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 #ifndef _SOCK_DIAG_H 18 #define _SOCK_DIAG_H 19 20 #include <unistd.h> 21 #include <sys/socket.h> 22 23 #include <linux/netlink.h> 24 #include <linux/sock_diag.h> 25 #include <linux/inet_diag.h> 26 27 #include <functional> 28 #include <set> 29 30 #include "Fwmark.h" 31 #include "NetlinkCommands.h" 32 #include "Permission.h" 33 #include "UidRanges.h" 34 35 struct inet_diag_msg; 36 struct tcp_info; 37 38 namespace android { 39 namespace net { 40 41 class SockDiag { 42 43 public: 44 static const int kBufferSize = 4096; 45 46 // Callback function that is called once for every socket in the sockDestroy dump. 47 // A return value of true means destroy the socket. 48 typedef std::function<bool(uint8_t proto, const inet_diag_msg *)> DestroyFilter; 49 50 // Callback function that is called once for every socket in the sockInfo dump. 51 // 'tcp_info_length' is the length in bytes of the INET_DIAG_INFO attribute read from Netlink. 52 // Knowing this length is necessary for handling struct tcp_info serialized from different 53 // kernel versions. 54 typedef std::function<void(Fwmark mark, const struct inet_diag_msg *, const struct tcp_info *, 55 uint32_t tcp_info_length)> TcpInfoReader; 56 57 struct DestroyRequest { 58 nlmsghdr nlh; 59 inet_diag_req_v2 req; 60 } __attribute__((__packed__)); 61 SockDiag()62 SockDiag() : mSock(-1), mWriteSock(-1), mSocketsDestroyed(0) {} 63 bool open(); ~SockDiag()64 virtual ~SockDiag() { closeSocks(); } 65 66 int sendDumpRequest(uint8_t proto, uint8_t family, uint32_t states); 67 int sendDumpRequest(uint8_t proto, uint8_t family, const char *addrstr); 68 int readDiagMsg(uint8_t proto, const DestroyFilter& callback); 69 int readDiagMsgWithTcpInfo(const TcpInfoReader& callback); 70 71 int sockDestroy(uint8_t proto, const inet_diag_msg *); 72 // Destroys all sockets on the given IPv4 or IPv6 address. 73 int destroySockets(const char* addrstr, int ifindex); 74 // Destroys all sockets for the given protocol and UID. 75 int destroySockets(uint8_t proto, uid_t uid, bool excludeLoopback); 76 // Destroys all "live" (CONNECTED, SYN_SENT, SYN_RECV) TCP sockets that no longer have 77 // the permissions required by the specified network. 78 int destroySocketsLackingPermission(unsigned netId, Permission permission, 79 bool excludeLoopback); 80 81 // Dump struct tcp_info for all "live" (CONNECTED, SYN_SENT, SYN_RECV) TCP sockets. 82 int getLiveTcpInfos(const TcpInfoReader& sockInfoReader); 83 84 private: 85 friend class SockDiagTest; 86 int mSock; 87 int mWriteSock; 88 int mSocketsDestroyed; 89 int sendDumpRequest(uint8_t proto, uint8_t family, uint8_t extensions, uint32_t states, 90 iovec *iov, int iovcnt); 91 int destroySockets(uint8_t proto, int family, const char* addrstr, int ifindex); 92 int destroyLiveSockets(const DestroyFilter& destroy, const char *what, iovec *iov, int iovcnt); hasSocks()93 bool hasSocks() { return mSock != -1 && mWriteSock != -1; } closeSocks()94 void closeSocks() { close(mSock); close(mWriteSock); mSock = mWriteSock = -1; } 95 static bool isLoopbackSocket(const inet_diag_msg *msg); 96 }; 97 98 } // namespace net 99 } // namespace android 100 101 #endif // _SOCK_DIAG_H 102