diff options
Diffstat (limited to 'mtpd.c')
| -rw-r--r-- | mtpd.c | 473 |
1 files changed, 0 insertions, 473 deletions
@@ -1,473 +0,0 @@ -/* - * Copyright (C) 2009 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 <stdarg.h> -#include <string.h> -#include <errno.h> -#include <sys/types.h> -#include <sys/socket.h> -#include <sys/poll.h> -#include <sys/wait.h> -#include <netdb.h> -#include <signal.h> -#include <unistd.h> -#include <fcntl.h> -#include <time.h> -#include <limits.h> - -#ifdef ANDROID_CHANGES -#include <android/log.h> -#include <cutils/sockets.h> -#endif - -#include "mtpd.h" -#include "NetdClient.h" - -#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0])) -/* Characters count in string with max value of unsigned type t */ -#define TYPE_STRLEN_U(t) ((((sizeof(t) * CHAR_BIT) * 1233) >> 12) + 1) -/* Length of string with max file descriptor value */ -#define FD_MAX_LEN TYPE_STRLEN_U(int) - -int the_socket = -1; - -extern struct protocol l2tp; -extern struct protocol pptp; -static struct protocol *protocols[] = {&l2tp, &pptp, NULL}; -static struct protocol *the_protocol; - -static char *interface; -static int pppd_argc; -static char **pppd_argv; -static pid_t pppd_pid; - -/* We redirect signals to a pipe in order to prevent race conditions. */ -static int signals[2]; - -static void interrupt(int signal) -{ - write(signals[1], &signal, sizeof(int)); -} - -static int initialize(int argc, char **argv) -{ - int i; - - for (i = 0; protocols[i]; ++i) { - struct protocol *p = protocols[i]; - if (argc - 3 >= p->arguments && !strcmp(argv[2], p->name)) { - log_print(INFO, "Using protocol %s", p->name); - the_protocol = p; - break; - } - } - - if (!the_protocol) { - printf("Usages:\n"); - for (i = 0; protocols[i]; ++i) { - struct protocol *p = protocols[i]; - printf(" %s interface %s %s pppd-arguments\n", - argv[0], p->name, p->usage); - } - exit(0); - } - - interface = argv[1]; - pppd_argc = argc - 3 - the_protocol->arguments; - pppd_argv = &argv[3 + the_protocol->arguments]; - return the_protocol->connect(&argv[3]); -} - -static void stop_pppd() -{ - if (pppd_pid) { - int status; - log_print(INFO, "Sending signal to pppd (pid = %d)", pppd_pid); - kill(pppd_pid, SIGTERM); - waitpid(pppd_pid, &status, 0); - pppd_pid = 0; - } -} - -#ifdef ANDROID_CHANGES - -static int android_get_control_and_arguments(int *argc, char ***argv) -{ - static char *args[32]; - int control; - int i; - - if ((i = android_get_control_socket("mtpd")) == -1) { - return -1; - } - log_print(DEBUG, "Waiting for control socket"); - if (listen(i, 1) == -1 || (control = accept(i, NULL, 0)) == -1) { - log_print(FATAL, "Cannot get control socket"); - exit(SYSTEM_ERROR); - } - close(i); - fcntl(control, F_SETFD, FD_CLOEXEC); - - args[0] = (*argv)[0]; - for (i = 1; i < 32; ++i) { - unsigned char bytes[2]; - if (recv(control, &bytes[0], 1, 0) != 1 || - recv(control, &bytes[1], 1, 0) != 1) { - log_print(FATAL, "Cannot get argument length"); - exit(SYSTEM_ERROR); - } else { - int length = bytes[0] << 8 | bytes[1]; - int offset = 0; - - if (length == 0xFFFF) { - break; - } - args[i] = malloc(length + 1); - while (offset < length) { - int n = recv(control, &args[i][offset], length - offset, 0); - if (n > 0) { - offset += n; - } else { - log_print(FATAL, "Cannot get argument value"); - exit(SYSTEM_ERROR); - } - } - args[i][length] = 0; - } - } - log_print(DEBUG, "Received %d arguments", i - 1); - - *argc = i; - *argv = args; - return control; -} - -#endif - -int main(int argc, char **argv) -{ - struct pollfd pollfds[3]; - int control = -1; - int timeout; - int status; - -#ifdef ANDROID_CHANGES - control = android_get_control_and_arguments(&argc, &argv); - shutdown(control, SHUT_WR); -#endif - - srandom(time(NULL)); - - if (pipe(signals) == -1) { - log_print(FATAL, "Pipe() %s", strerror(errno)); - exit(SYSTEM_ERROR); - } - fcntl(signals[0], F_SETFD, FD_CLOEXEC); - fcntl(signals[1], F_SETFD, FD_CLOEXEC); - - timeout = initialize(argc, argv); - - signal(SIGHUP, interrupt); - signal(SIGINT, interrupt); - signal(SIGTERM, interrupt); - signal(SIGCHLD, interrupt); - signal(SIGPIPE, SIG_IGN); - atexit(stop_pppd); - - pollfds[0].fd = the_socket; - pollfds[0].events = POLLIN; - pollfds[1].fd = signals[0]; - pollfds[1].events = POLLIN; - pollfds[2].fd = control; - pollfds[2].events = 0; - - while (timeout >= 0) { - if (poll(pollfds, 3, timeout ? timeout : -1) == -1 && errno != EINTR) { - log_print(FATAL, "Poll() %s", strerror(errno)); - exit(SYSTEM_ERROR); - } - if (pollfds[1].revents) { - break; - } - if (pollfds[2].revents) { - interrupt(SIGTERM); - } - timeout = pollfds[0].revents ? - the_protocol->process() : the_protocol->timeout(); -#ifdef ANDROID_CHANGES - if (!access("/data/misc/vpn/abort", F_OK)) { - interrupt(SIGTERM); - } - if (!timeout) { - timeout = 5000; - } -#endif - } - - if (timeout < 0) { - status = -timeout; - } else { - int signal; - read(signals[0], &signal, sizeof(int)); - log_print(INFO, "Received signal %d", signal); - if (signal == SIGCHLD && waitpid(pppd_pid, &status, WNOHANG) == pppd_pid - && WIFEXITED(status)) { - status = WEXITSTATUS(status); - log_print(INFO, "Pppd is terminated (status = %d)", status); - status += PPPD_EXITED; - pppd_pid = 0; - } else { - status = USER_REQUESTED; - } - } - - stop_pppd(); - the_protocol->shutdown(); - log_print(INFO, "Mtpd is terminated (status = %d)", status); - return status; -} - -void log_print(int level, char *format, ...) -{ - if (level >= 0 && level <= LOG_MAX) { -#ifdef ANDROID_CHANGES - static int levels[5] = { - ANDROID_LOG_DEBUG, ANDROID_LOG_INFO, ANDROID_LOG_WARN, - ANDROID_LOG_ERROR, ANDROID_LOG_FATAL - }; - va_list ap; - va_start(ap, format); - __android_log_vprint(levels[level], "mtpd", format, ap); - va_end(ap); -#else - static char *levels = "DIWEF"; - va_list ap; - fprintf(stderr, "%c: ", levels[level]); - va_start(ap, format); - vfprintf(stderr, format, ap); - va_end(ap); - fputc('\n', stderr); -#endif - } -} - -void create_socket(int family, int type, char *server, char *port) -{ - struct addrinfo hints = { - .ai_flags = AI_NUMERICSERV, - .ai_family = family, - .ai_socktype = type, - }; - struct addrinfo *records; - struct addrinfo *r; - int error; - - log_print(INFO, "Connecting to %s port %s via %s", server, port, interface); - - error = getaddrinfo(server, port, &hints, &records); - if (error) { - log_print(FATAL, "Getaddrinfo() %s", (error == EAI_SYSTEM) ? - strerror(errno) : gai_strerror(error)); - exit(NETWORK_ERROR); - } - - for (r = records; r; r = r->ai_next) { - int s = socket(r->ai_family, r->ai_socktype, r->ai_protocol); - if (!setsockopt(s, SOL_SOCKET, SO_BINDTODEVICE, interface, - strlen(interface)) && !connect(s, r->ai_addr, r->ai_addrlen)) { - the_socket = s; - break; - } - close(s); - } - - freeaddrinfo(records); - - if (the_socket == -1) { - log_print(FATAL, "Connect() %s", strerror(errno)); - exit(NETWORK_ERROR); - } - -#ifdef ANDROID_CHANGES - protectFromVpn(the_socket); -#endif - - fcntl(the_socket, F_SETFD, FD_CLOEXEC); - log_print(INFO, "Connection established (socket = %d)", the_socket); -} - -void start_pppd(int pppox) -{ - if (pppd_pid) { - log_print(WARNING, "Pppd is already started (pid = %d)", pppd_pid); - close(pppox); - return; - } - - log_print(INFO, "Starting pppd (pppox = %d)", pppox); - - pppd_pid = fork(); - if (pppd_pid < 0) { - log_print(FATAL, "Fork() %s", strerror(errno)); - exit(SYSTEM_ERROR); - } - - if (!pppd_pid) { - char *args[pppd_argc + 5]; - char number[FD_MAX_LEN + 1]; - - snprintf(number, FD_MAX_LEN + 1, "%d", pppox); - args[0] = "pppd"; - args[1] = "nodetach"; - args[2] = "pppox"; - args[3] = number; - memcpy(&args[4], pppd_argv, sizeof(char *) * pppd_argc); - args[4 + pppd_argc] = NULL; - - execvp("pppd", args); - log_print(FATAL, "Exec() %s", strerror(errno)); - exit(SYSTEM_ERROR); /* Pretending a fatal error in pppd. */ - } - - log_print(INFO, "Pppd started (pid = %d)", pppd_pid); - close(pppox); -} - -/** - * Start pppd daemon with pppol2tp-android plugin. - * - * @param tunnel_fd Tunnel socket file descriptor - * @param session_fd Session socket file descriptor - * @param tunnel_id Tunnel ID; must be in host byte order - * @param session_id Session ID; must be in host byte order - */ -void start_pppd_ol2tp(int tunnel_fd, int session_fd, int tunnel_id, - int session_id) -{ - if (pppd_pid) { - log_print(WARNING, "Pppd is already started (pid = %d)", pppd_pid); - goto ret; - } - - log_print(INFO, "Starting pppd (tunnel_fd = %d, session_fd = %d)", - tunnel_fd, session_fd); - - pppd_pid = fork(); - if (pppd_pid < 0) { - log_print(FATAL, "Fork() %s", strerror(errno)); - exit(SYSTEM_ERROR); - } - - if (!pppd_pid) { - char tunnel_fd_str[FD_MAX_LEN + 1]; - char session_fd_str[FD_MAX_LEN + 1]; - char tunnel_id_str[FD_MAX_LEN + 1]; - char session_id_str[FD_MAX_LEN + 1]; - - snprintf(tunnel_fd_str, FD_MAX_LEN + 1, "%d", tunnel_fd); - snprintf(session_fd_str, FD_MAX_LEN + 1, "%d", session_fd); - snprintf(tunnel_id_str, FD_MAX_LEN + 1, "%d", tunnel_id); - snprintf(session_id_str, FD_MAX_LEN + 1, "%d", session_id); - - const char *l2tp_args[] = { - "pppd", - "nodetach", - "plugin", - "pppol2tp-android.so", - "session_fd", - session_fd_str, - "tunnel_fd", - tunnel_fd_str, - "session_id", - session_id_str, - "tunnel_id", - tunnel_id_str, - }; - const size_t args_len = ARRAY_SIZE(l2tp_args) + pppd_argc + 1; - char *args[args_len]; - - /* Populate args[] from l2tp_args[] and pppd_argv[] */ - memcpy(args, l2tp_args, sizeof(l2tp_args)); - memcpy(args + ARRAY_SIZE(l2tp_args), pppd_argv, - sizeof(char *) * pppd_argc); - args[args_len - 1] = NULL; - - execvp("pppd", args); - log_print(FATAL, "Exec() %s", strerror(errno)); - exit(SYSTEM_ERROR); /* Pretending a fatal error in pppd. */ - } - - log_print(INFO, "Pppd started (pid = %d)", pppd_pid); - -ret: - close(session_fd); - close(tunnel_fd); -} - -/** - * Start pppd daemon with pppopptp-android plugin. - * - * @param pptp_fd PPTP socket file descriptor - */ -void start_pppd_pptp(int pptp_fd) -{ - if (pppd_pid) { - log_print(WARNING, "Pppd is already started (pid = %d)", pppd_pid); - goto ret; - } - - log_print(INFO, "Starting pppd (pptp_fd = %d)", pptp_fd); - - pppd_pid = fork(); - if (pppd_pid < 0) { - log_print(FATAL, "Fork() %s", strerror(errno)); - exit(SYSTEM_ERROR); - } - - if (!pppd_pid) { - char pptp_fd_str[FD_MAX_LEN + 1]; - - snprintf(pptp_fd_str, FD_MAX_LEN + 1, "%d", pptp_fd); - - const char *pptp_args[] = { - "pppd", - "nodetach", - "plugin", - "pppopptp-android.so", - "pptp_socket", - pptp_fd_str, - }; - const size_t args_len = ARRAY_SIZE(pptp_args) + pppd_argc + 1; - char *args[args_len]; - - /* Populate args[] from pptp_args[] and pppd_argv[] */ - memcpy(args, pptp_args, sizeof(pptp_args)); - memcpy(args + ARRAY_SIZE(pptp_args), pppd_argv, - sizeof(char *) * pppd_argc); - args[args_len - 1] = NULL; - - execvp("pppd", args); - log_print(FATAL, "Exec() %s", strerror(errno)); - exit(SYSTEM_ERROR); /* Pretending a fatal error in pppd. */ - } - - log_print(INFO, "Pppd started (pid = %d)", pppd_pid); - -ret: - close(pptp_fd); -} |