xref: /netbsd-src/external/ibm-public/postfix/dist/src/local/forward.c (revision e6c7e151de239c49d2e38720a061ed9d1fa99309)
1 /*	$NetBSD: forward.c,v 1.3 2020/03/18 19:05:16 christos Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	forward 3
6 /* SUMMARY
7 /*	message forwarding
8 /* SYNOPSIS
9 /*	#include "local.h"
10 /*
11 /*	int	forward_init()
12 /*
13 /*	int	forward_append(attr)
14 /*	DELIVER_ATTR attr;
15 /*
16 /*	int	forward_finish(request, attr, cancel)
17 /*	DELIVER_REQUEST *request;
18 /*	DELIVER_ATTR attr;
19 /*	int	cancel;
20 /* DESCRIPTION
21 /*	This module implements the client interface for message
22 /*	forwarding.
23 /*
24 /*	forward_init() initializes internal data structures.
25 /*
26 /*	forward_append() appends a recipient to the list of recipients
27 /*	that will receive a message with the specified message sender
28 /*	and delivered-to addresses.
29 /*
30 /*	forward_finish() forwards the actual message contents and
31 /*	releases the memory allocated by forward_init() and by
32 /*	forward_append(). When the \fIcancel\fR argument is true, no
33 /*	messages will be forwarded. The \fIattr\fR argument specifies
34 /*	the original message delivery attributes as they were before
35 /*	alias or forward expansions.
36 /* DIAGNOSTICS
37 /*	A non-zero result means that the requested operation should
38 /*	be tried again.
39 /*	Warnings: problems connecting to the forwarding service,
40 /*	corrupt message file. A corrupt message is saved to the
41 /*	"corrupt" queue for further inspection.
42 /*	Fatal: out of memory.
43 /*	Panic: missing forward_init() or forward_finish() call.
44 /* LICENSE
45 /* .ad
46 /* .fi
47 /*	The Secure Mailer license must be distributed with this software.
48 /* AUTHOR(S)
49 /*	Wietse Venema
50 /*	IBM T.J. Watson Research
51 /*	P.O. Box 704
52 /*	Yorktown Heights, NY 10598, USA
53 /*
54 /*	Wietse Venema
55 /*	Google, Inc.
56 /*	111 8th Avenue
57 /*	New York, NY 10011, USA
58 /*--*/
59 
60 /* System library. */
61 
62 #include <sys_defs.h>
63 #include <sys/time.h>
64 #include <unistd.h>
65 
66 /* Utility library. */
67 
68 #include <msg.h>
69 #include <mymalloc.h>
70 #include <htable.h>
71 #include <argv.h>
72 #include <vstring.h>
73 #include <vstream.h>
74 #include <vstring_vstream.h>
75 #include <iostuff.h>
76 #include <stringops.h>
77 
78 /* Global library. */
79 
80 #include <mail_proto.h>
81 #include <cleanup_user.h>
82 #include <sent.h>
83 #include <record.h>
84 #include <rec_type.h>
85 #include <mark_corrupt.h>
86 #include <mail_date.h>
87 #include <mail_params.h>
88 #include <dsn_mask.h>
89 #include <smtputf8.h>
90 
91 /* Application-specific. */
92 
93 #include "local.h"
94 
95  /*
96   * Use one cleanup service connection for each (delivered to, sender) pair.
97   */
98 static HTABLE *forward_dt;
99 
100 typedef struct FORWARD_INFO {
101     VSTREAM *cleanup;			/* clean up service handle */
102     char   *queue_id;			/* forwarded message queue id */
103     struct timeval posting_time;	/* posting time */
104 } FORWARD_INFO;
105 
106 /* forward_init - prepare for forwarding */
107 
108 int     forward_init(void)
109 {
110 
111     /*
112      * Sanity checks.
113      */
114     if (forward_dt != 0)
115 	msg_panic("forward_init: missing forward_finish call");
116 
117     forward_dt = htable_create(0);
118     return (0);
119 }
120 
121 /* forward_open - open connection to cleanup service */
122 
123 static FORWARD_INFO *forward_open(DELIVER_REQUEST *request, const char *sender)
124 {
125     VSTRING *buffer = vstring_alloc(100);
126     FORWARD_INFO *info;
127     VSTREAM *cleanup;
128 
129 #define FORWARD_OPEN_RETURN(res) do { \
130 	vstring_free(buffer); \
131 	return (res); \
132     } while (0)
133 
134     /*
135      * Contact the cleanup service and save the new mail queue id. Request
136      * that the cleanup service bounces bad messages to the sender so that we
137      * can avoid the trouble of bounce management.
138      *
139      * In case you wonder what kind of bounces, examples are "too many hops",
140      * "message too large", perhaps some others. The reason not to bounce
141      * ourselves is that we don't really know who the recipients are.
142      */
143     cleanup = mail_connect(MAIL_CLASS_PUBLIC, var_cleanup_service, BLOCKING);
144     if (cleanup == 0) {
145 	msg_warn("connect to %s/%s: %m",
146 		 MAIL_CLASS_PUBLIC, var_cleanup_service);
147 	FORWARD_OPEN_RETURN(0);
148     }
149     close_on_exec(vstream_fileno(cleanup), CLOSE_ON_EXEC);
150     if (attr_scan(cleanup, ATTR_FLAG_STRICT,
151 		  RECV_ATTR_STR(MAIL_ATTR_QUEUEID, buffer),
152 		  ATTR_TYPE_END) != 1) {
153 	vstream_fclose(cleanup);
154 	FORWARD_OPEN_RETURN(0);
155     }
156     info = (FORWARD_INFO *) mymalloc(sizeof(FORWARD_INFO));
157     info->cleanup = cleanup;
158     info->queue_id = mystrdup(STR(buffer));
159     GETTIMEOFDAY(&info->posting_time);
160 
161 #define FORWARD_CLEANUP_FLAGS \
162 	(CLEANUP_FLAG_BOUNCE | CLEANUP_FLAG_MASK_INTERNAL \
163 	| smtputf8_autodetect(MAIL_SRC_MASK_FORWARD) \
164 	| ((request->smtputf8 & SMTPUTF8_FLAG_REQUESTED) ? \
165 	CLEANUP_FLAG_SMTPUTF8 : 0))
166 
167     attr_print(cleanup, ATTR_FLAG_NONE,
168 	       SEND_ATTR_INT(MAIL_ATTR_FLAGS, FORWARD_CLEANUP_FLAGS),
169 	       ATTR_TYPE_END);
170 
171     /*
172      * Send initial message envelope information. For bounces, set the
173      * designated sender: mailing list owner, posting user, whatever.
174      */
175     rec_fprintf(cleanup, REC_TYPE_TIME, REC_TYPE_TIME_FORMAT,
176 		REC_TYPE_TIME_ARG(info->posting_time));
177     rec_fputs(cleanup, REC_TYPE_FROM, sender);
178 
179     /*
180      * Don't send the original envelope ID or full/headers return mask if it
181      * was reset due to mailing list expansion.
182      */
183     if (request->dsn_ret)
184 	rec_fprintf(cleanup, REC_TYPE_ATTR, "%s=%d",
185 		    MAIL_ATTR_DSN_RET, request->dsn_ret);
186     if (request->dsn_envid && *(request->dsn_envid))
187 	rec_fprintf(cleanup, REC_TYPE_ATTR, "%s=%s",
188 		    MAIL_ATTR_DSN_ENVID, request->dsn_envid);
189 
190     /*
191      * Zero-length attribute values are place holders for unavailable
192      * attribute values. See qmgr_message.c. They are not meant to be
193      * propagated to queue files.
194      */
195 #define PASS_ATTR(fp, name, value) do { \
196     if ((value) && *(value)) \
197 	rec_fprintf((fp), REC_TYPE_ATTR, "%s=%s", (name), (value)); \
198     } while (0)
199 
200     /*
201      * XXX encapsulate these as one object.
202      */
203     PASS_ATTR(cleanup, MAIL_ATTR_LOG_CLIENT_NAME, request->client_name);
204     PASS_ATTR(cleanup, MAIL_ATTR_LOG_CLIENT_ADDR, request->client_addr);
205     PASS_ATTR(cleanup, MAIL_ATTR_LOG_PROTO_NAME, request->client_proto);
206     PASS_ATTR(cleanup, MAIL_ATTR_LOG_HELO_NAME, request->client_helo);
207     PASS_ATTR(cleanup, MAIL_ATTR_SASL_METHOD, request->sasl_method);
208     PASS_ATTR(cleanup, MAIL_ATTR_SASL_USERNAME, request->sasl_username);
209     PASS_ATTR(cleanup, MAIL_ATTR_SASL_SENDER, request->sasl_sender);
210     PASS_ATTR(cleanup, MAIL_ATTR_LOG_IDENT, request->log_ident);
211     PASS_ATTR(cleanup, MAIL_ATTR_RWR_CONTEXT, request->rewrite_context);
212 
213     FORWARD_OPEN_RETURN(info);
214 }
215 
216 /* forward_append - append recipient to message envelope */
217 
218 int     forward_append(DELIVER_ATTR attr)
219 {
220     FORWARD_INFO *info;
221     HTABLE *table_snd;
222 
223     /*
224      * Sanity checks.
225      */
226     if (msg_verbose)
227 	msg_info("forward delivered=%s sender=%s recip=%s",
228 		 attr.delivered, attr.sender, attr.rcpt.address);
229     if (forward_dt == 0)
230 	msg_panic("forward_append: missing forward_init call");
231 
232     /*
233      * In order to find the recipient list, first index a table by
234      * delivered-to header address, then by envelope sender address.
235      */
236     if ((table_snd = (HTABLE *) htable_find(forward_dt, attr.delivered)) == 0) {
237 	table_snd = htable_create(0);
238 	htable_enter(forward_dt, attr.delivered, (void *) table_snd);
239     }
240     if ((info = (FORWARD_INFO *) htable_find(table_snd, attr.sender)) == 0) {
241 	if ((info = forward_open(attr.request, attr.sender)) == 0)
242 	    return (-1);
243 	htable_enter(table_snd, attr.sender, (void *) info);
244     }
245 
246     /*
247      * Append the recipient to the message envelope. Don't send the original
248      * recipient or notification mask if it was reset due to mailing list
249      * expansion.
250      */
251     if (*attr.rcpt.dsn_orcpt)
252 	rec_fprintf(info->cleanup, REC_TYPE_ATTR, "%s=%s",
253 		    MAIL_ATTR_DSN_ORCPT, attr.rcpt.dsn_orcpt);
254     if (attr.rcpt.dsn_notify)
255 	rec_fprintf(info->cleanup, REC_TYPE_ATTR, "%s=%d",
256 		    MAIL_ATTR_DSN_NOTIFY, attr.rcpt.dsn_notify);
257     if (*attr.rcpt.orig_addr)
258 	rec_fputs(info->cleanup, REC_TYPE_ORCP, attr.rcpt.orig_addr);
259     rec_fputs(info->cleanup, REC_TYPE_RCPT, attr.rcpt.address);
260 
261     return (vstream_ferror(info->cleanup));
262 }
263 
264 /* forward_send - send forwarded message */
265 
266 static int forward_send(FORWARD_INFO *info, DELIVER_REQUEST *request,
267 			        DELIVER_ATTR attr, char *delivered)
268 {
269     const char *myname = "forward_send";
270     VSTRING *buffer = vstring_alloc(100);
271     VSTRING *folded;
272     int     status;
273     int     rec_type = 0;
274 
275     /*
276      * Start the message content segment. Prepend our Delivered-To: header to
277      * the message data. Stop at the first error. XXX Rely on the front-end
278      * services to enforce record size limits.
279      */
280     rec_fputs(info->cleanup, REC_TYPE_MESG, "");
281     vstring_strcpy(buffer, delivered);
282     rec_fprintf(info->cleanup, REC_TYPE_NORM, "Received: by %s (%s)",
283 		var_myhostname, var_mail_name);
284     rec_fprintf(info->cleanup, REC_TYPE_NORM, "\tid %s; %s",
285 		info->queue_id, mail_date(info->posting_time.tv_sec));
286     if (local_deliver_hdr_mask & DELIVER_HDR_FWD) {
287 	folded = vstring_alloc(100);
288 	rec_fprintf(info->cleanup, REC_TYPE_NORM, "Delivered-To: %s",
289 		    casefold(folded, (STR(buffer))));
290 	vstring_free(folded);
291     }
292     if ((status = vstream_ferror(info->cleanup)) == 0)
293 	if (vstream_fseek(attr.fp, attr.offset, SEEK_SET) < 0)
294 	    msg_fatal("%s: seek queue file %s: %m:",
295 		      myname, VSTREAM_PATH(attr.fp));
296     while (status == 0 && (rec_type = rec_get(attr.fp, buffer, 0)) > 0) {
297 	if (rec_type != REC_TYPE_CONT && rec_type != REC_TYPE_NORM)
298 	    break;
299 	status = (REC_PUT_BUF(info->cleanup, rec_type, buffer) != rec_type);
300     }
301     if (status == 0 && rec_type != REC_TYPE_XTRA) {
302 	msg_warn("%s: bad record type: %d in message content",
303 		 info->queue_id, rec_type);
304 	status |= mark_corrupt(attr.fp);
305     }
306 
307     /*
308      * Send the end-of-data marker only when there were no errors.
309      */
310     if (status == 0) {
311 	rec_fputs(info->cleanup, REC_TYPE_XTRA, "");
312 	rec_fputs(info->cleanup, REC_TYPE_END, "");
313     }
314 
315     /*
316      * Retrieve the cleanup service completion status only if there are no
317      * problems.
318      */
319     if (status == 0)
320 	if (vstream_fflush(info->cleanup)
321 	    || attr_scan(info->cleanup, ATTR_FLAG_MISSING,
322 			 RECV_ATTR_INT(MAIL_ATTR_STATUS, &status),
323 			 ATTR_TYPE_END) != 1)
324 	    status = 1;
325 
326     /*
327      * Log successful forwarding.
328      *
329      * XXX DSN alias and .forward expansion already report SUCCESS, so don't do
330      * it again here.
331      */
332     if (status == 0) {
333 	attr.rcpt.dsn_notify =
334 	    (attr.rcpt.dsn_notify == DSN_NOTIFY_SUCCESS ?
335 	     DSN_NOTIFY_NEVER : attr.rcpt.dsn_notify & ~DSN_NOTIFY_SUCCESS);
336 	dsb_update(attr.why, "2.0.0", "relayed", DSB_SKIP_RMTA, DSB_SKIP_REPLY,
337 		   "forwarded as %s", info->queue_id);
338 	status = sent(BOUNCE_FLAGS(request), SENT_ATTR(attr));
339     }
340 
341     /*
342      * Cleanup.
343      */
344     vstring_free(buffer);
345     return (status);
346 }
347 
348 /* forward_finish - complete message forwarding requests and clean up */
349 
350 int     forward_finish(DELIVER_REQUEST *request, DELIVER_ATTR attr, int cancel)
351 {
352     HTABLE_INFO **dt_list;
353     HTABLE_INFO **dt;
354     HTABLE_INFO **sn_list;
355     HTABLE_INFO **sn;
356     HTABLE *table_snd;
357     char   *delivered;
358     char   *sender;
359     FORWARD_INFO *info;
360     int     status = cancel;
361 
362     /*
363      * Sanity checks.
364      */
365     if (forward_dt == 0)
366 	msg_panic("forward_finish: missing forward_init call");
367 
368     /*
369      * Walk over all delivered-to header addresses and over each envelope
370      * sender address.
371      */
372     for (dt = dt_list = htable_list(forward_dt); *dt; dt++) {
373 	delivered = dt[0]->key;
374 	table_snd = (HTABLE *) dt[0]->value;
375 	for (sn = sn_list = htable_list(table_snd); *sn; sn++) {
376 	    sender = sn[0]->key;
377 	    info = (FORWARD_INFO *) sn[0]->value;
378 	    if (status == 0)
379 		status |= forward_send(info, request, attr, delivered);
380 	    if (msg_verbose)
381 		msg_info("forward_finish: delivered %s sender %s status %d",
382 			 delivered, sender, status);
383 	    (void) vstream_fclose(info->cleanup);
384 	    myfree(info->queue_id);
385 	    myfree((void *) info);
386 	}
387 	myfree((void *) sn_list);
388 	htable_free(table_snd, (void (*) (void *)) 0);
389     }
390     myfree((void *) dt_list);
391     htable_free(forward_dt, (void (*) (void *)) 0);
392     forward_dt = 0;
393     return (status);
394 }
395