path: root/usr/initiator.c

/*
 * iSCSI Session Management and Slow-path Control
 *
 * Copyright (C) 2004 Dmitry Yusupov, Alex Aizman
 * Copyright (C) 2006 Mike Christie
 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
 * 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.
 */

#include <sys/time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/resource.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <dirent.h>
#include <fcntl.h>

#include "initiator.h"
#include "transport.h"
#include "iscsid.h"
#include "iscsi_if.h"
#include "mgmt_ipc.h"
#include "event_poll.h"
#include "iscsi_ipc.h"
#include "idbm.h"
#include "log.h"
#include "iscsi_util.h"
#include "scsi.h"
#include "iscsi_sysfs.h"
#include "iscsi_settings.h"
#include "iface.h"
#include "host.h"
#include "sysdeps.h"
#include "iscsi_err.h"
#include "kern_err_table.h"

#define ISCSI_CONN_ERR_REOPEN_DELAY	3
#define ISCSI_INTERNAL_ERR_REOPEN_DELAY	5

#define PROC_DIR "/proc"

struct login_task_retry_info {
	actor_t retry_actor;
	queue_task_t *qtask;
	node_rec_t *rec;
	int retry_count;
};

static void iscsi_login_timedout(void *data);
static int iscsi_sched_ev_context(struct iscsi_ev_context *ev_context,
				  struct iscsi_conn *conn, unsigned long tmo,
				  int event);
static int queue_session_login_task_retry(struct login_task_retry_info *info,
					  node_rec_t *rec, queue_task_t *qtask);

static int iscsi_ev_context_alloc(iscsi_conn_t *conn)
{
	int i;

	for (i = 0; i < CONTEXT_POOL_MAX; i++) {
		conn->context_pool[i] = calloc(1,
					   sizeof(struct iscsi_ev_context) +
					   ipc->ctldev_bufmax);
		if (!conn->context_pool[i]) {
			int j;
			for (j = 0; j < i; j++)
				free(conn->context_pool[j]);
			return ENOMEM;
		}
		conn->context_pool[i]->conn = conn;
	}

	return 0;
}

static void iscsi_ev_context_free(iscsi_conn_t *conn)
{
	int i;

	for (i = 0; i < CONTEXT_POOL_MAX; i++) {
		if (!conn->context_pool[i])
			continue;

		if (conn->context_pool[i]->allocated)
			/* missing flush on shutdown */
			conn_error(conn, "BUG: context_pool leak %p",
				  conn->context_pool[i]);
		free(conn->context_pool[i]);
	}
}

static struct iscsi_ev_context *
iscsi_ev_context_get(iscsi_conn_t *conn, int ev_size)
{
	struct iscsi_ev_context *ev_context;
	int i;

	if (ev_size > ipc->ctldev_bufmax)
		return NULL;

	for (i = 0; i < CONTEXT_POOL_MAX; i++) {
		if (!conn->context_pool[i])
			continue;

		if (!conn->context_pool[i]->allocated) {
			ev_context = conn->context_pool[i];

			memset(&ev_context->actor, 0,
				sizeof(struct actor));
			ev_context->allocated = 1;
			/* some callers abuse this pointer */
			ev_context->data = (void *)ev_context +
					sizeof(struct iscsi_ev_context);
			conn_debug(7, conn, "get ev context %p",
				  &ev_context->actor);
			return ev_context;
		}
	}
	return NULL;
}

static void iscsi_ev_context_put(struct iscsi_ev_context *ev_context)
{
	log_debug(7, "put ev context %p:%s", &ev_context->actor,
		  (&ev_context->actor)->name);
	ev_context->allocated = 0;
}

static void session_online_devs(int host_no, int sid)
{
	iscsi_sysfs_for_each_device(NULL, host_no, sid,
				    iscsi_sysfs_set_device_online);
}

static conn_login_status_e
__login_response_status(iscsi_conn_t *conn,
		      enum iscsi_login_status login_status)
{
	switch (login_status) {
	case LOGIN_OK:
		/* check the status class and detail */
		return CONN_LOGIN_SUCCESS;
	case LOGIN_REDIRECT:
		return CONN_LOGIN_IMM_REDIRECT_RETRY;
	case LOGIN_IO_ERROR:
	case LOGIN_REDIRECTION_FAILED:
		return CONN_LOGIN_RETRY;
	default:
		conn_error(conn, "Login error (Login status %d)", login_status);
		break;
	}

	return CONN_LOGIN_FAILED;
}

static conn_login_status_e
__check_iscsi_status_class(iscsi_session_t *session, int cid,
			uint8_t status_class, uint8_t status_detail)
{
	iscsi_conn_t *conn = &session->conn[cid];

	switch (status_class) {
	case ISCSI_STATUS_CLS_SUCCESS:
		return CONN_LOGIN_SUCCESS;
	case ISCSI_STATUS_CLS_REDIRECT:
		switch (status_detail) {
		case ISCSI_LOGIN_STATUS_TGT_MOVED_TEMP:
			return CONN_LOGIN_IMM_RETRY;
		case ISCSI_LOGIN_STATUS_TGT_MOVED_PERM:
			/*
			 * for a permanent redirect, we need to update the
			 * failback address
			 */
			memset(&conn->failback_saddr, 0,
				sizeof(struct sockaddr_storage));
			conn->failback_saddr = conn->saddr;
                        return CONN_LOGIN_IMM_REDIRECT_RETRY;
		default:
			conn_error(conn, "login rejected: redirection "
			        "type 0x%x not supported", status_detail);
			return CONN_LOGIN_RETRY;
		}
	case ISCSI_STATUS_CLS_INITIATOR_ERR:
		switch (status_detail) {
		case ISCSI_LOGIN_STATUS_AUTH_FAILED:
			log_error("session %d login rejected: Initiator "
			       "failed authentication with target",
				session->id);
			return CONN_LOGIN_AUTH_FAILED;
		case ISCSI_LOGIN_STATUS_TGT_FORBIDDEN:
			conn_error(conn, "login rejected: initiator "
			       "failed authorization with target");
			return CONN_LOGIN_AUTH_FAILED;
		case ISCSI_LOGIN_STATUS_TGT_NOT_FOUND:
			conn_error(conn, "login rejected: initiator "
			       "error - target not found (%02x/%02x)",
			       status_class, status_detail);
			return CONN_LOGIN_FAILED;
		case ISCSI_LOGIN_STATUS_NO_VERSION:
			/*
			 * FIXME: if we handle multiple protocol versions,
			 * before we log an error, try the other supported
			 * versions.
			 */
			conn_error(conn, "login rejected: incompatible "
			       "version (%02x/%02x), non-retryable, "
			       "giving up", status_class, status_detail);
			return CONN_LOGIN_FAILED;
		default:
			conn_error(conn, "login rejected: initiator "
			       "error (%02x/%02x)", status_class, status_detail);
			return CONN_LOGIN_FAILED;
		}
	case ISCSI_STATUS_CLS_TARGET_ERR:
		conn_error(conn, "login rejected: target error "
		       "(%02x/%02x)", status_class, status_detail);
		/*
		 * We have no idea what the problem is. But spec says initiator
		 * may retry later.
		 */
		 return CONN_LOGIN_RETRY;
	default:
		conn_error(conn, "login response with unknown status "
		       "class 0x%x, detail 0x%x", status_class, status_detail);
		break;
	}

	return CONN_LOGIN_FAILED;
}

static int
__session_conn_create(iscsi_session_t *session, int cid)
{
	iscsi_conn_t *conn = &session->conn[cid];
	conn_rec_t *conn_rec = &session->nrec.conn[cid];
	node_rec_t *rec = &session->nrec;
	int err;

	conn->id = cid;
	if (iscsi_ev_context_alloc(conn)) {
		conn_error(conn, "cannot allocate context_pool");
		return ISCSI_ERR_NOMEM;
	}

	/* set session reconnection retry max */
	session->reopen_max = rec->session.reopen_max;

	conn->state = ISCSI_CONN_STATE_FREE;
	conn->session = session;
	actor_init(&conn->login_timer, iscsi_login_timedout, conn);
	/*
	 * TODO: we must export the socket_fd/transport_eph from sysfs
	 * so if iscsid is resyncing up we can pick that up and cleanup up
	 * the old connection. Right now we leak a connection.
	 * We can also probably merge these two fields.
	 */
	conn->socket_fd = -1;
	conn->transport_ep_handle = -1;
	/* connection's timeouts */
	conn->logout_timeout = conn_rec->timeo.logout_timeout;
	if (!conn->logout_timeout) {
		conn_error(conn, "Invalid timeo.logout_timeout. Must be greater "
			  "than zero. Using default %d.",
			  DEF_LOGOUT_TIMEO);
		conn->logout_timeout = DEF_LOGOUT_TIMEO;
	}

	conn->login_timeout = conn_rec->timeo.login_timeout;
	if (!conn->login_timeout) {
		conn_error(conn, "Invalid timeo.login_timeout. Must be greater "
			  "than zero. Using default %d.",
			  DEF_LOGIN_TIMEO);
		conn->login_timeout = DEF_LOGIN_TIMEO;
	}

	conn->auth_timeout = conn_rec->timeo.auth_timeout;

	/* noop-out setting */
	conn->noop_out_interval = conn_rec->timeo.noop_out_interval;
	conn->noop_out_timeout = conn_rec->timeo.noop_out_timeout;
	if (conn->noop_out_interval && !conn->noop_out_timeout) {
		conn_error(conn, "Invalid timeo.noop_out_timeout. Must be greater "
			  "than zero. Using default %d.",
			  DEF_NOOP_OUT_TIMEO);
		conn->noop_out_timeout = DEF_NOOP_OUT_TIMEO;
	}

	if (conn->noop_out_timeout && !conn->noop_out_interval) {
		conn_error(conn, "Invalid timeo.noop_out_interval. Must be greater "
			  "than zero. Using default %d.",
			  DEF_NOOP_OUT_INTERVAL);
		conn->noop_out_interval = DEF_NOOP_OUT_INTERVAL;
	}

	iscsi_copy_operational_params(conn, &session->nrec.session.iscsi,
				      &conn_rec->iscsi);

	/* TCP options */
	conn->tcp_window_size = conn_rec->tcp.window_size;
	/* FIXME: type_of_service */

	/* resolve the string address to an IP address */
	err = iscsi_setup_portal(conn, conn_rec->address, conn_rec->port);
	if (err)
		return err;
	return 0;
}

static void
session_release(iscsi_session_t *session)
{
	log_debug(2, "Releasing session:%d %p", session->id, session);

	if (session->target_alias)
		free(session->target_alias);
	iscsi_ev_context_free(&session->conn[0]);
	free(session);
}

static iscsi_session_t*
__session_create(node_rec_t *rec, struct iscsi_transport *t, int *rc)
{
	iscsi_session_t *session;
	int hostno;

	*rc = 0;

	session = calloc(1, sizeof (*session));
	if (session == NULL) {
		log_debug(1, "can not allocate memory for session");
		*rc = ISCSI_ERR_NOMEM;
		return NULL;
	}
	log_debug(2, "Allocted session %p", session);

	INIT_LIST_HEAD(&session->list);
	session->t = t;
	session->id = INVALID_SESSION_ID;
	session->use_ipc = 1;

	/* save node record. we might need it for redirection */
	memcpy(&session->nrec, rec, sizeof(node_rec_t));

	session->portal_group_tag = rec->tpgt;
	session->type = ISCSI_SESSION_TYPE_NORMAL;
	session->r_stage = R_STAGE_NO_CHANGE;
	strlcpy(session->target_name, rec->name, TARGET_NAME_MAXLEN);

	if (strlen(session->nrec.iface.iname))
		session->initiator_name = session->nrec.iface.iname;
	else if (dconfig->initiator_name)
		session->initiator_name = dconfig->initiator_name;
	else {
		log_error("No initiator name set. Cannot create session.");
		*rc = ISCSI_ERR_INVAL;
		goto free_session;
	}

	if (strlen(session->nrec.iface.alias))
		session->initiator_alias = session->nrec.iface.alias;
	else
		session->initiator_alias = dconfig->initiator_alias;

	/* session's eh parameters */
	session->replacement_timeout = rec->session.timeo.replacement_timeout;
	session->fast_abort = rec->session.iscsi.FastAbort;
	session->abort_timeout = rec->session.err_timeo.abort_timeout;
	session->lu_reset_timeout = rec->session.err_timeo.lu_reset_timeout;
	session->tgt_reset_timeout = rec->session.err_timeo.tgt_reset_timeout;
	session->host_reset_timeout = rec->session.err_timeo.host_reset_timeout;

	/* OUI and uniqifying number */
	session->isid[0] = DRIVER_ISID_0;
	session->isid[1] = DRIVER_ISID_1;
	session->isid[2] = DRIVER_ISID_2;
	session->isid[3] = 0;
	session->isid[4] = 0;
	session->isid[5] = 0;

	/* setup authentication variables for the session*/
	iscsi_setup_authentication(session, &rec->session.auth);

	iscsi_session_init_params(session);

        if (t->template->bind_ep_required) {
                hostno = iscsi_sysfs_get_host_no_from_hwinfo(&rec->iface, rc);
                if (!*rc) {
                        /*
                         * if the netdev or mac was set, then we are going to want
                         * to want to bind the all the conns/eps to a specific host
                         * if offload is used.
                         */
                        session->conn[0].bind_ep = 1;
                        session->hostno = hostno;
                } else if (*rc == ISCSI_ERR_HOST_NOT_FOUND) {
                        goto free_session;	
                } else {
                         *rc = 0;
                }
        }

	/* reset session reopen count */
	session->reopen_cnt = 0;

	list_add_tail(&session->list, &t->sessions);
	return session;

free_session:
	free(session);
	return NULL;
}

static void iscsi_flush_context_pool(struct iscsi_session *session)
{
	struct iscsi_ev_context *ev_context;
	struct iscsi_conn *conn = &session->conn[0];
	int i;

	for (i = 0; i < CONTEXT_POOL_MAX; i++) {
		ev_context = conn->context_pool[i];
		if (!ev_context)
			continue;

		if (ev_context->allocated) {
			actor_delete(&(conn->context_pool[i]->actor));
			iscsi_ev_context_put(ev_context);
		}
	}
}

static void
__session_destroy(iscsi_session_t *session)
{
	log_debug(1, "destroying session:%d", session->id);
	list_del(&session->list);
	iscsi_flush_context_pool(session);
	session_release(session);
}

static void
conn_delete_timers(iscsi_conn_t *conn)
{
	actor_delete(&conn->login_timer);
	actor_delete(&conn->nop_out_timer);
}

static int 
session_conn_shutdown(iscsi_conn_t *conn, int err)
{
	iscsi_session_t *session = conn->session;
	queue_task_t *qtask = NULL;

	if (conn->login_qtask) {
		qtask = conn->login_qtask;
		conn->login_qtask = NULL;
	} else if (conn->logout_qtask) {
		qtask = conn->logout_qtask;
		conn->logout_qtask = NULL;
	}

	conn_debug(2, conn, "disconnect conn");
	/* this will check for a valid interconnect connection */
	if (session->t->template->ep_disconnect)
		session->t->template->ep_disconnect(conn);

	if (session->id == INVALID_SESSION_ID)
		goto cleanup;

	if (!iscsi_sysfs_session_has_leadconn(session->id))
		goto cleanup;

	if (conn->state == ISCSI_CONN_STATE_IN_LOGIN ||
	    conn->state == ISCSI_CONN_STATE_IN_LOGOUT ||
	    conn->state == ISCSI_CONN_STATE_LOGGED_IN) {
		conn_debug(2, conn, "stop conn (conn state %d)", conn->state);
		if (ipc->stop_conn(session->t->handle, session->id,
				   conn->id, STOP_CONN_TERM)) {
			conn_error(conn, "can't stop connection (%d)", errno);
			return ISCSI_ERR_INTERNAL;
		}
	}

	conn_debug(2, conn, "kdestroy conn");
	if (ipc->destroy_conn(session->t->handle, session->id,
		conn->id)) {
		conn_error(conn, "can not safely destroy connection");
		return ISCSI_ERR_INTERNAL;
	}

cleanup:
	if (session->id != INVALID_SESSION_ID) {
		log_debug(2, "kdestroy session %u", session->id);
		session->r_stage = R_STAGE_SESSION_DESTOYED;
		if (ipc->destroy_session(session->t->handle, session->id)) {
			log_error("can not safely destroy session %d",
				  session->id);
			return ISCSI_ERR_INTERNAL;
		}
	}

	log_warning("Connection%d:%d to [target: %s, portal: %s,%d] "
		    "through [iface: %s] is shutdown.",
		    session->id, conn->id, session->nrec.name,
		    session->nrec.conn[conn->id].address,
		    session->nrec.conn[conn->id].port,
		    session->nrec.iface.name);

	if (qtask)
		mgmt_ipc_write_rsp(qtask, err);
	conn_delete_timers(conn);
	__session_destroy(session);
	return ISCSI_SUCCESS;
}

static void
queue_delayed_reopen(struct iscsi_conn *conn, int delay)
{
	conn_debug(4, conn, "Requeue reopen attempt in %d secs", delay);

	/*
 	 * iscsi_login_eh can handle the login resched as
 	 * if it were login time out
 	 */
	actor_timer_mod(&conn->login_timer, delay, conn);
}

static int iscsi_conn_connect(struct iscsi_conn *conn)
{
	struct iscsi_ev_context *ev_context;
	int rc;

	ev_context = iscsi_ev_context_get(conn, 0);
	if (!ev_context) {
		/* while reopening the recv pool should be full */
		conn_error(conn, "BUG: __session_conn_reopen could not get conn "
			  "context for recv.");
		return ENOMEM;
	}

	rc = conn->session->t->template->ep_connect(conn, 1);
	if (rc < 0 && errno != EINPROGRESS) {
		char serv[NI_MAXSERV];

		getnameinfo((struct sockaddr *) &conn->saddr,
			    sizeof(conn->saddr),
			    conn->host, sizeof(conn->host), serv, sizeof(serv),
			    NI_NUMERICHOST|NI_NUMERICSERV);

		conn_error(conn, "cannot make a connection to %s:%s (%d,%d)",
			  conn->host, serv, rc, errno);
		iscsi_ev_context_put(ev_context);
		return ENOTCONN;
	}

	iscsi_sched_ev_context(ev_context, conn, 0, EV_CONN_POLL);
	conn_debug(3, conn, "Setting login timer %p timeout %d", &conn->login_timer,
		  conn->login_timeout);
	actor_timer_mod(&conn->login_timer, conn->login_timeout, conn);
	return 0;
}

static void
__session_conn_reopen(iscsi_conn_t *conn, int do_stop, int redirected)
{
	iscsi_session_t *session = conn->session;
	uint32_t delay;

	log_debug(1, "re-opening session %d (reopen_cnt %d)", session->id,
			session->reopen_cnt);

	/* flush stale polls or errors queued */
	iscsi_flush_context_pool(session);
	conn_delete_timers(conn);
	conn->state = ISCSI_CONN_STATE_XPT_WAIT;

	conn->session->t->template->ep_disconnect(conn);
	if (do_stop) {
		/* state: ISCSI_CONN_STATE_CLEANUP_WAIT */
		if (ipc->stop_conn(session->t->handle, session->id,
				   conn->id, do_stop)) {
			log_error("can't stop connection %d:%d (%d)",
				  session->id, conn->id, errno);
			delay = ISCSI_INTERNAL_ERR_REOPEN_DELAY;
			goto queue_reopen;
		}
		log_debug(3, "connection %d:%d is stopped for recovery",
			  session->id, conn->id);
	}

	if (!redirected) {
		delay = session->def_time2wait;
		session->def_time2wait = 0;
		if (delay)
			goto queue_reopen;
	}

	if (!redirected)
		session->reopen_cnt++;

	/* uIP will needs to be re-triggered on the connection re-open */
	if (iscsi_set_net_config(conn->session->t, conn->session,
				 &conn->session->nrec.iface) != 0)
		goto queue_reopen;

	if (iscsi_conn_connect(conn)) {
		delay = ISCSI_CONN_ERR_REOPEN_DELAY;
		goto queue_reopen;
	}
	return;

queue_reopen:
	conn_debug(4, conn, "Waiting %u seconds before trying to reconnect.", delay);
	queue_delayed_reopen(conn, delay);
}

static void
session_conn_reopen(iscsi_conn_t *conn, int do_stop)
{
	/*
	 * If we were temporarily redirected, we need to fall back to
	 * the original address to see where the target will send us
	 * for the retry
	 */
	memset(&conn->saddr, 0, sizeof(struct sockaddr_storage));
	conn->saddr = conn->failback_saddr;

	__session_conn_reopen(conn, do_stop, 0);
}

static int iscsi_retry_initial_login(struct iscsi_conn *conn)
{
	int initial_login_retry_max;
	struct timeval now, timeout, fail_time;

	initial_login_retry_max =
			conn->session->nrec.session.initial_login_retry_max;

	memset(&now, 0, sizeof(now));
	memset(&timeout, 0, sizeof(timeout));
	memset(&fail_time, 0, sizeof(fail_time));

	timeout.tv_sec = initial_login_retry_max * conn->login_timeout;
	if (gettimeofday(&now, NULL)) {
		conn_error(conn, "Could not get time of day. Dropping down to "
			  "max retry check.");
		return initial_login_retry_max > conn->session->reopen_cnt;
	}
	timeradd(&conn->initial_connect_time, &timeout, &fail_time);

	/*
	 * if we have been trying for login_retry_max * login_timeout
	 * then it is time to give up
	 */
	if (timercmp(&now, &fail_time, >)) {
		conn_debug(1, conn, "Giving up on initial login attempt after "
			  "%u seconds.",
			  initial_login_retry_max * conn->login_timeout);
		return 0;
	}

	return 1;
}

static int iscsi_login_is_fatal_err(int err)
{
	if (err == ISCSI_ERR_LOGIN_AUTH_FAILED ||
	    err == ISCSI_ERR_FATAL_LOGIN)
		return 1;
	return 0;
}

static void iscsi_login_eh(struct iscsi_conn *conn, int err)
{
	struct iscsi_session *session = conn->session;
	int stop_flag = 0;

	conn_debug(3, conn, "iscsi_login_eh state %d/%d", session->r_stage,
		   conn->state);
	/*
	 * Flush polls and other events
	 */
	iscsi_flush_context_pool(conn->session);

	switch (conn->state) {
	case ISCSI_CONN_STATE_XPT_WAIT:
		switch (session->r_stage) {
		case R_STAGE_NO_CHANGE:
			conn_debug(6, conn, "login failed ISCSI_CONN_STATE_XPT_WAIT/"
				  "R_STAGE_NO_CHANGE");
			/* timeout during initial connect.
			 * clean connection. write ipc rsp or retry */
			if (iscsi_login_is_fatal_err(err) ||
			    !iscsi_retry_initial_login(conn))
				session_conn_shutdown(conn, err);
			else {
				stop_flag = (session->id < INVALID_SESSION_ID) ? STOP_CONN_TERM : 0;
				conn_debug(6, conn, "connection %p socket_fd: %d stop_flag: %d\n",
					  conn, conn->socket_fd, stop_flag);
				session_conn_reopen(conn, stop_flag);
			}
			break;
		case R_STAGE_SESSION_REDIRECT:
			conn_debug(6, conn, "login failed ISCSI_CONN_STATE_XPT_WAIT/"
				  "R_STAGE_SESSION_REDIRECT");
			/* timeout during initial redirect connect
			 * clean connection. write ipc rsp or retry */
			if (iscsi_login_is_fatal_err(err) ||
			    !iscsi_retry_initial_login(conn))
				session_conn_shutdown(conn, err);
			else
				session_conn_reopen(conn, 0);
			break;
		case R_STAGE_SESSION_REOPEN:
			conn_debug(6, conn, "login failed ISCSI_CONN_STATE_XPT_WAIT/"
				  "R_STAGE_SESSION_REOPEN (reopen_cnt=%d, reopen_max=%d)",
				  session->reopen_cnt, session->reopen_max);
			if (session->reopen_max &&
			    (session->reopen_cnt > session->reopen_max)) {
				log_info("Giving up on session %d after %d retries", 
						session->id, session->reopen_max);
				session_conn_shutdown(conn, err);
				break;
			}
			/* timeout during reopen connect. try again */
			session_conn_reopen(conn, 0);
			break;
		case R_STAGE_SESSION_CLEANUP:
			session_conn_shutdown(conn, err);
			break;
		default:
			break;
		}

		break;
	case ISCSI_CONN_STATE_IN_LOGIN:
		switch (session->r_stage) {
		case R_STAGE_NO_CHANGE:
		case R_STAGE_SESSION_REDIRECT:
			conn_debug(6, conn, "login failed ISCSI_CONN_STATE_IN_LOGIN/"
				  "R_STAGE_NO_CHANGE %d",
				  session->reopen_cnt);
			/*
			 * send pdu timeout during initial connect or
			 * initial redirected connect. Clean connection
			 * and write rsp or retry.
			 */
			if (iscsi_login_is_fatal_err(err) ||
			    !iscsi_retry_initial_login(conn))
				session_conn_shutdown(conn, err);
			else
				session_conn_reopen(conn, STOP_CONN_RECOVER);
			break;
		case R_STAGE_SESSION_REOPEN:
			conn_debug(6, conn, "login failed ISCSI_CONN_STATE_IN_LOGIN/"
				  "R_STAGE_SESSION_REOPEN %d",
				  session->reopen_cnt);
			session_conn_reopen(conn, STOP_CONN_RECOVER);
			break;
		case R_STAGE_SESSION_CLEANUP:
			session_conn_shutdown(conn, ISCSI_ERR_PDU_TIMEOUT);
			break;
		default:
			break;
		}

		break;
	default:
		conn_error(conn, "Ignoring login error %d in conn state %d.",
			  err, conn->state);
		break;
	}
}

static void
__conn_error_handle(iscsi_session_t *session, iscsi_conn_t *conn)
{
	int i;

	/*
	 * if we got an error while trying to logout for the user then
	 * just cleanup and return to the user.
	 */
	if (conn->logout_qtask) {
		session_conn_shutdown(conn, ISCSI_SUCCESS);
		return;
	}

	switch (conn->state) {
	case ISCSI_CONN_STATE_IN_LOGOUT:
		/* logout was from eh - fall down to cleanup */
	case ISCSI_CONN_STATE_LOGGED_IN:
		/* mark failed connection */
		conn->state = ISCSI_CONN_STATE_CLEANUP_WAIT;

		if (session->erl > 0) {
			/* check if we still have some logged in connections */
			for (i=0; i<ISCSI_CONN_MAX; i++) {
				if (session->conn[i].state ==
				    ISCSI_CONN_STATE_LOGGED_IN)
					break;
			}
			if (i != ISCSI_CONN_MAX) {
				/* FIXME: re-assign leading connection
				 *        for ERL>0 */
			}

			break;
		}

		/* mark all connections as failed */
		for (i=0; i<ISCSI_CONN_MAX; i++) {
			if (session->conn[i].state ==
			    ISCSI_CONN_STATE_LOGGED_IN)
				session->conn[i].state =
						ISCSI_CONN_STATE_CLEANUP_WAIT;
		}
		session->r_stage = R_STAGE_SESSION_REOPEN;
		break;
	case ISCSI_CONN_STATE_IN_LOGIN:
		if (session->r_stage == R_STAGE_SESSION_REOPEN) {
			iscsi_login_eh(conn, ISCSI_ERR_TRANS);
			return;
		}
		conn_debug(1, conn, "ignoring conn error in login. "
			  "let it timeout");
		return;
	case ISCSI_CONN_STATE_XPT_WAIT:
		conn_debug(1, conn, "ignoring conn error in XPT_WAIT. "
			  "let connection fail on its own");
		return;
	case ISCSI_CONN_STATE_CLEANUP_WAIT:
		conn_debug(1, conn, "ignoring conn error in CLEANUP_WAIT. "
			  "let connection stop");
		return;
	default:
		conn_debug(8, conn, "invalid state %d", conn->state);
		return;
	}

	if (session->r_stage == R_STAGE_SESSION_REOPEN) {
		session_conn_reopen(conn, STOP_CONN_RECOVER);
		return;
	}
}

static void session_conn_error(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	enum iscsi_err error = *(enum iscsi_err *)ev_context->data;
	iscsi_conn_t *conn = ev_context->conn;
	iscsi_session_t *session = conn->session;
	int sid = session->id;

	log_warning("Kernel reported iSCSI connection %d:%d error (%d - %s) "
		    "state (%d)", session->id, conn->id, error,
		    kern_err_code_to_string(error), conn->state);

	iscsi_ev_context_put(ev_context);

	switch (error) {
	case ISCSI_ERR_INVALID_HOST:
		if (session_conn_shutdown(conn, ISCSI_SUCCESS))
			log_error("BUG: Could not shutdown session:%d.", sid);
		break;
	default:
		__conn_error_handle(session, conn);
	}
}

static void iscsi_login_timedout(void *data)
{
	struct iscsi_conn *conn = data;

	switch (conn->state) {
	case ISCSI_CONN_STATE_XPT_WAIT:
		iscsi_login_eh(conn, ISCSI_ERR_TRANS_TIMEOUT);
		break;
	case ISCSI_CONN_STATE_IN_LOGIN:
		iscsi_login_eh(conn, ISCSI_ERR_PDU_TIMEOUT);
		break;
	default:
		iscsi_login_eh(conn, ISCSI_ERR_INTERNAL);
		break;
	}
}

static void iscsi_login_redirect(iscsi_conn_t *conn)
{
	iscsi_session_t *session = conn->session;

	conn_debug(3, conn, "login redirect ...");

	if (session->r_stage == R_STAGE_NO_CHANGE)
		session->r_stage = R_STAGE_SESSION_REDIRECT;

	__session_conn_reopen(conn, STOP_CONN_RECOVER, 1);
}

static int
__send_nopin_rsp(iscsi_conn_t *conn, struct iscsi_nopin *rhdr, char *data)
{
	struct iscsi_nopout hdr;

	memset(&hdr, 0, sizeof(struct iscsi_nopout));
	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
	hdr.flags = ISCSI_FLAG_CMD_FINAL;
	hdr.dlength[0] = rhdr->dlength[0];
	hdr.dlength[1] = rhdr->dlength[1];
	hdr.dlength[2] = rhdr->dlength[2];
	memcpy(hdr.lun, rhdr->lun, 8);
	hdr.ttt = rhdr->ttt;
	hdr.itt = ISCSI_RESERVED_TAG;

	return iscsi_io_send_pdu(conn, (struct iscsi_hdr*)&hdr,
	       ISCSI_DIGEST_NONE, data, ISCSI_DIGEST_NONE, 0);
}

static int
__send_nopout(iscsi_conn_t *conn)
{
	struct iscsi_nopout hdr;

	memset(&hdr, 0, sizeof(struct iscsi_nopout));
	hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
	hdr.flags = ISCSI_FLAG_CMD_FINAL;
	hdr.itt = 0;  /* XXX: let kernel send_pdu set for us*/
	hdr.ttt = ISCSI_RESERVED_TAG;
	/* we have hdr.lun reserved, and no data */
	return iscsi_io_send_pdu(conn, (struct iscsi_hdr*)&hdr,
		ISCSI_DIGEST_NONE, NULL, ISCSI_DIGEST_NONE, 0);
}

static void conn_nop_out_timeout(void *data)
{
	iscsi_conn_t *conn = (iscsi_conn_t*)data;
	iscsi_session_t *session = conn->session;

	log_warning("Nop-out timedout after %d seconds on connection %d:%d "
		    "state (%d). Dropping session.", conn->noop_out_timeout,
		    session->id, conn->id, conn->state);
	/* XXX: error handle */
	__conn_error_handle(session, conn);
}

static void conn_send_nop_out(void *data)
{
	iscsi_conn_t *conn = data;

	/*
	 * we cannot start new request during logout and the logout timer
	 * will figure things out.
	 */
	if (conn->state == ISCSI_CONN_STATE_IN_LOGOUT)
		return;

	__send_nopout(conn);

	actor_timer(&conn->nop_out_timer, conn->noop_out_timeout,
		    conn_nop_out_timeout, conn);
	conn_debug(3, conn, "noop out timeout timer %p start, timeout %d",
		 &conn->nop_out_timer, conn->noop_out_timeout);
}

void free_initiator(void)
{
	struct iscsi_transport *t;
	iscsi_session_t *session, *tmp;

	list_for_each_entry(t, &transports, list) {
		list_for_each_entry_safe(session, tmp, &t->sessions, list) {
			list_del(&session->list);
			iscsi_flush_context_pool(session);
			session_release(session);
		}
	}

	free_transports();
}

static void session_scan_host(struct iscsi_session *session, int hostno,
			      queue_task_t *qtask)
{
	pid_t pid;

	pid = iscsi_sysfs_scan_host(hostno, 1, idbm_session_autoscan(session));
	if (pid == 0) {
		mgmt_ipc_write_rsp(qtask, ISCSI_SUCCESS);

		if (session)
			iscsi_sysfs_for_each_device(
					&session->nrec.session.queue_depth,
					hostno, session->id,
					iscsi_sysfs_set_queue_depth);
		exit(0);
	} else if (pid > 0) {
		reap_inc();
		if (qtask && qtask->mgmt_ipc_fd >= 0) {
			close(qtask->mgmt_ipc_fd);
			free(qtask);
		}
	} else
		mgmt_ipc_write_rsp(qtask, ISCSI_ERR_INTERNAL);
}

static void
setup_full_feature_phase(iscsi_conn_t *conn)
{
	iscsi_session_t *session = conn->session;
	int rc;

	actor_delete(&conn->login_timer);

	if (iscsi_session_set_neg_params(conn)) {
		iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
		return;
	}

	if (ipc->start_conn(session->t->handle, session->id, conn->id,
			    &rc) || rc) {
		log_error("can't start connection %d:%d retcode %d (%d)",
			  session->id, conn->id, rc, errno);
		iscsi_login_eh(conn, ISCSI_ERR_INTERNAL);
		return;
	}

	conn->state = ISCSI_CONN_STATE_LOGGED_IN;
	if (session->r_stage == R_STAGE_NO_CHANGE ||
	    session->r_stage == R_STAGE_SESSION_REDIRECT) {
		/*
		 * scan host is one-time deal. We
		 * don't want to re-scan it on recovery.
		 */
		if (conn->id == 0)
			session_scan_host(session, session->hostno,
					  conn->login_qtask);

		log_warning("Connection%d:%d to [target: %s, portal: %s,%d] "
			    "through [iface: %s] is operational now",
			    session->id, conn->id, session->nrec.name,
			    session->nrec.conn[conn->id].address,
			    session->nrec.conn[conn->id].port,
			    session->nrec.iface.name);
	} else {
		session_online_devs(session->hostno, session->id);
		mgmt_ipc_write_rsp(conn->login_qtask, ISCSI_SUCCESS);
		log_warning("connection%d:%d is operational after recovery "
			    "(%d attempts)", session->id, conn->id,
			     session->reopen_cnt);
	}
	conn->login_qtask = NULL;

	/*
	 * reset ERL=0 reopen counter
	 */
	session->reopen_cnt = 0;
	session->r_stage = R_STAGE_NO_CHANGE;

	/* noop_out */
	if (conn->userspace_nop && conn->noop_out_interval) {
		actor_timer(&conn->nop_out_timer, conn->noop_out_interval,
			   conn_send_nop_out, conn);
		conn_debug(3, conn, "noop out timer %p start",
			  &conn->nop_out_timer);
	}
}

static void iscsi_logout_timedout(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	struct iscsi_conn *conn = ev_context->conn;

	iscsi_ev_context_put(ev_context);
	/*
	 * assume we were in ISCSI_CONN_STATE_IN_LOGOUT or there
	 * was some nasty error
	 */
	conn_debug(3, conn, "logout timeout, dropping conn...");
	__conn_error_handle(conn->session, conn);
}

static int iscsi_send_logout(iscsi_conn_t *conn)
{
	struct iscsi_logout hdr;
	struct iscsi_ev_context *ev_context;

	if (conn->state != ISCSI_CONN_STATE_LOGGED_IN)
		return EINVAL;

	memset(&hdr, 0, sizeof(struct iscsi_logout));
	hdr.opcode = ISCSI_OP_LOGOUT | ISCSI_OP_IMMEDIATE;
	hdr.flags = ISCSI_FLAG_CMD_FINAL |
	   (ISCSI_LOGOUT_REASON_CLOSE_SESSION & ISCSI_FLAG_LOGOUT_REASON_MASK);
	/* kernel will set the rest */

	if (!iscsi_io_send_pdu(conn, (struct iscsi_hdr*)&hdr,
			       ISCSI_DIGEST_NONE, NULL, ISCSI_DIGEST_NONE, 0))
		return EIO;
	conn->state = ISCSI_CONN_STATE_IN_LOGOUT;

	ev_context = iscsi_ev_context_get(conn, 0);
	if (!ev_context)
		/* unbounded logout */
		log_warning("connection%d:%d Could not allocate conn context for logout.",
			conn->session->id, conn->id);
	else {
		iscsi_sched_ev_context(ev_context, conn,
					 conn->logout_timeout,
					 EV_CONN_LOGOUT_TIMER);
		conn_debug(3, conn, "logout timeout timer %u",
			  conn->logout_timeout * 1000);
	}

	return 0;
}

static void iscsi_stop(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	struct iscsi_conn *conn = ev_context->conn;
	int rc = 0;
	int sid = conn->session->id;

	iscsi_ev_context_put(ev_context);

	if (!(conn->session->t->caps & CAP_LOGIN_OFFLOAD)) {
		if (!iscsi_send_logout(conn))
			return;
	}

	rc = session_conn_shutdown(conn, ISCSI_SUCCESS);
	if (rc)
		log_error("BUG: Could not shutdown session:%d.", sid);
}

static void iscsi_recv_nop_in(iscsi_conn_t *conn, struct iscsi_hdr *hdr)
{
	if (!conn->userspace_nop) {
		conn_error(conn, "Got nop in, but kernel supports nop handling.");
		return;
	}

	if (hdr->ttt == ISCSI_RESERVED_TAG) {
		/* noop out rsp */
		actor_delete(&conn->nop_out_timer);
		/* schedule a new ping */
		actor_timer(&conn->nop_out_timer, conn->noop_out_interval,
			    conn_send_nop_out, conn);
	} else /*  noop in req */
		if (!__send_nopin_rsp(conn, (struct iscsi_nopin*)hdr,
				      conn->data)) {
			conn_error(conn, "can not send nopin response");
		}
}

static void iscsi_recv_logout_rsp(iscsi_conn_t *conn, struct iscsi_hdr *hdr)
{
	struct iscsi_logout_rsp *logout_rsp = (struct iscsi_logout_rsp *)hdr;

	conn_debug(3, conn, "Recv: logout response %d", logout_rsp->response);
	if (logout_rsp->response == 2 || logout_rsp->response == 3) {
		conn->session->def_time2wait = ntohs(logout_rsp->t2wait);
		conn_debug(4, conn, "logout rsp returned time2wait %u",
			  conn->session->def_time2wait);
	}
	/* TODO process the hdr */
	__conn_error_handle(conn->session, conn);
}

static void iscsi_recv_async_msg(iscsi_conn_t *conn, struct iscsi_hdr *hdr)
{
	iscsi_session_t *session = conn->session;
	struct iscsi_async *async_hdr = (struct iscsi_async *)hdr;
	char *buf = conn->data;
	unsigned int senselen;
	struct scsi_sense_hdr sshdr;

	conn_debug(3, conn, "Read AEN %d", async_hdr->async_event);

	switch (async_hdr->async_event) {
	case ISCSI_ASYNC_MSG_SCSI_EVENT:
		senselen = (buf[0] << 8) | buf[1];
		buf += 2;

		if (!scsi_normalize_sense((uint8_t *)buf, senselen, &sshdr)) {
			conn_error(conn, "Could not handle AEN %d. Invalid sense.",
				  async_hdr->async_event);
			break;
		}

		if (sshdr.asc == 0x3f && sshdr.ascq == 0x0e
		    && idbm_session_autoscan(session))
			session_scan_host(session, session->hostno, NULL);
		break;
	case ISCSI_ASYNC_MSG_REQUEST_LOGOUT:
		conn_warn(conn, "Target requests logout within %u seconds" , ntohs(async_hdr->param3));
		if (iscsi_send_logout(conn))
			conn_error(conn, "Could not send logout in response to"
				 "logout request aen");
		break;
	case ISCSI_ASYNC_MSG_DROPPING_CONNECTION:
		conn_warn(conn, "Target dropping %u, reconnect min %u max %u", ntohs(async_hdr->param1),
			    ntohs(async_hdr->param2), ntohs(async_hdr->param3));
		session->def_time2wait =
			(uint32_t)ntohs(async_hdr->param2) & 0x0000FFFFFL;
		break;
	case ISCSI_ASYNC_MSG_DROPPING_ALL_CONNECTIONS:
		log_warning("Target dropping all connections, reconnect min %u "
			    "max %u", ntohs(async_hdr->param2),
			     ntohs(async_hdr->param3));
		session->def_time2wait =
			(uint32_t)ntohs(async_hdr->param2) & 0x0000FFFFFL;
		break;
	case ISCSI_ASYNC_MSG_PARAM_NEGOTIATION:
		log_warning("Received async event param negotiation, "
			    "dropping session:%d", session->id);
		__conn_error_handle(session, conn);
		break;
	case ISCSI_ASYNC_MSG_VENDOR_SPECIFIC:
	default:
		log_warning("AEN not supported");
	}
}

static void iscsi_recv_login_rsp(struct iscsi_conn *conn)
{ 
	struct iscsi_session *session = conn->session;
	iscsi_login_context_t *c = &conn->login_context;
	int err = ISCSI_ERR_FATAL_LOGIN;

	if (iscsi_login_rsp(session, c)) {
		conn_debug(1, conn, "login_rsp ret (%d)", c->ret);

		switch (__login_response_status(conn, c->ret)) {
		case CONN_LOGIN_FAILED:
			goto failed;
		case CONN_LOGIN_RETRY:
			goto retry;
		case CONN_LOGIN_IMM_REDIRECT_RETRY:
			iscsi_login_redirect(conn);
			return;
		default:
			; /* success - fall through */
		}

		/* check the login status */
		switch (__check_iscsi_status_class(session, conn->id,
						   c->status_class,
						   c->status_detail)) {
		case CONN_LOGIN_AUTH_FAILED:
			err = ISCSI_ERR_LOGIN_AUTH_FAILED;
			goto failed;
		case CONN_LOGIN_FAILED:
			goto failed;
		case CONN_LOGIN_IMM_REDIRECT_RETRY:
			iscsi_login_redirect(conn);
			return;
		case CONN_LOGIN_IMM_RETRY:
		case CONN_LOGIN_RETRY:
			goto retry;
		default:
			; /* success - fall through */
		}
	}

	if (conn->current_stage != ISCSI_FULL_FEATURE_PHASE) {
		/* more nego. needed! */
		conn->state = ISCSI_CONN_STATE_IN_LOGIN;
		if (iscsi_login_req(session, c)) {
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}
	} else
		setup_full_feature_phase(conn);

	return;
retry:
	/* retry if not initial login or initial login has not timed out */
	iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
	return;
failed:
	/* force failure if initial login */
	session->reopen_cnt = session->nrec.session.initial_login_retry_max;
	iscsi_login_eh(conn, err);
	return;
}

static void session_conn_recv_pdu(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	iscsi_conn_t *conn = ev_context->conn;
	struct iscsi_hdr hdr;

	conn->recv_context = ev_context;

	switch (conn->state) {
	case ISCSI_CONN_STATE_IN_LOGIN:
		iscsi_recv_login_rsp(conn);
		break;
	case ISCSI_CONN_STATE_LOGGED_IN:
	case ISCSI_CONN_STATE_IN_LOGOUT:
	case ISCSI_CONN_STATE_LOGOUT_REQUESTED:
		/* read incoming PDU */
		if (iscsi_io_recv_pdu(conn, &hdr, ISCSI_DIGEST_NONE,
				      conn->data, ISCSI_DEF_MAX_RECV_SEG_LEN,
				      ISCSI_DIGEST_NONE, 0) < 0)
			return;

		switch (hdr.opcode & ISCSI_OPCODE_MASK) {
		case ISCSI_OP_NOOP_IN:
			iscsi_recv_nop_in(conn, &hdr);
			break;
		case ISCSI_OP_LOGOUT_RSP:
			iscsi_recv_logout_rsp(conn, &hdr);
			break;
		case ISCSI_OP_ASYNC_EVENT:
			iscsi_recv_async_msg(conn, &hdr);
			break;
		default:
			conn_error(conn, "unsupported opcode 0x%x", hdr.opcode);
			break;
		}
		break;
	case ISCSI_CONN_STATE_XPT_WAIT:
		iscsi_ev_context_put(ev_context);
		conn_debug(1, conn, "ignoring incoming PDU in XPT_WAIT. "
			  "let connection re-establish or fail");
		break;
	case ISCSI_CONN_STATE_CLEANUP_WAIT:
		iscsi_ev_context_put(ev_context);
		conn_debug(1, conn, "ignoring incoming PDU in XPT_WAIT. "
			  "let connection cleanup");
		break;
	default:
		iscsi_ev_context_put(ev_context);
		conn_error(conn, "Invalid state %d. Dropping PDU.", conn->state);
	}
}

static void session_increase_wq_priority(struct iscsi_session *session)
{
	DIR *proc_dir;
	struct dirent *proc_dent;
	struct stat statb;
	char stat_file[PATH_SIZE];
	char sbuf[1024];	/* got this from ps */
	int pid, stat_fd, num_read;
	char *proc_name, *proc_name_end;
	uint32_t host_no;

	/* drivers like bnx2i and qla4xxx do not have a write wq */
	if (session->t->caps & CAP_DATA_PATH_OFFLOAD)
		return;

	proc_dir = opendir(PROC_DIR);
	if (!proc_dir)
		goto fail;

	while ((proc_dent = readdir(proc_dir))) {
		if (!strcmp(proc_dent->d_name, ".") ||
		    !strcmp(proc_dent->d_name, ".."))
			continue;
		if (sscanf(proc_dent->d_name, "%d", &pid) != 1)
			continue;

		memset(stat_file, 0, sizeof(stat_file));
		sprintf(stat_file, PROC_DIR"/%d/stat", pid);
		if (stat(stat_file, &statb))
			continue;

		if (!S_ISREG( statb.st_mode))
			continue;

		stat_fd = open(stat_file, O_RDONLY);
		if (stat_fd == -1)
			continue;

		memset(sbuf, 0, sizeof(sbuf));
		num_read = read(stat_fd, sbuf, sizeof(sbuf));
		close(stat_fd);
		if (num_read == -1)
			continue;
		if (num_read == sizeof(sbuf))
			sbuf[num_read - 1] = '\0';
		else
			sbuf[num_read] = '\0';

		/*
		 * Finally match proc name to iscsi thread name.
		 * In newer kernels the name is iscsi_wq_%HOST_NO.
		 * In older kernels before 2.6.30, it was scsi_wq_%HOST_NO.
		 *
		 * We only support newer kernels.
		 */
		proc_name = strchr(sbuf, '(') + 1;
		if (!proc_name)
			continue;

		proc_name_end = strchr(proc_name, ')');
		if (!proc_name_end)
			continue;

		*proc_name_end = '\0';

		if (sscanf(proc_name, "iscsi_q_%u\n", &host_no) == 1) {
			if (host_no == session->hostno) {
				if (!setpriority(PRIO_PROCESS, pid,
					session->nrec.session.xmit_thread_priority)) {
					closedir(proc_dir);
					return;
				} else
					break;
			}
		}
	}
	closedir(proc_dir);
fail:
	log_error("Could not set session%d priority. "
		  "READ/WRITE throughout and latency could be "
		  "affected.", session->id);
}

static int session_ipc_create(struct iscsi_session *session)
{
	struct iscsi_conn *conn = &session->conn[0];
	int err = 0, pass_ep = 1;
	uint32_t host_no = -1;

	if (session->t->template->ep_connect != ktransport_ep_connect)
		pass_ep = 0;
retry_create:
	err = ipc->create_session(session->t->handle,
				  pass_ep ? conn->transport_ep_handle : 0,
				  session->nrec.session.initial_cmdsn,
				  session->nrec.session.cmds_max,
				  session->nrec.session.queue_depth,
				  &session->id, &host_no);
	/*
	 * Older kernels were not passed the sessions's leading conn ep,
	 * so we will get -EINVAL || -ENOSYS for iser.
	 *
	 * 2.6.22 and earlier would send -EINVAL instead of -ENOSYS.
	 */
	if (pass_ep && (err == -ENOSYS || err == -EINVAL)) {
		pass_ep = 0;
		goto retry_create;
	}

	if (!err) {
		session->hostno = host_no;
		session_increase_wq_priority(session);
	}
	return err;
}

static void setup_offload_login_phase(iscsi_conn_t *conn)
{
	iscsi_session_t *session = conn->session;
	int rc;

	actor_delete(&conn->login_timer);

	if (iscsi_session_set_params(conn)) {
		iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
		return;
	}

	if (iscsi_session_set_neg_params(conn)) {
		iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
		return;
	}

	if (iscsi_host_set_params(session)) {
		iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
		return;
	}

	conn->state = ISCSI_CONN_STATE_IN_LOGIN;
	if (ipc->start_conn(session->t->handle, session->id, conn->id,
			    &rc) || rc) {
		if (rc == -EEXIST) {
			conn_error(conn, "Session already exists.");
			session_conn_shutdown(conn, ISCSI_ERR_SESS_EXISTS);
		} else {
			log_error("can't start connection %d:%d retcode (%d)",
				  session->id, conn->id, rc);
			iscsi_login_eh(conn, ISCSI_ERR_INTERNAL);
		}
		return;
	}
}


static void session_conn_poll(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	iscsi_conn_t *conn = ev_context->conn;
	struct iscsi_session *session = conn->session;
	int err = ISCSI_SUCCESS;
	iscsi_login_context_t *c = &conn->login_context;
	int rc;

	iscsi_ev_context_put(ev_context);

	if (conn->state != ISCSI_CONN_STATE_XPT_WAIT)
		return;

	rc = session->t->template->ep_poll(conn, 1);
	if (rc == 0) {
		conn_debug(4, conn, "poll not connected %d", rc);
		ev_context = iscsi_ev_context_get(conn, 0);
		if (!ev_context) {
			/* while polling the recv pool should be full */
			conn_error(conn, "BUG: session_conn_poll could not get conn "
				  "context.");
			iscsi_login_eh(conn, ISCSI_ERR_INTERNAL);
			return;
		}
		/* not connected yet, check later */
		iscsi_sched_ev_context(ev_context, conn, 1, EV_CONN_POLL);
	} else if (rc > 0) {
		/* connected! */
		memset(c, 0, sizeof(iscsi_login_context_t));

		/* do not allocate new connection in case of reopen */
		if (session->id == INVALID_SESSION_ID) {
			if (conn->id == 0 && session_ipc_create(session)) {
				log_error("Can't create session.");
				err = ISCSI_ERR_INTERNAL;
				goto cleanup;
			}
			log_debug(3, "created new iSCSI session sid %d host "
				  "no %u", session->id, session->hostno);

			err = ipc->create_conn(session->t->handle,
					session->id, conn->id, &conn->id);
			if (err) {
				log_error("Can't create connection for session%d.",
					session->id);
				err = ISCSI_ERR_INTERNAL;
				goto cleanup;
			}
			log_debug(3, "created new iSCSI connection "
				  "%d:%d", session->id, conn->id);
		}

		iscsi_copy_operational_params(conn,
					&session->nrec.session.iscsi,
					&session->nrec.conn[conn->id].iscsi);
		/*
		 * TODO: use the iface number or some other value
		 * so this will be persistent
		 */
		session->isid[3] = (session->id >> 16) & 0xff;
		session->isid[4] = (session->id >>  8) & 0xff;
		session->isid[5] = session->id & 0xff;

		if (ipc->bind_conn(session->t->handle, session->id,
				   conn->id, conn->transport_ep_handle,
				   (conn->id == 0), &rc) || rc) {
			log_error("can't bind conn %d:%d to session %d, "
				  "retcode %d (%d)", session->id, conn->id,
				   session->id, rc, errno);
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}
		log_debug(3, "bound iSCSI connection %d:%d to session %d",
			  session->id, conn->id, session->id);

		c->cid = conn->id;
		c->buffer = conn->data;
		c->bufsize = sizeof(conn->data);

		conn->exp_statsn = iscsi_sysfs_get_exp_statsn(session->id);

		if (session->t->caps & CAP_LOGIN_OFFLOAD) {
			setup_offload_login_phase(conn);
			return;
		}

		if (iscsi_session_set_params(conn)) {
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}

		if (iscsi_host_set_params(session)) {
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}

		if (iscsi_login_begin(session, c)) {
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}

		conn->state = ISCSI_CONN_STATE_IN_LOGIN;
		if (iscsi_login_req(session, c)) {
			iscsi_login_eh(conn, ISCSI_ERR_LOGIN);
			return;
		}
	} else {
		conn_debug(4, conn, "poll error %d", rc);
		queue_delayed_reopen(conn, ISCSI_CONN_ERR_REOPEN_DELAY);
	}

	return;

cleanup:
	session_conn_shutdown(conn, err);
}

static void session_conn_process_login(void *data)
{
	struct iscsi_ev_context *ev_context = data;
	enum iscsi_conn_state state = *(enum iscsi_conn_state *)
							ev_context->data;
	struct iscsi_conn *conn = ev_context->conn;
	struct iscsi_session *session = conn->session;

	iscsi_ev_context_put(ev_context);
	if (!(session->t->caps & CAP_LOGIN_OFFLOAD))
		return;

	if (state == ISCSI_CONN_STATE_FREE)
		goto failed_login;

	if (conn->state == ISCSI_CONN_STATE_LOGGED_IN)
		return;

	conn->state = ISCSI_CONN_STATE_LOGGED_IN;
	/*
	 * ok we were in_login and now we got the notification that we are
	 * logged in
	 */
	log_debug(3, "session created sid %u host no %d", session->id,
		  session->hostno);

	if (session->r_stage == R_STAGE_NO_CHANGE ||
	    session->r_stage == R_STAGE_SESSION_REDIRECT) {
		/*
		 * scan host is one-time deal. We
		 * don't want to re-scan it on recovery.
		 */
		session_scan_host(session, session->hostno,
				  conn->login_qtask);

		log_warning("Connection%d:%d to [target: %s, portal: %s,%d] "
			    "through [iface: %s] is operational now",
			    session->id, conn->id, session->nrec.name,
			    session->nrec.conn[conn->id].address,
			    session->nrec.conn[conn->id].port,
			    session->nrec.iface.name);
	} else {
		mgmt_ipc_write_rsp(conn->login_qtask, ISCSI_SUCCESS);
	}

	conn->login_qtask = NULL;

	/*
	 * reset ERL=0 reopen counter
	 */
	session->reopen_cnt = 0;
	session->r_stage = R_STAGE_NO_CHANGE;

	return;

failed_login:
	mgmt_ipc_write_rsp(conn->login_qtask, ISCSI_ERR_LOGIN);
	conn->login_qtask = NULL;

	if (ipc->destroy_conn(session->t->handle, session->id, conn->id))
		log_error("can not safely destroy connection%d:%d",
			session->id, conn->id);
	if (ipc->destroy_session(session->t->handle, session->id))
		log_error("can not safely destroy session %d", session->id);
	__session_destroy(session);

}

static int iscsi_sched_ev_context(struct iscsi_ev_context *ev_context,
				  struct iscsi_conn *conn, unsigned long tmo,
				  int event)
{
	enum iscsi_err error;

	conn_debug(7, conn, "sched conn context %p event %d, tmo %lu",
		  &ev_context->actor, event, tmo);

	ev_context->conn = conn;
	switch (event) {
	case EV_CONN_RECV_PDU:
		actor_init(&ev_context->actor, session_conn_recv_pdu,
			  ev_context);
		actor_schedule(&ev_context->actor);
		break;
	case EV_CONN_ERROR:
		error = *(enum iscsi_err *)ev_context->data;

		actor_init(&ev_context->actor, session_conn_error,
			  ev_context);
		/*
		 * We handle invalid host, by killing the session.
		 * It must go at the head of the queue, so we do not
		 * initiate error handling or logout or some other op.
		 */
		if (error == ISCSI_ERR_INVALID_HOST)
			actor_schedule_head(&ev_context->actor);
		else
			actor_schedule(&ev_context->actor);
		break;
	case EV_CONN_LOGIN:
		actor_init(&ev_context->actor, session_conn_process_login,
			  ev_context);
		actor_schedule(&ev_context->actor);
		break;
	case EV_CONN_POLL:
		actor_timer(&ev_context->actor, tmo,
			    session_conn_poll, ev_context);
		break;
	case EV_CONN_LOGOUT_TIMER:
		actor_timer(&ev_context->actor, tmo,
			    iscsi_logout_timedout, ev_context);
		break;
	case EV_CONN_STOP:
		actor_init(&ev_context->actor, iscsi_stop,
			  ev_context);
		actor_schedule(&ev_context->actor);
		break;
	default:
		conn_error(conn, "Invalid event type %d.", event);
	}
	return 0;
}

static iscsi_session_t* session_find_by_rec(node_rec_t *rec)
{
	struct iscsi_transport *t;
	iscsi_session_t *session;

	list_for_each_entry(t, &transports, list) {
		list_for_each_entry(session, &t->sessions, list) {
			if (__iscsi_match_session(rec, session->nrec.name,
					 session->nrec.conn[0].address,
					 session->nrec.conn[0].port,
					 &session->nrec.iface,
					 MATCH_ANY_SID))
				return session;
		}
	}
	return NULL;
}

/*
 * a session could be running in the kernel but not in iscsid
 * due to a resync or because some other app started the session
 */
static int session_is_running(node_rec_t *rec)
{
	int nr_found = 0;

	if (session_find_by_rec(rec))
		return 1;

	if (iscsi_sysfs_for_each_session(rec, &nr_found, iscsi_match_session,
					 0))
		return 1;

	return 0;
}

static int __session_login_task(node_rec_t *rec, queue_task_t *qtask)
{
	iscsi_session_t *session;
	iscsi_conn_t *conn;
	struct iscsi_transport *t;
	int rc;

	if (session_is_running(rec)) {
		if (rec->session.multiple)
			log_debug(2, "Adding a copy of an existing session");
		else
			return ISCSI_ERR_SESS_EXISTS;
	}

	t = iscsi_sysfs_get_transport_by_name(rec->iface.transport_name);
	if (!t)
		return ISCSI_ERR_TRANS_NOT_FOUND;

	if ((!(t->caps & CAP_RECOVERY_L0) &&
	     rec->session.iscsi.ERL != 0) ||
	    (!(t->caps & CAP_RECOVERY_L1) &&
	     rec->session.iscsi.ERL > 1)) {
		log_error("Transport '%s' does not support ERL %d."
			  "Setting ERL to ERL0.",
			  t->name, rec->session.iscsi.ERL);
		rec->session.iscsi.ERL = 0;
	}

	if (!(t->caps & CAP_MULTI_R2T) &&
	    rec->session.iscsi.MaxOutstandingR2T) {
		log_error("Transport '%s' does not support "
			  "MaxOutstandingR2T %d. Setting "
			  "MaxOutstandingR2T to 1.", t->name,
			  rec->session.iscsi.MaxOutstandingR2T);
		rec->session.iscsi.MaxOutstandingR2T = 1;		
	}

	if (!(t->caps & CAP_HDRDGST) &&
	    rec->conn[0].iscsi.HeaderDigest) {
		log_error("Transport '%s' does not support "
			  "HeaderDigest != None. Setting HeaderDigest "
			  "to None.", t->name);
		rec->conn[0].iscsi.HeaderDigest = CONFIG_DIGEST_NEVER;
	}

	if (!(t->caps & CAP_DATADGST) &&
	    rec->conn[0].iscsi.DataDigest) {
		log_error("Transport '%s' does not support "
			  "DataDigest != None. Setting DataDigest "
			  "to None", t->name);
		rec->conn[0].iscsi.DataDigest = CONFIG_DIGEST_NEVER;
	}

	if (!(t->caps & CAP_MARKERS) &&
	    rec->conn[0].iscsi.IFMarker) {
		log_error("Transport '%s' does not support IFMarker. "
			  "Disabling IFMarkers.", t->name);
		rec->conn[0].iscsi.IFMarker = 0;
	}

	if (!(t->caps & CAP_MARKERS) &&
	    rec->conn[0].iscsi.OFMarker) {
		log_error("Transport '%s' does not support OFMarker."
			  "Disabling OFMarkers.", t->name);
		rec->conn[0].iscsi.OFMarker = 0;
	}

	session = __session_create(rec, t, &rc);
	if (rc == ISCSI_ERR_HOST_NOT_FOUND)
		return rc;
	else if (!session)
		return ISCSI_ERR_LOGIN;

	/* FIXME: login all connections! marked as "automatic" */

	/* create leading connection */
	rc = __session_conn_create(session, 0);
	if (rc) {
		__session_destroy(session);
		return rc;
	}
	conn = &session->conn[0];
	qtask->conn = conn;

	rc = iscsi_host_set_net_params(&rec->iface, session);
	if (rc == ISCSI_ERR_AGAIN) {
		/*
		 * host/iscsiuio not ready. Cannot block iscsid, so caller is
		 * going to internally retry the operation.
		 */
		__session_destroy(session);
		return ISCSI_ERR_HOST_NOT_FOUND;
	} else if (rc) {
		__session_destroy(session);
		return ISCSI_ERR_LOGIN;
	}

	if (gettimeofday(&conn->initial_connect_time, NULL))
		log_error("Could not get initial connect time. If "
			  "login errors iscsid may give up the initial "
			  "login early. You should manually login.");

	conn->state = ISCSI_CONN_STATE_XPT_WAIT;
	conn->login_qtask = qtask;

	qtask->rsp.command = MGMT_IPC_SESSION_LOGIN;
	qtask->rsp.err = ISCSI_SUCCESS;

	if (iscsi_conn_connect(conn)) {
		log_debug(4, "Initial connect failed. Waiting %u seconds "
			  "before trying to reconnect.",
			  ISCSI_CONN_ERR_REOPEN_DELAY);
		queue_delayed_reopen(conn, ISCSI_CONN_ERR_REOPEN_DELAY);
	}

	return ISCSI_SUCCESS;
}

int
session_login_task(node_rec_t *rec, queue_task_t *qtask)
{
	int rc;

	rc = __session_login_task(rec, qtask);
	if (rc == ISCSI_ERR_HOST_NOT_FOUND) {
		rc = queue_session_login_task_retry(NULL, rec, qtask);
		if (rc)
			return rc;
		/*
		 * we are going to internally retry. Will return final rc
		 * when completed
		 */
		return ISCSI_SUCCESS;
	}
	return rc;
}

static void session_login_task_retry(void *data)
{
	struct login_task_retry_info *info = data;
	struct node_rec *rec = info->rec;
	int rc;

	rc = __session_login_task(rec, info->qtask);
	if (rc == ISCSI_ERR_HOST_NOT_FOUND) {
		if (info->retry_count == rec->conn[0].timeo.login_timeout) {
			/* give up */
			goto write_rsp;
		}

		rc = queue_session_login_task_retry(info, rec, info->qtask);
		if (rc)
			goto write_rsp;
		/* we are going to internally retry */
		return;
	} else if (rc) {
		/* hard error - no retry */
		goto write_rsp;
	} else
		/* successfully started login operation */
		goto free;
write_rsp:
	mgmt_ipc_write_rsp(info->qtask, rc);
free:
	free(info);
}

static int queue_session_login_task_retry(struct login_task_retry_info *info,
					  node_rec_t *rec, queue_task_t *qtask)
{
	if (!info) {
		info = malloc(sizeof(*info));
		if (!info)
			return ISCSI_ERR_NOMEM;
		memset(info, 0, sizeof(*info));
		info->qtask = qtask;
		info->rec = rec;
	}

	info->retry_count++;
	log_debug(4, "queue session setup attempt in %d secs, retries %d",
		  1, info->retry_count);
	actor_timer(&info->retry_actor, 1, session_login_task_retry, info);
	return 0;
}

int
iscsi_sync_session(node_rec_t *rec, queue_task_t *qtask, uint32_t sid)
{
	char state_buff[SCSI_MAX_STATE_VALUE];
	struct iscsi_transport *t;
	iscsi_session_t *session;
	iscsi_conn_t *conn;
	int err;

	session = session_find_by_sid(sid);
	if (session != NULL)
		return ISCSI_ERR_SESS_EXISTS;

	t = iscsi_sysfs_get_transport_by_name(rec->iface.transport_name);
	if (!t)
		return ISCSI_ERR_TRANS_NOT_FOUND;

	session = __session_create(rec, t, &err);
	if (!session)
		return ISCSI_ERR_LOGIN;

	session->id = sid;
	session->hostno = iscsi_sysfs_get_host_no_from_sid(sid, &err);
	if (err) {
		log_error("Could not get hostno for session %d", sid);
		goto destroy_session;
	}

	err = __session_conn_create(session, 0);
	if (err)
		goto destroy_session;
	conn = &session->conn[0];

	/*
	 * The caller only cares we have rebuilt our state, and can process
	 * errors from the kernel and new commands like logout, so send the
	 * response now.
	 */
	qtask->rsp.command = MGMT_IPC_SESSION_SYNC;
	mgmt_ipc_write_rsp(qtask, ISCSI_SUCCESS);

	/*
	 * Older kernels do not support needs_cleanup and/or the conn state
	 * field, so we have to force the relogin.
	 */
	if (iscsi_sysfs_conn_needs_cleanup(sid)) {
		conn_debug(4, conn, "Conn needs recovery cleanup.");
		goto reopen;
	}

	memset(state_buff, 0, SCSI_MAX_STATE_VALUE);
	if (iscsi_sysfs_get_conn_state(state_buff, sid)) {
		goto reopen;
	}
	conn_debug(4, conn, "Conn in %s state.\n", state_buff);

	if (strcmp("up", state_buff))
		goto reopen;

	conn->state = ISCSI_CONN_STATE_LOGGED_IN;
	session->r_stage = R_STAGE_NO_CHANGE;
	log_info("connection%d:%d is operational after resync.", session->id,
		conn->id);
	return 0;

reopen:
	conn_debug(3, conn, "Started sync iSCSI session");
	conn->state = ISCSI_CONN_STATE_CLEANUP_WAIT;
	session->r_stage = R_STAGE_SESSION_REOPEN;
	session_conn_reopen(&session->conn[0], STOP_CONN_RECOVER);

	return 0;

destroy_session:
	__session_destroy(session);
	log_error("Could not sync session%d err %d", sid, err);
	return err;
}

static int session_unbind(struct iscsi_session *session)
{
	int err;

	err = ipc->unbind_session(session->t->handle, session->id);
	if (err)
		/* older kernels did not support unbind */
		log_debug(2, "Could not unbind session%d %d.", session->id, err);
	return err;
}

int session_logout_task(int sid, queue_task_t *qtask)
{
	iscsi_session_t *session;
	iscsi_conn_t *conn;
	int rc = ISCSI_SUCCESS;

	session = session_find_by_sid(sid);
	if (!session) {
                log_debug(1, "session sid %d not found.", sid);
		return ISCSI_ERR_SESS_NOT_FOUND;
	}
	conn = &session->conn[0];

	/*
	 * TODO: We can check the iscsid and kernel state and kill an
	 * in progress login.
	 */
	if (conn->login_qtask) {
		log_error("Logout failed. Login in progress.\n");
		return ISCSI_ERR_INTERNAL;
	}

	if (dconfig->safe_logout && session_in_use(sid)) {
		log_error("Session %d is actively in use for mounted storage, "
			  "and iscsid.safe_logout is configured.", session->id);
		return ISCSI_ERR_BUSY;
	}

	/* FIXME: logout all active connections */
	conn = &session->conn[0];
	if (conn->logout_qtask) {
		log_error("Could not logout. Logout in progress.");
		return ISCSI_ERR_INTERNAL;
	}

	qtask->conn = conn;
	qtask->rsp.command = MGMT_IPC_SESSION_LOGOUT;
	conn->logout_qtask = qtask;

	switch (conn->state) {
	case ISCSI_CONN_STATE_LOGGED_IN:
		if (!session_unbind(session))
			return ISCSI_SUCCESS;

		/* LLDs that offload login also offload logout */
		if (!(session->t->caps & CAP_LOGIN_OFFLOAD)) {
			/* unbind is not supported so just do old logout */
			if (!iscsi_send_logout(conn))
				return ISCSI_SUCCESS;
		}

		conn_error(conn, "Could not send logout pdu. Dropping session");
		/* fallthrough */
	default:
		rc = session_conn_shutdown(conn, ISCSI_SUCCESS);
		break;
	}

	return rc;
}

int
iscsi_host_send_targets(__attribute__((unused))queue_task_t *qtask,
			int host_no,
			__attribute__((unused))int do_login,
			struct sockaddr_storage *ss)
{
	struct iscsi_transport *t;

	t = iscsi_sysfs_get_transport_by_hba(host_no);
	if (!t) {
		log_error("Invalid host no %d for sendtargets", host_no);
		return ISCSI_ERR_TRANS_NOT_FOUND;
	}
	if (!(t->caps & CAP_SENDTARGETS_OFFLOAD))
		return ISCSI_ERR_TRANS_CAPS;

	if (ipc->sendtargets(t->handle, host_no, (struct sockaddr *)ss))
		return ISCSI_ERR;

	return ISCSI_SUCCESS;
}

/*
 * HW drivers like qla4xxx present an interface that hides most of the iscsi
 * details. Userspace sends down a discovery event then it gets notified
 * if the sessions that were logged in as a result asynchronously, or
 * the card will have sessions preset in the FLASH and will log into them
 * automaotically then send us notification that a session is setup.
 */
static void iscsi_async_session_creation(uint32_t host_no, uint32_t sid)
{
	struct iscsi_transport *transport;

	transport = iscsi_sysfs_get_transport_by_hba(host_no);
	if (!transport)
		return;

	if (!(transport->caps & CAP_FW_DB))
		return;

	log_debug(3, "session created sid %u host no %d", sid, host_no);
	session_online_devs(host_no, sid);
	session_scan_host(NULL, host_no, NULL);
}

static void iscsi_async_session_destruction(uint32_t host_no, uint32_t sid)
{
	log_debug(3, "session destroyed sid %u host no %d", sid, host_no);
}

static struct iscsi_ipc_ev_clbk ipc_clbk = {
	.create_session		= iscsi_async_session_creation,
	.destroy_session	= iscsi_async_session_destruction,
	.get_ev_context		= iscsi_ev_context_get,
	.put_ev_context		= iscsi_ev_context_put,
	.sched_ev_context	= iscsi_sched_ev_context,
};

void iscsi_initiator_init(void)
{
	ipc_register_ev_callback(&ipc_clbk);
}