SecondaryTableController.cpp revision 5ea0c05a1e7d8e664b808aa1bb1efd08fdb2fb13 
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
34extern "C" int system_nosh(const char *command);
35
36#include "ResponseCode.h"
37#include "SecondaryTableController.h"
38
39static char IP_PATH[] = "/system/bin/ip";
40static char ADD[] = "add";
41static char DEL[] = "del";
42
43SecondaryTableController::SecondaryTableController() {
44    int i;
45    for (i=0; i < INTERFACES_TRACKED; i++) {
46        mInterfaceTable[i][0] = 0;
47        // TODO - use a hashtable or other prebuilt container class
48        mInterfaceRuleCount[i] = 0;
49    }
50}
51
52SecondaryTableController::~SecondaryTableController() {
53}
54
55int SecondaryTableController::findTableNumber(const char *iface) {
56    int i;
57    for (i = 0; i < INTERFACES_TRACKED; i++) {
58        if (strncmp(iface, mInterfaceTable[i], MAX_IFACE_LENGTH) == 0) {
59            return i;
60        }
61    }
62    return -1;
63}
64
65int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix,
66        char *gateway) {
67    int tableIndex = findTableNumber(iface);
68    if (tableIndex == -1) {
69        tableIndex = findTableNumber(""); // look for an empty slot
70        if (tableIndex == -1) {
71            ALOGE("Max number of NATed interfaces reached");
72            errno = ENODEV;
73            cli->sendMsg(ResponseCode::OperationFailed, "Max number NATed", true);
74            return -1;
75        }
76        strncpy(mInterfaceTable[tableIndex], iface, MAX_IFACE_LENGTH);
77    }
78
79    return modifyRoute(cli, ADD, iface, dest, prefix, gateway, tableIndex);
80}
81
82int SecondaryTableController::modifyRoute(SocketClient *cli, char *action, char *iface, char *dest,
83        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    cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false);
112    return 0;
113}
114
115int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix,
116        char *gateway) {
117    int tableIndex = findTableNumber(iface);
118    if (tableIndex == -1) {
119        ALOGE("Interface not found");
120        errno = ENODEV;
121        cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true);
122        return -1;
123    }
124
125    return modifyRoute(cli, DEL, iface, dest, prefix, gateway, tableIndex);
126}
127
128int SecondaryTableController::runAndFree(SocketClient *cli, char *cmd) {
129    int ret = 0;
130    if (strlen(cmd) >= 255) {
131        ALOGE("ip command (%s) too long", cmd);
132        errno = E2BIG;
133        cli->sendMsg(ResponseCode::CommandSyntaxError, "Too long", true);
134        free(cmd);
135        return -1;
136    }
137    ret = system_nosh(cmd);
138    free(cmd);
139    return ret;
140}
141