Make spamd stutter at greylisted connections for a short period before talking

full speed. By default do this for 10 seconds. Many spammers disconnect by
then. Adds -S option to select the amount of time greylisted connections
will be stuttered at.

	feedback from jmc@, deraadt@,   ok deraadt@

2 files changed, 22 insertions, 4 deletions

diff --git a/libexec/spamd/spamd.8 b/libexec/spamd/spamd.8
index 6f4191b7ae4..9248d2ff438 100644
--- a/libexec/spamd/spamd.8
+++ b/libexec/spamd/spamd.8
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: spamd.8,v 1.53 2005/03/11 23:09:53 beck Exp $
+.\"	$OpenBSD: spamd.8,v 1.54 2005/04/14 16:07:52 beck Exp $
 .\"
 .\" Copyright (c) 2002 Theo de Raadt.  All rights reserved.
 .\"
@@ -39,6 +39,7 @@
 .Op Fl n Ar name
 .Op Fl p Ar port
 .Op Fl r Ar reply
+.Op Fl S Ar secs
 .Op Fl s Ar secs
 .Op Fl w Ar window
 .Ek
@@ -108,6 +109,10 @@ using
 .It Fl r Ar reply
 The SMTP error to return to the spammer, i.e. 450, 451, 550.
 This defaults to 450.
+.It Fl S Ar secs
+Stutter at greylisted connections for the specified amount
+of seconds, after which the connection is not stuttered at.
+Defaults to 10.
 .It Fl s Ar secs
 Delay each character sent to the client by the specified
 amount of seconds.
diff --git a/libexec/spamd/spamd.c b/libexec/spamd/spamd.c
index 52a73bac2e9..5f91854e045 100644
--- a/libexec/spamd/spamd.c
+++ b/libexec/spamd/spamd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: spamd.c,v 1.75 2005/03/11 23:09:53 beck Exp $	*/
+/*	$OpenBSD: spamd.c,v 1.76 2005/04/14 16:07:52 beck Exp $	*/
 
 /*
  * Copyright (c) 2002 Theo de Raadt.  All rights reserved.
@@ -132,6 +132,7 @@ int blackcount;
 int clients;
 int debug;
 int greylist;
+int grey_stutter = 10;
 int verbose;
 int stutter = 1;
 int window;
@@ -145,7 +146,7 @@ usage(void)
 	fprintf(stderr,
 	    "             [-G mins:hours:hours] [-n name] [-p port]\n");
 	fprintf(stderr,
-	    "             [-r reply] [-s secs] [-w window]\n");
+	    "             [-r reply] [-S secs] [-s secs] [-w window]\n");
 	exit(1);
 }
 
@@ -578,7 +579,7 @@ initcon(struct con *cp, int fd, struct sockaddr *sa)
 	cp->af = sa->sa_family;
 	cp->ia = &((struct sockaddr_in *)sa)->sin_addr;
 	cp->blacklists = sdl_lookup(blacklists, cp->af, cp->ia);
-	cp->stutter = (greylist && cp->blacklists == NULL) ? 0 : stutter;
+	cp->stutter = (greylist && !grey_stutter && cp->blacklists == NULL) ? 0 : stutter;
 	error = getnameinfo(sa, sa->sa_len, cp->addr, sizeof(cp->addr), NULL, 0,
 	    NI_NUMERICHOST);
 	if (error)
@@ -887,6 +888,11 @@ handlew(struct con *cp, int one)
 {
 	int n;
 
+	/* kill stutter on greylisted connections after initial delay */
+	if (cp->stutter && greylist && cp->blacklists == NULL &&
+	    (t - cp->s) > grey_stutter)
+		cp->stutter=0;
+
 	if (cp->w) {
 		if (*cp->op == '\n' && !cp->sr) {
 			/* insert \r before \n */
@@ -937,6 +943,7 @@ main(int argc, char *argv[])
 	struct servent *ent;
 	struct rlimit rlp;
 	char *bind_address = NULL;
+	const char *errstr;
 
 	tzset();
 	openlog_r("spamd", LOG_PID | LOG_NDELAY, LOG_DAEMON, &sdata);
@@ -1002,6 +1009,12 @@ main(int argc, char *argv[])
 				usage();
 			stutter = i;
 			break;
+		case 'S':
+			i = strtonum(optarg, 0, 90, &errstr);
+			if (errstr)
+				usage();
+			grey_stutter = i;
+			break;
 		case 'n':
 			spamd = optarg;
 			break;