[PATCH net-next v6 11/14] net/smc: Introduce SMCR get link command

Karsten Graul
2020-11-26T20:39:13Z

Introduce get link command which loops through
all available links of all available link groups. 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 | 18 ++++++++
net/smc/smc_core.c | 91 ++++++++++++++++++++++++++++++++++++++--
net/smc/smc_core.h | 14 +++++++
net/smc/smc_diag.c | 13 ------
net/smc/smc_netlink.c | 5 +++
5 files changed, 124 insertions(+), 17 deletions(-)

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index 3ae8ca4e5256..ed638dbfff08 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -41,6 +41,7 @@ enum { /* SMC PNET Table commands */
enum {
SMC_NETLINK_GET_SYS_INFO = 1,
SMC_NETLINK_GET_LGR_SMCR,
+ SMC_NETLINK_GET_LINK_SMCR,
};

/* SMC_GENL_FAMILY top level attributes */
@@ -48,6 +49,7 @@ enum {
SMC_GEN_UNSPEC,
SMC_GEN_SYS_INFO, /* nest */
SMC_GEN_LGR_SMCR, /* nest */
+ SMC_GEN_LINK_SMCR, /* nest */
__SMC_GEN_MAX,
SMC_GEN_MAX = __SMC_GEN_MAX - 1
};
@@ -77,4 +79,20 @@ enum {
SMC_NLA_LGR_R_MAX = __SMC_NLA_LGR_R_MAX - 1
};

+/* SMC_GEN_LINK_SMCR attributes */
+enum {
+ SMC_NLA_LINK_UNSPEC,
+ SMC_NLA_LINK_ID, /* u8 */
+ SMC_NLA_LINK_IB_DEV, /* string */
+ SMC_NLA_LINK_IB_PORT, /* u8 */
+ SMC_NLA_LINK_GID, /* string */
+ SMC_NLA_LINK_PEER_GID, /* string */
+ SMC_NLA_LINK_CONN_CNT, /* u32 */
+ SMC_NLA_LINK_NET_DEV, /* u32 */
+ SMC_NLA_LINK_UID, /* u32 */
+ SMC_NLA_LINK_PEER_UID, /* u32 */
+ SMC_NLA_LINK_STATE, /* u32 */
+ __SMC_NLA_LINK_MAX,
+ SMC_NLA_LINK_MAX = __SMC_NLA_LINK_MAX - 1
+};
#endif /* _UAPI_LINUX_SMC_H */
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 008ec6e778fa..960c3853ba15 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -307,11 +307,74 @@ static int smc_nl_fill_lgr(struct smc_link_group *lgr,
return -EMSGSIZE;
}

+static int smc_nl_fill_lgr_link(struct smc_link_group *lgr,
+ struct smc_link *link,
+ struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ char smc_ibname[IB_DEVICE_NAME_MAX + 1];
+ u8 smc_gid_target[41];
+ struct nlattr *attrs;
+ u32 link_uid = 0;
+ 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_LINK_SMCR);
+ if (!nlh)
+ goto errmsg;
+
+ attrs = nla_nest_start_noflag(skb, SMC_GEN_LINK_SMCR);
+ if (!attrs)
+ goto errout;
+
+ if (nla_put_u8(skb, SMC_NLA_LINK_ID, link->link_id))
+ goto errattr;
+ if (nla_put_u32(skb, SMC_NLA_LINK_STATE, link->state))
+ goto errattr;
+ if (nla_put_u32(skb, SMC_NLA_LINK_CONN_CNT,
+ atomic_read(&link->conn_cnt)))
+ goto errattr;
+ if (nla_put_u8(skb, SMC_NLA_LINK_IB_PORT, link->ibport))
+ goto errattr;
+ if (nla_put_u32(skb, SMC_NLA_LINK_NET_DEV, link->ndev_ifidx))
+ goto errattr;
+ snprintf(smc_ibname, sizeof(smc_ibname), "%s", link->ibname);
+ if (nla_put_string(skb, SMC_NLA_LINK_IB_DEV, smc_ibname))
+ goto errattr;
+ memcpy(&link_uid, link->link_uid, sizeof(link_uid));
+ if (nla_put_u32(skb, SMC_NLA_LINK_UID, link_uid))
+ goto errattr;
+ memcpy(&link_uid, link->peer_link_uid, sizeof(link_uid));
+ if (nla_put_u32(skb, SMC_NLA_LINK_PEER_UID, link_uid))
+ goto errattr;
+ memset(smc_gid_target, 0, sizeof(smc_gid_target));
+ smc_gid_be16_convert(smc_gid_target, link->gid);
+ if (nla_put_string(skb, SMC_NLA_LINK_GID, smc_gid_target))
+ goto errattr;
+ memset(smc_gid_target, 0, sizeof(smc_gid_target));
+ smc_gid_be16_convert(smc_gid_target, link->peer_gid);
+ if (nla_put_string(skb, SMC_NLA_LINK_PEER_GID, smc_gid_target))
+ goto errattr;
+
+ nla_nest_end(skb, attrs);
+ genlmsg_end(skb, nlh);
+ return 0;
+errattr:
+ nla_nest_cancel(skb, attrs);
+errout:
+ genlmsg_cancel(skb, nlh);
+errmsg:
+ return -EMSGSIZE;
+}
+
static int smc_nl_handle_lgr(struct smc_link_group *lgr,
struct sk_buff *skb,
- struct netlink_callback *cb)
+ struct netlink_callback *cb,
+ bool list_links)
{
void *nlh;
+ int i;

nlh = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
&smc_gen_nl_family, NLM_F_MULTI,
@@ -322,6 +385,15 @@ static int smc_nl_handle_lgr(struct smc_link_group *lgr,
goto errout;

genlmsg_end(skb, nlh);
+ if (!list_links)
+ goto out;
+ for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
+ if (!smc_link_usable(&lgr->lnk[i]))
+ continue;
+ if (smc_nl_fill_lgr_link(lgr, &lgr->lnk[i], skb, cb))
+ goto errout;
+ }
+out:
return 0;

errout:
@@ -332,7 +404,8 @@ static int smc_nl_handle_lgr(struct smc_link_group *lgr,

static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
struct sk_buff *skb,
- struct netlink_callback *cb)
+ struct netlink_callback *cb,
+ bool list_links)
{
struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
struct smc_link_group *lgr;
@@ -343,7 +416,7 @@ static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,
list_for_each_entry(lgr, &smc_lgr->list, list) {
if (num < snum)
goto next;
- if (smc_nl_handle_lgr(lgr, skb, cb))
+ if (smc_nl_handle_lgr(lgr, skb, cb, list_links))
goto errout;
next:
num++;
@@ -355,7 +428,17 @@ static void smc_nl_fill_lgr_list(struct smc_lgr_list *smc_lgr,

int smcr_nl_get_lgr(struct sk_buff *skb, struct netlink_callback *cb)
{
- smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb);
+ bool list_links = false;
+
+ smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
+ return skb->len;
+}
+
+int smcr_nl_get_link(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ bool list_links = true;
+
+ smc_nl_fill_lgr_list(&smc_lgr_list, skb, cb, list_links);
return skb->len;
}

diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 662315beb605..7995621f318d 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -367,6 +367,19 @@ static inline bool smc_link_active(struct smc_link *lnk)
return lnk->state == SMC_LNK_ACTIVE;
}

+static inline void smc_gid_be16_convert(__u8 *buf, u8 *gid_raw)
+{
+ sprintf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
+ be16_to_cpu(((__be16 *)gid_raw)[0]),
+ be16_to_cpu(((__be16 *)gid_raw)[1]),
+ be16_to_cpu(((__be16 *)gid_raw)[2]),
+ be16_to_cpu(((__be16 *)gid_raw)[3]),
+ be16_to_cpu(((__be16 *)gid_raw)[4]),
+ be16_to_cpu(((__be16 *)gid_raw)[5]),
+ be16_to_cpu(((__be16 *)gid_raw)[6]),
+ be16_to_cpu(((__be16 *)gid_raw)[7]));
+}
+
struct smc_sock;
struct smc_clc_msg_accept_confirm;
struct smc_clc_msg_local;
@@ -416,6 +429,7 @@ 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);
+int smcr_nl_get_link(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_diag.c b/net/smc/smc_diag.c
index c2225231f679..c952986a6aca 100644
--- a/net/smc/smc_diag.c
+++ b/net/smc/smc_diag.c
@@ -31,19 +31,6 @@ static struct smc_diag_dump_ctx *smc_dump_context(struct netlink_callback *cb)
return (struct smc_diag_dump_ctx *)cb->ctx;
}

-static void smc_gid_be16_convert(__u8 *buf, u8 *gid_raw)
-{
- sprintf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x",
- be16_to_cpu(((__be16 *)gid_raw)[0]),
- be16_to_cpu(((__be16 *)gid_raw)[1]),
- be16_to_cpu(((__be16 *)gid_raw)[2]),
- be16_to_cpu(((__be16 *)gid_raw)[3]),
- be16_to_cpu(((__be16 *)gid_raw)[4]),
- be16_to_cpu(((__be16 *)gid_raw)[5]),
- be16_to_cpu(((__be16 *)gid_raw)[6]),
- be16_to_cpu(((__be16 *)gid_raw)[7]));
-}
-
static void smc_diag_msg_common_fill(struct smc_diag_msg *r, struct sock *sk)
{
struct smc_sock *smc = smc_sk(sk);
diff --git a/net/smc/smc_netlink.c b/net/smc/smc_netlink.c
index 074b57877fcf..4212408cc091 100644
--- a/net/smc/smc_netlink.c
+++ b/net/smc/smc_netlink.c
@@ -31,6 +31,11 @@ static const struct genl_ops smc_gen_nl_ops[] = {
/* can be retrieved by unprivileged users */
.dumpit = smcr_nl_get_lgr,
},
+ {
+ .cmd = SMC_NETLINK_GET_LINK_SMCR,
+ /* can be retrieved by unprivileged users */
+ .dumpit = smcr_nl_get_link,
+ },
};

/* SMC_GENL family definition */
--
2.17.1