2 * iSCSI Initiator TCP Transport
3 * Copyright (C) 2004 Dmitry Yusupov
4 * Copyright (C) 2004 Alex Aizman
5 * Copyright (C) 2005 Mike Christie
6 * maintained by open-iscsi@googlegroups.com
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * See the file COPYING included with this distribution for more details.
24 /* Session's states */
25 #define ISCSI_STATE_FREE 1
26 #define ISCSI_STATE_LOGGED_IN 2
27 #define ISCSI_STATE_FAILED 3
28 #define ISCSI_STATE_TERMINATE 4
30 /* Connection's states */
31 #define ISCSI_CONN_INITIAL_STAGE 0
32 #define ISCSI_CONN_STARTED 1
33 #define ISCSI_CONN_STOPPED 2
34 #define ISCSI_CONN_CLEANUP_WAIT 3
36 /* Connection suspend "bit" */
39 /* Socket's Receive state machine */
40 #define IN_PROGRESS_WAIT_HEADER 0x0
41 #define IN_PROGRESS_HEADER_GATHER 0x1
42 #define IN_PROGRESS_DATA_RECV 0x2
43 #define IN_PROGRESS_DDIGEST_RECV 0x3
45 /* Task Mgmt states */
46 #define TMABORT_INITIAL 0x0
47 #define TMABORT_SUCCESS 0x1
48 #define TMABORT_FAILED 0x2
49 #define TMABORT_TIMEDOUT 0x3
51 /* xmit state machine */
52 #define XMSTATE_IDLE 0x0
53 #define XMSTATE_R_HDR 0x1
54 #define XMSTATE_W_HDR 0x2
55 #define XMSTATE_IMM_HDR 0x4
56 #define XMSTATE_IMM_DATA 0x8
57 #define XMSTATE_UNS_INIT 0x10
58 #define XMSTATE_UNS_HDR 0x20
59 #define XMSTATE_UNS_DATA 0x40
60 #define XMSTATE_SOL_HDR 0x80
61 #define XMSTATE_SOL_DATA 0x100
62 #define XMSTATE_W_PAD 0x200
63 #define XMSTATE_DATA_DIGEST 0x400
65 #define ISCSI_CONN_MAX 1
66 #define ISCSI_CONN_RCVBUF_MIN 262144
67 #define ISCSI_CONN_SNDBUF_MIN 262144
68 #define ISCSI_PAD_LEN 4
69 #define ISCSI_R2T_MAX 16
70 #define ISCSI_XMIT_CMDS_MAX 128 /* must be power of 2 */
71 #define ISCSI_MGMT_CMDS_MAX 32 /* must be power of 2 */
72 #define ISCSI_MGMT_ITT_OFFSET 0xa00
73 #define ISCSI_SG_TABLESIZE SG_ALL
74 #define ISCSI_DEF_CMD_PER_LUN 32
75 #define ISCSI_MAX_CMD_PER_LUN 128
76 #define ISCSI_TCP_MAX_CMD_LEN 16
78 #define ITT_MASK (0xfff)
80 #define CID_MASK (0xffff<<CID_SHIFT)
82 #define AGE_MASK (0xf<<AGE_SHIFT)
85 struct kfifo *queue; /* FIFO Queue */
86 void **pool; /* Pool of elements */
87 int max; /* Max number of elements */
91 struct iscsi_cmd_task;
92 struct iscsi_mgmt_task;
94 /* Socket connection recieve helper */
95 struct iscsi_tcp_recv {
96 struct iscsi_hdr *hdr;
104 struct iscsi_cmd_task *ctask; /* current cmd in progress */
106 /* copied and flipped values */
116 struct iscsi_cls_conn;
119 struct iscsi_cls_conn *cls_conn; /* ptr to class connection */
120 struct iscsi_hdr hdr; /* header placeholder */
121 char hdrext[4*sizeof(__u16) +
124 char *data; /* data placeholder */
125 struct socket *sock; /* TCP socket */
126 int data_size; /* actual recv_dlength */
127 int stop_stage; /* conn_stop() flag: *
129 * stop to terminate */
130 /* iSCSI connection-wide sequencing */
132 int hdr_size; /* PDU header size */
133 unsigned long suspend_rx; /* suspend Rx */
135 struct crypto_tfm *rx_tfm; /* CRC32C (Rx) */
136 struct crypto_tfm *data_rx_tfm; /* CRC32C (Rx) for data */
139 int senselen; /* scsi sense length */
141 struct iscsi_tcp_recv in; /* TCP receive context */
142 struct iscsi_session *session; /* parent session */
143 struct list_head item; /* maintains list of conns */
144 int in_progress; /* connection state machine */
145 int c_stage; /* connection state */
146 struct iscsi_mgmt_task *login_mtask; /* mtask used for login/text */
147 struct iscsi_mgmt_task *mtask; /* xmit mtask in progress */
148 struct iscsi_cmd_task *ctask; /* xmit ctask in progress */
150 /* old values for socket callbacks */
151 void (*old_data_ready)(struct sock *, int);
152 void (*old_state_change)(struct sock *);
153 void (*old_write_space)(struct sock *);
156 struct crypto_tfm *tx_tfm; /* CRC32C (Tx) */
157 struct crypto_tfm *data_tx_tfm; /* CRC32C (Tx) for data */
158 struct kfifo *writequeue; /* write cmds for Data-Outs */
159 struct kfifo *immqueue; /* immediate xmit queue */
160 struct kfifo *mgmtqueue; /* mgmt (control) xmit queue */
161 struct kfifo *xmitqueue; /* data-path cmd queue */
162 struct list_head run_list; /* list of cmds in progress */
163 struct work_struct xmitwork; /* per-conn. xmit workqueue */
164 struct mutex xmitmutex; /* serializes connection xmit,
165 * access to kfifos: *
166 * xmitqueue, writequeue, *
167 * immqueue, mgmtqueue */
168 unsigned long suspend_tx; /* suspend Tx */
171 wait_queue_head_t ehwait; /* used in eh_abort() */
172 struct iscsi_tm tmhdr;
173 struct timer_list tmabort_timer; /* abort timer */
174 int tmabort_state; /* see TMABORT_INITIAL, etc.*/
176 /* negotiated params */
177 int max_recv_dlength;
178 int max_xmit_dlength;
183 uint64_t txdata_octets;
184 uint64_t rxdata_octets;
185 uint32_t scsicmd_pdus_cnt;
186 uint32_t dataout_pdus_cnt;
187 uint32_t scsirsp_pdus_cnt;
188 uint32_t datain_pdus_cnt;
189 uint32_t r2t_pdus_cnt;
190 uint32_t tmfcmd_pdus_cnt;
191 int32_t tmfrsp_pdus_cnt;
193 /* custom statistics */
194 uint32_t sendpage_failures_cnt;
195 uint32_t discontiguous_hdr_cnt;
196 uint32_t eh_abort_cnt;
198 ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
201 struct iscsi_session {
202 /* iSCSI session-wide sequencing */
216 int dataseq_inorder_en;
222 struct Scsi_Host *host;
224 struct iscsi_conn *leadconn; /* leading connection */
225 spinlock_t lock; /* protects session state, *
226 * sequence numbers, *
227 * session resources: *
231 int state; /* session state */
233 struct list_head item;
236 int age; /* counts session re-opens */
238 struct list_head connections; /* list of connections */
239 int cmds_max; /* size of cmds array */
240 struct iscsi_cmd_task **cmds; /* Original Cmds arr */
241 struct iscsi_queue cmdpool; /* PDU's pool */
242 int mgmtpool_max; /* size of mgmt array */
243 struct iscsi_mgmt_task **mgmt_cmds; /* Original mgmt arr */
244 struct iscsi_queue mgmtpool; /* Mgmt PDU's pool */
248 struct scatterlist sg;
253 struct iscsi_data_task {
254 struct iscsi_data hdr; /* PDU */
255 char hdrext[sizeof(__u32)]; /* Header-Digest */
256 struct list_head item; /* data queue item */
257 struct iscsi_buf digestbuf; /* digest buffer */
258 uint32_t digest; /* data digest */
260 #define ISCSI_DTASK_DEFAULT_MAX ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
262 struct iscsi_mgmt_task {
263 struct iscsi_hdr hdr; /* mgmt. PDU */
264 char hdrext[sizeof(__u32)]; /* Header-Digest */
265 char *data; /* mgmt payload */
266 int xmstate; /* mgmt xmit progress */
267 int data_count; /* counts data to be sent */
268 struct iscsi_buf headbuf; /* header buffer */
269 struct iscsi_buf sendbuf; /* in progress buffer */
271 uint32_t itt; /* this ITT */
274 struct iscsi_r2t_info {
275 __be32 ttt; /* copied from R2T */
276 __be32 exp_statsn; /* copied from R2T */
277 uint32_t data_length; /* copied from R2T */
278 uint32_t data_offset; /* copied from R2T */
279 struct iscsi_buf headbuf; /* Data-Out Header Buffer */
280 struct iscsi_buf sendbuf; /* Data-Out in progress buffer*/
281 int sent; /* R2T sequence progress */
282 int data_count; /* DATA-Out payload progress */
283 struct scatterlist *sg; /* per-R2T SG list */
285 struct iscsi_data_task *dtask; /* which data task */
288 struct iscsi_cmd_task {
289 struct iscsi_cmd hdr; /* iSCSI PDU header */
290 char hdrext[4*sizeof(__u16)+ /* AHS */
291 sizeof(__u32)]; /* HeaderDigest */
292 char pad[ISCSI_PAD_LEN];
293 int itt; /* this ITT */
294 int datasn; /* DataSN */
295 struct iscsi_buf headbuf; /* header buf (xmit) */
296 struct iscsi_buf sendbuf; /* in progress buffer*/
298 struct scatterlist *sg; /* per-cmd SG list */
299 struct scatterlist *bad_sg; /* assert statement */
300 int sg_count; /* SG's to process */
301 uint32_t unsol_datasn;
303 int xmstate; /* xmit xtate machine */
304 int imm_count; /* imm-data (bytes) */
305 int unsol_count; /* unsolicited (bytes)*/
306 int r2t_data_count; /* R2T Data-Out bytes */
307 int data_count; /* remaining Data-Out */
308 int pad_count; /* padded bytes */
309 struct scsi_cmnd *sc; /* associated SCSI cmd*/
312 struct iscsi_conn *conn; /* used connection */
313 struct iscsi_mgmt_task *mtask; /* tmf mtask in progr */
315 struct list_head running; /* running cmd list */
316 struct iscsi_r2t_info *r2t; /* in progress R2T */
317 struct iscsi_queue r2tpool;
318 struct kfifo *r2tqueue;
319 struct iscsi_r2t_info **r2ts;
320 struct list_head dataqueue; /* Data-Out dataqueue */
322 uint32_t datadigest; /* for recover digest */
324 uint32_t immdigest; /* for imm data */
325 struct iscsi_buf immbuf; /* for imm data digest */
326 struct iscsi_data_task *dtask; /* data task in progress*/
327 int digest_offset; /* for partial buff digest */