net/smc: add support for user defined EIDs

SMC-Dv2 allows users to define EIDs which allows to create separate
name spaces enabling users to cluster their SMC-Dv2 connections.
Add support for user defined EIDs and extent the generic netlink
interface so users can add, remove and dump EIDs.
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Guvenc Gulce  <guvenc@linux.ibm.com>
Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/smc.h

@@ -38,6 +38,9 @@ enum {				/* SMC PNET Table commands */
 #define SMC_GENL_FAMILY_VERSION		1
 
 #define SMC_PCI_ID_STR_LEN		16 /* Max length of pci id string */
+#define SMC_MAX_HOSTNAME_LEN		32 /* Max length of the hostname */
+#define SMC_MAX_UEID			4  /* Max number of user EIDs */
+#define SMC_MAX_EID_LEN			32 /* Max length of an EID */
 
 /* SMC_GENL_FAMILY commands */
 enum {
@@ -49,6 +52,10 @@ enum {
 	SMC_NETLINK_GET_DEV_SMCR,
 	SMC_NETLINK_GET_STATS,
 	SMC_NETLINK_GET_FBACK_STATS,
+	SMC_NETLINK_DUMP_UEID,
+	SMC_NETLINK_ADD_UEID,
+	SMC_NETLINK_REMOVE_UEID,
+	SMC_NETLINK_FLUSH_UEID,
 };
 
 /* SMC_GENL_FAMILY top level attributes */
@@ -242,4 +249,12 @@ enum {
 	__SMC_NLA_FBACK_STATS_MAX,
 	SMC_NLA_FBACK_STATS_MAX = __SMC_NLA_FBACK_STATS_MAX - 1
 };
+
+/* SMC_NETLINK_UEID attributes */
+enum {
+	SMC_NLA_EID_TABLE_UNSPEC,
+	SMC_NLA_EID_TABLE_ENTRY,	/* string */
+	__SMC_NLA_EID_TABLE_MAX,
+	SMC_NLA_EID_TABLE_MAX = __SMC_NLA_EID_TABLE_MAX - 1
+};
 #endif /* _UAPI_LINUX_SMC_H */

net/smc/af_smc.c

@@ -829,7 +829,7 @@ static int smc_connect_rdma(struct smc_sock *smc,
 	smc_rmb_sync_sg_for_device(&smc->conn);
 
 	reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
-					   SMC_V1);
+					   SMC_V1, NULL);
 	if (reason_code)
 		goto connect_abort;
 
@@ -883,6 +883,7 @@ static int smc_connect_ism(struct smc_sock *smc,
 			   struct smc_clc_msg_accept_confirm *aclc,
 			   struct smc_init_info *ini)
 {
+	u8 *eid = NULL;
 	int rc = 0;
 
 	ini->is_smcd = true;
@@ -918,8 +919,15 @@ static int smc_connect_ism(struct smc_sock *smc,
 	smc_rx_init(smc);
 	smc_tx_init(smc);
 
+	if (aclc->hdr.version > SMC_V1) {
+		struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
+			(struct smc_clc_msg_accept_confirm_v2 *)aclc;
+
+		eid = clc_v2->eid;
+	}
+
 	rc = smc_clc_send_confirm(smc, ini->first_contact_local,
-				  aclc->hdr.version);
+				  aclc->hdr.version, eid);
 	if (rc)
 		goto connect_abort;
 	mutex_unlock(&smc_server_lgr_pending);
@@ -1533,9 +1541,8 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
 	pclc_smcd = smc_get_clc_msg_smcd(pclc);
 	smc_v2_ext = smc_get_clc_v2_ext(pclc);
 	smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
-	if (!smcd_v2_ext ||
-	    !smc_v2_ext->hdr.flag.seid) { /* no system EID support for SMCD */
-		smc_find_ism_store_rc(SMC_CLC_DECL_NOSEID, ini);
+	if (!smcd_v2_ext) {
+		smc_find_ism_store_rc(SMC_CLC_DECL_NOV2DEXT, ini);
 		goto not_found;
 	}
 
@@ -1555,13 +1562,13 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
 	}
 	mutex_unlock(&smcd_dev_list.mutex);
 
-	if (ini->ism_dev[0]) {
-		smc_ism_get_system_eid(ini->ism_dev[0], &eid);
-		if (memcmp(eid, smcd_v2_ext->system_eid, SMC_MAX_EID_LEN))
-			goto not_found;
-	} else {
+	if (!ini->ism_dev[0])
+		goto not_found;
+
+	smc_ism_get_system_eid(ini->ism_dev[0], &eid);
+	if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
+			       smcd_v2_ext->system_eid, eid))
 		goto not_found;
-	}
 
 	/* separate - outside the smcd_dev_list.lock */
 	smcd_version = ini->smcd_version;
@@ -1579,6 +1586,7 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
 	}
 	/* no V2 ISM device could be initialized */
 	ini->smcd_version = smcd_version;	/* restore original value */
+	ini->negotiated_eid[0] = 0;
 
 not_found:
 	ini->smcd_version &= ~SMC_V2;
@@ -1788,7 +1796,8 @@ static void smc_listen_work(struct work_struct *work)
 
 	/* send SMC Accept CLC message */
 	rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
-				 ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1);
+				 ini->smcd_version == SMC_V2 ? SMC_V2 : SMC_V1,
+				 ini->negotiated_eid);
 	if (rc)
 		goto out_unlock;
 
@@ -2662,6 +2671,7 @@ static void __exit smc_exit(void)
 	proto_unregister(&smc_proto);
 	smc_pnet_exit();
 	smc_nl_exit();
+	smc_clc_exit();
 	unregister_pernet_subsys(&smc_net_stat_ops);
 	unregister_pernet_subsys(&smc_net_ops);
 	rcu_barrier();

net/smc/smc.h

@@ -29,9 +29,6 @@
 					 * devices
 					 */
 
-#define SMC_MAX_HOSTNAME_LEN	32
-#define SMC_MAX_EID_LEN		32
-
 extern struct proto smc_proto;
 extern struct proto smc_proto6;
 

net/smc/smc_clc.h

@@ -14,8 +14,10 @@
 #define _SMC_CLC_H
 
 #include <rdma/ib_verbs.h>
+#include <linux/smc.h>
 
 #include "smc.h"
+#include "smc_netlink.h"
 
 #define SMC_CLC_PROPOSAL	0x01
 #define SMC_CLC_ACCEPT		0x02
@@ -158,6 +160,7 @@ struct smc_clc_msg_proposal {	/* clc proposal message sent by Linux */
 } __aligned(4);
 
 #define SMC_CLC_MAX_V6_PREFIX		8
+#define SMC_CLC_MAX_UEID		8
 
 struct smc_clc_msg_proposal_area {
 	struct smc_clc_msg_proposal		pclc_base;
@@ -165,6 +168,7 @@ struct smc_clc_msg_proposal_area {
 	struct smc_clc_msg_proposal_prefix	pclc_prfx;
 	struct smc_clc_ipv6_prefix	pclc_prfx_ipv6[SMC_CLC_MAX_V6_PREFIX];
 	struct smc_clc_v2_extension		pclc_v2_ext;
+	u8			user_eids[SMC_CLC_MAX_UEID][SMC_MAX_EID_LEN];
 	struct smc_clc_smcd_v2_extension	pclc_smcd_v2_ext;
 	struct smc_clc_smcd_gid_chid		pclc_gidchids[SMC_MAX_ISM_DEVS];
 	struct smc_clc_msg_trail		pclc_trl;
@@ -330,10 +334,18 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
 int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version);
 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 version, u8 *eid);
 int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
-			u8 version);
+			u8 version, u8 *negotiated_eid);
 void smc_clc_init(void) __init;
+void smc_clc_exit(void);
 void smc_clc_get_hostname(u8 **host);
+bool smc_clc_match_eid(u8 *negotiated_eid,
+		       struct smc_clc_v2_extension *smc_v2_ext,
+		       u8 *peer_eid, u8 *local_eid);
+int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb);
+int smc_nl_add_ueid(struct sk_buff *skb, struct genl_info *info);
+int smc_nl_remove_ueid(struct sk_buff *skb, struct genl_info *info);
+int smc_nl_flush_ueid(struct sk_buff *skb, struct genl_info *info);
 
 #endif

net/smc/smc_core.h

@@ -310,6 +310,7 @@ struct smc_init_info {
 	u8			first_contact_local;
 	unsigned short		vlan_id;
 	u32			rc;
+	u8			negotiated_eid[SMC_MAX_EID_LEN];
 	/* SMC-R */
 	struct smc_clc_msg_local *ib_lcl;
 	struct smc_ib_device	*ib_dev;

net/smc/smc_netlink.c

@@ -19,11 +19,19 @@
 #include "smc_core.h"
 #include "smc_ism.h"
 #include "smc_ib.h"
+#include "smc_clc.h"
 #include "smc_stats.h"
 #include "smc_netlink.h"
 
-#define SMC_CMD_MAX_ATTR 1
+const struct nla_policy
+smc_gen_ueid_policy[SMC_NLA_EID_TABLE_MAX + 1] = {
+	[SMC_NLA_EID_TABLE_UNSPEC]	= { .type = NLA_UNSPEC },
+	[SMC_NLA_EID_TABLE_ENTRY]	= { .type = NLA_STRING,
+					    .len = SMC_MAX_EID_LEN,
+					  },
+};
 
+#define SMC_CMD_MAX_ATTR 1
 /* SMC_GENL generic netlink operation definition */
 static const struct genl_ops smc_gen_nl_ops[] = {
 	{
@@ -66,6 +74,28 @@ static const struct genl_ops smc_gen_nl_ops[] = {
 		/* can be retrieved by unprivileged users */
 		.dumpit = smc_nl_get_fback_stats,
 	},
+	{
+		.cmd = SMC_NETLINK_DUMP_UEID,
+		/* can be retrieved by unprivileged users */
+		.dumpit = smc_nl_dump_ueid,
+	},
+	{
+		.cmd = SMC_NETLINK_ADD_UEID,
+		.flags = GENL_ADMIN_PERM,
+		.doit = smc_nl_add_ueid,
+		.policy = smc_gen_ueid_policy,
+	},
+	{
+		.cmd = SMC_NETLINK_REMOVE_UEID,
+		.flags = GENL_ADMIN_PERM,
+		.doit = smc_nl_remove_ueid,
+		.policy = smc_gen_ueid_policy,
+	},
+	{
+		.cmd = SMC_NETLINK_FLUSH_UEID,
+		.flags = GENL_ADMIN_PERM,
+		.doit = smc_nl_flush_ueid,
+	},
 };
 
 static const struct nla_policy smc_gen_nl_policy[2] = {

net/smc/smc_netlink.h

@@ -17,6 +17,8 @@
 
 extern struct genl_family smc_gen_nl_family;
 
+extern const struct nla_policy smc_gen_ueid_policy[];
+
 struct smc_nl_dmp_ctx {
 	int pos[3];
 };