devlink: add device information API

ethtool -i has served us well for a long time, but its showing
its limitations more and more. The device information should
also be reported per device not per-netdev.

Lay foundation for a simple devlink-based way of reading device
info. Add driver name and device serial number as initial pieces
of information exposed via this new API.

v3:
 - rename helpers (Jiri);
 - rename driver name attr (Jiri);
 - remove double spacing in commit message (Jiri).
RFC v2:
 - wrap the skb into an opaque structure (Jiri);
 - allow the serial number of be any length (Jiri & Andrew);
 - add driver name (Jonathan).

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 85c9eabaf0561381cbf0a7bf273daeb3c7d7eeff..a6d0a530483d41f1dd2b7a5fdbbb15243bc03217 100644 (file)
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -429,6 +429,7 @@ enum devlink_param_wol_types {
 }
 
 struct devlink_region;
+struct devlink_info_req;
 
 typedef void devlink_snapshot_data_dest_t(const void *data);
 
@@ -484,6 +485,8 @@ struct devlink_ops {
        int (*eswitch_encap_mode_get)(struct devlink *devlink, u8 *p_encap_mode);
        int (*eswitch_encap_mode_set)(struct devlink *devlink, u8 encap_mode,
                                      struct netlink_ext_ack *extack);
+       int (*info_get)(struct devlink *devlink, struct devlink_info_req *req,
+                       struct netlink_ext_ack *extack);
 };
 
 static inline void *devlink_priv(struct devlink *devlink)
@@ -607,6 +610,10 @@ u32 devlink_region_shapshot_id_get(struct devlink *devlink);
 int devlink_region_snapshot_create(struct devlink_region *region, u64 data_len,
                                   u8 *data, u32 snapshot_id,
                                   devlink_snapshot_data_dest_t *data_destructor);
+int devlink_info_serial_number_put(struct devlink_info_req *req,
+                                  const char *sn);
+int devlink_info_driver_name_put(struct devlink_info_req *req,
+                                const char *name);
 
 #else
 
@@ -905,6 +912,17 @@ devlink_region_snapshot_create(struct devlink_region *region, u64 data_len,
        return 0;
 }
 
+static inline int
+devlink_info_driver_name_put(struct devlink_info_req *req, const char *name)
+{
+       return 0;
+}
+
+static inline int
+devlink_info_serial_number_put(struct devlink_info_req *req, const char *sn)
+{
+       return 0;
+}
 #endif
 
 #endif /* _NET_DEVLINK_H_ */

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 61b4447a6c5b66b5a53208f2b85ae63f69ec0f34..142710d450930424cc5afeb87d84c483a36ec29d 100644 (file)
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -94,6 +94,8 @@ enum devlink_command {
        DEVLINK_CMD_PORT_PARAM_NEW,
        DEVLINK_CMD_PORT_PARAM_DEL,
 
+       DEVLINK_CMD_INFO_GET,           /* can dump */
+
        /* add new commands above here */
        __DEVLINK_CMD_MAX,
        DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1
@@ -290,6 +292,9 @@ enum devlink_attr {
        DEVLINK_ATTR_REGION_CHUNK_ADDR,         /* u64 */
        DEVLINK_ATTR_REGION_CHUNK_LEN,          /* u64 */
 
+       DEVLINK_ATTR_INFO_DRIVER_NAME,          /* string */
+       DEVLINK_ATTR_INFO_SERIAL_NUMBER,        /* string */
+
        /* add new attributes above here, update the policy in devlink.c */
 
        __DEVLINK_ATTR_MAX,

diff --git a/net/core/devlink.c b/net/core/devlink.c
index e6f170caf449c0c0ad2b0260269dc1ec362278e4..f456f6aa3d402673a427c6bca94dfa3a14b2ffdf 100644 (file)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3714,6 +3714,110 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
        return 0;
 }
 
+struct devlink_info_req {
+       struct sk_buff *msg;
+};
+
+int devlink_info_driver_name_put(struct devlink_info_req *req, const char *name)
+{
+       return nla_put_string(req->msg, DEVLINK_ATTR_INFO_DRIVER_NAME, name);
+}
+EXPORT_SYMBOL_GPL(devlink_info_driver_name_put);
+
+int devlink_info_serial_number_put(struct devlink_info_req *req, const char *sn)
+{
+       return nla_put_string(req->msg, DEVLINK_ATTR_INFO_SERIAL_NUMBER, sn);
+}
+EXPORT_SYMBOL_GPL(devlink_info_serial_number_put);
+
+static int
+devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
+                    enum devlink_command cmd, u32 portid,
+                    u32 seq, int flags, struct netlink_ext_ack *extack)
+{
+       struct devlink_info_req req;
+       void *hdr;
+       int err;
+
+       hdr = genlmsg_put(msg, portid, seq, &devlink_nl_family, flags, cmd);
+       if (!hdr)
+               return -EMSGSIZE;
+
+       err = -EMSGSIZE;
+       if (devlink_nl_put_handle(msg, devlink))
+               goto err_cancel_msg;
+
+       req.msg = msg;
+       err = devlink->ops->info_get(devlink, &req, extack);
+       if (err)
+               goto err_cancel_msg;
+
+       genlmsg_end(msg, hdr);
+       return 0;
+
+err_cancel_msg:
+       genlmsg_cancel(msg, hdr);
+       return err;
+}
+
+static int devlink_nl_cmd_info_get_doit(struct sk_buff *skb,
+                                       struct genl_info *info)
+{
+       struct devlink *devlink = info->user_ptr[0];
+       struct sk_buff *msg;
+       int err;
+
+       if (!devlink->ops || !devlink->ops->info_get)
+               return -EOPNOTSUPP;
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return -ENOMEM;
+
+       err = devlink_nl_info_fill(msg, devlink, DEVLINK_CMD_INFO_GET,
+                                  info->snd_portid, info->snd_seq, 0,
+                                  info->extack);
+       if (err) {
+               nlmsg_free(msg);
+               return err;
+       }
+
+       return genlmsg_reply(msg, info);
+}
+
+static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg,
+                                         struct netlink_callback *cb)
+{
+       struct devlink *devlink;
+       int start = cb->args[0];
+       int idx = 0;
+       int err;
+
+       mutex_lock(&devlink_mutex);
+       list_for_each_entry(devlink, &devlink_list, list) {
+               if (!net_eq(devlink_net(devlink), sock_net(msg->sk)))
+                       continue;
+               if (idx < start) {
+                       idx++;
+                       continue;
+               }
+
+               mutex_lock(&devlink->lock);
+               err = devlink_nl_info_fill(msg, devlink, DEVLINK_CMD_INFO_GET,
+                                          NETLINK_CB(cb->skb).portid,
+                                          cb->nlh->nlmsg_seq, NLM_F_MULTI,
+                                          cb->extack);
+               mutex_unlock(&devlink->lock);
+               if (err)
+                       break;
+               idx++;
+       }
+       mutex_unlock(&devlink_mutex);
+
+       cb->args[0] = idx;
+       return msg->len;
+}
+
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
        [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING },
        [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING },
@@ -3974,6 +4078,14 @@ static const struct genl_ops devlink_nl_ops[] = {
                .flags = GENL_ADMIN_PERM,
                .internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
        },
+       {
+               .cmd = DEVLINK_CMD_INFO_GET,
+               .doit = devlink_nl_cmd_info_get_doit,
+               .dumpit = devlink_nl_cmd_info_get_dumpit,
+               .policy = devlink_nl_policy,
+               .internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+               /* can be retrieved by unprivileged users */
+       },
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {