xref: /linux/security/selinux/hooks.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2  *  NSA Security-Enhanced Linux (SELinux) security module
3  *
4  *  This file contains the SELinux hook function implementations.
5  *
6  *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
7  *            Chris Vance, <cvance@nai.com>
8  *            Wayne Salamon, <wsalamon@nai.com>
9  *            James Morris <jmorris@redhat.com>
10  *
11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12  *  Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
13  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14  *                          <dgoeddel@trustedcs.com>
15  *
16  *	This program is free software; you can redistribute it and/or modify
17  *	it under the terms of the GNU General Public License version 2,
18  *      as published by the Free Software Foundation.
19  */
20 
21 #include <linux/config.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/kernel.h>
25 #include <linux/ptrace.h>
26 #include <linux/errno.h>
27 #include <linux/sched.h>
28 #include <linux/security.h>
29 #include <linux/xattr.h>
30 #include <linux/capability.h>
31 #include <linux/unistd.h>
32 #include <linux/mm.h>
33 #include <linux/mman.h>
34 #include <linux/slab.h>
35 #include <linux/pagemap.h>
36 #include <linux/swap.h>
37 #include <linux/smp_lock.h>
38 #include <linux/spinlock.h>
39 #include <linux/syscalls.h>
40 #include <linux/file.h>
41 #include <linux/namei.h>
42 #include <linux/mount.h>
43 #include <linux/ext2_fs.h>
44 #include <linux/proc_fs.h>
45 #include <linux/kd.h>
46 #include <linux/netfilter_ipv4.h>
47 #include <linux/netfilter_ipv6.h>
48 #include <linux/tty.h>
49 #include <net/icmp.h>
50 #include <net/ip.h>		/* for sysctl_local_port_range[] */
51 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
52 #include <asm/uaccess.h>
53 #include <asm/semaphore.h>
54 #include <asm/ioctls.h>
55 #include <linux/bitops.h>
56 #include <linux/interrupt.h>
57 #include <linux/netdevice.h>	/* for network interface checks */
58 #include <linux/netlink.h>
59 #include <linux/tcp.h>
60 #include <linux/udp.h>
61 #include <linux/quota.h>
62 #include <linux/un.h>		/* for Unix socket types */
63 #include <net/af_unix.h>	/* for Unix socket types */
64 #include <linux/parser.h>
65 #include <linux/nfs_mount.h>
66 #include <net/ipv6.h>
67 #include <linux/hugetlb.h>
68 #include <linux/personality.h>
69 #include <linux/sysctl.h>
70 #include <linux/audit.h>
71 #include <linux/string.h>
72 
73 #include "avc.h"
74 #include "objsec.h"
75 #include "netif.h"
76 #include "xfrm.h"
77 
78 #define XATTR_SELINUX_SUFFIX "selinux"
79 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
80 
81 extern unsigned int policydb_loaded_version;
82 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
83 
84 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
85 int selinux_enforcing = 0;
86 
87 static int __init enforcing_setup(char *str)
88 {
89 	selinux_enforcing = simple_strtol(str,NULL,0);
90 	return 1;
91 }
92 __setup("enforcing=", enforcing_setup);
93 #endif
94 
95 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
96 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
97 
98 static int __init selinux_enabled_setup(char *str)
99 {
100 	selinux_enabled = simple_strtol(str, NULL, 0);
101 	return 1;
102 }
103 __setup("selinux=", selinux_enabled_setup);
104 #endif
105 
106 /* Original (dummy) security module. */
107 static struct security_operations *original_ops = NULL;
108 
109 /* Minimal support for a secondary security module,
110    just to allow the use of the dummy or capability modules.
111    The owlsm module can alternatively be used as a secondary
112    module as long as CONFIG_OWLSM_FD is not enabled. */
113 static struct security_operations *secondary_ops = NULL;
114 
115 /* Lists of inode and superblock security structures initialized
116    before the policy was loaded. */
117 static LIST_HEAD(superblock_security_head);
118 static DEFINE_SPINLOCK(sb_security_lock);
119 
120 static kmem_cache_t *sel_inode_cache;
121 
122 /* Return security context for a given sid or just the context
123    length if the buffer is null or length is 0 */
124 static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
125 {
126 	char *context;
127 	unsigned len;
128 	int rc;
129 
130 	rc = security_sid_to_context(sid, &context, &len);
131 	if (rc)
132 		return rc;
133 
134 	if (!buffer || !size)
135 		goto getsecurity_exit;
136 
137 	if (size < len) {
138 		len = -ERANGE;
139 		goto getsecurity_exit;
140 	}
141 	memcpy(buffer, context, len);
142 
143 getsecurity_exit:
144 	kfree(context);
145 	return len;
146 }
147 
148 /* Allocate and free functions for each kind of security blob. */
149 
150 static int task_alloc_security(struct task_struct *task)
151 {
152 	struct task_security_struct *tsec;
153 
154 	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
155 	if (!tsec)
156 		return -ENOMEM;
157 
158 	tsec->task = task;
159 	tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
160 	task->security = tsec;
161 
162 	return 0;
163 }
164 
165 static void task_free_security(struct task_struct *task)
166 {
167 	struct task_security_struct *tsec = task->security;
168 	task->security = NULL;
169 	kfree(tsec);
170 }
171 
172 static int inode_alloc_security(struct inode *inode)
173 {
174 	struct task_security_struct *tsec = current->security;
175 	struct inode_security_struct *isec;
176 
177 	isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL);
178 	if (!isec)
179 		return -ENOMEM;
180 
181 	memset(isec, 0, sizeof(*isec));
182 	init_MUTEX(&isec->sem);
183 	INIT_LIST_HEAD(&isec->list);
184 	isec->inode = inode;
185 	isec->sid = SECINITSID_UNLABELED;
186 	isec->sclass = SECCLASS_FILE;
187 	isec->task_sid = tsec->sid;
188 	inode->i_security = isec;
189 
190 	return 0;
191 }
192 
193 static void inode_free_security(struct inode *inode)
194 {
195 	struct inode_security_struct *isec = inode->i_security;
196 	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
197 
198 	spin_lock(&sbsec->isec_lock);
199 	if (!list_empty(&isec->list))
200 		list_del_init(&isec->list);
201 	spin_unlock(&sbsec->isec_lock);
202 
203 	inode->i_security = NULL;
204 	kmem_cache_free(sel_inode_cache, isec);
205 }
206 
207 static int file_alloc_security(struct file *file)
208 {
209 	struct task_security_struct *tsec = current->security;
210 	struct file_security_struct *fsec;
211 
212 	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
213 	if (!fsec)
214 		return -ENOMEM;
215 
216 	fsec->file = file;
217 	fsec->sid = tsec->sid;
218 	fsec->fown_sid = tsec->sid;
219 	file->f_security = fsec;
220 
221 	return 0;
222 }
223 
224 static void file_free_security(struct file *file)
225 {
226 	struct file_security_struct *fsec = file->f_security;
227 	file->f_security = NULL;
228 	kfree(fsec);
229 }
230 
231 static int superblock_alloc_security(struct super_block *sb)
232 {
233 	struct superblock_security_struct *sbsec;
234 
235 	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
236 	if (!sbsec)
237 		return -ENOMEM;
238 
239 	init_MUTEX(&sbsec->sem);
240 	INIT_LIST_HEAD(&sbsec->list);
241 	INIT_LIST_HEAD(&sbsec->isec_head);
242 	spin_lock_init(&sbsec->isec_lock);
243 	sbsec->sb = sb;
244 	sbsec->sid = SECINITSID_UNLABELED;
245 	sbsec->def_sid = SECINITSID_FILE;
246 	sb->s_security = sbsec;
247 
248 	return 0;
249 }
250 
251 static void superblock_free_security(struct super_block *sb)
252 {
253 	struct superblock_security_struct *sbsec = sb->s_security;
254 
255 	spin_lock(&sb_security_lock);
256 	if (!list_empty(&sbsec->list))
257 		list_del_init(&sbsec->list);
258 	spin_unlock(&sb_security_lock);
259 
260 	sb->s_security = NULL;
261 	kfree(sbsec);
262 }
263 
264 static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
265 {
266 	struct sk_security_struct *ssec;
267 
268 	if (family != PF_UNIX)
269 		return 0;
270 
271 	ssec = kzalloc(sizeof(*ssec), priority);
272 	if (!ssec)
273 		return -ENOMEM;
274 
275 	ssec->sk = sk;
276 	ssec->peer_sid = SECINITSID_UNLABELED;
277 	sk->sk_security = ssec;
278 
279 	return 0;
280 }
281 
282 static void sk_free_security(struct sock *sk)
283 {
284 	struct sk_security_struct *ssec = sk->sk_security;
285 
286 	if (sk->sk_family != PF_UNIX)
287 		return;
288 
289 	sk->sk_security = NULL;
290 	kfree(ssec);
291 }
292 
293 /* The security server must be initialized before
294    any labeling or access decisions can be provided. */
295 extern int ss_initialized;
296 
297 /* The file system's label must be initialized prior to use. */
298 
299 static char *labeling_behaviors[6] = {
300 	"uses xattr",
301 	"uses transition SIDs",
302 	"uses task SIDs",
303 	"uses genfs_contexts",
304 	"not configured for labeling",
305 	"uses mountpoint labeling",
306 };
307 
308 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
309 
310 static inline int inode_doinit(struct inode *inode)
311 {
312 	return inode_doinit_with_dentry(inode, NULL);
313 }
314 
315 enum {
316 	Opt_context = 1,
317 	Opt_fscontext = 2,
318 	Opt_defcontext = 4,
319 };
320 
321 static match_table_t tokens = {
322 	{Opt_context, "context=%s"},
323 	{Opt_fscontext, "fscontext=%s"},
324 	{Opt_defcontext, "defcontext=%s"},
325 };
326 
327 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
328 
329 static int try_context_mount(struct super_block *sb, void *data)
330 {
331 	char *context = NULL, *defcontext = NULL;
332 	const char *name;
333 	u32 sid;
334 	int alloc = 0, rc = 0, seen = 0;
335 	struct task_security_struct *tsec = current->security;
336 	struct superblock_security_struct *sbsec = sb->s_security;
337 
338 	if (!data)
339 		goto out;
340 
341 	name = sb->s_type->name;
342 
343 	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
344 
345 		/* NFS we understand. */
346 		if (!strcmp(name, "nfs")) {
347 			struct nfs_mount_data *d = data;
348 
349 			if (d->version <  NFS_MOUNT_VERSION)
350 				goto out;
351 
352 			if (d->context[0]) {
353 				context = d->context;
354 				seen |= Opt_context;
355 			}
356 		} else
357 			goto out;
358 
359 	} else {
360 		/* Standard string-based options. */
361 		char *p, *options = data;
362 
363 		while ((p = strsep(&options, ",")) != NULL) {
364 			int token;
365 			substring_t args[MAX_OPT_ARGS];
366 
367 			if (!*p)
368 				continue;
369 
370 			token = match_token(p, tokens, args);
371 
372 			switch (token) {
373 			case Opt_context:
374 				if (seen) {
375 					rc = -EINVAL;
376 					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
377 					goto out_free;
378 				}
379 				context = match_strdup(&args[0]);
380 				if (!context) {
381 					rc = -ENOMEM;
382 					goto out_free;
383 				}
384 				if (!alloc)
385 					alloc = 1;
386 				seen |= Opt_context;
387 				break;
388 
389 			case Opt_fscontext:
390 				if (seen & (Opt_context|Opt_fscontext)) {
391 					rc = -EINVAL;
392 					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
393 					goto out_free;
394 				}
395 				context = match_strdup(&args[0]);
396 				if (!context) {
397 					rc = -ENOMEM;
398 					goto out_free;
399 				}
400 				if (!alloc)
401 					alloc = 1;
402 				seen |= Opt_fscontext;
403 				break;
404 
405 			case Opt_defcontext:
406 				if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
407 					rc = -EINVAL;
408 					printk(KERN_WARNING "SELinux:  "
409 					       "defcontext option is invalid "
410 					       "for this filesystem type\n");
411 					goto out_free;
412 				}
413 				if (seen & (Opt_context|Opt_defcontext)) {
414 					rc = -EINVAL;
415 					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
416 					goto out_free;
417 				}
418 				defcontext = match_strdup(&args[0]);
419 				if (!defcontext) {
420 					rc = -ENOMEM;
421 					goto out_free;
422 				}
423 				if (!alloc)
424 					alloc = 1;
425 				seen |= Opt_defcontext;
426 				break;
427 
428 			default:
429 				rc = -EINVAL;
430 				printk(KERN_WARNING "SELinux:  unknown mount "
431 				       "option\n");
432 				goto out_free;
433 
434 			}
435 		}
436 	}
437 
438 	if (!seen)
439 		goto out;
440 
441 	if (context) {
442 		rc = security_context_to_sid(context, strlen(context), &sid);
443 		if (rc) {
444 			printk(KERN_WARNING "SELinux: security_context_to_sid"
445 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
446 			       context, sb->s_id, name, rc);
447 			goto out_free;
448 		}
449 
450 		rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
451 		                  FILESYSTEM__RELABELFROM, NULL);
452 		if (rc)
453 			goto out_free;
454 
455 		rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
456 		                  FILESYSTEM__RELABELTO, NULL);
457 		if (rc)
458 			goto out_free;
459 
460 		sbsec->sid = sid;
461 
462 		if (seen & Opt_context)
463 			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
464 	}
465 
466 	if (defcontext) {
467 		rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
468 		if (rc) {
469 			printk(KERN_WARNING "SELinux: security_context_to_sid"
470 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
471 			       defcontext, sb->s_id, name, rc);
472 			goto out_free;
473 		}
474 
475 		if (sid == sbsec->def_sid)
476 			goto out_free;
477 
478 		rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
479 				  FILESYSTEM__RELABELFROM, NULL);
480 		if (rc)
481 			goto out_free;
482 
483 		rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
484 				  FILESYSTEM__ASSOCIATE, NULL);
485 		if (rc)
486 			goto out_free;
487 
488 		sbsec->def_sid = sid;
489 	}
490 
491 out_free:
492 	if (alloc) {
493 		kfree(context);
494 		kfree(defcontext);
495 	}
496 out:
497 	return rc;
498 }
499 
500 static int superblock_doinit(struct super_block *sb, void *data)
501 {
502 	struct superblock_security_struct *sbsec = sb->s_security;
503 	struct dentry *root = sb->s_root;
504 	struct inode *inode = root->d_inode;
505 	int rc = 0;
506 
507 	down(&sbsec->sem);
508 	if (sbsec->initialized)
509 		goto out;
510 
511 	if (!ss_initialized) {
512 		/* Defer initialization until selinux_complete_init,
513 		   after the initial policy is loaded and the security
514 		   server is ready to handle calls. */
515 		spin_lock(&sb_security_lock);
516 		if (list_empty(&sbsec->list))
517 			list_add(&sbsec->list, &superblock_security_head);
518 		spin_unlock(&sb_security_lock);
519 		goto out;
520 	}
521 
522 	/* Determine the labeling behavior to use for this filesystem type. */
523 	rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
524 	if (rc) {
525 		printk(KERN_WARNING "%s:  security_fs_use(%s) returned %d\n",
526 		       __FUNCTION__, sb->s_type->name, rc);
527 		goto out;
528 	}
529 
530 	rc = try_context_mount(sb, data);
531 	if (rc)
532 		goto out;
533 
534 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
535 		/* Make sure that the xattr handler exists and that no
536 		   error other than -ENODATA is returned by getxattr on
537 		   the root directory.  -ENODATA is ok, as this may be
538 		   the first boot of the SELinux kernel before we have
539 		   assigned xattr values to the filesystem. */
540 		if (!inode->i_op->getxattr) {
541 			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
542 			       "xattr support\n", sb->s_id, sb->s_type->name);
543 			rc = -EOPNOTSUPP;
544 			goto out;
545 		}
546 		rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
547 		if (rc < 0 && rc != -ENODATA) {
548 			if (rc == -EOPNOTSUPP)
549 				printk(KERN_WARNING "SELinux: (dev %s, type "
550 				       "%s) has no security xattr handler\n",
551 				       sb->s_id, sb->s_type->name);
552 			else
553 				printk(KERN_WARNING "SELinux: (dev %s, type "
554 				       "%s) getxattr errno %d\n", sb->s_id,
555 				       sb->s_type->name, -rc);
556 			goto out;
557 		}
558 	}
559 
560 	if (strcmp(sb->s_type->name, "proc") == 0)
561 		sbsec->proc = 1;
562 
563 	sbsec->initialized = 1;
564 
565 	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
566 		printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
567 		       sb->s_id, sb->s_type->name);
568 	}
569 	else {
570 		printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
571 		       sb->s_id, sb->s_type->name,
572 		       labeling_behaviors[sbsec->behavior-1]);
573 	}
574 
575 	/* Initialize the root inode. */
576 	rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
577 
578 	/* Initialize any other inodes associated with the superblock, e.g.
579 	   inodes created prior to initial policy load or inodes created
580 	   during get_sb by a pseudo filesystem that directly
581 	   populates itself. */
582 	spin_lock(&sbsec->isec_lock);
583 next_inode:
584 	if (!list_empty(&sbsec->isec_head)) {
585 		struct inode_security_struct *isec =
586 				list_entry(sbsec->isec_head.next,
587 				           struct inode_security_struct, list);
588 		struct inode *inode = isec->inode;
589 		spin_unlock(&sbsec->isec_lock);
590 		inode = igrab(inode);
591 		if (inode) {
592 			if (!IS_PRIVATE (inode))
593 				inode_doinit(inode);
594 			iput(inode);
595 		}
596 		spin_lock(&sbsec->isec_lock);
597 		list_del_init(&isec->list);
598 		goto next_inode;
599 	}
600 	spin_unlock(&sbsec->isec_lock);
601 out:
602 	up(&sbsec->sem);
603 	return rc;
604 }
605 
606 static inline u16 inode_mode_to_security_class(umode_t mode)
607 {
608 	switch (mode & S_IFMT) {
609 	case S_IFSOCK:
610 		return SECCLASS_SOCK_FILE;
611 	case S_IFLNK:
612 		return SECCLASS_LNK_FILE;
613 	case S_IFREG:
614 		return SECCLASS_FILE;
615 	case S_IFBLK:
616 		return SECCLASS_BLK_FILE;
617 	case S_IFDIR:
618 		return SECCLASS_DIR;
619 	case S_IFCHR:
620 		return SECCLASS_CHR_FILE;
621 	case S_IFIFO:
622 		return SECCLASS_FIFO_FILE;
623 
624 	}
625 
626 	return SECCLASS_FILE;
627 }
628 
629 static inline int default_protocol_stream(int protocol)
630 {
631 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
632 }
633 
634 static inline int default_protocol_dgram(int protocol)
635 {
636 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
637 }
638 
639 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
640 {
641 	switch (family) {
642 	case PF_UNIX:
643 		switch (type) {
644 		case SOCK_STREAM:
645 		case SOCK_SEQPACKET:
646 			return SECCLASS_UNIX_STREAM_SOCKET;
647 		case SOCK_DGRAM:
648 			return SECCLASS_UNIX_DGRAM_SOCKET;
649 		}
650 		break;
651 	case PF_INET:
652 	case PF_INET6:
653 		switch (type) {
654 		case SOCK_STREAM:
655 			if (default_protocol_stream(protocol))
656 				return SECCLASS_TCP_SOCKET;
657 			else
658 				return SECCLASS_RAWIP_SOCKET;
659 		case SOCK_DGRAM:
660 			if (default_protocol_dgram(protocol))
661 				return SECCLASS_UDP_SOCKET;
662 			else
663 				return SECCLASS_RAWIP_SOCKET;
664 		default:
665 			return SECCLASS_RAWIP_SOCKET;
666 		}
667 		break;
668 	case PF_NETLINK:
669 		switch (protocol) {
670 		case NETLINK_ROUTE:
671 			return SECCLASS_NETLINK_ROUTE_SOCKET;
672 		case NETLINK_FIREWALL:
673 			return SECCLASS_NETLINK_FIREWALL_SOCKET;
674 		case NETLINK_INET_DIAG:
675 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
676 		case NETLINK_NFLOG:
677 			return SECCLASS_NETLINK_NFLOG_SOCKET;
678 		case NETLINK_XFRM:
679 			return SECCLASS_NETLINK_XFRM_SOCKET;
680 		case NETLINK_SELINUX:
681 			return SECCLASS_NETLINK_SELINUX_SOCKET;
682 		case NETLINK_AUDIT:
683 			return SECCLASS_NETLINK_AUDIT_SOCKET;
684 		case NETLINK_IP6_FW:
685 			return SECCLASS_NETLINK_IP6FW_SOCKET;
686 		case NETLINK_DNRTMSG:
687 			return SECCLASS_NETLINK_DNRT_SOCKET;
688 		case NETLINK_KOBJECT_UEVENT:
689 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
690 		default:
691 			return SECCLASS_NETLINK_SOCKET;
692 		}
693 	case PF_PACKET:
694 		return SECCLASS_PACKET_SOCKET;
695 	case PF_KEY:
696 		return SECCLASS_KEY_SOCKET;
697 	}
698 
699 	return SECCLASS_SOCKET;
700 }
701 
702 #ifdef CONFIG_PROC_FS
703 static int selinux_proc_get_sid(struct proc_dir_entry *de,
704 				u16 tclass,
705 				u32 *sid)
706 {
707 	int buflen, rc;
708 	char *buffer, *path, *end;
709 
710 	buffer = (char*)__get_free_page(GFP_KERNEL);
711 	if (!buffer)
712 		return -ENOMEM;
713 
714 	buflen = PAGE_SIZE;
715 	end = buffer+buflen;
716 	*--end = '\0';
717 	buflen--;
718 	path = end-1;
719 	*path = '/';
720 	while (de && de != de->parent) {
721 		buflen -= de->namelen + 1;
722 		if (buflen < 0)
723 			break;
724 		end -= de->namelen;
725 		memcpy(end, de->name, de->namelen);
726 		*--end = '/';
727 		path = end;
728 		de = de->parent;
729 	}
730 	rc = security_genfs_sid("proc", path, tclass, sid);
731 	free_page((unsigned long)buffer);
732 	return rc;
733 }
734 #else
735 static int selinux_proc_get_sid(struct proc_dir_entry *de,
736 				u16 tclass,
737 				u32 *sid)
738 {
739 	return -EINVAL;
740 }
741 #endif
742 
743 /* The inode's security attributes must be initialized before first use. */
744 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
745 {
746 	struct superblock_security_struct *sbsec = NULL;
747 	struct inode_security_struct *isec = inode->i_security;
748 	u32 sid;
749 	struct dentry *dentry;
750 #define INITCONTEXTLEN 255
751 	char *context = NULL;
752 	unsigned len = 0;
753 	int rc = 0;
754 	int hold_sem = 0;
755 
756 	if (isec->initialized)
757 		goto out;
758 
759 	down(&isec->sem);
760 	hold_sem = 1;
761 	if (isec->initialized)
762 		goto out;
763 
764 	sbsec = inode->i_sb->s_security;
765 	if (!sbsec->initialized) {
766 		/* Defer initialization until selinux_complete_init,
767 		   after the initial policy is loaded and the security
768 		   server is ready to handle calls. */
769 		spin_lock(&sbsec->isec_lock);
770 		if (list_empty(&isec->list))
771 			list_add(&isec->list, &sbsec->isec_head);
772 		spin_unlock(&sbsec->isec_lock);
773 		goto out;
774 	}
775 
776 	switch (sbsec->behavior) {
777 	case SECURITY_FS_USE_XATTR:
778 		if (!inode->i_op->getxattr) {
779 			isec->sid = sbsec->def_sid;
780 			break;
781 		}
782 
783 		/* Need a dentry, since the xattr API requires one.
784 		   Life would be simpler if we could just pass the inode. */
785 		if (opt_dentry) {
786 			/* Called from d_instantiate or d_splice_alias. */
787 			dentry = dget(opt_dentry);
788 		} else {
789 			/* Called from selinux_complete_init, try to find a dentry. */
790 			dentry = d_find_alias(inode);
791 		}
792 		if (!dentry) {
793 			printk(KERN_WARNING "%s:  no dentry for dev=%s "
794 			       "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
795 			       inode->i_ino);
796 			goto out;
797 		}
798 
799 		len = INITCONTEXTLEN;
800 		context = kmalloc(len, GFP_KERNEL);
801 		if (!context) {
802 			rc = -ENOMEM;
803 			dput(dentry);
804 			goto out;
805 		}
806 		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
807 					   context, len);
808 		if (rc == -ERANGE) {
809 			/* Need a larger buffer.  Query for the right size. */
810 			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
811 						   NULL, 0);
812 			if (rc < 0) {
813 				dput(dentry);
814 				goto out;
815 			}
816 			kfree(context);
817 			len = rc;
818 			context = kmalloc(len, GFP_KERNEL);
819 			if (!context) {
820 				rc = -ENOMEM;
821 				dput(dentry);
822 				goto out;
823 			}
824 			rc = inode->i_op->getxattr(dentry,
825 						   XATTR_NAME_SELINUX,
826 						   context, len);
827 		}
828 		dput(dentry);
829 		if (rc < 0) {
830 			if (rc != -ENODATA) {
831 				printk(KERN_WARNING "%s:  getxattr returned "
832 				       "%d for dev=%s ino=%ld\n", __FUNCTION__,
833 				       -rc, inode->i_sb->s_id, inode->i_ino);
834 				kfree(context);
835 				goto out;
836 			}
837 			/* Map ENODATA to the default file SID */
838 			sid = sbsec->def_sid;
839 			rc = 0;
840 		} else {
841 			rc = security_context_to_sid_default(context, rc, &sid,
842 			                                     sbsec->def_sid);
843 			if (rc) {
844 				printk(KERN_WARNING "%s:  context_to_sid(%s) "
845 				       "returned %d for dev=%s ino=%ld\n",
846 				       __FUNCTION__, context, -rc,
847 				       inode->i_sb->s_id, inode->i_ino);
848 				kfree(context);
849 				/* Leave with the unlabeled SID */
850 				rc = 0;
851 				break;
852 			}
853 		}
854 		kfree(context);
855 		isec->sid = sid;
856 		break;
857 	case SECURITY_FS_USE_TASK:
858 		isec->sid = isec->task_sid;
859 		break;
860 	case SECURITY_FS_USE_TRANS:
861 		/* Default to the fs SID. */
862 		isec->sid = sbsec->sid;
863 
864 		/* Try to obtain a transition SID. */
865 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
866 		rc = security_transition_sid(isec->task_sid,
867 					     sbsec->sid,
868 					     isec->sclass,
869 					     &sid);
870 		if (rc)
871 			goto out;
872 		isec->sid = sid;
873 		break;
874 	default:
875 		/* Default to the fs SID. */
876 		isec->sid = sbsec->sid;
877 
878 		if (sbsec->proc) {
879 			struct proc_inode *proci = PROC_I(inode);
880 			if (proci->pde) {
881 				isec->sclass = inode_mode_to_security_class(inode->i_mode);
882 				rc = selinux_proc_get_sid(proci->pde,
883 							  isec->sclass,
884 							  &sid);
885 				if (rc)
886 					goto out;
887 				isec->sid = sid;
888 			}
889 		}
890 		break;
891 	}
892 
893 	isec->initialized = 1;
894 
895 out:
896 	if (isec->sclass == SECCLASS_FILE)
897 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
898 
899 	if (hold_sem)
900 		up(&isec->sem);
901 	return rc;
902 }
903 
904 /* Convert a Linux signal to an access vector. */
905 static inline u32 signal_to_av(int sig)
906 {
907 	u32 perm = 0;
908 
909 	switch (sig) {
910 	case SIGCHLD:
911 		/* Commonly granted from child to parent. */
912 		perm = PROCESS__SIGCHLD;
913 		break;
914 	case SIGKILL:
915 		/* Cannot be caught or ignored */
916 		perm = PROCESS__SIGKILL;
917 		break;
918 	case SIGSTOP:
919 		/* Cannot be caught or ignored */
920 		perm = PROCESS__SIGSTOP;
921 		break;
922 	default:
923 		/* All other signals. */
924 		perm = PROCESS__SIGNAL;
925 		break;
926 	}
927 
928 	return perm;
929 }
930 
931 /* Check permission betweeen a pair of tasks, e.g. signal checks,
932    fork check, ptrace check, etc. */
933 static int task_has_perm(struct task_struct *tsk1,
934 			 struct task_struct *tsk2,
935 			 u32 perms)
936 {
937 	struct task_security_struct *tsec1, *tsec2;
938 
939 	tsec1 = tsk1->security;
940 	tsec2 = tsk2->security;
941 	return avc_has_perm(tsec1->sid, tsec2->sid,
942 			    SECCLASS_PROCESS, perms, NULL);
943 }
944 
945 /* Check whether a task is allowed to use a capability. */
946 static int task_has_capability(struct task_struct *tsk,
947 			       int cap)
948 {
949 	struct task_security_struct *tsec;
950 	struct avc_audit_data ad;
951 
952 	tsec = tsk->security;
953 
954 	AVC_AUDIT_DATA_INIT(&ad,CAP);
955 	ad.tsk = tsk;
956 	ad.u.cap = cap;
957 
958 	return avc_has_perm(tsec->sid, tsec->sid,
959 			    SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
960 }
961 
962 /* Check whether a task is allowed to use a system operation. */
963 static int task_has_system(struct task_struct *tsk,
964 			   u32 perms)
965 {
966 	struct task_security_struct *tsec;
967 
968 	tsec = tsk->security;
969 
970 	return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
971 			    SECCLASS_SYSTEM, perms, NULL);
972 }
973 
974 /* Check whether a task has a particular permission to an inode.
975    The 'adp' parameter is optional and allows other audit
976    data to be passed (e.g. the dentry). */
977 static int inode_has_perm(struct task_struct *tsk,
978 			  struct inode *inode,
979 			  u32 perms,
980 			  struct avc_audit_data *adp)
981 {
982 	struct task_security_struct *tsec;
983 	struct inode_security_struct *isec;
984 	struct avc_audit_data ad;
985 
986 	tsec = tsk->security;
987 	isec = inode->i_security;
988 
989 	if (!adp) {
990 		adp = &ad;
991 		AVC_AUDIT_DATA_INIT(&ad, FS);
992 		ad.u.fs.inode = inode;
993 	}
994 
995 	return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
996 }
997 
998 /* Same as inode_has_perm, but pass explicit audit data containing
999    the dentry to help the auditing code to more easily generate the
1000    pathname if needed. */
1001 static inline int dentry_has_perm(struct task_struct *tsk,
1002 				  struct vfsmount *mnt,
1003 				  struct dentry *dentry,
1004 				  u32 av)
1005 {
1006 	struct inode *inode = dentry->d_inode;
1007 	struct avc_audit_data ad;
1008 	AVC_AUDIT_DATA_INIT(&ad,FS);
1009 	ad.u.fs.mnt = mnt;
1010 	ad.u.fs.dentry = dentry;
1011 	return inode_has_perm(tsk, inode, av, &ad);
1012 }
1013 
1014 /* Check whether a task can use an open file descriptor to
1015    access an inode in a given way.  Check access to the
1016    descriptor itself, and then use dentry_has_perm to
1017    check a particular permission to the file.
1018    Access to the descriptor is implicitly granted if it
1019    has the same SID as the process.  If av is zero, then
1020    access to the file is not checked, e.g. for cases
1021    where only the descriptor is affected like seek. */
1022 static int file_has_perm(struct task_struct *tsk,
1023 				struct file *file,
1024 				u32 av)
1025 {
1026 	struct task_security_struct *tsec = tsk->security;
1027 	struct file_security_struct *fsec = file->f_security;
1028 	struct vfsmount *mnt = file->f_vfsmnt;
1029 	struct dentry *dentry = file->f_dentry;
1030 	struct inode *inode = dentry->d_inode;
1031 	struct avc_audit_data ad;
1032 	int rc;
1033 
1034 	AVC_AUDIT_DATA_INIT(&ad, FS);
1035 	ad.u.fs.mnt = mnt;
1036 	ad.u.fs.dentry = dentry;
1037 
1038 	if (tsec->sid != fsec->sid) {
1039 		rc = avc_has_perm(tsec->sid, fsec->sid,
1040 				  SECCLASS_FD,
1041 				  FD__USE,
1042 				  &ad);
1043 		if (rc)
1044 			return rc;
1045 	}
1046 
1047 	/* av is zero if only checking access to the descriptor. */
1048 	if (av)
1049 		return inode_has_perm(tsk, inode, av, &ad);
1050 
1051 	return 0;
1052 }
1053 
1054 /* Check whether a task can create a file. */
1055 static int may_create(struct inode *dir,
1056 		      struct dentry *dentry,
1057 		      u16 tclass)
1058 {
1059 	struct task_security_struct *tsec;
1060 	struct inode_security_struct *dsec;
1061 	struct superblock_security_struct *sbsec;
1062 	u32 newsid;
1063 	struct avc_audit_data ad;
1064 	int rc;
1065 
1066 	tsec = current->security;
1067 	dsec = dir->i_security;
1068 	sbsec = dir->i_sb->s_security;
1069 
1070 	AVC_AUDIT_DATA_INIT(&ad, FS);
1071 	ad.u.fs.dentry = dentry;
1072 
1073 	rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1074 			  DIR__ADD_NAME | DIR__SEARCH,
1075 			  &ad);
1076 	if (rc)
1077 		return rc;
1078 
1079 	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1080 		newsid = tsec->create_sid;
1081 	} else {
1082 		rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1083 					     &newsid);
1084 		if (rc)
1085 			return rc;
1086 	}
1087 
1088 	rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1089 	if (rc)
1090 		return rc;
1091 
1092 	return avc_has_perm(newsid, sbsec->sid,
1093 			    SECCLASS_FILESYSTEM,
1094 			    FILESYSTEM__ASSOCIATE, &ad);
1095 }
1096 
1097 #define MAY_LINK   0
1098 #define MAY_UNLINK 1
1099 #define MAY_RMDIR  2
1100 
1101 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1102 static int may_link(struct inode *dir,
1103 		    struct dentry *dentry,
1104 		    int kind)
1105 
1106 {
1107 	struct task_security_struct *tsec;
1108 	struct inode_security_struct *dsec, *isec;
1109 	struct avc_audit_data ad;
1110 	u32 av;
1111 	int rc;
1112 
1113 	tsec = current->security;
1114 	dsec = dir->i_security;
1115 	isec = dentry->d_inode->i_security;
1116 
1117 	AVC_AUDIT_DATA_INIT(&ad, FS);
1118 	ad.u.fs.dentry = dentry;
1119 
1120 	av = DIR__SEARCH;
1121 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1122 	rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1123 	if (rc)
1124 		return rc;
1125 
1126 	switch (kind) {
1127 	case MAY_LINK:
1128 		av = FILE__LINK;
1129 		break;
1130 	case MAY_UNLINK:
1131 		av = FILE__UNLINK;
1132 		break;
1133 	case MAY_RMDIR:
1134 		av = DIR__RMDIR;
1135 		break;
1136 	default:
1137 		printk(KERN_WARNING "may_link:  unrecognized kind %d\n", kind);
1138 		return 0;
1139 	}
1140 
1141 	rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1142 	return rc;
1143 }
1144 
1145 static inline int may_rename(struct inode *old_dir,
1146 			     struct dentry *old_dentry,
1147 			     struct inode *new_dir,
1148 			     struct dentry *new_dentry)
1149 {
1150 	struct task_security_struct *tsec;
1151 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1152 	struct avc_audit_data ad;
1153 	u32 av;
1154 	int old_is_dir, new_is_dir;
1155 	int rc;
1156 
1157 	tsec = current->security;
1158 	old_dsec = old_dir->i_security;
1159 	old_isec = old_dentry->d_inode->i_security;
1160 	old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1161 	new_dsec = new_dir->i_security;
1162 
1163 	AVC_AUDIT_DATA_INIT(&ad, FS);
1164 
1165 	ad.u.fs.dentry = old_dentry;
1166 	rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1167 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1168 	if (rc)
1169 		return rc;
1170 	rc = avc_has_perm(tsec->sid, old_isec->sid,
1171 			  old_isec->sclass, FILE__RENAME, &ad);
1172 	if (rc)
1173 		return rc;
1174 	if (old_is_dir && new_dir != old_dir) {
1175 		rc = avc_has_perm(tsec->sid, old_isec->sid,
1176 				  old_isec->sclass, DIR__REPARENT, &ad);
1177 		if (rc)
1178 			return rc;
1179 	}
1180 
1181 	ad.u.fs.dentry = new_dentry;
1182 	av = DIR__ADD_NAME | DIR__SEARCH;
1183 	if (new_dentry->d_inode)
1184 		av |= DIR__REMOVE_NAME;
1185 	rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1186 	if (rc)
1187 		return rc;
1188 	if (new_dentry->d_inode) {
1189 		new_isec = new_dentry->d_inode->i_security;
1190 		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1191 		rc = avc_has_perm(tsec->sid, new_isec->sid,
1192 				  new_isec->sclass,
1193 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1194 		if (rc)
1195 			return rc;
1196 	}
1197 
1198 	return 0;
1199 }
1200 
1201 /* Check whether a task can perform a filesystem operation. */
1202 static int superblock_has_perm(struct task_struct *tsk,
1203 			       struct super_block *sb,
1204 			       u32 perms,
1205 			       struct avc_audit_data *ad)
1206 {
1207 	struct task_security_struct *tsec;
1208 	struct superblock_security_struct *sbsec;
1209 
1210 	tsec = tsk->security;
1211 	sbsec = sb->s_security;
1212 	return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1213 			    perms, ad);
1214 }
1215 
1216 /* Convert a Linux mode and permission mask to an access vector. */
1217 static inline u32 file_mask_to_av(int mode, int mask)
1218 {
1219 	u32 av = 0;
1220 
1221 	if ((mode & S_IFMT) != S_IFDIR) {
1222 		if (mask & MAY_EXEC)
1223 			av |= FILE__EXECUTE;
1224 		if (mask & MAY_READ)
1225 			av |= FILE__READ;
1226 
1227 		if (mask & MAY_APPEND)
1228 			av |= FILE__APPEND;
1229 		else if (mask & MAY_WRITE)
1230 			av |= FILE__WRITE;
1231 
1232 	} else {
1233 		if (mask & MAY_EXEC)
1234 			av |= DIR__SEARCH;
1235 		if (mask & MAY_WRITE)
1236 			av |= DIR__WRITE;
1237 		if (mask & MAY_READ)
1238 			av |= DIR__READ;
1239 	}
1240 
1241 	return av;
1242 }
1243 
1244 /* Convert a Linux file to an access vector. */
1245 static inline u32 file_to_av(struct file *file)
1246 {
1247 	u32 av = 0;
1248 
1249 	if (file->f_mode & FMODE_READ)
1250 		av |= FILE__READ;
1251 	if (file->f_mode & FMODE_WRITE) {
1252 		if (file->f_flags & O_APPEND)
1253 			av |= FILE__APPEND;
1254 		else
1255 			av |= FILE__WRITE;
1256 	}
1257 
1258 	return av;
1259 }
1260 
1261 /* Set an inode's SID to a specified value. */
1262 static int inode_security_set_sid(struct inode *inode, u32 sid)
1263 {
1264 	struct inode_security_struct *isec = inode->i_security;
1265 	struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1266 
1267 	if (!sbsec->initialized) {
1268 		/* Defer initialization to selinux_complete_init. */
1269 		return 0;
1270 	}
1271 
1272 	down(&isec->sem);
1273 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
1274 	isec->sid = sid;
1275 	isec->initialized = 1;
1276 	up(&isec->sem);
1277 	return 0;
1278 }
1279 
1280 /* Hook functions begin here. */
1281 
1282 static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1283 {
1284 	struct task_security_struct *psec = parent->security;
1285 	struct task_security_struct *csec = child->security;
1286 	int rc;
1287 
1288 	rc = secondary_ops->ptrace(parent,child);
1289 	if (rc)
1290 		return rc;
1291 
1292 	rc = task_has_perm(parent, child, PROCESS__PTRACE);
1293 	/* Save the SID of the tracing process for later use in apply_creds. */
1294 	if (!(child->ptrace & PT_PTRACED) && !rc)
1295 		csec->ptrace_sid = psec->sid;
1296 	return rc;
1297 }
1298 
1299 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1300                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1301 {
1302 	int error;
1303 
1304 	error = task_has_perm(current, target, PROCESS__GETCAP);
1305 	if (error)
1306 		return error;
1307 
1308 	return secondary_ops->capget(target, effective, inheritable, permitted);
1309 }
1310 
1311 static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1312                                 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1313 {
1314 	int error;
1315 
1316 	error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1317 	if (error)
1318 		return error;
1319 
1320 	return task_has_perm(current, target, PROCESS__SETCAP);
1321 }
1322 
1323 static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1324                                kernel_cap_t *inheritable, kernel_cap_t *permitted)
1325 {
1326 	secondary_ops->capset_set(target, effective, inheritable, permitted);
1327 }
1328 
1329 static int selinux_capable(struct task_struct *tsk, int cap)
1330 {
1331 	int rc;
1332 
1333 	rc = secondary_ops->capable(tsk, cap);
1334 	if (rc)
1335 		return rc;
1336 
1337 	return task_has_capability(tsk,cap);
1338 }
1339 
1340 static int selinux_sysctl(ctl_table *table, int op)
1341 {
1342 	int error = 0;
1343 	u32 av;
1344 	struct task_security_struct *tsec;
1345 	u32 tsid;
1346 	int rc;
1347 
1348 	rc = secondary_ops->sysctl(table, op);
1349 	if (rc)
1350 		return rc;
1351 
1352 	tsec = current->security;
1353 
1354 	rc = selinux_proc_get_sid(table->de, (op == 001) ?
1355 	                          SECCLASS_DIR : SECCLASS_FILE, &tsid);
1356 	if (rc) {
1357 		/* Default to the well-defined sysctl SID. */
1358 		tsid = SECINITSID_SYSCTL;
1359 	}
1360 
1361 	/* The op values are "defined" in sysctl.c, thereby creating
1362 	 * a bad coupling between this module and sysctl.c */
1363 	if(op == 001) {
1364 		error = avc_has_perm(tsec->sid, tsid,
1365 				     SECCLASS_DIR, DIR__SEARCH, NULL);
1366 	} else {
1367 		av = 0;
1368 		if (op & 004)
1369 			av |= FILE__READ;
1370 		if (op & 002)
1371 			av |= FILE__WRITE;
1372 		if (av)
1373 			error = avc_has_perm(tsec->sid, tsid,
1374 					     SECCLASS_FILE, av, NULL);
1375         }
1376 
1377 	return error;
1378 }
1379 
1380 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1381 {
1382 	int rc = 0;
1383 
1384 	if (!sb)
1385 		return 0;
1386 
1387 	switch (cmds) {
1388 		case Q_SYNC:
1389 		case Q_QUOTAON:
1390 		case Q_QUOTAOFF:
1391 	        case Q_SETINFO:
1392 		case Q_SETQUOTA:
1393 			rc = superblock_has_perm(current,
1394 						 sb,
1395 						 FILESYSTEM__QUOTAMOD, NULL);
1396 			break;
1397 	        case Q_GETFMT:
1398 	        case Q_GETINFO:
1399 		case Q_GETQUOTA:
1400 			rc = superblock_has_perm(current,
1401 						 sb,
1402 						 FILESYSTEM__QUOTAGET, NULL);
1403 			break;
1404 		default:
1405 			rc = 0;  /* let the kernel handle invalid cmds */
1406 			break;
1407 	}
1408 	return rc;
1409 }
1410 
1411 static int selinux_quota_on(struct dentry *dentry)
1412 {
1413 	return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1414 }
1415 
1416 static int selinux_syslog(int type)
1417 {
1418 	int rc;
1419 
1420 	rc = secondary_ops->syslog(type);
1421 	if (rc)
1422 		return rc;
1423 
1424 	switch (type) {
1425 		case 3:         /* Read last kernel messages */
1426 		case 10:        /* Return size of the log buffer */
1427 			rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1428 			break;
1429 		case 6:         /* Disable logging to console */
1430 		case 7:         /* Enable logging to console */
1431 		case 8:		/* Set level of messages printed to console */
1432 			rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1433 			break;
1434 		case 0:         /* Close log */
1435 		case 1:         /* Open log */
1436 		case 2:         /* Read from log */
1437 		case 4:         /* Read/clear last kernel messages */
1438 		case 5:         /* Clear ring buffer */
1439 		default:
1440 			rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1441 			break;
1442 	}
1443 	return rc;
1444 }
1445 
1446 /*
1447  * Check that a process has enough memory to allocate a new virtual
1448  * mapping. 0 means there is enough memory for the allocation to
1449  * succeed and -ENOMEM implies there is not.
1450  *
1451  * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1452  * if the capability is granted, but __vm_enough_memory requires 1 if
1453  * the capability is granted.
1454  *
1455  * Do not audit the selinux permission check, as this is applied to all
1456  * processes that allocate mappings.
1457  */
1458 static int selinux_vm_enough_memory(long pages)
1459 {
1460 	int rc, cap_sys_admin = 0;
1461 	struct task_security_struct *tsec = current->security;
1462 
1463 	rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1464 	if (rc == 0)
1465 		rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1466 					SECCLASS_CAPABILITY,
1467 					CAP_TO_MASK(CAP_SYS_ADMIN),
1468 					NULL);
1469 
1470 	if (rc == 0)
1471 		cap_sys_admin = 1;
1472 
1473 	return __vm_enough_memory(pages, cap_sys_admin);
1474 }
1475 
1476 /* binprm security operations */
1477 
1478 static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1479 {
1480 	struct bprm_security_struct *bsec;
1481 
1482 	bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1483 	if (!bsec)
1484 		return -ENOMEM;
1485 
1486 	bsec->bprm = bprm;
1487 	bsec->sid = SECINITSID_UNLABELED;
1488 	bsec->set = 0;
1489 
1490 	bprm->security = bsec;
1491 	return 0;
1492 }
1493 
1494 static int selinux_bprm_set_security(struct linux_binprm *bprm)
1495 {
1496 	struct task_security_struct *tsec;
1497 	struct inode *inode = bprm->file->f_dentry->d_inode;
1498 	struct inode_security_struct *isec;
1499 	struct bprm_security_struct *bsec;
1500 	u32 newsid;
1501 	struct avc_audit_data ad;
1502 	int rc;
1503 
1504 	rc = secondary_ops->bprm_set_security(bprm);
1505 	if (rc)
1506 		return rc;
1507 
1508 	bsec = bprm->security;
1509 
1510 	if (bsec->set)
1511 		return 0;
1512 
1513 	tsec = current->security;
1514 	isec = inode->i_security;
1515 
1516 	/* Default to the current task SID. */
1517 	bsec->sid = tsec->sid;
1518 
1519 	/* Reset create SID on execve. */
1520 	tsec->create_sid = 0;
1521 
1522 	if (tsec->exec_sid) {
1523 		newsid = tsec->exec_sid;
1524 		/* Reset exec SID on execve. */
1525 		tsec->exec_sid = 0;
1526 	} else {
1527 		/* Check for a default transition on this program. */
1528 		rc = security_transition_sid(tsec->sid, isec->sid,
1529 		                             SECCLASS_PROCESS, &newsid);
1530 		if (rc)
1531 			return rc;
1532 	}
1533 
1534 	AVC_AUDIT_DATA_INIT(&ad, FS);
1535 	ad.u.fs.mnt = bprm->file->f_vfsmnt;
1536 	ad.u.fs.dentry = bprm->file->f_dentry;
1537 
1538 	if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1539 		newsid = tsec->sid;
1540 
1541         if (tsec->sid == newsid) {
1542 		rc = avc_has_perm(tsec->sid, isec->sid,
1543 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1544 		if (rc)
1545 			return rc;
1546 	} else {
1547 		/* Check permissions for the transition. */
1548 		rc = avc_has_perm(tsec->sid, newsid,
1549 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1550 		if (rc)
1551 			return rc;
1552 
1553 		rc = avc_has_perm(newsid, isec->sid,
1554 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1555 		if (rc)
1556 			return rc;
1557 
1558 		/* Clear any possibly unsafe personality bits on exec: */
1559 		current->personality &= ~PER_CLEAR_ON_SETID;
1560 
1561 		/* Set the security field to the new SID. */
1562 		bsec->sid = newsid;
1563 	}
1564 
1565 	bsec->set = 1;
1566 	return 0;
1567 }
1568 
1569 static int selinux_bprm_check_security (struct linux_binprm *bprm)
1570 {
1571 	return secondary_ops->bprm_check_security(bprm);
1572 }
1573 
1574 
1575 static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1576 {
1577 	struct task_security_struct *tsec = current->security;
1578 	int atsecure = 0;
1579 
1580 	if (tsec->osid != tsec->sid) {
1581 		/* Enable secure mode for SIDs transitions unless
1582 		   the noatsecure permission is granted between
1583 		   the two SIDs, i.e. ahp returns 0. */
1584 		atsecure = avc_has_perm(tsec->osid, tsec->sid,
1585 					 SECCLASS_PROCESS,
1586 					 PROCESS__NOATSECURE, NULL);
1587 	}
1588 
1589 	return (atsecure || secondary_ops->bprm_secureexec(bprm));
1590 }
1591 
1592 static void selinux_bprm_free_security(struct linux_binprm *bprm)
1593 {
1594 	kfree(bprm->security);
1595 	bprm->security = NULL;
1596 }
1597 
1598 extern struct vfsmount *selinuxfs_mount;
1599 extern struct dentry *selinux_null;
1600 
1601 /* Derived from fs/exec.c:flush_old_files. */
1602 static inline void flush_unauthorized_files(struct files_struct * files)
1603 {
1604 	struct avc_audit_data ad;
1605 	struct file *file, *devnull = NULL;
1606 	struct tty_struct *tty = current->signal->tty;
1607 	struct fdtable *fdt;
1608 	long j = -1;
1609 
1610 	if (tty) {
1611 		file_list_lock();
1612 		file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1613 		if (file) {
1614 			/* Revalidate access to controlling tty.
1615 			   Use inode_has_perm on the tty inode directly rather
1616 			   than using file_has_perm, as this particular open
1617 			   file may belong to another process and we are only
1618 			   interested in the inode-based check here. */
1619 			struct inode *inode = file->f_dentry->d_inode;
1620 			if (inode_has_perm(current, inode,
1621 					   FILE__READ | FILE__WRITE, NULL)) {
1622 				/* Reset controlling tty. */
1623 				current->signal->tty = NULL;
1624 				current->signal->tty_old_pgrp = 0;
1625 			}
1626 		}
1627 		file_list_unlock();
1628 	}
1629 
1630 	/* Revalidate access to inherited open files. */
1631 
1632 	AVC_AUDIT_DATA_INIT(&ad,FS);
1633 
1634 	spin_lock(&files->file_lock);
1635 	for (;;) {
1636 		unsigned long set, i;
1637 		int fd;
1638 
1639 		j++;
1640 		i = j * __NFDBITS;
1641 		fdt = files_fdtable(files);
1642 		if (i >= fdt->max_fds || i >= fdt->max_fdset)
1643 			break;
1644 		set = fdt->open_fds->fds_bits[j];
1645 		if (!set)
1646 			continue;
1647 		spin_unlock(&files->file_lock);
1648 		for ( ; set ; i++,set >>= 1) {
1649 			if (set & 1) {
1650 				file = fget(i);
1651 				if (!file)
1652 					continue;
1653 				if (file_has_perm(current,
1654 						  file,
1655 						  file_to_av(file))) {
1656 					sys_close(i);
1657 					fd = get_unused_fd();
1658 					if (fd != i) {
1659 						if (fd >= 0)
1660 							put_unused_fd(fd);
1661 						fput(file);
1662 						continue;
1663 					}
1664 					if (devnull) {
1665 						get_file(devnull);
1666 					} else {
1667 						devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1668 						if (!devnull) {
1669 							put_unused_fd(fd);
1670 							fput(file);
1671 							continue;
1672 						}
1673 					}
1674 					fd_install(fd, devnull);
1675 				}
1676 				fput(file);
1677 			}
1678 		}
1679 		spin_lock(&files->file_lock);
1680 
1681 	}
1682 	spin_unlock(&files->file_lock);
1683 }
1684 
1685 static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1686 {
1687 	struct task_security_struct *tsec;
1688 	struct bprm_security_struct *bsec;
1689 	u32 sid;
1690 	int rc;
1691 
1692 	secondary_ops->bprm_apply_creds(bprm, unsafe);
1693 
1694 	tsec = current->security;
1695 
1696 	bsec = bprm->security;
1697 	sid = bsec->sid;
1698 
1699 	tsec->osid = tsec->sid;
1700 	bsec->unsafe = 0;
1701 	if (tsec->sid != sid) {
1702 		/* Check for shared state.  If not ok, leave SID
1703 		   unchanged and kill. */
1704 		if (unsafe & LSM_UNSAFE_SHARE) {
1705 			rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1706 					PROCESS__SHARE, NULL);
1707 			if (rc) {
1708 				bsec->unsafe = 1;
1709 				return;
1710 			}
1711 		}
1712 
1713 		/* Check for ptracing, and update the task SID if ok.
1714 		   Otherwise, leave SID unchanged and kill. */
1715 		if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1716 			rc = avc_has_perm(tsec->ptrace_sid, sid,
1717 					  SECCLASS_PROCESS, PROCESS__PTRACE,
1718 					  NULL);
1719 			if (rc) {
1720 				bsec->unsafe = 1;
1721 				return;
1722 			}
1723 		}
1724 		tsec->sid = sid;
1725 	}
1726 }
1727 
1728 /*
1729  * called after apply_creds without the task lock held
1730  */
1731 static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1732 {
1733 	struct task_security_struct *tsec;
1734 	struct rlimit *rlim, *initrlim;
1735 	struct itimerval itimer;
1736 	struct bprm_security_struct *bsec;
1737 	int rc, i;
1738 
1739 	tsec = current->security;
1740 	bsec = bprm->security;
1741 
1742 	if (bsec->unsafe) {
1743 		force_sig_specific(SIGKILL, current);
1744 		return;
1745 	}
1746 	if (tsec->osid == tsec->sid)
1747 		return;
1748 
1749 	/* Close files for which the new task SID is not authorized. */
1750 	flush_unauthorized_files(current->files);
1751 
1752 	/* Check whether the new SID can inherit signal state
1753 	   from the old SID.  If not, clear itimers to avoid
1754 	   subsequent signal generation and flush and unblock
1755 	   signals. This must occur _after_ the task SID has
1756 	  been updated so that any kill done after the flush
1757 	  will be checked against the new SID. */
1758 	rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1759 			  PROCESS__SIGINH, NULL);
1760 	if (rc) {
1761 		memset(&itimer, 0, sizeof itimer);
1762 		for (i = 0; i < 3; i++)
1763 			do_setitimer(i, &itimer, NULL);
1764 		flush_signals(current);
1765 		spin_lock_irq(&current->sighand->siglock);
1766 		flush_signal_handlers(current, 1);
1767 		sigemptyset(&current->blocked);
1768 		recalc_sigpending();
1769 		spin_unlock_irq(&current->sighand->siglock);
1770 	}
1771 
1772 	/* Check whether the new SID can inherit resource limits
1773 	   from the old SID.  If not, reset all soft limits to
1774 	   the lower of the current task's hard limit and the init
1775 	   task's soft limit.  Note that the setting of hard limits
1776 	   (even to lower them) can be controlled by the setrlimit
1777 	   check. The inclusion of the init task's soft limit into
1778 	   the computation is to avoid resetting soft limits higher
1779 	   than the default soft limit for cases where the default
1780 	   is lower than the hard limit, e.g. RLIMIT_CORE or
1781 	   RLIMIT_STACK.*/
1782 	rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1783 			  PROCESS__RLIMITINH, NULL);
1784 	if (rc) {
1785 		for (i = 0; i < RLIM_NLIMITS; i++) {
1786 			rlim = current->signal->rlim + i;
1787 			initrlim = init_task.signal->rlim+i;
1788 			rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1789 		}
1790 		if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1791 			/*
1792 			 * This will cause RLIMIT_CPU calculations
1793 			 * to be refigured.
1794 			 */
1795 			current->it_prof_expires = jiffies_to_cputime(1);
1796 		}
1797 	}
1798 
1799 	/* Wake up the parent if it is waiting so that it can
1800 	   recheck wait permission to the new task SID. */
1801 	wake_up_interruptible(&current->parent->signal->wait_chldexit);
1802 }
1803 
1804 /* superblock security operations */
1805 
1806 static int selinux_sb_alloc_security(struct super_block *sb)
1807 {
1808 	return superblock_alloc_security(sb);
1809 }
1810 
1811 static void selinux_sb_free_security(struct super_block *sb)
1812 {
1813 	superblock_free_security(sb);
1814 }
1815 
1816 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1817 {
1818 	if (plen > olen)
1819 		return 0;
1820 
1821 	return !memcmp(prefix, option, plen);
1822 }
1823 
1824 static inline int selinux_option(char *option, int len)
1825 {
1826 	return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1827 	        match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1828 	        match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1829 }
1830 
1831 static inline void take_option(char **to, char *from, int *first, int len)
1832 {
1833 	if (!*first) {
1834 		**to = ',';
1835 		*to += 1;
1836 	}
1837 	else
1838 		*first = 0;
1839 	memcpy(*to, from, len);
1840 	*to += len;
1841 }
1842 
1843 static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1844 {
1845 	int fnosec, fsec, rc = 0;
1846 	char *in_save, *in_curr, *in_end;
1847 	char *sec_curr, *nosec_save, *nosec;
1848 
1849 	in_curr = orig;
1850 	sec_curr = copy;
1851 
1852 	/* Binary mount data: just copy */
1853 	if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1854 		copy_page(sec_curr, in_curr);
1855 		goto out;
1856 	}
1857 
1858 	nosec = (char *)get_zeroed_page(GFP_KERNEL);
1859 	if (!nosec) {
1860 		rc = -ENOMEM;
1861 		goto out;
1862 	}
1863 
1864 	nosec_save = nosec;
1865 	fnosec = fsec = 1;
1866 	in_save = in_end = orig;
1867 
1868 	do {
1869 		if (*in_end == ',' || *in_end == '\0') {
1870 			int len = in_end - in_curr;
1871 
1872 			if (selinux_option(in_curr, len))
1873 				take_option(&sec_curr, in_curr, &fsec, len);
1874 			else
1875 				take_option(&nosec, in_curr, &fnosec, len);
1876 
1877 			in_curr = in_end + 1;
1878 		}
1879 	} while (*in_end++);
1880 
1881 	strcpy(in_save, nosec_save);
1882 	free_page((unsigned long)nosec_save);
1883 out:
1884 	return rc;
1885 }
1886 
1887 static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1888 {
1889 	struct avc_audit_data ad;
1890 	int rc;
1891 
1892 	rc = superblock_doinit(sb, data);
1893 	if (rc)
1894 		return rc;
1895 
1896 	AVC_AUDIT_DATA_INIT(&ad,FS);
1897 	ad.u.fs.dentry = sb->s_root;
1898 	return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1899 }
1900 
1901 static int selinux_sb_statfs(struct super_block *sb)
1902 {
1903 	struct avc_audit_data ad;
1904 
1905 	AVC_AUDIT_DATA_INIT(&ad,FS);
1906 	ad.u.fs.dentry = sb->s_root;
1907 	return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
1908 }
1909 
1910 static int selinux_mount(char * dev_name,
1911                          struct nameidata *nd,
1912                          char * type,
1913                          unsigned long flags,
1914                          void * data)
1915 {
1916 	int rc;
1917 
1918 	rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1919 	if (rc)
1920 		return rc;
1921 
1922 	if (flags & MS_REMOUNT)
1923 		return superblock_has_perm(current, nd->mnt->mnt_sb,
1924 		                           FILESYSTEM__REMOUNT, NULL);
1925 	else
1926 		return dentry_has_perm(current, nd->mnt, nd->dentry,
1927 		                       FILE__MOUNTON);
1928 }
1929 
1930 static int selinux_umount(struct vfsmount *mnt, int flags)
1931 {
1932 	int rc;
1933 
1934 	rc = secondary_ops->sb_umount(mnt, flags);
1935 	if (rc)
1936 		return rc;
1937 
1938 	return superblock_has_perm(current,mnt->mnt_sb,
1939 	                           FILESYSTEM__UNMOUNT,NULL);
1940 }
1941 
1942 /* inode security operations */
1943 
1944 static int selinux_inode_alloc_security(struct inode *inode)
1945 {
1946 	return inode_alloc_security(inode);
1947 }
1948 
1949 static void selinux_inode_free_security(struct inode *inode)
1950 {
1951 	inode_free_security(inode);
1952 }
1953 
1954 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1955 				       char **name, void **value,
1956 				       size_t *len)
1957 {
1958 	struct task_security_struct *tsec;
1959 	struct inode_security_struct *dsec;
1960 	struct superblock_security_struct *sbsec;
1961 	u32 newsid, clen;
1962 	int rc;
1963 	char *namep = NULL, *context;
1964 
1965 	tsec = current->security;
1966 	dsec = dir->i_security;
1967 	sbsec = dir->i_sb->s_security;
1968 
1969 	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1970 		newsid = tsec->create_sid;
1971 	} else {
1972 		rc = security_transition_sid(tsec->sid, dsec->sid,
1973 					     inode_mode_to_security_class(inode->i_mode),
1974 					     &newsid);
1975 		if (rc) {
1976 			printk(KERN_WARNING "%s:  "
1977 			       "security_transition_sid failed, rc=%d (dev=%s "
1978 			       "ino=%ld)\n",
1979 			       __FUNCTION__,
1980 			       -rc, inode->i_sb->s_id, inode->i_ino);
1981 			return rc;
1982 		}
1983 	}
1984 
1985 	inode_security_set_sid(inode, newsid);
1986 
1987 	if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
1988 		return -EOPNOTSUPP;
1989 
1990 	if (name) {
1991 		namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
1992 		if (!namep)
1993 			return -ENOMEM;
1994 		*name = namep;
1995 	}
1996 
1997 	if (value && len) {
1998 		rc = security_sid_to_context(newsid, &context, &clen);
1999 		if (rc) {
2000 			kfree(namep);
2001 			return rc;
2002 		}
2003 		*value = context;
2004 		*len = clen;
2005 	}
2006 
2007 	return 0;
2008 }
2009 
2010 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2011 {
2012 	return may_create(dir, dentry, SECCLASS_FILE);
2013 }
2014 
2015 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2016 {
2017 	int rc;
2018 
2019 	rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2020 	if (rc)
2021 		return rc;
2022 	return may_link(dir, old_dentry, MAY_LINK);
2023 }
2024 
2025 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2026 {
2027 	int rc;
2028 
2029 	rc = secondary_ops->inode_unlink(dir, dentry);
2030 	if (rc)
2031 		return rc;
2032 	return may_link(dir, dentry, MAY_UNLINK);
2033 }
2034 
2035 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2036 {
2037 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
2038 }
2039 
2040 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2041 {
2042 	return may_create(dir, dentry, SECCLASS_DIR);
2043 }
2044 
2045 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2046 {
2047 	return may_link(dir, dentry, MAY_RMDIR);
2048 }
2049 
2050 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2051 {
2052 	int rc;
2053 
2054 	rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2055 	if (rc)
2056 		return rc;
2057 
2058 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
2059 }
2060 
2061 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2062                                 struct inode *new_inode, struct dentry *new_dentry)
2063 {
2064 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2065 }
2066 
2067 static int selinux_inode_readlink(struct dentry *dentry)
2068 {
2069 	return dentry_has_perm(current, NULL, dentry, FILE__READ);
2070 }
2071 
2072 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2073 {
2074 	int rc;
2075 
2076 	rc = secondary_ops->inode_follow_link(dentry,nameidata);
2077 	if (rc)
2078 		return rc;
2079 	return dentry_has_perm(current, NULL, dentry, FILE__READ);
2080 }
2081 
2082 static int selinux_inode_permission(struct inode *inode, int mask,
2083 				    struct nameidata *nd)
2084 {
2085 	int rc;
2086 
2087 	rc = secondary_ops->inode_permission(inode, mask, nd);
2088 	if (rc)
2089 		return rc;
2090 
2091 	if (!mask) {
2092 		/* No permission to check.  Existence test. */
2093 		return 0;
2094 	}
2095 
2096 	return inode_has_perm(current, inode,
2097 			       file_mask_to_av(inode->i_mode, mask), NULL);
2098 }
2099 
2100 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2101 {
2102 	int rc;
2103 
2104 	rc = secondary_ops->inode_setattr(dentry, iattr);
2105 	if (rc)
2106 		return rc;
2107 
2108 	if (iattr->ia_valid & ATTR_FORCE)
2109 		return 0;
2110 
2111 	if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2112 			       ATTR_ATIME_SET | ATTR_MTIME_SET))
2113 		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2114 
2115 	return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2116 }
2117 
2118 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2119 {
2120 	return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2121 }
2122 
2123 static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2124 {
2125 	struct task_security_struct *tsec = current->security;
2126 	struct inode *inode = dentry->d_inode;
2127 	struct inode_security_struct *isec = inode->i_security;
2128 	struct superblock_security_struct *sbsec;
2129 	struct avc_audit_data ad;
2130 	u32 newsid;
2131 	int rc = 0;
2132 
2133 	if (strcmp(name, XATTR_NAME_SELINUX)) {
2134 		if (!strncmp(name, XATTR_SECURITY_PREFIX,
2135 			     sizeof XATTR_SECURITY_PREFIX - 1) &&
2136 		    !capable(CAP_SYS_ADMIN)) {
2137 			/* A different attribute in the security namespace.
2138 			   Restrict to administrator. */
2139 			return -EPERM;
2140 		}
2141 
2142 		/* Not an attribute we recognize, so just check the
2143 		   ordinary setattr permission. */
2144 		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2145 	}
2146 
2147 	sbsec = inode->i_sb->s_security;
2148 	if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2149 		return -EOPNOTSUPP;
2150 
2151 	if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2152 		return -EPERM;
2153 
2154 	AVC_AUDIT_DATA_INIT(&ad,FS);
2155 	ad.u.fs.dentry = dentry;
2156 
2157 	rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2158 			  FILE__RELABELFROM, &ad);
2159 	if (rc)
2160 		return rc;
2161 
2162 	rc = security_context_to_sid(value, size, &newsid);
2163 	if (rc)
2164 		return rc;
2165 
2166 	rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2167 			  FILE__RELABELTO, &ad);
2168 	if (rc)
2169 		return rc;
2170 
2171 	rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2172 	                                  isec->sclass);
2173 	if (rc)
2174 		return rc;
2175 
2176 	return avc_has_perm(newsid,
2177 			    sbsec->sid,
2178 			    SECCLASS_FILESYSTEM,
2179 			    FILESYSTEM__ASSOCIATE,
2180 			    &ad);
2181 }
2182 
2183 static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2184                                         void *value, size_t size, int flags)
2185 {
2186 	struct inode *inode = dentry->d_inode;
2187 	struct inode_security_struct *isec = inode->i_security;
2188 	u32 newsid;
2189 	int rc;
2190 
2191 	if (strcmp(name, XATTR_NAME_SELINUX)) {
2192 		/* Not an attribute we recognize, so nothing to do. */
2193 		return;
2194 	}
2195 
2196 	rc = security_context_to_sid(value, size, &newsid);
2197 	if (rc) {
2198 		printk(KERN_WARNING "%s:  unable to obtain SID for context "
2199 		       "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2200 		return;
2201 	}
2202 
2203 	isec->sid = newsid;
2204 	return;
2205 }
2206 
2207 static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2208 {
2209 	return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2210 }
2211 
2212 static int selinux_inode_listxattr (struct dentry *dentry)
2213 {
2214 	return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2215 }
2216 
2217 static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2218 {
2219 	if (strcmp(name, XATTR_NAME_SELINUX)) {
2220 		if (!strncmp(name, XATTR_SECURITY_PREFIX,
2221 			     sizeof XATTR_SECURITY_PREFIX - 1) &&
2222 		    !capable(CAP_SYS_ADMIN)) {
2223 			/* A different attribute in the security namespace.
2224 			   Restrict to administrator. */
2225 			return -EPERM;
2226 		}
2227 
2228 		/* Not an attribute we recognize, so just check the
2229 		   ordinary setattr permission. Might want a separate
2230 		   permission for removexattr. */
2231 		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2232 	}
2233 
2234 	/* No one is allowed to remove a SELinux security label.
2235 	   You can change the label, but all data must be labeled. */
2236 	return -EACCES;
2237 }
2238 
2239 static const char *selinux_inode_xattr_getsuffix(void)
2240 {
2241       return XATTR_SELINUX_SUFFIX;
2242 }
2243 
2244 /*
2245  * Copy the in-core inode security context value to the user.  If the
2246  * getxattr() prior to this succeeded, check to see if we need to
2247  * canonicalize the value to be finally returned to the user.
2248  *
2249  * Permission check is handled by selinux_inode_getxattr hook.
2250  */
2251 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
2252 {
2253 	struct inode_security_struct *isec = inode->i_security;
2254 
2255 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
2256 		return -EOPNOTSUPP;
2257 
2258 	return selinux_getsecurity(isec->sid, buffer, size);
2259 }
2260 
2261 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2262                                      const void *value, size_t size, int flags)
2263 {
2264 	struct inode_security_struct *isec = inode->i_security;
2265 	u32 newsid;
2266 	int rc;
2267 
2268 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
2269 		return -EOPNOTSUPP;
2270 
2271 	if (!value || !size)
2272 		return -EACCES;
2273 
2274 	rc = security_context_to_sid((void*)value, size, &newsid);
2275 	if (rc)
2276 		return rc;
2277 
2278 	isec->sid = newsid;
2279 	return 0;
2280 }
2281 
2282 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2283 {
2284 	const int len = sizeof(XATTR_NAME_SELINUX);
2285 	if (buffer && len <= buffer_size)
2286 		memcpy(buffer, XATTR_NAME_SELINUX, len);
2287 	return len;
2288 }
2289 
2290 /* file security operations */
2291 
2292 static int selinux_file_permission(struct file *file, int mask)
2293 {
2294 	struct inode *inode = file->f_dentry->d_inode;
2295 
2296 	if (!mask) {
2297 		/* No permission to check.  Existence test. */
2298 		return 0;
2299 	}
2300 
2301 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2302 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2303 		mask |= MAY_APPEND;
2304 
2305 	return file_has_perm(current, file,
2306 			     file_mask_to_av(inode->i_mode, mask));
2307 }
2308 
2309 static int selinux_file_alloc_security(struct file *file)
2310 {
2311 	return file_alloc_security(file);
2312 }
2313 
2314 static void selinux_file_free_security(struct file *file)
2315 {
2316 	file_free_security(file);
2317 }
2318 
2319 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2320 			      unsigned long arg)
2321 {
2322 	int error = 0;
2323 
2324 	switch (cmd) {
2325 		case FIONREAD:
2326 		/* fall through */
2327 		case FIBMAP:
2328 		/* fall through */
2329 		case FIGETBSZ:
2330 		/* fall through */
2331 		case EXT2_IOC_GETFLAGS:
2332 		/* fall through */
2333 		case EXT2_IOC_GETVERSION:
2334 			error = file_has_perm(current, file, FILE__GETATTR);
2335 			break;
2336 
2337 		case EXT2_IOC_SETFLAGS:
2338 		/* fall through */
2339 		case EXT2_IOC_SETVERSION:
2340 			error = file_has_perm(current, file, FILE__SETATTR);
2341 			break;
2342 
2343 		/* sys_ioctl() checks */
2344 		case FIONBIO:
2345 		/* fall through */
2346 		case FIOASYNC:
2347 			error = file_has_perm(current, file, 0);
2348 			break;
2349 
2350 	        case KDSKBENT:
2351 	        case KDSKBSENT:
2352 			error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2353 			break;
2354 
2355 		/* default case assumes that the command will go
2356 		 * to the file's ioctl() function.
2357 		 */
2358 		default:
2359 			error = file_has_perm(current, file, FILE__IOCTL);
2360 
2361 	}
2362 	return error;
2363 }
2364 
2365 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2366 {
2367 #ifndef CONFIG_PPC32
2368 	if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2369 		/*
2370 		 * We are making executable an anonymous mapping or a
2371 		 * private file mapping that will also be writable.
2372 		 * This has an additional check.
2373 		 */
2374 		int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2375 		if (rc)
2376 			return rc;
2377 	}
2378 #endif
2379 
2380 	if (file) {
2381 		/* read access is always possible with a mapping */
2382 		u32 av = FILE__READ;
2383 
2384 		/* write access only matters if the mapping is shared */
2385 		if (shared && (prot & PROT_WRITE))
2386 			av |= FILE__WRITE;
2387 
2388 		if (prot & PROT_EXEC)
2389 			av |= FILE__EXECUTE;
2390 
2391 		return file_has_perm(current, file, av);
2392 	}
2393 	return 0;
2394 }
2395 
2396 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2397 			     unsigned long prot, unsigned long flags)
2398 {
2399 	int rc;
2400 
2401 	rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2402 	if (rc)
2403 		return rc;
2404 
2405 	if (selinux_checkreqprot)
2406 		prot = reqprot;
2407 
2408 	return file_map_prot_check(file, prot,
2409 				   (flags & MAP_TYPE) == MAP_SHARED);
2410 }
2411 
2412 static int selinux_file_mprotect(struct vm_area_struct *vma,
2413 				 unsigned long reqprot,
2414 				 unsigned long prot)
2415 {
2416 	int rc;
2417 
2418 	rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2419 	if (rc)
2420 		return rc;
2421 
2422 	if (selinux_checkreqprot)
2423 		prot = reqprot;
2424 
2425 #ifndef CONFIG_PPC32
2426 	if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2427 		rc = 0;
2428 		if (vma->vm_start >= vma->vm_mm->start_brk &&
2429 		    vma->vm_end <= vma->vm_mm->brk) {
2430 			rc = task_has_perm(current, current,
2431 					   PROCESS__EXECHEAP);
2432 		} else if (!vma->vm_file &&
2433 			   vma->vm_start <= vma->vm_mm->start_stack &&
2434 			   vma->vm_end >= vma->vm_mm->start_stack) {
2435 			rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2436 		} else if (vma->vm_file && vma->anon_vma) {
2437 			/*
2438 			 * We are making executable a file mapping that has
2439 			 * had some COW done. Since pages might have been
2440 			 * written, check ability to execute the possibly
2441 			 * modified content.  This typically should only
2442 			 * occur for text relocations.
2443 			 */
2444 			rc = file_has_perm(current, vma->vm_file,
2445 					   FILE__EXECMOD);
2446 		}
2447 		if (rc)
2448 			return rc;
2449 	}
2450 #endif
2451 
2452 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
2453 }
2454 
2455 static int selinux_file_lock(struct file *file, unsigned int cmd)
2456 {
2457 	return file_has_perm(current, file, FILE__LOCK);
2458 }
2459 
2460 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
2461 			      unsigned long arg)
2462 {
2463 	int err = 0;
2464 
2465 	switch (cmd) {
2466 	        case F_SETFL:
2467 			if (!file->f_dentry || !file->f_dentry->d_inode) {
2468 				err = -EINVAL;
2469 				break;
2470 			}
2471 
2472 			if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
2473 				err = file_has_perm(current, file,FILE__WRITE);
2474 				break;
2475 			}
2476 			/* fall through */
2477 	        case F_SETOWN:
2478 	        case F_SETSIG:
2479 	        case F_GETFL:
2480 	        case F_GETOWN:
2481 	        case F_GETSIG:
2482 			/* Just check FD__USE permission */
2483 			err = file_has_perm(current, file, 0);
2484 			break;
2485 		case F_GETLK:
2486 		case F_SETLK:
2487 	        case F_SETLKW:
2488 #if BITS_PER_LONG == 32
2489 	        case F_GETLK64:
2490 		case F_SETLK64:
2491 	        case F_SETLKW64:
2492 #endif
2493 			if (!file->f_dentry || !file->f_dentry->d_inode) {
2494 				err = -EINVAL;
2495 				break;
2496 			}
2497 			err = file_has_perm(current, file, FILE__LOCK);
2498 			break;
2499 	}
2500 
2501 	return err;
2502 }
2503 
2504 static int selinux_file_set_fowner(struct file *file)
2505 {
2506 	struct task_security_struct *tsec;
2507 	struct file_security_struct *fsec;
2508 
2509 	tsec = current->security;
2510 	fsec = file->f_security;
2511 	fsec->fown_sid = tsec->sid;
2512 
2513 	return 0;
2514 }
2515 
2516 static int selinux_file_send_sigiotask(struct task_struct *tsk,
2517 				       struct fown_struct *fown, int signum)
2518 {
2519         struct file *file;
2520 	u32 perm;
2521 	struct task_security_struct *tsec;
2522 	struct file_security_struct *fsec;
2523 
2524 	/* struct fown_struct is never outside the context of a struct file */
2525         file = (struct file *)((long)fown - offsetof(struct file,f_owner));
2526 
2527 	tsec = tsk->security;
2528 	fsec = file->f_security;
2529 
2530 	if (!signum)
2531 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
2532 	else
2533 		perm = signal_to_av(signum);
2534 
2535 	return avc_has_perm(fsec->fown_sid, tsec->sid,
2536 			    SECCLASS_PROCESS, perm, NULL);
2537 }
2538 
2539 static int selinux_file_receive(struct file *file)
2540 {
2541 	return file_has_perm(current, file, file_to_av(file));
2542 }
2543 
2544 /* task security operations */
2545 
2546 static int selinux_task_create(unsigned long clone_flags)
2547 {
2548 	int rc;
2549 
2550 	rc = secondary_ops->task_create(clone_flags);
2551 	if (rc)
2552 		return rc;
2553 
2554 	return task_has_perm(current, current, PROCESS__FORK);
2555 }
2556 
2557 static int selinux_task_alloc_security(struct task_struct *tsk)
2558 {
2559 	struct task_security_struct *tsec1, *tsec2;
2560 	int rc;
2561 
2562 	tsec1 = current->security;
2563 
2564 	rc = task_alloc_security(tsk);
2565 	if (rc)
2566 		return rc;
2567 	tsec2 = tsk->security;
2568 
2569 	tsec2->osid = tsec1->osid;
2570 	tsec2->sid = tsec1->sid;
2571 
2572 	/* Retain the exec and create SIDs across fork */
2573 	tsec2->exec_sid = tsec1->exec_sid;
2574 	tsec2->create_sid = tsec1->create_sid;
2575 
2576 	/* Retain ptracer SID across fork, if any.
2577 	   This will be reset by the ptrace hook upon any
2578 	   subsequent ptrace_attach operations. */
2579 	tsec2->ptrace_sid = tsec1->ptrace_sid;
2580 
2581 	return 0;
2582 }
2583 
2584 static void selinux_task_free_security(struct task_struct *tsk)
2585 {
2586 	task_free_security(tsk);
2587 }
2588 
2589 static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
2590 {
2591 	/* Since setuid only affects the current process, and
2592 	   since the SELinux controls are not based on the Linux
2593 	   identity attributes, SELinux does not need to control
2594 	   this operation.  However, SELinux does control the use
2595 	   of the CAP_SETUID and CAP_SETGID capabilities using the
2596 	   capable hook. */
2597 	return 0;
2598 }
2599 
2600 static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
2601 {
2602 	return secondary_ops->task_post_setuid(id0,id1,id2,flags);
2603 }
2604 
2605 static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
2606 {
2607 	/* See the comment for setuid above. */
2608 	return 0;
2609 }
2610 
2611 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
2612 {
2613 	return task_has_perm(current, p, PROCESS__SETPGID);
2614 }
2615 
2616 static int selinux_task_getpgid(struct task_struct *p)
2617 {
2618 	return task_has_perm(current, p, PROCESS__GETPGID);
2619 }
2620 
2621 static int selinux_task_getsid(struct task_struct *p)
2622 {
2623 	return task_has_perm(current, p, PROCESS__GETSESSION);
2624 }
2625 
2626 static int selinux_task_setgroups(struct group_info *group_info)
2627 {
2628 	/* See the comment for setuid above. */
2629 	return 0;
2630 }
2631 
2632 static int selinux_task_setnice(struct task_struct *p, int nice)
2633 {
2634 	int rc;
2635 
2636 	rc = secondary_ops->task_setnice(p, nice);
2637 	if (rc)
2638 		return rc;
2639 
2640 	return task_has_perm(current,p, PROCESS__SETSCHED);
2641 }
2642 
2643 static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
2644 {
2645 	struct rlimit *old_rlim = current->signal->rlim + resource;
2646 	int rc;
2647 
2648 	rc = secondary_ops->task_setrlimit(resource, new_rlim);
2649 	if (rc)
2650 		return rc;
2651 
2652 	/* Control the ability to change the hard limit (whether
2653 	   lowering or raising it), so that the hard limit can
2654 	   later be used as a safe reset point for the soft limit
2655 	   upon context transitions. See selinux_bprm_apply_creds. */
2656 	if (old_rlim->rlim_max != new_rlim->rlim_max)
2657 		return task_has_perm(current, current, PROCESS__SETRLIMIT);
2658 
2659 	return 0;
2660 }
2661 
2662 static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp)
2663 {
2664 	return task_has_perm(current, p, PROCESS__SETSCHED);
2665 }
2666 
2667 static int selinux_task_getscheduler(struct task_struct *p)
2668 {
2669 	return task_has_perm(current, p, PROCESS__GETSCHED);
2670 }
2671 
2672 static int selinux_task_kill(struct task_struct *p, struct siginfo *info, int sig)
2673 {
2674 	u32 perm;
2675 	int rc;
2676 
2677 	rc = secondary_ops->task_kill(p, info, sig);
2678 	if (rc)
2679 		return rc;
2680 
2681 	if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
2682 		return 0;
2683 
2684 	if (!sig)
2685 		perm = PROCESS__SIGNULL; /* null signal; existence test */
2686 	else
2687 		perm = signal_to_av(sig);
2688 
2689 	return task_has_perm(current, p, perm);
2690 }
2691 
2692 static int selinux_task_prctl(int option,
2693 			      unsigned long arg2,
2694 			      unsigned long arg3,
2695 			      unsigned long arg4,
2696 			      unsigned long arg5)
2697 {
2698 	/* The current prctl operations do not appear to require
2699 	   any SELinux controls since they merely observe or modify
2700 	   the state of the current process. */
2701 	return 0;
2702 }
2703 
2704 static int selinux_task_wait(struct task_struct *p)
2705 {
2706 	u32 perm;
2707 
2708 	perm = signal_to_av(p->exit_signal);
2709 
2710 	return task_has_perm(p, current, perm);
2711 }
2712 
2713 static void selinux_task_reparent_to_init(struct task_struct *p)
2714 {
2715   	struct task_security_struct *tsec;
2716 
2717 	secondary_ops->task_reparent_to_init(p);
2718 
2719 	tsec = p->security;
2720 	tsec->osid = tsec->sid;
2721 	tsec->sid = SECINITSID_KERNEL;
2722 	return;
2723 }
2724 
2725 static void selinux_task_to_inode(struct task_struct *p,
2726 				  struct inode *inode)
2727 {
2728 	struct task_security_struct *tsec = p->security;
2729 	struct inode_security_struct *isec = inode->i_security;
2730 
2731 	isec->sid = tsec->sid;
2732 	isec->initialized = 1;
2733 	return;
2734 }
2735 
2736 /* Returns error only if unable to parse addresses */
2737 static int selinux_parse_skb_ipv4(struct sk_buff *skb, struct avc_audit_data *ad)
2738 {
2739 	int offset, ihlen, ret = -EINVAL;
2740 	struct iphdr _iph, *ih;
2741 
2742 	offset = skb->nh.raw - skb->data;
2743 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
2744 	if (ih == NULL)
2745 		goto out;
2746 
2747 	ihlen = ih->ihl * 4;
2748 	if (ihlen < sizeof(_iph))
2749 		goto out;
2750 
2751 	ad->u.net.v4info.saddr = ih->saddr;
2752 	ad->u.net.v4info.daddr = ih->daddr;
2753 	ret = 0;
2754 
2755 	switch (ih->protocol) {
2756         case IPPROTO_TCP: {
2757         	struct tcphdr _tcph, *th;
2758 
2759         	if (ntohs(ih->frag_off) & IP_OFFSET)
2760         		break;
2761 
2762 		offset += ihlen;
2763 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
2764 		if (th == NULL)
2765 			break;
2766 
2767 		ad->u.net.sport = th->source;
2768 		ad->u.net.dport = th->dest;
2769 		break;
2770         }
2771 
2772         case IPPROTO_UDP: {
2773         	struct udphdr _udph, *uh;
2774 
2775         	if (ntohs(ih->frag_off) & IP_OFFSET)
2776         		break;
2777 
2778 		offset += ihlen;
2779         	uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
2780 		if (uh == NULL)
2781 			break;
2782 
2783         	ad->u.net.sport = uh->source;
2784         	ad->u.net.dport = uh->dest;
2785         	break;
2786         }
2787 
2788         default:
2789         	break;
2790         }
2791 out:
2792 	return ret;
2793 }
2794 
2795 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2796 
2797 /* Returns error only if unable to parse addresses */
2798 static int selinux_parse_skb_ipv6(struct sk_buff *skb, struct avc_audit_data *ad)
2799 {
2800 	u8 nexthdr;
2801 	int ret = -EINVAL, offset;
2802 	struct ipv6hdr _ipv6h, *ip6;
2803 
2804 	offset = skb->nh.raw - skb->data;
2805 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
2806 	if (ip6 == NULL)
2807 		goto out;
2808 
2809 	ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
2810 	ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
2811 	ret = 0;
2812 
2813 	nexthdr = ip6->nexthdr;
2814 	offset += sizeof(_ipv6h);
2815 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
2816 	if (offset < 0)
2817 		goto out;
2818 
2819 	switch (nexthdr) {
2820 	case IPPROTO_TCP: {
2821         	struct tcphdr _tcph, *th;
2822 
2823 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
2824 		if (th == NULL)
2825 			break;
2826 
2827 		ad->u.net.sport = th->source;
2828 		ad->u.net.dport = th->dest;
2829 		break;
2830 	}
2831 
2832 	case IPPROTO_UDP: {
2833 		struct udphdr _udph, *uh;
2834 
2835 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
2836 		if (uh == NULL)
2837 			break;
2838 
2839 		ad->u.net.sport = uh->source;
2840 		ad->u.net.dport = uh->dest;
2841 		break;
2842 	}
2843 
2844 	/* includes fragments */
2845 	default:
2846 		break;
2847 	}
2848 out:
2849 	return ret;
2850 }
2851 
2852 #endif /* IPV6 */
2853 
2854 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
2855 			     char **addrp, int *len, int src)
2856 {
2857 	int ret = 0;
2858 
2859 	switch (ad->u.net.family) {
2860 	case PF_INET:
2861 		ret = selinux_parse_skb_ipv4(skb, ad);
2862 		if (ret || !addrp)
2863 			break;
2864 		*len = 4;
2865 		*addrp = (char *)(src ? &ad->u.net.v4info.saddr :
2866 					&ad->u.net.v4info.daddr);
2867 		break;
2868 
2869 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2870 	case PF_INET6:
2871 		ret = selinux_parse_skb_ipv6(skb, ad);
2872 		if (ret || !addrp)
2873 			break;
2874 		*len = 16;
2875 		*addrp = (char *)(src ? &ad->u.net.v6info.saddr :
2876 					&ad->u.net.v6info.daddr);
2877 		break;
2878 #endif	/* IPV6 */
2879 	default:
2880 		break;
2881 	}
2882 
2883 	return ret;
2884 }
2885 
2886 /* socket security operations */
2887 static int socket_has_perm(struct task_struct *task, struct socket *sock,
2888 			   u32 perms)
2889 {
2890 	struct inode_security_struct *isec;
2891 	struct task_security_struct *tsec;
2892 	struct avc_audit_data ad;
2893 	int err = 0;
2894 
2895 	tsec = task->security;
2896 	isec = SOCK_INODE(sock)->i_security;
2897 
2898 	if (isec->sid == SECINITSID_KERNEL)
2899 		goto out;
2900 
2901 	AVC_AUDIT_DATA_INIT(&ad,NET);
2902 	ad.u.net.sk = sock->sk;
2903 	err = avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
2904 
2905 out:
2906 	return err;
2907 }
2908 
2909 static int selinux_socket_create(int family, int type,
2910 				 int protocol, int kern)
2911 {
2912 	int err = 0;
2913 	struct task_security_struct *tsec;
2914 
2915 	if (kern)
2916 		goto out;
2917 
2918 	tsec = current->security;
2919 	err = avc_has_perm(tsec->sid, tsec->sid,
2920 			   socket_type_to_security_class(family, type,
2921 			   protocol), SOCKET__CREATE, NULL);
2922 
2923 out:
2924 	return err;
2925 }
2926 
2927 static void selinux_socket_post_create(struct socket *sock, int family,
2928 				       int type, int protocol, int kern)
2929 {
2930 	struct inode_security_struct *isec;
2931 	struct task_security_struct *tsec;
2932 
2933 	isec = SOCK_INODE(sock)->i_security;
2934 
2935 	tsec = current->security;
2936 	isec->sclass = socket_type_to_security_class(family, type, protocol);
2937 	isec->sid = kern ? SECINITSID_KERNEL : tsec->sid;
2938 	isec->initialized = 1;
2939 
2940 	return;
2941 }
2942 
2943 /* Range of port numbers used to automatically bind.
2944    Need to determine whether we should perform a name_bind
2945    permission check between the socket and the port number. */
2946 #define ip_local_port_range_0 sysctl_local_port_range[0]
2947 #define ip_local_port_range_1 sysctl_local_port_range[1]
2948 
2949 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
2950 {
2951 	u16 family;
2952 	int err;
2953 
2954 	err = socket_has_perm(current, sock, SOCKET__BIND);
2955 	if (err)
2956 		goto out;
2957 
2958 	/*
2959 	 * If PF_INET or PF_INET6, check name_bind permission for the port.
2960 	 * Multiple address binding for SCTP is not supported yet: we just
2961 	 * check the first address now.
2962 	 */
2963 	family = sock->sk->sk_family;
2964 	if (family == PF_INET || family == PF_INET6) {
2965 		char *addrp;
2966 		struct inode_security_struct *isec;
2967 		struct task_security_struct *tsec;
2968 		struct avc_audit_data ad;
2969 		struct sockaddr_in *addr4 = NULL;
2970 		struct sockaddr_in6 *addr6 = NULL;
2971 		unsigned short snum;
2972 		struct sock *sk = sock->sk;
2973 		u32 sid, node_perm, addrlen;
2974 
2975 		tsec = current->security;
2976 		isec = SOCK_INODE(sock)->i_security;
2977 
2978 		if (family == PF_INET) {
2979 			addr4 = (struct sockaddr_in *)address;
2980 			snum = ntohs(addr4->sin_port);
2981 			addrlen = sizeof(addr4->sin_addr.s_addr);
2982 			addrp = (char *)&addr4->sin_addr.s_addr;
2983 		} else {
2984 			addr6 = (struct sockaddr_in6 *)address;
2985 			snum = ntohs(addr6->sin6_port);
2986 			addrlen = sizeof(addr6->sin6_addr.s6_addr);
2987 			addrp = (char *)&addr6->sin6_addr.s6_addr;
2988 		}
2989 
2990 		if (snum&&(snum < max(PROT_SOCK,ip_local_port_range_0) ||
2991 			   snum > ip_local_port_range_1)) {
2992 			err = security_port_sid(sk->sk_family, sk->sk_type,
2993 						sk->sk_protocol, snum, &sid);
2994 			if (err)
2995 				goto out;
2996 			AVC_AUDIT_DATA_INIT(&ad,NET);
2997 			ad.u.net.sport = htons(snum);
2998 			ad.u.net.family = family;
2999 			err = avc_has_perm(isec->sid, sid,
3000 					   isec->sclass,
3001 					   SOCKET__NAME_BIND, &ad);
3002 			if (err)
3003 				goto out;
3004 		}
3005 
3006 		switch(isec->sclass) {
3007 		case SECCLASS_TCP_SOCKET:
3008 			node_perm = TCP_SOCKET__NODE_BIND;
3009 			break;
3010 
3011 		case SECCLASS_UDP_SOCKET:
3012 			node_perm = UDP_SOCKET__NODE_BIND;
3013 			break;
3014 
3015 		default:
3016 			node_perm = RAWIP_SOCKET__NODE_BIND;
3017 			break;
3018 		}
3019 
3020 		err = security_node_sid(family, addrp, addrlen, &sid);
3021 		if (err)
3022 			goto out;
3023 
3024 		AVC_AUDIT_DATA_INIT(&ad,NET);
3025 		ad.u.net.sport = htons(snum);
3026 		ad.u.net.family = family;
3027 
3028 		if (family == PF_INET)
3029 			ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3030 		else
3031 			ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3032 
3033 		err = avc_has_perm(isec->sid, sid,
3034 		                   isec->sclass, node_perm, &ad);
3035 		if (err)
3036 			goto out;
3037 	}
3038 out:
3039 	return err;
3040 }
3041 
3042 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3043 {
3044 	struct inode_security_struct *isec;
3045 	int err;
3046 
3047 	err = socket_has_perm(current, sock, SOCKET__CONNECT);
3048 	if (err)
3049 		return err;
3050 
3051 	/*
3052 	 * If a TCP socket, check name_connect permission for the port.
3053 	 */
3054 	isec = SOCK_INODE(sock)->i_security;
3055 	if (isec->sclass == SECCLASS_TCP_SOCKET) {
3056 		struct sock *sk = sock->sk;
3057 		struct avc_audit_data ad;
3058 		struct sockaddr_in *addr4 = NULL;
3059 		struct sockaddr_in6 *addr6 = NULL;
3060 		unsigned short snum;
3061 		u32 sid;
3062 
3063 		if (sk->sk_family == PF_INET) {
3064 			addr4 = (struct sockaddr_in *)address;
3065 			if (addrlen < sizeof(struct sockaddr_in))
3066 				return -EINVAL;
3067 			snum = ntohs(addr4->sin_port);
3068 		} else {
3069 			addr6 = (struct sockaddr_in6 *)address;
3070 			if (addrlen < SIN6_LEN_RFC2133)
3071 				return -EINVAL;
3072 			snum = ntohs(addr6->sin6_port);
3073 		}
3074 
3075 		err = security_port_sid(sk->sk_family, sk->sk_type,
3076 					sk->sk_protocol, snum, &sid);
3077 		if (err)
3078 			goto out;
3079 
3080 		AVC_AUDIT_DATA_INIT(&ad,NET);
3081 		ad.u.net.dport = htons(snum);
3082 		ad.u.net.family = sk->sk_family;
3083 		err = avc_has_perm(isec->sid, sid, isec->sclass,
3084 				   TCP_SOCKET__NAME_CONNECT, &ad);
3085 		if (err)
3086 			goto out;
3087 	}
3088 
3089 out:
3090 	return err;
3091 }
3092 
3093 static int selinux_socket_listen(struct socket *sock, int backlog)
3094 {
3095 	return socket_has_perm(current, sock, SOCKET__LISTEN);
3096 }
3097 
3098 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3099 {
3100 	int err;
3101 	struct inode_security_struct *isec;
3102 	struct inode_security_struct *newisec;
3103 
3104 	err = socket_has_perm(current, sock, SOCKET__ACCEPT);
3105 	if (err)
3106 		return err;
3107 
3108 	newisec = SOCK_INODE(newsock)->i_security;
3109 
3110 	isec = SOCK_INODE(sock)->i_security;
3111 	newisec->sclass = isec->sclass;
3112 	newisec->sid = isec->sid;
3113 	newisec->initialized = 1;
3114 
3115 	return 0;
3116 }
3117 
3118 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3119  				  int size)
3120 {
3121 	return socket_has_perm(current, sock, SOCKET__WRITE);
3122 }
3123 
3124 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3125 				  int size, int flags)
3126 {
3127 	return socket_has_perm(current, sock, SOCKET__READ);
3128 }
3129 
3130 static int selinux_socket_getsockname(struct socket *sock)
3131 {
3132 	return socket_has_perm(current, sock, SOCKET__GETATTR);
3133 }
3134 
3135 static int selinux_socket_getpeername(struct socket *sock)
3136 {
3137 	return socket_has_perm(current, sock, SOCKET__GETATTR);
3138 }
3139 
3140 static int selinux_socket_setsockopt(struct socket *sock,int level,int optname)
3141 {
3142 	return socket_has_perm(current, sock, SOCKET__SETOPT);
3143 }
3144 
3145 static int selinux_socket_getsockopt(struct socket *sock, int level,
3146 				     int optname)
3147 {
3148 	return socket_has_perm(current, sock, SOCKET__GETOPT);
3149 }
3150 
3151 static int selinux_socket_shutdown(struct socket *sock, int how)
3152 {
3153 	return socket_has_perm(current, sock, SOCKET__SHUTDOWN);
3154 }
3155 
3156 static int selinux_socket_unix_stream_connect(struct socket *sock,
3157 					      struct socket *other,
3158 					      struct sock *newsk)
3159 {
3160 	struct sk_security_struct *ssec;
3161 	struct inode_security_struct *isec;
3162 	struct inode_security_struct *other_isec;
3163 	struct avc_audit_data ad;
3164 	int err;
3165 
3166 	err = secondary_ops->unix_stream_connect(sock, other, newsk);
3167 	if (err)
3168 		return err;
3169 
3170 	isec = SOCK_INODE(sock)->i_security;
3171 	other_isec = SOCK_INODE(other)->i_security;
3172 
3173 	AVC_AUDIT_DATA_INIT(&ad,NET);
3174 	ad.u.net.sk = other->sk;
3175 
3176 	err = avc_has_perm(isec->sid, other_isec->sid,
3177 			   isec->sclass,
3178 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
3179 	if (err)
3180 		return err;
3181 
3182 	/* connecting socket */
3183 	ssec = sock->sk->sk_security;
3184 	ssec->peer_sid = other_isec->sid;
3185 
3186 	/* server child socket */
3187 	ssec = newsk->sk_security;
3188 	ssec->peer_sid = isec->sid;
3189 
3190 	return 0;
3191 }
3192 
3193 static int selinux_socket_unix_may_send(struct socket *sock,
3194 					struct socket *other)
3195 {
3196 	struct inode_security_struct *isec;
3197 	struct inode_security_struct *other_isec;
3198 	struct avc_audit_data ad;
3199 	int err;
3200 
3201 	isec = SOCK_INODE(sock)->i_security;
3202 	other_isec = SOCK_INODE(other)->i_security;
3203 
3204 	AVC_AUDIT_DATA_INIT(&ad,NET);
3205 	ad.u.net.sk = other->sk;
3206 
3207 	err = avc_has_perm(isec->sid, other_isec->sid,
3208 			   isec->sclass, SOCKET__SENDTO, &ad);
3209 	if (err)
3210 		return err;
3211 
3212 	return 0;
3213 }
3214 
3215 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3216 {
3217 	u16 family;
3218 	char *addrp;
3219 	int len, err = 0;
3220 	u32 netif_perm, node_perm, node_sid, if_sid, recv_perm = 0;
3221 	u32 sock_sid = 0;
3222 	u16 sock_class = 0;
3223 	struct socket *sock;
3224 	struct net_device *dev;
3225 	struct avc_audit_data ad;
3226 
3227 	family = sk->sk_family;
3228 	if (family != PF_INET && family != PF_INET6)
3229 		goto out;
3230 
3231 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
3232 	if (family == PF_INET6 && skb->protocol == ntohs(ETH_P_IP))
3233 		family = PF_INET;
3234 
3235  	read_lock_bh(&sk->sk_callback_lock);
3236  	sock = sk->sk_socket;
3237  	if (sock) {
3238  		struct inode *inode;
3239  		inode = SOCK_INODE(sock);
3240  		if (inode) {
3241  			struct inode_security_struct *isec;
3242  			isec = inode->i_security;
3243  			sock_sid = isec->sid;
3244  			sock_class = isec->sclass;
3245  		}
3246  	}
3247  	read_unlock_bh(&sk->sk_callback_lock);
3248  	if (!sock_sid)
3249   		goto out;
3250 
3251 	dev = skb->dev;
3252 	if (!dev)
3253 		goto out;
3254 
3255 	err = sel_netif_sids(dev, &if_sid, NULL);
3256 	if (err)
3257 		goto out;
3258 
3259 	switch (sock_class) {
3260 	case SECCLASS_UDP_SOCKET:
3261 		netif_perm = NETIF__UDP_RECV;
3262 		node_perm = NODE__UDP_RECV;
3263 		recv_perm = UDP_SOCKET__RECV_MSG;
3264 		break;
3265 
3266 	case SECCLASS_TCP_SOCKET:
3267 		netif_perm = NETIF__TCP_RECV;
3268 		node_perm = NODE__TCP_RECV;
3269 		recv_perm = TCP_SOCKET__RECV_MSG;
3270 		break;
3271 
3272 	default:
3273 		netif_perm = NETIF__RAWIP_RECV;
3274 		node_perm = NODE__RAWIP_RECV;
3275 		break;
3276 	}
3277 
3278 	AVC_AUDIT_DATA_INIT(&ad, NET);
3279 	ad.u.net.netif = dev->name;
3280 	ad.u.net.family = family;
3281 
3282 	err = selinux_parse_skb(skb, &ad, &addrp, &len, 1);
3283 	if (err)
3284 		goto out;
3285 
3286 	err = avc_has_perm(sock_sid, if_sid, SECCLASS_NETIF, netif_perm, &ad);
3287 	if (err)
3288 		goto out;
3289 
3290 	/* Fixme: this lookup is inefficient */
3291 	err = security_node_sid(family, addrp, len, &node_sid);
3292 	if (err)
3293 		goto out;
3294 
3295 	err = avc_has_perm(sock_sid, node_sid, SECCLASS_NODE, node_perm, &ad);
3296 	if (err)
3297 		goto out;
3298 
3299 	if (recv_perm) {
3300 		u32 port_sid;
3301 
3302 		/* Fixme: make this more efficient */
3303 		err = security_port_sid(sk->sk_family, sk->sk_type,
3304 		                        sk->sk_protocol, ntohs(ad.u.net.sport),
3305 		                        &port_sid);
3306 		if (err)
3307 			goto out;
3308 
3309 		err = avc_has_perm(sock_sid, port_sid,
3310 				   sock_class, recv_perm, &ad);
3311 	}
3312 
3313 	if (!err)
3314 		err = selinux_xfrm_sock_rcv_skb(sock_sid, skb);
3315 
3316 out:
3317 	return err;
3318 }
3319 
3320 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
3321 					    int __user *optlen, unsigned len)
3322 {
3323 	int err = 0;
3324 	char *scontext;
3325 	u32 scontext_len;
3326 	struct sk_security_struct *ssec;
3327 	struct inode_security_struct *isec;
3328 	u32 peer_sid = 0;
3329 
3330 	isec = SOCK_INODE(sock)->i_security;
3331 
3332 	/* if UNIX_STREAM check peer_sid, if TCP check dst for labelled sa */
3333 	if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET) {
3334 		ssec = sock->sk->sk_security;
3335 		peer_sid = ssec->peer_sid;
3336 	}
3337 	else if (isec->sclass == SECCLASS_TCP_SOCKET) {
3338 		peer_sid = selinux_socket_getpeer_stream(sock->sk);
3339 
3340 		if (peer_sid == SECSID_NULL) {
3341 			err = -ENOPROTOOPT;
3342 			goto out;
3343 		}
3344 	}
3345 	else {
3346 		err = -ENOPROTOOPT;
3347 		goto out;
3348 	}
3349 
3350 	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
3351 
3352 	if (err)
3353 		goto out;
3354 
3355 	if (scontext_len > len) {
3356 		err = -ERANGE;
3357 		goto out_len;
3358 	}
3359 
3360 	if (copy_to_user(optval, scontext, scontext_len))
3361 		err = -EFAULT;
3362 
3363 out_len:
3364 	if (put_user(scontext_len, optlen))
3365 		err = -EFAULT;
3366 
3367 	kfree(scontext);
3368 out:
3369 	return err;
3370 }
3371 
3372 static int selinux_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, u32 *seclen)
3373 {
3374 	int err = 0;
3375 	u32 peer_sid = selinux_socket_getpeer_dgram(skb);
3376 
3377 	if (peer_sid == SECSID_NULL)
3378 		return -EINVAL;
3379 
3380 	err = security_sid_to_context(peer_sid, secdata, seclen);
3381 	if (err)
3382 		return err;
3383 
3384 	return 0;
3385 }
3386 
3387 
3388 
3389 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
3390 {
3391 	return sk_alloc_security(sk, family, priority);
3392 }
3393 
3394 static void selinux_sk_free_security(struct sock *sk)
3395 {
3396 	sk_free_security(sk);
3397 }
3398 
3399 static unsigned int selinux_sk_getsid_security(struct sock *sk, struct flowi *fl, u8 dir)
3400 {
3401 	struct inode_security_struct *isec;
3402 	u32 sock_sid = SECINITSID_ANY_SOCKET;
3403 
3404 	if (!sk)
3405 		return selinux_no_sk_sid(fl);
3406 
3407 	read_lock_bh(&sk->sk_callback_lock);
3408 	isec = get_sock_isec(sk);
3409 
3410 	if (isec)
3411 		sock_sid = isec->sid;
3412 
3413 	read_unlock_bh(&sk->sk_callback_lock);
3414 	return sock_sid;
3415 }
3416 
3417 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
3418 {
3419 	int err = 0;
3420 	u32 perm;
3421 	struct nlmsghdr *nlh;
3422 	struct socket *sock = sk->sk_socket;
3423 	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3424 
3425 	if (skb->len < NLMSG_SPACE(0)) {
3426 		err = -EINVAL;
3427 		goto out;
3428 	}
3429 	nlh = (struct nlmsghdr *)skb->data;
3430 
3431 	err = selinux_nlmsg_lookup(isec->sclass, nlh->nlmsg_type, &perm);
3432 	if (err) {
3433 		if (err == -EINVAL) {
3434 			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
3435 				  "SELinux:  unrecognized netlink message"
3436 				  " type=%hu for sclass=%hu\n",
3437 				  nlh->nlmsg_type, isec->sclass);
3438 			if (!selinux_enforcing)
3439 				err = 0;
3440 		}
3441 
3442 		/* Ignore */
3443 		if (err == -ENOENT)
3444 			err = 0;
3445 		goto out;
3446 	}
3447 
3448 	err = socket_has_perm(current, sock, perm);
3449 out:
3450 	return err;
3451 }
3452 
3453 #ifdef CONFIG_NETFILTER
3454 
3455 static unsigned int selinux_ip_postroute_last(unsigned int hooknum,
3456                                               struct sk_buff **pskb,
3457                                               const struct net_device *in,
3458                                               const struct net_device *out,
3459                                               int (*okfn)(struct sk_buff *),
3460                                               u16 family)
3461 {
3462 	char *addrp;
3463 	int len, err = NF_ACCEPT;
3464 	u32 netif_perm, node_perm, node_sid, if_sid, send_perm = 0;
3465 	struct sock *sk;
3466 	struct socket *sock;
3467 	struct inode *inode;
3468 	struct sk_buff *skb = *pskb;
3469 	struct inode_security_struct *isec;
3470 	struct avc_audit_data ad;
3471 	struct net_device *dev = (struct net_device *)out;
3472 
3473 	sk = skb->sk;
3474 	if (!sk)
3475 		goto out;
3476 
3477 	sock = sk->sk_socket;
3478 	if (!sock)
3479 		goto out;
3480 
3481 	inode = SOCK_INODE(sock);
3482 	if (!inode)
3483 		goto out;
3484 
3485 	err = sel_netif_sids(dev, &if_sid, NULL);
3486 	if (err)
3487 		goto out;
3488 
3489 	isec = inode->i_security;
3490 
3491 	switch (isec->sclass) {
3492 	case SECCLASS_UDP_SOCKET:
3493 		netif_perm = NETIF__UDP_SEND;
3494 		node_perm = NODE__UDP_SEND;
3495 		send_perm = UDP_SOCKET__SEND_MSG;
3496 		break;
3497 
3498 	case SECCLASS_TCP_SOCKET:
3499 		netif_perm = NETIF__TCP_SEND;
3500 		node_perm = NODE__TCP_SEND;
3501 		send_perm = TCP_SOCKET__SEND_MSG;
3502 		break;
3503 
3504 	default:
3505 		netif_perm = NETIF__RAWIP_SEND;
3506 		node_perm = NODE__RAWIP_SEND;
3507 		break;
3508 	}
3509 
3510 
3511 	AVC_AUDIT_DATA_INIT(&ad, NET);
3512 	ad.u.net.netif = dev->name;
3513 	ad.u.net.family = family;
3514 
3515 	err = selinux_parse_skb(skb, &ad, &addrp,
3516 				&len, 0) ? NF_DROP : NF_ACCEPT;
3517 	if (err != NF_ACCEPT)
3518 		goto out;
3519 
3520 	err = avc_has_perm(isec->sid, if_sid, SECCLASS_NETIF,
3521 	                   netif_perm, &ad) ? NF_DROP : NF_ACCEPT;
3522 	if (err != NF_ACCEPT)
3523 		goto out;
3524 
3525 	/* Fixme: this lookup is inefficient */
3526 	err = security_node_sid(family, addrp, len,
3527 				&node_sid) ? NF_DROP : NF_ACCEPT;
3528 	if (err != NF_ACCEPT)
3529 		goto out;
3530 
3531 	err = avc_has_perm(isec->sid, node_sid, SECCLASS_NODE,
3532 	                   node_perm, &ad) ? NF_DROP : NF_ACCEPT;
3533 	if (err != NF_ACCEPT)
3534 		goto out;
3535 
3536 	if (send_perm) {
3537 		u32 port_sid;
3538 
3539 		/* Fixme: make this more efficient */
3540 		err = security_port_sid(sk->sk_family,
3541 		                        sk->sk_type,
3542 		                        sk->sk_protocol,
3543 		                        ntohs(ad.u.net.dport),
3544 		                        &port_sid) ? NF_DROP : NF_ACCEPT;
3545 		if (err != NF_ACCEPT)
3546 			goto out;
3547 
3548 		err = avc_has_perm(isec->sid, port_sid, isec->sclass,
3549 		                   send_perm, &ad) ? NF_DROP : NF_ACCEPT;
3550 	}
3551 
3552 	if (err != NF_ACCEPT)
3553 		goto out;
3554 
3555 	err = selinux_xfrm_postroute_last(isec->sid, skb);
3556 
3557 out:
3558 	return err;
3559 }
3560 
3561 static unsigned int selinux_ipv4_postroute_last(unsigned int hooknum,
3562 						struct sk_buff **pskb,
3563 						const struct net_device *in,
3564 						const struct net_device *out,
3565 						int (*okfn)(struct sk_buff *))
3566 {
3567 	return selinux_ip_postroute_last(hooknum, pskb, in, out, okfn, PF_INET);
3568 }
3569 
3570 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3571 
3572 static unsigned int selinux_ipv6_postroute_last(unsigned int hooknum,
3573 						struct sk_buff **pskb,
3574 						const struct net_device *in,
3575 						const struct net_device *out,
3576 						int (*okfn)(struct sk_buff *))
3577 {
3578 	return selinux_ip_postroute_last(hooknum, pskb, in, out, okfn, PF_INET6);
3579 }
3580 
3581 #endif	/* IPV6 */
3582 
3583 #endif	/* CONFIG_NETFILTER */
3584 
3585 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
3586 {
3587 	struct task_security_struct *tsec;
3588 	struct av_decision avd;
3589 	int err;
3590 
3591 	err = secondary_ops->netlink_send(sk, skb);
3592 	if (err)
3593 		return err;
3594 
3595 	tsec = current->security;
3596 
3597 	avd.allowed = 0;
3598 	avc_has_perm_noaudit(tsec->sid, tsec->sid,
3599 				SECCLASS_CAPABILITY, ~0, &avd);
3600 	cap_mask(NETLINK_CB(skb).eff_cap, avd.allowed);
3601 
3602 	if (policydb_loaded_version >= POLICYDB_VERSION_NLCLASS)
3603 		err = selinux_nlmsg_perm(sk, skb);
3604 
3605 	return err;
3606 }
3607 
3608 static int selinux_netlink_recv(struct sk_buff *skb)
3609 {
3610 	if (!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
3611 		return -EPERM;
3612 	return 0;
3613 }
3614 
3615 static int ipc_alloc_security(struct task_struct *task,
3616 			      struct kern_ipc_perm *perm,
3617 			      u16 sclass)
3618 {
3619 	struct task_security_struct *tsec = task->security;
3620 	struct ipc_security_struct *isec;
3621 
3622 	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
3623 	if (!isec)
3624 		return -ENOMEM;
3625 
3626 	isec->sclass = sclass;
3627 	isec->ipc_perm = perm;
3628 	isec->sid = tsec->sid;
3629 	perm->security = isec;
3630 
3631 	return 0;
3632 }
3633 
3634 static void ipc_free_security(struct kern_ipc_perm *perm)
3635 {
3636 	struct ipc_security_struct *isec = perm->security;
3637 	perm->security = NULL;
3638 	kfree(isec);
3639 }
3640 
3641 static int msg_msg_alloc_security(struct msg_msg *msg)
3642 {
3643 	struct msg_security_struct *msec;
3644 
3645 	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
3646 	if (!msec)
3647 		return -ENOMEM;
3648 
3649 	msec->msg = msg;
3650 	msec->sid = SECINITSID_UNLABELED;
3651 	msg->security = msec;
3652 
3653 	return 0;
3654 }
3655 
3656 static void msg_msg_free_security(struct msg_msg *msg)
3657 {
3658 	struct msg_security_struct *msec = msg->security;
3659 
3660 	msg->security = NULL;
3661 	kfree(msec);
3662 }
3663 
3664 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
3665 			u32 perms)
3666 {
3667 	struct task_security_struct *tsec;
3668 	struct ipc_security_struct *isec;
3669 	struct avc_audit_data ad;
3670 
3671 	tsec = current->security;
3672 	isec = ipc_perms->security;
3673 
3674 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3675 	ad.u.ipc_id = ipc_perms->key;
3676 
3677 	return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
3678 }
3679 
3680 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
3681 {
3682 	return msg_msg_alloc_security(msg);
3683 }
3684 
3685 static void selinux_msg_msg_free_security(struct msg_msg *msg)
3686 {
3687 	msg_msg_free_security(msg);
3688 }
3689 
3690 /* message queue security operations */
3691 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
3692 {
3693 	struct task_security_struct *tsec;
3694 	struct ipc_security_struct *isec;
3695 	struct avc_audit_data ad;
3696 	int rc;
3697 
3698 	rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
3699 	if (rc)
3700 		return rc;
3701 
3702 	tsec = current->security;
3703 	isec = msq->q_perm.security;
3704 
3705 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3706  	ad.u.ipc_id = msq->q_perm.key;
3707 
3708 	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
3709 			  MSGQ__CREATE, &ad);
3710 	if (rc) {
3711 		ipc_free_security(&msq->q_perm);
3712 		return rc;
3713 	}
3714 	return 0;
3715 }
3716 
3717 static void selinux_msg_queue_free_security(struct msg_queue *msq)
3718 {
3719 	ipc_free_security(&msq->q_perm);
3720 }
3721 
3722 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
3723 {
3724 	struct task_security_struct *tsec;
3725 	struct ipc_security_struct *isec;
3726 	struct avc_audit_data ad;
3727 
3728 	tsec = current->security;
3729 	isec = msq->q_perm.security;
3730 
3731 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3732 	ad.u.ipc_id = msq->q_perm.key;
3733 
3734 	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
3735 			    MSGQ__ASSOCIATE, &ad);
3736 }
3737 
3738 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
3739 {
3740 	int err;
3741 	int perms;
3742 
3743 	switch(cmd) {
3744 	case IPC_INFO:
3745 	case MSG_INFO:
3746 		/* No specific object, just general system-wide information. */
3747 		return task_has_system(current, SYSTEM__IPC_INFO);
3748 	case IPC_STAT:
3749 	case MSG_STAT:
3750 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
3751 		break;
3752 	case IPC_SET:
3753 		perms = MSGQ__SETATTR;
3754 		break;
3755 	case IPC_RMID:
3756 		perms = MSGQ__DESTROY;
3757 		break;
3758 	default:
3759 		return 0;
3760 	}
3761 
3762 	err = ipc_has_perm(&msq->q_perm, perms);
3763 	return err;
3764 }
3765 
3766 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
3767 {
3768 	struct task_security_struct *tsec;
3769 	struct ipc_security_struct *isec;
3770 	struct msg_security_struct *msec;
3771 	struct avc_audit_data ad;
3772 	int rc;
3773 
3774 	tsec = current->security;
3775 	isec = msq->q_perm.security;
3776 	msec = msg->security;
3777 
3778 	/*
3779 	 * First time through, need to assign label to the message
3780 	 */
3781 	if (msec->sid == SECINITSID_UNLABELED) {
3782 		/*
3783 		 * Compute new sid based on current process and
3784 		 * message queue this message will be stored in
3785 		 */
3786 		rc = security_transition_sid(tsec->sid,
3787 					     isec->sid,
3788 					     SECCLASS_MSG,
3789 					     &msec->sid);
3790 		if (rc)
3791 			return rc;
3792 	}
3793 
3794 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3795 	ad.u.ipc_id = msq->q_perm.key;
3796 
3797 	/* Can this process write to the queue? */
3798 	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
3799 			  MSGQ__WRITE, &ad);
3800 	if (!rc)
3801 		/* Can this process send the message */
3802 		rc = avc_has_perm(tsec->sid, msec->sid,
3803 				  SECCLASS_MSG, MSG__SEND, &ad);
3804 	if (!rc)
3805 		/* Can the message be put in the queue? */
3806 		rc = avc_has_perm(msec->sid, isec->sid,
3807 				  SECCLASS_MSGQ, MSGQ__ENQUEUE, &ad);
3808 
3809 	return rc;
3810 }
3811 
3812 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
3813 				    struct task_struct *target,
3814 				    long type, int mode)
3815 {
3816 	struct task_security_struct *tsec;
3817 	struct ipc_security_struct *isec;
3818 	struct msg_security_struct *msec;
3819 	struct avc_audit_data ad;
3820 	int rc;
3821 
3822 	tsec = target->security;
3823 	isec = msq->q_perm.security;
3824 	msec = msg->security;
3825 
3826 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3827  	ad.u.ipc_id = msq->q_perm.key;
3828 
3829 	rc = avc_has_perm(tsec->sid, isec->sid,
3830 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
3831 	if (!rc)
3832 		rc = avc_has_perm(tsec->sid, msec->sid,
3833 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
3834 	return rc;
3835 }
3836 
3837 /* Shared Memory security operations */
3838 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
3839 {
3840 	struct task_security_struct *tsec;
3841 	struct ipc_security_struct *isec;
3842 	struct avc_audit_data ad;
3843 	int rc;
3844 
3845 	rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
3846 	if (rc)
3847 		return rc;
3848 
3849 	tsec = current->security;
3850 	isec = shp->shm_perm.security;
3851 
3852 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3853  	ad.u.ipc_id = shp->shm_perm.key;
3854 
3855 	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
3856 			  SHM__CREATE, &ad);
3857 	if (rc) {
3858 		ipc_free_security(&shp->shm_perm);
3859 		return rc;
3860 	}
3861 	return 0;
3862 }
3863 
3864 static void selinux_shm_free_security(struct shmid_kernel *shp)
3865 {
3866 	ipc_free_security(&shp->shm_perm);
3867 }
3868 
3869 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
3870 {
3871 	struct task_security_struct *tsec;
3872 	struct ipc_security_struct *isec;
3873 	struct avc_audit_data ad;
3874 
3875 	tsec = current->security;
3876 	isec = shp->shm_perm.security;
3877 
3878 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3879 	ad.u.ipc_id = shp->shm_perm.key;
3880 
3881 	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
3882 			    SHM__ASSOCIATE, &ad);
3883 }
3884 
3885 /* Note, at this point, shp is locked down */
3886 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
3887 {
3888 	int perms;
3889 	int err;
3890 
3891 	switch(cmd) {
3892 	case IPC_INFO:
3893 	case SHM_INFO:
3894 		/* No specific object, just general system-wide information. */
3895 		return task_has_system(current, SYSTEM__IPC_INFO);
3896 	case IPC_STAT:
3897 	case SHM_STAT:
3898 		perms = SHM__GETATTR | SHM__ASSOCIATE;
3899 		break;
3900 	case IPC_SET:
3901 		perms = SHM__SETATTR;
3902 		break;
3903 	case SHM_LOCK:
3904 	case SHM_UNLOCK:
3905 		perms = SHM__LOCK;
3906 		break;
3907 	case IPC_RMID:
3908 		perms = SHM__DESTROY;
3909 		break;
3910 	default:
3911 		return 0;
3912 	}
3913 
3914 	err = ipc_has_perm(&shp->shm_perm, perms);
3915 	return err;
3916 }
3917 
3918 static int selinux_shm_shmat(struct shmid_kernel *shp,
3919 			     char __user *shmaddr, int shmflg)
3920 {
3921 	u32 perms;
3922 	int rc;
3923 
3924 	rc = secondary_ops->shm_shmat(shp, shmaddr, shmflg);
3925 	if (rc)
3926 		return rc;
3927 
3928 	if (shmflg & SHM_RDONLY)
3929 		perms = SHM__READ;
3930 	else
3931 		perms = SHM__READ | SHM__WRITE;
3932 
3933 	return ipc_has_perm(&shp->shm_perm, perms);
3934 }
3935 
3936 /* Semaphore security operations */
3937 static int selinux_sem_alloc_security(struct sem_array *sma)
3938 {
3939 	struct task_security_struct *tsec;
3940 	struct ipc_security_struct *isec;
3941 	struct avc_audit_data ad;
3942 	int rc;
3943 
3944 	rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
3945 	if (rc)
3946 		return rc;
3947 
3948 	tsec = current->security;
3949 	isec = sma->sem_perm.security;
3950 
3951 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3952  	ad.u.ipc_id = sma->sem_perm.key;
3953 
3954 	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
3955 			  SEM__CREATE, &ad);
3956 	if (rc) {
3957 		ipc_free_security(&sma->sem_perm);
3958 		return rc;
3959 	}
3960 	return 0;
3961 }
3962 
3963 static void selinux_sem_free_security(struct sem_array *sma)
3964 {
3965 	ipc_free_security(&sma->sem_perm);
3966 }
3967 
3968 static int selinux_sem_associate(struct sem_array *sma, int semflg)
3969 {
3970 	struct task_security_struct *tsec;
3971 	struct ipc_security_struct *isec;
3972 	struct avc_audit_data ad;
3973 
3974 	tsec = current->security;
3975 	isec = sma->sem_perm.security;
3976 
3977 	AVC_AUDIT_DATA_INIT(&ad, IPC);
3978 	ad.u.ipc_id = sma->sem_perm.key;
3979 
3980 	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
3981 			    SEM__ASSOCIATE, &ad);
3982 }
3983 
3984 /* Note, at this point, sma is locked down */
3985 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
3986 {
3987 	int err;
3988 	u32 perms;
3989 
3990 	switch(cmd) {
3991 	case IPC_INFO:
3992 	case SEM_INFO:
3993 		/* No specific object, just general system-wide information. */
3994 		return task_has_system(current, SYSTEM__IPC_INFO);
3995 	case GETPID:
3996 	case GETNCNT:
3997 	case GETZCNT:
3998 		perms = SEM__GETATTR;
3999 		break;
4000 	case GETVAL:
4001 	case GETALL:
4002 		perms = SEM__READ;
4003 		break;
4004 	case SETVAL:
4005 	case SETALL:
4006 		perms = SEM__WRITE;
4007 		break;
4008 	case IPC_RMID:
4009 		perms = SEM__DESTROY;
4010 		break;
4011 	case IPC_SET:
4012 		perms = SEM__SETATTR;
4013 		break;
4014 	case IPC_STAT:
4015 	case SEM_STAT:
4016 		perms = SEM__GETATTR | SEM__ASSOCIATE;
4017 		break;
4018 	default:
4019 		return 0;
4020 	}
4021 
4022 	err = ipc_has_perm(&sma->sem_perm, perms);
4023 	return err;
4024 }
4025 
4026 static int selinux_sem_semop(struct sem_array *sma,
4027 			     struct sembuf *sops, unsigned nsops, int alter)
4028 {
4029 	u32 perms;
4030 
4031 	if (alter)
4032 		perms = SEM__READ | SEM__WRITE;
4033 	else
4034 		perms = SEM__READ;
4035 
4036 	return ipc_has_perm(&sma->sem_perm, perms);
4037 }
4038 
4039 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
4040 {
4041 	u32 av = 0;
4042 
4043 	av = 0;
4044 	if (flag & S_IRUGO)
4045 		av |= IPC__UNIX_READ;
4046 	if (flag & S_IWUGO)
4047 		av |= IPC__UNIX_WRITE;
4048 
4049 	if (av == 0)
4050 		return 0;
4051 
4052 	return ipc_has_perm(ipcp, av);
4053 }
4054 
4055 static int selinux_ipc_getsecurity(struct kern_ipc_perm *ipcp, void *buffer, size_t size)
4056 {
4057 	struct ipc_security_struct *isec = ipcp->security;
4058 
4059 	return selinux_getsecurity(isec->sid, buffer, size);
4060 }
4061 
4062 /* module stacking operations */
4063 static int selinux_register_security (const char *name, struct security_operations *ops)
4064 {
4065 	if (secondary_ops != original_ops) {
4066 		printk(KERN_INFO "%s:  There is already a secondary security "
4067 		       "module registered.\n", __FUNCTION__);
4068 		return -EINVAL;
4069  	}
4070 
4071 	secondary_ops = ops;
4072 
4073 	printk(KERN_INFO "%s:  Registering secondary module %s\n",
4074 	       __FUNCTION__,
4075 	       name);
4076 
4077 	return 0;
4078 }
4079 
4080 static int selinux_unregister_security (const char *name, struct security_operations *ops)
4081 {
4082 	if (ops != secondary_ops) {
4083 		printk (KERN_INFO "%s:  trying to unregister a security module "
4084 		        "that is not registered.\n", __FUNCTION__);
4085 		return -EINVAL;
4086 	}
4087 
4088 	secondary_ops = original_ops;
4089 
4090 	return 0;
4091 }
4092 
4093 static void selinux_d_instantiate (struct dentry *dentry, struct inode *inode)
4094 {
4095 	if (inode)
4096 		inode_doinit_with_dentry(inode, dentry);
4097 }
4098 
4099 static int selinux_getprocattr(struct task_struct *p,
4100 			       char *name, void *value, size_t size)
4101 {
4102 	struct task_security_struct *tsec;
4103 	u32 sid;
4104 	int error;
4105 
4106 	if (current != p) {
4107 		error = task_has_perm(current, p, PROCESS__GETATTR);
4108 		if (error)
4109 			return error;
4110 	}
4111 
4112 	tsec = p->security;
4113 
4114 	if (!strcmp(name, "current"))
4115 		sid = tsec->sid;
4116 	else if (!strcmp(name, "prev"))
4117 		sid = tsec->osid;
4118 	else if (!strcmp(name, "exec"))
4119 		sid = tsec->exec_sid;
4120 	else if (!strcmp(name, "fscreate"))
4121 		sid = tsec->create_sid;
4122 	else
4123 		return -EINVAL;
4124 
4125 	if (!sid)
4126 		return 0;
4127 
4128 	return selinux_getsecurity(sid, value, size);
4129 }
4130 
4131 static int selinux_setprocattr(struct task_struct *p,
4132 			       char *name, void *value, size_t size)
4133 {
4134 	struct task_security_struct *tsec;
4135 	u32 sid = 0;
4136 	int error;
4137 	char *str = value;
4138 
4139 	if (current != p) {
4140 		/* SELinux only allows a process to change its own
4141 		   security attributes. */
4142 		return -EACCES;
4143 	}
4144 
4145 	/*
4146 	 * Basic control over ability to set these attributes at all.
4147 	 * current == p, but we'll pass them separately in case the
4148 	 * above restriction is ever removed.
4149 	 */
4150 	if (!strcmp(name, "exec"))
4151 		error = task_has_perm(current, p, PROCESS__SETEXEC);
4152 	else if (!strcmp(name, "fscreate"))
4153 		error = task_has_perm(current, p, PROCESS__SETFSCREATE);
4154 	else if (!strcmp(name, "current"))
4155 		error = task_has_perm(current, p, PROCESS__SETCURRENT);
4156 	else
4157 		error = -EINVAL;
4158 	if (error)
4159 		return error;
4160 
4161 	/* Obtain a SID for the context, if one was specified. */
4162 	if (size && str[1] && str[1] != '\n') {
4163 		if (str[size-1] == '\n') {
4164 			str[size-1] = 0;
4165 			size--;
4166 		}
4167 		error = security_context_to_sid(value, size, &sid);
4168 		if (error)
4169 			return error;
4170 	}
4171 
4172 	/* Permission checking based on the specified context is
4173 	   performed during the actual operation (execve,
4174 	   open/mkdir/...), when we know the full context of the
4175 	   operation.  See selinux_bprm_set_security for the execve
4176 	   checks and may_create for the file creation checks. The
4177 	   operation will then fail if the context is not permitted. */
4178 	tsec = p->security;
4179 	if (!strcmp(name, "exec"))
4180 		tsec->exec_sid = sid;
4181 	else if (!strcmp(name, "fscreate"))
4182 		tsec->create_sid = sid;
4183 	else if (!strcmp(name, "current")) {
4184 		struct av_decision avd;
4185 
4186 		if (sid == 0)
4187 			return -EINVAL;
4188 
4189 		/* Only allow single threaded processes to change context */
4190 		if (atomic_read(&p->mm->mm_users) != 1) {
4191 			struct task_struct *g, *t;
4192 			struct mm_struct *mm = p->mm;
4193 			read_lock(&tasklist_lock);
4194 			do_each_thread(g, t)
4195 				if (t->mm == mm && t != p) {
4196 					read_unlock(&tasklist_lock);
4197 					return -EPERM;
4198 				}
4199 			while_each_thread(g, t);
4200 			read_unlock(&tasklist_lock);
4201                 }
4202 
4203 		/* Check permissions for the transition. */
4204 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
4205 		                     PROCESS__DYNTRANSITION, NULL);
4206 		if (error)
4207 			return error;
4208 
4209 		/* Check for ptracing, and update the task SID if ok.
4210 		   Otherwise, leave SID unchanged and fail. */
4211 		task_lock(p);
4212 		if (p->ptrace & PT_PTRACED) {
4213 			error = avc_has_perm_noaudit(tsec->ptrace_sid, sid,
4214 						     SECCLASS_PROCESS,
4215 						     PROCESS__PTRACE, &avd);
4216 			if (!error)
4217 				tsec->sid = sid;
4218 			task_unlock(p);
4219 			avc_audit(tsec->ptrace_sid, sid, SECCLASS_PROCESS,
4220 				  PROCESS__PTRACE, &avd, error, NULL);
4221 			if (error)
4222 				return error;
4223 		} else {
4224 			tsec->sid = sid;
4225 			task_unlock(p);
4226 		}
4227 	}
4228 	else
4229 		return -EINVAL;
4230 
4231 	return size;
4232 }
4233 
4234 static struct security_operations selinux_ops = {
4235 	.ptrace =			selinux_ptrace,
4236 	.capget =			selinux_capget,
4237 	.capset_check =			selinux_capset_check,
4238 	.capset_set =			selinux_capset_set,
4239 	.sysctl =			selinux_sysctl,
4240 	.capable =			selinux_capable,
4241 	.quotactl =			selinux_quotactl,
4242 	.quota_on =			selinux_quota_on,
4243 	.syslog =			selinux_syslog,
4244 	.vm_enough_memory =		selinux_vm_enough_memory,
4245 
4246 	.netlink_send =			selinux_netlink_send,
4247         .netlink_recv =			selinux_netlink_recv,
4248 
4249 	.bprm_alloc_security =		selinux_bprm_alloc_security,
4250 	.bprm_free_security =		selinux_bprm_free_security,
4251 	.bprm_apply_creds =		selinux_bprm_apply_creds,
4252 	.bprm_post_apply_creds =	selinux_bprm_post_apply_creds,
4253 	.bprm_set_security =		selinux_bprm_set_security,
4254 	.bprm_check_security =		selinux_bprm_check_security,
4255 	.bprm_secureexec =		selinux_bprm_secureexec,
4256 
4257 	.sb_alloc_security =		selinux_sb_alloc_security,
4258 	.sb_free_security =		selinux_sb_free_security,
4259 	.sb_copy_data =			selinux_sb_copy_data,
4260 	.sb_kern_mount =	        selinux_sb_kern_mount,
4261 	.sb_statfs =			selinux_sb_statfs,
4262 	.sb_mount =			selinux_mount,
4263 	.sb_umount =			selinux_umount,
4264 
4265 	.inode_alloc_security =		selinux_inode_alloc_security,
4266 	.inode_free_security =		selinux_inode_free_security,
4267 	.inode_init_security =		selinux_inode_init_security,
4268 	.inode_create =			selinux_inode_create,
4269 	.inode_link =			selinux_inode_link,
4270 	.inode_unlink =			selinux_inode_unlink,
4271 	.inode_symlink =		selinux_inode_symlink,
4272 	.inode_mkdir =			selinux_inode_mkdir,
4273 	.inode_rmdir =			selinux_inode_rmdir,
4274 	.inode_mknod =			selinux_inode_mknod,
4275 	.inode_rename =			selinux_inode_rename,
4276 	.inode_readlink =		selinux_inode_readlink,
4277 	.inode_follow_link =		selinux_inode_follow_link,
4278 	.inode_permission =		selinux_inode_permission,
4279 	.inode_setattr =		selinux_inode_setattr,
4280 	.inode_getattr =		selinux_inode_getattr,
4281 	.inode_setxattr =		selinux_inode_setxattr,
4282 	.inode_post_setxattr =		selinux_inode_post_setxattr,
4283 	.inode_getxattr =		selinux_inode_getxattr,
4284 	.inode_listxattr =		selinux_inode_listxattr,
4285 	.inode_removexattr =		selinux_inode_removexattr,
4286 	.inode_xattr_getsuffix =        selinux_inode_xattr_getsuffix,
4287 	.inode_getsecurity =            selinux_inode_getsecurity,
4288 	.inode_setsecurity =            selinux_inode_setsecurity,
4289 	.inode_listsecurity =           selinux_inode_listsecurity,
4290 
4291 	.file_permission =		selinux_file_permission,
4292 	.file_alloc_security =		selinux_file_alloc_security,
4293 	.file_free_security =		selinux_file_free_security,
4294 	.file_ioctl =			selinux_file_ioctl,
4295 	.file_mmap =			selinux_file_mmap,
4296 	.file_mprotect =		selinux_file_mprotect,
4297 	.file_lock =			selinux_file_lock,
4298 	.file_fcntl =			selinux_file_fcntl,
4299 	.file_set_fowner =		selinux_file_set_fowner,
4300 	.file_send_sigiotask =		selinux_file_send_sigiotask,
4301 	.file_receive =			selinux_file_receive,
4302 
4303 	.task_create =			selinux_task_create,
4304 	.task_alloc_security =		selinux_task_alloc_security,
4305 	.task_free_security =		selinux_task_free_security,
4306 	.task_setuid =			selinux_task_setuid,
4307 	.task_post_setuid =		selinux_task_post_setuid,
4308 	.task_setgid =			selinux_task_setgid,
4309 	.task_setpgid =			selinux_task_setpgid,
4310 	.task_getpgid =			selinux_task_getpgid,
4311 	.task_getsid =		        selinux_task_getsid,
4312 	.task_setgroups =		selinux_task_setgroups,
4313 	.task_setnice =			selinux_task_setnice,
4314 	.task_setrlimit =		selinux_task_setrlimit,
4315 	.task_setscheduler =		selinux_task_setscheduler,
4316 	.task_getscheduler =		selinux_task_getscheduler,
4317 	.task_kill =			selinux_task_kill,
4318 	.task_wait =			selinux_task_wait,
4319 	.task_prctl =			selinux_task_prctl,
4320 	.task_reparent_to_init =	selinux_task_reparent_to_init,
4321 	.task_to_inode =                selinux_task_to_inode,
4322 
4323 	.ipc_permission =		selinux_ipc_permission,
4324 	.ipc_getsecurity =		selinux_ipc_getsecurity,
4325 
4326 	.msg_msg_alloc_security =	selinux_msg_msg_alloc_security,
4327 	.msg_msg_free_security =	selinux_msg_msg_free_security,
4328 
4329 	.msg_queue_alloc_security =	selinux_msg_queue_alloc_security,
4330 	.msg_queue_free_security =	selinux_msg_queue_free_security,
4331 	.msg_queue_associate =		selinux_msg_queue_associate,
4332 	.msg_queue_msgctl =		selinux_msg_queue_msgctl,
4333 	.msg_queue_msgsnd =		selinux_msg_queue_msgsnd,
4334 	.msg_queue_msgrcv =		selinux_msg_queue_msgrcv,
4335 
4336 	.shm_alloc_security =		selinux_shm_alloc_security,
4337 	.shm_free_security =		selinux_shm_free_security,
4338 	.shm_associate =		selinux_shm_associate,
4339 	.shm_shmctl =			selinux_shm_shmctl,
4340 	.shm_shmat =			selinux_shm_shmat,
4341 
4342 	.sem_alloc_security = 		selinux_sem_alloc_security,
4343 	.sem_free_security =  		selinux_sem_free_security,
4344 	.sem_associate =		selinux_sem_associate,
4345 	.sem_semctl =			selinux_sem_semctl,
4346 	.sem_semop =			selinux_sem_semop,
4347 
4348 	.register_security =		selinux_register_security,
4349 	.unregister_security =		selinux_unregister_security,
4350 
4351 	.d_instantiate =                selinux_d_instantiate,
4352 
4353 	.getprocattr =                  selinux_getprocattr,
4354 	.setprocattr =                  selinux_setprocattr,
4355 
4356         .unix_stream_connect =		selinux_socket_unix_stream_connect,
4357 	.unix_may_send =		selinux_socket_unix_may_send,
4358 
4359 	.socket_create =		selinux_socket_create,
4360 	.socket_post_create =		selinux_socket_post_create,
4361 	.socket_bind =			selinux_socket_bind,
4362 	.socket_connect =		selinux_socket_connect,
4363 	.socket_listen =		selinux_socket_listen,
4364 	.socket_accept =		selinux_socket_accept,
4365 	.socket_sendmsg =		selinux_socket_sendmsg,
4366 	.socket_recvmsg =		selinux_socket_recvmsg,
4367 	.socket_getsockname =		selinux_socket_getsockname,
4368 	.socket_getpeername =		selinux_socket_getpeername,
4369 	.socket_getsockopt =		selinux_socket_getsockopt,
4370 	.socket_setsockopt =		selinux_socket_setsockopt,
4371 	.socket_shutdown =		selinux_socket_shutdown,
4372 	.socket_sock_rcv_skb =		selinux_socket_sock_rcv_skb,
4373 	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
4374 	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
4375 	.sk_alloc_security =		selinux_sk_alloc_security,
4376 	.sk_free_security =		selinux_sk_free_security,
4377 	.sk_getsid = 			selinux_sk_getsid_security,
4378 
4379 #ifdef CONFIG_SECURITY_NETWORK_XFRM
4380 	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,
4381 	.xfrm_policy_clone_security =	selinux_xfrm_policy_clone,
4382 	.xfrm_policy_free_security =	selinux_xfrm_policy_free,
4383 	.xfrm_state_alloc_security =	selinux_xfrm_state_alloc,
4384 	.xfrm_state_free_security =	selinux_xfrm_state_free,
4385 	.xfrm_policy_lookup = 		selinux_xfrm_policy_lookup,
4386 #endif
4387 };
4388 
4389 static __init int selinux_init(void)
4390 {
4391 	struct task_security_struct *tsec;
4392 
4393 	if (!selinux_enabled) {
4394 		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
4395 		return 0;
4396 	}
4397 
4398 	printk(KERN_INFO "SELinux:  Initializing.\n");
4399 
4400 	/* Set the security state for the initial task. */
4401 	if (task_alloc_security(current))
4402 		panic("SELinux:  Failed to initialize initial task.\n");
4403 	tsec = current->security;
4404 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
4405 
4406 	sel_inode_cache = kmem_cache_create("selinux_inode_security",
4407 					    sizeof(struct inode_security_struct),
4408 					    0, SLAB_PANIC, NULL, NULL);
4409 	avc_init();
4410 
4411 	original_ops = secondary_ops = security_ops;
4412 	if (!secondary_ops)
4413 		panic ("SELinux: No initial security operations\n");
4414 	if (register_security (&selinux_ops))
4415 		panic("SELinux: Unable to register with kernel.\n");
4416 
4417 	if (selinux_enforcing) {
4418 		printk(KERN_INFO "SELinux:  Starting in enforcing mode\n");
4419 	} else {
4420 		printk(KERN_INFO "SELinux:  Starting in permissive mode\n");
4421 	}
4422 	return 0;
4423 }
4424 
4425 void selinux_complete_init(void)
4426 {
4427 	printk(KERN_INFO "SELinux:  Completing initialization.\n");
4428 
4429 	/* Set up any superblocks initialized prior to the policy load. */
4430 	printk(KERN_INFO "SELinux:  Setting up existing superblocks.\n");
4431 	spin_lock(&sb_security_lock);
4432 next_sb:
4433 	if (!list_empty(&superblock_security_head)) {
4434 		struct superblock_security_struct *sbsec =
4435 				list_entry(superblock_security_head.next,
4436 				           struct superblock_security_struct,
4437 				           list);
4438 		struct super_block *sb = sbsec->sb;
4439 		spin_lock(&sb_lock);
4440 		sb->s_count++;
4441 		spin_unlock(&sb_lock);
4442 		spin_unlock(&sb_security_lock);
4443 		down_read(&sb->s_umount);
4444 		if (sb->s_root)
4445 			superblock_doinit(sb, NULL);
4446 		drop_super(sb);
4447 		spin_lock(&sb_security_lock);
4448 		list_del_init(&sbsec->list);
4449 		goto next_sb;
4450 	}
4451 	spin_unlock(&sb_security_lock);
4452 }
4453 
4454 /* SELinux requires early initialization in order to label
4455    all processes and objects when they are created. */
4456 security_initcall(selinux_init);
4457 
4458 #if defined(CONFIG_NETFILTER)
4459 
4460 static struct nf_hook_ops selinux_ipv4_op = {
4461 	.hook =		selinux_ipv4_postroute_last,
4462 	.owner =	THIS_MODULE,
4463 	.pf =		PF_INET,
4464 	.hooknum =	NF_IP_POST_ROUTING,
4465 	.priority =	NF_IP_PRI_SELINUX_LAST,
4466 };
4467 
4468 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4469 
4470 static struct nf_hook_ops selinux_ipv6_op = {
4471 	.hook =		selinux_ipv6_postroute_last,
4472 	.owner =	THIS_MODULE,
4473 	.pf =		PF_INET6,
4474 	.hooknum =	NF_IP6_POST_ROUTING,
4475 	.priority =	NF_IP6_PRI_SELINUX_LAST,
4476 };
4477 
4478 #endif	/* IPV6 */
4479 
4480 static int __init selinux_nf_ip_init(void)
4481 {
4482 	int err = 0;
4483 
4484 	if (!selinux_enabled)
4485 		goto out;
4486 
4487 	printk(KERN_INFO "SELinux:  Registering netfilter hooks\n");
4488 
4489 	err = nf_register_hook(&selinux_ipv4_op);
4490 	if (err)
4491 		panic("SELinux: nf_register_hook for IPv4: error %d\n", err);
4492 
4493 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4494 
4495 	err = nf_register_hook(&selinux_ipv6_op);
4496 	if (err)
4497 		panic("SELinux: nf_register_hook for IPv6: error %d\n", err);
4498 
4499 #endif	/* IPV6 */
4500 
4501 out:
4502 	return err;
4503 }
4504 
4505 __initcall(selinux_nf_ip_init);
4506 
4507 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
4508 static void selinux_nf_ip_exit(void)
4509 {
4510 	printk(KERN_INFO "SELinux:  Unregistering netfilter hooks\n");
4511 
4512 	nf_unregister_hook(&selinux_ipv4_op);
4513 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4514 	nf_unregister_hook(&selinux_ipv6_op);
4515 #endif	/* IPV6 */
4516 }
4517 #endif
4518 
4519 #else /* CONFIG_NETFILTER */
4520 
4521 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
4522 #define selinux_nf_ip_exit()
4523 #endif
4524 
4525 #endif /* CONFIG_NETFILTER */
4526 
4527 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
4528 int selinux_disable(void)
4529 {
4530 	extern void exit_sel_fs(void);
4531 	static int selinux_disabled = 0;
4532 
4533 	if (ss_initialized) {
4534 		/* Not permitted after initial policy load. */
4535 		return -EINVAL;
4536 	}
4537 
4538 	if (selinux_disabled) {
4539 		/* Only do this once. */
4540 		return -EINVAL;
4541 	}
4542 
4543 	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
4544 
4545 	selinux_disabled = 1;
4546 
4547 	/* Reset security_ops to the secondary module, dummy or capability. */
4548 	security_ops = secondary_ops;
4549 
4550 	/* Unregister netfilter hooks. */
4551 	selinux_nf_ip_exit();
4552 
4553 	/* Unregister selinuxfs. */
4554 	exit_sel_fs();
4555 
4556 	return 0;
4557 }
4558 #endif
4559 
4560 
4561