SecondaryTableController.cpp revision 063af322b48ab1bb0c3e09eb0b64915ba568275b 
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";
38static char ADD[] = "add";
39static char DEL[] = "del";
40
41SecondaryTableController::SecondaryTableController() {
42    int i;
43    for (i=0; i < INTERFACES_TRACKED; i++) {
44        mInterfaceTable[i][0] = 0;
45        // TODO - use a hashtable or other prebuilt container class
46        mInterfaceRuleCount[i] = 0;
47    }
48}
49
50SecondaryTableController::~SecondaryTableController() {
51}
52
53int SecondaryTableController::findTableNumber(const char *iface) {
54    int i;
55    for (i = 0; i < INTERFACES_TRACKED; i++) {
56        if (strncmp(iface, mInterfaceTable[i], MAX_IFACE_LENGTH) == 0) {
57            return i;
58        }
59    }
60    return -1;
61}
62
63int 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            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    return modifyRoute(cli, ADD, iface, dest, prefix, gateway, tableIndex);
78}
79
80int SecondaryTableController::modifyRoute(SocketClient *cli, char *action, char *iface, char *dest,
81        int prefix, char *gateway, int tableIndex) {
82    char *cmd;
83
84    if (strcmp("::", gateway) == 0) {
85        //  IP tool doesn't like "::" - the equiv of 0.0.0.0 that it accepts for ipv4
86        asprintf(&cmd, "%s route %s %s/%d dev %s table %d",
87                IP_PATH, action, dest, prefix, iface, tableIndex+BASE_TABLE_NUMBER);
88    } else {
89        asprintf(&cmd, "%s route %s %s/%d via %s dev %s table %d",
90                IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER);
91    }
92
93    if (runAndFree(cli, cmd)) {
94        LOGE("ip route %s failed: %s route %s %s/%d via %s dev %s table %d", action,
95                IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER);
96        errno = ENODEV;
97        cli->sendMsg(ResponseCode::OperationFailed, "ip route modification failed", true);
98        return -1;
99    }
100
101    if (strcmp(action, ADD) == 0) {
102        mInterfaceRuleCount[tableIndex]++;
103    } else {
104        if (--mInterfaceRuleCount[tableIndex] < 1) {
105            mInterfaceRuleCount[tableIndex] = 0;
106            mInterfaceTable[tableIndex][0] = 0;
107        }
108    }
109    cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false);
110    return 0;
111}
112
113int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix,
114        char *gateway) {
115    int tableIndex = findTableNumber(iface);
116    if (tableIndex == -1) {
117        LOGE("Interface not found");
118        errno = ENODEV;
119        cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true);
120        return -1;
121    }
122
123    return modifyRoute(cli, DEL, iface, dest, prefix, gateway, tableIndex);
124}
125
126int SecondaryTableController::runAndFree(SocketClient *cli, char *cmd) {
127    int ret = 0;
128    if (strlen(cmd) >= 255) {
129        LOGE("ip command (%s) too long", cmd);
130        errno = E2BIG;
131        cli->sendMsg(ResponseCode::CommandSyntaxError, "Too long", true);
132        free(cmd);
133        return -1;
134    }
135    ret = system(cmd);
136    free(cmd);
137    return ret;
138}
139