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>

1 files changed, 95 insertions, 0 deletions

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_ */