| /* |
| * Copyright 2018 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. |
| * |
| * main.c - main function |
| */ |
| |
| #include <arpa/inet.h> |
| #include <errno.h> |
| #include <netinet/in.h> |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/capability.h> |
| #include <unistd.h> |
| |
| #include "clatd.h" |
| #include "common.h" |
| #include "config.h" |
| #include "logging.h" |
| |
| #define DEVICEPREFIX "v4-" |
| |
| /* function: stop_loop |
| * signal handler: stop the event loop |
| */ |
| static void stop_loop() { running = 0; }; |
| |
| /* function: print_help |
| * in case the user is running this on the command line |
| */ |
| void print_help() { |
| printf("android-clat arguments:\n"); |
| printf("-i [uplink interface]\n"); |
| printf("-p [plat prefix]\n"); |
| printf("-4 [IPv4 address]\n"); |
| printf("-6 [IPv6 address]\n"); |
| printf("-t [tun file descriptor number]\n"); |
| printf("-r [read socket descriptor number]\n"); |
| printf("-w [write socket descriptor number]\n"); |
| } |
| |
| /* function: main |
| * allocate and setup the tun device, then run the event loop |
| */ |
| int main(int argc, char **argv) { |
| struct tun_data tunnel; |
| int opt; |
| char *uplink_interface = NULL, *plat_prefix = NULL; |
| char *v4_addr = NULL, *v6_addr = NULL, *tunfd_str = NULL, *read_sock_str = NULL, |
| *write_sock_str = NULL; |
| unsigned len; |
| |
| while ((opt = getopt(argc, argv, "i:p:4:6:t:r:w:h")) != -1) { |
| switch (opt) { |
| case 'i': |
| uplink_interface = optarg; |
| break; |
| case 'p': |
| plat_prefix = optarg; |
| break; |
| case '4': |
| v4_addr = optarg; |
| break; |
| case '6': |
| v6_addr = optarg; |
| break; |
| case 't': |
| tunfd_str = optarg; |
| break; |
| case 'r': |
| read_sock_str = optarg; |
| break; |
| case 'w': |
| write_sock_str = optarg; |
| break; |
| case 'h': |
| print_help(); |
| exit(0); |
| default: |
| logmsg(ANDROID_LOG_FATAL, "Unknown option -%c. Exiting.", (char)optopt); |
| exit(1); |
| } |
| } |
| |
| if (uplink_interface == NULL) { |
| logmsg(ANDROID_LOG_FATAL, "clatd called without an interface"); |
| exit(1); |
| } |
| |
| if (tunfd_str != NULL && !parse_int(tunfd_str, &tunnel.fd4)) { |
| logmsg(ANDROID_LOG_FATAL, "invalid tunfd %s", tunfd_str); |
| exit(1); |
| } |
| if (!tunnel.fd4) { |
| logmsg(ANDROID_LOG_FATAL, "no tunfd specified on commandline."); |
| exit(1); |
| } |
| |
| if (read_sock_str != NULL && !parse_int(read_sock_str, &tunnel.read_fd6)) { |
| logmsg(ANDROID_LOG_FATAL, "invalid read socket %s", read_sock_str); |
| exit(1); |
| } |
| if (!tunnel.read_fd6) { |
| logmsg(ANDROID_LOG_FATAL, "no read_fd6 specified on commandline."); |
| exit(1); |
| } |
| |
| if (write_sock_str != NULL && !parse_int(write_sock_str, &tunnel.write_fd6)) { |
| logmsg(ANDROID_LOG_FATAL, "invalid write socket %s", write_sock_str); |
| exit(1); |
| } |
| if (!tunnel.write_fd6) { |
| logmsg(ANDROID_LOG_FATAL, "no write_fd6 specified on commandline."); |
| exit(1); |
| } |
| |
| len = snprintf(tunnel.device4, sizeof(tunnel.device4), "%s%s", DEVICEPREFIX, uplink_interface); |
| if (len >= sizeof(tunnel.device4)) { |
| logmsg(ANDROID_LOG_FATAL, "interface name too long '%s'", tunnel.device4); |
| exit(1); |
| } |
| |
| Global_Clatd_Config.native_ipv6_interface = uplink_interface; |
| if (!plat_prefix || inet_pton(AF_INET6, plat_prefix, &Global_Clatd_Config.plat_subnet) <= 0) { |
| logmsg(ANDROID_LOG_FATAL, "invalid IPv6 address specified for plat prefix: %s", plat_prefix); |
| exit(1); |
| } |
| |
| if (!v4_addr || !inet_pton(AF_INET, v4_addr, &Global_Clatd_Config.ipv4_local_subnet.s_addr)) { |
| logmsg(ANDROID_LOG_FATAL, "Invalid IPv4 address %s", v4_addr); |
| exit(1); |
| } |
| |
| if (!v6_addr || !inet_pton(AF_INET6, v6_addr, &Global_Clatd_Config.ipv6_local_subnet)) { |
| logmsg(ANDROID_LOG_FATAL, "Invalid source address %s", v6_addr); |
| exit(1); |
| } |
| |
| logmsg(ANDROID_LOG_INFO, "Starting clat version %s on %s plat=%s v4=%s v6=%s", CLATD_VERSION, |
| uplink_interface, plat_prefix ? plat_prefix : "(none)", v4_addr ? v4_addr : "(none)", |
| v6_addr ? v6_addr : "(none)"); |
| |
| // Loop until someone sends us a signal or brings down the tun interface. |
| if (signal(SIGTERM, stop_loop) == SIG_ERR) { |
| logmsg(ANDROID_LOG_FATAL, "sigterm handler failed: %s", strerror(errno)); |
| exit(1); |
| } |
| |
| event_loop(&tunnel); |
| |
| logmsg(ANDROID_LOG_INFO, "Shutting down clat on %s", uplink_interface); |
| |
| if (running) { |
| logmsg(ANDROID_LOG_INFO, "Clatd on %s waiting for SIGTERM", uplink_interface); |
| while (running) sleep(60); |
| logmsg(ANDROID_LOG_INFO, "Clatd on %s received SIGTERM", uplink_interface); |
| } else { |
| logmsg(ANDROID_LOG_INFO, "Clatd on %s already received SIGTERM", uplink_interface); |
| } |
| return 0; |
| } |