(int d, int type, int protocol, evutil_socket_t sv[2]);
    391 /** Do platform-specific operations as needed to make a socket nonblocking.
    392 
    393    @param sock The socket to make nonblocking
    394    @return 0 on success, -1 on failure
    395 */
    396 EVENT2_EXPORT_SYMBOL
    397 int evutil_make_socket_nonblocking(evutil_socket_t sock);
    398 
    399 /** Do platform-specific operations to make a listener socket reusable.
    400 
    401    Specifically, we want to make sure that another program will be able
    402    to bind this address right after we've closed the listener.
    403 
    404    This differs from Windows's interpretation of "reusable", which
    405    allows multiple listeners to bind the same address at the same time.
    406 
    407    @param sock The socket to make reusable
    408    @return 0 on success, -1 on failure
    409 */
    410 EVENT2_EXPORT_SYMBOL
    411 int evutil_make_listen_socket_reuseable(evutil_socket_t sock);
    412 
    413 /** Do platform-specific operations to make a listener port reusable.
    414 
    415    Specifically, we want to make sure that multiple programs which also
    416    set the same socket option will be able to bind, listen at the same time.
    417 
    418    This is a feature available only to Linux 3.9+
    419 
    420    @param sock The socket to make reusable
    421    @return 0 on success, -1 on failure
    422 */
    423 EVENT2_EXPORT_SYMBOL
    424 int evutil_make_listen_socket_reuseable_port(evutil_socket_t sock);
    425 
    426 /** Set ipv6 only bind socket option to make listener work only in ipv6 sockets.
    427 
    428    According to RFC3493 and most Linux distributions, default value for the
    429    sockets is to work in IPv4-mapped mode. In IPv4-mapped mode, it is not possible
    430    to bind same port from different IPv4 and IPv6 handlers.
    431 
    432    @param sock The socket to make in ipv6only working mode
    433    @return 0 on success, -1 on failure
    434 */
    435 EVENT2_EXPORT_SYMBOL
    436 int evutil_make_listen_socket_ipv6only(evutil_socket_t sock);
    437 
    438 /** Do platform-specific operations as needed to close a socket upon a
    439    successful execution of one of the exec*() functions.
    440 
    441    @param sock The socket to be closed
    442    @return 0 on success, -1 on failure
    443 */
    444 EVENT2_EXPORT_SYMBOL
    445 int evutil_make_socket_closeonexec(evutil_socket_t sock);
    446 
    447 /** Do the platform-specific call needed to close a socket returned from
    448    socket() or accept().
    449 
    450    @param sock The socket to be closed
    451    @return 0 on success (whether the operation is supported or not),
    452            -1 on failure
    453 */
    454 EVENT2_EXPORT_SYMBOL
    455 int evutil_closesocket(evutil_socket_t sock);
    456 #define EVUTIL_CLOSESOCKET(s) evutil_closesocket(s)
    457 
    458 /** Do platform-specific operations, if possible, to make a tcp listener
    459 *  socket defer accept()s until there is data to read.
    460 *  
    461 *  Not all platforms support this.  You don't want to do this for every
    462 *  listener socket: only the ones that implement a protocol where the
    463 *  client transmits before the server needs to respond.
    464 *
    465 *  @param sock The listening socket to to make deferred
    466 *  @return 0 on success (whether the operation is supported or not),
    467 *       -1 on failure
    468 */ 
    469 EVENT2_EXPORT_SYMBOL
    470 int evutil_make_tcp_listen_socket_deferred(evutil_socket_t sock);
    471 
    472 #ifdef _WIN32
    473 /** Return the most recent socket error.  Not idempotent on all platforms. */
    474 #define EVUTIL_SOCKET_ERROR() WSAGetLastError()
    475 /** Replace the most recent socket error with errcode */
    476 #define EVUTIL_SET_SOCKET_ERROR(errcode)		\
    477 do { WSASetLastError(errcode); } while (0)
    478 /** Return the most recent socket error to occur on sock. */
    479 EVENT2_EXPORT_SYMBOL
    480 int evutil_socket_geterror(evutil_socket_t sock);
    481 /** Convert a socket error to a string. */
    482 EVENT2_EXPORT_SYMBOL
    483 const char *evutil_socket_error_to_string(int errcode);
    484 #define EVUTIL_INVALID_SOCKET INVALID_SOCKET
    485 #elif defined(EVENT_IN_DOXYGEN_)
    486 /**
    487   @name Socket error functions
    488 
    489   These functions are needed for making programs compatible between
    490   Windows and Unix-like platforms.
    491 
    492   You see, Winsock handles socket errors differently from the rest of
    493   the world.  Elsewhere, a socket error is like any other error and is
    494   stored in errno.  But winsock functions require you to retrieve the
    495   error with a special function, and don't let you use strerror for
    496   the error codes.  And handling EWOULDBLOCK is ... different.
    497 
    498   @{
    499 */
    500 /** Return the most recent socket error.  Not idempotent on all platforms. */
    501 #define EVUTIL_SOCKET_ERROR() ...
    502 /** Replace the most recent socket error with errcode */
    503 #define EVUTIL_SET_SOCKET_ERROR(errcode) ...
    504 /** Return the most recent socket error to occur on sock. */
    505 #define evutil_socket_geterror(sock) ...
    506 /** Convert a socket error to a string. */
    507 #define evutil_socket_error_to_string(errcode) ...
    508 #define EVUTIL_INVALID_SOCKET -1
    509 /**@}*/
    510 #else /** !EVENT_IN_DOXYGEN_ && !_WIN32 */
    511 #define EVUTIL_SOCKET_ERROR() (errno)
    512 #define EVUTIL_SET_SOCKET_ERROR(errcode)		\
    513 	do { errno = (errcode); } while (0)
    514 #define evutil_socket_geterror(sock) (errno)
    515 #define evutil_socket_error_to_string(errcode) (strerror(errcode))
    516 #define EVUTIL_INVALID_SOCKET -1
    517 #endif /** !_WIN32 */
    518 
    519 
    520 /**
    521 * @name Manipulation macros for struct timeval.
    522 *
    523 * We define replacements
    524 * for timeradd, timersub, timerclear, timercmp, and timerisset.
    525 *
    526 * @{
    527 */
    528 #ifdef EVENT__HAVE_TIMERADD
    529 #define evutil_timeradd(tvp, uvp, vvp) timeradd((tvp), (uvp), (vvp))
    530 #define evutil_timersub(tvp, uvp, vvp) timersub((tvp), (uvp), (vvp))
    531 #else
    532 #define evutil_timeradd(tvp, uvp, vvp)					\
    533 do {								\
    534 	(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
    535 	(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;       \
    536 	if ((vvp)->tv_usec >= 1000000) {			\
    537 		(vvp)->tv_sec++;				\
    538 		(vvp)->tv_usec -= 1000000;			\
    539 	}							\
    540 } while (0)
    541 #define	evutil_timersub(tvp, uvp, vvp)					\
    542 do {								\
    543 	(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
    544 	(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
    545 	if ((vvp)->tv_usec < 0) {				\
    546 		(vvp)->tv_sec--;				\
    547 		(vvp)->tv_usec += 1000000;			\
    548 	}							\
    549 } while (0)
    550 #endif /* !EVENT__HAVE_TIMERADD */
    551 
    552 #ifdef EVENT__HAVE_TIMERCLEAR
    553 #define evutil_timerclear(tvp) timerclear(tvp)
    554 #else
    555 #define	evutil_timerclear(tvp)	(tvp)->tv_sec = (tvp)->tv_usec = 0
    556 #endif
    557 /**@}*/
    558 
    559 /** Return true iff the tvp is related to uvp according to the relational
    560 * operator cmp.  Recognized values for cmp are ==, <=, <, >=, and >. */
    561 #define	evutil_timercmp(tvp, uvp, cmp)					\
    562 (((tvp)->tv_sec == (uvp)->tv_sec) ?				\
    563  ((tvp)->tv_usec cmp (uvp)->tv_usec) :				\
    564  ((tvp)->tv_sec cmp (uvp)->tv_sec))
    565 
    566 #ifdef EVENT__HAVE_TIMERISSET
    567 #define evutil_timerisset(tvp) timerisset(tvp)
    568 #else
    569 #define	evutil_timerisset(tvp)	((tvp)->tv_sec || (tvp)->tv_usec)
    570 #endif
    571 
    572 /** Replacement for offsetof on platforms that don't define it. */
    573 #ifdef offsetof
    574 #define evutil_offsetof(type, field) offsetof(type, field)
    575 #else
    576 #define evutil_offsetof(type, field) ((off_t)(&((type *)0)->field))
    577 #endif
    578 
    579 /* big-int related functions */
    580 /** Parse a 64-bit value from a string.  Arguments are as for strtol. */
    581 EVENT2_EXPORT_SYMBOL
    582 ev_int64_t evutil_strtoll(const char *s, char **endptr, int base);
    583 
    584 /** Replacement for gettimeofday on platforms that lack it. */
    585 #ifdef EVENT__HAVE_GETTIMEOFDAY
    586 #define evutil_gettimeofday(tv, tz) gettimeofday((tv), (tz))
    587 #else
    588 struct timezone;
    589 EVENT2_EXPORT_SYMBOL
    590 int evutil_gettimeofday(struct timeval *tv, struct timezone *tz);
    591 #endif
    592 
    593 /** Replacement for snprintf to get consistent behavior on platforms for
    594    which the return value of snprintf does not conform to C99.
    595 */
    596 EVENT2_EXPORT_SYMBOL
    597 int evutil_snprintf(char *buf, size_t buflen, const char *format, ...)
    598 #ifdef __GNUC__
    599 __attribute__((format(printf, 3, 4)))
    600 #endif
    601 ;
    602 /** Replacement for vsnprintf to get consistent behavior on platforms for
    603    which the return value of snprintf does not conform to C99.
    604 */
    605 EVENT2_EXPORT_SYMBOL
    606 int evutil_vsnprintf(char *buf, size_t buflen, const char *format, va_list ap)
    607 #ifdef __GNUC__
    608 __attribute__((format(printf, 3, 0)))
    609 #endif
    610 ;
    611 
    612 /** Replacement for inet_ntop for platforms which lack it. */
    613 EVENT2_EXPORT_SYMBOL
    614 const char *evutil_inet_ntop(int af, const void *src, char *dst, size_t len);
    615 /** Variation of inet_pton that also parses IPv6 scopes. Public for
    616    unit tests. No reason to call this directly.
    617 */
    618 EVENT2_EXPORT_SYMBOL
    619 int evutil_inet_pton_scope(int af, const char *src, void *dst,
    620 unsigned *indexp);
    621 /** Replacement for inet_pton for platforms which lack it. */
    622 EVENT2_EXPORT_SYMBOL
    623 int evutil_inet_pton(int af, const char *src, void *dst);
    624 struct sockaddr;
    625 
    626 /** Parse an IPv4 or IPv6 address, with optional port, from a string.
    627 
    628    Recognized formats are:
    629    - [IPv6Address]:port
    630    - [IPv6Address]
    631    - IPv6Address
    632    - IPv4Address:port
    633    - IPv4Address
    634 
    635    If no port is specified, the port in the output is set to 0.
    636 
    637    @param str The string to parse.
    638    @param out A struct sockaddr to hold the result.  This should probably be
    639       a struct sockaddr_storage.
    640    @param outlen A pointer to the number of bytes that that 'out' can safely
    641       hold.  Set to the number of bytes used in 'out' on success.
    642    @return -1 if the address is not well-formed, if the port is out of range,
    643       or if out is not large enough to hold the result.  Otherwise returns
    644       0 on success.
    645 */
    646 EVENT2_EXPORT_SYMBOL
    647 int evutil_parse_sockaddr_port(const char *str, struct sockaddr *out, int *outlen);
    648 
    649 /** Compare two sockaddrs; return 0 if they are equal, or less than 0 if sa1
    650 * preceeds sa2, or greater than 0 if sa1 follows sa2.  If include_port is
    651 * true, consider the port as well as the address.  Only implemented for
    652 * AF_INET and AF_INET6 addresses. The ordering is not guaranteed to remain
    653 * the same between Libevent versions. */
    654 EVENT2_EXPORT_SYMBOL
    655 int evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2,
    656    int include_port);
    657 
    658 /** As strcasecmp, but always compares the characters in locale-independent
    659    ASCII.  That's useful if you're handling data in ASCII-based protocols.
    660 */
    661 EVENT2_EXPORT_SYMBOL
    662 int evutil_ascii_strcasecmp(const char *str1, const char *str2);
    663 /** As strncasecmp, but always compares the characters in locale-independent
    664    ASCII.  That's useful if you're handling data in ASCII-based protocols.
    665 */
    666 EVENT2_EXPORT_SYMBOL
    667 int evutil_ascii_strncasecmp(const char *str1, const char *str2, size_t n);
    668 
    669 /* Here we define evutil_addrinfo to the native addrinfo type, or redefine it
    670 * if this system has no getaddrinfo(). */
    671 #ifdef EVENT__HAVE_STRUCT_ADDRINFO
    672 #define evutil_addrinfo addrinfo
    673 #else
    674 /** A definition of struct addrinfo for systems that lack it.
    675 
    676    (This is just an alias for struct addrinfo if the system defines
    677    struct addrinfo.)
    678 */
    679 struct evutil_addrinfo {
    680 int     ai_flags;     /* AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST */
    681 int     ai_family;    /* PF_xxx */
    682 int     ai_socktype;  /* SOCK_xxx */
    683 int     ai_protocol;  /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
    684 size_t  ai_addrlen;   /* length of ai_addr */
    685 char   *ai_canonname; /* canonical name for nodename */
    686 struct sockaddr  *ai_addr; /* binary address */
    687 struct evutil_addrinfo  *ai_next; /* next structure in linked list */
    688 };
    689 #endif
    690 /** @name evutil_getaddrinfo() error codes
    691 
    692    These values are possible error codes for evutil_getaddrinfo() and
    693    related functions.
    694 
    695    @{
    696 */
    697 #if defined(EAI_ADDRFAMILY) && defined(EVENT__HAVE_GETADDRINFO)
    698 #define EVUTIL_EAI_ADDRFAMILY EAI_ADDRFAMILY
    699 #else
    700 #define EVUTIL_EAI_ADDRFAMILY -901
    701 #endif
    702 #if defined(EAI_AGAIN) && defined(EVENT__HAVE_GETADDRINFO)
    703 #define EVUTIL_EAI_AGAIN EAI_AGAIN
    704 #else
    705 #define EVUTIL_EAI_AGAIN -902
    706 #endif
    707 #if defined(EAI_BADFLAGS) && defined(EVENT__HAVE_GETADDRINFO)
    708 #define EVUTIL_EAI_BADFLAGS EAI_BADFLAGS
    709 #else
    710 #define EVUTIL_EAI_BADFLAGS -903
    711 #endif
    712 #if defined(EAI_FAIL) && defined(EVENT__HAVE_GETADDRINFO)
    713 #define EVUTIL_EAI_FAIL EAI_FAIL
    714 #else
    715 #define EVUTIL_EAI_FAIL -904
    716 #endif
    717 #if defined(EAI_FAMILY) && defined(EVENT__HAVE_GETADDRINFO)
    718 #define EVUTIL_EAI_FAMILY EAI_FAMILY
    719 #else
    720 #define EVUTIL_EAI_FAMILY -905
    721 #endif
    722 #if defined(EAI_MEMORY) && defined(EVENT__HAVE_GETADDRINFO)
    723 #define EVUTIL_EAI_MEMORY EAI_MEMORY
    724 #else
    725 #define EVUTIL_EAI_MEMORY -906
    726 #endif
    727 /* This test is a bit complicated, since some MS SDKs decide to
    728 * remove NODATA or redefine it to be the same as NONAME, in a
    729 * fun interpretation of RFC 2553 and RFC 3493. */
    730 #if defined(EAI_NODATA) && defined(EVENT__HAVE_GETADDRINFO) && (!defined(EAI_NONAME) || EAI_NODATA != EAI_NONAME)
    731 #define EVUTIL_EAI_NODATA EAI_NODATA
    732 #else
    733 #define EVUTIL_EAI_NODATA -907
    734 #endif
    735 #if defined(EAI_NONAME) && defined(EVENT__HAVE_GETADDRINFO)
    736 #define EVUTIL_EAI_NONAME EAI_NONAME
    737 #else
    738 #define EVUTIL_EAI_NONAME -908
    739 #endif
    740 #if defined(EAI_SERVICE) && defined(EVENT__HAVE_GETADDRINFO)
    741 #define EVUTIL_EAI_SERVICE EAI_SERVICE
    742 #else
    743 #define EVUTIL_EAI_SERVICE -909
    744 #endif
    745 #if defined(EAI_SOCKTYPE) && defined(EVENT__HAVE_GETADDRINFO)
    746 #define EVUTIL_EAI_SOCKTYPE EAI_SOCKTYPE
    747 #else
    748 #define EVUTIL_EAI_SOCKTYPE -910
    749 #endif
    750 #if defined(EAI_SYSTEM) && defined(EVENT__HAVE_GETADDRINFO)
    751 #define EVUTIL_EAI_SYSTEM EAI_SYSTEM
    752 #else
    753 #define EVUTIL_EAI_SYSTEM -911
    754 #endif
    755 
    756 #define EVUTIL_EAI_CANCEL -90001
    757 
    758 #if defined(AI_PASSIVE) && defined(EVENT__HAVE_GETADDRINFO)
    759 #define EVUTIL_AI_PASSIVE AI_PASSIVE
    760 #else
    761 #define EVUTIL_AI_PASSIVE 0x1000
    762 #endif
    763 #if defined(AI_CANONNAME) && defined(EVENT__HAVE_GETADDRINFO)
    764 #define EVUTIL_AI_CANONNAME AI_CANONNAME
    765 #else
    766 #define EVUTIL_AI_CANONNAME 0x2000
    767 #endif
    768 #if defined(AI_NUMERICHOST) && defined(EVENT__HAVE_GETADDRINFO)
    769 #define EVUTIL_AI_NUMERICHOST AI_NUMERICHOST
    770 #else
    771 #define EVUTIL_AI_NUMERICHOST 0x4000
    772 #endif
    773 #if defined(AI_NUMERICSERV) && defined(EVENT__HAVE_GETADDRINFO)
    774 #define EVUTIL_AI_NUMERICSERV AI_NUMERICSERV
    775 #else
    776 #define EVUTIL_AI_NUMERICSERV 0x8000
    777 #endif
    778 #if defined(AI_V4MAPPED) && defined(EVENT__HAVE_GETADDRINFO)
    779 #define EVUTIL_AI_V4MAPPED AI_V4MAPPED
    780 #else
    781 #define EVUTIL_AI_V4MAPPED 0x10000
    782 #endif
    783 #if defined(AI_ALL) && defined(EVENT__HAVE_GETADDRINFO)
    784 #define EVUTIL_AI_ALL AI_ALL
    785 #else
    786 #define EVUTIL_AI_ALL 0x20000
    787 #endif
    788 #if defined(AI_ADDRCONFIG) && defined(EVENT__HAVE_GETADDRINFO)
    789 #define EVUTIL_AI_ADDRCONFIG AI_ADDRCONFIG
    790 #else
    791 #define EVUTIL_AI_ADDRCONFIG 0x40000
    792 #endif
    793 /**@}*/
    794 
    795 struct evutil_addrinfo;
    796 /**
    797 * This function clones getaddrinfo for systems that don't have it.  For full
    798 * details, see RFC 3493, section 6.1.
    799 *
    800 * Limitations:
    801 * - When the system has no getaddrinfo, we fall back to gethostbyname_r or
    802 *   gethostbyname, with their attendant issues.
    803 * - The AI_V4MAPPED and AI_ALL flags are not currently implemented.
    804 *
    805 * For a nonblocking variant, see evdns_getaddrinfo.
    806 */
    807 EVENT2_EXPORT_SYMBOL
    808 int evutil_getaddrinfo(const char *nodename, const char *servname,
    809    const struct evutil_addrinfo *hints_in, struct evutil_addrinfo **res);
    810 
    811 /** Release storage allocated by evutil_getaddrinfo or evdns_getaddrinfo. */
    812 EVENT2_EXPORT_SYMBOL
    813 void evutil_freeaddrinfo(struct evutil_addrinfo *ai);
    814 
    815 EVENT2_EXPORT_SYMBOL
    816 const char *evutil_gai_strerror(int err);
    817 
    818 /** Generate n bytes of secure pseudorandom data, and store them in buf.
    819 *
    820 * Current versions of Libevent use an ARC4-based random number generator,
    821 * seeded using the platform's entropy source (/dev/urandom on Unix-like
    822 * systems; CryptGenRandom on Windows).  This is not actually as secure as it
    823 * should be: ARC4 is a pretty lousy cipher, and the current implementation
    824 * provides only rudimentary prediction- and backtracking-resistance.  Don't
    825 * use this for serious cryptographic applications.
    826 */
    827 EVENT2_EXPORT_SYMBOL
    828 void evutil_secure_rng_get_bytes(void *buf, size_t n);
    829 
    830 /**
    831 * Seed the secure random number generator if needed, and return 0 on
    832 * success or -1 on failure.
    833 *
    834 * It is okay to call this function more than once; it will still return
    835 * 0 if the RNG has been successfully seeded and -1 if it can't be
    836 * seeded.
    837 *
    838 * Ordinarily you don't need to call this function from your own code;
    839 * Libevent will seed the RNG itself the first time it needs good random
    840 * numbers.  You only need to call it if (a) you want to double-check
    841 * that one of the seeding methods did succeed, or (b) you plan to drop
    842 * the capability to seed (by chrooting, or dropping capabilities, or
    843 * whatever), and you want to make sure that seeding happens before your
    844 * program loses the ability to do it.
    845 */
    846 EVENT2_EXPORT_SYMBOL
    847 int evutil_secure_rng_init(void);
    848 
    849 /**
    850 * Set a filename to use in place of /dev/urandom for seeding the secure
    851 * PRNG. Return 0 on success, -1 on failure.
    852 *
    853 * Call this function BEFORE calling any other initialization or RNG
    854 * functions.
    855 *
    856 * (This string will _NOT_ be copied internally. Do not free it while any
    857 * user of the secure RNG might be running. Don't pass anything other than a
    858 * real /dev/...random device file here, or you might lose security.)
    859 *
    860 * This API is unstable, and might change in a future libevent version.
    861 */
    862 EVENT2_EXPORT_SYMBOL
    863 int evutil_secure_rng_set_urandom_device_file(char *fname);
    864 
    865 #if !defined(EVENT__HAVE_ARC4RANDOM) || defined(EVENT__HAVE_ARC4RANDOM_ADDRANDOM)
    866 /** Seed the random number generator with extra random bytes.
    867 
    868    You should almost never need to call this function; it should be
    869    sufficient to invoke evutil_secure_rng_init(), or let Libevent take
    870    care of calling evutil_secure_rng_init() on its own.
    871 
    872    If you call this function as a _replacement_ for the regular
    873    entropy sources, then you need to be sure that your input
    874    contains a fairly large amount of strong entropy.  Doing so is
    875    notoriously hard: most people who try get it wrong.  Watch out!
    876 
    877    @param dat a buffer full of a strong source of random numbers
    878    @param datlen the number of bytes to read from datlen
    879 */
    880 EVENT2_EXPORT_SYMBOL
    881 void evutil_secure_rng_add_bytes(const char *dat, size_t datlen);
    882 #endif
    883 
    884 #ifdef __cplusplus
    885 }
    886 #endif
    887 
    888 #endif /* EVENT1_EVUTIL_H_INCLUDED_ */