xref: /linux/include/scsi/libiscsi.h (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
1 /*
2  * iSCSI lib definitions
3  *
4  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
5  * Copyright (C) 2004 - 2006 Mike Christie
6  * Copyright (C) 2004 - 2005 Dmitry Yusupov
7  * Copyright (C) 2004 - 2005 Alex Aizman
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 LIBISCSI_H
24 #define LIBISCSI_H
25 
26 #include <linux/types.h>
27 #include <linux/mutex.h>
28 #include <scsi/iscsi_proto.h>
29 #include <scsi/iscsi_if.h>
30 
31 struct scsi_transport_template;
32 struct scsi_device;
33 struct Scsi_Host;
34 struct scsi_cmnd;
35 struct socket;
36 struct iscsi_transport;
37 struct iscsi_cls_session;
38 struct iscsi_cls_conn;
39 struct iscsi_session;
40 struct iscsi_nopin;
41 
42 /* #define DEBUG_SCSI */
43 #ifdef DEBUG_SCSI
44 #define debug_scsi(fmt...) printk(KERN_INFO "iscsi: " fmt)
45 #else
46 #define debug_scsi(fmt...)
47 #endif
48 
49 #define ISCSI_XMIT_CMDS_MAX	128	/* must be power of 2 */
50 #define ISCSI_MGMT_CMDS_MAX	32	/* must be power of 2 */
51 #define ISCSI_CONN_MAX			1
52 
53 #define ISCSI_MGMT_ITT_OFFSET	0xa00
54 
55 #define ISCSI_DEF_CMD_PER_LUN		32
56 #define ISCSI_MAX_CMD_PER_LUN		128
57 
58 /* Task Mgmt states */
59 #define TMABORT_INITIAL			0x0
60 #define TMABORT_SUCCESS			0x1
61 #define TMABORT_FAILED			0x2
62 #define TMABORT_TIMEDOUT		0x3
63 
64 /* Connection suspend "bit" */
65 #define ISCSI_SUSPEND_BIT		1
66 
67 #define ISCSI_ITT_MASK			(0xfff)
68 #define ISCSI_CID_SHIFT			12
69 #define ISCSI_CID_MASK			(0xffff << ISCSI_CID_SHIFT)
70 #define ISCSI_AGE_SHIFT			28
71 #define ISCSI_AGE_MASK			(0xf << ISCSI_AGE_SHIFT)
72 
73 struct iscsi_mgmt_task {
74 	/*
75 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
76 	 * that storage. It must be setup at session creation time.
77 	 */
78 	struct iscsi_hdr	*hdr;
79 	char			*data;		/* mgmt payload */
80 	int			data_count;	/* counts data to be sent */
81 	uint32_t		itt;		/* this ITT */
82 	void			*dd_data;	/* driver/transport data */
83 	struct list_head	running;
84 };
85 
86 struct iscsi_cmd_task {
87 	/*
88 	 * Becuae LLDs allocate their hdr differently, this is a pointer to
89 	 * that storage. It must be setup at session creation time.
90 	 */
91 	struct iscsi_cmd	*hdr;
92 	int			itt;		/* this ITT */
93 	int			datasn;		/* DataSN */
94 
95 	uint32_t		unsol_datasn;
96 	int			imm_count;	/* imm-data (bytes)   */
97 	int			unsol_count;	/* unsolicited (bytes)*/
98 	int			data_count;	/* remaining Data-Out */
99 	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
100 	int			total_length;
101 	struct iscsi_conn	*conn;		/* used connection    */
102 	struct iscsi_mgmt_task	*mtask;		/* tmf mtask in progr */
103 
104 	struct list_head	running;	/* running cmd list */
105 	void			*dd_data;	/* driver/transport data */
106 };
107 
108 struct iscsi_conn {
109 	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
110 	void			*dd_data;	/* iscsi_transport data */
111 	struct iscsi_session	*session;	/* parent session */
112 	/*
113 	 * LLDs should set this lock. It protects the transport recv
114 	 * code
115 	 */
116 	rwlock_t		*recv_lock;
117 	/*
118 	 * conn_stop() flag: stop to recover, stop to terminate
119 	 */
120         int			stop_stage;
121 
122 	/* iSCSI connection-wide sequencing */
123 	uint32_t		exp_statsn;
124 
125 	/* control data */
126 	int			id;		/* CID */
127 	struct list_head	item;		/* maintains list of conns */
128 	int			c_stage;	/* connection state */
129 	struct iscsi_mgmt_task	*login_mtask;	/* mtask used for login/text */
130 	struct iscsi_mgmt_task	*mtask;		/* xmit mtask in progress */
131 	struct iscsi_cmd_task	*ctask;		/* xmit ctask in progress */
132 
133 	/* xmit */
134 	struct kfifo		*immqueue;	/* immediate xmit queue */
135 	struct kfifo		*mgmtqueue;	/* mgmt (control) xmit queue */
136 	struct list_head	mgmt_run_list;	/* list of control tasks */
137 	struct kfifo		*xmitqueue;	/* data-path cmd queue */
138 	struct list_head	run_list;	/* list of cmds in progress */
139 	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
140 	/*
141 	 * serializes connection xmit, access to kfifos:
142 	 * xmitqueue, immqueue, mgmtqueue
143 	 */
144 	struct mutex		xmitmutex;
145 
146 	unsigned long		suspend_tx;	/* suspend Tx */
147 	unsigned long		suspend_rx;	/* suspend Rx */
148 
149 	/* abort */
150 	wait_queue_head_t	ehwait;		/* used in eh_abort() */
151 	struct iscsi_tm		tmhdr;
152 	struct timer_list	tmabort_timer;
153 	int			tmabort_state;	/* see TMABORT_INITIAL, etc.*/
154 
155 	/* negotiated params */
156 	int			max_recv_dlength; /* initiator_max_recv_dsl*/
157 	int			max_xmit_dlength; /* target_max_recv_dsl */
158 	int			hdrdgst_en;
159 	int			datadgst_en;
160 	int			ifmarker_en;
161 	int			ofmarker_en;
162 	/* values userspace uses to id a conn */
163 	int			persistent_port;
164 	char			*persistent_address;
165 
166 	/* MIB-statistics */
167 	uint64_t		txdata_octets;
168 	uint64_t		rxdata_octets;
169 	uint32_t		scsicmd_pdus_cnt;
170 	uint32_t		dataout_pdus_cnt;
171 	uint32_t		scsirsp_pdus_cnt;
172 	uint32_t		datain_pdus_cnt;
173 	uint32_t		r2t_pdus_cnt;
174 	uint32_t		tmfcmd_pdus_cnt;
175 	int32_t			tmfrsp_pdus_cnt;
176 
177 	/* custom statistics */
178 	uint32_t		eh_abort_cnt;
179 };
180 
181 struct iscsi_queue {
182 	struct kfifo		*queue;		/* FIFO Queue */
183 	void			**pool;		/* Pool of elements */
184 	int			max;		/* Max number of elements */
185 };
186 
187 struct iscsi_session {
188 	/* iSCSI session-wide sequencing */
189 	uint32_t		cmdsn;
190 	uint32_t		exp_cmdsn;
191 	uint32_t		max_cmdsn;
192 
193 	/* configuration */
194 	int			initial_r2t_en;
195 	int			max_r2t;
196 	int			imm_data_en;
197 	int			first_burst;
198 	int			max_burst;
199 	int			time2wait;
200 	int			time2retain;
201 	int			pdu_inorder_en;
202 	int			dataseq_inorder_en;
203 	int			erl;
204 	int			tpgt;
205 	char			*targetname;
206 
207 	/* control data */
208 	struct iscsi_transport	*tt;
209 	struct Scsi_Host	*host;
210 	struct iscsi_conn	*leadconn;	/* leading connection */
211 	spinlock_t		lock;		/* protects session state, *
212 						 * sequence numbers,       *
213 						 * session resources:      *
214 						 * - cmdpool,		   *
215 						 * - mgmtpool,		   *
216 						 * - r2tpool		   */
217 	int			state;		/* session state           */
218 	struct list_head	item;
219 	int			age;		/* counts session re-opens */
220 
221 	struct list_head	connections;	/* list of connections */
222 	int			cmds_max;	/* size of cmds array */
223 	struct iscsi_cmd_task	**cmds;		/* Original Cmds arr */
224 	struct iscsi_queue	cmdpool;	/* PDU's pool */
225 	int			mgmtpool_max;	/* size of mgmt array */
226 	struct iscsi_mgmt_task	**mgmt_cmds;	/* Original mgmt arr */
227 	struct iscsi_queue	mgmtpool;	/* Mgmt PDU's pool */
228 };
229 
230 /*
231  * scsi host template
232  */
233 extern int iscsi_change_queue_depth(struct scsi_device *sdev, int depth);
234 extern int iscsi_eh_abort(struct scsi_cmnd *sc);
235 extern int iscsi_eh_host_reset(struct scsi_cmnd *sc);
236 extern int iscsi_queuecommand(struct scsi_cmnd *sc,
237 			      void (*done)(struct scsi_cmnd *));
238 
239 /*
240  * session management
241  */
242 extern struct iscsi_cls_session *
243 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
244 		    int, int, uint32_t, uint32_t *);
245 extern void iscsi_session_teardown(struct iscsi_cls_session *);
246 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
247 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
248 extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
249 			   enum iscsi_param param, char *buf, int buflen);
250 extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
251 				   enum iscsi_param param, char *buf);
252 
253 #define session_to_cls(_sess) \
254 	hostdata_session(_sess->host->hostdata)
255 
256 /*
257  * connection management
258  */
259 extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
260 					       uint32_t);
261 extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
262 extern int iscsi_conn_start(struct iscsi_cls_conn *);
263 extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
264 extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
265 			   int);
266 extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
267 extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
268 				enum iscsi_param param, char *buf);
269 
270 /*
271  * pdu and task processing
272  */
273 extern int iscsi_check_assign_cmdsn(struct iscsi_session *,
274 				    struct iscsi_nopin *);
275 extern void iscsi_prep_unsolicit_data_pdu(struct iscsi_cmd_task *,
276 					struct iscsi_data *hdr,
277 					int transport_data_cnt);
278 extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
279 				char *, uint32_t);
280 extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
281 			      char *, int);
282 extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
283 				char *, int);
284 extern int iscsi_verify_itt(struct iscsi_conn *, struct iscsi_hdr *,
285 			    uint32_t *);
286 
287 /*
288  * generic helpers
289  */
290 extern void iscsi_pool_free(struct iscsi_queue *, void **);
291 extern int iscsi_pool_init(struct iscsi_queue *, int, void ***, int);
292 
293 #endif
294