xref: /freebsd/contrib/sendmail/libsm/findfp.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /*
2  * Copyright (c) 2000-2002, 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 
15 #include <sm/gen.h>
16 SM_RCSID("@(#)$Id: findfp.c,v 1.68 2013-11-22 20:51:42 ca Exp $")
17 #include <stdlib.h>
18 #include <unistd.h>
19 #include <sys/param.h>
20 #include <errno.h>
21 #include <string.h>
22 #include <syslog.h>
23 #include <sm/io.h>
24 #include <sm/assert.h>
25 #include <sm/heap.h>
26 #include <sm/string.h>
27 #include <sm/conf.h>
28 #include "local.h"
29 #include "glue.h"
30 
31 bool	Sm_IO_DidInit;	/* IO system has been initialized? */
32 
33 const char SmFileMagic[] = "sm_file";
34 
35 /* An open type to map to fopen()-like behavior */
36 SM_FILE_T SmFtStdio_def =
37     {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
38 	sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
39 	sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
40 	SM_TIME_BLOCK, "stdio" };
41 
42 /* An open type to map to fdopen()-like behavior */
43 SM_FILE_T SmFtStdiofd_def =
44     {SmFileMagic, 0, 0, 0, (SMRW|SMFBF), -1, {0, 0}, 0, 0, 0,
45 	sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,
46 	sm_stdfdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,
47 	SM_TIME_BLOCK, "stdiofd" };
48 
49 /* A string file type */
50 SM_FILE_T SmFtString_def =
51     {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
52 	sm_strclose, sm_strread, sm_strseek, sm_strwrite,
53 	sm_stropen, sm_strsetinfo, sm_strgetinfo, SM_TIME_FOREVER,
54 	SM_TIME_BLOCK, "string" };
55 
56 #if 0
57 /* A file type for syslog communications */
58 SM_FILE_T SmFtSyslog_def =
59     {SmFileMagic, 0, 0, 0, (SMRW|SMNBF), -1, {0, 0}, 0, 0, 0,
60 	sm_syslogclose, sm_syslogread, sm_syslogseek, sm_syslogwrite,
61 	sm_syslogopen, sm_syslogsetinfo, sm_sysloggetinfo, SM_TIME_FOREVER,
62 	SM_TIME_BLOCK, "syslog" };
63 #endif /* 0 */
64 
65 #define NDYNAMIC 10		/* add ten more whenever necessary */
66 
67 #define smio(flags, file, name)						\
68     {SmFileMagic, 0, 0, 0, flags, file, {0}, 0, SmIoF+file, 0,		\
69 	sm_stdclose, sm_stdread, sm_stdseek, sm_stdwrite,		\
70 	sm_stdopen, sm_stdsetinfo, sm_stdgetinfo, SM_TIME_FOREVER,	\
71 	SM_TIME_BLOCK, name}
72 
73 /* sm_magic p r w flags file bf lbfsize cookie ival */
74 #define smstd(flags, file, name)					\
75     {SmFileMagic, 0, 0, 0, flags, -1, {0}, 0, 0, file,			\
76 	sm_stdioclose, sm_stdioread, sm_stdioseek, sm_stdiowrite,	\
77 	sm_stdioopen, sm_stdiosetinfo, sm_stdiogetinfo, SM_TIME_FOREVER,\
78 	SM_TIME_BLOCK, name}
79 
80 /* A file type for interfacing to stdio FILE* streams. */
81 SM_FILE_T SmFtRealStdio_def = smstd(SMRW|SMNBF, -1, "realstdio");
82 
83 				/* the usual - (stdin + stdout + stderr) */
84 static SM_FILE_T usual[SM_IO_OPEN_MAX - 3];
85 static struct sm_glue smuglue = { 0, SM_IO_OPEN_MAX - 3, usual };
86 
87 /* List of builtin automagically already open file pointers */
88 SM_FILE_T SmIoF[6] =
89 {
90 	smio(SMRD|SMLBF, SMIOIN_FILENO, "smioin"),	/* smioin */
91 	smio(SMWR|SMLBF, SMIOOUT_FILENO, "smioout"),	/* smioout */
92 	smio(SMWR|SMNBF, SMIOERR_FILENO, "smioerr"),	/* smioerr */
93 	smstd(SMRD|SMNBF, SMIOIN_FILENO, "smiostdin"),	/* smiostdin */
94 	smstd(SMWR|SMNBF, SMIOOUT_FILENO, "smiostdout"),/* smiostdout */
95 	smstd(SMWR|SMNBF, SMIOERR_FILENO, "smiostderr") /* smiostderr */
96 };
97 
98 /* Structure containing list of currently open file pointers */
99 struct sm_glue smglue = { &smuglue, 3, SmIoF };
100 
101 /*
102 **  SM_MOREGLUE -- adds more space for open file pointers
103 **
104 **	Parameters:
105 **		n -- number of new spaces for file pointers
106 **
107 **	Returns:
108 **		Raises an exception if no more memory.
109 **		Otherwise, returns a pointer to new spaces.
110 */
111 
112 static struct sm_glue *sm_moreglue_x __P((int));
113 static SM_FILE_T empty;
114 
115 static struct sm_glue *
116 sm_moreglue_x(n)
117 	register int n;
118 {
119 	register struct sm_glue *g;
120 	register SM_FILE_T *p;
121 
122 	g = (struct sm_glue *) sm_pmalloc_x(sizeof(*g) + SM_ALIGN_BITS +
123 					    n * sizeof(SM_FILE_T));
124 	p = (SM_FILE_T *) SM_ALIGN(g + 1);
125 	g->gl_next = NULL;
126 	g->gl_niobs = n;
127 	g->gl_iobs = p;
128 	while (--n >= 0)
129 		*p++ = empty;
130 	return g;
131 }
132 
133 /*
134 **  SM_FP -- allocate and initialize an SM_FILE structure
135 **
136 **	Parameters:
137 **		t -- file type requested to be opened.
138 **		flags -- control flags for file type behavior
139 **		oldfp -- file pointer to reuse if available (optional)
140 **
141 **	Returns:
142 **		Raises exception on memory exhaustion.
143 **		Aborts if type is invalid.
144 **		Otherwise, returns file pointer for requested file type.
145 */
146 
147 SM_FILE_T *
148 sm_fp(t, flags, oldfp)
149 	const SM_FILE_T *t;
150 	const int flags;
151 	SM_FILE_T *oldfp;
152 {
153 	register SM_FILE_T *fp;
154 	register int n;
155 	register struct sm_glue *g;
156 
157 	SM_REQUIRE(t->f_open && t->f_close && (t->f_read || t->f_write));
158 
159 	if (!Sm_IO_DidInit)
160 		sm_init();
161 
162 	if (oldfp != NULL)
163 	{
164 		fp = oldfp;
165 		goto found; /* for opening reusing an 'fp' */
166 	}
167 
168 	for (g = &smglue;; g = g->gl_next)
169 	{
170 		for (fp = g->gl_iobs, n = g->gl_niobs; --n >= 0; fp++)
171 			if (fp->sm_magic == NULL)
172 				goto found;
173 		if (g->gl_next == NULL)
174 			g->gl_next = sm_moreglue_x(NDYNAMIC);
175 	}
176 found:
177 	fp->sm_magic = SmFileMagic; /* 'fp' now valid and in-use */
178 	fp->f_p = NULL;		/* no current pointer */
179 	fp->f_w = 0;		/* nothing to write */
180 	fp->f_r = 0;		/* nothing to read */
181 	fp->f_flags = flags;
182 	fp->f_file = -1;		/* no file */
183 	fp->f_bf.smb_base = NULL;	/* no buffer */
184 	fp->f_bf.smb_size = 0;	/* no buffer size with no buffer */
185 	fp->f_lbfsize = 0;	/* not line buffered */
186 	fp->f_flushfp = NULL;	/* no associated flush file */
187 
188 	fp->f_cookie = fp;	/* default: *open* overrides cookie setting */
189 	fp->f_close = t->f_close;	/* assign close function */
190 	fp->f_read = t->f_read;		/* assign read function */
191 	fp->f_seek = t->f_seek;		/* assign seek function */
192 	fp->f_write = t->f_write;	/* assign write function */
193 	fp->f_open = t->f_open;		/* assign open function */
194 	fp->f_setinfo = t->f_setinfo;	/* assign setinfo function */
195 	fp->f_getinfo = t->f_getinfo;	/* assign getinfo function */
196 	fp->f_type = t->f_type;		/* file type */
197 
198 	fp->f_ub.smb_base = NULL;	/* no ungetc buffer */
199 	fp->f_ub.smb_size = 0;		/* no size for no ungetc buffer */
200 
201 	if (fp->f_timeout == SM_TIME_DEFAULT)
202 		fp->f_timeout = SM_TIME_FOREVER;
203 	else
204 		fp->f_timeout = t->f_timeout; /* traditional behavior */
205 	fp->f_timeoutstate = SM_TIME_BLOCK; /* by default */
206 
207 	return fp;
208 }
209 
210 /*
211 **  SM_CLEANUP -- cleanup function when exit called.
212 **
213 **	This function is registered via atexit().
214 **
215 **	Parameters:
216 **		none
217 **
218 **	Returns:
219 **		nothing.
220 **
221 **	Side Effects:
222 **		flushes open files before they are forced closed
223 */
224 
225 void
226 sm_cleanup()
227 {
228 	int timeout = SM_TIME_DEFAULT;
229 
230 	(void) sm_fwalk(sm_flush, &timeout); /* `cheating' */
231 }
232 
233 /*
234 **  SM_INIT -- called whenever sm_io's internal variables must be set up.
235 **
236 **	Parameters:
237 **		none
238 **
239 **	Returns:
240 **		none
241 **
242 **	Side Effects:
243 **		Registers sm_cleanup() using atexit().
244 */
245 
246 void
247 sm_init()
248 {
249 	if (Sm_IO_DidInit)	/* paranoia */
250 		return;
251 
252 	/* more paranoia: initialize pointers in a static variable */
253 	empty.f_type = NULL;
254 	empty.sm_magic = NULL;
255 
256 	/* make sure we clean up on exit */
257 	atexit(sm_cleanup);		/* conservative */
258 	Sm_IO_DidInit = true;
259 }
260 
261 /*
262 **  SM_IO_SETINFO -- change info for an open file type (fp)
263 **
264 **	The generic SM_IO_WHAT_VECTORS is auto supplied for all file types.
265 **	If the request is to set info other than SM_IO_WHAT_VECTORS then
266 **	the request is passed on to the file type's specific setinfo vector.
267 **	WARNING: this is working on an active/open file type.
268 **
269 **	Parameters:
270 **		fp -- file to make the setting on
271 **		what -- type of information to set
272 **		valp -- structure to obtain info from
273 **
274 **	Returns:
275 **		0 on success
276 **		-1 on error and sets errno:
277 **			- when what != SM_IO_WHAT_VECTORS and setinfo vector
278 **				not set
279 **			- when vectored setinfo returns -1
280 */
281 
282 int
283 sm_io_setinfo(fp, what, valp)
284 	SM_FILE_T *fp;
285 	int what;
286 	void *valp;
287 {
288 	SM_FILE_T *v = (SM_FILE_T *) valp;
289 
290 	SM_REQUIRE_ISA(fp, SmFileMagic);
291 	switch (what)
292 	{
293 	  case SM_IO_WHAT_VECTORS:
294 
295 		/*
296 		**  This is the "generic" available for all.
297 		**  This allows the function vectors to be replaced
298 		**  while the file type is active.
299 		*/
300 
301 		fp->f_close = v->f_close;
302 		fp->f_read = v->f_read;
303 		fp->f_seek = v->f_seek;
304 		fp->f_write = v->f_write;
305 		fp->f_open = v->f_open;
306 		fp->f_setinfo = v->f_setinfo;
307 		fp->f_getinfo = v->f_getinfo;
308 		sm_free(fp->f_type);
309 		fp->f_type = sm_strdup_x(v->f_type);
310 		return 0;
311 	  case SM_IO_WHAT_TIMEOUT:
312 		fp->f_timeout = *((int *)valp);
313 		return 0;
314 	}
315 
316 	/* Otherwise the vector will check it out */
317 	if (fp->f_setinfo == NULL)
318 	{
319 		errno = EINVAL;
320 		return -1;
321 	}
322 	else
323 		return (*fp->f_setinfo)(fp, what, valp);
324 }
325 
326 /*
327 **  SM_IO_GETINFO -- get information for an active file type (fp)
328 **
329 **  This function supplies for all file types the answers for the
330 **		three requests SM_IO_WHAT_VECTORS, SM_IO_WHAT_TYPE and
331 **		SM_IO_WHAT_ISTYPE. Other requests are handled by the getinfo
332 **		vector if available for the open file type.
333 **	SM_IO_WHAT_VECTORS returns information for the file pointer vectors.
334 **	SM_IO_WHAT_TYPE returns the type identifier for the file pointer
335 **	SM_IO_WHAT_ISTYPE returns >0 if the passed in type matches the
336 **		file pointer's type.
337 **	SM_IO_IS_READABLE returns 1 if there is data available for reading,
338 **		0 otherwise.
339 **
340 **	Parameters:
341 **		fp -- file pointer for active file type
342 **		what -- type of information request
343 **		valp -- structure to place obtained info into
344 **
345 **	Returns:
346 **		-1 on error and sets errno:
347 **			- when valp==NULL and request expects otherwise
348 **			- when request is not SM_IO_WHAT_VECTORS and not
349 **				SM_IO_WHAT_TYPE and not SM_IO_WHAT_ISTYPE
350 **				and getinfo vector is NULL
351 **			- when getinfo type vector returns -1
352 **		>=0 on success
353 */
354 
355 int
356 sm_io_getinfo(fp, what, valp)
357 	SM_FILE_T *fp;
358 	int what;
359 	void *valp;
360 {
361 	SM_FILE_T *v = (SM_FILE_T *) valp;
362 
363 	SM_REQUIRE_ISA(fp, SmFileMagic);
364 
365 	switch (what)
366 	{
367 	  case SM_IO_WHAT_VECTORS:
368 		if (valp == NULL)
369 		{
370 			errno = EINVAL;
371 			return -1;
372 		}
373 
374 		/* This is the "generic" available for all */
375 		v->f_close = fp->f_close;
376 		v->f_read = fp->f_read;
377 		v->f_seek = fp->f_seek;
378 		v->f_write = fp->f_write;
379 		v->f_open = fp->f_open;
380 		v->f_setinfo = fp->f_setinfo;
381 		v->f_getinfo = fp->f_getinfo;
382 		v->f_type = fp->f_type;
383 		return 0;
384 
385 	  case SM_IO_WHAT_TYPE:
386 		if (valp == NULL)
387 		{
388 			errno = EINVAL;
389 			return -1;
390 		}
391 		valp = sm_strdup_x(fp->f_type);
392 		return 0;
393 
394 	  case SM_IO_WHAT_ISTYPE:
395 		if (valp == NULL)
396 		{
397 			errno = EINVAL;
398 			return -1;
399 		}
400 		return strcmp(fp->f_type, valp) == 0;
401 
402 	  case SM_IO_IS_READABLE:
403 
404 		/* if there is data in the buffer, it must be readable */
405 		if (fp->f_r > 0)
406 			return 1;
407 
408 		/* otherwise query the underlying file */
409 		break;
410 
411 	   case SM_IO_WHAT_TIMEOUT:
412 		*((int *) valp) = fp->f_timeout;
413 		return 0;
414 
415 	  case SM_IO_WHAT_FD:
416 		if (fp->f_file > -1)
417 			return fp->f_file;
418 
419 		/* try the file type specific getinfo to see if it knows */
420 		break;
421 	}
422 
423 	/* Otherwise the vector will check it out */
424 	if (fp->f_getinfo == NULL)
425 	{
426 		errno = EINVAL;
427 		return -1;
428 	}
429 	return (*fp->f_getinfo)(fp, what, valp);
430 }
431