xref: /csrg-svn/usr.sbin/sendmail/src/udb.c (revision 51761)
1 /*
2  * Copyright (c) 1983 Eric P. Allman
3  * Copyright (c) 1988 Regents of the University of California.
4  * All rights reserved.
5  *
6  * %sccs.include.redist.c%
7  */
8 
9 #ifndef lint
10 #ifdef USERDB
11 static char sccsid [] = "@(#)udb.c	5.8 (Berkeley) 11/20/91 (with USERDB)";
12 #else
13 static char sccsid [] = "@(#)udb.c	5.8 (Berkeley) 11/20/91 (without USERDB)";
14 #endif
15 #endif
16 
17 #include "sendmail.h"
18 
19 #ifdef USERDB
20 
21 #include <sys/file.h>
22 #include <sys/time.h>
23 #include <fcntl.h>
24 #include <netdb.h>
25 #include <db.h>
26 
27 /*
28 **  UDBEXPAND.C -- interface between sendmail and Berkeley User Data Base.
29 **
30 **	This depends on the 4.4BSD db package.
31 */
32 
33 
34 struct udbent
35 {
36 	char	*udb_spec;		/* string version of spec */
37 	int	udb_type;		/* type of entry */
38 	union
39 	{
40 		/* type UE_REMOTE -- do remote call for lookup */
41 		struct
42 		{
43 			struct sockaddr_in _udb_addr;	/* address */
44 			int		_udb_timeout;	/* timeout */
45 		} udb_remote;
46 #define udb_addr	udb_u.udb_remote._udb_addr
47 #define udb_timeout	udb_u.udb_remote._udb_timeout
48 
49 		/* type UE_FORWARD -- forward message to remote */
50 		struct
51 		{
52 			char	*_udb_fwdhost;	/* name of forward host */
53 		} udb_forward;
54 #define udb_fwdhost	udb_u.udb_forward._udb_fwdhost
55 
56 		/* type UE_LOOKUP -- lookup in local database */
57 		struct
58 		{
59 			char	*_udb_dbname;	/* pathname of database */
60 			DB	*_udb_dbp;	/* open database ptr */
61 		} udb_lookup;
62 #define udb_dbname	udb_u.udb_lookup._udb_dbname
63 #define udb_dbp		udb_u.udb_lookup._udb_dbp
64 	} udb_u;
65 };
66 
67 #define UDB_EOLIST	0	/* end of list */
68 #define UDB_SKIP	1	/* skip this entry */
69 #define UDB_REMOTE	2	/* look up in remote database */
70 #define UDB_LOOKUP	3	/* look up in local database */
71 #define UDB_FORWARD	4	/* forward to remote host */
72 
73 #define MAXUDBENT	10	/* maximum number of UDB entries */
74 
75 
76 struct option
77 {
78 	char	*name;
79 	char	*val;
80 };
81 /*
82 **  UDBEXPAND -- look up user in database and expand
83 **
84 **	Parameters:
85 **		a -- address to expand.
86 **		sendq -- pointer to head of sendq to put the expansions in.
87 **
88 **	Returns:
89 **		none.
90 **
91 **	Side Effects:
92 **		Modifies sendq.
93 */
94 
95 int	UdbPort = 1616;
96 int	UdbTimeout = 10;
97 
98 struct udbent	UdbEnts[MAXUDBENT + 1];
99 int		UdbSock = -1;
100 
101 void
102 udbexpand(a, sendq)
103 	register ADDRESS *a;
104 	ADDRESS **sendq;
105 {
106 	int i;
107 	register char *p;
108 	DBT key;
109 	DBT info;
110 	static bool firstcall = TRUE;
111 	bool breakout;
112 	register struct udbent *up;
113 	int keylen;
114 	char keybuf[128];
115 	char buf[8192];
116 
117 	if (tTd(28, 1))
118 		printf("expand(%s)\n", a->q_paddr);
119 
120 	/* make certain we are supposed to send to this address */
121 	if (bitset(QDONTSEND, a->q_flags) ||
122 	    UdbSpec == NULL || UdbSpec[0] == '\0')
123 		return;
124 	CurEnv->e_to = a->q_paddr;
125 
126 	/* on first call, locate the database */
127 	if (firstcall)
128 	{
129 		extern void _udbx_init();
130 
131 		_udbx_init();
132 		firstcall = FALSE;
133 	}
134 
135 	/* if name is too long, assume it won't match */
136 	if (strlen(a->q_user) > sizeof keybuf - 12)
137 		return;
138 
139 	/* if name begins with a colon, it indicates our metadata */
140 	if (a->q_user[0] == ':')
141 		return;
142 
143 	/* build actual database key */
144 	(void) strcpy(keybuf, a->q_user);
145 	(void) strcat(keybuf, ":maildrop");
146 	keylen = strlen(keybuf);
147 
148 	breakout = FALSE;
149 	for (up = UdbEnts; !breakout; up++)
150 	{
151 		char *user;
152 		struct timeval timeout;
153 		fd_set fdset;
154 
155 		/*
156 		**  Select action based on entry type.
157 		**
158 		**	On dropping out of this switch, "class" should
159 		**	explain the type of the data, and "user" should
160 		**	contain the user information.
161 		*/
162 
163 		switch (up->udb_type)
164 		{
165 		  case UDB_LOOKUP:
166 			key.data = keybuf;
167 			key.size = keylen;
168 			i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_CURSOR);
169 			if (i != 0 || info.size <= 0)
170 			{
171 				if (i < 0)
172 					syserr("udbexpand: db-get stat %s");
173 				if (tTd(28, 2))
174 					printf("expand: no match on %s\n", keybuf);
175 				continue;
176 			}
177 
178 			/* there is at least one match -- start processing */
179 			breakout = TRUE;
180 			do
181 			{
182 				if (info.size < sizeof buf)
183 					user = buf;
184 				else
185 					user = xalloc(info.size + 1);
186 				bcopy(info.data, user, info.size);
187 				user[info.size] = '\0';
188 
189 				message(Arpa_Info, "expanded to %s", user);
190 				AliasLevel++;
191 				sendtolist(user, a, sendq);
192 				AliasLevel--;
193 
194 				if (user != buf)
195 					free(user);
196 
197 				/* get the next record */
198 				i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_NEXT);
199 			} while (i == 0 && key.size == keylen &&
200 					bcmp(key.data, keybuf, keylen) == 0);
201 			break;
202 
203 		  case UDB_REMOTE:
204 			/* not yet implemented */
205 			continue;
206 
207 		  case UDB_FORWARD:
208 			i = strlen(up->udb_fwdhost) + strlen(a->q_user) + 1;
209 			if (i < sizeof buf)
210 				user = buf;
211 			else
212 				user = xalloc(i + 1);
213 			(void) sprintf(user, "%s@%s", a->q_user, up->udb_fwdhost);
214 			message(Arpa_Info, "expanded to %s", user);
215 			AliasLevel++;
216 			sendtolist(user, a, sendq);
217 			AliasLevel--;
218 			if (user != buf)
219 				free(user);
220 			breakout = TRUE;
221 			break;
222 
223 		  case UDB_EOLIST:
224 			breakout = TRUE;
225 			continue;
226 
227 		  default:
228 			/* unknown entry type */
229 			continue;
230 		}
231 	}
232 }
233 
234 #define MAXUDBOPTS	27
235 
236 void
237 _udbx_init()
238 {
239 	register char *p;
240 	int i;
241 	register struct udbent *up;
242 	char buf[8192];
243 
244 	p = UdbSpec;
245 	up = UdbEnts;
246 	for (;;)
247 	{
248 		char *spec;
249 		auto int rcode;
250 		int nopts;
251 		int nmx;
252 		register struct hostent *h;
253 		char *mxhosts[MAXMXHOSTS + 1];
254 		struct option opts[MAXUDBOPTS + 1];
255 
256 		while (*p == ' ' || *p == '\t' || *p == ',')
257 			p++;
258 		if (*p == '\0')
259 			break;
260 		spec = p;
261 		p = index(p, ',');
262 		if (p != NULL)
263 			*p++ = '\0';
264 
265 		/* extract options */
266 		nopts = _udb_parsespec(spec, opts, MAXUDBOPTS);
267 
268 		/*
269 		**  Decode database specification.
270 		**
271 		**	In the sendmail tradition, the leading character
272 		**	defines the semantics of the rest of the entry.
273 		**
274 		**	+hostname --	send a datagram to the udb server
275 		**			on host "hostname" asking for the
276 		**			home mail server for this user.
277 		**	*hostname --	similar to +hostname, except that the
278 		**			hostname is searched as an MX record;
279 		**			resulting hosts are searched as for
280 		**			+mxhostname.  If no MX host is found,
281 		**			this is the same as +hostname.
282 		**	@hostname --	forward email to the indicated host.
283 		**			This should be the last in the list,
284 		**			since it always matches the input.
285 		**	/dbname	 --	search the named database on the local
286 		**			host using the Berkeley db package.
287 		*/
288 
289 		switch (*spec)
290 		{
291 		  case '+':	/* search remote database */
292 		  case '*':	/* search remote database (expand MX) */
293 			if (*spec == '*')
294 			{
295 				nmx = getmxrr(spec + 1, mxhosts, "", &rcode);
296 				if (tTd(28, 16))
297 				{
298 					int i;
299 
300 					printf("getmxrr(%s): %d", spec + 1, nmx);
301 					for (i = 0; i <= nmx; i++)
302 						printf(" %s", mxhosts[i]);
303 					printf("\n");
304 				}
305 			}
306 			else
307 			{
308 				nmx = 1;
309 				mxhosts[0] = spec + 1;
310 			}
311 
312 			for (i = 0; i < nmx; i++)
313 			{
314 				h = gethostbyname(mxhosts[i]);
315 				if (h == NULL)
316 					continue;
317 				up->udb_type = UDB_REMOTE;
318 				up->udb_addr.sin_family = h->h_addrtype;
319 				bcopy(h->h_addr_list[0],
320 				      (char *) &up->udb_addr.sin_addr,
321 				      h->h_length);
322 				up->udb_addr.sin_port = UdbPort;
323 				up->udb_timeout = UdbTimeout;
324 				up++;
325 			}
326 
327 			/* set up a datagram socket */
328 			if (UdbSock < 0)
329 			{
330 				UdbSock = socket(AF_INET, SOCK_DGRAM, 0);
331 				(void) fcntl(UdbSock, F_SETFD, 1);
332 			}
333 			break;
334 
335 		  case '@':	/* forward to remote host */
336 			up->udb_type = UDB_FORWARD;
337 			up->udb_fwdhost = spec + 1;
338 			up++;
339 			break;
340 
341 		  case '/':	/* look up remote name */
342 			up->udb_dbp = dbopen(spec, O_RDONLY, 0644, DB_BTREE, NULL);
343 			if (up->udb_dbp == NULL)
344 				break;
345 			up->udb_type = UDB_LOOKUP;
346 			up++;
347 			break;
348 		}
349 	}
350 	up->udb_type = UDB_EOLIST;
351 
352 	if (tTd(28, 4))
353 	{
354 		for (up = UdbEnts; ; up++)
355 		{
356 			switch (up->udb_type)
357 			{
358 			  case UDB_EOLIST:
359 				return;
360 
361 			  case UDB_REMOTE:
362 				printf("REMOTE: addr %s, timeo %d\n",
363 					inet_ntoa(up->udb_addr.sin_addr),
364 					up->udb_timeout);
365 				break;
366 
367 			  case UDB_LOOKUP:
368 				printf("LOOKUP\n");
369 				break;
370 
371 			  case UDB_FORWARD:
372 				printf("FORWARD: host %s\n",
373 					up->udb_fwdhost);
374 				break;
375 
376 			  default:
377 				printf("UNKNOWN\n");
378 				break;
379 			}
380 		}
381 	}
382 }
383 
384 int
385 _udb_parsespec(udbspec, opt, maxopts)
386 	char *udbspec;
387 	struct option opt[];
388 	int maxopts;
389 {
390 	register char *spec;
391 	register char *spec_end;
392 	register int optnum;
393 
394 	spec_end = index(udbspec, ':');
395 	for (optnum = 0; optnum < maxopts && (spec = spec_end) != NULL; optnum++)
396 	{
397 		register char *p;
398 
399 		while (isspace(*spec))
400 			spec++;
401 		spec_end = index(spec, ':');
402 		if (spec_end != NULL)
403 			*spec_end++ = '\0';
404 
405 		opt[optnum].name = spec;
406 		opt[optnum].val = NULL;
407 		p = index(spec, '=');
408 		if (p != NULL)
409 			opt[optnum].val = ++p;
410 	}
411 	return optnum;
412 }
413 
414 #else /* not USERDB */
415 
416 void
417 udbexpand(a, sendq)
418 	ADDRESS *a;
419 	ADDRESS **sendq;
420 {
421 	return;
422 }
423 
424 #endif /* USERDB */
425