replicant-frameworks_native/cmds/ip-up-vpn/ip-up-vpn.c

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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <linux/if.h>
#include <linux/route.h>
#define LOG_TAG "ip-up-vpn"
#include <cutils/log.h>
#define DIR "/data/misc/vpn/"
static const char *env(const char *name) {
const char *value = getenv(name);
return value ? value : "";
}
static int set_address(struct sockaddr *sa, const char *address) {
sa->sa_family = AF_INET;
errno = EINVAL;
return inet_pton(AF_INET, address, &((struct sockaddr_in *)sa)->sin_addr);
}
/*
* The primary goal is to create a file with VPN parameters. Currently they
* are interface, addresses, routes, DNS servers, and search domains and VPN
* server address. Each parameter occupies one line in the file, and it can be
* an empty string or space-separated values. The order and the format must be
* consistent with com.android.server.connectivity.Vpn. Here is an example.
*
* ppp0
* 192.168.1.100/24
* 0.0.0.0/0
* 192.168.1.1 192.168.1.2
* example.org
* 192.0.2.1
*
* The secondary goal is to unify the outcome of VPN. The current baseline
* is to have an interface configured with the given address and netmask
* and maybe add a host route to protect the tunnel. PPP-based VPN already
* does this, but others might not. Routes, DNS servers, and search domains
* are handled by the framework since they can be overridden by the users.
*/
int main(int argc, char **argv)
{
FILE *state = fopen(DIR ".tmp", "wb");
if (!state) {
ALOGE("Cannot create state: %s", strerror(errno));
return 1;
}
if (argc >= 6) {
/* Invoked by pppd. */
fprintf(state, "%s\n", argv[1]);
fprintf(state, "%s/32\n", argv[4]);
fprintf(state, "0.0.0.0/0\n");
fprintf(state, "%s %s\n", env("DNS1"), env("DNS2"));
fprintf(state, "\n");
fprintf(state, "\n");
} else if (argc == 2) {
/* Invoked by racoon. */
const char *interface = env("INTERFACE");
const char *address = env("INTERNAL_ADDR4");
const char *routes = env("SPLIT_INCLUDE_CIDR");
int s = socket(AF_INET, SOCK_DGRAM, 0);
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
/* Bring up the interface. */
ifr.ifr_flags = IFF_UP;
strncpy(ifr.ifr_name, interface, IFNAMSIZ);
if (ioctl(s, SIOCSIFFLAGS, &ifr)) {
ALOGE("Cannot bring up %s: %s", interface, strerror(errno));
return 1;
}
/* Set the address. */
if (!set_address(&ifr.ifr_addr, address) ||
ioctl(s, SIOCSIFADDR, &ifr)) {
ALOGE("Cannot set address: %s", strerror(errno));
return 1;
}
/* Set the netmask. */
if (set_address(&ifr.ifr_netmask, env("INTERNAL_NETMASK4"))) {
if (ioctl(s, SIOCSIFNETMASK, &ifr)) {
ALOGE("Cannot set netmask: %s", strerror(errno));
return 1;
}
}
/* TODO: Send few packets to trigger phase 2? */
fprintf(state, "%s\n", interface);
fprintf(state, "%s/%s\n", address, env("INTERNAL_CIDR4"));
fprintf(state, "%s\n", routes[0] ? routes : "0.0.0.0/0");
fprintf(state, "%s\n", env("INTERNAL_DNS4_LIST"));
fprintf(state, "%s\n", env("DEFAULT_DOMAIN"));
fprintf(state, "%s\n", env("REMOTE_ADDR"));
} else {
ALOGE("Cannot parse parameters");
return 1;
}
fclose(state);
if (chmod(DIR ".tmp", 0444) || rename(DIR ".tmp", DIR "state")) {
ALOGE("Cannot write state: %s", strerror(errno));
return 1;
}
return 0;
}