14a78199ee1fd4fe7a09eca9b4ce8db2b271674d
[linux-3.10.git] / security / selinux / hooks.c
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  *  Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
16  *                     Paul Moore, <paul.moore@hp.com>
17  *
18  *      This program is free software; you can redistribute it and/or modify
19  *      it under the terms of the GNU General Public License version 2,
20  *      as published by the Free Software Foundation.
21  */
22
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/kernel.h>
26 #include <linux/ptrace.h>
27 #include <linux/errno.h>
28 #include <linux/sched.h>
29 #include <linux/security.h>
30 #include <linux/xattr.h>
31 #include <linux/capability.h>
32 #include <linux/unistd.h>
33 #include <linux/mm.h>
34 #include <linux/mman.h>
35 #include <linux/slab.h>
36 #include <linux/pagemap.h>
37 #include <linux/swap.h>
38 #include <linux/smp_lock.h>
39 #include <linux/spinlock.h>
40 #include <linux/syscalls.h>
41 #include <linux/file.h>
42 #include <linux/namei.h>
43 #include <linux/mount.h>
44 #include <linux/ext2_fs.h>
45 #include <linux/proc_fs.h>
46 #include <linux/kd.h>
47 #include <linux/netfilter_ipv4.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <linux/tty.h>
50 #include <net/icmp.h>
51 #include <net/ip.h>             /* for sysctl_local_port_range[] */
52 #include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
53 #include <asm/uaccess.h>
54 #include <asm/semaphore.h>
55 #include <asm/ioctls.h>
56 #include <linux/bitops.h>
57 #include <linux/interrupt.h>
58 #include <linux/netdevice.h>    /* for network interface checks */
59 #include <linux/netlink.h>
60 #include <linux/tcp.h>
61 #include <linux/udp.h>
62 #include <linux/quota.h>
63 #include <linux/un.h>           /* for Unix socket types */
64 #include <net/af_unix.h>        /* for Unix socket types */
65 #include <linux/parser.h>
66 #include <linux/nfs_mount.h>
67 #include <net/ipv6.h>
68 #include <linux/hugetlb.h>
69 #include <linux/personality.h>
70 #include <linux/sysctl.h>
71 #include <linux/audit.h>
72 #include <linux/string.h>
73 #include <linux/selinux.h>
74
75 #include "avc.h"
76 #include "objsec.h"
77 #include "netif.h"
78 #include "xfrm.h"
79 #include "selinux_netlabel.h"
80
81 #define XATTR_SELINUX_SUFFIX "selinux"
82 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
83
84 extern unsigned int policydb_loaded_version;
85 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
86 extern int selinux_compat_net;
87
88 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
89 int selinux_enforcing = 0;
90
91 static int __init enforcing_setup(char *str)
92 {
93         selinux_enforcing = simple_strtol(str,NULL,0);
94         return 1;
95 }
96 __setup("enforcing=", enforcing_setup);
97 #endif
98
99 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
100 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
101
102 static int __init selinux_enabled_setup(char *str)
103 {
104         selinux_enabled = simple_strtol(str, NULL, 0);
105         return 1;
106 }
107 __setup("selinux=", selinux_enabled_setup);
108 #else
109 int selinux_enabled = 1;
110 #endif
111
112 /* Original (dummy) security module. */
113 static struct security_operations *original_ops = NULL;
114
115 /* Minimal support for a secondary security module,
116    just to allow the use of the dummy or capability modules.
117    The owlsm module can alternatively be used as a secondary
118    module as long as CONFIG_OWLSM_FD is not enabled. */
119 static struct security_operations *secondary_ops = NULL;
120
121 /* Lists of inode and superblock security structures initialized
122    before the policy was loaded. */
123 static LIST_HEAD(superblock_security_head);
124 static DEFINE_SPINLOCK(sb_security_lock);
125
126 static kmem_cache_t *sel_inode_cache;
127
128 /* Return security context for a given sid or just the context 
129    length if the buffer is null or length is 0 */
130 static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
131 {
132         char *context;
133         unsigned len;
134         int rc;
135
136         rc = security_sid_to_context(sid, &context, &len);
137         if (rc)
138                 return rc;
139
140         if (!buffer || !size)
141                 goto getsecurity_exit;
142
143         if (size < len) {
144                 len = -ERANGE;
145                 goto getsecurity_exit;
146         }
147         memcpy(buffer, context, len);
148
149 getsecurity_exit:
150         kfree(context);
151         return len;
152 }
153
154 /* Allocate and free functions for each kind of security blob. */
155
156 static int task_alloc_security(struct task_struct *task)
157 {
158         struct task_security_struct *tsec;
159
160         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
161         if (!tsec)
162                 return -ENOMEM;
163
164         tsec->task = task;
165         tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
166         task->security = tsec;
167
168         return 0;
169 }
170
171 static void task_free_security(struct task_struct *task)
172 {
173         struct task_security_struct *tsec = task->security;
174         task->security = NULL;
175         kfree(tsec);
176 }
177
178 static int inode_alloc_security(struct inode *inode)
179 {
180         struct task_security_struct *tsec = current->security;
181         struct inode_security_struct *isec;
182
183         isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL);
184         if (!isec)
185                 return -ENOMEM;
186
187         memset(isec, 0, sizeof(*isec));
188         init_MUTEX(&isec->sem);
189         INIT_LIST_HEAD(&isec->list);
190         isec->inode = inode;
191         isec->sid = SECINITSID_UNLABELED;
192         isec->sclass = SECCLASS_FILE;
193         isec->task_sid = tsec->sid;
194         inode->i_security = isec;
195
196         return 0;
197 }
198
199 static void inode_free_security(struct inode *inode)
200 {
201         struct inode_security_struct *isec = inode->i_security;
202         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
203
204         spin_lock(&sbsec->isec_lock);
205         if (!list_empty(&isec->list))
206                 list_del_init(&isec->list);
207         spin_unlock(&sbsec->isec_lock);
208
209         inode->i_security = NULL;
210         kmem_cache_free(sel_inode_cache, isec);
211 }
212
213 static int file_alloc_security(struct file *file)
214 {
215         struct task_security_struct *tsec = current->security;
216         struct file_security_struct *fsec;
217
218         fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
219         if (!fsec)
220                 return -ENOMEM;
221
222         fsec->file = file;
223         fsec->sid = tsec->sid;
224         fsec->fown_sid = tsec->sid;
225         file->f_security = fsec;
226
227         return 0;
228 }
229
230 static void file_free_security(struct file *file)
231 {
232         struct file_security_struct *fsec = file->f_security;
233         file->f_security = NULL;
234         kfree(fsec);
235 }
236
237 static int superblock_alloc_security(struct super_block *sb)
238 {
239         struct superblock_security_struct *sbsec;
240
241         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
242         if (!sbsec)
243                 return -ENOMEM;
244
245         init_MUTEX(&sbsec->sem);
246         INIT_LIST_HEAD(&sbsec->list);
247         INIT_LIST_HEAD(&sbsec->isec_head);
248         spin_lock_init(&sbsec->isec_lock);
249         sbsec->sb = sb;
250         sbsec->sid = SECINITSID_UNLABELED;
251         sbsec->def_sid = SECINITSID_FILE;
252         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
253         sb->s_security = sbsec;
254
255         return 0;
256 }
257
258 static void superblock_free_security(struct super_block *sb)
259 {
260         struct superblock_security_struct *sbsec = sb->s_security;
261
262         spin_lock(&sb_security_lock);
263         if (!list_empty(&sbsec->list))
264                 list_del_init(&sbsec->list);
265         spin_unlock(&sb_security_lock);
266
267         sb->s_security = NULL;
268         kfree(sbsec);
269 }
270
271 static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
272 {
273         struct sk_security_struct *ssec;
274
275         ssec = kzalloc(sizeof(*ssec), priority);
276         if (!ssec)
277                 return -ENOMEM;
278
279         ssec->sk = sk;
280         ssec->peer_sid = SECINITSID_UNLABELED;
281         ssec->sid = SECINITSID_UNLABELED;
282         sk->sk_security = ssec;
283
284         selinux_netlbl_sk_security_init(ssec, family);
285
286         return 0;
287 }
288
289 static void sk_free_security(struct sock *sk)
290 {
291         struct sk_security_struct *ssec = sk->sk_security;
292
293         sk->sk_security = NULL;
294         kfree(ssec);
295 }
296
297 /* The security server must be initialized before
298    any labeling or access decisions can be provided. */
299 extern int ss_initialized;
300
301 /* The file system's label must be initialized prior to use. */
302
303 static char *labeling_behaviors[6] = {
304         "uses xattr",
305         "uses transition SIDs",
306         "uses task SIDs",
307         "uses genfs_contexts",
308         "not configured for labeling",
309         "uses mountpoint labeling",
310 };
311
312 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
313
314 static inline int inode_doinit(struct inode *inode)
315 {
316         return inode_doinit_with_dentry(inode, NULL);
317 }
318
319 enum {
320         Opt_context = 1,
321         Opt_fscontext = 2,
322         Opt_defcontext = 4,
323         Opt_rootcontext = 8,
324 };
325
326 static match_table_t tokens = {
327         {Opt_context, "context=%s"},
328         {Opt_fscontext, "fscontext=%s"},
329         {Opt_defcontext, "defcontext=%s"},
330         {Opt_rootcontext, "rootcontext=%s"},
331 };
332
333 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
334
335 static int may_context_mount_sb_relabel(u32 sid,
336                         struct superblock_security_struct *sbsec,
337                         struct task_security_struct *tsec)
338 {
339         int rc;
340
341         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
342                           FILESYSTEM__RELABELFROM, NULL);
343         if (rc)
344                 return rc;
345
346         rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
347                           FILESYSTEM__RELABELTO, NULL);
348         return rc;
349 }
350
351 static int may_context_mount_inode_relabel(u32 sid,
352                         struct superblock_security_struct *sbsec,
353                         struct task_security_struct *tsec)
354 {
355         int rc;
356         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
357                           FILESYSTEM__RELABELFROM, NULL);
358         if (rc)
359                 return rc;
360
361         rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
362                           FILESYSTEM__ASSOCIATE, NULL);
363         return rc;
364 }
365
366 static int try_context_mount(struct super_block *sb, void *data)
367 {
368         char *context = NULL, *defcontext = NULL;
369         char *fscontext = NULL, *rootcontext = NULL;
370         const char *name;
371         u32 sid;
372         int alloc = 0, rc = 0, seen = 0;
373         struct task_security_struct *tsec = current->security;
374         struct superblock_security_struct *sbsec = sb->s_security;
375
376         if (!data)
377                 goto out;
378
379         name = sb->s_type->name;
380
381         if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
382
383                 /* NFS we understand. */
384                 if (!strcmp(name, "nfs")) {
385                         struct nfs_mount_data *d = data;
386
387                         if (d->version <  NFS_MOUNT_VERSION)
388                                 goto out;
389
390                         if (d->context[0]) {
391                                 context = d->context;
392                                 seen |= Opt_context;
393                         }
394                 } else
395                         goto out;
396
397         } else {
398                 /* Standard string-based options. */
399                 char *p, *options = data;
400
401                 while ((p = strsep(&options, ",")) != NULL) {
402                         int token;
403                         substring_t args[MAX_OPT_ARGS];
404
405                         if (!*p)
406                                 continue;
407
408                         token = match_token(p, tokens, args);
409
410                         switch (token) {
411                         case Opt_context:
412                                 if (seen & (Opt_context|Opt_defcontext)) {
413                                         rc = -EINVAL;
414                                         printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
415                                         goto out_free;
416                                 }
417                                 context = match_strdup(&args[0]);
418                                 if (!context) {
419                                         rc = -ENOMEM;
420                                         goto out_free;
421                                 }
422                                 if (!alloc)
423                                         alloc = 1;
424                                 seen |= Opt_context;
425                                 break;
426
427                         case Opt_fscontext:
428                                 if (seen & Opt_fscontext) {
429                                         rc = -EINVAL;
430                                         printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
431                                         goto out_free;
432                                 }
433                                 fscontext = match_strdup(&args[0]);
434                                 if (!fscontext) {
435                                         rc = -ENOMEM;
436                                         goto out_free;
437                                 }
438                                 if (!alloc)
439                                         alloc = 1;
440                                 seen |= Opt_fscontext;
441                                 break;
442
443                         case Opt_rootcontext:
444                                 if (seen & Opt_rootcontext) {
445                                         rc = -EINVAL;
446                                         printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
447                                         goto out_free;
448                                 }
449                                 rootcontext = match_strdup(&args[0]);
450                                 if (!rootcontext) {
451                                         rc = -ENOMEM;
452                                         goto out_free;
453                                 }
454                                 if (!alloc)
455                                         alloc = 1;
456                                 seen |= Opt_rootcontext;
457                                 break;
458
459                         case Opt_defcontext:
460                                 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
461                                         rc = -EINVAL;
462                                         printk(KERN_WARNING "SELinux:  "
463                                                "defcontext option is invalid "
464                                                "for this filesystem type\n");
465                                         goto out_free;
466                                 }
467                                 if (seen & (Opt_context|Opt_defcontext)) {
468                                         rc = -EINVAL;
469                                         printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
470                                         goto out_free;
471                                 }
472                                 defcontext = match_strdup(&args[0]);
473                                 if (!defcontext) {
474                                         rc = -ENOMEM;
475                                         goto out_free;
476                                 }
477                                 if (!alloc)
478                                         alloc = 1;
479                                 seen |= Opt_defcontext;
480                                 break;
481
482                         default:
483                                 rc = -EINVAL;
484                                 printk(KERN_WARNING "SELinux:  unknown mount "
485                                        "option\n");
486                                 goto out_free;
487
488                         }
489                 }
490         }
491
492         if (!seen)
493                 goto out;
494
495         /* sets the context of the superblock for the fs being mounted. */
496         if (fscontext) {
497                 rc = security_context_to_sid(fscontext, strlen(fscontext), &sid);
498                 if (rc) {
499                         printk(KERN_WARNING "SELinux: security_context_to_sid"
500                                "(%s) failed for (dev %s, type %s) errno=%d\n",
501                                fscontext, sb->s_id, name, rc);
502                         goto out_free;
503                 }
504
505                 rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
506                 if (rc)
507                         goto out_free;
508
509                 sbsec->sid = sid;
510         }
511
512         /*
513          * Switch to using mount point labeling behavior.
514          * sets the label used on all file below the mountpoint, and will set
515          * the superblock context if not already set.
516          */
517         if (context) {
518                 rc = security_context_to_sid(context, strlen(context), &sid);
519                 if (rc) {
520                         printk(KERN_WARNING "SELinux: security_context_to_sid"
521                                "(%s) failed for (dev %s, type %s) errno=%d\n",
522                                context, sb->s_id, name, rc);
523                         goto out_free;
524                 }
525
526                 if (!fscontext) {
527                         rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
528                         if (rc)
529                                 goto out_free;
530                         sbsec->sid = sid;
531                 } else {
532                         rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
533                         if (rc)
534                                 goto out_free;
535                 }
536                 sbsec->mntpoint_sid = sid;
537
538                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
539         }
540
541         if (rootcontext) {
542                 struct inode *inode = sb->s_root->d_inode;
543                 struct inode_security_struct *isec = inode->i_security;
544                 rc = security_context_to_sid(rootcontext, strlen(rootcontext), &sid);
545                 if (rc) {
546                         printk(KERN_WARNING "SELinux: security_context_to_sid"
547                                "(%s) failed for (dev %s, type %s) errno=%d\n",
548                                rootcontext, sb->s_id, name, rc);
549                         goto out_free;
550                 }
551
552                 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
553                 if (rc)
554                         goto out_free;
555
556                 isec->sid = sid;
557                 isec->initialized = 1;
558         }
559
560         if (defcontext) {
561                 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
562                 if (rc) {
563                         printk(KERN_WARNING "SELinux: security_context_to_sid"
564                                "(%s) failed for (dev %s, type %s) errno=%d\n",
565                                defcontext, sb->s_id, name, rc);
566                         goto out_free;
567                 }
568
569                 if (sid == sbsec->def_sid)
570                         goto out_free;
571
572                 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
573                 if (rc)
574                         goto out_free;
575
576                 sbsec->def_sid = sid;
577         }
578
579 out_free:
580         if (alloc) {
581                 kfree(context);
582                 kfree(defcontext);
583                 kfree(fscontext);
584                 kfree(rootcontext);
585         }
586 out:
587         return rc;
588 }
589
590 static int superblock_doinit(struct super_block *sb, void *data)
591 {
592         struct superblock_security_struct *sbsec = sb->s_security;
593         struct dentry *root = sb->s_root;
594         struct inode *inode = root->d_inode;
595         int rc = 0;
596
597         down(&sbsec->sem);
598         if (sbsec->initialized)
599                 goto out;
600
601         if (!ss_initialized) {
602                 /* Defer initialization until selinux_complete_init,
603                    after the initial policy is loaded and the security
604                    server is ready to handle calls. */
605                 spin_lock(&sb_security_lock);
606                 if (list_empty(&sbsec->list))
607                         list_add(&sbsec->list, &superblock_security_head);
608                 spin_unlock(&sb_security_lock);
609                 goto out;
610         }
611
612         /* Determine the labeling behavior to use for this filesystem type. */
613         rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
614         if (rc) {
615                 printk(KERN_WARNING "%s:  security_fs_use(%s) returned %d\n",
616                        __FUNCTION__, sb->s_type->name, rc);
617                 goto out;
618         }
619
620         rc = try_context_mount(sb, data);
621         if (rc)
622                 goto out;
623
624         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
625                 /* Make sure that the xattr handler exists and that no
626                    error other than -ENODATA is returned by getxattr on
627                    the root directory.  -ENODATA is ok, as this may be
628                    the first boot of the SELinux kernel before we have
629                    assigned xattr values to the filesystem. */
630                 if (!inode->i_op->getxattr) {
631                         printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
632                                "xattr support\n", sb->s_id, sb->s_type->name);
633                         rc = -EOPNOTSUPP;
634                         goto out;
635                 }
636                 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
637                 if (rc < 0 && rc != -ENODATA) {
638                         if (rc == -EOPNOTSUPP)
639                                 printk(KERN_WARNING "SELinux: (dev %s, type "
640                                        "%s) has no security xattr handler\n",
641                                        sb->s_id, sb->s_type->name);
642                         else
643                                 printk(KERN_WARNING "SELinux: (dev %s, type "
644                                        "%s) getxattr errno %d\n", sb->s_id,
645                                        sb->s_type->name, -rc);
646                         goto out;
647                 }
648         }
649
650         if (strcmp(sb->s_type->name, "proc") == 0)
651                 sbsec->proc = 1;
652
653         sbsec->initialized = 1;
654
655         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
656                 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
657                        sb->s_id, sb->s_type->name);
658         }
659         else {
660                 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
661                        sb->s_id, sb->s_type->name,
662                        labeling_behaviors[sbsec->behavior-1]);
663         }
664
665         /* Initialize the root inode. */
666         rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
667
668         /* Initialize any other inodes associated with the superblock, e.g.
669            inodes created prior to initial policy load or inodes created
670            during get_sb by a pseudo filesystem that directly
671            populates itself. */
672         spin_lock(&sbsec->isec_lock);
673 next_inode:
674         if (!list_empty(&sbsec->isec_head)) {
675                 struct inode_security_struct *isec =
676                                 list_entry(sbsec->isec_head.next,
677                                            struct inode_security_struct, list);
678                 struct inode *inode = isec->inode;
679                 spin_unlock(&sbsec->isec_lock);
680                 inode = igrab(inode);
681                 if (inode) {
682                         if (!IS_PRIVATE (inode))
683                                 inode_doinit(inode);
684                         iput(inode);
685                 }
686                 spin_lock(&sbsec->isec_lock);
687                 list_del_init(&isec->list);
688                 goto next_inode;
689         }
690         spin_unlock(&sbsec->isec_lock);
691 out:
692         up(&sbsec->sem);
693         return rc;
694 }
695
696 static inline u16 inode_mode_to_security_class(umode_t mode)
697 {
698         switch (mode & S_IFMT) {
699         case S_IFSOCK:
700                 return SECCLASS_SOCK_FILE;
701         case S_IFLNK:
702                 return SECCLASS_LNK_FILE;
703         case S_IFREG:
704                 return SECCLASS_FILE;
705         case S_IFBLK:
706                 return SECCLASS_BLK_FILE;
707         case S_IFDIR:
708                 return SECCLASS_DIR;
709         case S_IFCHR:
710                 return SECCLASS_CHR_FILE;
711         case S_IFIFO:
712                 return SECCLASS_FIFO_FILE;
713
714         }
715
716         return SECCLASS_FILE;
717 }
718
719 static inline int default_protocol_stream(int protocol)
720 {
721         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
722 }
723
724 static inline int default_protocol_dgram(int protocol)
725 {
726         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
727 }
728
729 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
730 {
731         switch (family) {
732         case PF_UNIX:
733                 switch (type) {
734                 case SOCK_STREAM:
735                 case SOCK_SEQPACKET:
736                         return SECCLASS_UNIX_STREAM_SOCKET;
737                 case SOCK_DGRAM:
738                         return SECCLASS_UNIX_DGRAM_SOCKET;
739                 }
740                 break;
741         case PF_INET:
742         case PF_INET6:
743                 switch (type) {
744                 case SOCK_STREAM:
745                         if (default_protocol_stream(protocol))
746                                 return SECCLASS_TCP_SOCKET;
747                         else
748                                 return SECCLASS_RAWIP_SOCKET;
749                 case SOCK_DGRAM:
750                         if (default_protocol_dgram(protocol))
751                                 return SECCLASS_UDP_SOCKET;
752                         else
753                                 return SECCLASS_RAWIP_SOCKET;
754                 default:
755                         return SECCLASS_RAWIP_SOCKET;
756                 }
757                 break;
758         case PF_NETLINK:
759                 switch (protocol) {
760                 case NETLINK_ROUTE:
761                         return SECCLASS_NETLINK_ROUTE_SOCKET;
762                 case NETLINK_FIREWALL:
763                         return SECCLASS_NETLINK_FIREWALL_SOCKET;
764                 case NETLINK_INET_DIAG:
765                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
766                 case NETLINK_NFLOG:
767                         return SECCLASS_NETLINK_NFLOG_SOCKET;
768                 case NETLINK_XFRM:
769                         return SECCLASS_NETLINK_XFRM_SOCKET;
770                 case NETLINK_SELINUX:
771                         return SECCLASS_NETLINK_SELINUX_SOCKET;
772                 case NETLINK_AUDIT:
773                         return SECCLASS_NETLINK_AUDIT_SOCKET;
774                 case NETLINK_IP6_FW:
775                         return SECCLASS_NETLINK_IP6FW_SOCKET;
776                 case NETLINK_DNRTMSG:
777                         return SECCLASS_NETLINK_DNRT_SOCKET;
778                 case NETLINK_KOBJECT_UEVENT:
779                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
780                 default:
781                         return SECCLASS_NETLINK_SOCKET;
782                 }
783         case PF_PACKET:
784                 return SECCLASS_PACKET_SOCKET;
785         case PF_KEY:
786                 return SECCLASS_KEY_SOCKET;
787         case PF_APPLETALK:
788                 return SECCLASS_APPLETALK_SOCKET;
789         }
790
791         return SECCLASS_SOCKET;
792 }
793
794 #ifdef CONFIG_PROC_FS
795 static int selinux_proc_get_sid(struct proc_dir_entry *de,
796                                 u16 tclass,
797                                 u32 *sid)
798 {
799         int buflen, rc;
800         char *buffer, *path, *end;
801
802         buffer = (char*)__get_free_page(GFP_KERNEL);
803         if (!buffer)
804                 return -ENOMEM;
805
806         buflen = PAGE_SIZE;
807         end = buffer+buflen;
808         *--end = '\0';
809         buflen--;
810         path = end-1;
811         *path = '/';
812         while (de && de != de->parent) {
813                 buflen -= de->namelen + 1;
814                 if (buflen < 0)
815                         break;
816                 end -= de->namelen;
817                 memcpy(end, de->name, de->namelen);
818                 *--end = '/';
819                 path = end;
820                 de = de->parent;
821         }
822         rc = security_genfs_sid("proc", path, tclass, sid);
823         free_page((unsigned long)buffer);
824         return rc;
825 }
826 #else
827 static int selinux_proc_get_sid(struct proc_dir_entry *de,
828                                 u16 tclass,
829                                 u32 *sid)
830 {
831         return -EINVAL;
832 }
833 #endif
834
835 /* The inode's security attributes must be initialized before first use. */
836 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
837 {
838         struct superblock_security_struct *sbsec = NULL;
839         struct inode_security_struct *isec = inode->i_security;
840         u32 sid;
841         struct dentry *dentry;
842 #define INITCONTEXTLEN 255
843         char *context = NULL;
844         unsigned len = 0;
845         int rc = 0;
846         int hold_sem = 0;
847
848         if (isec->initialized)
849                 goto out;
850
851         down(&isec->sem);
852         hold_sem = 1;
853         if (isec->initialized)
854                 goto out;
855
856         sbsec = inode->i_sb->s_security;
857         if (!sbsec->initialized) {
858                 /* Defer initialization until selinux_complete_init,
859                    after the initial policy is loaded and the security
860                    server is ready to handle calls. */
861                 spin_lock(&sbsec->isec_lock);
862                 if (list_empty(&isec->list))
863                         list_add(&isec->list, &sbsec->isec_head);
864                 spin_unlock(&sbsec->isec_lock);
865                 goto out;
866         }
867
868         switch (sbsec->behavior) {
869         case SECURITY_FS_USE_XATTR:
870                 if (!inode->i_op->getxattr) {
871                         isec->sid = sbsec->def_sid;
872                         break;
873                 }
874
875                 /* Need a dentry, since the xattr API requires one.
876                    Life would be simpler if we could just pass the inode. */
877                 if (opt_dentry) {
878                         /* Called from d_instantiate or d_splice_alias. */
879                         dentry = dget(opt_dentry);
880                 } else {
881                         /* Called from selinux_complete_init, try to find a dentry. */
882                         dentry = d_find_alias(inode);
883                 }
884                 if (!dentry) {
885                         printk(KERN_WARNING "%s:  no dentry for dev=%s "
886                                "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
887                                inode->i_ino);
888                         goto out;
889                 }
890
891                 len = INITCONTEXTLEN;
892                 context = kmalloc(len, GFP_KERNEL);
893                 if (!context) {
894                         rc = -ENOMEM;
895                         dput(dentry);
896                         goto out;
897                 }
898                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
899                                            context, len);
900                 if (rc == -ERANGE) {
901                         /* Need a larger buffer.  Query for the right size. */
902                         rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
903                                                    NULL, 0);
904                         if (rc < 0) {
905                                 dput(dentry);
906                                 goto out;
907                         }
908                         kfree(context);
909                         len = rc;
910                         context = kmalloc(len, GFP_KERNEL);
911                         if (!context) {
912                                 rc = -ENOMEM;
913                                 dput(dentry);
914                                 goto out;
915                         }
916                         rc = inode->i_op->getxattr(dentry,
917                                                    XATTR_NAME_SELINUX,
918                                                    context, len);
919                 }
920                 dput(dentry);
921                 if (rc < 0) {
922                         if (rc != -ENODATA) {
923                                 printk(KERN_WARNING "%s:  getxattr returned "
924                                        "%d for dev=%s ino=%ld\n", __FUNCTION__,
925                                        -rc, inode->i_sb->s_id, inode->i_ino);
926                                 kfree(context);
927                                 goto out;
928                         }
929                         /* Map ENODATA to the default file SID */
930                         sid = sbsec->def_sid;
931                         rc = 0;
932                 } else {
933                         rc = security_context_to_sid_default(context, rc, &sid,
934                                                              sbsec->def_sid);
935                         if (rc) {
936                                 printk(KERN_WARNING "%s:  context_to_sid(%s) "
937                                        "returned %d for dev=%s ino=%ld\n",
938                                        __FUNCTION__, context, -rc,
939                                        inode->i_sb->s_id, inode->i_ino);
940                                 kfree(context);
941                                 /* Leave with the unlabeled SID */
942                                 rc = 0;
943                                 break;
944                         }
945                 }
946                 kfree(context);
947                 isec->sid = sid;
948                 break;
949         case SECURITY_FS_USE_TASK:
950                 isec->sid = isec->task_sid;
951                 break;
952         case SECURITY_FS_USE_TRANS:
953                 /* Default to the fs SID. */
954                 isec->sid = sbsec->sid;
955
956                 /* Try to obtain a transition SID. */
957                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
958                 rc = security_transition_sid(isec->task_sid,
959                                              sbsec->sid,
960                                              isec->sclass,
961                                              &sid);
962                 if (rc)
963                         goto out;
964                 isec->sid = sid;
965                 break;
966         case SECURITY_FS_USE_MNTPOINT:
967                 isec->sid = sbsec->mntpoint_sid;
968                 break;
969         default:
970                 /* Default to the fs superblock SID. */
971                 isec->sid = sbsec->sid;
972
973                 if (sbsec->proc) {
974                         struct proc_inode *proci = PROC_I(inode);
975                         if (proci->pde) {
976                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
977                                 rc = selinux_proc_get_sid(proci->pde,
978                                                           isec->sclass,
979                                                           &sid);
980                                 if (rc)
981                                         goto out;
982                                 isec->sid = sid;
983                         }
984                 }
985                 break;
986         }
987
988         isec->initialized = 1;
989
990 out:
991         if (isec->sclass == SECCLASS_FILE)
992                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
993
994         if (hold_sem)
995                 up(&isec->sem);
996         return rc;
997 }
998
999 /* Convert a Linux signal to an access vector. */
1000 static inline u32 signal_to_av(int sig)
1001 {
1002         u32 perm = 0;
1003
1004         switch (sig) {
1005         case SIGCHLD:
1006                 /* Commonly granted from child to parent. */
1007                 perm = PROCESS__SIGCHLD;
1008                 break;
1009         case SIGKILL:
1010                 /* Cannot be caught or ignored */
1011                 perm = PROCESS__SIGKILL;
1012                 break;
1013         case SIGSTOP:
1014                 /* Cannot be caught or ignored */
1015                 perm = PROCESS__SIGSTOP;
1016                 break;
1017         default:
1018                 /* All other signals. */
1019                 perm = PROCESS__SIGNAL;
1020                 break;
1021         }
1022
1023         return perm;
1024 }
1025
1026 /* Check permission betweeen a pair of tasks, e.g. signal checks,
1027    fork check, ptrace check, etc. */
1028 static int task_has_perm(struct task_struct *tsk1,
1029                          struct task_struct *tsk2,
1030                          u32 perms)
1031 {
1032         struct task_security_struct *tsec1, *tsec2;
1033
1034         tsec1 = tsk1->security;
1035         tsec2 = tsk2->security;
1036         return avc_has_perm(tsec1->sid, tsec2->sid,
1037                             SECCLASS_PROCESS, perms, NULL);
1038 }
1039
1040 /* Check whether a task is allowed to use a capability. */
1041 static int task_has_capability(struct task_struct *tsk,
1042                                int cap)
1043 {
1044         struct task_security_struct *tsec;
1045         struct avc_audit_data ad;
1046
1047         tsec = tsk->security;
1048
1049         AVC_AUDIT_DATA_INIT(&ad,CAP);
1050         ad.tsk = tsk;
1051         ad.u.cap = cap;
1052
1053         return avc_has_perm(tsec->sid, tsec->sid,
1054                             SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
1055 }
1056
1057 /* Check whether a task is allowed to use a system operation. */
1058 static int task_has_system(struct task_struct *tsk,
1059                            u32 perms)
1060 {
1061         struct task_security_struct *tsec;
1062
1063         tsec = tsk->security;
1064
1065         return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
1066                             SECCLASS_SYSTEM, perms, NULL);
1067 }
1068
1069 /* Check whether a task has a particular permission to an inode.
1070    The 'adp' parameter is optional and allows other audit
1071    data to be passed (e.g. the dentry). */
1072 static int inode_has_perm(struct task_struct *tsk,
1073                           struct inode *inode,
1074                           u32 perms,
1075                           struct avc_audit_data *adp)
1076 {
1077         struct task_security_struct *tsec;
1078         struct inode_security_struct *isec;
1079         struct avc_audit_data ad;
1080
1081         tsec = tsk->security;
1082         isec = inode->i_security;
1083
1084         if (!adp) {
1085                 adp = &ad;
1086                 AVC_AUDIT_DATA_INIT(&ad, FS);
1087                 ad.u.fs.inode = inode;
1088         }
1089
1090         return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1091 }
1092
1093 /* Same as inode_has_perm, but pass explicit audit data containing
1094    the dentry to help the auditing code to more easily generate the
1095    pathname if needed. */
1096 static inline int dentry_has_perm(struct task_struct *tsk,
1097                                   struct vfsmount *mnt,
1098                                   struct dentry *dentry,
1099                                   u32 av)
1100 {
1101         struct inode *inode = dentry->d_inode;
1102         struct avc_audit_data ad;
1103         AVC_AUDIT_DATA_INIT(&ad,FS);
1104         ad.u.fs.mnt = mnt;
1105         ad.u.fs.dentry = dentry;
1106         return inode_has_perm(tsk, inode, av, &ad);
1107 }
1108
1109 /* Check whether a task can use an open file descriptor to
1110    access an inode in a given way.  Check access to the
1111    descriptor itself, and then use dentry_has_perm to
1112    check a particular permission to the file.
1113    Access to the descriptor is implicitly granted if it
1114    has the same SID as the process.  If av is zero, then
1115    access to the file is not checked, e.g. for cases
1116    where only the descriptor is affected like seek. */
1117 static int file_has_perm(struct task_struct *tsk,
1118                                 struct file *file,
1119                                 u32 av)
1120 {
1121         struct task_security_struct *tsec = tsk->security;
1122         struct file_security_struct *fsec = file->f_security;
1123         struct vfsmount *mnt = file->f_vfsmnt;
1124         struct dentry *dentry = file->f_dentry;
1125         struct inode *inode = dentry->d_inode;
1126         struct avc_audit_data ad;
1127         int rc;
1128
1129         AVC_AUDIT_DATA_INIT(&ad, FS);
1130         ad.u.fs.mnt = mnt;
1131         ad.u.fs.dentry = dentry;
1132
1133         if (tsec->sid != fsec->sid) {
1134                 rc = avc_has_perm(tsec->sid, fsec->sid,
1135                                   SECCLASS_FD,
1136                                   FD__USE,
1137                                   &ad);
1138                 if (rc)
1139                         return rc;
1140         }
1141
1142         /* av is zero if only checking access to the descriptor. */
1143         if (av)
1144                 return inode_has_perm(tsk, inode, av, &ad);
1145
1146         return 0;
1147 }
1148
1149 /* Check whether a task can create a file. */
1150 static int may_create(struct inode *dir,
1151                       struct dentry *dentry,
1152                       u16 tclass)
1153 {
1154         struct task_security_struct *tsec;
1155         struct inode_security_struct *dsec;
1156         struct superblock_security_struct *sbsec;
1157         u32 newsid;
1158         struct avc_audit_data ad;
1159         int rc;
1160
1161         tsec = current->security;
1162         dsec = dir->i_security;
1163         sbsec = dir->i_sb->s_security;
1164
1165         AVC_AUDIT_DATA_INIT(&ad, FS);
1166         ad.u.fs.dentry = dentry;
1167
1168         rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1169                           DIR__ADD_NAME | DIR__SEARCH,
1170                           &ad);
1171         if (rc)
1172                 return rc;
1173
1174         if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1175                 newsid = tsec->create_sid;
1176         } else {
1177                 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1178                                              &newsid);
1179                 if (rc)
1180                         return rc;
1181         }
1182
1183         rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1184         if (rc)
1185                 return rc;
1186
1187         return avc_has_perm(newsid, sbsec->sid,
1188                             SECCLASS_FILESYSTEM,
1189                             FILESYSTEM__ASSOCIATE, &ad);
1190 }
1191
1192 /* Check whether a task can create a key. */
1193 static int may_create_key(u32 ksid,
1194                           struct task_struct *ctx)
1195 {
1196         struct task_security_struct *tsec;
1197
1198         tsec = ctx->security;
1199
1200         return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1201 }
1202
1203 #define MAY_LINK   0
1204 #define MAY_UNLINK 1
1205 #define MAY_RMDIR  2
1206
1207 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1208 static int may_link(struct inode *dir,
1209                     struct dentry *dentry,
1210                     int kind)
1211
1212 {
1213         struct task_security_struct *tsec;
1214         struct inode_security_struct *dsec, *isec;
1215         struct avc_audit_data ad;
1216         u32 av;
1217         int rc;
1218
1219         tsec = current->security;
1220         dsec = dir->i_security;
1221         isec = dentry->d_inode->i_security;
1222
1223         AVC_AUDIT_DATA_INIT(&ad, FS);
1224         ad.u.fs.dentry = dentry;
1225
1226         av = DIR__SEARCH;
1227         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1228         rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1229         if (rc)
1230                 return rc;
1231
1232         switch (kind) {
1233         case MAY_LINK:
1234                 av = FILE__LINK;
1235                 break;
1236         case MAY_UNLINK:
1237                 av = FILE__UNLINK;
1238                 break;
1239         case MAY_RMDIR:
1240                 av = DIR__RMDIR;
1241                 break;
1242         default:
1243                 printk(KERN_WARNING "may_link:  unrecognized kind %d\n", kind);
1244                 return 0;
1245         }
1246
1247         rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1248         return rc;
1249 }
1250
1251 static inline int may_rename(struct inode *old_dir,
1252                              struct dentry *old_dentry,
1253                              struct inode *new_dir,
1254                              struct dentry *new_dentry)
1255 {
1256         struct task_security_struct *tsec;
1257         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1258         struct avc_audit_data ad;
1259         u32 av;
1260         int old_is_dir, new_is_dir;
1261         int rc;
1262
1263         tsec = current->security;
1264         old_dsec = old_dir->i_security;
1265         old_isec = old_dentry->d_inode->i_security;
1266         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1267         new_dsec = new_dir->i_security;
1268
1269         AVC_AUDIT_DATA_INIT(&ad, FS);
1270
1271         ad.u.fs.dentry = old_dentry;
1272         rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1273                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1274         if (rc)
1275                 return rc;
1276         rc = avc_has_perm(tsec->sid, old_isec->sid,
1277                           old_isec->sclass, FILE__RENAME, &ad);
1278         if (rc)
1279                 return rc;
1280         if (old_is_dir && new_dir != old_dir) {
1281                 rc = avc_has_perm(tsec->sid, old_isec->sid,
1282                                   old_isec->sclass, DIR__REPARENT, &ad);
1283                 if (rc)
1284                         return rc;
1285         }
1286
1287         ad.u.fs.dentry = new_dentry;
1288         av = DIR__ADD_NAME | DIR__SEARCH;
1289         if (new_dentry->d_inode)
1290                 av |= DIR__REMOVE_NAME;
1291         rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1292         if (rc)
1293                 return rc;
1294         if (new_dentry->d_inode) {
1295                 new_isec = new_dentry->d_inode->i_security;
1296                 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1297                 rc = avc_has_perm(tsec->sid, new_isec->sid,
1298                                   new_isec->sclass,
1299                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1300                 if (rc)
1301                         return rc;
1302         }
1303
1304         return 0;
1305 }
1306
1307 /* Check whether a task can perform a filesystem operation. */
1308 static int superblock_has_perm(struct task_struct *tsk,
1309                                struct super_block *sb,
1310                                u32 perms,
1311                                struct avc_audit_data *ad)
1312 {
1313         struct task_security_struct *tsec;
1314         struct superblock_security_struct *sbsec;
1315
1316         tsec = tsk->security;
1317         sbsec = sb->s_security;
1318         return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1319                             perms, ad);
1320 }
1321
1322 /* Convert a Linux mode and permission mask to an access vector. */
1323 static inline u32 file_mask_to_av(int mode, int mask)
1324 {
1325         u32 av = 0;
1326
1327         if ((mode & S_IFMT) != S_IFDIR) {
1328                 if (mask & MAY_EXEC)
1329                         av |= FILE__EXECUTE;
1330                 if (mask & MAY_READ)
1331                         av |= FILE__READ;
1332
1333                 if (mask & MAY_APPEND)
1334                         av |= FILE__APPEND;
1335                 else if (mask & MAY_WRITE)
1336                         av |= FILE__WRITE;
1337
1338         } else {
1339                 if (mask & MAY_EXEC)
1340                         av |= DIR__SEARCH;
1341                 if (mask & MAY_WRITE)
1342                         av |= DIR__WRITE;
1343                 if (mask & MAY_READ)
1344                         av |= DIR__READ;
1345         }
1346
1347         return av;
1348 }
1349
1350 /* Convert a Linux file to an access vector. */
1351 static inline u32 file_to_av(struct file *file)
1352 {
1353         u32 av = 0;
1354
1355         if (file->f_mode & FMODE_READ)
1356                 av |= FILE__READ;
1357         if (file->f_mode & FMODE_WRITE) {
1358                 if (file->f_flags & O_APPEND)
1359                         av |= FILE__APPEND;
1360                 else
1361                         av |= FILE__WRITE;
1362         }
1363
1364         return av;
1365 }
1366
1367 /* Hook functions begin here. */
1368
1369 static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1370 {
1371         struct task_security_struct *psec = parent->security;
1372         struct task_security_struct *csec = child->security;
1373         int rc;
1374
1375         rc = secondary_ops->ptrace(parent,child);
1376         if (rc)
1377                 return rc;
1378
1379         rc = task_has_perm(parent, child, PROCESS__PTRACE);
1380         /* Save the SID of the tracing process for later use in apply_creds. */
1381         if (!(child->ptrace & PT_PTRACED) && !rc)
1382                 csec->ptrace_sid = psec->sid;
1383         return rc;
1384 }
1385
1386 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1387                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1388 {
1389         int error;
1390
1391         error = task_has_perm(current, target, PROCESS__GETCAP);
1392         if (error)
1393                 return error;
1394
1395         return secondary_ops->capget(target, effective, inheritable, permitted);
1396 }
1397
1398 static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1399                                 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1400 {
1401         int error;
1402
1403         error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1404         if (error)
1405                 return error;
1406
1407         return task_has_perm(current, target, PROCESS__SETCAP);
1408 }
1409
1410 static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1411                                kernel_cap_t *inheritable, kernel_cap_t *permitted)
1412 {
1413         secondary_ops->capset_set(target, effective, inheritable, permitted);
1414 }
1415
1416 static int selinux_capable(struct task_struct *tsk, int cap)
1417 {
1418         int rc;
1419
1420         rc = secondary_ops->capable(tsk, cap);
1421         if (rc)
1422                 return rc;
1423
1424         return task_has_capability(tsk,cap);
1425 }
1426
1427 static int selinux_sysctl(ctl_table *table, int op)
1428 {
1429         int error = 0;
1430         u32 av;
1431         struct task_security_struct *tsec;
1432         u32 tsid;
1433         int rc;
1434
1435         rc = secondary_ops->sysctl(table, op);
1436         if (rc)
1437                 return rc;
1438
1439         tsec = current->security;
1440
1441         rc = selinux_proc_get_sid(table->de, (op == 001) ?
1442                                   SECCLASS_DIR : SECCLASS_FILE, &tsid);
1443         if (rc) {
1444                 /* Default to the well-defined sysctl SID. */
1445                 tsid = SECINITSID_SYSCTL;
1446         }
1447
1448         /* The op values are "defined" in sysctl.c, thereby creating
1449          * a bad coupling between this module and sysctl.c */
1450         if(op == 001) {
1451                 error = avc_has_perm(tsec->sid, tsid,
1452                                      SECCLASS_DIR, DIR__SEARCH, NULL);
1453         } else {
1454                 av = 0;
1455                 if (op & 004)
1456                         av |= FILE__READ;
1457                 if (op & 002)
1458                         av |= FILE__WRITE;
1459                 if (av)
1460                         error = avc_has_perm(tsec->sid, tsid,
1461                                              SECCLASS_FILE, av, NULL);
1462         }
1463
1464         return error;
1465 }
1466
1467 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1468 {
1469         int rc = 0;
1470
1471         if (!sb)
1472                 return 0;
1473
1474         switch (cmds) {
1475                 case Q_SYNC:
1476                 case Q_QUOTAON:
1477                 case Q_QUOTAOFF:
1478                 case Q_SETINFO:
1479                 case Q_SETQUOTA:
1480                         rc = superblock_has_perm(current,
1481                                                  sb,
1482                                                  FILESYSTEM__QUOTAMOD, NULL);
1483                         break;
1484                 case Q_GETFMT:
1485                 case Q_GETINFO:
1486                 case Q_GETQUOTA:
1487                         rc = superblock_has_perm(current,
1488                                                  sb,
1489                                                  FILESYSTEM__QUOTAGET, NULL);
1490                         break;
1491                 default:
1492                         rc = 0;  /* let the kernel handle invalid cmds */
1493                         break;
1494         }
1495         return rc;
1496 }
1497
1498 static int selinux_quota_on(struct dentry *dentry)
1499 {
1500         return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1501 }
1502
1503 static int selinux_syslog(int type)
1504 {
1505         int rc;
1506
1507         rc = secondary_ops->syslog(type);
1508         if (rc)
1509                 return rc;
1510
1511         switch (type) {
1512                 case 3:         /* Read last kernel messages */
1513                 case 10:        /* Return size of the log buffer */
1514                         rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1515                         break;
1516                 case 6:         /* Disable logging to console */
1517                 case 7:         /* Enable logging to console */
1518                 case 8:         /* Set level of messages printed to console */
1519                         rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1520                         break;
1521                 case 0:         /* Close log */
1522                 case 1:         /* Open log */
1523                 case 2:         /* Read from log */
1524                 case 4:         /* Read/clear last kernel messages */
1525                 case 5:         /* Clear ring buffer */
1526                 default:
1527                         rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1528                         break;
1529         }
1530         return rc;
1531 }
1532
1533 /*
1534  * Check that a process has enough memory to allocate a new virtual
1535  * mapping. 0 means there is enough memory for the allocation to
1536  * succeed and -ENOMEM implies there is not.
1537  *
1538  * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1539  * if the capability is granted, but __vm_enough_memory requires 1 if
1540  * the capability is granted.
1541  *
1542  * Do not audit the selinux permission check, as this is applied to all
1543  * processes that allocate mappings.
1544  */
1545 static int selinux_vm_enough_memory(long pages)
1546 {
1547         int rc, cap_sys_admin = 0;
1548         struct task_security_struct *tsec = current->security;
1549
1550         rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1551         if (rc == 0)
1552                 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1553                                         SECCLASS_CAPABILITY,
1554                                         CAP_TO_MASK(CAP_SYS_ADMIN),
1555                                         NULL);
1556
1557         if (rc == 0)
1558                 cap_sys_admin = 1;
1559
1560         return __vm_enough_memory(pages, cap_sys_admin);
1561 }
1562
1563 /* binprm security operations */
1564
1565 static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1566 {
1567         struct bprm_security_struct *bsec;
1568
1569         bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1570         if (!bsec)
1571                 return -ENOMEM;
1572
1573         bsec->bprm = bprm;
1574         bsec->sid = SECINITSID_UNLABELED;
1575         bsec->set = 0;
1576
1577         bprm->security = bsec;
1578         return 0;
1579 }
1580
1581 static int selinux_bprm_set_security(struct linux_binprm *bprm)
1582 {
1583         struct task_security_struct *tsec;
1584         struct inode *inode = bprm->file->f_dentry->d_inode;
1585         struct inode_security_struct *isec;
1586         struct bprm_security_struct *bsec;
1587         u32 newsid;
1588         struct avc_audit_data ad;
1589         int rc;
1590
1591         rc = secondary_ops->bprm_set_security(bprm);
1592         if (rc)
1593                 return rc;
1594
1595         bsec = bprm->security;
1596
1597         if (bsec->set)
1598                 return 0;
1599
1600         tsec = current->security;
1601         isec = inode->i_security;
1602
1603         /* Default to the current task SID. */
1604         bsec->sid = tsec->sid;
1605
1606         /* Reset fs, key, and sock SIDs on execve. */
1607         tsec->create_sid = 0;
1608         tsec->keycreate_sid = 0;
1609         tsec->sockcreate_sid = 0;
1610
1611         if (tsec->exec_sid) {
1612                 newsid = tsec->exec_sid;
1613                 /* Reset exec SID on execve. */
1614                 tsec->exec_sid = 0;
1615         } else {
1616                 /* Check for a default transition on this program. */
1617                 rc = security_transition_sid(tsec->sid, isec->sid,
1618                                              SECCLASS_PROCESS, &newsid);
1619                 if (rc)
1620                         return rc;
1621         }
1622
1623         AVC_AUDIT_DATA_INIT(&ad, FS);
1624         ad.u.fs.mnt = bprm->file->f_vfsmnt;
1625         ad.u.fs.dentry = bprm->file->f_dentry;
1626
1627         if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1628                 newsid = tsec->sid;
1629
1630         if (tsec->sid == newsid) {
1631                 rc = avc_has_perm(tsec->sid, isec->sid,
1632                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1633                 if (rc)
1634                         return rc;
1635         } else {
1636                 /* Check permissions for the transition. */
1637                 rc = avc_has_perm(tsec->sid, newsid,
1638                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1639                 if (rc)
1640                         return rc;
1641
1642                 rc = avc_has_perm(newsid, isec->sid,
1643                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1644                 if (rc)
1645                         return rc;
1646
1647                 /* Clear any possibly unsafe personality bits on exec: */
1648                 current->personality &= ~PER_CLEAR_ON_SETID;
1649
1650                 /* Set the security field to the new SID. */
1651                 bsec->sid = newsid;
1652         }
1653
1654         bsec->set = 1;
1655         return 0;
1656 }
1657
1658 static int selinux_bprm_check_security (struct linux_binprm *bprm)
1659 {
1660         return secondary_ops->bprm_check_security(bprm);
1661 }
1662
1663
1664 static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1665 {
1666         struct task_security_struct *tsec = current->security;
1667         int atsecure = 0;
1668
1669         if (tsec->osid != tsec->sid) {
1670                 /* Enable secure mode for SIDs transitions unless
1671                    the noatsecure permission is granted between
1672                    the two SIDs, i.e. ahp returns 0. */
1673                 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1674                                          SECCLASS_PROCESS,
1675                                          PROCESS__NOATSECURE, NULL);
1676         }
1677
1678         return (atsecure || secondary_ops->bprm_secureexec(bprm));
1679 }
1680
1681 static void selinux_bprm_free_security(struct linux_binprm *bprm)
1682 {
1683         kfree(bprm->security);
1684         bprm->security = NULL;
1685 }
1686
1687 extern struct vfsmount *selinuxfs_mount;
1688 extern struct dentry *selinux_null;
1689
1690 /* Derived from fs/exec.c:flush_old_files. */
1691 static inline void flush_unauthorized_files(struct files_struct * files)
1692 {
1693         struct avc_audit_data ad;
1694         struct file *file, *devnull = NULL;
1695         struct tty_struct *tty = current->signal->tty;
1696         struct fdtable *fdt;
1697         long j = -1;
1698
1699         if (tty) {
1700                 file_list_lock();
1701                 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1702                 if (file) {
1703                         /* Revalidate access to controlling tty.
1704                            Use inode_has_perm on the tty inode directly rather
1705                            than using file_has_perm, as this particular open
1706                            file may belong to another process and we are only
1707                            interested in the inode-based check here. */
1708                         struct inode *inode = file->f_dentry->d_inode;
1709                         if (inode_has_perm(current, inode,
1710                                            FILE__READ | FILE__WRITE, NULL)) {
1711                                 /* Reset controlling tty. */
1712                                 current->signal->tty = NULL;
1713                                 current->signal->tty_old_pgrp = 0;
1714                         }
1715                 }
1716                 file_list_unlock();
1717         }
1718
1719         /* Revalidate access to inherited open files. */
1720
1721         AVC_AUDIT_DATA_INIT(&ad,FS);
1722
1723         spin_lock(&files->file_lock);
1724         for (;;) {
1725                 unsigned long set, i;
1726                 int fd;
1727
1728                 j++;
1729                 i = j * __NFDBITS;
1730                 fdt = files_fdtable(files);
1731                 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1732                         break;
1733                 set = fdt->open_fds->fds_bits[j];
1734                 if (!set)
1735                         continue;
1736                 spin_unlock(&files->file_lock);
1737                 for ( ; set ; i++,set >>= 1) {
1738                         if (set & 1) {
1739                                 file = fget(i);
1740                                 if (!file)
1741                                         continue;
1742                                 if (file_has_perm(current,
1743                                                   file,
1744                                                   file_to_av(file))) {
1745                                         sys_close(i);
1746                                         fd = get_unused_fd();
1747                                         if (fd != i) {
1748                                                 if (fd >= 0)
1749                                                         put_unused_fd(fd);
1750                                                 fput(file);
1751                                                 continue;
1752                                         }
1753                                         if (devnull) {
1754                                                 get_file(devnull);
1755                                         } else {
1756                                                 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1757                                                 if (!devnull) {
1758                                                         put_unused_fd(fd);
1759                                                         fput(file);
1760                                                         continue;
1761                                                 }
1762                                         }
1763                                         fd_install(fd, devnull);
1764                                 }
1765                                 fput(file);
1766                         }
1767                 }
1768                 spin_lock(&files->file_lock);
1769
1770         }
1771         spin_unlock(&files->file_lock);
1772 }
1773
1774 static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1775 {
1776         struct task_security_struct *tsec;
1777         struct bprm_security_struct *bsec;
1778         u32 sid;
1779         int rc;
1780
1781         secondary_ops->bprm_apply_creds(bprm, unsafe);
1782
1783         tsec = current->security;
1784
1785         bsec = bprm->security;
1786         sid = bsec->sid;
1787
1788         tsec->osid = tsec->sid;
1789         bsec->unsafe = 0;
1790         if (tsec->sid != sid) {
1791                 /* Check for shared state.  If not ok, leave SID
1792                    unchanged and kill. */
1793                 if (unsafe & LSM_UNSAFE_SHARE) {
1794                         rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1795                                         PROCESS__SHARE, NULL);
1796                         if (rc) {
1797                                 bsec->unsafe = 1;
1798                                 return;
1799                         }
1800                 }
1801
1802                 /* Check for ptracing, and update the task SID if ok.
1803                    Otherwise, leave SID unchanged and kill. */
1804                 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1805                         rc = avc_has_perm(tsec->ptrace_sid, sid,
1806                                           SECCLASS_PROCESS, PROCESS__PTRACE,
1807                                           NULL);
1808                         if (rc) {
1809                                 bsec->unsafe = 1;
1810                                 return;
1811                         }
1812                 }
1813                 tsec->sid = sid;
1814         }
1815 }
1816
1817 /*
1818  * called after apply_creds without the task lock held
1819  */
1820 static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1821 {
1822         struct task_security_struct *tsec;
1823         struct rlimit *rlim, *initrlim;
1824         struct itimerval itimer;
1825         struct bprm_security_struct *bsec;
1826         int rc, i;
1827
1828         tsec = current->security;
1829         bsec = bprm->security;
1830
1831         if (bsec->unsafe) {
1832                 force_sig_specific(SIGKILL, current);
1833                 return;
1834         }
1835         if (tsec->osid == tsec->sid)
1836                 return;
1837
1838         /* Close files for which the new task SID is not authorized. */
1839         flush_unauthorized_files(current->files);
1840
1841         /* Check whether the new SID can inherit signal state
1842            from the old SID.  If not, clear itimers to avoid
1843            subsequent signal generation and flush and unblock
1844            signals. This must occur _after_ the task SID has
1845           been updated so that any kill done after the flush
1846           will be checked against the new SID. */
1847         rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1848                           PROCESS__SIGINH, NULL);
1849         if (rc) {
1850                 memset(&itimer, 0, sizeof itimer);
1851                 for (i = 0; i < 3; i++)
1852                         do_setitimer(i, &itimer, NULL);
1853                 flush_signals(current);
1854                 spin_lock_irq(&current->sighand->siglock);
1855                 flush_signal_handlers(current, 1);
1856                 sigemptyset(&current->blocked);
1857                 recalc_sigpending();
1858                 spin_unlock_irq(&current->sighand->siglock);
1859         }
1860
1861         /* Check whether the new SID can inherit resource limits
1862            from the old SID.  If not, reset all soft limits to
1863            the lower of the current task's hard limit and the init
1864            task's soft limit.  Note that the setting of hard limits
1865            (even to lower them) can be controlled by the setrlimit
1866            check. The inclusion of the init task's soft limit into
1867            the computation is to avoid resetting soft limits higher
1868            than the default soft limit for cases where the default
1869            is lower than the hard limit, e.g. RLIMIT_CORE or
1870            RLIMIT_STACK.*/
1871         rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1872                           PROCESS__RLIMITINH, NULL);
1873         if (rc) {
1874                 for (i = 0; i < RLIM_NLIMITS; i++) {
1875                         rlim = current->signal->rlim + i;
1876                         initrlim = init_task.signal->rlim+i;
1877                         rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1878                 }
1879                 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1880                         /*
1881                          * This will cause RLIMIT_CPU calculations
1882                          * to be refigured.
1883                          */
1884                         current->it_prof_expires = jiffies_to_cputime(1);
1885                 }
1886         }
1887
1888         /* Wake up the parent if it is waiting so that it can
1889            recheck wait permission to the new task SID. */
1890         wake_up_interruptible(&current->parent->signal->wait_chldexit);
1891 }
1892
1893 /* superblock security operations */
1894
1895 static int selinux_sb_alloc_security(struct super_block *sb)
1896 {
1897         return superblock_alloc_security(sb);
1898 }
1899
1900 static void selinux_sb_free_security(struct super_block *sb)
1901 {
1902         superblock_free_security(sb);
1903 }
1904
1905 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1906 {
1907         if (plen > olen)
1908                 return 0;
1909
1910         return !memcmp(prefix, option, plen);
1911 }
1912
1913 static inline int selinux_option(char *option, int len)
1914 {
1915         return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1916                 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1917                 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len) ||
1918                 match_prefix("rootcontext=", sizeof("rootcontext=")-1, option, len));
1919 }
1920
1921 static inline void take_option(char **to, char *from, int *first, int len)
1922 {
1923         if (!*first) {
1924                 **to = ',';
1925                 *to += 1;
1926         }
1927         else
1928                 *first = 0;
1929         memcpy(*to, from, len);
1930         *to += len;
1931 }
1932
1933 static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1934 {
1935         int fnosec, fsec, rc = 0;
1936         char *in_save, *in_curr, *in_end;
1937         char *sec_curr, *nosec_save, *nosec;
1938
1939         in_curr = orig;
1940         sec_curr = copy;
1941
1942         /* Binary mount data: just copy */
1943         if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1944                 copy_page(sec_curr, in_curr);
1945                 goto out;
1946         }
1947
1948         nosec = (char *)get_zeroed_page(GFP_KERNEL);
1949         if (!nosec) {
1950                 rc = -ENOMEM;
1951                 goto out;
1952         }
1953
1954         nosec_save = nosec;
1955         fnosec = fsec = 1;
1956         in_save = in_end = orig;
1957
1958         do {
1959                 if (*in_end == ',' || *in_end == '\0') {
1960                         int len = in_end - in_curr;
1961
1962                         if (selinux_option(in_curr, len))
1963                                 take_option(&sec_curr, in_curr, &fsec, len);
1964                         else
1965                                 take_option(&nosec, in_curr, &fnosec, len);
1966
1967                         in_curr = in_end + 1;
1968                 }
1969         } while (*in_end++);
1970
1971         strcpy(in_save, nosec_save);
1972         free_page((unsigned long)nosec_save);
1973 out:
1974         return rc;
1975 }
1976
1977 static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1978 {
1979         struct avc_audit_data ad;
1980         int rc;
1981
1982         rc = superblock_doinit(sb, data);
1983         if (rc)
1984                 return rc;
1985
1986         AVC_AUDIT_DATA_INIT(&ad,FS);
1987         ad.u.fs.dentry = sb->s_root;
1988         return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1989 }
1990
1991 static int selinux_sb_statfs(struct dentry *dentry)
1992 {
1993         struct avc_audit_data ad;
1994
1995         AVC_AUDIT_DATA_INIT(&ad,FS);
1996         ad.u.fs.dentry = dentry->d_sb->s_root;
1997         return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1998 }
1999
2000 static int selinux_mount(char * dev_name,
2001                          struct nameidata *nd,
2002                          char * type,
2003                          unsigned long flags,
2004                          void * data)
2005 {
2006         int rc;
2007
2008         rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
2009         if (rc)
2010                 return rc;
2011
2012         if (flags & MS_REMOUNT)
2013                 return superblock_has_perm(current, nd->mnt->mnt_sb,
2014                                            FILESYSTEM__REMOUNT, NULL);
2015         else
2016                 return dentry_has_perm(current, nd->mnt, nd->dentry,
2017                                        FILE__MOUNTON);
2018 }
2019
2020 static int selinux_umount(struct vfsmount *mnt, int flags)
2021 {
2022         int rc;
2023
2024         rc = secondary_ops->sb_umount(mnt, flags);
2025         if (rc)
2026                 return rc;
2027
2028         return superblock_has_perm(current,mnt->mnt_sb,
2029                                    FILESYSTEM__UNMOUNT,NULL);
2030 }
2031
2032 /* inode security operations */
2033
2034 static int selinux_inode_alloc_security(struct inode *inode)
2035 {
2036         return inode_alloc_security(inode);
2037 }
2038
2039 static void selinux_inode_free_security(struct inode *inode)
2040 {
2041         inode_free_security(inode);
2042 }
2043
2044 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2045                                        char **name, void **value,
2046                                        size_t *len)
2047 {
2048         struct task_security_struct *tsec;
2049         struct inode_security_struct *dsec;
2050         struct superblock_security_struct *sbsec;
2051         u32 newsid, clen;
2052         int rc;
2053         char *namep = NULL, *context;
2054
2055         tsec = current->security;
2056         dsec = dir->i_security;
2057         sbsec = dir->i_sb->s_security;
2058
2059         if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2060                 newsid = tsec->create_sid;
2061         } else {
2062                 rc = security_transition_sid(tsec->sid, dsec->sid,
2063                                              inode_mode_to_security_class(inode->i_mode),
2064                                              &newsid);
2065                 if (rc) {
2066                         printk(KERN_WARNING "%s:  "
2067                                "security_transition_sid failed, rc=%d (dev=%s "
2068                                "ino=%ld)\n",
2069                                __FUNCTION__,
2070                                -rc, inode->i_sb->s_id, inode->i_ino);
2071                         return rc;
2072                 }
2073         }
2074
2075         /* Possibly defer initialization to selinux_complete_init. */
2076         if (sbsec->initialized) {
2077                 struct inode_security_struct *isec = inode->i_security;
2078                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2079                 isec->sid = newsid;
2080                 isec->initialized = 1;
2081         }
2082
2083         if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2084                 return -EOPNOTSUPP;
2085
2086         if (name) {
2087                 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2088                 if (!namep)
2089                         return -ENOMEM;
2090                 *name = namep;
2091         }
2092
2093         if (value && len) {
2094                 rc = security_sid_to_context(newsid, &context, &clen);
2095                 if (rc) {
2096                         kfree(namep);
2097                         return rc;
2098                 }
2099                 *value = context;
2100                 *len = clen;
2101         }
2102
2103         return 0;
2104 }
2105
2106 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2107 {
2108         return may_create(dir, dentry, SECCLASS_FILE);
2109 }
2110
2111 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2112 {
2113         int rc;
2114
2115         rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2116         if (rc)
2117                 return rc;
2118         return may_link(dir, old_dentry, MAY_LINK);
2119 }
2120
2121 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2122 {
2123         int rc;
2124
2125         rc = secondary_ops->inode_unlink(dir, dentry);
2126         if (rc)
2127                 return rc;
2128         return may_link(dir, dentry, MAY_UNLINK);
2129 }
2130
2131 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2132 {
2133         return may_create(dir, dentry, SECCLASS_LNK_FILE);
2134 }
2135
2136 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2137 {
2138         return may_create(dir, dentry, SECCLASS_DIR);
2139 }
2140
2141 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2142 {
2143         return may_link(dir, dentry, MAY_RMDIR);
2144 }
2145
2146 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2147 {
2148         int rc;
2149
2150         rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2151         if (rc)
2152                 return rc;
2153
2154         return may_create(dir, dentry, inode_mode_to_security_class(mode));
2155 }
2156
2157 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2158                                 struct inode *new_inode, struct dentry *new_dentry)
2159 {
2160         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2161 }
2162
2163 static int selinux_inode_readlink(struct dentry *dentry)
2164 {
2165         return dentry_has_perm(current, NULL, dentry, FILE__READ);
2166 }
2167
2168 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2169 {
2170         int rc;
2171
2172         rc = secondary_ops->inode_follow_link(dentry,nameidata);
2173         if (rc)
2174                 return rc;
2175         return dentry_has_perm(current, NULL, dentry, FILE__READ);
2176 }
2177
2178 static int selinux_inode_permission(struct inode *inode, int mask,
2179                                     struct nameidata *nd)
2180 {
2181         int rc;
2182
2183         rc = secondary_ops->inode_permission(inode, mask, nd);
2184         if (rc)
2185                 return rc;
2186
2187         if (!mask) {
2188                 /* No permission to check.  Existence test. */
2189                 return 0;
2190         }
2191
2192         return inode_has_perm(current, inode,
2193                                file_mask_to_av(inode->i_mode, mask), NULL);
2194 }
2195
2196 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2197 {
2198         int rc;
2199
2200         rc = secondary_ops->inode_setattr(dentry, iattr);
2201         if (rc)
2202                 return rc;
2203
2204         if (iattr->ia_valid & ATTR_FORCE)
2205                 return 0;
2206
2207         if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2208                                ATTR_ATIME_SET | ATTR_MTIME_SET))
2209                 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2210
2211         return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2212 }
2213
2214 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2215 {
2216         return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2217 }
2218
2219 static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2220 {
2221         struct task_security_struct *tsec = current->security;
2222         struct inode *inode = dentry->d_inode;
2223         struct inode_security_struct *isec = inode->i_security;
2224         struct superblock_security_struct *sbsec;
2225         struct avc_audit_data ad;
2226         u32 newsid;
2227         int rc = 0;
2228
2229         if (strcmp(name, XATTR_NAME_SELINUX)) {
2230                 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2231                              sizeof XATTR_SECURITY_PREFIX - 1) &&
2232                     !capable(CAP_SYS_ADMIN)) {
2233                         /* A different attribute in the security namespace.
2234                            Restrict to administrator. */
2235                         return -EPERM;
2236                 }
2237
2238                 /* Not an attribute we recognize, so just check the
2239                    ordinary setattr permission. */
2240                 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2241         }
2242
2243         sbsec = inode->i_sb->s_security;
2244         if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2245                 return -EOPNOTSUPP;
2246
2247         if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2248                 return -EPERM;
2249
2250         AVC_AUDIT_DATA_INIT(&ad,FS);
2251         ad.u.fs.dentry = dentry;
2252
2253         rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2254                           FILE__RELABELFROM, &ad);
2255         if (rc)
2256                 return rc;
2257
2258         rc = security_context_to_sid(value, size, &newsid);
2259         if (rc)
2260                 return rc;
2261
2262         rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2263                           FILE__RELABELTO, &ad);
2264         if (rc)
2265                 return rc;
2266
2267         rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2268                                           isec->sclass);
2269         if (rc)
2270                 return rc;
2271
2272         return avc_has_perm(newsid,
2273                             sbsec->sid,
2274                             SECCLASS_FILESYSTEM,
2275                             FILESYSTEM__ASSOCIATE,
2276                             &ad);
2277 }
2278
2279 static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2280                                         void *value, size_t size, int flags)
2281 {
2282         struct inode *inode = dentry->d_inode;
2283         struct inode_security_struct *isec = inode->i_security;
2284         u32 newsid;
2285         int rc;
2286
2287         if (strcmp(name, XATTR_NAME_SELINUX)) {
2288                 /* Not an attribute we recognize, so nothing to do. */
2289                 return;
2290         }
2291
2292         rc = security_context_to_sid(value, size, &newsid);
2293         if (rc) {
2294                 printk(KERN_WARNING "%s:  unable to obtain SID for context "
2295                        "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2296                 return;
2297         }
2298
2299         isec->sid = newsid;
2300         return;
2301 }
2302
2303 static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2304 {
2305         return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2306 }
2307
2308 static int selinux_inode_listxattr (struct dentry *dentry)
2309 {
2310         return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2311 }
2312
2313 static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2314 {
2315         if (strcmp(name, XATTR_NAME_SELINUX)) {
2316                 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2317                              sizeof XATTR_SECURITY_PREFIX - 1) &&
2318                     !capable(CAP_SYS_ADMIN)) {
2319                         /* A different attribute in the security namespace.
2320                            Restrict to administrator. */
2321                         return -EPERM;
2322                 }
2323
2324                 /* Not an attribute we recognize, so just check the
2325                    ordinary setattr permission. Might want a separate
2326                    permission for removexattr. */
2327                 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2328         }
2329
2330         /* No one is allowed to remove a SELinux security label.
2331            You can change the label, but all data must be labeled. */
2332         return -EACCES;
2333 }
2334
2335 static const char *selinux_inode_xattr_getsuffix(void)
2336 {
2337       return XATTR_SELINUX_SUFFIX;
2338 }
2339
2340 /*
2341  * Copy the in-core inode security context value to the user.  If the
2342  * getxattr() prior to this succeeded, check to see if we need to
2343  * canonicalize the value to be finally returned to the user.
2344  *
2345  * Permission check is handled by selinux_inode_getxattr hook.
2346  */
2347 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
2348 {
2349         struct inode_security_struct *isec = inode->i_security;
2350
2351         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2352                 return -EOPNOTSUPP;
2353
2354         return selinux_getsecurity(isec->sid, buffer, size);
2355 }
2356
2357 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2358                                      const void *value, size_t size, int flags)
2359 {
2360         struct inode_security_struct *isec = inode->i_security;
2361         u32 newsid;
2362         int rc;
2363
2364         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2365                 return -EOPNOTSUPP;
2366
2367         if (!value || !size)
2368                 return -EACCES;
2369
2370         rc = security_context_to_sid((void*)value, size, &newsid);
2371         if (rc)
2372                 return rc;
2373
2374         isec->sid = newsid;
2375         return 0;
2376 }
2377
2378 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2379 {
2380         const int len = sizeof(XATTR_NAME_SELINUX);
2381         if (buffer && len <= buffer_size)
2382                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2383         return len;
2384 }
2385
2386 /* file security operations */
2387
2388 static int selinux_file_permission(struct file *file, int mask)
2389 {
2390         int rc;
2391         struct inode *inode = file->f_dentry->d_inode;
2392
2393         if (!mask) {
2394                 /* No permission to check.  Existence test. */
2395                 return 0;
2396         }
2397
2398         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2399         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2400                 mask |= MAY_APPEND;
2401
2402         rc = file_has_perm(current, file,
2403                            file_mask_to_av(inode->i_mode, mask));
2404         if (rc)
2405                 return rc;
2406
2407         return selinux_netlbl_inode_permission(inode, mask);
2408 }
2409
2410 static int selinux_file_alloc_security(struct file *file)
2411 {
2412         return file_alloc_security(file);
2413 }
2414
2415 static void selinux_file_free_security(struct file *file)
2416 {
2417         file_free_security(file);
2418 }
2419
2420 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2421                               unsigned long arg)
2422 {
2423         int error = 0;
2424
2425         switch (cmd) {
2426                 case FIONREAD:
2427                 /* fall through */
2428                 case FIBMAP:
2429                 /* fall through */
2430                 case FIGETBSZ:
2431                 /* fall through */
2432                 case EXT2_IOC_GETFLAGS:
2433                 /* fall through */
2434                 case EXT2_IOC_GETVERSION:
2435                         error = file_has_perm(current, file, FILE__GETATTR);
2436                         break;
2437
2438                 case EXT2_IOC_SETFLAGS:
2439                 /* fall through */
2440                 case EXT2_IOC_SETVERSION:
2441                         error = file_has_perm(current, file, FILE__SETATTR);
2442                         break;
2443
2444                 /* sys_ioctl() checks */
2445                 case FIONBIO:
2446                 /* fall through */
2447                 case FIOASYNC:
2448                         error = file_has_perm(current, file, 0);
2449                         break;
2450
2451                 case KDSKBENT:
2452                 case KDSKBSENT:
2453                         error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2454                         break;
2455
2456                 /* default case assumes that the command will go
2457                  * to the file's ioctl() function.
2458                  */
2459                 default:
2460                         error = file_has_perm(current, file, FILE__IOCTL);
2461
2462         }
2463         return error;
2464 }
2465
2466 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2467 {
2468 #ifndef CONFIG_PPC32
2469         if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2470                 /*
2471                  * We are making executable an anonymous mapping or a
2472                  * private file mapping that will also be writable.
2473                  * This has an additional check.
2474                  */
2475                 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2476                 if (rc)
2477                         return rc;
2478         }
2479 #endif
2480
2481         if (file) {
2482                 /* read access is always possible with a mapping */
2483                 u32 av = FILE__READ;
2484
2485                 /* write access only matters if the mapping is shared */
2486                 if (shared && (prot & PROT_WRITE))
2487                         av |= FILE__WRITE;
2488
2489                 if (prot & PROT_EXEC)
2490                         av |= FILE__EXECUTE;
2491
2492                 return file_has_perm(current, file, av);
2493         }
2494         return 0;
2495 }
2496
2497 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2498                              unsigned long prot, unsigned long flags)
2499 {
2500         int rc;
2501
2502         rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2503         if (rc)
2504                 return rc;
2505
2506         if (selinux_checkreqprot)
2507                 prot = reqprot;
2508
2509         return file_map_prot_check(file, prot,
2510                                    (flags & MAP_TYPE) == MAP_SHARED);
2511 }
2512
2513 static int selinux_file_mprotect(struct vm_area_struct *vma,
2514                                  unsigned long reqprot,
2515                                  unsigned long prot)
2516 {
2517         int rc;
2518
2519         rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2520         if (rc)
2521                 return rc;
2522
2523         if (selinux_checkreqprot)
2524                 prot = reqprot;
2525
2526 #ifndef CONFIG_PPC32
2527         if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2528                 rc = 0;
2529                 if (vma->vm_start >= vma->vm_mm->start_brk &&
2530                     vma->vm_end <= vma->vm_mm->brk) {
2531                         rc = task_has_perm(current, current,
2532                                            PROCESS__EXECHEAP);
2533                 } else if (!vma->vm_file &&
2534                            vma->vm_start <= vma->vm_mm->start_stack &&
2535                            vma->vm_end >= vma->vm_mm->start_stack) {
2536                         rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2537                 } else if (vma->vm_file && vma->anon_vma) {
2538                         /*
2539                          * We are making executable a file mapping that has
2540                          * had some COW done. Since pages might have been
2541                          * written, check ability to execute the possibly
2542                          * modified content.  This typically should only
2543                          * occur for text relocations.
2544                          */
2545                         rc = file_has_perm(current, vma->vm_file,
2546                                            FILE__EXECMOD);
2547                 }
2548                 if (rc)
2549                         return rc;
2550         }
2551 #endif
2552
2553         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
2554 }
2555
2556 static int selinux_file_lock(struct file *file, unsigned int cmd)
2557 {
2558         return file_has_perm(current, file, FILE__LOCK);
2559 }
2560
2561 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
2562                               unsigned long arg)
2563 {
2564         int err = 0;
2565
2566         switch (cmd) {
2567                 case F_SETFL:
2568                         if (!file->f_dentry || !file->f_dentry->d_inode) {
2569                                 err = -EINVAL;
2570                                 break;
2571                         }
2572
2573                         if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
2574                                 err = file_has_perm(current, file,FILE__WRITE);
2575                                 break;
2576                         }
2577                         /* fall through */
2578                 case F_SETOWN:
2579                 case F_SETSIG:
2580                 case F_GETFL:
2581                 case F_GETOWN:
2582                 case F_GETSIG:
2583                         /* Just check FD__USE permission */
2584                         err = file_has_perm(current, file, 0);
2585                         break;
2586                 case F_GETLK:
2587                 case F_SETLK:
2588                 case F_SETLKW:
2589 #if BITS_PER_LONG == 32
2590                 case F_GETLK64:
2591                 case F_SETLK64:
2592                 case F_SETLKW64:
2593 #endif
2594                         if (!file->f_dentry || !file->f_dentry->d_inode) {
2595                                 err = -EINVAL;
2596                                 break;
2597                         }
2598                         err = file_has_perm(current, file, FILE__LOCK);
2599                         break;
2600         }
2601
2602         return err;
2603 }
2604
2605 static int selinux_file_set_fowner(struct file *file)
2606 {
2607         struct task_security_struct *tsec;
2608         struct file_security_struct *fsec;
2609
2610         tsec = current->security;
2611         fsec = file->f_security;
2612         fsec->fown_sid = tsec->sid;
2613
2614         return 0;
2615 }
2616
2617 static int selinux_file_send_sigiotask(struct task_struct *tsk,
2618                                        struct fown_struct *fown, int signum)
2619 {
2620         struct file *file;
2621         u32 perm;
2622         struct task_security_struct *tsec;
2623         struct file_security_struct *fsec;
2624
2625         /* struct fown_struct is never outside the context of a struct file */
2626         file = (struct file *)((long)fown - offsetof(struct file,f_owner));
2627
2628         tsec = tsk->security;
2629         fsec = file->f_security;
2630
2631         if (!signum)
2632                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
2633         else
2634                 perm = signal_to_av(signum);
2635
2636         return avc_has_perm(fsec->fown_sid, tsec->sid,
2637                             SECCLASS_PROCESS, perm, NULL);
2638 }
2639
2640 static int selinux_file_receive(struct file *file)
2641 {
2642         return file_has_perm(current, file, file_to_av(file));
2643 }
2644
2645 /* task security operations */
2646
2647 static int selinux_task_create(unsigned long clone_flags)
2648 {
2649         int rc;
2650
2651         rc = secondary_ops->task_create(clone_flags);
2652         if (rc)
2653                 return rc;
2654
2655         return task_has_perm(current, current, PROCESS__FORK);
2656 }
2657
2658 static int selinux_task_alloc_security(struct task_struct *tsk)
2659 {
2660         struct task_security_struct *tsec1, *tsec2;
2661         int rc;
2662
2663         tsec1 = current->security;
2664
2665         rc = task_alloc_security(tsk);
2666         if (rc)
2667                 return rc;
2668         tsec2 = tsk->security;
2669
2670         tsec2->osid = tsec1->osid;
2671         tsec2->sid = tsec1->sid;
2672
2673         /* Retain the exec, fs, key, and sock SIDs across fork */
2674         tsec2->exec_sid = tsec1->exec_sid;
2675         tsec2->create_sid = tsec1->create_sid;
2676         tsec2->keycreate_sid = tsec1->keycreate_sid;
2677         tsec2->sockcreate_sid = tsec1->sockcreate_sid;
2678
2679         /* Retain ptracer SID across fork, if any.
2680            This will be reset by the ptrace hook upon any
2681            subsequent ptrace_attach operations. */
2682         tsec2->ptrace_sid = tsec1->ptrace_sid;
2683
2684         return 0;
2685 }
2686
2687 static void selinux_task_free_security(struct task_struct *tsk)
2688 {
2689         task_free_security(tsk);
2690 }
2691
2692 static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
2693 {
2694         /* Since setuid only affects the current process, and
2695            since the SELinux controls are not based on the Linux
2696            identity attributes, SELinux does not need to control
2697            this operation.  However, SELinux does control the use
2698            of the CAP_SETUID and CAP_SETGID capabilities using the
2699            capable hook. */
2700         return 0;
2701 }
2702
2703 static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
2704 {
2705         return secondary_ops->task_post_setuid(id0,id1,id2,flags);
2706 }
2707
2708 static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
2709 {
2710         /* See the comment for setuid above. */
2711         return 0;
2712 }
2713
2714 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
2715 {
2716         return task_has_perm(current, p, PROCESS__SETPGID);
2717 }
2718
2719 static int selinux_task_getpgid(struct task_struct *p)
2720 {
2721         return task_has_perm(current, p, PROCESS__GETPGID);
2722 }
2723
2724 static int selinux_task_getsid(struct task_struct *p)
2725 {
2726         return task_has_perm(current, p, PROCESS__GETSESSION);
2727 }
2728
2729 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
2730 {
2731         selinux_get_task_sid(p, secid);
2732 }
2733
2734 static int selinux_task_setgroups(struct group_info *group_info)
2735 {
2736         /* See the comment for setuid above. */
2737         return 0;
2738 }
2739
2740 static int selinux_task_setnice(struct task_struct *p, int nice)
2741 {
2742         int rc;
2743
2744         rc = secondary_ops->task_setnice(p, nice);
2745         if (rc)
2746                 return rc;
2747
2748         return task_has_perm(current,p, PROCESS__SETSCHED);
2749 }
2750
2751 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
2752 {
2753         return task_has_perm(current, p, PROCESS__SETSCHED);
2754 }
2755
2756 static int selinux_task_getioprio(struct task_struct *p)
2757 {
2758         return task_has_perm(current, p, PROCESS__GETSCHED);
2759 }
2760
2761 static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
2762 {
2763         struct rlimit *old_rlim = current->signal->rlim + resource;
2764         int rc;
2765
2766         rc = secondary_ops->task_setrlimit(resource, new_rlim);
2767         if (rc)
2768                 return rc;
2769
2770         /* Control the ability to change the hard limit (whether
2771            lowering or raising it), so that the hard limit can
2772            later be used as a safe reset point for the soft limit
2773            upon context transitions. See selinux_bprm_apply_creds. */
2774         if (old_rlim->rlim_max != new_rlim->rlim_max)
2775                 return task_has_perm(current, current, PROCESS__SETRLIMIT);
2776
2777         return 0;
2778 }
2779
2780 static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp)
2781 {
2782         return task_has_perm(current, p, PROCESS__SETSCHED);
2783 }
2784
2785 static int selinux_task_getscheduler(struct task_struct *p)
2786 {
2787         return task_has_perm(current, p, PROCESS__GETSCHED);
2788 }
2789
2790 static int selinux_task_movememory(struct task_struct *p)
2791 {
2792         return task_has_perm(current, p, PROCESS__SETSCHED);
2793 }
2794
2795 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
2796                                 int sig, u32 secid)
2797 {
2798         u32 perm;
2799         int rc;
2800         struct task_security_struct *tsec;
2801
2802         rc = secondary_ops->task_kill(p, info, sig, secid);
2803         if (rc)
2804                 return rc;
2805
2806         if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
2807                 return 0;
2808
2809         if (!sig)
2810                 perm = PROCESS__SIGNULL; /* null signal; existence test */
2811         else
2812                 perm = signal_to_av(sig);
2813         tsec = p->security;
2814         if (secid)
2815                 rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL);
2816         else
2817                 rc = task_has_perm(current, p, perm);
2818         return rc;
2819 }
2820
2821 static int selinux_task_prctl(int option,
2822                               unsigned long arg2,
2823                               unsigned long arg3,
2824                               unsigned long arg4,
2825                               unsigned long arg5)
2826 {
2827         /* The current prctl operations do not appear to require
2828            any SELinux controls since they merely observe or modify
2829            the state of the current process. */
2830         return 0;
2831 }
2832
2833 static int selinux_task_wait(struct task_struct *p)
2834 {
2835         u32 perm;
2836
2837         perm = signal_to_av(p->exit_signal);
2838
2839         return task_has_perm(p, current, perm);
2840 }
2841
2842 static void selinux_task_reparent_to_init(struct task_struct *p)
2843 {
2844         struct task_security_struct *tsec;
2845
2846         secondary_ops->task_reparent_to_init(p);
2847
2848         tsec = p->security;
2849         tsec->osid = tsec->sid;
2850         tsec->sid = SECINITSID_KERNEL;
2851         return;
2852 }
2853
2854 static void selinux_task_to_inode(struct task_struct *p,
2855                                   struct inode *inode)
2856 {
2857         struct task_security_struct *tsec = p->security;
2858         struct inode_security_struct *isec = inode->i_security;
2859
2860         isec->sid = tsec->sid;
2861         isec->initialized = 1;
2862         return;
2863 }
2864
2865 /* Returns error only if unable to parse addresses */
2866 static int selinux_parse_skb_ipv4(struct sk_buff *skb, struct avc_audit_data *ad)
2867 {
2868         int offset, ihlen, ret = -EINVAL;
2869         struct iphdr _iph, *ih;
2870
2871         offset = skb->nh.raw - skb->data;
2872         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
2873         if (ih == NULL)
2874                 goto out;
2875
2876         ihlen = ih->ihl * 4;
2877         if (ihlen < sizeof(_iph))
2878                 goto out;
2879
2880         ad->u.net.v4info.saddr = ih->saddr;
2881         ad->u.net.v4info.daddr = ih->daddr;
2882         ret = 0;
2883
2884         switch (ih->protocol) {
2885         case IPPROTO_TCP: {
2886                 struct tcphdr _tcph, *th;
2887
2888                 if (ntohs(ih->frag_off) & IP_OFFSET)
2889                         break;
2890
2891                 offset += ihlen;
2892                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
2893                 if (th == NULL)
2894                         break;
2895
2896                 ad->u.net.sport = th->source;
2897                 ad->u.net.dport = th->dest;
2898                 break;
2899         }
2900         
2901         case IPPROTO_UDP: {
2902                 struct udphdr _udph, *uh;
2903                 
2904                 if (ntohs(ih->frag_off) & IP_OFFSET)
2905                         break;
2906                         
2907                 offset += ihlen;
2908                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
2909                 if (uh == NULL)
2910                         break;  
2911
2912                 ad->u.net.sport = uh->source;
2913                 ad->u.net.dport = uh->dest;
2914                 break;
2915         }
2916
2917         default:
2918                 break;
2919         }
2920 out:
2921         return ret;
2922 }
2923
2924 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2925
2926 /* Returns error only if unable to parse addresses */
2927 static int selinux_parse_skb_ipv6(struct sk_buff *skb, struct avc_audit_data *ad)
2928 {
2929         u8 nexthdr;
2930         int ret = -EINVAL, offset;
2931         struct ipv6hdr _ipv6h, *ip6;
2932
2933         offset = skb->nh.raw - skb->data;
2934         ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
2935         if (ip6 == NULL)
2936                 goto out;
2937
2938         ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
2939         ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
2940         ret = 0;
2941
2942         nexthdr = ip6->nexthdr;
2943         offset += sizeof(_ipv6h);
2944         offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
2945         if (offset < 0)
2946                 goto out;
2947
2948         switch (nexthdr) {
2949         case IPPROTO_TCP: {
2950                 struct tcphdr _tcph, *th;
2951
2952                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
2953                 if (th == NULL)
2954                         break;
2955
2956                 ad->u.net.sport = th->source;
2957                 ad->u.net.dport = th->dest;
2958                 break;
2959         }
2960
2961         case IPPROTO_UDP: {
2962                 struct udphdr _udph, *uh;
2963
2964                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
2965                 if (uh == NULL)
2966                         break;
2967
2968                 ad->u.net.sport = uh->source;
2969                 ad->u.net.dport = uh->dest;
2970                 break;
2971         }
2972
2973         /* includes fragments */
2974         default:
2975                 break;
2976         }
2977 out:
2978         return ret;
2979 }
2980
2981 #endif /* IPV6 */
2982
2983 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
2984                              char **addrp, int *len, int src)
2985 {
2986         int ret = 0;
2987
2988         switch (ad->u.net.family) {
2989         case PF_INET:
2990                 ret = selinux_parse_skb_ipv4(skb, ad);
2991                 if (ret || !addrp)
2992                         break;
2993                 *len = 4;
2994                 *addrp = (char *)(src ? &ad->u.net.v4info.saddr :
2995                                         &ad->u.net.v4info.daddr);
2996                 break;
2997
2998 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
2999         case PF_INET6:
3000                 ret = selinux_parse_skb_ipv6(skb, ad);
3001                 if (ret || !addrp)
3002                         break;
3003                 *len = 16;
3004                 *addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3005                                         &ad->u.net.v6info.daddr);
3006                 break;
3007 #endif  /* IPV6 */
3008         default:
3009                 break;
3010         }
3011
3012         return ret;
3013 }
3014
3015 /* socket security operations */
3016 static int socket_has_perm(struct task_struct *task, struct socket *sock,
3017                            u32 perms)
3018 {
3019         struct inode_security_struct *isec;
3020         struct task_security_struct *tsec;
3021         struct avc_audit_data ad;
3022         int err = 0;
3023
3024         tsec = task->security;
3025         isec = SOCK_INODE(sock)->i_security;
3026
3027         if (isec->sid == SECINITSID_KERNEL)
3028                 goto out;
3029
3030         AVC_AUDIT_DATA_INIT(&ad,NET);
3031         ad.u.net.sk = sock->sk;
3032         err = avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
3033
3034 out:
3035         return err;
3036 }
3037
3038 static int selinux_socket_create(int family, int type,
3039                                  int protocol, int kern)
3040 {
3041         int err = 0;
3042         struct task_security_struct *tsec;
3043         u32 newsid;
3044
3045         if (kern)
3046                 goto out;
3047
3048         tsec = current->security;
3049         newsid = tsec->sockcreate_sid ? : tsec->sid;
3050         err = avc_has_perm(tsec->sid, newsid,
3051                            socket_type_to_security_class(family, type,
3052                            protocol), SOCKET__CREATE, NULL);
3053
3054 out:
3055         return err;
3056 }
3057
3058 static int selinux_socket_post_create(struct socket *sock, int family,
3059                                       int type, int protocol, int kern)
3060 {
3061         int err = 0;
3062         struct inode_security_struct *isec;
3063         struct task_security_struct *tsec;
3064         struct sk_security_struct *sksec;
3065         u32 newsid;
3066
3067         isec = SOCK_INODE(sock)->i_security;
3068
3069         tsec = current->security;
3070         newsid = tsec->sockcreate_sid ? : tsec->sid;
3071         isec->sclass = socket_type_to_security_class(family, type, protocol);
3072         isec->sid = kern ? SECINITSID_KERNEL : newsid;
3073         isec->initialized = 1;
3074
3075         if (sock->sk) {
3076                 sksec = sock->sk->sk_security;
3077                 sksec->sid = isec->sid;
3078                 err = selinux_netlbl_socket_post_create(sock,
3079                                                         family,
3080                                                         isec->sid);
3081         }
3082
3083         return err;
3084 }
3085
3086 /* Range of port numbers used to automatically bind.
3087    Need to determine whether we should perform a name_bind
3088    permission check between the socket and the port number. */
3089 #define ip_local_port_range_0 sysctl_local_port_range[0]
3090 #define ip_local_port_range_1 sysctl_local_port_range[1]
3091
3092 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3093 {
3094         u16 family;
3095         int err;
3096
3097         err = socket_has_perm(current, sock, SOCKET__BIND);
3098         if (err)
3099                 goto out;
3100
3101         /*
3102          * If PF_INET or PF_INET6, check name_bind permission for the port.
3103          * Multiple address binding for SCTP is not supported yet: we just
3104          * check the first address now.
3105          */
3106         family = sock->sk->sk_family;
3107         if (family == PF_INET || family == PF_INET6) {
3108                 char *addrp;
3109                 struct inode_security_struct *isec;
3110                 struct task_security_struct *tsec;
3111                 struct avc_audit_data ad;
3112                 struct sockaddr_in *addr4 = NULL;
3113                 struct sockaddr_in6 *addr6 = NULL;
3114                 unsigned short snum;
3115                 struct sock *sk = sock->sk;
3116                 u32 sid, node_perm, addrlen;
3117
3118                 tsec = current->security;
3119                 isec = SOCK_INODE(sock)->i_security;
3120
3121                 if (family == PF_INET) {
3122                         addr4 = (struct sockaddr_in *)address;
3123                         snum = ntohs(addr4->sin_port);
3124                         addrlen = sizeof(addr4->sin_addr.s_addr);
3125                         addrp = (char *)&addr4->sin_addr.s_addr;
3126                 } else {
3127                         addr6 = (struct sockaddr_in6 *)address;
3128                         snum = ntohs(addr6->sin6_port);
3129                         addrlen = sizeof(addr6->sin6_addr.s6_addr);
3130                         addrp = (char *)&addr6->sin6_addr.s6_addr;
3131                 }
3132
3133                 if (snum&&(snum < max(PROT_SOCK,ip_local_port_range_0) ||
3134                            snum > ip_local_port_range_1)) {
3135                         err = security_port_sid(sk->sk_family, sk->sk_type,
3136                                                 sk->sk_protocol, snum, &sid);
3137                         if (err)
3138                                 goto out;
3139                         AVC_AUDIT_DATA_INIT(&ad,NET);
3140                         ad.u.net.sport = htons(snum);
3141                         ad.u.net.family = family;
3142                         err = avc_has_perm(isec->sid, sid,
3143                                            isec->sclass,
3144                                            SOCKET__NAME_BIND, &ad);
3145                         if (err)
3146                                 goto out;
3147                 }
3148                 
3149                 switch(isec->sclass) {
3150                 case SECCLASS_TCP_SOCKET:
3151                         node_perm = TCP_SOCKET__NODE_BIND;
3152                         break;
3153                         
3154                 case SECCLASS_UDP_SOCKET:
3155                         node_perm = UDP_SOCKET__NODE_BIND;
3156                         break;
3157                         
3158                 default:
3159                         node_perm = RAWIP_SOCKET__NODE_BIND;
3160                         break;
3161                 }
3162                 
3163                 err = security_node_sid(family, addrp, addrlen, &sid);
3164                 if (err)
3165                         goto out;
3166                 
3167                 AVC_AUDIT_DATA_INIT(&ad,NET);
3168                 ad.u.net.sport = htons(snum);
3169                 ad.u.net.family = family;
3170
3171                 if (family == PF_INET)
3172                         ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3173                 else
3174                         ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);
3175
3176                 err = avc_has_perm(isec->sid, sid,
3177                                    isec->sclass, node_perm, &ad);
3178                 if (err)
3179                         goto out;
3180         }
3181 out:
3182         return err;
3183 }
3184
3185 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3186 {
3187         struct inode_security_struct *isec;
3188         int err;
3189
3190         err = socket_has_perm(current, sock, SOCKET__CONNECT);
3191         if (err)
3192                 return err;
3193
3194         /*
3195          * If a TCP socket, check name_connect permission for the port.
3196          */
3197         isec = SOCK_INODE(sock)->i_security;
3198         if (isec->sclass == SECCLASS_TCP_SOCKET) {
3199                 struct sock *sk = sock->sk;
3200                 struct avc_audit_data ad;
3201                 struct sockaddr_in *addr4 = NULL;
3202                 struct sockaddr_in6 *addr6 = NULL;
3203                 unsigned short snum;
3204                 u32 sid;
3205
3206                 if (sk->sk_family == PF_INET) {
3207                         addr4 = (struct sockaddr_in *)address;
3208                         if (addrlen < sizeof(struct sockaddr_in))
3209                                 return -EINVAL;
3210                         snum = ntohs(addr4->sin_port);
3211                 } else {
3212                         addr6 = (struct sockaddr_in6 *)address;
3213                         if (addrlen < SIN6_LEN_RFC2133)
3214                                 return -EINVAL;
3215                         snum = ntohs(addr6->sin6_port);
3216                 }
3217
3218                 err = security_port_sid(sk->sk_family, sk->sk_type,
3219                                         sk->sk_protocol, snum, &sid);
3220                 if (err)
3221                         goto out;
3222
3223                 AVC_AUDIT_DATA_INIT(&ad,NET);
3224                 ad.u.net.dport = htons(snum);
3225                 ad.u.net.family = sk->sk_family;
3226                 err = avc_has_perm(isec->sid, sid, isec->sclass,
3227                                    TCP_SOCKET__NAME_CONNECT, &ad);
3228                 if (err)
3229                         goto out;
3230         }
3231
3232 out:
3233         return err;
3234 }
3235
3236 static int selinux_socket_listen(struct socket *sock, int backlog)
3237 {
3238         return socket_has_perm(current, sock, SOCKET__LISTEN);
3239 }
3240
3241 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3242 {
3243         int err;
3244         struct inode_security_struct *isec;
3245         struct inode_security_struct *newisec;
3246
3247         err = socket_has_perm(current, sock, SOCKET__ACCEPT);
3248         if (err)
3249                 return err;
3250
3251         newisec = SOCK_INODE(newsock)->i_security;
3252
3253         isec = SOCK_INODE(sock)->i_security;
3254         newisec->sclass = isec->sclass;
3255         newisec->sid = isec->sid;
3256         newisec->initialized = 1;
3257
3258         return 0;
3259 }
3260
3261 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3262                                   int size)
3263 {
3264         int rc;
3265
3266         rc = socket_has_perm(current, sock, SOCKET__WRITE);
3267         if (rc)
3268                 return rc;
3269
3270         return selinux_netlbl_inode_permission(SOCK_INODE(sock), MAY_WRITE);
3271 }
3272
3273 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
3274                                   int size, int flags)
3275 {
3276         return socket_has_perm(current, sock, SOCKET__READ);
3277 }
3278