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iscsi_tcp.h 9.66 KiB
/*
* iSCSI Initiator TCP Transport
* Copyright (C) 2004 Dmitry Yusupov
* Copyright (C) 2004 Alex Aizman
* Copyright (C) 2005 Mike Christie
* maintained by open-iscsi@googlegroups.com
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* See the file COPYING included with this distribution for more details.
*/
#ifndef ISCSI_TCP_H
#define ISCSI_TCP_H
/* Session's states */
#define ISCSI_STATE_FREE 1
#define ISCSI_STATE_LOGGED_IN 2
#define ISCSI_STATE_FAILED 3
#define ISCSI_STATE_TERMINATE 4
/* Connection's states */
#define ISCSI_CONN_INITIAL_STAGE 0
#define ISCSI_CONN_STARTED 1
#define ISCSI_CONN_STOPPED 2
#define ISCSI_CONN_CLEANUP_WAIT 3
/* Connection suspend "bit" */
#define SUSPEND_BIT 1
/* Socket's Receive state machine */
#define IN_PROGRESS_WAIT_HEADER 0x0
#define IN_PROGRESS_HEADER_GATHER 0x1
#define IN_PROGRESS_DATA_RECV 0x2
#define IN_PROGRESS_DDIGEST_RECV 0x3
/* Task Mgmt states */
#define TMABORT_INITIAL 0x0
#define TMABORT_SUCCESS 0x1
#define TMABORT_FAILED 0x2
#define TMABORT_TIMEDOUT 0x3
/* xmit state machine */
#define XMSTATE_IDLE 0x0
#define XMSTATE_R_HDR 0x1
#define XMSTATE_W_HDR 0x2
#define XMSTATE_IMM_HDR 0x4
#define XMSTATE_IMM_DATA 0x8
#define XMSTATE_UNS_INIT 0x10
#define XMSTATE_UNS_HDR 0x20
#define XMSTATE_UNS_DATA 0x40
#define XMSTATE_SOL_HDR 0x80
#define XMSTATE_SOL_DATA 0x100
#define XMSTATE_W_PAD 0x200
#define XMSTATE_DATA_DIGEST 0x400
#define ISCSI_CONN_MAX 1
#define ISCSI_CONN_RCVBUF_MIN 262144
#define ISCSI_CONN_SNDBUF_MIN 262144
#define ISCSI_PAD_LEN 4
#define ISCSI_R2T_MAX 16
#define ISCSI_XMIT_CMDS_MAX 128 /* must be power of 2 */#define ISCSI_MGMT_CMDS_MAX 32 /* must be power of 2 */
#define ISCSI_MGMT_ITT_OFFSET 0xa00
#define ISCSI_SG_TABLESIZE SG_ALL
#define ISCSI_CMD_PER_LUN 128
#define ISCSI_TCP_MAX_CMD_LEN 16
#define ITT_MASK (0xfff)
#define CID_SHIFT 12
#define CID_MASK (0xffff<<CID_SHIFT)
#define AGE_SHIFT 28
#define AGE_MASK (0xf<<AGE_SHIFT)
struct iscsi_queue {
struct kfifo *queue; /* FIFO Queue */
void **pool; /* Pool of elements */
int max; /* Max number of elements */
};
struct iscsi_session;
struct iscsi_cmd_task;
struct iscsi_mgmt_task;
/* Socket connection recieve helper */
struct iscsi_tcp_recv {
struct iscsi_hdr *hdr;
struct sk_buff *skb;
int offset;
int len;
int hdr_offset;
int copy;
int copied;
int padding;
struct iscsi_cmd_task *ctask; /* current cmd in progress */
/* copied and flipped values */
int opcode;
int flags;
int cmd_status;
int ahslen;
int datalen;
uint32_t itt;
int datadgst;
};
struct iscsi_conn {
struct iscsi_hdr hdr; /* header placeholder */
char hdrext[4*sizeof(__u16) +
sizeof(__u32)];
int data_copied;
char *data; /* data placeholder */
struct socket *sock; /* TCP socket */
int data_size; /* actual recv_dlength */
int stop_stage; /* conn_stop() flag: *
* stop to recover, *
* stop to terminate */
/* iSCSI connection-wide sequencing */
uint32_t exp_statsn;
int hdr_size; /* PDU header size */
unsigned long suspend_rx; /* suspend Rx */
struct crypto_tfm *rx_tfm; /* CRC32C (Rx) */
struct crypto_tfm *data_rx_tfm; /* CRC32C (Rx) for data */
/* control data */
int senselen; /* scsi sense length */
int id; /* CID */
struct iscsi_tcp_recv in; /* TCP receive context */
struct iscsi_session *session; /* parent session */
struct list_head item; /* maintains list of conns */
int in_progress; /* connection state machine */ int c_stage; /* connection state */
struct iscsi_mgmt_task *login_mtask; /* mtask used for login/text */
struct iscsi_mgmt_task *mtask; /* xmit mtask in progress */
struct iscsi_cmd_task *ctask; /* xmit ctask in progress */
spinlock_t lock; /* FIXME: to be removed */
/* old values for socket callbacks */
void (*old_data_ready)(struct sock *, int);
void (*old_state_change)(struct sock *);
void (*old_write_space)(struct sock *);
/* xmit */
struct crypto_tfm *tx_tfm; /* CRC32C (Tx) */
struct crypto_tfm *data_tx_tfm; /* CRC32C (Tx) for data */
struct kfifo *writequeue; /* write cmds for Data-Outs */
struct kfifo *immqueue; /* immediate xmit queue */
struct kfifo *mgmtqueue; /* mgmt (control) xmit queue */
struct kfifo *xmitqueue; /* data-path cmd queue */
struct work_struct xmitwork; /* per-conn. xmit workqueue */
struct semaphore xmitsema; /* serializes connection xmit,
* access to kfifos: *
* xmitqueue, writequeue, *
* immqueue, mgmtqueue */
unsigned long suspend_tx; /* suspend Tx */
/* abort */
wait_queue_head_t ehwait; /* used in eh_abort() */
struct iscsi_tm tmhdr;
struct timer_list tmabort_timer; /* abort timer */
int tmabort_state; /* see TMABORT_INITIAL, etc.*/
/* negotiated params */
int max_recv_dlength;
int max_xmit_dlength;
int hdrdgst_en;
int datadgst_en;
/* MIB-statistics */
uint64_t txdata_octets;
uint64_t rxdata_octets;
uint32_t scsicmd_pdus_cnt;
uint32_t dataout_pdus_cnt;
uint32_t scsirsp_pdus_cnt;
uint32_t datain_pdus_cnt;
uint32_t r2t_pdus_cnt;
uint32_t tmfcmd_pdus_cnt;
int32_t tmfrsp_pdus_cnt;
/* custom statistics */
uint32_t sendpage_failures_cnt;
uint32_t discontiguous_hdr_cnt;
uint32_t eh_abort_cnt;
};
struct iscsi_session {
/* iSCSI session-wide sequencing */
uint32_t cmdsn;
uint32_t exp_cmdsn;
uint32_t max_cmdsn;
/* configuration */
int initial_r2t_en;
int max_r2t;
int imm_data_en;
int first_burst;
int max_burst;
int time2wait;
int time2retain;
int pdu_inorder_en;
int dataseq_inorder_en; int erl;
int ifmarker_en;
int ofmarker_en;
/* control data */
struct Scsi_Host *host;
int id;
struct iscsi_conn *leadconn; /* leading connection */
spinlock_t lock; /* protects session state, *
* sequence numbers, *
* session resources: *
* - cmdpool, *
* - mgmtpool, *
* - r2tpool */
int state; /* session state */
struct list_head item;
void *auth_client;
int conn_cnt;
int age; /* counts session re-opens */
struct list_head connections; /* list of connections */
int cmds_max; /* size of cmds array */
struct iscsi_cmd_task **cmds; /* Original Cmds arr */
struct iscsi_queue cmdpool; /* PDU's pool */
int mgmtpool_max; /* size of mgmt array */
struct iscsi_mgmt_task **mgmt_cmds; /* Original mgmt arr */
struct iscsi_queue mgmtpool; /* Mgmt PDU's pool */
};
struct iscsi_buf {
struct scatterlist sg;
struct kvec iov;
unsigned int sent;
};
struct iscsi_data_task {
struct iscsi_data hdr; /* PDU */
char hdrext[sizeof(__u32)]; /* Header-Digest */
struct list_head item; /* data queue item */
struct iscsi_buf digestbuf; /* digest buffer */
uint32_t digest; /* data digest */
};
#define ISCSI_DTASK_DEFAULT_MAX ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
struct iscsi_mgmt_task {
struct iscsi_hdr hdr; /* mgmt. PDU */
char hdrext[sizeof(__u32)]; /* Header-Digest */
char *data; /* mgmt payload */
int xmstate; /* mgmt xmit progress */
int data_count; /* counts data to be sent */
struct iscsi_buf headbuf; /* header buffer */
struct iscsi_buf sendbuf; /* in progress buffer */
int sent;
uint32_t itt; /* this ITT */
};
struct iscsi_r2t_info {
__be32 ttt; /* copied from R2T */
__be32 exp_statsn; /* copied from R2T */
uint32_t data_length; /* copied from R2T */
uint32_t data_offset; /* copied from R2T */
struct iscsi_buf headbuf; /* Data-Out Header Buffer */
struct iscsi_buf sendbuf; /* Data-Out in progress buffer*/
int sent; /* R2T sequence progress */
int data_count; /* DATA-Out payload progress */
struct scatterlist *sg; /* per-R2T SG list */
int solicit_datasn;
struct iscsi_data_task *dtask; /* which data task */
};
struct iscsi_cmd_task {
struct iscsi_cmd hdr; /* iSCSI PDU header */
char hdrext[4*sizeof(__u16)+ /* AHS */
sizeof(__u32)]; /* HeaderDigest */
char pad[ISCSI_PAD_LEN];
int itt; /* this ITT */
int datasn; /* DataSN */
struct iscsi_buf headbuf; /* header buf (xmit) */
struct iscsi_buf sendbuf; /* in progress buffer*/
int sent;
struct scatterlist *sg; /* per-cmd SG list */
struct scatterlist *bad_sg; /* assert statement */
int sg_count; /* SG's to process */
uint32_t unsol_datasn;
uint32_t exp_r2tsn;
int xmstate; /* xmit xtate machine */
int imm_count; /* imm-data (bytes) */
int unsol_count; /* unsolicited (bytes)*/
int r2t_data_count; /* R2T Data-Out bytes */
int data_count; /* remaining Data-Out */
int pad_count; /* padded bytes */
struct scsi_cmnd *sc; /* associated SCSI cmd*/
int total_length;
int data_offset;
struct iscsi_conn *conn; /* used connection */
struct iscsi_mgmt_task *mtask; /* tmf mtask in progr */
struct iscsi_r2t_info *r2t; /* in progress R2T */
struct iscsi_queue r2tpool;
struct kfifo *r2tqueue;
struct iscsi_r2t_info **r2ts;
struct list_head dataqueue; /* Data-Out dataqueue */
mempool_t *datapool;
uint32_t datadigest; /* for recover digest */
int digest_count;
uint32_t immdigest; /* for imm data */
struct iscsi_buf immbuf; /* for imm data digest */
struct iscsi_data_task *dtask; /* data task in progress*/
int digest_offset; /* for partial buff digest */
};
#endif /* ISCSI_H */