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      1 /*
      2  * Copyright (C) 2014 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 NETD_SERVER_NETWORK_CONTROLLER_H
     18 #define NETD_SERVER_NETWORK_CONTROLLER_H
     19 
     20 #include "NetdConstants.h"
     21 #include "Permission.h"
     22 
     23 #include "utils/RWLock.h"
     24 
     25 #include <list>
     26 #include <map>
     27 #include <set>
     28 #include <sys/types.h>
     29 #include <vector>
     30 
     31 class DumpWriter;
     32 class Network;
     33 class UidRanges;
     34 class VirtualNetwork;
     35 
     36 /*
     37  * Keeps track of default, per-pid, and per-uid-range network selection, as
     38  * well as the mark associated with each network. Networks are identified
     39  * by netid. In all set* commands netid == 0 means "unspecified" and is
     40  * equivalent to clearing the mapping.
     41  */
     42 class NetworkController {
     43 public:
     44     static const unsigned MIN_OEM_ID;
     45     static const unsigned MAX_OEM_ID;
     46     static const unsigned LOCAL_NET_ID;
     47     static const unsigned DUMMY_NET_ID;
     48 
     49     NetworkController();
     50 
     51     unsigned getDefaultNetwork() const;
     52     int setDefaultNetwork(unsigned netId) WARN_UNUSED_RESULT;
     53 
     54     // Sets |*netId| to an appropriate NetId to use for DNS for the given user. Call with |*netId|
     55     // set to a non-NETID_UNSET value if the user already has indicated a preference. Returns the
     56     // fwmark value to set on the socket when performing the DNS request.
     57     uint32_t getNetworkForDns(unsigned* netId, uid_t uid) const;
     58     unsigned getNetworkForUser(uid_t uid) const;
     59     unsigned getNetworkForConnect(uid_t uid) const;
     60     void getNetworkContext(unsigned netId, uid_t uid, struct android_net_context* netcontext) const;
     61     unsigned getNetworkForInterface(const char* interface) const;
     62     bool isVirtualNetwork(unsigned netId) const;
     63 
     64     int createPhysicalNetwork(unsigned netId, Permission permission) WARN_UNUSED_RESULT;
     65     int createVirtualNetwork(unsigned netId, bool hasDns, bool secure) WARN_UNUSED_RESULT;
     66     int destroyNetwork(unsigned netId) WARN_UNUSED_RESULT;
     67 
     68     int addInterfaceToNetwork(unsigned netId, const char* interface) WARN_UNUSED_RESULT;
     69     int removeInterfaceFromNetwork(unsigned netId, const char* interface) WARN_UNUSED_RESULT;
     70 
     71     Permission getPermissionForUser(uid_t uid) const;
     72     void setPermissionForUsers(Permission permission, const std::vector<uid_t>& uids);
     73     int checkUserNetworkAccess(uid_t uid, unsigned netId) const;
     74     int setPermissionForNetworks(Permission permission,
     75                                  const std::vector<unsigned>& netIds) WARN_UNUSED_RESULT;
     76 
     77     int addUsersToNetwork(unsigned netId, const UidRanges& uidRanges) WARN_UNUSED_RESULT;
     78     int removeUsersFromNetwork(unsigned netId, const UidRanges& uidRanges) WARN_UNUSED_RESULT;
     79 
     80     // |nexthop| can be NULL (to indicate a directly-connected route), "unreachable" (to indicate a
     81     // route that's blocked), "throw" (to indicate the lack of a match), or a regular IP address.
     82     //
     83     // Routes are added to tables determined by the interface, so only |interface| is actually used.
     84     // |netId| is given only to sanity check that the interface has the correct netId.
     85     int addRoute(unsigned netId, const char* interface, const char* destination,
     86                  const char* nexthop, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
     87     int removeRoute(unsigned netId, const char* interface, const char* destination,
     88                     const char* nexthop, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
     89 
     90     bool canProtect(uid_t uid) const;
     91     void allowProtect(const std::vector<uid_t>& uids);
     92     void denyProtect(const std::vector<uid_t>& uids);
     93 
     94     void dump(DumpWriter& dw);
     95 
     96 private:
     97     bool isValidNetwork(unsigned netId) const;
     98     Network* getNetworkLocked(unsigned netId) const;
     99     VirtualNetwork* getVirtualNetworkForUserLocked(uid_t uid) const;
    100     Permission getPermissionForUserLocked(uid_t uid) const;
    101     int checkUserNetworkAccessLocked(uid_t uid, unsigned netId) const;
    102 
    103     int modifyRoute(unsigned netId, const char* interface, const char* destination,
    104                     const char* nexthop, bool add, bool legacy, uid_t uid) WARN_UNUSED_RESULT;
    105     int modifyFallthroughLocked(unsigned vpnNetId, bool add) WARN_UNUSED_RESULT;
    106 
    107     class DelegateImpl;
    108     DelegateImpl* const mDelegateImpl;
    109 
    110     // mRWLock guards all accesses to mDefaultNetId, mNetworks, mUsers and mProtectableUsers.
    111     mutable android::RWLock mRWLock;
    112     unsigned mDefaultNetId;
    113     std::map<unsigned, Network*> mNetworks;  // Map keys are NetIds.
    114     std::map<uid_t, Permission> mUsers;
    115     std::set<uid_t> mProtectableUsers;
    116 };
    117 
    118 #endif  // NETD_SERVER_NETWORK_CONTROLLER_H
    119