/*
   * 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/lsm_hooks.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_cxt(cred));
  	cred_cxt(cred) = 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_cxt(cred) = 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, cred_cxt(old));
  	cred_cxt(new) = 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 = cred_cxt(old);
  	struct aa_task_cxt *new_cxt = cred_cxt(new);
  
  	aa_dup_task_context(new_cxt, old_cxt);
  }
  
  static int apparmor_ptrace_access_check(struct task_struct *child,
  					unsigned int mode)
  {
  	return aa_ptrace(current, child, mode);
  }
  
  static int apparmor_ptrace_traceme(struct task_struct *parent)
  {
  	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);
  
  	/*
  	 * cap_capget is stacked ahead of this and will
  	 * initialize effective and 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;
  	int error = 0;
  
  	profile = aa_cred_profile(cred);
  	if (!unconfined(profile))
  		error = aa_capable(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 = { d_backing_inode(dentry)->i_uid,
  				  d_backing_inode(dentry)->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 = d_backing_inode(dentry);
  	struct path_cond cond = { };
  
  	if (!inode || !dir->mnt || !mediated_filesystem(dentry))
  		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))
  		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 = { d_backing_inode(path->dentry)->i_uid,
  				  d_backing_inode(path->dentry)->i_mode
  	};
  
  	if (!path->mnt || !mediated_filesystem(path->dentry))
  		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))
  		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))
  		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 = { d_backing_inode(old_dentry)->i_uid,
  					  d_backing_inode(old_dentry)->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))
  		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 =  { d_backing_inode(path->dentry)->i_uid,
  				   d_backing_inode(path->dentry)->i_mode
  	};
  
  	if (!mediated_filesystem(path->dentry))
  		return 0;
  
  	return common_perm(OP_CHOWN, path, AA_MAY_CHOWN, &cond);
  }
  
  static int apparmor_inode_getattr(const struct path *path)
  {
  	if (!mediated_filesystem(path->dentry))
  		return 0;
  
  	return common_perm_mnt_dentry(OP_GETATTR, path->mnt, path->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->f_path.dentry))
  		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->f_path.dentry))
  		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)
  {
  	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;
  
  	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;
  	/* released below */
  	const struct cred *cred = get_task_cred(task);
  	struct aa_task_cxt *cxt = cred_cxt(cred);
  	struct aa_profile *profile = NULL;
  
  	if (strcmp(name, "current") == 0)
  		profile = aa_get_newest_profile(cxt->profile);
  	else if (strcmp(name, "prev") == 0  && cxt->previous)
  		profile = aa_get_newest_profile(cxt->previous);
  	else if (strcmp(name, "exec") == 0 && cxt->onexec)
  		profile = aa_get_newest_profile(cxt->onexec);
  	else
  		error = -EINVAL;
  
  	if (profile)
  		error = aa_getprocattr(profile, value);
  
  	aa_put_profile(profile);
  	put_cred(cred);
  
  	return error;
  }
  
  static int apparmor_setprocattr(struct task_struct *task, char *name,
  				void *value, size_t size)
  {
  	struct common_audit_data sa;
  	struct apparmor_audit_data aad = {0,};
  	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
  			goto fail;
  	} else if (strcmp(name, "exec") == 0) {
  		if (strcmp(command, "exec") == 0)
  			error = aa_setprocattr_changeprofile(args, AA_ONEXEC,
  							     !AA_DO_TEST);
  		else
  			goto fail;
  	} else
  		/* only support the "current" and "exec" process attributes */
  		return -EINVAL;
  
  	if (!error)
  		error = size;
  	return error;
  
  fail:
  	sa.type = LSM_AUDIT_DATA_NONE;
  	sa.aad = &aad;
  	aad.profile = aa_current_profile();
  	aad.op = OP_SETPROCATTR;
  	aad.info = name;
  	aad.error = -EINVAL;
  	aa_audit_msg(AUDIT_APPARMOR_DENIED, &sa, NULL);
  	return -EINVAL;
  }
  
  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_hook_list apparmor_hooks[] = {
  	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
  	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
  	LSM_HOOK_INIT(capget, apparmor_capget),
  	LSM_HOOK_INIT(capable, apparmor_capable),
  
  	LSM_HOOK_INIT(path_link, apparmor_path_link),
  	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
  	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
  	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
  	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
  	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
  	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
  	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
  	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
  	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
  	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
  
  	LSM_HOOK_INIT(file_open, apparmor_file_open),
  	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
  	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
  	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
  	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
  	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
  	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
  
  	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
  	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
  
  	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
  	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
  	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
  	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
  
  	LSM_HOOK_INIT(bprm_set_creds, apparmor_bprm_set_creds),
  	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
  	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
  	LSM_HOOK_INIT(bprm_secureexec, apparmor_bprm_secureexec),
  
  	LSM_HOOK_INIT(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 const struct kernel_param_ops param_ops_aabool = {
  	.flags = KERNEL_PARAM_OPS_FL_NOARG,
  	.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 const 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 const struct kernel_param_ops param_ops_aalockpolicy = {
  	.flags = KERNEL_PARAM_OPS_FL_NOARG,
  	.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, bool, S_IRUGO);
  
  static int __init apparmor_enabled_setup(char *str)
  {
  	unsigned long enabled;
  	int error = kstrtoul(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", aa_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_MODE_NAMES_MAX_INDEX; i++) {
  		if (strcmp(val, aa_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_cxt(cred) = cxt;
  
  	return 0;
  }
  
  static int __init apparmor_init(void)
  {
  	int error;
  
  	if (!apparmor_enabled || !security_module_enable("apparmor")) {
  		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
  ");
  		goto alloc_out;
  	}
  
  	error = set_init_cxt();
  	if (error) {
  		AA_ERROR("Failed to set context on init task
  ");
  		aa_free_root_ns();
  		goto alloc_out;
  	}
  	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks));
  
  	/* 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;
  
  alloc_out:
  	aa_destroy_aafs();
  
  	apparmor_enabled = 0;
  	return error;
  }
  
  security_initcall(apparmor_init);