net/smc: add vendor unique experimental options area in clc handshake

Add vendor unique experimental options area in clc handshake. In clc
accept and confirm msg, vendor unique experimental options use the
16-Bytes reserved field, which defined in struct smc_clc_fce_gid_ext
in previous version. Because of the struct smc_clc_first_contact_ext
is widely used and limit the scope of modification, this patch moves
the 16-Bytes reserved field out of struct smc_clc_fce_gid_ext, and
followed with the struct smc_clc_first_contact_ext in a new struct
names struct smc_clc_first_contact_ext_v2x.

For SMC-R first connection, in previous version, the struct smc_clc_
first_contact_ext and the 16-Bytes reserved field has already been
included in clc accept and confirm msg. Thus, this patch use struct
smc_clc_first_contact_ext_v2x instead of the struct smc_clc_first_
contact_ext and the 16-Bytes reserved field in SMC-R clc accept and
confirm msg is compatible with previous version.

For SMC-D first connection, in previous version, only the struct smc_
clc_first_contact_ext is included in clc accept and confirm msg, and
the 16-Bytes reserved field is not included. Thus, when the negotiated
smc release version is the version before v2.1, we still use struct
smc_clc_first_contact_ext for compatible consideration. If the negotiated
smc release version is v2.1 or later, use struct smc_clc_first_contact_
ext_v2x instead.
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Reviewed-by: Jan Karcher <jaka@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/smc/af_smc.c

@@ -1144,7 +1144,7 @@ static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
 
 #define SMC_CLC_MAX_ACCEPT_LEN \
 	(sizeof(struct smc_clc_msg_accept_confirm_v2) + \
-	 sizeof(struct smc_clc_first_contact_ext) + \
+	 sizeof(struct smc_clc_first_contact_ext_v2x) + \
 	 sizeof(struct smc_clc_msg_trail))
 
 /* CLC handshake during connect */

net/smc/smc_clc.c

@@ -391,9 +391,7 @@ smc_clc_msg_acc_conf_valid(struct smc_clc_msg_accept_confirm_v2 *clc_v2)
 			return false;
 	} else {
 		if (hdr->typev1 == SMC_TYPE_D &&
-		    ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 &&
-		    (ntohs(hdr->length) != SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 +
-				sizeof(struct smc_clc_first_contact_ext)))
+		    ntohs(hdr->length) < SMCD_CLC_ACCEPT_CONFIRM_LEN_V2)
 			return false;
 		if (hdr->typev1 == SMC_TYPE_R &&
 		    ntohs(hdr->length) < SMCR_CLC_ACCEPT_CONFIRM_LEN_V2)
@@ -420,13 +418,19 @@ 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, int release_nr)
+static int smc_clc_fill_fce(struct smc_clc_first_contact_ext_v2x *fce,
+			    struct smc_init_info *ini)
 {
+	int ret = sizeof(*fce);
+
 	memset(fce, 0, sizeof(*fce));
-	fce->os_type = SMC_CLC_OS_LINUX;
-	fce->release = release_nr;
-	memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname));
-	(*len) += sizeof(*fce);
+	fce->fce_v2_base.os_type = SMC_CLC_OS_LINUX;
+	fce->fce_v2_base.release = ini->release_nr;
+	memcpy(fce->fce_v2_base.hostname, smc_hostname, sizeof(smc_hostname));
+	if (ini->is_smcd && ini->release_nr < SMC_RELEASE_1)
+		ret = sizeof(struct smc_clc_first_contact_ext);
+
+	return ret;
 }
 
 /* check if received message has a correct header length and contains valid
@@ -986,13 +990,13 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				       u8 *eid, struct smc_init_info *ini)
 {
 	struct smc_connection *conn = &smc->conn;
+	struct smc_clc_first_contact_ext_v2x fce;
 	struct smc_clc_msg_accept_confirm *clc;
-	struct smc_clc_first_contact_ext fce;
 	struct smc_clc_fce_gid_ext gle;
 	struct smc_clc_msg_trail trl;
+	int i, len, fce_len;
 	struct kvec vec[5];
 	struct msghdr msg;
-	int i, len;
 
 	/* send SMC Confirm CLC msg */
 	clc = (struct smc_clc_msg_accept_confirm *)clc_v2;
@@ -1018,8 +1022,10 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 			if (eid && eid[0])
 				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, ini->release_nr);
+			if (first_contact) {
+				fce_len = smc_clc_fill_fce(&fce, ini);
+				len += fce_len;
+			}
 			clc_v2->hdr.length = htons(len);
 		}
 		memcpy(trl.eyecatcher, SMCD_EYECATCHER,
@@ -1063,15 +1069,14 @@ 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, ini->release_nr);
-				fce.v2_direct = !link->lgr->uses_gateway;
-				memset(&gle, 0, sizeof(gle));
+				fce_len = smc_clc_fill_fce(&fce, ini);
+				len += fce_len;
+				fce.fce_v2_base.v2_direct = !link->lgr->uses_gateway;
 				if (clc->hdr.type == SMC_CLC_CONFIRM) {
+					memset(&gle, 0, sizeof(gle));
 					gle.gid_cnt = ini->smcrv2.gidlist.len;
 					len += sizeof(gle);
 					len += gle.gid_cnt * sizeof(gle.gid[0]);
-				} else {
-					len += sizeof(gle.reserved);
 				}
 			}
 			clc_v2->hdr.length = htons(len);
@@ -1094,7 +1099,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				   sizeof(trl);
 	if (version > SMC_V1 && first_contact) {
 		vec[i].iov_base = &fce;
-		vec[i++].iov_len = sizeof(fce);
+		vec[i++].iov_len = fce_len;
 		if (!conn->lgr->is_smcd) {
 			if (clc->hdr.type == SMC_CLC_CONFIRM) {
 				vec[i].iov_base = &gle;
@@ -1102,9 +1107,6 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc,
 				vec[i].iov_base = &ini->smcrv2.gidlist.list;
 				vec[i++].iov_len = gle.gid_cnt *
 						   sizeof(gle.gid[0]);
-			} else {
-				vec[i].iov_base = &gle.reserved;
-				vec[i++].iov_len = sizeof(gle.reserved);
 			}
 		}
 	}

net/smc/smc_clc.h

@@ -147,7 +147,9 @@ struct smc_clc_msg_proposal_prefix {	/* prefix part of clc proposal message*/
 struct smc_clc_msg_smcd {	/* SMC-D GID information */
 	struct smc_clc_smcd_gid_chid ism; /* ISM native GID+CHID of requestor */
 	__be16 v2_ext_offset;	/* SMC Version 2 Extension Offset */
-	u8 reserved[28];
+	u8 vendor_oui[3];	/* vendor organizationally unique identifier */
+	u8 vendor_exp_options[5];
+	u8 reserved[20];
 };
 
 struct smc_clc_smcd_v2_extension {
@@ -231,8 +233,17 @@ struct smc_clc_first_contact_ext {
 	u8 hostname[SMC_MAX_HOSTNAME_LEN];
 };
 
+struct smc_clc_first_contact_ext_v2x {
+	struct smc_clc_first_contact_ext fce_v2_base;
+	u8 reserved3[4];
+	__be32 vendor_exp_options;
+	u8 reserved4[8];
+} __packed;		/* format defined in
+			 * IBM Shared Memory Communications Version 2 (Third Edition)
+			 * (https://www.ibm.com/support/pages/node/7009315)
+			 */
+
 struct smc_clc_fce_gid_ext {
-	u8 reserved[16];
 	u8 gid_cnt;
 	u8 reserved2[3];
 	u8 gid[][SMC_GID_SIZE];