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 if (!whitelisted_libs_.empty()) {
42 const char *lib_name = basename(file.c_str());
43 if (std::find(whitelisted_libs_.begin(), whitelisted_libs_.end(),
44 lib_name) == whitelisted_libs_.end()) {
45 return false;
46 }
47 }
48
49 for (const auto& dir : ld_library_paths_) {
50 if (file_is_in_dir(file, dir)) {
51 return true;
52 }
53 }
54
55 for (const auto& dir : default_library_paths_) {
56 if (file_is_in_dir(file, dir)) {
57 return true;
58 }
59 }
60
61 for (const auto& dir : permitted_paths_) {
62 if (file_is_under_dir(file, dir)) {
63 return true;
64 }
65 }
66
67 return false;
68 }
69
is_accessible(soinfo * s)70 bool android_namespace_t::is_accessible(soinfo* s) {
71 auto is_accessible_ftor = [this] (soinfo* si) {
72 // This is workaround for apps hacking into soinfo list.
73 // and inserting their own entries into it. (http://b/37191433)
74 if (!si->has_min_version(3)) {
75 DL_WARN("Warning: invalid soinfo version for \"%s\" (assuming inaccessible)",
76 si->get_soname());
77 return false;
78 }
79
80 if (si->get_primary_namespace() == this) {
81 return true;
82 }
83
84 const android_namespace_list_t& secondary_namespaces = si->get_secondary_namespaces();
85 if (secondary_namespaces.find(this) != secondary_namespaces.end()) {
86 return true;
87 }
88
89 return false;
90 };
91
92 if (is_accessible_ftor(s)) {
93 return true;
94 }
95
96 return !s->get_parents().visit([&](soinfo* si) {
97 return !is_accessible_ftor(si);
98 });
99 }
100
101 // TODO: this is slightly unusual way to construct
102 // the global group for relocation. Not every RTLD_GLOBAL
103 // library is included in this group for backwards-compatibility
104 // reasons.
105 //
106 // This group consists of the main executable, LD_PRELOADs
107 // and libraries with the DF_1_GLOBAL flag set.
get_global_group()108 soinfo_list_t android_namespace_t::get_global_group() {
109 soinfo_list_t global_group;
110 soinfo_list().for_each([&](soinfo* si) {
111 if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
112 global_group.push_back(si);
113 }
114 });
115
116 return global_group;
117 }
118
119 // This function provides a list of libraries to be shared
120 // by the namespace. For the default namespace this is the global
121 // group (see get_global_group). For all others this is a group
122 // of RTLD_GLOBAL libraries (which includes the global group from
123 // the default namespace).
get_shared_group()124 soinfo_list_t android_namespace_t::get_shared_group() {
125 if (this == &g_default_namespace) {
126 return get_global_group();
127 }
128
129 soinfo_list_t shared_group;
130 soinfo_list().for_each([&](soinfo* si) {
131 if ((si->get_rtld_flags() & RTLD_GLOBAL) != 0) {
132 shared_group.push_back(si);
133 }
134 });
135
136 return shared_group;
137 }
138