xref: /freebsd/contrib/sendmail/libsm/local.h (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*
2  * Copyright (c) 2000-2002, 2004-2006 Proofpoint, 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 1.59 2013-11-22 20:51:43 ca Exp $
15  */
16 
17 /*
18 **  Information local to this implementation of stdio,
19 **  in particular, macros and private variables.
20 */
21 
22 #include <sm/time.h>
23 #include <sm/fdset.h>
24 #if !SM_CONF_MEMCHR
25 # include <memory.h>
26 #endif /* !SM_CONF_MEMCHR */
27 #include <sm/heap.h>
28 
29 int	sm_flush __P((SM_FILE_T *, int *));
30 SM_FILE_T	*smfp __P((void));
31 int	sm_refill __P((SM_FILE_T *, int));
32 void	sm_init __P((void));
33 void	sm_cleanup __P((void));
34 void	sm_makebuf __P((SM_FILE_T *));
35 int	sm_whatbuf __P((SM_FILE_T *, size_t *, int *));
36 int	sm_fwalk __P((int (*)(SM_FILE_T *, int *), int *));
37 int	sm_wsetup __P((SM_FILE_T *));
38 int	sm_flags __P((int));
39 SM_FILE_T	*sm_fp __P((const SM_FILE_T *, const int, SM_FILE_T *));
40 int	sm_vprintf __P((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 extern bool Sm_IO_DidInit;
80 
81 /* Return true iff the given SM_FILE_T cannot be written now. */
82 #define cantwrite(fp) \
83 	((((fp)->f_flags & SMWR) == 0 || (fp)->f_bf.smb_base == NULL) && \
84 	 sm_wsetup(fp))
85 
86 /*
87 **  Test whether the given stdio file has an active ungetc buffer;
88 **   release such a buffer, without restoring ordinary unread data.
89 */
90 
91 #define HASUB(fp) ((fp)->f_ub.smb_base != NULL)
92 #define FREEUB(fp)					\
93 {							\
94 	if ((fp)->f_ub.smb_base != (fp)->f_ubuf)	\
95 		sm_free((char *)(fp)->f_ub.smb_base);	\
96 	(fp)->f_ub.smb_base = NULL;			\
97 }
98 
99 extern const char SmFileMagic[];
100 
101 #define SM_ALIGN(p)	(((unsigned long)(p) + SM_ALIGN_BITS) & ~SM_ALIGN_BITS)
102 
103 #define sm_io_flockfile(fp)	((void) 0)
104 #define sm_io_funlockfile(fp)	((void) 0)
105 
106 int sm_flags __P((int));
107 
108 #ifndef FDSET_CAST
109 # define FDSET_CAST		/* empty cast for fd_set arg to select */
110 #endif
111 
112 /*
113 **  SM_CONVERT_TIME -- convert the API timeout flag for select() usage.
114 **
115 **	This takes a 'fp' (a file type pointer) and obtains the "raw"
116 **	file descriptor (fd) if possible. The 'fd' is needed to possibly
117 **	switch the mode of the file (blocking/non-blocking) to match
118 **	the type of timeout. If timeout is SM_TIME_FOREVER then the
119 **	timeout using select won't be needed and the file is best placed
120 **	in blocking mode. If there is to be a finite timeout then the file
121 **	is best placed in non-blocking mode. Then, if not enough can be
122 **	written, select() can be used to test when something can be written
123 **	yet still timeout if the wait is too long.
124 **	If the mode is already in the correct state we don't change it.
125 **	Iff (yes "iff") the 'fd' is "-1" in value then the mode change
126 **	will not happen. This situation arises when a late-binding-to-disk
127 **	file type is in use. An example of this is the sendmail buffered
128 **	file type (in sendmail/bf.c).
129 **
130 **	Parameters
131 **		fp -- the file pointer the timeout is for
132 **		fd -- to become the file descriptor value from 'fp'
133 **		val -- the timeout value to be converted
134 **		time -- a struct timeval holding the converted value
135 **
136 **	Returns
137 **		nothing, this is flow-through code
138 **
139 **	Side Effects:
140 **		May or may not change the mode of a currently open file.
141 **		The file mode may be changed to O_NONBLOCK or ~O_NONBLOCK
142 **		(meaning block). This is done to best match the type of
143 **		timeout and for (possible) use with select().
144 */
145 
146 # define SM_CONVERT_TIME(fp, fd, val, time) { \
147 	if (((fd) = sm_io_getinfo(fp, SM_IO_WHAT_FD, NULL)) == -1) \
148 	{ \
149 		/* can't get an fd, likely internal 'fake' fp */ \
150 		errno = 0; \
151 	} \
152 	if ((val) == SM_TIME_DEFAULT) \
153 		(val) = (fp)->f_timeout; \
154 	if ((val) == SM_TIME_IMMEDIATE || (val) == SM_TIME_FOREVER) \
155 	{ \
156 		(time)->tv_sec = 0; \
157 		(time)->tv_usec = 0; \
158 	} \
159 	else \
160 	{ \
161 		(time)->tv_sec = (val) / 1000; \
162 		(time)->tv_usec = ((val) - ((time)->tv_sec * 1000)) * 1000; \
163 	} \
164 	if ((val) == SM_TIME_FOREVER) \
165 	{ \
166 		if ((fp)->f_timeoutstate == SM_TIME_NONBLOCK && (fd) != -1) \
167 		{ \
168 			int ret; \
169 			ret = fcntl((fd), F_GETFL, 0); \
170 			if (ret == -1 || fcntl((fd), F_SETFL, \
171 					       ret & ~O_NONBLOCK) == -1) \
172 			{ \
173 				/* errno should be set */ \
174 				return SM_IO_EOF; \
175 			} \
176 			(fp)->f_timeoutstate = SM_TIME_BLOCK; \
177 			if ((fp)->f_modefp != NULL) \
178 				(fp)->f_modefp->f_timeoutstate = SM_TIME_BLOCK; \
179 		} \
180 	} \
181 	else { \
182 		if ((fp)->f_timeoutstate == SM_TIME_BLOCK && (fd) != -1) \
183 		{ \
184 			int ret; \
185 			ret = fcntl((fd), F_GETFL, 0); \
186 			if (ret == -1 || fcntl((fd), F_SETFL, \
187 					       ret | O_NONBLOCK) == -1) \
188 			{ \
189 				/* errno should be set */ \
190 				return SM_IO_EOF; \
191 			} \
192 			(fp)->f_timeoutstate = SM_TIME_NONBLOCK; \
193 			if ((fp)->f_modefp != NULL) \
194 				(fp)->f_modefp->f_timeoutstate = SM_TIME_NONBLOCK; \
195 		} \
196 	} \
197 }
198 
199 /*
200 **  SM_IO_WR_TIMEOUT -- setup the timeout for the write
201 **
202 **  This #define uses a select() to wait for the 'fd' to become writable.
203 **  The select() can be active for up to 'to' time. The select may not
204 **  use all of the the 'to' time. Hence, the amount of "wall-clock" time is
205 **  measured to decide how much to subtract from 'to' to update it. On some
206 **  BSD-based/like systems the timeout for a select is updated for the
207 **  amount of time used. On many/most systems this does not happen. Therefore
208 **  the updating of 'to' must be done ourselves; a copy of 'to' is passed
209 **  since a BSD-like system will have updated it and we don't want to
210 **  double the time used!
211 **  Note: if a valid 'fd' doesn't exist yet, don't use this (e.g. the
212 **  sendmail buffered file type in sendmail/bf.c; see fvwrite.c).
213 **
214 **	Parameters
215 **		fd -- a file descriptor for doing select() with
216 **		timeout -- the original user set value.
217 **
218 **	Returns
219 **		nothing, this is flow through code
220 **
221 **	Side Effects:
222 **		adjusts 'timeout' for time used
223 */
224 
225 #define SM_IO_WR_TIMEOUT(fp, fd, to) { \
226 	struct timeval sm_io_to_before, sm_io_to_after, sm_io_to_diff; \
227 	struct timeval sm_io_to; \
228 	int sm_io_to_sel; \
229 	fd_set sm_io_to_mask, sm_io_x_mask; \
230 	errno = 0; \
231 	if ((to) == SM_TIME_DEFAULT) \
232 		(to) = (fp)->f_timeout; \
233 	if ((to) == SM_TIME_IMMEDIATE) \
234 	{ \
235 		errno = EAGAIN; \
236 		return SM_IO_EOF; \
237 	} \
238 	else if ((to) == SM_TIME_FOREVER) \
239 	{ \
240 		errno = EINVAL; \
241 		return SM_IO_EOF; \
242 	} \
243 	else \
244 	{ \
245 		sm_io_to.tv_sec = (to) / 1000; \
246 		sm_io_to.tv_usec = ((to) - (sm_io_to.tv_sec * 1000)) * 1000; \
247 	} \
248 	if (!SM_FD_OK_SELECT(fd)) \
249 	{ \
250 		errno = EINVAL; \
251 		return SM_IO_EOF; \
252 	} \
253 	FD_ZERO(&sm_io_to_mask); \
254 	FD_SET((fd), &sm_io_to_mask); \
255 	FD_ZERO(&sm_io_x_mask); \
256 	FD_SET((fd), &sm_io_x_mask); \
257 	if (gettimeofday(&sm_io_to_before, NULL) < 0) \
258 		return SM_IO_EOF; \
259 	do \
260 	{	\
261 		sm_io_to_sel = select((fd) + 1, NULL, &sm_io_to_mask, \
262 					&sm_io_x_mask, &sm_io_to); \
263 	} while (sm_io_to_sel < 0 && errno == EINTR); \
264 	if (sm_io_to_sel < 0) \
265 	{ \
266 		/* something went wrong, errno set */ \
267 		return SM_IO_EOF; \
268 	} \
269 	else if (sm_io_to_sel == 0) \
270 	{ \
271 		/* timeout */ \
272 		errno = EAGAIN; \
273 		return SM_IO_EOF; \
274 	} \
275 	/* else loop again */ \
276 	if (gettimeofday(&sm_io_to_after, NULL) < 0) \
277 		return SM_IO_EOF; \
278 	timersub(&sm_io_to_after, &sm_io_to_before, &sm_io_to_diff); \
279 	(to) -= (sm_io_to_diff.tv_sec * 1000); \
280 	(to) -= (sm_io_to_diff.tv_usec / 1000); \
281 	if ((to) < 0) \
282 		(to) = 0; \
283 }
284 
285 /*
286 **  If there is no 'fd' just error (we can't timeout). If the timeout
287 **  is SM_TIME_FOREVER then there is no need to do a timeout with
288 **  select since this will be a real error.  If the error is not
289 **  EAGAIN/EWOULDBLOCK (from a nonblocking) then it's a real error.
290 **  Specify the condition here as macro so it can be used in several places.
291 */
292 
293 #define IS_IO_ERROR(fd, ret, to) \
294 	((fd) < 0 ||	\
295 	 ((ret) < 0 && errno != EAGAIN && errno != EWOULDBLOCK) ||	\
296 	 (to) == SM_TIME_FOREVER)
297 
298