release/src/router/dnscrypt/src/libevent-modified/include/event2/util.h

   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_
  27 #define _EVENT2_UTIL_H_
  28
  29 /** @file event2/util.h
  30
  31   Common convenience functions for cross-platform portability and
  32   related socket manipulations.
  33
  34  */
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 #include <event2/event-config.h>
  41 #ifdef _EVENT_HAVE_SYS_TIME_H
  42 #include <sys/time.h>
  43 #endif
  44 #ifdef _EVENT_HAVE_STDINT_H
  45 #include <stdint.h>
  46 #elif defined(_EVENT_HAVE_INTTYPES_H)
  47 #include <inttypes.h>
  48 #endif
  49 #ifdef _EVENT_HAVE_SYS_TYPES_H
  50 #include <sys/types.h>
  51 #endif
  52 #ifdef _EVENT_HAVE_STDDEF_H
  53 #include <stddef.h>
  54 #endif
  55 #ifdef _MSC_VER
  56 #include <BaseTsd.h>
  57 #endif
  58 #include <stdarg.h>
  59 #ifdef _EVENT_HAVE_NETDB_H
  60 #if !defined(_GNU_SOURCE)
  61 #define _GNU_SOURCE
  62 #endif
  63 #include <netdb.h>
  64 #endif
  65
  66 #ifdef WIN32
  67 #include <winsock2.h>
  68 #else
  69 #include <sys/socket.h>
  70 #endif
  71
  72 /* Some openbsd autoconf versions get the name of this macro wrong. */
  73 #if defined(_EVENT_SIZEOF_VOID__) && !defined(_EVENT_SIZEOF_VOID_P)
  74 #define _EVENT_SIZEOF_VOID_P _EVENT_SIZEOF_VOID__
  75 #endif
  76
  77 /**
  78  * @name Standard integer types.
  79  *
  80  * Integer type definitions for types that are supposed to be defined in the
  81  * C99-specified stdint.h.  Shamefully, some platforms do not include
  82  * stdint.h, so we need to replace it.  (If you are on a platform like this,
  83  * your C headers are now over 10 years out of date.  You should bug them to
  84  * do something about this.)
  85  *
  86  * We define:
  87  *
  88  * <dl>
  89  *   <dt>ev_uint64_t, ev_uint32_t, ev_uint16_t, ev_uint8_t</dt>
  90  *      <dd>unsigned integer types of exactly 64, 32, 16, and 8 bits
  91  *          respectively.</dd>
  92  *    <dt>ev_int64_t, ev_int32_t, ev_int16_t, ev_int8_t</dt>
  93  *      <dd>signed integer types of exactly 64, 32, 16, and 8 bits
  94  *          respectively.</dd>
  95  *    <dt>ev_uintptr_t, ev_intptr_t</dt>
  96  *      <dd>unsigned/signed integers large enough
  97  *      to hold a pointer without loss of bits.</dd>
  98  *    <dt>ev_ssize_t</dt>
  99  *      <dd>A signed type of the same size as size_t</dd>
 100  *    <dt>ev_off_t</dt>
 101  *      <dd>A signed type typically used to represent offsets within a
 102  *      (potentially large) file</dd>
 103  *
 104  * @{
 105  */
 106 #ifdef _EVENT_HAVE_UINT64_T
 107 #define ev_uint64_t uint64_t
 108 #define ev_int64_t int64_t
 109 #elif defined(WIN32)
 110 #define ev_uint64_t unsigned __int64
 111 #define ev_int64_t signed __int64
 112 #elif _EVENT_SIZEOF_LONG_LONG == 8
 113 #define ev_uint64_t unsigned long long
 114 #define ev_int64_t long long
 115 #elif _EVENT_SIZEOF_LONG == 8
 116 #define ev_uint64_t unsigned long
 117 #define ev_int64_t long
 118 #elif defined(_EVENT_IN_DOXYGEN)
 119 #define ev_uint64_t ...
 120 #define ev_int64_t ...
 121 #else
 122 #error "No way to define ev_uint64_t"
 123 #endif
 124
 125 #ifdef _EVENT_HAVE_UINT32_T
 126 #define ev_uint32_t uint32_t
 127 #define ev_int32_t int32_t
 128 #elif defined(WIN32)
 129 #define ev_uint32_t unsigned int
 130 #define ev_int32_t signed int
 131 #elif _EVENT_SIZEOF_LONG == 4
 132 #define ev_uint32_t unsigned long
 133 #define ev_int32_t signed long
 134 #elif _EVENT_SIZEOF_INT == 4
 135 #define ev_uint32_t unsigned int
 136 #define ev_int32_t signed int
 137 #elif defined(_EVENT_IN_DOXYGEN)
 138 #define ev_uint32_t ...
 139 #define ev_int32_t ...
 140 #else
 141 #error "No way to define ev_uint32_t"
 142 #endif
 143
 144 #ifdef _EVENT_HAVE_UINT16_T
 145 #define ev_uint16_t uint16_t
 146 #define ev_int16_t  int16_t
 147 #elif defined(WIN32)
 148 #define ev_uint16_t unsigned short
 149 #define ev_int16_t  signed short
 150 #elif _EVENT_SIZEOF_INT == 2
 151 #define ev_uint16_t unsigned int
 152 #define ev_int16_t  signed int
 153 #elif _EVENT_SIZEOF_SHORT == 2
 154 #define ev_uint16_t unsigned short
 155 #define ev_int16_t  signed short
 156 #elif defined(_EVENT_IN_DOXYGEN)
 157 #define ev_uint16_t ...
 158 #define ev_int16_t ...
 159 #else
 160 #error "No way to define ev_uint16_t"
 161 #endif
 162
 163 #ifdef _EVENT_HAVE_UINT8_T
 164 #define ev_uint8_t uint8_t
 165 #define ev_int8_t int8_t
 166 #elif defined(_EVENT_IN_DOXYGEN)
 167 #define ev_uint8_t ...
 168 #define ev_int8_t ...
 169 #else
 170 #define ev_uint8_t unsigned char
 171 #define ev_int8_t signed char
 172 #endif
 173
 174 #ifdef _EVENT_HAVE_UINTPTR_T
 175 #define ev_uintptr_t uintptr_t
 176 #define ev_intptr_t intptr_t
 177 #elif _EVENT_SIZEOF_VOID_P <= 4
 178 #define ev_uintptr_t ev_uint32_t
 179 #define ev_intptr_t ev_int32_t
 180 #elif _EVENT_SIZEOF_VOID_P <= 8
 181 #define ev_uintptr_t ev_uint64_t
 182 #define ev_intptr_t ev_int64_t
 183 #elif defined(_EVENT_IN_DOXYGEN)
 184 #define ev_uintptr_t ...
 185 #define ev_intptr_t ...
 186 #else
 187 #error "No way to define ev_uintptr_t"
 188 #endif
 189
 190 #ifdef _EVENT_ssize_t
 191 #define ev_ssize_t _EVENT_ssize_t
 192 #else
 193 #define ev_ssize_t ssize_t
 194 #endif
 195
 196 #ifdef WIN32
 197 #define ev_off_t ev_int64_t
 198 #else
 199 #define ev_off_t off_t
 200 #endif
 201 /**@}*/
 202
 203 /* Limits for integer types.
 204
 205    We're making two assumptions here:
 206      - The compiler does constant folding properly.
 207      - The platform does signed arithmetic in two's complement.
 208 */
 209
 210 /**
 211    @name Limits for integer types
 212
 213    These macros hold the largest or smallest values possible for the
 214    ev_[u]int*_t types.
 215
 216    @{
 217 */
 218 #define EV_UINT64_MAX ((((ev_uint64_t)0xffffffffUL) << 32) | 0xffffffffUL)
 219 #define EV_INT64_MAX  ((((ev_int64_t) 0x7fffffffL) << 32) | 0xffffffffL)
 220 #define EV_INT64_MIN  ((-EV_INT64_MAX) - 1)
 221 #define EV_UINT32_MAX ((ev_uint32_t)0xffffffffUL)
 222 #define EV_INT32_MAX  ((ev_int32_t) 0x7fffffffL)
 223 #define EV_INT32_MIN  ((-EV_INT32_MAX) - 1)
 224 #define EV_UINT16_MAX ((ev_uint16_t)0xffffUL)
 225 #define EV_INT16_MAX  ((ev_int16_t) 0x7fffL)
 226 #define EV_INT16_MIN  ((-EV_INT16_MAX) - 1)
 227 #define EV_UINT8_MAX  255
 228 #define EV_INT8_MAX   127
 229 #define EV_INT8_MIN   ((-EV_INT8_MAX) - 1)
 230 /** @} */
 231
 232 /**
 233    @name Limits for SIZE_T and SSIZE_T
 234
 235    @{
 236 */
 237 #if _EVENT_SIZEOF_SIZE_T == 8
 238 #define EV_SIZE_MAX EV_UINT64_MAX
 239 #define EV_SSIZE_MAX EV_INT64_MAX
 240 #elif _EVENT_SIZEOF_SIZE_T == 4
 241 #define EV_SIZE_MAX EV_UINT32_MAX
 242 #define EV_SSIZE_MAX EV_INT32_MAX
 243 #elif defined(_EVENT_IN_DOXYGEN)
 244 #define EV_SIZE_MAX ...
 245 #define EV_SSIZE_MAX ...
 246 #else
 247 #error "No way to define SIZE_MAX"
 248 #endif
 249
 250 #define EV_SSIZE_MIN ((-EV_SSIZE_MAX) - 1)
 251 /**@}*/
 252
 253 #ifdef WIN32
 254 #define ev_socklen_t int
 255 #elif defined(_EVENT_socklen_t)
 256 #define ev_socklen_t _EVENT_socklen_t
 257 #else
 258 #define ev_socklen_t socklen_t
 259 #endif
 260
 261 #ifdef _EVENT_HAVE_STRUCT_SOCKADDR_STORAGE___SS_FAMILY
 262 #if !defined(_EVENT_HAVE_STRUCT_SOCKADDR_STORAGE_SS_FAMILY) \
 263  && !defined(ss_family)
 264 #define ss_family __ss_family
 265 #endif
 266 #endif
 267
 268 /**
 269  * A type wide enough to hold the output of "socket()" or "accept()".  On
 270  * Windows, this is an intptr_t; elsewhere, it is an int. */
 271 #ifdef WIN32
 272 #define evutil_socket_t intptr_t
 273 #else
 274 #define evutil_socket_t int
 275 #endif
 276
 277 /** Create two new sockets that are connected to each other.
 278
 279     On Unix, this simply calls socketpair().  On Windows, it uses the
 280     loopback network interface on 127.0.0.1, and only
 281     AF_INET,SOCK_STREAM are supported.
 282
 283     (This may fail on some Windows hosts where firewall software has cleverly
 284     decided to keep 127.0.0.1 from talking to itself.)
 285
 286     Parameters and return values are as for socketpair()
 287 */
 288 int evutil_socketpair(int d, int type, int protocol, evutil_socket_t sv[2]);
 289 /** Do platform-specific operations as needed to make a socket nonblocking.
 290
 291     @param sock The socket to make nonblocking
 292     @return 0 on success, -1 on failure
 293  */
 294 int evutil_make_socket_nonblocking(evutil_socket_t sock);
 295
 296 /** Do platform-specific operations to make a listener socket reusable.
 297
 298     Specifically, we want to make sure that another program will be able
 299     to bind this address right after we've closed the listener.
 300
 301     This differs from Windows's interpretation of "reusable", which
 302     allows multiple listeners to bind the same address at the same time.
 303
 304     @param sock The socket to make reusable
 305     @return 0 on success, -1 on failure
 306  */
 307 int evutil_make_listen_socket_reuseable(evutil_socket_t sock);
 308
 309 /** Do platform-specific operations as needed to close a socket upon a
 310     successful execution of one of the exec*() functions.
 311
 312     @param sock The socket to be closed
 313     @return 0 on success, -1 on failure
 314  */
 315 int evutil_make_socket_closeonexec(evutil_socket_t sock);
 316
 317 /** Do the platform-specific call needed to close a socket returned from
 318     socket() or accept().
 319
 320     @param sock The socket to be closed
 321     @return 0 on success, -1 on failure
 322  */
 323 int evutil_closesocket(evutil_socket_t sock);
 324 #define EVUTIL_CLOSESOCKET(s) evutil_closesocket(s)
 325
 326
 327 #ifdef WIN32
 328 /** Return the most recent socket error.  Not idempotent on all platforms. */
 329 #define EVUTIL_SOCKET_ERROR() WSAGetLastError()
 330 /** Replace the most recent socket error with errcode */
 331 #define EVUTIL_SET_SOCKET_ERROR(errcode)                \
 332         do { WSASetLastError(errcode); } while (0)
 333 /** Return the most recent socket error to occur on sock. */
 334 int evutil_socket_geterror(evutil_socket_t sock);
 335 /** Convert a socket error to a string. */
 336 const char *evutil_socket_error_to_string(int errcode);
 337 #elif defined(_EVENT_IN_DOXYGEN)
 338 /**
 339    @name Socket error functions
 340
 341    These functions are needed for making programs compatible between
 342    Windows and Unix-like platforms.
 343
 344    You see, Winsock handles socket errors differently from the rest of
 345    the world.  Elsewhere, a socket error is like any other error and is
 346    stored in errno.  But winsock functions require you to retrieve the
 347    error with a special function, and don't let you use strerror for
 348    the error codes.  And handling EWOULDBLOCK is ... different.
 349
 350    @{
 351 */
 352 /** Return the most recent socket error.  Not idempotent on all platforms. */
 353 #define EVUTIL_SOCKET_ERROR() ...
 354 /** Replace the most recent socket error with errcode */
 355 #define EVUTIL_SET_SOCKET_ERROR(errcode) ...
 356 /** Return the most recent socket error to occur on sock. */
 357 #define evutil_socket_geterror(sock) ...
 358 /** Convert a socket error to a string. */
 359 #define evutil_socket_error_to_string(errcode) ...
 360 /**@}*/
 361 #else
 362 #define EVUTIL_SOCKET_ERROR() (errno)
 363 #define EVUTIL_SET_SOCKET_ERROR(errcode)                \
 364                 do { errno = (errcode); } while (0)
 365 #define evutil_socket_geterror(sock) (errno)
 366 #define evutil_socket_error_to_string(errcode) (strerror(errcode))
 367 #endif
 368
 369
 370 /**
 371  * @name Manipulation macros for struct timeval.
 372  *
 373  * We define replacements
 374  * for timeradd, timersub, timerclear, timercmp, and timerisset.
 375  *
 376  * @{
 377  */
 378 #ifdef _EVENT_HAVE_TIMERADD
 379 #define evutil_timeradd(tvp, uvp, vvp) timeradd((tvp), (uvp), (vvp))
 380 #define evutil_timersub(tvp, uvp, vvp) timersub((tvp), (uvp), (vvp))
 381 #else
 382 #define evutil_timeradd(tvp, uvp, vvp)                                  \
 383         do {                                                            \
 384                 (vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;          \
 385                 (vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;       \
 386                 if ((vvp)->tv_usec >= 1000000) {                        \
 387                         (vvp)->tv_sec++;                                \
 388                         (vvp)->tv_usec -= 1000000;                      \
 389                 }                                                       \
 390         } while (0)
 391 #define evutil_timersub(tvp, uvp, vvp)                                  \
 392         do {                                                            \
 393                 (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;          \
 394                 (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;       \
 395                 if ((vvp)->tv_usec < 0) {                               \
 396                         (vvp)->tv_sec--;                                \
 397                         (vvp)->tv_usec += 1000000;                      \
 398                 }                                                       \
 399         } while (0)
 400 #endif /* !_EVENT_HAVE_HAVE_TIMERADD */
 401
 402 #ifdef _EVENT_HAVE_TIMERCLEAR
 403 #define evutil_timerclear(tvp) timerclear(tvp)
 404 #else
 405 #define evutil_timerclear(tvp)  (tvp)->tv_sec = (tvp)->tv_usec = 0
 406 #endif
 407 /**@}*/
 408
 409 /** Return true iff the tvp is related to uvp according to the relational
 410  * operator cmp.  Recognized values for cmp are ==, <=, <, >=, and >. */
 411 #define evutil_timercmp(tvp, uvp, cmp)                                  \
 412         (((tvp)->tv_sec == (uvp)->tv_sec) ?                             \
 413          ((tvp)->tv_usec cmp (uvp)->tv_usec) :                          \
 414          ((tvp)->tv_sec cmp (uvp)->tv_sec))
 415
 416 #ifdef _EVENT_HAVE_TIMERISSET
 417 #define evutil_timerisset(tvp) timerisset(tvp)
 418 #else
 419 #define evutil_timerisset(tvp)  ((tvp)->tv_sec || (tvp)->tv_usec)
 420 #endif
 421
 422 /** Replacement for offsetof on platforms that don't define it. */
 423 #ifdef offsetof
 424 #define evutil_offsetof(type, field) offsetof(type, field)
 425 #else
 426 #define evutil_offsetof(type, field) ((off_t)(&((type *)0)->field))
 427 #endif
 428
 429 /* big-int related functions */
 430 /** Parse a 64-bit value from a string.  Arguments are as for strtol. */
 431 ev_int64_t evutil_strtoll(const char *s, char **endptr, int base);
 432
 433 /** Replacement for gettimeofday on platforms that lack it. */
 434 #ifdef _EVENT_HAVE_GETTIMEOFDAY
 435 #define evutil_gettimeofday(tv, tz) gettimeofday((tv), (tz))
 436 #else
 437 struct timezone;
 438 int evutil_gettimeofday(struct timeval *tv, struct timezone *tz);
 439 #endif
 440
 441 /** Replacement for snprintf to get consistent behavior on platforms for
 442     which the return value of snprintf does not conform to C99.
 443  */
 444 int evutil_snprintf(char *buf, size_t buflen, const char *format, ...)
 445 #ifdef __GNUC__
 446         __attribute__((format(printf, 3, 4)))
 447 #endif
 448 ;
 449 /** Replacement for vsnprintf to get consistent behavior on platforms for
 450     which the return value of snprintf does not conform to C99.
 451  */
 452 int evutil_vsnprintf(char *buf, size_t buflen, const char *format, va_list ap)
 453 #ifdef __GNUC__
 454         __attribute__((format(printf, 3, 0)))
 455 #endif
 456 ;
 457
 458 /** Replacement for inet_ntop for platforms which lack it. */
 459 const char *evutil_inet_ntop(int af, const void *src, char *dst, size_t len);
 460 /** Replacement for inet_pton for platforms which lack it. */
 461 int evutil_inet_pton(int af, const char *src, void *dst);
 462 struct sockaddr;
 463
 464 /** Parse an IPv4 or IPv6 address, with optional port, from a string.
 465
 466     Recognized formats are:
 467     - [IPv6Address]:port
 468     - [IPv6Address]
 469     - IPv6Address
 470     - IPv4Address:port
 471     - IPv4Address
 472
 473     If no port is specified, the port in the output is set to 0.
 474
 475     @param str The string to parse.
 476     @param out A struct sockaddr to hold the result.  This should probably be
 477        a struct sockaddr_storage.
 478     @param outlen A pointer to the number of bytes that that 'out' can safely
 479        hold.  Set to the number of bytes used in 'out' on success.
 480     @return -1 if the address is not well-formed, if the port is out of range,
 481        or if out is not large enough to hold the result.  Otherwise returns
 482        0 on success.
 483 */
 484 int evutil_parse_sockaddr_port(const char *str, struct sockaddr *out, int *outlen);
 485
 486 /**
 487  * Format an address to ipv4:port or [ipv6]:port
 488  *
 489  * @param sa A struct sockaddr
 490  * @param out The output buffer
 491  * @param outlen The output buffer length
 492  * @return 0 on success
 493  */
 494 const char *evutil_format_sockaddr_port(const struct sockaddr *sa, char *out,
 495                                         size_t outlen);
 496
 497 /** Compare two sockaddrs; return 0 if they are equal, or less than 0 if sa1
 498  * preceeds sa2, or greater than 0 if sa1 follows sa2.  If include_port is
 499  * true, consider the port as well as the address.  Only implemented for
 500  * AF_INET and AF_INET6 addresses. The ordering is not guaranteed to remain
 501  * the same between Libevent versions. */
 502 int evutil_sockaddr_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2,
 503     int include_port);
 504
 505 /** As strcasecmp, but always compares the characters in locale-independent
 506     ASCII.  That's useful if you're handling data in ASCII-based protocols.
 507  */
 508 int evutil_ascii_strcasecmp(const char *str1, const char *str2);
 509 /** As strncasecmp, but always compares the characters in locale-independent
 510     ASCII.  That's useful if you're handling data in ASCII-based protocols.
 511  */
 512 int evutil_ascii_strncasecmp(const char *str1, const char *str2, size_t n);
 513
 514 /* Here we define evutil_addrinfo to the native addrinfo type, or redefine it
 515  * if this system has no getaddrinfo(). */
 516 #ifdef _EVENT_HAVE_STRUCT_ADDRINFO
 517 #define evutil_addrinfo addrinfo
 518 #else
 519 /** A definition of struct addrinfo for systems that lack it.
 520
 521     (This is just an alias for struct addrinfo if the system defines
 522     struct addrinfo.)
 523 */
 524 struct evutil_addrinfo {
 525         int     ai_flags;     /* AI_PASSIVE, AI_CANONNAME, AI_NUMERICHOST */
 526         int     ai_family;    /* PF_xxx */
 527         int     ai_socktype;  /* SOCK_xxx */
 528         int     ai_protocol;  /* 0 or IPPROTO_xxx for IPv4 and IPv6 */
 529         size_t  ai_addrlen;   /* length of ai_addr */
 530         char   *ai_canonname; /* canonical name for nodename */
 531         struct sockaddr  *ai_addr; /* binary address */
 532         struct evutil_addrinfo  *ai_next; /* next structure in linked list */
 533 };
 534 #endif
 535 /** @name evutil_getaddrinfo() error codes
 536
 537     These values are possible error codes for evutil_getaddrinfo() and
 538     related functions.
 539
 540     @{
 541 */
 542 #ifdef EAI_ADDRFAMILY
 543 #define EVUTIL_EAI_ADDRFAMILY EAI_ADDRFAMILY
 544 #else
 545 #define EVUTIL_EAI_ADDRFAMILY -901
 546 #endif
 547 #ifdef EAI_AGAIN
 548 #define EVUTIL_EAI_AGAIN EAI_AGAIN
 549 #else
 550 #define EVUTIL_EAI_AGAIN -902
 551 #endif
 552 #ifdef EAI_BADFLAGS
 553 #define EVUTIL_EAI_BADFLAGS EAI_BADFLAGS
 554 #else
 555 #define EVUTIL_EAI_BADFLAGS -903
 556 #endif
 557 #ifdef EAI_FAIL
 558 #define EVUTIL_EAI_FAIL EAI_FAIL
 559 #else
 560 #define EVUTIL_EAI_FAIL -904
 561 #endif
 562 #ifdef EAI_FAMILY
 563 #define EVUTIL_EAI_FAMILY EAI_FAMILY
 564 #else
 565 #define EVUTIL_EAI_FAMILY -905
 566 #endif
 567 #ifdef EAI_MEMORY
 568 #define EVUTIL_EAI_MEMORY EAI_MEMORY
 569 #else
 570 #define EVUTIL_EAI_MEMORY -906
 571 #endif
 572 /* This test is a bit complicated, since some MS SDKs decide to
 573  * remove NODATA or redefine it to be the same as NONAME, in a
 574  * fun interpretation of RFC 2553 and RFC 3493. */
 575 #if defined(EAI_NODATA) && (!defined(EAI_NONAME) || EAI_NODATA != EAI_NONAME)
 576 #define EVUTIL_EAI_NODATA EAI_NODATA
 577 #else
 578 #define EVUTIL_EAI_NODATA -907
 579 #endif
 580 #ifdef EAI_NONAME
 581 #define EVUTIL_EAI_NONAME EAI_NONAME
 582 #else
 583 #define EVUTIL_EAI_NONAME -908
 584 #endif
 585 #ifdef EAI_SERVICE
 586 #define EVUTIL_EAI_SERVICE EAI_SERVICE
 587 #else
 588 #define EVUTIL_EAI_SERVICE -909
 589 #endif
 590 #ifdef EAI_SOCKTYPE
 591 #define EVUTIL_EAI_SOCKTYPE EAI_SOCKTYPE
 592 #else
 593 #define EVUTIL_EAI_SOCKTYPE -910
 594 #endif
 595 #ifdef EAI_SYSTEM
 596 #define EVUTIL_EAI_SYSTEM EAI_SYSTEM
 597 #else
 598 #define EVUTIL_EAI_SYSTEM -911
 599 #endif
 600
 601 #define EVUTIL_EAI_CANCEL -90001
 602
 603 #ifdef AI_PASSIVE
 604 #define EVUTIL_AI_PASSIVE AI_PASSIVE
 605 #else
 606 #define EVUTIL_AI_PASSIVE 0x1000
 607 #endif
 608 #ifdef AI_CANONNAME
 609 #define EVUTIL_AI_CANONNAME AI_CANONNAME
 610 #else
 611 #define EVUTIL_AI_CANONNAME 0x2000
 612 #endif
 613 #ifdef AI_NUMERICHOST
 614 #define EVUTIL_AI_NUMERICHOST AI_NUMERICHOST
 615 #else
 616 #define EVUTIL_AI_NUMERICHOST 0x4000
 617 #endif
 618 #ifdef AI_NUMERICSERV
 619 #define EVUTIL_AI_NUMERICSERV AI_NUMERICSERV
 620 #else
 621 #define EVUTIL_AI_NUMERICSERV 0x8000
 622 #endif
 623 #ifdef AI_V4MAPPED
 624 #define EVUTIL_AI_V4MAPPED AI_V4MAPPED
 625 #else
 626 #define EVUTIL_AI_V4MAPPED 0x10000
 627 #endif
 628 #ifdef AI_ALL
 629 #define EVUTIL_AI_ALL AI_ALL
 630 #else
 631 #define EVUTIL_AI_ALL 0x20000
 632 #endif
 633 #ifdef AI_ADDRCONFIG
 634 #define EVUTIL_AI_ADDRCONFIG AI_ADDRCONFIG
 635 #else
 636 #define EVUTIL_AI_ADDRCONFIG 0x40000
 637 #endif
 638 /**@}*/
 639
 640 struct evutil_addrinfo;
 641 /**
 642  * This function clones getaddrinfo for systems that don't have it.  For full
 643  * details, see RFC 3493, section 6.1.
 644  *
 645  * Limitations:
 646  * - When the system has no getaddrinfo, we fall back to gethostbyname_r or
 647  *   gethostbyname, with their attendant issues.
 648  * - The AI_V4MAPPED and AI_ALL flags are not currently implemented.
 649  *
 650  * For a nonblocking variant, see evdns_getaddrinfo.
 651  */
 652 int evutil_getaddrinfo(const char *nodename, const char *servname,
 653     const struct evutil_addrinfo *hints_in, struct evutil_addrinfo **res);
 654
 655 /** Release storage allocated by evutil_getaddrinfo or evdns_getaddrinfo. */
 656 void evutil_freeaddrinfo(struct evutil_addrinfo *ai);
 657
 658 const char *evutil_gai_strerror(int err);
 659
 660 /** Generate n bytes of secure pseudorandom data, and store them in buf.
 661  *
 662  * By default, Libevent uses an ARC4-based random number generator, seeded
 663  * using the platform's entropy source (/dev/urandom on Unix-like systems;
 664  * CryptGenRandom on Windows).
 665  */
 666 void evutil_secure_rng_get_bytes(void *buf, size_t n);
 667
 668 /**
 669  * Seed the secure random number generator if needed, and return 0 on
 670  * success or -1 on failure.
 671  *
 672  * It is okay to call this function more than once; it will still return
 673  * 0 if the RNG has been successfully seeded and -1 if it can't be
 674  * seeded.
 675  *
 676  * Ordinarily you don't need to call this function from your own code;
 677  * Libevent will seed the RNG itself the first time it needs good random
 678  * numbers.  You only need to call it if (a) you want to double-check
 679  * that one of the seeding methods did succeed, or (b) you plan to drop
 680  * the capability to seed (by chrooting, or dropping capabilities, or
 681  * whatever), and you want to make sure that seeding happens before your
 682  * program loses the ability to do it.
 683  */
 684 int evutil_secure_rng_init(void);
 685
 686 /** Seed the random number generator with extra random bytes.
 687
 688     You should almost never need to call this function; it should be
 689     sufficient to invoke evutil_secure_rng_init(), or let Libevent take
 690     care of calling evutil_secure_rng_init() on its own.
 691
 692     If you call this function as a _replacement_ for the regular
 693     entropy sources, then you need to be sure that your input
 694     contains a fairly large amount of strong entropy.  Doing so is
 695     notoriously hard: most people who try get it wrong.  Watch out!
 696
 697     @param dat a buffer full of a strong source of random numbers
 698     @param datlen the number of bytes to read from datlen
 699  */
 700 void evutil_secure_rng_add_bytes(const char *dat, size_t datlen);
 701
 702 #ifdef __cplusplus
 703 }
 704 #endif
 705
 706 #endif /* _EVUTIL_H_ */