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  */
  17 static 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  */
  33 static 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  */
  49 int 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  */
  75 static 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  */
  93 static 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  */
 117 int 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 }