Add CacheWriteThrough clause: external cache write through policy. This feature is particularly useful for active-active setup without connection persistency, ie. you cannot know which firewall would filter a packet that belongs to a connection.

8 files changed, 125 insertions, 35 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 83511fa..8f5c620 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -14,7 +14,7 @@ conntrackd_SOURCES = alarm.c main.c run.c hash.c buffer.c \
 		    local.c log.c mcast.c netlink.c \
 		    ignore_pool.c \
 		    cache.c cache_iterators.c \
-		    cache_lifetime.c cache_timer.c \
+		    cache_lifetime.c cache_timer.c cache_wt.c \
 		    sync-mode.c sync-notrack.c sync-nack.c \
 		    traffic_stats.c stats-mode.c \
 		    network.c \
diff --git a/src/cache.c b/src/cache.c
index 1e20d95..80cde01 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -110,6 +110,7 @@ static int compare6(const void *data1, const void *data2)
 struct cache_feature *cache_feature[CACHE_MAX_FEATURE] = {
 	[TIMER_FEATURE]		= &timer_feature,
 	[LIFETIME_FEATURE]	= &lifetime_feature,
+	[WRITE_THROUGH_FEATURE] = &writethrough_feature,
 };
 
 struct cache *cache_create(char *name, 
@@ -263,14 +264,6 @@ static struct us_conntrack *__update(struct cache *c, struct nf_conntrack *ct)
 		int i;
 		void *data = u->data;
 
-		for (i = 0; i < c->num_features; i++) {
-			c->features[i]->update(u, data);
-			data += c->features[i]->size;
-		}
-
-		if (c->extra && c->extra->update)
-			c->extra->update(u, ((void *) u) + c->extra_offset);
-
 		if (nfct_attr_is_set(ct, ATTR_STATUS))
 		    	nfct_set_attr_u32(u->ct, ATTR_STATUS,
 					  nfct_get_attr_u32(ct, ATTR_STATUS));
@@ -281,6 +274,14 @@ static struct us_conntrack *__update(struct cache *c, struct nf_conntrack *ct)
 			nfct_set_attr_u32(u->ct, ATTR_TIMEOUT,
 					  nfct_get_attr_u32(ct, ATTR_TIMEOUT));
 
+		for (i = 0; i < c->num_features; i++) {
+			c->features[i]->update(u, data);
+			data += c->features[i]->size;
+		}
+
+		if (c->extra && c->extra->update)
+			c->extra->update(u, ((void *) u) + c->extra_offset);
+
 		return u;
 	} 
 	return NULL;
diff --git a/src/cache_iterators.c b/src/cache_iterators.c
index 24506e4..c29100c 100644
--- a/src/cache_iterators.c
+++ b/src/cache_iterators.c
@@ -78,36 +78,17 @@ void cache_dump(struct cache *c, int fd, int type)
 static int do_commit(void *data1, void *data2)
 {
 	int ret;
-	u_int8_t flags;
 	struct cache *c = data1;
 	struct us_conntrack *u = data2;
 	struct nf_conntrack *ct = u->ct;
 
-	/* XXX: related connections */
-	if (nfct_attr_is_set(ct, ATTR_STATUS)) {
-		u_int32_t status = nfct_get_attr_u32(ct, ATTR_STATUS);
-		status &= ~IPS_EXPECTED;
-		nfct_set_attr_u32(ct, ATTR_STATUS, status);
-	}
-
-	nfct_setobjopt(ct, NFCT_SOPT_SETUP_REPLY);
-
         /* 
 	 * Set a reduced timeout for candidate-to-be-committed
 	 * conntracks that live in the external cache
 	 */
 	nfct_set_attr_u32(ct, ATTR_TIMEOUT, CONFIG(commit_timeout));
 
-	/*
-	 * TCP flags to overpass window tracking for recovered connections
-	 */
-	flags = IP_CT_TCP_FLAG_BE_LIBERAL | IP_CT_TCP_FLAG_SACK_PERM;
-	nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_ORIG, flags);
-	nfct_set_attr_u8(ct, ATTR_TCP_MASK_ORIG, flags);
-	nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_REPL, flags);
-	nfct_set_attr_u8(ct, ATTR_TCP_MASK_REPL, flags);
-
-	ret = nfct_query(STATE(dump), NFCT_Q_CREATE_UPDATE, ct);
+	ret = nl_create_conntrack(ct);
 	if (ret == -1) {
 		switch(errno) {
 			case EEXIST:
diff --git a/src/cache_wt.c b/src/cache_wt.c
new file mode 100644
index 0000000..2a9d8e7
--- /dev/null
+++ b/src/cache_wt.c
@@ -0,0 +1,53 @@
+/*
+ * (C) 2007 by Pablo Neira Ayuso <pablo@netfilter.org>
+ * 
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdio.h>
+#include "conntrackd.h"
+#include "us-conntrack.h"
+#include "cache.h"
+
+static void add_update(struct us_conntrack *u)
+{
+	char __ct[nfct_maxsize()];
+	struct nf_conntrack *ct = (struct nf_conntrack *) __ct;
+
+	memcpy(ct, u->ct, nfct_maxsize());
+
+	nl_create_conntrack(ct);
+}
+
+static void writethrough_add(struct us_conntrack *u, void *data)
+{
+	add_update(u);
+}
+
+static void writethrough_update(struct us_conntrack *u, void *data)
+{
+	add_update(u);
+}
+
+static void writethrough_destroy(struct us_conntrack *u, void *data)
+{
+	nl_destroy_conntrack(u->ct);
+}
+
+struct cache_feature writethrough_feature = {
+	.add		= writethrough_add,
+	.update		= writethrough_update,
+	.destroy	= writethrough_destroy,
+};
diff --git a/src/netlink.c b/src/netlink.c
index 693646f..d453fe1 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -194,3 +194,34 @@ int nl_dump_conntrack_table(void)
 {
 	return nfct_query(STATE(dump), NFCT_Q_DUMP, &CONFIG(family));
 }
+
+/* This function modifies the conntrack passed as argument! */
+int nl_create_conntrack(struct nf_conntrack *ct)
+{
+	u_int8_t flags;
+
+	/* XXX: related connections */
+	if (nfct_attr_is_set(ct, ATTR_STATUS)) {
+		u_int32_t status = nfct_get_attr_u32(ct, ATTR_STATUS);
+		status &= ~IPS_EXPECTED;
+		nfct_set_attr_u32(ct, ATTR_STATUS, status);
+	}
+
+	nfct_setobjopt(ct, NFCT_SOPT_SETUP_REPLY);
+
+	/*
+	 * TCP flags to overpass window tracking for recovered connections
+	 */
+	flags = IP_CT_TCP_FLAG_BE_LIBERAL | IP_CT_TCP_FLAG_SACK_PERM;
+	nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_ORIG, flags);
+	nfct_set_attr_u8(ct, ATTR_TCP_MASK_ORIG, flags);
+	nfct_set_attr_u8(ct, ATTR_TCP_FLAGS_REPL, flags);
+	nfct_set_attr_u8(ct, ATTR_TCP_MASK_REPL, flags);
+
+	return nfct_query(STATE(dump), NFCT_Q_CREATE_UPDATE, ct);
+}
+
+int nl_destroy_conntrack(struct nf_conntrack *ct)
+{
+	return nfct_query(STATE(dump), NFCT_Q_DESTROY, ct);
+}
diff --git a/src/read_config_lex.l b/src/read_config_lex.l
index 48c0409..844cae1 100644
--- a/src/read_config_lex.l
+++ b/src/read_config_lex.l
@@ -90,6 +90,7 @@ nack		[N|n][A|a][C|c][K|k]
 "ACKWindowSize"			{ return T_WINDOWSIZE; }
 "Replicate"			{ return T_REPLICATE; }
 "for"				{ return T_FOR; }
+"CacheWriteThrough"		{ return T_WRITE_THROUGH; }
 "SYN_SENT"			{ return T_SYN_SENT; }
 "SYN_RECV"			{ return T_SYN_RECV; }
 "ESTABLISHED"			{ return T_ESTABLISHED; }
diff --git a/src/read_config_yy.y b/src/read_config_yy.y
index 8bc83fe..e5ce195 100644
--- a/src/read_config_yy.y
+++ b/src/read_config_yy.y
@@ -49,7 +49,7 @@ struct ct_conf conf;
 %token T_REPLICATE T_FOR T_IFACE 
 %token T_ESTABLISHED T_SYN_SENT T_SYN_RECV T_FIN_WAIT 
 %token T_CLOSE_WAIT T_LAST_ACK T_TIME_WAIT T_CLOSE T_LISTEN
-%token T_SYSLOG
+%token T_SYSLOG T_WRITE_THROUGH
 
 
 %token <string> T_IP T_PATH_VAL
@@ -366,6 +366,7 @@ sync_line: refreshtime
 	 | sync_mode_nack
 	 | listen_to
 	 | state_replication
+	 | cache_writethrough
 	 ;
 
 sync_mode_persistent: T_SYNC_MODE T_PERSISTENT '{' sync_mode_persistent_list '}'
@@ -500,6 +501,16 @@ tcp_state: T_LISTEN
 	state_helper_register(&tcp_state_helper, TCP_CONNTRACK_LISTEN);
 };
 
+cache_writethrough: T_WRITE_THROUGH T_ON
+{
+	conf.cache_write_through = 1;
+};
+
+cache_writethrough: T_WRITE_THROUGH T_OFF
+{
+	conf.cache_write_through = 0;
+};
+
 general: T_GENERAL '{' general_list '}';
 
 general_list:
diff --git a/src/sync-mode.c b/src/sync-mode.c
index e48b121..8a19ac5 100644
--- a/src/sync-mode.c
+++ b/src/sync-mode.c
@@ -147,6 +147,10 @@ static int init_sync(void)
 		return -1;
 	}
 
+	/* straight forward commit of conntrack to kernel space */
+	if (CONFIG(cache_write_through))
+		STATE_SYNC(sync)->external_cache_flags |= WRITE_THROUGH;
+
 	STATE_SYNC(external) = 
 		cache_create("external",
 			     STATE_SYNC(sync)->external_cache_flags,
@@ -301,8 +305,10 @@ static int local_handler_sync(int fd, int type, void *data)
 
 static void dump_sync(struct nf_conntrack *ct)
 {
+	if (!CONFIG(cache_write_through))
+		nfct_attr_unset(ct, ATTR_TIMEOUT);
+
 	/* This is required by kernels < 2.6.20 */
-	nfct_attr_unset(ct, ATTR_TIMEOUT);
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_BYTES);
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_PACKETS);
 	nfct_attr_unset(ct, ATTR_REPL_COUNTER_BYTES);
@@ -339,8 +345,10 @@ static int overrun_cb(enum nf_conntrack_msg_type type,
 	if (ignore_conntrack(ct))
 		return NFCT_CB_CONTINUE;
 
+	if (!CONFIG(cache_write_through))
+		nfct_attr_unset(ct, ATTR_TIMEOUT);
+
 	/* This is required by kernels < 2.6.20 */
-	nfct_attr_unset(ct, ATTR_TIMEOUT);
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_BYTES);
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_PACKETS);
 	nfct_attr_unset(ct, ATTR_REPL_COUNTER_BYTES);
@@ -420,12 +428,14 @@ static void event_new_sync(struct nf_conntrack *ct)
 {
 	struct us_conntrack *u;
 
+	if (!CONFIG(cache_write_through))
+		nfct_attr_unset(ct, ATTR_TIMEOUT);
+
 	/* required by linux kernel <= 2.6.20 */
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_BYTES);
 	nfct_attr_unset(ct, ATTR_ORIG_COUNTER_PACKETS);
 	nfct_attr_unset(ct, ATTR_REPL_COUNTER_BYTES);
 	nfct_attr_unset(ct, ATTR_REPL_COUNTER_PACKETS);
-	nfct_attr_unset(ct, ATTR_TIMEOUT);
 retry:
 	if ((u = cache_add(STATE_SYNC(internal), ct))) {
 		mcast_send_sync(u, ct, NFCT_Q_CREATE);
@@ -447,7 +457,8 @@ static void event_update_sync(struct nf_conntrack *ct)
 {
 	struct us_conntrack *u;
 
-	nfct_attr_unset(ct, ATTR_TIMEOUT);
+	if (!CONFIG(cache_write_through))
+		nfct_attr_unset(ct, ATTR_TIMEOUT);
 
 	if ((u = cache_update_force(STATE_SYNC(internal), ct)) == NULL) {
 		debug_ct(ct, "can't update");
@@ -459,7 +470,8 @@ static void event_update_sync(struct nf_conntrack *ct)
 
 static int event_destroy_sync(struct nf_conntrack *ct)
 {
-	nfct_attr_unset(ct, ATTR_TIMEOUT);
+	if (!CONFIG(cache_write_through))
+		nfct_attr_unset(ct, ATTR_TIMEOUT);
 
 	if (cache_del(STATE_SYNC(internal), ct)) {
 		mcast_send_sync(NULL, ct, NFCT_Q_DESTROY);