net/smc: add generic netlink support for system EID

With SMC-Dv2 users can configure if the static system EID should be used
during CLC handshake, or if only user EIDs are allowed.
Add generic netlink support to enable and disable the system EID, and
to retrieve the system EID and its current enabled state.

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>

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index e3728af2832b17d41f86e0ebc207085efc741ff2..b175bd0165a101b74f0361117aaca9041fa60520 100644 (file)
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -56,6 +56,9 @@ enum {
        SMC_NETLINK_ADD_UEID,
        SMC_NETLINK_REMOVE_UEID,
        SMC_NETLINK_FLUSH_UEID,
+       SMC_NETLINK_DUMP_SEID,
+       SMC_NETLINK_ENABLE_SEID,
+       SMC_NETLINK_DISABLE_SEID,
 };
 
 /* SMC_GENL_FAMILY top level attributes */
@@ -257,4 +260,13 @@ enum {
        __SMC_NLA_EID_TABLE_MAX,
        SMC_NLA_EID_TABLE_MAX = __SMC_NLA_EID_TABLE_MAX - 1
 };
+
+/* SMC_NETLINK_SEID attributes */
+enum {
+       SMC_NLA_SEID_UNSPEC,
+       SMC_NLA_SEID_ENTRY,     /* string */
+       SMC_NLA_SEID_ENABLED,   /* u8 */
+       __SMC_NLA_SEID_TABLE_MAX,
+       SMC_NLA_SEID_TABLE_MAX = __SMC_NLA_SEID_TABLE_MAX - 1
+};
 #endif /* _UAPI_LINUX_SMC_H */

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 5a5ebf752860679770e24fe35a6e143dc509d00b..4afd9e71e5c23fce2c937608f45b13217df024b2 100644 (file)
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -143,6 +143,10 @@ static int smc_clc_ueid_remove(char *ueid)
                        rc = 0;
                }
        }
+       if (!rc && !smc_clc_eid_table.ueid_cnt) {
+               smc_clc_eid_table.seid_enabled = 1;
+               rc = -EAGAIN;   /* indicate success and enabling of seid */
+       }
        write_unlock(&smc_clc_eid_table.lock);
        return rc;
 }
@@ -216,6 +220,64 @@ int smc_nl_dump_ueid(struct sk_buff *skb, struct netlink_callback *cb)
        return skb->len;
 }
 
+int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb)
+{
+       struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+       char seid_str[SMC_MAX_EID_LEN + 1];
+       u8 seid_enabled;
+       void *hdr;
+       u8 *seid;
+
+       if (cb_ctx->pos[0])
+               return skb->len;
+
+       hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+                         &smc_gen_nl_family, NLM_F_MULTI,
+                         SMC_NETLINK_DUMP_SEID);
+       if (!hdr)
+               return -ENOMEM;
+       if (!smc_ism_is_v2_capable())
+               goto end;
+
+       smc_ism_get_system_eid(&seid);
+       snprintf(seid_str, sizeof(seid_str), "%s", seid);
+       if (nla_put_string(skb, SMC_NLA_SEID_ENTRY, seid_str))
+               goto err;
+       read_lock(&smc_clc_eid_table.lock);
+       seid_enabled = smc_clc_eid_table.seid_enabled;
+       read_unlock(&smc_clc_eid_table.lock);
+       if (nla_put_u8(skb, SMC_NLA_SEID_ENABLED, seid_enabled))
+               goto err;
+end:
+       genlmsg_end(skb, hdr);
+       cb_ctx->pos[0]++;
+       return skb->len;
+err:
+       genlmsg_cancel(skb, hdr);
+       return -EMSGSIZE;
+}
+
+int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info)
+{
+       write_lock(&smc_clc_eid_table.lock);
+       smc_clc_eid_table.seid_enabled = 1;
+       write_unlock(&smc_clc_eid_table.lock);
+       return 0;
+}
+
+int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info)
+{
+       int rc = 0;
+
+       write_lock(&smc_clc_eid_table.lock);
+       if (!smc_clc_eid_table.ueid_cnt)
+               rc = -ENOENT;
+       else
+               smc_clc_eid_table.seid_enabled = 0;
+       write_unlock(&smc_clc_eid_table.lock);
+       return rc;
+}
+
 static bool _smc_clc_match_ueid(u8 *peer_ueid)
 {
        struct smc_clc_eid_entry *tmp_ueid;

diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 0699e0cee3081ffd77b6ed5b90842c8c0a52bc9c..974d01d16bb5bd82dcb3b0190320bdb25115806a 100644 (file)
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -347,5 +347,8 @@ 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);
+int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb);
+int smc_nl_enable_seid(struct sk_buff *skb, struct genl_info *info);
+int smc_nl_disable_seid(struct sk_buff *skb, struct genl_info *info);
 
 #endif

diff --git a/net/smc/smc_netlink.c b/net/smc/smc_netlink.c
index 4548ff2df245b2557704497e21ce223836781f33..f13ab0661ed5ee615e5f3dca2b87e7a5edcd11f4 100644 (file)
--- a/net/smc/smc_netlink.c
+++ b/net/smc/smc_netlink.c
@@ -96,6 +96,21 @@ static const struct genl_ops smc_gen_nl_ops[] = {
                .flags = GENL_ADMIN_PERM,
                .doit = smc_nl_flush_ueid,
        },
+       {
+               .cmd = SMC_NETLINK_DUMP_SEID,
+               /* can be retrieved by unprivileged users */
+               .dumpit = smc_nl_dump_seid,
+       },
+       {
+               .cmd = SMC_NETLINK_ENABLE_SEID,
+               .flags = GENL_ADMIN_PERM,
+               .doit = smc_nl_enable_seid,
+       },
+       {
+               .cmd = SMC_NETLINK_DISABLE_SEID,
+               .flags = GENL_ADMIN_PERM,
+               .doit = smc_nl_disable_seid,
+       },
 };
 
 static const struct nla_policy smc_gen_nl_policy[2] = {