security: smack: fix memleak in smk_write_rules_list()
[linux-2.6-block.git] / security / smack / smack.h
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1/*
2 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, version 2.
7 *
8 * Author:
9 * Casey Schaufler <casey@schaufler-ca.com>
10 *
11 */
12
13#ifndef _SECURITY_SMACK_H
14#define _SECURITY_SMACK_H
15
16#include <linux/capability.h>
17#include <linux/spinlock.h>
076c54c5 18#include <linux/security.h>
6d3dc07c 19#include <linux/in.h>
e114e473 20#include <net/netlabel.h>
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21#include <linux/list.h>
22#include <linux/rculist.h>
ecfcc53f 23#include <linux/lsm_audit.h>
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24
25/*
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26 * Smack labels were limited to 23 characters for a long time.
27 */
28#define SMK_LABELLEN 24
29#define SMK_LONGLABEL 256
30
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31/*
32 * This is the repository for labels seen so that it is
33 * not necessary to keep allocating tiny chuncks of memory
34 * and so that they can be shared.
35 *
36 * Labels are never modified in place. Anytime a label
37 * is imported (e.g. xattrset on a file) the list is checked
38 * for it and it is added if it doesn't exist. The address
39 * is passed out in either case. Entries are added, but
40 * never deleted.
41 *
42 * Since labels are hanging around anyway it doesn't
43 * hurt to maintain a secid for those awkward situations
44 * where kernel components that ought to use LSM independent
45 * interfaces don't. The secid should go away when all of
46 * these components have been repaired.
47 *
48 * The cipso value associated with the label gets stored here, too.
49 *
50 * Keep the access rules for this subject label here so that
51 * the entire set of rules does not need to be examined every
52 * time.
53 */
54struct smack_known {
55 struct list_head list;
56 char *smk_known;
57 u32 smk_secid;
58 struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */
59 struct list_head smk_rules; /* access rules */
60 struct mutex smk_rules_lock; /* lock for rules */
61};
62
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63/*
64 * Maximum number of bytes for the levels in a CIPSO IP option.
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65 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
66 * bigger than can be used, and 24 is the next lower multiple
67 * of 8, and there are too many issues if there isn't space set
68 * aside for the terminating null byte.
69 */
f7112e6c 70#define SMK_CIPSOLEN 24
e114e473 71
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72struct superblock_smack {
73 char *smk_root;
74 char *smk_floor;
75 char *smk_hat;
76 char *smk_default;
77 int smk_initialized;
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78};
79
80struct socket_smack {
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81 struct smack_known *smk_out; /* outbound label */
82 char *smk_in; /* inbound label */
83 char *smk_packet; /* TCP peer label */
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84};
85
86/*
87 * Inode smack data
88 */
89struct inode_smack {
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90 char *smk_inode; /* label of the fso */
91 struct smack_known *smk_task; /* label of the task */
92 struct smack_known *smk_mmap; /* label of the mmap domain */
93 struct mutex smk_lock; /* initialization lock */
94 int smk_flags; /* smack inode flags */
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95};
96
676dac4b 97struct task_smack {
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98 struct smack_known *smk_task; /* label for access control */
99 struct smack_known *smk_forked; /* label when forked */
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100 struct list_head smk_rules; /* per task access rules */
101 struct mutex smk_rules_lock; /* lock for the rules */
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102};
103
e114e473 104#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */
5c6d1125 105#define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */
2267b13a 106#define SMK_INODE_CHANGED 0x04 /* smack was transmuted */
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107
108/*
109 * A label access rule.
110 */
111struct smack_rule {
7198e2ee 112 struct list_head list;
2f823ff8 113 struct smack_known *smk_subject;
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114 char *smk_object;
115 int smk_access;
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116};
117
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118/*
119 * An entry in the table identifying hosts.
120 */
121struct smk_netlbladdr {
7198e2ee 122 struct list_head list;
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123 struct sockaddr_in smk_host; /* network address */
124 struct in_addr smk_mask; /* network mask */
125 char *smk_label; /* label */
126};
127
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128/*
129 * An entry in the table identifying ports.
130 */
131struct smk_port_label {
132 struct list_head list;
133 struct sock *smk_sock; /* socket initialized on */
134 unsigned short smk_port; /* the port number */
135 char *smk_in; /* incoming label */
2f823ff8 136 struct smack_known *smk_out; /* outgoing label */
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137};
138
139/*
140 * Mount options
141 */
142#define SMK_FSDEFAULT "smackfsdef="
143#define SMK_FSFLOOR "smackfsfloor="
144#define SMK_FSHAT "smackfshat="
145#define SMK_FSROOT "smackfsroot="
e830b394 146#define SMK_FSTRANS "smackfstransmute="
e114e473 147
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148#define SMACK_CIPSO_OPTION "-CIPSO"
149
e114e473 150/*
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151 * How communications on this socket are treated.
152 * Usually it's determined by the underlying netlabel code
153 * but there are certain cases, including single label hosts
154 * and potentially single label interfaces for which the
155 * treatment can not be known in advance.
156 *
157 * The possibility of additional labeling schemes being
158 * introduced in the future exists as well.
159 */
160#define SMACK_UNLABELED_SOCKET 0
161#define SMACK_CIPSO_SOCKET 1
162
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163/*
164 * CIPSO defaults.
165 */
166#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */
6d3dc07c 167#define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */
e114e473 168#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */
f7112e6c 169#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */
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170#define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */
171#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */
172#define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */
173
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174/*
175 * Flag for transmute access
176 */
177#define MAY_TRANSMUTE 64
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178/*
179 * Just to make the common cases easier to deal with
180 */
e114e473 181#define MAY_ANYREAD (MAY_READ | MAY_EXEC)
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182#define MAY_READWRITE (MAY_READ | MAY_WRITE)
183#define MAY_NOT 0
184
ecfcc53f 185/*
ce8a4321 186 * Number of access types used by Smack (rwxat)
ecfcc53f 187 */
ce8a4321 188#define SMK_NUM_ACCESS_TYPE 5
ecfcc53f 189
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190/* SMACK data */
191struct smack_audit_data {
192 const char *function;
193 char *subject;
194 char *object;
195 char *request;
196 int result;
197};
198
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199/*
200 * Smack audit data; is empty if CONFIG_AUDIT not set
201 * to save some stack
202 */
203struct smk_audit_info {
204#ifdef CONFIG_AUDIT
205 struct common_audit_data a;
3b3b0e4f 206 struct smack_audit_data sad;
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207#endif
208};
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209/*
210 * These functions are in smack_lsm.c
211 */
212struct inode_smack *new_inode_smack(char *);
213
214/*
215 * These functions are in smack_access.c
216 */
7898e1f8 217int smk_access_entry(char *, char *, struct list_head *);
2f823ff8 218int smk_access(struct smack_known *, char *, int, struct smk_audit_info *);
ecfcc53f 219int smk_curacc(char *, u32, struct smk_audit_info *);
2f823ff8 220struct smack_known *smack_from_secid(const u32);
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221char *smk_parse_smack(const char *string, int len);
222int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
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223char *smk_import(const char *, int);
224struct smack_known *smk_import_entry(const char *, int);
272cd7a8 225struct smack_known *smk_find_entry(const char *);
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226u32 smack_to_secid(const char *);
227
228/*
229 * Shared data.
230 */
231extern int smack_cipso_direct;
f7112e6c 232extern int smack_cipso_mapped;
2f823ff8 233extern struct smack_known *smack_net_ambient;
15446235 234extern char *smack_onlycap;
4303154e 235extern const char *smack_cipso_option;
e114e473 236
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237extern struct smack_known smack_known_floor;
238extern struct smack_known smack_known_hat;
239extern struct smack_known smack_known_huh;
240extern struct smack_known smack_known_invalid;
241extern struct smack_known smack_known_star;
6d3dc07c 242extern struct smack_known smack_known_web;
e114e473 243
f7112e6c 244extern struct mutex smack_known_lock;
7198e2ee 245extern struct list_head smack_known_list;
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246extern struct list_head smk_netlbladdr_list;
247
076c54c5 248extern struct security_operations smack_ops;
e114e473 249
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250/*
251 * Is the directory transmuting?
252 */
253static inline int smk_inode_transmutable(const struct inode *isp)
254{
255 struct inode_smack *sip = isp->i_security;
256 return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
257}
258
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259/*
260 * Present a pointer to the smack label in an inode blob.
261 */
262static inline char *smk_of_inode(const struct inode *isp)
263{
264 struct inode_smack *sip = isp->i_security;
265 return sip->smk_inode;
266}
267
676dac4b 268/*
2f823ff8 269 * Present a pointer to the smack label entry in an task blob.
676dac4b 270 */
2f823ff8 271static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
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272{
273 return tsp->smk_task;
274}
275
276/*
2f823ff8 277 * Present a pointer to the forked smack label entry in an task blob.
676dac4b 278 */
2f823ff8 279static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)
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280{
281 return tsp->smk_forked;
282}
283
284/*
5c6d1125 285 * Present a pointer to the smack label in the current task blob.
676dac4b 286 */
2f823ff8 287static inline struct smack_known *smk_of_current(void)
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288{
289 return smk_of_task(current_security());
290}
291
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292/*
293 * Is the task privileged and allowed to be privileged
294 * by the onlycap rule.
295 */
296static inline int smack_privileged(int cap)
297{
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298 struct smack_known *skp = smk_of_current();
299
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300 if (!capable(cap))
301 return 0;
2f823ff8 302 if (smack_onlycap == NULL || smack_onlycap == skp->smk_known)
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303 return 1;
304 return 0;
305}
306
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307/*
308 * logging functions
309 */
310#define SMACK_AUDIT_DENIED 0x1
311#define SMACK_AUDIT_ACCEPT 0x2
312extern int log_policy;
313
314void smack_log(char *subject_label, char *object_label,
315 int request,
316 int result, struct smk_audit_info *auditdata);
317
318#ifdef CONFIG_AUDIT
319
320/*
321 * some inline functions to set up audit data
322 * they do nothing if CONFIG_AUDIT is not set
323 *
324 */
325static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
326 char type)
327{
50c205f5 328 memset(&a->sad, 0, sizeof(a->sad));
ecfcc53f 329 a->a.type = type;
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330 a->a.smack_audit_data = &a->sad;
331 a->a.smack_audit_data->function = func;
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332}
333
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334static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
335 char type, struct lsm_network_audit *net)
336{
337 smk_ad_init(a, func, type);
338 memset(net, 0, sizeof(*net));
339 a->a.u.net = net;
340}
341
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342static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
343 struct task_struct *t)
344{
345 a->a.u.tsk = t;
346}
347static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
348 struct dentry *d)
349{
a269434d 350 a->a.u.dentry = d;
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351}
352static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
353 struct inode *i)
354{
f48b7399 355 a->a.u.inode = i;
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356}
357static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
358 struct path p)
359{
f48b7399 360 a->a.u.path = p;
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361}
362static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
363 struct sock *sk)
364{
48c62af6 365 a->a.u.net->sk = sk;
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366}
367
368#else /* no AUDIT */
369
370static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
371 char type)
372{
373}
374static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
375 struct task_struct *t)
376{
377}
378static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
379 struct dentry *d)
380{
381}
382static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a,
383 struct vfsmount *m)
384{
385}
386static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
387 struct inode *i)
388{
389}
390static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
391 struct path p)
392{
393}
394static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
395 struct sock *sk)
396{
397}
398#endif
399
e114e473 400#endif /* _SECURITY_SMACK_H */