gsmtap: rework GSMTAP API to be more future-proof
* use write_queue where applicable
* provide functions that work on raw FD and those with osmo_fd
* add support for multiple gsmtap instances (no global variables)
diff --git a/include/osmocom/core/socket.h b/include/osmocom/core/socket.h
new file mode 100644
index 0000000..3ede524
--- /dev/null
+++ b/include/osmocom/core/socket.h
@@ -0,0 +1,16 @@
+#ifndef _OSMOCORE_SOCKET_H
+#define _OSMOCORE_SOCKET_H
+
+#include <stdint.h>
+#include <sys/socket.h>
+
+int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
+ const char *host, uint16_t port, int connect0_bind1);
+
+int osmo_sock_init_sa(struct sockaddr *ss, uint16_t type,
+ uint8_t proto, int connect0_bind1);
+
+/* determine if the given address is a local address */
+int osmo_sockaddr_is_local(struct sockaddr *addr, socklen_t addrlen);
+
+#endif /* _OSMOCORE_SOCKET_H */