1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "descriptors.h"
18
19 #include <ctype.h>
20 #include <fcntl.h>
21 #include <sys/stat.h>
22 #include <unistd.h>
23
24 #include <android-base/logging.h>
25 #include <android-base/stringprintf.h>
26 #include <android-base/strings.h>
27 #include <android-base/unique_fd.h>
28 #include <cutils/android_get_control_file.h>
29 #include <cutils/sockets.h>
30
31 #include "util.h"
32
33 namespace android {
34 namespace init {
35
DescriptorInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)36 DescriptorInfo::DescriptorInfo(const std::string& name, const std::string& type, uid_t uid,
37 gid_t gid, int perm, const std::string& context)
38 : name_(name), type_(type), uid_(uid), gid_(gid), perm_(perm), context_(context) {
39 }
40
~DescriptorInfo()41 DescriptorInfo::~DescriptorInfo() {
42 }
43
operator <<(std::ostream & os,const DescriptorInfo & info)44 std::ostream& operator<<(std::ostream& os, const DescriptorInfo& info) {
45 return os << " descriptors " << info.name_ << " " << info.type_ << " " << std::oct << info.perm_;
46 }
47
operator ==(const DescriptorInfo & other) const48 bool DescriptorInfo::operator==(const DescriptorInfo& other) const {
49 return name_ == other.name_ && type_ == other.type_ && key() == other.key();
50 }
51
CreateAndPublish(const std::string & globalContext) const52 void DescriptorInfo::CreateAndPublish(const std::string& globalContext) const {
53 // Create
54 const std::string& contextStr = context_.empty() ? globalContext : context_;
55 int fd = Create(contextStr);
56 if (fd < 0) return;
57
58 // Publish
59 std::string publishedName = key() + name_;
60 std::for_each(publishedName.begin(), publishedName.end(),
61 [] (char& c) { c = isalnum(c) ? c : '_'; });
62
63 std::string val = std::to_string(fd);
64 setenv(publishedName.c_str(), val.c_str(), 1);
65
66 // make sure we don't close on exec
67 fcntl(fd, F_SETFD, 0);
68 }
69
Clean() const70 void DescriptorInfo::Clean() const {
71 }
72
SocketInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)73 SocketInfo::SocketInfo(const std::string& name, const std::string& type, uid_t uid,
74 gid_t gid, int perm, const std::string& context)
75 : DescriptorInfo(name, type, uid, gid, perm, context) {
76 }
77
Clean() const78 void SocketInfo::Clean() const {
79 std::string path = android::base::StringPrintf("%s/%s", ANDROID_SOCKET_DIR, name().c_str());
80 unlink(path.c_str());
81 }
82
Create(const std::string & context) const83 int SocketInfo::Create(const std::string& context) const {
84 auto types = android::base::Split(type(), "+");
85 int flags =
86 ((types[0] == "stream" ? SOCK_STREAM : (types[0] == "dgram" ? SOCK_DGRAM : SOCK_SEQPACKET)));
87 bool passcred = types.size() > 1 && types[1] == "passcred";
88 return CreateSocket(name().c_str(), flags, passcred, perm(), uid(), gid(), context.c_str());
89 }
90
key() const91 const std::string SocketInfo::key() const {
92 return ANDROID_SOCKET_ENV_PREFIX;
93 }
94
FileInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)95 FileInfo::FileInfo(const std::string& name, const std::string& type, uid_t uid,
96 gid_t gid, int perm, const std::string& context)
97 // defaults OK for uid,..., they are ignored for this class.
98 : DescriptorInfo(name, type, uid, gid, perm, context) {
99 }
100
Create(const std::string &) const101 int FileInfo::Create(const std::string&) const {
102 int flags = (type() == "r") ? O_RDONLY :
103 (type() == "w") ? O_WRONLY :
104 O_RDWR;
105
106 // Make sure we do not block on open (eg: devices can chose to block on
107 // carrier detect). Our intention is never to delay launch of a service
108 // for such a condition. The service can perform its own blocking on
109 // carrier detect.
110 android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(name().c_str(),
111 flags | O_NONBLOCK)));
112
113 if (fd < 0) {
114 PLOG(ERROR) << "Failed to open file '" << name().c_str() << "'";
115 return -1;
116 }
117
118 // Fixup as we set O_NONBLOCK for open, the intent for fd is to block reads.
119 fcntl(fd, F_SETFL, flags);
120
121 LOG(INFO) << "Opened file '" << name().c_str() << "'"
122 << ", flags " << std::oct << flags << std::dec;
123
124 return fd.release();
125 }
126
key() const127 const std::string FileInfo::key() const {
128 return ANDROID_FILE_ENV_PREFIX;
129 }
130
131 } // namespace init
132 } // namespace android
133