/* SPDX-License-Identifier: GPL-2.0-or-later */
/* audit -- definition of audit_context structure and supporting types
 *
 * Copyright 2003-2004 Red Hat, Inc.
 * Copyright 2005 Hewlett-Packard Development Company, L.P.
 * Copyright 2005 IBM Corporation
 */

#ifndef _KERNEL_AUDIT_H_
#define _KERNEL_AUDIT_H_

#include <linux/fs.h>
#include <linux/audit.h>
#include <linux/security.h>
#include <linux/skbuff.h>
#include <uapi/linux/mqueue.h>
#include <linux/tty.h>
#include <uapi/linux/openat2.h> // struct open_how

/* AUDIT_NAMES is the number of slots we reserve in the audit_context
 * for saving names from getname().  If we get more names we will allocate
 * a name dynamically and also add those to the list anchored by names_list. */
#define AUDIT_NAMES     5

/* At task start time, the audit_state is set in the audit_context using
   a per-task filter.  At syscall entry, the audit_state is augmented by
   the syscall filter. */
enum audit_state {
        AUDIT_STATE_DISABLED,   /* Do not create per-task audit_context.
                                 * No syscall-specific audit records can
                                 * be generated. */
        AUDIT_STATE_BUILD,      /* Create the per-task audit_context,
                                 * and fill it in at syscall
                                 * entry time.  This makes a full
                                 * syscall record available if some
                                 * other part of the kernel decides it
                                 * should be recorded. */
        AUDIT_STATE_RECORD      /* Create the per-task audit_context,
                                 * always fill it in at syscall entry
                                 * time, and always write out the audit
                                 * record at syscall exit time.  */
};

/* Rule lists */
struct audit_watch;
struct audit_fsnotify_mark;
struct audit_tree;
struct audit_chunk;

struct audit_entry {
        struct list_head        list;
        struct rcu_head         rcu;
        struct audit_krule      rule;
};

struct audit_cap_data {
        kernel_cap_t            permitted;
        kernel_cap_t            inheritable;
        union {
                unsigned int    fE;             /* effective bit of file cap */
                kernel_cap_t    effective;      /* effective set of process */
        };
        kernel_cap_t            ambient;
        kuid_t                  rootid;
};

/* When fs/namei.c:getname() is called, we store the pointer in name and bump
 * the refcnt in the associated filename struct.
 *
 * Further, in fs/namei.c:path_lookup() we store the inode and device.
 */
struct audit_names {
        struct list_head        list;           /* audit_context->names_list */

        struct filename         *name;
        int                     name_len;       /* number of chars to log */
        bool                    hidden;         /* don't log this record */

        unsigned long           ino;
        dev_t                   dev;
        umode_t                 mode;
        kuid_t                  uid;
        kgid_t                  gid;
        dev_t                   rdev;
        struct lsm_prop         oprop;
        struct audit_cap_data   fcap;
        unsigned int            fcap_ver;
        unsigned char           type;           /* record type */
        /*
         * This was an allocated audit_names and not from the array of
         * names allocated in the task audit context.  Thus this name
         * should be freed on syscall exit.
         */
        bool                    should_free;
};

struct audit_proctitle {
        int     len;    /* length of the cmdline field. */
        char    *value; /* the cmdline field */
};

/* A timestamp/serial pair to identify an event */
struct audit_stamp {
        struct timespec64       ctime;  /* time of syscall entry */
        unsigned int            serial; /* serial number for record */
};

/* The per-task audit context. */
struct audit_context {
        int                 dummy;      /* must be the first element */
        enum {
                AUDIT_CTX_UNUSED,       /* audit_context is currently unused */
                AUDIT_CTX_SYSCALL,      /* in use by syscall */
                AUDIT_CTX_URING,        /* in use by io_uring */
        } context;
        enum audit_state    state, current_state;
        struct audit_stamp  stamp;      /* event identifier */
        int                 major;      /* syscall number */
        int                 uring_op;   /* uring operation */
        unsigned long       argv[4];    /* syscall arguments */
        long                return_code;/* syscall return code */
        u64                 prio;
        int                 return_valid; /* return code is valid */
        /*
         * The names_list is the list of all audit_names collected during this
         * syscall.  The first AUDIT_NAMES entries in the names_list will
         * actually be from the preallocated_names array for performance
         * reasons.  Except during allocation they should never be referenced
         * through the preallocated_names array and should only be found/used
         * by running the names_list.
         */
        struct audit_names  preallocated_names[AUDIT_NAMES];
        int                 name_count; /* total records in names_list */
        struct list_head    names_list; /* struct audit_names->list anchor */
        char                *filterkey; /* key for rule that triggered record */
        struct path         pwd;
        struct audit_aux_data *aux;
        struct audit_aux_data *aux_pids;
        struct sockaddr_storage *sockaddr;
        size_t sockaddr_len;
        /* Save things to print about task_struct */
        pid_t               ppid;
        kuid_t              uid, euid, suid, fsuid;
        kgid_t              gid, egid, sgid, fsgid;
        unsigned long       personality;
        int                 arch;

        pid_t               target_pid;
        kuid_t              target_auid;
        kuid_t              target_uid;
        unsigned int        target_sessionid;
        struct lsm_prop     target_ref;
        char                target_comm[TASK_COMM_LEN];

        struct audit_tree_refs *trees, *first_trees;
        struct list_head killed_trees;
        int tree_count;

        int type;
        union {
                struct {
                        int nargs;
                        long args[6];
                } socketcall;
                struct {
                        kuid_t                  uid;
                        kgid_t                  gid;
                        umode_t                 mode;
                        struct lsm_prop         oprop;
                        int                     has_perm;
                        uid_t                   perm_uid;
                        gid_t                   perm_gid;
                        umode_t                 perm_mode;
                        unsigned long           qbytes;
                } ipc;
                struct {
                        mqd_t                   mqdes;
                        struct mq_attr          mqstat;
                } mq_getsetattr;
                struct {
                        mqd_t                   mqdes;
                        int                     sigev_signo;
                } mq_notify;
                struct {
                        mqd_t                   mqdes;
                        size_t                  msg_len;
                        unsigned int            msg_prio;
                        struct timespec64       abs_timeout;
                } mq_sendrecv;
                struct {
                        int                     oflag;
                        umode_t                 mode;
                        struct mq_attr          attr;
                } mq_open;
                struct {
                        pid_t                   pid;
                        struct audit_cap_data   cap;
                } capset;
                struct {
                        int                     fd;
                        int                     flags;
                } mmap;
                struct open_how openat2;
                struct {
                        int                     argc;
                } execve;
                struct {
                        const char              *name;
                } module;
                struct {
                        struct audit_ntp_data   ntp_data;
                        struct timespec64       tk_injoffset;
                } time;
        };
        int fds[2];
        struct audit_proctitle proctitle;
};

extern bool audit_ever_enabled;

extern void audit_log_session_info(struct audit_buffer *ab);

extern int auditd_test_task(struct task_struct *task);

#define AUDIT_INODE_BUCKETS     32
extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];

static inline int audit_hash_ino(u32 ino)
{
        return (ino & (AUDIT_INODE_BUCKETS-1));
}

/* Indicates that audit should log the full pathname. */
#define AUDIT_NAME_FULL -1

extern int audit_match_class(int class, unsigned syscall);
extern int audit_comparator(const u32 left, const u32 op, const u32 right);
extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
extern int parent_len(const char *path);
extern int audit_compare_dname_path(const struct qstr *dname, const char *path, int plen);
extern struct sk_buff *audit_make_reply(int seq, int type, int done, int multi,
                                        const void *payload, int size);
extern void                 audit_panic(const char *message);

struct audit_netlink_list {
        __u32 portid;
        struct net *net;
        struct sk_buff_head q;
};

int audit_send_list_thread(void *_dest);

extern struct mutex audit_filter_mutex;
extern int audit_del_rule(struct audit_entry *entry);
extern void audit_free_rule_rcu(struct rcu_head *head);
extern struct list_head audit_filter_list[];

extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);

extern void audit_log_d_path_exe(struct audit_buffer *ab,
                                 struct mm_struct *mm);

extern struct tty_struct *audit_get_tty(void);
extern void audit_put_tty(struct tty_struct *tty);

/* audit watch/mark/tree functions */
extern unsigned int audit_serial(void);
#ifdef CONFIG_AUDITSYSCALL
extern int auditsc_get_stamp(struct audit_context *ctx,
                             struct audit_stamp *stamp);

extern void audit_put_watch(struct audit_watch *watch);
extern void audit_get_watch(struct audit_watch *watch);
extern int audit_to_watch(struct audit_krule *krule, char *path, int len,
                          u32 op);
extern int audit_add_watch(struct audit_krule *krule, struct list_head **list);
extern void audit_remove_watch_rule(struct audit_krule *krule);
extern char *audit_watch_path(struct audit_watch *watch);
extern int audit_watch_compare(struct audit_watch *watch, unsigned long ino,
                               dev_t dev);

extern struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule,
                                                    char *pathname, int len);
extern char *audit_mark_path(struct audit_fsnotify_mark *mark);
extern void audit_remove_mark(struct audit_fsnotify_mark *audit_mark);
extern void audit_remove_mark_rule(struct audit_krule *krule);
extern int audit_mark_compare(struct audit_fsnotify_mark *mark,
                              unsigned long ino, dev_t dev);
extern int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old);
extern int audit_exe_compare(struct task_struct *tsk,
                             struct audit_fsnotify_mark *mark);

extern struct audit_chunk *audit_tree_lookup(const struct inode *inode);
extern void audit_put_chunk(struct audit_chunk *chunk);
extern bool audit_tree_match(struct audit_chunk *chunk,
                             struct audit_tree *tree);
extern int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op);
extern int audit_add_tree_rule(struct audit_krule *rule);
extern int audit_remove_tree_rule(struct audit_krule *rule);
extern void audit_trim_trees(void);
extern int audit_tag_tree(char *old, char *new);
extern const char *audit_tree_path(struct audit_tree *tree);
extern void audit_put_tree(struct audit_tree *tree);
extern void audit_kill_trees(struct audit_context *context);

extern int audit_signal_info_syscall(struct task_struct *t);
extern void audit_filter_inodes(struct task_struct *tsk,
                                struct audit_context *ctx);
extern struct list_head *audit_killed_trees(void);
#else /* CONFIG_AUDITSYSCALL */
#define auditsc_get_stamp(c, s) 0
#define audit_put_watch(w) do { } while (0)
#define audit_get_watch(w) do { } while (0)
#define audit_to_watch(k, p, l, o) (-EINVAL)
#define audit_add_watch(k, l) (-EINVAL)
#define audit_remove_watch_rule(k) BUG()
#define audit_watch_path(w) ""
#define audit_watch_compare(w, i, d) 0

#define audit_alloc_mark(k, p, l) (ERR_PTR(-EINVAL))
#define audit_mark_path(m) ""
#define audit_remove_mark(m) do { } while (0)
#define audit_remove_mark_rule(k) do { } while (0)
#define audit_mark_compare(m, i, d) 0
#define audit_exe_compare(t, m) (-EINVAL)
#define audit_dupe_exe(n, o) (-EINVAL)

#define audit_remove_tree_rule(rule) BUG()
#define audit_add_tree_rule(rule) -EINVAL
#define audit_make_tree(rule, str, op) -EINVAL
#define audit_trim_trees() do { } while (0)
#define audit_put_tree(tree) do { } while (0)
#define audit_tag_tree(old, new) -EINVAL
#define audit_tree_path(rule) ""        /* never called */
#define audit_kill_trees(context) BUG()

static inline int audit_signal_info_syscall(struct task_struct *t)
{
        return 0;
}

#define audit_filter_inodes(t, c) do { } while (0)
#endif /* CONFIG_AUDITSYSCALL */

extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);

extern int audit_filter(int msgtype, unsigned int listtype);

extern void audit_ctl_lock(void);
extern void audit_ctl_unlock(void);

#endif