xref: /freebsd/usr.bin/mail/fio.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 #include "rcv.h"
33 #include <sys/file.h>
34 #include <sys/wait.h>
35 
36 #include <unistd.h>
37 #include <paths.h>
38 #include <errno.h>
39 #include "extern.h"
40 
41 /*
42  * Mail -- a mail program
43  *
44  * File I/O.
45  */
46 
47 extern int wait_status;
48 
49 /*
50  * Set up the input pointers while copying the mail file into /tmp.
51  */
52 void
53 setptr(FILE *ibuf, off_t offset)
54 {
55 	int c, count;
56 	char *cp, *cp2;
57 	struct message this;
58 	FILE *mestmp;
59 	int maybe, inhead;
60 	char linebuf[LINESIZE], pathbuf[PATHSIZE];
61 	int omsgCount;
62 
63 	/* Get temporary file. */
64 	(void)snprintf(pathbuf, sizeof(pathbuf), "%s/mail.XXXXXXXXXX", tmpdir);
65 	if ((c = mkstemp(pathbuf)) == -1 || (mestmp = Fdopen(c, "r+")) == NULL)
66 		err(1, "can't open %s", pathbuf);
67 	(void)rm(pathbuf);
68 
69 	if (offset == 0) {
70 		 msgCount = 0;
71 	} else {
72 		/* Seek into the file to get to the new messages */
73 		(void)fseeko(ibuf, offset, SEEK_SET);
74 		/*
75 		 * We need to make "offset" a pointer to the end of
76 		 * the temp file that has the copy of the mail file.
77 		 * If any messages have been edited, this will be
78 		 * different from the offset into the mail file.
79 		 */
80 		(void)fseeko(otf, (off_t)0, SEEK_END);
81 		offset = ftello(otf);
82 	}
83 	omsgCount = msgCount;
84 	maybe = 1;
85 	inhead = 0;
86 	this.m_flag = MUSED|MNEW;
87 	this.m_size = 0;
88 	this.m_lines = 0;
89 	this.m_block = 0;
90 	this.m_offset = 0;
91 	for (;;) {
92 		if (fgets(linebuf, sizeof(linebuf), ibuf) == NULL) {
93 			if (append(&this, mestmp))
94 				errx(1, "temporary file");
95 			makemessage(mestmp, omsgCount);
96 			return;
97 		}
98 		count = strlen(linebuf);
99 		/*
100 		 * Transforms lines ending in <CR><LF> to just <LF>.
101 		 * This allows mail to be able to read Eudora mailboxes.
102 		 */
103 		if (count >= 2 && linebuf[count - 1] == '\n' &&
104 		    linebuf[count - 2] == '\r') {
105 			count--;
106 			linebuf[count - 1] = '\n';
107 		}
108 
109 		(void)fwrite(linebuf, sizeof(*linebuf), count, otf);
110 		if (ferror(otf))
111 			errx(1, "/tmp");
112 		if (count)
113 			linebuf[count - 1] = '\0';
114 		if (maybe && linebuf[0] == 'F' && ishead(linebuf)) {
115 			msgCount++;
116 			if (append(&this, mestmp))
117 				errx(1, "temporary file");
118 			this.m_flag = MUSED|MNEW;
119 			this.m_size = 0;
120 			this.m_lines = 0;
121 			this.m_block = blockof(offset);
122 			this.m_offset = boffsetof(offset);
123 			inhead = 1;
124 		} else if (linebuf[0] == 0) {
125 			inhead = 0;
126 		} else if (inhead) {
127 			for (cp = linebuf, cp2 = "status";; cp++) {
128 				if ((c = *cp2++) == '\0') {
129 					while (isspace((unsigned char)*cp++))
130 						;
131 					if (cp[-1] != ':')
132 						break;
133 					while ((c = *cp++) != '\0')
134 						if (c == 'R')
135 							this.m_flag |= MREAD;
136 						else if (c == 'O')
137 							this.m_flag &= ~MNEW;
138 					inhead = 0;
139 					break;
140 				}
141 				if (*cp != c && *cp != toupper((unsigned char)c))
142 					break;
143 			}
144 		}
145 		offset += count;
146 		this.m_size += count;
147 		this.m_lines++;
148 		maybe = linebuf[0] == 0;
149 	}
150 }
151 
152 /*
153  * Drop the passed line onto the passed output buffer.
154  * If a write error occurs, return -1, else the count of
155  * characters written, including the newline if requested.
156  */
157 int
158 putline(FILE *obuf, char *linebuf, int outlf)
159 {
160 	int c;
161 
162 	c = strlen(linebuf);
163 	(void)fwrite(linebuf, sizeof(*linebuf), c, obuf);
164 	if (outlf) {
165 		fprintf(obuf, "\n");
166 		c++;
167 	}
168 	if (ferror(obuf))
169 		return (-1);
170 	return (c);
171 }
172 
173 /*
174  * Read up a line from the specified input into the line
175  * buffer.  Return the number of characters read.  Do not
176  * include the newline (or carriage return) at the end.
177  */
178 int
179 readline(FILE *ibuf, char *linebuf, int linesize)
180 {
181 	int n;
182 
183 	clearerr(ibuf);
184 	if (fgets(linebuf, linesize, ibuf) == NULL)
185 		return (-1);
186 	n = strlen(linebuf);
187 	if (n > 0 && linebuf[n - 1] == '\n')
188 		linebuf[--n] = '\0';
189 	if (n > 0 && linebuf[n - 1] == '\r')
190 		linebuf[--n] = '\0';
191 	return (n);
192 }
193 
194 /*
195  * Return a file buffer all ready to read up the
196  * passed message pointer.
197  */
198 FILE *
199 setinput(struct message *mp)
200 {
201 
202 	(void)fflush(otf);
203 	if (fseeko(itf,
204 		   positionof(mp->m_block, mp->m_offset), SEEK_SET) < 0)
205 		err(1, "fseeko");
206 	return (itf);
207 }
208 
209 /*
210  * Take the data out of the passed ghost file and toss it into
211  * a dynamically allocated message structure.
212  */
213 void
214 makemessage(FILE *f, int omsgCount)
215 {
216 	size_t size;
217 	struct message *nmessage;
218 
219 	size = (msgCount + 1) * sizeof(struct message);
220 	nmessage = (struct message *)realloc(message, size);
221 	if (nmessage == NULL)
222 		errx(1, "Insufficient memory for %d messages\n",
223 		    msgCount);
224 	if (omsgCount == 0 || message == NULL)
225 		dot = nmessage;
226 	else
227 		dot = nmessage + (dot - message);
228 	message = nmessage;
229 	size -= (omsgCount + 1) * sizeof(struct message);
230 	(void)fflush(f);
231 	(void)lseek(fileno(f), (off_t)sizeof(*message), 0);
232 	if (read(fileno(f), (void *)&message[omsgCount], size) != size)
233 		errx(1, "Message temporary file corrupted");
234 	message[msgCount].m_size = 0;
235 	message[msgCount].m_lines = 0;
236 	(void)Fclose(f);
237 }
238 
239 /*
240  * Append the passed message descriptor onto the temp file.
241  * If the write fails, return 1, else 0
242  */
243 int
244 append(struct message *mp, FILE *f)
245 {
246 	return (fwrite((char *)mp, sizeof(*mp), 1, f) != 1);
247 }
248 
249 /*
250  * Delete a file, but only if the file is a plain file.
251  */
252 int
253 rm(char *name)
254 {
255 	struct stat sb;
256 
257 	if (stat(name, &sb) < 0)
258 		return (-1);
259 	if (!S_ISREG(sb.st_mode)) {
260 		errno = EISDIR;
261 		return (-1);
262 	}
263 	return (unlink(name));
264 }
265 
266 static int sigdepth;		/* depth of holdsigs() */
267 static sigset_t nset, oset;
268 /*
269  * Hold signals SIGHUP, SIGINT, and SIGQUIT.
270  */
271 void
272 holdsigs(void)
273 {
274 
275 	if (sigdepth++ == 0) {
276 		(void)sigemptyset(&nset);
277 		(void)sigaddset(&nset, SIGHUP);
278 		(void)sigaddset(&nset, SIGINT);
279 		(void)sigaddset(&nset, SIGQUIT);
280 		(void)sigprocmask(SIG_BLOCK, &nset, &oset);
281 	}
282 }
283 
284 /*
285  * Release signals SIGHUP, SIGINT, and SIGQUIT.
286  */
287 void
288 relsesigs(void)
289 {
290 
291 	if (--sigdepth == 0)
292 		(void)sigprocmask(SIG_SETMASK, &oset, NULL);
293 }
294 
295 /*
296  * Determine the size of the file possessed by
297  * the passed buffer.
298  */
299 off_t
300 fsize(FILE *iob)
301 {
302 	struct stat sbuf;
303 
304 	if (fstat(fileno(iob), &sbuf) < 0)
305 		return (0);
306 	return (sbuf.st_size);
307 }
308 
309 /*
310  * Evaluate the string given as a new mailbox name.
311  * Supported meta characters:
312  *	%	for my system mail box
313  *	%user	for user's system mail box
314  *	#	for previous file
315  *	&	invoker's mbox file
316  *	+file	file in folder directory
317  *	any shell meta character
318  * Return the file name as a dynamic string.
319  */
320 char *
321 expand(char *name)
322 {
323 	char xname[PATHSIZE];
324 	char cmdbuf[PATHSIZE];		/* also used for file names */
325 	int pid, l;
326 	char *cp, *sh;
327 	int pivec[2];
328 	struct stat sbuf;
329 
330 	/*
331 	 * The order of evaluation is "%" and "#" expand into constants.
332 	 * "&" can expand into "+".  "+" can expand into shell meta characters.
333 	 * Shell meta characters expand into constants.
334 	 * This way, we make no recursive expansion.
335 	 */
336 	switch (*name) {
337 	case '%':
338 		findmail(name[1] ? name + 1 : myname, xname, sizeof(xname));
339 		return (savestr(xname));
340 	case '#':
341 		if (name[1] != 0)
342 			break;
343 		if (prevfile[0] == 0) {
344 			printf("No previous file\n");
345 			return (NULL);
346 		}
347 		return (savestr(prevfile));
348 	case '&':
349 		if (name[1] == 0 && (name = value("MBOX")) == NULL)
350 			name = "~/mbox";
351 		/* fall through */
352 	}
353 	if (name[0] == '+' && getfold(cmdbuf, sizeof(cmdbuf)) >= 0) {
354 		(void)snprintf(xname, sizeof(xname), "%s/%s", cmdbuf, name + 1);
355 		name = savestr(xname);
356 	}
357 	/* catch the most common shell meta character */
358 	if (name[0] == '~' && homedir != NULL &&
359 	    (name[1] == '/' || name[1] == '\0')) {
360 		(void)snprintf(xname, sizeof(xname), "%s%s", homedir, name + 1);
361 		name = savestr(xname);
362 	}
363 	if (!strpbrk(name, "~{[*?$`'\"\\"))
364 		return (savestr(name));
365 	if (pipe(pivec) < 0) {
366 		warn("pipe");
367 		return (NULL);
368 	}
369 	(void)snprintf(cmdbuf, sizeof(cmdbuf), "echo %s", name);
370 	if ((sh = value("SHELL")) == NULL)
371 		sh = _PATH_CSHELL;
372 	pid = start_command(sh, 0, -1, pivec[1], "-c", cmdbuf, NULL);
373 	if (pid < 0) {
374 		(void)close(pivec[0]);
375 		(void)close(pivec[1]);
376 		return (NULL);
377 	}
378 	(void)close(pivec[1]);
379 	l = read(pivec[0], xname, BUFSIZ);
380 	(void)close(pivec[0]);
381 	if (wait_child(pid) < 0 && WIFSIGNALED(wait_status) &&
382 	    WTERMSIG(wait_status) != SIGPIPE) {
383 		fprintf(stderr, "\"%s\": Expansion failed.\n", name);
384 		return (NULL);
385 	}
386 	if (l < 0) {
387 		warn("read");
388 		return (NULL);
389 	}
390 	if (l == 0) {
391 		fprintf(stderr, "\"%s\": No match.\n", name);
392 		return (NULL);
393 	}
394 	if (l == BUFSIZ) {
395 		fprintf(stderr, "\"%s\": Expansion buffer overflow.\n", name);
396 		return (NULL);
397 	}
398 	xname[l] = '\0';
399 	for (cp = &xname[l-1]; *cp == '\n' && cp > xname; cp--)
400 		;
401 	cp[1] = '\0';
402 	if (strchr(xname, ' ') && stat(xname, &sbuf) < 0) {
403 		fprintf(stderr, "\"%s\": Ambiguous.\n", name);
404 		return (NULL);
405 	}
406 	return (savestr(xname));
407 }
408 
409 /*
410  * Determine the current folder directory name.
411  */
412 int
413 getfold(char *name, int namelen)
414 {
415 	char *folder;
416 	int copylen;
417 
418 	if ((folder = value("folder")) == NULL)
419 		return (-1);
420 	if (*folder == '/')
421 		copylen = strlcpy(name, folder, namelen);
422 	else
423 		copylen = snprintf(name, namelen, "%s/%s",
424 		    homedir ? homedir : ".", folder);
425 	return (copylen < 0 || copylen >= namelen ? (-1) : (0));
426 }
427 
428 /*
429  * Return the name of the dead.letter file.
430  */
431 char *
432 getdeadletter(void)
433 {
434 	char *cp;
435 
436 	if ((cp = value("DEAD")) == NULL || (cp = expand(cp)) == NULL)
437 		cp = expand("~/dead.letter");
438 	else if (*cp != '/') {
439 		char buf[PATHSIZE];
440 
441 		(void)snprintf(buf, sizeof(buf), "~/%s", cp);
442 		cp = expand(buf);
443 	}
444 	return (cp);
445 }
446