conntrackd: add support state-replication based on TCP

This patch adds support for TCP as protocol to replicate
state-changes between two daemons. Note that this only
makes sense with the notrack mode.

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

5 files changed, 95 insertions, 2 deletions

diff --git a/include/Makefile.am b/include/Makefile.am
index 844c5b8..a89490e 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -1,6 +1,6 @@
 
 noinst_HEADERS = alarm.h jhash.h cache.h linux_list.h linux_rbtree.h \
-		 sync.h conntrackd.h local.h udp.h \
+		 sync.h conntrackd.h local.h udp.h tcp.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 channel.h \
diff --git a/include/channel.h b/include/channel.h
index 1d3c48c..98605d9 100644
--- a/include/channel.h
+++ b/include/channel.h
@@ -3,6 +3,7 @@
 
 #include "mcast.h"
 #include "udp.h"
+#include "tcp.h"
 
 struct channel;
 struct nethdr;
@@ -11,6 +12,7 @@ enum {
 	CHANNEL_NONE,
 	CHANNEL_MCAST,
 	CHANNEL_UDP,
+	CHANNEL_TCP,
 	CHANNEL_MAX,
 };
 
@@ -24,13 +26,20 @@ struct udp_channel {
 	struct udp_sock *server;
 };
 
+struct tcp_channel {
+	struct tcp_sock *client;
+	struct tcp_sock *server;
+};
+
 #define CHANNEL_F_DEFAULT	(1 << 0)
 #define CHANNEL_F_BUFFERED	(1 << 1)
-#define CHANNEL_F_MAX		(1 << 2)
+#define CHANNEL_F_STREAM	(1 << 2)
+#define CHANNEL_F_MAX		(1 << 3)
 
 union channel_type_conf {
 	struct mcast_conf mcast;
 	struct udp_conf udp;
+	struct tcp_conf tcp;
 };
 
 struct channel_conf {
@@ -47,7 +56,10 @@ struct channel_ops {
 	void	(*close)(void *channel);
 	int	(*send)(void *channel, const void *data, int len);
 	int	(*recv)(void *channel, char *buf, int len);
+	int	(*accept)(struct channel *c);
 	int	(*get_fd)(void *channel);
+	int	(*isset)(struct channel *c, fd_set *readfds);
+	int	(*accept_isset)(struct channel *c, fd_set *readfds);
 	void	(*stats)(struct channel *c, int fd);
 	void	(*stats_extended)(struct channel *c, int active,
 				  struct nlif_handle *h, int fd);
@@ -72,8 +84,12 @@ 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_accept(struct channel *c);
 
 int channel_get_fd(struct channel *c);
+int channel_accept_isset(struct channel *c, fd_set *readfds);
+int channel_isset(struct channel *c, fd_set *readfds);
+
 void channel_stats(struct channel *c, int fd);
 void channel_stats_extended(struct channel *c, int active,
 			    struct nlif_handle *h, int fd);
diff --git a/include/mcast.h b/include/mcast.h
index 38c77f9..402a033 100644
--- a/include/mcast.h
+++ b/include/mcast.h
@@ -48,6 +48,7 @@ ssize_t mcast_send(struct mcast_sock *m, const 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_isset(struct mcast_sock *m, fd_set *readfds);
 
 int mcast_snprintf_stats(char *buf, size_t buflen, char *ifname,
 			 struct mcast_stats *s, struct mcast_stats *r);
diff --git a/include/tcp.h b/include/tcp.h
new file mode 100644
index 0000000..1b1d391
--- /dev/null
+++ b/include/tcp.h
@@ -0,0 +1,75 @@
+#ifndef _TCP_H_
+#define _TCP_H_
+
+#include <stdint.h>
+#include <netinet/in.h>
+
+struct tcp_conf {
+	int ipproto;
+	int reuseaddr;
+	int checksum;
+	unsigned short port;
+	union {
+		struct {
+			struct in_addr inet_addr;
+		} ipv4;
+		struct {
+			struct in6_addr inet_addr6;
+			int scope_id;
+		} ipv6;
+	} server;
+	union {
+		struct in_addr inet_addr;
+		struct in6_addr inet_addr6;
+	} client;
+	int sndbuf;
+	int rcvbuf;
+};
+
+struct tcp_stats {
+	uint64_t bytes;
+	uint64_t messages;
+	uint64_t error;
+};
+
+enum tcp_sock_state {
+	TCP_SERVER_ACCEPTING,
+	TCP_SERVER_CONNECTED,
+	TCP_CLIENT_DISCONNECTED,
+	TCP_CLIENT_CONNECTED
+};
+
+struct tcp_sock {
+	int state;	/* enum tcp_sock_state */
+	int fd;
+	int client_fd;	/* only for the server side */
+	union {
+		struct sockaddr_in ipv4;
+		struct sockaddr_in6 ipv6;
+	} addr;
+	socklen_t sockaddr_len;
+	struct tcp_stats stats;
+};
+
+struct tcp_sock *tcp_server_create(struct tcp_conf *conf);
+void tcp_server_destroy(struct tcp_sock *m);
+
+struct tcp_sock *tcp_client_create(struct tcp_conf *conf);
+void tcp_client_destroy(struct tcp_sock *m);
+
+ssize_t tcp_send(struct tcp_sock *m, const void *data, int size);
+ssize_t tcp_recv(struct tcp_sock *m, void *data, int size);
+int tcp_accept(struct tcp_sock *m);
+
+int tcp_get_fd(struct tcp_sock *m);
+int tcp_isset(struct tcp_sock *m, fd_set *readfds);
+int tcp_accept_isset(struct tcp_sock *m, fd_set *readfds);
+
+int tcp_snprintf_stats(char *buf, size_t buflen, char *ifname,
+		       struct tcp_sock *s, struct tcp_sock *r);
+
+int tcp_snprintf_stats2(char *buf, size_t buflen, const char *ifname,
+			const char *status, int active,
+			struct tcp_stats *s, struct tcp_stats *r);
+
+#endif
diff --git a/include/udp.h b/include/udp.h
index 6c659b9..9f9c17a 100644
--- a/include/udp.h
+++ b/include/udp.h
@@ -52,6 +52,7 @@ ssize_t udp_send(struct udp_sock *m, const void *data, int size);
 ssize_t udp_recv(struct udp_sock *m, void *data, int size);
 
 int udp_get_fd(struct udp_sock *m);
+int udp_isset(struct udp_sock *m, fd_set *readfds);
 
 int udp_snprintf_stats(char *buf, size_t buflen, char *ifname,
 		       struct udp_stats *s, struct udp_stats *r);