1 files changed, 166 insertions, 0 deletions
diff --git a/src/core/osmo_io_internal.h b/src/core/osmo_io_internal.h
new file mode 100644
index 00000000..a4b0749d
--- /dev/null
+++ b/src/core/osmo_io_internal.h
@@ -0,0 +1,166 @@
+/*! \file osmo_io_internal.h */
+
+#pragma once
+
+#include <unistd.h>
+#include <stdbool.h>
+#include <netinet/sctp.h>
+
+#include <osmocom/core/osmo_io.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+
+#include "../config.h"
+
+#define OSMO_IO_DEFAULT_MSGB_SIZE 1024
+#define OSMO_IO_DEFAULT_MSGB_HEADROOM 128
+
+extern const struct iofd_backend_ops iofd_poll_ops;
+#define OSMO_IO_BACKEND_DEFAULT "POLL"
+
+#if defined(HAVE_URING)
+extern const struct iofd_backend_ops iofd_uring_ops;
+#endif
+
+struct iofd_backend_ops {
+	int (*register_fd)(struct osmo_io_fd *iofd);
+	int (*unregister_fd)(struct osmo_io_fd *iofd);
+	int (*close)(struct osmo_io_fd *iofd);
+	void (*write_enable)(struct osmo_io_fd *iofd);
+	void (*write_disable)(struct osmo_io_fd *iofd);
+	void (*read_enable)(struct osmo_io_fd *iofd);
+	void (*read_disable)(struct osmo_io_fd *iofd);
+	void (*notify_connected)(struct osmo_io_fd *iofd);
+};
+
+#define IOFD_FLAG_CLOSED (1<<0)
+#define IOFD_FLAG_IN_CALLBACK (1<<1)
+#define IOFD_FLAG_TO_FREE (1<<2)
+#define IOFD_FLAG_NOTIFY_CONNECTED (1<<3)
+#define IOFD_FLAG_FD_REGISTERED (1<<4)
+
+#define IOFD_FLAG_SET(iofd, flag) \
+	(iofd)->flags |= (flag)
+
+#define IOFD_FLAG_UNSET(iofd, flag) \
+	(iofd)->flags &= ~(flag)
+
+#define IOFD_FLAG_ISSET(iofd, flag) ((iofd)->flags & (flag))
+
+struct osmo_io_fd {
+	/*! linked list for internal management */
+	struct llist_head list;
+	/*! actual operating-system level file decriptor */
+	int fd;
+	/*! type of read/write mode to use */
+	enum osmo_io_fd_mode mode;
+
+	/*! flags to guard closing/freeing of iofd */
+	uint32_t flags;
+
+	/*! human-readable name to associte with fd */
+	char *name;
+
+	/*! send/recv (msg) callback functions */
+	struct osmo_io_ops io_ops;
+	/*! Pending msgb to keep partial data during segmentation */
+	struct msgb *pending;
+
+	/*! data pointer passed through to call-back function */
+	void *data;
+	/*! private number, extending \a data */
+	unsigned int priv_nr;
+
+	/*! size of iofd_msghdr.cmsg[] when allocated in recvmsg path */
+	size_t cmsg_size;
+
+	struct {
+		/*! talloc context from which to allocate msgb when reading */
+		const void *ctx;
+		/*! size of msgb to allocate (excluding headroom) */
+		unsigned int size;
+		/*! headroom to allocate when allocating msgb's */
+		unsigned int headroom;
+	} msgb_alloc;
+
+	struct {
+		/*! maximum length of write queue */
+		unsigned int max_length;
+		/*! current length of write queue */
+		unsigned int current_length;
+		/*! actual linked list implementing the transmit queue */
+		struct llist_head msg_queue;
+	} tx_queue;
+
+	union {
+		struct {
+			struct osmo_fd ofd;
+		} poll;
+		struct {
+			bool read_enabled;
+			bool write_enabled;
+			void *read_msghdr;
+			void *write_msghdr;
+			/* TODO: index into array of registered fd's? */
+			/* osmo_fd for non-blocking connect handling */
+			struct osmo_fd connect_ofd;
+		} uring;
+	} u;
+};
+
+enum iofd_msg_action {
+	IOFD_ACT_READ,
+	IOFD_ACT_WRITE,
+	IOFD_ACT_RECVFROM,
+	IOFD_ACT_SENDTO,
+	IOFD_ACT_RECVMSG,
+	IOFD_ACT_SENDMSG,
+};
+
+
+/*! serialized version of 'struct msghdr' employed by sendmsg/recvmsg */
+struct iofd_msghdr {
+	/*! entry into osmo_io_fd.tx_queue.msg_queue */
+	struct llist_head list;
+	enum iofd_msg_action action;
+	/*! the 'struct msghdr' we are wrapping/ecapsulating here */
+	struct msghdr hdr;
+	/*! socket address of the remote peer */
+	struct osmo_sockaddr osa;
+	/*! io-vector we need to pass as argument to sendmsg/recvmsg; is set up
+	 * to point into msg below */
+	struct iovec iov[1];
+	/*! flags we pass as argument to sendmsg / recvmsg */
+	int flags;
+
+	/*! message-buffer containing data for this I/O operation */
+	struct msgb *msg;
+	/*! I/O file descriptor on which we perform this I/O operation */
+	struct osmo_io_fd *iofd;
+
+	/*! control message buffer for passing sctp_sndrcvinfo along */
+	char cmsg[0]; /* size is determined by iofd->cmsg_size on recvmsg, and by mcghdr->msg_controllen on sendmsg */
+};
+
+enum iofd_seg_act {
+	IOFD_SEG_ACT_HANDLE_ONE,
+	IOFD_SEG_ACT_HANDLE_MORE,
+	IOFD_SEG_ACT_DEFER,
+};
+
+struct iofd_msghdr *iofd_msghdr_alloc(struct osmo_io_fd *iofd, enum iofd_msg_action action, struct msgb *msg, size_t cmsg_size);
+void iofd_msghdr_free(struct iofd_msghdr *msghdr);
+
+struct msgb *iofd_msgb_alloc(struct osmo_io_fd *iofd);
+struct msgb *iofd_msgb_pending(struct osmo_io_fd *iofd);
+struct msgb *iofd_msgb_pending_or_alloc(struct osmo_io_fd *iofd);
+
+void iofd_handle_recv(struct osmo_io_fd *iofd, struct msgb *msg, int rc, struct iofd_msghdr *msghdr);
+void iofd_handle_send_completion(struct osmo_io_fd *iofd, int rc, struct iofd_msghdr *msghdr);
+void iofd_handle_segmented_read(struct osmo_io_fd *iofd, struct msgb *msg, int rc);
+
+int iofd_txqueue_enqueue(struct osmo_io_fd *iofd, struct iofd_msghdr *msghdr);
+void iofd_txqueue_enqueue_front(struct osmo_io_fd *iofd, struct iofd_msghdr *msghdr);
+struct iofd_msghdr *iofd_txqueue_dequeue(struct osmo_io_fd *iofd);