diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/target/tcm_fc/tfc_sess.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c new file mode 100644 index 000000000..593540da9 --- /dev/null +++ b/drivers/target/tcm_fc/tfc_sess.c @@ -0,0 +1,503 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2010 Cisco Systems, Inc. + */ + +/* XXX TBD some includes may be extraneous */ + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/utsname.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/kthread.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/configfs.h> +#include <linux/ctype.h> +#include <linux/hash.h> +#include <linux/rcupdate.h> +#include <linux/rculist.h> +#include <linux/kref.h> +#include <asm/unaligned.h> +#include <scsi/libfc.h> + +#include <target/target_core_base.h> +#include <target/target_core_fabric.h> + +#include "tcm_fc.h" + +#define TFC_SESS_DBG(lport, fmt, args...) \ + pr_debug("host%u: rport %6.6x: " fmt, \ + (lport)->host->host_no, \ + (lport)->port_id, ##args ) + +static void ft_sess_delete_all(struct ft_tport *); + +/* + * Lookup or allocate target local port. + * Caller holds ft_lport_lock. + */ +static struct ft_tport *ft_tport_get(struct fc_lport *lport) +{ + struct ft_tpg *tpg; + struct ft_tport *tport; + int i; + + tport = rcu_dereference_protected(lport->prov[FC_TYPE_FCP], + lockdep_is_held(&ft_lport_lock)); + if (tport && tport->tpg) + return tport; + + tpg = ft_lport_find_tpg(lport); + if (!tpg) + return NULL; + + if (tport) { + tport->tpg = tpg; + tpg->tport = tport; + return tport; + } + + tport = kzalloc(sizeof(*tport), GFP_KERNEL); + if (!tport) + return NULL; + + tport->lport = lport; + tport->tpg = tpg; + tpg->tport = tport; + for (i = 0; i < FT_SESS_HASH_SIZE; i++) + INIT_HLIST_HEAD(&tport->hash[i]); + + rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport); + return tport; +} + +/* + * Delete a target local port. + * Caller holds ft_lport_lock. + */ +static void ft_tport_delete(struct ft_tport *tport) +{ + struct fc_lport *lport; + struct ft_tpg *tpg; + + ft_sess_delete_all(tport); + lport = tport->lport; + lport->service_params &= ~FCP_SPPF_TARG_FCN; + BUG_ON(tport != lport->prov[FC_TYPE_FCP]); + RCU_INIT_POINTER(lport->prov[FC_TYPE_FCP], NULL); + + tpg = tport->tpg; + if (tpg) { + tpg->tport = NULL; + tport->tpg = NULL; + } + kfree_rcu(tport, rcu); +} + +/* + * Add local port. + * Called thru fc_lport_iterate(). + */ +void ft_lport_add(struct fc_lport *lport, void *arg) +{ + mutex_lock(&ft_lport_lock); + ft_tport_get(lport); + lport->service_params |= FCP_SPPF_TARG_FCN; + mutex_unlock(&ft_lport_lock); +} + +/* + * Delete local port. + * Called thru fc_lport_iterate(). + */ +void ft_lport_del(struct fc_lport *lport, void *arg) +{ + struct ft_tport *tport; + + mutex_lock(&ft_lport_lock); + tport = lport->prov[FC_TYPE_FCP]; + if (tport) + ft_tport_delete(tport); + mutex_unlock(&ft_lport_lock); +} + +/* + * Notification of local port change from libfc. + * Create or delete local port and associated tport. + */ +int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg) +{ + struct fc_lport *lport = arg; + + switch (event) { + case FC_LPORT_EV_ADD: + ft_lport_add(lport, NULL); + break; + case FC_LPORT_EV_DEL: + ft_lport_del(lport, NULL); + break; + } + return NOTIFY_DONE; +} + +/* + * Hash function for FC_IDs. + */ +static u32 ft_sess_hash(u32 port_id) +{ + return hash_32(port_id, FT_SESS_HASH_BITS); +} + +/* + * Find session in local port. + * Sessions and hash lists are RCU-protected. + * A reference is taken which must be eventually freed. + */ +static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id) +{ + struct ft_tport *tport; + struct hlist_head *head; + struct ft_sess *sess; + char *reason = "no session created"; + + rcu_read_lock(); + tport = rcu_dereference(lport->prov[FC_TYPE_FCP]); + if (!tport) { + reason = "not an FCP port"; + goto out; + } + + head = &tport->hash[ft_sess_hash(port_id)]; + hlist_for_each_entry_rcu(sess, head, hash) { + if (sess->port_id == port_id) { + kref_get(&sess->kref); + rcu_read_unlock(); + TFC_SESS_DBG(lport, "port_id %x found %p\n", + port_id, sess); + return sess; + } + } +out: + rcu_read_unlock(); + TFC_SESS_DBG(lport, "port_id %x not found, %s\n", + port_id, reason); + return NULL; +} + +static int ft_sess_alloc_cb(struct se_portal_group *se_tpg, + struct se_session *se_sess, void *p) +{ + struct ft_sess *sess = p; + struct ft_tport *tport = sess->tport; + struct hlist_head *head = &tport->hash[ft_sess_hash(sess->port_id)]; + + TFC_SESS_DBG(tport->lport, "port_id %x sess %p\n", sess->port_id, sess); + hlist_add_head_rcu(&sess->hash, head); + tport->sess_count++; + + return 0; +} + +/* + * Allocate session and enter it in the hash for the local port. + * Caller holds ft_lport_lock. + */ +static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id, + struct fc_rport_priv *rdata) +{ + struct se_portal_group *se_tpg = &tport->tpg->se_tpg; + struct ft_sess *sess; + struct hlist_head *head; + unsigned char initiatorname[TRANSPORT_IQN_LEN]; + + ft_format_wwn(&initiatorname[0], TRANSPORT_IQN_LEN, rdata->ids.port_name); + + head = &tport->hash[ft_sess_hash(port_id)]; + hlist_for_each_entry_rcu(sess, head, hash) + if (sess->port_id == port_id) + return sess; + + sess = kzalloc(sizeof(*sess), GFP_KERNEL); + if (!sess) + return ERR_PTR(-ENOMEM); + + kref_init(&sess->kref); /* ref for table entry */ + sess->tport = tport; + sess->port_id = port_id; + + sess->se_sess = target_setup_session(se_tpg, TCM_FC_DEFAULT_TAGS, + sizeof(struct ft_cmd), + TARGET_PROT_NORMAL, &initiatorname[0], + sess, ft_sess_alloc_cb); + if (IS_ERR(sess->se_sess)) { + int rc = PTR_ERR(sess->se_sess); + kfree(sess); + sess = ERR_PTR(rc); + } + return sess; +} + +/* + * Unhash the session. + * Caller holds ft_lport_lock. + */ +static void ft_sess_unhash(struct ft_sess *sess) +{ + struct ft_tport *tport = sess->tport; + + hlist_del_rcu(&sess->hash); + BUG_ON(!tport->sess_count); + tport->sess_count--; + sess->port_id = -1; + sess->params = 0; +} + +/* + * Delete session from hash. + * Caller holds ft_lport_lock. + */ +static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id) +{ + struct hlist_head *head; + struct ft_sess *sess; + + head = &tport->hash[ft_sess_hash(port_id)]; + hlist_for_each_entry_rcu(sess, head, hash) { + if (sess->port_id == port_id) { + ft_sess_unhash(sess); + return sess; + } + } + return NULL; +} + +static void ft_close_sess(struct ft_sess *sess) +{ + target_stop_session(sess->se_sess); + target_wait_for_sess_cmds(sess->se_sess); + ft_sess_put(sess); +} + +/* + * Delete all sessions from tport. + * Caller holds ft_lport_lock. + */ +static void ft_sess_delete_all(struct ft_tport *tport) +{ + struct hlist_head *head; + struct ft_sess *sess; + + for (head = tport->hash; + head < &tport->hash[FT_SESS_HASH_SIZE]; head++) { + hlist_for_each_entry_rcu(sess, head, hash) { + ft_sess_unhash(sess); + ft_close_sess(sess); /* release from table */ + } + } +} + +/* + * TCM ops for sessions. + */ + +/* + * Remove session and send PRLO. + * This is called when the ACL is being deleted or queue depth is changing. + */ +void ft_sess_close(struct se_session *se_sess) +{ + struct ft_sess *sess = se_sess->fabric_sess_ptr; + u32 port_id; + + mutex_lock(&ft_lport_lock); + port_id = sess->port_id; + if (port_id == -1) { + mutex_unlock(&ft_lport_lock); + return; + } + TFC_SESS_DBG(sess->tport->lport, "port_id %x close session\n", port_id); + ft_sess_unhash(sess); + mutex_unlock(&ft_lport_lock); + ft_close_sess(sess); + /* XXX Send LOGO or PRLO */ + synchronize_rcu(); /* let transport deregister happen */ +} + +u32 ft_sess_get_index(struct se_session *se_sess) +{ + struct ft_sess *sess = se_sess->fabric_sess_ptr; + + return sess->port_id; /* XXX TBD probably not what is needed */ +} + +u32 ft_sess_get_port_name(struct se_session *se_sess, + unsigned char *buf, u32 len) +{ + struct ft_sess *sess = se_sess->fabric_sess_ptr; + + return ft_format_wwn(buf, len, sess->port_name); +} + +/* + * libfc ops involving sessions. + */ + +static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len, + const struct fc_els_spp *rspp, struct fc_els_spp *spp) +{ + struct ft_tport *tport; + struct ft_sess *sess; + u32 fcp_parm; + + tport = ft_tport_get(rdata->local_port); + if (!tport) + goto not_target; /* not a target for this local port */ + + if (!rspp) + goto fill; + + if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL)) + return FC_SPP_RESP_NO_PA; + + /* + * If both target and initiator bits are off, the SPP is invalid. + */ + fcp_parm = ntohl(rspp->spp_params); + if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN))) + return FC_SPP_RESP_INVL; + + /* + * Create session (image pair) only if requested by + * EST_IMG_PAIR flag and if the requestor is an initiator. + */ + if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) { + spp->spp_flags |= FC_SPP_EST_IMG_PAIR; + if (!(fcp_parm & FCP_SPPF_INIT_FCN)) + return FC_SPP_RESP_CONF; + sess = ft_sess_create(tport, rdata->ids.port_id, rdata); + if (IS_ERR(sess)) { + if (PTR_ERR(sess) == -EACCES) { + spp->spp_flags &= ~FC_SPP_EST_IMG_PAIR; + return FC_SPP_RESP_CONF; + } else + return FC_SPP_RESP_RES; + } + if (!sess->params) + rdata->prli_count++; + sess->params = fcp_parm; + sess->port_name = rdata->ids.port_name; + sess->max_frame = rdata->maxframe_size; + + /* XXX TBD - clearing actions. unit attn, see 4.10 */ + } + + /* + * OR in our service parameters with other provider (initiator), if any. + */ +fill: + fcp_parm = ntohl(spp->spp_params); + fcp_parm &= ~FCP_SPPF_RETRY; + spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN); + return FC_SPP_RESP_ACK; + +not_target: + fcp_parm = ntohl(spp->spp_params); + fcp_parm &= ~FCP_SPPF_TARG_FCN; + spp->spp_params = htonl(fcp_parm); + return 0; +} + +/** + * ft_prli() - Handle incoming or outgoing PRLI for the FCP target + * @rdata: remote port private + * @spp_len: service parameter page length + * @rspp: received service parameter page (NULL for outgoing PRLI) + * @spp: response service parameter page + * + * Returns spp response code. + */ +static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len, + const struct fc_els_spp *rspp, struct fc_els_spp *spp) +{ + int ret; + + mutex_lock(&ft_lport_lock); + ret = ft_prli_locked(rdata, spp_len, rspp, spp); + mutex_unlock(&ft_lport_lock); + TFC_SESS_DBG(rdata->local_port, "port_id %x flags %x ret %x\n", + rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret); + return ret; +} + +static void ft_sess_free(struct kref *kref) +{ + struct ft_sess *sess = container_of(kref, struct ft_sess, kref); + + target_remove_session(sess->se_sess); + kfree_rcu(sess, rcu); +} + +void ft_sess_put(struct ft_sess *sess) +{ + int sess_held = kref_read(&sess->kref); + + BUG_ON(!sess_held); + kref_put(&sess->kref, ft_sess_free); +} + +static void ft_prlo(struct fc_rport_priv *rdata) +{ + struct ft_sess *sess; + struct ft_tport *tport; + + mutex_lock(&ft_lport_lock); + tport = rcu_dereference_protected(rdata->local_port->prov[FC_TYPE_FCP], + lockdep_is_held(&ft_lport_lock)); + + if (!tport) { + mutex_unlock(&ft_lport_lock); + return; + } + sess = ft_sess_delete(tport, rdata->ids.port_id); + if (!sess) { + mutex_unlock(&ft_lport_lock); + return; + } + mutex_unlock(&ft_lport_lock); + ft_close_sess(sess); /* release from table */ + rdata->prli_count--; + /* XXX TBD - clearing actions. unit attn, see 4.10 */ +} + +/* + * Handle incoming FCP request. + * Caller has verified that the frame is type FCP. + */ +static void ft_recv(struct fc_lport *lport, struct fc_frame *fp) +{ + struct ft_sess *sess; + u32 sid = fc_frame_sid(fp); + + TFC_SESS_DBG(lport, "recv sid %x\n", sid); + + sess = ft_sess_get(lport, sid); + if (!sess) { + TFC_SESS_DBG(lport, "sid %x sess lookup failed\n", sid); + /* TBD XXX - if FCP_CMND, send PRLO */ + fc_frame_free(fp); + return; + } + ft_recv_req(sess, fp); /* must do ft_sess_put() */ +} + +/* + * Provider ops for libfc. + */ +struct fc4_prov ft_prov = { + .prli = ft_prli, + .prlo = ft_prlo, + .recv = ft_recv, + .module = THIS_MODULE, +}; |