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+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * RDMA Transport Layer
+ *
+ * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
+ * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
+ * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
+ */
+#ifndef RTRS_H
+#define RTRS_H
+
+#include <linux/socket.h>
+#include <linux/scatterlist.h>
+
+struct rtrs_permit;
+struct rtrs_clt;
+struct rtrs_srv_ctx;
+struct rtrs_srv;
+struct rtrs_srv_op;
+
+/*
+ * RDMA transport (RTRS) client API
+ */
+
+/**
+ * enum rtrs_clt_link_ev - Events about connectivity state of a client
+ * @RTRS_CLT_LINK_EV_RECONNECTED Client was reconnected.
+ * @RTRS_CLT_LINK_EV_DISCONNECTED Client was disconnected.
+ */
+enum rtrs_clt_link_ev {
+ RTRS_CLT_LINK_EV_RECONNECTED,
+ RTRS_CLT_LINK_EV_DISCONNECTED,
+};
+
+/**
+ * Source and destination address of a path to be established
+ */
+struct rtrs_addr {
+ struct sockaddr_storage *src;
+ struct sockaddr_storage *dst;
+};
+
+/**
+ * rtrs_clt_ops - it holds the link event callback and private pointer.
+ * @priv: User supplied private data.
+ * @link_ev: Event notification callback function for connection state changes
+ * @priv: User supplied data that was passed to rtrs_clt_open()
+ * @ev: Occurred event
+ */
+struct rtrs_clt_ops {
+ void *priv;
+ void (*link_ev)(void *priv, enum rtrs_clt_link_ev ev);
+};
+
+struct rtrs_clt *rtrs_clt_open(struct rtrs_clt_ops *ops,
+ const char *sessname,
+ const struct rtrs_addr *paths,
+ size_t path_cnt, u16 port,
+ size_t pdu_sz, u8 reconnect_delay_sec,
+ u16 max_segments,
+ s16 max_reconnect_attempts);
+
+void rtrs_clt_close(struct rtrs_clt *sess);
+
+/**
+ * rtrs_permit_to_pdu() - converts rtrs_permit to opaque pdu pointer
+ * @permit: RTRS permit pointer, it associates the memory allocation for future
+ * RDMA operation.
+ */
+void *rtrs_permit_to_pdu(struct rtrs_permit *permit);
+
+enum {
+ RTRS_PERMIT_NOWAIT = 0,
+ RTRS_PERMIT_WAIT = 1,
+};
+
+/**
+ * enum rtrs_clt_con_type() type of ib connection to use with a given
+ * rtrs_permit
+ * @ADMIN_CON - use connection reserved for "service" messages
+ * @IO_CON - use a connection reserved for IO
+ */
+enum rtrs_clt_con_type {
+ RTRS_ADMIN_CON,
+ RTRS_IO_CON
+};
+
+struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *sess,
+ enum rtrs_clt_con_type con_type,
+ int wait);
+
+void rtrs_clt_put_permit(struct rtrs_clt *sess, struct rtrs_permit *permit);
+
+/**
+ * rtrs_clt_req_ops - it holds the request confirmation callback
+ * and a private pointer.
+ * @priv: User supplied private data.
+ * @conf_fn: callback function to be called as confirmation
+ * @priv: User provided data, passed back with corresponding
+ * @(conf) confirmation.
+ * @errno: error number.
+ */
+struct rtrs_clt_req_ops {
+ void *priv;
+ void (*conf_fn)(void *priv, int errno);
+};
+
+int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
+ struct rtrs_clt *sess, struct rtrs_permit *permit,
+ const struct kvec *vec, size_t nr, size_t len,
+ struct scatterlist *sg, unsigned int sg_cnt);
+
+/**
+ * rtrs_attrs - RTRS session attributes
+ */
+struct rtrs_attrs {
+ u32 queue_depth;
+ u32 max_io_size;
+ u8 sessname[NAME_MAX];
+ struct kobject *sess_kobj;
+};
+
+int rtrs_clt_query(struct rtrs_clt *sess, struct rtrs_attrs *attr);
+
+/*
+ * Here goes RTRS server API
+ */
+
+/**
+ * enum rtrs_srv_link_ev - Server link events
+ * @RTRS_SRV_LINK_EV_CONNECTED: Connection from client established
+ * @RTRS_SRV_LINK_EV_DISCONNECTED: Connection was disconnected, all
+ * connection RTRS resources were freed.
+ */
+enum rtrs_srv_link_ev {
+ RTRS_SRV_LINK_EV_CONNECTED,
+ RTRS_SRV_LINK_EV_DISCONNECTED,
+};
+
+struct rtrs_srv_ops {
+ /**
+ * rdma_ev(): Event notification for RDMA operations
+ * If the callback returns a value != 0, an error
+ * message for the data transfer will be sent to
+ * the client.
+
+ * @sess: Session
+ * @priv: Private data set by rtrs_srv_set_sess_priv()
+ * @id: internal RTRS operation id
+ * @dir: READ/WRITE
+ * @data: Pointer to (bidirectional) rdma memory area:
+ * - in case of %RTRS_SRV_RDMA_EV_RECV contains
+ * data sent by the client
+ * - in case of %RTRS_SRV_RDMA_EV_WRITE_REQ points
+ * to the memory area where the response is to be
+ * written to
+ * @datalen: Size of the memory area in @data
+ * @usr: The extra user message sent by the client (%vec)
+ * @usrlen: Size of the user message
+ */
+ int (*rdma_ev)(struct rtrs_srv *sess, void *priv,
+ struct rtrs_srv_op *id, int dir,
+ void *data, size_t datalen, const void *usr,
+ size_t usrlen);
+ /**
+ * link_ev(): Events about connectivity state changes
+ * If the callback returns != 0 and the event
+ * %RTRS_SRV_LINK_EV_CONNECTED the corresponding
+ * session will be destroyed.
+ * @sess: Session
+ * @ev: event
+ * @priv: Private data from user if previously set with
+ * rtrs_srv_set_sess_priv()
+ */
+ int (*link_ev)(struct rtrs_srv *sess, enum rtrs_srv_link_ev ev,
+ void *priv);
+};
+
+struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port);
+
+void rtrs_srv_close(struct rtrs_srv_ctx *ctx);
+
+bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int errno);
+
+void rtrs_srv_set_sess_priv(struct rtrs_srv *sess, void *priv);
+
+int rtrs_srv_get_sess_name(struct rtrs_srv *sess, char *sessname, size_t len);
+
+int rtrs_srv_get_queue_depth(struct rtrs_srv *sess);
+
+int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
+ struct rtrs_addr *addr);
+
+int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len);
+#endif