/*
   * AppArmor security module
   *
   * This file contains AppArmor /proc/<pid>/attr/ interface 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 "include/apparmor.h"
  #include "include/context.h"
  #include "include/policy.h"
  #include "include/domain.h"
  #include "include/procattr.h"
  
  
  /**
   * aa_getprocattr - Return the profile information for @profile
   * @profile: the profile to print profile info about  (NOT NULL)
   * @string: Returns - string containing the profile info (NOT NULL)
   *
   * Returns: length of @string on success else error on failure
   *
   * Requires: profile != NULL
   *
   * Creates a string containing the namespace_name://profile_name for
   * @profile.
   *
   * Returns: size of string placed in @string else error code on failure
   */
  int aa_getprocattr(struct aa_profile *profile, char **string)
  {
  	char *str;
  	int len = 0, mode_len = 0, ns_len = 0, name_len;
  	const char *mode_str = aa_profile_mode_names[profile->mode];
  	const char *ns_name = NULL;
  	struct aa_namespace *ns = profile->ns;
  	struct aa_namespace *current_ns = __aa_current_profile()->ns;
  	char *s;
  
  	if (!aa_ns_visible(current_ns, ns))
  		return -EACCES;
  
  	ns_name = aa_ns_name(current_ns, ns);
  	ns_len = strlen(ns_name);
  
  	/* if the visible ns_name is > 0 increase size for : :// seperator */
  	if (ns_len)
  		ns_len += 4;
  
  	/* unconfined profiles don't have a mode string appended */
  	if (!unconfined(profile))
  		mode_len = strlen(mode_str) + 3;	/* + 3 for _() */
  
  	name_len = strlen(profile->base.hname);
  	len = mode_len + ns_len + name_len + 1;	    /* + 1 for 
   */
  	s = str = kmalloc(len + 1, GFP_KERNEL);	    /* + 1 \0 */
  	if (!str)
  		return -ENOMEM;
  
  	if (ns_len) {
  		/* skip over prefix current_ns->base.hname and separating // */
  		sprintf(s, ":%s://", ns_name);
  		s += ns_len;
  	}
  	if (unconfined(profile))
  		/* mode string not being appended */
  		sprintf(s, "%s
  ", profile->base.hname);
  	else
  		sprintf(s, "%s (%s)
  ", profile->base.hname, mode_str);
  	*string = str;
  
  	/* NOTE: len does not include \0 of string, not saved as part of file */
  	return len;
  }
  
  /**
   * split_token_from_name - separate a string of form  <token>^<name>
   * @op: operation being checked
   * @args: string to parse  (NOT NULL)
   * @token: stores returned parsed token value  (NOT NULL)
   *
   * Returns: start position of name after token else NULL on failure
   */
  static char *split_token_from_name(int op, char *args, u64 * token)
  {
  	char *name;
  
  	*token = simple_strtoull(args, &name, 16);
  	if ((name == args) || *name != '^') {
  		AA_ERROR("%s: Invalid input '%s'", op_table[op], args);
  		return ERR_PTR(-EINVAL);
  	}
  
  	name++;			/* skip ^ */
  	if (!*name)
  		name = NULL;
  	return name;
  }
  
  /**
   * aa_setprocattr_chagnehat - handle procattr interface to change_hat
   * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
   * @size: size of the args
   * @test: true if this is a test of change_hat permissions
   *
   * Returns: %0 or error code if change_hat fails
   */
  int aa_setprocattr_changehat(char *args, size_t size, int test)
  {
  	char *hat;
  	u64 token;
  	const char *hats[16];		/* current hard limit on # of names */
  	int count = 0;
  
  	hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
  	if (IS_ERR(hat))
  		return PTR_ERR(hat);
  
  	if (!hat && !token) {
  		AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
  		return -EINVAL;
  	}
  
  	if (hat) {
  		/* set up hat name vector, args guaranteed null terminated
  		 * at args[size] by setprocattr.
  		 *
  		 * If there are multiple hat names in the buffer each is
  		 * separated by a \0.  Ie. userspace writes them pre tokenized
  		 */
  		char *end = args + size;
  		for (count = 0; (hat < end) && count < 16; ++count) {
  			char *next = hat + strlen(hat) + 1;
  			hats[count] = hat;
  			hat = next;
  		}
  	}
  
  	AA_DEBUG("%s: Magic 0x%llx Hat '%s'
  ",
  		 __func__, token, hat ? hat : NULL);
  
  	return aa_change_hat(hats, count, token, test);
  }
  
  /**
   * aa_setprocattr_changeprofile - handle procattr interface to changeprofile
   * @fqname: args received from writting to /proc/<pid>/attr/current (NOT NULL)
   * @onexec: true if change_profile should be delayed until exec
   * @test: true if this is a test of change_profile permissions
   *
   * Returns: %0 or error code if change_profile fails
   */
  int aa_setprocattr_changeprofile(char *fqname, bool onexec, int test)
  {
  	char *name, *ns_name;
  
  	name = aa_split_fqname(fqname, &ns_name);
  	return aa_change_profile(ns_name, name, onexec, test);
  }