v19

It appears that using a signed int causes the reads from libsystemd-journal
to return incorrect values when comparing time stamps. I've fixed them
to unsigned ones and monitored the performance on 2 systems for 3 days and
it no longer misbehaves. I've also made it use `atoll` instead of `atoi`
to prevent incomplete results.

.gitignore

@@ -10,9 +10,9 @@ depcomp
 install-sh
 missing
 tallow
-tallow-*.tar.gz
+tallow-*.tar.*
 tallow-*/
-tallow.o
+*.o
 tallow.service
 *~
 DEADJOE

.travis.yml

@@ -16,6 +16,7 @@ addons:
             - valgrind
             - autoconf
             - automake
+            - libjson-c-dev
 
 script:
     - ./configure && make && make distcheck

Makefile.am

@@ -1,26 +1,42 @@
 
-AM_CFLAGS = -g $(PCRE_CFLAGS) $(LIBSYSTEMD_CFLAGS) -Wall -Wno-uninitialized -W -D_FORTIFY_SOURCE=2
+AM_CFLAGS = -g \
+	$(JSON_C_CFLAGS) $(PCRE_CFLAGS) $(LIBSYSTEMD_CFLAGS) \
+	-Wall -Wno-uninitialized -W -D_FORTIFY_SOURCE=2
+
+AM_CPPFLAGS = \
+	-DDATADIR='"$(datadir)"' -DSYSCONFDIR='"$(sysconfdir)"'
 
 systemdsystemunitdir = @SYSTEMD_SYSTEMUNITDIR@
-systemdsystemunit_DATA = tallow.service
+systemdsystemunit_DATA = data/tallow.service
 
 sbin_PROGRAMS = tallow
-tallow_SOURCES = tallow.c
-tallow_LDADD = $(PCRE_LIBS) $(LIBSYSTEMD_LIBS)
+tallow_SOURCES = \
+	src/tallow.c \
+	src/json.c \
+	src/json.h \
+	src/data.c \
+	src/data.h
+tallow_LDADD = $(JSON_C_LIBS) $(PCRE_LIBS) $(LIBSYSTEMD_LIBS)
 
-EXTRA_DIST = AUTHORS COPYING INSTALL README.md tallow.service.in tallow.conf.5.md tallow.1.md
+pkgdata_DATA = data/sshd.json
 
-dist_man_MANS = tallow.1 tallow.conf.5
+EXTRA_DIST = \
+	AUTHORS COPYING INSTALL README.md \
+	data/tallow.service.in \
+	data/sshd.json \
+	man/tallow.conf.5.md \
+	man/tallow.1.md
+
+dist_man_MANS = man/tallow.1 man/tallow.conf.5
 
 dist_doc_DATA = tallow.conf
 
 DISTCHECK_CONFIGURE_FLAGS = \
 	--with-systemdsystemunitdir=$(DESTDIR)$(SYSTEMDSYSTEMUNITDIR)
 
-docs: tallow.1 tallow.conf.5
-tallow.conf.5: tallow.conf.5.md
-	ronn -r tallow.conf.5.md --pipe > tallow.conf.5
-
-tallow.1: tallow.1.md
-	ronn -r tallow.1.md --pipe > tallow.1
+docs: $(dist_man_MANS)
+man/%.5: man/%.5.md
+	ronn -r $< --pipe > $@
 
+man/%.1: man/%.1.md
+	ronn -r $< --pipe > $@

README.md

@@ -16,7 +16,9 @@ Tallow attaches to the journal and subscribes to messages from
 /usr/sbin/sshd. The messages are matched against rules and the IP
 address is extracted from the message.  For each IP address that is
 extracted, the last timestamp and count is kept. Once the count exceeds
-a threshold, iptables is executed to set a IP-based blocking rule.
+a threshold, the offending IP address is added to an ipset and blocked 
+with a corresponding firewall rule. It will use firewalld or 
+iptables / ip6tables.
 
 The timestamp is kept for pruning. Records are pruned from the list
 if the IP address hasn't been seen by tallow for longer than the
@@ -66,4 +68,4 @@ tallow.
 
 Be very careful if you deploy tallow on systems that expect valid
 users to log on from many random source addresses. If your user
-mistypes their username, they could find themselves denied access.
+mistypes their username, they could find themselves denied access.

configure.ac

@@ -2,8 +2,9 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ([2.64])
-AC_INIT([tallow], [9], [auke-jan.h.kok@intel.com])
-AM_INIT_AUTOMAKE([foreign])
+AC_INIT([tallow], [19], [auke-jan.h.kok@intel.com])
+AM_INIT_AUTOMAKE([foreign -Wall -Werror -Wno-portability silent-rules subdir-objects color-tests
+	no-dist-gzip dist-xz])
 AC_CONFIG_FILES([Makefile])
 
 # Checks for programs.
@@ -11,6 +12,7 @@ AC_PROG_CC
 AC_PROG_INSTALL
 
 PKG_CHECK_MODULES(PCRE, libpcre)
+PKG_CHECK_MODULES(JSON_C, json-c)
 PKG_CHECK_MODULES(LIBSYSTEMD, libsystemd,, [PKG_CHECK_MODULES(LIBSYSTEMD, libsystemd-journal)])
 AC_SUBST(LIBSYSTEMD_CFLAGS)
 AC_SUBST(LIBSYSTEMD_LIBS)
@@ -28,5 +30,5 @@ fi
 AC_CHECK_HEADERS([stdlib.h stdio.h string.h stdarg.h limits.h sys/time.h])
 
 AC_OUTPUT([
-tallow.service
+data/tallow.service
 ])

data/dovecot.json

@@ -0,0 +1,12 @@
+[
+  {
+    "filter": "SYSLOG_IDENTIFIER=auth",
+    "items": [
+      {
+        "ban": 50,
+        "score": 0.6,
+        "pattern": "MESSAGE=pam_unix[(]dovecot:auth[)]: authentication failure; logname= uid=0 euid=0 tty=dovecot ruser=.*@.* rhost=([0-9a-z:.]+)"
+      }
+    ]
+  }
+]

data/sshd.json

@@ -0,0 +1,57 @@
+[
+  {
+    "filter": "SYSLOG_IDENTIFIER=sshd",
+    "items": [
+      {
+        "ban": 0,
+        "score": 0.2,
+        "pattern": "MESSAGE=Failed .* for .* from ([0-9a-z:.]+) port \\d+ ssh2"
+      },
+      {
+        "ban": 0,
+        "score": 0.2,
+        "pattern": "MESSAGE=error: PAM: Authentication failure for .* from ([0-9a-z:.]+)"
+      },
+      {
+        "ban": 10,
+        "score": 0.2,
+        "pattern": "MESSAGE=Invalid user .* from ([0-9a-z:.]+) port \\d+"
+      },
+      {
+        "ban": 10,
+        "score": 0.3,
+        "pattern": "MESSAGE=Did not receive identification string from ([0-9a-z:.]+) port \\d+"
+      },
+      {
+        "ban": 15,
+        "score": 0.4,
+        "pattern": "MESSAGE=Bad protocol version identification .* from ([0-9a-z:.]+)"
+      },
+      {
+        "ban": 15,
+        "score": 0.4,
+        "pattern": "MESSAGE=Connection closed by authenticating user .* ([0-9a-z:.]+) port \\d+"
+      },
+      {
+        "ban": 10,
+        "score": 0.3,
+        "pattern": "MESSAGE=Received disconnect from ([0-9a-z:.]+) port .*\\[preauth\\]"
+      },
+      {
+        "ban": 10,
+        "score": 0.3,
+        "pattern": "MESSAGE=Connection closed by ([0-9a-z:.]+) port .*\\[preauth\\]"
+      },
+      {
+        "ban": 30,
+        "score": 0.5,
+        "pattern": "MESSAGE=Failed .* for root from ([0-9a-z:.]+) port \\d+ ssh2"
+      },
+      {
+        "ban": 60,
+        "score": 0.6,
+        "pattern": "MESSAGE=Unable to negotiate with ([0-9a-z:.]+) port \\d+: no matching key exchange method found."
+      }
+    ]
+  }
+]

data/tallow.service.in

@@ -6,6 +6,7 @@ Description=Tallow Service
 ExecStart=@prefix@/sbin/tallow
 Restart=always
 RestartSec=3
+Nice=10
 
 [Install]
 WantedBy=network.target

man/tallow.1

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "TALLOW" "1" "January 2018" "" ""
+.TH "TALLOW" "1" "October 2018" "" ""
 .
 .SH "NAME"
 \fBtallow\fR
@@ -28,7 +28,7 @@ Care should be taken to assure that legitimate users are not blocked inadvertent
 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\.
+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)

man/tallow.1.md

@@ -43,7 +43,8 @@ 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.
+table of IP addresses. This requires that tallow is compiled with
+the `-DDEBUG=1` symbol passed to the compiler.
 
 ## SEE ALSO
 

man/tallow.conf.5

@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "TALLOW" "5" "January 2018" "" ""
+.TH "TALLOW" "5" "October 2019" "" ""
 .
 .SH "NAME"
 \fBtallow\fR
@@ -19,32 +19,52 @@ tallow\.conf \- Tallow daemon configuration file
 This file is read on startup by the tallow(1) daemon, and can be used to provide options to the tallow daemon\. If not present, tallow will operate with built\-in defaults\.
 .
 .SH "OPTIONS"
-\fBipt_path\fR=\fB<string>\fR Specifies the location of the ipset(1), iptables(1) or ip6tables(1) program\. By default, tallow will look in "/usr/sbin" for them\.
+\fBipt_path\fR=\fB<string>\fR Specifies the location of the ipset(1) program and iptables(1), ip6tables(1), or firewall\-cmd(1) programs\. By default, tallow will look in "/usr/sbin" for them\.
 .
 .P
 \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<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\.
+\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, 127\.0\.0\.1, 192\.168\., and 10\. are whitelisted\. If you create a manual whitelist, you must include these entries if you want to continue them to be whitelisted as well, otherwise they will be omitted from the whitelist\.
 .
 .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\.
+\fBipv6\fR=\fB<0|1>\fR Enable or 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\.
 .
 .P
-\fBnocreate\fR=\fB<0|1>\fR Disable the creation of iptables rules and ipset sets\. By default, tallow will create new iptables(1) and ip6tables(1) rules when needed automatically\. If set to \fB1\fR, \fBtallow(1)\fR will not create any new iptables rules or ipset sets to work\. You should create them manually before tallow starts up and remove them afterwards\. To create them manually, you can use the following commands:
+\fBnocreate\fR=\fB<0|1>\fR Disable the creation of firewall rules and ipset sets\. By default, tallow will create new firewall\-cmd(1) or iptables(1) and ip6tables(1) rules when needed automatically\. If set to \fB1\fR, \fBtallow(1)\fR will not create any new firewall DROP rules or ipset sets that are needed work\. You should create them manually before tallow starts up and remove them afterwards using the sets of commands below\.
+.
+.P
+Use the following commands if you\'re using iptables(1):
 .
 .IP "" 4
 .
 .nf
 
-  iptables \-t filter \-I INPUT \-m set \-\-match\-set tallow src \-j DROP
   ipset create tallow hash:ip family inet timeout 3600
+  iptables \-t filter \-I INPUT 1 \-m set \-\-match\-set tallow src \-j DROP
 
-  ip6tables \-t filter \-I INPUT \-m set \-\-match\-set tallow6 src \-j DROP
   ipset create tallow6 hash:ip family inet6 timeout 3600
+  ip6tables \-t filter \-I INPUT 1 \-m set \-\-match\-set tallow6 src \-j DROP
+.
+.fi
+.
+.IP "" 0
+.
+.P
+Use the following commands if you\'re using firewalld(1):
+.
+.IP "" 4
+.
+.nf
+
+  firewall\-cmd \-\-permanent \-\-new\-ipset=tallow \-\-type=hash:ip \-\-family=inet \-\-option=timeout=3600
+  firewall\-cmd \-\-permanent \-\-direct \-\-add\-rule ipv4 filter INPUT 1 \-m set \-\-match\-set tallow src \-j DROP
+
+  firewall\-cmd \-\-permanent \-\-new\-ipset=tallow6 \-\-type=hash:ip \-\-family=inet6 \-\-option=timeout=3600
+  firewall\-cmd \-\-permanent \-\-direct \-\-add\-rule ipv6 filter INPUT 1 \-m set \-\-match\-set tallow6 src \-j DROP
 .
 .fi
 .

man/tallow.conf.5.md

@@ -20,8 +20,9 @@ tallow will operate with built-in defaults.
 ## OPTIONS
 
 `ipt_path`=`<string>`
-Specifies the location of the ipset(1), iptables(1) or ip6tables(1)
-program. By default, tallow will look in "/usr/sbin" for them.
+Specifies the location of the ipset(1) program and iptables(1), 
+ip6tables(1), or firewall-cmd(1) programs. By default, tallow will 
+look in "/usr/sbin" for them.
 
 `expires`=`<int>`
 The number of seconds that IP addresses are blocked for. Note that
@@ -33,8 +34,10 @@ watch list. Defaults to 3600s.
 `whitelist`=`<ip address|pattern>`
 Specify an IP address or `pattern` that should never be
 blocked. Multiple IP addresses can be included by repeating the
-`whitelist` option several times. By default, only 127.0.0.1 is
-whitelisted.
+`whitelist` option several times. By default, 127.0.0.1, 192.168., and
+10. are whitelisted. If you create a manual whitelist, you must include
+these entries if you want to continue them to be whitelisted as
+well, otherwise they will be omitted from the whitelist.
 
 If the last character of the listed ip adress is a `.` or a `:`, then
 the matching is only performed on the leftmost characters of an IP
@@ -43,27 +46,39 @@ address against the whitelist entry. For instance, if you whitelist
 whitelist entry and never be blocked.
 
 `ipv6`=`<0|1>`
-Enable of disable ipv6 (ip6tables) support. Ipv6 is disabled
+Enable or 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.
 
-`nocreate`=`<0|1>`
-Disable the creation of iptables rules and ipset sets. By default,
-tallow will create new iptables(1) and ip6tables(1) rules when needed
-automatically. If set to `1`, `tallow(1)` will not create any new
-iptables rules or ipset sets to work. You should create them manually
-before tallow starts up and remove them afterwards. To create them
-manually, you can use the following commands:
+`nocreate`=`<0|1>` Disable the creation of firewall rules and ipset sets. By
+default, tallow will create new firewall-cmd(1) or iptables(1) and ip6tables(1)
+rules when needed automatically. If set to `1`, `tallow(1)` will not create any
+new firewall DROP rules or ipset sets that are needed work. You should create
+them manually before tallow starts up and remove them afterwards using the sets
+of commands below. 
+
+Use the following commands if you're using iptables(1):
 
   ```
-  iptables -t filter -I INPUT -m set --match-set tallow src -j DROP
   ipset create tallow hash:ip family inet timeout 3600
+  iptables -t filter -I INPUT 1 -m set --match-set tallow src -j DROP
 
-  ip6tables -t filter -I INPUT -m set --match-set tallow6 src -j DROP
   ipset create tallow6 hash:ip family inet6 timeout 3600
+  ip6tables -t filter -I INPUT 1 -m set --match-set tallow6 src -j DROP
+  ```
+
+Use the following commands if you're using firewalld(1):
+
+```
+  firewall-cmd --permanent --new-ipset=tallow --type=hash:ip --family=inet --option=timeout=3600
+  firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 1 -m set --match-set tallow src -j DROP
+  
+  firewall-cmd --permanent --new-ipset=tallow6 --type=hash:ip --family=inet6 --option=timeout=3600
+  firewall-cmd --permanent --direct --add-rule ipv6 filter INPUT 1 -m set --match-set tallow6 src -j DROP
+  
   ```
 
 ## SEE ALSO
@@ -73,4 +88,3 @@ tallow(1)
 ## AUTHOR
 
 Auke Kok <auke-jan.h.kok@intel.com>
-

src/data.c

@@ -0,0 +1,175 @@
+/*
+ * data.h - IP block sshd login abuse
+ *
+ * (C) Copyright 2019 Intel Corporation
+ * Authors:
+ *     Auke Kok <auke-jan.h.kok@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 3
+ * of the License.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/time.h>
+#include <malloc.h>
+
+#include <pcre.h>
+
+#include "data.h"
+
+struct block_struct *blocks;
+struct pattern_struct *patterns;
+struct filter_struct *filters;
+struct whitelist_struct *whitelist;
+
+void filter_add(const char *filter)
+{
+	struct filter_struct *h = filters;
+
+	/* filter duplicates */
+	while (h) {
+		if (strcmp(h->filter, filter) == 0)
+			return;
+
+		h = h->next;
+	}
+
+	struct filter_struct *f = calloc(1, sizeof(struct filter_struct));
+	if (!f) {
+		perror("calloc()");
+		exit(EXIT_FAILURE);
+	}
+
+	f->filter = strdup(filter);
+
+	h = filters;
+	if (!h) {
+		filters = f;
+	} else {
+		while (h->next)
+			h = h->next;
+		h->next = f;
+	}
+}
+
+void pattern_add(const char *pattern, int ban, double score)
+{
+	struct pattern_struct *p = calloc(1, sizeof(struct pattern_struct));
+	if (!p) {
+		perror("calloc()");
+		exit(EXIT_FAILURE);
+	}
+
+	p->pattern = strdup(pattern);
+	p->instant_block = ban;
+	p->weight = score;
+
+	const char *pcre_err;
+	int err;
+	p->re = pcre_compile(pattern, 0, &pcre_err, &err, NULL);
+	if (!p->re) {
+		fprintf(stderr, "PCRE compilation failed. Offset %d: %s\n",
+			err, pcre_err);
+		exit(EXIT_FAILURE);
+	}
+
+	struct pattern_struct *h = patterns;
+	if (!h) {
+		patterns = p;
+	} else {
+		while (h->next)
+			h = h->next;
+		h->next = p;
+	}
+}
+
+void whitelist_add(const char *ip)
+{
+	struct whitelist_struct *w = calloc(1, sizeof(struct whitelist_struct));
+
+	if (!w) {
+		perror("calloc()");
+		exit(EXIT_FAILURE);
+	}
+
+	w->ip = strdup(ip);
+
+	size_t l = strlen(ip);
+	if ((ip[l-1] == '.') || (ip[l-1] == ':'))
+		w->len = l;
+	else
+		w->len = -1;
+
+	struct whitelist_struct *h = whitelist;
+	if (!h) {
+		whitelist = w;
+	} else {
+		while (h->next)
+			h = h->next;
+		h->next = w;
+	}
+}
+
+bool whitelist_find(const char *ip)
+{
+	struct whitelist_struct *w = whitelist;
+	while (w) {
+		if (w->len > 0) {
+			if (!strncmp(w->ip, ip, w->len))
+				return (true);
+		} else {
+			if (!strcmp(w->ip, ip))
+				return (true);
+		}
+		w = w->next;
+	}
+
+	return (false);
+}
+
+void prune(int expires)
+{
+	struct block_struct *s = blocks;
+	struct block_struct *p;
+	struct timeval tv;
+
+	(void) gettimeofday(&tv, NULL);
+	p = NULL;
+
+	while (s) {
+		/*
+		 * Expire all records, but if they are blocked, make sure to
+		 * expire them *before* the ipset rule expires, otherwise
+		 * you might get an IP to bypass checks.
+		 */
+		time_t age = tv.tv_sec - s->time.tv_sec;
+		if ((age > expires) ||
+		    ((s->blocked) && (age > expires / 2))) {
+			dbg("Expired record for %s\n", s->ip);
+			if (p) {
+				p->next = s->next;
+				free(s->ip);
+				free(s);
+				s = p->next;
+				continue;
+			} else {
+				blocks = s->next;
+				free(s->ip);
+				free(s);
+				s = blocks;
+				p = NULL;
+				continue;
+			}
+		}
+		p = s;
+		s = s->next;
+	}
+
+	/* return some memory */
+	malloc_trim(0);
+}

src/data.h

@@ -0,0 +1,60 @@
+/*
+ * data.h - IP block sshd login abuse
+ *
+ * (C) Copyright 2019 Intel Corporation
+ * Authors:
+ *     Auke Kok <auke-jan.h.kok@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 3
+ * of the License.
+ */
+
+#pragma once
+
+#include <pcre.h>
+
+#ifdef DEBUG
+#define dbg(args...) fprintf(stderr, ##args)
+#else
+#define dbg(args...) do {} while (0)
+#endif
+
+struct block_struct {
+	char *ip;
+	float score;
+	struct timeval time;
+	struct block_struct *next;
+	bool blocked;
+};
+
+struct whitelist_struct {
+	char *ip;
+	size_t len;
+	struct whitelist_struct *next;
+};
+
+struct pattern_struct {
+	int instant_block;
+	float weight;
+	char *pattern;
+	pcre *re;
+	struct pattern_struct *next;
+};
+
+struct filter_struct {
+	char *filter;
+	struct filter_struct *next;
+};
+
+extern struct block_struct *blocks;
+extern struct pattern_struct *patterns;
+extern struct filter_struct *filters;
+extern struct whitelist_struct *whitelist;
+
+void filter_add(const char *filter);
+void pattern_add(const char *pattern, int ban, double score);
+void whitelist_add(const char *ip);
+bool whitelist_find(const char *ip);
+void prune(int expires);

src/json.c

@@ -0,0 +1,218 @@
+/*
+ * json.c - IP block sshd login abuse
+ *
+ * (C) Copyright 2019 Intel Corporation
+ * Authors:
+ *     Auke Kok <auke-jan.h.kok@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 3
+ * of the License.
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <dirent.h>
+#include <fcntl.h>
+
+#include <json-c/json.h>
+
+#include "data.h"
+
+static const char *s_pattern;
+static const char *s_filter;
+static int s_ban;
+static double s_score;
+static bool g_filter, g_ban, g_score, g_pattern = false;
+
+static int json_parse(json_object *ob)
+{
+	int i, count = 0;
+	bool l_filter, l_ban, l_score, l_pattern = false;
+
+	json_object_object_foreach(ob, key, val) {
+		enum json_type type;
+		type = json_object_get_type(val);
+		switch (type) {
+		case json_type_null:
+			break;
+		case json_type_boolean:
+			break;
+		case json_type_double:
+			if (strcmp(key, "score") == 0) {
+				l_score = g_score = true;
+				s_score = json_object_get_double(val);
+			} else {
+				fprintf(stderr, "Invalid JSON key \"%s\"\n", key);
+				return (0);
+			}
+			break;
+		case json_type_int:
+			if (strcmp(key, "ban") == 0) {
+				l_ban = g_ban = true;
+				s_ban = json_object_get_int(val);
+			} else {
+				fprintf(stderr, "Invalid JSON key \"%s\"\n", key);
+				return (0);
+			}
+			break;
+		case json_type_string:
+			if (strcmp(key, "filter") == 0) {
+				l_filter = g_filter = true;
+				s_filter = json_object_get_string(val);
+			} else if (strcmp(key, "pattern") == 0) {
+				l_pattern = g_pattern = true;
+				s_pattern = json_object_get_string(val);
+			} else {
+				fprintf(stderr, "Invalid JSON key \"%s\"\n", key);
+				return (0);
+			}
+			break;
+		case json_type_array:
+			ob = json_object_object_get(ob, key);
+			int len = json_object_array_length(ob);
+			json_object *val;
+			for (i = 0; i < len; i++) {
+				val = json_object_array_get_idx(ob, i);
+				count += json_parse(val);
+			}
+			break;
+		case json_type_object:
+			ob = json_object_object_get(ob, key);
+			count += json_parse(ob);
+			break;
+		}
+	}
+
+	/* check and finish if can */
+	if (g_score && g_ban && g_pattern && g_filter) {
+#ifdef DEBUG
+		fprintf(stderr, "Adding: %s %s %d %lf\n", s_filter, s_pattern, s_ban, s_score);
+#endif
+		filter_add(s_filter);
+		pattern_add(s_pattern, s_ban, s_score);
+		count++;
+	}
+
+	/* cleanup */
+	if (l_score) {
+		l_score = g_score = false;
+	} else if (l_ban) {
+		l_ban = g_ban = false;
+	} else if (l_pattern) {
+		l_pattern = g_pattern = false;
+	} else if (l_filter) {
+		l_filter = g_filter = false;
+	}
+
+	return (count);
+}
+
+static int json_load_file(const char* file)
+{
+	int i, count = 0;
+	char *json;
+	int fd;
+	struct stat st;
+	fd = open(file, O_RDONLY);
+	fstat(fd, &st);
+	json = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+
+	struct json_object *obj;
+
+	obj = json_tokener_parse(json);
+	if (json_object_is_type(obj,json_type_array)) {
+		int len = json_object_array_length(obj);
+		json_object *val;
+		for (i = 0; i < len; i++) {
+			val = json_object_array_get_idx(obj, i);
+			count += json_parse(val);
+		}
+	} else if (json_object_is_type(obj, json_type_object)) {
+		count += json_parse(obj);
+	} else {
+		fprintf(stderr, "This does not look like JSON: %s\n", file);
+		return (0);
+	}
+
+	json_object_put(obj);
+
+	munmap(json, st.st_size);
+	return (count);
+}
+
+static int json_load_dir(const char *dir)
+{
+	int count = 0;
+
+	DIR *d = opendir(dir);
+	if (!d) {
+		fprintf(stderr, "Skipped reading %s: %s\n", dir, strerror(errno));
+		return (count);
+	}
+	struct dirent *entry;
+	for (;;) {
+		entry = readdir(d);
+		if (!entry)
+			break;
+		size_t l = strlen(entry->d_name);
+		if (l < strlen(".json"))
+			continue;
+		if (strcmp(entry->d_name + l - strlen(".json"), ".json") == 0) {
+			char *p;
+			if (!asprintf(&p, "%s/%s", dir, entry->d_name)) {
+				fprintf(stderr, "asprintf: %s\n", strerror(errno));
+				exit(EXIT_FAILURE);
+			}
+
+			/* allow /etc/tallow files to override /usr/share/tallow files */
+			if (strcmp(dir, DATADIR "/" PACKAGE_NAME) == 0) {
+				char *sp;
+				if (!asprintf(&sp, SYSCONFDIR "/" PACKAGE_NAME "/%s", entry->d_name)) {
+					fprintf(stderr, "asprintf: %s\n", strerror(errno));
+					exit(EXIT_FAILURE);
+				}
+
+				struct stat st;
+				if (stat(sp, &st) == 0) {
+					dbg("Skipped " SYSCONFDIR "/" PACKAGE_NAME "/%s\n", entry->d_name);
+					free(sp);
+					continue;
+				}
+				free(sp);
+			}
+
+			int c = json_load_file(p);
+			fprintf(stderr, "%s: %d patterns\n", p, c);
+			count += c;
+			free(p);
+		}
+
+	}
+	closedir(d);
+
+	return (count);
+}
+
+void json_load_patterns(void)
+{
+	int count = 0;
+	count += json_load_dir(DATADIR "/" PACKAGE_NAME);
+	count += json_load_dir(SYSCONFDIR "/" PACKAGE_NAME);
+	fprintf(stderr, "Loaded %d patterns total\n", count);
+	if (count < 1) {
+		/* consider sending a special exit code here */
+		fprintf(stderr, "No patterns loaded, nothing to do!\n");
+		exit(EXIT_SUCCESS);
+	}
+}

src/json.h

@@ -0,0 +1,16 @@
+/*
+ * json.h - IP block sshd login abuse
+ *
+ * (C) Copyright 2019 Intel Corporation
+ * Authors:
+ *     Auke Kok <auke-jan.h.kok@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 3
+ * of the License.
+ */
+
+#pragma once
+
+void json_load_patterns(void);

src/tallow.c

@@ -1,7 +1,7 @@
 /*
  * tallow.c - IP block sshd login abuse
  *
- * (C) Copyright 2015 Intel Corporation
+ * (C) Copyright 2015-2019 Intel Corporation
  * Authors:
  *     Auke Kok <auke-jan.h.kok@intel.com>
  *
@@ -11,6 +11,8 @@
  * of the License.
  */
 
+#define _GNU_SOURCE
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -20,55 +22,15 @@
 #include <unistd.h>
 #include <limits.h>
 #include <sys/time.h>
-#include <pcre.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/limits.h>
 
+#include <pcre.h>
 #include <systemd/sd-journal.h>
 
-#ifdef DEBUG
-#define dbg(args...) fprintf(stderr, ##args)
-#else
-#define dbg(args...) do {} while (0)
-#endif
-
-struct tallow_struct {
-	char *ip;
-	float score;
-	struct timeval time;
-	struct tallow_struct *next;
-	bool blocked;
-};
-
-static struct tallow_struct *head;
-
-struct whitelist_struct {
-	char *ip;
-	size_t len;
-	struct whitelist_struct *next;
-};
-
-static struct whitelist_struct *whitelist;
-
-#define FILTER_STRING "SYSLOG_IDENTIFIER=sshd"
-struct pattern_struct {
-	int instant_block;
-	float weight;
-	char *pattern;
-	pcre *re;
-};
-
-#define PATTERN_COUNT 10
-static struct pattern_struct patterns[PATTERN_COUNT] = {
-	{ 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},
-	{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}
-};
+#include "json.h"
+#include "data.h"
 
 #define MAX_OFFSETS 30
 
@@ -106,6 +68,26 @@ static void ext_ignore(char *fmt, ...)
 	__attribute__((unused)) int ret = system(cmd);
 }
 
+static void reset_rules(void)
+{
+	/* reset all rules in case the running fw changes */
+	ext_ignore("%s/firewall-cmd --permanent --direct --remove-rule ipv4 filter INPUT 1 -m set --match-set tallow src -j DROP 2> /dev/null", ipt_path);
+	ext_ignore("%s/firewall-cmd --permanent --delete-ipset=tallow 2> /dev/null", ipt_path);
+
+	/* delete iptables ref to set before the ipset! */
+	ext_ignore("%s/iptables -t filter -D INPUT -m set --match-set tallow src -j DROP 2> /dev/null", ipt_path);
+	ext_ignore("%s/ipset destroy tallow 2> /dev/null", ipt_path);
+
+	if (has_ipv6) {
+		ext_ignore("%s/firewall-cmd --permanent --direct --remove-rule ipv6 filter INPUT 1 -m set --match-set tallow6 src -j DROP 2> /dev/null", ipt_path);
+		ext_ignore("%s/firewall-cmd --permanent --delete-ipset=tallow6 2> /dev/null", ipt_path);
+		
+		/* delete iptables ref to set before the ipset! */
+		ext_ignore("%s/ip6tables -t filter -D INPUT -m set --match-set tallow6 src -j DROP 2> /dev/null", ipt_path);
+		ext_ignore("%s/ipset destroy tallow6 2> /dev/null", ipt_path);
+	}
+}
+
 static void setup(void)
 {
 	static bool done = false;
@@ -116,38 +98,78 @@ static void setup(void)
 	if (nocreate)
 		return;
 
-	/* init ipset and iptables */
-	/* delete iptables ref to set before the ipset! */
-	ext_ignore("%s/iptables -t filter -D INPUT -m set --match-set tallow src -j DROP 2> /dev/null", ipt_path);
-	ext_ignore("%s/ipset destroy tallow 2> /dev/null", ipt_path);
-	if (ext("%s/ipset create tallow hash:ip family inet timeout %d", ipt_path, expires)) {
-		fprintf(stderr, "Unable to create ipv4 ipset.\n");
-		exit(EXIT_FAILURE);
-	}
-	if (ext("%s/iptables -t filter -A INPUT -m set --match-set tallow src -j DROP", ipt_path)) {
-		fprintf(stderr, "Unable to create iptables rule.\n");
+	/* firewalld */
+	char *fwd_path;
+	if (asprintf(&fwd_path, "%s/firewall-cmd", ipt_path) < 0) {
 		exit(EXIT_FAILURE);
 	}
 
-	if (has_ipv6) {
-		ext_ignore("%s/ip6tables -t filter -D INPUT -m set --match-set tallow6 src -j DROP 2> /dev/null", ipt_path);
-		ext_ignore("%s/ipset destroy tallow6 2> /dev/null", ipt_path);
-		if (ext("%s/ipset create tallow6 hash:ip family inet6 timeout %d", ipt_path, expires)) {
-			fprintf(stderr, "Unable to create ipv6 ipset.\n");
+	if ((access(fwd_path, X_OK) == 0) && ext("%s/firewall-cmd --state --quiet", ipt_path) == 0) {
+		fprintf(stdout, "firewalld is running and will be used by tallow.\n");
+
+		reset_rules();
+
+		/* create ipv4 rule and ipset */
+		if (ext("%s/firewall-cmd --permanent --quiet --new-ipset=tallow --type=hash:ip --family=inet --option=timeout=%d", ipt_path, expires)) {
+			fprintf(stderr, "Unable to create ipv4 ipset with firewall-cmd.\n");
 			exit(EXIT_FAILURE);
 		}
-		if (ext("%s/ip6tables -t filter -A INPUT -m set --match-set tallow6 src -j DROP", ipt_path)) {
-			fprintf(stderr, "Unable to create ipt6ables rule.\n");
+		if (ext("%s/firewall-cmd --permanent --direct --quiet --add-rule ipv4 filter INPUT 1 -m set --match-set tallow src -j DROP", ipt_path)) {
+			fprintf(stderr, "Unable to create ipv4 firewalld rule.\n");
 			exit(EXIT_FAILURE);
 		}
+
+		/* create ipv6 rule and ipset */
+		if (has_ipv6) {
+			if (ext("%s/firewall-cmd --permanent --quiet --new-ipset=tallow6 --type=hash:ip --family=inet6 --option=timeout=%d", ipt_path, expires)) {
+				fprintf(stderr, "Unable to create ipv6 ipset with firewall-cmd.\n");
+				exit(EXIT_FAILURE);
+			}
+			if (ext("%s/firewall-cmd --permanent --direct --quiet --add-rule ipv6 filter INPUT 1 -m set --match-set tallow6 src -j DROP ", ipt_path)) {
+				fprintf(stderr, "Unable to create ipv6 firewalld rule.\n");
+				exit(EXIT_FAILURE);
+			}
+		}
+
+		/* reload firewalld for ipsets to load */
+		if (ext("%s/firewall-cmd --reload --quiet", ipt_path, expires)) {
+			fprintf(stderr, "Unable to reload firewalld rules.\n");
+			exit(EXIT_FAILURE);
+		}
+	} else {
+		/* iptables */
+		reset_rules();
+
+		/* create ipv4 rule and ipset */
+		if (ext("%s/ipset create tallow hash:ip family inet timeout %d", ipt_path, expires)) {
+			fprintf(stderr, "Unable to create ipv4 ipset.\n");
+			exit(EXIT_FAILURE);
+		}
+		if (ext("%s/iptables -t filter -A INPUT -m set --match-set tallow src -j DROP", ipt_path)) {
+			fprintf(stderr, "Unable to create iptables rule.\n");
+			exit(EXIT_FAILURE);
+		}
+
+		/* create ipv6 rule and ipset */
+		if (has_ipv6) {
+			if (ext("%s/ipset create tallow6 hash:ip family inet6 timeout %d", ipt_path, expires)) {
+				fprintf(stderr, "Unable to create ipv6 ipset.\n");
+				exit(EXIT_FAILURE);
+			}
+			if (ext("%s/ip6tables -t filter -A INPUT -m set --match-set tallow6 src -j DROP", ipt_path)) {
+				fprintf(stderr, "Unable to create ipt6ables rule.\n");
+				exit(EXIT_FAILURE);
+			}
+		}
 	}
+
+	free(fwd_path);
 }
 
-static void block(struct tallow_struct *s, int instant_block)
+static void block(struct block_struct *s, int instant_block)
 {
 	setup();
 
-
 	if (strchr(s->ip, ':')) {
 		if (has_ipv6) {
 			if (instant_block > 0) {
@@ -175,38 +197,10 @@ static void block(struct tallow_struct *s, int instant_block)
 	}
 }
 
-static void whitelist_add(char *ip)
+void find(const char *ip, float weight, int instant_block)
 {
-	struct whitelist_struct *w = whitelist;
-	struct whitelist_struct *n;
-
-	while (w && w->next)
-		w = w->next;
-
-	n = calloc(1, sizeof(struct whitelist_struct));
-	if (!n) {
-		fprintf(stderr, "Out of memory.\n");
-		exit(EXIT_FAILURE);
-	}
-
-	n->ip = strdup(ip);
-	size_t l = strlen(ip);
-	if ((ip[l-1] == '.') || (ip[l-1] == ':'))
-		n->len = l;
-	else
-		n->len = -1;
-
-	if (!whitelist)
-		whitelist = n;
-	else
-		w->next = n;
-}
-
-static void find(const char *ip, float weight, int instant_block)
-{
-	struct tallow_struct *s = head;
-	struct tallow_struct *n;
-	struct whitelist_struct *w = whitelist;
+	struct block_struct *s = blocks;
+	struct block_struct *n;
 
 	if (!ip)
 		return;
@@ -219,17 +213,8 @@ static void find(const char *ip, float weight, int instant_block)
 	if (strspn(ip, "0123456789abcdef:.") != strlen(ip))
 		return;
 
-	/* whitelist */
-	while (w) {
-		if (w->len > 0) {
-			if (!strncmp(w->ip, ip, w->len))
-				return;
-		} else {
-			if (!strcmp(w->ip, ip))
-				return;
-		}
-		w = w->next;
-	}
+	if (whitelist_find(ip))
+		return;
 
 	/* walk and update entry */
 	while (s) {
@@ -258,14 +243,14 @@ static void find(const char *ip, float weight, int instant_block)
 	}
 
 	/* append */
-	n = calloc(1, sizeof(struct tallow_struct));
+	n = calloc(1, sizeof(struct block_struct));
 	if (!n) {
 		fprintf(stderr, "Out of memory.\n");
 		exit(EXIT_FAILURE);
 	}
 
-	if (!head)
-		head = n;
+	if (!blocks)
+		blocks = n;
 	else
 		s->next = n;
 
@@ -284,95 +269,44 @@ 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");
-	struct tallow_struct *s = head;
+	struct block_struct *s = blocks;
 	while (s) {
 		fprintf(stderr, "%ld %s %1.3f\n", s->time.tv_sec, s->ip, s->score);
 		s = s->next;
 	}
 }
+#endif
 
-static void prune(void)
-{
-	struct tallow_struct *s = head;
-	struct tallow_struct *p;
-	struct timeval tv;
-
-	(void) gettimeofday(&tv, NULL);
-	p = NULL;
-
-	while (s) {
-		/*
-		 * Expire all records, but if they are blocked, make sure to
-		 * expire them *before* the ipset rule expires, otherwise
-		 * you might get an IP to bypass checks.
-		 */
-		time_t age = tv.tv_sec - s->time.tv_sec;
-		if ((age > expires) ||
-		    ((s->blocked) && (age > expires / 2))) {
-			dbg("Expired record for %s\n", s->ip);
-			if (p) {
-				p->next = s->next;
-				free(s->ip);
-				free(s);
-				s = p->next;
-				continue;
-			} else {
-				head = s->next;
-				free(s->ip);
-				free(s);
-				s = head;
-				p = NULL;
-				continue;
-			}
-		}
-		p = s;
-		s = s->next;
-	}
-}
 
 int main(void)
 {
 	int r;
 	FILE *f;
-	struct sigaction s;
 	int timeout = 60;
+	long long unsigned int last_timestamp = 0;
+
+	json_load_patterns();
 
 	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
+	fprintf(stderr, "Debug output enabled. Send SIGUSR1 to dump internal state table\n");
+
+	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;
 
-	f = fopen("/etc/tallow.conf", "r");
+	f = fopen(SYSCONFDIR "/tallow.conf", "r");
 	if (f) {
 		char buf[256];
 		char *key;
@@ -412,8 +346,11 @@ int main(void)
 	if (!has_ipv6)
 		fprintf(stdout, "ipv6 support disabled.\n");
 
-	if (!whitelist)
+	if (!whitelist) {
 		whitelist_add("127.0.0.1");
+		whitelist_add("192.168.");
+		whitelist_add("10.");
+	}
 
 	r = sd_journal_open(&j, SD_JOURNAL_LOCAL_ONLY);
 	if (r < 0) {
@@ -421,9 +358,14 @@ int main(void)
 		exit(EXIT_FAILURE);
 	}
 
+	/* add all filters */
+	struct filter_struct *flt = filters;
+	while (flt) {
+		sd_journal_add_match(j, flt->filter, 0);
+		flt = flt->next;
+	}
 
-	/* ffwd journal */
-	sd_journal_add_match(j, FILTER_STRING, 0);
+	/* go to the tail and wait */
 	r = sd_journal_seek_tail(j);
 	sd_journal_wait(j, (uint64_t) 0);
 	dbg("sd_journal_seek_tail() returned %d\n", r);
@@ -431,59 +373,68 @@ int main(void)
 		r++;
 	dbg("Forwarded through %d items in the journal to reach the end\n", r);
 
-	fprintf(stderr, "Started\n");
-
-	for (int i = 0; i < PATTERN_COUNT; i++) {
-		int err;
-		const char *pcre_err;
-		patterns[i].re = pcre_compile(patterns[i].pattern, 0, &pcre_err, &err, NULL);
-		if (!patterns[i].re) {
-			fprintf(stderr, "PCRE compilation failed. Pattern %d, offset %d: %s\n",
-				i, err, pcre_err);
-			exit(EXIT_FAILURE);
-		}
-	}
+	fprintf(stderr, PACKAGE_STRING " Started\n");
 
 	for (;;) {
-		const void *d;
-		size_t l;
+		const void *d, *dt;
+		size_t l, dl;
 
 		r = sd_journal_wait(j, (uint64_t) timeout * 1000000);
 		if (r == SD_JOURNAL_INVALIDATE) {
 			fprintf(stderr, "Journal was rotated, resetting\n");
 			sd_journal_seek_tail(j);
+		} else if (r == SD_JOURNAL_NOP) {
+			dbg("Timeout reached, waiting again\n");
+			continue;
 		}
 
 		while (sd_journal_next(j) != 0) {
 			char *m;
 
+			/*
+			 * discard messages older than ones we've already seen before
+			 * this happens when the journal rotates - we get replayed events
+			 */
+			if (sd_journal_get_data(j, "_SOURCE_REALTIME_TIMESTAMP", &dt, &dl) == 0) {
+				long long unsigned int lt = atoll(dt + strlen("_SOURCE_REALTIME_TIMESTAMP="));
+				if (lt > last_timestamp)
+					last_timestamp = lt;
+				else if (lt < last_timestamp) {
+					dbg("Discarding old entry: %llu - %llu\n", lt, last_timestamp);
+					continue;
+				}
+			}
+
 			if (sd_journal_get_data(j, "MESSAGE", &d, &l) < 0) {
 				fprintf(stderr, "Failed to read message field: %s\n", strerror(-r));
-				continue;
+				break;
 			}
 
 			m = strndup(d, l+1);
 			m[l] = '\0';
 
-			for (int i = 0; i < PATTERN_COUNT; i++) {
+			struct pattern_struct *pat = patterns;
+			while (pat) {
 				int off[MAX_OFFSETS];
-				int ret = pcre_exec(patterns[i].re, NULL, m, l, 0, 0, off, MAX_OFFSETS);
+				int ret = pcre_exec(pat->re, NULL, m, l, 0, 0, off, MAX_OFFSETS);
 				if (ret == 2) {
 					const char *s;
 					ret = pcre_get_substring(m, off, 2, 1, &s);
 					if (ret > 0) {
-						dbg("%s == %s\n", s, patterns[i].pattern);
-						find(s, patterns[i].weight, patterns[i].instant_block);
+						dbg("%s == %s\n", s, pat->pattern);
+						find(s, pat->weight, pat->instant_block);
 						pcre_free_substring(s);
 					}
 				}
+
+				pat = pat->next;
 			}
 
 			free(m);
 
 		}
 
-		prune();
+		prune(expires);
 	}
 
 	sd_journal_close(j);

tallow.conf

@@ -4,4 +4,6 @@
 #ipt_path=/usr/sbin
 #expires=3600
 #whitelist=127.0.0.1
+#whitelist=192.168.
+#whitelist=10.
 #ipv6=0