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      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 _EVENT_UTIL_INTERNAL_H
     27 #define _EVENT_UTIL_INTERNAL_H
     28 
     29 #include "event2/event-config.h"
     30 #include <errno.h>
     31 
     32 /* For EVUTIL_ASSERT */
     33 #include "log-internal.h"
     34 #include <stdio.h>
     35 #include <stdlib.h>
     36 #ifdef _EVENT_HAVE_SYS_SOCKET_H
     37 #include <sys/socket.h>
     38 #endif
     39 #include "event2/util.h"
     40 
     41 #include "ipv6-internal.h"
     42 
     43 #ifdef __cplusplus
     44 extern "C" {
     45 #endif
     46 
     47 /* If we need magic to say "inline", get it for free internally. */
     48 #ifdef _EVENT_inline
     49 #define inline _EVENT_inline
     50 #endif
     51 #ifdef _EVENT___func__
     52 #define __func__ _EVENT___func__
     53 #endif
     54 
     55 /* A good no-op to use in macro definitions. */
     56 #define _EVUTIL_NIL_STMT ((void)0)
     57 /* A no-op that tricks the compiler into thinking a condition is used while
     58  * definitely not making any code for it.  Used to compile out asserts while
     59  * avoiding "unused variable" warnings.  The "!" forces the compiler to
     60  * do the sizeof() on an int, in case "condition" is a bitfield value.
     61  */
     62 #define _EVUTIL_NIL_CONDITION(condition) do { \
     63 	(void)sizeof(!(condition));  \
     64 } while(0)
     65 
     66 /* Internal use only: macros to match patterns of error codes in a
     67    cross-platform way.  We need these macros because of two historical
     68    reasons: first, nonblocking IO functions are generally written to give an
     69    error on the "blocked now, try later" case, so sometimes an error from a
     70    read, write, connect, or accept means "no error; just wait for more
     71    data," and we need to look at the error code.  Second, Windows defines
     72    a different set of error codes for sockets. */
     73 
     74 #ifndef WIN32
     75 
     76 /* True iff e is an error that means a read/write operation can be retried. */
     77 #define EVUTIL_ERR_RW_RETRIABLE(e)				\
     78 	((e) == EINTR || (e) == EAGAIN)
     79 /* True iff e is an error that means an connect can be retried. */
     80 #define EVUTIL_ERR_CONNECT_RETRIABLE(e)			\
     81 	((e) == EINTR || (e) == EINPROGRESS)
     82 /* True iff e is an error that means a accept can be retried. */
     83 #define EVUTIL_ERR_ACCEPT_RETRIABLE(e)			\
     84 	((e) == EINTR || (e) == EAGAIN || (e) == ECONNABORTED)
     85 
     86 /* True iff e is an error that means the connection was refused */
     87 #define EVUTIL_ERR_CONNECT_REFUSED(e)					\
     88 	((e) == ECONNREFUSED)
     89 
     90 #else
     91 
     92 #define EVUTIL_ERR_RW_RETRIABLE(e)					\
     93 	((e) == WSAEWOULDBLOCK ||					\
     94 	    (e) == WSAEINTR)
     95 
     96 #define EVUTIL_ERR_CONNECT_RETRIABLE(e)					\
     97 	((e) == WSAEWOULDBLOCK ||					\
     98 	    (e) == WSAEINTR ||						\
     99 	    (e) == WSAEINPROGRESS ||					\
    100 	    (e) == WSAEINVAL)
    101 
    102 #define EVUTIL_ERR_ACCEPT_RETRIABLE(e)			\
    103 	EVUTIL_ERR_RW_RETRIABLE(e)
    104 
    105 #define EVUTIL_ERR_CONNECT_REFUSED(e)					\
    106 	((e) == WSAECONNREFUSED)
    107 
    108 #endif
    109 
    110 #ifdef _EVENT_socklen_t
    111 #define socklen_t _EVENT_socklen_t
    112 #endif
    113 
    114 /* Arguments for shutdown() */
    115 #ifdef SHUT_RD
    116 #define EVUTIL_SHUT_RD SHUT_RD
    117 #else
    118 #define EVUTIL_SHUT_RD 0
    119 #endif
    120 #ifdef SHUT_WR
    121 #define EVUTIL_SHUT_WR SHUT_WR
    122 #else
    123 #define EVUTIL_SHUT_WR 1
    124 #endif
    125 #ifdef SHUT_BOTH
    126 #define EVUTIL_SHUT_BOTH SHUT_BOTH
    127 #else
    128 #define EVUTIL_SHUT_BOTH 2
    129 #endif
    130 
    131 /* Locale-independent replacements for some ctypes functions.  Use these
    132  * when you care about ASCII's notion of character types, because you are about
    133  * to send those types onto the wire.
    134  */
    135 int EVUTIL_ISALPHA(char c);
    136 int EVUTIL_ISALNUM(char c);
    137 int EVUTIL_ISSPACE(char c);
    138 int EVUTIL_ISDIGIT(char c);
    139 int EVUTIL_ISXDIGIT(char c);
    140 int EVUTIL_ISPRINT(char c);
    141 int EVUTIL_ISLOWER(char c);
    142 int EVUTIL_ISUPPER(char c);
    143 char EVUTIL_TOUPPER(char c);
    144 char EVUTIL_TOLOWER(char c);
    145 
    146 /** Helper macro.  If we know that a given pointer points to a field in a
    147     structure, return a pointer to the structure itself.  Used to implement
    148     our half-baked C OO.  Example:
    149 
    150     struct subtype {
    151 	int x;
    152 	struct supertype common;
    153 	int y;
    154     };
    155     ...
    156     void fn(struct supertype *super) {
    157 	struct subtype *sub = EVUTIL_UPCAST(super, struct subtype, common);
    158 	...
    159     }
    160  */
    161 #define EVUTIL_UPCAST(ptr, type, field)				\
    162 	((type *)(((char*)(ptr)) - evutil_offsetof(type, field)))
    163 
    164 /* As open(pathname, flags, mode), except that the file is always opened with
    165  * the close-on-exec flag set. (And the mode argument is mandatory.)
    166  */
    167 int evutil_open_closeonexec(const char *pathname, int flags, unsigned mode);
    168 
    169 int evutil_read_file(const char *filename, char **content_out, size_t *len_out,
    170     int is_binary);
    171 
    172 int evutil_socket_connect(evutil_socket_t *fd_ptr, struct sockaddr *sa, int socklen);
    173 
    174 int evutil_socket_finished_connecting(evutil_socket_t fd);
    175 
    176 int evutil_ersatz_socketpair(int, int , int, evutil_socket_t[]);
    177 
    178 int evutil_resolve(int family, const char *hostname, struct sockaddr *sa,
    179     ev_socklen_t *socklen, int port);
    180 
    181 const char *evutil_getenv(const char *name);
    182 
    183 long _evutil_weakrand(void);
    184 
    185 /* Evaluates to the same boolean value as 'p', and hints to the compiler that
    186  * we expect this value to be false. */
    187 #if defined(__GNUC__) && __GNUC__ >= 3         /* gcc 3.0 or later */
    188 #define EVUTIL_UNLIKELY(p) __builtin_expect(!!(p),0)
    189 #else
    190 #define EVUTIL_UNLIKELY(p) (p)
    191 #endif
    192 
    193 /* Replacement for assert() that calls event_errx on failure. */
    194 #ifdef NDEBUG
    195 #define EVUTIL_ASSERT(cond) _EVUTIL_NIL_CONDITION(cond)
    196 #define EVUTIL_FAILURE_CHECK(cond) 0
    197 #else
    198 #define EVUTIL_ASSERT(cond)						\
    199 	do {								\
    200 		if (EVUTIL_UNLIKELY(!(cond))) {				\
    201 			event_errx(_EVENT_ERR_ABORT,			\
    202 			    "%s:%d: Assertion %s failed in %s",		\
    203 			    __FILE__,__LINE__,#cond,__func__);		\
    204 			/* In case a user-supplied handler tries to */	\
    205 			/* return control to us, log and abort here. */	\
    206 			(void)fprintf(stderr,				\
    207 			    "%s:%d: Assertion %s failed in %s",		\
    208 			    __FILE__,__LINE__,#cond,__func__);		\
    209 			abort();					\
    210 		}							\
    211 	} while (0)
    212 #define EVUTIL_FAILURE_CHECK(cond) EVUTIL_UNLIKELY(cond)
    213 #endif
    214 
    215 #ifndef _EVENT_HAVE_STRUCT_SOCKADDR_STORAGE
    216 /* Replacement for sockaddr storage that we can use internally on platforms
    217  * that lack it.  It is not space-efficient, but neither is sockaddr_storage.
    218  */
    219 struct sockaddr_storage {
    220 	union {
    221 		struct sockaddr ss_sa;
    222 		struct sockaddr_in ss_sin;
    223 		struct sockaddr_in6 ss_sin6;
    224 		char ss_padding[128];
    225 	} ss_union;
    226 };
    227 #define ss_family ss_union.ss_sa.sa_family
    228 #endif
    229 
    230 /* Internal addrinfo error code.  This one is returned from only from
    231  * evutil_getaddrinfo_common, when we are sure that we'll have to hit a DNS
    232  * server. */
    233 #define EVUTIL_EAI_NEED_RESOLVE      -90002
    234 
    235 struct evdns_base;
    236 struct evdns_getaddrinfo_request;
    237 typedef struct evdns_getaddrinfo_request* (*evdns_getaddrinfo_fn)(
    238     struct evdns_base *base,
    239     const char *nodename, const char *servname,
    240     const struct evutil_addrinfo *hints_in,
    241     void (*cb)(int, struct evutil_addrinfo *, void *), void *arg);
    242 
    243 void evutil_set_evdns_getaddrinfo_fn(evdns_getaddrinfo_fn fn);
    244 
    245 struct evutil_addrinfo *evutil_new_addrinfo(struct sockaddr *sa,
    246     ev_socklen_t socklen, const struct evutil_addrinfo *hints);
    247 struct evutil_addrinfo *evutil_addrinfo_append(struct evutil_addrinfo *first,
    248     struct evutil_addrinfo *append);
    249 void evutil_adjust_hints_for_addrconfig(struct evutil_addrinfo *hints);
    250 int evutil_getaddrinfo_common(const char *nodename, const char *servname,
    251     struct evutil_addrinfo *hints, struct evutil_addrinfo **res, int *portnum);
    252 
    253 int evutil_getaddrinfo_async(struct evdns_base *dns_base,
    254     const char *nodename, const char *servname,
    255     const struct evutil_addrinfo *hints_in,
    256     void (*cb)(int, struct evutil_addrinfo *, void *), void *arg);
    257 
    258 /** Return true iff sa is a looback address. (That is, it is 127.0.0.1/8, or
    259  * ::1). */
    260 int evutil_sockaddr_is_loopback(const struct sockaddr *sa);
    261 
    262 
    263 /**
    264     Formats a sockaddr sa into a string buffer of size outlen stored in out.
    265     Returns a pointer to out.  Always writes something into out, so it's safe
    266     to use the output of this function without checking it for NULL.
    267  */
    268 const char *evutil_format_sockaddr_port(const struct sockaddr *sa, char *out, size_t outlen);
    269 
    270 long evutil_tv_to_msec(const struct timeval *tv);
    271 
    272 int evutil_hex_char_to_int(char c);
    273 
    274 #ifdef WIN32
    275 HANDLE evutil_load_windows_system_library(const TCHAR *library_name);
    276 #endif
    277 
    278 #ifndef EV_SIZE_FMT
    279 #if defined(_MSC_VER) || defined(__MINGW32__) || defined(__MINGW64__)
    280 #define EV_U64_FMT "%I64u"
    281 #define EV_I64_FMT "%I64d"
    282 #define EV_I64_ARG(x) ((__int64)(x))
    283 #define EV_U64_ARG(x) ((unsigned __int64)(x))
    284 #else
    285 #define EV_U64_FMT "%llu"
    286 #define EV_I64_FMT "%lld"
    287 #define EV_I64_ARG(x) ((long long)(x))
    288 #define EV_U64_ARG(x) ((unsigned long long)(x))
    289 #endif
    290 #endif
    291 
    292 #ifdef _WIN32
    293 #define EV_SOCK_FMT EV_I64_FMT
    294 #define EV_SOCK_ARG(x) EV_I64_ARG((x))
    295 #else
    296 #define EV_SOCK_FMT "%d"
    297 #define EV_SOCK_ARG(x) (x)
    298 #endif
    299 
    300 #if defined(__STDC__) && defined(__STDC_VERSION__)
    301 #if (__STDC_VERSION__ >= 199901L)
    302 #define EV_SIZE_FMT "%zu"
    303 #define EV_SSIZE_FMT "%zd"
    304 #define EV_SIZE_ARG(x) (x)
    305 #define EV_SSIZE_ARG(x) (x)
    306 #endif
    307 #endif
    308 
    309 #ifndef EV_SIZE_FMT
    310 #if (_EVENT_SIZEOF_SIZE_T <= _EVENT_SIZEOF_LONG)
    311 #define EV_SIZE_FMT "%lu"
    312 #define EV_SSIZE_FMT "%ld"
    313 #define EV_SIZE_ARG(x) ((unsigned long)(x))
    314 #define EV_SSIZE_ARG(x) ((long)(x))
    315 #else
    316 #define EV_SIZE_FMT EV_U64_FMT
    317 #define EV_SSIZE_FMT EV_I64_FMT
    318 #define EV_SIZE_ARG(x) EV_U64_ARG(x)
    319 #define EV_SSIZE_ARG(x) EV_I64_ARG(x)
    320 #endif
    321 #endif
    322 
    323 void evutil_memclear_(void *mem, size_t len);
    324 
    325 #ifdef __cplusplus
    326 }
    327 #endif
    328 
    329 #endif
    330