xref: /linux/include/scsi/scsi_transport_iscsi.h (revision 5e8d780d745c1619aba81fe7166c5a4b5cad2b84)
1 /*
2  * iSCSI transport class definitions
3  *
4  * Copyright (C) IBM Corporation, 2004
5  * Copyright (C) Mike Christie, 2004 - 2006
6  * Copyright (C) Dmitry Yusupov, 2004 - 2005
7  * Copyright (C) Alex Aizman, 2004 - 2005
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22  */
23 #ifndef SCSI_TRANSPORT_ISCSI_H
24 #define SCSI_TRANSPORT_ISCSI_H
25 
26 #include <linux/device.h>
27 #include <scsi/iscsi_if.h>
28 
29 struct scsi_transport_template;
30 struct iscsi_transport;
31 struct Scsi_Host;
32 struct mempool_zone;
33 struct iscsi_cls_conn;
34 struct iscsi_conn;
35 struct iscsi_cmd_task;
36 struct iscsi_mgmt_task;
37 
38 /**
39  * struct iscsi_transport - iSCSI Transport template
40  *
41  * @name:		transport name
42  * @caps:		iSCSI Data-Path capabilities
43  * @create_session:	create new iSCSI session object
44  * @destroy_session:	destroy existing iSCSI session object
45  * @create_conn:	create new iSCSI connection
46  * @bind_conn:		associate this connection with existing iSCSI session
47  *			and specified transport descriptor
48  * @destroy_conn:	destroy inactive iSCSI connection
49  * @set_param:		set iSCSI Data-Path operational parameter
50  * @start_conn:		set connection to be operational
51  * @stop_conn:		suspend/recover/terminate connection
52  * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
53  * @session_recovery_timedout: notify LLD a block during recovery timed out
54  * @suspend_conn_recv:	susepend the recv side of the connection
55  * @termincate_conn:	destroy socket connection. Called with mutex lock.
56  * @init_cmd_task:	Initialize a iscsi_cmd_task and any internal structs.
57  *			Called from queuecommand with session lock held.
58  * @init_mgmt_task:	Initialize a iscsi_mgmt_task and any internal structs.
59  *			Called from iscsi_conn_send_generic with xmitmutex.
60  * @xmit_cmd_task:	Requests LLD to transfer cmd task. Returns 0 or the
61  *			the number of bytes transferred on success, and -Exyz
62  *			value on error.
63  * @xmit_mgmt_task:	Requests LLD to transfer mgmt task. Returns 0 or the
64  *			the number of bytes transferred on success, and -Exyz
65  *			value on error.
66  * @cleanup_cmd_task:	requests LLD to fail cmd task. Called with xmitmutex
67  *			and session->lock after the connection has been
68  *			suspended and terminated during recovery. If called
69  *			from abort task then connection is not suspended
70  *			or terminated but sk_callback_lock is held
71  *
72  * Template API provided by iSCSI Transport
73  */
74 struct iscsi_transport {
75 	struct module *owner;
76 	char *name;
77 	unsigned int caps;
78 	/* LLD sets this to indicate what values it can export to sysfs */
79 	unsigned int param_mask;
80 	struct scsi_host_template *host_template;
81 	/* LLD connection data size */
82 	int conndata_size;
83 	/* LLD session data size */
84 	int sessiondata_size;
85 	int max_lun;
86 	unsigned int max_conn;
87 	unsigned int max_cmd_len;
88 	struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
89 		struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
90 	void (*destroy_session) (struct iscsi_cls_session *session);
91 	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
92 				uint32_t cid);
93 	int (*bind_conn) (struct iscsi_cls_session *session,
94 			  struct iscsi_cls_conn *cls_conn,
95 			  uint64_t transport_eph, int is_leading);
96 	int (*start_conn) (struct iscsi_cls_conn *conn);
97 	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
98 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
99 	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
100 			  uint32_t value);
101 	int (*get_conn_param) (struct iscsi_cls_conn *conn,
102 			       enum iscsi_param param, uint32_t *value);
103 	int (*get_session_param) (struct iscsi_cls_session *session,
104 				  enum iscsi_param param, uint32_t *value);
105 	int (*get_conn_str_param) (struct iscsi_cls_conn *conn,
106 				   enum iscsi_param param, char *buf);
107 	int (*get_session_str_param) (struct iscsi_cls_session *session,
108 				      enum iscsi_param param, char *buf);
109 	int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
110 			 char *data, uint32_t data_size);
111 	void (*get_stats) (struct iscsi_cls_conn *conn,
112 			   struct iscsi_stats *stats);
113 	void (*suspend_conn_recv) (struct iscsi_conn *conn);
114 	void (*terminate_conn) (struct iscsi_conn *conn);
115 	void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
116 	void (*init_mgmt_task) (struct iscsi_conn *conn,
117 				struct iscsi_mgmt_task *mtask,
118 				char *data, uint32_t data_size);
119 	int (*xmit_cmd_task) (struct iscsi_conn *conn,
120 			      struct iscsi_cmd_task *ctask);
121 	void (*cleanup_cmd_task) (struct iscsi_conn *conn,
122 				  struct iscsi_cmd_task *ctask);
123 	int (*xmit_mgmt_task) (struct iscsi_conn *conn,
124 			       struct iscsi_mgmt_task *mtask);
125 	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
126 	int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
127 			   uint64_t *ep_handle);
128 	int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
129 	void (*ep_disconnect) (uint64_t ep_handle);
130 };
131 
132 /*
133  * transport registration upcalls
134  */
135 extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
136 extern int iscsi_unregister_transport(struct iscsi_transport *tt);
137 
138 /*
139  * control plane upcalls
140  */
141 extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
142 extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
143 			  char *data, uint32_t data_size);
144 
145 
146 /* Connection's states */
147 #define ISCSI_CONN_INITIAL_STAGE	0
148 #define ISCSI_CONN_STARTED		1
149 #define ISCSI_CONN_STOPPED		2
150 #define ISCSI_CONN_CLEANUP_WAIT		3
151 
152 struct iscsi_cls_conn {
153 	struct list_head conn_list;	/* item in connlist */
154 	void *dd_data;			/* LLD private data */
155 	struct iscsi_transport *transport;
156 	uint32_t cid;			/* connection id */
157 
158 	/* portal/group values we got during discovery */
159 	char *persistent_address;
160 	int persistent_port;
161 	/* portal/group values we are currently using */
162 	char *address;
163 	int port;
164 
165 	int active;			/* must be accessed with the connlock */
166 	struct device dev;		/* sysfs transport/container device */
167 	struct mempool_zone *z_error;
168 	struct mempool_zone *z_pdu;
169 	struct list_head freequeue;
170 };
171 
172 #define iscsi_dev_to_conn(_dev) \
173 	container_of(_dev, struct iscsi_cls_conn, dev)
174 
175 /* Session's states */
176 #define ISCSI_STATE_FREE		1
177 #define ISCSI_STATE_LOGGED_IN		2
178 #define ISCSI_STATE_FAILED		3
179 #define ISCSI_STATE_TERMINATE		4
180 #define ISCSI_STATE_IN_RECOVERY		5
181 #define ISCSI_STATE_RECOVERY_FAILED	6
182 
183 struct iscsi_cls_session {
184 	struct list_head sess_list;		/* item in session_list */
185 	struct list_head host_list;
186 	struct iscsi_transport *transport;
187 
188 	/* iSCSI values used as unique id by userspace. */
189 	char *targetname;
190 	int tpgt;
191 
192 	/* recovery fields */
193 	int recovery_tmo;
194 	struct work_struct recovery_work;
195 
196 	int target_id;
197 	int channel;
198 
199 	int sid;				/* session id */
200 	void *dd_data;				/* LLD private data */
201 	struct device dev;	/* sysfs transport/container device */
202 };
203 
204 #define iscsi_dev_to_session(_dev) \
205 	container_of(_dev, struct iscsi_cls_session, dev)
206 
207 #define iscsi_session_to_shost(_session) \
208 	dev_to_shost(_session->dev.parent)
209 
210 struct iscsi_host {
211 	int next_target_id;
212 	struct list_head sessions;
213 	struct mutex mutex;
214 };
215 
216 /*
217  * session and connection functions that can be used by HW iSCSI LLDs
218  */
219 extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
220 				struct iscsi_transport *t, int channel);
221 extern int iscsi_destroy_session(struct iscsi_cls_session *session);
222 extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
223 					    uint32_t cid);
224 extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
225 extern void iscsi_unblock_session(struct iscsi_cls_session *session);
226 extern void iscsi_block_session(struct iscsi_cls_session *session);
227 
228 #endif
229