/* SPDX-License-Identifier: MIT */

#ifndef LIB_URING_H

#define LIB_URING_H

#include <sys/socket.h>

#include <sys/uio.h>

#include <sys/stat.h>

#include <errno.h>

#include <signal.h>

#include <stdbool.h>

#include <inttypes.h>

#include <time.h>

#include <linux/swab.h>

#include "liburing/compat.h"

#include "liburing/io_uring.h"

#include "liburing/barrier.h"

#ifdef __cplusplus

extern "C" {

#endif

/*

 * Library interface to io_uring

 */

struct io_uring_sq {

	unsigned *khead;

	unsigned *ktail;

	unsigned *kring_mask;

	unsigned *kring_entries;

	unsigned *kflags;

	unsigned *kdropped;

	unsigned *array;

	struct io_uring_sqe *sqes;

	unsigned sqe_head;

	unsigned sqe_tail;

	size_t ring_sz;

	void *ring_ptr;

};

struct io_uring_cq {

	unsigned *khead;

	unsigned *ktail;

	unsigned *kring_mask;

	unsigned *kring_entries;

	unsigned *kflags;

	unsigned *koverflow;

	struct io_uring_cqe *cqes;

	size_t ring_sz;

	void *ring_ptr;

};

struct io_uring {

	struct io_uring_sq sq;

	struct io_uring_cq cq;

	unsigned flags;

	int ring_fd;

};

/*

 * Library interface

 */

/*

 * return an allocated io_uring_probe structure, or NULL if probe fails (for

 * example, if it is not available). The caller is responsible for freeing it

 */

extern struct io_uring_probe *io_uring_get_probe_ring(struct io_uring *ring);

/* same as io_uring_get_probe_ring, but takes care of ring init and teardown */

extern struct io_uring_probe *io_uring_get_probe(void);

static inline int io_uring_opcode_supported(struct io_uring_probe *p, int op)

{

	if (op > p->last_op)

		return 0;

	return (p->ops[op].flags & IO_URING_OP_SUPPORTED) != 0;

}

extern int io_uring_queue_init_params(unsigned entries, struct io_uring *ring,

	struct io_uring_params *p);

extern int io_uring_queue_init(unsigned entries, struct io_uring *ring,

	unsigned flags);

extern int io_uring_queue_mmap(int fd, struct io_uring_params *p,

	struct io_uring *ring);

extern int io_uring_ring_dontfork(struct io_uring *ring);

extern void io_uring_queue_exit(struct io_uring *ring);

unsigned io_uring_peek_batch_cqe(struct io_uring *ring,

	struct io_uring_cqe **cqes, unsigned count);

extern int io_uring_wait_cqes(struct io_uring *ring,

	struct io_uring_cqe **cqe_ptr, unsigned wait_nr,

	struct __kernel_timespec *ts, sigset_t *sigmask);

extern int io_uring_wait_cqe_timeout(struct io_uring *ring,

	struct io_uring_cqe **cqe_ptr, struct __kernel_timespec *ts);

extern int io_uring_submit(struct io_uring *ring);

extern int io_uring_submit_and_wait(struct io_uring *ring, unsigned wait_nr);

extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);

extern int io_uring_register_buffers(struct io_uring *ring,

					const struct iovec *iovecs,

					unsigned nr_iovecs);

extern int io_uring_unregister_buffers(struct io_uring *ring);

extern int io_uring_register_files(struct io_uring *ring, const int *files,

					unsigned nr_files);

extern int io_uring_unregister_files(struct io_uring *ring);

extern int io_uring_register_files_update(struct io_uring *ring, unsigned off,

					int *files, unsigned nr_files);

extern int io_uring_register_eventfd(struct io_uring *ring, int fd);

extern int io_uring_register_eventfd_async(struct io_uring *ring, int fd);

extern int io_uring_unregister_eventfd(struct io_uring *ring);

extern int io_uring_register_probe(struct io_uring *ring,

					struct io_uring_probe *p, unsigned nr);

extern int io_uring_register_personality(struct io_uring *ring);

extern int io_uring_unregister_personality(struct io_uring *ring, int id);

/*

 * Helper for the peek/wait single cqe functions. Exported because of that,

 * but probably shouldn't be used directly in an application.

 */

extern int __io_uring_get_cqe(struct io_uring *ring,

			      struct io_uring_cqe **cqe_ptr, unsigned submit,

			      unsigned wait_nr, sigset_t *sigmask);

#define LIBURING_UDATA_TIMEOUT	((__u64) -1)

#define io_uring_for_each_cqe(ring, head, cqe)				\

	/*								\

	 * io_uring_smp_load_acquire() enforces the order of tail	\

	 * and CQE reads.						\

	 */								\

	for (head = *(ring)->cq.khead;					\

	     (cqe = (head != io_uring_smp_load_acquire((ring)->cq.ktail) ? \

		&(ring)->cq.cqes[head & (*(ring)->cq.kring_mask)] : NULL)); \

	     head++)							\

/*

 * Must be called after io_uring_for_each_cqe()

 */

static inline void io_uring_cq_advance(struct io_uring *ring,

				       unsigned nr)

{

	if (nr) {

		struct io_uring_cq *cq = &ring->cq;

		/*

		 * Ensure that the kernel only sees the new value of the head

		 * index after the CQEs have been read.

		 */

		io_uring_smp_store_release(cq->khead, *cq->khead + nr);

	}

}

/*

 * Must be called after io_uring_{peek,wait}_cqe() after the cqe has

 * been processed by the application.

 */

static inline void io_uring_cqe_seen(struct io_uring *ring,

				     struct io_uring_cqe *cqe)

{

	if (cqe)

		io_uring_cq_advance(ring, 1);

}

/*

 * Command prep helpers

 */

static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)

{

	sqe->user_data = (unsigned long) data;

}

static inline void *io_uring_cqe_get_data(const struct io_uring_cqe *cqe)

{

	return (void *) (uintptr_t) cqe->user_data;

}

static inline void io_uring_sqe_set_flags(struct io_uring_sqe *sqe,

					  unsigned flags)

{

	sqe->flags = flags;

}

static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd,

				    const void *addr, unsigned len,

				    __u64 offset)

{

	sqe->opcode = op;

	sqe->flags = 0;

	sqe->ioprio = 0;

	sqe->fd = fd;

	sqe->off = offset;

	sqe->addr = (unsigned long) addr;

	sqe->len = len;

	sqe->rw_flags = 0;

	sqe->user_data = 0;

	sqe->__pad2[0] = sqe->__pad2[1] = sqe->__pad2[2] = 0;

}

static inline void io_uring_prep_splice(struct io_uring_sqe *sqe,

					int fd_in, uint64_t off_in,

					int fd_out, uint64_t off_out,

					unsigned int nbytes,

					unsigned int splice_flags)

{

	io_uring_prep_rw(IORING_OP_SPLICE, sqe, fd_out, NULL, nbytes, off_out);

	sqe->splice_off_in = off_in;

	sqe->splice_fd_in = fd_in;

	sqe->splice_flags = splice_flags;

}

static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd,

				       const struct iovec *iovecs,

				       unsigned nr_vecs, off_t offset)

{

	io_uring_prep_rw(IORING_OP_READV, sqe, fd, iovecs, nr_vecs, offset);

}

static inline void io_uring_prep_read_fixed(struct io_uring_sqe *sqe, int fd,

					    void *buf, unsigned nbytes,

					    off_t offset, int buf_index)

{

	io_uring_prep_rw(IORING_OP_READ_FIXED, sqe, fd, buf, nbytes, offset);

	sqe->buf_index = buf_index;

}

static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd,

					const struct iovec *iovecs,

					unsigned nr_vecs, off_t offset)

{

	io_uring_prep_rw(IORING_OP_WRITEV, sqe, fd, iovecs, nr_vecs, offset);

}

static inline void io_uring_prep_write_fixed(struct io_uring_sqe *sqe, int fd,

					     const void *buf, unsigned nbytes,

					     off_t offset, int buf_index)

{

	io_uring_prep_rw(IORING_OP_WRITE_FIXED, sqe, fd, buf, nbytes, offset);

	sqe->buf_index = buf_index;

}

static inline void io_uring_prep_recvmsg(struct io_uring_sqe *sqe, int fd,

					 struct msghdr *msg, unsigned flags)

{

	io_uring_prep_rw(IORING_OP_RECVMSG, sqe, fd, msg, 1, 0);

	sqe->msg_flags = flags;

}

static inline void io_uring_prep_sendmsg(struct io_uring_sqe *sqe, int fd,

					 const struct msghdr *msg, unsigned flags)

{

	io_uring_prep_rw(IORING_OP_SENDMSG, sqe, fd, msg, 1, 0);

	sqe->msg_flags = flags;

}

static inline void io_uring_prep_poll_add(struct io_uring_sqe *sqe, int fd,

					  unsigned poll_mask)

{

	io_uring_prep_rw(IORING_OP_POLL_ADD, sqe, fd, NULL, 0, 0);

#if __BYTE_ORDER == __BIG_ENDIAN

	poll_mask = __swahw32(poll_mask);

#endif

	sqe->poll32_events = poll_mask;

}

static inline void io_uring_prep_poll_remove(struct io_uring_sqe *sqe,

					     void *user_data)

{

	io_uring_prep_rw(IORING_OP_POLL_REMOVE, sqe, -1, user_data, 0, 0);

}

static inline void io_uring_prep_fsync(struct io_uring_sqe *sqe, int fd,

				       unsigned fsync_flags)

{

	io_uring_prep_rw(IORING_OP_FSYNC, sqe, fd, NULL, 0, 0);

	sqe->fsync_flags = fsync_flags;

}

static inline void io_uring_prep_nop(struct io_uring_sqe *sqe)

{

	io_uring_prep_rw(IORING_OP_NOP, sqe, -1, NULL, 0, 0);

}

static inline void io_uring_prep_timeout(struct io_uring_sqe *sqe,

					 struct __kernel_timespec *ts,

					 unsigned count, unsigned flags)

{

	io_uring_prep_rw(IORING_OP_TIMEOUT, sqe, -1, ts, 1, count);

	sqe->timeout_flags = flags;

}

static inline void io_uring_prep_timeout_remove(struct io_uring_sqe *sqe,

						__u64 user_data, unsigned flags)

{

	io_uring_prep_rw(IORING_OP_TIMEOUT_REMOVE, sqe, -1,

				(void *)(unsigned long)user_data, 0, 0);

	sqe->timeout_flags = flags;

}

static inline void io_uring_prep_accept(struct io_uring_sqe *sqe, int fd,

					struct sockaddr *addr,

					socklen_t *addrlen, int flags)

{

	io_uring_prep_rw(IORING_OP_ACCEPT, sqe, fd, addr, 0,

				(__u64) (unsigned long) addrlen);

	sqe->accept_flags = flags;

}

static inline void io_uring_prep_cancel(struct io_uring_sqe *sqe, void *user_data,

					int flags)

{

	io_uring_prep_rw(IORING_OP_ASYNC_CANCEL, sqe, -1, user_data, 0, 0);

	sqe->cancel_flags = flags;

}

static inline void io_uring_prep_link_timeout(struct io_uring_sqe *sqe,

					      struct __kernel_timespec *ts,

					      unsigned flags)

{

	io_uring_prep_rw(IORING_OP_LINK_TIMEOUT, sqe, -1, ts, 1, 0);

	sqe->timeout_flags = flags;

}

static inline void io_uring_prep_connect(struct io_uring_sqe *sqe, int fd,

					 const struct sockaddr *addr,

					 socklen_t addrlen)

{

	io_uring_prep_rw(IORING_OP_CONNECT, sqe, fd, addr, 0, addrlen);

}

static inline void io_uring_prep_files_update(struct io_uring_sqe *sqe,

					      int *fds, unsigned nr_fds,

					      int offset)

{

	io_uring_prep_rw(IORING_OP_FILES_UPDATE, sqe, -1, fds, nr_fds, offset);

}

static inline void io_uring_prep_fallocate(struct io_uring_sqe *sqe, int fd,

					   int mode, off_t offset, off_t len)

{

	io_uring_prep_rw(IORING_OP_FALLOCATE, sqe, fd,

			(const uintptr_t *) (unsigned long) len, mode, offset);

}

static inline void io_uring_prep_openat(struct io_uring_sqe *sqe, int dfd,

					const char *path, int flags, mode_t mode)

{

	io_uring_prep_rw(IORING_OP_OPENAT, sqe, dfd, path, mode, 0);

	sqe->open_flags = flags;

}

static inline void io_uring_prep_close(struct io_uring_sqe *sqe, int fd)

{

	io_uring_prep_rw(IORING_OP_CLOSE, sqe, fd, NULL, 0, 0);

}

static inline void io_uring_prep_read(struct io_uring_sqe *sqe, int fd,

				      void *buf, unsigned nbytes, off_t offset)

{

	io_uring_prep_rw(IORING_OP_READ, sqe, fd, buf, nbytes, offset);

}

static inline void io_uring_prep_write(struct io_uring_sqe *sqe, int fd,

				       const void *buf, unsigned nbytes, off_t offset)

{

	io_uring_prep_rw(IORING_OP_WRITE, sqe, fd, buf, nbytes, offset);

}

struct statx;

static inline void io_uring_prep_statx(struct io_uring_sqe *sqe, int dfd,

				const char *path, int flags, unsigned mask,

				struct statx *statxbuf)

{

	io_uring_prep_rw(IORING_OP_STATX, sqe, dfd, path, mask,

				(__u64) (unsigned long) statxbuf);

	sqe->statx_flags = flags;

}

static inline void io_uring_prep_fadvise(struct io_uring_sqe *sqe, int fd,

					 off_t offset, off_t len, int advice)

{

	io_uring_prep_rw(IORING_OP_FADVISE, sqe, fd, NULL, len, offset);

	sqe->fadvise_advice = advice;

}

static inline void io_uring_prep_madvise(struct io_uring_sqe *sqe, void *addr,

					 off_t length, int advice)

{

	io_uring_prep_rw(IORING_OP_MADVISE, sqe, -1, addr, length, 0);

	sqe->fadvise_advice = advice;

}

static inline void io_uring_prep_send(struct io_uring_sqe *sqe, int sockfd,

				      const void *buf, size_t len, int flags)

{

	io_uring_prep_rw(IORING_OP_SEND, sqe, sockfd, buf, len, 0);

	sqe->msg_flags = flags;

}

static inline void io_uring_prep_recv(struct io_uring_sqe *sqe, int sockfd,

				      void *buf, size_t len, int flags)

{

	io_uring_prep_rw(IORING_OP_RECV, sqe, sockfd, buf, len, 0);

	sqe->msg_flags = flags;

}

static inline void io_uring_prep_openat2(struct io_uring_sqe *sqe, int dfd,

					const char *path, struct open_how *how)

{

	io_uring_prep_rw(IORING_OP_OPENAT2, sqe, dfd, path, sizeof(*how),

				(uint64_t) (uintptr_t) how);

}

struct epoll_event;

static inline void io_uring_prep_epoll_ctl(struct io_uring_sqe *sqe, int epfd,

					   int fd, int op,

					   struct epoll_event *ev)

{

	io_uring_prep_rw(IORING_OP_EPOLL_CTL, sqe, epfd, ev, op, fd);

}

static inline void io_uring_prep_provide_buffers(struct io_uring_sqe *sqe,

						 void *addr, int len, int nr,

						 int bgid, int bid)

{

	io_uring_prep_rw(IORING_OP_PROVIDE_BUFFERS, sqe, nr, addr, len, bid);

	sqe->buf_group = bgid;

}

static inline void io_uring_prep_remove_buffers(struct io_uring_sqe *sqe,

						int nr, int bgid)

{

	io_uring_prep_rw(IORING_OP_REMOVE_BUFFERS, sqe, nr, NULL, 0, 0);

	sqe->buf_group = bgid;

}

static inline unsigned io_uring_sq_ready(struct io_uring *ring)

{

	/* always use real head, to avoid losing sync for short submit */

	return ring->sq.sqe_tail - *ring->sq.khead;

}

static inline unsigned io_uring_sq_space_left(struct io_uring *ring)

{

	return *ring->sq.kring_entries - io_uring_sq_ready(ring);

}

static inline unsigned io_uring_cq_ready(struct io_uring *ring)

{

	return io_uring_smp_load_acquire(ring->cq.ktail) - *ring->cq.khead;

}

static inline bool io_uring_cq_eventfd_enabled(struct io_uring *ring)

{

	if (!ring->cq.kflags)

		return true;

	return !(*ring->cq.kflags & IORING_CQ_EVENTFD_DISABLED);

}

static inline int io_uring_cq_eventfd_toggle(struct io_uring *ring,

					     bool enabled)

{

	uint32_t flags;

	if (!!enabled == io_uring_cq_eventfd_enabled(ring))

		return 0;

	if (!ring->cq.kflags)

		return -EOPNOTSUPP;

	flags = *ring->cq.kflags;

	if (enabled)

		flags &= ~IORING_CQ_EVENTFD_DISABLED;

	else

		flags |= IORING_CQ_EVENTFD_DISABLED;

	IO_URING_WRITE_ONCE(*ring->cq.kflags, flags);

	return 0;

}

/*

 * Return an IO completion, waiting for 'wait_nr' completions if one isn't

 * readily available. Returns 0 with cqe_ptr filled in on success, -errno on

 * failure.

 */

static inline int io_uring_wait_cqe_nr(struct io_uring *ring,

				      struct io_uring_cqe **cqe_ptr,

				      unsigned wait_nr)

{

	return __io_uring_get_cqe(ring, cqe_ptr, 0, wait_nr, NULL);

}

/*

 * Return an IO completion, if one is readily available. Returns 0 with

 * cqe_ptr filled in on success, -errno on failure.

 */

static inline int io_uring_peek_cqe(struct io_uring *ring,

				    struct io_uring_cqe **cqe_ptr)

{

	return io_uring_wait_cqe_nr(ring, cqe_ptr, 0);

}

/*

 * Return an IO completion, waiting for it if necessary. Returns 0 with

 * cqe_ptr filled in on success, -errno on failure.

 */

static inline int io_uring_wait_cqe(struct io_uring *ring,

				    struct io_uring_cqe **cqe_ptr)

{

	return io_uring_wait_cqe_nr(ring, cqe_ptr, 1);

}

#ifdef __cplusplus

}

#endif

#endif