SecondaryTableController.cpp revision fc97b82e02979f246d56a4bfd60e4aab8686d3f6 
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#include "ResponseCode.h"
35#include "SecondaryTableController.h"
36
37static char IP_PATH[] = "/system/bin/ip";
38
39SecondaryTableController::SecondaryTableController() {
40    int i;
41    for (i=0; i < INTERFACES_TRACKED; i++) {
42        mInterfaceTable[i][0] = 0;
43        // TODO - use a hashtable or other prebuilt container class
44        mInterfaceRuleCount[i] = 0;
45    }
46}
47
48SecondaryTableController::~SecondaryTableController() {
49}
50
51int SecondaryTableController::findTableNumber(const char *iface) {
52    int i;
53    for (i = 0; i < INTERFACES_TRACKED; i++) {
54        if (strncmp(iface, mInterfaceTable[i], MAX_IFACE_LENGTH) == 0) {
55            return i;
56        }
57    }
58    return -1;
59}
60
61int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix,
62        char *gateway) {
63    char *cmd;
64
65    int tableIndex = findTableNumber(iface);
66    if (tableIndex == -1) {
67        tableIndex = findTableNumber(""); // look for an empty slot
68        if (tableIndex == -1) {
69            LOGE("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, MAX_IFACE_LENGTH);
75    }
76
77    asprintf(&cmd, "%s route add %s/%d via %s table %d",
78            IP_PATH, dest, prefix, gateway, tableIndex+BASE_TABLE_NUMBER);
79    if (runAndFree(cli, cmd)) {
80        LOGE("ip route add failed: %s", cmd);
81        errno = ENODEV;
82        cli->sendMsg(ResponseCode::OperationFailed, "ip route add failed", true);
83        return -1;
84    }
85    mInterfaceRuleCount[tableIndex]++;
86    cli->sendMsg(ResponseCode::CommandOkay, "Route added", false);
87    return 0;
88}
89
90int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix,
91        char *gateway) {
92    char *cmd;
93    int tableIndex = findTableNumber(iface);
94    if (tableIndex == -1) {
95        LOGE("Interface not found");
96        errno = ENODEV;
97        cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true);
98        return -1;
99    }
100
101    asprintf(&cmd, "%s route del %s/%d via %s table %d",
102            IP_PATH, dest, prefix, gateway, tableIndex+BASE_TABLE_NUMBER);
103    if (runAndFree(cli, cmd)) {
104        LOGE("ip route del failed");
105        errno = ENODEV;
106        cli->sendMsg(ResponseCode::OperationFailed, "ip route del failed", true);
107        return -1;
108    }
109    if (--mInterfaceRuleCount[tableIndex]<1) {
110        mInterfaceTable[tableIndex][0]=0;
111    }
112    cli->sendMsg(ResponseCode::CommandOkay, "Route removed", false);
113    return 0;
114}
115
116int SecondaryTableController::runAndFree(SocketClient *cli, char *cmd) {
117    int ret = 0;
118    if (strlen(cmd) >= 255) {
119        LOGE("ip command (%s) too long", cmd);
120        errno = E2BIG;
121        cli->sendMsg(ResponseCode::CommandSyntaxError, "Too long", true);
122        free(cmd);
123        return -1;
124    }
125    ret = system(cmd);
126    free(cmd);
127    return ret;
128}
129