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 <unistd.h>
18 #include <sys/socket.h>
19 
20 #include <linux/netlink.h>
21 #include <linux/sock_diag.h>
22 #include <linux/inet_diag.h>
23 
24 #include <functional>
25 #include <set>
26 
27 #include "UidRanges.h"
28 
29 struct inet_diag_msg;
30 class SockDiagTest;
31 
32 class SockDiag {
33 
34   public:
35     static const int kBufferSize = 4096;
36 
37     // Callback function that is called once for every socket in the dump. A return value of true
38     // means destroy the socket.
39     typedef std::function<bool(uint8_t proto, const inet_diag_msg *)> DumpCallback;
40 
41     struct DestroyRequest {
42         nlmsghdr nlh;
43         inet_diag_req_v2 req;
44     } __attribute__((__packed__));
45 
SockDiag()46     SockDiag() : mSock(-1), mWriteSock(-1), mSocketsDestroyed(0) {}
47     bool open();
~SockDiag()48     virtual ~SockDiag() { closeSocks(); }
49 
50     int sendDumpRequest(uint8_t proto, uint8_t family, uint32_t states);
51     int sendDumpRequest(uint8_t proto, uint8_t family, const char *addrstr);
52     int readDiagMsg(uint8_t proto, DumpCallback callback);
53     int sockDestroy(uint8_t proto, const inet_diag_msg *);
54     int destroySockets(const char *addrstr);
55     int destroySockets(uint8_t proto, uid_t uid);
56     int destroySockets(const UidRanges& uidRanges, const std::set<uid_t>& skipUids);
57 
58   private:
59     int mSock;
60     int mWriteSock;
61     int mSocketsDestroyed;
62     int sendDumpRequest(uint8_t proto, uint8_t family, uint32_t states, iovec *iov, int iovcnt);
63     int destroySockets(uint8_t proto, int family, const char *addrstr);
64     int destroyLiveSockets(DumpCallback destroy);
hasSocks()65     bool hasSocks() { return mSock != -1 && mWriteSock != -1; }
closeSocks()66     void closeSocks() { close(mSock); close(mWriteSock); mSock = mWriteSock = -1; }
67 };
68