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
is_accessible(const std::string & file)36 bool 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
is_accessible(soinfo * s)62 bool 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("Warning: invalid soinfo version for \"%s\" (assuming inaccessible)",
68 si->get_soname());
69 return false;
70 }
71
72 if (si->get_primary_namespace() == this) {
73 return true;
74 }
75
76 const android_namespace_list_t& secondary_namespaces = si->get_secondary_namespaces();
77 if (secondary_namespaces.find(this) != secondary_namespaces.end()) {
78 return true;
79 }
80
81 return false;
82 };
83
84 if (is_accessible_ftor(s)) {
85 return true;
86 }
87
88 return !s->get_parents().visit([&](soinfo* si) {
89 return !is_accessible_ftor(si);
90 });
91 }
92
93 // TODO: this is slightly unusual way to construct
94 // the global group for relocation. Not every RTLD_GLOBAL
95 // library is included in this group for backwards-compatibility
96 // reasons.
97 //
98 // This group consists of the main executable, LD_PRELOADs
99 // and libraries with the DF_1_GLOBAL flag set.
get_global_group()100 soinfo_list_t android_namespace_t::get_global_group() {
101 soinfo_list_t global_group;
102 soinfo_list().for_each([&](soinfo* si) {
103 if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
104 global_group.push_back(si);
105 }
106 });
107
108 return global_group;
109 }
110
111 // This function provides a list of libraries to be shared
112 // by the namespace. For the default namespace this is the global
113 // group (see get_global_group). For all others this is a group
114 // of RTLD_GLOBAL libraries (which includes the global group from
115 // the default namespace).
get_shared_group()116 soinfo_list_t android_namespace_t::get_shared_group() {
117 if (this == &g_default_namespace) {
118 return get_global_group();
119 }
120
121 soinfo_list_t shared_group;
122 soinfo_list().for_each([&](soinfo* si) {
123 if ((si->get_rtld_flags() & RTLD_GLOBAL) != 0) {
124 shared_group.push_back(si);
125 }
126 });
127
128 return shared_group;
129 }
130