xref: /titanic_51/usr/src/cmd/sendmail/libsm/local.h (revision 5aefb6555731130ca4fd295960123d71f2d21fe8)
1 /*
2  * Copyright (c) 2000-2002, 2004 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 1.54 2005/06/14 23:07:20 ca Exp $
15  */
16 
17 #pragma ident	"%Z%%M%	%I%	%E% SMI"
18 
19 /*
20 **  Information local to this implementation of stdio,
21 **  in particular, macros and private variables.
22 */
23 
24 #include <sm/time.h>
25 #if !SM_CONF_MEMCHR
26 # include <memory.h>
27 #endif /* !SM_CONF_MEMCHR */
28 #include <sm/heap.h>
29 
30 int	sm_flush __P((SM_FILE_T *, int *));
31 SM_FILE_T	*smfp __P((void));
32 int	sm_refill __P((SM_FILE_T *, int));
33 void	sm_init __P((void));
34 void	sm_cleanup __P((void));
35 void	sm_makebuf __P((SM_FILE_T *));
36 int	sm_whatbuf __P((SM_FILE_T *, size_t *, int *));
37 int	sm_fwalk __P((int (*)(SM_FILE_T *, int *), int *));
38 int	sm_wsetup __P((SM_FILE_T *));
39 int	sm_flags __P((int));
40 SM_FILE_T	*sm_fp __P((const SM_FILE_T *, const int, SM_FILE_T *));
41 int	sm_vprintf __P((int, char const *, va_list));
42 
43 /* std io functions */
44 ssize_t	sm_stdread __P((SM_FILE_T *, char *, size_t));
45 ssize_t	sm_stdwrite __P((SM_FILE_T *, char const *, size_t));
46 off_t	sm_stdseek __P((SM_FILE_T *, off_t, int));
47 int	sm_stdclose __P((SM_FILE_T *));
48 int	sm_stdopen __P((SM_FILE_T *, const void *, int, const void *));
49 int	sm_stdfdopen __P((SM_FILE_T *, const void *, int, const void *));
50 int	sm_stdsetinfo __P((SM_FILE_T *, int , void *));
51 int	sm_stdgetinfo __P((SM_FILE_T *, int , void *));
52 
53 /* stdio io functions */
54 ssize_t	sm_stdioread __P((SM_FILE_T *, char *, size_t));
55 ssize_t	sm_stdiowrite __P((SM_FILE_T *, char const *, size_t));
56 off_t	sm_stdioseek __P((SM_FILE_T *, off_t, int));
57 int	sm_stdioclose __P((SM_FILE_T *));
58 int	sm_stdioopen __P((SM_FILE_T *, const void *, int, const void *));
59 int	sm_stdiosetinfo __P((SM_FILE_T *, int , void *));
60 int	sm_stdiogetinfo __P((SM_FILE_T *, int , void *));
61 
62 /* string io functions */
63 ssize_t	sm_strread __P((SM_FILE_T *, char *, size_t));
64 ssize_t	sm_strwrite __P((SM_FILE_T *, char const *, size_t));
65 off_t	sm_strseek __P((SM_FILE_T *, off_t, int));
66 int	sm_strclose __P((SM_FILE_T *));
67 int	sm_stropen __P((SM_FILE_T *, const void *, int, const void *));
68 int	sm_strsetinfo __P((SM_FILE_T *, int , void *));
69 int	sm_strgetinfo __P((SM_FILE_T *, int , void *));
70 
71 /* syslog io functions */
72 ssize_t	sm_syslogread __P((SM_FILE_T *, char *, size_t));
73 ssize_t	sm_syslogwrite __P((SM_FILE_T *, char const *, size_t));
74 off_t	sm_syslogseek __P((SM_FILE_T *, off_t, int));
75 int	sm_syslogclose __P((SM_FILE_T *));
76 int	sm_syslogopen __P((SM_FILE_T *, const void *, int, const void *));
77 int	sm_syslogsetinfo __P((SM_FILE_T *, int , void *));
78 int	sm_sysloggetinfo __P((SM_FILE_T *, int , void *));
79 
80 extern bool Sm_IO_DidInit;
81 
82 /* Return true iff the given SM_FILE_T cannot be written now. */
83 #define cantwrite(fp) \
84 	((((fp)->f_flags & SMWR) == 0 || (fp)->f_bf.smb_base == NULL) && \
85 	 sm_wsetup(fp))
86 
87 /*
88 **  Test whether the given stdio file has an active ungetc buffer;
89 **   release such a buffer, without restoring ordinary unread data.
90 */
91 
92 #define HASUB(fp) ((fp)->f_ub.smb_base != NULL)
93 #define FREEUB(fp)					\
94 {							\
95 	if ((fp)->f_ub.smb_base != (fp)->f_ubuf)	\
96 		sm_free((char *)(fp)->f_ub.smb_base);	\
97 	(fp)->f_ub.smb_base = NULL;			\
98 }
99 
100 extern const char SmFileMagic[];
101 
102 #define SM_ALIGN(p)	(((unsigned long)(p) + SM_ALIGN_BITS) & ~SM_ALIGN_BITS)
103 
104 #define sm_io_flockfile(fp)	((void) 0)
105 #define sm_io_funlockfile(fp)	((void) 0)
106 
107 #ifndef FDSET_CAST
108 # define FDSET_CAST		/* empty cast for fd_set arg to select */
109 #endif
110 
111 /*
112 **  SM_CONVERT_TIME -- convert the API timeout flag for select() usage.
113 **
114 **	This takes a 'fp' (a file type pointer) and obtains the "raw"
115 **	file descriptor (fd) if possible. The 'fd' is needed to possibly
116 **	switch the mode of the file (blocking/non-blocking) to match
117 **	the type of timeout. If timeout is SM_TIME_FOREVER then the
118 **	timeout using select won't be needed and the file is best placed
119 **	in blocking mode. If there is to be a finite timeout then the file
120 **	is best placed in non-blocking mode. Then, if not enough can be
121 **	written, select() can be used to test when something can be written
122 **	yet still timeout if the wait is too long.
123 **	If the mode is already in the correct state we don't change it.
124 **	Iff (yes "iff") the 'fd' is "-1" in value then the mode change
125 **	will not happen. This situation arises when a late-binding-to-disk
126 **	file type is in use. An example of this is the sendmail buffered
127 **	file type (in sendmail/bf.c).
128 **
129 **	Parameters
130 **		fp -- the file pointer the timeout is for
131 **		fd -- to become the file descriptor value from 'fp'
132 **		val -- the timeout value to be converted
133 **		time -- a struct timeval holding the converted value
134 **
135 **	Returns
136 **		nothing, this is flow-through code
137 **
138 **	Side Effects:
139 **		May or may not change the mode of a currently open file.
140 **		The file mode may be changed to O_NONBLOCK or ~O_NONBLOCK
141 **		(meaning block). This is done to best match the type of
142 **		timeout and for (possible) use with select().
143 */
144 
145 # define SM_CONVERT_TIME(fp, fd, val, time) { \
146 	if (((fd) = sm_io_getinfo(fp, SM_IO_WHAT_FD, NULL)) == -1) \
147 	{ \
148 		/* can't get an fd, likely internal 'fake' fp */ \
149 		errno = 0; \
150 	} \
151 	if ((val) == SM_TIME_DEFAULT) \
152 		(val) = (fp)->f_timeout; \
153 	if ((val) == SM_TIME_IMMEDIATE || (val) == SM_TIME_FOREVER) \
154 	{ \
155 		(time)->tv_sec = 0; \
156 		(time)->tv_usec = 0; \
157 	} \
158 	else \
159 	{ \
160 		(time)->tv_sec = (val) / 1000; \
161 		(time)->tv_usec = ((val) - ((time)->tv_sec * 1000)) * 10; \
162 	} \
163 	if ((val) == SM_TIME_FOREVER) \
164 	{ \
165 		if ((fp)->f_timeoutstate == SM_TIME_NONBLOCK && (fd) != -1) \
166 		{ \
167 			int ret; \
168 			ret = fcntl((fd), F_GETFL, 0); \
169 			if (ret == -1 || fcntl((fd), F_SETFL, \
170 					       ret & ~O_NONBLOCK) == -1) \
171 			{ \
172 				/* errno should be set */ \
173 				return SM_IO_EOF; \
174 			} \
175 			(fp)->f_timeoutstate = SM_TIME_BLOCK; \
176 			if ((fp)->f_modefp != NULL) \
177 				(fp)->f_modefp->f_timeoutstate = SM_TIME_BLOCK; \
178 		} \
179 	} \
180 	else { \
181 		if ((fp)->f_timeoutstate == SM_TIME_BLOCK && (fd) != -1) \
182 		{ \
183 			int ret; \
184 			ret = fcntl((fd), F_GETFL, 0); \
185 			if (ret == -1 || fcntl((fd), F_SETFL, \
186 					       ret | O_NONBLOCK) == -1) \
187 			{ \
188 				/* errno should be set */ \
189 				return SM_IO_EOF; \
190 			} \
191 			(fp)->f_timeoutstate = SM_TIME_NONBLOCK; \
192 			if ((fp)->f_modefp != NULL) \
193 				(fp)->f_modefp->f_timeoutstate = SM_TIME_NONBLOCK; \
194 		} \
195 	} \
196 }
197 
198 /*
199 **  SM_IO_WR_TIMEOUT -- setup the timeout for the write
200 **
201 **  This #define uses a select() to wait for the 'fd' to become writable.
202 **  The select() can be active for up to 'to' time. The select may not
203 **  use all of the the 'to' time. Hence, the amount of "wall-clock" time is
204 **  measured to decide how much to subtract from 'to' to update it. On some
205 **  BSD-based/like systems the timeout for a select is updated for the
206 **  amount of time used. On many/most systems this does not happen. Therefore
207 **  the updating of 'to' must be done ourselves; a copy of 'to' is passed
208 **  since a BSD-like system will have updated it and we don't want to
209 **  double the time used!
210 **  Note: if a valid 'fd' doesn't exist yet, don't use this (e.g. the
211 **  sendmail buffered file type in sendmail/bf.c; see fvwrite.c).
212 **
213 **	Parameters
214 **		fd -- a file descriptor for doing select() with
215 **		timeout -- the original user set value.
216 **
217 **	Returns
218 **		nothing, this is flow through code
219 **
220 **	Side Effects:
221 **		adjusts 'timeout' for time used
222 */
223 
224 #define SM_IO_WR_TIMEOUT(fp, fd, to) { \
225 	struct timeval sm_io_to_before, sm_io_to_after, sm_io_to_diff; \
226 	struct timeval sm_io_to; \
227 	int sm_io_to_sel; \
228 	fd_set sm_io_to_mask, sm_io_x_mask; \
229 	errno = 0; \
230 	if ((to) == SM_TIME_DEFAULT) \
231 		(to) = (fp)->f_timeout; \
232 	if ((to) == SM_TIME_IMMEDIATE) \
233 	{ \
234 		errno = EAGAIN; \
235 		return SM_IO_EOF; \
236 	} \
237 	else if ((to) == SM_TIME_FOREVER) \
238 	{ \
239 		errno = EINVAL; \
240 		return SM_IO_EOF; \
241 	} \
242 	else \
243 	{ \
244 		sm_io_to.tv_sec = (to) / 1000; \
245 		sm_io_to.tv_usec = ((to) - (sm_io_to.tv_sec * 1000)) * 10; \
246 	} \
247 	if (FD_SETSIZE > 0 && (fd) >= FD_SETSIZE) \
248 	{ \
249 		errno = EINVAL; \
250 		return SM_IO_EOF; \
251 	} \
252 	FD_ZERO(&sm_io_to_mask); \
253 	FD_SET((fd), &sm_io_to_mask); \
254 	FD_ZERO(&sm_io_x_mask); \
255 	FD_SET((fd), &sm_io_x_mask); \
256 	if (gettimeofday(&sm_io_to_before, NULL) < 0) \
257 		return SM_IO_EOF; \
258 	sm_io_to_sel = select((fd) + 1, NULL, &sm_io_to_mask, &sm_io_x_mask, \
259 			      &sm_io_to); \
260 	if (sm_io_to_sel < 0) \
261 	{ \
262 		/* something went wrong, errno set */ \
263 		return SM_IO_EOF; \
264 	} \
265 	else if (sm_io_to_sel == 0) \
266 	{ \
267 		/* timeout */ \
268 		errno = EAGAIN; \
269 		return SM_IO_EOF; \
270 	} \
271 	/* else loop again */ \
272 	if (gettimeofday(&sm_io_to_after, NULL) < 0) \
273 		return SM_IO_EOF; \
274 	timersub(&sm_io_to_before, &sm_io_to_after, &sm_io_to_diff); \
275 	timersub(&sm_io_to, &sm_io_to_diff, &sm_io_to); \
276 	(to) -= (sm_io_to.tv_sec * 1000); \
277 	(to) -= (sm_io_to.tv_usec / 10); \
278 	if ((to) < 0) \
279 		(to) = 0; \
280 }
281 
282 /*
283 **  If there is no 'fd' just error (we can't timeout). If the timeout
284 **  is SM_TIME_FOREVER then there is no need to do a timeout with
285 **  select since this will be a real error.  If the error is not
286 **  EAGAIN/EWOULDBLOCK (from a nonblocking) then it's a real error.
287 **  Specify the condition here as macro so it can be used in several places.
288 */
289 
290 #define IS_IO_ERROR(fd, ret, to) \
291 	((fd) < 0 ||	\
292 	 ((ret) < 0 && errno != EAGAIN && errno != EWOULDBLOCK) ||	\
293 	 (to) == SM_TIME_FOREVER)
294 
295