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0ed3b28a JJ |
1 | /* |
2 | * AppArmor security module | |
3 | * | |
4 | * This file contains AppArmor capability mediation functions | |
5 | * | |
6 | * Copyright (C) 1998-2008 Novell/SUSE | |
7 | * Copyright 2009-2010 Canonical Ltd. | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License as | |
11 | * published by the Free Software Foundation, version 2 of the | |
12 | * License. | |
13 | */ | |
14 | ||
15 | #include <linux/capability.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/gfp.h> | |
18 | ||
19 | #include "include/apparmor.h" | |
20 | #include "include/capability.h" | |
21 | #include "include/context.h" | |
22 | #include "include/policy.h" | |
23 | #include "include/audit.h" | |
24 | ||
25 | /* | |
26 | * Table of capability names: we generate it from capabilities.h. | |
27 | */ | |
28 | #include "capability_names.h" | |
29 | ||
30 | struct audit_cache { | |
31 | struct aa_profile *profile; | |
32 | kernel_cap_t caps; | |
33 | }; | |
34 | ||
35 | static DEFINE_PER_CPU(struct audit_cache, audit_cache); | |
36 | ||
37 | /** | |
38 | * audit_cb - call back for capability components of audit struct | |
39 | * @ab - audit buffer (NOT NULL) | |
40 | * @va - audit struct to audit data from (NOT NULL) | |
41 | */ | |
42 | static void audit_cb(struct audit_buffer *ab, void *va) | |
43 | { | |
44 | struct common_audit_data *sa = va; | |
45 | audit_log_format(ab, " capname="); | |
46 | audit_log_untrustedstring(ab, capability_names[sa->u.cap]); | |
47 | } | |
48 | ||
49 | /** | |
50 | * audit_caps - audit a capability | |
51 | * @profile: profile confining task (NOT NULL) | |
52 | * @task: task capability test was performed against (NOT NULL) | |
53 | * @cap: capability tested | |
54 | * @error: error code returned by test | |
55 | * | |
56 | * Do auditing of capability and handle, audit/complain/kill modes switching | |
57 | * and duplicate message elimination. | |
58 | * | |
59 | * Returns: 0 or sa->error on success, error code on failure | |
60 | */ | |
61 | static int audit_caps(struct aa_profile *profile, struct task_struct *task, | |
62 | int cap, int error) | |
63 | { | |
64 | struct audit_cache *ent; | |
65 | int type = AUDIT_APPARMOR_AUTO; | |
66 | struct common_audit_data sa; | |
3b3b0e4f | 67 | struct apparmor_audit_data aad = {0,}; |
0ed3b28a | 68 | COMMON_AUDIT_DATA_INIT(&sa, CAP); |
3b3b0e4f | 69 | sa.aad = &aad; |
0ed3b28a JJ |
70 | sa.tsk = task; |
71 | sa.u.cap = cap; | |
3b3b0e4f EP |
72 | sa.aad->op = OP_CAPABLE; |
73 | sa.aad->error = error; | |
0ed3b28a JJ |
74 | |
75 | if (likely(!error)) { | |
76 | /* test if auditing is being forced */ | |
77 | if (likely((AUDIT_MODE(profile) != AUDIT_ALL) && | |
78 | !cap_raised(profile->caps.audit, cap))) | |
79 | return 0; | |
80 | type = AUDIT_APPARMOR_AUDIT; | |
81 | } else if (KILL_MODE(profile) || | |
82 | cap_raised(profile->caps.kill, cap)) { | |
83 | type = AUDIT_APPARMOR_KILL; | |
84 | } else if (cap_raised(profile->caps.quiet, cap) && | |
85 | AUDIT_MODE(profile) != AUDIT_NOQUIET && | |
86 | AUDIT_MODE(profile) != AUDIT_ALL) { | |
87 | /* quiet auditing */ | |
88 | return error; | |
89 | } | |
90 | ||
91 | /* Do simple duplicate message elimination */ | |
92 | ent = &get_cpu_var(audit_cache); | |
93 | if (profile == ent->profile && cap_raised(ent->caps, cap)) { | |
94 | put_cpu_var(audit_cache); | |
95 | if (COMPLAIN_MODE(profile)) | |
96 | return complain_error(error); | |
97 | return error; | |
98 | } else { | |
99 | aa_put_profile(ent->profile); | |
100 | ent->profile = aa_get_profile(profile); | |
101 | cap_raise(ent->caps, cap); | |
102 | } | |
103 | put_cpu_var(audit_cache); | |
104 | ||
105 | return aa_audit(type, profile, GFP_ATOMIC, &sa, audit_cb); | |
106 | } | |
107 | ||
108 | /** | |
109 | * profile_capable - test if profile allows use of capability @cap | |
110 | * @profile: profile being enforced (NOT NULL, NOT unconfined) | |
111 | * @cap: capability to test if allowed | |
112 | * | |
113 | * Returns: 0 if allowed else -EPERM | |
114 | */ | |
115 | static int profile_capable(struct aa_profile *profile, int cap) | |
116 | { | |
117 | return cap_raised(profile->caps.allow, cap) ? 0 : -EPERM; | |
118 | } | |
119 | ||
120 | /** | |
121 | * aa_capable - test permission to use capability | |
122 | * @task: task doing capability test against (NOT NULL) | |
123 | * @profile: profile confining @task (NOT NULL) | |
124 | * @cap: capability to be tested | |
125 | * @audit: whether an audit record should be generated | |
126 | * | |
127 | * Look up capability in profile capability set. | |
128 | * | |
129 | * Returns: 0 on success, or else an error code. | |
130 | */ | |
131 | int aa_capable(struct task_struct *task, struct aa_profile *profile, int cap, | |
132 | int audit) | |
133 | { | |
134 | int error = profile_capable(profile, cap); | |
135 | ||
136 | if (!audit) { | |
137 | if (COMPLAIN_MODE(profile)) | |
138 | return complain_error(error); | |
139 | return error; | |
140 | } | |
141 | ||
142 | return audit_caps(profile, task, cap, error); | |
143 | } |