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Diffstat (limited to 'security/apparmor/include/lib.h')
| -rw-r--r-- | security/apparmor/include/lib.h | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h new file mode 100644 index 000000000..73c8a32c6 --- /dev/null +++ b/security/apparmor/include/lib.h @@ -0,0 +1,304 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AppArmor security module + * + * This file contains AppArmor lib definitions + * + * 2017 Canonical Ltd. + */ + +#ifndef __AA_LIB_H +#define __AA_LIB_H + +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/lsm_hooks.h> + +#include "match.h" + +/* + * 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) +/* + * split individual debug cases out in preparation for finer grained + * debug controls in the future. + */ +#define AA_DEBUG_LABEL DEBUG_ON +#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...) \ + do { \ + _Pragma("GCC diagnostic ignored \"-Wformat-zero-length\""); \ + AA_BUG_FMT((X), "" args); \ + _Pragma("GCC diagnostic warning \"-Wformat-zero-length\""); \ + } while (0) +#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...) no_printk(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); + +/* Security blob offsets */ +extern struct lsm_blob_sizes apparmor_blob_sizes; + +/** + * 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]; +} + +/** + * 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 aa_state_t aa_dfa_null_transition(struct aa_dfa *dfa, + aa_state_t start) +{ + /* the null transition only needs the string's null terminator byte */ + return aa_dfa_next(dfa, start, 0); +} + +static inline bool path_mediated_fs(struct dentry *dentry) +{ + return !(dentry->d_sb->s_flags & SB_NOUSER); +} + +struct aa_str_table { + int size; + char **table; +}; + +void aa_free_str_table(struct aa_str_table *table); + +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; +} + +static inline void aa_put_str(__counted char *str) +{ + if (str) + kref_put(&str_to_counted(str)->count, aa_str_kref); +} + + +/* 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; +} + +/** + * __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; +} + +/** + * __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; +} + +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__ __do_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 __do_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; \ +__do_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 */ |