/*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.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.
*
* Author:
* Casey Schaufler <casey@schaufler-ca.com>
*
*/
#ifndef _SECURITY_SMACK_H
#define _SECURITY_SMACK_H
#include <linux/capability.h>
#include <linux/spinlock.h>
#include <linux/lsm_hooks.h>
#include <linux/in.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/in6.h>
#endif /* CONFIG_IPV6 */
#include <net/netlabel.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/lsm_audit.h>
/*
* Use IPv6 port labeling if IPv6 is enabled and secmarks
* are not being used.
*/
#if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
#define SMACK_IPV6_PORT_LABELING 1
#endif
#if IS_ENABLED(CONFIG_IPV6) && defined(CONFIG_SECURITY_SMACK_NETFILTER)
#define SMACK_IPV6_SECMARK_LABELING 1
#endif
/*
* Smack labels were limited to 23 characters for a long time.
*/
#define SMK_LABELLEN 24
#define SMK_LONGLABEL 256
/*
* This is the repository for labels seen so that it is
* not necessary to keep allocating tiny chuncks of memory
* and so that they can be shared.
*
* Labels are never modified in place. Anytime a label
* is imported (e.g. xattrset on a file) the list is checked
* for it and it is added if it doesn't exist. The address
* is passed out in either case. Entries are added, but
* never deleted.
*
* Since labels are hanging around anyway it doesn't
* hurt to maintain a secid for those awkward situations
* where kernel components that ought to use LSM independent
* interfaces don't. The secid should go away when all of
* these components have been repaired.
*
* The cipso value associated with the label gets stored here, too.
*
* Keep the access rules for this subject label here so that
* the entire set of rules does not need to be examined every
* time.
*/
struct smack_known {
struct list_head list;
struct hlist_node smk_hashed;
char *smk_known;
u32 smk_secid;
struct netlbl_lsm_secattr smk_netlabel; /* on wire labels */
struct list_head smk_rules; /* access rules */
struct mutex smk_rules_lock; /* lock for rules */
};
/*
* Maximum number of bytes for the levels in a CIPSO IP option.
* Why 23? CIPSO is constrained to 30, so a 32 byte buffer is
* bigger than can be used, and 24 is the next lower multiple
* of 8, and there are too many issues if there isn't space set
* aside for the terminating null byte.
*/
#define SMK_CIPSOLEN 24
struct superblock_smack {
struct smack_known *smk_root;
struct smack_known *smk_floor;
struct smack_known *smk_hat;
struct smack_known *smk_default;
int smk_flags;
};
/*
* Superblock flags
*/
#define SMK_SB_INITIALIZED 0x01
#define SMK_SB_UNTRUSTED 0x02
struct socket_smack {
struct smack_known *smk_out; /* outbound label */
struct smack_known *smk_in; /* inbound label */
struct smack_known *smk_packet; /* TCP peer label */
};
/*
* Inode smack data
*/
struct inode_smack {
struct smack_known *smk_inode; /* label of the fso */
struct smack_known *smk_task; /* label of the task */
struct smack_known *smk_mmap; /* label of the mmap domain */
struct mutex smk_lock; /* initialization lock */
int smk_flags; /* smack inode flags */
struct rcu_head smk_rcu; /* for freeing inode_smack */
};
struct task_smack {
struct smack_known *smk_task; /* label for access control */
struct smack_known *smk_forked; /* label when forked */
struct list_head smk_rules; /* per task access rules */
struct mutex smk_rules_lock; /* lock for the rules */
struct list_head smk_relabel; /* transit allowed labels */
};
#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */
#define SMK_INODE_TRANSMUTE 0x02 /* directory is transmuting */
#define SMK_INODE_CHANGED 0x04 /* smack was transmuted */
#define SMK_INODE_IMPURE 0x08 /* involved in an impure transaction */
/*
* A label access rule.
*/
struct smack_rule {
struct list_head list;
struct smack_known *smk_subject;
struct smack_known *smk_object;
int smk_access;
};
/*
* An entry in the table identifying IPv4 hosts.
*/
struct smk_net4addr {
struct list_head list;
struct in_addr smk_host; /* network address */
struct in_addr smk_mask; /* network mask */
int smk_masks; /* mask size */
struct smack_known *smk_label; /* label */
};
#if IS_ENABLED(CONFIG_IPV6)
/*
* An entry in the table identifying IPv6 hosts.
*/
struct smk_net6addr {
struct list_head list;
struct in6_addr smk_host; /* network address */
struct in6_addr smk_mask; /* network mask */
int smk_masks; /* mask size */
struct smack_known *smk_label; /* label */
};
#endif /* CONFIG_IPV6 */
#ifdef SMACK_IPV6_PORT_LABELING
/*
* An entry in the table identifying ports.
*/
struct smk_port_label {
struct list_head list;
struct sock *smk_sock; /* socket initialized on */
unsigned short smk_port; /* the port number */
struct smack_known *smk_in; /* inbound label */
struct smack_known *smk_out; /* outgoing label */
short smk_sock_type; /* Socket type */
short smk_can_reuse;
};
#endif /* SMACK_IPV6_PORT_LABELING */
struct smack_known_list_elem {
struct list_head list;
struct smack_known *smk_label;
};
/* Super block security struct flags for mount options */
#define FSDEFAULT_MNT 0x01
#define FSFLOOR_MNT 0x02
#define FSHAT_MNT 0x04
#define FSROOT_MNT 0x08
#define FSTRANS_MNT 0x10
#define NUM_SMK_MNT_OPTS 5
enum {
Opt_error = -1,
Opt_fsdefault = 1,
Opt_fsfloor = 2,
Opt_fshat = 3,
Opt_fsroot = 4,
Opt_fstransmute = 5,
};
/*
* Mount options
*/
#define SMK_FSDEFAULT "smackfsdef="
#define SMK_FSFLOOR "smackfsfloor="
#define SMK_FSHAT "smackfshat="
#define SMK_FSROOT "smackfsroot="
#define SMK_FSTRANS "smackfstransmute="
#define SMACK_DELETE_OPTION "-DELETE"
#define SMACK_CIPSO_OPTION "-CIPSO"
/*
* How communications on this socket are treated.
* Usually it's determined by the underlying netlabel code
* but there are certain cases, including single label hosts
* and potentially single label interfaces for which the
* treatment can not be known in advance.
*
* The possibility of additional labeling schemes being
* introduced in the future exists as well.
*/
#define SMACK_UNLABELED_SOCKET 0
#define SMACK_CIPSO_SOCKET 1
/*
* CIPSO defaults.
*/
#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */
#define SMACK_CIPSO_DOI_INVALID -1 /* Not a DOI */
#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */
#define SMACK_CIPSO_MAPPED_DEFAULT 251 /* Also arbitrary */
#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */
/*
* CIPSO 2.2 standard is 239, but Smack wants to use the
* categories in a structured way that limits the value to
* the bits in 23 bytes, hence the unusual number.
*/
#define SMACK_CIPSO_MAXCATNUM 184 /* 23 * 8 */
/*
* Ptrace rules
*/
#define SMACK_PTRACE_DEFAULT 0
#define SMACK_PTRACE_EXACT 1
#define SMACK_PTRACE_DRACONIAN 2
#define SMACK_PTRACE_MAX SMACK_PTRACE_DRACONIAN
/*
* Flags for untraditional access modes.
* It shouldn't be necessary to avoid conflicts with definitions
* in fs.h, but do so anyway.
*/
#define MAY_TRANSMUTE 0x00001000 /* Controls directory labeling */
#define MAY_LOCK 0x00002000 /* Locks should be writes, but ... */
#define MAY_BRINGUP 0x00004000 /* Report use of this rule */
/*
* The policy for delivering signals is configurable.
* It is usually "write", but can be "append".
*/
#ifdef CONFIG_SECURITY_SMACK_APPEND_SIGNALS
#define MAY_DELIVER MAY_APPEND /* Signal delivery requires append */
#else
#define MAY_DELIVER MAY_WRITE /* Signal delivery requires write */
#endif
#define SMACK_BRINGUP_ALLOW 1 /* Allow bringup mode */
#define SMACK_UNCONFINED_SUBJECT 2 /* Allow unconfined label */
#define SMACK_UNCONFINED_OBJECT 3 /* Allow unconfined label */
/*
* Just to make the common cases easier to deal with
*/
#define MAY_ANYREAD (MAY_READ | MAY_EXEC)
#define MAY_READWRITE (MAY_READ | MAY_WRITE)
#define MAY_NOT 0
/*
* Number of access types used by Smack (rwxatlb)
*/
#define SMK_NUM_ACCESS_TYPE 7
/* SMACK data */
struct smack_audit_data {
const char *function;
char *subject;
char *object;
char *request;
int result;
};
/*
* Smack audit data; is empty if CONFIG_AUDIT not set
* to save some stack
*/
struct smk_audit_info {
#ifdef CONFIG_AUDIT
struct common_audit_data a;
struct smack_audit_data sad;
#endif
};
/*
* These functions are in smack_access.c
*/
int smk_access_entry(char *, char *, struct list_head *);
int smk_access(struct smack_known *, struct smack_known *,
int, struct smk_audit_info *);
int smk_tskacc(struct task_smack *, struct smack_known *,
u32, struct smk_audit_info *);
int smk_curacc(struct smack_known *, u32, struct smk_audit_info *);
struct smack_known *smack_from_secid(const u32);
char *smk_parse_smack(const char *string, int len);
int smk_netlbl_mls(int, char *, struct netlbl_lsm_secattr *, int);
struct smack_known *smk_import_entry(const char *, int);
void smk_insert_entry(struct smack_known *skp);
struct smack_known *smk_find_entry(const char *);
bool smack_privileged(int cap);
void smk_destroy_label_list(struct list_head *list);
/*
* Shared data.
*/
extern int smack_enabled;
extern int smack_cipso_direct;
extern int smack_cipso_mapped;
extern struct smack_known *smack_net_ambient;
extern struct smack_known *smack_syslog_label;
#ifdef CONFIG_SECURITY_SMACK_BRINGUP
extern struct smack_known *smack_unconfined;
#endif
extern int smack_ptrace_rule;
extern struct smack_known smack_known_floor;
extern struct smack_known smack_known_hat;
extern struct smack_known smack_known_huh;
extern struct smack_known smack_known_star;
extern struct smack_known smack_known_web;
extern struct mutex smack_known_lock;
extern struct list_head smack_known_list;
extern struct list_head smk_net4addr_list;
#if IS_ENABLED(CONFIG_IPV6)
extern struct list_head smk_net6addr_list;
#endif /* CONFIG_IPV6 */
extern struct mutex smack_onlycap_lock;
extern struct list_head smack_onlycap_list;
#define SMACK_HASH_SLOTS 16
extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS];
/*
* Is the directory transmuting?
*/
static inline int smk_inode_transmutable(const struct inode *isp)
{
struct inode_smack *sip = isp->i_security;
return (sip->smk_flags & SMK_INODE_TRANSMUTE) != 0;
}
/*
* Present a pointer to the smack label entry in an inode blob.
*/
static inline struct smack_known *smk_of_inode(const struct inode *isp)
{
struct inode_smack *sip = isp->i_security;
return sip->smk_inode;
}
/*
* Present a pointer to the smack label entry in an task blob.
*/
static inline struct smack_known *smk_of_task(const struct task_smack *tsp)
{
return tsp->smk_task;
}
static inline struct smack_known *smk_of_task_struct(const struct task_struct *t)
{
struct smack_known *skp;
rcu_read_lock();
skp = smk_of_task(__task_cred(t)->security);
rcu_read_unlock();
return skp;
}
/*
* Present a pointer to the forked smack label entry in an task blob.
*/
static inline struct smack_known *smk_of_forked(const struct task_smack *tsp)
{
return tsp->smk_forked;
}
/*
* Present a pointer to the smack label in the current task blob.
*/
static inline struct smack_known *smk_of_current(void)
{
return smk_of_task(current_security());
}
/*
* logging functions
*/
#define SMACK_AUDIT_DENIED 0x1
#define SMACK_AUDIT_ACCEPT 0x2
extern int log_policy;
void smack_log(char *subject_label, char *object_label,
int request,
int result, struct smk_audit_info *auditdata);
#ifdef CONFIG_AUDIT
/*
* some inline functions to set up audit data
* they do nothing if CONFIG_AUDIT is not set
*
*/
static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
char type)
{
memset(&a->sad, 0, sizeof(a->sad));
a->a.type = type;
a->a.smack_audit_data = &a->sad;
a->a.smack_audit_data->function = func;
}
static inline void smk_ad_init_net(struct smk_audit_info *a, const char *func,
char type, struct lsm_network_audit *net)
{
smk_ad_init(a, func, type);
memset(net, 0, sizeof(*net));
a->a.u.net = net;
}
static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
struct task_struct *t)
{
a->a.u.tsk = t;
}
static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
struct dentry *d)
{
a->a.u.dentry = d;
}
static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
struct inode *i)
{
a->a.u.inode = i;
}
static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
struct path p)
{
a->a.u.path = p;
}
static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
struct sock *sk)
{
a->a.u.net->sk = sk;
}
#else /* no AUDIT */
static inline void smk_ad_init(struct smk_audit_info *a, const char *func,
char type)
{
}
static inline void smk_ad_setfield_u_tsk(struct smk_audit_info *a,
struct task_struct *t)
{
}
static inline void smk_ad_setfield_u_fs_path_dentry(struct smk_audit_info *a,
struct dentry *d)
{
}
static inline void smk_ad_setfield_u_fs_path_mnt(struct smk_audit_info *a,
struct vfsmount *m)
{
}
static inline void smk_ad_setfield_u_fs_inode(struct smk_audit_info *a,
struct inode *i)
{
}
static inline void smk_ad_setfield_u_fs_path(struct smk_audit_info *a,
struct path p)
{
}
static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
struct sock *sk)
{
}
#endif
#endif /* _SECURITY_SMACK_H */
