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 <stdlib.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <string.h>
21
22 #include <sys/socket.h>
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 #include <sys/wait.h>
26
27 #include <netinet/in.h>
28 #include <arpa/inet.h>
29
30 #define LOG_TAG "SecondaryTablController"
31 #include <cutils/log.h>
32 #include <cutils/properties.h>
33
34 extern "C" int system_nosh(const char *command);
35
36 #include "ResponseCode.h"
37 #include "NetdConstants.h"
38 #include "SecondaryTableController.h"
39
SecondaryTableController()40 SecondaryTableController::SecondaryTableController() {
41 int i;
42 for (i=0; i < INTERFACES_TRACKED; i++) {
43 mInterfaceTable[i][0] = 0;
44 // TODO - use a hashtable or other prebuilt container class
45 mInterfaceRuleCount[i] = 0;
46 }
47 }
48
~SecondaryTableController()49 SecondaryTableController::~SecondaryTableController() {
50 }
51
findTableNumber(const char * iface)52 int SecondaryTableController::findTableNumber(const char *iface) {
53 int i;
54 for (i = 0; i < INTERFACES_TRACKED; i++) {
55 // compare through the final null, hence +1
56 if (strncmp(iface, mInterfaceTable[i], IFNAMSIZ + 1) == 0) {
57 return i;
58 }
59 }
60 return -1;
61 }
62
addRoute(SocketClient * cli,char * iface,char * dest,int prefix,char * gateway)63 int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix,
64 char *gateway) {
65 int tableIndex = findTableNumber(iface);
66 if (tableIndex == -1) {
67 tableIndex = findTableNumber(""); // look for an empty slot
68 if (tableIndex == -1) {
69 ALOGE("Max number of NATed interfaces reached");
70 errno = ENODEV;
71 cli->sendMsg(ResponseCode::OperationFailed, "Max number NATed", true);
72 return -1;
73 }
74 strncpy(mInterfaceTable[tableIndex], iface, IFNAMSIZ);
75 // Ensure null termination even if truncation happened
76 mInterfaceTable[tableIndex][IFNAMSIZ] = 0;
77 }
78
79 return modifyRoute(cli, ADD, iface, dest, prefix, gateway, tableIndex);
80 }
81
modifyRoute(SocketClient * cli,const char * action,char * iface,char * dest,int prefix,char * gateway,int tableIndex)82 int SecondaryTableController::modifyRoute(SocketClient *cli, const char *action, char *iface,
83 char *dest, int prefix, char *gateway, int tableIndex) {
84 char *cmd;
85
86 if (strcmp("::", gateway) == 0) {
87 // IP tool doesn't like "::" - the equiv of 0.0.0.0 that it accepts for ipv4
88 asprintf(&cmd, "%s route %s %s/%d dev %s table %d",
89 IP_PATH, action, dest, prefix, iface, tableIndex+BASE_TABLE_NUMBER);
90 } else {
91 asprintf(&cmd, "%s route %s %s/%d via %s dev %s table %d",
92 IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER);
93 }
94
95 if (runAndFree(cli, cmd)) {
96 ALOGE("ip route %s failed: %s route %s %s/%d via %s dev %s table %d", action,
97 IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER);
98 errno = ENODEV;
99 cli->sendMsg(ResponseCode::OperationFailed, "ip route modification failed", true);
100 return -1;
101 }
102
103 if (strcmp(action, ADD) == 0) {
104 mInterfaceRuleCount[tableIndex]++;
105 } else {
106 if (--mInterfaceRuleCount[tableIndex] < 1) {
107 mInterfaceRuleCount[tableIndex] = 0;
108 mInterfaceTable[tableIndex][0] = 0;
109 }
110 }
111 modifyRuleCount(tableIndex, action);
112 cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false);
113 return 0;
114 }
115
modifyRuleCount(int tableIndex,const char * action)116 void SecondaryTableController::modifyRuleCount(int tableIndex, const char *action) {
117 if (strcmp(action, ADD) == 0) {
118 mInterfaceRuleCount[tableIndex]++;
119 } else {
120 if (--mInterfaceRuleCount[tableIndex] < 1) {
121 mInterfaceRuleCount[tableIndex] = 0;
122 mInterfaceTable[tableIndex][0] = 0;
123 }
124 }
125 }
126
verifyTableIndex(int tableIndex)127 int SecondaryTableController::verifyTableIndex(int tableIndex) {
128 if ((tableIndex < 0) ||
129 (tableIndex >= INTERFACES_TRACKED) ||
130 (mInterfaceTable[tableIndex][0] == 0)) {
131 return -1;
132 } else {
133 return 0;
134 }
135 }
136
getVersion(const char * addr)137 const char *SecondaryTableController::getVersion(const char *addr) {
138 if (strchr(addr, ':') != NULL) {
139 return "-6";
140 } else {
141 return "-4";
142 }
143 }
144
removeRoute(SocketClient * cli,char * iface,char * dest,int prefix,char * gateway)145 int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix,
146 char *gateway) {
147 int tableIndex = findTableNumber(iface);
148 if (tableIndex == -1) {
149 ALOGE("Interface not found");
150 errno = ENODEV;
151 cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true);
152 return -1;
153 }
154
155 return modifyRoute(cli, DEL, iface, dest, prefix, gateway, tableIndex);
156 }
157
modifyFromRule(int tableIndex,const char * action,const char * addr)158 int SecondaryTableController::modifyFromRule(int tableIndex, const char *action,
159 const char *addr) {
160 char *cmd;
161
162 if (verifyTableIndex(tableIndex)) {
163 return -1;
164 }
165 asprintf(&cmd, "%s %s rule %s from %s table %d", IP_PATH, getVersion(addr),
166 action, addr, tableIndex + BASE_TABLE_NUMBER);
167 if (runAndFree(NULL, cmd)) {
168 return -1;
169 }
170
171 modifyRuleCount(tableIndex, action);
172 return 0;
173 }
174
modifyLocalRoute(int tableIndex,const char * action,const char * iface,const char * addr)175 int SecondaryTableController::modifyLocalRoute(int tableIndex, const char *action,
176 const char *iface, const char *addr) {
177 char *cmd;
178
179 if (verifyTableIndex(tableIndex)) {
180 return -1;
181 }
182
183 modifyRuleCount(tableIndex, action); // some del's will fail as the iface is already gone.
184
185 asprintf(&cmd, "%s route %s %s dev %s table %d", IP_PATH, action, addr, iface,
186 tableIndex+BASE_TABLE_NUMBER);
187 return runAndFree(NULL, cmd);
188 }
189
runAndFree(SocketClient * cli,char * cmd)190 int SecondaryTableController::runAndFree(SocketClient *cli, char *cmd) {
191 int ret = 0;
192 if (strlen(cmd) >= 255) {
193 if (cli != NULL) {
194 ALOGE("ip command (%s) too long", cmd);
195 errno = E2BIG;
196 cli->sendMsg(ResponseCode::CommandSyntaxError, "Too long", true);
197 }
198 free(cmd);
199 return -1;
200 }
201 ret = system_nosh(cmd);
202 free(cmd);
203 return ret;
204 }
205