1 /*
2 * Copyright 2017, 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 <cutils/qtaguid.h>
18
19 // #define LOG_NDEBUG 0
20
21 #define LOG_TAG "qtaguid"
22
23 #include <dlfcn.h>
24 #include <errno.h>
25 #include <fcntl.h>
26 #include <inttypes.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include <log/log.h>
32
33 class netdHandler {
34 public:
35 int (*netdTagSocket)(int, uint32_t, uid_t);
36 int (*netdUntagSocket)(int);
37 int (*netdSetCounterSet)(uint32_t, uid_t);
38 int (*netdDeleteTagData)(uint32_t, uid_t);
39 };
40
dummyTagSocket(int,uint32_t,uid_t)41 int dummyTagSocket(int, uint32_t, uid_t) {
42 return -EREMOTEIO;
43 }
44
dummyUntagSocket(int)45 int dummyUntagSocket(int) {
46 return -EREMOTEIO;
47 }
48
dummySetCounterSet(uint32_t,uid_t)49 int dummySetCounterSet(uint32_t, uid_t) {
50 return -EREMOTEIO;
51 }
52
dummyDeleteTagData(uint32_t,uid_t)53 int dummyDeleteTagData(uint32_t, uid_t) {
54 return -EREMOTEIO;
55 }
56
initHandler(void)57 netdHandler initHandler(void) {
58 netdHandler handler = {dummyTagSocket, dummyUntagSocket, dummySetCounterSet, dummyDeleteTagData};
59
60 void* netdClientHandle = dlopen("libnetd_client.so", RTLD_NOW);
61 if (!netdClientHandle) {
62 ALOGE("Failed to open libnetd_client.so: %s", dlerror());
63 return handler;
64 }
65
66 handler.netdTagSocket = (int (*)(int, uint32_t, uid_t))dlsym(netdClientHandle, "tagSocket");
67 if (!handler.netdTagSocket) {
68 ALOGE("load netdTagSocket handler failed: %s", dlerror());
69 }
70
71 handler.netdUntagSocket = (int (*)(int))dlsym(netdClientHandle, "untagSocket");
72 if (!handler.netdUntagSocket) {
73 ALOGE("load netdUntagSocket handler failed: %s", dlerror());
74 }
75
76 handler.netdSetCounterSet = (int (*)(uint32_t, uid_t))dlsym(netdClientHandle, "setCounterSet");
77 if (!handler.netdSetCounterSet) {
78 ALOGE("load netdSetCounterSet handler failed: %s", dlerror());
79 }
80
81 handler.netdDeleteTagData = (int (*)(uint32_t, uid_t))dlsym(netdClientHandle, "deleteTagData");
82 if (!handler.netdDeleteTagData) {
83 ALOGE("load netdDeleteTagData handler failed: %s", dlerror());
84 }
85 return handler;
86 }
87
88 // The language guarantees that this object will be initialized in a thread-safe way.
getHandler()89 static netdHandler& getHandler() {
90 static netdHandler instance = initHandler();
91 return instance;
92 }
93
qtaguid_tagSocket(int sockfd,int tag,uid_t uid)94 int qtaguid_tagSocket(int sockfd, int tag, uid_t uid) {
95 // Check the socket fd passed to us is still valid before we load the netd
96 // client. Pass a already closed socket fd to netd client may let netd open
97 // the unix socket with the same fd number and pass it to server for
98 // tagging.
99 // TODO: move the check into netdTagSocket.
100 int res = fcntl(sockfd, F_GETFD);
101 if (res < 0) return res;
102
103 ALOGV("Tagging socket %d with tag %u for uid %d", sockfd, tag, uid);
104 return getHandler().netdTagSocket(sockfd, tag, uid);
105 }
106
qtaguid_untagSocket(int sockfd)107 int qtaguid_untagSocket(int sockfd) {
108 // Similiar to tag socket. We need a check before untag to make sure untag a closed socket fail
109 // as expected.
110 // TODO: move the check into netdTagSocket.
111 int res = fcntl(sockfd, F_GETFD);
112 if (res < 0) return res;
113
114 ALOGV("Untagging socket %d", sockfd);
115 return getHandler().netdUntagSocket(sockfd);
116 }
117
qtaguid_setCounterSet(int counterSetNum,uid_t uid)118 int qtaguid_setCounterSet(int counterSetNum, uid_t uid) {
119 ALOGV("Setting counters to set %d for uid %d", counterSetNum, uid);
120 return getHandler().netdSetCounterSet(counterSetNum, uid);
121 }
122
qtaguid_deleteTagData(int tag,uid_t uid)123 int qtaguid_deleteTagData(int tag, uid_t uid) {
124 ALOGV("Deleting tag data with tag %u for uid %d", tag, uid);
125 return getHandler().netdDeleteTagData(tag, uid);
126 }
127