--- /dev/null
+/*
+ mtetherd
+ (c) 2010 Gregor Riepl <onitake@gmail.com>
+
+ Tethering utility for Maemo
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <signal.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/sysctl.h>
+#include <sys/wait.h>
+#include <dbus/dbus.h>
+#include "device.h"
+
+static const char *INETDEV = "gprs0";
+static const char *DEVICES[] = {
+ "usb0",
+ "bnep0",
+ NULL
+};
+static const char *ADDRESSES[] = {
+ "192.168.253.254",
+ "192.168.254.254",
+ NULL
+};
+static const char *STARTADDRESSES[] = {
+ "192.168.253.1",
+ "192.168.254.1",
+ NULL
+};
+static const char *ENDADDRESSES[] = {
+ "192.168.253.254",
+ "192.168.254.254",
+ NULL
+};
+// Wait x seconds for process termination
+static const unsigned int TERMINATE_WAIT = 5;
+// Poll the main loop after x milliseconds
+static const unsigned int POLL_MAINLOOP = 500;
+
+// Run loop active flag
+static int running;
+// Number of active tethering connections
+static unsigned int active;
+
+static void siginthandler(int sig) {
+ if (running) {
+ fprintf(stderr, "SIGINIT received, exiting\n");
+ running = 0;
+ } else {
+ fprintf(stderr, "Another SIGINIT received, aborting\n");
+ if (kill(getpid(), SIGKILL) == -1) {
+ fprintf(stderr, "PANIC! Error killing self: %s\n", strerror(errno));
+ }
+ }
+}
+
+static int launch(const char *args[]) {
+ pid_t pid = fork();
+ if (pid == 0) {
+ if (execv(args[0], (char **const) args) == -1) {
+ fprintf(stderr, "Error launching external process %s: %s\n", args[0], strerror(errno));
+ exit(1);
+ }
+ } else if (pid == -1) {
+ fprintf(stderr, "Can't fork external process %s: %s\n", args[0], strerror(errno));
+ return -1;
+ } else {
+ /*printf("Launching:");
+ size_t a;
+ for (a = 0; args[a]; a++) {
+ printf(" %s", args[a]);
+ }
+ printf("\n");*/
+ int status = 0;
+ if (waitpid(pid, &status, WNOHANG) == -1) {
+ fprintf(stderr, "Error waiting for child process completion: %s\n", strerror(errno));
+ return -2;
+ }
+ size_t i;
+ for (i = 0; i < TERMINATE_WAIT && !WIFEXITED(status); i++) {
+ if (WIFEXITED(status)) {
+ if (WEXITSTATUS(status) != 0) {
+ fprintf(stderr, "Child process returned error: %d\n", WEXITSTATUS(status));
+ return -3;
+ }
+ } else if (WIFSIGNALED(status)) {
+ fprintf(stderr, "Child process killed by signal: %d\n", WTERMSIG(status));
+ return -4;
+ }
+ sleep(1);
+ if (waitpid(pid, &status, WNOHANG) == -1) {
+ fprintf(stderr, "Error waiting for child process completion: %s\n", strerror(errno));
+ return -2;
+ }
+ }
+ if (i >= TERMINATE_WAIT) {
+ fprintf(stderr, "Child process %s still running after %u seconds, ignoring.\n", args[0], TERMINATE_WAIT);
+ return -5;
+ }
+ }
+ return 0;
+}
+
+static void added(Device *device, const char *inetdev) {
+ printf("Got org.kernel.kevent.add on %s\n", device->name);
+ char *runfile = NULL;
+ if (asprintf(&runfile, "/var/run/tethering.%s.pid", device->name) == -1) {
+ fprintf(stderr, "Can't construct PID file name for device %s: %s\n", device->name, strerror(errno));
+ return;
+ }
+ char *range = NULL;
+ if (asprintf(&range, "%s,%s,3600", device->startaddress, device->endaddress) == -1) {
+ fprintf(stderr, "Can't construct address range parameter for device %s: %s\n", device->name, strerror(errno));
+ free(runfile);
+ return;
+ }
+ const char *ifconfig[] = { "/sbin/ifconfig", device->name, device->address, "up", NULL };
+ const char *modprobe[] = { "/sbin/modprobe", "ipt_MASQUERADE", NULL };
+ const char *iptables[] = { "/usr/sbin/iptables", "-t", "nat", "-A", "POSTROUTING", "-o", inetdev, "-j", "MASQUERADE", NULL };
+ const char *dnsmasq[] = { "/sbin/start-stop-daemon", "-S", "-p", runfile, "-b", "-x", "/usr/sbin/dnsmasq", "--", "-x", runfile, "-k", "-I", "lo", "-i", device->name, "-a", device->address, "-z", "-F", range, NULL };
+ char *forwsysctl = NULL;
+ if (asprintf(&forwsysctl, "/proc/sys/net/ipv4/conf/%s/forwarding", device->name) == -1) {
+ fprintf(stderr, "Can't construct sysctl path for device %s: %s\n", device->name, strerror(errno));
+ free(runfile);
+ free(range);
+ return;
+ }
+ char *inetforwsysctl = NULL;
+ if (asprintf(&inetforwsysctl, "/proc/sys/net/ipv4/conf/%s/forwarding", inetdev) == -1) {
+ fprintf(stderr, "Can't construct inet sysctl path for device %s: %s\n", inetdev, strerror(errno));
+ free(runfile);
+ free(range);
+ free(forwsysctl);
+ return;
+ }
+
+
+ if (launch(ifconfig) == 0) {
+ if (launch(modprobe) == 0) {
+ if (launch(iptables) == 0) {
+ if (launch(dnsmasq) == 0) {
+ int ffd = open(forwsysctl, O_WRONLY, 0666);
+ if (ffd < 0) {
+ fprintf(stderr, "Can't enable forwarding on PAN device %s: %s\n", device->name, strerror(errno));
+ } else {
+ if (write(ffd, "1", 1) == -1) {
+ fprintf(stderr, "Can't enable forwarding on PAN device %s: %s\n", device->name, strerror(errno));
+ } else {
+ int ifd = open(inetforwsysctl, O_WRONLY, 0666);
+ if (ifd < 0) {
+ fprintf(stderr, "Can't enable forwarding on WAN device %s (path %s): %s\n", inetdev, inetforwsysctl, strerror(errno));
+ } else {
+ if (write(ifd, "1", 1) == -1) {
+ fprintf(stderr, "Can't enable forwarding on WAN device %s: %s\n", inetdev, strerror(errno));
+ }
+ close(ifd);
+ }
+ }
+ close(ffd);
+ }
+ }
+ }
+ }
+ }
+
+ free(range);
+ free(runfile);
+ free(forwsysctl);
+ free(inetforwsysctl);
+
+ active++;
+}
+
+static void removed(Device *device, const char *inetdev) {
+ printf("Got org.kernel.kevent.remove on %s\n", device->name);
+
+ char *runfile = NULL;
+ if (asprintf(&runfile, "/var/run/tethering.%s.pid", device->name) == -1) {
+ fprintf(stderr, "Can't construct PID file name for device %s: %s\n", device->name, strerror(errno));
+ return;
+ }
+ const char *dnsmasq[] = { "/sbin/start-stop-daemon", "-K", "-p", runfile, "-x", "/usr/sbin/dnsmasq", NULL };
+ const char *iptables[] = { "/usr/sbin/iptables", "-t", "nat", "-D", "POSTROUTING", "-o", inetdev, "-j", "MASQUERADE", NULL };
+
+ // Errors are ignored here: we just disable as much as we can.
+ launch(dnsmasq);
+ if (unlink(runfile) == -1) {
+ fprintf(stderr, "Error removing PID file for device %s: %s\n", device->name, strerror(errno));
+ }
+ launch(iptables);
+
+ free(runfile);
+
+ if (active > 0) active--;
+ if (active == 0) {
+ char *inetforwsysctl = NULL;
+ if (asprintf(&inetforwsysctl, "/proc/sys/net/ipv4/conf/%s/forwarding", inetdev) == -1) {
+ fprintf(stderr, "Can't construct inet sysctl path for device %s: %s\n", inetdev, strerror(errno));
+ return;
+ }
+ int fd = open(inetforwsysctl, O_WRONLY, 0666);
+ if (fd < 0) {
+ fprintf(stderr, "Can't enable forwarding on WAN device %s: %s\n", inetdev, strerror(errno));
+ } else {
+ if (write(fd, "0", 1) == -1) {
+ fprintf(stderr, "Can't enable forwarding on WAN device %s: %s\n", inetdev, strerror(errno));
+ }
+ close(fd);
+ }
+ free(inetforwsysctl);
+ }
+}
+
+int main(int argc, const char *argv[]) {
+ active = 0;
+
+ Device *devices = NULL;
+ Device *node = NULL;
+ size_t i;
+ for (i = 0; DEVICES[i]; i++) {
+ Device *device = device_new(DEVICES[i]);
+ if (device) {
+ device_set_address(device, ADDRESSES[i]);
+ device_set_startaddress(device, STARTADDRESSES[i]);
+ device_set_endaddress(device, ENDADDRESSES[i]);
+ if (device_validate(device)) {
+ node = device_append(node, device);
+ if (!devices) {
+ devices = node;
+ }
+ } else {
+ device_delete(device);
+ }
+ }
+ }
+
+ if (!devices) {
+ fprintf(stderr, "Warning, no devices configured. I will just sit here and wait for nicer weather.\n");
+ }
+
+ DBusError err;
+ dbus_error_init(&err);
+ DBusConnection *conn = dbus_bus_get(DBUS_BUS_SYSTEM, &err);
+ if (dbus_error_is_set(&err)) {
+ fprintf(stderr, "Error %s occured: %s\n", err.name, err.message);
+ dbus_error_free(&err);
+ }
+ if (!conn) {
+ return 1;
+ }
+
+ for (node = devices; node; node = node->next) {
+ char *filter = NULL;
+ if (!asprintf(&filter, "type='signal',interface='org.kernel.kevent',path='/org/kernel/class/net/%s'", node->name)) {
+ fprintf(stderr, "Can't construct filter rule for device %s: %s\n", node->name, strerror(errno));
+ } else {
+ dbus_bus_add_match(conn, filter, NULL);
+ free(filter);
+ }
+ }
+ dbus_connection_flush(conn);
+
+ running = 1;
+ signal(SIGINT, siginthandler);
+ while (running) {
+ dbus_connection_read_write(conn, POLL_MAINLOOP);
+ DBusMessage* msg = dbus_connection_pop_message(conn);
+ if (msg) {
+ if (dbus_message_is_signal(msg, "org.kernel.kevent", "add")) {
+ char **path = NULL;
+ if (!dbus_message_get_path_decomposed(msg, &path)) {
+ fprintf(stderr, "Can't get add message path!\n");
+ } else {
+ unsigned int last;
+ for (last = 0; path[last] && last <= 6; last++);
+ if (last == 0 || last > 6) {
+ fprintf(stderr, "Add message has no path or path too long!\n");
+ } else {
+ Device *device = device_search(devices, path[last - 1]);
+ if (device) {
+ added(device, INETDEV);
+ }
+ }
+ dbus_free_string_array(path);
+ }
+ } else if (dbus_message_is_signal(msg, "org.kernel.kevent", "remove")) {
+ char **path = NULL;
+ if (!dbus_message_get_path_decomposed(msg, &path)) {
+ fprintf(stderr, "Can't get remove message path!\n");
+ } else {
+ unsigned int last;
+ for (last = 0; path[last] && last <= 6; last++);
+ if (last == 0 || last > 6) {
+ fprintf(stderr, "Remove message has no path or path too long!\n");
+ } else {
+ Device *device = device_search(devices, path[last - 1]);
+ if (device) {
+ removed(device, INETDEV);
+ }
+ }
+ dbus_free_string_array(path);
+ }
+ }
+ dbus_message_unref(msg);
+ }
+ }
+
+ device_delete_all(devices);
+ dbus_connection_unref(conn);
+ return 0;
+}
projects / mtetherd / blobdiff