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