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mime_attach.c revision 1.1
      1 /*	$NetBSD: mime_attach.c,v 1.1 2006/10/21 21:37:21 christos 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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 #ifdef MIME_SUPPORT
     40 
     41 #include <sys/cdefs.h>
     42 #ifndef __lint__
     43 __RCSID("$NetBSD: mime_attach.c,v 1.1 2006/10/21 21:37:21 christos Exp $");
     44 #endif /* not __lint__ */
     45 
     46 #include <assert.h>
     47 #include <err.h>
     48 #include <fcntl.h>
     49 #include <libgen.h>
     50 #include <magic.h>
     51 #include <setjmp.h>
     52 #include <signal.h>
     53 #include <stdio.h>
     54 #include <stdlib.h>
     55 #include <string.h>
     56 #include <unistd.h>
     57 #include <util.h>
     58 
     59 #include "def.h"
     60 #include "extern.h"
     61 #ifdef USE_EDITLINE
     62 #include "complete.h"
     63 #endif
     64 #ifdef MIME_SUPPORT
     65 #include "mime.h"
     66 #include "mime_codecs.h"
     67 #include "mime_child.h"
     68 #endif
     69 #include "glob.h"
     70 
     71 
     72 #if 0
     73 #ifndef __lint__
     74 /*
     75  * XXX - This block for debugging only and eventually should go away.
     76  */
     77 static void
     78 show_name(const char *prefix, struct name *np)
     79 {
     80 	int i;
     81 
     82 	i = 0;
     83 	for (/* EMPTY */; np; np = np->n_flink) {
     84 		(void)printf("%s[%d]: %s\n", prefix, i, np->n_name);
     85 		i++;
     86 	}
     87 }
     88 
     89 PUBLIC void
     90 show_attach(const char *prefix, struct attachment *ap)
     91 {
     92 	int i;
     93 	i = 1;
     94 	for (/* EMPTY */; ap; ap = ap->a_flink) {
     95 		(void)printf("%s[%d]:\n", prefix, i);
     96 		fput_mime_content(stdout, &ap->a_Content);
     97 		i++;
     98 	}
     99 }
    100 
    101 PUBLIC void
    102 show_header(struct header *hp)
    103 {
    104 	show_name("TO", hp->h_to);
    105 	(void)printf("SUBJECT: %s\n", hp->h_subject);
    106 	show_name("CC", hp->h_cc);
    107 	show_name("BCC", hp->h_bcc);
    108 	show_name("SMOPTS", hp->h_smopts);
    109 	show_attach("ATTACH", hp->h_attach);
    110 }
    111 #endif	/* __lint__ */
    112 #endif
    113 
    114 
    115 /***************************
    116  * boundary string routines
    117  */
    118 static char *
    119 getrandstring(size_t length)
    120 {
    121 	void *vbin;
    122 	uint32_t *bin;
    123 	size_t binlen;
    124 	size_t i;
    125 	char *b64;
    126 
    127 	/* XXX - check this stuff again!!! */
    128 
    129 	binlen = 3 * roundup(length, 4) / 4;	/* bytes of binary to encode base64 */
    130 	bin = vbin = salloc(roundup(binlen, 4));
    131 	for (i = 0; i < roundup(binlen, 4) / 4; i++)
    132 		bin[i] = arc4random();
    133 
    134 	b64 = salloc(roundup(length, 4));
    135 	mime_bintob64(b64, vbin, binlen);
    136 	b64[length] = '\0';
    137 
    138 	return b64;
    139 }
    140 
    141 /*
    142  * Generate a boundary for MIME multipart messages.
    143  */
    144 static char *
    145 make_boundary(void)
    146 {
    147 #define BOUND_LEN 70	/* maximum length is 70 characters: RFC2046 sec 5.1.1 */
    148 
    149 	char *bound;
    150 	time_t	now;
    151 
    152 	(void)time(&now);
    153 	bound = salloc(BOUND_LEN);
    154 	(void)snprintf(bound, BOUND_LEN, "=_%08lx.%s",
    155 	    (long)now, getrandstring(BOUND_LEN - 12));
    156 	return bound;
    157 
    158 #undef BOUND_LEN
    159 }
    160 
    161 
    162 /***************************
    163  * Transfer coding routines
    164  */
    165 /*
    166  * We determine the recommended transfer encoding type for a file as
    167  * follows:
    168  *
    169  * 1) If there is a NULL byte or a stray CR (not in a CRLF
    170  *    combination) in the file, play it safe and use base64.
    171  *
    172  * 2) If any high bit is set, use quoted-printable if the content type
    173  *    is "text" and base64 otherwise.
    174  *
    175  * 3) Otherwise:
    176  *    a) use quoted-printable if there are any long lines, control
    177  *       chars (including CR), end-of-line blank space, or a missing
    178  *       terminating NL.
    179  *    b) use 7bit in all remaining case, including an empty file.
    180  *
    181  * NOTE: This means that CRLF text (MSDOS) files will be encoded
    182  * quoted-printable.
    183  */
    184 /*
    185  * RFC 821 imposes the following line length limit:
    186  *  The maximum total length of a text line including the
    187  *  <CRLF> is 1000 characters (but not counting the leading
    188  *  dot duplicated for transparency).
    189  */
    190 #define MIME_UNENCODED_LINE_MAX	(1000 - 2)
    191 static size_t
    192 line_limit(void)
    193 {
    194 	int limit;
    195 	const char *cp;
    196 	limit = -1;
    197 
    198 	if ((cp = value(ENAME_MIME_UNENC_LINE_MAX)) != NULL)
    199 		limit = atoi(cp);
    200 
    201 	if (limit < 0 || limit > MIME_UNENCODED_LINE_MAX)
    202 		limit = MIME_UNENCODED_LINE_MAX;
    203 
    204 	return (size_t)limit;
    205 }
    206 
    207 static inline
    208 int is_text(const char *ctype)
    209 {
    210 	return ctype &&
    211 	    strncasecmp(ctype, "text/", sizeof("text/") - 1) == 0;
    212 }
    213 
    214 static const char *
    215 content_encoding_core(void *fh, const char *ctype)
    216 {
    217 	int c, lastc;
    218 	int ctrlchar, endwhite;
    219 	size_t curlen, maxlen;
    220 
    221 	curlen = 0;
    222 	maxlen = 0;
    223 	ctrlchar = 0;
    224 	endwhite = 0;
    225 	lastc = EOF;
    226 	while ((c = fgetc(fh)) != EOF) {
    227 		curlen++;
    228 
    229 		if (c == '\0' || (lastc == '\r' && c != '\n'))
    230 			return MIME_TRANSFER_BASE64;
    231 
    232 		if (c > 0x7f) {
    233 			if (is_text(ctype))
    234 				return MIME_TRANSFER_QUOTED;
    235 			else
    236 				return MIME_TRANSFER_BASE64;
    237 		}
    238 		if (c == '\n') {
    239 			if (isblank((unsigned char)lastc))
    240 				endwhite = 1;
    241 			if (curlen > maxlen)
    242 				maxlen = curlen;
    243 			curlen = 0;
    244 		}
    245 		else if ((c < 0x20 && c != '\t') || c == 0x7f)
    246 			ctrlchar = 1;
    247 
    248 		lastc = c;
    249 	}
    250 	if (lastc == EOF) /* no characters read */
    251 		return MIME_TRANSFER_7BIT;
    252 
    253 	if (lastc != '\n' || ctrlchar || endwhite || maxlen > line_limit())
    254 		return MIME_TRANSFER_QUOTED;
    255 
    256 	return MIME_TRANSFER_7BIT;
    257 }
    258 
    259 static const char *
    260 content_encoding_by_name(const char *filename, const char *ctype)
    261 {
    262 	FILE *fp;
    263 	const char *enc;
    264 	fp = fopen(filename, "r");
    265 	if (fp == NULL) {
    266 		warn("content_encoding_by_name: %s", filename);
    267 		return MIME_TRANSFER_BASE64;	/* safe */
    268 	}
    269 	enc = content_encoding_core(fp, ctype);
    270 	(void)fclose(fp);
    271 	return enc;
    272 }
    273 
    274 static const char *
    275 content_encoding_by_fileno(int fd, const char *ctype)
    276 {
    277 	FILE *fp;
    278 	const char *encoding;
    279 	off_t cur_pos;
    280 
    281 	cur_pos = lseek(fd, (off_t)0, SEEK_CUR);
    282 	fp = fdopen(fd, "r");
    283 	if (fp == NULL) {
    284 		warn("content_encoding_by_fileno");
    285 		return MIME_TRANSFER_BASE64;
    286 	}
    287 	encoding = content_encoding_core(fp, ctype);
    288 	(void)lseek(fd, cur_pos, SEEK_SET);
    289 	return encoding;
    290 }
    291 
    292 static const char *
    293 content_encoding(struct attachment *attach, const char *ctype)
    294 {
    295 	switch (attach->a_type) {
    296 	case ATTACH_FNAME:
    297 		return content_encoding_by_name(attach->a_name, ctype);
    298 	case ATTACH_MSG:
    299 		errx(EXIT_FAILURE, "msgno not supported yet\n");
    300 		/* NOTREACHED */
    301 	case ATTACH_FILENO:
    302 		return content_encoding_by_fileno(attach->a_fileno, ctype);
    303 	default:
    304 		errx(EXIT_FAILURE, "invalid attach type: %d\n", attach->a_type);
    305 	}
    306 	/* NOTREACHED */
    307 }
    308 
    309 
    310 
    311 /************************
    312  * Content type routines
    313  */
    314 /*
    315  * We use libmagic(3) to get the content type, except in the case of a
    316  * 0 or 1 byte file, which we declare "text/plain".
    317  */
    318 static const char *
    319 content_type_by_name(const char *filename)
    320 {
    321 	const char *cp;
    322 	magic_t magic;
    323 	struct stat sb;
    324 
    325 	/*
    326 	 * libmagic produces annoying results on very short files.
    327 	 * Note: a 1-byte file always consists of a newline, so size
    328 	 * determines all here.
    329 	 */
    330 	if ((filename != NULL && stat(filename, &sb) == 0) ||
    331 	    (filename == NULL && fstat(0, &sb) == 0))
    332 		if (sb.st_size < 2 && S_ISREG(sb.st_mode))
    333 			return "text/plain";
    334 
    335 	magic = magic_open(MAGIC_MIME);
    336 	if (magic == NULL) {
    337 		warn("magic_open: %s", magic_error(magic));
    338 		return NULL;
    339 	}
    340 	if (magic_load(magic, NULL) != 0) {
    341 		warn("magic_load: %s", magic_error(magic));
    342 		return NULL;
    343 	}
    344 	cp = magic_file(magic, filename);
    345 	if (cp == NULL) {
    346 		warn("magic_load: %s", magic_error(magic));
    347 		return NULL;
    348 	}
    349 	cp = savestr(cp);
    350 	magic_close(magic);
    351 	return cp;
    352 }
    353 
    354 static const char *
    355 content_type_by_fileno(int fd)
    356 {
    357 	const char *cp;
    358 	off_t cur_pos;
    359 	int ofd;
    360 
    361 	cur_pos = lseek(fd, (off_t)0, SEEK_CUR);
    362 
    363 	ofd = dup(0);		/* save stdin */
    364 	if (dup2(fd, 0) == -1)	/* become stdin */
    365 		warn("dup2");
    366 
    367 	cp = content_type_by_name(NULL);
    368 
    369 	if (dup2(ofd, 0) == -1)	/* restore stdin */
    370 		warn("dup2");
    371 	(void)close(ofd);	/* close the copy */
    372 
    373 	(void)lseek(fd, cur_pos, SEEK_SET);
    374 	return cp;
    375 }
    376 
    377 
    378 static const char *
    379 content_type(struct attachment *attach)
    380 {
    381 	switch (attach->a_type) {
    382 	case ATTACH_FNAME:
    383 		return content_type_by_name(attach->a_name);
    384 	case ATTACH_MSG:
    385 		return "message/rfc822";
    386 	case ATTACH_FILENO:
    387 		return content_type_by_fileno(attach->a_fileno);
    388 	default:
    389 		/* This is a coding error! */
    390 		assert(/* CONSTCOND */ 0);
    391 		return NULL;
    392 	}
    393 }
    394 
    395 
    396 /*************************
    397  * Other content routines
    398  */
    399 
    400 static const char *
    401 content_disposition(struct attachment *ap)
    402 {
    403 	switch (ap->a_type) {
    404 	case ATTACH_FNAME: {
    405 		char *buf;
    406 		char *disp;
    407 		(void)easprintf(&buf, "attachment; filename=\"%s\"", basename(ap->a_name));
    408 		disp = savestr(buf);
    409 		free(buf);
    410 		return disp;
    411 	}
    412 	case ATTACH_MSG:
    413 	case ATTACH_FILENO:
    414 		return "inline";
    415 
    416 	default:
    417 		return NULL;
    418 	}
    419 }
    420 
    421 /*ARGSUSED*/
    422 static const char *
    423 content_id(struct attachment *attach __unused)
    424 {
    425 	/* XXX - to be written. */
    426 
    427 	return NULL;
    428 }
    429 
    430 static const char *
    431 content_description(struct attachment *attach, int attach_num)
    432 {
    433 	if (attach_num) {
    434 		char *description;
    435 		char *cp;
    436 		(void)easprintf(&cp, "attachment %d", attach_num);
    437 		description = savestr(cp);
    438 		free(cp);
    439 		return description;
    440 	}
    441 	else
    442 		return attach->a_Content.C_description;
    443 }
    444 
    445 /*******************************************
    446  * Routines to get the MIME content strings.
    447  */
    448 static struct Content
    449 get_mime_content(struct attachment *ap, int i)
    450 {
    451 	struct Content Cp;
    452 
    453 	Cp.C_type	 = content_type(ap);
    454 	Cp.C_encoding	 = content_encoding(ap, Cp.C_type);
    455 	Cp.C_disposition = content_disposition(ap);
    456 	Cp.C_id		 = content_id(ap);
    457 	Cp.C_description = content_description(ap, i);
    458 
    459 	return Cp;
    460 }
    461 
    462 /*
    463  * A hook to complete the content part of the attachment struct.  This
    464  * is used when a file is attached by the '-a' to complete the process
    465  * after the flags have been processed.
    466  */
    467 PUBLIC void
    468 mime_attach_content(struct attachment *ap)
    469 {
    470 	int i;
    471 	i = 1;
    472 
    473 	for (/* EMPTY */; ap; ap = ap->a_flink)
    474 		ap->a_Content = get_mime_content(ap, i++);
    475 }
    476 
    477 
    478 /******************
    479  * Output routines
    480  */
    481 static void
    482 fput_mime_content(FILE *fp, struct Content *Cp)
    483 {
    484 	(void)fprintf(fp, MIME_HDR_TYPE ": %s\n", Cp->C_type);
    485 	(void)fprintf(fp, MIME_HDR_ENCODING ": %s\n", Cp->C_encoding);
    486 	if (Cp->C_disposition)
    487 		(void)fprintf(fp, MIME_HDR_DISPOSITION ": %s\n",
    488 		    Cp->C_disposition);
    489 	if (Cp->C_id)
    490 		(void)fprintf(fp, MIME_HDR_ID ": %s\n", Cp->C_id);
    491 	if (Cp->C_description)
    492 		(void)fprintf(fp, MIME_HDR_DESCRIPTION ": %s\n",
    493 		    Cp->C_description);
    494 }
    495 
    496 static void
    497 fput_body(FILE *fi, FILE *fo, struct Content *Cp)
    498 {
    499 	mime_codec_t enc;
    500 
    501 	enc = mime_fio_encoder(Cp->C_encoding);
    502 	if (enc == NULL)
    503 		warnx("unknown transfer encoding type: %s\n", Cp->C_encoding);
    504 	else
    505 		enc(fi, fo, 0);
    506 }
    507 
    508 
    509 static void
    510 fput_attachment(FILE *fo, struct attachment *ap)
    511 {
    512 	FILE *fi;
    513 	struct Content *Cp = &ap->a_Content;
    514 
    515 	fput_mime_content(fo, &ap->a_Content);
    516 	(void)putc('\n', fo);
    517 
    518 	switch (ap->a_type) {
    519 	case ATTACH_FNAME:
    520 		fi = fopen(ap->a_name, "r");
    521 		if (fi == NULL)
    522 			err(EXIT_FAILURE, "fopen: %s", ap->a_name);
    523 		break;
    524 
    525 	case ATTACH_FILENO:
    526 		fi = fdopen(ap->a_fileno, "r");
    527 		if (fi == NULL)
    528 			err(EXIT_FAILURE, "fdopen: %d", ap->a_fileno);
    529 		break;
    530 
    531 	case ATTACH_MSG:
    532 	default:
    533 		errx(EXIT_FAILURE, "unsupported attachment type");
    534 	}
    535 
    536 	fput_body(fi, fo, Cp);
    537 
    538 	if (ap->a_type == ATTACH_FNAME)
    539 		(void)fclose(fi);
    540 }
    541 
    542 /***********************************
    543  * Higher level attachment routines.
    544  */
    545 
    546 static int
    547 mktemp_file(FILE **nfo, FILE **nfi, const char *hint)
    548 {
    549 	char tempname[PATHSIZE];
    550 	int fd, fd2;
    551 	(void)snprintf(tempname, sizeof(tempname), "%s/%sXXXXXXXXXX",
    552 	    tmpdir, hint);
    553 	if ((fd = mkstemp(tempname)) == -1 ||
    554 	    (*nfo = Fdopen(fd, "w")) == NULL) {
    555 		if (fd != -1)
    556 			(void)close(fd);
    557 		warn("%s", tempname);
    558 		return -1;
    559 	}
    560 	(void)rm(tempname);
    561 	if ((fd2 = dup(fd)) == -1 ||
    562 	    (*nfi = Fdopen(fd2, "r")) == NULL) {
    563 		warn("%s", tempname);
    564 		(void)Fclose(*nfo);
    565 		return -1;
    566 	}
    567 	return 0;
    568 }
    569 
    570 
    571 /*
    572  * Repackage the mail as a multipart MIME message.  This should always
    573  * be called whenever there are attachments, but might be called even
    574  * if there are none if we want to wrap the message in a MIME package.
    575  */
    576 PUBLIC FILE *
    577 mime_encode(FILE *fi, struct header *header)
    578 {
    579 	struct attachment map;	/* fake structure for the message body */
    580 	struct attachment *attach;
    581 	struct attachment *ap;
    582 	FILE *nfi, *nfo;
    583 
    584 	attach = header->h_attach;
    585 
    586 	/*
    587 	 * Make new phantom temporary file with read and write file
    588 	 * handles: nfi and nfo, resp.
    589 	 */
    590 	if (mktemp_file(&nfo, &nfi, "mail.Rs") != 0)
    591 		return fi;
    592 
    593 	(void)memset(&map, 0, sizeof(map));
    594 	map.a_type = ATTACH_FILENO;
    595 	map.a_fileno = fileno(fi);
    596 
    597  	map.a_Content = get_mime_content(&map, 0);
    598 
    599 	if (attach) {
    600 		/* Multi-part message:
    601 		 * Make an attachment structure for the body message
    602 		 * and make that the first element in the attach list.
    603 		 */
    604 		if (fsize(fi)) {
    605 			map.a_flink = attach;
    606 			attach->a_blink = &map;
    607 			attach = &map;
    608 		}
    609 
    610 		/* Construct our MIME boundary string - used by mime_putheader() */
    611 		header->h_mime_boundary = make_boundary();
    612 
    613 		(void)fprintf(nfo, "This is a multi-part message in MIME format.\n");
    614 
    615 		for (ap = attach; ap; ap = ap->a_flink) {
    616 			(void)fprintf(nfo, "\n--%s\n", header->h_mime_boundary);
    617 			fput_attachment(nfo, ap);
    618 		}
    619 
    620 		/* the final boundary with two attached dashes */
    621 		(void)fprintf(nfo, "\n--%s--\n", header->h_mime_boundary);
    622 	}
    623 	else {
    624 		/* Single-part message (no attachments):
    625 		 * Update header->h_Content (used by mime_putheader()).
    626 		 * Output the body contents.
    627 		 */
    628 		char *encoding;
    629 
    630 		header->h_Content = map.a_Content;
    631 
    632 		/* check for an encoding override */
    633 		if ((encoding = value(ENAME_MIME_ENCODE_MSG)) && *encoding)
    634 			header->h_Content.C_encoding = encoding;
    635 
    636 		fput_body(fi, nfo, &header->h_Content);
    637 	}
    638 	(void)Fclose(fi);
    639 	(void)Fclose(nfo);
    640 	rewind(nfi);
    641 	return(nfi);
    642 }
    643 
    644 static char*
    645 check_filename(char *filename, char *canon_name)
    646 {
    647 	int fd;
    648 	struct stat sb;
    649 	char *fname = filename;
    650 	/*
    651 	 * 1) check that filename is really a file.
    652 	 * 2) check that filename is readable.
    653 	 * 3) allocate an attachment structure.
    654 	 * 4) save cananonical name for filename, so cd won't screw things later.
    655 	 * 5) add the structure to the end of the chain.
    656 	 */
    657 
    658 	if (fname[0] == '~' && fname[1] == '/') {
    659 		char *home = getenv("HOME");
    660 		/*
    661 		 * XXX - we could use the global 'homedir' here if we
    662 		 * move tinit() before getopt() in main.c
    663 		 */
    664 		if (home && home[0] != '~')
    665 			(void)easprintf(&fname, "%s/%s", home, fname + 2);
    666 	}
    667 	if (realpath(fname, canon_name) == NULL) {
    668 		warn("realpath: %s", filename);
    669 		canon_name = NULL;
    670 		goto done;
    671 	}
    672 	fd = open(canon_name, O_RDONLY, 0);
    673 	if (fd == -1) {
    674 		warnx("open: cannot read %s", filename);
    675 		canon_name = NULL;
    676 		goto done;
    677 	}
    678 	if (fstat(fd, &sb) == -1) {
    679 		warn("stat: %s", canon_name);
    680 		canon_name = NULL;
    681 		goto do_close;
    682 	}
    683 	if (!S_ISREG(sb.st_mode)) {
    684 		warnx("stat: %s is not a file", filename);
    685 		canon_name = NULL;
    686 	/*	goto do_close; */
    687 	}
    688  do_close:
    689 	(void)close(fd);
    690  done:
    691 	if (fname != filename)
    692 		free(fname);
    693 
    694 	return canon_name;
    695 }
    696 
    697 static struct attachment *
    698 attach_one_file(struct attachment *attach, char *filename, int attach_num)
    699 {
    700 	char canon_name[MAXPATHLEN];
    701 	struct attachment *ap, *nap;
    702 
    703 	if (check_filename(filename, canon_name) == NULL)
    704 		return NULL;
    705 
    706 	nap = csalloc(1, sizeof(*nap));
    707 	nap->a_type = ATTACH_FNAME;
    708 	nap->a_name = savestr(canon_name);
    709 
    710 	if (attach == NULL)
    711 		attach = nap;
    712 	else {
    713 		for (ap = attach; ap->a_flink != NULL; ap = ap->a_flink)
    714 			continue;
    715 		ap->a_flink = nap;
    716 		nap->a_blink = ap;
    717 	}
    718 
    719 	if (attach_num)
    720 		nap->a_Content = get_mime_content(nap, attach_num);
    721 
    722 	return attach;
    723 }
    724 
    725 
    726 static jmp_buf intjmp;
    727 /*ARGSUSED*/
    728 static void
    729 sigint(int signum __unused)
    730 {
    731 	siglongjmp(intjmp, 1);
    732 }
    733 
    734 static char *
    735 get_line(el_mode_t *em, const char *pr, const char *str, int i)
    736 {
    737 	sig_t saveint;
    738 	char *cp;
    739 	char *line;
    740 	char *prompt;
    741 
    742 	saveint = signal(SIGINT, sigint);
    743 	if (sigsetjmp(intjmp, 1)) {
    744 		(void)signal(SIGINT, saveint);
    745 		(void)putc('\n', stdout);
    746 		return __UNCONST("");
    747 	}
    748 
    749 	/* Don't use a '\t' in the format string here as completion
    750 	 * seems to handle it badly. */
    751 	(void)easprintf(&prompt, "#%-8d%s: ", i, pr);
    752 	line = my_gets(em, prompt, __UNCONST(str));
    753 	/* LINTED */
    754 	line = line ? savestr(line) : __UNCONST("");
    755 	free(prompt);
    756 
    757 	(void)signal(SIGINT, saveint);
    758 
    759 	/* strip trailing white space */
    760 	for (cp = line + strlen(line) - 1;
    761 	     cp >= line && isblank((unsigned char)*cp); cp--)
    762 		*cp = '\0';
    763 
    764 	/* skip leading white space */
    765 	cp = skip_white(line);
    766 
    767 	return cp;
    768 }
    769 
    770 static void
    771 sget_line(el_mode_t *em, const char *pr, const char **str, int i)
    772 {
    773 	char *line;
    774 	line = get_line(em, pr, *str, i);
    775 	if (strcmp(line, *str) != 0)
    776 		*str = savestr(line);
    777 }
    778 
    779 static void
    780 sget_encoding(const char **str, const char *filename, const char *ctype, int num)
    781 {
    782 	const char *ename;
    783 	const char *defename;
    784 
    785 	defename = NULL;
    786 	ename = *str;
    787 	for (;;) {
    788 		ename = get_line(&elm.mime_enc, "encoding", ename, num);
    789 
    790 		if (*ename == '\0') {
    791 			if (defename == NULL)
    792 				defename = content_encoding_by_name(filename, ctype);
    793 			ename = defename;
    794 		}
    795 		else if (mime_fio_encoder(ename) == NULL) {
    796 			const void *cookie;
    797 			(void)printf("Sorry: valid encoding modes are: ");
    798 			cookie = NULL;
    799 			ename = mime_next_encoding_name(&cookie);
    800 			for (;;) {
    801 				(void)printf("%s", ename);
    802 				ename = mime_next_encoding_name(&cookie);
    803 				if (ename == NULL)
    804 					break;
    805 				(void)fputc(',', stdout);
    806 			}
    807 			ename = *str;
    808 		}
    809 		else {
    810 			if (strcmp(ename, *str) != 0)
    811 				*str = savestr(ename);
    812 			break;
    813 		}
    814 	}
    815 }
    816 
    817 static struct attachment *
    818 edit_attachments(struct attachment *attach)
    819 {
    820 	char canon_name[MAXPATHLEN];
    821 	struct attachment *ap;
    822 	char *line;
    823 	int i;
    824 
    825 	(void)printf("Attachments:\n");
    826 
    827 	i = 1;
    828 	ap = attach;
    829 	while (ap) {
    830 		line = get_line(&elm.filec, "filename", ap->a_name, i);
    831 		if (*line == '\0') {	/* omit this attachment */
    832 			if (ap->a_blink)
    833 				ap->a_blink->a_flink = ap->a_flink;
    834 			else
    835 				attach = ap->a_flink;
    836 		}
    837 		else {
    838 			if (strcmp(line, ap->a_name) != 0) { /* new filename */
    839 				if (check_filename(line, canon_name) == NULL)
    840 					continue;
    841 				ap->a_name = savestr(canon_name);
    842 				ap->a_Content = get_mime_content(ap, 0);
    843 			}
    844 			sget_line(&elm.string, "description", &ap->a_Content.C_description, i);
    845 			sget_encoding(&ap->a_Content.C_encoding, ap->a_name, ap->a_Content.C_type, i);
    846 		}
    847 		i++;
    848 		if (ap->a_flink == NULL)
    849 			break;
    850 
    851 		ap = ap->a_flink;
    852 	}
    853 
    854 	do {
    855 		struct attachment *nap;
    856 
    857 		line = get_line(&elm.filec, "filename", "", i);
    858 		if (*line == '\0')
    859 			break;
    860 
    861 		nap = attach_one_file(ap, line, i);
    862 		if (nap == NULL)
    863 			continue;
    864 
    865 		if (ap)
    866 			ap = ap->a_flink;
    867 		else
    868 			ap = attach = nap;
    869 
    870 		sget_line(&elm.string, "description", &ap->a_Content.C_description, i);
    871 		sget_encoding(&ap->a_Content.C_encoding, ap->a_name, ap->a_Content.C_type, i);
    872 		i++;
    873 
    874 	} while (ap);
    875 
    876 	return attach;
    877 }
    878 
    879 /*
    880  * Hook used by the '-a' flag and '~@' escape to attach files.
    881  */
    882 PUBLIC struct attachment*
    883 mime_attach_files(struct attachment *attach, char *linebuf, int with_content)
    884 {
    885 	struct attachment *ap;
    886 	char *argv[MAXARGC];
    887 	int argc;
    888 	int attach_num;
    889 
    890 	argc = getrawlist(linebuf, argv, sizeof(argv)/sizeof(*argv));
    891 
    892 	attach_num = attach ? 1 : 0;
    893 	for (ap = attach; ap && ap->a_flink; ap = ap->a_flink)
    894 			attach_num++;
    895 
    896 	if (argc) {
    897 		int i;
    898 		for (i = 0; i < argc; i++) {
    899 			attach_num++;
    900 			ap = attach_one_file(ap, argv[i], with_content ? attach_num : 0);
    901 			if (attach == NULL)
    902 				attach = ap;
    903 		}
    904 	}
    905 	else {
    906 		attach = edit_attachments(attach);
    907 		(void)printf("--- end attachments ---\n");
    908 	}
    909 
    910 	return attach;
    911 }
    912 
    913 /*
    914  * Output MIME header strings as specified in the header structure.
    915  */
    916 PUBLIC void
    917 mime_putheader(FILE *fp, struct header *header)
    918 {
    919 	(void)fprintf(fp, MIME_HDR_VERSION ": " MIME_VERSION "\n");
    920 	if (header->h_attach) {
    921 		(void)fprintf(fp, MIME_HDR_TYPE ": multipart/mixed;\n");
    922 		(void)fprintf(fp, "\tboundary=\"%s\"\n", header->h_mime_boundary);
    923 	}
    924 	else {
    925 		fput_mime_content(fp, &header->h_Content);
    926 	}
    927 }
    928 
    929 #endif /* MIME_SUPPORT */
    930