From: Karsten Graul <kgraul@linux.ibm.com>
Date: Mon, 4 May 2020 14:18:45 +0200
Subject: net/smc: add termination reason and handle LLC protocol violation
Git-commit: 3e0c40afce4ea5b08bb7e3f65c55157817116640
Patch-mainline: v5.8-rc1
References: jsc#SLE-13763

Allow to set the reason code for the link group termination, and set
meaningful values before termination processing is triggered. This
reason code is sent to the peer in the final delete link message.
When the LLC request or response layer receives a message type that was
not handled, drop a warning and terminate the link group.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/smc_core.c |    8 ++++++--
 net/smc/smc_core.h |    2 ++
 net/smc/smc_llc.c  |   14 ++++++++++++++
 net/smc/smc_llc.h  |    8 ++++++++
 4 files changed, 30 insertions(+), 2 deletions(-)

--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -878,8 +878,11 @@ static void smc_lgr_cleanup(struct smc_l
 		smc_ism_put_vlan(lgr->smcd, lgr->vlan_id);
 		put_device(&lgr->smcd->dev);
 	} else {
-		smc_llc_send_link_delete_all(lgr, false,
-					     SMC_LLC_DEL_OP_INIT_TERM);
+		u32 rsn = lgr->llc_termination_rsn;
+
+		if (!rsn)
+			rsn = SMC_LLC_DEL_PROG_INIT_TERM;
+		smc_llc_send_link_delete_all(lgr, false, rsn);
 		for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
 			struct smc_link *lnk = &lgr->lnk[i];
 
@@ -1018,6 +1021,7 @@ void smc_smcr_terminate_all(struct smc_i
 
 	list_for_each_entry_safe(lgr, lg, &lgr_free_list, list) {
 		list_del_init(&lgr->list);
+		smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_OP_INIT_TERM);
 		__smc_lgr_terminate(lgr, false);
 	}
 
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -271,6 +271,8 @@ struct smc_link_group {
 						/* protects llc flow */
 			int			llc_testlink_time;
 						/* link keep alive time */
+			u32			llc_termination_rsn;
+						/* rsn code for termination */
 		};
 		struct { /* SMC-D */
 			u64			peer_gid;
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -1420,6 +1420,14 @@ static void smc_llc_rmt_delete_rkey(stru
 	smc_llc_flow_qentry_del(&lgr->llc_flow_rmt);
 }
 
+static void smc_llc_protocol_violation(struct smc_link_group *lgr, u8 type)
+{
+	pr_warn_ratelimited("smc: SMC-R lg %*phN LLC protocol violation: "
+			    "llc_type %d\n", SMC_LGR_ID_SIZE, &lgr->id, type);
+	smc_llc_set_termination_rsn(lgr, SMC_LLC_DEL_PROT_VIOL);
+	smc_lgr_terminate_sched(lgr);
+}
+
 /* flush the llc event queue */
 static void smc_llc_event_flush(struct smc_link_group *lgr)
 {
@@ -1520,6 +1528,9 @@ static void smc_llc_event_handler(struct
 			smc_llc_flow_stop(lgr, &lgr->llc_flow_rmt);
 		}
 		return;
+	default:
+		smc_llc_protocol_violation(lgr, llc->raw.hdr.common.type);
+		break;
 	}
 out:
 	kfree(qentry);
@@ -1579,6 +1590,9 @@ static void smc_llc_rx_response(struct s
 	case SMC_LLC_CONFIRM_RKEY_CONT:
 		/* not used because max links is 3 */
 		break;
+	default:
+		smc_llc_protocol_violation(link->lgr, llc_type);
+		break;
 	}
 	kfree(qentry);
 }
--- a/net/smc/smc_llc.h
+++ b/net/smc/smc_llc.h
@@ -60,6 +60,14 @@ static inline struct smc_link *smc_llc_u
 	return NULL;
 }
 
+/* set the termination reason code for the link group */
+static inline void smc_llc_set_termination_rsn(struct smc_link_group *lgr,
+					       u32 rsn)
+{
+	if (!lgr->llc_termination_rsn)
+		lgr->llc_termination_rsn = rsn;
+}
+
 /* transmit */
 int smc_llc_send_confirm_link(struct smc_link *lnk,
 			      enum smc_llc_reqresp reqresp);