smbtxt.c 13 KB
Newer Older
1
2
3
4
5
6
7
8
/* Synchronet message base (SMB) message text library routines */

/* $Id$ */

/****************************************************************************
 * @format.tab-size 4		(Plain Text/Source Code File Header)			*
 * @format.use-tabs true	(see http://www.synchro.net/ptsc_hdr.html)		*
 *																			*
rswindell's avatar
rswindell committed
9
 * Copyright Rob Swindell - http://www.synchro.net/copyright.html			*
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
 *																			*
 * This library is free software; you can redistribute it and/or			*
 * modify it under the terms of the GNU Lesser General Public License		*
 * as published by the Free Software Foundation; either version 2			*
 * of the License, or (at your option) any later version.					*
 * See the GNU Lesser General Public License for more details: lgpl.txt or	*
 * http://www.fsf.org/copyleft/lesser.html									*
 *																			*
 * Anonymous FTP access to the most recent released source is available at	*
 * ftp://vert.synchro.net, ftp://cvs.synchro.net and ftp://ftp.synchro.net	*
 *																			*
 * Anonymous CVS access to the development source and modification history	*
 * is available at cvs.synchro.net:/cvsroot/sbbs, example:					*
 * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs login			*
 *     (just hit return, no password is necessary)							*
 * cvs -d :pserver:anonymous@cvs.synchro.net:/cvsroot/sbbs checkout src		*
 *																			*
 * For Synchronet coding style and modification guidelines, see				*
 * http://www.synchro.net/source.html										*
 *																			*
 * You are encouraged to submit any modifications (preferably in Unix diff	*
 * format) via e-mail to mods@synchro.net									*
 *																			*
 * Note: If this box doesn't appear square, then you need to fix your tabs.	*
 ****************************************************************************/

/* ANSI */
37
38
#include <stdlib.h>	/* malloc/realloc/free */
#include <string.h>	/* strlen */
39
40
41

/* SMB-specific */
#include "smblib.h"
42
#include "base64.h"
43

44
char* SMBCALL smb_getmsgtxt(smb_t* smb, smbmsg_t* msg, ulong mode)
45
{
46
47
48
	char*	buf;
	char*	lzhbuf;
	char*	p;
49
	char*	str;
deuce's avatar
64-bit    
deuce committed
50
	uint16_t	xlat;
51
52
	uint 	i;
	int		lzh;	/* BOOL */
53
54
	long	l=0,lzhlen,length;

55
	if((buf=(char*)malloc(sizeof(char)))==NULL) {
56
		sprintf(smb->last_error
57
58
			,"%s malloc failure of %" XP_PRIsize_t "u bytes for buffer"
			,__FUNCTION__, sizeof(char));
59
60
61
62
		return(NULL);
	}
	*buf=0;

63
64
65
66
67
68
69
70
	if(!(mode&GETMSGTXT_NO_HFIELDS)) {
		for(i=0;i<(uint)msg->total_hfields;i++) {			/* comment headers are part of text */
			if(msg->hfield[i].type!=SMB_COMMENT && msg->hfield[i].type!=SMTPSYSMSG)
				continue;
			str=(char*)msg->hfield_dat[i];
			length=strlen(str)+2;	/* +2 for crlf */
			if((p=(char*)realloc(buf,l+length+1))==NULL) {
				sprintf(smb->last_error
71
72
					,"%s realloc failure of %ld bytes for comment buffer"
					, __FUNCTION__, l+length+1);
rswindell's avatar
rswindell committed
73
74
				free(buf);
				return(NULL);
75
76
77
			}
			buf=p;
			l+=sprintf(buf+l,"%s\r\n",str);
78
		}
rswindell's avatar
rswindell committed
79
80
81
		if(l) {	/* Add a blank line after comments */
			if((p=(char*)realloc(buf,l+3))==NULL) {
				sprintf(smb->last_error
82
83
					,"%s realloc failure of %ld bytes for comment buffer"
					, __FUNCTION__, l+3);
rswindell's avatar
rswindell committed
84
85
86
87
88
89
90
91
92
93
94
95
96
97
				free(buf);
				return(NULL);
			}
			buf=p;
			l+=sprintf(buf+l,"\r\n");
		}
		unsigned answers = 0;
		for(i=0;i<(uint)msg->total_hfields;i++) {			/* Poll Answers are part of text */
			if(msg->hfield[i].type!=SMB_POLL_ANSWER)
				continue;
			char tmp[128];
			length = safe_snprintf(tmp, sizeof(tmp), "%2u: %s\r\n", ++answers, (char*)msg->hfield_dat[i]);
			if((p=(char*)realloc(buf,l+length+1))==NULL) {
				sprintf(smb->last_error
98
99
					,"%s realloc failure of %ld bytes for comment buffer"
					, __FUNCTION__, l+length+1);
rswindell's avatar
rswindell committed
100
101
102
103
104
105
106
107
				free(buf);
				return(NULL);
			}
			buf=p;
			memcpy(buf+l, tmp, length);
			l += length;
			buf[l] = 0;
		}
108
109
	}

110
	for(i=0;i<(uint)msg->hdr.total_dfields;i++) {
111
		if(msg->dfield[i].length<=sizeof(xlat))
112
			continue;
113
114
115
116
117
118
119
120
121
122
123
124
		switch(msg->dfield[i].type) {
			case TEXT_BODY:
				if(mode&GETMSGTXT_NO_BODY)
					continue;
				break;
			case TEXT_TAIL:
				if(!(mode&GETMSGTXT_TAILS))
					continue;
				break;
			default:	/* ignore other data types */
				continue;
		}
125
126
		fseek(smb->sdt_fp,msg->hdr.offset+msg->dfield[i].offset
			,SEEK_SET);
127
128
		if(fread(&xlat, 1, sizeof(xlat), smb->sdt_fp) != sizeof(xlat))
			continue;
129
130
131
		lzh=0;
		if(xlat==XLAT_LZH) {
			lzh=1;
132
133
			if(fread(&xlat, 1, sizeof(xlat), smb->sdt_fp) != sizeof(xlat))
				continue;
134
135
136
137
		}
		if(xlat!=XLAT_NONE) 	/* no other translations currently supported */
			continue;

138
		length=msg->dfield[i].length-sizeof(xlat);
139
		if(lzh) {
140
			length-=sizeof(xlat);
141
142
			if(length<1)
				continue;
143
			if((lzhbuf=(char*)malloc(length))==NULL) {
144
				sprintf(smb->last_error
145
146
					,"%s malloc failure of %ld bytes for LZH buffer"
					, __FUNCTION__, length);
rswindell's avatar
rswindell committed
147
148
				free(buf);
				return(NULL);
149
			}
150
151
152
153
154
155
156
157
			if(smb_fread(smb,lzhbuf,length,smb->sdt_fp) != length) {
				sprintf(smb->last_error
					,"%s read failure of %ld bytes for LZH data"
					, __FUNCTION__, length);
				free(lzhbuf);
				free(buf);
				return(NULL);
			}
deuce's avatar
deuce committed
158
			lzhlen=*(int32_t*)lzhbuf;
159
			if((p=(char*)realloc(buf,l+lzhlen+3L))==NULL) {
160
				sprintf(smb->last_error
161
162
					,"%s realloc failure of %ld bytes for text buffer"
					, __FUNCTION__, l+lzhlen+3L);
163
				free(lzhbuf);
rswindell's avatar
rswindell committed
164
				free(buf);
165
				return(NULL);
166
167
			}
			buf=p;
deuce's avatar
deuce committed
168
			lzh_decode((uint8_t *)lzhbuf,length,(uint8_t *)buf+l);
169
			free(lzhbuf);
170
			l+=lzhlen;
171
172
		}
		else {
173
			if((p=(char*)realloc(buf,l+length+3L))==NULL) {
174
				sprintf(smb->last_error
175
176
					,"%s realloc failure of %ld bytes for text buffer"
					, __FUNCTION__, l+length+3L);
rswindell's avatar
rswindell committed
177
178
				free(buf);
				return(NULL);
179
180
181
182
183
184
185
186
187
188
			}
			buf=p;
			p=buf+l;
			l+=fread(p,1,length,smb->sdt_fp);
		}
		if(!l)
			continue;
		l--;
		while(l && buf[l]==0) l--;
		l++;
189
		*(buf+l)='\r';	/* CR */
190
		l++;
191
		*(buf+l)='\n';	/* LF */
192
		l++;
193
		*(buf+l)=0;
194
	}
195

196
197
198
199
200
	if(mode&GETMSGTXT_PLAIN) {
		char* plaintext = smb_getplaintext(msg, buf);
		if(plaintext != NULL)
			return plaintext;
	}
201
202
203
	return(buf);
}

204
void SMBCALL smb_freemsgtxt(char* buf)
205
206
{
	if(buf!=NULL)
207
		free(buf);
208
}
rswindell's avatar
rswindell committed
209

210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
enum content_transfer_encoding {
	CONTENT_TRANFER_ENCODING_NONE,
	CONTENT_TRANFER_ENCODING_BASE64,
	CONTENT_TRANFER_ENCODING_QUOTED_PRINTABLE,
	CONTENT_TRANFER_ENCODING_OTHER
};

/* Decode quoted-printable content-transfer-encoded text */
/* Ignores (strips) unsupported ctrl chars and non-ASCII chars */
/* Does not enforce 76 char line length limit */
char* qp_decode(char* buf)
{
	uchar*	p=(uchar*)buf;
	uchar*	dest=p;

225
	for(;*p != 0; p++) {
226
		if(*p==' ' || (*p>='!' && *p<='~' && *p!='=') || *p=='\t'|| *p=='\r'|| *p=='\n')
227
228
229
			*dest++=*p;
		else if(*p=='=') {
			p++;
230
231
232
			if(*p == '\r')	/* soft link break */
				p++;
			if(*p == 0)
233
				break;
234
235
			if(*p == '\n')
				continue;
236
			if(isxdigit(*p) && isxdigit(*(p+1))) {
237
				uchar ch = HEX_CHAR_TO_INT(*p) << 4;
238
				p++;
239
240
241
				ch |= HEX_CHAR_TO_INT(*p);
				if(ch == '\t' || ch >= ' ')
					*dest++=ch;
242
243
244
245
246
247
			} else {	/* bad encoding */
				*dest++='=';
				*dest++=*p;
			}
		}
	}
248
249
	*dest++='\r';
	*dest++='\n';
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
	*dest=0;
	return buf;
}

static enum content_transfer_encoding mime_getxferencoding(char* beg, char* end)
{
	char* p = beg;

	while(p < end) {
		SKIP_WHITESPACE(p);
		if(strnicmp(p, "content-transfer-encoding:", 26) != 0) {
			FIND_CHAR(p, '\n');
			continue;
		}
		p += 26;
		SKIP_WHITESPACE(p);
		if(strnicmp(p, "base64", 6) == 0)
			return CONTENT_TRANFER_ENCODING_BASE64;
		if(strnicmp(p, "quoted-printable", 16) == 0)
			return CONTENT_TRANFER_ENCODING_QUOTED_PRINTABLE;
		if(strnicmp(p, "7bit", 4) == 0 || strnicmp(p, "8bit", 4) == 0 || strnicmp(p, "binary", 6) == 0)
			return CONTENT_TRANFER_ENCODING_NONE;
		return CONTENT_TRANFER_ENCODING_OTHER;
	}

	return CONTENT_TRANFER_ENCODING_NONE;
}

/* ToDo: parse and return the "modification-date" value */
279
static BOOL mime_getattachment(char* beg, char* end, char* attachment, size_t attachment_len)
280
{
281
	char fname[MAX_PATH+1];
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
	char* p = beg;

	while(p < end) {
		SKIP_WHITESPACE(p);
		if(strnicmp(p, "content-disposition:", 20) != 0) {
			FIND_CHAR(p, '\n');
			continue;
		}
		p += 20;
		SKIP_WHITESPACE(p);
		if(strnicmp(p, "inline", 6) == 0) {
			FIND_CHAR(p, '\n');
			continue;
		}
		char* filename = strstr(p, "filename=");
		if(filename == NULL) {
			FIND_CHAR(p, '\n');
			continue;
		}
		filename += 9;
		char* term;
		if(*filename == '"') {
			filename++;
			term = strchr(filename, '"');
		} else
			term = strchr(filename, ';');
		if(term == NULL) {
			term = filename;
			FIND_WHITESPACE(term);
		}
312
313
		if(term - filename >= sizeof(fname))
			term = filename + sizeof(fname) - 1;
314
315
		memcpy(fname, filename, term - filename);
		fname[term - filename] = 0;
316
317
318
		term = fname;
		FIND_WHITESPACE(term);
		*term = 0;
319
320
321
322
		if(attachment != NULL && attachment_len > 0) {
			strncpy(attachment, getfname(fname), attachment_len);
			attachment[attachment_len] = '\0';
		}
323
324
325
326
327
328
329
		return TRUE;
	}
	return FALSE;
}

/* Find the specified content-type in a MIME-encoded message body, recursively */
static char* mime_getcontent(char* buf, const char* content_type, const char* content_match
330
	,int depth, enum content_transfer_encoding* encoding, char* attachment, size_t attachment_len, int index)
rswindell's avatar
rswindell committed
331
332
333
334
{
	char*	txt;
	char*	p;
	char	boundary[256];
335
336
337
	char	match1[128];
	char	match2[128];
	int		match_len = 0;
338
	int		found = 0;
339

340
341
342
343
	if(content_match != NULL) {
		match_len = sprintf(match1, "Content-Type: %s;", content_match);
					sprintf(match2, "Content-Type: %s\r", content_match);
	}
rswindell's avatar
rswindell committed
344

345
346
	if(depth > 2)
		return NULL;
rswindell's avatar
rswindell committed
347
	if(content_type == NULL)	/* Not MIME-encoded */
348
		return NULL;
rswindell's avatar
rswindell committed
349
350
351
352
353
354
355
	content_type += 13;
	SKIP_WHITESPACE(content_type);
	if(strstr(content_type, "multipart/alternative;") == content_type)
		content_type += 22;
	else if(strstr(content_type, "multipart/mixed;") == content_type)
		content_type +=16;
	else
356
		return NULL;
357
	p = strstr(content_type, "boundary=");
rswindell's avatar
rswindell committed
358
	if(p == NULL)
359
		return NULL;
360
361
362
363
364
365
	p += 9;
	if(*p == '"')
		p++;
	SAFEPRINTF(boundary, "--%s", p);
	if((p = strchr(boundary,'"')) != NULL)
		*p = 0;
rswindell's avatar
rswindell committed
366
367
368
369
370
371
372
	txt = buf;
	while((p = strstr(txt, boundary)) != NULL) {
		txt = p+strlen(boundary);
		SKIP_WHITESPACE(txt);
		p = strstr(txt, "\r\n\r\n");	/* End of header */
		if(p==NULL)
			continue;
373
374
375
376
377
378
379
380
381
		for(content_type = txt; content_type < p; content_type++) {
			SKIP_WHITESPACE(content_type);
			if(strnicmp(content_type, "Content-Type:", 13) == 0)
				break;
			FIND_CHAR(content_type, '\r');
		}
		if(content_type >= p)
			continue;
		if((match_len && strnicmp(content_type, match1, match_len) && strnicmp(content_type, match2, match_len))
382
383
			|| (attachment != NULL && !mime_getattachment(txt, p, attachment, attachment_len))) {
			if((p = mime_getcontent(p, content_type, content_match, depth + 1, encoding, attachment, attachment_len, index)) != NULL)
384
385
386
387
				return p;
			continue;
		}
		if(found++ != index) {
388
			if((p = mime_getcontent(p, content_type, content_match, depth + 1, encoding, attachment, attachment_len, index)) != NULL)
389
390
391
				return p;
			continue;
		}
392
393
		if(encoding != NULL)
			*encoding = mime_getxferencoding(txt, p);
rswindell's avatar
rswindell committed
394
395
396
397
		txt = p;
		SKIP_WHITESPACE(txt);
		if((p = strstr(txt, boundary)) != NULL)
			*p = 0;
398
		return txt;
rswindell's avatar
rswindell committed
399
	}
400
401
402
403
	return NULL;
}

/* Get just the plain-text portion of a MIME-encoded message body */
404
/* Returns NULL if there is no MIME-encoded plain-text portion of the message */
405
406
407
408
409
char* SMBCALL smb_getplaintext(smbmsg_t* msg, char* buf)
{
	int		i;
	char*	txt;
	char*	content_type = NULL;
410
	enum content_transfer_encoding xfer_encoding = CONTENT_TRANFER_ENCODING_NONE;
411

412
413
	for(i=0;i<msg->total_hfields;i++) {
		if(msg->hfield[i].type==RFC822HEADER) {
414
415
416
417
418
419
			if(strnicmp((char*)msg->hfield_dat[i],"Content-Type:",13)==0) {
				content_type=msg->hfield_dat[i];
				break;
			}
        }
    }
420
	if(content_type == NULL)	/* not MIME */
421
		return NULL;
422
	txt = mime_getcontent(buf, content_type, "text/plain", 0, &xfer_encoding
423
		,/* attachment: */NULL, /* attachment_len: */0, /* index: */0);
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
	if(txt == NULL)
		return NULL;

	memmove(buf, txt, strlen(txt)+1);
	if(*buf == 0)	/* No decoding necessary */
		return buf;
	if(xfer_encoding == CONTENT_TRANFER_ENCODING_QUOTED_PRINTABLE)
		qp_decode(buf);
	else if(xfer_encoding == CONTENT_TRANFER_ENCODING_BASE64) {
		char* decoded = strdup(buf);
		if(decoded == NULL)
			return NULL;
		if(b64_decode(decoded, strlen(decoded), buf, strlen(buf)) > 0)
			strcpy(buf, decoded);
		free(decoded);
439
440
	}

rswindell's avatar
rswindell committed
441
442
	return buf;
}
443
444

/* Get just an attachment (just one) from MIME-encoded message body */
445
uint8_t* SMBCALL smb_getattachment(smbmsg_t* msg, char* buf, char* filename, size_t filename_len, uint32_t* filelen, int index)
446
447
448
449
450
451
{
	int		i;
	char*	txt;
	char*	content_type = NULL;
	enum content_transfer_encoding xfer_encoding = CONTENT_TRANFER_ENCODING_NONE;

452
453
	for(i=0;i<msg->total_hfields;i++) {
		if(msg->hfield[i].type==RFC822HEADER) {
454
455
456
457
458
459
460
461
			if(strnicmp((char*)msg->hfield_dat[i],"Content-Type:",13)==0) {
				content_type=msg->hfield_dat[i];
				break;
			}
        }
    }
	if(content_type == NULL)	/* not MIME */
		return NULL;
462
	txt = mime_getcontent(buf, content_type, /* match-type: */NULL, 0, &xfer_encoding
463
		,/* attachment: */filename, filename_len, index);
464
465
	if(txt != NULL && xfer_encoding == CONTENT_TRANFER_ENCODING_BASE64) {
		memmove(buf, txt, strlen(txt)+1);
466
467
468
469
		int result = b64_decode(buf, strlen(buf), buf, strlen(buf));
		if(result < 1)
			return NULL;
		*filelen = result;
470
		return (uint8_t*)buf;
471
472
473
474
	}

	return NULL;	/* No attachment */
}