1 /*
2 * Copyright (C) 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 #include "common/libs/net/network_interface_manager.h"
17
18 #include <stddef.h>
19 #include <stdint.h>
20
21 #include <arpa/inet.h>
22 #include <linux/if_addr.h>
23 #include <linux/if_link.h>
24 #include <linux/netlink.h>
25 #include <linux/rtnetlink.h>
26 #include <net/if.h>
27 #include <netinet/in.h>
28
29 #include <memory>
30 #include <ostream>
31 #include <string>
32 #include <utility>
33
34 #include "android-base/logging.h"
35 #include "common/libs/net/netlink_client.h"
36 #include "common/libs/net/netlink_request.h"
37 #include "common/libs/net/network_interface.h"
38
39 namespace cuttlefish {
40 namespace {
BuildLinkRequest(const NetworkInterface & interface)41 NetlinkRequest BuildLinkRequest(
42 const NetworkInterface& interface) {
43 NetlinkRequest request(RTM_SETLINK, 0);
44 request.AddIfInfo(interface.Index(), interface.IsOperational());
45 if (!interface.Name().empty()) {
46 request.AddString(IFLA_IFNAME, interface.Name());
47 }
48
49 return request;
50 }
51
BuildAddrRequest(const NetworkInterface & interface)52 NetlinkRequest BuildAddrRequest(
53 const NetworkInterface& interface) {
54 NetlinkRequest request(RTM_NEWADDR, 0);
55 request.AddAddrInfo(interface.Index(), interface.PrefixLength());
56 in_addr_t address{inet_addr(interface.Address().c_str())};
57 request.AddInt(IFA_LOCAL, address);
58 request.AddInt(IFA_ADDRESS, address);
59 request.AddInt(IFA_BROADCAST,
60 inet_addr(interface.BroadcastAddress().c_str()));
61
62 return request;
63 }
64 } // namespace
65
New(NetlinkClientFactory * nl_factory)66 std::unique_ptr<NetworkInterfaceManager> NetworkInterfaceManager::New(
67 NetlinkClientFactory* nl_factory) {
68 std::unique_ptr<NetworkInterfaceManager> mgr;
69
70 if (nl_factory == NULL) {
71 nl_factory = NetlinkClientFactory::Default();
72 }
73
74 auto client = nl_factory->New(NETLINK_ROUTE);
75 if (client) {
76 mgr.reset(new NetworkInterfaceManager(std::move(client)));
77 }
78
79 return mgr;
80 }
81
NetworkInterfaceManager(std::unique_ptr<NetlinkClient> nl_client)82 NetworkInterfaceManager::NetworkInterfaceManager(
83 std::unique_ptr<NetlinkClient> nl_client)
84 : nl_client_(std::move(nl_client)) {}
85
Open(const std::string & if_name,const std::string & if_name_alt)86 std::unique_ptr<NetworkInterface> NetworkInterfaceManager::Open(
87 const std::string& if_name, const std::string& if_name_alt) {
88 std::unique_ptr<NetworkInterface> iface;
89 // NOTE: do not replace this code with an IOCTL call.
90 // On SELinux enabled Androids, RILD is not permitted to execute an IOCTL
91 // and this call will fail.
92 int32_t index = if_nametoindex(if_name.c_str());
93 if (index == 0) {
94 // Try the alternate name. This will be renamed to our preferred name
95 // by the kernel, because we specify IFLA_IFNAME, but open by index.
96 LOG(ERROR) << "Failed to get interface (" << if_name << ") index, "
97 << "trying alternate.";
98 index = if_nametoindex(if_name_alt.c_str());
99 if (index == 0) {
100 LOG(ERROR) << "Failed to get interface (" << if_name_alt << ") index.";
101 return iface;
102 }
103 }
104
105 iface.reset(new NetworkInterface(index));
106 return iface;
107 }
108
ApplyChanges(const NetworkInterface & iface)109 bool NetworkInterfaceManager::ApplyChanges(const NetworkInterface& iface) {
110 if (!nl_client_->Send(BuildLinkRequest(iface))) {
111 return false;
112 }
113 // Terminate immediately if interface is down.
114 if (!iface.IsOperational()) {
115 return true;
116 }
117 return nl_client_->Send(BuildAddrRequest(iface));
118 }
119
120 } // namespace cuttlefish
121