xref: /freebsd/contrib/sendmail/libsm/local.h (revision 2ef40764f06885f97d380ee8de0ced64930423db)
1 /*
2  * Copyright (c) 2000-2002 Sendmail, Inc. and its suppliers.
3  *      All rights reserved.
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Chris Torek.
9  *
10  * By using this file, you agree to the terms and conditions set
11  * forth in the LICENSE file which can be found at the top level of
12  * the sendmail distribution.
13  *
14  *	$Id: local.h,v 1.51.2.1 2002/09/09 21:38:08 gshapiro Exp $
15  */
16 
17 /*
18 **  Information local to this implementation of stdio,
19 **  in particular, macros and private variables.
20 */
21 
22 #include <sys/time.h>
23 #if !SM_CONF_MEMCHR
24 # include <memory.h>
25 #endif /* !SM_CONF_MEMCHR */
26 #include <sm/heap.h>
27 
28 int	sm_flush __P((SM_FILE_T *, int *));
29 SM_FILE_T	*smfp __P((void));
30 int	sm_refill __P((SM_FILE_T *, int));
31 void	sm_init __P((void));
32 void	sm_cleanup __P((void));
33 void	sm_makebuf __P((SM_FILE_T *));
34 int	sm_whatbuf __P((SM_FILE_T *, size_t *, int *));
35 int	sm_fwalk __P((int (*)(SM_FILE_T *, int *), int *));
36 int	sm_wsetup __P((SM_FILE_T *));
37 int	sm_flags __P((int));
38 SM_FILE_T	*sm_fp __P((const SM_FILE_T *, const int, SM_FILE_T *));
39 int	sm_vprintf __P((int, char const *, va_list));
40 int	sm_vfscanf __P((SM_FILE_T *, int, char const *, va_list));
41 
42 /* std io functions */
43 ssize_t	sm_stdread __P((SM_FILE_T *, char *, size_t));
44 ssize_t	sm_stdwrite __P((SM_FILE_T *, char const *, size_t));
45 off_t	sm_stdseek __P((SM_FILE_T *, off_t, int));
46 int	sm_stdclose __P((SM_FILE_T *));
47 int	sm_stdopen __P((SM_FILE_T *, const void *, int, const void *));
48 int	sm_stdfdopen __P((SM_FILE_T *, const void *, int, const void *));
49 int	sm_stdsetinfo __P((SM_FILE_T *, int , void *));
50 int	sm_stdgetinfo __P((SM_FILE_T *, int , void *));
51 
52 /* stdio io functions */
53 ssize_t	sm_stdioread __P((SM_FILE_T *, char *, size_t));
54 ssize_t	sm_stdiowrite __P((SM_FILE_T *, char const *, size_t));
55 off_t	sm_stdioseek __P((SM_FILE_T *, off_t, int));
56 int	sm_stdioclose __P((SM_FILE_T *));
57 int	sm_stdioopen __P((SM_FILE_T *, const void *, int, const void *));
58 int	sm_stdiosetinfo __P((SM_FILE_T *, int , void *));
59 int	sm_stdiogetinfo __P((SM_FILE_T *, int , void *));
60 
61 /* string io functions */
62 ssize_t	sm_strread __P((SM_FILE_T *, char *, size_t));
63 ssize_t	sm_strwrite __P((SM_FILE_T *, char const *, size_t));
64 off_t	sm_strseek __P((SM_FILE_T *, off_t, int));
65 int	sm_strclose __P((SM_FILE_T *));
66 int	sm_stropen __P((SM_FILE_T *, const void *, int, const void *));
67 int	sm_strsetinfo __P((SM_FILE_T *, int , void *));
68 int	sm_strgetinfo __P((SM_FILE_T *, int , void *));
69 
70 /* syslog io functions */
71 ssize_t	sm_syslogread __P((SM_FILE_T *, char *, size_t));
72 ssize_t	sm_syslogwrite __P((SM_FILE_T *, char const *, size_t));
73 off_t	sm_syslogseek __P((SM_FILE_T *, off_t, int));
74 int	sm_syslogclose __P((SM_FILE_T *));
75 int	sm_syslogopen __P((SM_FILE_T *, const void *, int, const void *));
76 int	sm_syslogsetinfo __P((SM_FILE_T *, int , void *));
77 int	sm_sysloggetinfo __P((SM_FILE_T *, int , void *));
78 
79 /* should be defined in sys/time.h */
80 #ifndef timersub
81 # define timersub(tvp, uvp, vvp)					\
82 	do								\
83 	{								\
84 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
85 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
86 		if ((vvp)->tv_usec < 0)					\
87 		{							\
88 			(vvp)->tv_sec--;				\
89 			(vvp)->tv_usec += 1000000;			\
90 		}							\
91 	} while (0)
92 #endif /* !timersub */
93 
94 #ifndef timeradd
95 # define timeradd(tvp, uvp, vvp)					\
96 	do								\
97 	{								\
98 		(vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;		\
99 		(vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;	\
100 		if ((vvp)->tv_usec >= 1000000)				\
101 		{							\
102 			(vvp)->tv_sec++;				\
103 			(vvp)->tv_usec -= 1000000;			\
104 		}							\
105 	} while (0)
106 #endif /* !timeradd */
107 
108 #ifndef timercmp
109 # define timercmp(tvp, uvp, cmp)					\
110 	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
111 	    ((tvp)->tv_usec cmp (uvp)->tv_usec) :			\
112 	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
113 #endif /* !timercmp */
114 
115 extern bool Sm_IO_DidInit;
116 
117 /* Return true iff the given SM_FILE_T cannot be written now. */
118 #define cantwrite(fp) \
119 	((((fp)->f_flags & SMWR) == 0 || (fp)->f_bf.smb_base == NULL) && \
120 	 sm_wsetup(fp))
121 
122 /*
123 **  Test whether the given stdio file has an active ungetc buffer;
124 **   release such a buffer, without restoring ordinary unread data.
125 */
126 
127 #define HASUB(fp) ((fp)->f_ub.smb_base != NULL)
128 #define FREEUB(fp)					\
129 {							\
130 	if ((fp)->f_ub.smb_base != (fp)->f_ubuf)	\
131 		sm_free((char *)(fp)->f_ub.smb_base);	\
132 	(fp)->f_ub.smb_base = NULL;			\
133 }
134 
135 extern const char SmFileMagic[];
136 
137 #define SM_ALIGN(p)	(((unsigned long)(p) + SM_ALIGN_BITS) & ~SM_ALIGN_BITS)
138 
139 #define sm_io_flockfile(fp)	((void) 0)
140 #define sm_io_funlockfile(fp)	((void) 0)
141 
142 #ifndef FDSET_CAST
143 # define FDSET_CAST		/* empty cast for fd_set arg to select */
144 #endif
145 
146 /*
147 **  SM_CONVERT_TIME -- convert the API timeout flag for select() usage.
148 **
149 **	This takes a 'fp' (a file type pointer) and obtains the "raw"
150 **	file descriptor (fd) if possible. The 'fd' is needed to possibly
151 **	switch the mode of the file (blocking/non-blocking) to match
152 **	the type of timeout. If timeout is SM_TIME_FOREVER then the
153 **	timeout using select won't be needed and the file is best placed
154 **	in blocking mode. If there is to be a finite timeout then the file
155 **	is best placed in non-blocking mode. Then, if not enough can be
156 **	written, select() can be used to test when something can be written
157 **	yet still timeout if the wait is too long.
158 **	If the mode is already in the correct state we don't change it.
159 **	Iff (yes "iff") the 'fd' is "-1" in value then the mode change
160 **	will not happen. This situation arises when a late-binding-to-disk
161 **	file type is in use. An example of this is the sendmail buffered
162 **	file type (in sendmail/bf.c).
163 **
164 **	Parameters
165 **		fp -- the file pointer the timeout is for
166 **		fd -- to become the file descriptor value from 'fp'
167 **		val -- the timeout value to be converted
168 **		time -- a struct timeval holding the converted value
169 **
170 **	Returns
171 **		nothing, this is flow-through code
172 **
173 **	Side Effects:
174 **		May or may not change the mode of a currently open file.
175 **		The file mode may be changed to O_NONBLOCK or ~O_NONBLOCK
176 **		(meaning block). This is done to best match the type of
177 **		timeout and for (possible) use with select().
178 */
179 
180 # define SM_CONVERT_TIME(fp, fd, val, time) { \
181 	if (((fd) = sm_io_getinfo(fp, SM_IO_WHAT_FD, NULL)) == -1) \
182 	{ \
183 		/* can't get an fd, likely internal 'fake' fp */ \
184 		errno = 0; \
185 	} \
186 	if ((val) == SM_TIME_DEFAULT) \
187 		(val) = (fp)->f_timeout; \
188 	if ((val) == SM_TIME_IMMEDIATE || (val) == SM_TIME_FOREVER) \
189 	{ \
190 		(time)->tv_sec = 0; \
191 		(time)->tv_usec = 0; \
192 	} \
193 	else \
194 	{ \
195 		(time)->tv_sec = (val) / 1000; \
196 		(time)->tv_usec = ((val) - ((time)->tv_sec * 1000)) * 10; \
197 	} \
198 	if ((val) == SM_TIME_FOREVER) \
199 	{ \
200 		if ((fp)->f_timeoutstate == SM_TIME_NONBLOCK && (fd) != -1) \
201 		{ \
202 			int ret; \
203 			ret = fcntl((fd), F_GETFL, 0); \
204 			if (ret == -1 || fcntl((fd), F_SETFL, \
205 					       ret & ~O_NONBLOCK) == -1) \
206 			{ \
207 				/* errno should be set */ \
208 				return SM_IO_EOF; \
209 			} \
210 			(fp)->f_timeoutstate = SM_TIME_BLOCK; \
211 			if ((fp)->f_modefp != NULL) \
212 				(fp)->f_modefp->f_timeoutstate = SM_TIME_BLOCK; \
213 		} \
214 	} \
215 	else { \
216 		if ((fp)->f_timeoutstate == SM_TIME_BLOCK && (fd) != -1) \
217 		{ \
218 			int ret; \
219 			ret = fcntl((fd), F_GETFL, 0); \
220 			if (ret == -1 || fcntl((fd), F_SETFL, \
221 					       ret | O_NONBLOCK) == -1) \
222 			{ \
223 				/* errno should be set */ \
224 				return SM_IO_EOF; \
225 			} \
226 			(fp)->f_timeoutstate = SM_TIME_NONBLOCK; \
227 			if ((fp)->f_modefp != NULL) \
228 				(fp)->f_modefp->f_timeoutstate = SM_TIME_NONBLOCK; \
229 		} \
230 	} \
231 }
232 
233 /*
234 **  SM_IO_WR_TIMEOUT -- setup the timeout for the write
235 **
236 **  This #define uses a select() to wait for the 'fd' to become writable.
237 **  The select() can be active for up to 'to' time. The select may not
238 **  use all of the the 'to' time. Hence, the amount of "wall-clock" time is
239 **  measured to decide how much to subtract from 'to' to update it. On some
240 **  BSD-based/like systems the timeout for a select is updated for the
241 **  amount of time used. On many/most systems this does not happen. Therefore
242 **  the updating of 'to' must be done ourselves; a copy of 'to' is passed
243 **  since a BSD-like system will have updated it and we don't want to
244 **  double the time used!
245 **  Note: if a valid 'fd' doesn't exist yet, don't use this (e.g. the
246 **  sendmail buffered file type in sendmail/bf.c; see fvwrite.c).
247 **
248 **	Parameters
249 **		fd -- a file descriptor for doing select() with
250 **		timeout -- the original user set value.
251 **
252 **	Returns
253 **		nothing, this is flow through code
254 **
255 **	Side Effects:
256 **		adjusts 'timeout' for time used
257 */
258 
259 #define SM_IO_WR_TIMEOUT(fp, fd, to) { \
260 	struct timeval sm_io_to_before, sm_io_to_after, sm_io_to_diff; \
261 	struct timeval sm_io_to; \
262 	int sm_io_to_sel; \
263 	fd_set sm_io_to_mask, sm_io_x_mask; \
264 	errno = 0; \
265 	if ((to) == SM_TIME_DEFAULT) \
266 		(to) = (fp)->f_timeout; \
267 	if ((to) == SM_TIME_IMMEDIATE) \
268 	{ \
269 		errno = EAGAIN; \
270 		return SM_IO_EOF; \
271 	} \
272 	else if ((to) == SM_TIME_FOREVER) \
273 	{ \
274 		errno = EINVAL; \
275 		return SM_IO_EOF; \
276 	} \
277 	else \
278 	{ \
279 		sm_io_to.tv_sec = (to) / 1000; \
280 		sm_io_to.tv_usec = ((to) - (sm_io_to.tv_sec * 1000)) * 10; \
281 	} \
282 	if (FD_SETSIZE > 0 && (fd) >= FD_SETSIZE) \
283 	{ \
284 		errno = EINVAL; \
285 		return SM_IO_EOF; \
286 	} \
287 	FD_ZERO(&sm_io_to_mask); \
288 	FD_SET((fd), &sm_io_to_mask); \
289 	FD_ZERO(&sm_io_x_mask); \
290 	FD_SET((fd), &sm_io_x_mask); \
291 	if (gettimeofday(&sm_io_to_before, NULL) < 0) \
292 		return SM_IO_EOF; \
293 	sm_io_to_sel = select((fd) + 1, NULL, &sm_io_to_mask, &sm_io_x_mask, \
294 			      &sm_io_to); \
295 	if (sm_io_to_sel < 0) \
296 	{ \
297 		/* something went wrong, errno set */ \
298 		return SM_IO_EOF; \
299 	} \
300 	else if (sm_io_to_sel == 0) \
301 	{ \
302 		/* timeout */ \
303 		errno = EAGAIN; \
304 		return SM_IO_EOF; \
305 	} \
306 	/* else loop again */ \
307 	if (gettimeofday(&sm_io_to_after, NULL) < 0) \
308 		return SM_IO_EOF; \
309 	timersub(&sm_io_to_before, &sm_io_to_after, &sm_io_to_diff); \
310 	timersub(&sm_io_to, &sm_io_to_diff, &sm_io_to); \
311 	(to) -= (sm_io_to.tv_sec * 1000); \
312 	(to) -= (sm_io_to.tv_usec / 10); \
313 	if ((to) < 0) \
314 		(to) = 0; \
315 }
316 
317 /*
318 **  If there is no 'fd' just error (we can't timeout). If the timeout
319 **  is SM_TIME_FOREVER then there is no need to do a timeout with
320 **  select since this will be a real error.  If the error is not
321 **  EAGAIN/EWOULDBLOCK (from a nonblocking) then it's a real error.
322 **  Specify the condition here as macro so it can be used in several places.
323 */
324 
325 #define IS_IO_ERROR(fd, ret, to) \
326 	((fd) < 0 ||	\
327 	 ((ret) < 0 && errno != EAGAIN && errno != EWOULDBLOCK) ||	\
328 	 (to) == SM_TIME_FOREVER)
329 
330