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_ROUTE_CONTROLLER_H
18 #define NETD_SERVER_ROUTE_CONTROLLER_H
19 
20 #include "NetdConstants.h"
21 #include "Permission.h"
22 
23 #include <sys/types.h>
24 #include <linux/netlink.h>
25 
26 namespace android {
27 namespace net {
28 
29 class UidRanges;
30 
31 class RouteController {
32 public:
33     // How the routing table number is determined for route modification requests.
34     enum TableType {
35         INTERFACE,       // Compute the table number based on the interface index.
36         LOCAL_NETWORK,   // A fixed table used for routes to directly-connected clients/peers.
37         LEGACY_NETWORK,  // Use a fixed table that's used to override the default network.
38         LEGACY_SYSTEM,   // A fixed table, only modifiable by system apps; overrides VPNs too.
39     };
40 
41     static const int ROUTE_TABLE_OFFSET_FROM_INDEX = 1000;
42 
43     static int Init(unsigned localNetId) WARN_UNUSED_RESULT;
44 
45     static int addInterfaceToLocalNetwork(unsigned netId, const char* interface) WARN_UNUSED_RESULT;
46     static int removeInterfaceFromLocalNetwork(unsigned netId,
47                                                const char* interface) WARN_UNUSED_RESULT;
48 
49     static int addInterfaceToPhysicalNetwork(unsigned netId, const char* interface,
50                                              Permission permission) WARN_UNUSED_RESULT;
51     static int removeInterfaceFromPhysicalNetwork(unsigned netId, const char* interface,
52                                                   Permission permission) WARN_UNUSED_RESULT;
53 
54     static int addInterfaceToVirtualNetwork(unsigned netId, const char* interface, bool secure,
55                                             const UidRanges& uidRanges) WARN_UNUSED_RESULT;
56     static int removeInterfaceFromVirtualNetwork(unsigned netId, const char* interface, bool secure,
57                                                  const UidRanges& uidRanges) WARN_UNUSED_RESULT;
58 
59     static int modifyPhysicalNetworkPermission(unsigned netId, const char* interface,
60                                                Permission oldPermission,
61                                                Permission newPermission) WARN_UNUSED_RESULT;
62 
63     static int addUsersToVirtualNetwork(unsigned netId, const char* interface, bool secure,
64                                         const UidRanges& uidRanges) WARN_UNUSED_RESULT;
65     static int removeUsersFromVirtualNetwork(unsigned netId, const char* interface, bool secure,
66                                              const UidRanges& uidRanges) WARN_UNUSED_RESULT;
67 
68     static int addUsersToRejectNonSecureNetworkRule(const UidRanges& uidRanges)
69                                                     WARN_UNUSED_RESULT;
70     static int removeUsersFromRejectNonSecureNetworkRule(const UidRanges& uidRanges)
71                                                          WARN_UNUSED_RESULT;
72 
73     static int addInterfaceToDefaultNetwork(const char* interface,
74                                             Permission permission) WARN_UNUSED_RESULT;
75     static int removeInterfaceFromDefaultNetwork(const char* interface,
76                                                  Permission permission) WARN_UNUSED_RESULT;
77 
78     // |nexthop| can be NULL (to indicate a directly-connected route), "unreachable" (to indicate a
79     // route that's blocked), "throw" (to indicate the lack of a match), or a regular IP address.
80     static int addRoute(const char* interface, const char* destination, const char* nexthop,
81                         TableType tableType) WARN_UNUSED_RESULT;
82     static int removeRoute(const char* interface, const char* destination, const char* nexthop,
83                            TableType tableType) WARN_UNUSED_RESULT;
84 
85     static int enableTethering(const char* inputInterface,
86                                const char* outputInterface) WARN_UNUSED_RESULT;
87     static int disableTethering(const char* inputInterface,
88                                 const char* outputInterface) WARN_UNUSED_RESULT;
89 
90     static int addVirtualNetworkFallthrough(unsigned vpnNetId, const char* physicalInterface,
91                                             Permission permission) WARN_UNUSED_RESULT;
92     static int removeVirtualNetworkFallthrough(unsigned vpnNetId, const char* physicalInterface,
93                                                Permission permission) WARN_UNUSED_RESULT;
94 
95     // For testing.
96     static int (*iptablesRestoreCommandFunction)(IptablesTarget, const std::string&,
97                                                  const std::string&, std::string *);
98 };
99 
100 // Public because they are called by by RouteControllerTest.cpp.
101 // TODO: come up with a scheme of unit testing this code that does not rely on making all its
102 // functions public.
103 int modifyIpRoute(uint16_t action, uint32_t table, const char* interface, const char* destination,
104                   const char* nexthop) WARN_UNUSED_RESULT;
105 int flushRoutes(uint32_t table) WARN_UNUSED_RESULT;
106 uint32_t getRulePriority(const nlmsghdr *nlh);
107 WARN_UNUSED_RESULT int modifyIncomingPacketMark(unsigned netId, const char* interface,
108                                                 Permission permission, bool add);
109 
110 }  // namespace net
111 }  // namespace android
112 
113 #endif  // NETD_SERVER_ROUTE_CONTROLLER_H
114