1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
4 *
5 * Author:
6 *      Casey Schaufler <casey@schaufler-ca.com>
7 */
8
9#ifndef _SECURITY_SMACK_H
10#define _SECURITY_SMACK_H
11
12#include <linux/capability.h>
13#include <linux/spinlock.h>
14#include <linux/lsm_hooks.h>
15#include <linux/in.h>
16#if IS_ENABLED(CONFIG_IPV6)
17#include <linux/in6.h>
18#endif /* CONFIG_IPV6 */
19#include <net/netlabel.h>
20#include <linux/list.h>
21#include <linux/rculist.h>
22#include <linux/lsm_audit.h>
23#include <linux/msg.h>
24
25/*
26 * Use IPv6 port labeling if IPv6 is enabled and secmarks
27 * are not being used.
28 */
29#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
30#define SMACK_IPV6_PORT_LABELING 1
31#endif
32
33#if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER)
34#define SMACK_IPV6_SECMARK_LABELING 1
35#endif
36
37/*
38 * Smack labels were limited to 23 characters for a long time.
39 */
40#define SMK_LABELLEN	24
41#define SMK_LONGLABEL	256
42
43/*
44 * This is the repository for labels seen so that it is
45 * not necessary to keep allocating tiny chuncks of memory
46 * and so that they can be shared.
47 *
48 * Labels are never modified in place. Anytime a label
49 * is imported (e.g. xattrset on a file) the list is checked
50 * for it and it is added if it doesn't exist. The address
51 * is passed out in either case. Entries are added, but
52 * never deleted.
53 *
54 * Since labels are hanging around anyway it doesn't
55 * hurt to maintain a secid for those awkward situations
56 * where kernel components that ought to use LSM independent
57 * interfaces don't. The secid should go away when all of
58 * these components have been repaired.
59 *
60 * The cipso value associated with the label gets stored here, too.
61 *
62 * Keep the access rules for this subject label here so that
63 * the entire set of rules does not need to be examined every
64 * time.
65 */
66struct smack_known {
67	struct list_head		list;
68	struct hlist_node		smk_hashed;
69	char				*smk_known;
70	u32				smk_secid;
71	struct netlbl_lsm_secattr	smk_netlabel;	/* on wire labels */
72	struct list_head		smk_rules;	/* access rules */
73	struct mutex			smk_rules_lock;	/* lock for rules */
74};
75
76/*
77 * Maximum number of bytes for the levels in a CIPSO IP option.
78 * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
79 * bigger than can be used, and 24 is the next lower multiple
80 * of 8, and there are too many issues if there isn't space set
81 * aside for the terminating null byte.
82 */
83#define SMK_CIPSOLEN	24
84
85struct superblock_smack {
86	struct smack_known	*smk_root;
87	struct smack_known	*smk_floor;
88	struct smack_known	*smk_hat;
89	struct smack_known	*smk_default;
90	int			smk_flags;
91};
92
93/*
94 * Superblock flags
95 */
96#define SMK_SB_INITIALIZED	0x01
97#define SMK_SB_UNTRUSTED	0x02
98
99struct socket_smack {
100	struct smack_known	*smk_out;	/* outbound label */
101	struct smack_known	*smk_in;	/* inbound label */
102	struct smack_known	*smk_packet;	/* TCP peer label */
103	int			smk_state;	/* netlabel socket states */
104};
105#define	SMK_NETLBL_UNSET	0
106#define	SMK_NETLBL_UNLABELED	1
107#define	SMK_NETLBL_LABELED	2
108#define	SMK_NETLBL_REQSKB	3
109
110/*
111 * Inode smack data
112 */
113struct inode_smack {
114	struct smack_known	*smk_inode;	/* label of the fso */
115	struct smack_known	*smk_task;	/* label of the task */
116	struct smack_known	*smk_mmap;	/* label of the mmap domain */
117	int			smk_flags;	/* smack inode flags */
118};
119
120struct task_smack {
121	struct smack_known	*smk_task;	/* label for access control */
122	struct smack_known	*smk_forked;	/* label when forked */
123	struct smack_known	*smk_transmuted;/* label when transmuted */
124	struct list_head	smk_rules;	/* per task access rules */
125	struct mutex		smk_rules_lock;	/* lock for the rules */
126	struct list_head	smk_relabel;	/* transit allowed labels */
127};
128
129#define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */
130#define	SMK_INODE_TRANSMUTE	0x02	/* directory is transmuting */
131#define	SMK_INODE_CHANGED	0x04	/* smack was transmuted (unused) */
132#define	SMK_INODE_IMPURE	0x08	/* involved in an impure transaction */
133
134/*
135 * A label access rule.
136 */
137struct smack_rule {
138	struct list_head	list;
139	struct smack_known	*smk_subject;
140	struct smack_known	*smk_object;
141	int			smk_access;
142};
143
144/*
145 * An entry in the table identifying IPv4 hosts.
146 */
147struct smk_net4addr {
148	struct list_head	list;
149	struct in_addr		smk_host;	/* network address */
150	struct in_addr		smk_mask;	/* network mask */
151	int			smk_masks;	/* mask size */
152	struct smack_known	*smk_label;	/* label */
153};
154
155/*
156 * An entry in the table identifying IPv6 hosts.
157 */
158struct smk_net6addr {
159	struct list_head	list;
160	struct in6_addr		smk_host;	/* network address */
161	struct in6_addr		smk_mask;	/* network mask */
162	int			smk_masks;	/* mask size */
163	struct smack_known	*smk_label;	/* label */
164};
165
166/*
167 * An entry in the table identifying ports.
168 */
169struct smk_port_label {
170	struct list_head	list;
171	struct sock		*smk_sock;	/* socket initialized on */
172	unsigned short		smk_port;	/* the port number */
173	struct smack_known	*smk_in;	/* inbound label */
174	struct smack_known	*smk_out;	/* outgoing label */
175	short			smk_sock_type;	/* Socket type */
176	short			smk_can_reuse;
177};
178
179struct smack_known_list_elem {
180	struct list_head	list;
181	struct smack_known	*smk_label;
182};
183
184enum {
185	Opt_error = -1,
186	Opt_fsdefault = 0,
187	Opt_fsfloor = 1,
188	Opt_fshat = 2,
189	Opt_fsroot = 3,
190	Opt_fstransmute = 4,
191};
192
193#define SMACK_DELETE_OPTION	"-DELETE"
194#define SMACK_CIPSO_OPTION 	"-CIPSO"
195
196/*
197 * CIPSO defaults.
198 */
199#define SMACK_CIPSO_DOI_DEFAULT		3	/* Historical */
200#define SMACK_CIPSO_DOI_INVALID		-1	/* Not a DOI */
201#define SMACK_CIPSO_DIRECT_DEFAULT	250	/* Arbitrary */
202#define SMACK_CIPSO_MAPPED_DEFAULT	251	/* Also arbitrary */
203#define SMACK_CIPSO_MAXLEVEL            255     /* CIPSO 2.2 standard */
204/*
205 * CIPSO 2.2 standard is 239, but Smack wants to use the
206 * categories in a structured way that limits the value to
207 * the bits in 23 bytes, hence the unusual number.
208 */
209#define SMACK_CIPSO_MAXCATNUM           184     /* 23 * 8 */
210
211/*
212 * Ptrace rules
213 */
214#define SMACK_PTRACE_DEFAULT	0
215#define SMACK_PTRACE_EXACT	1
216#define SMACK_PTRACE_DRACONIAN	2
217#define SMACK_PTRACE_MAX	SMACK_PTRACE_DRACONIAN
218
219/*
220 * Flags for untraditional access modes.
221 * It shouldn't be necessary to avoid conflicts with definitions
222 * in fs.h, but do so anyway.
223 */
224#define MAY_TRANSMUTE	0x00001000	/* Controls directory labeling */
225#define MAY_LOCK	0x00002000	/* Locks should be writes, but ... */
226#define MAY_BRINGUP	0x00004000	/* Report use of this rule */
227
228/*
229 * The policy for delivering signals is configurable.
230 * It is usually "write", but can be "append".
231 */
232#ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS
233#define MAY_DELIVER	MAY_APPEND	/* Signal delivery requires append */
234#else
235#define MAY_DELIVER	MAY_WRITE	/* Signal delivery requires write */
236#endif
237
238#define SMACK_BRINGUP_ALLOW		1	/* Allow bringup mode */
239#define SMACK_UNCONFINED_SUBJECT	2	/* Allow unconfined label */
240#define SMACK_UNCONFINED_OBJECT		3	/* Allow unconfined label */
241
242/*
243 * Just to make the common cases easier to deal with
244 */
245#define MAY_ANYREAD	(MAY_READ | MAY_EXEC)
246#define MAY_READWRITE	(MAY_READ | MAY_WRITE)
247#define MAY_NOT		0
248
249/*
250 * Number of access types used by Smack (rwxatlb)
251 */
252#define SMK_NUM_ACCESS_TYPE 7
253
254/* SMACK data */
255struct smack_audit_data {
256	const char *function;
257	char *subject;
258	char *object;
259	char *request;
260	int result;
261};
262
263/*
264 * Smack audit data; is empty if CONFIG_AUDIT not set
265 * to save some stack
266 */
267struct smk_audit_info {
268#ifdef CONFIG_AUDIT
269	struct common_audit_data a;
270	struct smack_audit_data sad;
271#endif
272};
273
274/*
275 * These functions are in smack_access.c
276 */
277int smk_access_entry(char *, char *, struct list_head *);
278int smk_access(struct smack_known *, struct smack_known *,
279	       int, struct smk_audit_info *);
280int smk_tskacc(struct task_smack *, struct smack_known *,
281	       u32, struct smk_audit_info *);
282int smk_curacc(struct smack_known *, u32, struct smk_audit_info *);
283struct smack_known *smack_from_secid(const u32);
284char *smk_parse_smack(const char *string, int len);
285int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
286struct smack_known *smk_import_entry(const char *, int);
287void smk_insert_entry(struct smack_known *skp);
288struct smack_known *smk_find_entry(const char *);
289bool smack_privileged(int cap);
290bool smack_privileged_cred(int cap, const struct cred *cred);
291void smk_destroy_label_list(struct list_head *list);
292int smack_populate_secattr(struct smack_known *skp);
293
294/*
295 * Shared data.
296 */
297extern int smack_enabled __initdata;
298extern int smack_cipso_direct;
299extern int smack_cipso_mapped;
300extern struct smack_known *smack_net_ambient;
301extern struct smack_known *smack_syslog_label;
302#ifdef CONFIG_SECURITY_SMACK_BRINGUP
303extern struct smack_known *smack_unconfined;
304#endif
305extern int smack_ptrace_rule;
306extern struct lsm_blob_sizes smack_blob_sizes;
307
308extern struct smack_known smack_known_floor;
309extern struct smack_known smack_known_hat;
310extern struct smack_known smack_known_huh;
311extern struct smack_known smack_known_star;
312extern struct smack_known smack_known_web;
313
314extern struct mutex	smack_known_lock;
315extern struct list_head smack_known_list;
316extern struct list_head smk_net4addr_list;
317extern struct list_head smk_net6addr_list;
318
319extern struct mutex     smack_onlycap_lock;
320extern struct list_head smack_onlycap_list;
321
322#define SMACK_HASH_SLOTS 16
323extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
324extern struct kmem_cache *smack_rule_cache;
325
326static inline struct task_smack *smack_cred(const struct cred *cred)
327{
328	return cred->security + smack_blob_sizes.lbs_cred;
329}
330
331static inline struct smack_known **smack_file(const struct file *file)
332{
333	return (struct smack_known **)(file->f_security +
334				       smack_blob_sizes.lbs_file);
335}
336
337static inline struct inode_smack *smack_inode(const struct inode *inode)
338{
339	return inode->i_security + smack_blob_sizes.lbs_inode;
340}
341
342static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg)
343{
344	return msg->security + smack_blob_sizes.lbs_msg_msg;
345}
346
347static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc)
348{
349	return ipc->security + smack_blob_sizes.lbs_ipc;
350}
351
352static inline struct superblock_smack *smack_superblock(
353					const struct super_block *superblock)
354{
355	return superblock->s_security + smack_blob_sizes.lbs_superblock;
356}
357
358/*
359 * Is the directory transmuting?
360 */
361static inline int smk_inode_transmutable(const struct inode *isp)
362{
363	struct inode_smack *sip = smack_inode(isp);
364	return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
365}
366
367/*
368 * Present a pointer to the smack label entry in an inode blob.
369 */
370static inline struct smack_known *smk_of_inode(const struct inode *isp)
371{
372	struct inode_smack *sip = smack_inode(isp);
373	return sip->smk_inode;
374}
375
376/*
377 * Present a pointer to the smack label entry in an task blob.
378 */
379static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
380{
381	return tsp->smk_task;
382}
383
384static inline struct smack_known *smk_of_task_struct_obj(
385						const struct task_struct *t)
386{
387	struct smack_known *skp;
388	const struct cred *cred;
389
390	rcu_read_lock();
391
392	cred = __task_cred(t);
393	skp = smk_of_task(smack_cred(cred));
394
395	rcu_read_unlock();
396
397	return skp;
398}
399
400/*
401 * Present a pointer to the forked smack label entry in an task blob.
402 */
403static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)
404{
405	return tsp->smk_forked;
406}
407
408/*
409 * Present a pointer to the smack label in the current task blob.
410 */
411static inline struct smack_known *smk_of_current(void)
412{
413	return smk_of_task(smack_cred(current_cred()));
414}
415
416/*
417 * logging functions
418 */
419#define SMACK_AUDIT_DENIED 0x1
420#define SMACK_AUDIT_ACCEPT 0x2
421extern int log_policy;
422
423void smack_log(char *subject_label, char *object_label,
424		int request,
425		int result, struct smk_audit_info *auditdata);
426
427#ifdef CONFIG_AUDIT
428
429/*
430 * some inline functions to set up audit data
431 * they do nothing if CONFIG_AUDIT is not set
432 *
433 */
434static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
435			       char type)
436{
437	memset(&a->sad, 0, sizeof(a->sad));
438	a->a.type = type;
439	a->a.smack_audit_data = &a->sad;
440	a->a.smack_audit_data->function = func;
441}
442
443static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
444				   char type, struct lsm_network_audit *net)
445{
446	smk_ad_init(a, func, type);
447	memset(net, 0, sizeof(*net));
448	a->a.u.net = net;
449}
450
451static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
452					 struct task_struct *t)
453{
454	a->a.u.tsk = t;
455}
456static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
457						    struct dentry *d)
458{
459	a->a.u.dentry = d;
460}
461static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
462					      struct inode *i)
463{
464	a->a.u.inode = i;
465}
466static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
467					     struct path p)
468{
469	a->a.u.path = p;
470}
471static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
472					    struct sock *sk)
473{
474	a->a.u.net->sk = sk;
475}
476
477#else /* no AUDIT */
478
479static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
480			       char type)
481{
482}
483static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
484					 struct task_struct *t)
485{
486}
487static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
488						    struct dentry *d)
489{
490}
491static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
492					      struct inode *i)
493{
494}
495static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
496					     struct path p)
497{
498}
499static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
500					    struct sock *sk)
501{
502}
503#endif
504
505#endif  /* _SECURITY_SMACK_H */
506