xref: /freebsd/usr.bin/mail/fio.c (revision b51f459a2098622c31ed54f5c1bf0e03efce403b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 #if 0
34 static char sccsid[] = "@(#)fio.c	8.2 (Berkeley) 4/20/95";
35 #endif
36 #endif /* not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include "rcv.h"
41 #include <sys/file.h>
42 #include <sys/wait.h>
43 
44 #include <unistd.h>
45 #include <paths.h>
46 #include <errno.h>
47 #include "extern.h"
48 
49 /*
50  * Mail -- a mail program
51  *
52  * File I/O.
53  */
54 
55 extern int wait_status;
56 
57 /*
58  * Set up the input pointers while copying the mail file into /tmp.
59  */
60 void
61 setptr(FILE *ibuf, off_t offset)
62 {
63 	int c, count;
64 	char *cp, *cp2;
65 	struct message this;
66 	FILE *mestmp;
67 	int maybe, inhead;
68 	char linebuf[LINESIZE], pathbuf[PATHSIZE];
69 	int omsgCount;
70 
71 	/* Get temporary file. */
72 	(void)snprintf(pathbuf, sizeof(pathbuf), "%s/mail.XXXXXXXXXX", tmpdir);
73 	if ((c = mkstemp(pathbuf)) == -1 || (mestmp = Fdopen(c, "r+")) == NULL)
74 		err(1, "can't open %s", pathbuf);
75 	(void)rm(pathbuf);
76 
77 	if (offset == 0) {
78 		 msgCount = 0;
79 	} else {
80 		/* Seek into the file to get to the new messages */
81 		(void)fseeko(ibuf, offset, SEEK_SET);
82 		/*
83 		 * We need to make "offset" a pointer to the end of
84 		 * the temp file that has the copy of the mail file.
85 		 * If any messages have been edited, this will be
86 		 * different from the offset into the mail file.
87 		 */
88 		(void)fseeko(otf, (off_t)0, SEEK_END);
89 		offset = ftello(otf);
90 	}
91 	omsgCount = msgCount;
92 	maybe = 1;
93 	inhead = 0;
94 	this.m_flag = MUSED|MNEW;
95 	this.m_size = 0;
96 	this.m_lines = 0;
97 	this.m_block = 0;
98 	this.m_offset = 0;
99 	for (;;) {
100 		if (fgets(linebuf, sizeof(linebuf), ibuf) == NULL) {
101 			if (append(&this, mestmp))
102 				errx(1, "temporary file");
103 			makemessage(mestmp, omsgCount);
104 			return;
105 		}
106 		count = strlen(linebuf);
107 		/*
108 		 * Transforms lines ending in <CR><LF> to just <LF>.
109 		 * This allows mail to be able to read Eudora mailboxes.
110 		 */
111 		if (count >= 2 && linebuf[count - 1] == '\n' &&
112 		    linebuf[count - 2] == '\r') {
113 			count--;
114 			linebuf[count - 1] = '\n';
115 		}
116 
117 		(void)fwrite(linebuf, sizeof(*linebuf), count, otf);
118 		if (ferror(otf))
119 			errx(1, "/tmp");
120 		if (count)
121 			linebuf[count - 1] = '\0';
122 		if (maybe && linebuf[0] == 'F' && ishead(linebuf)) {
123 			msgCount++;
124 			if (append(&this, mestmp))
125 				errx(1, "temporary file");
126 			this.m_flag = MUSED|MNEW;
127 			this.m_size = 0;
128 			this.m_lines = 0;
129 			this.m_block = blockof(offset);
130 			this.m_offset = boffsetof(offset);
131 			inhead = 1;
132 		} else if (linebuf[0] == 0) {
133 			inhead = 0;
134 		} else if (inhead) {
135 			for (cp = linebuf, cp2 = "status";; cp++) {
136 				if ((c = *cp2++) == '\0') {
137 					while (isspace((unsigned char)*cp++))
138 						;
139 					if (cp[-1] != ':')
140 						break;
141 					while ((c = *cp++) != '\0')
142 						if (c == 'R')
143 							this.m_flag |= MREAD;
144 						else if (c == 'O')
145 							this.m_flag &= ~MNEW;
146 					inhead = 0;
147 					break;
148 				}
149 				if (*cp != c && *cp != toupper((unsigned char)c))
150 					break;
151 			}
152 		}
153 		offset += count;
154 		this.m_size += count;
155 		this.m_lines++;
156 		maybe = linebuf[0] == 0;
157 	}
158 }
159 
160 /*
161  * Drop the passed line onto the passed output buffer.
162  * If a write error occurs, return -1, else the count of
163  * characters written, including the newline if requested.
164  */
165 int
166 putline(FILE *obuf, char *linebuf, int outlf)
167 {
168 	int c;
169 
170 	c = strlen(linebuf);
171 	(void)fwrite(linebuf, sizeof(*linebuf), c, obuf);
172 	if (outlf) {
173 		fprintf(obuf, "\n");
174 		c++;
175 	}
176 	if (ferror(obuf))
177 		return (-1);
178 	return (c);
179 }
180 
181 /*
182  * Read up a line from the specified input into the line
183  * buffer.  Return the number of characters read.  Do not
184  * include the newline (or carriage return) at the end.
185  */
186 int
187 readline(FILE *ibuf, char *linebuf, int linesize)
188 {
189 	int n;
190 
191 	clearerr(ibuf);
192 	if (fgets(linebuf, linesize, ibuf) == NULL)
193 		return (-1);
194 	n = strlen(linebuf);
195 	if (n > 0 && linebuf[n - 1] == '\n')
196 		linebuf[--n] = '\0';
197 	if (n > 0 && linebuf[n - 1] == '\r')
198 		linebuf[--n] = '\0';
199 	return (n);
200 }
201 
202 /*
203  * Return a file buffer all ready to read up the
204  * passed message pointer.
205  */
206 FILE *
207 setinput(struct message *mp)
208 {
209 
210 	(void)fflush(otf);
211 	if (fseeko(itf,
212 		   positionof(mp->m_block, mp->m_offset), SEEK_SET) < 0)
213 		err(1, "fseeko");
214 	return (itf);
215 }
216 
217 /*
218  * Take the data out of the passed ghost file and toss it into
219  * a dynamically allocated message structure.
220  */
221 void
222 makemessage(FILE *f, int omsgCount)
223 {
224 	size_t size;
225 	struct message *nmessage;
226 
227 	size = (msgCount + 1) * sizeof(struct message);
228 	nmessage = (struct message *)realloc(message, size);
229 	if (nmessage == NULL)
230 		errx(1, "Insufficient memory for %d messages\n",
231 		    msgCount);
232 	if (omsgCount == 0 || message == NULL)
233 		dot = nmessage;
234 	else
235 		dot = nmessage + (dot - message);
236 	message = nmessage;
237 	size -= (omsgCount + 1) * sizeof(struct message);
238 	(void)fflush(f);
239 	(void)lseek(fileno(f), (off_t)sizeof(*message), 0);
240 	if (read(fileno(f), (void *)&message[omsgCount], size) != size)
241 		errx(1, "Message temporary file corrupted");
242 	message[msgCount].m_size = 0;
243 	message[msgCount].m_lines = 0;
244 	(void)Fclose(f);
245 }
246 
247 /*
248  * Append the passed message descriptor onto the temp file.
249  * If the write fails, return 1, else 0
250  */
251 int
252 append(struct message *mp, FILE *f)
253 {
254 	return (fwrite((char *)mp, sizeof(*mp), 1, f) != 1);
255 }
256 
257 /*
258  * Delete a file, but only if the file is a plain file.
259  */
260 int
261 rm(char *name)
262 {
263 	struct stat sb;
264 
265 	if (stat(name, &sb) < 0)
266 		return (-1);
267 	if (!S_ISREG(sb.st_mode)) {
268 		errno = EISDIR;
269 		return (-1);
270 	}
271 	return (unlink(name));
272 }
273 
274 static int sigdepth;		/* depth of holdsigs() */
275 static sigset_t nset, oset;
276 /*
277  * Hold signals SIGHUP, SIGINT, and SIGQUIT.
278  */
279 void
280 holdsigs(void)
281 {
282 
283 	if (sigdepth++ == 0) {
284 		(void)sigemptyset(&nset);
285 		(void)sigaddset(&nset, SIGHUP);
286 		(void)sigaddset(&nset, SIGINT);
287 		(void)sigaddset(&nset, SIGQUIT);
288 		(void)sigprocmask(SIG_BLOCK, &nset, &oset);
289 	}
290 }
291 
292 /*
293  * Release signals SIGHUP, SIGINT, and SIGQUIT.
294  */
295 void
296 relsesigs(void)
297 {
298 
299 	if (--sigdepth == 0)
300 		(void)sigprocmask(SIG_SETMASK, &oset, NULL);
301 }
302 
303 /*
304  * Determine the size of the file possessed by
305  * the passed buffer.
306  */
307 off_t
308 fsize(FILE *iob)
309 {
310 	struct stat sbuf;
311 
312 	if (fstat(fileno(iob), &sbuf) < 0)
313 		return (0);
314 	return (sbuf.st_size);
315 }
316 
317 /*
318  * Evaluate the string given as a new mailbox name.
319  * Supported meta characters:
320  *	%	for my system mail box
321  *	%user	for user's system mail box
322  *	#	for previous file
323  *	&	invoker's mbox file
324  *	+file	file in folder directory
325  *	any shell meta character
326  * Return the file name as a dynamic string.
327  */
328 char *
329 expand(char *name)
330 {
331 	char xname[PATHSIZE];
332 	char cmdbuf[PATHSIZE];		/* also used for file names */
333 	int pid, l;
334 	char *cp, *sh;
335 	int pivec[2];
336 	struct stat sbuf;
337 
338 	/*
339 	 * The order of evaluation is "%" and "#" expand into constants.
340 	 * "&" can expand into "+".  "+" can expand into shell meta characters.
341 	 * Shell meta characters expand into constants.
342 	 * This way, we make no recursive expansion.
343 	 */
344 	switch (*name) {
345 	case '%':
346 		findmail(name[1] ? name + 1 : myname, xname, sizeof(xname));
347 		return (savestr(xname));
348 	case '#':
349 		if (name[1] != 0)
350 			break;
351 		if (prevfile[0] == 0) {
352 			printf("No previous file\n");
353 			return (NULL);
354 		}
355 		return (savestr(prevfile));
356 	case '&':
357 		if (name[1] == 0 && (name = value("MBOX")) == NULL)
358 			name = "~/mbox";
359 		/* fall through */
360 	}
361 	if (name[0] == '+' && getfold(cmdbuf, sizeof(cmdbuf)) >= 0) {
362 		(void)snprintf(xname, sizeof(xname), "%s/%s", cmdbuf, name + 1);
363 		name = savestr(xname);
364 	}
365 	/* catch the most common shell meta character */
366 	if (name[0] == '~' && homedir != NULL &&
367 	    (name[1] == '/' || name[1] == '\0')) {
368 		(void)snprintf(xname, sizeof(xname), "%s%s", homedir, name + 1);
369 		name = savestr(xname);
370 	}
371 	if (!strpbrk(name, "~{[*?$`'\"\\"))
372 		return (savestr(name));
373 	if (pipe(pivec) < 0) {
374 		warn("pipe");
375 		return (NULL);
376 	}
377 	(void)snprintf(cmdbuf, sizeof(cmdbuf), "echo %s", name);
378 	if ((sh = value("SHELL")) == NULL)
379 		sh = _PATH_CSHELL;
380 	pid = start_command(sh, 0, -1, pivec[1], "-c", cmdbuf, NULL);
381 	if (pid < 0) {
382 		(void)close(pivec[0]);
383 		(void)close(pivec[1]);
384 		return (NULL);
385 	}
386 	(void)close(pivec[1]);
387 	l = read(pivec[0], xname, BUFSIZ);
388 	(void)close(pivec[0]);
389 	if (wait_child(pid) < 0 && WIFSIGNALED(wait_status) &&
390 	    WTERMSIG(wait_status) != SIGPIPE) {
391 		fprintf(stderr, "\"%s\": Expansion failed.\n", name);
392 		return (NULL);
393 	}
394 	if (l < 0) {
395 		warn("read");
396 		return (NULL);
397 	}
398 	if (l == 0) {
399 		fprintf(stderr, "\"%s\": No match.\n", name);
400 		return (NULL);
401 	}
402 	if (l == BUFSIZ) {
403 		fprintf(stderr, "\"%s\": Expansion buffer overflow.\n", name);
404 		return (NULL);
405 	}
406 	xname[l] = '\0';
407 	for (cp = &xname[l-1]; *cp == '\n' && cp > xname; cp--)
408 		;
409 	cp[1] = '\0';
410 	if (strchr(xname, ' ') && stat(xname, &sbuf) < 0) {
411 		fprintf(stderr, "\"%s\": Ambiguous.\n", name);
412 		return (NULL);
413 	}
414 	return (savestr(xname));
415 }
416 
417 /*
418  * Determine the current folder directory name.
419  */
420 int
421 getfold(char *name, int namelen)
422 {
423 	char *folder;
424 	int copylen;
425 
426 	if ((folder = value("folder")) == NULL)
427 		return (-1);
428 	if (*folder == '/')
429 		copylen = strlcpy(name, folder, namelen);
430 	else
431 		copylen = snprintf(name, namelen, "%s/%s",
432 		    homedir ? homedir : ".", folder);
433 	return (copylen < 0 || copylen >= namelen ? (-1) : (0));
434 }
435 
436 /*
437  * Return the name of the dead.letter file.
438  */
439 char *
440 getdeadletter(void)
441 {
442 	char *cp;
443 
444 	if ((cp = value("DEAD")) == NULL || (cp = expand(cp)) == NULL)
445 		cp = expand("~/dead.letter");
446 	else if (*cp != '/') {
447 		char buf[PATHSIZE];
448 
449 		(void)snprintf(buf, sizeof(buf), "~/%s", cp);
450 		cp = expand(buf);
451 	}
452 	return (cp);
453 }
454