xref: /openbsd-src/usr.bin/mail/fio.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: fio.c,v 1.33 2014/01/17 18:42:30 okan Exp $	*/
2 /*	$NetBSD: fio.c,v 1.8 1997/07/07 22:57:55 phil Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include "rcv.h"
34 #include <sys/file.h>
35 #include <sys/wait.h>
36 
37 #include <unistd.h>
38 #include <paths.h>
39 #include <errno.h>
40 #include "extern.h"
41 
42 /*
43  * Mail -- a mail program
44  *
45  * File I/O.
46  */
47 
48 static volatile sig_atomic_t fiosignal;
49 
50 /*
51  * Wrapper for read() to catch EINTR.
52  */
53 static ssize_t
54 myread(int fd, char *buf, int len)
55 {
56 	ssize_t nread;
57 
58 	while ((nread = read(fd, buf, len)) == -1 && errno == EINTR)
59 		;
60 	return(nread);
61 }
62 
63 /*
64  * Set up the input pointers while copying the mail file into /tmp.
65  */
66 void
67 setptr(FILE *ibuf, off_t offset)
68 {
69 	int c, count;
70 	char *cp, *cp2;
71 	struct message this;
72 	FILE *mestmp;
73 	int maybe, inhead, omsgCount;
74 	char linebuf[LINESIZE], pathbuf[PATHSIZE];
75 
76 	/* Get temporary file. */
77 	(void)snprintf(pathbuf, sizeof(pathbuf), "%s/mail.XXXXXXXXXX", tmpdir);
78 	if ((c = mkstemp(pathbuf)) == -1 || (mestmp = Fdopen(c, "r+")) == NULL)
79 		err(1, "can't open %s", pathbuf);
80 	(void)rm(pathbuf);
81 
82 	if (offset == 0) {
83 		msgCount = 0;
84 	} else {
85 		/* Seek into the file to get to the new messages */
86 		(void)fseeko(ibuf, offset, SEEK_SET);
87 		/*
88 		 * We need to make "offset" a pointer to the end of
89 		 * the temp file that has the copy of the mail file.
90 		 * If any messages have been edited, this will be
91 		 * different from the offset into the mail file.
92 		 */
93 		(void)fseeko(otf, (off_t)0, SEEK_END);
94 		offset = ftell(otf);
95 	}
96 	omsgCount = msgCount;
97 	maybe = 1;
98 	inhead = 0;
99 	this.m_flag = MUSED|MNEW;
100 	this.m_size = 0;
101 	this.m_lines = 0;
102 	this.m_block = 0;
103 	this.m_offset = 0;
104 	for (;;) {
105 		if (fgets(linebuf, sizeof(linebuf), ibuf) == NULL) {
106 			if (append(&this, mestmp))
107 				err(1, "temporary file");
108 			makemessage(mestmp, omsgCount);
109 			return;
110 		}
111 		count = strlen(linebuf);
112 		/*
113 		 * Transforms lines ending in <CR><LF> to just <LF>.
114 		 * This allows mail to be able to read Eudora mailboxes
115 		 * that reside on a DOS partition.
116 		 */
117 		if (count >= 2 && linebuf[count-1] == '\n' &&
118 		    linebuf[count - 2] == '\r') {
119 			linebuf[count - 2] = '\n';
120 			linebuf[count - 1] = '\0';
121 			count--;
122 		}
123 
124 		(void)fwrite(linebuf, sizeof(*linebuf), count, otf);
125 		if (ferror(otf))
126 			err(1, "%s", pathbuf);
127 		if (count && linebuf[count - 1] == '\n')
128 			linebuf[count - 1] = '\0';
129 		if (maybe && linebuf[0] == 'F' && ishead(linebuf)) {
130 			msgCount++;
131 			if (append(&this, mestmp))
132 				err(1, "temporary file");
133 			this.m_flag = MUSED|MNEW;
134 			this.m_size = 0;
135 			this.m_lines = 0;
136 			this.m_block = blockof(offset);
137 			this.m_offset = offsetof(offset);
138 			inhead = 1;
139 		} else if (linebuf[0] == 0) {
140 			inhead = 0;
141 		} else if (inhead) {
142 			for (cp = linebuf, cp2 = "status";; cp++) {
143 				if ((c = (unsigned char)*cp2++) == 0) {
144 					while (isspace(*cp++))
145 						;
146 					if (cp[-1] != ':')
147 						break;
148 					while ((c = (unsigned char)*cp++) != '\0')
149 						if (c == 'R')
150 							this.m_flag |= MREAD;
151 						else if (c == 'O')
152 							this.m_flag &= ~MNEW;
153 					inhead = 0;
154 					break;
155 				}
156 				if (*cp != c && *cp != toupper(c))
157 					break;
158 			}
159 		}
160 		offset += count;
161 		this.m_size += count;
162 		this.m_lines++;
163 		maybe = linebuf[0] == 0;
164 	}
165 }
166 
167 /*
168  * Drop the passed line onto the passed output buffer.
169  * If a write error occurs, return -1, else the count of
170  * characters written, including the newline if requested.
171  */
172 int
173 putline(FILE *obuf, char *linebuf, int outlf)
174 {
175 	int c;
176 
177 	c = strlen(linebuf);
178 	(void)fwrite(linebuf, sizeof(*linebuf), c, obuf);
179 	if (outlf) {
180 		(void)putc('\n', obuf);
181 		c++;
182 	}
183 	if (ferror(obuf))
184 		return(-1);
185 	return(c);
186 }
187 
188 /*
189  * Read up a line from the specified input into the line
190  * buffer.  Return the number of characters read.  Do not
191  * include the newline (or carriage return) at the end.
192  */
193 int
194 readline(FILE *ibuf, char *linebuf, int linesize, int *signo)
195 {
196 	struct sigaction act;
197 	struct sigaction savetstp;
198 	struct sigaction savettou;
199 	struct sigaction savettin;
200 	struct sigaction saveint;
201 	struct sigaction savehup;
202 	sigset_t oset;
203 	int n;
204 
205 	/*
206 	 * Setup signal handlers if the caller asked us to catch signals.
207 	 * Note that we do not restart system calls since we need the
208 	 * read to be interruptible.
209 	 */
210 	if (signo) {
211 		fiosignal = 0;
212 		sigemptyset(&act.sa_mask);
213 		act.sa_flags = 0;
214 		act.sa_handler = fioint;
215 		if (sigaction(SIGINT, NULL, &saveint) == 0 &&
216 		    saveint.sa_handler != SIG_IGN) {
217 			(void)sigaction(SIGINT, &act, &saveint);
218 			(void)sigprocmask(SIG_UNBLOCK, &intset, &oset);
219 		}
220 		if (sigaction(SIGHUP, NULL, &savehup) == 0 &&
221 		    savehup.sa_handler != SIG_IGN)
222 			(void)sigaction(SIGHUP, &act, &savehup);
223 		(void)sigaction(SIGTSTP, &act, &savetstp);
224 		(void)sigaction(SIGTTOU, &act, &savettou);
225 		(void)sigaction(SIGTTIN, &act, &savettin);
226 	}
227 
228 	clearerr(ibuf);
229 	if (fgets(linebuf, linesize, ibuf) == NULL) {
230 		if (ferror(ibuf))
231 			clearerr(ibuf);
232 		n = -1;
233 	} else {
234 		n = strlen(linebuf);
235 		if (n > 0 && linebuf[n - 1] == '\n')
236 			linebuf[--n] = '\0';
237 		if (n > 0 && linebuf[n - 1] == '\r')
238 			linebuf[--n] = '\0';
239 	}
240 
241 	if (signo) {
242 		(void)sigprocmask(SIG_SETMASK, &oset, NULL);
243 		(void)sigaction(SIGINT, &saveint, NULL);
244 		(void)sigaction(SIGHUP, &savehup, NULL);
245 		(void)sigaction(SIGTSTP, &savetstp, NULL);
246 		(void)sigaction(SIGTTOU, &savettou, NULL);
247 		(void)sigaction(SIGTTIN, &savettin, NULL);
248 		*signo = fiosignal;
249 	}
250 
251 	return(n);
252 }
253 
254 /*
255  * Return a file buffer all ready to read up the
256  * passed message pointer.
257  */
258 FILE *
259 setinput(struct message *mp)
260 {
261 
262 	fflush(otf);
263 	if (fseek(itf, (long)positionof(mp->m_block, mp->m_offset), SEEK_SET)
264 	    < 0)
265 		err(1, "fseek");
266 	return(itf);
267 }
268 
269 /*
270  * Take the data out of the passed ghost file and toss it into
271  * a dynamically allocated message structure.
272  */
273 void
274 makemessage(FILE *f, int omsgCount)
275 {
276 	size_t size;
277 	struct message *nmessage;
278 
279 	size = (msgCount + 1) * sizeof(struct message);
280 	nmessage = (struct message *)realloc(message, size);
281 	if (nmessage == 0)
282 		errx(1, "Insufficient memory for %d messages",
283 		    msgCount);
284 	if (omsgCount == 0 || message == NULL)
285 		dot = nmessage;
286 	else
287 		dot = nmessage + (dot - message);
288 	message = nmessage;
289 	size -= (omsgCount + 1) * sizeof(struct message);
290 	fflush(f);
291 	(void)lseek(fileno(f), (off_t)sizeof(*message), SEEK_SET);
292 	if (myread(fileno(f), (void *) &message[omsgCount], size) != size)
293 		errx(1, "Message temporary file corrupted");
294 	message[msgCount].m_size = 0;
295 	message[msgCount].m_lines = 0;
296 	(void)Fclose(f);
297 }
298 
299 /*
300  * Append the passed message descriptor onto the temp file.
301  * If the write fails, return 1, else 0
302  */
303 int
304 append(struct message *mp, FILE *f)
305 {
306 
307 	return(fwrite((char *) mp, sizeof(*mp), 1, f) != 1);
308 }
309 
310 /*
311  * Delete or truncate a file, but only if the file is a plain file.
312  */
313 int
314 rm(char *name)
315 {
316 	struct stat sb;
317 
318 	if (stat(name, &sb) < 0)
319 		return(-1);
320 	if (!S_ISREG(sb.st_mode)) {
321 		errno = EISDIR;
322 		return(-1);
323 	}
324 	if (unlink(name) == -1) {
325 		if (errno == EPERM)
326 			return(truncate(name, (off_t)0));
327 		else
328 			return(-1);
329 	}
330 	return(0);
331 }
332 
333 static int sigdepth;		/* depth of holdsigs() */
334 static sigset_t nset, oset;
335 /*
336  * Hold signals SIGHUP, SIGINT, and SIGQUIT.
337  */
338 void
339 holdsigs(void)
340 {
341 
342 	if (sigdepth++ == 0) {
343 		sigemptyset(&nset);
344 		sigaddset(&nset, SIGHUP);
345 		sigaddset(&nset, SIGINT);
346 		sigaddset(&nset, SIGQUIT);
347 		sigprocmask(SIG_BLOCK, &nset, &oset);
348 	}
349 }
350 
351 /*
352  * Release signals SIGHUP, SIGINT, and SIGQUIT.
353  */
354 void
355 relsesigs(void)
356 {
357 
358 	if (--sigdepth == 0)
359 		sigprocmask(SIG_SETMASK, &oset, NULL);
360 }
361 
362 /*
363  * Unblock and ignore a signal
364  */
365 int
366 ignoresig(int sig, struct sigaction *oact, sigset_t *oset)
367 {
368 	struct sigaction act;
369 	sigset_t nset;
370 	int error;
371 
372 	sigemptyset(&act.sa_mask);
373 	act.sa_flags = SA_RESTART;
374 	act.sa_handler = SIG_IGN;
375 	error = sigaction(sig, &act, oact);
376 
377 	if (error == 0) {
378 		sigemptyset(&nset);
379 		sigaddset(&nset, sig);
380 		(void)sigprocmask(SIG_UNBLOCK, &nset, oset);
381 	} else if (oset != NULL)
382 		(void)sigprocmask(SIG_BLOCK, NULL, oset);
383 
384 	return(error);
385 }
386 
387 /*
388  * Determine the size of the file possessed by
389  * the passed buffer.
390  */
391 off_t
392 fsize(FILE *iob)
393 {
394 	struct stat sbuf;
395 
396 	if (fstat(fileno(iob), &sbuf) < 0)
397 		return(0);
398 	return(sbuf.st_size);
399 }
400 
401 /*
402  * Evaluate the string given as a new mailbox name.
403  * Supported meta characters:
404  *	%	for my system mail box
405  *	%user	for user's system mail box
406  *	#	for previous file
407  *	&	invoker's mbox file
408  *	+file	file in folder directory
409  *	any shell meta character
410  * Return the file name as a dynamic string.
411  */
412 char *
413 expand(char *name)
414 {
415 	char xname[PATHSIZE];
416 	char cmdbuf[PATHSIZE];		/* also used for file names */
417 	pid_t pid;
418 	int l;
419 	char *cp, *shell;
420 	int pivec[2];
421 	struct stat sbuf;
422 	extern int wait_status;
423 
424 	/*
425 	 * The order of evaluation is "%" and "#" expand into constants.
426 	 * "&" can expand into "+".  "+" can expand into shell meta characters.
427 	 * Shell meta characters expand into constants.
428 	 * This way, we make no recursive expansion.
429 	 */
430 	switch (*name) {
431 	case '%':
432 		findmail(name[1] ? name + 1 : myname, xname, sizeof(xname));
433 		return(savestr(xname));
434 	case '#':
435 		if (name[1] != 0)
436 			break;
437 		if (prevfile[0] == 0) {
438 			puts("No previous file");
439 			return(NULL);
440 		}
441 		return(savestr(prevfile));
442 	case '&':
443 		if (name[1] == 0 && (name = value("MBOX")) == NULL)
444 			name = "~/mbox";
445 		/* fall through */
446 	}
447 	if (name[0] == '+' && getfold(cmdbuf, sizeof(cmdbuf)) >= 0) {
448 		(void)snprintf(xname, sizeof(xname), "%s/%s", cmdbuf, name + 1);
449 		name = savestr(xname);
450 	}
451 	/* catch the most common shell meta character */
452 	if (name[0] == '~' && homedir && (name[1] == '/' || name[1] == '\0')) {
453 		(void)snprintf(xname, sizeof(xname), "%s%s", homedir, name + 1);
454 		name = savestr(xname);
455 	}
456 	if (strpbrk(name, "~{[*?$`'\"\\") == NULL)
457 		return(name);
458 	/* XXX - just use glob(3) and env expansion instead? */
459 	if (pipe(pivec) < 0) {
460 		warn("pipe");
461 		return(name);
462 	}
463 	(void)snprintf(cmdbuf, sizeof(cmdbuf), "echo %s", name);
464 	shell = value("SHELL");
465 	pid = start_command(shell, 0, -1, pivec[1], "-c", cmdbuf, NULL);
466 	if (pid < 0) {
467 		(void)close(pivec[0]);
468 		(void)close(pivec[1]);
469 		return(NULL);
470 	}
471 	(void)close(pivec[1]);
472 	l = myread(pivec[0], xname, PATHSIZE);
473 	if (l < 0)
474 		warn("read"); /* report error before errno changes */
475 	(void)close(pivec[0]);
476 	if (wait_child(pid) < 0 && WIFSIGNALED(wait_status) &&
477 	    WTERMSIG(wait_status) != SIGPIPE) {
478 		fprintf(stderr, "\"%s\": Expansion failed.\n", name);
479 		return(NULL);
480 	}
481 	if (l < 0)
482 		return(NULL);
483 	if (l == 0) {
484 		fprintf(stderr, "\"%s\": No match.\n", name);
485 		return(NULL);
486 	}
487 	if (l == PATHSIZE) {
488 		fprintf(stderr, "\"%s\": Expansion buffer overflow.\n", name);
489 		return(NULL);
490 	}
491 	xname[l] = '\0';
492 	for (cp = &xname[l-1]; *cp == '\n' && cp > xname; cp--)
493 		;
494 	cp[1] = '\0';
495 	if (strchr(xname, ' ') && stat(xname, &sbuf) < 0) {
496 		fprintf(stderr, "\"%s\": Ambiguous.\n", name);
497 		return(NULL);
498 	}
499 	return(savestr(xname));
500 }
501 
502 /*
503  * Determine the current folder directory name.
504  */
505 int
506 getfold(char *name, int namelen)
507 {
508 	char *folder;
509 
510 	if ((folder = value("folder")) == NULL)
511 		return(-1);
512 	if (*folder == '/')
513 		strlcpy(name, folder, namelen);
514 	else
515 		(void)snprintf(name, namelen, "%s/%s", homedir ? homedir : ".",
516 		    folder);
517 	return(0);
518 }
519 
520 /*
521  * Return the name of the dead.letter file.
522  */
523 char *
524 getdeadletter(void)
525 {
526 	char *cp;
527 
528 	if ((cp = value("DEAD")) == NULL || (cp = expand(cp)) == NULL)
529 		cp = expand("~/dead.letter");
530 	else if (*cp != '/') {
531 		char buf[PATHSIZE];
532 
533 		(void)snprintf(buf, sizeof(buf), "~/%s", cp);
534 		cp = expand(buf);
535 	}
536 	return(cp);
537 }
538 
539 /*
540  * Signal handler used by readline() to catch SIGINT, SIGHUP, SIGTSTP,
541  * SIGTTOU, SIGTTIN.
542  */
543 void
544 fioint(int s)
545 {
546 
547 	fiosignal = s;
548 }
549