1/*
2 * Copyright (C) 2008 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 <errno.h>
18#include <stdio.h>
19#include <string.h>
20
21#include <sys/socket.h>
22#include <sys/select.h>
23#include <sys/time.h>
24#include <sys/types.h>
25#include <sys/un.h>
26
27#include <linux/netlink.h>
28#include <linux/rtnetlink.h>
29
30#define LOG_TAG "Netd"
31
32#include <cutils/log.h>
33
34#include <linux/netfilter/nfnetlink.h>
35#include <linux/netfilter/nfnetlink_log.h>
36#include <linux/netfilter/nfnetlink_compat.h>
37
38#include <arpa/inet.h>
39
40#include "NetlinkManager.h"
41#include "NetlinkHandler.h"
42
43#include "pcap-netfilter-linux-android.h"
44
45namespace android {
46namespace net {
47
48const int NetlinkManager::NFLOG_QUOTA_GROUP = 1;
49const int NetlinkManager::NETFILTER_STRICT_GROUP = 2;
50const int NetlinkManager::NFLOG_WAKEUP_GROUP = 3;
51
52NetlinkManager *NetlinkManager::sInstance = NULL;
53
54NetlinkManager *NetlinkManager::Instance() {
55    if (!sInstance)
56        sInstance = new NetlinkManager();
57    return sInstance;
58}
59
60NetlinkManager::NetlinkManager() {
61    mBroadcaster = NULL;
62}
63
64NetlinkManager::~NetlinkManager() {
65}
66
67NetlinkHandler *NetlinkManager::setupSocket(int *sock, int netlinkFamily,
68    int groups, int format, bool configNflog) {
69
70    struct sockaddr_nl nladdr;
71    int sz = 64 * 1024;
72    int on = 1;
73
74    memset(&nladdr, 0, sizeof(nladdr));
75    nladdr.nl_family = AF_NETLINK;
76    // Kernel will assign a unique nl_pid if set to zero.
77    nladdr.nl_pid = 0;
78    nladdr.nl_groups = groups;
79
80    if ((*sock = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, netlinkFamily)) < 0) {
81        ALOGE("Unable to create netlink socket: %s", strerror(errno));
82        return NULL;
83    }
84
85    // When running in a net/user namespace, SO_RCVBUFFORCE will fail because
86    // it will check for the CAP_NET_ADMIN capability in the root namespace.
87    // Try using SO_RCVBUF if that fails.
88    if (setsockopt(*sock, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)) < 0 &&
89        setsockopt(*sock, SOL_SOCKET, SO_RCVBUF, &sz, sizeof(sz)) < 0) {
90        ALOGE("Unable to set uevent socket SO_RCVBUF option: %s", strerror(errno));
91        close(*sock);
92        return NULL;
93    }
94
95    if (setsockopt(*sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0) {
96        SLOGE("Unable to set uevent socket SO_PASSCRED option: %s", strerror(errno));
97        close(*sock);
98        return NULL;
99    }
100
101    if (bind(*sock, (struct sockaddr *) &nladdr, sizeof(nladdr)) < 0) {
102        ALOGE("Unable to bind netlink socket: %s", strerror(errno));
103        close(*sock);
104        return NULL;
105    }
106
107    if (configNflog) {
108        if (android_nflog_send_config_cmd(*sock, 0, NFULNL_CFG_CMD_PF_UNBIND, AF_INET) < 0) {
109            ALOGE("Failed NFULNL_CFG_CMD_PF_UNBIND: %s", strerror(errno));
110            return NULL;
111        }
112        if (android_nflog_send_config_cmd(*sock, 0, NFULNL_CFG_CMD_PF_BIND, AF_INET) < 0) {
113            ALOGE("Failed NFULNL_CFG_CMD_PF_BIND: %s", strerror(errno));
114            return NULL;
115        }
116        if (android_nflog_send_config_cmd(*sock, 0, NFULNL_CFG_CMD_BIND, AF_UNSPEC) < 0) {
117            ALOGE("Failed NFULNL_CFG_CMD_BIND: %s", strerror(errno));
118            return NULL;
119        }
120    }
121
122    NetlinkHandler *handler = new NetlinkHandler(this, *sock, format);
123    if (handler->start()) {
124        ALOGE("Unable to start NetlinkHandler: %s", strerror(errno));
125        close(*sock);
126        return NULL;
127    }
128
129    return handler;
130}
131
132int NetlinkManager::start() {
133    if ((mUeventHandler = setupSocket(&mUeventSock, NETLINK_KOBJECT_UEVENT,
134         0xffffffff, NetlinkListener::NETLINK_FORMAT_ASCII, false)) == NULL) {
135        return -1;
136    }
137
138    if ((mRouteHandler = setupSocket(&mRouteSock, NETLINK_ROUTE,
139                                     RTMGRP_LINK |
140                                     RTMGRP_IPV4_IFADDR |
141                                     RTMGRP_IPV6_IFADDR |
142                                     RTMGRP_IPV6_ROUTE |
143                                     (1 << (RTNLGRP_ND_USEROPT - 1)),
144         NetlinkListener::NETLINK_FORMAT_BINARY, false)) == NULL) {
145        return -1;
146    }
147
148    if ((mQuotaHandler = setupSocket(&mQuotaSock, NETLINK_NFLOG,
149            NFLOG_QUOTA_GROUP, NetlinkListener::NETLINK_FORMAT_BINARY, false)) == NULL) {
150        ALOGW("Unable to open qlog quota socket, check if xt_quota2 can send via UeventHandler");
151        // TODO: return -1 once the emulator gets a new kernel.
152    }
153
154    if ((mStrictHandler = setupSocket(&mStrictSock, NETLINK_NETFILTER,
155            0, NetlinkListener::NETLINK_FORMAT_BINARY_UNICAST, true)) == NULL) {
156        ALOGE("Unable to open strict socket");
157        // TODO: return -1 once the emulator gets a new kernel.
158    }
159
160    return 0;
161}
162
163int NetlinkManager::stop() {
164    int status = 0;
165
166    if (mUeventHandler->stop()) {
167        ALOGE("Unable to stop uevent NetlinkHandler: %s", strerror(errno));
168        status = -1;
169    }
170
171    delete mUeventHandler;
172    mUeventHandler = NULL;
173
174    close(mUeventSock);
175    mUeventSock = -1;
176
177    if (mRouteHandler->stop()) {
178        ALOGE("Unable to stop route NetlinkHandler: %s", strerror(errno));
179        status = -1;
180    }
181
182    delete mRouteHandler;
183    mRouteHandler = NULL;
184
185    close(mRouteSock);
186    mRouteSock = -1;
187
188    if (mQuotaHandler) {
189        if (mQuotaHandler->stop()) {
190            ALOGE("Unable to stop quota NetlinkHandler: %s", strerror(errno));
191            status = -1;
192        }
193
194        delete mQuotaHandler;
195        mQuotaHandler = NULL;
196
197        close(mQuotaSock);
198        mQuotaSock = -1;
199    }
200
201    if (mStrictHandler) {
202        if (mStrictHandler->stop()) {
203            ALOGE("Unable to stop strict NetlinkHandler: %s", strerror(errno));
204            status = -1;
205        }
206
207        delete mStrictHandler;
208        mStrictHandler = NULL;
209
210        close(mStrictSock);
211        mStrictSock = -1;
212    }
213
214    return status;
215}
216
217}  // namespace net
218}  // namespace android
219