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
29struct scsi_transport_template;
30struct iscsi_transport;
31struct Scsi_Host;
32struct iscsi_cls_conn;
33struct iscsi_conn;
34struct iscsi_cmd_task;
35struct iscsi_mgmt_task;
36struct sockaddr;
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 parameter. Return 0 on success, -ENODATA
50 *			when param is not supported, and a -Exx value on other
51 *			error.
52 * @get_param		get iSCSI parameter. Must return number of bytes
53 *			copied to buffer on success, -ENODATA when param
54 *			is not supported, and a -Exx value on other error
55 * @start_conn:		set connection to be operational
56 * @stop_conn:		suspend/recover/terminate connection
57 * @send_pdu:		send iSCSI PDU, Login, Logout, NOP-Out, Reject, Text.
58 * @session_recovery_timedout: notify LLD a block during recovery timed out
59 * @init_cmd_task:	Initialize a iscsi_cmd_task and any internal structs.
60 *			Called from queuecommand with session lock held.
61 * @init_mgmt_task:	Initialize a iscsi_mgmt_task and any internal structs.
62 *			Called from iscsi_conn_send_generic with xmitmutex.
63 * @xmit_cmd_task:	Requests LLD to transfer cmd task. Returns 0 or the
64 *			the number of bytes transferred on success, and -Exyz
65 *			value on error.
66 * @xmit_mgmt_task:	Requests LLD to transfer mgmt task. Returns 0 or the
67 *			the number of bytes transferred on success, and -Exyz
68 *			value on error.
69 * @cleanup_cmd_task:	requests LLD to fail cmd task. Called with xmitmutex
70 *			and session->lock after the connection has been
71 *			suspended and terminated during recovery. If called
72 *			from abort task then connection is not suspended
73 *			or terminated but sk_callback_lock is held
74 *
75 * Template API provided by iSCSI Transport
76 */
77struct iscsi_transport {
78	struct module *owner;
79	char *name;
80	unsigned int caps;
81	/* LLD sets this to indicate what values it can export to sysfs */
82	unsigned int param_mask;
83	struct scsi_host_template *host_template;
84	/* LLD connection data size */
85	int conndata_size;
86	/* LLD session data size */
87	int sessiondata_size;
88	int max_lun;
89	unsigned int max_conn;
90	unsigned int max_cmd_len;
91	struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
92		struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
93	void (*destroy_session) (struct iscsi_cls_session *session);
94	struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
95				uint32_t cid);
96	int (*bind_conn) (struct iscsi_cls_session *session,
97			  struct iscsi_cls_conn *cls_conn,
98			  uint64_t transport_eph, int is_leading);
99	int (*start_conn) (struct iscsi_cls_conn *conn);
100	void (*stop_conn) (struct iscsi_cls_conn *conn, int flag);
101	void (*destroy_conn) (struct iscsi_cls_conn *conn);
102	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
103			  char *buf, int buflen);
104	int (*get_conn_param) (struct iscsi_cls_conn *conn,
105			       enum iscsi_param param, char *buf);
106	int (*get_session_param) (struct iscsi_cls_session *session,
107				  enum iscsi_param param, char *buf);
108	int (*send_pdu) (struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
109			 char *data, uint32_t data_size);
110	void (*get_stats) (struct iscsi_cls_conn *conn,
111			   struct iscsi_stats *stats);
112	void (*init_cmd_task) (struct iscsi_cmd_task *ctask);
113	void (*init_mgmt_task) (struct iscsi_conn *conn,
114				struct iscsi_mgmt_task *mtask,
115				char *data, uint32_t data_size);
116	int (*xmit_cmd_task) (struct iscsi_conn *conn,
117			      struct iscsi_cmd_task *ctask);
118	void (*cleanup_cmd_task) (struct iscsi_conn *conn,
119				  struct iscsi_cmd_task *ctask);
120	int (*xmit_mgmt_task) (struct iscsi_conn *conn,
121			       struct iscsi_mgmt_task *mtask);
122	void (*session_recovery_timedout) (struct iscsi_cls_session *session);
123	int (*ep_connect) (struct sockaddr *dst_addr, int non_blocking,
124			   uint64_t *ep_handle);
125	int (*ep_poll) (uint64_t ep_handle, int timeout_ms);
126	void (*ep_disconnect) (uint64_t ep_handle);
127	int (*tgt_dscvr) (enum iscsi_tgt_dscvr type, uint32_t host_no,
128			  uint32_t enable, struct sockaddr *dst_addr);
129};
130
131/*
132 * transport registration upcalls
133 */
134extern struct scsi_transport_template *iscsi_register_transport(struct iscsi_transport *tt);
135extern int iscsi_unregister_transport(struct iscsi_transport *tt);
136
137/*
138 * control plane upcalls
139 */
140extern void iscsi_conn_error(struct iscsi_cls_conn *conn, enum iscsi_err error);
141extern int iscsi_recv_pdu(struct iscsi_cls_conn *conn, struct iscsi_hdr *hdr,
142			  char *data, uint32_t data_size);
143
144
145/* Connection's states */
146#define ISCSI_CONN_INITIAL_STAGE	0
147#define ISCSI_CONN_STARTED		1
148#define ISCSI_CONN_STOPPED		2
149#define ISCSI_CONN_CLEANUP_WAIT		3
150
151struct iscsi_cls_conn {
152	struct list_head conn_list;	/* item in connlist */
153	void *dd_data;			/* LLD private data */
154	struct iscsi_transport *transport;
155	uint32_t cid;			/* connection id */
156
157	int active;			/* must be accessed with the connlock */
158	struct device dev;		/* sysfs transport/container device */
159};
160
161#define iscsi_dev_to_conn(_dev) \
162	container_of(_dev, struct iscsi_cls_conn, dev)
163
164/* Session's states */
165#define ISCSI_STATE_FREE		1
166#define ISCSI_STATE_LOGGED_IN		2
167#define ISCSI_STATE_FAILED		3
168#define ISCSI_STATE_TERMINATE		4
169#define ISCSI_STATE_IN_RECOVERY		5
170#define ISCSI_STATE_RECOVERY_FAILED	6
171
172struct iscsi_cls_session {
173	struct list_head sess_list;		/* item in session_list */
174	struct list_head host_list;
175	struct iscsi_transport *transport;
176
177	/* recovery fields */
178	int recovery_tmo;
179	struct delayed_work recovery_work;
180
181	int target_id;
182
183	int sid;				/* session id */
184	void *dd_data;				/* LLD private data */
185	struct device dev;	/* sysfs transport/container device */
186};
187
188#define iscsi_dev_to_session(_dev) \
189	container_of(_dev, struct iscsi_cls_session, dev)
190
191#define iscsi_session_to_shost(_session) \
192	dev_to_shost(_session->dev.parent)
193
194#define starget_to_session(_stgt) \
195	iscsi_dev_to_session(_stgt->dev.parent)
196
197struct iscsi_host {
198	struct list_head sessions;
199	struct mutex mutex;
200};
201
202/*
203 * session and connection functions that can be used by HW iSCSI LLDs
204 */
205extern struct iscsi_cls_session *iscsi_alloc_session(struct Scsi_Host *shost,
206					struct iscsi_transport *transport);
207extern int iscsi_add_session(struct iscsi_cls_session *session,
208			     unsigned int target_id);
209extern int iscsi_if_create_session_done(struct iscsi_cls_conn *conn);
210extern int iscsi_if_destroy_session_done(struct iscsi_cls_conn *conn);
211extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost,
212						struct iscsi_transport *t,
213						unsigned int target_id);
214extern void iscsi_remove_session(struct iscsi_cls_session *session);
215extern void iscsi_free_session(struct iscsi_cls_session *session);
216extern int iscsi_destroy_session(struct iscsi_cls_session *session);
217extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,
218					    uint32_t cid);
219extern int iscsi_destroy_conn(struct iscsi_cls_conn *conn);
220extern void iscsi_unblock_session(struct iscsi_cls_session *session);
221extern void iscsi_block_session(struct iscsi_cls_session *session);
222
223
224#endif
225