[PATCH net-next v6 10/14] net/smc: Introduce SMCR get linkgroup command

Karsten Graul
2020-11-26T20:39:33Z

Introduce get linkgroup command which loops through
all available SMCR linkgroups. It uses the SMC-R linkgroup
list as entry point, not the socket list, which makes
linkgroup diagnosis possible, in case linkgroup does not
contain active connections anymore.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
include/uapi/linux/smc.h | 15 +++++++
net/smc/smc_core.c | 85 ++++++++++++++++++++++++++++++++++++++++
net/smc/smc_core.h | 1 +
net/smc/smc_netlink.c | 5 +++
4 files changed, 106 insertions(+)

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index 1b8d4e770be9..3ae8ca4e5256 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -40,12 +40,14 @@ enum { /* SMC PNET Table commands */
/* SMC_GENL_FAMILY commands */
enum {
SMC_NETLINK_GET_SYS_INFO = 1,
+ SMC_NETLINK_GET_LGR_SMCR,
};

/* SMC_GENL_FAMILY top level attributes */
enum {
SMC_GEN_UNSPEC,
SMC_GEN_SYS_INFO, /* nest */
+ SMC_GEN_LGR_SMCR, /* nest */
__SMC_GEN_MAX,
SMC_GEN_MAX = __SMC_GEN_MAX - 1
};
@@ -62,4 +64,17 @@ enum {
SMC_NLA_SYS_MAX = __SMC_NLA_SYS_MAX - 1
};

+/* SMC_GEN_LGR_SMCR attributes */
+enum {
+ SMC_NLA_LGR_R_UNSPEC,
+ SMC_NLA_LGR_R_ID, /* u32 */
+ SMC_NLA_LGR_R_ROLE, /* u8 */
+ SMC_NLA_LGR_R_TYPE, /* u8 */
+ SMC_NLA_LGR_R_PNETID, /* string */
+ SMC_NLA_LGR_R_VLAN_ID, /* u8 */
+ SMC_NLA_LGR_R_CONNS_NUM, /* u32 */
+ __SMC_NLA_LGR_R_MAX,
+ SMC_NLA_LGR_R_MAX = __SMC_NLA_LGR_R_MAX - 1
+};
+
#endif /* _UAPI_LINUX_SMC_H */
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 0524d7bbab67..008ec6e778fa 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -274,6 +274,91 @@ int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}

+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;
+
+ attrs = nla_nest_start_noflag(skb, SMC_GEN_LGR_SMCR);
+ if (!attrs)
+ goto errout;
+
+ if (nla_put_u32(skb, SMC_NLA_LGR_R_ID, *((u32 *)&lgr->id)))
+ goto errattr;
+ if (nla_put_u32(skb, SMC_NLA_LGR_R_CONNS_NUM, lgr->conns_num))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_LGR_R_ROLE, lgr->role))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_LGR_R_TYPE, lgr->type))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id))
+ goto errattr;
+ snprintf(smc_target, sizeof(smc_target), "%s", lgr->pnet_id);
+ if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target))
+ goto errattr;
+
+ nla_nest_end(skb, attrs);
+ return 0;
+errattr:
+ nla_nest_cancel(skb, attrs);
+errout:
+ return -EMSGSIZE;
+}
+
+static int smc_nl_handle_lgr(struct smc_link_group *lgr,
+ struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ void *nlh;
+
+ nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+ &smc_gen_nl_family, NLM_F_MULTI,
+ SMC_NETLINK_GET_LGR_SMCR);
+ if (!nlh)
+ goto errmsg;
+ if (smc_nl_fill_lgr(lgr, skb, cb))
+ goto errout;
+
+ genlmsg_end(skb, nlh);
+ return 0;
+
+errout:
+ genlmsg_cancel(skb, nlh);
+errmsg:
+ return -EMSGSIZE;
+}
+
+static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
+ struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+ struct smc_link_group *lgr;
+ int snum = cb_ctx->pos[0];
+ int num = 0;
+
+ spin_lock_bh(&smc_lgr->lock);
+ list_for_each_entry(lgr, &smc_lgr->list, list) {
+ if (num < snum)
+ goto next;
+ if (smc_nl_handle_lgr(lgr, skb, cb))
+ goto errout;
+next:
+ num++;
+ }
+errout:
+ spin_unlock_bh(&smc_lgr->lock);
+ cb_ctx->pos[0] = num;
+}
+
+int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb);
+ return skb->len;
+}
+
void smc_lgr_cleanup_early(struct smc_connection *conn)
{
struct smc_link_group *lgr = conn->lgr;
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index eaed25d4e76b..662315beb605 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -415,6 +415,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
void smcr_link_down_cond(struct smc_link *lnk);
void smcr_link_down_cond_sched(struct smc_link *lnk);
int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb);
+int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb);

static inline struct smc_link_group *smc_get_lgr(struct smc_link *link)
{
diff --git a/net/smc/smc_netlink.c b/net/smc/smc_netlink.c
index b1de58a6a1c4..074b57877fcf 100644
--- a/net/smc/smc_netlink.c
+++ b/net/smc/smc_netlink.c
@@ -26,6 +26,11 @@ static const struct genl_ops smc_gen_nl_ops[] = {
/* can be retrieved by unprivileged users */
.dumpit = smc_nl_get_sys_info,
},
+ {
+ .cmd = SMC_NETLINK_GET_LGR_SMCR,
+ /* can be retrieved by unprivileged users */
+ .dumpit = smcr_nl_get_lgr,
+ },
};

/* SMC_GENL family definition */
--
2.17.1