/*
 * AppArmor security module
 *
 * This file contains AppArmor LSM hooks.
 *
 * Copyright (C) 1998-2008 Novell/SUSE
 * Copyright 2009-2010 Canonical Ltd.
 *
 * 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 of the
 * License.
 */

#include <linux/security.h>
#include <linux/moduleparam.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/ptrace.h>
#include <linux/ctype.h>
#include <linux/sysctl.h>
#include <linux/audit.h>
#include <linux/user_namespace.h>
#include <net/sock.h>

#include "include/apparmor.h"
#include "include/apparmorfs.h"
#include "include/audit.h"
#include "include/capability.h"
#include "include/context.h"
#include "include/file.h"
#include "include/ipc.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/procattr.h"

/* Flag indicating whether initialization completed */
int apparmor_initialized __initdata;

/*
 * LSM hook functions
 */

/*
 * free the associated aa_task_cxt and put its profiles
 */
static void apparmor_cred_free(struct cred *cred)
{
        aa_free_task_context(cred->security);
        cred->security = NULL;
}

/*
 * allocate the apparmor part of blank credentials
 */
static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
        /* freed by apparmor_cred_free */
        struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
        if (!cxt)
                return -ENOMEM;

        cred->security = cxt;
        return 0;
}

/*
 * prepare new aa_task_cxt for modification by prepare_cred block
 */
static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
                                 gfp_t gfp)
{
        /* freed by apparmor_cred_free */
        struct aa_task_cxt *cxt = aa_alloc_task_context(gfp);
        if (!cxt)
                return -ENOMEM;

        aa_dup_task_context(cxt, old->security);
        new->security = cxt;
        return 0;
}

/*
 * transfer the apparmor data to a blank set of creds
 */
static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
{
        const struct aa_task_cxt *old_cxt = old->security;
        struct aa_task_cxt *new_cxt = new->security;

        aa_dup_task_context(new_cxt, old_cxt);
}

static int apparmor_ptrace_access_check(struct task_struct *child,
                                        unsigned int mode)
{
        int error = cap_ptrace_access_check(child, mode);
        if (error)
                return error;

        return aa_ptrace(current, child, mode);
}

static int apparmor_ptrace_traceme(struct task_struct *parent)
{
        int error = cap_ptrace_traceme(parent);
        if (error)
                return error;

        return aa_ptrace(parent, current, PTRACE_MODE_ATTACH);
}

/* Derived from security/commoncap.c:cap_capget */
static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
        struct aa_profile *profile;
        const struct cred *cred;

        rcu_read_lock();
        cred = __task_cred(target);
        profile = aa_cred_profile(cred);

        *effective = cred->cap_effective;
        *inheritable = cred->cap_inheritable;
        *permitted = cred->cap_permitted;

        if (!unconfined(profile) && !COMPLAIN_MODE(profile)) {
                *effective = cap_intersect(*effective, profile->caps.allow);
                *permitted = cap_intersect(*permitted, profile->caps.allow);
        }
        rcu_read_unlock();

        return 0;
}

static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
                            int cap, int audit)
{
        struct aa_profile *profile;
        /* cap_capable returns 0 on success, else -EPERM */
        int error = cap_capable(cred, ns, cap, audit);
        if (!error) {
                profile = aa_cred_profile(cred);
                if (!unconfined(profile))
                        error = aa_capable(current, profile, cap, audit);
        }
        return error;
}

/**
 * common_perm - basic common permission check wrapper fn for paths
 * @op: operation being checked
 * @path: path to check permission of  (NOT NULL)
 * @mask: requested permissions mask
 * @cond: conditional info for the permission request  (NOT NULL)
 *
 * Returns: %0 else error code if error or permission denied
 */
static int common_perm(int op, struct path *path, u32 mask,
                       struct path_cond *cond)
{
        struct aa_profile *profile;
        int error = 0;

        profile = __aa_current_profile();
        if (!unconfined(profile))
                error = aa_path_perm(op, profile, path, 0, mask, cond);

        return error;
}

/**
 * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
 * @op: operation being checked
 * @dir: directory of the dentry  (NOT NULL)
 * @dentry: dentry to check  (NOT NULL)
 * @mask: requested permissions mask
 * @cond: conditional info for the permission request  (NOT NULL)
 *
 * Returns: %0 else error code if error or permission denied
 */
static int common_perm_dir_dentry(int op, struct path *dir,
                                  struct dentry *dentry, u32 mask,
                                  struct path_cond *cond)
{
        struct path path = { dir->mnt, dentry };

        return common_perm(op, &path, mask, cond);
}

/**
 * common_perm_mnt_dentry - common permission wrapper when mnt, dentry
 * @op: operation being checked
 * @mnt: mount point of dentry (NOT NULL)
 * @dentry: dentry to check  (NOT NULL)
 * @mask: requested permissions mask
 *
 * Returns: %0 else error code if error or permission denied
 */
static int common_perm_mnt_dentry(int op, struct vfsmount *mnt,
                                  struct dentry *dentry, u32 mask)
{
        struct path path = { mnt, dentry };
        struct path_cond cond = { dentry->d_inode->i_uid,
                                  dentry->d_inode->i_mode
        };

        return common_perm(op, &path, mask, &cond);
}

/**
 * common_perm_rm - common permission wrapper for operations doing rm
 * @op: operation being checked
 * @dir: directory that the dentry is in  (NOT NULL)
 * @dentry: dentry being rm'd  (NOT NULL)
 * @mask: requested permission mask
 *
 * Returns: %0 else error code if error or permission denied
 */
static int common_perm_rm(int op, struct path *dir,
                          struct dentry *dentry, u32 mask)
{
        struct inode *inode = dentry->d_inode;
        struct path_cond cond = { };

        if (!inode || !dir->mnt || !mediated_filesystem(inode))
                return 0;

        cond.uid = inode->i_uid;
        cond.mode = inode->i_mode;

        return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
}

/**
 * common_perm_create - common permission wrapper for operations doing create
 * @op: operation being checked
 * @dir: directory that dentry will be created in  (NOT NULL)
 * @dentry: dentry to create   (NOT NULL)
 * @mask: request permission mask
 * @mode: created file mode
 *
 * Returns: %0 else error code if error or permission denied
 */
static int common_perm_create(int op, struct path *dir, struct dentry *dentry,
                              u32 mask, umode_t mode)
{
        struct path_cond cond = { current_fsuid(), mode };

        if (!dir->mnt || !mediated_filesystem(dir->dentry->d_inode))
                return 0;

        return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
}

static int apparmor_path_unlink(struct path *dir, struct dentry *dentry)
{
        return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
}

static int apparmor_path_mkdir(struct path *dir, struct dentry *dentry,
                               umode_t mode)
{
        return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
                                  S_IFDIR);
}

static int apparmor_path_rmdir(struct path *dir, struct dentry *dentry)
{
        return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
}

static int apparmor_path_mknod(struct path *dir, struct dentry *dentry,
                               umode_t mode, unsigned int dev)
{
        return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
}

static int apparmor_path_truncate(struct path *path)
{
        struct path_cond cond = { path->dentry->d_inode->i_uid,
                                  path->dentry->d_inode->i_mode
        };

        if (!path->mnt || !mediated_filesystem(path->dentry->d_inode))
                return 0;

        return common_perm(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE,
                           &cond);
}

static int apparmor_path_symlink(struct path *dir, struct dentry *dentry,
                                 const char *old_name)
{
        return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
                                  S_IFLNK);
}

static int apparmor_path_link(struct dentry *old_dentry, struct path *new_dir,
                              struct dentry *new_dentry)
{
        struct aa_profile *profile;
        int error = 0;

        if (!mediated_filesystem(old_dentry->d_inode))
                return 0;

        profile = aa_current_profile();
        if (!unconfined(profile))
                error = aa_path_link(profile, old_dentry, new_dir, new_dentry);
        return error;
}

static int apparmor_path_rename(struct path *old_dir, struct dentry *old_dentry,
                                struct path *new_dir, struct dentry *new_dentry)
{
        struct aa_profile *profile;
        int error = 0;

        if (!mediated_filesystem(old_dentry->d_inode))
                return 0;

        profile = aa_current_profile();
        if (!unconfined(profile)) {
                struct path old_path = { old_dir->mnt, old_dentry };
                struct path new_path = { new_dir->mnt, new_dentry };
                struct path_cond cond = { old_dentry->d_inode->i_uid,
                                          old_dentry->d_inode->i_mode
                };

                error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
                                     MAY_READ | AA_MAY_META_READ | MAY_WRITE |
                                     AA_MAY_META_WRITE | AA_MAY_DELETE,
                                     &cond);
                if (!error)
                        error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
                                             0, MAY_WRITE | AA_MAY_META_WRITE |
                                             AA_MAY_CREATE, &cond);

        }
        return error;
}

static int apparmor_path_chmod(struct path *path, umode_t mode)
{
        if (!mediated_filesystem(path->dentry->d_inode))
                return 0;

        return common_perm_mnt_dentry(OP_CHMOD, path->mnt, path->dentry, AA_MAY_CHMOD);
}

static int apparmor_path_chown(struct path *path, kuid_t uid, kgid_t gid)
{
        struct path_cond cond =  { path->dentry->d_inode->i_uid,
                                   path->dentry->d_inode->i_mode
        };

        if (!mediated_filesystem(path->dentry->d_inode))
                return 0;

        return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
}

static int apparmor_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
        if (!mediated_filesystem(dentry->d_inode))
                return 0;

        return common_perm_mnt_dentry(OP_GETATTR, mnt, dentry,
                                      AA_MAY_META_READ);
}

static int apparmor_file_open(struct file *file, const struct cred *cred)
{
        struct aa_file_cxt *fcxt = file->f_security;
        struct aa_profile *profile;
        int error = 0;

        if (!mediated_filesystem(file_inode(file)))
                return 0;

        /* If in exec, permission is handled by bprm hooks.
         * Cache permissions granted by the previous exec check, with
         * implicit read and executable mmap which are required to
         * actually execute the image.
         */
        if (current->in_execve) {
                fcxt->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
                return 0;
        }

        profile = aa_cred_profile(cred);
        if (!unconfined(profile)) {
                struct inode *inode = file_inode(file);
                struct path_cond cond = { inode->i_uid, inode->i_mode };

                error = aa_path_perm(OP_OPEN, profile, &file->f_path, 0,
                                     aa_map_file_to_perms(file), &cond);
                /* todo cache full allowed permissions set and state */
                fcxt->allow = aa_map_file_to_perms(file);
        }

        return error;
}

static int apparmor_file_alloc_security(struct file *file)
{
        /* freed by apparmor_file_free_security */
        file->f_security = aa_alloc_file_context(GFP_KERNEL);
        if (!file->f_security)
                return -ENOMEM;
        return 0;

}

static void apparmor_file_free_security(struct file *file)
{
        struct aa_file_cxt *cxt = file->f_security;

        aa_free_file_context(cxt);
}

static int common_file_perm(int op, struct file *file, u32 mask)
{
        struct aa_file_cxt *fcxt = file->f_security;
        struct aa_profile *profile, *fprofile = aa_cred_profile(file->f_cred);
        int error = 0;

        BUG_ON(!fprofile);

        if (!file->f_path.mnt ||
            !mediated_filesystem(file_inode(file)))
                return 0;

        profile = __aa_current_profile();

        /* revalidate access, if task is unconfined, or the cached cred
         * doesn't match or if the request is for more permissions than
         * was granted.
         *
         * Note: the test for !unconfined(fprofile) is to handle file
         *       delegation from unconfined tasks
         */
        if (!unconfined(profile) && !unconfined(fprofile) &&
            ((fprofile != profile) || (mask & ~fcxt->allow)))
                error = aa_file_perm(op, profile, file, mask);

        return error;
}

static int apparmor_file_permission(struct file *file, int mask)
{
        return common_file_perm(OP_FPERM, file, mask);
}

static int apparmor_file_lock(struct file *file, unsigned int cmd)
{
        u32 mask = AA_MAY_LOCK;

        if (cmd == F_WRLCK)
                mask |= MAY_WRITE;

        return common_file_perm(OP_FLOCK, file, mask);
}

static int common_mmap(int op, struct file *file, unsigned long prot,
                       unsigned long flags)
{
        struct dentry *dentry;
        int mask = 0;

        if (!file || !file->f_security)
                return 0;

        if (prot & PROT_READ)
                mask |= MAY_READ;
        /*
         * Private mappings don't require write perms since they don't
         * write back to the files
         */
        if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
                mask |= MAY_WRITE;
        if (prot & PROT_EXEC)
                mask |= AA_EXEC_MMAP;

        dentry = file->f_path.dentry;
        return common_file_perm(op, file, mask);
}

static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
                              unsigned long prot, unsigned long flags)
{
        return common_mmap(OP_FMMAP, file, prot, flags);
}

static int apparmor_file_mprotect(struct vm_area_struct *vma,
                                  unsigned long reqprot, unsigned long prot)
{
        return common_mmap(OP_FMPROT, vma->vm_file, prot,
                           !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0);
}

static int apparmor_getprocattr(struct task_struct *task, char *name,
                                char **value)
{
        int error = -ENOENT;
        struct aa_profile *profile;
        /* released below */
        const struct cred *cred = get_task_cred(task);
        struct aa_task_cxt *cxt = cred->security;
        profile = aa_cred_profile(cred);

        if (strcmp(name, "current") == 0)
                error = aa_getprocattr(aa_newest_version(cxt->profile),
                                       value);
        else if (strcmp(name, "prev") == 0  && cxt->previous)
                error = aa_getprocattr(aa_newest_version(cxt->previous),
                                       value);
        else if (strcmp(name, "exec") == 0 && cxt->onexec)
                error = aa_getprocattr(aa_newest_version(cxt->onexec),
                                       value);
        else
                error = -EINVAL;

        put_cred(cred);

        return error;
}

static int apparmor_setprocattr(struct task_struct *task, char *name,
                                void *value, size_t size)
{
        char *command, *args = value;
        size_t arg_size;
        int error;

        if (size == 0)
                return -EINVAL;
        /* args points to a PAGE_SIZE buffer, AppArmor requires that
         * the buffer must be null terminated or have size <= PAGE_SIZE -1
         * so that AppArmor can null terminate them
         */
        if (args[size - 1] != '\0') {
                if (size == PAGE_SIZE)
                        return -EINVAL;
                args[size] = '\0';
        }

        /* task can only write its own attributes */
        if (current != task)
                return -EACCES;

        args = value;
        args = strim(args);
        command = strsep(&args, " ");
        if (!args)
                return -EINVAL;
        args = skip_spaces(args);
        if (!*args)
                return -EINVAL;

        arg_size = size - (args - (char *) value);
        if (strcmp(name, "current") == 0) {
                if (strcmp(command, "changehat") == 0) {
                        error = aa_setprocattr_changehat(args, arg_size,
                                                         !AA_DO_TEST);
                } else if (strcmp(command, "permhat") == 0) {
                        error = aa_setprocattr_changehat(args, arg_size,
                                                         AA_DO_TEST);
                } else if (strcmp(command, "changeprofile") == 0) {
                        error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
                                                             !AA_DO_TEST);
                } else if (strcmp(command, "permprofile") == 0) {
                        error = aa_setprocattr_changeprofile(args, !AA_ONEXEC,
                                                             AA_DO_TEST);
                } else if (strcmp(command, "permipc") == 0) {
                        error = aa_setprocattr_permipc(args);
                } else {
                        struct common_audit_data sa;
                        struct apparmor_audit_data aad = {0,};
                        sa.type = LSM_AUDIT_DATA_NONE;
                        sa.aad = &aad;
                        aad.op = OP_SETPROCATTR;
                        aad.info = name;
                        aad.error = -EINVAL;
                        return aa_audit(AUDIT_APPARMOR_DENIED,
                                        __aa_current_profile(), GFP_KERNEL,
                                        &sa, NULL);
                }
        } else if (strcmp(name, "exec") == 0) {
                error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
                                                     !AA_DO_TEST);
        } else {
                /* only support the "current" and "exec" process attributes */
                return -EINVAL;
        }
        if (!error)
                error = size;
        return error;
}

static int apparmor_task_setrlimit(struct task_struct *task,
                unsigned int resource, struct rlimit *new_rlim)
{
        struct aa_profile *profile = __aa_current_profile();
        int error = 0;

        if (!unconfined(profile))
                error = aa_task_setrlimit(profile, task, resource, new_rlim);

        return error;
}

static struct security_operations apparmor_ops = {
        .name =                         "apparmor",

        .ptrace_access_check =          apparmor_ptrace_access_check,
        .ptrace_traceme =               apparmor_ptrace_traceme,
        .capget =                       apparmor_capget,
        .capable =                      apparmor_capable,

        .path_link =                    apparmor_path_link,
        .path_unlink =                  apparmor_path_unlink,
        .path_symlink =                 apparmor_path_symlink,
        .path_mkdir =                   apparmor_path_mkdir,
        .path_rmdir =                   apparmor_path_rmdir,
        .path_mknod =                   apparmor_path_mknod,
        .path_rename =                  apparmor_path_rename,
        .path_chmod =                   apparmor_path_chmod,
        .path_chown =                   apparmor_path_chown,
        .path_truncate =                apparmor_path_truncate,
        .inode_getattr =                apparmor_inode_getattr,

        .file_open =                    apparmor_file_open,
        .file_permission =              apparmor_file_permission,
        .file_alloc_security =          apparmor_file_alloc_security,
        .file_free_security =           apparmor_file_free_security,
        .mmap_file =                    apparmor_mmap_file,
        .mmap_addr =                    cap_mmap_addr,
        .file_mprotect =                apparmor_file_mprotect,
        .file_lock =                    apparmor_file_lock,

        .getprocattr =                  apparmor_getprocattr,
        .setprocattr =                  apparmor_setprocattr,

        .cred_alloc_blank =             apparmor_cred_alloc_blank,
        .cred_free =                    apparmor_cred_free,
        .cred_prepare =                 apparmor_cred_prepare,
        .cred_transfer =                apparmor_cred_transfer,

        .bprm_set_creds =               apparmor_bprm_set_creds,
        .bprm_committing_creds =        apparmor_bprm_committing_creds,
        .bprm_committed_creds =         apparmor_bprm_committed_creds,
        .bprm_secureexec =              apparmor_bprm_secureexec,

        .task_setrlimit =               apparmor_task_setrlimit,
};

/*
 * AppArmor sysfs module parameters
 */

static int param_set_aabool(const char *val, const struct kernel_param *kp);
static int param_get_aabool(char *buffer, const struct kernel_param *kp);
#define param_check_aabool param_check_bool
static struct kernel_param_ops param_ops_aabool = {
        .set = param_set_aabool,
        .get = param_get_aabool
};

static int param_set_aauint(const char *val, const struct kernel_param *kp);
static int param_get_aauint(char *buffer, const struct kernel_param *kp);
#define param_check_aauint param_check_uint
static struct kernel_param_ops param_ops_aauint = {
        .set = param_set_aauint,
        .get = param_get_aauint
};

static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
#define param_check_aalockpolicy param_check_bool
static struct kernel_param_ops param_ops_aalockpolicy = {
        .set = param_set_aalockpolicy,
        .get = param_get_aalockpolicy
};

static int param_set_audit(const char *val, struct kernel_param *kp);
static int param_get_audit(char *buffer, struct kernel_param *kp);

static int param_set_mode(const char *val, struct kernel_param *kp);
static int param_get_mode(char *buffer, struct kernel_param *kp);

/* Flag values, also controllable via /sys/module/apparmor/parameters
 * We define special types as we want to do additional mediation.
 */

/* AppArmor global enforcement switch - complain, enforce, kill */
enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
module_param_call(mode, param_set_mode, param_get_mode,
                  &aa_g_profile_mode, S_IRUSR | S_IWUSR);

/* Debug mode */
bool aa_g_debug;
module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);

/* Audit mode */
enum audit_mode aa_g_audit;
module_param_call(audit, param_set_audit, param_get_audit,
                  &aa_g_audit, S_IRUSR | S_IWUSR);

/* Determines if audit header is included in audited messages.  This
 * provides more context if the audit daemon is not running
 */
bool aa_g_audit_header = 1;
module_param_named(audit_header, aa_g_audit_header, aabool,
                   S_IRUSR | S_IWUSR);

/* lock out loading/removal of policy
 * TODO: add in at boot loading of policy, which is the only way to
 *       load policy, if lock_policy is set
 */
bool aa_g_lock_policy;
module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
                   S_IRUSR | S_IWUSR);

/* Syscall logging mode */
bool aa_g_logsyscall;
module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);

/* Maximum pathname length before accesses will start getting rejected */
unsigned int aa_g_path_max = 2 * PATH_MAX;
module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR | S_IWUSR);

/* Determines how paranoid loading of policy is and how much verification
 * on the loaded policy is done.
 */
bool aa_g_paranoid_load = 1;
module_param_named(paranoid_load, aa_g_paranoid_load, aabool,
                   S_IRUSR | S_IWUSR);

/* Boot time disable flag */
static bool apparmor_enabled = CONFIG_SECURITY_APPARMOR_BOOTPARAM_VALUE;
module_param_named(enabled, apparmor_enabled, aabool, S_IRUSR);

static int __init apparmor_enabled_setup(char *str)
{
        unsigned long enabled;
        int error = strict_strtoul(str, 0, &enabled);
        if (!error)
                apparmor_enabled = enabled ? 1 : 0;
        return 1;
}

__setup("apparmor=", apparmor_enabled_setup);

/* set global flag turning off the ability to load policy */
static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        if (aa_g_lock_policy)
                return -EACCES;
        return param_set_bool(val, kp);
}

static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        return param_get_bool(buffer, kp);
}

static int param_set_aabool(const char *val, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        return param_set_bool(val, kp);
}

static int param_get_aabool(char *buffer, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        return param_get_bool(buffer, kp);
}

static int param_set_aauint(const char *val, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        return param_set_uint(val, kp);
}

static int param_get_aauint(char *buffer, const struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;
        return param_get_uint(buffer, kp);
}

static int param_get_audit(char *buffer, struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;

        if (!apparmor_enabled)
                return -EINVAL;

        return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
}

static int param_set_audit(const char *val, struct kernel_param *kp)
{
        int i;
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;

        if (!apparmor_enabled)
                return -EINVAL;

        if (!val)
                return -EINVAL;

        for (i = 0; i < AUDIT_MAX_INDEX; i++) {
                if (strcmp(val, audit_mode_names[i]) == 0) {
                        aa_g_audit = i;
                        return 0;
                }
        }

        return -EINVAL;
}

static int param_get_mode(char *buffer, struct kernel_param *kp)
{
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;

        if (!apparmor_enabled)
                return -EINVAL;

        return sprintf(buffer, "%s", profile_mode_names[aa_g_profile_mode]);
}

static int param_set_mode(const char *val, struct kernel_param *kp)
{
        int i;
        if (!capable(CAP_MAC_ADMIN))
                return -EPERM;

        if (!apparmor_enabled)
                return -EINVAL;

        if (!val)
                return -EINVAL;

        for (i = 0; i < APPARMOR_NAMES_MAX_INDEX; i++) {
                if (strcmp(val, profile_mode_names[i]) == 0) {
                        aa_g_profile_mode = i;
                        return 0;
                }
        }

        return -EINVAL;
}

/*
 * AppArmor init functions
 */

/**
 * set_init_cxt - set a task context and profile on the first task.
 *
 * TODO: allow setting an alternate profile than unconfined
 */
static int __init set_init_cxt(void)
{
        struct cred *cred = (struct cred *)current->real_cred;
        struct aa_task_cxt *cxt;

        cxt = aa_alloc_task_context(GFP_KERNEL);
        if (!cxt)
                return -ENOMEM;

        cxt->profile = aa_get_profile(root_ns->unconfined);
        cred->security = cxt;

        return 0;
}

static int __init apparmor_init(void)
{
        int error;

        if (!apparmor_enabled || !security_module_enable(&apparmor_ops)) {
                aa_info_message("AppArmor disabled by boot time parameter");
                apparmor_enabled = 0;
                return 0;
        }

        error = aa_alloc_root_ns();
        if (error) {
                AA_ERROR("Unable to allocate default profile namespace\n");
                goto alloc_out;
        }

        error = set_init_cxt();
        if (error) {
                AA_ERROR("Failed to set context on init task\n");
                goto register_security_out;
        }

        error = register_security(&apparmor_ops);
        if (error) {
                AA_ERROR("Unable to register AppArmor\n");
                goto set_init_cxt_out;
        }

        /* Report that AppArmor successfully initialized */
        apparmor_initialized = 1;
        if (aa_g_profile_mode == APPARMOR_COMPLAIN)
                aa_info_message("AppArmor initialized: complain mode enabled");
        else if (aa_g_profile_mode == APPARMOR_KILL)
                aa_info_message("AppArmor initialized: kill mode enabled");
        else
                aa_info_message("AppArmor initialized");

        return error;

set_init_cxt_out:
        aa_free_task_context(current->real_cred->security);

register_security_out:
        aa_free_root_ns();

alloc_out:
        aa_destroy_aafs();

        apparmor_enabled = 0;
        return error;
}

security_initcall(apparmor_init);