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Diffstat (limited to 'security/smack/smack.h')
| -rw-r--r-- | security/smack/smack.h | 508 |
1 files changed, 508 insertions, 0 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h new file mode 100644 index 000000000..b5187915e --- /dev/null +++ b/security/smack/smack.h @@ -0,0 +1,508 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * 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> +#include <linux/msg.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 */ + int smk_state; /* netlabel socket states */ +}; +#define SMK_NETLBL_UNSET 0 +#define SMK_NETLBL_UNLABELED 1 +#define SMK_NETLBL_LABELED 2 +#define SMK_NETLBL_REQSKB 3 + +/* + * 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 */ + int smk_flags; /* smack inode flags */ +}; + +struct task_smack { + struct smack_known *smk_task; /* label for access control */ + struct smack_known *smk_forked; /* label when forked */ + struct smack_known *smk_transmuted;/* label when transmuted */ + 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 */ +}; + +/* + * 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 */ +}; + +/* + * 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; +}; + +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 = 0, + Opt_fsfloor = 1, + Opt_fshat = 2, + Opt_fsroot = 3, + Opt_fstransmute = 4, +}; + +#define SMACK_DELETE_OPTION "-DELETE" +#define SMACK_CIPSO_OPTION "-CIPSO" + +/* + * 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); +bool smack_privileged_cred(int cap, const struct cred *cred); +void smk_destroy_label_list(struct list_head *list); +int smack_populate_secattr(struct smack_known *skp); + +/* + * 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 lsm_blob_sizes smack_blob_sizes; + +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; +extern struct list_head smk_net6addr_list; + +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]; +extern struct kmem_cache *smack_rule_cache; + +static inline struct task_smack *smack_cred(const struct cred *cred) +{ + return cred->security + smack_blob_sizes.lbs_cred; +} + +static inline struct smack_known **smack_file(const struct file *file) +{ + return (struct smack_known **)(file->f_security + + smack_blob_sizes.lbs_file); +} + +static inline struct inode_smack *smack_inode(const struct inode *inode) +{ + return inode->i_security + smack_blob_sizes.lbs_inode; +} + +static inline struct smack_known **smack_msg_msg(const struct msg_msg *msg) +{ + return msg->security + smack_blob_sizes.lbs_msg_msg; +} + +static inline struct smack_known **smack_ipc(const struct kern_ipc_perm *ipc) +{ + return ipc->security + smack_blob_sizes.lbs_ipc; +} + +/* + * Is the directory transmuting? + */ +static inline int smk_inode_transmutable(const struct inode *isp) +{ + struct inode_smack *sip = smack_inode(isp); + 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 = smack_inode(isp); + 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; + const struct cred *cred; + + rcu_read_lock(); + + cred = __task_cred(t); + skp = smk_of_task(smack_cred(cred)); + + 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(smack_cred(current_cred())); +} + +/* + * 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_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 */ |