1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * RDMA Transport Layer
4 *
5 * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6 * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7 * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8 */
9#ifndef RTRS_H
10#define RTRS_H
11
12#include <linux/socket.h>
13#include <linux/scatterlist.h>
14
15struct rtrs_permit;
16struct rtrs_clt_sess;
17struct rtrs_srv_ctx;
18struct rtrs_srv_sess;
19struct rtrs_srv_op;
20
21/*
22 * RDMA transport (RTRS) client API
23 */
24
25/**
26 * enum rtrs_clt_link_ev - Events about connectivity state of a client
27 * @RTRS_CLT_LINK_EV_RECONNECTED	Client was reconnected.
28 * @RTRS_CLT_LINK_EV_DISCONNECTED	Client was disconnected.
29 */
30enum rtrs_clt_link_ev {
31	RTRS_CLT_LINK_EV_RECONNECTED,
32	RTRS_CLT_LINK_EV_DISCONNECTED,
33};
34
35/**
36 * Source and destination address of a path to be established
37 */
38struct rtrs_addr {
39	struct sockaddr_storage *src;
40	struct sockaddr_storage *dst;
41};
42
43/**
44 * rtrs_clt_ops - it holds the link event callback and private pointer.
45 * @priv: User supplied private data.
46 * @link_ev: Event notification callback function for connection state changes
47 *	@priv: User supplied data that was passed to rtrs_clt_open()
48 *	@ev: Occurred event
49 */
50struct rtrs_clt_ops {
51	void	*priv;
52	void	(*link_ev)(void *priv, enum rtrs_clt_link_ev ev);
53};
54
55struct rtrs_clt_sess *rtrs_clt_open(struct rtrs_clt_ops *ops,
56				 const char *pathname,
57				 const struct rtrs_addr *paths,
58				 size_t path_cnt, u16 port,
59				 size_t pdu_sz, u8 reconnect_delay_sec,
60				 s16 max_reconnect_attempts, u32 nr_poll_queues);
61
62void rtrs_clt_close(struct rtrs_clt_sess *clt);
63
64enum wait_type {
65	RTRS_PERMIT_NOWAIT = 0,
66	RTRS_PERMIT_WAIT   = 1
67};
68
69/**
70 * enum rtrs_clt_con_type() type of ib connection to use with a given
71 * rtrs_permit
72 * @ADMIN_CON - use connection reserved for "service" messages
73 * @IO_CON - use a connection reserved for IO
74 */
75enum rtrs_clt_con_type {
76	RTRS_ADMIN_CON,
77	RTRS_IO_CON
78};
79
80struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt_sess *sess,
81					enum rtrs_clt_con_type con_type,
82					enum wait_type wait);
83
84void rtrs_clt_put_permit(struct rtrs_clt_sess *sess,
85			 struct rtrs_permit *permit);
86
87/**
88 * rtrs_clt_req_ops - it holds the request confirmation callback
89 * and a private pointer.
90 * @priv: User supplied private data.
91 * @conf_fn:	callback function to be called as confirmation
92 *	@priv:	User provided data, passed back with corresponding
93 *		@(conf) confirmation.
94 *	@errno: error number.
95 */
96struct rtrs_clt_req_ops {
97	void	*priv;
98	void	(*conf_fn)(void *priv, int errno);
99};
100
101int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
102		     struct rtrs_clt_sess *sess, struct rtrs_permit *permit,
103		     const struct kvec *vec, size_t nr, size_t len,
104		     struct scatterlist *sg, unsigned int sg_cnt);
105int rtrs_clt_rdma_cq_direct(struct rtrs_clt_sess *clt, unsigned int index);
106
107/**
108 * rtrs_attrs - RTRS session attributes
109 */
110struct rtrs_attrs {
111	u32		queue_depth;
112	u32		max_io_size;
113	u32		max_segments;
114};
115
116int rtrs_clt_query(struct rtrs_clt_sess *sess, struct rtrs_attrs *attr);
117
118/*
119 * Here goes RTRS server API
120 */
121
122/**
123 * enum rtrs_srv_link_ev - Server link events
124 * @RTRS_SRV_LINK_EV_CONNECTED:	Connection from client established
125 * @RTRS_SRV_LINK_EV_DISCONNECTED:	Connection was disconnected, all
126 *					connection RTRS resources were freed.
127 */
128enum rtrs_srv_link_ev {
129	RTRS_SRV_LINK_EV_CONNECTED,
130	RTRS_SRV_LINK_EV_DISCONNECTED,
131};
132
133struct rtrs_srv_ops {
134	/**
135	 * rdma_ev():		Event notification for RDMA operations
136	 *			If the callback returns a value != 0, an error
137	 *			message for the data transfer will be sent to
138	 *			the client.
139
140	 *	@priv:		Private data set by rtrs_srv_set_sess_priv()
141	 *	@id:		internal RTRS operation id
142	 *	@data:		Pointer to (bidirectional) rdma memory area:
143	 *			- in case of %RTRS_SRV_RDMA_EV_RECV contains
144	 *			data sent by the client
145	 *			- in case of %RTRS_SRV_RDMA_EV_WRITE_REQ points
146	 *			to the memory area where the response is to be
147	 *			written to
148	 *	@datalen:	Size of the memory area in @data
149	 *	@usr:		The extra user message sent by the client (%vec)
150	 *	@usrlen:	Size of the user message
151	 */
152	int (*rdma_ev)(void *priv,
153		       struct rtrs_srv_op *id,
154		       void *data, size_t datalen, const void *usr,
155		       size_t usrlen);
156	/**
157	 * link_ev():		Events about connectivity state changes
158	 *			If the callback returns != 0 and the event
159	 *			%RTRS_SRV_LINK_EV_CONNECTED the corresponding
160	 *			session will be destroyed.
161	 *	@sess:		Session
162	 *	@ev:		event
163	 *	@priv:		Private data from user if previously set with
164	 *			rtrs_srv_set_sess_priv()
165	 */
166	int (*link_ev)(struct rtrs_srv_sess *sess, enum rtrs_srv_link_ev ev,
167		       void *priv);
168};
169
170struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port);
171
172void rtrs_srv_close(struct rtrs_srv_ctx *ctx);
173
174bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int errno);
175
176void rtrs_srv_set_sess_priv(struct rtrs_srv_sess *sess, void *priv);
177
178int rtrs_srv_get_path_name(struct rtrs_srv_sess *sess, char *pathname,
179			   size_t len);
180
181int rtrs_srv_get_queue_depth(struct rtrs_srv_sess *sess);
182
183int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
184			  struct rtrs_addr *addr);
185
186int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len);
187int rtrs_addr_to_str(const struct rtrs_addr *addr, char *buf, size_t len);
188#endif
189