LXR linux/security/tomoyo/environ.c

   1/*
   2 * security/tomoyo/environ.c
   3 *
   4 * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5 */
   6
   7#include "common.h"
   8
   9/**
  10 * tomoyo_check_env_acl - Check permission for environment variable's name.
  11 *
  12 * @r:   Pointer to "struct tomoyo_request_info".
  13 * @ptr: Pointer to "struct tomoyo_acl_info".
  14 *
  15 * Returns true if granted, false otherwise.
  16 */
  17static bool tomoyo_check_env_acl(struct tomoyo_request_info *r,
  18                                 const struct tomoyo_acl_info *ptr)
  19{
  20        const struct tomoyo_env_acl *acl =
  21                container_of(ptr, typeof(*acl), head);
  22
  23        return tomoyo_path_matches_pattern(r->param.environ.name, acl->env);
  24}
  25
  26/**
  27 * tomoyo_audit_env_log - Audit environment variable name log.
  28 *
  29 * @r: Pointer to "struct tomoyo_request_info".
  30 *
  31 * Returns 0 on success, negative value otherwise.
  32 */
  33static int tomoyo_audit_env_log(struct tomoyo_request_info *r)
  34{
  35        return tomoyo_supervisor(r, "misc env %s\n",
  36                                 r->param.environ.name->name);
  37}
  38
  39/**
  40 * tomoyo_env_perm - Check permission for environment variable's name.
  41 *
  42 * @r:   Pointer to "struct tomoyo_request_info".
  43 * @env: The name of environment variable.
  44 *
  45 * Returns 0 on success, negative value otherwise.
  46 *
  47 * Caller holds tomoyo_read_lock().
  48 */
  49int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env)
  50{
  51        struct tomoyo_path_info environ;
  52        int error;
  53
  54        if (!env || !*env)
  55                return 0;
  56        environ.name = env;
  57        tomoyo_fill_path_info(&environ);
  58        r->param_type = TOMOYO_TYPE_ENV_ACL;
  59        r->param.environ.name = &environ;
  60        do {
  61                tomoyo_check_acl(r, tomoyo_check_env_acl);
  62                error = tomoyo_audit_env_log(r);
  63        } while (error == TOMOYO_RETRY_REQUEST);
  64        return error;
  65}
  66
  67/**
  68 * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry.
  69 *
  70 * @a: Pointer to "struct tomoyo_acl_info".
  71 * @b: Pointer to "struct tomoyo_acl_info".
  72 *
  73 * Returns true if @a == @b, false otherwise.
  74 */
  75static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a,
  76                                const struct tomoyo_acl_info *b)
  77{
  78        const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head);
  79        const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head);
  80
  81        return p1->env == p2->env;
  82}
  83
  84/**
  85 * tomoyo_write_env - Write "struct tomoyo_env_acl" list.
  86 *
  87 * @param: Pointer to "struct tomoyo_acl_param".
  88 *
  89 * Returns 0 on success, negative value otherwise.
  90 *
  91 * Caller holds tomoyo_read_lock().
  92 */
  93static int tomoyo_write_env(struct tomoyo_acl_param *param)
  94{
  95        struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL };
  96        int error = -ENOMEM;
  97        const char *data = tomoyo_read_token(param);
  98
  99        if (!tomoyo_correct_word(data) || strchr(data, '='))
 100                return -EINVAL;
 101        e.env = tomoyo_get_name(data);
 102        if (!e.env)
 103                return error;
 104        error = tomoyo_update_domain(&e.head, sizeof(e), param,
 105                                  tomoyo_same_env_acl, NULL);
 106        tomoyo_put_name(e.env);
 107        return error;
 108}
 109
 110/**
 111 * tomoyo_write_misc - Update environment variable list.
 112 *
 113 * @param: Pointer to "struct tomoyo_acl_param".
 114 *
 115 * Returns 0 on success, negative value otherwise.
 116 */
 117int tomoyo_write_misc(struct tomoyo_acl_param *param)
 118{
 119        if (tomoyo_str_starts(&param->data, "env "))
 120                return tomoyo_write_env(param);
 121        return -EINVAL;
 122}
 123