xref: /netbsd-src/usr.bin/mail/mime_decode.c (revision ce099b40997c43048fb78bd578195f81d2456523)
1 /*	$NetBSD: mime_decode.c,v 1.13 2008/04/28 20:24:14 martin Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Anon Ymous.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 
33 #ifdef MIME_SUPPORT
34 
35 #include <sys/cdefs.h>
36 #ifndef __lint__
37 __RCSID("$NetBSD: mime_decode.c,v 1.13 2008/04/28 20:24:14 martin Exp $");
38 #endif /* not __lint__ */
39 
40 #include <assert.h>
41 #include <err.h>
42 #include <fcntl.h>
43 #include <libgen.h>
44 #include <setjmp.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <iconv.h>
51 
52 #include "def.h"
53 #include "extern.h"
54 #ifdef USE_EDITLINE
55 #include "complete.h"
56 #endif
57 #ifdef MIME_SUPPORT
58 #include "mime.h"
59 #include "mime_child.h"
60 #include "mime_codecs.h"
61 #include "mime_header.h"
62 #include "mime_detach.h"
63 #endif
64 #include "glob.h"
65 #include "thread.h"
66 
67 #if 0
68 #ifndef __lint__
69 /*
70  * XXX - This block for debugging only and eventually should go away.
71  */
72 static void
73 show_one_mime_info(FILE *fp, struct mime_info *mip)
74 {
75 #define XX(a) (a) ? (a) : "<null>"
76 
77 	(void)fprintf(fp, ">> --------\n");
78 	(void)fprintf(fp, "mip %d:\n", mip->mi_partnum);
79 	(void)fprintf(fp, "** Version: %s\n",  XX(mip->mi_version));
80 	(void)fprintf(fp, "** type: %s\n",     XX(mip->mi_type));
81 	(void)fprintf(fp, "** subtype: %s\n",  XX(mip->mi_subtype));
82 	(void)fprintf(fp, "** boundary: %s\n", XX(mip->mi_boundary));
83 	(void)fprintf(fp, "** charset: %s\n",  XX(mip->mi_charset));
84 	(void)fprintf(fp, "** encoding: %s\n", XX(mip->mi_encoding));
85 	(void)fprintf(fp, "** disposition: %s\n", XX(mip->mi_disposition));
86 	(void)fprintf(fp, "** filename: %s\n", XX(mip->mi_filename));
87 	(void)fprintf(fp, "** %p: flag: 0x%x, block: %ld, offset: %d, size: %lld, lines: %ld:%ld\n",
88 	    mip->mp,
89 	    mip->mp->m_flag,
90 	    mip->mp->m_block, mip->mp->m_offset, mip->mp->m_size,
91 	    mip->mp->m_lines, mip->mp->m_blines);
92 	(void)fprintf(fp, "** mip: %p\n", mip);
93 	(void)fprintf(fp, "** mi_flink: %p\n", mip->mi_flink);
94 	(void)fprintf(fp, "** mi_blink: %p\n", mip->mi_blink);
95 	(void)fprintf(fp, "** mip %p, mp %p,  parent_mip %p, parent_mp %p\n",
96 	    mip, mip->mp, mip->mi_parent.mip, mip->mi_parent.mp);
97 
98 	(void)fprintf(fp, "** mi_fo %p, mi_head_end %p, mi_pipe_end %p\n",
99 	    mip->mi_fo, mip->mi_head_end, mip->mi_pipe_end);
100 
101 	(void)fprintf(fp, "** mi_ignore_body: %d\n", mip->mi_ignore_body);
102 	(void)fprintf(fp, "** mi_partnum: %d\n", mip->mi_partnum);
103 	(void)fprintf(fp, "** mi_partstr: %s\n", mip->mi_partstr);
104 	(void)fprintf(fp, "** mi_msgstr: %s\n", mip->mi_msgstr);
105 
106 	(void)fflush(fp);
107 
108 #undef XX
109 }
110 
111 __unused
112 static void
113 show_mime_info(FILE *fp, struct mime_info *mip, struct mime_info *end_mip)
114 {
115 	for (/* EMTPY */; mip != end_mip; mip = mip->mi_flink)
116 		show_one_mime_info(fp, mip);
117 
118 	(void)fprintf(fp, "++ =========\n");
119 	(void)fflush(fp);
120 }
121 #endif /* __lint__ */
122 #endif /* #if */
123 
124 
125 /*
126  * Our interface to the file registry in popen.c
127  */
128 PUBLIC FILE *
129 pipe_end(struct mime_info *mip)
130 {
131 	FILE *fp;
132 	fp = last_registered_file(0);	/* get last registered file or pipe */
133 	if (fp == NULL)
134 		fp = mip->mi_fo;
135 	return fp;
136 }
137 
138 /*
139  * Copy the first ';' delimited substring from 'src' (null terminated)
140  * into 'dst', expanding quotes and removing comments (as per RFC
141  * 822).  Returns a pointer in src to the next non-white character
142  * following ';'.  The caller is responsible for ensuring 'dst' is
143  * sufficiently large to hold the result.
144  */
145 static char *
146 get_param(char *dst, char *src)
147 {
148 	char *lastq;
149 	char *cp;
150 	char *cp2;
151 	int nesting;
152 
153 	cp2 = dst;
154 	lastq = dst;
155 	for (cp = src; *cp && *cp != ';'; cp++) {
156 		switch (*cp) {
157 		case '"':	/* start of quoted string */
158 			for (cp++; *cp; cp++) {
159 				if (*cp == '"')
160 					break;
161 				if (*cp == '\\' && cp[1] != '\0')
162 					++cp;
163 				*cp2++ = *cp;
164 			}
165 			lastq = cp2-1;
166 			break;
167 		case '(':	/* start of comment */
168 			nesting = 1;
169 			while (nesting > 0 && *++cp) {
170 				if (*cp == '\\' && cp[1] != '\0')
171 					cp++;
172 				if (*cp == '(')
173 					nesting++;
174 				if (*cp == ')')
175 					nesting--;
176 			}
177 			break;
178 		default:
179 			*cp2++ = *cp;
180 			break;
181 		}
182 	}
183 	/* remove trailing white space */
184 	while (cp2 > lastq && is_WSP(cp2[-1]))
185 		cp2--;
186 	*cp2 = '\0';
187 	if (*cp == ';')
188 		cp++;
189 	cp = skip_WSP(cp);
190 	return cp;
191 }
192 
193 /*
194  * Content parameter
195  *    if field is NULL, return the content "specifier".
196  */
197 static char*
198 cparam(const char field[], char *src, int downcase)
199 {
200 	char *cp;
201 	char *dst;
202 
203 	if (src == NULL)
204 		return NULL;
205 
206 	dst = salloc(strlen(src) + 1); /* large enough for any param in src */
207 	cp = skip_WSP(src);
208 	cp = get_param(dst, cp);
209 
210 	if (field == NULL)
211 		return dst;
212 
213 	while (*cp != '\0') {
214 		size_t len = strlen(field);
215 		cp = get_param(dst, cp);
216 		if (strncasecmp(dst, field, len) == 0 && dst[len] == '=') {
217 			char *cp2;
218 			cp2 = dst + len + 1;
219 			if (downcase)
220 				istrcpy(cp2, cp2);
221 			return cp2;
222 		}
223 	}
224 	return NULL;
225 }
226 
227 
228 static void
229 get_content(struct mime_info *mip)
230 {
231 	char *mime_disposition_field;
232 	char *mime_type_field;
233 	char *filename;
234 	struct message *mp;
235 	char *cp;
236 
237 	mp = mip->mp;
238 	mip->mi_version  = cparam(NULL, hfield(MIME_HDR_VERSION,  mp), 0);
239 	mip->mi_encoding = cparam(NULL, hfield(MIME_HDR_ENCODING, mp), 1);
240 
241 	mime_type_field = hfield(MIME_HDR_TYPE, mp);
242 	mip->mi_type = cparam(NULL, mime_type_field, 1);
243 	if (mip->mi_type) {
244 		cp = strchr(mip->mi_type, '/');
245 		if (cp)
246 			*cp++ = '\0';
247 		mip->mi_subtype = cp;
248 	}
249 	mip->mi_boundary = cparam("boundary", mime_type_field, 0);
250 	mip->mi_charset  = cparam("charset",  mime_type_field, 1);
251 
252 	mime_disposition_field = hfield(MIME_HDR_DISPOSITION, mp);
253 	mip->mi_disposition = cparam(NULL, mime_disposition_field, 1);
254 	/*
255 	 * The type field typically has a "name" parameter for "image"
256 	 * and "video" types, and I assume for other types as well.
257 	 * We grab it, but override it if the disposition field has a
258 	 * filename parameter as it often does for "attachments".
259 	 * More careful analysis could be done, but this seems to work
260 	 * pretty well.
261 	 */
262 	filename = cparam("name", mime_type_field, 0);
263 	if ((cp = cparam("filename", mime_disposition_field, 0)) != NULL)
264 		filename = cp;
265 	if (filename) {
266 		filename = basename(filename);	/* avoid absolute pathnames */
267 		filename = savestr(filename);	/* save it! */
268 	}
269 	mip->mi_filename = filename;
270 }
271 
272 
273 static struct message *
274 salloc_message(int flag, long block, short offset)
275 {
276 	struct message *mp;
277 	/* use csalloc in case someone adds a field someday! */
278 	mp = csalloc(1, sizeof(*mp));
279 	mp->m_flag   = flag;
280 	mp->m_block  = block;
281 	mp->m_offset = offset;
282 #if 0
283 	mp->m_lines  = 0;
284 	mp->m_size   = 0;
285 	mp->m_blines = 0;
286 #endif
287 	return mp;
288 }
289 
290 static struct mime_info *
291 insert_new_mip(struct mime_info *this_mip, struct mime_info *top_mip,
292     struct message *top_mp, off_t end_pos, int partnum)
293 {
294 	struct mime_info *new_mip;
295 
296 	new_mip = csalloc(1, sizeof(*new_mip));
297 	new_mip->mi_blink = this_mip;
298 	new_mip->mi_flink = this_mip->mi_flink;
299 	this_mip->mi_flink = new_mip;
300 
301 	new_mip->mp = salloc_message(this_mip->mp->m_flag,
302 	    (long)blockof(end_pos), blkoffsetof(end_pos));
303 
304 	new_mip->mi_parent.mip = top_mip;
305 	new_mip->mi_parent.mp = top_mp;
306 	new_mip->mi_partnum = partnum;
307 
308 	return new_mip;
309 }
310 
311 static void
312 split_multipart(struct mime_info *top_mip)
313 {
314 	FILE *fp;
315 	struct message *top_mp;
316 	struct message *this_mp;
317 	struct mime_info *this_mip;
318 	off_t beg_pos;
319 	const char *boundary;
320 	size_t boundary_len;
321 	long lines_left;	/* must be signed and same size as m_lines */
322 	int partnum;
323 	int in_header;
324 
325 	top_mp = top_mip->mp;
326 	this_mp = salloc_message(top_mp->m_flag, top_mp->m_block, top_mp->m_offset);
327 	this_mip = top_mip;
328 	this_mip->mp = this_mp;
329 
330 	partnum = 1;
331 /*	top_mip->mi_partnum = partnum++;  */ /* Keep the number set by the caller */
332 	in_header = 1;
333 	boundary = top_mip->mi_boundary;
334 	boundary_len = boundary ? strlen(boundary) : 0;
335 
336 	fp = setinput(top_mp);
337 	beg_pos = ftello(fp);
338 #if 0
339 	warnx("beg_pos: %lld,  m_lines: %ld,  m_blines: %ld",
340 	    beg_pos, top_mp->m_lines, top_mp->m_blines);
341 #endif
342 	for (lines_left = top_mp->m_lines - 1; lines_left >= 0; lines_left--) {
343 		char *line;
344 		size_t line_len;
345 
346 		line = fgetln(fp, &line_len);
347 
348 		this_mp->m_lines++;		/* count the message lines */
349 
350 		if (!in_header)
351 			this_mp->m_blines++;	/* count the body lines */
352 
353 		if (lines_left == 0 || (
354 			    !in_header &&
355 			    line_len >= boundary_len + 2 &&
356 			    line[0] == '-' && line[1] == '-' &&
357 			    strncmp(line + 2, boundary, boundary_len) == 0)) {
358 			off_t cur_pos;
359 			off_t end_pos;
360 
361 			cur_pos = ftello(fp);
362 
363 			/* the boundary belongs to the next part */
364 			end_pos = cur_pos - line_len;
365 			this_mp->m_lines  -= 1;
366 			this_mp->m_blines -= 1;
367 
368 			this_mp->m_size = end_pos - beg_pos;
369 #if 0
370 			warnx("end_pos: %lld,  m_lines: %ld,  m_blines: %ld",
371 			    end_pos, this_mp->m_lines, this_mp->m_blines);
372 #endif
373 			if (line[boundary_len + 2] == '-' &&
374 			    line[boundary_len + 3] == '-') {/* end of multipart */
375 				/* do a sanity check on the EOM */
376 				if (lines_left != 1) {
377 					/*
378 					 * XXX - this can happen!
379 					 * Should we display the
380 					 * trailing garbage or check
381 					 * that it is blank or just
382 					 * ignore it?
383 					 */
384 #if 0
385 					(void)printf("EOM: lines left: %ld\n", lines_left);
386 #endif
387 				}
388 				break;	/* XXX - stop at this point or grab the rest? */
389 			}
390 			this_mip = insert_new_mip(this_mip, top_mip, top_mp, end_pos, partnum++);
391 			this_mp = this_mip->mp;
392 			this_mp->m_lines = 1; /* already read the first line in the header! */
393 			beg_pos = end_pos;
394 			in_header = 1;
395 		}
396 
397 		if (line_len == 1)
398 			in_header = 0;
399 	}
400 }
401 
402 static void
403 split_message(struct mime_info *top_mip)
404 {
405 	struct mime_info *this_mip;
406 	struct message *top_mp;
407 	struct message *this_mp;
408 	FILE *fp;
409 	off_t beg_pos;
410 	long lines_left;	/* must be same size as m_lines */
411 	int in_header;
412 
413 	top_mp = top_mip->mp;
414 	this_mp = salloc_message(top_mp->m_flag, top_mp->m_block, top_mp->m_offset);
415 	this_mip = top_mip;
416 	this_mip->mp = this_mp;
417 
418 	in_header = 1;
419 
420 	fp = setinput(top_mp);
421 	beg_pos = ftello(fp);
422 
423 	for (lines_left = top_mp->m_lines; lines_left > 0; lines_left--) {
424 		size_t line_len;
425 
426 		(void)fgetln(fp, &line_len);
427 
428 		this_mp->m_lines++;		/* count the message lines */
429 		if (!in_header)
430 			this_mp->m_blines++;	/* count the body lines */
431 
432 		if (in_header && line_len == 1) { /* end of header */
433 			off_t end_pos;
434 			end_pos = ftello(fp);
435 			this_mp->m_size = end_pos - beg_pos;
436 			this_mip = insert_new_mip(this_mip, top_mip,top_mp, end_pos, 0);
437 			this_mp = this_mip->mp;
438 			this_mp->m_lines = 1; /* we already counted one line in the header! */
439 			beg_pos = end_pos;
440 			in_header = 0;	/* never in header again */
441 		}
442 	}
443 
444 	/* close the last message */
445 	this_mp->m_size = ftello(fp) - beg_pos;
446 }
447 
448 
449 static const char *
450 get_command_hook(struct mime_info *mip, const char *domain)
451 {
452 	char *key;
453 	char *cmd;
454 
455 	if (mip->mi_type == NULL)
456 		return NULL;
457 
458 	/* XXX - should we use easprintf() here?  We are probably
459 	 * hosed elsewhere if this fails anyway. */
460 
461 	cmd = NULL;
462 	if (mip->mi_subtype) {
463 		if (asprintf(&key, "mime%s-%s-%s",
464 			domain,	mip->mi_type, mip->mi_subtype) == -1) {
465 			warn("get_command_hook: subtupe: asprintf");
466 			return NULL;
467 		}
468 		cmd = value(key);
469 		free(key);
470 	}
471 	if (cmd == NULL) {
472 		if (asprintf(&key, "mime%s-%s", domain, mip->mi_type) == -1) {
473 			warn("get_command_hook: type: asprintf");
474 			return NULL;
475 		}
476 		cmd = value(key);
477 		free(key);
478 	}
479 	return cmd;
480 }
481 
482 
483 static int
484 is_basic_alternative(struct mime_info *mip)
485 {
486 	return
487 	    strcasecmp(mip->mi_type, "text") == 0 &&
488 	    strcasecmp(mip->mi_subtype, "plain") == 0;
489 }
490 
491 static struct mime_info *
492 select_alternative(struct mime_info *top_mip, struct mime_info *end_mip)
493 {
494 	struct mime_info *the_mip;	/* the chosen alternate */
495 	struct mime_info *this_mip;
496 	/*
497 	 * The alternates are supposed to occur in order of
498 	 * increasing "complexity".  So: if there is at least
499 	 * one alternate of type "text/plain", use the last
500 	 * one, otherwise default to the first alternate.
501 	 */
502 	the_mip = top_mip->mi_flink;
503 	for (this_mip = top_mip->mi_flink;
504 	     this_mip != end_mip;
505 	     this_mip = this_mip->mi_flink) {
506 		const char *cmd;
507 
508 		if (this_mip->mi_type == NULL ||
509 		    this_mip->mi_subtype == NULL)
510 			continue;
511 
512 		if (is_basic_alternative(this_mip))
513 			the_mip = this_mip;
514 		else if (
515 			(cmd = get_command_hook(this_mip, "-hook")) ||
516 			(cmd = get_command_hook(this_mip, "-head")) ||
517 			(cmd = get_command_hook(this_mip, "-body"))) {
518 			int flags;
519 			/* just get the flags. */
520 			flags = mime_run_command(cmd, NULL);
521 			if ((flags & CMD_FLAG_ALTERNATIVE) != 0)
522 				the_mip = this_mip;
523 		}
524 	}
525 	return the_mip;
526 }
527 
528 
529 static inline int
530 is_multipart(struct mime_info *mip)
531 {
532 	return mip->mi_type &&
533 	    strcasecmp("multipart", mip->mi_type) == 0;
534 }
535 static inline int
536 is_message(struct mime_info *mip)
537 {
538 	return mip->mi_type &&
539 	    strcasecmp("message", mip->mi_type) == 0;
540 }
541 
542 static inline int
543 is_alternative(struct mime_info *mip)
544 {
545 	return mip->mi_subtype &&
546 	    strcasecmp("alternative", mip->mi_subtype) == 0;
547 }
548 
549 
550 /*
551  * Take a mime_info pointer and expand it recursively into all its
552  * mime parts.  Only "multipart" and "message" types recursed into;
553  * they are handled separately.
554  */
555 static struct mime_info *
556 expand_mip(struct mime_info *top_mip)
557 {
558 	struct mime_info *this_mip;
559 	struct mime_info *next_mip;
560 
561 	if (top_mip->mi_partnum == 0) {
562 		if (top_mip->mi_blink)
563 			top_mip->mi_partstr = top_mip->mi_blink->mi_partstr;
564 	}
565 	else if (top_mip->mi_parent.mip) {
566 		const char *prefix;
567 		char *cp;
568 		prefix = top_mip->mi_parent.mip->mi_partstr;
569 		(void)sasprintf(&cp, "%s%s%d", prefix,
570 		    *prefix ? "." : "", top_mip->mi_partnum);
571 		top_mip->mi_partstr = cp;
572 	}
573 
574 	next_mip = top_mip->mi_flink;
575 
576 	if (is_multipart(top_mip)) {
577 		top_mip->mi_ignore_body = 1; /* the first body is ignored */
578 		split_multipart(top_mip);
579 
580 		for (this_mip = top_mip->mi_flink;
581 		     this_mip != next_mip;
582 		     this_mip = this_mip->mi_flink) {
583 			get_content(this_mip);
584 		}
585 		if (is_alternative(top_mip)) {
586 			this_mip = select_alternative(top_mip, next_mip);
587 			this_mip->mi_partnum = 0; /* suppress partnum display */
588 			this_mip->mi_flink = next_mip;
589 			this_mip->mi_blink = top_mip;
590 			top_mip->mi_flink  = this_mip;
591 		}
592 		/*
593 		 * Recurse into each part.
594 		 */
595 		for (this_mip = top_mip->mi_flink;
596 		     this_mip != next_mip;
597 		     this_mip = expand_mip(this_mip))
598 			continue;
599 	}
600 	else if (is_message(top_mip)) {
601 		top_mip->mi_ignore_body = 1; /* the first body is ignored */
602 		split_message(top_mip);
603 
604 		this_mip = top_mip->mi_flink;
605 		if (this_mip) {
606 			get_content(this_mip);
607 			/*
608 			 * If the one part is MIME encoded, recurse into it.
609 			 * XXX - Should this be conditional on subtype "rcs822"?
610 			 */
611 			if (this_mip->mi_type &&
612 			    this_mip->mi_version &&
613 			    equal(this_mip->mi_version, MIME_VERSION)) {
614 				this_mip->mi_partnum = 0;
615 				(void)expand_mip(this_mip);
616 			}
617 		}
618 	}
619 	return next_mip;
620 }
621 
622 
623 #if 0
624 static int
625 show_partnum(FILE *fp, struct mime_info *mip)
626 {
627 	int need_dot;
628 	need_dot = 0;
629 	if (mip->mi_parent.mip && mip->mi_parent.mip->mi_parent.mip)
630 		need_dot = show_partnum(fp, mip->mi_parent.mip);
631 
632 	if (mip->mi_partnum) {
633 		(void)fprintf(fp, "%s%d", need_dot ? "." : "",  mip->mi_partnum);
634 		need_dot = 1;
635 	}
636 	return need_dot;
637 }
638 #endif
639 
640 
641 PUBLIC struct mime_info *
642 mime_decode_open(struct message *mp)
643 {
644 	struct mime_info *mip;
645 	struct mime_info *p;
646 
647 	mip = csalloc(1, sizeof(*mip));
648 	mip->mp = salloc(sizeof(*mip->mp));
649 	*mip->mp = *mp;		/* copy this so we don't trash the master mp */
650 
651 	get_content(mip);
652 
653 	/* RFC 2049 - sec 2 item 1 */
654 	if (mip->mi_version == NULL ||
655 	    !equal(mip->mi_version, MIME_VERSION))
656 		return NULL;
657 
658 	mip->mi_partstr = "";
659 	if (mip->mi_type)
660 		(void)expand_mip(mip);
661 
662 	/*
663 	 * Get the pipe_end and propagate it down the chain.
664 	 */
665 	mip->mi_pipe_end = last_registered_file(0); /* for mime_decode_close() */
666 	for (p = mip->mi_flink; p; p = p->mi_flink)
667 		p->mi_pipe_end = mip->mi_pipe_end;
668 
669 /*	show_mime_info(stderr, mip, NULL); */
670 
671 	return mip;
672 }
673 
674 
675 PUBLIC void
676 mime_decode_close(struct mime_info *mip)
677 {
678 	if (mip)
679 		close_top_files(mip->mi_pipe_end);
680 }
681 
682 
683 struct prefix_line_args_s {
684 	const char *prefix;
685 	size_t prefixlen;
686 };
687 
688 static void
689 prefix_line(FILE *fi, FILE *fo, void *cookie)
690 {
691 	struct prefix_line_args_s *args;
692 	const char *line;
693 	const char *prefix;
694 	size_t prefixlen;
695 	size_t length;
696 
697 	args = cookie;
698 	prefix    = args->prefix;
699 	prefixlen = args->prefixlen;
700 
701 	while ((line = fgetln(fi, &length)) != NULL) {
702 		if (length > 1)
703 			(void)fputs(prefix, fo);
704 		else
705 			(void)fwrite(prefix, sizeof(*prefix),
706 			    prefixlen, fo);
707 		(void)fwrite(line, sizeof(*line), length, fo);
708 	}
709 	(void)fflush(fo);
710 }
711 
712 PUBLIC int
713 mime_sendmessage(struct message *mp, FILE *obuf, struct ignoretab *igntab,
714     const char *prefix, struct mime_info *mip)
715 {
716 	int error;
717 	int detachall_flag;
718 	const char *detachdir;
719 	FILE *end_of_prefix;
720 
721 	if (mip == NULL)
722 		return obuf ?	/* were we trying to detach? */
723 		    sendmessage(mp, obuf, igntab, prefix, NULL) : 0;
724 	/*
725 	 * The prefix has two meanigs which we handle here:
726 	 * 1) If obuf == NULL, then we are detaching to the 'prefix' directory.
727 	 * 2) If obuf != NULL, then the prefix is prepended to each line.
728 	 */
729 	detachdir = NULL;
730 	detachall_flag = igntab == detachall;
731 	if (obuf == NULL) {
732 		assert(prefix != NULL);		/* coding error! */
733 		if ((obuf = last_registered_file(0)) == NULL)
734 			obuf = stdout;
735 		detachdir = prefix;
736 		prefix = NULL;
737 		igntab = ignoreall;	/* always ignore the headers */
738 	}
739 	/*
740 	 * Set this early so pipe_end() will work!
741 	 */
742 	mip->mi_fo = obuf;
743 
744 	(void)fflush(obuf);  /* Be safe and flush!  XXX - necessary? */
745 
746 	/*
747 	 * Handle the prefix as a pipe stage so it doesn't get seen by
748 	 * any decoding or hooks.
749 	 */
750 	if (prefix != NULL) {
751 		static struct prefix_line_args_s prefix_line_args;
752 		const char *dp, *dp2 = NULL;
753 		for (dp = prefix; *dp; dp++)
754 			if (!is_WSP(*dp))
755 				dp2 = dp;
756 		prefix_line_args.prefixlen = dp2 == 0 ? 0 : dp2 - prefix + 1;
757 		prefix_line_args.prefix = prefix;
758 		mime_run_function(prefix_line, pipe_end(mip), (void*)&prefix_line_args);
759 	}
760 
761 	end_of_prefix = last_registered_file(0);
762 	error = 0;
763 	for (/*EMPTY*/; mip; mip = mip->mi_flink) {
764 		mip->mi_fo = obuf;
765 		mip->mi_head_end = obuf;
766 		mip->mi_detachdir = detachdir;
767 		mip->mi_detachall = detachall_flag;
768 		error |= sendmessage(mip->mp, pipe_end(mip), igntab, NULL, mip);
769 		close_top_files(end_of_prefix);	/* don't close the prefixer! */
770 	}
771 	return error;
772 }
773 
774 
775 #ifdef CHARSET_SUPPORT
776 /**********************************************
777  * higher level interface to run mime_ficonv().
778  */
779 static void
780 run_mime_ficonv(struct mime_info *mip, const char *charset)
781 {
782 	FILE *fo;
783 	iconv_t cd;
784 
785 	fo = pipe_end(mip);
786 
787 	if (charset == NULL ||
788 	    mip->mi_charset == NULL ||
789 	    strcasecmp(mip->mi_charset, charset) == 0 ||
790 	    strcasecmp(mip->mi_charset, "unknown") == 0)
791 		return;
792 
793 	cd = iconv_open(charset, mip->mi_charset);
794 	if (cd == (iconv_t)-1) {
795 		(void)fprintf(fo, "\t [ iconv_open failed: %s ]\n\n",
796 		    strerror(errno));
797 		(void)fflush(fo);	/* flush here or see double! */
798 		return;
799 	}
800 
801 	if (mip->mi_detachdir == NULL && /* don't contaminate the detach! */
802 	    value(ENAME_MIME_CHARSET_VERBOSE))
803 		(void)fprintf(fo, "\t[ converting %s -> %s ]\n\n",
804 		    mip->mi_charset, charset);
805 
806 	mime_run_function(mime_ficonv, fo, cd);
807 
808 	(void)iconv_close(cd);
809 }
810 #endif /* CHARSET_SUPPORT */
811 
812 
813 PUBLIC void
814 run_decoder(struct mime_info *mip, void(*fn)(FILE*, FILE*, void *))
815 {
816 #ifdef CHARSET_SUPPORT
817 	char *charset;
818 
819 	charset = value(ENAME_MIME_CHARSET);
820 	if (charset && mip->mi_type && strcasecmp(mip->mi_type, "text") == 0)
821 		run_mime_ficonv(mip, charset);
822 #endif /* CHARSET_SUPPORT */
823 
824 	if (mip->mi_detachdir == NULL &&
825 	    fn == mime_fio_copy)/* XXX - avoid an extra unnecessary pipe stage */
826 		return;
827 
828 	mime_run_function(fn, pipe_end(mip),
829 	    mip->mi_detachdir ? NULL : __UNCONST("add_lf"));
830 }
831 
832 
833 /*
834  * Determine how to handle the display based on the type and subtype
835  * fields.
836  */
837 enum dispmode_e {
838 	DM_IGNORE	= 0x00,	/* silently ignore part - must be zero! */
839 	DM_DISPLAY,		/* decode and display the part */
840 	DM_UNKNOWN,		/* unknown display */
841 	DM_BINARY,		/* indicate binary data */
842 	DM_PGPSIGN,		/* OpenPGP signed part */
843 	DM_PGPENCR,		/* OpenPGP encrypted part */
844 	DM_PGPKEYS		/* OpenPGP keys part */
845 };
846 #define APPLICATION_OCTET_STREAM	DM_BINARY
847 
848 static enum dispmode_e
849 get_display_mode(struct mime_info *mip, mime_codec_t dec)
850 {
851 	struct mime_subtype_s {
852 		const char *st_name;
853 		enum dispmode_e st_dispmode;
854 	};
855 	struct mime_type_s {
856 		const char *mt_type;
857 		const struct mime_subtype_s *mt_subtype;
858 		enum dispmode_e mt_dispmode;	/* default if NULL subtype */
859 	};
860 	static const struct mime_subtype_s text_subtype_tbl[] = {
861 		{ "plain",		DM_DISPLAY },
862 		{ "html", 		DM_DISPLAY },	/* rfc2854 */
863 		{ "rfc822-headers",	DM_DISPLAY },
864 		{ "css",		DM_DISPLAY },	/* rfc2318 */
865 		{ "enriched",		DM_DISPLAY },	/* rfc1523/rfc1563/rfc1896 */
866 		{ "graphics",		DM_DISPLAY },	/* rfc0553 */
867 		{ "nroff",		DM_DISPLAY },	/* rfc4263 */
868 		{ "red",		DM_DISPLAY },	/* rfc4102 */
869 		{ NULL,			DM_DISPLAY }	/* default */
870 	};
871 	static const struct mime_subtype_s image_subtype_tbl[] = {
872 		{ "tiff",		DM_BINARY },	/* rfc2302/rfc3302 */
873 		{ "tiff-fx",		DM_BINARY },	/* rfc3250/rfc3950 */
874 		{ "t38",		DM_BINARY },	/* rfc3362 */
875 		{ NULL,			DM_BINARY }	/* default */
876 	};
877 	static const struct mime_subtype_s audio_subtype_tbl[] = {
878 		{ "mpeg",		DM_BINARY },	/* rfc3003 */
879 		{ "t38",		DM_BINARY },	/* rfc4612 */
880 		{ NULL,			DM_BINARY }	/* default */
881 	};
882 	static const struct mime_subtype_s video_subtype_tbl[] = {
883 		{ NULL,			DM_BINARY }	/* default */
884 	};
885 	static const struct mime_subtype_s application_subtype_tbl[] = {
886 		{ "octet-stream",	APPLICATION_OCTET_STREAM },
887 		{ "pgp-encrypted",      DM_PGPENCR },   /* rfc3156 */
888 		{ "pgp-keys",           DM_PGPKEYS },   /* rfc3156 */
889 		{ "pgp-signature",      DM_PGPSIGN },   /* rfc3156 */
890 		{ "pdf",		DM_BINARY },	/* rfc3778 */
891 		{ "whoispp-query",	DM_UNKNOWN },	/* rfc2957 */
892 		{ "whoispp-response",	DM_UNKNOWN },	/* rfc2958 */
893 		{ "font-tdpfr",		DM_UNKNOWN },	/* rfc3073 */
894 		{ "xhtml+xml",		DM_UNKNOWN },	/* rfc3236 */
895 		{ "ogg",		DM_UNKNOWN },	/* rfc3534 */
896 		{ "rdf+xml",		DM_UNKNOWN },	/* rfc3870 */
897 		{ "soap+xml",		DM_UNKNOWN },	/* rfc3902 */
898 		{ "mbox",		DM_UNKNOWN },	/* rfc4155 */
899 		{ "xv+xml",		DM_UNKNOWN },	/* rfc4374 */
900 		{ "smil",		DM_UNKNOWN },	/* rfc4536 */
901 		{ "smil+xml",		DM_UNKNOWN },	/* rfc4536 */
902 		{ "json",		DM_UNKNOWN },	/* rfc4627 */
903 		{ "voicexml+xml",	DM_UNKNOWN },	/* rfc4267 */
904 		{ "ssml+xml",		DM_UNKNOWN },	/* rfc4267 */
905 		{ "srgs",		DM_UNKNOWN },	/* rfc4267 */
906 		{ "srgs+xml",		DM_UNKNOWN },	/* rfc4267 */
907 		{ "ccxml+xml",		DM_UNKNOWN },	/* rfc4267 */
908 		{ "pls+xml.",		DM_UNKNOWN },	/* rfc4267 */
909 		{ NULL,			APPLICATION_OCTET_STREAM } /* default */
910 	};
911 	static const struct mime_type_s mime_type_tbl[] = {
912 		{ "text",	 text_subtype_tbl,		DM_DISPLAY },
913 		{ "image",	 image_subtype_tbl,		DM_IGNORE },
914 		{ "audio",	 audio_subtype_tbl,		DM_IGNORE },
915 		{ "video",	 video_subtype_tbl,		DM_IGNORE },
916 		{ "application", application_subtype_tbl,	APPLICATION_OCTET_STREAM },
917 		{ NULL,		 NULL,				DM_UNKNOWN }, /* default */
918 	};
919 	const struct mime_type_s *mtp;
920 	const struct mime_subtype_s *stp;
921 	const char *mi_type;
922 	const char *mi_subtype;
923 
924 	/*
925 	 * Silently ignore all multipart bodies.
926 	 * 1) In the case of "multipart" types, this typically
927 	 *    contains a message for non-mime enabled mail readers.
928 	 * 2) In the case of "message" type, there should be no body.
929 	 */
930 	if (mip->mi_ignore_body)	/*is_multipart(mip) || is_message(mip))*/
931 		return DM_IGNORE;
932 
933 	/*
934 	 * If the encoding type given but not recognized, treat block
935 	 * as "application/octet-stream".  rfc 2049 sec 2 part 2.
936 	 */
937 	if (mip->mi_encoding && dec == NULL)
938 		return APPLICATION_OCTET_STREAM;
939 
940 	mi_type    = mip->mi_type;
941 	mi_subtype = mip->mi_type ? mip->mi_subtype : NULL;
942 
943 	/*
944 	 * If there was no type specified, display anyway so we don't
945 	 * miss anything.  (The encoding type is known.)
946 	 */
947 	if (mi_type == NULL)
948 		return DM_DISPLAY;	/* XXX - default to something safe! */
949 
950 	for (mtp = mime_type_tbl; mtp->mt_type; mtp++) {
951 		if (strcasecmp(mtp->mt_type, mi_type) == 0) {
952 			if (mi_subtype == NULL)
953 				return mtp->mt_dispmode;
954 			for (stp = mtp->mt_subtype; stp->st_name; stp++) {
955 				if (strcasecmp(stp->st_name, mi_subtype) == 0)
956 					return stp->st_dispmode;
957 			}
958 			return stp->st_dispmode;
959 		}
960 	}
961 	return mtp->mt_dispmode;
962 }
963 
964 
965 PUBLIC FILE *
966 mime_decode_body(struct mime_info *mip)
967 {
968 	static enum dispmode_e dispmode;
969 	mime_codec_t dec;
970 	const char *cmd;
971 
972 	/* close anything left over from mime_decode_head() */
973 	close_top_files(mip->mi_head_end);
974 
975 	/*
976 	 * Make sure we flush everything down the pipe so children
977 	 * don't see it.
978 	 */
979 	(void)fflush(pipe_end(mip));
980 
981 	if (mip->mi_detachdir)	/* We are detaching!  Ignore the hooks. */
982 		return mime_detach_parts(mip);
983 
984 	cmd = NULL;
985 	if (mip->mi_command_hook == NULL)
986 		cmd = get_command_hook(mip, "-body");
987 
988 	dec = mime_fio_decoder(mip->mi_encoding);
989 
990 	/*
991 	 * If there is a filter running, we need to send the message
992 	 * to it.  Otherwise, get the default display mode for this body.
993 	 */
994 	dispmode = cmd || mip->mi_command_hook ? DM_DISPLAY : get_display_mode(mip, dec);
995 
996 	if (dec == NULL)	/* make sure we have a usable decoder */
997 		dec = mime_fio_decoder(MIME_TRANSFER_7BIT);
998 
999 	if (dispmode == DM_DISPLAY) {
1000 		int flags;
1001 		if (cmd == NULL)
1002 			/* just get the flags */
1003 			flags = mime_run_command(mip->mi_command_hook, NULL);
1004 		else
1005 			flags = mime_run_command(cmd, pipe_end(mip));
1006 		if ((flags & CMD_FLAG_NO_DECODE) == 0)
1007 			run_decoder(mip, dec);
1008 		return pipe_end(mip);
1009 	}
1010 	else {
1011 		static const struct msg_tbl_s {
1012 			enum dispmode_e dm;
1013 			const char *msg;
1014 		} msg_tbl[] = {
1015 			{ DM_BINARY,	"binary content"	},
1016 			{ DM_PGPSIGN,	"OpenPGP signature"	},
1017 			{ DM_PGPENCR,	"OpenPGP encrypted"	},
1018 			{ DM_PGPKEYS,	"OpenPGP keys"		},
1019 			{ DM_UNKNOWN,	"unknown data"		},
1020 			{ DM_IGNORE,	NULL			},
1021 			{ -1,		NULL			},
1022 		};
1023 		const struct msg_tbl_s *mp;
1024 
1025 		for (mp = msg_tbl; mp->dm != -1; mp++)
1026 			if (mp->dm == dispmode)
1027 				break;
1028 
1029 		assert(mp->dm != -1);	/* msg_tbl is short if this happens! */
1030 
1031 		if (mp->msg)
1032 			(void)fprintf(pipe_end(mip), "  [%s]\n\n", mp->msg);
1033 
1034 		return NULL;
1035 	}
1036 }
1037 
1038 
1039 /************************************************************************
1040  * Higher level header decoding interface.
1041  *
1042  * The core routines are in mime_header.c.
1043  */
1044 
1045 /*
1046  * Decode a portion of the header field.
1047  *
1048  * linebuf	buffer to decode into.
1049  * bufsize	size of linebuf.
1050  * hdrline	full header line including header name.
1051  * srcstr	pointer to string to decode
1052  */
1053 PUBLIC char *
1054 mime_decode_hfield(char *linebuf, size_t bufsize, const char *hdrline, char *srcstr)
1055 {
1056 	hfield_decoder_t decode;
1057 	decode = mime_hfield_decoder(hdrline);
1058 	if (decode) {
1059 		decode(linebuf, bufsize, srcstr);
1060 		return linebuf;
1061 	}
1062 	return srcstr;
1063 }
1064 
1065 /*
1066  * Return the next header field found in the input stream.
1067  * Return 0 if something found, -1 otherwise.
1068  * For a proper header, "*colon" is set to point to the colon
1069  * terminating the header name.  Otherwise it is NULL.
1070  *
1071  * NOTE: unlike gethfield() in support.c this:
1072  * 1) preserves folding (newlines),
1073  * 2) reads until fgetln() gets an EOF,
1074  * 3) only sets *colon if there is a "proper" one.
1075  */
1076 static int
1077 get_folded_hfield(FILE *f, char *linebuf, size_t bufsize, char **colon)
1078 {
1079 	char *cp, *cp2;
1080 	char *line;
1081 	size_t len;
1082 
1083 	if ((cp = fgetln(f, &len)) == NULL)
1084 		return -1;
1085 	for (cp2 = cp;
1086 	     cp2 < cp + len && isprint((unsigned char)*cp2) &&
1087 		 !is_WSP(*cp2) && *cp2 != ':';
1088 	     cp2++)
1089 		continue;
1090 	len = MIN(bufsize - 1, len);
1091 	bufsize -= len;
1092 	(void)memcpy(linebuf, cp, len);
1093 	*colon = *cp2 == ':' ? linebuf + (cp2 - cp) : NULL;
1094 	line = linebuf + len;
1095 	for (;;) {
1096 		int c;
1097 		(void)ungetc(c = getc(f), f);
1098 		if (!is_WSP(c))
1099 			break;
1100 
1101 		if ((cp = fgetln(f, &len)) == NULL)
1102 			break;
1103 		len = MIN(bufsize - 1, len);
1104 		bufsize -= len;
1105 		if (len == 0)
1106 			break;
1107 		(void)memcpy(line, cp, len);
1108 		line += len;
1109 	}
1110 	*line = 0;
1111 	return 0;
1112 }
1113 
1114 static void
1115 decode_header(FILE *fi, FILE *fo, void *cookie __unused)
1116 {
1117 	char linebuf[LINESIZE];
1118 	char *colon;
1119 #ifdef __lint__
1120 	cookie = cookie;
1121 #endif
1122 	while (get_folded_hfield(fi, linebuf, sizeof(linebuf), &colon) >= 0) {
1123 		char decbuf[LINESIZE];
1124 		char *hdrstr;
1125 		hdrstr = linebuf;
1126 		if (colon)
1127 			hdrstr = mime_decode_hfield(decbuf, sizeof(decbuf), hdrstr, hdrstr);
1128 		(void)fprintf(fo, hdrstr);
1129 	}
1130 }
1131 
1132 PUBLIC FILE *
1133 mime_decode_header(struct mime_info *mip)
1134 {
1135 	int flags;
1136 	const char *cmd;
1137 	FILE *fo;
1138 
1139 	fo = pipe_end(mip);
1140 
1141 	if (mip->mi_detachdir) { /* We are detaching.  Don't run anything! */
1142 		(void)fflush(fo);
1143 		return pipe_end(mip);
1144 	}
1145 
1146 	if (mip->mi_partnum)
1147 		(void)fprintf(fo, "----- Part %s -----\n", mip->mi_partstr);
1148 
1149 	(void)fflush(fo);	/* Flush so the childern don't see it. */
1150 
1151 	/*
1152 	 * install the message hook before the head hook.
1153 	 */
1154 	cmd = get_command_hook(mip, "-hook");
1155 	mip->mi_command_hook = cmd;
1156 	if (cmd) {
1157 		flags = mime_run_command(cmd, pipe_end(mip));
1158 		mip->mi_head_end = last_registered_file(0);
1159 	}
1160 	else {
1161 		cmd = get_command_hook(mip, "-head");
1162 		mip->mi_head_end = last_registered_file(0);
1163 		flags = mime_run_command(cmd, pipe_end(mip));
1164 	}
1165 
1166 	if (value(ENAME_MIME_DECODE_HDR) && (flags & CMD_FLAG_NO_DECODE) == 0)
1167 		mime_run_function(decode_header, pipe_end(mip), NULL);
1168 
1169 	return pipe_end(mip);
1170 }
1171 
1172 #endif /* MIME_SUPPORT */
1173