[PATCH net-next 6/8] net/smc: do not allow eyecatchers in rmbe

[Ursula Braun <ubraun@linux.vnet.ibm.com>]

From: Karsten Graul <kgraul@linux.vnet.ibm.com>

SMC does not support eyecatchers in RMB elements,
decline peers requesting this support.

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 net/smc/af_smc.c   | 11 +++++++++--
 net/smc/smc_clc.h  |  1 +
 net/smc/smc_core.h |  2 ++
 net/smc/smc_llc.c  | 16 +++++++++++++++-
 4 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index cda3d5314e3f..0d491f505608 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -291,6 +291,9 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)
 		return rc;
 	}
 
+	if (link->llc_confirm_rc)
+		return SMC_CLC_DECL_RMBE_EC;
+
 	rc = smc_ib_modify_qp_rts(link);
 	if (rc)
 		return SMC_CLC_DECL_INTERR;
@@ -310,7 +313,7 @@ static int smc_clnt_conf_first_link(struct smc_sock *smc)
 	if (rc < 0)
 		return SMC_CLC_DECL_TCL;
 
-	return rc;
+	return 0;
 }
 
 static void smc_conn_save_peer_info(struct smc_sock *smc,
@@ -705,9 +708,13 @@ static int smc_serv_conf_first_link(struct smc_sock *smc)
 
 		rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
 				      SMC_CLC_DECLINE);
+		return rc;
 	}
 
-	return rc;
+	if (link->llc_confirm_resp_rc)
+		return SMC_CLC_DECL_RMBE_EC;
+
+	return 0;
 }
 
 /* setup for RDMA connection of server */
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index a20fc75efb24..20e048beac30 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -33,6 +33,7 @@
 #define SMC_CLC_DECL_INTERR	0x99990000  /* internal error                 */
 #define SMC_CLC_DECL_TCL	0x02040000  /* timeout w4 QP confirm          */
 #define SMC_CLC_DECL_SEND	0x07000000  /* sending problem                */
+#define SMC_CLC_DECL_RMBE_EC	0x08000000  /* peer has eyecatcher in RMBE    */
 
 struct smc_clc_msg_hdr {	/* header1 of clc messages */
 	u8 eyecatcher[4];	/* eye catcher */
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 7be693b940a2..2b65b3d7f1f5 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -89,6 +89,8 @@ struct smc_link {
 	u8			link_id;	/* unique # within link group */
 	struct completion	llc_confirm;	/* wait for rx of conf link */
 	struct completion	llc_confirm_resp; /* wait 4 rx of cnf lnk rsp */
+	int			llc_confirm_rc; /* rc from confirm link msg */
+	int			llc_confirm_resp_rc; /* rc from conf_resp msg */
 };
 
 /* For now we just allow one parallel link per link group. The SMC protocol
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 3e47b94608b5..838a160a3bd9 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -30,6 +30,8 @@ struct smc_llc_hdr {
 	u8 flags;
 };
 
+#define SMC_LLC_FLAG_NO_RMBE_EYEC	0x03
+
 struct smc_llc_msg_confirm_link {	/* type 0x01 */
 	struct smc_llc_hdr hd;
 	u8 sender_mac[ETH_ALEN];
@@ -166,6 +168,7 @@ int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[],
 	memset(confllc, 0, sizeof(*confllc));
 	confllc->hd.common.type = SMC_LLC_CONFIRM_LINK;
 	confllc->hd.length = sizeof(struct smc_llc_msg_confirm_link);
+	confllc->hd.flags |= SMC_LLC_FLAG_NO_RMBE_EYEC;
 	if (reqresp == SMC_LLC_RESP)
 		confllc->hd.flags |= SMC_LLC_FLAG_RESP;
 	memcpy(confllc->sender_mac, mac, ETH_ALEN);
@@ -225,13 +228,24 @@ static void smc_llc_rx_confirm_link(struct smc_link *link,
 				    struct smc_llc_msg_confirm_link *llc)
 {
 	struct smc_link_group *lgr;
+	int conf_rc;
 
 	lgr = container_of(link, struct smc_link_group, lnk[SMC_SINGLE_LINK]);
+
+	/* RMBE eyecatchers are not supported */
+	if (llc->hd.flags & SMC_LLC_FLAG_NO_RMBE_EYEC)
+		conf_rc = 0;
+	else
+		conf_rc = ENOTSUPP;
+
 	if (llc->hd.flags & SMC_LLC_FLAG_RESP) {
-		if (lgr->role == SMC_SERV)
+		if (lgr->role == SMC_SERV) {
+			link->llc_confirm_resp_rc = conf_rc;
 			complete(&link->llc_confirm_resp);
+		}
 	} else {
 		if (lgr->role == SMC_CLNT) {
+			link->llc_confirm_rc = conf_rc;
 			link->link_id = llc->link_num;
 			complete(&link->llc_confirm);
 		}
-- 
2.13.5