xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/util-internal.h (revision 5d681e99340ceeda0a51163a65763ffea6d9a189)
1 /*	$NetBSD: util-internal.h,v 1.4 2015/07/10 14:20:34 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 #ifndef UTIL_INTERNAL_H_INCLUDED_
29 #define UTIL_INTERNAL_H_INCLUDED_
30 
31 #include "event2/event-config.h"
32 #include "evconfig-private.h"
33 
34 #include <errno.h>
35 
36 /* For EVUTIL_ASSERT */
37 #include "log-internal.h"
38 #include <stdio.h>
39 #include <stdlib.h>
40 #ifdef EVENT__HAVE_SYS_SOCKET_H
41 #include <sys/socket.h>
42 #endif
43 #ifdef EVENT__HAVE_SYS_EVENTFD_H
44 #include <sys/eventfd.h>
45 #endif
46 #include "event2/util.h"
47 
48 #include "time-internal.h"
49 #include "ipv6-internal.h"
50 
51 #ifdef __cplusplus
52 extern "C" {
53 #endif
54 
55 /* If we need magic to say "inline", get it for free internally. */
56 #ifdef EVENT__inline
57 #define inline EVENT__inline
58 #endif
59 #ifdef EVENT____func__
60 #define __func__ EVENT____func__
61 #endif
62 
63 /* A good no-op to use in macro definitions. */
64 #define EVUTIL_NIL_STMT_ ((void)0)
65 /* A no-op that tricks the compiler into thinking a condition is used while
66  * definitely not making any code for it.  Used to compile out asserts while
67  * avoiding "unused variable" warnings.  The "!" forces the compiler to
68  * do the sizeof() on an int, in case "condition" is a bitfield value.
69  */
70 #define EVUTIL_NIL_CONDITION_(condition) do { \
71 	(void)sizeof(!(condition));  \
72 } while(0)
73 
74 /* Internal use only: macros to match patterns of error codes in a
75    cross-platform way.  We need these macros because of two historical
76    reasons: first, nonblocking IO functions are generally written to give an
77    error on the "blocked now, try later" case, so sometimes an error from a
78    read, write, connect, or accept means "no error; just wait for more
79    data," and we need to look at the error code.  Second, Windows defines
80    a different set of error codes for sockets. */
81 
82 #ifndef _WIN32
83 
84 #if EAGAIN == EWOULDBLOCK
85 #define EVUTIL_ERR_IS_EAGAIN(e) \
86 	((e) == EAGAIN)
87 #else
88 #define EVUTIL_ERR_IS_EAGAIN(e) \
89 	((e) == EAGAIN || (e) == EWOULDBLOCK)
90 #endif
91 
92 /* True iff e is an error that means a read/write operation can be retried. */
93 #define EVUTIL_ERR_RW_RETRIABLE(e)				\
94 	((e) == EINTR || EVUTIL_ERR_IS_EAGAIN(e))
95 /* True iff e is an error that means an connect can be retried. */
96 #define EVUTIL_ERR_CONNECT_RETRIABLE(e)			\
97 	((e) == EINTR || (e) == EINPROGRESS)
98 /* True iff e is an error that means a accept can be retried. */
99 #define EVUTIL_ERR_ACCEPT_RETRIABLE(e)			\
100 	((e) == EINTR || EVUTIL_ERR_IS_EAGAIN(e) || (e) == ECONNABORTED)
101 
102 /* True iff e is an error that means the connection was refused */
103 #define EVUTIL_ERR_CONNECT_REFUSED(e)					\
104 	((e) == ECONNREFUSED)
105 
106 #else
107 /* Win32 */
108 
109 #define EVUTIL_ERR_IS_EAGAIN(e) \
110 	((e) == WSAEWOULDBLOCK || (e) == EAGAIN)
111 
112 #define EVUTIL_ERR_RW_RETRIABLE(e)					\
113 	((e) == WSAEWOULDBLOCK ||					\
114 	    (e) == WSAEINTR)
115 
116 #define EVUTIL_ERR_CONNECT_RETRIABLE(e)					\
117 	((e) == WSAEWOULDBLOCK ||					\
118 	    (e) == WSAEINTR ||						\
119 	    (e) == WSAEINPROGRESS ||					\
120 	    (e) == WSAEINVAL)
121 
122 #define EVUTIL_ERR_ACCEPT_RETRIABLE(e)			\
123 	EVUTIL_ERR_RW_RETRIABLE(e)
124 
125 #define EVUTIL_ERR_CONNECT_REFUSED(e)					\
126 	((e) == WSAECONNREFUSED)
127 
128 #endif
129 
130 /* Arguments for shutdown() */
131 #ifdef SHUT_RD
132 #define EVUTIL_SHUT_RD SHUT_RD
133 #else
134 #define EVUTIL_SHUT_RD 0
135 #endif
136 #ifdef SHUT_WR
137 #define EVUTIL_SHUT_WR SHUT_WR
138 #else
139 #define EVUTIL_SHUT_WR 1
140 #endif
141 #ifdef SHUT_BOTH
142 #define EVUTIL_SHUT_BOTH SHUT_BOTH
143 #else
144 #define EVUTIL_SHUT_BOTH 2
145 #endif
146 
147 /* Helper: Verify that all the elements in 'dlist' are internally consistent.
148  * Checks for circular lists and bad prev/next pointers.
149  *
150  * Example usage:
151  *    EVUTIL_ASSERT_LIST_OK(eventlist, event, ev_next);
152  */
153 #define EVUTIL_ASSERT_LIST_OK(dlist, type, field) do {			\
154 		struct type *elm1, *elm2, **nextp;			\
155 		if (LIST_EMPTY((dlist)))				\
156 			break;						\
157 									\
158 		/* Check list for circularity using Floyd's */		\
159 		/* 'Tortoise and Hare' algorithm */			\
160 		elm1 = LIST_FIRST((dlist));				\
161 		elm2 = LIST_NEXT(elm1, field);				\
162 		while (elm1 && elm2) {					\
163 			EVUTIL_ASSERT(elm1 != elm2);			\
164 			elm1 = LIST_NEXT(elm1, field);			\
165 			elm2 = LIST_NEXT(elm2, field);			\
166 			if (!elm2)					\
167 				break;					\
168 			EVUTIL_ASSERT(elm1 != elm2);			\
169 			elm2 = LIST_NEXT(elm2, field);			\
170 		}							\
171 									\
172 		/* Now check next and prev pointers for consistency. */ \
173 		nextp = &LIST_FIRST((dlist));				\
174 		elm1 = LIST_FIRST((dlist));				\
175 		while (elm1) {						\
176 			EVUTIL_ASSERT(*nextp == elm1);			\
177 			EVUTIL_ASSERT(nextp == elm1->field.le_prev);	\
178 			nextp = &LIST_NEXT(elm1, field);		\
179 			elm1 = *nextp;					\
180 		}							\
181 	} while (0)
182 
183 /* Helper: Verify that all the elements in a TAILQ are internally consistent.
184  * Checks for circular lists and bad prev/next pointers.
185  *
186  * Example usage:
187  *    EVUTIL_ASSERT_TAILQ_OK(activelist, event, ev_active_next);
188  */
189 #define EVUTIL_ASSERT_TAILQ_OK(tailq, type, field) do {			\
190 		struct type *elm1, *elm2, **nextp;			\
191 		if (TAILQ_EMPTY((tailq)))				\
192 			break;						\
193 									\
194 		/* Check list for circularity using Floyd's */		\
195 		/* 'Tortoise and Hare' algorithm */			\
196 		elm1 = TAILQ_FIRST((tailq));				\
197 		elm2 = TAILQ_NEXT(elm1, field);				\
198 		while (elm1 && elm2) {					\
199 			EVUTIL_ASSERT(elm1 != elm2);			\
200 			elm1 = TAILQ_NEXT(elm1, field);			\
201 			elm2 = TAILQ_NEXT(elm2, field);			\
202 			if (!elm2)					\
203 				break;					\
204 			EVUTIL_ASSERT(elm1 != elm2);			\
205 			elm2 = TAILQ_NEXT(elm2, field);			\
206 		}							\
207 									\
208 		/* Now check next and prev pointers for consistency. */ \
209 		nextp = &TAILQ_FIRST((tailq));				\
210 		elm1 = TAILQ_FIRST((tailq));				\
211 		while (elm1) {						\
212 			EVUTIL_ASSERT(*nextp == elm1);			\
213 			EVUTIL_ASSERT(nextp == elm1->field.tqe_prev);	\
214 			nextp = &TAILQ_NEXT(elm1, field);		\
215 			elm1 = *nextp;					\
216 		}							\
217 		EVUTIL_ASSERT(nextp == (tailq)->tqh_last);		\
218 	} while (0)
219 
220 /* Locale-independent replacements for some ctypes functions.  Use these
221  * when you care about ASCII's notion of character types, because you are about
222  * to send those types onto the wire.
223  */
224 int EVUTIL_ISALPHA_(char c);
225 int EVUTIL_ISALNUM_(char c);
226 int EVUTIL_ISSPACE_(char c);
227 int EVUTIL_ISDIGIT_(char c);
228 int EVUTIL_ISXDIGIT_(char c);
229 int EVUTIL_ISPRINT_(char c);
230 int EVUTIL_ISLOWER_(char c);
231 int EVUTIL_ISUPPER_(char c);
232 char EVUTIL_TOUPPER_(char c);
233 char EVUTIL_TOLOWER_(char c);
234 
235 /** Remove all trailing horizontal whitespace (space or tab) from the end of a
236  * string */
237 void evutil_rtrim_lws_(char *);
238 
239 
240 /** Helper macro.  If we know that a given pointer points to a field in a
241     structure, return a pointer to the structure itself.  Used to implement
242     our half-baked C OO.  Example:
243 
244     struct subtype {
245 	int x;
246 	struct supertype common;
247 	int y;
248     };
249     ...
250     void fn(struct supertype *super) {
251 	struct subtype *sub = EVUTIL_UPCAST(super, struct subtype, common);
252 	...
253     }
254  */
255 #define EVUTIL_UPCAST(ptr, type, field)				\
256 	((type *)(((char*)(ptr)) - evutil_offsetof(type, field)))
257 
258 /* As open(pathname, flags, mode), except that the file is always opened with
259  * the close-on-exec flag set. (And the mode argument is mandatory.)
260  */
261 int evutil_open_closeonexec_(const char *pathname, int flags, unsigned mode);
262 
263 int evutil_read_file_(const char *filename, char **content_out, size_t *len_out,
264     int is_binary);
265 
266 int evutil_socket_connect_(evutil_socket_t *fd_ptr, struct sockaddr *sa, int socklen);
267 
268 int evutil_socket_finished_connecting_(evutil_socket_t fd);
269 
270 int evutil_ersatz_socketpair_(int, int , int, evutil_socket_t[]);
271 
272 int evutil_resolve_(int family, const char *hostname, struct sockaddr *sa,
273     ev_socklen_t *socklen, int port);
274 
275 const char *evutil_getenv_(const char *name);
276 
277 /* Structure to hold the state of our weak random number generator.
278  */
279 struct evutil_weakrand_state {
280 	ev_uint32_t seed;
281 };
282 
283 #define EVUTIL_WEAKRAND_MAX EV_INT32_MAX
284 
285 /* Initialize the state of a week random number generator based on 'seed'.  If
286  * the seed is 0, construct a new seed based on not-very-strong platform
287  * entropy, like the PID and the time of day.
288  *
289  * This function, and the other evutil_weakrand* functions, are meant for
290  * speed, not security or statistical strength.  If you need a RNG which an
291  * attacker can't predict, or which passes strong statistical tests, use the
292  * evutil_secure_rng* functions instead.
293  */
294 ev_uint32_t evutil_weakrand_seed_(struct evutil_weakrand_state *state, ev_uint32_t seed);
295 /* Return a pseudorandom value between 0 and EVUTIL_WEAKRAND_MAX inclusive.
296  * Updates the state in 'seed' as needed -- this value must be protected by a
297  * lock.
298  */
299 ev_int32_t evutil_weakrand_(struct evutil_weakrand_state *seed);
300 /* Return a pseudorandom value x such that 0 <= x < top. top must be no more
301  * than EVUTIL_WEAKRAND_MAX. Updates the state in 'seed' as needed -- this
302  * value must be proteced by a lock */
303 ev_int32_t evutil_weakrand_range_(struct evutil_weakrand_state *seed, ev_int32_t top);
304 
305 /* Evaluates to the same boolean value as 'p', and hints to the compiler that
306  * we expect this value to be false. */
307 #if defined(__GNUC__) && __GNUC__ >= 3         /* gcc 3.0 or later */
308 #define EVUTIL_UNLIKELY(p) __builtin_expect(!!(p),0)
309 #else
310 #define EVUTIL_UNLIKELY(p) (p)
311 #endif
312 
313 /* Replacement for assert() that calls event_errx on failure. */
314 #ifdef NDEBUG
315 #define EVUTIL_ASSERT(cond) EVUTIL_NIL_CONDITION_(cond)
316 #define EVUTIL_FAILURE_CHECK(cond) 0
317 #else
318 #define EVUTIL_ASSERT(cond)						\
319 	do {								\
320 		if (EVUTIL_UNLIKELY(!(cond))) {				\
321 			event_errx(EVENT_ERR_ABORT_,			\
322 			    "%s:%d: Assertion %s failed in %s",		\
323 			    __FILE__,__LINE__,#cond,__func__);		\
324 			/* In case a user-supplied handler tries to */	\
325 			/* return control to us, log and abort here. */	\
326 			(void)fprintf(stderr,				\
327 			    "%s:%d: Assertion %s failed in %s",		\
328 			    __FILE__,__LINE__,#cond,__func__);		\
329 			abort();					\
330 		}							\
331 	} while (0)
332 #define EVUTIL_FAILURE_CHECK(cond) EVUTIL_UNLIKELY(cond)
333 #endif
334 
335 #ifndef EVENT__HAVE_STRUCT_SOCKADDR_STORAGE
336 /* Replacement for sockaddr storage that we can use internally on platforms
337  * that lack it.  It is not space-efficient, but neither is sockaddr_storage.
338  */
339 struct sockaddr_storage {
340 	union {
341 		struct sockaddr ss_sa;
342 		struct sockaddr_in ss_sin;
343 		struct sockaddr_in6 ss_sin6;
344 		char ss_padding[128];
345 	} ss_union;
346 };
347 #define ss_family ss_union.ss_sa.sa_family
348 #endif
349 
350 /* Internal addrinfo error code.  This one is returned from only from
351  * evutil_getaddrinfo_common_, when we are sure that we'll have to hit a DNS
352  * server. */
353 #define EVUTIL_EAI_NEED_RESOLVE      -90002
354 
355 struct evdns_base;
356 struct evdns_getaddrinfo_request;
357 typedef struct evdns_getaddrinfo_request* (*evdns_getaddrinfo_fn)(
358     struct evdns_base *base,
359     const char *nodename, const char *servname,
360     const struct evutil_addrinfo *hints_in,
361     void (*cb)(int, struct evutil_addrinfo *, void *), void *arg);
362 
363 void evutil_set_evdns_getaddrinfo_fn_(evdns_getaddrinfo_fn fn);
364 
365 struct evutil_addrinfo *evutil_new_addrinfo_(struct sockaddr *sa,
366     ev_socklen_t socklen, const struct evutil_addrinfo *hints);
367 struct evutil_addrinfo *evutil_addrinfo_append_(struct evutil_addrinfo *first,
368     struct evutil_addrinfo *append);
369 void evutil_adjust_hints_for_addrconfig_(struct evutil_addrinfo *hints);
370 int evutil_getaddrinfo_common_(const char *nodename, const char *servname,
371     struct evutil_addrinfo *hints, struct evutil_addrinfo **res, int *portnum);
372 
373 int evutil_getaddrinfo_async_(struct evdns_base *dns_base,
374     const char *nodename, const char *servname,
375     const struct evutil_addrinfo *hints_in,
376     void (*cb)(int, struct evutil_addrinfo *, void *), void *arg);
377 
378 /** Return true iff sa is a looback address. (That is, it is 127.0.0.1/8, or
379  * ::1). */
380 int evutil_sockaddr_is_loopback_(const struct sockaddr *sa);
381 
382 
383 /**
384     Formats a sockaddr sa into a string buffer of size outlen stored in out.
385     Returns a pointer to out.  Always writes something into out, so it's safe
386     to use the output of this function without checking it for NULL.
387  */
388 const char *evutil_format_sockaddr_port_(const struct sockaddr *sa, char *out, size_t outlen);
389 
390 int evutil_hex_char_to_int_(char c);
391 
392 
393 void evutil_free_secure_rng_globals_(void);
394 void evutil_free_globals_(void);
395 
396 #ifdef _WIN32
397 HMODULE evutil_load_windows_system_library_(const TCHAR *library_name);
398 #endif
399 
400 #ifndef EV_SIZE_FMT
401 #if defined(_MSC_VER) || defined(__MINGW32__) || defined(__MINGW64__)
402 #define EV_U64_FMT "%I64u"
403 #define EV_I64_FMT "%I64d"
404 #define EV_I64_ARG(x) ((__int64)(x))
405 #define EV_U64_ARG(x) ((unsigned __int64)(x))
406 #else
407 #define EV_U64_FMT "%llu"
408 #define EV_I64_FMT "%lld"
409 #define EV_I64_ARG(x) ((long long)(x))
410 #define EV_U64_ARG(x) ((unsigned long long)(x))
411 #endif
412 #endif
413 
414 #ifdef _WIN32
415 #define EV_SOCK_FMT EV_I64_FMT
416 #define EV_SOCK_ARG(x) EV_I64_ARG((x))
417 #else
418 #define EV_SOCK_FMT "%d"
419 #define EV_SOCK_ARG(x) (x)
420 #endif
421 
422 #if defined(__STDC__) && defined(__STDC_VERSION__)
423 #if (__STDC_VERSION__ >= 199901L)
424 #define EV_SIZE_FMT "%zu"
425 #define EV_SSIZE_FMT "%zd"
426 #define EV_SIZE_ARG(x) (x)
427 #define EV_SSIZE_ARG(x) (x)
428 #endif
429 #endif
430 
431 #ifndef EV_SIZE_FMT
432 #if (EVENT__SIZEOF_SIZE_T <= EVENT__SIZEOF_LONG)
433 #define EV_SIZE_FMT "%lu"
434 #define EV_SSIZE_FMT "%ld"
435 #define EV_SIZE_ARG(x) ((unsigned long)(x))
436 #define EV_SSIZE_ARG(x) ((long)(x))
437 #else
438 #define EV_SIZE_FMT EV_U64_FMT
439 #define EV_SSIZE_FMT EV_I64_FMT
440 #define EV_SIZE_ARG(x) EV_U64_ARG(x)
441 #define EV_SSIZE_ARG(x) EV_I64_ARG(x)
442 #endif
443 #endif
444 
445 evutil_socket_t evutil_socket_(int domain, int type, int protocol);
446 evutil_socket_t evutil_accept4_(evutil_socket_t sockfd, struct sockaddr *addr,
447     ev_socklen_t *addrlen, int flags);
448 
449     /* used by one of the test programs.. */
450 EVENT2_EXPORT_SYMBOL
451 int evutil_make_internal_pipe_(evutil_socket_t fd[2]);
452 evutil_socket_t evutil_eventfd_(unsigned initval, int flags);
453 
454 #ifdef SOCK_NONBLOCK
455 #define EVUTIL_SOCK_NONBLOCK SOCK_NONBLOCK
456 #else
457 #define EVUTIL_SOCK_NONBLOCK 0x4000000
458 #endif
459 #ifdef SOCK_CLOEXEC
460 #define EVUTIL_SOCK_CLOEXEC SOCK_CLOEXEC
461 #else
462 #define EVUTIL_SOCK_CLOEXEC 0x80000000
463 #endif
464 #ifdef EFD_NONBLOCK
465 #define EVUTIL_EFD_NONBLOCK EFD_NONBLOCK
466 #else
467 #define EVUTIL_EFD_NONBLOCK 0x4000
468 #endif
469 #ifdef EFD_CLOEXEC
470 #define EVUTIL_EFD_CLOEXEC EFD_CLOEXEC
471 #else
472 #define EVUTIL_EFD_CLOEXEC 0x8000
473 #endif
474 
475 void evutil_memclear_(void *mem, size_t len);
476 
477 #ifdef __cplusplus
478 }
479 #endif
480 
481 #endif
482