acrn-kernel/security/selinux/ss/conditional.h

86 lines
2.4 KiB
C
Raw Normal View History

/* SPDX-License-Identifier: GPL-2.0-only */
/* Authors: Karl MacMillan <kmacmillan@tresys.com>
* Frank Mayer <mayerf@tresys.com>
*
* Copyright (C) 2003 - 2004 Tresys Technology, LLC
*/
#ifndef _CONDITIONAL_H_
#define _CONDITIONAL_H_
#include "avtab.h"
#include "symtab.h"
#include "policydb.h"
#include "../include/conditional.h"
#define COND_EXPR_MAXDEPTH 10
/*
* A conditional expression is a list of operators and operands
* in reverse polish notation.
*/
struct cond_expr_node {
#define COND_BOOL 1 /* plain bool */
#define COND_NOT 2 /* !bool */
#define COND_OR 3 /* bool || bool */
#define COND_AND 4 /* bool && bool */
#define COND_XOR 5 /* bool ^ bool */
#define COND_EQ 6 /* bool == bool */
#define COND_NEQ 7 /* bool != bool */
#define COND_LAST COND_NEQ
u32 expr_type;
u32 bool;
};
struct cond_expr {
struct cond_expr_node *nodes;
u32 len;
};
/*
* Each cond_node contains a list of rules to be enabled/disabled
* depending on the current value of the conditional expression. This
* struct is for that list.
*/
struct cond_av_list {
struct avtab_node **nodes;
u32 len;
};
/*
* A cond node represents a conditional block in a policy. It
* contains a conditional expression, the current state of the expression,
* two lists of rules to enable/disable depending on the value of the
* expression (the true list corresponds to if and the false list corresponds
* to else)..
*/
struct cond_node {
int cur_state;
struct cond_expr expr;
struct cond_av_list true_list;
struct cond_av_list false_list;
};
void cond_policydb_init(struct policydb *p);
void cond_policydb_destroy(struct policydb *p);
int cond_init_bool_indexes(struct policydb *p);
int cond_destroy_bool(void *key, void *datum, void *p);
int cond_index_bool(void *key, void *datum, void *datap);
int cond_read_bool(struct policydb *p, struct symtab *s, void *fp);
int cond_read_list(struct policydb *p, void *fp);
int cond_write_bool(void *key, void *datum, void *ptr);
int cond_write_list(struct policydb *p, void *fp);
selinux: extended permissions for ioctls Add extended permissions logic to selinux. Extended permissions provides additional permissions in 256 bit increments. Extend the generic ioctl permission check to use the extended permissions for per-command filtering. Source/target/class sets including the ioctl permission may additionally include a set of commands. Example: allowxperm <source> <target>:<class> ioctl unpriv_app_socket_cmds auditallowxperm <source> <target>:<class> ioctl priv_gpu_cmds Where unpriv_app_socket_cmds and priv_gpu_cmds are macros representing commonly granted sets of ioctl commands. When ioctl commands are omitted only the permissions are checked. This feature is intended to provide finer granularity for the ioctl permission that may be too imprecise. For example, the same driver may use ioctls to provide important and benign functionality such as driver version or socket type as well as dangerous capabilities such as debugging features, read/write/execute to physical memory or access to sensitive data. Per-command filtering provides a mechanism to reduce the attack surface of the kernel, and limit applications to the subset of commands required. The format of the policy binary has been modified to include ioctl commands, and the policy version number has been incremented to POLICYDB_VERSION_XPERMS_IOCTL=30 to account for the format change. The extended permissions logic is deliberately generic to allow components to be reused e.g. netlink filters Signed-off-by: Jeff Vander Stoep <jeffv@google.com> Acked-by: Nick Kralevich <nnk@google.com> Signed-off-by: Paul Moore <pmoore@redhat.com>
2015-07-11 05:19:56 +08:00
void cond_compute_av(struct avtab *ctab, struct avtab_key *key,
struct av_decision *avd, struct extended_perms *xperms);
void cond_compute_xperms(struct avtab *ctab, struct avtab_key *key,
struct extended_perms_decision *xpermd);
void evaluate_cond_nodes(struct policydb *p);
selinux: refactor changing booleans Refactor the logic for changing SELinux policy booleans in a similar manner to the refactoring of policy load, thereby reducing the size of the critical section when the policy write-lock is held and making it easier to convert the policy rwlock to RCU in the future. Instead of directly modifying the policydb in place, modify a copy and then swap it into place through a single pointer update. Only fully copy the portions of the policydb that are affected by boolean changes to avoid the full cost of a deep policydb copy. Introduce another level of indirection for the sidtab since changing booleans does not require updating the sidtab, unlike policy load. While we are here, create a common helper for notifying other kernel components and userspace of a policy change and call it from both security_set_bools() and selinux_policy_commit(). Based on an old (2004) patch by Kaigai Kohei [1] to convert the policy rwlock to RCU that was deferred at the time since it did not significantly improve performance and introduced complexity. Peter Enderborg later submitted a patch series to convert to RCU [2] that would have made changing booleans a much more expensive operation by requiring a full policydb_write();policydb_read(); sequence to deep copy the entire policydb and also had concerns regarding atomic allocations. This change is now simplified by the earlier work to encapsulate policy state in the selinux_policy struct and to refactor policy load. After this change, the last major obstacle to converting the policy rwlock to RCU is likely the sidtab live convert support. [1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/ [2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-12 03:01:56 +08:00
void cond_policydb_destroy_dup(struct policydb *p);
int cond_policydb_dup(struct policydb *new, struct policydb *orig);
#endif /* _CONDITIONAL_H_ */