1 /* $OpenBSD: spamd.c,v 1.163 2024/05/09 08:35:03 florian Exp $ */
2
3 /*
4 * Copyright (c) 2015 Henning Brauer <henning@openbsd.org>
5 * Copyright (c) 2002-2007 Bob Beck. All rights reserved.
6 * Copyright (c) 2002 Theo de Raadt. All rights reserved.
7 *
8 * Permission to use, copy, modify, and distribute this software for any
9 * purpose with or without fee is hereby granted, provided that the above
10 * copyright notice and this permission notice appear in all copies.
11 *
12 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
13 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
14 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
15 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
16 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 */
20
21 #include <sys/types.h>
22 #include <sys/socket.h>
23 #include <sys/sysctl.h>
24 #include <sys/resource.h>
25 #include <sys/signal.h>
26 #include <sys/stat.h>
27
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
30
31 #include <err.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <limits.h>
35 #include <poll.h>
36 #include <pwd.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <syslog.h>
41 #include <unistd.h>
42 #include <tls.h>
43
44 #include <netdb.h>
45
46 #include "sdl.h"
47 #include "grey.h"
48 #include "sync.h"
49
50 struct con {
51 struct pollfd *pfd;
52 int state;
53 int laststate;
54 int af;
55 int il;
56 struct sockaddr_storage ss;
57 void *ia;
58 char addr[32];
59 char caddr[32];
60 char helo[MAX_MAIL], mail[MAX_MAIL], rcpt[MAX_MAIL];
61 struct sdlist **blacklists;
62 struct tls *cctx;
63
64 /*
65 * we will do stuttering by changing these to time_t's of
66 * now + n, and only advancing when the time is in the past/now
67 */
68 time_t r;
69 time_t w;
70 time_t s;
71
72 char ibuf[8192];
73 char *ip;
74 char rend[5]; /* any chars in here causes input termination */
75
76 char *obuf;
77 char *lists;
78 size_t osize;
79 char *op;
80 int ol;
81 int data_lines;
82 int data_body;
83 int stutter;
84 int badcmd;
85 int sr;
86 int tlsaction;
87 } *con;
88
89 #define SPAMD_TLS_ACT_NONE 0
90 #define SPAMD_TLS_ACT_READ_POLLIN 1
91 #define SPAMD_TLS_ACT_READ_POLLOUT 2
92 #define SPAMD_TLS_ACT_WRITE_POLLIN 3
93 #define SPAMD_TLS_ACT_WRITE_POLLOUT 4
94
95 #define SPAMD_USER "_spamd"
96
97 void usage(void);
98 char *grow_obuf(struct con *, int);
99 int parse_configline(char *);
100 void parse_configs(void);
101 void do_config(void);
102 int append_error_string (struct con *, size_t, char *, int, void *);
103 void doreply(struct con *);
104 void setlog(char *, size_t, char *);
105 void initcon(struct con *, int, struct sockaddr *);
106 void closecon(struct con *);
107 int match(const char *, const char *);
108 void nextstate(struct con *);
109 void handler(struct con *);
110 void handlew(struct con *, int one);
111 char *loglists(struct con *);
112 void getcaddr(struct con *);
113 void gethelo(char *, size_t, char *);
114 int read_configline(FILE *);
115 void spamd_tls_init(void);
116 void check_spamd_db(void);
117 void blackcheck(int);
118
119 char hostname[HOST_NAME_MAX+1];
120 struct syslog_data sdata = SYSLOG_DATA_INIT;
121 char *nreply = "450";
122 char *spamd = "spamd IP-based SPAM blocker";
123 int greyback[2];
124 int greypipe[2];
125 int trappipe[2];
126 FILE *grey;
127 FILE *trapcfg;
128 time_t passtime = PASSTIME;
129 time_t greyexp = GREYEXP;
130 time_t whiteexp = WHITEEXP;
131 time_t trapexp = TRAPEXP;
132 struct passwd *pw;
133 pid_t jail_pid = -1;
134 u_short cfg_port;
135 u_short sync_port;
136 struct tls_config *tlscfg;
137 struct tls *tlsctx;
138 char *tlskeyfile = NULL;
139 char *tlscertfile = NULL;
140
141 extern struct sdlist *blacklists;
142 extern int pfdev;
143 extern char *low_prio_mx_ip;
144
145 time_t slowdowntill;
146
147 int conffd = -1;
148 int trapfd = -1;
149 char *cb;
150 size_t cbs, cbu;
151
152 time_t t;
153
154 #define MAXCON 800
155 int maxfiles;
156 int maxcon = MAXCON;
157 int maxblack = MAXCON;
158 int blackcount;
159 int clients;
160 int debug;
161 int greylist = 1;
162 int grey_stutter = 10;
163 int verbose;
164 int stutter = 1;
165 int window;
166 int syncrecv;
167 int syncsend;
168 #define MAXTIME 400
169
170 #define MAXIMUM(a,b) (((a)>(b))?(a):(b))
171
172 void
usage(void)173 usage(void)
174 {
175 extern char *__progname;
176
177 fprintf(stderr,
178 "usage: %s [-45bdv] [-B maxblack] [-C file] [-c maxcon] "
179 "[-G passtime:greyexp:whiteexp]\n"
180 "\t[-h hostname] [-K file] [-l address] [-M address] [-n name]\n"
181 "\t[-p port] [-S secs] [-s secs] "
182 "[-w window] [-Y synctarget] [-y synclisten]\n",
183 __progname);
184
185 exit(1);
186 }
187
188 char *
grow_obuf(struct con * cp,int off)189 grow_obuf(struct con *cp, int off)
190 {
191 char *tmp;
192
193 tmp = realloc(cp->obuf, cp->osize + 8192);
194 if (tmp == NULL) {
195 free(cp->obuf);
196 cp->obuf = NULL;
197 cp->osize = 0;
198 return (NULL);
199 } else {
200 cp->osize += 8192;
201 cp->obuf = tmp;
202 return (cp->obuf + off);
203 }
204 }
205
206 int
parse_configline(char * line)207 parse_configline(char *line)
208 {
209 char *cp, prev, *name, *msg, *tmp;
210 char **v4 = NULL, **v6 = NULL;
211 const char *errstr;
212 u_int nv4 = 0, nv6 = 0;
213 int mdone = 0;
214 sa_family_t af;
215
216 name = line;
217
218 for (cp = name; *cp && *cp != ';'; cp++)
219 ;
220 if (*cp != ';')
221 goto parse_error;
222 *cp++ = '\0';
223 if (!*cp) {
224 sdl_del(name);
225 return (0);
226 }
227 msg = cp;
228 if (*cp++ != '"')
229 goto parse_error;
230 prev = '\0';
231 for (; !mdone; cp++) {
232 switch (*cp) {
233 case '\\':
234 if (!prev)
235 prev = *cp;
236 else
237 prev = '\0';
238 break;
239 case '"':
240 if (prev != '\\') {
241 cp++;
242 if (*cp == ';') {
243 mdone = 1;
244 *cp = '\0';
245 } else {
246 if (debug > 0)
247 printf("bad message: %s\n", msg);
248 goto parse_error;
249 }
250 }
251 break;
252 case '\0':
253 if (debug > 0)
254 printf("bad message: %s\n", msg);
255 goto parse_error;
256 default:
257 prev = '\0';
258 break;
259 }
260 }
261
262 while ((tmp = strsep(&cp, ";")) != NULL) {
263 char **av;
264 u_int au, ac;
265
266 if (*tmp == '\0')
267 continue;
268
269 if (strncmp(tmp, "inet", 4) != 0)
270 goto parse_error;
271 switch (tmp[4]) {
272 case '\0':
273 af = AF_INET;
274 break;
275 case '6':
276 if (tmp[5] == '\0') {
277 af = AF_INET6;
278 break;
279 }
280 /* FALLTHROUGH */
281 default:
282 if (debug > 0)
283 printf("unsupported address family: %s\n", tmp);
284 goto parse_error;
285 }
286
287 tmp = strsep(&cp, ";");
288 if (tmp == NULL) {
289 if (debug > 0)
290 printf("missing address count\n");
291 goto parse_error;
292 }
293 ac = strtonum(tmp, 0, UINT_MAX, &errstr);
294 if (errstr != NULL) {
295 if (debug > 0)
296 printf("count \"%s\" is %s\n", tmp, errstr);
297 goto parse_error;
298 }
299
300 av = reallocarray(NULL, ac, sizeof(char *));
301 for (au = 0; au < ac; au++) {
302 tmp = strsep(&cp, ";");
303 if (tmp == NULL) {
304 if (debug > 0)
305 printf("expected %u addrs, got %u\n",
306 ac, au + 1);
307 free(av);
308 goto parse_error;
309 }
310 if (*tmp == '\0')
311 continue;
312 av[au] = tmp;
313 }
314 if (af == AF_INET) {
315 if (v4 != NULL) {
316 if (debug > 0)
317 printf("duplicate inet\n");
318 goto parse_error;
319 }
320 v4 = av;
321 nv4 = ac;
322 } else {
323 if (v6 != NULL) {
324 if (debug > 0)
325 printf("duplicate inet6\n");
326 goto parse_error;
327 }
328 v6 = av;
329 nv6 = ac;
330 }
331 }
332 if (nv4 == 0 && nv6 == 0) {
333 if (debug > 0)
334 printf("no addresses\n");
335 goto parse_error;
336 }
337 sdl_add(name, msg, v4, nv4, v6, nv6);
338 free(v4);
339 free(v6);
340 return (0);
341
342 parse_error:
343 if (debug > 0)
344 printf("bogus config line - need 'tag;message;af;count;a/m;a/m;a/m...'\n");
345 free(v4);
346 free(v6);
347 return (-1);
348 }
349
350 void
parse_configs(void)351 parse_configs(void)
352 {
353 char *start, *end;
354 size_t i;
355
356 /* We always leave an extra byte for the NUL. */
357 cb[cbu++] = '\0';
358
359 start = cb;
360 end = start;
361 for (i = 0; i < cbu; i++) {
362 if (*end == '\n') {
363 *end = '\0';
364 if (end > start + 1)
365 parse_configline(start);
366 start = ++end;
367 } else
368 ++end;
369 }
370 if (end > start + 1)
371 parse_configline(start);
372 }
373
374 void
do_config(void)375 do_config(void)
376 {
377 int n;
378
379 if (debug > 0)
380 printf("got configuration connection\n");
381
382 /* Leave an extra byte for the terminating NUL. */
383 if (cbu + 1 >= cbs) {
384 char *tmp;
385
386 tmp = realloc(cb, cbs + (1024 * 1024));
387 if (tmp == NULL) {
388 if (debug > 0)
389 warn("realloc");
390 goto configdone;
391 }
392 cbs += 1024 * 1024;
393 cb = tmp;
394 }
395
396 n = read(conffd, cb + cbu, cbs - cbu);
397 if (debug > 0)
398 printf("read %d config bytes\n", n);
399 if (n == 0) {
400 if (cbu != 0)
401 parse_configs();
402 goto configdone;
403 } else if (n == -1) {
404 if (debug > 0)
405 warn("read");
406 goto configdone;
407 } else
408 cbu += n;
409 return;
410
411 configdone:
412 free(cb);
413 cb = NULL;
414 cbs = 0;
415 cbu = 0;
416 close(conffd);
417 conffd = -1;
418 slowdowntill = 0;
419 }
420
421 int
read_configline(FILE * config)422 read_configline(FILE *config)
423 {
424 char *buf;
425 size_t len;
426
427 if ((buf = fgetln(config, &len))) {
428 if (buf[len - 1] == '\n')
429 buf[len - 1] = '\0';
430 else
431 return (-1); /* all valid lines end in \n */
432 parse_configline(buf);
433 } else {
434 syslog_r(LOG_DEBUG, &sdata, "read_configline: fgetln (%m)");
435 return (-1);
436 }
437 return (0);
438 }
439
440 void
spamd_tls_init(void)441 spamd_tls_init(void)
442 {
443 if (tlskeyfile == NULL && tlscertfile == NULL)
444 return;
445 if (tlskeyfile == NULL || tlscertfile == NULL)
446 errx(1, "need key and certificate for TLS");
447
448 if ((tlscfg = tls_config_new()) == NULL)
449 errx(1, "failed to get tls config");
450 if ((tlsctx = tls_server()) == NULL)
451 errx(1, "failed to get tls server");
452
453 if (tls_config_set_protocols(tlscfg, TLS_PROTOCOLS_ALL) != 0)
454 errx(1, "failed to set tls protocols");
455
456 /* might need user-specified ciphers, tls_config_set_ciphers */
457 if (tls_config_set_ciphers(tlscfg, "all") != 0)
458 errx(1, "failed to set tls ciphers");
459
460 if (tls_config_set_cert_file(tlscfg, tlscertfile) == -1)
461 errx(1, "unable to set TLS certificate file %s", tlscertfile);
462 if (tls_config_set_key_file(tlscfg, tlskeyfile) == -1)
463 errx(1, "unable to set TLS key file %s", tlskeyfile);
464 if (tls_configure(tlsctx, tlscfg) != 0)
465 errx(1, "failed to configure TLS - %s", tls_error(tlsctx));
466
467 /* set hostname to cert's CN unless explicitly given? */
468 }
469
470 int
append_error_string(struct con * cp,size_t off,char * fmt,int af,void * ia)471 append_error_string(struct con *cp, size_t off, char *fmt, int af, void *ia)
472 {
473 char sav = '\0';
474 static int lastcont = 0;
475 char *c = cp->obuf + off;
476 char *s = fmt;
477 size_t len = cp->osize - off;
478 int i = 0;
479
480 if (off == 0)
481 lastcont = 0;
482
483 if (lastcont != 0)
484 cp->obuf[lastcont] = '-';
485 snprintf(c, len, "%s ", nreply);
486 i += strlen(c);
487 lastcont = off + i - 1;
488 if (*s == '"')
489 s++;
490 while (*s) {
491 /*
492 * Make sure we at minimum, have room to add a
493 * format code (4 bytes), and a v6 address(39 bytes)
494 * and a byte saved in sav.
495 */
496 if (i >= len - 46) {
497 c = grow_obuf(cp, off);
498 if (c == NULL)
499 return (-1);
500 len = cp->osize - (off + i);
501 }
502
503 if (c[i-1] == '\n') {
504 if (lastcont != 0)
505 cp->obuf[lastcont] = '-';
506 snprintf(c + i, len, "%s ", nreply);
507 i += strlen(c);
508 lastcont = off + i - 1;
509 }
510
511 switch (*s) {
512 case '\\':
513 case '%':
514 if (!sav)
515 sav = *s;
516 else {
517 c[i++] = sav;
518 sav = '\0';
519 c[i] = '\0';
520 }
521 break;
522 case '"':
523 case 'A':
524 case 'n':
525 if (*(s+1) == '\0') {
526 break;
527 }
528 if (sav == '\\' && *s == 'n') {
529 c[i++] = '\n';
530 sav = '\0';
531 c[i] = '\0';
532 break;
533 } else if (sav == '\\' && *s == '"') {
534 c[i++] = '"';
535 sav = '\0';
536 c[i] = '\0';
537 break;
538 } else if (sav == '%' && *s == 'A') {
539 inet_ntop(af, ia, c + i, (len - i));
540 i += strlen(c + i);
541 sav = '\0';
542 break;
543 }
544 /* FALLTHROUGH */
545 default:
546 if (sav)
547 c[i++] = sav;
548 c[i++] = *s;
549 sav = '\0';
550 c[i] = '\0';
551 break;
552 }
553 s++;
554 }
555 return (i);
556 }
557
558 char *
loglists(struct con * cp)559 loglists(struct con *cp)
560 {
561 static char matchlists[80];
562 struct sdlist **matches;
563 int s = sizeof(matchlists) - 4;
564
565 matchlists[0] = '\0';
566 matches = cp->blacklists;
567 if (matches == NULL)
568 return (NULL);
569 for (; *matches; matches++) {
570
571 /* don't report an insane amount of lists in the logs.
572 * just truncate and indicate with ...
573 */
574 if (strlen(matchlists) + strlen(matches[0]->tag) + 1 >= s)
575 strlcat(matchlists, " ...", sizeof(matchlists));
576 else {
577 strlcat(matchlists, " ", s);
578 strlcat(matchlists, matches[0]->tag, s);
579 }
580 }
581 return matchlists;
582 }
583
584 void
doreply(struct con * cp)585 doreply(struct con *cp)
586 {
587 struct sdlist **matches;
588 int off = 0;
589
590 matches = cp->blacklists;
591 if (matches == NULL)
592 goto nomatch;
593 for (; *matches; matches++) {
594 int used = 0;
595 int left = cp->osize - off;
596
597 used = append_error_string(cp, off, matches[0]->string,
598 cp->af, cp->ia);
599 if (used == -1)
600 goto bad;
601 off += used;
602 left -= used;
603 if (cp->obuf[off - 1] != '\n') {
604 if (left < 1) {
605 if (grow_obuf(cp, off) == NULL)
606 goto bad;
607 }
608 cp->obuf[off++] = '\n';
609 cp->obuf[off] = '\0';
610 }
611 }
612 return;
613 nomatch:
614 /* No match. give generic reply */
615 free(cp->obuf);
616 if (cp->blacklists != NULL)
617 cp->osize = asprintf(&cp->obuf,
618 "%s-Sorry %s\n"
619 "%s-You are trying to send mail from an address "
620 "listed by one\n"
621 "%s or more IP-based registries as being a SPAM source.\n",
622 nreply, cp->addr, nreply, nreply);
623 else
624 cp->osize = asprintf(&cp->obuf,
625 "451 Temporary failure, please try again later.\r\n");
626 if (cp->osize == -1)
627 cp->obuf = NULL;
628 cp->osize++; /* size includes the NUL (also changes -1 to 0) */
629 return;
630 bad:
631 if (cp->obuf != NULL) {
632 free(cp->obuf);
633 cp->obuf = NULL;
634 cp->osize = 0;
635 }
636 }
637
638 void
setlog(char * p,size_t len,char * f)639 setlog(char *p, size_t len, char *f)
640 {
641 char *s;
642
643 s = strsep(&f, ":");
644 if (!f)
645 return;
646 while (*f == ' ' || *f == '\t')
647 f++;
648 s = strsep(&f, " \t");
649 if (s == NULL)
650 return;
651 strlcpy(p, s, len);
652 s = strsep(&p, " \t\n\r");
653 if (s == NULL)
654 return;
655 s = strsep(&p, " \t\n\r");
656 if (s)
657 *s = '\0';
658 }
659
660 /*
661 * Get address client connected to, by doing a getsockname call.
662 * Must not be used with a NAT'ed connection (use divert-to instead of rdr-to).
663 */
664 void
getcaddr(struct con * cp)665 getcaddr(struct con *cp)
666 {
667 struct sockaddr_storage original_destination;
668 struct sockaddr *odp = (struct sockaddr *) &original_destination;
669 socklen_t len = sizeof(struct sockaddr_storage);
670 int error;
671
672 cp->caddr[0] = '\0';
673 if (getsockname(cp->pfd->fd, odp, &len) == -1)
674 return;
675 error = getnameinfo(odp, odp->sa_len, cp->caddr, sizeof(cp->caddr),
676 NULL, 0, NI_NUMERICHOST);
677 if (error)
678 cp->caddr[0] = '\0';
679 }
680
681 void
gethelo(char * p,size_t len,char * f)682 gethelo(char *p, size_t len, char *f)
683 {
684 char *s;
685
686 /* skip HELO/EHLO */
687 f+=4;
688 /* skip whitespace */
689 while (*f == ' ' || *f == '\t')
690 f++;
691 s = strsep(&f, " \t");
692 if (s == NULL)
693 return;
694 strlcpy(p, s, len);
695 s = strsep(&p, " \t\n\r");
696 if (s == NULL)
697 return;
698 s = strsep(&p, " \t\n\r");
699 if (s)
700 *s = '\0';
701 }
702
703 void
initcon(struct con * cp,int fd,struct sockaddr * sa)704 initcon(struct con *cp, int fd, struct sockaddr *sa)
705 {
706 struct pollfd *pfd = cp->pfd;
707 char ctimebuf[26];
708 time_t tt;
709 int error;
710
711 if (sa->sa_family != AF_INET)
712 errx(1, "not supported yet");
713
714 time(&tt);
715 free(cp->obuf);
716 free(cp->blacklists);
717 free(cp->lists);
718 memset(cp, 0, sizeof(*cp));
719 if (grow_obuf(cp, 0) == NULL)
720 err(1, "malloc");
721 cp->pfd = pfd;
722 cp->pfd->fd = fd;
723 memcpy(&cp->ss, sa, sa->sa_len);
724 cp->af = sa->sa_family;
725 cp->ia = &((struct sockaddr_in *)&cp->ss)->sin_addr;
726 cp->blacklists = sdl_lookup(blacklists, cp->af, cp->ia);
727 cp->stutter = (greylist && !grey_stutter && cp->blacklists == NULL) ?
728 0 : stutter;
729 error = getnameinfo(sa, sa->sa_len, cp->addr, sizeof(cp->addr), NULL, 0,
730 NI_NUMERICHOST);
731 if (error)
732 strlcpy(cp->addr, "<unknown>", sizeof(cp->addr));
733 memset(ctimebuf, 0, sizeof(ctimebuf));
734 ctime_r(&t, ctimebuf);
735 ctimebuf[sizeof(ctimebuf) - 2] = '\0'; /* nuke newline */
736 snprintf(cp->obuf, cp->osize, "220 %s ESMTP %s; %s\r\n",
737 hostname, spamd, ctimebuf);
738 cp->op = cp->obuf;
739 cp->ol = strlen(cp->op);
740 cp->w = tt + cp->stutter;
741 cp->s = tt;
742 strlcpy(cp->rend, "\n", sizeof cp->rend);
743 clients++;
744 if (cp->blacklists != NULL) {
745 blackcount++;
746 if (greylist && blackcount > maxblack)
747 cp->stutter = 0;
748 cp->lists = strdup(loglists(cp));
749 if (cp->lists == NULL)
750 err(1, "malloc");
751 }
752 else
753 cp->lists = NULL;
754 }
755
756 void
closecon(struct con * cp)757 closecon(struct con *cp)
758 {
759 time_t tt;
760
761 if (cp->cctx) {
762 tls_close(cp->cctx);
763 tls_free(cp->cctx);
764 }
765 close(cp->pfd->fd);
766 cp->pfd->fd = -1;
767
768 slowdowntill = 0;
769
770 time(&tt);
771 syslog_r(LOG_INFO, &sdata, "%s: disconnected after %lld seconds.%s%s",
772 cp->addr, (long long)(tt - cp->s),
773 ((cp->lists == NULL) ? "" : " lists:"),
774 ((cp->lists == NULL) ? "": cp->lists));
775 if (debug > 0)
776 printf("%s connected for %lld seconds.\n", cp->addr,
777 (long long)(tt - cp->s));
778 free(cp->lists);
779 cp->lists = NULL;
780 if (cp->blacklists != NULL) {
781 blackcount--;
782 free(cp->blacklists);
783 cp->blacklists = NULL;
784 }
785 if (cp->obuf != NULL) {
786 free(cp->obuf);
787 cp->obuf = NULL;
788 cp->osize = 0;
789 }
790 clients--;
791 }
792
793 int
match(const char * s1,const char * s2)794 match(const char *s1, const char *s2)
795 {
796 return (strncasecmp(s1, s2, strlen(s2)) == 0);
797 }
798
799 void
nextstate(struct con * cp)800 nextstate(struct con *cp)
801 {
802 if (match(cp->ibuf, "QUIT") && cp->state < 99) {
803 snprintf(cp->obuf, cp->osize, "221 %s\r\n", hostname);
804 cp->op = cp->obuf;
805 cp->ol = strlen(cp->op);
806 cp->w = t + cp->stutter;
807 cp->laststate = cp->state;
808 cp->state = 99;
809 return;
810 }
811
812 if (match(cp->ibuf, "RSET") && cp->state > 2 && cp->state < 50) {
813 snprintf(cp->obuf, cp->osize,
814 "250 Ok to start over.\r\n");
815 cp->op = cp->obuf;
816 cp->ol = strlen(cp->op);
817 cp->w = t + cp->stutter;
818 cp->laststate = cp->state;
819 cp->state = 2;
820 return;
821 }
822 switch (cp->state) {
823 case 0:
824 tlsinitdone:
825 /* banner sent; wait for input */
826 cp->ip = cp->ibuf;
827 cp->il = sizeof(cp->ibuf) - 1;
828 cp->laststate = cp->state;
829 cp->state = 1;
830 cp->r = t;
831 break;
832 case 1:
833 /* received input: parse, and select next state */
834 if (match(cp->ibuf, "HELO") ||
835 match(cp->ibuf, "EHLO")) {
836 int nextstate = 2;
837 cp->helo[0] = '\0';
838 gethelo(cp->helo, sizeof cp->helo, cp->ibuf);
839 if (cp->helo[0] == '\0') {
840 nextstate = 0;
841 snprintf(cp->obuf, cp->osize,
842 "501 helo requires domain name.\r\n");
843 } else {
844 if (cp->cctx == NULL && tlsctx != NULL &&
845 cp->blacklists == NULL &&
846 match(cp->ibuf, "EHLO")) {
847 snprintf(cp->obuf, cp->osize,
848 "250-%s\r\n"
849 "250-8BITMIME\r\n"
850 "250-SMTPUTF8\r\n"
851 "250 STARTTLS\r\n",
852 hostname);
853 nextstate = 7;
854 } else {
855 snprintf(cp->obuf, cp->osize,
856 "250 Hello, spam sender. Pleased "
857 "to be wasting your time.\r\n");
858 }
859 }
860 cp->op = cp->obuf;
861 cp->ol = strlen(cp->op);
862 cp->laststate = cp->state;
863 cp->state = nextstate;
864 cp->w = t + cp->stutter;
865 break;
866 }
867 goto mail;
868 case 2:
869 /* sent 250 Hello, wait for input */
870 cp->ip = cp->ibuf;
871 cp->il = sizeof(cp->ibuf) - 1;
872 cp->laststate = cp->state;
873 cp->state = 3;
874 cp->r = t;
875 break;
876 case 3:
877 mail:
878 if (match(cp->ibuf, "MAIL")) {
879 setlog(cp->mail, sizeof cp->mail, cp->ibuf);
880 snprintf(cp->obuf, cp->osize,
881 "250 You are about to try to deliver spam. "
882 "Your time will be spent, for nothing.\r\n");
883 cp->op = cp->obuf;
884 cp->ol = strlen(cp->op);
885 cp->laststate = cp->state;
886 cp->state = 4;
887 cp->w = t + cp->stutter;
888 break;
889 }
890 goto rcpt;
891 case 4:
892 /* sent 250 Sender ok */
893 cp->ip = cp->ibuf;
894 cp->il = sizeof(cp->ibuf) - 1;
895 cp->laststate = cp->state;
896 cp->state = 5;
897 cp->r = t;
898 break;
899 case 5:
900 rcpt:
901 if (match(cp->ibuf, "RCPT")) {
902 setlog(cp->rcpt, sizeof(cp->rcpt), cp->ibuf);
903 snprintf(cp->obuf, cp->osize,
904 "250 This is hurting you more than it is "
905 "hurting me.\r\n");
906 cp->op = cp->obuf;
907 cp->ol = strlen(cp->op);
908 cp->laststate = cp->state;
909 cp->state = 6;
910 cp->w = t + cp->stutter;
911
912 if (cp->mail[0] && cp->rcpt[0]) {
913 if (verbose)
914 syslog_r(LOG_INFO, &sdata,
915 "(%s) %s: %s -> %s",
916 cp->blacklists ? "BLACK" : "GREY",
917 cp->addr, cp->mail,
918 cp->rcpt);
919 if (debug)
920 fprintf(stderr, "(%s) %s: %s -> %s\n",
921 cp->blacklists ? "BLACK" : "GREY",
922 cp->addr, cp->mail, cp->rcpt);
923 if (greylist && cp->blacklists == NULL) {
924 /* send this info to the greylister */
925 getcaddr(cp);
926 fprintf(grey,
927 "CO:%s\nHE:%s\nIP:%s\nFR:%s\nTO:%s\n",
928 cp->caddr, cp->helo, cp->addr,
929 cp->mail, cp->rcpt);
930 fflush(grey);
931 }
932 }
933 break;
934 }
935 goto spam;
936 case 6:
937 /* sent 250 blah */
938 cp->ip = cp->ibuf;
939 cp->il = sizeof(cp->ibuf) - 1;
940 cp->laststate = cp->state;
941 cp->state = 5;
942 cp->r = t;
943 break;
944 case 7:
945 /* sent 250 STARTTLS, wait for input */
946 cp->ip = cp->ibuf;
947 cp->il = sizeof(cp->ibuf) - 1;
948 cp->laststate = cp->state;
949 cp->state = 8;
950 cp->r = t;
951 break;
952 case 8:
953 if (tlsctx != NULL && cp->blacklists == NULL &&
954 cp->cctx == NULL && match(cp->ibuf, "STARTTLS")) {
955 snprintf(cp->obuf, cp->osize,
956 "220 glad you want to burn more CPU cycles on "
957 "your spam\r\n");
958 cp->op = cp->obuf;
959 cp->ol = strlen(cp->op);
960 cp->laststate = cp->state;
961 cp->state = 9;
962 cp->w = t + cp->stutter;
963 break;
964 }
965 goto mail;
966 case 9:
967 if (tls_accept_socket(tlsctx, &cp->cctx, cp->pfd->fd) == -1) {
968 snprintf(cp->obuf, cp->osize,
969 "500 STARTTLS failed\r\n");
970 cp->op = cp->obuf;
971 cp->ol = strlen(cp->op);
972 cp->laststate = cp->state;
973 cp->state = 98;
974 goto done;
975 }
976 goto tlsinitdone;
977
978 case 50:
979 spam:
980 if (match(cp->ibuf, "DATA")) {
981 snprintf(cp->obuf, cp->osize,
982 "354 Enter spam, end with \".\" on a line by "
983 "itself\r\n");
984 cp->state = 60;
985 if (window && setsockopt(cp->pfd->fd, SOL_SOCKET,
986 SO_RCVBUF, &window, sizeof(window)) == -1) {
987 syslog_r(LOG_DEBUG, &sdata,"setsockopt: %m");
988 /* don't fail if this doesn't work. */
989 }
990 cp->ip = cp->ibuf;
991 cp->il = sizeof(cp->ibuf) - 1;
992 cp->op = cp->obuf;
993 cp->ol = strlen(cp->op);
994 cp->w = t + cp->stutter;
995 if (greylist && cp->blacklists == NULL) {
996 cp->laststate = cp->state;
997 cp->state = 98;
998 goto done;
999 }
1000 } else {
1001 if (match(cp->ibuf, "NOOP"))
1002 snprintf(cp->obuf, cp->osize,
1003 "250 2.0.0 OK I did nothing\r\n");
1004 else {
1005 snprintf(cp->obuf, cp->osize,
1006 "500 5.5.1 Command unrecognized\r\n");
1007 cp->badcmd++;
1008 if (cp->badcmd > 20) {
1009 cp->laststate = cp->state;
1010 cp->state = 98;
1011 goto done;
1012 }
1013 }
1014 cp->state = cp->laststate;
1015 cp->ip = cp->ibuf;
1016 cp->il = sizeof(cp->ibuf) - 1;
1017 cp->op = cp->obuf;
1018 cp->ol = strlen(cp->op);
1019 cp->w = t + cp->stutter;
1020 }
1021 break;
1022 case 60:
1023 /* sent 354 blah */
1024 cp->ip = cp->ibuf;
1025 cp->il = sizeof(cp->ibuf) - 1;
1026 cp->laststate = cp->state;
1027 cp->state = 70;
1028 cp->r = t;
1029 break;
1030 case 70: {
1031 char *p, *q;
1032
1033 for (p = q = cp->ibuf; q <= cp->ip; ++q)
1034 if (*q == '\n' || q == cp->ip) {
1035 *q = 0;
1036 if (q > p && q[-1] == '\r')
1037 q[-1] = 0;
1038 if (!strcmp(p, ".") ||
1039 (cp->data_body && ++cp->data_lines >= 10)) {
1040 cp->laststate = cp->state;
1041 cp->state = 98;
1042 goto done;
1043 }
1044 if (!cp->data_body && !*p)
1045 cp->data_body = 1;
1046 if (verbose && cp->data_body && *p)
1047 syslog_r(LOG_DEBUG, &sdata, "%s: "
1048 "Body: %s", cp->addr, p);
1049 else if (verbose && (match(p, "FROM:") ||
1050 match(p, "TO:") || match(p, "SUBJECT:")))
1051 syslog_r(LOG_INFO, &sdata, "%s: %s",
1052 cp->addr, p);
1053 p = ++q;
1054 }
1055 cp->ip = cp->ibuf;
1056 cp->il = sizeof(cp->ibuf) - 1;
1057 cp->r = t;
1058 break;
1059 }
1060 case 98:
1061 done:
1062 doreply(cp);
1063 cp->op = cp->obuf;
1064 cp->ol = strlen(cp->op);
1065 cp->w = t + cp->stutter;
1066 cp->laststate = cp->state;
1067 cp->state = 99;
1068 break;
1069 case 99:
1070 closecon(cp);
1071 break;
1072 default:
1073 errx(1, "illegal state %d", cp->state);
1074 break;
1075 }
1076 }
1077
1078 void
handler(struct con * cp)1079 handler(struct con *cp)
1080 {
1081 int end = 0;
1082 ssize_t n;
1083
1084 if (cp->r || cp->tlsaction != SPAMD_TLS_ACT_NONE) {
1085 if (cp->cctx) {
1086 cp->tlsaction = SPAMD_TLS_ACT_NONE;
1087 n = tls_read(cp->cctx, cp->ip, cp->il);
1088 if (n == TLS_WANT_POLLIN)
1089 cp->tlsaction = SPAMD_TLS_ACT_READ_POLLIN;
1090 if (n == TLS_WANT_POLLOUT)
1091 cp->tlsaction = SPAMD_TLS_ACT_READ_POLLOUT;
1092 if (cp->tlsaction != SPAMD_TLS_ACT_NONE)
1093 return;
1094 } else
1095 n = read(cp->pfd->fd, cp->ip, cp->il);
1096
1097 if (n == 0)
1098 closecon(cp);
1099 else if (n == -1) {
1100 if (errno == EAGAIN)
1101 return;
1102 if (debug > 0)
1103 warn("read");
1104 closecon(cp);
1105 } else {
1106 cp->ip[n] = '\0';
1107 if (cp->rend[0])
1108 if (strpbrk(cp->ip, cp->rend))
1109 end = 1;
1110 cp->ip += n;
1111 cp->il -= n;
1112 }
1113 }
1114 if (end || cp->il == 0) {
1115 while (cp->ip > cp->ibuf &&
1116 (cp->ip[-1] == '\r' || cp->ip[-1] == '\n'))
1117 cp->ip--;
1118 *cp->ip = '\0';
1119 cp->r = 0;
1120 nextstate(cp);
1121 }
1122 }
1123
1124 void
handlew(struct con * cp,int one)1125 handlew(struct con *cp, int one)
1126 {
1127 ssize_t n;
1128
1129 /* kill stutter on greylisted connections after initial delay */
1130 if (cp->stutter && greylist && cp->blacklists == NULL &&
1131 (t - cp->s) > grey_stutter)
1132 cp->stutter=0;
1133
1134 if (cp->w || cp->tlsaction != SPAMD_TLS_ACT_NONE) {
1135 if (*cp->op == '\n' && !cp->sr) {
1136 /* insert \r before \n */
1137 if (cp->cctx) {
1138 cp->tlsaction = SPAMD_TLS_ACT_NONE;
1139 n = tls_write(cp->cctx, "\r", 1);
1140 if (n == TLS_WANT_POLLIN)
1141 cp->tlsaction =
1142 SPAMD_TLS_ACT_WRITE_POLLIN;
1143 if (n == TLS_WANT_POLLOUT)
1144 cp->tlsaction =
1145 SPAMD_TLS_ACT_WRITE_POLLOUT;
1146 if (cp->tlsaction != SPAMD_TLS_ACT_NONE)
1147 return;
1148 } else
1149 n = write(cp->pfd->fd, "\r", 1);
1150
1151 if (n == 0) {
1152 closecon(cp);
1153 goto handled;
1154 } else if (n == -1) {
1155 if (errno == EAGAIN)
1156 return;
1157 if (debug > 0 && errno != EPIPE)
1158 warn("write");
1159 closecon(cp);
1160 goto handled;
1161 }
1162 }
1163 if (*cp->op == '\r')
1164 cp->sr = 1;
1165 else
1166 cp->sr = 0;
1167 if (cp->cctx) {
1168 cp->tlsaction = SPAMD_TLS_ACT_NONE;
1169 n = tls_write(cp->cctx, cp->op, cp->ol);
1170 if (n == TLS_WANT_POLLIN)
1171 cp->tlsaction = SPAMD_TLS_ACT_WRITE_POLLIN;
1172 if (n == TLS_WANT_POLLOUT)
1173 cp->tlsaction = SPAMD_TLS_ACT_WRITE_POLLOUT;
1174 if (cp->tlsaction != SPAMD_TLS_ACT_NONE)
1175 return;
1176 } else
1177 n = write(cp->pfd->fd, cp->op,
1178 (one && cp->stutter) ? 1 : cp->ol);
1179
1180 if (n == 0)
1181 closecon(cp);
1182 else if (n == -1) {
1183 if (errno == EAGAIN)
1184 return;
1185 if (debug > 0 && errno != EPIPE)
1186 warn("write");
1187 closecon(cp);
1188 } else {
1189 cp->op += n;
1190 cp->ol -= n;
1191 }
1192 }
1193 handled:
1194 cp->w = t + cp->stutter;
1195 if (cp->ol == 0) {
1196 cp->w = 0;
1197 nextstate(cp);
1198 }
1199 }
1200
1201 static int
get_maxfiles(void)1202 get_maxfiles(void)
1203 {
1204 int mib[2], maxfiles;
1205 size_t len;
1206
1207 mib[0] = CTL_KERN;
1208 mib[1] = KERN_MAXFILES;
1209 len = sizeof(maxfiles);
1210 if (sysctl(mib, 2, &maxfiles, &len, NULL, 0) == -1)
1211 return(MAXCON);
1212 if ((maxfiles - 200) < 10)
1213 errx(1, "kern.maxfiles is only %d, can not continue\n",
1214 maxfiles);
1215 else
1216 return(maxfiles - 200);
1217 }
1218
1219 /* Symbolic indexes for pfd[] below */
1220 #define PFD_SMTPLISTEN 0
1221 #define PFD_CONFLISTEN 1
1222 #define PFD_SYNCFD 2
1223 #define PFD_CONFFD 3
1224 #define PFD_TRAPFD 4
1225 #define PFD_GREYBACK 5
1226 #define PFD_FIRSTCON 6
1227
1228 int
main(int argc,char * argv[])1229 main(int argc, char *argv[])
1230 {
1231 struct pollfd *pfd;
1232 struct sockaddr_in sin;
1233 struct sockaddr_in lin;
1234 int ch, smtplisten, conflisten, syncfd = -1, i, one = 1;
1235 u_short port;
1236 long long passt, greyt, whitet;
1237 struct servent *ent;
1238 struct rlimit rlp;
1239 char *bind_address = NULL;
1240 const char *errstr;
1241 char *sync_iface = NULL;
1242 char *sync_baddr = NULL;
1243 struct addrinfo hints, *res;
1244 char *addr;
1245 char portstr[6];
1246 int error;
1247
1248 tzset();
1249 openlog_r("spamd", LOG_PID | LOG_NDELAY, LOG_DAEMON, &sdata);
1250
1251 if ((ent = getservbyname("spamd", "tcp")) == NULL)
1252 errx(1, "Can't find service \"spamd\" in /etc/services");
1253 port = ntohs(ent->s_port);
1254 if ((ent = getservbyname("spamd-cfg", "tcp")) == NULL)
1255 errx(1, "Can't find service \"spamd-cfg\" in /etc/services");
1256 cfg_port = ntohs(ent->s_port);
1257 if ((ent = getservbyname("spamd-sync", "udp")) == NULL)
1258 errx(1, "Can't find service \"spamd-sync\" in /etc/services");
1259 sync_port = ntohs(ent->s_port);
1260
1261 if (gethostname(hostname, sizeof hostname) == -1)
1262 err(1, "gethostname");
1263 maxfiles = get_maxfiles();
1264 if (maxcon > maxfiles)
1265 maxcon = maxfiles;
1266 if (maxblack > maxfiles)
1267 maxblack = maxfiles;
1268 while ((ch =
1269 getopt(argc, argv, "45l:c:B:p:bdG:h:s:S:M:n:vw:y:Y:C:K:")) != -1) {
1270 switch (ch) {
1271 case '4':
1272 nreply = "450";
1273 break;
1274 case '5':
1275 nreply = "550";
1276 break;
1277 case 'l':
1278 bind_address = optarg;
1279 break;
1280 case 'B':
1281 maxblack = strtonum(optarg, 0, INT_MAX, &errstr);
1282 if (errstr)
1283 errx(1, "-B %s: %s", optarg, errstr);
1284 break;
1285 case 'c':
1286 maxcon = strtonum(optarg, 1, maxfiles, &errstr);
1287 if (errstr) {
1288 fprintf(stderr, "-c %s: %s\n", optarg, errstr);
1289 usage();
1290 }
1291 break;
1292 case 'p':
1293 port = strtonum(optarg, 1, USHRT_MAX, &errstr);
1294 if (errstr)
1295 errx(1, "-p %s: %s", optarg, errstr);
1296 break;
1297 case 'd':
1298 debug = 1;
1299 break;
1300 case 'b':
1301 greylist = 0;
1302 break;
1303 case 'G':
1304 if (sscanf(optarg, "%lld:%lld:%lld", &passt, &greyt,
1305 &whitet) != 3)
1306 usage();
1307 passtime = passt;
1308 greyexp = greyt;
1309 whiteexp = whitet;
1310 /* convert to seconds from minutes */
1311 passtime *= 60;
1312 /* convert to seconds from hours */
1313 whiteexp *= (60 * 60);
1314 /* convert to seconds from hours */
1315 greyexp *= (60 * 60);
1316 break;
1317 case 'h':
1318 memset(hostname, 0, sizeof(hostname));
1319 if (strlcpy(hostname, optarg, sizeof(hostname)) >=
1320 sizeof(hostname))
1321 errx(1, "-h arg too long");
1322 break;
1323 case 's':
1324 stutter = strtonum(optarg, 0, 10, &errstr);
1325 if (errstr)
1326 usage();
1327 break;
1328 case 'S':
1329 grey_stutter = strtonum(optarg, 0, 90, &errstr);
1330 if (errstr)
1331 usage();
1332 break;
1333 case 'M':
1334 low_prio_mx_ip = optarg;
1335 break;
1336 case 'n':
1337 spamd = optarg;
1338 break;
1339 case 'v':
1340 verbose = 1;
1341 break;
1342 case 'w':
1343 window = strtonum(optarg, 1, INT_MAX, &errstr);
1344 if (errstr)
1345 errx(1, "-w %s: %s", optarg, errstr);
1346 break;
1347 case 'Y':
1348 if (sync_addhost(optarg, sync_port) != 0)
1349 sync_iface = optarg;
1350 syncsend++;
1351 break;
1352 case 'y':
1353 sync_baddr = optarg;
1354 syncrecv++;
1355 break;
1356 case 'C':
1357 tlscertfile = optarg;
1358 break;
1359 case 'K':
1360 tlskeyfile = optarg;
1361 break;
1362 default:
1363 usage();
1364 break;
1365 }
1366 }
1367
1368 setproctitle("[priv]%s%s",
1369 greylist ? " (greylist)" : "",
1370 (syncrecv || syncsend) ? " (sync)" : "");
1371
1372 if (syncsend || syncrecv) {
1373 syncfd = sync_init(sync_iface, sync_baddr, sync_port);
1374 if (syncfd == -1)
1375 err(1, "sync init");
1376 }
1377
1378 if (geteuid())
1379 errx(1, "need root privileges");
1380
1381 if ((pw = getpwnam(SPAMD_USER)) == NULL)
1382 errx(1, "no such user %s", SPAMD_USER);
1383
1384 if (!greylist) {
1385 maxblack = maxcon;
1386 } else if (maxblack > maxcon)
1387 usage();
1388
1389 spamd_tls_init();
1390
1391 rlp.rlim_cur = rlp.rlim_max = maxcon + 15;
1392 if (setrlimit(RLIMIT_NOFILE, &rlp) == -1)
1393 err(1, "setrlimit");
1394
1395 pfd = reallocarray(NULL, PFD_FIRSTCON + maxcon, sizeof(*pfd));
1396 if (pfd == NULL)
1397 err(1, "reallocarray");
1398
1399 con = calloc(maxcon, sizeof(*con));
1400 if (con == NULL)
1401 err(1, "calloc");
1402
1403 con->obuf = malloc(8192);
1404
1405 if (con->obuf == NULL)
1406 err(1, "malloc");
1407 con->osize = 8192;
1408
1409 for (i = 0; i < maxcon; i++) {
1410 con[i].pfd = &pfd[PFD_FIRSTCON + i];
1411 con[i].pfd->fd = -1;
1412 }
1413
1414 signal(SIGPIPE, SIG_IGN);
1415
1416 smtplisten = socket(AF_INET, SOCK_STREAM, 0);
1417 if (smtplisten == -1)
1418 err(1, "socket");
1419
1420 if (setsockopt(smtplisten, SOL_SOCKET, SO_REUSEADDR, &one,
1421 sizeof(one)) == -1)
1422 return (-1);
1423
1424 conflisten = socket(AF_INET, SOCK_STREAM, 0);
1425 if (conflisten == -1)
1426 err(1, "socket");
1427
1428 if (setsockopt(conflisten, SOL_SOCKET, SO_REUSEADDR, &one,
1429 sizeof(one)) == -1)
1430 return (-1);
1431
1432 memset(&hints, 0, sizeof(hints));
1433 hints.ai_family = AF_INET;
1434 addr = bind_address;
1435 snprintf(portstr, sizeof(portstr), "%hu", port);
1436
1437 if ((error = getaddrinfo(addr, portstr, &hints, &res)) != 0) {
1438 errx(1, "getaddrinfo: %s", gai_strerror(error));
1439 }
1440
1441 if (bind(smtplisten, res->ai_addr, res->ai_addrlen) == -1) {
1442 freeaddrinfo(res);
1443 err(1, "bind");
1444 }
1445 freeaddrinfo(res);
1446
1447 memset(&lin, 0, sizeof sin);
1448 lin.sin_len = sizeof(sin);
1449 lin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
1450 lin.sin_family = AF_INET;
1451 lin.sin_port = htons(cfg_port);
1452
1453 if (bind(conflisten, (struct sockaddr *)&lin, sizeof lin) == -1)
1454 err(1, "bind local");
1455
1456 if (debug == 0) {
1457 if (daemon(1, 1) == -1)
1458 err(1, "daemon");
1459 }
1460
1461 if (greylist) {
1462 pfdev = open("/dev/pf", O_RDWR);
1463 if (pfdev == -1) {
1464 syslog_r(LOG_ERR, &sdata, "open /dev/pf: %m");
1465 exit(1);
1466 }
1467
1468 check_spamd_db();
1469
1470 maxblack = (maxblack >= maxcon) ? maxcon - 100 : maxblack;
1471 if (maxblack < 0)
1472 maxblack = 0;
1473
1474 /* open pipe to talk to greylister */
1475 if (socketpair(AF_UNIX, SOCK_DGRAM, 0, greyback) == -1) {
1476 syslog(LOG_ERR, "socketpair (%m)");
1477 exit(1);
1478 }
1479 if (pipe(greypipe) == -1) {
1480 syslog(LOG_ERR, "pipe (%m)");
1481 exit(1);
1482 }
1483 /* open pipe to receive spamtrap configs */
1484 if (pipe(trappipe) == -1) {
1485 syslog(LOG_ERR, "pipe (%m)");
1486 exit(1);
1487 }
1488 jail_pid = fork();
1489 switch (jail_pid) {
1490 case -1:
1491 syslog(LOG_ERR, "fork (%m)");
1492 exit(1);
1493 case 0:
1494 /* child - continue */
1495 signal(SIGPIPE, SIG_IGN);
1496 grey = fdopen(greypipe[1], "w");
1497 if (grey == NULL) {
1498 syslog(LOG_ERR, "fdopen (%m)");
1499 _exit(1);
1500 }
1501 close(greyback[0]);
1502 close(greypipe[0]);
1503 trapfd = trappipe[0];
1504 trapcfg = fdopen(trappipe[0], "r");
1505 if (trapcfg == NULL) {
1506 syslog(LOG_ERR, "fdopen (%m)");
1507 _exit(1);
1508 }
1509 close(trappipe[1]);
1510
1511 if (setgroups(1, &pw->pw_gid) ||
1512 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
1513 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
1514 err(1, "failed to drop privs");
1515
1516 goto jail;
1517 }
1518 /* parent - run greylister */
1519 close(greyback[1]);
1520 grey = fdopen(greypipe[0], "r");
1521 if (grey == NULL) {
1522 syslog(LOG_ERR, "fdopen (%m)");
1523 exit(1);
1524 }
1525 close(greypipe[1]);
1526 trapcfg = fdopen(trappipe[1], "w");
1527 if (trapcfg == NULL) {
1528 syslog(LOG_ERR, "fdopen (%m)");
1529 exit(1);
1530 }
1531 close(trappipe[0]);
1532 return (greywatcher());
1533 }
1534
1535 jail:
1536 if (pledge("stdio inet", NULL) == -1)
1537 err(1, "pledge");
1538
1539 if (listen(smtplisten, 10) == -1)
1540 err(1, "listen");
1541
1542 if (listen(conflisten, 10) == -1)
1543 err(1, "listen");
1544
1545 if (debug != 0)
1546 printf("listening for incoming connections.\n");
1547 syslog_r(LOG_WARNING, &sdata, "listening for incoming connections.");
1548
1549 /* We always check for trap and sync events if configured. */
1550 if (trapfd != -1) {
1551 pfd[PFD_TRAPFD].fd = trapfd;
1552 pfd[PFD_TRAPFD].events = POLLIN;
1553 } else {
1554 pfd[PFD_TRAPFD].fd = -1;
1555 pfd[PFD_TRAPFD].events = 0;
1556 }
1557 if (syncrecv) {
1558 pfd[PFD_SYNCFD].fd = syncfd;
1559 pfd[PFD_SYNCFD].events = POLLIN;
1560 } else {
1561 pfd[PFD_SYNCFD].fd = -1;
1562 pfd[PFD_SYNCFD].events = 0;
1563 }
1564 if (greylist) {
1565 pfd[PFD_GREYBACK].fd = greyback[1];
1566 pfd[PFD_GREYBACK].events = POLLIN;
1567 } else {
1568 pfd[PFD_GREYBACK].fd = -1;
1569 pfd[PFD_GREYBACK].events = 0;
1570 }
1571
1572 /* events and pfd entries for con[] are filled in below. */
1573 pfd[PFD_SMTPLISTEN].fd = smtplisten;
1574 pfd[PFD_CONFLISTEN].fd = conflisten;
1575
1576 while (1) {
1577 int numcon = 0, n, timeout, writers;
1578
1579 time(&t);
1580
1581 writers = 0;
1582 for (i = 0; i < maxcon; i++) {
1583 if (con[i].pfd->fd == -1)
1584 continue;
1585 con[i].pfd->events = 0;
1586 if (con[i].r) {
1587 if (con[i].r + MAXTIME <= t) {
1588 closecon(&con[i]);
1589 continue;
1590 }
1591 con[i].pfd->events |= POLLIN;
1592 }
1593 if (con[i].w) {
1594 if (con[i].w + MAXTIME <= t) {
1595 closecon(&con[i]);
1596 continue;
1597 }
1598 if (con[i].w <= t)
1599 con[i].pfd->events |= POLLOUT;
1600 writers = 1;
1601 }
1602 if (con[i].tlsaction == SPAMD_TLS_ACT_READ_POLLIN ||
1603 con[i].tlsaction == SPAMD_TLS_ACT_WRITE_POLLIN)
1604 con[i].pfd->events = POLLIN;
1605 if (con[i].tlsaction == SPAMD_TLS_ACT_READ_POLLOUT ||
1606 con[i].tlsaction == SPAMD_TLS_ACT_WRITE_POLLOUT)
1607 con[i].pfd->events = POLLOUT;
1608 if (i + 1 > numcon)
1609 numcon = i + 1;
1610 }
1611 pfd[PFD_SMTPLISTEN].events = 0;
1612 pfd[PFD_CONFLISTEN].events = 0;
1613 pfd[PFD_CONFFD].events = 0;
1614 pfd[PFD_CONFFD].fd = conffd;
1615 if (slowdowntill == 0) {
1616 pfd[PFD_SMTPLISTEN].events = POLLIN;
1617
1618 /* only one active config conn at a time */
1619 if (conffd == -1)
1620 pfd[PFD_CONFLISTEN].events = POLLIN;
1621 else
1622 pfd[PFD_CONFFD].events = POLLIN;
1623 }
1624
1625 /* If we are not listening, wake up at least once a second */
1626 if (writers == 0 && slowdowntill == 0)
1627 timeout = INFTIM;
1628 else
1629 timeout = 1000;
1630
1631 n = poll(pfd, PFD_FIRSTCON + numcon, timeout);
1632 if (n == -1) {
1633 if (errno != EINTR)
1634 err(1, "poll");
1635 continue;
1636 }
1637
1638 /* Check if we can speed up accept() calls */
1639 if (slowdowntill && slowdowntill > t)
1640 slowdowntill = 0;
1641
1642 for (i = 0; i < maxcon; i++) {
1643 if (con[i].pfd->fd == -1)
1644 continue;
1645 if (pfd[PFD_FIRSTCON + i].revents & POLLHUP) {
1646 closecon(&con[i]);
1647 continue;
1648 }
1649 if (pfd[PFD_FIRSTCON + i].revents & POLLIN) {
1650 if (con[i].tlsaction ==
1651 SPAMD_TLS_ACT_WRITE_POLLIN)
1652 handlew(&con[i], clients + 5 < maxcon);
1653 else
1654 handler(&con[i]);
1655 }
1656 if (pfd[PFD_FIRSTCON + i].revents & POLLOUT) {
1657 if (con[i].tlsaction ==
1658 SPAMD_TLS_ACT_READ_POLLOUT)
1659 handler(&con[i]);
1660 else
1661 handlew(&con[i], clients + 5 < maxcon);
1662 }
1663 }
1664 if (pfd[PFD_SMTPLISTEN].revents & (POLLIN|POLLHUP)) {
1665 socklen_t sinlen;
1666 int s2;
1667
1668 sinlen = sizeof(sin);
1669 s2 = accept4(smtplisten, (struct sockaddr *)&sin, &sinlen,
1670 SOCK_NONBLOCK);
1671 if (s2 == -1) {
1672 switch (errno) {
1673 case EINTR:
1674 case ECONNABORTED:
1675 break;
1676 case EMFILE:
1677 case ENFILE:
1678 slowdowntill = time(NULL) + 1;
1679 break;
1680 default:
1681 errx(1, "accept");
1682 }
1683 } else {
1684 /* Check if we hit the chosen fd limit */
1685 for (i = 0; i < maxcon; i++)
1686 if (con[i].pfd->fd == -1)
1687 break;
1688 if (i == maxcon) {
1689 close(s2);
1690 slowdowntill = 0;
1691 } else {
1692 initcon(&con[i], s2,
1693 (struct sockaddr *)&sin);
1694 syslog_r(LOG_INFO, &sdata,
1695 "%s: connected (%d/%d)%s%s",
1696 con[i].addr, clients, blackcount,
1697 ((con[i].lists == NULL) ? "" :
1698 ", lists:"),
1699 ((con[i].lists == NULL) ? "":
1700 con[i].lists));
1701 }
1702 }
1703 }
1704 if (pfd[PFD_CONFLISTEN].revents & (POLLIN|POLLHUP)) {
1705 socklen_t sinlen;
1706
1707 sinlen = sizeof(lin);
1708 conffd = accept(conflisten, (struct sockaddr *)&lin,
1709 &sinlen);
1710 if (conffd == -1) {
1711 switch (errno) {
1712 case EINTR:
1713 case ECONNABORTED:
1714 break;
1715 case EMFILE:
1716 case ENFILE:
1717 slowdowntill = time(NULL) + 1;
1718 break;
1719 default:
1720 errx(1, "accept");
1721 }
1722 } else if (ntohs(lin.sin_port) >= IPPORT_RESERVED) {
1723 close(conffd);
1724 conffd = -1;
1725 slowdowntill = 0;
1726 }
1727 } else if (pfd[PFD_CONFFD].revents & (POLLIN|POLLHUP))
1728 do_config();
1729 if (pfd[PFD_TRAPFD].revents & (POLLIN|POLLHUP))
1730 read_configline(trapcfg);
1731 if (pfd[PFD_SYNCFD].revents & (POLLIN|POLLHUP))
1732 sync_recv();
1733 if (pfd[PFD_GREYBACK].revents & (POLLIN|POLLHUP))
1734 blackcheck(greyback[1]);
1735 }
1736 exit(1);
1737 }
1738
1739 void
blackcheck(int fd)1740 blackcheck(int fd)
1741 {
1742 struct sockaddr_storage ss;
1743 ssize_t nread;
1744 void *ia;
1745 char ch;
1746
1747 /* Read sockaddr from greylister and look it up in the blacklists. */
1748 nread = recv(fd, &ss, sizeof(ss), 0);
1749 if (nread == -1) {
1750 syslog(LOG_ERR, "%s: recv: %m", __func__);
1751 return;
1752 }
1753 if (nread != sizeof(struct sockaddr_in) &&
1754 nread != sizeof(struct sockaddr_in6)) {
1755 syslog(LOG_ERR, "%s: invalid size %zd", __func__, nread);
1756 return;
1757 }
1758 if (ss.ss_family == AF_INET) {
1759 ia = &((struct sockaddr_in *)&ss)->sin_addr;
1760 } else if (ss.ss_family == AF_INET6) {
1761 ia = &((struct sockaddr_in6 *)&ss)->sin6_addr;
1762 } else {
1763 syslog(LOG_ERR, "%s: bad family %d", __func__, ss.ss_family);
1764 return;
1765 }
1766 ch = sdl_check(blacklists, ss.ss_family, ia) ? '1' : '0';
1767
1768 /* Send '1' for match or '0' for no match. */
1769 if (send(fd, &ch, sizeof(ch), 0) == -1) {
1770 syslog(LOG_ERR, "%s: send: %m", __func__);
1771 return;
1772 }
1773 }
1774