1 files changed, 513 insertions, 0 deletions

diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
new file mode 100644
index 0000000000..7282555adf
--- /dev/null
+++ b/include/scsi/libiscsi.h
@@ -0,0 +1,513 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * iSCSI lib definitions
+ *
+ * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2004 - 2006 Mike Christie
+ * Copyright (C) 2004 - 2005 Dmitry Yusupov
+ * Copyright (C) 2004 - 2005 Alex Aizman
+ */
+#ifndef LIBISCSI_H
+#define LIBISCSI_H
+
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/mutex.h>
+#include <linux/timer.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+#include <linux/refcount.h>
+#include <scsi/iscsi_proto.h>
+#include <scsi/iscsi_if.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_transport_iscsi.h>
+
+struct scsi_transport_template;
+struct scsi_host_template;
+struct scsi_device;
+struct Scsi_Host;
+struct scsi_target;
+struct scsi_cmnd;
+struct socket;
+struct iscsi_transport;
+struct iscsi_cls_session;
+struct iscsi_cls_conn;
+struct iscsi_session;
+struct iscsi_nopin;
+struct device;
+
+#define ISCSI_DEF_XMIT_CMDS_MAX	128	/* must be power of 2 */
+#define ISCSI_MGMT_CMDS_MAX	15
+
+#define ISCSI_DEF_CMD_PER_LUN	32
+
+/* Task Mgmt states */
+enum {
+	TMF_INITIAL,
+	TMF_QUEUED,
+	TMF_SUCCESS,
+	TMF_FAILED,
+	TMF_TIMEDOUT,
+	TMF_NOT_FOUND,
+};
+
+#define ISID_SIZE			6
+
+/* Connection flags */
+#define ISCSI_CONN_FLAG_SUSPEND_TX	0
+#define ISCSI_CONN_FLAG_SUSPEND_RX	1
+#define ISCSI_CONN_FLAG_BOUND		2
+
+#define ISCSI_ITT_MASK			0x1fff
+#define ISCSI_TOTAL_CMDS_MAX		4096
+/* this must be a power of two greater than ISCSI_MGMT_CMDS_MAX */
+#define ISCSI_TOTAL_CMDS_MIN		16
+#define ISCSI_AGE_SHIFT			28
+#define ISCSI_AGE_MASK			0xf
+
+#define ISCSI_ADDRESS_BUF_LEN		64
+
+enum {
+	/* this is the maximum possible storage for AHSs */
+	ISCSI_MAX_AHS_SIZE = sizeof(struct iscsi_ecdb_ahdr) +
+				sizeof(struct iscsi_rlength_ahdr),
+	ISCSI_DIGEST_SIZE = sizeof(__u32),
+};
+
+
+enum {
+	ISCSI_TASK_FREE,
+	ISCSI_TASK_COMPLETED,
+	ISCSI_TASK_PENDING,
+	ISCSI_TASK_RUNNING,
+	ISCSI_TASK_ABRT_TMF,		/* aborted due to TMF */
+	ISCSI_TASK_ABRT_SESS_RECOV,	/* aborted due to session recovery */
+	ISCSI_TASK_REQUEUE_SCSIQ,	/* qcmd requeueing to scsi-ml */
+};
+
+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 */
+	int			data_count;	/* DATA-Out payload progress */
+	int			datasn;
+	/* LLDs should set/update these values */
+	int			sent;		/* R2T sequence progress */
+};
+
+struct iscsi_task {
+	/*
+	 * Because LLDs allocate their hdr differently, this is a pointer
+	 * and length to that storage. It must be setup at session
+	 * creation time.
+	 */
+	struct iscsi_hdr	*hdr;
+	unsigned short		hdr_max;
+	unsigned short		hdr_len;	/* accumulated size of hdr used */
+	/* copied values in case we need to send tmfs */
+	itt_t			hdr_itt;
+	__be32			cmdsn;
+	struct scsi_lun		lun;
+
+	int			itt;		/* this ITT */
+
+	unsigned		imm_count;	/* imm-data (bytes)   */
+	/* offset in unsolicited stream (bytes); */
+	struct iscsi_r2t_info	unsol_r2t;
+	char			*data;		/* mgmt payload */
+	unsigned		data_count;
+	struct scsi_cmnd	*sc;		/* associated SCSI cmd*/
+	struct iscsi_conn	*conn;		/* used connection    */
+
+	/* data processing tracking */
+	unsigned long		last_xfer;
+	unsigned long		last_timeout;
+	bool			have_checked_conn;
+
+	/* T10 protection information */
+	bool			protected;
+
+	/* state set/tested under session->lock */
+	int			state;
+	refcount_t		refcount;
+	struct list_head	running;	/* running cmd list */
+	void			*dd_data;	/* driver/transport data */
+};
+
+static inline int iscsi_task_has_unsol_data(struct iscsi_task *task)
+{
+	return task->unsol_r2t.data_length > task->unsol_r2t.sent;
+}
+
+static inline void* iscsi_next_hdr(struct iscsi_task *task)
+{
+	return (void*)task->hdr + task->hdr_len;
+}
+
+static inline bool iscsi_task_is_completed(struct iscsi_task *task)
+{
+	return task->state == ISCSI_TASK_COMPLETED ||
+	       task->state == ISCSI_TASK_ABRT_TMF ||
+	       task->state == ISCSI_TASK_ABRT_SESS_RECOV;
+}
+
+/* Private data associated with struct scsi_cmnd. */
+struct iscsi_cmd {
+	struct iscsi_task	*task;
+	int			age;
+};
+
+static inline struct iscsi_cmd *iscsi_cmd(struct scsi_cmnd *cmd)
+{
+	return scsi_cmd_priv(cmd);
+}
+
+/* Connection's states */
+enum {
+	ISCSI_CONN_INITIAL_STAGE,
+	ISCSI_CONN_STARTED,
+	ISCSI_CONN_STOPPED,
+	ISCSI_CONN_CLEANUP_WAIT,
+};
+
+struct iscsi_conn {
+	struct iscsi_cls_conn	*cls_conn;	/* ptr to class connection */
+	void			*dd_data;	/* iscsi_transport data */
+	struct iscsi_session	*session;	/* parent session */
+	/*
+	 * conn_stop() flag: stop to recover, stop to terminate
+	 */
+        int			stop_stage;
+	struct timer_list	transport_timer;
+	unsigned long		last_recv;
+	unsigned long		last_ping;
+	int			ping_timeout;
+	int			recv_timeout;
+	struct iscsi_task 	*ping_task;
+
+	/* iSCSI connection-wide sequencing */
+	uint32_t		exp_statsn;
+	uint32_t		statsn;
+
+	/* control data */
+	int			id;		/* CID */
+	int			c_stage;	/* connection state */
+	/*
+	 * Preallocated buffer for pdus that have data but do not
+	 * originate from scsi-ml. We never have two pdus using the
+	 * buffer at the same time. It is only allocated to
+	 * the default max recv size because the pdus we support
+	 * should always fit in this buffer
+	 */
+	char			*data;
+	struct iscsi_task 	*login_task;	/* mtask used for login/text */
+	struct iscsi_task	*task;		/* xmit task in progress */
+
+	/* xmit */
+	/* items must be added/deleted under frwd lock */
+	struct list_head	mgmtqueue;	/* mgmt (control) xmit queue */
+	struct list_head	cmdqueue;	/* data-path cmd queue */
+	struct list_head	requeue;	/* tasks needing another run */
+	struct work_struct	xmitwork;	/* per-conn. xmit workqueue */
+	/* recv */
+	struct work_struct	recvwork;
+	unsigned long		flags;		/* ISCSI_CONN_FLAGs */
+
+	/* negotiated params */
+	unsigned		max_recv_dlength; /* initiator_max_recv_dsl*/
+	unsigned		max_xmit_dlength; /* target_max_recv_dsl */
+	int			hdrdgst_en;
+	int			datadgst_en;
+	int			ifmarker_en;
+	int			ofmarker_en;
+	/* values userspace uses to id a conn */
+	int			persistent_port;
+	char			*persistent_address;
+
+	unsigned		max_segment_size;
+	unsigned		tcp_xmit_wsf;
+	unsigned		tcp_recv_wsf;
+	uint16_t		keepalive_tmo;
+	uint16_t		local_port;
+	uint8_t			tcp_timestamp_stat;
+	uint8_t			tcp_nagle_disable;
+	uint8_t			tcp_wsf_disable;
+	uint8_t			tcp_timer_scale;
+	uint8_t			tcp_timestamp_en;
+	uint8_t			fragment_disable;
+	uint8_t			ipv4_tos;
+	uint8_t			ipv6_traffic_class;
+	uint8_t			ipv6_flow_label;
+	uint8_t			is_fw_assigned_ipv6;
+	char			*local_ipaddr;
+
+	/* 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		eh_abort_cnt;
+	uint32_t		fmr_unalign_cnt;
+};
+
+struct iscsi_pool {
+	struct kfifo		queue;		/* FIFO Queue */
+	void			**pool;		/* Pool of elements */
+	int			max;		/* Max number of elements */
+};
+
+/* Session's states */
+enum {
+	ISCSI_STATE_FREE = 1,
+	ISCSI_STATE_LOGGED_IN,
+	ISCSI_STATE_FAILED,
+	ISCSI_STATE_TERMINATE,
+	ISCSI_STATE_IN_RECOVERY,
+	ISCSI_STATE_RECOVERY_FAILED,
+	ISCSI_STATE_LOGGING_OUT,
+};
+
+struct iscsi_session {
+	struct iscsi_cls_session *cls_session;
+	/*
+	 * Syncs up the scsi eh thread with the iscsi eh thread when sending
+	 * task management functions. This must be taken before the session
+	 * and recv lock.
+	 */
+	struct mutex		eh_mutex;
+	/* abort */
+	wait_queue_head_t	ehwait;		/* used in eh_abort() */
+	struct iscsi_tm		tmhdr;
+	struct timer_list	tmf_timer;
+	int			tmf_state;	/* see TMF_INITIAL, etc.*/
+	struct iscsi_task	*running_aborted_task;
+
+	/* iSCSI session-wide sequencing */
+	uint32_t		cmdsn;
+	uint32_t		exp_cmdsn;
+	uint32_t		max_cmdsn;
+
+	/* This tracks the reqs queued into the initiator */
+	uint32_t		queued_cmdsn;
+
+	/* configuration */
+	int			abort_timeout;
+	int			lu_reset_timeout;
+	int			tgt_reset_timeout;
+	int			initial_r2t_en;
+	unsigned short		max_r2t;
+	int			imm_data_en;
+	unsigned		first_burst;
+	unsigned		max_burst;
+	int			time2wait;
+	int			time2retain;
+	int			pdu_inorder_en;
+	int			dataseq_inorder_en;
+	int			erl;
+	int			fast_abort;
+	int			tpgt;
+	char			*username;
+	char			*username_in;
+	char			*password;
+	char			*password_in;
+	char			*targetname;
+	char			*targetalias;
+	char			*ifacename;
+	char			*initiatorname;
+	char			*boot_root;
+	char			*boot_nic;
+	char			*boot_target;
+	char			*portal_type;
+	char			*discovery_parent_type;
+	uint16_t		discovery_parent_idx;
+	uint16_t		def_taskmgmt_tmo;
+	uint16_t		tsid;
+	uint8_t			auto_snd_tgt_disable;
+	uint8_t			discovery_sess;
+	uint8_t			chap_auth_en;
+	uint8_t			discovery_logout_en;
+	uint8_t			bidi_chap_en;
+	uint8_t			discovery_auth_optional;
+	uint8_t			isid[ISID_SIZE];
+
+	/* control data */
+	struct iscsi_transport	*tt;
+	struct Scsi_Host	*host;
+	struct iscsi_conn	*leadconn;	/* leading connection */
+	/* Between the forward and the backward locks exists a strict locking
+	 * hierarchy. The mutual exclusion zone protected by the forward lock
+	 * can enclose the mutual exclusion zone protected by the backward lock
+	 * but not vice versa.
+	 */
+	spinlock_t		frwd_lock;	/* protects session state, *
+						 * cmdsn, queued_cmdsn     *
+						 * session resources:      *
+						 * - cmdpool kfifo_out ,   *
+						 * - mgmtpool, queues	   */
+	spinlock_t		back_lock;	/* protects cmdsn_exp      *
+						 * cmdsn_max,              *
+						 * cmdpool kfifo_in        */
+	int			state;		/* session state           */
+	int			age;		/* counts session re-opens */
+
+	int			scsi_cmds_max; 	/* max scsi commands */
+	int			cmds_max;	/* size of cmds array */
+	struct iscsi_task	**cmds;		/* Original Cmds arr */
+	struct iscsi_pool	cmdpool;	/* PDU's pool */
+	void			*dd_data;	/* LLD private data */
+};
+
+enum {
+	ISCSI_HOST_SETUP,
+	ISCSI_HOST_REMOVED,
+};
+
+struct iscsi_host {
+	char			*initiatorname;
+	/* hw address or netdev iscsi connection is bound to */
+	char			*hwaddress;
+	char			*netdev;
+
+	wait_queue_head_t	session_removal_wq;
+	/* protects sessions and state */
+	spinlock_t		lock;
+	int			num_sessions;
+	int			state;
+
+	struct workqueue_struct	*workq;
+};
+
+/*
+ * scsi host template
+ */
+extern int iscsi_eh_abort(struct scsi_cmnd *sc);
+extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
+extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
+extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
+extern int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc);
+extern enum scsi_timeout_action iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc);
+
+/*
+ * iSCSI host helpers.
+ */
+#define iscsi_host_priv(_shost) \
+	(shost_priv(_shost) + sizeof(struct iscsi_host))
+
+extern int iscsi_host_set_param(struct Scsi_Host *shost,
+				enum iscsi_host_param param, char *buf,
+				int buflen);
+extern int iscsi_host_get_param(struct Scsi_Host *shost,
+				enum iscsi_host_param param, char *buf);
+extern int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev);
+extern struct Scsi_Host *iscsi_host_alloc(const struct scsi_host_template *sht,
+					  int dd_data_size,
+					  bool xmit_can_sleep);
+extern void iscsi_host_remove(struct Scsi_Host *shost, bool is_shutdown);
+extern void iscsi_host_free(struct Scsi_Host *shost);
+extern int iscsi_target_alloc(struct scsi_target *starget);
+extern int iscsi_host_get_max_scsi_cmds(struct Scsi_Host *shost,
+					uint16_t requested_cmds_max);
+
+/*
+ * session management
+ */
+extern struct iscsi_cls_session *
+iscsi_session_setup(struct iscsi_transport *, struct Scsi_Host *shost,
+		    uint16_t, int, int, uint32_t, unsigned int);
+void iscsi_session_remove(struct iscsi_cls_session *cls_session);
+void iscsi_session_free(struct iscsi_cls_session *cls_session);
+extern void iscsi_session_teardown(struct iscsi_cls_session *);
+extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);
+extern int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
+			   enum iscsi_param param, char *buf, int buflen);
+extern int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
+				   enum iscsi_param param, char *buf);
+
+#define iscsi_session_printk(prefix, _sess, fmt, a...)	\
+	iscsi_cls_session_printk(prefix, _sess->cls_session, fmt, ##a)
+
+/*
+ * connection management
+ */
+extern struct iscsi_cls_conn *iscsi_conn_setup(struct iscsi_cls_session *,
+					       int, uint32_t);
+extern void iscsi_conn_teardown(struct iscsi_cls_conn *);
+extern int iscsi_conn_start(struct iscsi_cls_conn *);
+extern void iscsi_conn_stop(struct iscsi_cls_conn *, int);
+extern int iscsi_conn_bind(struct iscsi_cls_session *, struct iscsi_cls_conn *,
+			   int);
+extern void iscsi_conn_unbind(struct iscsi_cls_conn *cls_conn, bool is_active);
+extern void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err);
+extern void iscsi_session_failure(struct iscsi_session *session,
+				  enum iscsi_err err);
+extern int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
+				enum iscsi_param param, char *buf);
+extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
+				     enum iscsi_param param, char *buf);
+extern void iscsi_suspend_tx(struct iscsi_conn *conn);
+extern void iscsi_suspend_rx(struct iscsi_conn *conn);
+extern void iscsi_suspend_queue(struct iscsi_conn *conn);
+extern void iscsi_conn_queue_xmit(struct iscsi_conn *conn);
+extern void iscsi_conn_queue_recv(struct iscsi_conn *conn);
+
+#define iscsi_conn_printk(prefix, _c, fmt, a...) \
+	iscsi_cls_conn_printk(prefix, ((struct iscsi_conn *)_c)->cls_conn, \
+			      fmt, ##a)
+
+/*
+ * pdu and task processing
+ */
+extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
+extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
+				    struct iscsi_r2t_info *r2t,
+				    struct iscsi_data *hdr);
+extern int iscsi_conn_send_pdu(struct iscsi_cls_conn *, struct iscsi_hdr *,
+				char *, uint32_t);
+extern int iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
+			      char *, int);
+extern int __iscsi_complete_pdu(struct iscsi_conn *, struct iscsi_hdr *,
+				char *, int);
+extern int iscsi_verify_itt(struct iscsi_conn *, itt_t);
+extern struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *, itt_t);
+extern struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *, itt_t);
+extern void iscsi_requeue_task(struct iscsi_task *task);
+extern void iscsi_put_task(struct iscsi_task *task);
+extern void __iscsi_put_task(struct iscsi_task *task);
+extern bool iscsi_get_task(struct iscsi_task *task);
+extern void iscsi_complete_scsi_task(struct iscsi_task *task,
+				     uint32_t exp_cmdsn, uint32_t max_cmdsn);
+
+/*
+ * generic helpers
+ */
+extern void iscsi_pool_free(struct iscsi_pool *);
+extern int iscsi_pool_init(struct iscsi_pool *, int, void ***, int);
+extern int iscsi_switch_str_param(char **, char *);
+
+/*
+ * inline functions to deal with padding.
+ */
+static inline unsigned int
+iscsi_padded(unsigned int len)
+{
+	return (len + ISCSI_PAD_LEN - 1) & ~(ISCSI_PAD_LEN - 1);
+}
+
+static inline unsigned int
+iscsi_padding(unsigned int len)
+{
+	len &= (ISCSI_PAD_LEN - 1);
+	if (len)
+		len = ISCSI_PAD_LEN - len;
+	return len;
+}
+
+#endif