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linux/security/selinux/ss/services.c
Darrel Goeddel 376bd9cb35 [PATCH] support for context based audit filtering 
The following patch provides selinux interfaces that will allow the audit
system to perform filtering based on the process context (user, role, type,
sensitivity, and clearance).  These interfaces will allow the selinux
module to perform efficient matches based on lower level selinux constructs,
rather than relying on context retrievals and string comparisons within
the audit module.  It also allows for dominance checks on the mls portion
of the contexts that are impossible with only string comparisons.

Signed-off-by: Darrel Goeddel <dgoeddel@trustedcs.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-05-01 06:06:24 -04:00

2047 lines
47 KiB
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/*
* Implementation of the security services.
*
* Authors : Stephen Smalley, <sds@epoch.ncsc.mil>
* James Morris <jmorris@redhat.com>
*
* Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com>
*
* Support for enhanced MLS infrastructure.
* Support for context based audit filters.
*
* Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com>
*
* Added conditional policy language extensions
*
* Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 2.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/sched.h>
#include <linux/audit.h>
#include <linux/mutex.h>
#include "flask.h"
#include "avc.h"
#include "avc_ss.h"
#include "security.h"
#include "context.h"
#include "policydb.h"
#include "sidtab.h"
#include "services.h"
#include "conditional.h"
#include "mls.h"
extern void selnl_notify_policyload(u32 seqno);
unsigned int policydb_loaded_version;
static DEFINE_RWLOCK(policy_rwlock);
#define POLICY_RDLOCK read_lock(&policy_rwlock)
#define POLICY_WRLOCK write_lock_irq(&policy_rwlock)
#define POLICY_RDUNLOCK read_unlock(&policy_rwlock)
#define POLICY_WRUNLOCK write_unlock_irq(&policy_rwlock)
static DEFINE_MUTEX(load_mutex);
#define LOAD_LOCK mutex_lock(&load_mutex)
#define LOAD_UNLOCK mutex_unlock(&load_mutex)
static struct sidtab sidtab;
struct policydb policydb;
int ss_initialized = 0;
/*
* The largest sequence number that has been used when
* providing an access decision to the access vector cache.
* The sequence number only changes when a policy change
* occurs.
*/
static u32 latest_granting = 0;
/* Forward declaration. */
static int context_struct_to_string(struct context *context, char **scontext,
u32 *scontext_len);
/*
* Return the boolean value of a constraint expression
* when it is applied to the specified source and target
* security contexts.
*
* xcontext is a special beast... It is used by the validatetrans rules
* only. For these rules, scontext is the context before the transition,
* tcontext is the context after the transition, and xcontext is the context
* of the process performing the transition. All other callers of
* constraint_expr_eval should pass in NULL for xcontext.
*/
static int constraint_expr_eval(struct context *scontext,
struct context *tcontext,
struct context *xcontext,
struct constraint_expr *cexpr)
{
u32 val1, val2;
struct context *c;
struct role_datum *r1, *r2;
struct mls_level *l1, *l2;
struct constraint_expr *e;
int s[CEXPR_MAXDEPTH];
int sp = -1;
for (e = cexpr; e; e = e->next) {
switch (e->expr_type) {
case CEXPR_NOT:
BUG_ON(sp < 0);
s[sp] = !s[sp];
break;
case CEXPR_AND:
BUG_ON(sp < 1);
sp--;
s[sp] &= s[sp+1];
break;
case CEXPR_OR:
BUG_ON(sp < 1);
sp--;
s[sp] |= s[sp+1];
break;
case CEXPR_ATTR:
if (sp == (CEXPR_MAXDEPTH-1))
return 0;
switch (e->attr) {
case CEXPR_USER:
val1 = scontext->user;
val2 = tcontext->user;
break;
case CEXPR_TYPE:
val1 = scontext->type;
val2 = tcontext->type;
break;
case CEXPR_ROLE:
val1 = scontext->role;
val2 = tcontext->role;
r1 = policydb.role_val_to_struct[val1 - 1];
r2 = policydb.role_val_to_struct[val2 - 1];
switch (e->op) {
case CEXPR_DOM:
s[++sp] = ebitmap_get_bit(&r1->dominates,
val2 - 1);
continue;
case CEXPR_DOMBY:
s[++sp] = ebitmap_get_bit(&r2->dominates,
val1 - 1);
continue;
case CEXPR_INCOMP:
s[++sp] = ( !ebitmap_get_bit(&r1->dominates,
val2 - 1) &&
!ebitmap_get_bit(&r2->dominates,
val1 - 1) );
continue;
default:
break;
}
break;
case CEXPR_L1L2:
l1 = &(scontext->range.level[0]);
l2 = &(tcontext->range.level[0]);
goto mls_ops;
case CEXPR_L1H2:
l1 = &(scontext->range.level[0]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
case CEXPR_H1L2:
l1 = &(scontext->range.level[1]);
l2 = &(tcontext->range.level[0]);
goto mls_ops;
case CEXPR_H1H2:
l1 = &(scontext->range.level[1]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
case CEXPR_L1H1:
l1 = &(scontext->range.level[0]);
l2 = &(scontext->range.level[1]);
goto mls_ops;
case CEXPR_L2H2:
l1 = &(tcontext->range.level[0]);
l2 = &(tcontext->range.level[1]);
goto mls_ops;
mls_ops:
switch (e->op) {
case CEXPR_EQ:
s[++sp] = mls_level_eq(l1, l2);
continue;
case CEXPR_NEQ:
s[++sp] = !mls_level_eq(l1, l2);
continue;
case CEXPR_DOM:
s[++sp] = mls_level_dom(l1, l2);
continue;
case CEXPR_DOMBY:
s[++sp] = mls_level_dom(l2, l1);
continue;
case CEXPR_INCOMP:
s[++sp] = mls_level_incomp(l2, l1);
continue;
default:
BUG();
return 0;
}
break;
default:
BUG();
return 0;
}
switch (e->op) {
case CEXPR_EQ:
s[++sp] = (val1 == val2);
break;
case CEXPR_NEQ:
s[++sp] = (val1 != val2);
break;
default:
BUG();
return 0;
}
break;
case CEXPR_NAMES:
if (sp == (CEXPR_MAXDEPTH-1))
return 0;
c = scontext;
if (e->attr & CEXPR_TARGET)
c = tcontext;
else if (e->attr & CEXPR_XTARGET) {
c = xcontext;
if (!c) {
BUG();
return 0;
}
}
if (e->attr & CEXPR_USER)
val1 = c->user;
else if (e->attr & CEXPR_ROLE)
val1 = c->role;
else if (e->attr & CEXPR_TYPE)
val1 = c->type;
else {
BUG();
return 0;
}
switch (e->op) {
case CEXPR_EQ:
s[++sp] = ebitmap_get_bit(&e->names, val1 - 1);
break;
case CEXPR_NEQ:
s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1);
break;
default:
BUG();
return 0;
}
break;
default:
BUG();
return 0;
}
}
BUG_ON(sp != 0);
return s[0];
}
/*
* Compute access vectors based on a context structure pair for
* the permissions in a particular class.
*/
static int context_struct_compute_av(struct context *scontext,
struct context *tcontext,
u16 tclass,
u32 requested,
struct av_decision *avd)
{
struct constraint_node *constraint;
struct role_allow *ra;
struct avtab_key avkey;
struct avtab_node *node;
struct class_datum *tclass_datum;
struct ebitmap *sattr, *tattr;
struct ebitmap_node *snode, *tnode;
unsigned int i, j;
/*
* Remap extended Netlink classes for old policy versions.
* Do this here rather than socket_type_to_security_class()
* in case a newer policy version is loaded, allowing sockets
* to remain in the correct class.
*/
if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
tclass = SECCLASS_NETLINK_SOCKET;
if (!tclass || tclass > policydb.p_classes.nprim) {
printk(KERN_ERR "security_compute_av: unrecognized class %d\n",
tclass);
return -EINVAL;
}
tclass_datum = policydb.class_val_to_struct[tclass - 1];
/*
* Initialize the access vectors to the default values.
*/
avd->allowed = 0;
avd->decided = 0xffffffff;
avd->auditallow = 0;
avd->auditdeny = 0xffffffff;
avd->seqno = latest_granting;
/*
* If a specific type enforcement rule was defined for
* this permission check, then use it.
*/
avkey.target_class = tclass;
avkey.specified = AVTAB_AV;
sattr = &policydb.type_attr_map[scontext->type - 1];
tattr = &policydb.type_attr_map[tcontext->type - 1];
ebitmap_for_each_bit(sattr, snode, i) {
if (!ebitmap_node_get_bit(snode, i))
continue;
ebitmap_for_each_bit(tattr, tnode, j) {
if (!ebitmap_node_get_bit(tnode, j))
continue;
avkey.source_type = i + 1;
avkey.target_type = j + 1;
for (node = avtab_search_node(&policydb.te_avtab, &avkey);
node != NULL;
node = avtab_search_node_next(node, avkey.specified)) {
if (node->key.specified == AVTAB_ALLOWED)
avd->allowed |= node->datum.data;
else if (node->key.specified == AVTAB_AUDITALLOW)
avd->auditallow |= node->datum.data;
else if (node->key.specified == AVTAB_AUDITDENY)
avd->auditdeny &= node->datum.data;
}
/* Check conditional av table for additional permissions */
cond_compute_av(&policydb.te_cond_avtab, &avkey, avd);
}
}
/*
* Remove any permissions prohibited by a constraint (this includes
* the MLS policy).
*/
constraint = tclass_datum->constraints;
while (constraint) {
if ((constraint->permissions & (avd->allowed)) &&
!constraint_expr_eval(scontext, tcontext, NULL,
constraint->expr)) {
avd->allowed = (avd->allowed) & ~(constraint->permissions);
}
constraint = constraint->next;
}
/*
* If checking process transition permission and the
* role is changing, then check the (current_role, new_role)
* pair.
*/
if (tclass == SECCLASS_PROCESS &&
(avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) &&
scontext->role != tcontext->role) {
for (ra = policydb.role_allow; ra; ra = ra->next) {
if (scontext->role == ra->role &&
tcontext->role == ra->new_role)
break;
}
if (!ra)
avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION |
PROCESS__DYNTRANSITION);
}
return 0;
}
static int security_validtrans_handle_fail(struct context *ocontext,
struct context *ncontext,
struct context *tcontext,
u16 tclass)
{
char *o = NULL, *n = NULL, *t = NULL;
u32 olen, nlen, tlen;
if (context_struct_to_string(ocontext, &o, &olen) < 0)
goto out;
if (context_struct_to_string(ncontext, &n, &nlen) < 0)
goto out;
if (context_struct_to_string(tcontext, &t, &tlen) < 0)
goto out;
audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"security_validate_transition: denied for"
" oldcontext=%s newcontext=%s taskcontext=%s tclass=%s",
o, n, t, policydb.p_class_val_to_name[tclass-1]);
out:
kfree(o);
kfree(n);
kfree(t);
if (!selinux_enforcing)
return 0;
return -EPERM;
}
int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
u16 tclass)
{
struct context *ocontext;
struct context *ncontext;
struct context *tcontext;
struct class_datum *tclass_datum;
struct constraint_node *constraint;
int rc = 0;
if (!ss_initialized)
return 0;
POLICY_RDLOCK;
/*
* Remap extended Netlink classes for old policy versions.
* Do this here rather than socket_type_to_security_class()
* in case a newer policy version is loaded, allowing sockets
* to remain in the correct class.
*/
if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS)
if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET &&
tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
tclass = SECCLASS_NETLINK_SOCKET;
if (!tclass || tclass > policydb.p_classes.nprim) {
printk(KERN_ERR "security_validate_transition: "
"unrecognized class %d\n", tclass);
rc = -EINVAL;
goto out;
}
tclass_datum = policydb.class_val_to_struct[tclass - 1];
ocontext = sidtab_search(&sidtab, oldsid);
if (!ocontext) {
printk(KERN_ERR "security_validate_transition: "
" unrecognized SID %d\n", oldsid);
rc = -EINVAL;
goto out;
}
ncontext = sidtab_search(&sidtab, newsid);
if (!ncontext) {
printk(KERN_ERR "security_validate_transition: "
" unrecognized SID %d\n", newsid);
rc = -EINVAL;
goto out;
}
tcontext = sidtab_search(&sidtab, tasksid);
if (!tcontext) {
printk(KERN_ERR "security_validate_transition: "
" unrecognized SID %d\n", tasksid);
rc = -EINVAL;
goto out;
}
constraint = tclass_datum->validatetrans;
while (constraint) {
if (!constraint_expr_eval(ocontext, ncontext, tcontext,
constraint->expr)) {
rc = security_validtrans_handle_fail(ocontext, ncontext,
tcontext, tclass);
goto out;
}
constraint = constraint->next;
}
out:
POLICY_RDUNLOCK;
return rc;
}
/**
* security_compute_av - Compute access vector decisions.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @requested: requested permissions
* @avd: access vector decisions
*
* Compute a set of access vector decisions based on the
* SID pair (@ssid, @tsid) for the permissions in @tclass.
* Return -%EINVAL if any of the parameters are invalid or %0
* if the access vector decisions were computed successfully.
*/
int security_compute_av(u32 ssid,
u32 tsid,
u16 tclass,
u32 requested,
struct av_decision *avd)
{
struct context *scontext = NULL, *tcontext = NULL;
int rc = 0;
if (!ss_initialized) {
avd->allowed = 0xffffffff;
avd->decided = 0xffffffff;
avd->auditallow = 0;
avd->auditdeny = 0xffffffff;
avd->seqno = latest_granting;
return 0;
}
POLICY_RDLOCK;
scontext = sidtab_search(&sidtab, ssid);
if (!scontext) {
printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
ssid);
rc = -EINVAL;
goto out;
}
tcontext = sidtab_search(&sidtab, tsid);
if (!tcontext) {
printk(KERN_ERR "security_compute_av: unrecognized SID %d\n",
tsid);
rc = -EINVAL;
goto out;
}
rc = context_struct_compute_av(scontext, tcontext, tclass,
requested, avd);
out:
POLICY_RDUNLOCK;
return rc;
}
/*
* Write the security context string representation of
* the context structure `context' into a dynamically
* allocated string of the correct size. Set `*scontext'
* to point to this string and set `*scontext_len' to
* the length of the string.
*/
static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len)
{
char *scontextp;
*scontext = NULL;
*scontext_len = 0;
/* Compute the size of the context. */
*scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1;
*scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1;
*scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1;
*scontext_len += mls_compute_context_len(context);
/* Allocate space for the context; caller must free this space. */
scontextp = kmalloc(*scontext_len, GFP_ATOMIC);
if (!scontextp) {
return -ENOMEM;
}
*scontext = scontextp;
/*
* Copy the user name, role name and type name into the context.
*/
sprintf(scontextp, "%s:%s:%s",
policydb.p_user_val_to_name[context->user - 1],
policydb.p_role_val_to_name[context->role - 1],
policydb.p_type_val_to_name[context->type - 1]);
scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) +
1 + strlen(policydb.p_role_val_to_name[context->role - 1]) +
1 + strlen(policydb.p_type_val_to_name[context->type - 1]);
mls_sid_to_context(context, &scontextp);
*scontextp = 0;
return 0;
}
#include "initial_sid_to_string.h"
/**
* security_sid_to_context - Obtain a context for a given SID.
* @sid: security identifier, SID
* @scontext: security context
* @scontext_len: length in bytes
*
* Write the string representation of the context associated with @sid
* into a dynamically allocated string of the correct size. Set @scontext
* to point to this string and set @scontext_len to the length of the string.
*/
int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len)
{
struct context *context;
int rc = 0;
if (!ss_initialized) {
if (sid <= SECINITSID_NUM) {
char *scontextp;
*scontext_len = strlen(initial_sid_to_string[sid]) + 1;
scontextp = kmalloc(*scontext_len,GFP_ATOMIC);
strcpy(scontextp, initial_sid_to_string[sid]);
*scontext = scontextp;
goto out;
}
printk(KERN_ERR "security_sid_to_context: called before initial "
"load_policy on unknown SID %d\n", sid);
rc = -EINVAL;
goto out;
}
POLICY_RDLOCK;
context = sidtab_search(&sidtab, sid);
if (!context) {
printk(KERN_ERR "security_sid_to_context: unrecognized SID "
"%d\n", sid);
rc = -EINVAL;
goto out_unlock;
}
rc = context_struct_to_string(context, scontext, scontext_len);
out_unlock:
POLICY_RDUNLOCK;
out:
return rc;
}
static int security_context_to_sid_core(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
{
char *scontext2;
struct context context;
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
char *scontextp, *p, oldc;
int rc = 0;
if (!ss_initialized) {
int i;
for (i = 1; i < SECINITSID_NUM; i++) {
if (!strcmp(initial_sid_to_string[i], scontext)) {
*sid = i;
goto out;
}
}
*sid = SECINITSID_KERNEL;
goto out;
}
*sid = SECSID_NULL;
/* Copy the string so that we can modify the copy as we parse it.
The string should already by null terminated, but we append a
null suffix to the copy to avoid problems with the existing
attr package, which doesn't view the null terminator as part
of the attribute value. */
scontext2 = kmalloc(scontext_len+1,GFP_KERNEL);
if (!scontext2) {
rc = -ENOMEM;
goto out;
}
memcpy(scontext2, scontext, scontext_len);
scontext2[scontext_len] = 0;
context_init(&context);
*sid = SECSID_NULL;
POLICY_RDLOCK;
/* Parse the security context. */
rc = -EINVAL;
scontextp = (char *) scontext2;
/* Extract the user. */
p = scontextp;
while (*p && *p != ':')
p++;
if (*p == 0)
goto out_unlock;
*p++ = 0;
usrdatum = hashtab_search(policydb.p_users.table, scontextp);
if (!usrdatum)
goto out_unlock;
context.user = usrdatum->value;
/* Extract role. */
scontextp = p;
while (*p && *p != ':')
p++;
if (*p == 0)
goto out_unlock;
*p++ = 0;
role = hashtab_search(policydb.p_roles.table, scontextp);
if (!role)
goto out_unlock;
context.role = role->value;
/* Extract type. */
scontextp = p;
while (*p && *p != ':')
p++;
oldc = *p;
*p++ = 0;
typdatum = hashtab_search(policydb.p_types.table, scontextp);
if (!typdatum)
goto out_unlock;
context.type = typdatum->value;
rc = mls_context_to_sid(oldc, &p, &context, &sidtab, def_sid);
if (rc)
goto out_unlock;
if ((p - scontext2) < scontext_len) {
rc = -EINVAL;
goto out_unlock;
}
/* Check the validity of the new context. */
if (!policydb_context_isvalid(&policydb, &context)) {
rc = -EINVAL;
goto out_unlock;
}
/* Obtain the new sid. */
rc = sidtab_context_to_sid(&sidtab, &context, sid);
out_unlock:
POLICY_RDUNLOCK;
context_destroy(&context);
kfree(scontext2);
out:
return rc;
}
/**
* security_context_to_sid - Obtain a SID for a given security context.
* @scontext: security context
* @scontext_len: length in bytes
* @sid: security identifier, SID
*
* Obtains a SID associated with the security context that
* has the string representation specified by @scontext.
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
* memory is available, or 0 on success.
*/
int security_context_to_sid(char *scontext, u32 scontext_len, u32 *sid)
{
return security_context_to_sid_core(scontext, scontext_len,
sid, SECSID_NULL);
}
/**
* security_context_to_sid_default - Obtain a SID for a given security context,
* falling back to specified default if needed.
*
* @scontext: security context
* @scontext_len: length in bytes
* @sid: security identifier, SID
* @def_sid: default SID to assign on errror
*
* Obtains a SID associated with the security context that
* has the string representation specified by @scontext.
* The default SID is passed to the MLS layer to be used to allow
* kernel labeling of the MLS field if the MLS field is not present
* (for upgrading to MLS without full relabel).
* Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient
* memory is available, or 0 on success.
*/
int security_context_to_sid_default(char *scontext, u32 scontext_len, u32 *sid, u32 def_sid)
{
return security_context_to_sid_core(scontext, scontext_len,
sid, def_sid);
}
static int compute_sid_handle_invalid_context(
struct context *scontext,
struct context *tcontext,
u16 tclass,
struct context *newcontext)
{
char *s = NULL, *t = NULL, *n = NULL;
u32 slen, tlen, nlen;
if (context_struct_to_string(scontext, &s, &slen) < 0)
goto out;
if (context_struct_to_string(tcontext, &t, &tlen) < 0)
goto out;
if (context_struct_to_string(newcontext, &n, &nlen) < 0)
goto out;
audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"security_compute_sid: invalid context %s"
" for scontext=%s"
" tcontext=%s"
" tclass=%s",
n, s, t, policydb.p_class_val_to_name[tclass-1]);
out:
kfree(s);
kfree(t);
kfree(n);
if (!selinux_enforcing)
return 0;
return -EACCES;
}
static int security_compute_sid(u32 ssid,
u32 tsid,
u16 tclass,
u32 specified,
u32 *out_sid)
{
struct context *scontext = NULL, *tcontext = NULL, newcontext;
struct role_trans *roletr = NULL;
struct avtab_key avkey;
struct avtab_datum *avdatum;
struct avtab_node *node;
int rc = 0;
if (!ss_initialized) {
switch (tclass) {
case SECCLASS_PROCESS:
*out_sid = ssid;
break;
default:
*out_sid = tsid;
break;
}
goto out;
}
POLICY_RDLOCK;
scontext = sidtab_search(&sidtab, ssid);
if (!scontext) {
printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
ssid);
rc = -EINVAL;
goto out_unlock;
}
tcontext = sidtab_search(&sidtab, tsid);
if (!tcontext) {
printk(KERN_ERR "security_compute_sid: unrecognized SID %d\n",
tsid);
rc = -EINVAL;
goto out_unlock;
}
context_init(&newcontext);
/* Set the user identity. */
switch (specified) {
case AVTAB_TRANSITION:
case AVTAB_CHANGE:
/* Use the process user identity. */
newcontext.user = scontext->user;
break;
case AVTAB_MEMBER:
/* Use the related object owner. */
newcontext.user = tcontext->user;
break;
}
/* Set the role and type to default values. */
switch (tclass) {
case SECCLASS_PROCESS:
/* Use the current role and type of process. */
newcontext.role = scontext->role;
newcontext.type = scontext->type;
break;
default:
/* Use the well-defined object role. */
newcontext.role = OBJECT_R_VAL;
/* Use the type of the related object. */
newcontext.type = tcontext->type;
}
/* Look for a type transition/member/change rule. */
avkey.source_type = scontext->type;
avkey.target_type = tcontext->type;
avkey.target_class = tclass;
avkey.specified = specified;
avdatum = avtab_search(&policydb.te_avtab, &avkey);
/* If no permanent rule, also check for enabled conditional rules */
if(!avdatum) {
node = avtab_search_node(&policydb.te_cond_avtab, &avkey);
for (; node != NULL; node = avtab_search_node_next(node, specified)) {
if (node->key.specified & AVTAB_ENABLED) {
avdatum = &node->datum;
break;
}
}
}
if (avdatum) {
/* Use the type from the type transition/member/change rule. */
newcontext.type = avdatum->data;
}
/* Check for class-specific changes. */
switch (tclass) {
case SECCLASS_PROCESS:
if (specified & AVTAB_TRANSITION) {
/* Look for a role transition rule. */
for (roletr = policydb.role_tr; roletr;
roletr = roletr->next) {
if (roletr->role == scontext->role &&
roletr->type == tcontext->type) {
/* Use the role transition rule. */
newcontext.role = roletr->new_role;
break;
}
}
}
break;
default:
break;
}
/* Set the MLS attributes.
This is done last because it may allocate memory. */
rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext);
if (rc)
goto out_unlock;
/* Check the validity of the context. */
if (!policydb_context_isvalid(&policydb, &newcontext)) {
rc = compute_sid_handle_invalid_context(scontext,
tcontext,
tclass,
&newcontext);
if (rc)
goto out_unlock;
}
/* Obtain the sid for the context. */
rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid);
out_unlock:
POLICY_RDUNLOCK;
context_destroy(&newcontext);
out:
return rc;
}
/**
* security_transition_sid - Compute the SID for a new subject/object.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @out_sid: security identifier for new subject/object
*
* Compute a SID to use for labeling a new subject or object in the
* class @tclass based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the new SID was
* computed successfully.
*/
int security_transition_sid(u32 ssid,
u32 tsid,
u16 tclass,
u32 *out_sid)
{
return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid);
}
/**
* security_member_sid - Compute the SID for member selection.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @out_sid: security identifier for selected member
*
* Compute a SID to use when selecting a member of a polyinstantiated
* object of class @tclass based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the SID was
* computed successfully.
*/
int security_member_sid(u32 ssid,
u32 tsid,
u16 tclass,
u32 *out_sid)
{
return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid);
}
/**
* security_change_sid - Compute the SID for object relabeling.
* @ssid: source security identifier
* @tsid: target security identifier
* @tclass: target security class
* @out_sid: security identifier for selected member
*
* Compute a SID to use for relabeling an object of class @tclass
* based on a SID pair (@ssid, @tsid).
* Return -%EINVAL if any of the parameters are invalid, -%ENOMEM
* if insufficient memory is available, or %0 if the SID was
* computed successfully.
*/
int security_change_sid(u32 ssid,
u32 tsid,
u16 tclass,
u32 *out_sid)
{
return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid);
}
/*
* Verify that each permission that is defined under the
* existing policy is still defined with the same value
* in the new policy.
*/
static int validate_perm(void *key, void *datum, void *p)
{
struct hashtab *h;
struct perm_datum *perdatum, *perdatum2;
int rc = 0;
h = p;
perdatum = datum;
perdatum2 = hashtab_search(h, key);
if (!perdatum2) {
printk(KERN_ERR "security: permission %s disappeared",
(char *)key);
rc = -ENOENT;
goto out;
}
if (perdatum->value != perdatum2->value) {
printk(KERN_ERR "security: the value of permission %s changed",
(char *)key);
rc = -EINVAL;
}
out:
return rc;
}
/*
* Verify that each class that is defined under the
* existing policy is still defined with the same
* attributes in the new policy.
*/
static int validate_class(void *key, void *datum, void *p)
{
struct policydb *newp;
struct class_datum *cladatum, *cladatum2;
int rc;
newp = p;
cladatum = datum;
cladatum2 = hashtab_search(newp->p_classes.table, key);
if (!cladatum2) {
printk(KERN_ERR "security: class %s disappeared\n",
(char *)key);
rc = -ENOENT;
goto out;
}
if (cladatum->value != cladatum2->value) {
printk(KERN_ERR "security: the value of class %s changed\n",
(char *)key);
rc = -EINVAL;
goto out;
}
if ((cladatum->comdatum && !cladatum2->comdatum) ||
(!cladatum->comdatum && cladatum2->comdatum)) {
printk(KERN_ERR "security: the inherits clause for the access "
"vector definition for class %s changed\n", (char *)key);
rc = -EINVAL;
goto out;
}
if (cladatum->comdatum) {
rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm,
cladatum2->comdatum->permissions.table);
if (rc) {
printk(" in the access vector definition for class "
"%s\n", (char *)key);
goto out;
}
}
rc = hashtab_map(cladatum->permissions.table, validate_perm,
cladatum2->permissions.table);
if (rc)
printk(" in access vector definition for class %s\n",
(char *)key);
out:
return rc;
}
/* Clone the SID into the new SID table. */
static int clone_sid(u32 sid,
struct context *context,
void *arg)
{
struct sidtab *s = arg;
return sidtab_insert(s, sid, context);
}
static inline int convert_context_handle_invalid_context(struct context *context)
{
int rc = 0;
if (selinux_enforcing) {
rc = -EINVAL;
} else {
char *s;
u32 len;
context_struct_to_string(context, &s, &len);
printk(KERN_ERR "security: context %s is invalid\n", s);
kfree(s);
}
return rc;
}
struct convert_context_args {
struct policydb *oldp;
struct policydb *newp;
};
/*
* Convert the values in the security context
* structure `c' from the values specified
* in the policy `p->oldp' to the values specified
* in the policy `p->newp'. Verify that the
* context is valid under the new policy.
*/
static int convert_context(u32 key,
struct context *c,
void *p)
{
struct convert_context_args *args;
struct context oldc;
struct role_datum *role;
struct type_datum *typdatum;
struct user_datum *usrdatum;
char *s;
u32 len;
int rc;
args = p;
rc = context_cpy(&oldc, c);
if (rc)
goto out;
rc = -EINVAL;
/* Convert the user. */
usrdatum = hashtab_search(args->newp->p_users.table,
args->oldp->p_user_val_to_name[c->user - 1]);
if (!usrdatum) {
goto bad;
}
c->user = usrdatum->value;
/* Convert the role. */
role = hashtab_search(args->newp->p_roles.table,
args->oldp->p_role_val_to_name[c->role - 1]);
if (!role) {
goto bad;
}
c->role = role->value;
/* Convert the type. */
typdatum = hashtab_search(args->newp->p_types.table,
args->oldp->p_type_val_to_name[c->type - 1]);
if (!typdatum) {
goto bad;
}
c->type = typdatum->value;
rc = mls_convert_context(args->oldp, args->newp, c);
if (rc)
goto bad;
/* Check the validity of the new context. */
if (!policydb_context_isvalid(args->newp, c)) {
rc = convert_context_handle_invalid_context(&oldc);
if (rc)
goto bad;
}
context_destroy(&oldc);
out:
return rc;
bad:
context_struct_to_string(&oldc, &s, &len);
context_destroy(&oldc);
printk(KERN_ERR "security: invalidating context %s\n", s);
kfree(s);
goto out;
}
extern void selinux_complete_init(void);
/**
* security_load_policy - Load a security policy configuration.
* @data: binary policy data
* @len: length of data in bytes
*
* Load a new set of security policy configuration data,
* validate it and convert the SID table as necessary.
* This function will flush the access vector cache after
* loading the new policy.
*/
int security_load_policy(void *data, size_t len)
{
struct policydb oldpolicydb, newpolicydb;
struct sidtab oldsidtab, newsidtab;
struct convert_context_args args;
u32 seqno;
int rc = 0;
struct policy_file file = { data, len }, *fp = &file;
LOAD_LOCK;
if (!ss_initialized) {
avtab_cache_init();
if (policydb_read(&policydb, fp)) {
LOAD_UNLOCK;
avtab_cache_destroy();
return -EINVAL;
}
if (policydb_load_isids(&policydb, &sidtab)) {
LOAD_UNLOCK;
policydb_destroy(&policydb);
avtab_cache_destroy();
return -EINVAL;
}
policydb_loaded_version = policydb.policyvers;
ss_initialized = 1;
seqno = ++latest_granting;
LOAD_UNLOCK;
selinux_complete_init();
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
return 0;
}
#if 0
sidtab_hash_eval(&sidtab, "sids");
#endif
if (policydb_read(&newpolicydb, fp)) {
LOAD_UNLOCK;
return -EINVAL;
}
sidtab_init(&newsidtab);
/* Verify that the existing classes did not change. */
if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) {
printk(KERN_ERR "security: the definition of an existing "
"class changed\n");
rc = -EINVAL;
goto err;
}
/* Clone the SID table. */
sidtab_shutdown(&sidtab);
if (sidtab_map(&sidtab, clone_sid, &newsidtab)) {
rc = -ENOMEM;
goto err;
}
/* Convert the internal representations of contexts
in the new SID table and remove invalid SIDs. */
args.oldp = &policydb;
args.newp = &newpolicydb;
sidtab_map_remove_on_error(&newsidtab, convert_context, &args);
/* Save the old policydb and SID table to free later. */
memcpy(&oldpolicydb, &policydb, sizeof policydb);
sidtab_set(&oldsidtab, &sidtab);
/* Install the new policydb and SID table. */
POLICY_WRLOCK;
memcpy(&policydb, &newpolicydb, sizeof policydb);
sidtab_set(&sidtab, &newsidtab);
seqno = ++latest_granting;
policydb_loaded_version = policydb.policyvers;
POLICY_WRUNLOCK;
LOAD_UNLOCK;
/* Free the old policydb and SID table. */
policydb_destroy(&oldpolicydb);
sidtab_destroy(&oldsidtab);
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
return 0;
err:
LOAD_UNLOCK;
sidtab_destroy(&newsidtab);
policydb_destroy(&newpolicydb);
return rc;
}
/**
* security_port_sid - Obtain the SID for a port.
* @domain: communication domain aka address family
* @type: socket type
* @protocol: protocol number
* @port: port number
* @out_sid: security identifier
*/
int security_port_sid(u16 domain,
u16 type,
u8 protocol,
u16 port,
u32 *out_sid)
{
struct ocontext *c;
int rc = 0;
POLICY_RDLOCK;
c = policydb.ocontexts[OCON_PORT];
while (c) {
if (c->u.port.protocol == protocol &&
c->u.port.low_port <= port &&
c->u.port.high_port >= port)
break;
c = c->next;
}
if (c) {
if (!c->sid[0]) {
rc = sidtab_context_to_sid(&sidtab,
&c->context[0],
&c->sid[0]);
if (rc)
goto out;
}
*out_sid = c->sid[0];
} else {
*out_sid = SECINITSID_PORT;
}
out:
POLICY_RDUNLOCK;
return rc;
}
/**
* security_netif_sid - Obtain the SID for a network interface.
* @name: interface name
* @if_sid: interface SID
* @msg_sid: default SID for received packets
*/
int security_netif_sid(char *name,
u32 *if_sid,
u32 *msg_sid)
{
int rc = 0;
struct ocontext *c;
POLICY_RDLOCK;
c = policydb.ocontexts[OCON_NETIF];
while (c) {
if (strcmp(name, c->u.name) == 0)
break;
c = c->next;
}
if (c) {
if (!c->sid[0] || !c->sid[1]) {
rc = sidtab_context_to_sid(&sidtab,
&c->context[0],
&c->sid[0]);
if (rc)
goto out;
rc = sidtab_context_to_sid(&sidtab,
&c->context[1],
&c->sid[1]);
if (rc)
goto out;
}
*if_sid = c->sid[0];
*msg_sid = c->sid[1];
} else {
*if_sid = SECINITSID_NETIF;
*msg_sid = SECINITSID_NETMSG;
}
out:
POLICY_RDUNLOCK;
return rc;
}
static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask)
{
int i, fail = 0;
for(i = 0; i < 4; i++)
if(addr[i] != (input[i] & mask[i])) {
fail = 1;
break;
}
return !fail;
}
/**
* security_node_sid - Obtain the SID for a node (host).
* @domain: communication domain aka address family
* @addrp: address
* @addrlen: address length in bytes
* @out_sid: security identifier
*/
int security_node_sid(u16 domain,
void *addrp,
u32 addrlen,
u32 *out_sid)
{
int rc = 0;
struct ocontext *c;
POLICY_RDLOCK;
switch (domain) {
case AF_INET: {
u32 addr;
if (addrlen != sizeof(u32)) {
rc = -EINVAL;
goto out;
}
addr = *((u32 *)addrp);
c = policydb.ocontexts[OCON_NODE];
while (c) {
if (c->u.node.addr == (addr & c->u.node.mask))
break;
c = c->next;
}
break;
}
case AF_INET6:
if (addrlen != sizeof(u64) * 2) {
rc = -EINVAL;
goto out;
}
c = policydb.ocontexts[OCON_NODE6];
while (c) {
if (match_ipv6_addrmask(addrp, c->u.node6.addr,
c->u.node6.mask))
break;
c = c->next;
}
break;
default:
*out_sid = SECINITSID_NODE;
goto out;
}
if (c) {
if (!c->sid[0]) {
rc = sidtab_context_to_sid(&sidtab,
&c->context[0],
&c->sid[0]);
if (rc)
goto out;
}
*out_sid = c->sid[0];
} else {
*out_sid = SECINITSID_NODE;
}
out:
POLICY_RDUNLOCK;
return rc;
}
#define SIDS_NEL 25
/**
* security_get_user_sids - Obtain reachable SIDs for a user.
* @fromsid: starting SID
* @username: username
* @sids: array of reachable SIDs for user
* @nel: number of elements in @sids
*
* Generate the set of SIDs for legal security contexts
* for a given user that can be reached by @fromsid.
* Set *@sids to point to a dynamically allocated
* array containing the set of SIDs. Set *@nel to the
* number of elements in the array.
*/
int security_get_user_sids(u32 fromsid,
char *username,
u32 **sids,
u32 *nel)
{
struct context *fromcon, usercon;
u32 *mysids, *mysids2, sid;
u32 mynel = 0, maxnel = SIDS_NEL;
struct user_datum *user;
struct role_datum *role;
struct av_decision avd;
struct ebitmap_node *rnode, *tnode;
int rc = 0, i, j;
if (!ss_initialized) {
*sids = NULL;
*nel = 0;
goto out;
}
POLICY_RDLOCK;
fromcon = sidtab_search(&sidtab, fromsid);
if (!fromcon) {
rc = -EINVAL;
goto out_unlock;
}
user = hashtab_search(policydb.p_users.table, username);
if (!user) {
rc = -EINVAL;
goto out_unlock;
}
usercon.user = user->value;
mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC);
if (!mysids) {
rc = -ENOMEM;
goto out_unlock;
}
ebitmap_for_each_bit(&user->roles, rnode, i) {
if (!ebitmap_node_get_bit(rnode, i))
continue;
role = policydb.role_val_to_struct[i];
usercon.role = i+1;
ebitmap_for_each_bit(&role->types, tnode, j) {
if (!ebitmap_node_get_bit(tnode, j))
continue;
usercon.type = j+1;
if (mls_setup_user_range(fromcon, user, &usercon))
continue;
rc = context_struct_compute_av(fromcon, &usercon,
SECCLASS_PROCESS,
PROCESS__TRANSITION,
&avd);
if (rc || !(avd.allowed & PROCESS__TRANSITION))
continue;
rc = sidtab_context_to_sid(&sidtab, &usercon, &sid);
if (rc) {
kfree(mysids);
goto out_unlock;
}
if (mynel < maxnel) {
mysids[mynel++] = sid;
} else {
maxnel += SIDS_NEL;
mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
if (!mysids2) {
rc = -ENOMEM;
kfree(mysids);
goto out_unlock;
}
memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
kfree(mysids);
mysids = mysids2;
mysids[mynel++] = sid;
}
}
}
*sids = mysids;
*nel = mynel;
out_unlock:
POLICY_RDUNLOCK;
out:
return rc;
}
/**
* security_genfs_sid - Obtain a SID for a file in a filesystem
* @fstype: filesystem type
* @path: path from root of mount
* @sclass: file security class
* @sid: SID for path
*
* Obtain a SID to use for a file in a filesystem that
* cannot support xattr or use a fixed labeling behavior like
* transition SIDs or task SIDs.
*/
int security_genfs_sid(const char *fstype,
char *path,
u16 sclass,
u32 *sid)
{
int len;
struct genfs *genfs;
struct ocontext *c;
int rc = 0, cmp = 0;
POLICY_RDLOCK;
for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
cmp = strcmp(fstype, genfs->fstype);
if (cmp <= 0)
break;
}
if (!genfs || cmp) {
*sid = SECINITSID_UNLABELED;
rc = -ENOENT;
goto out;
}
for (c = genfs->head; c; c = c->next) {
len = strlen(c->u.name);
if ((!c->v.sclass || sclass == c->v.sclass) &&
(strncmp(c->u.name, path, len) == 0))
break;
}
if (!c) {
*sid = SECINITSID_UNLABELED;
rc = -ENOENT;
goto out;
}
if (!c->sid[0]) {
rc = sidtab_context_to_sid(&sidtab,
&c->context[0],
&c->sid[0]);
if (rc)
goto out;
}
*sid = c->sid[0];
out:
POLICY_RDUNLOCK;
return rc;
}
/**
* security_fs_use - Determine how to handle labeling for a filesystem.
* @fstype: filesystem type
* @behavior: labeling behavior
* @sid: SID for filesystem (superblock)
*/
int security_fs_use(
const char *fstype,
unsigned int *behavior,
u32 *sid)
{
int rc = 0;
struct ocontext *c;
POLICY_RDLOCK;
c = policydb.ocontexts[OCON_FSUSE];
while (c) {
if (strcmp(fstype, c->u.name) == 0)
break;
c = c->next;
}
if (c) {
*behavior = c->v.behavior;
if (!c->sid[0]) {
rc = sidtab_context_to_sid(&sidtab,
&c->context[0],
&c->sid[0]);
if (rc)
goto out;
}
*sid = c->sid[0];
} else {
rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid);
if (rc) {
*behavior = SECURITY_FS_USE_NONE;
rc = 0;
} else {
*behavior = SECURITY_FS_USE_GENFS;
}
}
out:
POLICY_RDUNLOCK;
return rc;
}
int security_get_bools(int *len, char ***names, int **values)
{
int i, rc = -ENOMEM;
POLICY_RDLOCK;
*names = NULL;
*values = NULL;
*len = policydb.p_bools.nprim;
if (!*len) {
rc = 0;
goto out;
}
*names = kcalloc(*len, sizeof(char*), GFP_ATOMIC);
if (!*names)
goto err;
*values = kcalloc(*len, sizeof(int), GFP_ATOMIC);
if (!*values)
goto err;
for (i = 0; i < *len; i++) {
size_t name_len;
(*values)[i] = policydb.bool_val_to_struct[i]->state;
name_len = strlen(policydb.p_bool_val_to_name[i]) + 1;
(*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC);
if (!(*names)[i])
goto err;
strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len);
(*names)[i][name_len - 1] = 0;
}
rc = 0;
out:
POLICY_RDUNLOCK;
return rc;
err:
if (*names) {
for (i = 0; i < *len; i++)
kfree((*names)[i]);
}
kfree(*values);
goto out;
}
int security_set_bools(int len, int *values)
{
int i, rc = 0;
int lenp, seqno = 0;
struct cond_node *cur;
POLICY_WRLOCK;
lenp = policydb.p_bools.nprim;
if (len != lenp) {
rc = -EFAULT;
goto out;
}
for (i = 0; i < len; i++) {
if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
audit_log(current->audit_context, GFP_ATOMIC,
AUDIT_MAC_CONFIG_CHANGE,
"bool=%s val=%d old_val=%d auid=%u",
policydb.p_bool_val_to_name[i],
!!values[i],
policydb.bool_val_to_struct[i]->state,
audit_get_loginuid(current->audit_context));
}
if (values[i]) {
policydb.bool_val_to_struct[i]->state = 1;
} else {
policydb.bool_val_to_struct[i]->state = 0;
}
}
for (cur = policydb.cond_list; cur != NULL; cur = cur->next) {
rc = evaluate_cond_node(&policydb, cur);
if (rc)
goto out;
}
seqno = ++latest_granting;
out:
POLICY_WRUNLOCK;
if (!rc) {
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
}
return rc;
}
int security_get_bool_value(int bool)
{
int rc = 0;
int len;
POLICY_RDLOCK;
len = policydb.p_bools.nprim;
if (bool >= len) {
rc = -EFAULT;
goto out;
}
rc = policydb.bool_val_to_struct[bool]->state;
out:
POLICY_RDUNLOCK;
return rc;
}
struct selinux_audit_rule {
u32 au_seqno;
struct context au_ctxt;
};
void selinux_audit_rule_free(struct selinux_audit_rule *rule)
{
if (rule) {
context_destroy(&rule->au_ctxt);
kfree(rule);
}
}
int selinux_audit_rule_init(u32 field, u32 op, char *rulestr,
struct selinux_audit_rule **rule)
{
struct selinux_audit_rule *tmprule;
struct role_datum *roledatum;
struct type_datum *typedatum;
struct user_datum *userdatum;
int rc = 0;
*rule = NULL;
if (!ss_initialized)
return -ENOTSUPP;
switch (field) {
case AUDIT_SE_USER:
case AUDIT_SE_ROLE:
case AUDIT_SE_TYPE:
/* only 'equals' and 'not equals' fit user, role, and type */
if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
return -EINVAL;
break;
case AUDIT_SE_SEN:
case AUDIT_SE_CLR:
/* we do not allow a range, indicated by the presense of '-' */
if (strchr(rulestr, '-'))
return -EINVAL;
break;
default:
/* only the above fields are valid */
return -EINVAL;
}
tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL);
if (!tmprule)
return -ENOMEM;
context_init(&tmprule->au_ctxt);
POLICY_RDLOCK;
tmprule->au_seqno = latest_granting;
switch (field) {
case AUDIT_SE_USER:
userdatum = hashtab_search(policydb.p_users.table, rulestr);
if (!userdatum)
rc = -EINVAL;
else
tmprule->au_ctxt.user = userdatum->value;
break;
case AUDIT_SE_ROLE:
roledatum = hashtab_search(policydb.p_roles.table, rulestr);
if (!roledatum)
rc = -EINVAL;
else
tmprule->au_ctxt.role = roledatum->value;
break;
case AUDIT_SE_TYPE:
typedatum = hashtab_search(policydb.p_types.table, rulestr);
if (!typedatum)
rc = -EINVAL;
else
tmprule->au_ctxt.type = typedatum->value;
break;
case AUDIT_SE_SEN:
case AUDIT_SE_CLR:
rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC);
break;
}
POLICY_RDUNLOCK;
if (rc) {
selinux_audit_rule_free(tmprule);
tmprule = NULL;
}
*rule = tmprule;
return rc;
}
int selinux_audit_rule_match(u32 ctxid, u32 field, u32 op,
struct selinux_audit_rule *rule,
struct audit_context *actx)
{
struct context *ctxt;
struct mls_level *level;
int match = 0;
if (!rule) {
audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"selinux_audit_rule_match: missing rule\n");
return -ENOENT;
}
POLICY_RDLOCK;
if (rule->au_seqno < latest_granting) {
audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"selinux_audit_rule_match: stale rule\n");
match = -ESTALE;
goto out;
}
ctxt = sidtab_search(&sidtab, ctxid);
if (!ctxt) {
audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
"selinux_audit_rule_match: unrecognized SID %d\n",
ctxid);
match = -ENOENT;
goto out;
}
/* a field/op pair that is not caught here will simply fall through
without a match */
switch (field) {
case AUDIT_SE_USER:
switch (op) {
case AUDIT_EQUAL:
match = (ctxt->user == rule->au_ctxt.user);
break;
case AUDIT_NOT_EQUAL:
match = (ctxt->user != rule->au_ctxt.user);
break;
}
break;
case AUDIT_SE_ROLE:
switch (op) {
case AUDIT_EQUAL:
match = (ctxt->role == rule->au_ctxt.role);
break;
case AUDIT_NOT_EQUAL:
match = (ctxt->role != rule->au_ctxt.role);
break;
}
break;
case AUDIT_SE_TYPE:
switch (op) {
case AUDIT_EQUAL:
match = (ctxt->type == rule->au_ctxt.type);
break;
case AUDIT_NOT_EQUAL:
match = (ctxt->type != rule->au_ctxt.type);
break;
}
break;
case AUDIT_SE_SEN:
case AUDIT_SE_CLR:
level = (op == AUDIT_SE_SEN ?
&ctxt->range.level[0] : &ctxt->range.level[1]);
switch (op) {
case AUDIT_EQUAL:
match = mls_level_eq(&rule->au_ctxt.range.level[0],
level);
break;
case AUDIT_NOT_EQUAL:
match = !mls_level_eq(&rule->au_ctxt.range.level[0],
level);
break;
case AUDIT_LESS_THAN:
match = (mls_level_dom(&rule->au_ctxt.range.level[0],
level) &&
!mls_level_eq(&rule->au_ctxt.range.level[0],
level));
break;
case AUDIT_LESS_THAN_OR_EQUAL:
match = mls_level_dom(&rule->au_ctxt.range.level[0],
level);
break;
case AUDIT_GREATER_THAN:
match = (mls_level_dom(level,
&rule->au_ctxt.range.level[0]) &&
!mls_level_eq(level,
&rule->au_ctxt.range.level[0]));
break;
case AUDIT_GREATER_THAN_OR_EQUAL:
match = mls_level_dom(level,
&rule->au_ctxt.range.level[0]);
break;
}
}
out:
POLICY_RDUNLOCK;
return match;
}
static int (*aurule_callback)(void) = NULL;
static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid,
u16 class, u32 perms, u32 *retained)
{
int err = 0;
if (event == AVC_CALLBACK_RESET && aurule_callback)
err = aurule_callback();
return err;
}
static int __init aurule_init(void)
{
int err;
err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET,
SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0);
if (err)
panic("avc_add_callback() failed, error %d\n", err);
return err;
}
__initcall(aurule_init);
void selinux_audit_set_callback(int (*callback)(void))
{
aurule_callback = callback;
}
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