/*
   * AppArmor security module
   *
   * This file contains AppArmor auditing functions
   *
   * 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/audit.h>
  #include <linux/socket.h>
  
  #include "include/apparmor.h"
  #include "include/audit.h"
  #include "include/policy.h"

  #include "include/policy_ns.h"

  #include "include/secid.h"

  const char *const audit_mode_names[] = {

  	"normal",
  	"quiet_denied",
  	"quiet",
  	"noquiet",
  	"all"
  };

  static const char *const aa_audit_type[] = {

  	"AUDIT",
  	"ALLOWED",
  	"DENIED",
  	"HINT",
  	"STATUS",
  	"ERROR",

  	"KILLED",

  	"AUTO"

  };
  
  /*
   * Currently AppArmor auditing is fed straight into the audit framework.
   *
   * TODO:
   * netlink interface for complain mode
   * user auditing, - send user auditing to netlink interface
   * system control of whether user audit messages go to system log
   */
  
  /**
   * audit_base - core AppArmor function.
   * @ab: audit buffer to fill (NOT NULL)
   * @ca: audit structure containing data to audit (NOT NULL)
   *
   * Record common AppArmor audit data from @sa
   */
  static void audit_pre(struct audit_buffer *ab, void *ca)
  {
  	struct common_audit_data *sa = ca;

  
  	if (aa_g_audit_header) {
  		audit_log_format(ab, "apparmor=");

  		audit_log_string(ab, aa_audit_type[aad(sa)->type]);

  	}

  	if (aad(sa)->op) {

  		audit_log_format(ab, " operation=");

  		audit_log_string(ab, aad(sa)->op);

  	}

  	if (aad(sa)->info) {

  		audit_log_format(ab, " info=");

  		audit_log_string(ab, aad(sa)->info);
  		if (aad(sa)->error)
  			audit_log_format(ab, " error=%d", aad(sa)->error);

  	}

  	if (aad(sa)->label) {
  		struct aa_label *label = aad(sa)->label;
  
  		if (label_isprofile(label)) {
  			struct aa_profile *profile = labels_profile(label);
  
  			if (profile->ns != root_ns) {
  				audit_log_format(ab, " namespace=");
  				audit_log_untrustedstring(ab,
  						       profile->ns->base.hname);
  			}
  			audit_log_format(ab, " profile=");
  			audit_log_untrustedstring(ab, profile->base.hname);
  		} else {
  			audit_log_format(ab, " label=");
  			aa_label_xaudit(ab, root_ns, label, FLAG_VIEW_SUBNS,
  					GFP_ATOMIC);

  		}

  	}

  	if (aad(sa)->name) {

  		audit_log_format(ab, " name=");

  		audit_log_untrustedstring(ab, aad(sa)->name);

  	}
  }
  
  /**
   * aa_audit_msg - Log a message to the audit subsystem
   * @sa: audit event structure (NOT NULL)
   * @cb: optional callback fn for type specific fields (MAYBE NULL)
   */
  void aa_audit_msg(int type, struct common_audit_data *sa,
  		  void (*cb) (struct audit_buffer *, void *))
  {

  	aad(sa)->type = type;

  	common_lsm_audit(sa, audit_pre, cb);

  }
  
  /**
   * aa_audit - Log a profile based audit event to the audit subsystem
   * @type: audit type for the message
   * @profile: profile to check against (NOT NULL)

   * @sa: audit event (NOT NULL)
   * @cb: optional callback fn for type specific fields (MAYBE NULL)
   *
   * Handle default message switching based off of audit mode flags
   *
   * Returns: error on failure
   */

  int aa_audit(int type, struct aa_profile *profile, struct common_audit_data *sa,

  	     void (*cb) (struct audit_buffer *, void *))
  {

  	AA_BUG(!profile);

  
  	if (type == AUDIT_APPARMOR_AUTO) {

  		if (likely(!aad(sa)->error)) {

  			if (AUDIT_MODE(profile) != AUDIT_ALL)
  				return 0;
  			type = AUDIT_APPARMOR_AUDIT;
  		} else if (COMPLAIN_MODE(profile))
  			type = AUDIT_APPARMOR_ALLOWED;
  		else
  			type = AUDIT_APPARMOR_DENIED;
  	}
  	if (AUDIT_MODE(profile) == AUDIT_QUIET ||
  	    (type == AUDIT_APPARMOR_DENIED &&
  	     AUDIT_MODE(profile) == AUDIT_QUIET))

  		return aad(sa)->error;

  
  	if (KILL_MODE(profile) && type == AUDIT_APPARMOR_DENIED)
  		type = AUDIT_APPARMOR_KILL;

  	aad(sa)->label = &profile->label;

  
  	aa_audit_msg(type, sa, cb);

  	if (aad(sa)->type == AUDIT_APPARMOR_KILL)

  		(void)send_sig_info(SIGKILL, NULL,

  			sa->type == LSM_AUDIT_DATA_TASK && sa->u.tsk ?
  				    sa->u.tsk : current);

  	if (aad(sa)->type == AUDIT_APPARMOR_ALLOWED)
  		return complain_error(aad(sa)->error);

  	return aad(sa)->error;

  }

  
  struct aa_audit_rule {

  	struct aa_label *label;

  };
  
  void aa_audit_rule_free(void *vrule)
  {
  	struct aa_audit_rule *rule = vrule;
  
  	if (rule) {

  		if (!IS_ERR(rule->label))
  			aa_put_label(rule->label);

  		kfree(rule);
  	}
  }
  
  int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
  {
  	struct aa_audit_rule *rule;
  
  	switch (field) {
  	case AUDIT_SUBJ_ROLE:
  		if (op != Audit_equal && op != Audit_not_equal)
  			return -EINVAL;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	rule = kzalloc(sizeof(struct aa_audit_rule), GFP_KERNEL);
  
  	if (!rule)
  		return -ENOMEM;

  	/* Currently rules are treated as coming from the root ns */
  	rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
  				     GFP_KERNEL, true, false);

  	if (IS_ERR(rule->label)) {
  		aa_audit_rule_free(rule);

  		return PTR_ERR(rule->label);

  	}

  	*vrule = rule;

  	return 0;
  }
  
  int aa_audit_rule_known(struct audit_krule *rule)
  {
  	int i;
  
  	for (i = 0; i < rule->field_count; i++) {
  		struct audit_field *f = &rule->fields[i];
  
  		switch (f->type) {
  		case AUDIT_SUBJ_ROLE:
  			return 1;
  		}
  	}
  
  	return 0;
  }
  
  int aa_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule,
  			struct audit_context *actx)
  {
  	struct aa_audit_rule *rule = vrule;
  	struct aa_label *label;

  	int found = 0;
  
  	label = aa_secid_to_label(sid);
  
  	if (!label)
  		return -ENOENT;

  	if (aa_label_is_subset(label, rule->label))
  		found = 1;

  
  	switch (field) {
  	case AUDIT_SUBJ_ROLE:
  		switch (op) {
  		case Audit_equal:
  			return found;
  		case Audit_not_equal:
  			return !found;
  		}
  	}
  	return 0;
  }