1 /*
2  *  Copyright (c) 1999-2003 Sendmail, Inc. and its suppliers.
3  *	All rights reserved.
4  *
5  * By using this file, you agree to the terms and conditions set
6  * forth in the LICENSE file which can be found at the top level of
7  * the sendmail distribution.
8  *
9  */
10 
11 #pragma ident	"%Z%%M%	%I%	%E% SMI"
12 
13 #include <sm/gen.h>
14 SM_RCSID("@(#)$Id: engine.c,v 8.120 2004/10/20 21:09:00 ca Exp $")
15 
16 #include "libmilter.h"
17 
18 #if NETINET || NETINET6
19 # include <arpa/inet.h>
20 #endif /* NETINET || NETINET6 */
21 
22 /* generic argument for functions in the command table */
23 struct arg_struct
24 {
25 	size_t		a_len;		/* length of buffer */
26 	char		*a_buf;		/* argument string */
27 	int		a_idx;		/* index for macro array */
28 	SMFICTX_PTR	a_ctx;		/* context */
29 };
30 
31 typedef struct arg_struct genarg;
32 
33 /* structure for commands received from MTA */
34 struct cmdfct_t
35 {
36 	char	cm_cmd;				/* command */
37 	int	cm_argt;			/* type of arguments expected */
38 	int	cm_next;			/* next state */
39 	int	cm_todo;			/* what to do next */
40 	int	cm_macros;			/* index for macros */
41 	int	(*cm_fct) __P((genarg *));	/* function to execute */
42 };
43 
44 typedef struct cmdfct_t cmdfct;
45 
46 /* possible values for cm_argt */
47 #define	CM_ARG0	0	/* no args */
48 #define	CM_ARG1	1	/* one arg (string) */
49 #define	CM_ARG2	2	/* two args (strings) */
50 #define	CM_ARGA	4	/* one string and _SOCK_ADDR */
51 #define	CM_ARGO	5	/* two integers */
52 #define	CM_ARGV	8	/* \0 separated list of args, NULL-terminated */
53 #define	CM_ARGN	9	/* \0 separated list of args (strings) */
54 
55 /* possible values for cm_todo */
56 #define	CT_CONT		0x0000	/* continue reading commands */
57 #define	CT_IGNO		0x0001	/* continue even when error  */
58 
59 /* not needed right now, done via return code instead */
60 #define	CT_KEEP		0x0004	/* keep buffer (contains symbols) */
61 #define	CT_END		0x0008	/* start replying */
62 
63 /* index in macro array: macros only for these commands */
64 #define	CI_NONE		(-1)
65 #define	CI_CONN		0
66 #define	CI_HELO		1
67 #define	CI_MAIL		2
68 #define CI_RCPT		3
69 #define CI_EOM		4
70 #if CI_EOM >= MAX_MACROS_ENTRIES
71 ERROR: do not compile with CI_EOM >= MAX_MACROS_ENTRIES
72 #endif
73 
74 /* function prototypes */
75 static int	st_abortfct __P((genarg *));
76 static int	st_macros __P((genarg *));
77 static int	st_optionneg __P((genarg *));
78 static int	st_bodychunk __P((genarg *));
79 static int	st_connectinfo __P((genarg *));
80 static int	st_bodyend __P((genarg *));
81 static int	st_helo __P((genarg *));
82 static int	st_header __P((genarg *));
83 static int	st_sender __P((genarg *));
84 static int	st_rcpt __P((genarg *));
85 #if SMFI_VERSION > 2
86 static int	st_unknown __P((genarg *));
87 #endif /* SMFI_VERSION > 2 */
88 #if SMFI_VERSION > 3
89 static int	st_data __P((genarg *));
90 #endif /* SMFI_VERSION > 3 */
91 static int	st_eoh __P((genarg *));
92 static int	st_quit __P((genarg *));
93 static int	sendreply __P((sfsistat, socket_t, struct timeval *, SMFICTX_PTR));
94 static void	fix_stm __P((SMFICTX_PTR));
95 static bool	trans_ok __P((int, int));
96 static char	**dec_argv __P((char *, size_t));
97 static int	dec_arg2 __P((char *, size_t, char **, char **));
98 
99 /* states */
100 #define ST_NONE	(-1)
101 #define ST_INIT	0	/* initial state */
102 #define ST_OPTS	1	/* option negotiation */
103 #define ST_CONN	2	/* connection info */
104 #define ST_HELO	3	/* helo */
105 #define ST_MAIL	4	/* mail from */
106 #define ST_RCPT	5	/* rcpt to */
107 #define ST_DATA	6	/* data */
108 #define ST_HDRS	7	/* headers */
109 #define ST_EOHS	8	/* end of headers */
110 #define ST_BODY	9	/* body */
111 #define ST_ENDM	10	/* end of message */
112 #define ST_QUIT	11	/* quit */
113 #define ST_ABRT	12	/* abort */
114 #define ST_UNKN 13	/* unknown SMTP command */
115 #define ST_LAST	ST_UNKN	/* last valid state */
116 #define ST_SKIP	15	/* not a state but required for the state table */
117 
118 /* in a mail transaction? must be before eom according to spec. */
119 #define ST_IN_MAIL(st)	((st) >= ST_MAIL && (st) < ST_ENDM)
120 
121 /*
122 **  set of next states
123 **  each state (ST_*) corresponds to bit in an int value (1 << state)
124 **  each state has a set of allowed transitions ('or' of bits of states)
125 **  so a state transition is valid if the mask of the next state
126 **  is set in the NX_* value
127 **  this function is coded in trans_ok(), see below.
128 */
129 
130 #define MI_MASK(x)	(0x0001 << (x))	/* generate a bit "mask" for a state */
131 #define NX_INIT	(MI_MASK(ST_OPTS))
132 #define NX_OPTS	(MI_MASK(ST_CONN) | MI_MASK(ST_UNKN))
133 #define NX_CONN	(MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN))
134 #define NX_HELO	(MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN))
135 #define NX_MAIL	(MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | MI_MASK(ST_UNKN))
136 #define NX_RCPT	(MI_MASK(ST_HDRS) | MI_MASK(ST_EOHS) | MI_MASK(ST_DATA) | \
137 		 MI_MASK(ST_BODY) | MI_MASK(ST_ENDM) | \
138 		 MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | MI_MASK(ST_UNKN))
139 #define NX_DATA	(MI_MASK(ST_EOHS) | MI_MASK(ST_HDRS) | MI_MASK(ST_ABRT))
140 #define NX_HDRS	(MI_MASK(ST_EOHS) | MI_MASK(ST_HDRS) | MI_MASK(ST_ABRT))
141 #define NX_EOHS	(MI_MASK(ST_BODY) | MI_MASK(ST_ENDM) | MI_MASK(ST_ABRT))
142 #define NX_BODY	(MI_MASK(ST_ENDM) | MI_MASK(ST_BODY) | MI_MASK(ST_ABRT))
143 #define NX_ENDM	(MI_MASK(ST_QUIT) | MI_MASK(ST_MAIL) | MI_MASK(ST_UNKN))
144 #define NX_QUIT	0
145 #define NX_ABRT	0
146 #define NX_UNKN (MI_MASK(ST_HELO) | MI_MASK(ST_MAIL) | \
147 		 MI_MASK(ST_RCPT) | MI_MASK(ST_ABRT) | \
148 		 MI_MASK(ST_DATA) | \
149 		 MI_MASK(ST_BODY) | MI_MASK(ST_UNKN) | \
150 		 MI_MASK(ST_ABRT) | MI_MASK(ST_QUIT))
151 #define NX_SKIP MI_MASK(ST_SKIP)
152 
153 static int next_states[] =
154 {
155 	NX_INIT,
156 	NX_OPTS,
157 	NX_CONN,
158 	NX_HELO,
159 	NX_MAIL,
160 	NX_RCPT,
161 	NX_DATA,
162 	NX_HDRS,
163 	NX_EOHS,
164 	NX_BODY,
165 	NX_ENDM,
166 	NX_QUIT,
167 	NX_ABRT,
168 	NX_UNKN
169 };
170 
171 /* commands received by milter */
172 static cmdfct cmds[] =
173 {
174 {SMFIC_ABORT,	CM_ARG0, ST_ABRT,  CT_CONT,	CI_NONE, st_abortfct	},
175 {SMFIC_MACRO,	CM_ARGV, ST_NONE,  CT_KEEP,	CI_NONE, st_macros	},
176 {SMFIC_BODY,	CM_ARG1, ST_BODY,  CT_CONT,	CI_NONE, st_bodychunk	},
177 {SMFIC_CONNECT,	CM_ARG2, ST_CONN,  CT_CONT,	CI_CONN, st_connectinfo	},
178 {SMFIC_BODYEOB,	CM_ARG1, ST_ENDM,  CT_CONT,	CI_EOM,  st_bodyend	},
179 {SMFIC_HELO,	CM_ARG1, ST_HELO,  CT_CONT,	CI_HELO, st_helo	},
180 {SMFIC_HEADER,	CM_ARG2, ST_HDRS,  CT_CONT,	CI_NONE, st_header	},
181 {SMFIC_MAIL,	CM_ARGV, ST_MAIL,  CT_CONT,	CI_MAIL, st_sender	},
182 {SMFIC_OPTNEG,	CM_ARGO, ST_OPTS,  CT_CONT,	CI_NONE, st_optionneg	},
183 {SMFIC_EOH,	CM_ARG0, ST_EOHS,  CT_CONT,	CI_NONE, st_eoh		},
184 {SMFIC_QUIT,	CM_ARG0, ST_QUIT,  CT_END,	CI_NONE, st_quit	},
185 #if SMFI_VERSION > 3
186 {SMFIC_DATA,	CM_ARG0, ST_DATA,  CT_CONT,	CI_NONE, st_data	},
187 #endif /* SMFI_VERSION > 3 */
188 {SMFIC_RCPT,	CM_ARGV, ST_RCPT,  CT_IGNO,	CI_RCPT, st_rcpt	}
189 #if SMFI_VERSION > 2
190 ,{SMFIC_UNKNOWN,CM_ARG1, ST_UNKN,  CT_IGNO,	CI_NONE, st_unknown	}
191 #endif /* SMFI_VERSION > 2 */
192 };
193 
194 /* additional (internal) reply codes */
195 #define _SMFIS_KEEP	20
196 #define _SMFIS_ABORT	21
197 #define _SMFIS_OPTIONS	22
198 #define _SMFIS_NOREPLY	23
199 #define _SMFIS_FAIL	(-1)
200 #define _SMFIS_NONE	(-2)
201 
202 /*
203 **  MI_ENGINE -- receive commands and process them
204 **
205 **	Parameters:
206 **		ctx -- context structure
207 **
208 **	Returns:
209 **		MI_FAILURE/MI_SUCCESS
210 */
211 int
212 mi_engine(ctx)
213 	SMFICTX_PTR ctx;
214 {
215 	size_t len;
216 	int i;
217 	socket_t sd;
218 	int ret = MI_SUCCESS;
219 	int ncmds = sizeof(cmds) / sizeof(cmdfct);
220 	int curstate = ST_INIT;
221 	int newstate;
222 	bool call_abort;
223 	sfsistat r;
224 	char cmd;
225 	char *buf = NULL;
226 	genarg arg;
227 	struct timeval timeout;
228 	int (*f) __P((genarg *));
229 	sfsistat (*fi_abort) __P((SMFICTX *));
230 	sfsistat (*fi_close) __P((SMFICTX *));
231 
232 	arg.a_ctx = ctx;
233 	sd = ctx->ctx_sd;
234 	fi_abort = ctx->ctx_smfi->xxfi_abort;
235 	mi_clr_macros(ctx, 0);
236 	fix_stm(ctx);
237 	r = _SMFIS_NONE;
238 	do
239 	{
240 		/* call abort only if in a mail transaction */
241 		call_abort = ST_IN_MAIL(curstate);
242 		timeout.tv_sec = ctx->ctx_timeout;
243 		timeout.tv_usec = 0;
244 		if (mi_stop() == MILTER_ABRT)
245 		{
246 			if (ctx->ctx_dbg > 3)
247 				sm_dprintf("[%d] milter_abort\n",
248 					(int) ctx->ctx_id);
249 			ret = MI_FAILURE;
250 			break;
251 		}
252 
253 		/*
254 		**  Notice: buf is allocated by mi_rd_cmd() and it will
255 		**  usually be free()d after it has been used in f().
256 		**  However, if the function returns _SMFIS_KEEP then buf
257 		**  contains macros and will not be free()d.
258 		**  Hence r must be set to _SMFIS_NONE if a new buf is
259 		**  allocated to avoid problem with housekeeping, esp.
260 		**  if the code "break"s out of the loop.
261 		*/
262 
263 		r = _SMFIS_NONE;
264 		if ((buf = mi_rd_cmd(sd, &timeout, &cmd, &len,
265 				     ctx->ctx_smfi->xxfi_name)) == NULL &&
266 		    cmd < SMFIC_VALIDCMD)
267 		{
268 			if (ctx->ctx_dbg > 5)
269 				sm_dprintf("[%d] mi_engine: mi_rd_cmd error (%x)\n",
270 					(int) ctx->ctx_id, (int) cmd);
271 
272 			/*
273 			**  eof is currently treated as failure ->
274 			**  abort() instead of close(), otherwise use:
275 			**  if (cmd != SMFIC_EOF)
276 			*/
277 
278 			ret = MI_FAILURE;
279 			break;
280 		}
281 		if (ctx->ctx_dbg > 4)
282 			sm_dprintf("[%d] got cmd '%c' len %d\n",
283 				(int) ctx->ctx_id, cmd, (int) len);
284 		for (i = 0; i < ncmds; i++)
285 		{
286 			if (cmd == cmds[i].cm_cmd)
287 				break;
288 		}
289 		if (i >= ncmds)
290 		{
291 			/* unknown command */
292 			if (ctx->ctx_dbg > 1)
293 				sm_dprintf("[%d] cmd '%c' unknown\n",
294 					(int) ctx->ctx_id, cmd);
295 			ret = MI_FAILURE;
296 			break;
297 		}
298 		if ((f = cmds[i].cm_fct) == NULL)
299 		{
300 			/* stop for now */
301 			if (ctx->ctx_dbg > 1)
302 				sm_dprintf("[%d] cmd '%c' not impl\n",
303 					(int) ctx->ctx_id, cmd);
304 			ret = MI_FAILURE;
305 			break;
306 		}
307 
308 		/* is new state ok? */
309 		newstate = cmds[i].cm_next;
310 		if (ctx->ctx_dbg > 5)
311 			sm_dprintf("[%d] cur %x new %x nextmask %x\n",
312 				(int) ctx->ctx_id,
313 				curstate, newstate, next_states[curstate]);
314 
315 		if (newstate != ST_NONE && !trans_ok(curstate, newstate))
316 		{
317 			if (ctx->ctx_dbg > 1)
318 				sm_dprintf("[%d] abort: cur %d (%x) new %d (%x) next %x\n",
319 					(int) ctx->ctx_id,
320 					curstate, MI_MASK(curstate),
321 					newstate, MI_MASK(newstate),
322 					next_states[curstate]);
323 
324 			/* call abort only if in a mail transaction */
325 			if (fi_abort != NULL && call_abort)
326 				(void) (*fi_abort)(ctx);
327 
328 			/*
329 			**  try to reach the new state from HELO
330 			**  if it can't be reached, ignore the command.
331 			*/
332 
333 			curstate = ST_HELO;
334 			if (!trans_ok(curstate, newstate))
335 			{
336 				if (buf != NULL)
337 				{
338 					free(buf);
339 					buf = NULL;
340 				}
341 				continue;
342 			}
343 		}
344 		arg.a_len = len;
345 		arg.a_buf = buf;
346 		if (newstate != ST_NONE)
347 		{
348 			curstate = newstate;
349 			ctx->ctx_state = curstate;
350 		}
351 		arg.a_idx = cmds[i].cm_macros;
352 		call_abort = ST_IN_MAIL(curstate);
353 
354 		/* call function to deal with command */
355 		r = (*f)(&arg);
356 		if (r != _SMFIS_KEEP && buf != NULL)
357 		{
358 			free(buf);
359 			buf = NULL;
360 		}
361 		if (sendreply(r, sd, &timeout, ctx) != MI_SUCCESS)
362 		{
363 			ret = MI_FAILURE;
364 			break;
365 		}
366 
367 		if (r == SMFIS_ACCEPT)
368 		{
369 			/* accept mail, no further actions taken */
370 			curstate = ST_HELO;
371 		}
372 		else if (r == SMFIS_REJECT || r == SMFIS_DISCARD ||
373 			 r ==  SMFIS_TEMPFAIL)
374 		{
375 			/*
376 			**  further actions depend on current state
377 			**  if the IGNO bit is set: "ignore" the error,
378 			**  i.e., stay in the current state
379 			*/
380 			if (!bitset(CT_IGNO, cmds[i].cm_todo))
381 				curstate = ST_HELO;
382 		}
383 		else if (r == _SMFIS_ABORT)
384 		{
385 			if (ctx->ctx_dbg > 5)
386 				sm_dprintf("[%d] function returned abort\n",
387 					(int) ctx->ctx_id);
388 			ret = MI_FAILURE;
389 			break;
390 		}
391 	} while (!bitset(CT_END, cmds[i].cm_todo));
392 
393 	if (ret != MI_SUCCESS)
394 	{
395 		/* call abort only if in a mail transaction */
396 		if (fi_abort != NULL && call_abort)
397 			(void) (*fi_abort)(ctx);
398 	}
399 
400 	/* close must always be called */
401 	if ((fi_close = ctx->ctx_smfi->xxfi_close) != NULL)
402 		(void) (*fi_close)(ctx);
403 	if (r != _SMFIS_KEEP && buf != NULL)
404 		free(buf);
405 	mi_clr_macros(ctx, 0);
406 	return ret;
407 }
408 /*
409 **  SENDREPLY -- send a reply to the MTA
410 **
411 **	Parameters:
412 **		r -- reply code
413 **		sd -- socket descriptor
414 **		timeout_ptr -- (ptr to) timeout to use for sending
415 **		ctx -- context structure
416 **
417 **	Returns:
418 **		MI_SUCCESS/MI_FAILURE
419 */
420 
421 static int
422 sendreply(r, sd, timeout_ptr, ctx)
423 	sfsistat r;
424 	socket_t sd;
425 	struct timeval *timeout_ptr;
426 	SMFICTX_PTR ctx;
427 {
428 	int ret = MI_SUCCESS;
429 
430 	switch (r)
431 	{
432 	  case SMFIS_CONTINUE:
433 		ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_CONTINUE, NULL, 0);
434 		break;
435 	  case SMFIS_TEMPFAIL:
436 	  case SMFIS_REJECT:
437 		if (ctx->ctx_reply != NULL &&
438 		    ((r == SMFIS_TEMPFAIL && *ctx->ctx_reply == '4') ||
439 		     (r == SMFIS_REJECT && *ctx->ctx_reply == '5')))
440 		{
441 			ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_REPLYCODE,
442 					ctx->ctx_reply,
443 					strlen(ctx->ctx_reply) + 1);
444 			free(ctx->ctx_reply);
445 			ctx->ctx_reply = NULL;
446 		}
447 		else
448 		{
449 			ret = mi_wr_cmd(sd, timeout_ptr, r == SMFIS_REJECT ?
450 					SMFIR_REJECT : SMFIR_TEMPFAIL, NULL, 0);
451 		}
452 		break;
453 	  case SMFIS_DISCARD:
454 		ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_DISCARD, NULL, 0);
455 		break;
456 	  case SMFIS_ACCEPT:
457 		ret = mi_wr_cmd(sd, timeout_ptr, SMFIR_ACCEPT, NULL, 0);
458 		break;
459 	  case _SMFIS_OPTIONS:
460 		{
461 			char buf[MILTER_OPTLEN];
462 			mi_int32 v;
463 
464 			v = htonl(ctx->ctx_smfi->xxfi_version);
465 			(void) memcpy(&(buf[0]), (void *) &v, MILTER_LEN_BYTES);
466 			v = htonl(ctx->ctx_smfi->xxfi_flags);
467 			(void) memcpy(&(buf[MILTER_LEN_BYTES]), (void *) &v,
468 				      MILTER_LEN_BYTES);
469 			v = htonl(ctx->ctx_pflags);
470 			(void) memcpy(&(buf[MILTER_LEN_BYTES * 2]), (void *) &v,
471 				      MILTER_LEN_BYTES);
472 			ret = mi_wr_cmd(sd, timeout_ptr, SMFIC_OPTNEG, buf,
473 				       MILTER_OPTLEN);
474 		}
475 		break;
476 	  default:	/* don't send a reply */
477 		break;
478 	}
479 	return ret;
480 }
481 
482 /*
483 **  CLR_MACROS -- clear set of macros starting from a given index
484 **
485 **	Parameters:
486 **		ctx -- context structure
487 **		m -- index from which to clear all macros
488 **
489 **	Returns:
490 **		None.
491 */
492 void
493 mi_clr_macros(ctx, m)
494 	SMFICTX_PTR ctx;
495 	int m;
496 {
497 	int i;
498 
499 	for (i = m; i < MAX_MACROS_ENTRIES; i++)
500 	{
501 		if (ctx->ctx_mac_ptr[i] != NULL)
502 		{
503 			free(ctx->ctx_mac_ptr[i]);
504 			ctx->ctx_mac_ptr[i] = NULL;
505 		}
506 		if (ctx->ctx_mac_buf[i] != NULL)
507 		{
508 			free(ctx->ctx_mac_buf[i]);
509 			ctx->ctx_mac_buf[i] = NULL;
510 		}
511 	}
512 }
513 /*
514 **  ST_OPTIONNEG -- negotiate options
515 **
516 **	Parameters:
517 **		g -- generic argument structure
518 **
519 **	Returns:
520 **		abort/send options/continue
521 */
522 
523 static int
524 st_optionneg(g)
525 	genarg *g;
526 {
527 	mi_int32 i, v;
528 
529 	if (g == NULL || g->a_ctx->ctx_smfi == NULL)
530 		return SMFIS_CONTINUE;
531 	mi_clr_macros(g->a_ctx, g->a_idx + 1);
532 
533 	/* check for minimum length */
534 	if (g->a_len < MILTER_OPTLEN)
535 	{
536 		smi_log(SMI_LOG_ERR,
537 			"%s: st_optionneg[%d]: len too short %d < %d",
538 			g->a_ctx->ctx_smfi->xxfi_name,
539 			(int) g->a_ctx->ctx_id, (int) g->a_len,
540 			MILTER_OPTLEN);
541 		return _SMFIS_ABORT;
542 	}
543 
544 	(void) memcpy((void *) &i, (void *) &(g->a_buf[0]),
545 		      MILTER_LEN_BYTES);
546 	v = ntohl(i);
547 	if (v < g->a_ctx->ctx_smfi->xxfi_version)
548 	{
549 		/* hard failure for now! */
550 		smi_log(SMI_LOG_ERR,
551 			"%s: st_optionneg[%d]: version mismatch MTA: %d < milter: %d",
552 			g->a_ctx->ctx_smfi->xxfi_name,
553 			(int) g->a_ctx->ctx_id, (int) v,
554 			g->a_ctx->ctx_smfi->xxfi_version);
555 		return _SMFIS_ABORT;
556 	}
557 
558 	(void) memcpy((void *) &i, (void *) &(g->a_buf[MILTER_LEN_BYTES]),
559 		      MILTER_LEN_BYTES);
560 	v = ntohl(i);
561 
562 	/* no flags? set to default value for V1 actions */
563 	if (v == 0)
564 		v = SMFI_V1_ACTS;
565 	i = g->a_ctx->ctx_smfi->xxfi_flags;
566 	if ((v & i) != i)
567 	{
568 		smi_log(SMI_LOG_ERR,
569 			"%s: st_optionneg[%d]: 0x%x does not fulfill action requirements 0x%x",
570 			g->a_ctx->ctx_smfi->xxfi_name,
571 			(int) g->a_ctx->ctx_id, v, i);
572 		return _SMFIS_ABORT;
573 	}
574 
575 	(void) memcpy((void *) &i, (void *) &(g->a_buf[MILTER_LEN_BYTES * 2]),
576 		      MILTER_LEN_BYTES);
577 	v = ntohl(i);
578 
579 	/* no flags? set to default value for V1 protocol */
580 	if (v == 0)
581 		v = SMFI_V1_PROT;
582 	i = g->a_ctx->ctx_pflags;
583 	if ((v & i) != i)
584 	{
585 		smi_log(SMI_LOG_ERR,
586 			"%s: st_optionneg[%d]: 0x%x does not fulfill protocol requirements 0x%x",
587 			g->a_ctx->ctx_smfi->xxfi_name,
588 			(int) g->a_ctx->ctx_id, v, i);
589 		return _SMFIS_ABORT;
590 	}
591 
592 	return _SMFIS_OPTIONS;
593 }
594 /*
595 **  ST_CONNECTINFO -- receive connection information
596 **
597 **	Parameters:
598 **		g -- generic argument structure
599 **
600 **	Returns:
601 **		continue or filter-specified value
602 */
603 
604 static int
605 st_connectinfo(g)
606 	genarg *g;
607 {
608 	size_t l;
609 	size_t i;
610 	char *s, family;
611 	unsigned short port = 0;
612 	_SOCK_ADDR sockaddr;
613 	sfsistat (*fi_connect) __P((SMFICTX *, char *, _SOCK_ADDR *));
614 
615 	if (g == NULL)
616 		return _SMFIS_ABORT;
617 	mi_clr_macros(g->a_ctx, g->a_idx + 1);
618 	if (g->a_ctx->ctx_smfi == NULL ||
619 	    (fi_connect = g->a_ctx->ctx_smfi->xxfi_connect) == NULL)
620 		return SMFIS_CONTINUE;
621 
622 	s = g->a_buf;
623 	i = 0;
624 	l = g->a_len;
625 	while (s[i] != '\0' && i <= l)
626 		++i;
627 	if (i + 1 >= l)
628 		return _SMFIS_ABORT;
629 
630 	/* Move past trailing \0 in host string */
631 	i++;
632 	family = s[i++];
633 	(void) memset(&sockaddr, '\0', sizeof sockaddr);
634 	if (family != SMFIA_UNKNOWN)
635 	{
636 		if (i + sizeof port >= l)
637 		{
638 			smi_log(SMI_LOG_ERR,
639 				"%s: connect[%d]: wrong len %d >= %d",
640 				g->a_ctx->ctx_smfi->xxfi_name,
641 				(int) g->a_ctx->ctx_id, (int) i, (int) l);
642 			return _SMFIS_ABORT;
643 		}
644 		(void) memcpy((void *) &port, (void *) (s + i),
645 			      sizeof port);
646 		i += sizeof port;
647 
648 		/* make sure string is terminated */
649 		if (s[l - 1] != '\0')
650 			return _SMFIS_ABORT;
651 # if NETINET
652 		if (family == SMFIA_INET)
653 		{
654 			if (inet_aton(s + i, (struct in_addr *) &sockaddr.sin.sin_addr)
655 			    != 1)
656 			{
657 				smi_log(SMI_LOG_ERR,
658 					"%s: connect[%d]: inet_aton failed",
659 					g->a_ctx->ctx_smfi->xxfi_name,
660 					(int) g->a_ctx->ctx_id);
661 				return _SMFIS_ABORT;
662 			}
663 			sockaddr.sa.sa_family = AF_INET;
664 			if (port > 0)
665 				sockaddr.sin.sin_port = port;
666 		}
667 		else
668 # endif /* NETINET */
669 # if NETINET6
670 		if (family == SMFIA_INET6)
671 		{
672 			if (mi_inet_pton(AF_INET6, s + i,
673 					 &sockaddr.sin6.sin6_addr) != 1)
674 			{
675 				smi_log(SMI_LOG_ERR,
676 					"%s: connect[%d]: mi_inet_pton failed",
677 					g->a_ctx->ctx_smfi->xxfi_name,
678 					(int) g->a_ctx->ctx_id);
679 				return _SMFIS_ABORT;
680 			}
681 			sockaddr.sa.sa_family = AF_INET6;
682 			if (port > 0)
683 				sockaddr.sin6.sin6_port = port;
684 		}
685 		else
686 # endif /* NETINET6 */
687 # if NETUNIX
688 		if (family == SMFIA_UNIX)
689 		{
690 			if (sm_strlcpy(sockaddr.sunix.sun_path, s + i,
691 			    sizeof sockaddr.sunix.sun_path) >=
692 			    sizeof sockaddr.sunix.sun_path)
693 			{
694 				smi_log(SMI_LOG_ERR,
695 					"%s: connect[%d]: path too long",
696 					g->a_ctx->ctx_smfi->xxfi_name,
697 					(int) g->a_ctx->ctx_id);
698 				return _SMFIS_ABORT;
699 			}
700 			sockaddr.sunix.sun_family = AF_UNIX;
701 		}
702 		else
703 # endif /* NETUNIX */
704 		{
705 			smi_log(SMI_LOG_ERR,
706 				"%s: connect[%d]: unknown family %d",
707 				g->a_ctx->ctx_smfi->xxfi_name,
708 				(int) g->a_ctx->ctx_id, family);
709 			return _SMFIS_ABORT;
710 		}
711 	}
712 	return (*fi_connect)(g->a_ctx, g->a_buf,
713 			     family != SMFIA_UNKNOWN ? &sockaddr : NULL);
714 }
715 
716 /*
717 **  ST_EOH -- end of headers
718 **
719 **	Parameters:
720 **		g -- generic argument structure
721 **
722 **	Returns:
723 **		continue or filter-specified value
724 */
725 
726 static int
727 st_eoh(g)
728 	genarg *g;
729 {
730 	sfsistat (*fi_eoh) __P((SMFICTX *));
731 
732 	if (g == NULL)
733 		return _SMFIS_ABORT;
734 	if (g->a_ctx->ctx_smfi != NULL &&
735 	    (fi_eoh = g->a_ctx->ctx_smfi->xxfi_eoh) != NULL)
736 		return (*fi_eoh)(g->a_ctx);
737 	return SMFIS_CONTINUE;
738 }
739 
740 #if SMFI_VERSION > 3
741 /*
742 **  ST_DATA -- DATA command
743 **
744 **	Parameters:
745 **		g -- generic argument structure
746 **
747 **	Returns:
748 **		continue or filter-specified value
749 */
750 
751 static int
752 st_data(g)
753 	genarg *g;
754 {
755 	sfsistat (*fi_data) __P((SMFICTX *));
756 
757 	if (g == NULL)
758 		return _SMFIS_ABORT;
759 	if (g->a_ctx->ctx_smfi != NULL &&
760 	    (fi_data = g->a_ctx->ctx_smfi->xxfi_data) != NULL)
761 		return (*fi_data)(g->a_ctx);
762 	return SMFIS_CONTINUE;
763 }
764 #endif /* SMFI_VERSION > 3 */
765 
766 /*
767 **  ST_HELO -- helo/ehlo command
768 **
769 **	Parameters:
770 **		g -- generic argument structure
771 **
772 **	Returns:
773 **		continue or filter-specified value
774 */
775 static int
776 st_helo(g)
777 	genarg *g;
778 {
779 	sfsistat (*fi_helo) __P((SMFICTX *, char *));
780 
781 	if (g == NULL)
782 		return _SMFIS_ABORT;
783 	mi_clr_macros(g->a_ctx, g->a_idx + 1);
784 	if (g->a_ctx->ctx_smfi != NULL &&
785 	    (fi_helo = g->a_ctx->ctx_smfi->xxfi_helo) != NULL)
786 	{
787 		/* paranoia: check for terminating '\0' */
788 		if (g->a_len == 0 || g->a_buf[g->a_len - 1] != '\0')
789 			return MI_FAILURE;
790 		return (*fi_helo)(g->a_ctx, g->a_buf);
791 	}
792 	return SMFIS_CONTINUE;
793 }
794 /*
795 **  ST_HEADER -- header line
796 **
797 **	Parameters:
798 **		g -- generic argument structure
799 **
800 **	Returns:
801 **		continue or filter-specified value
802 */
803 
804 static int
805 st_header(g)
806 	genarg *g;
807 {
808 	char *hf, *hv;
809 	sfsistat (*fi_header) __P((SMFICTX *, char *, char *));
810 
811 	if (g == NULL)
812 		return _SMFIS_ABORT;
813 	if (g->a_ctx->ctx_smfi == NULL ||
814 	    (fi_header = g->a_ctx->ctx_smfi->xxfi_header) == NULL)
815 		return SMFIS_CONTINUE;
816 	if (dec_arg2(g->a_buf, g->a_len, &hf, &hv) == MI_SUCCESS)
817 		return (*fi_header)(g->a_ctx, hf, hv);
818 	else
819 		return _SMFIS_ABORT;
820 }
821 
822 #define ARGV_FCT(lf, rf, idx)					\
823 	char **argv;						\
824 	sfsistat (*lf) __P((SMFICTX *, char **));		\
825 	int r;							\
826 								\
827 	if (g == NULL)						\
828 		return _SMFIS_ABORT;				\
829 	mi_clr_macros(g->a_ctx, g->a_idx + 1);			\
830 	if (g->a_ctx->ctx_smfi == NULL ||			\
831 	    (lf = g->a_ctx->ctx_smfi->rf) == NULL)		\
832 		return SMFIS_CONTINUE;				\
833 	if ((argv = dec_argv(g->a_buf, g->a_len)) == NULL)	\
834 		return _SMFIS_ABORT;				\
835 	r = (*lf)(g->a_ctx, argv);				\
836 	free(argv);						\
837 	return r;
838 
839 /*
840 **  ST_SENDER -- MAIL FROM command
841 **
842 **	Parameters:
843 **		g -- generic argument structure
844 **
845 **	Returns:
846 **		continue or filter-specified value
847 */
848 
849 static int
850 st_sender(g)
851 	genarg *g;
852 {
853 	ARGV_FCT(fi_envfrom, xxfi_envfrom, CI_MAIL)
854 }
855 /*
856 **  ST_RCPT -- RCPT TO command
857 **
858 **	Parameters:
859 **		g -- generic argument structure
860 **
861 **	Returns:
862 **		continue or filter-specified value
863 */
864 
865 static int
866 st_rcpt(g)
867 	genarg *g;
868 {
869 	ARGV_FCT(fi_envrcpt, xxfi_envrcpt, CI_RCPT)
870 }
871 
872 #if SMFI_VERSION > 2
873 /*
874 **  ST_UNKNOWN -- unrecognized or unimplemented command
875 **
876 **	Parameters:
877 **		g -- generic argument structure
878 **
879 **	Returns:
880 **		continue or filter-specified value
881 */
882 
883 static int
884 st_unknown(g)
885 	genarg *g;
886 {
887 	sfsistat (*fi_unknown) __P((SMFICTX *, char *));
888 
889 	if (g == NULL)
890 		return _SMFIS_ABORT;
891 	mi_clr_macros(g->a_ctx, g->a_idx + 1);
892 	if (g->a_ctx->ctx_smfi != NULL &&
893 	    (fi_unknown = g->a_ctx->ctx_smfi->xxfi_unknown) != NULL)
894 		return (*fi_unknown)(g->a_ctx, g->a_buf);
895 	return SMFIS_CONTINUE;
896 }
897 #endif /* SMFI_VERSION > 2 */
898 
899 /*
900 **  ST_MACROS -- deal with macros received from the MTA
901 **
902 **	Parameters:
903 **		g -- generic argument structure
904 **
905 **	Returns:
906 **		continue/keep
907 **
908 **	Side effects:
909 **		set pointer in macro array to current values.
910 */
911 
912 static int
913 st_macros(g)
914 	genarg *g;
915 {
916 	int i;
917 	char **argv;
918 
919 	if (g == NULL || g->a_len < 1)
920 		return _SMFIS_FAIL;
921 	if ((argv = dec_argv(g->a_buf + 1, g->a_len - 1)) == NULL)
922 		return _SMFIS_FAIL;
923 	switch (g->a_buf[0])
924 	{
925 	  case SMFIC_CONNECT:
926 		i = CI_CONN;
927 		break;
928 	  case SMFIC_HELO:
929 		i = CI_HELO;
930 		break;
931 	  case SMFIC_MAIL:
932 		i = CI_MAIL;
933 		break;
934 	  case SMFIC_RCPT:
935 		i = CI_RCPT;
936 		break;
937 	  case SMFIC_BODYEOB:
938 		i = CI_EOM;
939 		break;
940 	  default:
941 		free(argv);
942 		return _SMFIS_FAIL;
943 	}
944 	if (g->a_ctx->ctx_mac_ptr[i] != NULL)
945 		free(g->a_ctx->ctx_mac_ptr[i]);
946 	if (g->a_ctx->ctx_mac_buf[i] != NULL)
947 		free(g->a_ctx->ctx_mac_buf[i]);
948 	g->a_ctx->ctx_mac_ptr[i] = argv;
949 	g->a_ctx->ctx_mac_buf[i] = g->a_buf;
950 	return _SMFIS_KEEP;
951 }
952 /*
953 **  ST_QUIT -- quit command
954 **
955 **	Parameters:
956 **		g -- generic argument structure
957 **
958 **	Returns:
959 **		noreply
960 */
961 
962 /* ARGSUSED */
963 static int
964 st_quit(g)
965 	genarg *g;
966 {
967 	return _SMFIS_NOREPLY;
968 }
969 /*
970 **  ST_BODYCHUNK -- deal with a piece of the mail body
971 **
972 **	Parameters:
973 **		g -- generic argument structure
974 **
975 **	Returns:
976 **		continue or filter-specified value
977 */
978 
979 static int
980 st_bodychunk(g)
981 	genarg *g;
982 {
983 	sfsistat (*fi_body) __P((SMFICTX *, unsigned char *, size_t));
984 
985 	if (g == NULL)
986 		return _SMFIS_ABORT;
987 	if (g->a_ctx->ctx_smfi != NULL &&
988 	    (fi_body = g->a_ctx->ctx_smfi->xxfi_body) != NULL)
989 		return (*fi_body)(g->a_ctx, (unsigned char *)g->a_buf,
990 				  g->a_len);
991 	return SMFIS_CONTINUE;
992 }
993 /*
994 **  ST_BODYEND -- deal with the last piece of the mail body
995 **
996 **	Parameters:
997 **		g -- generic argument structure
998 **
999 **	Returns:
1000 **		continue or filter-specified value
1001 **
1002 **	Side effects:
1003 **		sends a reply for the body part (if non-empty).
1004 */
1005 
1006 static int
1007 st_bodyend(g)
1008 	genarg *g;
1009 {
1010 	sfsistat r;
1011 	sfsistat (*fi_body) __P((SMFICTX *, unsigned char *, size_t));
1012 	sfsistat (*fi_eom) __P((SMFICTX *));
1013 
1014 	if (g == NULL)
1015 		return _SMFIS_ABORT;
1016 	r = SMFIS_CONTINUE;
1017 	if (g->a_ctx->ctx_smfi != NULL)
1018 	{
1019 		if ((fi_body = g->a_ctx->ctx_smfi->xxfi_body) != NULL &&
1020 		    g->a_len > 0)
1021 		{
1022 			socket_t sd;
1023 			struct timeval timeout;
1024 
1025 			timeout.tv_sec = g->a_ctx->ctx_timeout;
1026 			timeout.tv_usec = 0;
1027 			sd = g->a_ctx->ctx_sd;
1028 			r = (*fi_body)(g->a_ctx, (unsigned char *)g->a_buf,
1029 				       g->a_len);
1030 			if (r != SMFIS_CONTINUE &&
1031 			    sendreply(r, sd, &timeout, g->a_ctx) != MI_SUCCESS)
1032 				return _SMFIS_ABORT;
1033 		}
1034 	}
1035 	if (r == SMFIS_CONTINUE &&
1036 	    (fi_eom = g->a_ctx->ctx_smfi->xxfi_eom) != NULL)
1037 		return (*fi_eom)(g->a_ctx);
1038 	return r;
1039 }
1040 /*
1041 **  ST_ABORTFCT -- deal with aborts
1042 **
1043 **	Parameters:
1044 **		g -- generic argument structure
1045 **
1046 **	Returns:
1047 **		abort or filter-specified value
1048 */
1049 
1050 static int
1051 st_abortfct(g)
1052 	genarg *g;
1053 {
1054 	sfsistat (*fi_abort) __P((SMFICTX *));
1055 
1056 	if (g == NULL)
1057 		return _SMFIS_ABORT;
1058 	if (g != NULL && g->a_ctx->ctx_smfi != NULL &&
1059 	    (fi_abort = g->a_ctx->ctx_smfi->xxfi_abort) != NULL)
1060 		(void) (*fi_abort)(g->a_ctx);
1061 	return _SMFIS_NOREPLY;
1062 }
1063 /*
1064 **  TRANS_OK -- is the state transition ok?
1065 **
1066 **	Parameters:
1067 **		old -- old state
1068 **		new -- new state
1069 **
1070 **	Returns:
1071 **		state transition ok
1072 */
1073 
1074 static bool
1075 trans_ok(old, new)
1076 	int old, new;
1077 {
1078 	int s, n;
1079 
1080 	s = old;
1081 	do
1082 	{
1083 		/* is this state transition allowed? */
1084 		if ((MI_MASK(new) & next_states[s]) != 0)
1085 			return true;
1086 
1087 		/*
1088 		**  no: try next state;
1089 		**  this works since the relevant states are ordered
1090 		**  strict sequentially
1091 		*/
1092 
1093 		n = s + 1;
1094 
1095 		/*
1096 		**  can we actually "skip" this state?
1097 		**  see fix_stm() which sets this bit for those
1098 		**  states which the filter program is not interested in
1099 		*/
1100 
1101 		if (bitset(NX_SKIP, next_states[n]))
1102 			s = n;
1103 		else
1104 			return false;
1105 	} while (s <= ST_LAST);
1106 	return false;
1107 }
1108 /*
1109 **  FIX_STM -- add "skip" bits to the state transition table
1110 **
1111 **	Parameters:
1112 **		ctx -- context structure
1113 **
1114 **	Returns:
1115 **		None.
1116 **
1117 **	Side effects:
1118 **		may change state transition table.
1119 */
1120 
1121 static void
1122 fix_stm(ctx)
1123 	SMFICTX_PTR ctx;
1124 {
1125 	unsigned long fl;
1126 
1127 	if (ctx == NULL || ctx->ctx_smfi == NULL)
1128 		return;
1129 	fl = ctx->ctx_pflags;
1130 	if (bitset(SMFIP_NOCONNECT, fl))
1131 		next_states[ST_CONN] |= NX_SKIP;
1132 	if (bitset(SMFIP_NOHELO, fl))
1133 		next_states[ST_HELO] |= NX_SKIP;
1134 	if (bitset(SMFIP_NOMAIL, fl))
1135 		next_states[ST_MAIL] |= NX_SKIP;
1136 	if (bitset(SMFIP_NORCPT, fl))
1137 		next_states[ST_RCPT] |= NX_SKIP;
1138 	if (bitset(SMFIP_NOHDRS, fl))
1139 		next_states[ST_HDRS] |= NX_SKIP;
1140 	if (bitset(SMFIP_NOEOH, fl))
1141 		next_states[ST_EOHS] |= NX_SKIP;
1142 	if (bitset(SMFIP_NOBODY, fl))
1143 		next_states[ST_BODY] |= NX_SKIP;
1144 }
1145 /*
1146 **  DEC_ARGV -- split a buffer into a list of strings, NULL terminated
1147 **
1148 **	Parameters:
1149 **		buf -- buffer with several strings
1150 **		len -- length of buffer
1151 **
1152 **	Returns:
1153 **		array of pointers to the individual strings
1154 */
1155 
1156 static char **
1157 dec_argv(buf, len)
1158 	char *buf;
1159 	size_t len;
1160 {
1161 	char **s;
1162 	size_t i;
1163 	int elem, nelem;
1164 
1165 	nelem = 0;
1166 	for (i = 0; i < len; i++)
1167 	{
1168 		if (buf[i] == '\0')
1169 			++nelem;
1170 	}
1171 	if (nelem == 0)
1172 		return NULL;
1173 
1174 	/* last entry is only for the name */
1175 	s = (char **)malloc((nelem + 1) * (sizeof *s));
1176 	if (s == NULL)
1177 		return NULL;
1178 	s[0] = buf;
1179 	for (i = 0, elem = 0; i < len && elem < nelem; i++)
1180 	{
1181 		if (buf[i] == '\0')
1182 		{
1183 			++elem;
1184 			if (i + 1 >= len)
1185 				s[elem] = NULL;
1186 			else
1187 				s[elem] = &(buf[i + 1]);
1188 		}
1189 	}
1190 
1191 	/* overwrite last entry (already done above, just paranoia) */
1192 	s[elem] = NULL;
1193 	return s;
1194 }
1195 /*
1196 **  DEC_ARG2 -- split a buffer into two strings
1197 **
1198 **	Parameters:
1199 **		buf -- buffer with two strings
1200 **		len -- length of buffer
1201 **		s1,s2 -- pointer to result strings
1202 **
1203 **	Returns:
1204 **		MI_FAILURE/MI_SUCCESS
1205 */
1206 
1207 static int
1208 dec_arg2(buf, len, s1, s2)
1209 	char *buf;
1210 	size_t len;
1211 	char **s1;
1212 	char **s2;
1213 {
1214 	size_t i;
1215 
1216 	/* paranoia: check for terminating '\0' */
1217 	if (len == 0 || buf[len - 1] != '\0')
1218 		return MI_FAILURE;
1219 	*s1 = buf;
1220 	for (i = 1; i < len && buf[i] != '\0'; i++)
1221 		continue;
1222 	if (i >= len - 1)
1223 		return MI_FAILURE;
1224 	*s2 = buf + i + 1;
1225 	return MI_SUCCESS;
1226 }
1227 /*
1228 **  SENDOK -- is it ok for the filter to send stuff to the MTA?
1229 **
1230 **	Parameters:
1231 **		ctx -- context structure
1232 **		flag -- flag to check
1233 **
1234 **	Returns:
1235 **		sending allowed (in current state)
1236 */
1237 
1238 bool
1239 mi_sendok(ctx, flag)
1240 	SMFICTX_PTR ctx;
1241 	int flag;
1242 {
1243 	if (ctx == NULL || ctx->ctx_smfi == NULL)
1244 		return false;
1245 
1246 	/* did the milter request this operation? */
1247 	if (flag != 0 && !bitset(flag, ctx->ctx_smfi->xxfi_flags))
1248 		return false;
1249 
1250 	/* are we in the correct state? It must be "End of Message". */
1251 	return ctx->ctx_state == ST_ENDM;
1252 }
1253