Add osmo_io with initial poll backend
* make backend configurable for later
* segmentation callback for chunked streams
* logging target for osmo_io
* support partial writes
Change-Id: I50d73cf550d6ce8154bf827bf47408131cf5b0a0
Related: SYS#5094, OS#5751
diff --git a/src/core/osmo_io_internal.h b/src/core/osmo_io_internal.h
new file mode 100644
index 0000000..7fc4b6b
--- /dev/null
+++ b/src/core/osmo_io_internal.h
@@ -0,0 +1,132 @@
+/*! \file osmo_io_internal.h */
+
+#pragma once
+
+#include <unistd.h>
+#include <stdbool.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"
+
+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);
+};
+
+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 */
+ bool closed;
+ bool in_callback;
+ bool to_free;
+
+ bool write_enabled;
+ bool read_enabled;
+
+ /*! human-readable name to associte with fd */
+ const 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;
+
+ 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 read_pending;
+ bool write_pending;
+ bool write_enabled;
+ /* TODO: index into array of registered fd's? */
+ } uring;
+ } u;
+};
+
+enum iofd_msg_action {
+ IOFD_ACT_READ,
+ IOFD_ACT_WRITE,
+ IOFD_ACT_RECVFROM,
+ IOFD_ACT_SENDTO,
+ // TODO: SCTP_*
+};
+
+
+/* serialized version of 'struct msghdr' employed by sendmsg/recvmsg */
+struct iofd_msghdr {
+ struct llist_head list;
+ enum iofd_msg_action action;
+ struct msghdr hdr;
+ struct osmo_sockaddr osa;
+ struct iovec iov[1];
+ int flags;
+
+ struct msgb *msg;
+ struct osmo_io_fd *iofd;
+};
+
+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);
+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_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);