summaryrefslogtreecommitdiffstats
path: root/src/global/mail_copy.c
blob: 8a56f84affe2b7fae7c23b7e89c532b17091d701 (plain)
1
2
3
4
5
6
7
8
9
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
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
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
279
280
281
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
312
313
314
315
/*++
/* NAME
/*	mail_copy 3
/* SUMMARY
/*	copy message with extreme prejudice
/* SYNOPSIS
/*	#include <mail_copy.h>
/*
/*	int	mail_copy(sender, orig_to, delivered, src, dst, flags, eol, why)
/*	const char *sender;
/*	const char *orig_to;
/*	const char *delivered;
/*	VSTREAM	*src;
/*	VSTREAM	*dst;
/*	int	flags;
/*	const char *eol;
/*	DSN_BUF	*why;
/* DESCRIPTION
/*	mail_copy() copies a mail message from record stream to stream-lf
/*	stream, and attempts to detect all possible I/O errors.
/*
/*	Arguments:
/* .IP sender
/*	The sender envelope address.
/* .IP delivered
/*	Null pointer or delivered-to: header address.
/* .IP src
/*	The source record stream, positioned at the beginning of the
/*	message contents.
/* .IP dst
/*	The destination byte stream (in stream-lf format). If the message
/*	ends in an incomplete line, a newline character is appended to
/*	the output.
/* .IP flags
/*	The binary OR of zero or more of the following:
/* .RS
/* .IP MAIL_COPY_QUOTE
/*	Prepend a `>' character to lines beginning with `From '.
/* .IP MAIL_COPY_DOT
/*	Prepend a `.' character to lines beginning with `.'.
/* .IP MAIL_COPY_TOFILE
/*	On systems that support this, use fsync() to flush the
/*	data to stable storage, and truncate the destination
/*	file to its original length in case of problems.
/* .IP MAIL_COPY_FROM
/*	Prepend a UNIX-style From_ line to the message.
/* .IP MAIL_COPY_BLANK
/*	Append an empty line to the end of the message.
/* .IP MAIL_COPY_DELIVERED
/*	Prepend a Delivered-To: header with the name of the
/*	\fIdelivered\fR attribute.
/*	The address is quoted according to RFC822 rules.
/* .IP MAIL_COPY_ORIG_RCPT
/*	Prepend an X-Original-To: header with the original
/*	envelope recipient address. This is a NOOP with
/*	var_enable_orcpt === 0.
/* .IP MAIL_COPY_RETURN_PATH
/*	Prepend a Return-Path: header with the value of the
/*	\fIsender\fR attribute.
/* .RE
/*	The manifest constant MAIL_COPY_MBOX is a convenient shorthand for
/*	all MAIL_COPY_XXX options that are appropriate for mailbox delivery.
/*	Use MAIL_COPY_NONE to copy a message without any options enabled.
/* .IP eol
/*	Record delimiter, for example, LF or CF LF.
/* .IP why
/*	A null pointer, or storage for the reason of failure in
/*	the form of a DSN detail code plus free text.
/* DIAGNOSTICS
/*	A non-zero result means the operation failed. Warnings: corrupt
/*	message file. A corrupt message is marked as corrupt.
/*
/*	The result is the bit-wise OR of zero or more of the following:
/* .IP MAIL_COPY_STAT_CORRUPT
/*	The queue file is marked as corrupt.
/* .IP MAIL_COPY_STAT_READ
/*	A read error was detected; errno specifies the nature of the problem.
/* .IP MAIL_COPY_STAT_WRITE
/*	A write error was detected; errno specifies the nature of the problem.
/* SEE ALSO
/*	mark_corrupt(3), mark queue file as corrupted.
/* LICENSE
/* .ad
/* .fi
/*	The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*	Wietse Venema
/*	IBM T.J. Watson Research
/*	P.O. Box 704
/*	Yorktown Heights, NY 10598, USA
/*
/*	Wietse Venema
/*	Google, Inc.
/*	111 8th Avenue
/*	New York, NY 10011, USA
/*--*/

/* System library. */

#include <sys_defs.h>
#include <sys/stat.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>

/* Utility library. */

#include <msg.h>
#include <htable.h>
#include <vstream.h>
#include <vstring.h>
#include <vstring_vstream.h>
#include <stringops.h>
#include <iostuff.h>
#include <warn_stat.h>

/* Global library. */

#include "quote_822_local.h"
#include "record.h"
#include "rec_type.h"
#include "mail_queue.h"
#include "mail_addr.h"
#include "mark_corrupt.h"
#include "mail_params.h"
#include "mail_copy.h"
#include "mbox_open.h"
#include "dsn_buf.h"
#include "sys_exits.h"

/* mail_copy - copy message with extreme prejudice */

int     mail_copy(const char *sender,
		          const char *orig_rcpt,
		          const char *delivered,
		          VSTREAM *src, VSTREAM *dst,
		          int flags, const char *eol, DSN_BUF *why)
{
    const char *myname = "mail_copy";
    VSTRING *buf;
    char   *bp;
    off_t   orig_length;
    int     read_error;
    int     write_error;
    int     corrupt_error = 0;
    time_t  now;
    int     type;
    int     prev_type;
    struct stat st;
    off_t   size_limit;

    /*
     * Workaround 20090114. This will hopefully get someone's attention. The
     * problem with file_size_limit < message_size_limit is that mail will be
     * delivered again and again until someone removes it from the queue by
     * hand, because Postfix cannot mark a recipient record as "completed".
     */
    if (fstat(vstream_fileno(src), &st) < 0)
	msg_fatal("fstat: %m");
    if ((size_limit = get_file_limit()) < st.st_size)
	msg_panic("file size limit %lu < message size %lu. This "
		  "causes large messages to be delivered repeatedly "
		  "after they were submitted with \"sendmail -t\" "
		  "or after recipients were added with the Milter "
		  "SMFIR_ADDRCPT request",
		  (unsigned long) size_limit,
		  (unsigned long) st.st_size);

    /*
     * Initialize.
     */
#ifndef NO_TRUNCATE
    if ((flags & MAIL_COPY_TOFILE) != 0)
	if ((orig_length = vstream_fseek(dst, (off_t) 0, SEEK_END)) < 0)
	    msg_fatal("seek file %s: %m", VSTREAM_PATH(dst));
#endif
    buf = vstring_alloc(100);

    /*
     * Prepend a bunch of headers to the message.
     */
    if (flags & (MAIL_COPY_FROM | MAIL_COPY_RETURN_PATH)) {
	if (sender == 0)
	    msg_panic("%s: null sender", myname);
	quote_822_local(buf, sender);
	if (flags & MAIL_COPY_FROM) {
	    time(&now);
	    vstream_fprintf(dst, "From %s  %.24s%s", *sender == 0 ?
			    MAIL_ADDR_MAIL_DAEMON : vstring_str(buf),
			    asctime(localtime(&now)), eol);
	}
	if (flags & MAIL_COPY_RETURN_PATH) {
	    vstream_fprintf(dst, "Return-Path: <%s>%s",
			    *sender ? vstring_str(buf) : "", eol);
	}
    }
    if (flags & MAIL_COPY_ORIG_RCPT) {
	if (orig_rcpt == 0)
	    msg_panic("%s: null orig_rcpt", myname);

	/*
	 * An empty original recipient record almost certainly means that
	 * original recipient processing was disabled.
	 */
	if (var_enable_orcpt && *orig_rcpt) {
	    quote_822_local(buf, orig_rcpt);
	    vstream_fprintf(dst, "X-Original-To: %s%s", vstring_str(buf), eol);
	}
    }
    if (flags & MAIL_COPY_DELIVERED) {
	if (delivered == 0)
	    msg_panic("%s: null delivered", myname);
	quote_822_local(buf, delivered);
	vstream_fprintf(dst, "Delivered-To: %s%s", vstring_str(buf), eol);
    }

    /*
     * Copy the message. Escape lines that could be confused with the ugly
     * From_ line. Make sure that there is a blank line at the end of the
     * message so that the next ugly From_ can be found by mail reading
     * software.
     * 
     * XXX Rely on the front-end services to enforce record size limits.
     */
#define VSTREAM_FWRITE_BUF(s,b) \
	vstream_fwrite((s),vstring_str(b),VSTRING_LEN(b))

    prev_type = REC_TYPE_NORM;
    while ((type = rec_get(src, buf, 0)) > 0) {
	if (type != REC_TYPE_NORM && type != REC_TYPE_CONT)
	    break;
	bp = vstring_str(buf);
	if (prev_type == REC_TYPE_NORM) {
	    if ((flags & MAIL_COPY_QUOTE) && *bp == 'F' && !strncmp(bp, "From ", 5))
		VSTREAM_PUTC('>', dst);
	    if ((flags & MAIL_COPY_DOT) && *bp == '.')
		VSTREAM_PUTC('.', dst);
	}
	if (VSTRING_LEN(buf) && VSTREAM_FWRITE_BUF(dst, buf) != VSTRING_LEN(buf))
	    break;
	if (type == REC_TYPE_NORM && vstream_fputs(eol, dst) == VSTREAM_EOF)
	    break;
	prev_type = type;
    }
    if (vstream_ferror(dst) == 0) {
	if (var_fault_inj_code == 1)
	    type = 0;
	if (type != REC_TYPE_XTRA) {
	    /* XXX Where is the queue ID? */
	    msg_warn("bad record type: %d in message content", type);
	    corrupt_error = mark_corrupt(src);
	}
	if (prev_type != REC_TYPE_NORM)
	    vstream_fputs(eol, dst);
	if (flags & MAIL_COPY_BLANK)
	    vstream_fputs(eol, dst);
    }
    vstring_free(buf);

    /*
     * Make sure we read and wrote all. Truncate the file to its original
     * length when the delivery failed. POSIX does not require ftruncate(),
     * so we may have a portability problem. Note that fclose() may fail even
     * while fflush and fsync() succeed. Think of remote file systems such as
     * AFS that copy the file back to the server upon close. Oh well, no
     * point optimizing the error case. XXX On systems that use flock()
     * locking, we must truncate the file file before closing it (and losing
     * the exclusive lock).
     */
    read_error = vstream_ferror(src);
    write_error = vstream_fflush(dst);
#ifdef HAS_FSYNC
    if ((flags & MAIL_COPY_TOFILE) != 0)
	write_error |= fsync(vstream_fileno(dst));
#endif
    if (var_fault_inj_code == 2) {
	read_error = 1;
	errno = ENOENT;
    }
    if (var_fault_inj_code == 3) {
	write_error = 1;
	errno = ENOENT;
    }
#ifndef NO_TRUNCATE
    if ((flags & MAIL_COPY_TOFILE) != 0)
	if (corrupt_error || read_error || write_error)
	    /* Complain about ignored "undo" errors? So sue me. */
	    (void) ftruncate(vstream_fileno(dst), orig_length);
#endif
    write_error |= vstream_fclose(dst);

    /*
     * Return the optional verbose error description.
     */
#define TRY_AGAIN_ERROR(errno) \
	(errno == EAGAIN || errno == ESTALE)

    if (why && read_error)
	dsb_unix(why, TRY_AGAIN_ERROR(errno) ? "4.3.0" : "5.3.0",
		 sys_exits_detail(EX_IOERR)->text,
		 "error reading message: %m");
    if (why && write_error)
	dsb_unix(why, mbox_dsn(errno, "5.3.0"),
		 sys_exits_detail(EX_IOERR)->text,
		 "error writing message: %m");

    /*
     * Use flag+errno description when the optional verbose description is
     * not desired.
     */
    return ((corrupt_error ? MAIL_COPY_STAT_CORRUPT : 0)
	    | (read_error ? MAIL_COPY_STAT_READ : 0)
	    | (write_error ? MAIL_COPY_STAT_WRITE : 0));
}