Add C FFI bindings

onetun.h

@@ -0,0 +1,40 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+
+/**
+ * The capacity of the channel for received IP packets.
+ */
+#define DISPATCH_CAPACITY 1000
+
+typedef struct Bus Bus;
+
+typedef struct Config Config;
+
+typedef struct PortForwardConfig PortForwardConfig;
+
+struct Bus *onetun_new_bus(void);
+
+struct Config *onetun_new_config(struct PortForwardConfig *const *port_forwards,
+                                 unsigned int port_forwards_len,
+                                 struct PortForwardConfig *const *remote_forwards,
+                                 unsigned int remote_forwards_len,
+                                 const char *private_key,
+                                 const char *public_key,
+                                 const char *endpoint_addr,
+                                 const char *endpoint_bind_addr,
+                                 const char *source_peer_ip,
+                                 int keepalive_seconds,
+                                 int max_transmission_unit,
+                                 const char *log,
+                                 const char *pcap_file);
+
+struct PortForwardConfig *onetun_new_port_forward(const char *source,
+                                                  const char *destination,
+                                                  const char *protocol,
+                                                  unsigned int remote);
+
+int32_t onetun_start_tunnels(struct Config *config, struct Bus *bus);