cregit-Linux how code gets into the kernel

Release 4.14 security/apparmor/include/lib.h

/*
 * AppArmor security module
 *
 * This file contains AppArmor lib definitions
 *
 * 2017 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 */

#ifndef __AA_LIB_H

#define __AA_LIB_H

#include <linux/slab.h>
#include <linux/fs.h>

#include "match.h"

/* Provide our own test for whether a write lock is held for asserts
 * this is because on none SMP systems write_can_lock will always
 * resolve to true, which is what you want for code making decisions
 * based on it, but wrong for asserts checking that the lock is held
 */
#ifdef CONFIG_SMP

#define write_is_locked(X) !write_can_lock(X)
#else

#define write_is_locked(X) (1)
#endif /* CONFIG_SMP */

/*
 * DEBUG remains global (no per profile flag) since it is mostly used in sysctl
 * which is not related to profile accesses.
 */


#define DEBUG_ON (aa_g_debug)

#define dbg_printk(__fmt, __args...) pr_debug(__fmt, ##__args)

#define AA_DEBUG(fmt, args...)						\
	do {                                                            \
                if (DEBUG_ON)                                           \
                        pr_debug_ratelimited("AppArmor: " fmt, ##args); \
        } while (0)


#define AA_WARN(X) WARN((X), "APPARMOR WARN %s: %s\n", __func__, #X)


#define AA_BUG(X, args...) AA_BUG_FMT((X), "" args)
#ifdef CONFIG_SECURITY_APPARMOR_DEBUG_ASSERTS

#define AA_BUG_FMT(X, fmt, args...)					\
	WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args)
#else

#define AA_BUG_FMT(X, fmt, args...)
#endif


#define AA_ERROR(fmt, args...)						\
	pr_err_ratelimited("AppArmor: " fmt, ##args)

/* Flag indicating whether initialization completed */
extern int apparmor_initialized;

/* fn's in lib */
const char *skipn_spaces(const char *str, size_t n);
char *aa_split_fqname(char *args, char **ns_name);
const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
			     size_t *ns_len);
void aa_info_message(const char *str);

/**
 * aa_strneq - compare null terminated @str to a non null terminated substring
 * @str: a null terminated string
 * @sub: a substring, not necessarily null terminated
 * @len: length of @sub to compare
 *
 * The @str string must be full consumed for this to be considered a match
 */

static inline bool aa_strneq(const char *str, const char *sub, int len) { return !strncmp(str, sub, len) && !str[len]; }

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/** * aa_dfa_null_transition - step to next state after null character * @dfa: the dfa to match against * @start: the state of the dfa to start matching in * * aa_dfa_null_transition transitions to the next state after a null * character which is not used in standard matching and is only * used to separate pairs. */
static inline unsigned int aa_dfa_null_transition(struct aa_dfa *dfa, unsigned int start) { /* the null transition only needs the string's null terminator byte */ return aa_dfa_next(dfa, start, 0); }

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John Johansen28100.00%1100.00%
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static inline bool path_mediated_fs(struct dentry *dentry) { return !(dentry->d_sb->s_flags & MS_NOUSER); }

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John Johansen24100.00%2100.00%
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struct counted_str { struct kref count; char name[]; }; #define str_to_counted(str) \ ((struct counted_str *)(str - offsetof(struct counted_str, name))) #define __counted /* atm just a notation */ void aa_str_kref(struct kref *kref); char *aa_str_alloc(int size, gfp_t gfp);
static inline __counted char *aa_get_str(__counted char *str) { if (str) kref_get(&(str_to_counted(str)->count)); return str; }

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John Johansen34100.00%1100.00%
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static inline void aa_put_str(__counted char *str) { if (str) kref_put(&str_to_counted(str)->count, aa_str_kref); }

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John Johansen29100.00%1100.00%
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/* struct aa_policy - common part of both namespaces and profiles * @name: name of the object * @hname - The hierarchical name * @list: list policy object is on * @profiles: head of the profiles list contained in the object */ struct aa_policy { const char *name; __counted char *hname; struct list_head list; struct list_head profiles; }; /** * basename - find the last component of an hname * @name: hname to find the base profile name component of (NOT NULL) * * Returns: the tail (base profile name) name component of an hname */
static inline const char *basename(const char *hname) { char *split; hname = strim((char *)hname); for (split = strstr(hname, "//"); split; split = strstr(hname, "//")) hname = split + 2; return hname; }

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John Johansen60100.00%2100.00%
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/** * __policy_find - find a policy by @name on a policy list * @head: list to search (NOT NULL) * @name: name to search for (NOT NULL) * * Requires: rcu_read_lock be held * * Returns: unrefcounted policy that match @name or NULL if not found */
static inline struct aa_policy *__policy_find(struct list_head *head, const char *name) { struct aa_policy *policy; list_for_each_entry_rcu(policy, head, list) { if (!strcmp(policy->name, name)) return policy; } return NULL; }

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John Johansen52100.00%1100.00%
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/** * __policy_strn_find - find a policy that's name matches @len chars of @str * @head: list to search (NOT NULL) * @str: string to search for (NOT NULL) * @len: length of match required * * Requires: rcu_read_lock be held * * Returns: unrefcounted policy that match @str or NULL if not found * * if @len == strlen(@strlen) then this is equiv to __policy_find * other wise it allows searching for policy by a partial match of name */
static inline struct aa_policy *__policy_strn_find(struct list_head *head, const char *str, int len) { struct aa_policy *policy; list_for_each_entry_rcu(policy, head, list) { if (aa_strneq(policy->name, str, len)) return policy; } return NULL; }

Contributors

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John Johansen56100.00%1100.00%
Total56100.00%1100.00%

bool aa_policy_init(struct aa_policy *policy, const char *prefix, const char *name, gfp_t gfp); void aa_policy_destroy(struct aa_policy *policy); /* * fn_label_build - abstract out the build of a label transition * @L: label the transition is being computed for * @P: profile parameter derived from L by this macro, can be passed to FN * @GFP: memory allocation type to use * @FN: fn to call for each profile transition. @P is set to the profile * * Returns: new label on success * ERR_PTR if build @FN fails * NULL if label_build fails due to low memory conditions * * @FN must return a label or ERR_PTR on failure. NULL is not allowed */ #define fn_label_build(L, P, GFP, FN) \ ({ \ __label__ __cleanup, __done; \ struct aa_label *__new_; \ \ if ((L)->size > 1) { \ /* TODO: add cache of transitions already done */ \ struct label_it __i; \ int __j, __k, __count; \ DEFINE_VEC(label, __lvec); \ DEFINE_VEC(profile, __pvec); \ if (vec_setup(label, __lvec, (L)->size, (GFP))) { \ __new_ = NULL; \ goto __done; \ } \ __j = 0; \ label_for_each(__i, (L), (P)) { \ __new_ = (FN); \ AA_BUG(!__new_); \ if (IS_ERR(__new_)) \ goto __cleanup; \ __lvec[__j++] = __new_; \ } \ for (__j = __count = 0; __j < (L)->size; __j++) \ __count += __lvec[__j]->size; \ if (!vec_setup(profile, __pvec, __count, (GFP))) { \ for (__j = __k = 0; __j < (L)->size; __j++) { \ label_for_each(__i, __lvec[__j], (P)) \ __pvec[__k++] = aa_get_profile(P); \ } \ __count -= aa_vec_unique(__pvec, __count, 0); \ if (__count > 1) { \ __new_ = aa_vec_find_or_create_label(__pvec,\ __count, (GFP)); \ /* only fails if out of Mem */ \ if (!__new_) \ __new_ = NULL; \ } else \ __new_ = aa_get_label(&__pvec[0]->label); \ vec_cleanup(profile, __pvec, __count); \ } else \ __new_ = NULL; \ __cleanup: \ vec_cleanup(label, __lvec, (L)->size); \ } else { \ (P) = labels_profile(L); \ __new_ = (FN); \ } \ __done: \ if (!__new_) \ AA_DEBUG("label build failed\n"); \ (__new_); \ }) #define __fn_build_in_ns(NS, P, NS_FN, OTHER_FN) \ ({ \ struct aa_label *__new; \ if ((P)->ns != (NS)) \ __new = (OTHER_FN); \ else \ __new = (NS_FN); \ (__new); \ }) #define fn_label_build_in_ns(L, P, GFP, NS_FN, OTHER_FN) \ ({ \ fn_label_build((L), (P), (GFP), \ __fn_build_in_ns(labels_ns(L), (P), (NS_FN), (OTHER_FN))); \ }) #endif /* __AA_LIB_H */

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John Johansen668100.00%12100.00%
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