drbd: replace genl_magic with explicit netlink serialization

Replace the genl_magic multi-include macro system with explicit
serialization and parsing.

The *_gen files were initially produced from a YNL spec via a
customized ynl-gen-c, but the DRBD netlink family is effectively
frozen, so the generator is kept unmodified.
All new functionality will land in a separate, properly-designed
family.
Carry the resulting code as ordinary in-tree source rather than
landing the spec and generator changes that produced it.

The bulk of the changes are mechanical renames to fit the YNL naming
conventions:
  - Handler functions: drbd_adm_* -> drbd_nl_*_doit/dumpit
  - GENL_MAGIC_VERSION -> DRBD_FAMILY_VERSION
  - GENL_MAGIC_FAMILY_HDRSZ -> sizeof(struct drbd_genlmsghdr)
  - drbd_genl_family -> drbd_nl_family
  - Attribute IDs: T_* -> DRBD_A_*

Remove the nested_attr_tb static global buffer and move to a per-call
allocation approach: each deserialization manages its own nested
attribute table. This will be needed anyway when we eventually move
to parallel_ops, and it's actually simpler this way, so make the
move now.

Replace the functionality of the "sensitive" flag: this was only used
by a single field (shared_secret); open-code redaction logic for that
locally.

Also replace the "invariant" flag: this only had a couple of users,
and those basically never change. Hard code the check directly inline.

The genl_family struct itself is defined manually in drbd_nl.c.

Also replace a couple of drbd-specific wrappers (nla_put_u64_0pad,
drbd_nla_find_nested) with standard kernel functions while we're at
it.

Finally, completely remove the genl_magic system; DRBD was its only
user.

Signed-off-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20260506124541.1951772-3-christoph.boehmwalder@linbit.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

2 files changed, 362 insertions, 0 deletions

diff --git a/include/uapi/linux/drbd.h b/include/uapi/linux/drbd.h
index 7930a972d8a4..5d4d677cf1ad 100644
--- a/include/uapi/linux/drbd.h
+++ b/include/uapi/linux/drbd.h
@@ -333,6 +333,9 @@ enum drbd_uuid_index {
 
 #define HISTORY_UUIDS MAX_PEERS
 
+#define DRBD_NL_UUIDS_SIZE		(UI_SIZE * sizeof(__u64))
+#define DRBD_NL_HISTORY_UUIDS_SIZE	(HISTORY_UUIDS * sizeof(__u64))
+
 enum drbd_timeout_flag {
 	UT_DEFAULT      = 0,
 	UT_DEGRADED     = 1,
diff --git a/include/uapi/linux/drbd_genl.h b/include/uapi/linux/drbd_genl.h
new file mode 100644
index 000000000000..8b25f08d8a90
--- /dev/null
+++ b/include/uapi/linux/drbd_genl.h
@@ -0,0 +1,359 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+
+#ifndef _UAPI_LINUX_DRBD_GENL_H
+#define _UAPI_LINUX_DRBD_GENL_H
+
+#define DRBD_FAMILY_NAME	"drbd"
+#define DRBD_FAMILY_VERSION	1
+
+enum {
+	DRBD_NLA_CFG_REPLY = 1,
+	DRBD_NLA_CFG_CONTEXT,
+	DRBD_NLA_DISK_CONF,
+	DRBD_NLA_RESOURCE_OPTS,
+	DRBD_NLA_NET_CONF,
+	DRBD_NLA_SET_ROLE_PARMS,
+	DRBD_NLA_RESIZE_PARMS,
+	DRBD_NLA_STATE_INFO,
+	DRBD_NLA_START_OV_PARMS,
+	DRBD_NLA_NEW_C_UUID_PARMS,
+	DRBD_NLA_TIMEOUT_PARMS,
+	DRBD_NLA_DISCONNECT_PARMS,
+	DRBD_NLA_DETACH_PARMS,
+	DRBD_NLA_RESOURCE_INFO = 15,
+	DRBD_NLA_DEVICE_INFO,
+	DRBD_NLA_CONNECTION_INFO,
+	DRBD_NLA_PEER_DEVICE_INFO,
+	DRBD_NLA_RESOURCE_STATISTICS,
+	DRBD_NLA_DEVICE_STATISTICS,
+	DRBD_NLA_CONNECTION_STATISTICS,
+	DRBD_NLA_PEER_DEVICE_STATISTICS,
+	DRBD_NLA_NOTIFICATION_HEADER,
+	DRBD_NLA_HELPER,
+
+	__DRBD_NLA_MAX,
+	DRBD_NLA_MAX = (__DRBD_NLA_MAX - 1)
+};
+
+enum {
+	DRBD_A_DRBD_CFG_REPLY_INFO_TEXT = 1,
+
+	__DRBD_A_DRBD_CFG_REPLY_MAX,
+	DRBD_A_DRBD_CFG_REPLY_MAX = (__DRBD_A_DRBD_CFG_REPLY_MAX - 1)
+};
+
+enum {
+	DRBD_A_DRBD_CFG_CONTEXT_CTX_VOLUME = 1,
+	DRBD_A_DRBD_CFG_CONTEXT_CTX_RESOURCE_NAME,
+	DRBD_A_DRBD_CFG_CONTEXT_CTX_MY_ADDR,
+	DRBD_A_DRBD_CFG_CONTEXT_CTX_PEER_ADDR,
+
+	__DRBD_A_DRBD_CFG_CONTEXT_MAX,
+	DRBD_A_DRBD_CFG_CONTEXT_MAX = (__DRBD_A_DRBD_CFG_CONTEXT_MAX - 1)
+};
+
+enum {
+	DRBD_A_DISK_CONF_BACKING_DEV = 1,
+	DRBD_A_DISK_CONF_META_DEV,
+	DRBD_A_DISK_CONF_META_DEV_IDX,
+	DRBD_A_DISK_CONF_DISK_SIZE,
+	DRBD_A_DISK_CONF_MAX_BIO_BVECS,
+	DRBD_A_DISK_CONF_ON_IO_ERROR,
+	DRBD_A_DISK_CONF_FENCING,
+	DRBD_A_DISK_CONF_RESYNC_RATE,
+	DRBD_A_DISK_CONF_RESYNC_AFTER,
+	DRBD_A_DISK_CONF_AL_EXTENTS,
+	DRBD_A_DISK_CONF_C_PLAN_AHEAD,
+	DRBD_A_DISK_CONF_C_DELAY_TARGET,
+	DRBD_A_DISK_CONF_C_FILL_TARGET,
+	DRBD_A_DISK_CONF_C_MAX_RATE,
+	DRBD_A_DISK_CONF_C_MIN_RATE,
+	DRBD_A_DISK_CONF_DISK_BARRIER,
+	DRBD_A_DISK_CONF_DISK_FLUSHES,
+	DRBD_A_DISK_CONF_DISK_DRAIN,
+	DRBD_A_DISK_CONF_MD_FLUSHES,
+	DRBD_A_DISK_CONF_DISK_TIMEOUT,
+	DRBD_A_DISK_CONF_READ_BALANCING,
+	DRBD_A_DISK_CONF_AL_UPDATES = 23,
+	DRBD_A_DISK_CONF_DISCARD_ZEROES_IF_ALIGNED,
+	DRBD_A_DISK_CONF_RS_DISCARD_GRANULARITY,
+	DRBD_A_DISK_CONF_DISABLE_WRITE_SAME,
+
+	__DRBD_A_DISK_CONF_MAX,
+	DRBD_A_DISK_CONF_MAX = (__DRBD_A_DISK_CONF_MAX - 1)
+};
+
+enum {
+	DRBD_A_RES_OPTS_CPU_MASK = 1,
+	DRBD_A_RES_OPTS_ON_NO_DATA,
+
+	__DRBD_A_RES_OPTS_MAX,
+	DRBD_A_RES_OPTS_MAX = (__DRBD_A_RES_OPTS_MAX - 1)
+};
+
+enum {
+	DRBD_A_NET_CONF_SHARED_SECRET = 1,
+	DRBD_A_NET_CONF_CRAM_HMAC_ALG,
+	DRBD_A_NET_CONF_INTEGRITY_ALG,
+	DRBD_A_NET_CONF_VERIFY_ALG,
+	DRBD_A_NET_CONF_CSUMS_ALG,
+	DRBD_A_NET_CONF_WIRE_PROTOCOL,
+	DRBD_A_NET_CONF_CONNECT_INT,
+	DRBD_A_NET_CONF_TIMEOUT,
+	DRBD_A_NET_CONF_PING_INT,
+	DRBD_A_NET_CONF_PING_TIMEO,
+	DRBD_A_NET_CONF_SNDBUF_SIZE,
+	DRBD_A_NET_CONF_RCVBUF_SIZE,
+	DRBD_A_NET_CONF_KO_COUNT,
+	DRBD_A_NET_CONF_MAX_BUFFERS,
+	DRBD_A_NET_CONF_MAX_EPOCH_SIZE,
+	DRBD_A_NET_CONF_UNPLUG_WATERMARK,
+	DRBD_A_NET_CONF_AFTER_SB_0P,
+	DRBD_A_NET_CONF_AFTER_SB_1P,
+	DRBD_A_NET_CONF_AFTER_SB_2P,
+	DRBD_A_NET_CONF_RR_CONFLICT,
+	DRBD_A_NET_CONF_ON_CONGESTION,
+	DRBD_A_NET_CONF_CONG_FILL,
+	DRBD_A_NET_CONF_CONG_EXTENTS,
+	DRBD_A_NET_CONF_TWO_PRIMARIES,
+	DRBD_A_NET_CONF_DISCARD_MY_DATA,
+	DRBD_A_NET_CONF_TCP_CORK,
+	DRBD_A_NET_CONF_ALWAYS_ASBP,
+	DRBD_A_NET_CONF_TENTATIVE,
+	DRBD_A_NET_CONF_USE_RLE,
+	DRBD_A_NET_CONF_CSUMS_AFTER_CRASH_ONLY = 33,
+	DRBD_A_NET_CONF_SOCK_CHECK_TIMEO,
+
+	__DRBD_A_NET_CONF_MAX,
+	DRBD_A_NET_CONF_MAX = (__DRBD_A_NET_CONF_MAX - 1)
+};
+
+enum {
+	DRBD_A_SET_ROLE_PARMS_ASSUME_UPTODATE = 1,
+
+	__DRBD_A_SET_ROLE_PARMS_MAX,
+	DRBD_A_SET_ROLE_PARMS_MAX = (__DRBD_A_SET_ROLE_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_RESIZE_PARMS_RESIZE_SIZE = 1,
+	DRBD_A_RESIZE_PARMS_RESIZE_FORCE,
+	DRBD_A_RESIZE_PARMS_NO_RESYNC,
+	DRBD_A_RESIZE_PARMS_AL_STRIPES,
+	DRBD_A_RESIZE_PARMS_AL_STRIPE_SIZE,
+
+	__DRBD_A_RESIZE_PARMS_MAX,
+	DRBD_A_RESIZE_PARMS_MAX = (__DRBD_A_RESIZE_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_STATE_INFO_SIB_REASON = 1,
+	DRBD_A_STATE_INFO_CURRENT_STATE,
+	DRBD_A_STATE_INFO_CAPACITY,
+	DRBD_A_STATE_INFO_ED_UUID,
+	DRBD_A_STATE_INFO_PREV_STATE,
+	DRBD_A_STATE_INFO_NEW_STATE,
+	DRBD_A_STATE_INFO_UUIDS,
+	DRBD_A_STATE_INFO_DISK_FLAGS,
+	DRBD_A_STATE_INFO_BITS_TOTAL,
+	DRBD_A_STATE_INFO_BITS_OOS,
+	DRBD_A_STATE_INFO_BITS_RS_TOTAL,
+	DRBD_A_STATE_INFO_BITS_RS_FAILED,
+	DRBD_A_STATE_INFO_HELPER,
+	DRBD_A_STATE_INFO_HELPER_EXIT_CODE,
+	DRBD_A_STATE_INFO_SEND_CNT,
+	DRBD_A_STATE_INFO_RECV_CNT,
+	DRBD_A_STATE_INFO_READ_CNT,
+	DRBD_A_STATE_INFO_WRIT_CNT,
+	DRBD_A_STATE_INFO_AL_WRIT_CNT,
+	DRBD_A_STATE_INFO_BM_WRIT_CNT,
+	DRBD_A_STATE_INFO_AP_BIO_CNT,
+	DRBD_A_STATE_INFO_AP_PENDING_CNT,
+	DRBD_A_STATE_INFO_RS_PENDING_CNT,
+
+	__DRBD_A_STATE_INFO_MAX,
+	DRBD_A_STATE_INFO_MAX = (__DRBD_A_STATE_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_A_START_OV_PARMS_OV_START_SECTOR = 1,
+	DRBD_A_START_OV_PARMS_OV_STOP_SECTOR,
+
+	__DRBD_A_START_OV_PARMS_MAX,
+	DRBD_A_START_OV_PARMS_MAX = (__DRBD_A_START_OV_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_NEW_C_UUID_PARMS_CLEAR_BM = 1,
+
+	__DRBD_A_NEW_C_UUID_PARMS_MAX,
+	DRBD_A_NEW_C_UUID_PARMS_MAX = (__DRBD_A_NEW_C_UUID_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_TIMEOUT_PARMS_TIMEOUT_TYPE = 1,
+
+	__DRBD_A_TIMEOUT_PARMS_MAX,
+	DRBD_A_TIMEOUT_PARMS_MAX = (__DRBD_A_TIMEOUT_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_DISCONNECT_PARMS_FORCE_DISCONNECT = 1,
+
+	__DRBD_A_DISCONNECT_PARMS_MAX,
+	DRBD_A_DISCONNECT_PARMS_MAX = (__DRBD_A_DISCONNECT_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_DETACH_PARMS_FORCE_DETACH = 1,
+
+	__DRBD_A_DETACH_PARMS_MAX,
+	DRBD_A_DETACH_PARMS_MAX = (__DRBD_A_DETACH_PARMS_MAX - 1)
+};
+
+enum {
+	DRBD_A_RESOURCE_INFO_RES_ROLE = 1,
+	DRBD_A_RESOURCE_INFO_RES_SUSP,
+	DRBD_A_RESOURCE_INFO_RES_SUSP_NOD,
+	DRBD_A_RESOURCE_INFO_RES_SUSP_FEN,
+
+	__DRBD_A_RESOURCE_INFO_MAX,
+	DRBD_A_RESOURCE_INFO_MAX = (__DRBD_A_RESOURCE_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_A_DEVICE_INFO_DEV_DISK_STATE = 1,
+
+	__DRBD_A_DEVICE_INFO_MAX,
+	DRBD_A_DEVICE_INFO_MAX = (__DRBD_A_DEVICE_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_A_CONNECTION_INFO_CONN_CONNECTION_STATE = 1,
+	DRBD_A_CONNECTION_INFO_CONN_ROLE,
+
+	__DRBD_A_CONNECTION_INFO_MAX,
+	DRBD_A_CONNECTION_INFO_MAX = (__DRBD_A_CONNECTION_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_A_PEER_DEVICE_INFO_PEER_REPL_STATE = 1,
+	DRBD_A_PEER_DEVICE_INFO_PEER_DISK_STATE,
+	DRBD_A_PEER_DEVICE_INFO_PEER_RESYNC_SUSP_USER,
+	DRBD_A_PEER_DEVICE_INFO_PEER_RESYNC_SUSP_PEER,
+	DRBD_A_PEER_DEVICE_INFO_PEER_RESYNC_SUSP_DEPENDENCY,
+
+	__DRBD_A_PEER_DEVICE_INFO_MAX,
+	DRBD_A_PEER_DEVICE_INFO_MAX = (__DRBD_A_PEER_DEVICE_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_A_RESOURCE_STATISTICS_RES_STAT_WRITE_ORDERING = 1,
+
+	__DRBD_A_RESOURCE_STATISTICS_MAX,
+	DRBD_A_RESOURCE_STATISTICS_MAX = (__DRBD_A_RESOURCE_STATISTICS_MAX - 1)
+};
+
+enum {
+	DRBD_A_DEVICE_STATISTICS_DEV_SIZE = 1,
+	DRBD_A_DEVICE_STATISTICS_DEV_READ,
+	DRBD_A_DEVICE_STATISTICS_DEV_WRITE,
+	DRBD_A_DEVICE_STATISTICS_DEV_AL_WRITES,
+	DRBD_A_DEVICE_STATISTICS_DEV_BM_WRITES,
+	DRBD_A_DEVICE_STATISTICS_DEV_UPPER_PENDING,
+	DRBD_A_DEVICE_STATISTICS_DEV_LOWER_PENDING,
+	DRBD_A_DEVICE_STATISTICS_DEV_UPPER_BLOCKED,
+	DRBD_A_DEVICE_STATISTICS_DEV_LOWER_BLOCKED,
+	DRBD_A_DEVICE_STATISTICS_DEV_AL_SUSPENDED,
+	DRBD_A_DEVICE_STATISTICS_DEV_EXPOSED_DATA_UUID,
+	DRBD_A_DEVICE_STATISTICS_DEV_CURRENT_UUID,
+	DRBD_A_DEVICE_STATISTICS_DEV_DISK_FLAGS,
+	DRBD_A_DEVICE_STATISTICS_HISTORY_UUIDS,
+
+	__DRBD_A_DEVICE_STATISTICS_MAX,
+	DRBD_A_DEVICE_STATISTICS_MAX = (__DRBD_A_DEVICE_STATISTICS_MAX - 1)
+};
+
+enum {
+	DRBD_A_CONNECTION_STATISTICS_CONN_CONGESTED = 1,
+
+	__DRBD_A_CONNECTION_STATISTICS_MAX,
+	DRBD_A_CONNECTION_STATISTICS_MAX = (__DRBD_A_CONNECTION_STATISTICS_MAX - 1)
+};
+
+enum {
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_RECEIVED = 1,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_SENT,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_PENDING,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_UNACKED,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_OUT_OF_SYNC,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_RESYNC_FAILED,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_BITMAP_UUID,
+	DRBD_A_PEER_DEVICE_STATISTICS_PEER_DEV_FLAGS = 9,
+
+	__DRBD_A_PEER_DEVICE_STATISTICS_MAX,
+	DRBD_A_PEER_DEVICE_STATISTICS_MAX = (__DRBD_A_PEER_DEVICE_STATISTICS_MAX - 1)
+};
+
+enum {
+	DRBD_A_DRBD_NOTIFICATION_HEADER_NH_TYPE = 1,
+
+	__DRBD_A_DRBD_NOTIFICATION_HEADER_MAX,
+	DRBD_A_DRBD_NOTIFICATION_HEADER_MAX = (__DRBD_A_DRBD_NOTIFICATION_HEADER_MAX - 1)
+};
+
+enum {
+	DRBD_A_DRBD_HELPER_INFO_HELPER_NAME = 1,
+	DRBD_A_DRBD_HELPER_INFO_HELPER_STATUS,
+
+	__DRBD_A_DRBD_HELPER_INFO_MAX,
+	DRBD_A_DRBD_HELPER_INFO_MAX = (__DRBD_A_DRBD_HELPER_INFO_MAX - 1)
+};
+
+enum {
+	DRBD_ADM_EVENT = 1,
+	DRBD_ADM_GET_STATUS,
+	DRBD_ADM_NEW_MINOR = 5,
+	DRBD_ADM_DEL_MINOR,
+	DRBD_ADM_NEW_RESOURCE,
+	DRBD_ADM_DEL_RESOURCE,
+	DRBD_ADM_RESOURCE_OPTS,
+	DRBD_ADM_CONNECT,
+	DRBD_ADM_DISCONNECT,
+	DRBD_ADM_ATTACH,
+	DRBD_ADM_RESIZE,
+	DRBD_ADM_PRIMARY,
+	DRBD_ADM_SECONDARY,
+	DRBD_ADM_NEW_C_UUID,
+	DRBD_ADM_START_OV,
+	DRBD_ADM_DETACH,
+	DRBD_ADM_INVALIDATE,
+	DRBD_ADM_INVAL_PEER,
+	DRBD_ADM_PAUSE_SYNC,
+	DRBD_ADM_RESUME_SYNC,
+	DRBD_ADM_SUSPEND_IO,
+	DRBD_ADM_RESUME_IO,
+	DRBD_ADM_OUTDATE,
+	DRBD_ADM_GET_TIMEOUT_TYPE,
+	DRBD_ADM_DOWN,
+	DRBD_ADM_CHG_DISK_OPTS,
+	DRBD_ADM_CHG_NET_OPTS,
+	DRBD_ADM_GET_RESOURCES,
+	DRBD_ADM_GET_DEVICES,
+	DRBD_ADM_GET_CONNECTIONS,
+	DRBD_ADM_GET_PEER_DEVICES,
+	DRBD_ADM_RESOURCE_STATE,
+	DRBD_ADM_DEVICE_STATE,
+	DRBD_ADM_CONNECTION_STATE,
+	DRBD_ADM_PEER_DEVICE_STATE,
+	DRBD_ADM_GET_INITIAL_STATE,
+	DRBD_ADM_HELPER = 40,
+	DRBD_ADM_INITIAL_STATE_DONE,
+
+	__DRBD_ADM_MAX,
+	DRBD_ADM_MAX = (__DRBD_ADM_MAX - 1)
+};
+
+#define DRBD_MCGRP_EVENTS	"events"
+
+#endif /* _UAPI_LINUX_DRBD_GENL_H */