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 "init.h"
32 #include "util.h"
33
34 namespace android {
35 namespace init {
36
DescriptorInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)37 DescriptorInfo::DescriptorInfo(const std::string& name, const std::string& type, uid_t uid,
38 gid_t gid, int perm, const std::string& context)
39 : name_(name), type_(type), uid_(uid), gid_(gid), perm_(perm), context_(context) {
40 }
41
~DescriptorInfo()42 DescriptorInfo::~DescriptorInfo() {
43 }
44
operator <<(std::ostream & os,const DescriptorInfo & info)45 std::ostream& operator<<(std::ostream& os, const DescriptorInfo& info) {
46 return os << " descriptors " << info.name_ << " " << info.type_ << " " << std::oct << info.perm_;
47 }
48
operator ==(const DescriptorInfo & other) const49 bool DescriptorInfo::operator==(const DescriptorInfo& other) const {
50 return name_ == other.name_ && type_ == other.type_ && key() == other.key();
51 }
52
CreateAndPublish(const std::string & globalContext) const53 void DescriptorInfo::CreateAndPublish(const std::string& globalContext) const {
54 // Create
55 const std::string& contextStr = context_.empty() ? globalContext : context_;
56 int fd = Create(contextStr);
57 if (fd < 0) return;
58
59 // Publish
60 std::string publishedName = key() + name_;
61 std::for_each(publishedName.begin(), publishedName.end(),
62 [] (char& c) { c = isalnum(c) ? c : '_'; });
63
64 std::string val = std::to_string(fd);
65 add_environment(publishedName.c_str(), val.c_str());
66
67 // make sure we don't close on exec
68 fcntl(fd, F_SETFD, 0);
69 }
70
Clean() const71 void DescriptorInfo::Clean() const {
72 }
73
SocketInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)74 SocketInfo::SocketInfo(const std::string& name, const std::string& type, uid_t uid,
75 gid_t gid, int perm, const std::string& context)
76 : DescriptorInfo(name, type, uid, gid, perm, context) {
77 }
78
Clean() const79 void SocketInfo::Clean() const {
80 std::string path = android::base::StringPrintf("%s/%s", ANDROID_SOCKET_DIR, name().c_str());
81 unlink(path.c_str());
82 }
83
Create(const std::string & context) const84 int SocketInfo::Create(const std::string& context) const {
85 auto types = android::base::Split(type(), "+");
86 int flags =
87 ((types[0] == "stream" ? SOCK_STREAM : (types[0] == "dgram" ? SOCK_DGRAM : SOCK_SEQPACKET)));
88 bool passcred = types.size() > 1 && types[1] == "passcred";
89 return CreateSocket(name().c_str(), flags, passcred, perm(), uid(), gid(), context.c_str(),
90 sehandle);
91 }
92
key() const93 const std::string SocketInfo::key() const {
94 return ANDROID_SOCKET_ENV_PREFIX;
95 }
96
FileInfo(const std::string & name,const std::string & type,uid_t uid,gid_t gid,int perm,const std::string & context)97 FileInfo::FileInfo(const std::string& name, const std::string& type, uid_t uid,
98 gid_t gid, int perm, const std::string& context)
99 // defaults OK for uid,..., they are ignored for this class.
100 : DescriptorInfo(name, type, uid, gid, perm, context) {
101 }
102
Create(const std::string &) const103 int FileInfo::Create(const std::string&) const {
104 int flags = (type() == "r") ? O_RDONLY :
105 (type() == "w") ? O_WRONLY :
106 O_RDWR;
107
108 // Make sure we do not block on open (eg: devices can chose to block on
109 // carrier detect). Our intention is never to delay launch of a service
110 // for such a condition. The service can perform its own blocking on
111 // carrier detect.
112 android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(name().c_str(),
113 flags | O_NONBLOCK)));
114
115 if (fd < 0) {
116 PLOG(ERROR) << "Failed to open file '" << name().c_str() << "'";
117 return -1;
118 }
119
120 // Fixup as we set O_NONBLOCK for open, the intent for fd is to block reads.
121 fcntl(fd, F_SETFL, flags);
122
123 LOG(INFO) << "Opened file '" << name().c_str() << "'"
124 << ", flags " << std::oct << flags << std::dec;
125
126 return fd.release();
127 }
128
key() const129 const std::string FileInfo::key() const {
130 return ANDROID_FILE_ENV_PREFIX;
131 }
132
133 } // namespace init
134 } // namespace android
135