[PATCH net-next v6 09/14] net/smc: Add support for obtaining system information

Karsten Graul
2020-11-26T20:39:32Z

Add new netlink command to obtain system information
of the smc module.

Signed-off-by: Guvenc Gulce <guvenc@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
include/uapi/linux/smc.h | 18 ++++++++++++
net/smc/smc_clc.c | 5 ++++
net/smc/smc_clc.h | 1 +
net/smc/smc_core.c | 60 ++++++++++++++++++++++++++++++++++++++++
net/smc/smc_core.h | 2 ++
net/smc/smc_netlink.c | 5 ++++
net/smc/smc_netlink.h | 9 ++++++
7 files changed, 100 insertions(+)

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index b604d64542e8..1b8d4e770be9 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -37,11 +37,29 @@ enum { /* SMC PNET Table commands */
#define SMC_GENL_FAMILY_NAME "SMC_GEN_NETLINK"
#define SMC_GENL_FAMILY_VERSION 1

+/* SMC_GENL_FAMILY commands */
+enum {
+ SMC_NETLINK_GET_SYS_INFO = 1,
+};
+
/* SMC_GENL_FAMILY top level attributes */
enum {
SMC_GEN_UNSPEC,
+ SMC_GEN_SYS_INFO, /* nest */
__SMC_GEN_MAX,
SMC_GEN_MAX = __SMC_GEN_MAX - 1
};

+/* SMC_GEN_SYS_INFO attributes */
+enum {
+ SMC_NLA_SYS_UNSPEC,
+ SMC_NLA_SYS_VER, /* u8 */
+ SMC_NLA_SYS_REL, /* u8 */
+ SMC_NLA_SYS_IS_ISM_V2, /* u8 */
+ SMC_NLA_SYS_LOCAL_HOST, /* string */
+ SMC_NLA_SYS_SEID, /* string */
+ __SMC_NLA_SYS_MAX,
+ SMC_NLA_SYS_MAX = __SMC_NLA_SYS_MAX - 1
+};
+
#endif /* _UAPI_LINUX_SMC_H */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 696d89c2dce4..e286dafd6e88 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -772,6 +772,11 @@ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,
return len > 0 ? 0 : len;
}

+void smc_clc_get_hostname(u8 **host)
+{
+ *host = &smc_hostname[0];
+}
+
void __init smc_clc_init(void)
{
struct new_utsname *u;
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 49752c997c51..32d37f7b70f2 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -334,5 +334,6 @@ int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact,
int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,
u8 version);
void smc_clc_init(void) __init;
+void smc_clc_get_hostname(u8 **host);

#endif
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 0088511e30bf..0524d7bbab67 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -16,6 +16,8 @@
#include <linux/wait.h>
#include <linux/reboot.h>
#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/smc.h>
#include <net/tcp.h>
#include <net/sock.h>
#include <rdma/ib_verbs.h>
@@ -30,6 +32,7 @@
#include "smc_cdc.h"
#include "smc_close.h"
#include "smc_ism.h"
+#include "smc_netlink.h"

#define SMC_LGR_NUM_INCR 256
#define SMC_LGR_FREE_DELAY_SERV (600 * HZ)
@@ -214,6 +217,63 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn)
conn->lgr = NULL;
}

+int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
+ char hostname[SMC_MAX_HOSTNAME_LEN + 1];
+ char smc_seid[SMC_MAX_EID_LEN + 1];
+ struct smcd_dev *smcd_dev;
+ struct nlattr *attrs;
+ u8 *seid = NULL;
+ u8 *host = NULL;
+ 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_SYS_INFO);
+ if (!nlh)
+ goto errmsg;
+ if (cb_ctx->pos[0])
+ goto errout;
+ attrs = nla_nest_start_noflag(skb, SMC_GEN_SYS_INFO);
+ if (!attrs)
+ goto errout;
+ if (nla_put_u8(skb, SMC_NLA_SYS_VER, SMC_V2))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_SYS_REL, SMC_RELEASE))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_SYS_IS_ISM_V2, smc_ism_is_v2_capable()))
+ goto errattr;
+ smc_clc_get_hostname(&host);
+ if (host) {
+ snprintf(hostname, sizeof(hostname), "%s", host);
+ if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname))
+ goto errattr;
+ }
+ mutex_lock(&smcd_dev_list.mutex);
+ smcd_dev = list_first_entry_or_null(&smcd_dev_list.list,
+ struct smcd_dev, list);
+ if (smcd_dev)
+ smc_ism_get_system_eid(smcd_dev, &seid);
+ mutex_unlock(&smcd_dev_list.mutex);
+ if (seid && smc_ism_is_v2_capable()) {
+ snprintf(smc_seid, sizeof(smc_seid), "%s", seid);
+ if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid))
+ goto errattr;
+ }
+ nla_nest_end(skb, attrs);
+ genlmsg_end(skb, nlh);
+ cb_ctx->pos[0] = 1;
+ return skb->len;
+
+errattr:
+ nla_nest_cancel(skb, attrs);
+errout:
+ genlmsg_cancel(skb, nlh);
+errmsg:
+ 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 3a1bb8e4b81f..eaed25d4e76b 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -14,6 +14,7 @@

#include <linux/atomic.h>
#include <rdma/ib_verbs.h>
+#include <net/genetlink.h>

#include "smc.h"
#include "smc_ib.h"
@@ -413,6 +414,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr,
struct smc_link *from_lnk, bool is_dev_err);
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);

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 e9a56148e71b..b1de58a6a1c4 100644
--- a/net/smc/smc_netlink.c
+++ b/net/smc/smc_netlink.c
@@ -21,6 +21,11 @@

/* SMC_GENL generic netlink operation definition */
static const struct genl_ops smc_gen_nl_ops[] = {
+ {
+ .cmd = SMC_NETLINK_GET_SYS_INFO,
+ /* can be retrieved by unprivileged users */
+ .dumpit = smc_nl_get_sys_info,
+ },
};

/* SMC_GENL family definition */
diff --git a/net/smc/smc_netlink.h b/net/smc/smc_netlink.h
index 0c757232c0d0..3477265cba6c 100644
--- a/net/smc/smc_netlink.h
+++ b/net/smc/smc_netlink.h
@@ -17,6 +17,15 @@

extern struct genl_family smc_gen_nl_family;

+struct smc_nl_dmp_ctx {
+ int pos[2];
+};
+
+static inline struct smc_nl_dmp_ctx *smc_nl_dmp_ctx(struct netlink_callback *c)
+{
+ return (struct smc_nl_dmp_ctx *)c->ctx;
+}
+
int smc_nl_init(void) __init;
void smc_nl_exit(void);

--
2.17.1