1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor file mediation function definitions.
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2010 Canonical Ltd.
9 */
10
11#ifndef __AA_FILE_H
12#define __AA_FILE_H
13
14#include <linux/spinlock.h>
15
16#include "domain.h"
17#include "match.h"
18#include "perms.h"
19
20struct aa_policydb;
21struct aa_profile;
22struct path;
23
24#define mask_mode_t(X) (X & (MAY_EXEC | MAY_WRITE | MAY_READ | MAY_APPEND))
25
26#define AA_AUDIT_FILE_MASK	(MAY_READ | MAY_WRITE | MAY_EXEC | MAY_APPEND |\
27				 AA_MAY_CREATE | AA_MAY_DELETE |	\
28				 AA_MAY_GETATTR | AA_MAY_SETATTR | \
29				 AA_MAY_CHMOD | AA_MAY_CHOWN | AA_MAY_LOCK | \
30				 AA_EXEC_MMAP | AA_MAY_LINK)
31
32static inline struct aa_file_ctx *file_ctx(struct file *file)
33{
34	return file->f_security + apparmor_blob_sizes.lbs_file;
35}
36
37/* struct aa_file_ctx - the AppArmor context the file was opened in
38 * @lock: lock to update the ctx
39 * @label: label currently cached on the ctx
40 * @perms: the permission the file was opened with
41 */
42struct aa_file_ctx {
43	spinlock_t lock;
44	struct aa_label __rcu *label;
45	u32 allow;
46};
47
48/**
49 * aa_alloc_file_ctx - allocate file_ctx
50 * @label: initial label of task creating the file
51 * @gfp: gfp flags for allocation
52 *
53 * Returns: file_ctx or NULL on failure
54 */
55static inline struct aa_file_ctx *aa_alloc_file_ctx(struct aa_label *label,
56						    gfp_t gfp)
57{
58	struct aa_file_ctx *ctx;
59
60	ctx = kzalloc(sizeof(struct aa_file_ctx), gfp);
61	if (ctx) {
62		spin_lock_init(&ctx->lock);
63		rcu_assign_pointer(ctx->label, aa_get_label(label));
64	}
65	return ctx;
66}
67
68/**
69 * aa_free_file_ctx - free a file_ctx
70 * @ctx: file_ctx to free  (MAYBE_NULL)
71 */
72static inline void aa_free_file_ctx(struct aa_file_ctx *ctx)
73{
74	if (ctx) {
75		aa_put_label(rcu_access_pointer(ctx->label));
76		kfree_sensitive(ctx);
77	}
78}
79
80static inline struct aa_label *aa_get_file_label(struct aa_file_ctx *ctx)
81{
82	return aa_get_label_rcu(&ctx->label);
83}
84
85/*
86 * The xindex is broken into 3 parts
87 * - index - an index into either the exec name table or the variable table
88 * - exec type - which determines how the executable name and index are used
89 * - flags - which modify how the destination name is applied
90 */
91#define AA_X_INDEX_MASK		AA_INDEX_MASK
92
93#define AA_X_TYPE_MASK		0x0c000000
94#define AA_X_NONE		AA_INDEX_NONE
95#define AA_X_NAME		0x04000000 /* use executable name px */
96#define AA_X_TABLE		0x08000000 /* use a specified name ->n# */
97
98#define AA_X_UNSAFE		0x10000000
99#define AA_X_CHILD		0x20000000
100#define AA_X_INHERIT		0x40000000
101#define AA_X_UNCONFINED		0x80000000
102
103/* need to make conditional which ones are being set */
104struct path_cond {
105	kuid_t uid;
106	umode_t mode;
107};
108
109#define COMBINED_PERM_MASK(X) ((X).allow | (X).audit | (X).quiet | (X).kill)
110
111int aa_audit_file(const struct cred *cred,
112		  struct aa_profile *profile, struct aa_perms *perms,
113		  const char *op, u32 request, const char *name,
114		  const char *target, struct aa_label *tlabel, kuid_t ouid,
115		  const char *info, int error);
116
117struct aa_perms *aa_lookup_fperms(struct aa_policydb *file_rules,
118				  aa_state_t state, struct path_cond *cond);
119aa_state_t aa_str_perms(struct aa_policydb *file_rules, aa_state_t start,
120			const char *name, struct path_cond *cond,
121			struct aa_perms *perms);
122
123int aa_path_perm(const char *op, const struct cred *subj_cred,
124		 struct aa_label *label, const struct path *path,
125		 int flags, u32 request, struct path_cond *cond);
126
127int aa_path_link(const struct cred *subj_cred, struct aa_label *label,
128		 struct dentry *old_dentry, const struct path *new_dir,
129		 struct dentry *new_dentry);
130
131int aa_file_perm(const char *op, const struct cred *subj_cred,
132		 struct aa_label *label, struct file *file,
133		 u32 request, bool in_atomic);
134
135void aa_inherit_files(const struct cred *cred, struct files_struct *files);
136
137
138/**
139 * aa_map_file_perms - map file flags to AppArmor permissions
140 * @file: open file to map flags to AppArmor permissions
141 *
142 * Returns: apparmor permission set for the file
143 */
144static inline u32 aa_map_file_to_perms(struct file *file)
145{
146	int flags = file->f_flags;
147	u32 perms = 0;
148
149	if (file->f_mode & FMODE_WRITE)
150		perms |= MAY_WRITE;
151	if (file->f_mode & FMODE_READ)
152		perms |= MAY_READ;
153
154	if ((flags & O_APPEND) && (perms & MAY_WRITE))
155		perms = (perms & ~MAY_WRITE) | MAY_APPEND;
156	/* trunc implies write permission */
157	if (flags & O_TRUNC)
158		perms |= MAY_WRITE;
159	if (flags & O_CREAT)
160		perms |= AA_MAY_CREATE;
161
162	return perms;
163}
164
165#endif /* __AA_FILE_H */
166