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 
15 struct rtrs_permit;
16 struct rtrs_clt;
17 struct rtrs_srv_ctx;
18 struct rtrs_srv;
19 struct 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  */
30 enum 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  */
38 struct 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  */
50 struct rtrs_clt_ops {
51 	void	*priv;
52 	void	(*link_ev)(void *priv, enum rtrs_clt_link_ev ev);
53 };
54 
55 struct 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 
64 void 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  */
71 void *rtrs_permit_to_pdu(struct rtrs_permit *permit);
72 
73 enum {
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  */
84 enum rtrs_clt_con_type {
85 	RTRS_ADMIN_CON,
86 	RTRS_IO_CON
87 };
88 
89 struct rtrs_permit *rtrs_clt_get_permit(struct rtrs_clt *sess,
90 				    enum rtrs_clt_con_type con_type,
91 				    int wait);
92 
93 void 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  */
104 struct rtrs_clt_req_ops {
105 	void	*priv;
106 	void	(*conf_fn)(void *priv, int errno);
107 };
108 
109 int 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  */
117 struct rtrs_attrs {
118 	u32		queue_depth;
119 	u32		max_io_size;
120 	u8		sessname[NAME_MAX];
121 	struct kobject	*sess_kobj;
122 };
123 
124 int 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  */
136 enum rtrs_srv_link_ev {
137 	RTRS_SRV_LINK_EV_CONNECTED,
138 	RTRS_SRV_LINK_EV_DISCONNECTED,
139 };
140 
141 struct 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 
180 struct rtrs_srv_ctx *rtrs_srv_open(struct rtrs_srv_ops *ops, u16 port);
181 
182 void rtrs_srv_close(struct rtrs_srv_ctx *ctx);
183 
184 bool rtrs_srv_resp_rdma(struct rtrs_srv_op *id, int errno);
185 
186 void rtrs_srv_set_sess_priv(struct rtrs_srv *sess, void *priv);
187 
188 int rtrs_srv_get_sess_name(struct rtrs_srv *sess, char *sessname, size_t len);
189 
190 int rtrs_srv_get_queue_depth(struct rtrs_srv *sess);
191 
192 int rtrs_addr_to_sockaddr(const char *str, size_t len, u16 port,
193 			  struct rtrs_addr *addr);
194 
195 int sockaddr_to_str(const struct sockaddr *addr, char *buf, size_t len);
196 #endif
197