net/smc: add netlink support for SMC-Rv2

Implement the netlink support for SMC-Rv2 related attributes that are
provided to user space.

Signed-off-by: Karsten Graul <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/smc.h

···
 	SMC_NLA_SYS_IS_ISM_V2,		/* u8 */
 	SMC_NLA_SYS_LOCAL_HOST,		/* string */
 	SMC_NLA_SYS_SEID,		/* string */
+	SMC_NLA_SYS_IS_SMCR_V2,		/* u8 */
 	__SMC_NLA_SYS_MAX,
 	SMC_NLA_SYS_MAX = __SMC_NLA_SYS_MAX - 1
 };
 
-/* SMC_NLA_LGR_V2 nested attributes */
+/* SMC_NLA_LGR_D_V2_COMMON and SMC_NLA_LGR_R_V2_COMMON nested attributes */
 enum {
 	SMC_NLA_LGR_V2_VER,		/* u8 */
 	SMC_NLA_LGR_V2_REL,		/* u8 */
 	SMC_NLA_LGR_V2_OS,		/* u8 */
 	SMC_NLA_LGR_V2_NEG_EID,		/* string */
 	SMC_NLA_LGR_V2_PEER_HOST,	/* string */
+	__SMC_NLA_LGR_V2_MAX,
+	SMC_NLA_LGR_V2_MAX = __SMC_NLA_LGR_V2_MAX - 1
+};
+
+/* SMC_NLA_LGR_R_V2 nested attributes */
+enum {
+	SMC_NLA_LGR_R_V2_UNSPEC,
+	SMC_NLA_LGR_R_V2_DIRECT,	/* u8 */
+	__SMC_NLA_LGR_R_V2_MAX,
+	SMC_NLA_LGR_R_V2_MAX = __SMC_NLA_LGR_R_V2_MAX - 1
 };
 
 /* SMC_GEN_LGR_SMCR attributes */
···
 	SMC_NLA_LGR_R_PNETID,		/* string */
 	SMC_NLA_LGR_R_VLAN_ID,		/* u8 */
 	SMC_NLA_LGR_R_CONNS_NUM,	/* u32 */
+	SMC_NLA_LGR_R_V2_COMMON,	/* nest */
+	SMC_NLA_LGR_R_V2,		/* nest */
 	__SMC_NLA_LGR_R_MAX,
 	SMC_NLA_LGR_R_MAX = __SMC_NLA_LGR_R_MAX - 1
 };
···
 	SMC_NLA_LGR_D_PNETID,		/* string */
 	SMC_NLA_LGR_D_CHID,		/* u16 */
 	SMC_NLA_LGR_D_PAD,		/* flag */
-	SMC_NLA_LGR_V2,			/* nest */
+	SMC_NLA_LGR_D_V2_COMMON,	/* nest */
 	__SMC_NLA_LGR_D_MAX,
 	SMC_NLA_LGR_D_MAX = __SMC_NLA_LGR_D_MAX - 1
 };

net/smc/smc_core.c

···
 		goto errattr;
 	if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
 		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_SYS_IS_SMCR_V2, true))
+		goto errattr;
 	smc_clc_get_hostname(&host);
 	if (host) {
 		memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN);
···
 	return skb->len;
 }
 
+/* Fill SMC_NLA_LGR_D_V2_COMMON/SMC_NLA_LGR_R_V2_COMMON nested attributes */
+static int smc_nl_fill_lgr_v2_common(struct smc_link_group *lgr,
+				     struct sk_buff *skb,
+				     struct netlink_callback *cb,
+				     struct nlattr *v2_attrs)
+{
+	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
+	char smc_eid[SMC_MAX_EID_LEN + 1];
+
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
+		goto errv2attr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
+		goto errv2attr;
+	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
+	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
+		goto errv2attr;
+	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
+	smc_eid[SMC_MAX_EID_LEN] = 0;
+	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
+		goto errv2attr;
+
+	nla_nest_end(skb, v2_attrs);
+	return 0;
+
+errv2attr:
+	nla_nest_cancel(skb, v2_attrs);
+	return -EMSGSIZE;
+}
+
+static int smc_nl_fill_smcr_lgr_v2(struct smc_link_group *lgr,
+				   struct sk_buff *skb,
+				   struct netlink_callback *cb)
+{
+	struct nlattr *v2_attrs;
+
+	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2);
+	if (!v2_attrs)
+		goto errattr;
+	if (nla_put_u8(skb, SMC_NLA_LGR_R_V2_DIRECT, !lgr->uses_gateway))
+		goto errv2attr;
+
+	nla_nest_end(skb, v2_attrs);
+	return 0;
+
+errv2attr:
+	nla_nest_cancel(skb, v2_attrs);
+errattr:
+	return -EMSGSIZE;
+}
+
 static int smc_nl_fill_lgr(struct smc_link_group *lgr,
 			   struct sk_buff *skb,
 			   struct netlink_callback *cb)
 {
 	char smc_target[SMC_MAX_PNETID_LEN + 1];
-	struct nlattr *attrs;
+	struct nlattr *attrs, *v2_attrs;
 
 	attrs = nla_nest_start(skb, SMC_GEN_LGR_SMCR);
 	if (!attrs)
···
 	smc_target[SMC_MAX_PNETID_LEN] = 0;
 	if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
 		goto errattr;
+	if (lgr->smc_version > SMC_V1) {
+		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_R_V2_COMMON);
+		if (!v2_attrs)
+			goto errattr;
+		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
+			goto errattr;
+		if (smc_nl_fill_smcr_lgr_v2(lgr, skb, cb))
+			goto errattr;
+	}
 
 	nla_nest_end(skb, attrs);
 	return 0;
···
 				struct sk_buff *skb,
 				struct netlink_callback *cb)
 {
-	char smc_host[SMC_MAX_HOSTNAME_LEN + 1];
 	char smc_pnet[SMC_MAX_PNETID_LEN + 1];
-	char smc_eid[SMC_MAX_EID_LEN + 1];
-	struct nlattr *v2_attrs;
 	struct nlattr *attrs;
 	void *nlh;
 
···
 	smc_pnet[SMC_MAX_PNETID_LEN] = 0;
 	if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet))
 		goto errattr;
+	if (lgr->smc_version > SMC_V1) {
+		struct nlattr *v2_attrs;
 
-	v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_V2);
-	if (!v2_attrs)
-		goto errattr;
-	if (nla_put_u8(skb, SMC_NLA_LGR_V2_VER, lgr->smc_version))
-		goto errv2attr;
-	if (nla_put_u8(skb, SMC_NLA_LGR_V2_REL, lgr->peer_smc_release))
-		goto errv2attr;
-	if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os))
-		goto errv2attr;
-	memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN);
-	smc_host[SMC_MAX_HOSTNAME_LEN] = 0;
-	if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host))
-		goto errv2attr;
-	memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN);
-	smc_eid[SMC_MAX_EID_LEN] = 0;
-	if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid))
-		goto errv2attr;
-
-	nla_nest_end(skb, v2_attrs);
+		v2_attrs = nla_nest_start(skb, SMC_NLA_LGR_D_V2_COMMON);
+		if (!v2_attrs)
+			goto errattr;
+		if (smc_nl_fill_lgr_v2_common(lgr, skb, cb, v2_attrs))
+			goto errattr;
+	}
 	nla_nest_end(skb, attrs);
 	genlmsg_end(skb, nlh);
 	return 0;
 
-errv2attr:
-	nla_nest_cancel(skb, v2_attrs);
 errattr:
 	nla_nest_cancel(skb, attrs);
 errout: