[RFC PATCH v2 net-next 1/6] net/smc: support smc release version negotiation in clc handshake

[Guangguan Wang]

Support smc release version negotiation in clc handshake. And set
the latest smc release version to 2.1.

Signed-off-by: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx>
---
 net/smc/af_smc.c   | 22 ++++++++++++++++++++--
 net/smc/smc.h      |  5 ++++-
 net/smc/smc_clc.c  | 14 +++++++-------
 net/smc/smc_clc.h  | 23 ++++++++++++++++++++++-
 net/smc/smc_core.h |  1 +
 5 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index a7f887d91d89..bac73eb0542d 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1187,6 +1187,11 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
 			return SMC_CLC_DECL_NOINDIRECT;
 		}
 	}
+
+	if (fce->release > SMC_RELEASE)
+		return SMC_CLC_DECL_VERSMISMAT;
+	ini->release_ver = fce->release;
+
 	return 0;
 }
 
@@ -1355,6 +1360,15 @@ static int smc_connect_ism(struct smc_sock *smc,
 		struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
 			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
 
+		if (ini->first_contact_peer) {
+			struct smc_clc_first_contact_ext *fce =
+				smc_get_clc_first_contact_ext(aclc_v2, true);
+
+			if (fce->release > SMC_RELEASE)
+				return SMC_CLC_DECL_VERSMISMAT;
+			ini->release_ver = fce->release;
+		}
+
 		rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
 		if (rc)
 			return rc;
@@ -1389,7 +1403,7 @@ static int smc_connect_ism(struct smc_sock *smc,
 	}
 
 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
-				  aclc->hdr.version, eid, NULL);
+				  aclc->hdr.version, eid, ini);
 	if (rc)
 		goto connect_abort;
 	mutex_unlock(&smc_server_lgr_pending);
@@ -1965,6 +1979,10 @@ static int smc_listen_v2_check(struct smc_sock *new_smc,
 		}
 	}
 
+	ini->release_ver = pclc_v2_ext->hdr.flag.release;
+	if (pclc_v2_ext->hdr.flag.release > SMC_RELEASE)
+		ini->release_ver = SMC_RELEASE;
+
 out:
 	if (!ini->smcd_version && !ini->smcr_version)
 		return rc;
@@ -2412,7 +2430,7 @@ static void smc_listen_work(struct work_struct *work)
 	/* send SMC Accept CLC message */
 	accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
-				 accept_version, ini->negotiated_eid);
+				 accept_version, ini->negotiated_eid, ini);
 	if (rc)
 		goto out_unlock;
 
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 2eeea4cdc718..9cce1a41e011 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -21,7 +21,10 @@
 
 #define SMC_V1		1		/* SMC version V1 */
 #define SMC_V2		2		/* SMC version V2 */
-#define SMC_RELEASE	0
+
+#define SMC_RELEASE_0 0
+#define SMC_RELEASE_1 1
+#define SMC_RELEASE	SMC_RELEASE_1 /* the latest release version */
 
 #define SMCPROTO_SMC		0	/* SMC protocol, IPv4 */
 #define SMCPROTO_SMC6		1	/* SMC protocol, IPv6 */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index b9b8b07aa702..4ae27bf65732 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -420,11 +420,11 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc)
 	return true;
 }
 
-static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len)
+static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len, int release_ver)
 {
 	memset(fce, 0, sizeof(*fce));
 	fce->os_type = SMC_CLC_OS_LINUX;
-	fce->release = SMC_RELEASE;
+	fce->release = release_ver;
 	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
 	(*len) += sizeof(*fce);
 }
@@ -1019,7 +1019,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2;
 			if (first_contact)
-				smc_clc_fill_fce(&fce, &len);
+				smc_clc_fill_fce(&fce, &len, ini->release_ver);
 			clc_v2->hdr.length = htons(len);
 		}
 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
@@ -1063,10 +1063,10 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN);
 			len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2;
 			if (first_contact) {
-				smc_clc_fill_fce(&fce, &len);
+				smc_clc_fill_fce(&fce, &len, ini->release_ver);
 				fce.v2_direct = !link->lgr->uses_gateway;
 				memset(&gle, 0, sizeof(gle));
-				if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
+				if (clc->hdr.type == SMC_CLC_CONFIRM) {
 					gle.gid_cnt = ini->smcrv2.gidlist.len;
 					len += sizeof(gle);
 					len += gle.gid_cnt * sizeof(gle.gid[0]);
@@ -1141,7 +1141,7 @@ int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
 
 /* send CLC ACCEPT message across internal TCP socket */
 int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
-			u8 version, u8 *negotiated_eid)
+			u8 version, u8 *negotiated_eid, struct smc_init_info *ini)
 {
 	struct smc_clc_msg_accept_confirm_v2 aclc_v2;
 	int len;
@@ -1149,7 +1149,7 @@ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
 	memset(&aclc_v2, 0, sizeof(aclc_v2));
 	aclc_v2.hdr.type = SMC_CLC_ACCEPT;
 	len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,
-					  version, negotiated_eid, NULL);
+					  version, negotiated_eid, ini);
 	if (len < ntohs(aclc_v2.hdr.length))
 		len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;
 
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 5fee545c9a10..b923e89acafb 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -370,6 +370,27 @@ smc_get_clc_smcd_v2_ext(struct smc_clc_v2_extension *prop_v2ext)
 		 ntohs(prop_v2ext->hdr.smcd_v2_ext_offset));
 }
 
+static inline struct smc_clc_first_contact_ext *
+smc_get_clc_first_contact_ext(struct smc_clc_msg_accept_confirm_v2 *clc_v2,
+			      bool is_smcd)
+{
+	int clc_v2_len;
+
+	if (clc_v2->hdr.version == SMC_V1 ||
+	    !(clc_v2->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
+		return NULL;
+
+	if (is_smcd)
+		clc_v2_len =
+			offsetofend(struct smc_clc_msg_accept_confirm_v2, d1);
+	else
+		clc_v2_len =
+			offsetofend(struct smc_clc_msg_accept_confirm_v2, r1);
+
+	return (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) +
+						    clc_v2_len);
+}
+
 struct smcd_dev;
 struct smc_init_info;
 
@@ -382,7 +403,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini);
 int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
 			 u8 version, u8 *eid, struct smc_init_info *ini);
 int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
-			u8 version, u8 *negotiated_eid);
+			u8 version, u8 *negotiated_eid, struct smc_init_info *ini);
 void smc_clc_init(void) __init;
 void smc_clc_exit(void);
 void smc_clc_get_hostname(u8 **host);
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 3c1b31bfa1cf..1a97fef39127 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -374,6 +374,7 @@ struct smc_init_info {
 	u8			is_smcd;
 	u8			smc_type_v1;
 	u8			smc_type_v2;
+	u8			release_ver;
 	u8			first_contact_peer;
 	u8			first_contact_local;
 	unsigned short		vlan_id;
-- 
2.24.3 (Apple Git-128)