Remove HUP/TERM/INT sighandler, shield USR1 sighandler.

We remove, by default, all signal handlers. The USR1 handler
remains, but is shielded behind `#ifdef DEBUG`.

Makefile.am

@@ -8,7 +8,7 @@ sbin_PROGRAMS = tallow
 tallow_SOURCES = tallow.c
 tallow_LDADD = $(PCRE_LIBS) $(LIBSYSTEMD_LIBS)
 
-EXTRA_DIST = AUTHORS COPYING INSTALL tallow.service.in tallow.1.md
+EXTRA_DIST = AUTHORS COPYING INSTALL README.md tallow.service.in tallow.conf.5.md tallow.1.md
 
 dist_man_MANS = tallow.1 tallow.conf.5
 
@@ -18,9 +18,9 @@ DISTCHECK_CONFIGURE_FLAGS = \
 	--with-systemdsystemunitdir=$(DESTDIR)$(SYSTEMDSYSTEMUNITDIR)
 
 docs: tallow.1 tallow.conf.5
-tallow.conf.5:
+tallow.conf.5: tallow.conf.5.md
 	ronn -r tallow.conf.5.md --pipe > tallow.conf.5
 
-tallow.1:
+tallow.1: tallow.1.md
 	ronn -r tallow.1.md --pipe > tallow.1
 

configure.ac

@@ -2,8 +2,8 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.64])
-AC_INIT([tallow], [7], [auke-jan.h.kok@intel.com])
-AM_INIT_AUTOMAKE([])
+AC_INIT([tallow], [10], [auke-jan.h.kok@intel.com])
+AM_INIT_AUTOMAKE([foreign])
 AC_CONFIG_FILES([Makefile])
 
 # Checks for programs.

tallow.1

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "TALLOW" "1" "December 2017" "" ""
+.TH "TALLOW" "1" "March 2018" "" ""
 .
 .SH "NAME"
 \fBtallow\fR
@@ -27,6 +27,9 @@ Care should be taken to assure that legitimate users are not blocked inadvertent
 .SH "OPTIONS"
 The \fBtallow\fR daemon itself has no runtime configuration\. All configuration is done through the tallow\.conf(5) config file\.
 .
+.SH "SIGNALS"
+The \fBUSR1\fR signal causes \fBtallow\fR to print out it\'s internal tracking table of IP addresses\. This requires that tallow is compiled with the \fB\-DDEBUG=1\fR symbol passed to the compiler\.
+.
 .SH "SEE ALSO"
 systemd\-journald(1), iptables(1), ipset(1), tallow\.conf(5)
 .

tallow.1.md

@@ -40,6 +40,12 @@ be whitelisted.
 The `tallow` daemon itself has no runtime configuration. All
 configuration is done through the tallow.conf(5) config file.
 
+## SIGNALS
+
+The `USR1` signal causes `tallow` to print out it's internal tracking
+table of IP addresses. This requires that tallow is compiled with
+the `-DDEBUG=1` symbol passed to the compiler.
+
 ## SEE ALSO
 
 systemd-journald(1), iptables(1), ipset(1), tallow.conf(5)

tallow.c

@@ -56,16 +56,17 @@ struct pattern_struct {
 	pcre *re;
 };
 
-#define PATTERN_COUNT 9
+#define PATTERN_COUNT 10
 static struct pattern_struct patterns[PATTERN_COUNT] = {
-	{ 0, 0.4, "MESSAGE=Failed .* for .* from ([0-9a-z:.]+) port \\d+ ssh2", NULL},
-	{ 0, 0.4, "MESSAGE=error: PAM: Authentication failure for .* from ([0-9a-z:.]+)", NULL},
+	{ 0, 0.3, "MESSAGE=Failed .* for .* from ([0-9a-z:.]+) port \\d+ ssh2", NULL},
+	{ 0, 0.3, "MESSAGE=error: PAM: Authentication failure for .* from ([0-9a-z:.]+)", NULL},
 	{15, 0.3, "MESSAGE=Invalid user .* from ([0-9a-z:.]+) port \\d+", NULL},
 	{15, 0.3, "MESSAGE=Did not receive identification string from ([0-9a-z:.]+) port \\d+", NULL},
-	{30, 0.3, "MESSAGE=Failed .* for root from ([0-9a-z:.]+) port \\d+ ssh2", NULL},
-	{15, 0.6, "MESSAGE=Bad protocol version identification .* from ([0-9a-z:.]+)", NULL},
-	{15, 0.6, "MESSAGE=Connection closed by authenticating user .* ([0-9a-z:.]+) port \\d+", NULL},
-	{15, 0.6, "MESSAGE=Received disconnect from ([0-9a-z:.]+) port .*\\[preauth\\]", NULL},
+	{15, 0.4, "MESSAGE=Bad protocol version identification .* from ([0-9a-z:.]+)", NULL},
+	{15, 0.4, "MESSAGE=Connection closed by authenticating user .* ([0-9a-z:.]+) port \\d+", NULL},
+	{15, 0.4, "MESSAGE=Received disconnect from ([0-9a-z:.]+) port .*\\[preauth\\]", NULL},
+	{15, 0.4, "MESSAGE=Connection closed by ([0-9a-z:.]+) port .*\\[preauth\\]", NULL},
+	{30, 0.5, "MESSAGE=Failed .* for root from ([0-9a-z:.]+) port \\d+ ssh2", NULL},
 	{60, 0.6, "MESSAGE=Unable to negotiate with ([0-9a-z:.]+) port \\d+: no matching key exchange method found.", NULL}
 };
 
@@ -283,23 +284,7 @@ static void find(const char *ip, float weight, int instant_block)
 	return;
 }
 
-static void sig(int u __attribute__ ((unused)))
-{
-	fprintf(stderr, "Exiting on request.\n");
-	sd_journal_close(j);
-
-	struct tallow_struct *s = head;
-	while (s) {
-		struct tallow_struct *n = NULL;
-
-		free(s->ip);
-		n = s;
-		s = s->next;
-		free(n);
-	}
-	exit(EXIT_SUCCESS);
-}
-
+#ifdef DEBUG
 static void sigusr1(int u __attribute__ ((unused)))
 {
 	fprintf(stderr, "Dumping score list on request:\n");
@@ -309,6 +294,7 @@ static void sigusr1(int u __attribute__ ((unused)))
 		s = s->next;
 	}
 }
+#endif
 
 static void prune(void)
 {
@@ -353,20 +339,17 @@ int main(void)
 {
 	int r;
 	FILE *f;
-	struct sigaction s;
 	int timeout = 60;
 
 	strcpy(ipt_path, "/usr/sbin");
 
-	memset(&s, 0, sizeof(struct sigaction));
-	s.sa_handler = sig;
-	sigaction(SIGHUP, &s, NULL);
-	sigaction(SIGTERM, &s, NULL);
-	sigaction(SIGINT, &s, NULL);
+#ifdef DEBUG
+	struct sigaction s;
 
 	memset(&s, 0, sizeof(struct sigaction));
 	s.sa_handler = sigusr1;
 	sigaction(SIGUSR1, &s, NULL);
+#endif
 
 	if (access("/proc/sys/net/ipv6", R_OK | X_OK) == 0)
 		has_ipv6 = 1;

tallow.conf.5

@@ -25,7 +25,10 @@ This file is read on startup by the tallow(1) daemon, and can be used to provide
 \fBexpires\fR=\fB<int>\fR The number of seconds that IP addresses are blocked for\. Note that due to the implementation, IP addresses may be blocked for much longer than this period\. If IP addresses are seen, but not blocked within this period, they are also removed from the watch list\. Defaults to 3600s\.
 .
 .P
-\fBwhitelist\fR=\fB<ipv4 address>\fR Specify an IP address that should never be blocked\. Multiple IP addresses can be included by repeating the \fBwhitelist\fR option several times\. By default, only 127\.0\.0\.1 is whitelisted\.
+\fBwhitelist\fR=\fB<ip address|pattern>\fR Specify an IP address or \fBpattern\fR that should never be blocked\. Multiple IP addresses can be included by repeating the \fBwhitelist\fR option several times\. By default, only 127\.0\.0\.1 is whitelisted\.
+.
+.P
+If the last character of the listed ip adress is a \fB\.\fR or a \fB:\fR, then the matching is only performed on the leftmost characters of an IP address against the whitelist entry\. For instance, if you whitelist \fB10\.\fR then all IP addresses in the \fB10/8\fR subnet mask will match this whitelist entry and never be blocked\.
 .
 .P
 \fBipv6\fR=\fB<0|1>\fR Enable of disable ipv6 (ip6tables) support\. Ipv6 is disabled automatically on systems that do not appear to have ipv6 support and enabled when ipv6 is present\. Use this option to explicitly disable ipv6 support if your system does not have ipv6 or is missing ip6tables\. Even with ipv6 disabled, tallow will track and log ipv6 addresses\.