drbd: prepare the transition from connector to genetlink

This adds the new API header and helper files.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Lars Ellenberg 2011-03-07 10:20:08 +01:00 committed by Philipp Reisner
parent 3cb7a2a90f
commit ec2c35ac1e
4 changed files with 1081 additions and 0 deletions

349
include/linux/drbd_genl.h Normal file
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/*
* General overview:
* full generic netlink message:
* |nlmsghdr|genlmsghdr|<payload>
*
* payload:
* |optional fixed size family header|<sequence of netlink attributes>
*
* sequence of netlink attributes:
* I chose to have all "top level" attributes NLA_NESTED,
* corresponding to some real struct.
* So we have a sequence of |tla, len|<nested nla sequence>
*
* nested nla sequence:
* may be empty, or contain a sequence of netlink attributes
* representing the struct fields.
*
* The tag number of any field (regardless of containing struct)
* will be available as T_ ## field_name,
* so you cannot have the same field name in two differnt structs.
*
* The tag numbers themselves are per struct, though,
* so should always begin at 1 (not 0, that is the special "NLA_UNSPEC" type,
* which we won't use here).
* The tag numbers are used as index in the respective nla_policy array.
*
* GENL_struct(tag_name, tag_number, struct name, struct fields) - struct and policy
* genl_magic_struct.h
* generates the struct declaration,
* generates an entry in the tla enum,
* genl_magic_func.h
* generates an entry in the static tla policy
* with .type = NLA_NESTED
* generates the static <struct_name>_nl_policy definition,
* and static conversion functions
*
* genl_magic_func.h
*
* GENL_mc_group(group)
* genl_magic_struct.h
* does nothing
* genl_magic_func.h
* defines and registers the mcast group,
* and provides a send helper
*
* GENL_notification(op_name, op_num, mcast_group, tla list)
* These are notifications to userspace.
*
* genl_magic_struct.h
* generates an entry in the genl_ops enum,
* genl_magic_func.h
* does nothing
*
* mcast group: the name of the mcast group this notification should be
* expected on
* tla list: the list of expected top level attributes,
* for documentation and sanity checking.
*
* GENL_op(op_name, op_num, flags and handler, tla list) - "genl operations"
* These are requests from userspace.
*
* _op and _notification share the same "number space",
* op_nr will be assigned to "genlmsghdr->cmd"
*
* genl_magic_struct.h
* generates an entry in the genl_ops enum,
* genl_magic_func.h
* generates an entry in the static genl_ops array,
* and static register/unregister functions to
* genl_register_family_with_ops().
*
* flags and handler:
* GENL_op_init( .doit = x, .dumpit = y, .flags = something)
* GENL_doit(x) => .dumpit = NULL, .flags = GENL_ADMIN_PERM
* tla list: the list of expected top level attributes,
* for documentation and sanity checking.
*/
/*
* STRUCTS
*/
/* this is sent kernel -> userland on various error conditions, and contains
* informational textual info, which is supposedly human readable.
* The computer relevant return code is in the drbd_genlmsghdr.
*/
GENL_struct(DRBD_NLA_CFG_REPLY, 1, drbd_cfg_reply,
/* "arbitrary" size strings, nla_policy.len = 0 */
__str_field(1, GENLA_F_MANDATORY, info_text, 0)
)
/* Configuration requests typically need a context to operate on.
* Possible keys are device minor (fits in the drbd_genlmsghdr),
* the replication link (aka connection) name,
* and/or the replication group (aka resource) name,
* and the volume id within the resource. */
GENL_struct(DRBD_NLA_CFG_CONTEXT, 2, drbd_cfg_context,
/* currently only 256 volumes per group,
* but maybe we still change that */
__u32_field(1, GENLA_F_MANDATORY, ctx_volume)
__str_field(2, GENLA_F_MANDATORY, ctx_conn_name, 128)
)
GENL_struct(DRBD_NLA_DISK_CONF, 3, disk_conf,
__u64_field(1, GENLA_F_MANDATORY, disk_size)
__str_field(2, GENLA_F_REQUIRED, backing_dev, 128)
__str_field(3, GENLA_F_REQUIRED, meta_dev, 128)
__u32_field(4, GENLA_F_REQUIRED, meta_dev_idx)
__u32_field(5, GENLA_F_MANDATORY, max_bio_bvecs)
__u32_field(6, GENLA_F_MANDATORY, on_io_error)
__u32_field(7, GENLA_F_MANDATORY, fencing)
__flg_field(8, GENLA_F_MANDATORY, no_disk_barrier)
__flg_field(9, GENLA_F_MANDATORY, no_disk_flush)
__flg_field(10, GENLA_F_MANDATORY, no_disk_drain)
__flg_field(11, GENLA_F_MANDATORY, no_md_flush)
__flg_field(12, GENLA_F_MANDATORY, use_bmbv)
)
GENL_struct(DRBD_NLA_SYNCER_CONF, 4, syncer_conf,
__u32_field(1, GENLA_F_MANDATORY, rate)
__u32_field(2, GENLA_F_MANDATORY, after)
__u32_field(3, GENLA_F_MANDATORY, al_extents)
__str_field(4, GENLA_F_MANDATORY, cpu_mask, 32)
__str_field(5, GENLA_F_MANDATORY, verify_alg, SHARED_SECRET_MAX)
__str_field(6, GENLA_F_MANDATORY, csums_alg, SHARED_SECRET_MAX)
__flg_field(7, GENLA_F_MANDATORY, use_rle)
__u32_field(8, GENLA_F_MANDATORY, on_no_data)
__u32_field(9, GENLA_F_MANDATORY, c_plan_ahead)
__u32_field(10, GENLA_F_MANDATORY, c_delay_target)
__u32_field(11, GENLA_F_MANDATORY, c_fill_target)
__u32_field(12, GENLA_F_MANDATORY, c_max_rate)
__u32_field(13, GENLA_F_MANDATORY, c_min_rate)
)
GENL_struct(DRBD_NLA_NET_CONF, 5, net_conf,
__str_field(1, GENLA_F_MANDATORY | GENLA_F_SENSITIVE,
shared_secret, SHARED_SECRET_MAX)
__str_field(2, GENLA_F_MANDATORY, cram_hmac_alg, SHARED_SECRET_MAX)
__str_field(3, GENLA_F_MANDATORY, integrity_alg, SHARED_SECRET_MAX)
__str_field(4, GENLA_F_REQUIRED, my_addr, 128)
__str_field(5, GENLA_F_REQUIRED, peer_addr, 128)
__u32_field(6, GENLA_F_REQUIRED, wire_protocol)
__u32_field(7, GENLA_F_MANDATORY, try_connect_int)
__u32_field(8, GENLA_F_MANDATORY, timeout)
__u32_field(9, GENLA_F_MANDATORY, ping_int)
__u32_field(10, GENLA_F_MANDATORY, ping_timeo)
__u32_field(11, GENLA_F_MANDATORY, sndbuf_size)
__u32_field(12, GENLA_F_MANDATORY, rcvbuf_size)
__u32_field(13, GENLA_F_MANDATORY, ko_count)
__u32_field(14, GENLA_F_MANDATORY, max_buffers)
__u32_field(15, GENLA_F_MANDATORY, max_epoch_size)
__u32_field(16, GENLA_F_MANDATORY, unplug_watermark)
__u32_field(17, GENLA_F_MANDATORY, after_sb_0p)
__u32_field(18, GENLA_F_MANDATORY, after_sb_1p)
__u32_field(19, GENLA_F_MANDATORY, after_sb_2p)
__u32_field(20, GENLA_F_MANDATORY, rr_conflict)
__u32_field(21, GENLA_F_MANDATORY, on_congestion)
__u32_field(22, GENLA_F_MANDATORY, cong_fill)
__u32_field(23, GENLA_F_MANDATORY, cong_extents)
__flg_field(24, GENLA_F_MANDATORY, two_primaries)
__flg_field(25, GENLA_F_MANDATORY, want_lose)
__flg_field(26, GENLA_F_MANDATORY, no_cork)
__flg_field(27, GENLA_F_MANDATORY, always_asbp)
__flg_field(28, GENLA_F_MANDATORY, dry_run)
)
GENL_struct(DRBD_NLA_SET_ROLE_PARMS, 6, set_role_parms,
__flg_field(1, GENLA_F_MANDATORY, assume_uptodate)
)
GENL_struct(DRBD_NLA_RESIZE_PARMS, 7, resize_parms,
__u64_field(1, GENLA_F_MANDATORY, resize_size)
__flg_field(2, GENLA_F_MANDATORY, resize_force)
__flg_field(3, GENLA_F_MANDATORY, no_resync)
)
GENL_struct(DRBD_NLA_STATE_INFO, 8, state_info,
/* the reason of the broadcast,
* if this is an event triggered broadcast. */
__u32_field(1, GENLA_F_MANDATORY, sib_reason)
__u32_field(2, GENLA_F_REQUIRED, current_state)
__u64_field(3, GENLA_F_MANDATORY, capacity)
__u64_field(4, GENLA_F_MANDATORY, ed_uuid)
/* These are for broadcast from after state change work.
* prev_state and new_state are from the moment the state change took
* place, new_state is not neccessarily the same as current_state,
* there may have been more state changes since. Which will be
* broadcasted soon, in their respective after state change work. */
__u32_field(5, GENLA_F_MANDATORY, prev_state)
__u32_field(6, GENLA_F_MANDATORY, new_state)
/* if we have a local disk: */
__bin_field(7, GENLA_F_MANDATORY, uuids, (UI_SIZE*sizeof(__u64)))
__u32_field(8, GENLA_F_MANDATORY, disk_flags)
__u64_field(9, GENLA_F_MANDATORY, bits_total)
__u64_field(10, GENLA_F_MANDATORY, bits_oos)
/* and in case resync or online verify is active */
__u64_field(11, GENLA_F_MANDATORY, bits_rs_total)
__u64_field(12, GENLA_F_MANDATORY, bits_rs_failed)
/* for pre and post notifications of helper execution */
__str_field(13, GENLA_F_MANDATORY, helper, 32)
__u32_field(14, GENLA_F_MANDATORY, helper_exit_code)
)
GENL_struct(DRBD_NLA_START_OV_PARMS, 9, start_ov_parms,
__u64_field(1, GENLA_F_MANDATORY, ov_start_sector)
)
GENL_struct(DRBD_NLA_NEW_C_UUID_PARMS, 10, new_c_uuid_parms,
__flg_field(1, GENLA_F_MANDATORY, clear_bm)
)
GENL_struct(DRBD_NLA_TIMEOUT_PARMS, 11, timeout_parms,
__u32_field(1, GENLA_F_REQUIRED, timeout_type)
)
GENL_struct(DRBD_NLA_DISCONNECT_PARMS, 12, disconnect_parms,
__flg_field(1, GENLA_F_MANDATORY, force_disconnect)
)
/*
* Notifications and commands (genlmsghdr->cmd)
*/
GENL_mc_group(events)
/* kernel -> userspace announcement of changes */
GENL_notification(
DRBD_EVENT, 1, events,
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_STATE_INFO, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_NET_CONF, GENLA_F_MANDATORY)
GENL_tla_expected(DRBD_NLA_DISK_CONF, GENLA_F_MANDATORY)
GENL_tla_expected(DRBD_NLA_SYNCER_CONF, GENLA_F_MANDATORY)
)
/* query kernel for specific or all info */
GENL_op(
DRBD_ADM_GET_STATUS, 2,
GENL_op_init(
.doit = drbd_adm_get_status,
.dumpit = drbd_adm_get_status_all,
/* anyone may ask for the status,
* it is broadcasted anyways */
),
/* To select the object .doit.
* Or a subset of objects in .dumpit. */
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_MANDATORY)
)
#if 0
/* TO BE DONE */
/* create or destroy resources, aka replication groups */
GENL_op(DRBD_ADM_CREATE_RESOURCE, 3, GENL_doit(drbd_adm_create_resource),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_DELETE_RESOURCE, 4, GENL_doit(drbd_adm_delete_resource),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
#endif
/* add DRBD minor devices as volumes to resources */
GENL_op(DRBD_ADM_ADD_MINOR, 5, GENL_doit(drbd_adm_add_minor),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_DEL_MINOR, 6, GENL_doit(drbd_adm_delete_minor),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
/* add or delete replication links to resources */
GENL_op(DRBD_ADM_ADD_LINK, 7, GENL_doit(drbd_adm_create_connection),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_DEL_LINK, 8, GENL_doit(drbd_adm_delete_connection),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
/* operates on replication links */
GENL_op(DRBD_ADM_SYNCER, 9,
GENL_doit(drbd_adm_syncer),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_SYNCER_CONF, GENLA_F_MANDATORY)
)
GENL_op(
DRBD_ADM_CONNECT, 10,
GENL_doit(drbd_adm_connect),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_NET_CONF, GENLA_F_REQUIRED)
)
GENL_op(DRBD_ADM_DISCONNECT, 11, GENL_doit(drbd_adm_disconnect),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
/* operates on minors */
GENL_op(DRBD_ADM_ATTACH, 12,
GENL_doit(drbd_adm_attach),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_DISK_CONF, GENLA_F_REQUIRED)
)
GENL_op(
DRBD_ADM_RESIZE, 13,
GENL_doit(drbd_adm_resize),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_RESIZE_PARMS, GENLA_F_MANDATORY)
)
/* operates on all volumes within a resource */
GENL_op(
DRBD_ADM_PRIMARY, 14,
GENL_doit(drbd_adm_set_role),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_SET_ROLE_PARMS, GENLA_F_REQUIRED)
)
GENL_op(
DRBD_ADM_SECONDARY, 15,
GENL_doit(drbd_adm_set_role),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_SET_ROLE_PARMS, GENLA_F_REQUIRED)
)
GENL_op(
DRBD_ADM_NEW_C_UUID, 16,
GENL_doit(drbd_adm_new_c_uuid),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED)
GENL_tla_expected(DRBD_NLA_NEW_C_UUID_PARMS, GENLA_F_MANDATORY)
)
GENL_op(
DRBD_ADM_START_OV, 17,
GENL_doit(drbd_adm_start_ov),
GENL_tla_expected(DRBD_NLA_START_OV_PARMS, GENLA_F_MANDATORY)
)
GENL_op(DRBD_ADM_DETACH, 18, GENL_doit(drbd_adm_detach),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_INVALIDATE, 19, GENL_doit(drbd_adm_invalidate),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_INVAL_PEER, 20, GENL_doit(drbd_adm_invalidate_peer),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_PAUSE_SYNC, 21, GENL_doit(drbd_adm_pause_sync),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_RESUME_SYNC, 22, GENL_doit(drbd_adm_resume_sync),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_SUSPEND_IO, 23, GENL_doit(drbd_adm_suspend_io),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_RESUME_IO, 24, GENL_doit(drbd_adm_resume_io),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_OUTDATE, 25, GENL_doit(drbd_adm_outdate),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))
GENL_op(DRBD_ADM_GET_TIMEOUT_TYPE, 26, GENL_doit(drbd_adm_get_timeout_type),
GENL_tla_expected(DRBD_NLA_CFG_CONTEXT, GENLA_F_REQUIRED))

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#ifndef DRBD_GENL_STRUCT_H
#define DRBD_GENL_STRUCT_H
/**
* struct drbd_genlmsghdr - DRBD specific header used in NETLINK_GENERIC requests
* @minor:
* For admin requests (user -> kernel): which minor device to operate on.
* For (unicast) replies or informational (broadcast) messages
* (kernel -> user): which minor device the information is about.
* If we do not operate on minors, but on connections or resources,
* the minor value shall be (~0), and the attribute DRBD_NLA_CFG_CONTEXT
* is used instead.
* @flags: possible operation modifiers (relevant only for user->kernel):
* DRBD_GENL_F_SET_DEFAULTS
* @volume:
* When creating a new minor (adding it to a resource), the resource needs
* to know which volume number within the resource this is supposed to be.
* The volume number corresponds to the same volume number on the remote side,
* whereas the minor number on the remote side may be different
* (union with flags).
* @ret_code: kernel->userland unicast cfg reply return code (union with flags);
*/
struct drbd_genlmsghdr {
__u32 minor;
union {
__u32 flags;
__s32 ret_code;
};
};
/* To be used in drbd_genlmsghdr.flags */
enum {
DRBD_GENL_F_SET_DEFAULTS = 1,
};
enum drbd_state_info_bcast_reason {
SIB_GET_STATUS_REPLY = 1,
SIB_STATE_CHANGE = 2,
SIB_HELPER_PRE = 3,
SIB_HELPER_POST = 4,
SIB_SYNC_PROGRESS = 5,
};
/* hack around predefined gcc/cpp "linux=1",
* we cannot possibly include <1/drbd_genl.h> */
#undef linux
#include <linux/drbd.h>
#define GENL_MAGIC_VERSION API_VERSION
#define GENL_MAGIC_FAMILY drbd
#define GENL_MAGIC_FAMILY_HDRSZ sizeof(struct drbd_genlmsghdr)
#define GENL_MAGIC_INCLUDE_FILE <linux/drbd_genl.h>
#include <linux/genl_magic_struct.h>
#endif

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#ifndef GENL_MAGIC_FUNC_H
#define GENL_MAGIC_FUNC_H
#include <linux/genl_magic_struct.h>
/*
* Extension of genl attribute validation policies {{{1
* {{{2
*/
/**
* nla_is_required - return true if this attribute is required
* @nla: netlink attribute
*/
static inline int nla_is_required(const struct nlattr *nla)
{
return nla->nla_type & GENLA_F_REQUIRED;
}
/**
* nla_is_mandatory - return true if understanding this attribute is mandatory
* @nla: netlink attribute
* Note: REQUIRED attributes are implicitly MANDATORY as well
*/
static inline int nla_is_mandatory(const struct nlattr *nla)
{
return nla->nla_type & (GENLA_F_MANDATORY | GENLA_F_REQUIRED);
}
/* Functionality to be integrated into nla_parse(), and validate_nla(),
* respectively.
*
* Enforcing the "mandatory" bit is done here,
* by rejecting unknown mandatory attributes.
*
* Part of enforcing the "required" flag would mean to embed it into
* nla_policy.type, and extending validate_nla(), which currently does
* BUG_ON(pt->type > NLA_TYPE_MAX); we have to work on existing kernels,
* so we cannot do that. Thats why enforcing "required" is done in the
* generated assignment functions below. */
static int nla_check_unknown(int maxtype, struct nlattr *head, int len)
{
struct nlattr *nla;
int rem;
nla_for_each_attr(nla, head, len, rem) {
__u16 type = nla_type(nla);
if (type > maxtype && nla_is_mandatory(nla))
return -EOPNOTSUPP;
}
return 0;
}
/*
* Magic: declare tla policy {{{1
* Magic: declare nested policies
* {{{2
*/
#undef GENL_mc_group
#define GENL_mc_group(group)
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list)
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
[tag_name] = { .type = NLA_NESTED },
static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static struct nla_policy s_name ## _nl_policy[] __read_mostly = \
{ s_fields };
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, _type, __get, __put) \
[__nla_type(attr_nr)] = { .type = nla_type },
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \
__get, __put) \
[__nla_type(attr_nr)] = { .type = nla_type, \
.len = maxlen - (nla_type == NLA_NUL_STRING) },
#include GENL_MAGIC_INCLUDE_FILE
#ifndef __KERNEL__
#ifndef pr_info
#define pr_info(args...) fprintf(stderr, args);
#endif
#endif
#if 1
static void dprint_field(const char *dir, int nla_type,
const char *name, void *valp)
{
__u64 val = valp ? *(__u32 *)valp : 1;
switch (nla_type) {
case NLA_U8: val = (__u8)val;
case NLA_U16: val = (__u16)val;
case NLA_U32: val = (__u32)val;
pr_info("%s attr %s: %d 0x%08x\n", dir,
name, (int)val, (unsigned)val);
break;
case NLA_U64:
val = *(__u64*)valp;
pr_info("%s attr %s: %lld 0x%08llx\n", dir,
name, (long long)val, (unsigned long long)val);
break;
case NLA_FLAG:
if (val)
pr_info("%s attr %s: set\n", dir, name);
break;
}
}
static void dprint_array(const char *dir, int nla_type,
const char *name, const char *val, unsigned len)
{
switch (nla_type) {
case NLA_NUL_STRING:
if (len && val[len-1] == '\0')
len--;
pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val);
break;
default:
/* we can always show 4 byte,
* thats what nlattr are aligned to. */
pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n",
dir, name, len, val[0], val[1], val[2], val[3]);
}
}
#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b);
/* Name is a member field name of the struct s.
* If s is NULL (only parsing, no copy requested in *_from_attrs()),
* nla is supposed to point to the attribute containing the information
* corresponding to that struct member. */
#define DPRINT_FIELD(dir, nla_type, name, s, nla) \
do { \
if (s) \
dprint_field(dir, nla_type, #name, &s->name); \
else if (nla) \
dprint_field(dir, nla_type, #name, \
(nla_type == NLA_FLAG) ? NULL \
: nla_data(nla)); \
} while (0)
#define DPRINT_ARRAY(dir, nla_type, name, s, nla) \
do { \
if (s) \
dprint_array(dir, nla_type, #name, \
s->name, s->name ## _len); \
else if (nla) \
dprint_array(dir, nla_type, #name, \
nla_data(nla), nla_len(nla)); \
} while (0)
#else
#define DPRINT_TLA(a, op, b) do {} while (0)
#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0)
#define DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0)
#endif
/*
* Magic: provide conversion functions {{{1
* populate struct from attribute table:
* {{{2
*/
/* processing of generic netlink messages is serialized.
* use one static buffer for parsing of nested attributes */
static struct nlattr *nested_attr_tb[128];
#ifndef BUILD_BUG_ON
/* Force a compilation error if condition is true */
#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
/* Force a compilation error if condition is true, but also produce a
result (of value 0 and type size_t), so the expression can be used
e.g. in a structure initializer (or where-ever else comma expressions
aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
#endif
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
/* static, potentially unused */ \
int s_name ## _from_attrs(struct s_name *s, struct nlattr *tb[]) \
{ \
const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1; \
struct nlattr *tla = tb[tag_number]; \
struct nlattr **ntb = nested_attr_tb; \
struct nlattr *nla; \
int err; \
BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb)); \
if (!tla) \
return -ENOMSG; \
DPRINT_TLA(#s_name, "<=-", #tag_name); \
err = nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \
if (err) \
return err; \
err = nla_check_unknown(maxtype, nla_data(tla), nla_len(tla)); \
if (err) \
return err; \
\
s_fields \
return 0; \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
nla = ntb[__nla_type(attr_nr)]; \
if (nla) { \
if (s) \
s->name = __get(nla); \
DPRINT_FIELD("<<", nla_type, name, s, nla); \
} else if ((attr_flag) & GENLA_F_REQUIRED) { \
pr_info("<< missing attr: %s\n", #name); \
return -ENOMSG; \
}
/* validate_nla() already checked nla_len <= maxlen appropriately. */
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
nla = ntb[__nla_type(attr_nr)]; \
if (nla) { \
if (s) \
s->name ## _len = \
__get(s->name, nla, maxlen); \
DPRINT_ARRAY("<<", nla_type, name, s, nla); \
} else if ((attr_flag) & GENLA_F_REQUIRED) { \
pr_info("<< missing attr: %s\n", #name); \
return -ENOMSG; \
} \
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
/*
* Magic: define op number to op name mapping {{{1
* {{{2
*/
const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
{
switch (cmd) {
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
case op_num: return #op_name;
#include GENL_MAGIC_INCLUDE_FILE
default:
return "unknown";
}
}
#ifdef __KERNEL__
#include <linux/stringify.h>
/*
* Magic: define genl_ops {{{1
* {{{2
*/
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
{ \
handler \
.cmd = op_name, \
.policy = CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy), \
},
#define ZZZ_genl_ops CONCAT_(GENL_MAGIC_FAMILY, _genl_ops)
static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list)
/*
* Define the genl_family, multicast groups, {{{1
* and provide register/unregister functions.
* {{{2
*/
#define ZZZ_genl_family CONCAT_(GENL_MAGIC_FAMILY, _genl_family)
static struct genl_family ZZZ_genl_family __read_mostly = {
.id = GENL_ID_GENERATE,
.name = __stringify(GENL_MAGIC_FAMILY),
.version = GENL_MAGIC_VERSION,
#ifdef GENL_MAGIC_FAMILY_HDRSZ
.hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
#endif
.maxattr = ARRAY_SIZE(drbd_tla_nl_policy)-1,
};
/*
* Magic: define multicast groups
* Magic: define multicast group registration helper
*/
#undef GENL_mc_group
#define GENL_mc_group(group) \
static struct genl_multicast_group \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group) __read_mostly = { \
.name = #group, \
}; \
static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
struct sk_buff *skb, gfp_t flags) \
{ \
unsigned int group_id = \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id; \
if (!group_id) \
return -EINVAL; \
return genlmsg_multicast(skb, 0, group_id, flags); \
}
#include GENL_MAGIC_INCLUDE_FILE
int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
{
int err = genl_register_family_with_ops(&ZZZ_genl_family,
ZZZ_genl_ops, ARRAY_SIZE(ZZZ_genl_ops));
if (err)
return err;
#undef GENL_mc_group
#define GENL_mc_group(group) \
err = genl_register_mc_group(&ZZZ_genl_family, \
&CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group)); \
if (err) \
goto fail; \
else \
pr_info("%s: mcg %s: %u\n", #group, \
__stringify(GENL_MAGIC_FAMILY), \
CONCAT_(GENL_MAGIC_FAMILY, _mcg_ ## group).id);
#include GENL_MAGIC_INCLUDE_FILE
#undef GENL_mc_group
#define GENL_mc_group(group)
return 0;
fail:
genl_unregister_family(&ZZZ_genl_family);
return err;
}
void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
{
genl_unregister_family(&ZZZ_genl_family);
}
/*
* Magic: provide conversion functions {{{1
* populate skb from struct.
* {{{2
*/
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \
const bool exclude_sensitive) \
{ \
struct nlattr *tla = nla_nest_start(skb, tag_number); \
if (!tla) \
goto nla_put_failure; \
DPRINT_TLA(#s_name, "-=>", #tag_name); \
s_fields \
nla_nest_end(skb, tla); \
return 0; \
\
nla_put_failure: \
if (tla) \
nla_nest_cancel(skb, tla); \
return -EMSGSIZE; \
} \
static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \
struct s_name *s) \
{ \
return s_name ## _to_skb(skb, s, 0); \
} \
static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \
struct s_name *s) \
{ \
return s_name ## _to_skb(skb, s, 1); \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \
DPRINT_FIELD(">>", nla_type, name, s, NULL); \
__put(skb, attr_nr, s->name); \
}
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
if (!exclude_sensitive || !((attr_flag) & GENLA_F_SENSITIVE)) { \
DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
__put(skb, attr_nr, min_t(int, maxlen, \
s->name ## _len + (nla_type == NLA_NUL_STRING)),\
s->name); \
}
#include GENL_MAGIC_INCLUDE_FILE
#endif /* __KERNEL__ */
/* }}}1 */
#endif /* GENL_MAGIC_FUNC_H */
/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */

View File

@ -0,0 +1,260 @@
#ifndef GENL_MAGIC_STRUCT_H
#define GENL_MAGIC_STRUCT_H
#ifndef GENL_MAGIC_FAMILY
# error "you need to define GENL_MAGIC_FAMILY before inclusion"
#endif
#ifndef GENL_MAGIC_VERSION
# error "you need to define GENL_MAGIC_VERSION before inclusion"
#endif
#ifndef GENL_MAGIC_INCLUDE_FILE
# error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion"
#endif
#include <linux/genetlink.h>
#include <linux/types.h>
#define CONCAT__(a,b) a ## b
#define CONCAT_(a,b) CONCAT__(a,b)
extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void);
extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void);
/*
* Extension of genl attribute validation policies {{{2
*/
/**
* GENLA_F_FLAGS - policy type flags to ease compatible ABI evolvement
*
* @GENLA_F_REQUIRED: attribute has to be present, or message is considered invalid.
* Adding new REQUIRED attributes breaks ABI compatibility, so don't do that.
*
* @GENLA_F_MANDATORY: if present, receiver _must_ understand it.
* Without this, unknown attributes (> maxtype) are _silently_ ignored
* by validate_nla().
*
* To be used for API extensions, so older kernel can reject requests for not
* yet implemented features, if newer userland tries to use them even though
* the genl_family version clearly indicates they are not available.
*
* @GENLA_F_MAY_IGNORE: To clearly document the fact, for good measure.
* To be used for API extensions for things that have sane defaults,
* so newer userland can still talk to older kernel, knowing it will
* silently ignore these attributes if not yet known.
*
* NOTE: These flags overload
* NLA_F_NESTED (1 << 15)
* NLA_F_NET_BYTEORDER (1 << 14)
* from linux/netlink.h, which are not useful for validate_nla():
* NET_BYTEORDER is not used anywhere, and NESTED would be specified by setting
* .type = NLA_NESTED in the appropriate policy.
*
* See also: nla_type()
*/
enum {
GENLA_F_MAY_IGNORE = 0,
GENLA_F_MANDATORY = 1 << 14,
GENLA_F_REQUIRED = 1 << 15,
/* This will not be present in the __u16 .nla_type, but can be
* triggered on in <struct>_to_skb, to exclude "sensitive"
* information from broadcasts, or on unpriviledged get requests.
* This is useful because genetlink multicast groups can be listened in
* on by anyone. */
GENLA_F_SENSITIVE = 1 << 16,
};
#define __nla_type(x) ((__u16)((__u16)(x) & (__u16)NLA_TYPE_MASK))
/* }}}1
* MAGIC
* multi-include macro expansion magic starts here
*/
/* MAGIC helpers {{{2 */
/* possible field types */
#define __flg_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_FLAG, char, \
nla_get_flag, __nla_put_flag)
#define __u8_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U8, unsigned char, \
nla_get_u8, NLA_PUT_U8)
#define __u16_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U16, __u16, \
nla_get_u16, NLA_PUT_U16)
#define __u32_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U32, __u32, \
nla_get_u32, NLA_PUT_U32)
#define __u64_field(attr_nr, attr_flag, name) \
__field(attr_nr, attr_flag, name, NLA_U64, __u64, \
nla_get_u64, NLA_PUT_U64)
#define __str_field(attr_nr, attr_flag, name, maxlen) \
__array(attr_nr, attr_flag, name, NLA_NUL_STRING, char, maxlen, \
nla_strlcpy, NLA_PUT)
#define __bin_field(attr_nr, attr_flag, name, maxlen) \
__array(attr_nr, attr_flag, name, NLA_BINARY, char, maxlen, \
nla_memcpy, NLA_PUT)
#define __nla_put_flag(skb, attrtype, value) \
do { \
if (value) \
NLA_PUT_FLAG(skb, attrtype); \
} while (0)
#define GENL_op_init(args...) args
#define GENL_doit(handler) \
.doit = handler, \
.flags = GENL_ADMIN_PERM,
#define GENL_dumpit(handler) \
.dumpit = handler, \
.flags = GENL_ADMIN_PERM,
/* }}}1
* Magic: define the enum symbols for genl_ops
* Magic: define the enum symbols for top level attributes
* Magic: define the enum symbols for nested attributes
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
#undef GENL_mc_group
#define GENL_mc_group(group)
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list) \
op_name = op_num,
#undef GENL_op
#define GENL_op(op_name, op_num, handler, tla_list) \
op_name = op_num,
enum {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list)
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
tag_name = tag_number,
enum {
#include GENL_MAGIC_INCLUDE_FILE
};
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
enum { \
s_fields \
};
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
T_ ## name = (__u16)(attr_nr | attr_flag),
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
T_ ## name = (__u16)(attr_nr | attr_flag),
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1
* Magic: compile time assert unique numbers for operations
* Magic: -"- unique numbers for top level attributes
* Magic: -"- unique numbers for nested attributes
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields)
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list) \
case op_name:
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list) \
case op_name:
static inline void ct_assert_unique_operations(void)
{
switch (0) {
#include GENL_MAGIC_INCLUDE_FILE
;
}
}
#undef GENL_op
#define GENL_op(op_name, op_num, handler, attr_list)
#undef GENL_notification
#define GENL_notification(op_name, op_num, mcast_group, tla_list)
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
case tag_number:
static inline void ct_assert_unique_top_level_attributes(void)
{
switch (0) {
#include GENL_MAGIC_INCLUDE_FILE
;
}
}
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
static inline void ct_assert_unique_ ## s_name ## _attributes(void) \
{ \
switch (0) { \
s_fields \
; \
} \
}
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
case attr_nr:
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
case attr_nr:
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1
* Magic: declare structs
* struct <name> {
* fields
* };
* {{{2
*/
#undef GENL_struct
#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
struct s_name { s_fields };
#undef __field
#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put) \
type name;
#undef __array
#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, __get, __put) \
type name[maxlen]; \
__u32 name ## _len;
#include GENL_MAGIC_INCLUDE_FILE
/* }}}1 */
#endif /* GENL_MAGIC_STRUCT_H */
/* vim: set foldmethod=marker nofoldenable : */