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![Johannes Berg](/assets/img/avatar_default.png)
Since maxattr is common, the policy can't really differ sanely, so make it common as well. The only user that did in fact manage to make a non-common policy is taskstats, which has to be really careful about it (since it's still using a common maxattr!). This is no longer supported, but we can fake it using pre_doit. This reduces the size of e.g. nl80211.o (which has lots of commands): text data bss dec hex filename 398745 14323 2240 415308 6564c net/wireless/nl80211.o (before) 397913 14331 2240 414484 65314 net/wireless/nl80211.o (after) -------------------------------- -832 +8 0 -824 Which is obviously just 8 bytes for each command, and an added 8 bytes for the new policy pointer. I'm not sure why the ops list is counted as .text though. Most of the code transformations were done using the following spatch: @ops@ identifier OPS; expression POLICY; @@ struct genl_ops OPS[] = { ..., { - .policy = POLICY, }, ... }; @@ identifier ops.OPS; expression ops.POLICY; identifier fam; expression M; @@ struct genl_family fam = { .ops = OPS, .maxattr = M, + .policy = POLICY, ... }; This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing the cb->data as ops, which we want to change in a later genl patch. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
407 lines
12 KiB
C
407 lines
12 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef GENL_MAGIC_FUNC_H
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#define GENL_MAGIC_FUNC_H
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#include <linux/build_bug.h>
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#include <linux/genl_magic_struct.h>
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/*
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* Magic: declare tla policy {{{1
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* Magic: declare nested policies
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* {{{2
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*/
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#undef GENL_mc_group
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#define GENL_mc_group(group)
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#undef GENL_notification
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#define GENL_notification(op_name, op_num, mcast_group, tla_list)
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#undef GENL_op
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#define GENL_op(op_name, op_num, handler, tla_list)
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
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[tag_name] = { .type = NLA_NESTED },
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static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
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#include GENL_MAGIC_INCLUDE_FILE
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};
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
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static struct nla_policy s_name ## _nl_policy[] __read_mostly = \
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{ s_fields };
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#undef __field
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#define __field(attr_nr, attr_flag, name, nla_type, _type, __get, \
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__put, __is_signed) \
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[attr_nr] = { .type = nla_type },
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#undef __array
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#define __array(attr_nr, attr_flag, name, nla_type, _type, maxlen, \
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__get, __put, __is_signed) \
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[attr_nr] = { .type = nla_type, \
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.len = maxlen - (nla_type == NLA_NUL_STRING) },
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#include GENL_MAGIC_INCLUDE_FILE
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#ifndef __KERNEL__
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#ifndef pr_info
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#define pr_info(args...) fprintf(stderr, args);
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#endif
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#endif
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#ifdef GENL_MAGIC_DEBUG
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static void dprint_field(const char *dir, int nla_type,
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const char *name, void *valp)
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{
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__u64 val = valp ? *(__u32 *)valp : 1;
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switch (nla_type) {
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case NLA_U8: val = (__u8)val;
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case NLA_U16: val = (__u16)val;
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case NLA_U32: val = (__u32)val;
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pr_info("%s attr %s: %d 0x%08x\n", dir,
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name, (int)val, (unsigned)val);
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break;
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case NLA_U64:
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val = *(__u64*)valp;
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pr_info("%s attr %s: %lld 0x%08llx\n", dir,
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name, (long long)val, (unsigned long long)val);
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break;
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case NLA_FLAG:
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if (val)
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pr_info("%s attr %s: set\n", dir, name);
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break;
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}
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}
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static void dprint_array(const char *dir, int nla_type,
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const char *name, const char *val, unsigned len)
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{
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switch (nla_type) {
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case NLA_NUL_STRING:
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if (len && val[len-1] == '\0')
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len--;
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pr_info("%s attr %s: [len:%u] '%s'\n", dir, name, len, val);
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break;
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default:
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/* we can always show 4 byte,
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* thats what nlattr are aligned to. */
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pr_info("%s attr %s: [len:%u] %02x%02x%02x%02x ...\n",
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dir, name, len, val[0], val[1], val[2], val[3]);
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}
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}
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#define DPRINT_TLA(a, op, b) pr_info("%s %s %s\n", a, op, b);
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/* Name is a member field name of the struct s.
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* If s is NULL (only parsing, no copy requested in *_from_attrs()),
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* nla is supposed to point to the attribute containing the information
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* corresponding to that struct member. */
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#define DPRINT_FIELD(dir, nla_type, name, s, nla) \
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do { \
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if (s) \
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dprint_field(dir, nla_type, #name, &s->name); \
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else if (nla) \
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dprint_field(dir, nla_type, #name, \
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(nla_type == NLA_FLAG) ? NULL \
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: nla_data(nla)); \
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} while (0)
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#define DPRINT_ARRAY(dir, nla_type, name, s, nla) \
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do { \
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if (s) \
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dprint_array(dir, nla_type, #name, \
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s->name, s->name ## _len); \
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else if (nla) \
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dprint_array(dir, nla_type, #name, \
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nla_data(nla), nla_len(nla)); \
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} while (0)
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#else
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#define DPRINT_TLA(a, op, b) do {} while (0)
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#define DPRINT_FIELD(dir, nla_type, name, s, nla) do {} while (0)
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#define DPRINT_ARRAY(dir, nla_type, name, s, nla) do {} while (0)
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#endif
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/*
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* Magic: provide conversion functions {{{1
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* populate struct from attribute table:
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* {{{2
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*/
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/* processing of generic netlink messages is serialized.
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* use one static buffer for parsing of nested attributes */
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static struct nlattr *nested_attr_tb[128];
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
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/* *_from_attrs functions are static, but potentially unused */ \
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static int __ ## s_name ## _from_attrs(struct s_name *s, \
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struct genl_info *info, bool exclude_invariants) \
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{ \
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const int maxtype = ARRAY_SIZE(s_name ## _nl_policy)-1; \
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struct nlattr *tla = info->attrs[tag_number]; \
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struct nlattr **ntb = nested_attr_tb; \
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struct nlattr *nla; \
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int err; \
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BUILD_BUG_ON(ARRAY_SIZE(s_name ## _nl_policy) > ARRAY_SIZE(nested_attr_tb)); \
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if (!tla) \
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return -ENOMSG; \
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DPRINT_TLA(#s_name, "<=-", #tag_name); \
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err = drbd_nla_parse_nested(ntb, maxtype, tla, s_name ## _nl_policy); \
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if (err) \
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return err; \
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\
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s_fields \
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return 0; \
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} __attribute__((unused)) \
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static int s_name ## _from_attrs(struct s_name *s, \
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struct genl_info *info) \
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{ \
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return __ ## s_name ## _from_attrs(s, info, false); \
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} __attribute__((unused)) \
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static int s_name ## _from_attrs_for_change(struct s_name *s, \
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struct genl_info *info) \
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{ \
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return __ ## s_name ## _from_attrs(s, info, true); \
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} __attribute__((unused)) \
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#define __assign(attr_nr, attr_flag, name, nla_type, type, assignment...) \
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nla = ntb[attr_nr]; \
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if (nla) { \
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if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
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pr_info("<< must not change invariant attr: %s\n", #name); \
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return -EEXIST; \
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} \
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assignment; \
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} else if (exclude_invariants && !!((attr_flag) & DRBD_F_INVARIANT)) { \
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/* attribute missing from payload, */ \
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/* which was expected */ \
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} else if ((attr_flag) & DRBD_F_REQUIRED) { \
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pr_info("<< missing attr: %s\n", #name); \
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return -ENOMSG; \
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}
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#undef __field
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#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
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__is_signed) \
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__assign(attr_nr, attr_flag, name, nla_type, type, \
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if (s) \
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s->name = __get(nla); \
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DPRINT_FIELD("<<", nla_type, name, s, nla))
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/* validate_nla() already checked nla_len <= maxlen appropriately. */
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#undef __array
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#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
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__get, __put, __is_signed) \
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__assign(attr_nr, attr_flag, name, nla_type, type, \
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if (s) \
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s->name ## _len = \
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__get(s->name, nla, maxlen); \
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DPRINT_ARRAY("<<", nla_type, name, s, nla))
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#include GENL_MAGIC_INCLUDE_FILE
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields)
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/*
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* Magic: define op number to op name mapping {{{1
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* {{{2
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*/
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const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
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{
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switch (cmd) {
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#undef GENL_op
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#define GENL_op(op_name, op_num, handler, tla_list) \
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case op_num: return #op_name;
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#include GENL_MAGIC_INCLUDE_FILE
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default:
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return "unknown";
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}
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}
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#ifdef __KERNEL__
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#include <linux/stringify.h>
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/*
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* Magic: define genl_ops {{{1
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* {{{2
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*/
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#undef GENL_op
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#define GENL_op(op_name, op_num, handler, tla_list) \
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{ \
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handler \
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.cmd = op_name, \
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},
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#define ZZZ_genl_ops CONCAT_(GENL_MAGIC_FAMILY, _genl_ops)
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static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
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#include GENL_MAGIC_INCLUDE_FILE
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};
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#undef GENL_op
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#define GENL_op(op_name, op_num, handler, tla_list)
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/*
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* Define the genl_family, multicast groups, {{{1
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* and provide register/unregister functions.
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* {{{2
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*/
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#define ZZZ_genl_family CONCAT_(GENL_MAGIC_FAMILY, _genl_family)
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static struct genl_family ZZZ_genl_family;
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/*
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* Magic: define multicast groups
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* Magic: define multicast group registration helper
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*/
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#define ZZZ_genl_mcgrps CONCAT_(GENL_MAGIC_FAMILY, _genl_mcgrps)
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static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
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#undef GENL_mc_group
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#define GENL_mc_group(group) { .name = #group, },
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#include GENL_MAGIC_INCLUDE_FILE
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};
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enum CONCAT_(GENL_MAGIC_FAMILY, group_ids) {
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#undef GENL_mc_group
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#define GENL_mc_group(group) CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group),
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#include GENL_MAGIC_INCLUDE_FILE
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};
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#undef GENL_mc_group
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#define GENL_mc_group(group) \
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static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)( \
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struct sk_buff *skb, gfp_t flags) \
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{ \
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unsigned int group_id = \
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CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group); \
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return genlmsg_multicast(&ZZZ_genl_family, skb, 0, \
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group_id, flags); \
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}
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#include GENL_MAGIC_INCLUDE_FILE
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#undef GENL_mc_group
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#define GENL_mc_group(group)
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static struct genl_family ZZZ_genl_family __ro_after_init = {
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.name = __stringify(GENL_MAGIC_FAMILY),
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.version = GENL_MAGIC_VERSION,
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#ifdef GENL_MAGIC_FAMILY_HDRSZ
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.hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
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#endif
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.maxattr = ARRAY_SIZE(CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
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.policy = CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy),
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.ops = ZZZ_genl_ops,
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.n_ops = ARRAY_SIZE(ZZZ_genl_ops),
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.mcgrps = ZZZ_genl_mcgrps,
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.n_mcgrps = ARRAY_SIZE(ZZZ_genl_mcgrps),
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.module = THIS_MODULE,
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};
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int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
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{
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return genl_register_family(&ZZZ_genl_family);
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}
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void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
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{
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genl_unregister_family(&ZZZ_genl_family);
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}
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/*
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* Magic: provide conversion functions {{{1
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* populate skb from struct.
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* {{{2
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*/
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#undef GENL_op
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#define GENL_op(op_name, op_num, handler, tla_list)
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
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static int s_name ## _to_skb(struct sk_buff *skb, struct s_name *s, \
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const bool exclude_sensitive) \
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{ \
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struct nlattr *tla = nla_nest_start(skb, tag_number); \
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if (!tla) \
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goto nla_put_failure; \
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DPRINT_TLA(#s_name, "-=>", #tag_name); \
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s_fields \
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nla_nest_end(skb, tla); \
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return 0; \
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\
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nla_put_failure: \
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if (tla) \
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nla_nest_cancel(skb, tla); \
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return -EMSGSIZE; \
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} \
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static inline int s_name ## _to_priv_skb(struct sk_buff *skb, \
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struct s_name *s) \
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{ \
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return s_name ## _to_skb(skb, s, 0); \
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} \
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static inline int s_name ## _to_unpriv_skb(struct sk_buff *skb, \
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struct s_name *s) \
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{ \
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return s_name ## _to_skb(skb, s, 1); \
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}
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#undef __field
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#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
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__is_signed) \
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if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
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DPRINT_FIELD(">>", nla_type, name, s, NULL); \
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if (__put(skb, attr_nr, s->name)) \
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goto nla_put_failure; \
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}
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#undef __array
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#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
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__get, __put, __is_signed) \
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if (!exclude_sensitive || !((attr_flag) & DRBD_F_SENSITIVE)) { \
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DPRINT_ARRAY(">>",nla_type, name, s, NULL); \
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if (__put(skb, attr_nr, min_t(int, maxlen, \
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s->name ## _len + (nla_type == NLA_NUL_STRING)),\
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s->name)) \
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goto nla_put_failure; \
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}
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#include GENL_MAGIC_INCLUDE_FILE
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/* Functions for initializing structs to default values. */
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#undef __field
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#define __field(attr_nr, attr_flag, name, nla_type, type, __get, __put, \
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__is_signed)
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#undef __array
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#define __array(attr_nr, attr_flag, name, nla_type, type, maxlen, \
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__get, __put, __is_signed)
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#undef __u32_field_def
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#define __u32_field_def(attr_nr, attr_flag, name, default) \
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x->name = default;
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#undef __s32_field_def
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#define __s32_field_def(attr_nr, attr_flag, name, default) \
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x->name = default;
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#undef __flg_field_def
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#define __flg_field_def(attr_nr, attr_flag, name, default) \
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x->name = default;
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#undef __str_field_def
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#define __str_field_def(attr_nr, attr_flag, name, maxlen) \
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memset(x->name, 0, sizeof(x->name)); \
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x->name ## _len = 0;
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#undef GENL_struct
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#define GENL_struct(tag_name, tag_number, s_name, s_fields) \
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static void set_ ## s_name ## _defaults(struct s_name *x) __attribute__((unused)); \
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static void set_ ## s_name ## _defaults(struct s_name *x) { \
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s_fields \
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}
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#include GENL_MAGIC_INCLUDE_FILE
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#endif /* __KERNEL__ */
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/* }}}1 */
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#endif /* GENL_MAGIC_FUNC_H */
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/* vim: set foldmethod=marker foldlevel=1 nofoldenable : */
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