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Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -07001/*
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#include "RouteController.h"
18
19#include "Fwmark.h"
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -070020#include "UidRanges.h"
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -070021
22#define LOG_TAG "Netd"
23#include "log/log.h"
24#include "logwrap/logwrap.h"
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -070025#include "resolv_netid.h"
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -070026
Lorenzo Colittiba25df92014-06-18 00:22:17 +090027#include <arpa/inet.h>
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070028#include <fcntl.h>
Lorenzo Colitti4753afd2014-06-20 23:03:29 +090029#include <linux/fib_rules.h>
Paul Jensena561e122014-06-12 16:46:37 -040030#include <map>
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -070031#include <net/if.h>
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070032#include <sys/stat.h>
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -070033
34namespace {
35
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -070036// BEGIN CONSTANTS --------------------------------------------------------------------------------
37
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -070038const uint32_t RULE_PRIORITY_VPN_OVERRIDE_SYSTEM = 10000;
39// const uint32_t RULE_PRIORITY_VPN_OVERRIDE_LOCAL = 11000;
40const uint32_t RULE_PRIORITY_SECURE_VPN = 12000;
41const uint32_t RULE_PRIORITY_EXPLICIT_NETWORK = 13000;
42const uint32_t RULE_PRIORITY_OUTPUT_INTERFACE = 14000;
43const uint32_t RULE_PRIORITY_LEGACY_SYSTEM = 15000;
44const uint32_t RULE_PRIORITY_LEGACY_NETWORK = 16000;
Sreeram Ramachandran6a773532014-07-11 09:10:20 -070045const uint32_t RULE_PRIORITY_LOCAL_NETWORK = 17000;
Sreeram Ramachandran87475a12014-07-15 16:20:28 -070046const uint32_t RULE_PRIORITY_TETHERING = 18000;
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -070047const uint32_t RULE_PRIORITY_IMPLICIT_NETWORK = 19000;
48// const uint32_t RULE_PRIORITY_BYPASSABLE_VPN = 20000;
49// const uint32_t RULE_PRIORITY_VPN_FALLTHROUGH = 21000;
50const uint32_t RULE_PRIORITY_DEFAULT_NETWORK = 22000;
51const uint32_t RULE_PRIORITY_DIRECTLY_CONNECTED = 23000;
52const uint32_t RULE_PRIORITY_UNREACHABLE = 24000;
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -070053
Sreeram Ramachandran87475a12014-07-15 16:20:28 -070054const uint32_t ROUTE_TABLE_LOCAL_NETWORK = 97;
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070055const uint32_t ROUTE_TABLE_LEGACY_NETWORK = 98;
56const uint32_t ROUTE_TABLE_LEGACY_SYSTEM = 99;
57
Sreeram Ramachandran87475a12014-07-15 16:20:28 -070058const char* const ROUTE_TABLE_NAME_LOCAL_NETWORK = "local_network";
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070059const char* const ROUTE_TABLE_NAME_LEGACY_NETWORK = "legacy_network";
60const char* const ROUTE_TABLE_NAME_LEGACY_SYSTEM = "legacy_system";
61
Sreeram Ramachandranbb40d512014-07-11 11:45:14 -070062const char* const ROUTE_TABLE_NAME_LOCAL = "local";
63const char* const ROUTE_TABLE_NAME_MAIN = "main";
64
Lorenzo Colitti59656512014-06-25 03:20:29 +090065// TODO: These values aren't defined by the Linux kernel, because our UID routing changes are not
66// upstream (yet?), so we can't just pick them up from kernel headers. When (if?) the changes make
67// it upstream, we'll remove this and rely on the kernel header values. For now, add a static assert
68// that will warn us if upstream has given these values some other meaning.
69const uint16_t FRA_UID_START = 18;
70const uint16_t FRA_UID_END = 19;
71static_assert(FRA_UID_START > FRA_MAX,
72 "Android-specific FRA_UID_{START,END} values also assigned in Linux uapi. "
73 "Check that these values match what the kernel does and then update this assertion.");
74
Lorenzo Colitti72723682014-06-26 13:51:10 +090075const uint16_t NETLINK_REQUEST_FLAGS = NLM_F_REQUEST | NLM_F_ACK;
76const uint16_t NETLINK_CREATE_REQUEST_FLAGS = NETLINK_REQUEST_FLAGS | NLM_F_CREATE | NLM_F_EXCL;
Lorenzo Colitti4753afd2014-06-20 23:03:29 +090077
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -070078const sockaddr_nl NETLINK_ADDRESS = {AF_NETLINK, 0, 0, 0};
79
80const uint8_t AF_FAMILIES[] = {AF_INET, AF_INET6};
81
82const char* const IP_VERSIONS[] = {"-4", "-6"};
83
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -070084const uid_t UID_ROOT = 0;
Sreeram Ramachandran87475a12014-07-15 16:20:28 -070085const char* const IIF_NONE = NULL;
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -070086const char* const OIF_NONE = NULL;
87const bool ACTION_ADD = true;
88const bool ACTION_DEL = false;
89const bool MODIFY_NON_UID_BASED_RULES = true;
90
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070091const char* const RT_TABLES_PATH = "/data/misc/net/rt_tables";
Sreeram Ramachandranc7d804c2014-07-09 07:39:30 -070092const int RT_TABLES_FLAGS = O_CREAT | O_TRUNC | O_WRONLY | O_NOFOLLOW | O_CLOEXEC;
93const mode_t RT_TABLES_MODE = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; // mode 0644, rw-r--r--
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -070094
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -070095// Avoids "non-constant-expression cannot be narrowed from type 'unsigned int' to 'unsigned short'"
96// warnings when using RTA_LENGTH(x) inside static initializers (even when x is already uint16_t).
97constexpr uint16_t U16_RTA_LENGTH(uint16_t x) {
98 return RTA_LENGTH(x);
99}
100
101// These are practically const, but can't be declared so, because they are used to initialize
102// non-const pointers ("void* iov_base") in iovec arrays.
103rtattr FRATTR_PRIORITY = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_PRIORITY };
104rtattr FRATTR_TABLE = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_TABLE };
105rtattr FRATTR_FWMARK = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_FWMARK };
106rtattr FRATTR_FWMASK = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_FWMASK };
107rtattr FRATTR_UID_START = { U16_RTA_LENGTH(sizeof(uid_t)), FRA_UID_START };
108rtattr FRATTR_UID_END = { U16_RTA_LENGTH(sizeof(uid_t)), FRA_UID_END };
109
110rtattr RTATTR_TABLE = { U16_RTA_LENGTH(sizeof(uint32_t)), RTA_TABLE };
111rtattr RTATTR_OIF = { U16_RTA_LENGTH(sizeof(uint32_t)), RTA_OIF };
112
113uint8_t PADDING_BUFFER[RTA_ALIGNTO] = {0, 0, 0, 0};
114
115// END CONSTANTS ----------------------------------------------------------------------------------
116
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700117// No locks needed because RouteController is accessed only from one thread (in CommandListener).
118std::map<std::string, uint32_t> interfaceToTable;
Paul Jensena561e122014-06-12 16:46:37 -0400119
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700120uint32_t getRouteTableForInterface(const char* interface) {
Sreeram Ramachandrana4811802014-04-10 12:10:24 -0700121 uint32_t index = if_nametoindex(interface);
Paul Jensena561e122014-06-12 16:46:37 -0400122 if (index) {
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700123 index += RouteController::ROUTE_TABLE_OFFSET_FROM_INDEX;
124 interfaceToTable[interface] = index;
125 return index;
Paul Jensena561e122014-06-12 16:46:37 -0400126 }
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700127 // If the interface goes away if_nametoindex() will return 0 but we still need to know
128 // the index so we can remove the rules and routes.
129 auto iter = interfaceToTable.find(interface);
130 if (iter == interfaceToTable.end()) {
131 ALOGE("cannot find interface %s", interface);
132 return RT_TABLE_UNSPEC;
133 }
134 return iter->second;
135}
136
137void addTableName(uint32_t table, const std::string& name, std::string* contents) {
138 char tableString[UINT32_STRLEN];
139 snprintf(tableString, sizeof(tableString), "%u", table);
140 *contents += tableString;
141 *contents += " ";
142 *contents += name;
143 *contents += "\n";
144}
145
146// Doesn't return success/failure as the file is optional; it's okay if we fail to update it.
147void updateTableNamesFile() {
148 std::string contents;
Sreeram Ramachandranbb40d512014-07-11 11:45:14 -0700149
150 addTableName(RT_TABLE_LOCAL, ROUTE_TABLE_NAME_LOCAL, &contents);
151 addTableName(RT_TABLE_MAIN, ROUTE_TABLE_NAME_MAIN, &contents);
152
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700153 addTableName(ROUTE_TABLE_LOCAL_NETWORK, ROUTE_TABLE_NAME_LOCAL_NETWORK, &contents);
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700154 addTableName(ROUTE_TABLE_LEGACY_NETWORK, ROUTE_TABLE_NAME_LEGACY_NETWORK, &contents);
155 addTableName(ROUTE_TABLE_LEGACY_SYSTEM, ROUTE_TABLE_NAME_LEGACY_SYSTEM, &contents);
Sreeram Ramachandranbb40d512014-07-11 11:45:14 -0700156
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700157 for (const auto& entry : interfaceToTable) {
158 addTableName(entry.second, entry.first, &contents);
159 }
160
Sreeram Ramachandranc7d804c2014-07-09 07:39:30 -0700161 int fd = open(RT_TABLES_PATH, RT_TABLES_FLAGS, RT_TABLES_MODE);
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700162 if (fd == -1) {
163 ALOGE("failed to create %s (%s)", RT_TABLES_PATH, strerror(errno));
164 return;
165 }
166 // File creation is affected by umask, so make sure the right mode bits are set.
Sreeram Ramachandranc7d804c2014-07-09 07:39:30 -0700167 if (fchmod(fd, RT_TABLES_MODE) == -1) {
168 ALOGE("failed to set mode 0%o on %s (%s)", RT_TABLES_MODE, RT_TABLES_PATH, strerror(errno));
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700169 }
170 ssize_t bytesWritten = write(fd, contents.data(), contents.size());
171 if (bytesWritten != static_cast<ssize_t>(contents.size())) {
172 ALOGE("failed to write to %s (%zd vs %zu bytes) (%s)", RT_TABLES_PATH, bytesWritten,
173 contents.size(), strerror(errno));
174 }
175 close(fd);
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700176}
177
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900178// Sends a netlink request and expects an ack.
179// |iov| is an array of struct iovec that contains the netlink message payload.
180// The netlink header is generated by this function based on |action| and |flags|.
181// Returns -errno if there was an error or if the kernel reported an error.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700182WARN_UNUSED_RESULT int sendNetlinkRequest(uint16_t action, uint16_t flags, iovec* iov, int iovlen) {
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900183 nlmsghdr nlmsg = {
184 .nlmsg_type = action,
185 .nlmsg_flags = flags,
186 };
187 iov[0].iov_base = &nlmsg;
188 iov[0].iov_len = sizeof(nlmsg);
189 for (int i = 0; i < iovlen; ++i) {
190 nlmsg.nlmsg_len += iov[i].iov_len;
191 }
192
193 int ret;
194 struct {
195 nlmsghdr msg;
196 nlmsgerr err;
197 } response;
198
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900199 int sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
200 if (sock != -1 &&
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700201 connect(sock, reinterpret_cast<const sockaddr*>(&NETLINK_ADDRESS),
202 sizeof(NETLINK_ADDRESS)) != -1 &&
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900203 writev(sock, iov, iovlen) != -1 &&
204 (ret = recv(sock, &response, sizeof(response), 0)) != -1) {
205 if (ret == sizeof(response)) {
206 ret = response.err.error; // Netlink errors are negative errno.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700207 if (ret) {
208 ALOGE("netlink response contains error (%s)", strerror(-ret));
209 }
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900210 } else {
Sreeram Ramachandran1201e842014-07-01 15:06:05 -0700211 ALOGE("bad netlink response message size (%d != %zu)", ret, sizeof(response));
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900212 ret = -EBADMSG;
213 }
214 } else {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700215 ALOGE("netlink socket/connect/writev/recv failed (%s)", strerror(errno));
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900216 ret = -errno;
217 }
218
219 if (sock != -1) {
220 close(sock);
221 }
222
223 return ret;
224}
225
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700226// Returns 0 on success or negative errno on failure.
227int padInterfaceName(const char* input, char* name, size_t* length, uint16_t* padding) {
228 if (!input) {
229 *length = 0;
230 *padding = 0;
231 return 0;
232 }
233 *length = strlcpy(name, input, IFNAMSIZ) + 1;
234 if (*length > IFNAMSIZ) {
235 ALOGE("interface name too long (%zu > %u)", *length, IFNAMSIZ);
236 return -ENAMETOOLONG;
237 }
238 *padding = RTA_SPACE(*length) - RTA_LENGTH(*length);
239 return 0;
240}
241
Sreeram Ramachandran8fe9c8e2014-04-16 12:08:05 -0700242// Adds or removes a routing rule for IPv4 and IPv6.
243//
244// + If |table| is non-zero, the rule points at the specified routing table. Otherwise, the rule
245// returns ENETUNREACH.
246// + If |mask| is non-zero, the rule matches the specified fwmark and mask. Otherwise, |fwmark| is
247// ignored.
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700248// + If |iif| is non-NULL, the rule matches the specified incoming interface.
249// + If |oif| is non-NULL, the rule matches the specified outgoing interface.
250// + If |uidStart| and |uidEnd| are not INVALID_UID, the rule matches packets from UIDs in that
251// range (inclusive). Otherwise, the rule matches packets from all UIDs.
Lorenzo Colitti96f261e2014-06-23 15:09:54 +0900252//
253// Returns 0 on success or negative errno on failure.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700254WARN_UNUSED_RESULT int modifyIpRule(uint16_t action, uint32_t priority, uint32_t table,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700255 uint32_t fwmark, uint32_t mask, const char* iif,
256 const char* oif, uid_t uidStart, uid_t uidEnd) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700257 // Ensure that if you set a bit in the fwmark, it's not being ignored by the mask.
258 if (fwmark & ~mask) {
259 ALOGE("mask 0x%x does not select all the bits set in fwmark 0x%x", mask, fwmark);
260 return -ERANGE;
261 }
262
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700263 // Interface names must include exactly one terminating NULL and be properly padded, or older
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900264 // kernels will refuse to delete rules.
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700265 char iifName[IFNAMSIZ], oifName[IFNAMSIZ];
266 size_t iifLength, oifLength;
267 uint16_t iifPadding, oifPadding;
268 if (int ret = padInterfaceName(iif, iifName, &iifLength, &iifPadding)) {
269 return ret;
270 }
271 if (int ret = padInterfaceName(oif, oifName, &oifLength, &oifPadding)) {
272 return ret;
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900273 }
274
Lorenzo Colitti59656512014-06-25 03:20:29 +0900275 // Either both start and end UID must be specified, or neither.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700276 if ((uidStart == INVALID_UID) != (uidEnd == INVALID_UID)) {
Sreeram Ramachandrancf891382014-07-01 15:49:20 -0700277 ALOGE("incompatible start and end UIDs (%u vs %u)", uidStart, uidEnd);
Lorenzo Colitti59656512014-06-25 03:20:29 +0900278 return -EUSERS;
279 }
Lorenzo Colitti72723682014-06-26 13:51:10 +0900280 bool isUidRule = (uidStart != INVALID_UID);
Lorenzo Colitti59656512014-06-25 03:20:29 +0900281
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900282 // Assemble a rule request and put it in an array of iovec structures.
283 fib_rule_hdr rule = {
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700284 .action = static_cast<uint8_t>(table != RT_TABLE_UNSPEC ? FR_ACT_TO_TBL :
285 FR_ACT_UNREACHABLE),
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900286 };
287
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700288 rtattr fraIifName = { U16_RTA_LENGTH(iifLength), FRA_IIFNAME };
289 rtattr fraOifName = { U16_RTA_LENGTH(oifLength), FRA_OIFNAME };
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900290
291 iovec iov[] = {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700292 { NULL, 0 },
293 { &rule, sizeof(rule) },
294 { &FRATTR_PRIORITY, sizeof(FRATTR_PRIORITY) },
295 { &priority, sizeof(priority) },
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700296 { &FRATTR_TABLE, table != RT_TABLE_UNSPEC ? sizeof(FRATTR_TABLE) : 0 },
297 { &table, table != RT_TABLE_UNSPEC ? sizeof(table) : 0 },
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700298 { &FRATTR_FWMARK, mask ? sizeof(FRATTR_FWMARK) : 0 },
299 { &fwmark, mask ? sizeof(fwmark) : 0 },
300 { &FRATTR_FWMASK, mask ? sizeof(FRATTR_FWMASK) : 0 },
301 { &mask, mask ? sizeof(mask) : 0 },
302 { &FRATTR_UID_START, isUidRule ? sizeof(FRATTR_UID_START) : 0 },
303 { &uidStart, isUidRule ? sizeof(uidStart) : 0 },
304 { &FRATTR_UID_END, isUidRule ? sizeof(FRATTR_UID_END) : 0 },
305 { &uidEnd, isUidRule ? sizeof(uidEnd) : 0 },
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700306 { &fraIifName, iif != IIF_NONE ? sizeof(fraIifName) : 0 },
307 { iifName, iifLength },
308 { PADDING_BUFFER, iifPadding },
309 { &fraOifName, oif != OIF_NONE ? sizeof(fraOifName) : 0 },
310 { oifName, oifLength },
311 { PADDING_BUFFER, oifPadding },
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900312 };
313
Lorenzo Colitti72723682014-06-26 13:51:10 +0900314 uint16_t flags = (action == RTM_NEWRULE) ? NETLINK_CREATE_REQUEST_FLAGS : NETLINK_REQUEST_FLAGS;
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700315 for (size_t i = 0; i < ARRAY_SIZE(AF_FAMILIES); ++i) {
316 rule.family = AF_FAMILIES[i];
317 if (int ret = sendNetlinkRequest(action, flags, iov, ARRAY_SIZE(iov))) {
Lorenzo Colitti96f261e2014-06-23 15:09:54 +0900318 return ret;
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700319 }
320 }
321
Lorenzo Colitti96f261e2014-06-23 15:09:54 +0900322 return 0;
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700323}
324
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700325WARN_UNUSED_RESULT int modifyIpRule(uint16_t action, uint32_t priority, uint32_t table,
326 uint32_t fwmark, uint32_t mask) {
327 return modifyIpRule(action, priority, table, fwmark, mask, IIF_NONE, OIF_NONE, INVALID_UID,
328 INVALID_UID);
329}
330
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900331// Adds or deletes an IPv4 or IPv6 route.
332// Returns 0 on success or negative errno on failure.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700333WARN_UNUSED_RESULT int modifyIpRoute(uint16_t action, uint32_t table, const char* interface,
334 const char* destination, const char* nexthop) {
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900335 // At least the destination must be non-null.
336 if (!destination) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700337 ALOGE("null destination");
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900338 return -EFAULT;
339 }
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700340
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900341 // Parse the prefix.
342 uint8_t rawAddress[sizeof(in6_addr)];
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700343 uint8_t family;
344 uint8_t prefixLength;
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900345 int rawLength = parsePrefix(destination, &family, rawAddress, sizeof(rawAddress),
346 &prefixLength);
347 if (rawLength < 0) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700348 ALOGE("parsePrefix failed for destination %s (%s)", destination, strerror(-rawLength));
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900349 return rawLength;
350 }
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700351
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900352 if (static_cast<size_t>(rawLength) > sizeof(rawAddress)) {
Sreeram Ramachandran1201e842014-07-01 15:06:05 -0700353 ALOGE("impossible! address too long (%d vs %zu)", rawLength, sizeof(rawAddress));
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900354 return -ENOBUFS; // Cannot happen; parsePrefix only supports IPv4 and IPv6.
355 }
356
357 // If an interface was specified, find the ifindex.
358 uint32_t ifindex;
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700359 if (interface != OIF_NONE) {
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900360 ifindex = if_nametoindex(interface);
361 if (!ifindex) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700362 ALOGE("cannot find interface %s", interface);
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900363 return -ENODEV;
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700364 }
365 }
366
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900367 // If a nexthop was specified, parse it as the same family as the prefix.
368 uint8_t rawNexthop[sizeof(in6_addr)];
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700369 if (nexthop && inet_pton(family, nexthop, rawNexthop) <= 0) {
370 ALOGE("inet_pton failed for nexthop %s", nexthop);
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900371 return -EINVAL;
372 }
373
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900374 // Assemble a rtmsg and put it in an array of iovec structures.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700375 rtmsg route = {
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900376 .rtm_protocol = RTPROT_STATIC,
377 .rtm_type = RTN_UNICAST,
378 .rtm_family = family,
379 .rtm_dst_len = prefixLength,
380 };
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900381
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700382 rtattr rtaDst = { U16_RTA_LENGTH(rawLength), RTA_DST };
383 rtattr rtaGateway = { U16_RTA_LENGTH(rawLength), RTA_GATEWAY };
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900384
385 iovec iov[] = {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700386 { NULL, 0 },
387 { &route, sizeof(route) },
388 { &RTATTR_TABLE, sizeof(RTATTR_TABLE) },
389 { &table, sizeof(table) },
390 { &rtaDst, sizeof(rtaDst) },
391 { rawAddress, static_cast<size_t>(rawLength) },
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700392 { &RTATTR_OIF, interface != OIF_NONE ? sizeof(RTATTR_OIF) : 0 },
393 { &ifindex, interface != OIF_NONE ? sizeof(ifindex) : 0 },
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700394 { &rtaGateway, nexthop ? sizeof(rtaGateway) : 0 },
395 { rawNexthop, nexthop ? static_cast<size_t>(rawLength) : 0 },
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900396 };
Lorenzo Colittiba25df92014-06-18 00:22:17 +0900397
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700398 uint16_t flags = (action == RTM_NEWROUTE) ? NETLINK_CREATE_REQUEST_FLAGS :
399 NETLINK_REQUEST_FLAGS;
Lorenzo Colitti4753afd2014-06-20 23:03:29 +0900400 return sendNetlinkRequest(action, flags, iov, ARRAY_SIZE(iov));
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700401}
402
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700403// An iptables rule to mark incoming packets on a network with the netId of the network.
404//
405// This is so that the kernel can:
406// + Use the right fwmark for (and thus correctly route) replies (e.g.: TCP RST, ICMP errors, ping
407// replies, SYN-ACKs, etc).
408// + Mark sockets that accept connections from this interface so that the connection stays on the
409// same interface.
410WARN_UNUSED_RESULT int modifyIncomingPacketMark(unsigned netId, const char* interface,
411 Permission permission, bool add) {
412 Fwmark fwmark;
413
414 fwmark.netId = netId;
415 fwmark.explicitlySelected = true;
416 fwmark.protectedFromVpn = true;
417 fwmark.permission = permission;
418
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700419 char markString[UINT32_HEX_STRLEN];
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700420 snprintf(markString, sizeof(markString), "0x%x", fwmark.intValue);
421
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700422 if (execIptables(V4V6, "-t", "mangle", add ? "-A" : "-D", "INPUT", "-i", interface, "-j",
423 "MARK", "--set-mark", markString, NULL)) {
424 ALOGE("failed to change iptables rule that sets incoming packet mark");
425 return -EREMOTEIO;
426 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700427
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700428 return 0;
429}
430
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700431// A rule to route all traffic from a given set of UIDs to go over the VPN.
432//
433// Notice that this rule doesn't use the netId. I.e., no matter what netId the user's socket may
434// have, if they are subject to this VPN, their traffic has to go through it. Allows the traffic to
435// bypass the VPN if the protectedFromVpn bit is set.
436WARN_UNUSED_RESULT int modifyVpnUidRangeRule(uint32_t table, uid_t uidStart, uid_t uidEnd,
437 bool add) {
438 Fwmark fwmark;
439 Fwmark mask;
440
441 fwmark.protectedFromVpn = false;
442 mask.protectedFromVpn = true;
443
444 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_SECURE_VPN, table,
445 fwmark.intValue, mask.intValue, IIF_NONE, OIF_NONE, uidStart, uidEnd);
446}
447
448// A rule to allow system apps to send traffic over this VPN even if they are not part of the target
449// set of UIDs.
450//
451// This is needed for DnsProxyListener to correctly resolve a request for a user who is in the
452// target set, but where the DnsProxyListener itself is not.
453WARN_UNUSED_RESULT int modifyVpnSystemPermissionRule(unsigned netId, uint32_t table, bool add) {
454 Fwmark fwmark;
455 Fwmark mask;
456
457 fwmark.netId = netId;
458 mask.netId = FWMARK_NET_ID_MASK;
459
460 fwmark.permission = PERMISSION_SYSTEM;
461 mask.permission = PERMISSION_SYSTEM;
462
463 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_SECURE_VPN, table,
464 fwmark.intValue, mask.intValue);
465}
466
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700467// A rule to route traffic based on an explicitly chosen network.
468//
469// Supports apps that use the multinetwork APIs to restrict their traffic to a network.
470//
471// Even though we check permissions at the time we set a netId into the fwmark of a socket, we need
472// to check it again in the rules here, because a network's permissions may have been updated via
473// modifyNetworkPermission().
474WARN_UNUSED_RESULT int modifyExplicitNetworkRule(unsigned netId, uint32_t table,
475 Permission permission, uid_t uidStart,
476 uid_t uidEnd, bool add) {
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700477 Fwmark fwmark;
478 Fwmark mask;
479
480 fwmark.netId = netId;
481 mask.netId = FWMARK_NET_ID_MASK;
482
Sreeram Ramachandran122f5812014-05-11 20:29:49 -0700483 fwmark.explicitlySelected = true;
484 mask.explicitlySelected = true;
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700485
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700486 fwmark.permission = permission;
487 mask.permission = permission;
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700488
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700489 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_EXPLICIT_NETWORK, table,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700490 fwmark.intValue, mask.intValue, IIF_NONE, OIF_NONE, uidStart, uidEnd);
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700491}
492
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700493// A rule to route traffic based on a chosen outgoing interface.
494//
495// Supports apps that use SO_BINDTODEVICE or IP_PKTINFO options and the kernel that already knows
496// the outgoing interface (typically for link-local communications).
497WARN_UNUSED_RESULT int modifyOutputInterfaceRule(const char* interface, uint32_t table,
498 Permission permission, uid_t uidStart,
499 uid_t uidEnd, bool add) {
500 Fwmark fwmark;
501 Fwmark mask;
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700502
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700503 fwmark.permission = permission;
504 mask.permission = permission;
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700505
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700506 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_OUTPUT_INTERFACE, table,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700507 fwmark.intValue, mask.intValue, IIF_NONE, interface, uidStart, uidEnd);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700508}
509
510// A rule to route traffic based on the chosen network.
511//
512// This is for sockets that have not explicitly requested a particular network, but have been
513// bound to one when they called connect(). This ensures that sockets connected on a particular
514// network stay on that network even if the default network changes.
515WARN_UNUSED_RESULT int modifyImplicitNetworkRule(unsigned netId, uint32_t table,
516 Permission permission, bool add) {
517 Fwmark fwmark;
518 Fwmark mask;
519
520 fwmark.netId = netId;
521 mask.netId = FWMARK_NET_ID_MASK;
522
523 fwmark.explicitlySelected = false;
524 mask.explicitlySelected = true;
525
526 fwmark.permission = permission;
527 mask.permission = permission;
528
529 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_IMPLICIT_NETWORK, table,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700530 fwmark.intValue, mask.intValue);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700531}
532
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700533// Add rules to allow legacy routes added through the requestRouteToHost() API.
534WARN_UNUSED_RESULT int addLegacyRouteRules() {
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700535 Fwmark fwmark;
536 Fwmark mask;
537
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700538 fwmark.explicitlySelected = false;
539 mask.explicitlySelected = true;
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700540
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700541 // Rules to allow legacy routes to override the default network.
542 if (int ret = modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LEGACY_SYSTEM, ROUTE_TABLE_LEGACY_SYSTEM,
543 fwmark.intValue, mask.intValue)) {
544 return ret;
545 }
546 if (int ret = modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LEGACY_NETWORK,
547 ROUTE_TABLE_LEGACY_NETWORK, fwmark.intValue, mask.intValue)) {
548 return ret;
549 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700550
551 fwmark.permission = PERMISSION_SYSTEM;
552 mask.permission = PERMISSION_SYSTEM;
553
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700554 // A rule to allow legacy routes from system apps to override VPNs.
555 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_VPN_OVERRIDE_SYSTEM, ROUTE_TABLE_LEGACY_SYSTEM,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700556 fwmark.intValue, mask.intValue);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700557}
558
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700559// Add rules to lookup the local network when specified explicitly or otherwise.
560WARN_UNUSED_RESULT int addLocalNetworkRules(unsigned localNetId) {
561 if (int ret = modifyExplicitNetworkRule(localNetId, ROUTE_TABLE_LOCAL_NETWORK, PERMISSION_NONE,
562 INVALID_UID, INVALID_UID, ACTION_ADD)) {
563 return ret;
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700564 }
565
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700566 Fwmark fwmark;
567 Fwmark mask;
568
569 fwmark.explicitlySelected = false;
570 mask.explicitlySelected = true;
571
572 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LOCAL_NETWORK, ROUTE_TABLE_LOCAL_NETWORK,
573 fwmark.intValue, mask.intValue);
574}
575
576// Add a new rule to look up the 'main' table, with the same selectors as the "default network"
577// rule, but with a lower priority. Since the default network rule points to a table with a default
578// route, the rule we're adding will never be used for normal routing lookups. However, the kernel
579// may fall-through to it to find directly-connected routes when it validates that a nexthop (in a
580// route being added) is reachable.
581WARN_UNUSED_RESULT int addDirectlyConnectedRule() {
582 Fwmark fwmark;
583 Fwmark mask;
584
585 fwmark.netId = NETID_UNSET;
586 mask.netId = FWMARK_NET_ID_MASK;
587
588 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_DIRECTLY_CONNECTED, RT_TABLE_MAIN,
589 fwmark.intValue, mask.intValue, IIF_NONE, OIF_NONE, UID_ROOT, UID_ROOT);
590}
591
592// Add a rule to preempt the pre-defined "from all lookup main" rule. Packets that reach this rule
593// will be null-routed, and won't fall-through to the main table.
594WARN_UNUSED_RESULT int addUnreachableRule() {
595 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_UNREACHABLE, RT_TABLE_UNSPEC, MARK_UNSET,
596 MARK_UNSET);
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700597}
598
599WARN_UNUSED_RESULT int modifyLocalNetwork(unsigned netId, const char* interface, bool add) {
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700600 if (int ret = modifyIncomingPacketMark(netId, interface, PERMISSION_NONE, add)) {
601 return ret;
602 }
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700603 return modifyOutputInterfaceRule(interface, ROUTE_TABLE_LOCAL_NETWORK, PERMISSION_NONE,
604 INVALID_UID, INVALID_UID, add);
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700605}
606
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700607WARN_UNUSED_RESULT int modifyPhysicalNetwork(unsigned netId, const char* interface,
608 Permission permission, bool add) {
609 uint32_t table = getRouteTableForInterface(interface);
610 if (table == RT_TABLE_UNSPEC) {
611 return -ESRCH;
612 }
613
614 if (int ret = modifyIncomingPacketMark(netId, interface, permission, add)) {
615 return ret;
616 }
617 if (int ret = modifyExplicitNetworkRule(netId, table, permission, INVALID_UID, INVALID_UID,
618 add)) {
619 return ret;
620 }
621 if (int ret = modifyOutputInterfaceRule(interface, table, permission, INVALID_UID, INVALID_UID,
622 add)) {
623 return ret;
624 }
625 return modifyImplicitNetworkRule(netId, table, permission, add);
626}
627
628WARN_UNUSED_RESULT int modifyVirtualNetwork(unsigned netId, const char* interface,
629 const UidRanges& uidRanges, bool add,
630 bool modifyNonUidBasedRules) {
631 uint32_t table = getRouteTableForInterface(interface);
632 if (table == RT_TABLE_UNSPEC) {
633 return -ESRCH;
634 }
635
Sreeram Ramachandrane09b20a2014-07-05 17:15:14 -0700636 for (const UidRanges::Range& range : uidRanges.getRanges()) {
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700637 if (int ret = modifyVpnUidRangeRule(table, range.first, range.second, add)) {
638 return ret;
639 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700640 if (int ret = modifyExplicitNetworkRule(netId, table, PERMISSION_NONE, range.first,
641 range.second, add)) {
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700642 return ret;
643 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700644 if (int ret = modifyOutputInterfaceRule(interface, table, PERMISSION_NONE, range.first,
645 range.second, add)) {
646 return ret;
647 }
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700648 }
649
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700650 if (modifyNonUidBasedRules) {
651 if (int ret = modifyIncomingPacketMark(netId, interface, PERMISSION_NONE, add)) {
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700652 return ret;
653 }
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700654 if (int ret = modifyVpnSystemPermissionRule(netId, table, add)) {
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700655 return ret;
656 }
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700657 return modifyExplicitNetworkRule(netId, table, PERMISSION_NONE, UID_ROOT, UID_ROOT, add);
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700658 }
659
660 return 0;
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700661}
662
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700663WARN_UNUSED_RESULT int modifyDefaultNetwork(uint16_t action, const char* interface,
664 Permission permission) {
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700665 uint32_t table = getRouteTableForInterface(interface);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700666 if (table == RT_TABLE_UNSPEC) {
Lorenzo Colitti96f261e2014-06-23 15:09:54 +0900667 return -ESRCH;
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700668 }
669
Sreeram Ramachandran122f5812014-05-11 20:29:49 -0700670 Fwmark fwmark;
Sreeram Ramachandran122f5812014-05-11 20:29:49 -0700671 Fwmark mask;
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700672
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700673 fwmark.netId = NETID_UNSET;
Sreeram Ramachandran122f5812014-05-11 20:29:49 -0700674 mask.netId = FWMARK_NET_ID_MASK;
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700675
676 fwmark.permission = permission;
Sreeram Ramachandran122f5812014-05-11 20:29:49 -0700677 mask.permission = permission;
678
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700679 return modifyIpRule(action, RULE_PRIORITY_DEFAULT_NETWORK, table, fwmark.intValue,
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700680 mask.intValue);
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700681}
682
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700683WARN_UNUSED_RESULT int modifyTetheredNetwork(uint16_t action, const char* inputInterface,
684 const char* outputInterface) {
685 uint32_t table = getRouteTableForInterface(outputInterface);
686 if (table == RT_TABLE_UNSPEC) {
687 return -ESRCH;
688 }
689
690 return modifyIpRule(action, RULE_PRIORITY_TETHERING, table, MARK_UNSET, MARK_UNSET,
691 inputInterface, OIF_NONE, INVALID_UID, INVALID_UID);
692}
693
Sreeram Ramachandranb717e742014-07-19 00:22:15 -0700694// Returns 0 on success or negative errno on failure.
695WARN_UNUSED_RESULT int flushRules() {
696 for (size_t i = 0; i < ARRAY_SIZE(IP_VERSIONS); ++i) {
697 const char* argv[] = {
698 IP_PATH,
699 IP_VERSIONS[i],
700 "rule",
701 "flush",
702 };
703 if (android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, false, false)) {
704 ALOGE("failed to flush rules");
705 return -EREMOTEIO;
706 }
707 }
708 return 0;
709}
710
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700711// Adds or removes an IPv4 or IPv6 route to the specified table and, if it's a directly-connected
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900712// route, to the main table as well.
713// Returns 0 on success or negative errno on failure.
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700714WARN_UNUSED_RESULT int modifyRoute(uint16_t action, const char* interface, const char* destination,
715 const char* nexthop, RouteController::TableType tableType) {
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700716 uint32_t table;
Sreeram Ramachandran38b7af12014-05-22 14:21:49 -0700717 switch (tableType) {
718 case RouteController::INTERFACE: {
719 table = getRouteTableForInterface(interface);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700720 if (table == RT_TABLE_UNSPEC) {
721 return -ESRCH;
722 }
Sreeram Ramachandran38b7af12014-05-22 14:21:49 -0700723 break;
724 }
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700725 case RouteController::LOCAL_NETWORK: {
726 table = ROUTE_TABLE_LOCAL_NETWORK;
727 break;
728 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700729 case RouteController::LEGACY_NETWORK: {
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700730 table = ROUTE_TABLE_LEGACY_NETWORK;
Sreeram Ramachandran38b7af12014-05-22 14:21:49 -0700731 break;
732 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700733 case RouteController::LEGACY_SYSTEM: {
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700734 table = ROUTE_TABLE_LEGACY_SYSTEM;
Sreeram Ramachandran38b7af12014-05-22 14:21:49 -0700735 break;
736 }
737 }
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700738
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900739 int ret = modifyIpRoute(action, table, interface, destination, nexthop);
Sreeram Ramachandran1077d292014-06-27 06:42:11 -0700740 // We allow apps to call requestRouteToHost() multiple times with the same route, so ignore
741 // EEXIST failures when adding routes to legacy tables.
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700742 if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST &&
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700743 (tableType == RouteController::LEGACY_NETWORK ||
744 tableType == RouteController::LEGACY_SYSTEM))) {
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900745 return ret;
Sreeram Ramachandranc9213372014-04-16 12:32:18 -0700746 }
747
748 // If there's no nexthop, this is a directly connected route. Add it to the main table also, to
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900749 // let the kernel find it when validating nexthops when global routes are added.
750 if (!nexthop) {
751 ret = modifyIpRoute(action, RT_TABLE_MAIN, interface, destination, NULL);
752 // A failure with action == ADD && errno == EEXIST means that the route already exists in
753 // the main table, perhaps because the kernel added it automatically as part of adding the
754 // IP address to the interface. Ignore this, but complain about everything else.
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700755 if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST)) {
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900756 return ret;
757 }
Sreeram Ramachandranc9213372014-04-16 12:32:18 -0700758 }
759
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900760 return 0;
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700761}
762
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700763// Returns 0 on success or negative errno on failure.
764WARN_UNUSED_RESULT int flushRoutes(const char* interface) {
Sreeram Ramachandran92b66c42014-04-15 14:28:55 -0700765 uint32_t table = getRouteTableForInterface(interface);
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700766 if (table == RT_TABLE_UNSPEC) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700767 return -ESRCH;
Sreeram Ramachandran92b66c42014-04-15 14:28:55 -0700768 }
769
Lorenzo Colitti357e5622014-06-17 16:14:17 +0900770 char tableString[UINT32_STRLEN];
771 snprintf(tableString, sizeof(tableString), "%u", table);
772
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700773 for (size_t i = 0; i < ARRAY_SIZE(IP_VERSIONS); ++i) {
Lorenzo Colitti357e5622014-06-17 16:14:17 +0900774 const char* argv[] = {
775 IP_PATH,
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700776 IP_VERSIONS[i],
Sreeram Ramachandran72999d62014-07-02 18:06:34 -0700777 "route",
Lorenzo Colitti357e5622014-06-17 16:14:17 +0900778 "flush",
779 "table",
780 tableString,
781 };
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700782 if (android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, false, false)) {
783 ALOGE("failed to flush routes");
784 return -EREMOTEIO;
Lorenzo Colitti357e5622014-06-17 16:14:17 +0900785 }
786 }
787
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700788 interfaceToTable.erase(interface);
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700789 return 0;
Sreeram Ramachandran92b66c42014-04-15 14:28:55 -0700790}
791
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700792} // namespace
793
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700794int RouteController::Init(unsigned localNetId) {
Sreeram Ramachandranb717e742014-07-19 00:22:15 -0700795 if (int ret = flushRules()) {
796 return ret;
797 }
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700798 if (int ret = addLegacyRouteRules()) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700799 return ret;
800 }
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700801 if (int ret = addLocalNetworkRules(localNetId)) {
802 return ret;
803 }
804 if (int ret = addDirectlyConnectedRule()) {
805 return ret;
806 }
Sreeram Ramachandranb717e742014-07-19 00:22:15 -0700807 if (int ret = addUnreachableRule()) {
808 return ret;
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700809 }
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700810 updateTableNamesFile();
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700811 return 0;
Sreeram Ramachandran8fe9c8e2014-04-16 12:08:05 -0700812}
813
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700814int RouteController::addInterfaceToLocalNetwork(unsigned netId, const char* interface) {
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700815 return modifyLocalNetwork(netId, interface, ACTION_ADD);
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700816}
817
818int RouteController::removeInterfaceFromLocalNetwork(unsigned netId, const char* interface) {
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700819 return modifyLocalNetwork(netId, interface, ACTION_DEL);
Sreeram Ramachandran6a773532014-07-11 09:10:20 -0700820}
821
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700822int RouteController::addInterfaceToPhysicalNetwork(unsigned netId, const char* interface,
823 Permission permission) {
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700824 if (int ret = modifyPhysicalNetwork(netId, interface, permission, ACTION_ADD)) {
825 return ret;
826 }
827 updateTableNamesFile();
828 return 0;
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700829}
830
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700831int RouteController::removeInterfaceFromPhysicalNetwork(unsigned netId, const char* interface,
832 Permission permission) {
833 if (int ret = modifyPhysicalNetwork(netId, interface, permission, ACTION_DEL)) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700834 return ret;
835 }
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700836 if (int ret = flushRoutes(interface)) {
837 return ret;
838 }
839 updateTableNamesFile();
840 return 0;
Sreeram Ramachandran379bd332014-04-10 19:58:06 -0700841}
842
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700843int RouteController::addInterfaceToVirtualNetwork(unsigned netId, const char* interface,
844 const UidRanges& uidRanges) {
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700845 if (int ret = modifyVirtualNetwork(netId, interface, uidRanges, ACTION_ADD,
846 MODIFY_NON_UID_BASED_RULES)) {
847 return ret;
848 }
849 updateTableNamesFile();
850 return 0;
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700851}
852
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700853int RouteController::removeInterfaceFromVirtualNetwork(unsigned netId, const char* interface,
854 const UidRanges& uidRanges) {
855 if (int ret = modifyVirtualNetwork(netId, interface, uidRanges, ACTION_DEL,
856 MODIFY_NON_UID_BASED_RULES)) {
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700857 return ret;
858 }
Sreeram Ramachandran4acd34a2014-07-07 22:11:37 -0700859 if (int ret = flushRoutes(interface)) {
860 return ret;
861 }
862 updateTableNamesFile();
863 return 0;
Sreeram Ramachandran4043f012014-06-23 12:41:37 -0700864}
865
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700866int RouteController::modifyPhysicalNetworkPermission(unsigned netId, const char* interface,
867 Permission oldPermission,
868 Permission newPermission) {
Sreeram Ramachandran379bd332014-04-10 19:58:06 -0700869 // Add the new rules before deleting the old ones, to avoid race conditions.
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700870 if (int ret = modifyPhysicalNetwork(netId, interface, newPermission, ACTION_ADD)) {
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700871 return ret;
872 }
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700873 return modifyPhysicalNetwork(netId, interface, oldPermission, ACTION_DEL);
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700874}
875
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700876int RouteController::addUsersToVirtualNetwork(unsigned netId, const char* interface,
877 const UidRanges& uidRanges) {
878 return modifyVirtualNetwork(netId, interface, uidRanges, ACTION_ADD,
879 !MODIFY_NON_UID_BASED_RULES);
Sreeram Ramachandranb1425cc2014-06-23 18:54:27 -0700880}
881
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700882int RouteController::removeUsersFromVirtualNetwork(unsigned netId, const char* interface,
883 const UidRanges& uidRanges) {
884 return modifyVirtualNetwork(netId, interface, uidRanges, ACTION_DEL,
885 !MODIFY_NON_UID_BASED_RULES);
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700886}
887
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700888int RouteController::addInterfaceToDefaultNetwork(const char* interface, Permission permission) {
889 return modifyDefaultNetwork(RTM_NEWRULE, interface, permission);
Sreeram Ramachandran9c0d3132014-04-10 20:35:04 -0700890}
891
Sreeram Ramachandran5009d5e2014-07-03 12:20:48 -0700892int RouteController::removeInterfaceFromDefaultNetwork(const char* interface,
893 Permission permission) {
894 return modifyDefaultNetwork(RTM_DELRULE, interface, permission);
Sreeram Ramachandran5c181bf2014-04-07 14:10:04 -0700895}
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700896
Sreeram Ramachandranf4f6c8d2014-06-23 09:54:06 -0700897int RouteController::addRoute(const char* interface, const char* destination, const char* nexthop,
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700898 TableType tableType) {
899 return modifyRoute(RTM_NEWROUTE, interface, destination, nexthop, tableType);
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700900}
901
Lorenzo Colittif7fc8ec2014-06-18 00:41:58 +0900902int RouteController::removeRoute(const char* interface, const char* destination,
Sreeram Ramachandraneb27b7e2014-07-01 14:30:30 -0700903 const char* nexthop, TableType tableType) {
904 return modifyRoute(RTM_DELROUTE, interface, destination, nexthop, tableType);
Sreeram Ramachandran7619e1b2014-04-15 14:23:08 -0700905}
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700906
907int RouteController::enableTethering(const char* inputInterface, const char* outputInterface) {
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700908 return modifyTetheredNetwork(RTM_NEWRULE, inputInterface, outputInterface);
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700909}
910
911int RouteController::disableTethering(const char* inputInterface, const char* outputInterface) {
Sreeram Ramachandranfa9f4dc2014-07-22 18:16:44 -0700912 return modifyTetheredNetwork(RTM_DELRULE, inputInterface, outputInterface);
Sreeram Ramachandran87475a12014-07-15 16:20:28 -0700913}