289 lines
7.7 KiB
C
289 lines
7.7 KiB
C
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/*
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* AppArmor security module
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*
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* This file contains AppArmor lib definitions
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*
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* 2017 Canonical Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#ifndef __AA_LIB_H
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#define __AA_LIB_H
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include "match.h"
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/*
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* DEBUG remains global (no per profile flag) since it is mostly used in sysctl
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* which is not related to profile accesses.
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*/
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#define DEBUG_ON (aa_g_debug)
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#define dbg_printk(__fmt, __args...) pr_debug(__fmt, ##__args)
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#define AA_DEBUG(fmt, args...) \
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do { \
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if (DEBUG_ON) \
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pr_debug_ratelimited("AppArmor: " fmt, ##args); \
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} while (0)
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#define AA_WARN(X) WARN((X), "APPARMOR WARN %s: %s\n", __func__, #X)
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#define AA_BUG(X, args...) AA_BUG_FMT((X), "" args)
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#ifdef CONFIG_SECURITY_APPARMOR_DEBUG_ASSERTS
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#define AA_BUG_FMT(X, fmt, args...) \
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WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args)
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#else
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#define AA_BUG_FMT(X, fmt, args...)
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#endif
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#define AA_ERROR(fmt, args...) \
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pr_err_ratelimited("AppArmor: " fmt, ##args)
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/* Flag indicating whether initialization completed */
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extern int apparmor_initialized;
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/* fn's in lib */
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const char *skipn_spaces(const char *str, size_t n);
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char *aa_split_fqname(char *args, char **ns_name);
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const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
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size_t *ns_len);
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void aa_info_message(const char *str);
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/**
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* aa_strneq - compare null terminated @str to a non null terminated substring
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* @str: a null terminated string
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* @sub: a substring, not necessarily null terminated
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* @len: length of @sub to compare
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*
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* The @str string must be full consumed for this to be considered a match
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*/
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static inline bool aa_strneq(const char *str, const char *sub, int len)
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{
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return !strncmp(str, sub, len) && !str[len];
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}
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/**
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* aa_dfa_null_transition - step to next state after null character
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* @dfa: the dfa to match against
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* @start: the state of the dfa to start matching in
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*
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* aa_dfa_null_transition transitions to the next state after a null
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* character which is not used in standard matching and is only
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* used to separate pairs.
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*/
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static inline unsigned int aa_dfa_null_transition(struct aa_dfa *dfa,
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unsigned int start)
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{
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/* the null transition only needs the string's null terminator byte */
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return aa_dfa_next(dfa, start, 0);
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}
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static inline bool path_mediated_fs(struct dentry *dentry)
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{
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return !(dentry->d_sb->s_flags & SB_NOUSER);
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}
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struct counted_str {
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struct kref count;
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char name[];
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};
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#define str_to_counted(str) \
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((struct counted_str *)(str - offsetof(struct counted_str, name)))
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#define __counted /* atm just a notation */
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void aa_str_kref(struct kref *kref);
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char *aa_str_alloc(int size, gfp_t gfp);
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static inline __counted char *aa_get_str(__counted char *str)
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{
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if (str)
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kref_get(&(str_to_counted(str)->count));
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return str;
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}
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static inline void aa_put_str(__counted char *str)
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{
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if (str)
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kref_put(&str_to_counted(str)->count, aa_str_kref);
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}
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/* struct aa_policy - common part of both namespaces and profiles
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* @name: name of the object
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* @hname - The hierarchical name
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* @list: list policy object is on
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* @profiles: head of the profiles list contained in the object
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*/
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struct aa_policy {
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const char *name;
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__counted char *hname;
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struct list_head list;
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struct list_head profiles;
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};
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/**
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* basename - find the last component of an hname
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* @name: hname to find the base profile name component of (NOT NULL)
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*
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* Returns: the tail (base profile name) name component of an hname
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*/
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static inline const char *basename(const char *hname)
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{
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char *split;
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hname = strim((char *)hname);
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for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
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hname = split + 2;
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return hname;
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}
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/**
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* __policy_find - find a policy by @name on a policy list
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* @head: list to search (NOT NULL)
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* @name: name to search for (NOT NULL)
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*
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* Requires: rcu_read_lock be held
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*
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* Returns: unrefcounted policy that match @name or NULL if not found
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*/
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static inline struct aa_policy *__policy_find(struct list_head *head,
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const char *name)
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{
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struct aa_policy *policy;
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list_for_each_entry_rcu(policy, head, list) {
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if (!strcmp(policy->name, name))
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return policy;
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}
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return NULL;
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}
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/**
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* __policy_strn_find - find a policy that's name matches @len chars of @str
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* @head: list to search (NOT NULL)
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* @str: string to search for (NOT NULL)
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* @len: length of match required
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*
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* Requires: rcu_read_lock be held
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*
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* Returns: unrefcounted policy that match @str or NULL if not found
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*
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* if @len == strlen(@strlen) then this is equiv to __policy_find
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* other wise it allows searching for policy by a partial match of name
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*/
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static inline struct aa_policy *__policy_strn_find(struct list_head *head,
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const char *str, int len)
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{
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struct aa_policy *policy;
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list_for_each_entry_rcu(policy, head, list) {
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if (aa_strneq(policy->name, str, len))
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return policy;
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}
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return NULL;
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}
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bool aa_policy_init(struct aa_policy *policy, const char *prefix,
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const char *name, gfp_t gfp);
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void aa_policy_destroy(struct aa_policy *policy);
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/*
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* fn_label_build - abstract out the build of a label transition
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* @L: label the transition is being computed for
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* @P: profile parameter derived from L by this macro, can be passed to FN
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* @GFP: memory allocation type to use
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* @FN: fn to call for each profile transition. @P is set to the profile
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*
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* Returns: new label on success
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* ERR_PTR if build @FN fails
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* NULL if label_build fails due to low memory conditions
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*
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* @FN must return a label or ERR_PTR on failure. NULL is not allowed
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*/
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#define fn_label_build(L, P, GFP, FN) \
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({ \
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__label__ __cleanup, __done; \
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struct aa_label *__new_; \
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\
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if ((L)->size > 1) { \
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/* TODO: add cache of transitions already done */ \
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struct label_it __i; \
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int __j, __k, __count; \
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DEFINE_VEC(label, __lvec); \
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DEFINE_VEC(profile, __pvec); \
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if (vec_setup(label, __lvec, (L)->size, (GFP))) { \
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__new_ = NULL; \
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goto __done; \
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} \
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__j = 0; \
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label_for_each(__i, (L), (P)) { \
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__new_ = (FN); \
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AA_BUG(!__new_); \
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if (IS_ERR(__new_)) \
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goto __cleanup; \
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__lvec[__j++] = __new_; \
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} \
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for (__j = __count = 0; __j < (L)->size; __j++) \
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__count += __lvec[__j]->size; \
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if (!vec_setup(profile, __pvec, __count, (GFP))) { \
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for (__j = __k = 0; __j < (L)->size; __j++) { \
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label_for_each(__i, __lvec[__j], (P)) \
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__pvec[__k++] = aa_get_profile(P); \
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} \
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__count -= aa_vec_unique(__pvec, __count, 0); \
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if (__count > 1) { \
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__new_ = aa_vec_find_or_create_label(__pvec,\
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__count, (GFP)); \
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/* only fails if out of Mem */ \
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if (!__new_) \
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__new_ = NULL; \
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} else \
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__new_ = aa_get_label(&__pvec[0]->label); \
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vec_cleanup(profile, __pvec, __count); \
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} else \
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__new_ = NULL; \
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__cleanup: \
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vec_cleanup(label, __lvec, (L)->size); \
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} else { \
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(P) = labels_profile(L); \
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__new_ = (FN); \
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} \
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__done: \
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if (!__new_) \
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AA_DEBUG("label build failed\n"); \
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(__new_); \
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})
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#define __fn_build_in_ns(NS, P, NS_FN, OTHER_FN) \
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({ \
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struct aa_label *__new; \
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if ((P)->ns != (NS)) \
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__new = (OTHER_FN); \
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else \
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__new = (NS_FN); \
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(__new); \
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})
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#define fn_label_build_in_ns(L, P, GFP, NS_FN, OTHER_FN) \
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({ \
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fn_label_build((L), (P), (GFP), \
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__fn_build_in_ns(labels_ns(L), (P), (NS_FN), (OTHER_FN))); \
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})
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#endif /* __AA_LIB_H */
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