1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include "linker_namespaces.h"
30#include "linker_globals.h"
31#include "linker_soinfo.h"
32#include "linker_utils.h"
33
34#include <dlfcn.h>
35
36bool android_namespace_t::is_accessible(const std::string& file) {
37  if (!is_isolated_) {
38    return true;
39  }
40
41  for (const auto& dir : ld_library_paths_) {
42    if (file_is_in_dir(file, dir)) {
43      return true;
44    }
45  }
46
47  for (const auto& dir : default_library_paths_) {
48    if (file_is_in_dir(file, dir)) {
49      return true;
50    }
51  }
52
53  for (const auto& dir : permitted_paths_) {
54    if (file_is_under_dir(file, dir)) {
55      return true;
56    }
57  }
58
59  return false;
60}
61
62bool android_namespace_t::is_accessible(soinfo* s) {
63  auto is_accessible_ftor = [this] (soinfo* si) {
64    // This is workaround for apps hacking into soinfo list.
65    // and inserting their own entries into it. (http://b/37191433)
66    if (!si->has_min_version(3)) {
67      DL_WARN("invalid soinfo version for \"%s\"", si->get_soname());
68      return false;
69    }
70
71    if (si->get_primary_namespace() == this) {
72      return true;
73    }
74
75    const android_namespace_list_t& secondary_namespaces = si->get_secondary_namespaces();
76    if (secondary_namespaces.find(this) != secondary_namespaces.end()) {
77      return true;
78    }
79
80    return false;
81  };
82
83  if (is_accessible_ftor(s)) {
84    return true;
85  }
86
87  return !s->get_parents().visit([&](soinfo* si) {
88    return !is_accessible_ftor(si);
89  });
90}
91
92// TODO: this is slightly unusual way to construct
93// the global group for relocation. Not every RTLD_GLOBAL
94// library is included in this group for backwards-compatibility
95// reasons.
96//
97// This group consists of the main executable, LD_PRELOADs
98// and libraries with the DF_1_GLOBAL flag set.
99soinfo_list_t android_namespace_t::get_global_group() {
100  soinfo_list_t global_group;
101  soinfo_list().for_each([&](soinfo* si) {
102    if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
103      global_group.push_back(si);
104    }
105  });
106
107  return global_group;
108}
109
110// This function provides a list of libraries to be shared
111// by the namespace. For the default namespace this is the global
112// group (see get_global_group). For all others this is a group
113// of RTLD_GLOBAL libraries (which includes the global group from
114// the default namespace).
115soinfo_list_t android_namespace_t::get_shared_group() {
116  if (this == &g_default_namespace) {
117    return get_global_group();
118  }
119
120  soinfo_list_t shared_group;
121  soinfo_list().for_each([&](soinfo* si) {
122    if ((si->get_rtld_flags() & RTLD_GLOBAL) != 0) {
123      shared_group.push_back(si);
124    }
125  });
126
127  return shared_group;
128}
129