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;
17struct rtrs_srv_ctx;
18struct rtrs_srv;
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 *rtrs_clt_open(struct rtrs_clt_ops *ops,
56				 const char *sessname,
57				 const struct rtrs_addr *paths,
58				 size_t path_cnt, u16 port,
59				 size_t pdu_sz, u8 reconnect_delay_sec,
60				 u16 max_segments,
61				 size_t max_segment_size,
62				 s16 max_reconnect_attempts);
63
64void rtrs_clt_close(struct rtrs_clt *sess);
65
66/**
67 * rtrs_permit_to_pdu() - converts rtrs_permit to opaque pdu pointer
68 * @permit: RTRS permit pointer, it associates the memory allocation for future
69 *          RDMA operation.
70 */
71void *rtrs_permit_to_pdu(struct rtrs_permit *permit);
72
73enum {
74	RTRS_PERMIT_NOWAIT = 0,
75	RTRS_PERMIT_WAIT   = 1,
76};
77
78/**
79 * enum rtrs_clt_con_type() type of ib connection to use with a given
80 * rtrs_permit
81 * @ADMIN_CON - use connection reserved for "service" messages
82 * @IO_CON - use a connection reserved for IO
83 */
84enum rtrs_clt_con_type {
85	RTRS_ADMIN_CON,
86	RTRS_IO_CON
87};
88
89struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *sess,
90				    enum rtrs_clt_con_type con_type,
91				    int wait);
92
93void rtrs_clt_put_permit(struct rtrs_clt *sess, struct rtrs_permit *permit);
94
95/**
96 * rtrs_clt_req_ops - it holds the request confirmation callback
97 * and a private pointer.
98 * @priv: User supplied private data.
99 * @conf_fn:	callback function to be called as confirmation
100 *	@priv:	User provided data, passed back with corresponding
101 *		@(conf) confirmation.
102 *	@errno: error number.
103 */
104struct rtrs_clt_req_ops {
105	void	*priv;
106	void	(*conf_fn)(void *priv, int errno);
107};
108
109int rtrs_clt_request(int dir, struct rtrs_clt_req_ops *ops,
110		     struct rtrs_clt *sess, struct rtrs_permit *permit,
111		     const struct kvec *vec, size_t nr, size_t len,
112		     struct scatterlist *sg, unsigned int sg_cnt);
113
114/**
115 * rtrs_attrs - RTRS session attributes
116 */
117struct rtrs_attrs {
118	u32		queue_depth;
119	u32		max_io_size;
120	u8		sessname[NAME_MAX];
121	struct kobject	*sess_kobj;
122};
123
124int rtrs_clt_query(struct rtrs_clt *sess, struct rtrs_attrs *attr);
125
126/*
127 * Here goes RTRS server API
128 */
129
130/**
131 * enum rtrs_srv_link_ev - Server link events
132 * @RTRS_SRV_LINK_EV_CONNECTED:	Connection from client established
133 * @RTRS_SRV_LINK_EV_DISCONNECTED:	Connection was disconnected, all
134 *					connection RTRS resources were freed.
135 */
136enum rtrs_srv_link_ev {
137	RTRS_SRV_LINK_EV_CONNECTED,
138	RTRS_SRV_LINK_EV_DISCONNECTED,
139};
140
141struct rtrs_srv_ops {
142	/**
143	 * rdma_ev():		Event notification for RDMA operations
144	 *			If the callback returns a value != 0, an error
145	 *			message for the data transfer will be sent to
146	 *			the client.
147
148	 *	@sess:		Session
149	 *	@priv:		Private data set by rtrs_srv_set_sess_priv()
150	 *	@id:		internal RTRS operation id
151	 *	@dir:		READ/WRITE
152	 *	@data:		Pointer to (bidirectional) rdma memory area:
153	 *			- in case of %RTRS_SRV_RDMA_EV_RECV contains
154	 *			data sent by the client
155	 *			- in case of %RTRS_SRV_RDMA_EV_WRITE_REQ points
156	 *			to the memory area where the response is to be
157	 *			written to
158	 *	@datalen:	Size of the memory area in @data
159	 *	@usr:		The extra user message sent by the client (%vec)
160	 *	@usrlen:	Size of the user message
161	 */
162	int (*rdma_ev)(struct rtrs_srv *sess, void *priv,
163		       struct rtrs_srv_op *id, int dir,
164		       void *data, size_t datalen, const void *usr,
165		       size_t usrlen);
166	/**
167	 * link_ev():		Events about connectivity state changes
168	 *			If the callback returns != 0 and the event
169	 *			%RTRS_SRV_LINK_EV_CONNECTED the corresponding
170	 *			session will be destroyed.
171	 *	@sess:		Session
172	 *	@ev:		event
173	 *	@priv:		Private data from user if previously set with
174	 *			rtrs_srv_set_sess_priv()
175	 */
176	int (*link_ev)(struct rtrs_srv *sess, enum rtrs_srv_link_ev ev,
177		       void *priv);
178};
179
180struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port);
181
182void rtrs_srv_close(struct rtrs_srv_ctx *ctx);
183
184bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int errno);
185
186void rtrs_srv_set_sess_priv(struct rtrs_srv *sess, void *priv);
187
188int rtrs_srv_get_sess_name(struct rtrs_srv *sess, char *sessname, size_t len);
189
190int rtrs_srv_get_queue_depth(struct rtrs_srv *sess);
191
192int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
193			  struct rtrs_addr *addr);
194
195int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len);
196#endif
197