1 /*
2 * Copyright (C) 2011 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 #define LOG_TAG "ip-up-vpn"
18
19 #include <arpa/inet.h>
20 #include <errno.h>
21 #include <linux/if.h>
22 #include <linux/route.h>
23 #include <netinet/in.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/ioctl.h>
28 #include <sys/socket.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31
32 #include <log/log.h>
33
34 #define DIR "/data/misc/vpn/"
35
env(const char * name)36 static const char *env(const char *name) {
37 const char *value = getenv(name);
38 return value ? value : "";
39 }
40
set_address(struct sockaddr * sa,const char * address)41 static int set_address(struct sockaddr *sa, const char *address) {
42 sa->sa_family = AF_INET;
43 errno = EINVAL;
44 return inet_pton(AF_INET, address, &((struct sockaddr_in *)sa)->sin_addr);
45 }
46
47 /*
48 * The primary goal is to create a file with VPN parameters. Currently they
49 * are interface, addresses, routes, DNS servers, and search domains and VPN
50 * server address. Each parameter occupies one line in the file, and it can be
51 * an empty string or space-separated values. The order and the format must be
52 * consistent with com.android.server.connectivity.Vpn. Here is an example.
53 *
54 * ppp0
55 * 192.168.1.100/24
56 * 0.0.0.0/0
57 * 192.168.1.1 192.168.1.2
58 * example.org
59 * 192.0.2.1
60 *
61 * The secondary goal is to unify the outcome of VPN. The current baseline
62 * is to have an interface configured with the given address and netmask
63 * and maybe add a host route to protect the tunnel. PPP-based VPN already
64 * does this, but others might not. Routes, DNS servers, and search domains
65 * are handled by the framework since they can be overridden by the users.
66 */
main(int argc,char ** argv)67 int main(int argc, char **argv)
68 {
69 FILE *state = fopen(DIR ".tmp", "wb");
70 if (!state) {
71 ALOGE("Cannot create state: %s", strerror(errno));
72 return 1;
73 }
74
75 if (argc >= 6) {
76 /* Invoked by pppd. */
77 fprintf(state, "%s\n", argv[1]);
78 fprintf(state, "%s/32\n", argv[4]);
79 fprintf(state, "0.0.0.0/0\n");
80 fprintf(state, "%s %s\n", env("DNS1"), env("DNS2"));
81 fprintf(state, "\n");
82 fprintf(state, "\n");
83 } else if (argc == 2) {
84 /* Invoked by racoon. */
85 const char *interface = env("INTERFACE");
86 const char *address = env("INTERNAL_ADDR4");
87 const char *routes = env("SPLIT_INCLUDE_CIDR");
88
89 int s = socket(AF_INET, SOCK_DGRAM, 0);
90 struct ifreq ifr;
91 memset(&ifr, 0, sizeof(ifr));
92
93 /* Bring up the interface. */
94 ifr.ifr_flags = IFF_UP;
95 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
96 if (ioctl(s, SIOCSIFFLAGS, &ifr)) {
97 ALOGE("Cannot bring up %s: %s", interface, strerror(errno));
98 fclose(state);
99 return 1;
100 }
101
102 /* Set the address. */
103 if (!set_address(&ifr.ifr_addr, address) ||
104 ioctl(s, SIOCSIFADDR, &ifr)) {
105 ALOGE("Cannot set address: %s", strerror(errno));
106 fclose(state);
107 return 1;
108 }
109
110 /* Set the netmask. */
111 if (set_address(&ifr.ifr_netmask, env("INTERNAL_NETMASK4"))) {
112 if (ioctl(s, SIOCSIFNETMASK, &ifr)) {
113 ALOGE("Cannot set netmask: %s", strerror(errno));
114 fclose(state);
115 return 1;
116 }
117 }
118
119 /* TODO: Send few packets to trigger phase 2? */
120
121 fprintf(state, "%s\n", interface);
122 fprintf(state, "%s/%s\n", address, env("INTERNAL_CIDR4"));
123 fprintf(state, "%s\n", routes[0] ? routes : "0.0.0.0/0");
124 fprintf(state, "%s\n", env("INTERNAL_DNS4_LIST"));
125 fprintf(state, "%s\n", env("DEFAULT_DOMAIN"));
126 fprintf(state, "%s\n", env("REMOTE_ADDR"));
127 } else {
128 ALOGE("Cannot parse parameters");
129 fclose(state);
130 return 1;
131 }
132
133 fclose(state);
134 if (chmod(DIR ".tmp", 0444) || rename(DIR ".tmp", DIR "state")) {
135 ALOGE("Cannot write state: %s", strerror(errno));
136 return 1;
137 }
138 return 0;
139 }
140