sync-mode: add abstract layer to make daemon independent of multicast

This patch reworks conntrackd to make it independent of the protocol
used to propagate state-changes. This patch adds the channel layer
abstraction, this layer allows you to add support for different
protocols like unicast UDP or TIPC.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

5 files changed, 106 insertions, 32 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index c3f8904..0265620 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -3,5 +3,5 @@ noinst_HEADERS = alarm.h jhash.h cache.h linux_list.h linux_rbtree.h \
 		 sync.h conntrackd.h local.h \
 		 debug.h log.h hash.h mcast.h conntrack.h \
 		 network.h filter.h queue.h vector.h cidr.h \
-		 traffic_stats.h netlink.h fds.h event.h bitops.h
+		 traffic_stats.h netlink.h fds.h event.h bitops.h channel.h
 
diff --git a/include/channel.h b/include/channel.h
new file mode 100644
index 0000000..ac1a93c
--- /dev/null
+++ b/include/channel.h
@@ -0,0 +1,95 @@
+#ifndef _CHANNEL_H_
+#define _CHANNEL_H_
+
+#include "mcast.h"
+
+struct channel;
+struct nethdr;
+
+enum {
+	CHANNEL_MCAST,
+	CHANNEL_MAX,
+};
+
+struct mcast_channel {
+	struct mcast_sock *client;
+	struct mcast_sock *server;
+};
+
+#define CHANNEL_F_DEFAULT	(1 << 0)
+#define CHANNEL_F_BUFFERED	(1 << 1)
+#define CHANNEL_F_MAX		(1 << 2)
+
+union channel_type_conf {
+	struct mcast_conf mcast;
+};
+
+struct channel_conf {
+	int				channel_type;
+	char				channel_ifname[IFNAMSIZ];
+	unsigned int			channel_flags;
+	union channel_type_conf		u;
+};
+
+struct nlif_handle;
+
+struct channel_ops {
+	void *	(*open)(void *conf);
+	void	(*close)(void *channel);
+	int	(*send)(void *channel, const void *data, int len);
+	int	(*recv)(void *channel, char *buf, int len);
+	int	(*get_fd)(void *channel);
+	void	(*stats)(struct channel *c, int fd);
+	void	(*stats_extended)(struct channel *c, int active,
+				  struct nlif_handle *h, int fd);
+};
+
+struct channel_buffer;
+
+struct channel {
+	int			channel_type;
+	int			channel_ifindex;
+	int			channel_ifmtu;
+	unsigned int		channel_flags;
+	struct channel_buffer	*buffer;
+	struct channel_ops	*ops;
+	void			*data;
+};
+
+void channel_init(void);
+struct channel *channel_open(struct channel_conf *conf);
+void channel_close(struct channel *c);
+
+int channel_send(struct channel *c, const struct nethdr *net);
+int channel_send_flush(struct channel *c);
+int channel_recv(struct channel *c, char *buf, int size);
+
+int channel_get_fd(struct channel *c);
+void channel_stats(struct channel *c, int fd);
+void channel_stats_extended(struct channel *c, int active,
+			    struct nlif_handle *h, int fd);
+
+#define MULTICHANNEL_MAX	4
+
+struct multichannel {
+	int		channel_num;
+	struct channel *channel[MULTICHANNEL_MAX];
+	struct channel *current;
+};
+
+struct multichannel *multichannel_open(struct channel_conf *conf, int len);
+void multichannel_close(struct multichannel *m);
+
+int multichannel_send(struct multichannel *c, const struct nethdr *net);
+int multichannel_send_flush(struct multichannel *c);
+int multichannel_recv(struct multichannel *c, char *buf, int size);
+
+void multichannel_stats(struct multichannel *m, int fd);
+void multichannel_stats_extended(struct multichannel *m,
+				 struct nlif_handle *h, int fd);
+
+int multichannel_get_ifindex(struct multichannel *m, int i);
+int multichannel_get_current_ifindex(struct multichannel *m);
+void multichannel_set_current_channel(struct multichannel *m, int i);
+
+#endif /* _CHANNEL_H_ */
diff --git a/include/conntrackd.h b/include/conntrackd.h
index 536abc9..cfb1ac5 100644
--- a/include/conntrackd.h
+++ b/include/conntrackd.h
@@ -5,6 +5,7 @@
 #include "local.h"
 #include "alarm.h"
 #include "filter.h"
+#include "channel.h"
 
 #include <stdint.h>
 #include <stdio.h>
@@ -71,9 +72,9 @@ struct ct_conf {
 	int syslog_facility;
 	char lockfile[FILENAME_MAXLEN];
 	int hashsize;			/* hashtable size */
-	int mcast_links;
-	int mcast_default_link;
-	struct mcast_conf mcast[MCAST_LINKS_MAX];
+	int channel_num;
+	int channel_default;
+	struct channel_conf channel[MULTICHANNEL_MAX];
 	struct local_conf local;	/* unix socket facilities */
 	int nice;
 	int limit;
@@ -163,8 +164,7 @@ struct ct_sync_state {
 	struct cache *internal; 	/* internal events cache (netlink) */
 	struct cache *external; 	/* external events cache (mcast) */
 
-	struct mcast_sock_multi *mcast_server;  /* multicast incoming */
-	struct mcast_sock_multi *mcast_client;  /* multicast outgoing  */
+	struct multichannel	*channel;
 	struct nlif_handle	*interface;
 	struct queue *tx_queue;
 
diff --git a/include/mcast.h b/include/mcast.h
index 623f390..68d18e8 100644
--- a/include/mcast.h
+++ b/include/mcast.h
@@ -42,38 +42,22 @@ struct mcast_sock {
 	struct mcast_stats stats;
 };
 
-#define MCAST_LINKS_MAX	4
-
-struct mcast_sock_multi {
-	int num_links;
-	int max_mtu;
-	struct mcast_sock *current_link;
-	struct mcast_sock *multi[MCAST_LINKS_MAX];
-};
-
 struct mcast_sock *mcast_server_create(struct mcast_conf *conf);
 void mcast_server_destroy(struct mcast_sock *m);
-struct mcast_sock_multi *mcast_server_create_multi(struct mcast_conf *conf, int conf_len);
-void mcast_server_destroy_multi(struct mcast_sock_multi *m);
 
 struct mcast_sock *mcast_client_create(struct mcast_conf *conf);
 void mcast_client_destroy(struct mcast_sock *m);
-struct mcast_sock_multi *mcast_client_create_multi(struct mcast_conf *conf, int conf_len);
-void mcast_client_destroy_multi(struct mcast_sock_multi*m);
 
 ssize_t mcast_send(struct mcast_sock *m, void *data, int size);
 ssize_t mcast_recv(struct mcast_sock *m, void *data, int size);
 
 int mcast_get_fd(struct mcast_sock *m);
-int mcast_get_ifidx(struct mcast_sock_multi *m, int i);
-int mcast_get_current_ifidx(struct mcast_sock_multi *m);
-
-struct mcast_sock *mcast_get_current_link(struct mcast_sock_multi *m);
-void mcast_set_current_link(struct mcast_sock_multi *m, int i);
 
-void mcast_dump_stats(int fd, const struct mcast_sock_multi *s, const struct mcast_sock_multi *r);
+int mcast_snprintf_stats(char *buf, size_t buflen, char *ifname,
+			 struct mcast_stats *s, struct mcast_stats *r);
 
-struct nlif_handle;
+int mcast_snprintf_stats2(char *buf, size_t buflen, const char *ifname,
+			  const char *status, int active,
+			  struct mcast_stats *s, struct mcast_stats *r);
 
-void mcast_dump_stats_extended(int fd, const struct mcast_sock_multi *s, const struct mcast_sock_multi *r, const struct nlif_handle *h);
 #endif
diff --git a/include/network.h b/include/network.h
index 29a6113..7019d7d 100644
--- a/include/network.h
+++ b/include/network.h
@@ -106,11 +106,6 @@ int mcast_track_is_seq_set(void);
 
 struct mcast_conf;
 
-int mcast_buffered_init(int mtu);
-void mcast_buffered_destroy(void);
-int mcast_buffered_send_netmsg(struct mcast_sock_multi *m, const struct nethdr *net);
-ssize_t mcast_buffered_pending_netmsg(struct mcast_sock_multi *m);
-
 #define IS_DATA(x)	(x->type <= NET_T_STATE_MAX && \
 			(x->flags & ~(NET_F_HELLO | NET_F_HELLO_BACK)) == 0)
 #define IS_ACK(x)	(x->type == NET_T_CTL && x->flags & NET_F_ACK)