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-rw-r--r--tsak/main.cpp462
1 files changed, 347 insertions, 115 deletions
diff --git a/tsak/main.cpp b/tsak/main.cpp
index 050d6c05f..df485a0e0 100644
--- a/tsak/main.cpp
+++ b/tsak/main.cpp
@@ -1,8 +1,8 @@
/*
Copyright 2010 Adam Marchetti
-Copyright 2011 Timothy Pearson <[email protected]>
+Copyright 2011-2012 Timothy Pearson <[email protected]>
-This file is part of tsak.
+This file is part of tsak, the TDE Secure Attention Key daemon
tsak is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as
@@ -35,9 +35,15 @@ License along with tsak. If not, see http://www.gnu.org/licenses/.
#include <sys/time.h>
#include <termios.h>
#include <signal.h>
+#include <libudev.h>
+#include <libgen.h>
#define FIFO_DIR "/tmp/ksocket-global"
#define FIFO_FILE_OUT "/tmp/ksocket-global/tsak"
+#define FIFO_LOCKFILE_OUT "/tmp/ksocket-global/tsak.lock"
+
+#define MAX_KEYBOARDS 64
+#define MAX_INPUT_NODE 128
#define TestBit(bit, array) (array[(bit) / 8] & (1 << ((bit) % 8)))
@@ -46,9 +52,18 @@ typedef unsigned char byte;
bool mPipeOpen_out = false;
int mPipe_fd_out = -1;
+int mPipe_lockfd_out = -1;
+
+char filename[32];
+char key_bitmask[(KEY_MAX + 7) / 8];
+
struct sigaction usr_action;
sigset_t block_mask;
+int keyboard_fd_num;
+int keyboard_fds[MAX_KEYBOARDS];
+int child_pids[MAX_KEYBOARDS];
+
const char *keycode[256] =
{
"", "<esc>", "1", "2", "3", "4", "5", "6", "7", "8",
@@ -79,6 +94,26 @@ int bit_set(size_t i, const byte* a)
return a[i/CHAR_BIT] & (1 << i%CHAR_BIT);
}
+// --------------------------------------------------------------------------------------
+// Useful function from Stack Overflow
+// http://stackoverflow.com/questions/874134/find-if-string-endswith-another-string-in-c
+// --------------------------------------------------------------------------------------
+/* returns 1 iff str ends with suffix */
+int str_ends_with(const char * str, const char * suffix) {
+
+ if( str == NULL || suffix == NULL )
+ return 0;
+
+ size_t str_len = strlen(str);
+ size_t suffix_len = strlen(suffix);
+
+ if(suffix_len > str_len)
+ return 0;
+
+ return 0 == strncmp( str + str_len - suffix_len, suffix, suffix_len );
+}
+// --------------------------------------------------------------------------------------
+
/* Assign features (supported axes and keys) of the physical input device (devin)
* to the virtual input device (devout) */
static void copy_features(int devin, int devout)
@@ -111,26 +146,40 @@ static void copy_features(int devin, int devout)
}
}
-int find_keyboard() {
+int find_keyboards() {
int i, j;
int fd;
- char filename[32];
- char key_bitmask[(KEY_MAX + 7) / 8];
+ char name[256] = "Unknown";
+
+ keyboard_fd_num = 0;
+ for (i=0; i<MAX_KEYBOARDS; i++) {
+ keyboard_fds[i] = 0;
+ }
- for (i=0; i<32; i++) {
+ for (i=0; i<MAX_INPUT_NODE; i++) {
snprintf(filename,sizeof(filename), "/dev/input/event%d", i);
-
+
fd = open(filename, O_RDWR|O_SYNC);
ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(key_bitmask)), key_bitmask);
-
- /* We assume that anything that has an alphabetic key in the
- QWERTYUIOP range in it is the main keyboard. */
- for (j = KEY_Q; j <= KEY_P; j++) {
- if (TestBit(j, key_bitmask))
- return fd;
+
+ // Ensure that we do not detect our own tsak faked keyboards
+ ioctl (fd, EVIOCGNAME (sizeof (name)), name);
+ if (str_ends_with(name, "+tsak") == 0) {
+ /* We assume that anything that has an alphabetic key in the
+ QWERTYUIOP range in it is the main keyboard. */
+ for (j = KEY_Q; j <= KEY_P; j++) {
+ if (TestBit(j, key_bitmask)) {
+ keyboard_fds[keyboard_fd_num] = fd;
+ }
+ }
+ }
+
+ if (keyboard_fds[keyboard_fd_num] == 0) {
+ close (fd);
+ }
+ else {
+ keyboard_fd_num++;
}
-
- close (fd);
}
return 0;
}
@@ -144,6 +193,12 @@ void tearDownPipe()
}
}
+void tearDownLockingPipe()
+{
+ close(mPipe_lockfd_out);
+ unlink(FIFO_LOCKFILE_OUT);
+}
+
bool setFileLock(int fd, bool close_on_failure)
{
struct flock fl;
@@ -154,8 +209,8 @@ bool setFileLock(int fd, bool close_on_failure)
fl.l_len = 1;
// Set the exclusive file lock
- if (fcntl(mPipe_fd_out, F_SETLK, &fl) == -1) {
- close(mPipe_fd_out);
+ if (fcntl(fd, F_SETLK, &fl) == -1) {
+ close(fd);
return false;
}
@@ -171,7 +226,7 @@ bool checkFileLock()
fl.l_whence = SEEK_SET;
fl.l_len = 0;
- int fd = open(FIFO_FILE_OUT, O_RDWR | O_NONBLOCK);
+ int fd = open(FIFO_LOCKFILE_OUT, O_RDWR | O_NONBLOCK);
fcntl(fd, F_GETLK, &fl); /* Overwrites lock structure with preventors. */
if (fd > -1) {
@@ -202,6 +257,71 @@ bool setupPipe()
return setFileLock(mPipe_fd_out, true);
}
+bool setupLockingPipe()
+{
+ /* Create the FIFOs if they do not exist */
+ umask(0);
+ mkdir(FIFO_DIR,0644);
+
+ mknod(FIFO_LOCKFILE_OUT, S_IFIFO|0600, 0);
+ chmod(FIFO_LOCKFILE_OUT, 0600);
+
+ mPipe_lockfd_out = open(FIFO_LOCKFILE_OUT, O_RDWR | O_NONBLOCK);
+ if (mPipe_lockfd_out > -1) {
+ // Set the exclusive file lock
+ return setFileLock(mPipe_lockfd_out, true);
+ }
+
+ return false;
+}
+
+void broadcast_sak()
+{
+ // Let anyone listening to our interface know that an SAK keypress was received
+ // I highly doubt there are more than 255 VTs active at once...
+ int i;
+ for (i=0;i<255;i++) {
+ write(mPipe_fd_out, "SAK\n\r", 6);
+ }
+}
+
+void restart_tsak()
+{
+ int i;
+
+ fprintf(stderr, "Forcibly terminating...\n");
+
+ // Close down all child processes
+ for (i=0; i<MAX_KEYBOARDS; i++) {
+ if (child_pids[i] != 0) {
+ kill(child_pids[i], SIGKILL);
+ }
+ }
+
+ // Wait for process termination
+ sleep(1);
+
+ // Release all exclusive keyboard locks
+ for (int current_keyboard=0;current_keyboard<keyboard_fd_num;current_keyboard++) {
+ if(ioctl(keyboard_fds[current_keyboard], EVIOCGRAB, 0) < 0) {
+ fprintf(stderr, "Failed to release exclusive input device lock");
+ }
+ close(keyboard_fds[current_keyboard]);
+ }
+
+#if 1
+ // Restart now
+ // Note that the execl function never returns
+ char me[2048];
+ int chars = readlink("/proc/self/exe", me, sizeof(me));
+ me[chars] = 0;
+ me[2047] = 0;
+ execl(me, basename(me), (char*)NULL);
+#else
+ _exit(0);
+#endif
+}
+
class PipeHandler
{
public:
@@ -215,7 +335,7 @@ PipeHandler::PipeHandler()
PipeHandler::~PipeHandler()
{
- tearDownPipe();
+ tearDownLockingPipe();
}
int main (int argc, char *argv[])
@@ -223,13 +343,19 @@ int main (int argc, char *argv[])
struct input_event ev[64];
struct input_event event;
struct uinput_user_dev devinfo={0};
- int fd, devout, rd, value, size = sizeof (struct input_event);
+ int devout[MAX_KEYBOARDS], rd, i, value, size = sizeof (struct input_event);
char name[256] = "Unknown";
bool ctrl_down = false;
bool alt_down = false;
bool hide_event = false;
bool established = false;
bool testrun = false;
+ int current_keyboard;
+ bool can_proceed;
+
+ for (i=0; i<MAX_KEYBOARDS; i++) {
+ child_pids[i] = 0;
+ }
if (argc == 2) {
if (strcmp(argv[1], "checkactive") == 0) {
@@ -239,7 +365,11 @@ int main (int argc, char *argv[])
// Check for existing file locks
if (!checkFileLock()) {
- fprintf(stderr, "Another instance of this program is already running\n");
+ fprintf(stderr, "Another instance of this program is already running [1]\n");
+ return 8;
+ }
+ if (!setupLockingPipe()) {
+ fprintf(stderr, "Another instance of this program is already running [2]\n");
return 8;
}
@@ -256,125 +386,227 @@ int main (int argc, char *argv[])
return 5;
}
- // Open Device
- fd = find_keyboard();
- if (fd == -1) {
- printf ("Could not find your keyboard!\n");
+ // Find keyboards
+ find_keyboards();
+ if (keyboard_fd_num == 0) {
+ printf ("Could not find any usable keyboard(s)!\n");
+ // Make sure everyone knows we physically can't detect a SAK
+ // Before we do this we broadcast one so that active dialogs are updated appropriately
+ // Also, we keep watching for a keyboard to be added via a forked child process...
+ broadcast_sak();
if (established)
sleep(1);
- else
- return 4;
+ else {
+ int i=fork();
+ if (i<0) return 12; // fork failed
+ if (i>0) {
+ return 4;
+ }
+ sleep(1);
+ restart_tsak();
+ }
}
else {
- // Print Device Name
- ioctl (fd, EVIOCGNAME (sizeof (name)), name);
- fprintf(stderr, "Reading From : (%s)\n", name);
-
- // Create filtered virtual output device
- devout=open("/dev/misc/uinput",O_WRONLY|O_NONBLOCK);
- if (devout<0) {
- perror("open(\"/dev/misc/uinput\")");
- devout=open("/dev/uinput",O_WRONLY|O_NONBLOCK);
- }
- if (devout<0) {
- fprintf(stderr,"Unable to open /dev/uinput or /dev/misc/uinput (char device 10:223).\nPossible causes:\n 1) Device node does not exist\n 2) Kernel not compiled with evdev [INPUT_EVDEV] and uinput [INPUT_UINPUT] user level driver support\n 3) Permission denied.\n");
- perror("open(\"/dev/uinput\")");
- if (established)
- sleep(1);
- else
- return 3;
- }
- else {
- if(ioctl(fd, EVIOCGRAB, 2) < 0) {
- close(fd);
- fprintf(stderr, "Failed to grab exclusive input device lock");
+ fprintf(stderr, "Found %d keyboard(s)\n", keyboard_fd_num);
+
+ can_proceed = true;
+ for (current_keyboard=0;current_keyboard<keyboard_fd_num;current_keyboard++) {
+ // Print Device Name
+ ioctl (keyboard_fds[current_keyboard], EVIOCGNAME (sizeof (name)), name);
+ fprintf(stderr, "Reading from keyboard: (%s)\n", name);
+
+ // Create filtered virtual output device
+ devout[current_keyboard]=open("/dev/misc/uinput",O_WRONLY|O_NONBLOCK);
+ if (devout[current_keyboard]<0) {
+ devout[current_keyboard]=open("/dev/uinput",O_WRONLY|O_NONBLOCK);
+ if (devout[current_keyboard]<0) {
+ perror("open(\"/dev/misc/uinput\")");
+ }
+ }
+ if (devout[current_keyboard]<0) {
+ can_proceed = false;
+ fprintf(stderr, "Unable to open /dev/uinput or /dev/misc/uinput (char device 10:223).\nPossible causes:\n 1) Device node does not exist\n 2) Kernel not compiled with evdev [INPUT_EVDEV] and uinput [INPUT_UINPUT] user level driver support\n 3) Permission denied.\n");
+ perror("open(\"/dev/uinput\")");
if (established)
sleep(1);
else
- return 1;
+ return 3;
}
- else {
- ioctl(fd, EVIOCGNAME(UINPUT_MAX_NAME_SIZE), devinfo.name);
- strncat(devinfo.name, "+tsak", UINPUT_MAX_NAME_SIZE-1);
- fprintf(stderr, "%s\n", devinfo.name);
- ioctl(fd, EVIOCGID, &devinfo.id);
-
- copy_features(fd, devout);
- write(devout,&devinfo,sizeof(devinfo));
- if (ioctl(devout,UI_DEV_CREATE)<0) {
- fprintf(stderr,"Unable to create input device with UI_DEV_CREATE\n");
+ }
+
+ if (can_proceed == true) {
+ for (current_keyboard=0;current_keyboard<keyboard_fd_num;current_keyboard++) {
+ if(ioctl(keyboard_fds[current_keyboard], EVIOCGRAB, 2) < 0) {
+ close(keyboard_fds[current_keyboard]);
+ fprintf(stderr, "Failed to grab exclusive input device lock");
if (established)
sleep(1);
else
- return 2;
+ return 1;
}
else {
- fprintf(stderr,"Device created.\n");
-
- if (established == false) {
- tearDownPipe();
- int i=fork();
- if (i<0) return 9; // fork failed
- if (i>0) {
- // close parent process
- close(mPipe_fd_out);
- return 0;
- }
- setupPipe();
+ ioctl(keyboard_fds[current_keyboard], EVIOCGNAME(UINPUT_MAX_NAME_SIZE), devinfo.name);
+ strncat(devinfo.name, "+tsak", UINPUT_MAX_NAME_SIZE-1);
+ fprintf(stderr, "%s\n", devinfo.name);
+ ioctl(keyboard_fds[current_keyboard], EVIOCGID, &devinfo.id);
+
+ copy_features(keyboard_fds[current_keyboard], devout[current_keyboard]);
+ write(devout[current_keyboard],&devinfo,sizeof(devinfo));
+ if (ioctl(devout[current_keyboard],UI_DEV_CREATE)<0) {
+ fprintf(stderr, "Unable to create input device with UI_DEV_CREATE\n");
+ if (established)
+ sleep(1);
+ else
+ return 2;
}
-
- established = true;
-
- if (testrun == true) {
- return 0;
- }
-
- while (1) {
- if ((rd = read (fd, ev, size * 2)) < size) {
- fprintf(stderr,"Read failed.\n");
- break;
- }
-
- value = ev[0].value;
-
- if (value != ' ' && ev[1].value == 0 && ev[1].type == 1){ // Read the key release event
- if (keycode[(ev[1].code)]) {
- if (strcmp(keycode[(ev[1].code)], "<control>") == 0) ctrl_down = false;
- if (strcmp(keycode[(ev[1].code)], "<alt>") == 0) alt_down = false;
+ else {
+ fprintf(stderr, "Device created.\n");
+
+ if (established == false) {
+ int i=fork();
+ if (i<0) return 9; // fork failed
+ if (i>0) {
+ child_pids[current_keyboard] = i;
+ continue;
}
+ setupLockingPipe();
}
- if (value != ' ' && ev[1].value == 1 && ev[1].type == 1){ // Read the key press event
- if (keycode[(ev[1].code)]) {
- if (strcmp(keycode[(ev[1].code)], "<control>") == 0) ctrl_down = true;
- if (strcmp(keycode[(ev[1].code)], "<alt>") == 0) alt_down = true;
- }
+
+ established = true;
+
+ if (testrun == true) {
+ return 0;
}
- hide_event = false;
- if (keycode[(ev[1].code)]) {
- if (alt_down && ctrl_down && (strcmp(keycode[(ev[1].code)], "<del>") == 0)) {
- hide_event = true;
+ while (1) {
+ if ((rd = read (keyboard_fds[current_keyboard], ev, size * 2)) < size) {
+ fprintf(stderr, "Read failed.\n");
+ break;
+ }
+
+ value = ev[0].value;
+
+ if (value != ' ' && ev[1].value == 0 && ev[1].type == 1){ // Read the key release event
+ if (keycode[(ev[1].code)]) {
+ if (strcmp(keycode[(ev[1].code)], "<control>") == 0) ctrl_down = false;
+ if (strcmp(keycode[(ev[1].code)], "<alt>") == 0) alt_down = false;
+ }
+ }
+ if (value != ' ' && ev[1].value == 1 && ev[1].type == 1){ // Read the key press event
+ if (keycode[(ev[1].code)]) {
+ if (strcmp(keycode[(ev[1].code)], "<control>") == 0) ctrl_down = true;
+ if (strcmp(keycode[(ev[1].code)], "<alt>") == 0) alt_down = true;
+ }
+ }
+
+ hide_event = false;
+ if (keycode[(ev[1].code)]) {
+ if (alt_down && ctrl_down && (strcmp(keycode[(ev[1].code)], "<del>") == 0)) {
+ hide_event = true;
+ }
+ }
+
+ if (hide_event == false) {
+ // Pass the event on...
+ event = ev[0];
+ write(devout[current_keyboard], &event, sizeof event);
+ event = ev[1];
+ write(devout[current_keyboard], &event, sizeof event);
+ }
+ if (hide_event == true) {
+ // Let anyone listening to our interface know that an SAK keypress was received
+ broadcast_sak();
}
}
+ }
+ }
+ }
+
+ // fork udev monitor process
+ int i=fork();
+ if (i<0) return 10; // fork failed
+ if (i>0) {
+ // Terminate parent
+ return 0;
+ }
+
+ // Prevent multiple process instances from starting
+ setupLockingPipe();
+
+ // Wait a little bit so that udev hotplug can stabilize before we start monitoring
+ sleep(1);
+
+ fprintf(stderr, "Hotplug monitoring process started\n");
+
+ // Monitor for hotplugged keyboards
+ int j;
+ int hotplug_fd;
+ bool is_new_keyboard;
+ struct udev *udev;
+ struct udev_device *dev;
+ struct udev_monitor *mon;
+
+ // Create the udev object
+ udev = udev_new();
+ if (!udev) {
+ fprintf(stderr, "Cannot connect to udev interface\n");
+ return 11;
+ }
+
+ // Set up a udev monitor to monitor input devices
+ mon = udev_monitor_new_from_netlink(udev, "udev");
+ udev_monitor_filter_add_match_subsystem_devtype(mon, "input", NULL);
+ udev_monitor_enable_receiving(mon);
+
+ while (1) {
+ // Watch for input from the monitoring process
+ dev = udev_monitor_receive_device(mon);
+ if (dev) {
+ // If a keyboard was removed we need to restart...
+ if (strcmp(udev_device_get_action(dev), "remove") == 0) {
+ udev_device_unref(dev);
+ udev_unref(udev);
+ restart_tsak();
+ }
+
+ is_new_keyboard = false;
+ snprintf(filename,sizeof(filename), "%s", udev_device_get_devnode(dev));
+ udev_device_unref(dev);
+
+ // Print name of keyboard
+ hotplug_fd = open(filename, O_RDWR|O_SYNC);
+ ioctl(hotplug_fd, EVIOCGBIT(EV_KEY, sizeof(key_bitmask)), key_bitmask);
- if (hide_event == false) {
- // Pass the event on...
- event = ev[0];
- write(devout, &event, sizeof event);
- event = ev[1];
- write(devout, &event, sizeof event);
- }
- if (hide_event == true) {
- // Let anyone listening to our interface know that an SAK keypress was received
- // I highly doubt there are more than 255 VTs active at once...
- int i;
- for (i=0;i<255;i++) {
- write(mPipe_fd_out, "SAK\n\r", 6);
- }
+ /* We assume that anything that has an alphabetic key in the
+ QWERTYUIOP range in it is the main keyboard. */
+ for (j = KEY_Q; j <= KEY_P; j++) {
+ if (TestBit(j, key_bitmask)) {
+ is_new_keyboard = true;
}
}
+ ioctl (hotplug_fd, EVIOCGNAME (sizeof (name)), name);
+ close(hotplug_fd);
+
+ // Ensure that we do not detect our own tsak faked keyboards
+ if (str_ends_with(name, "+tsak") == 1) {
+ is_new_keyboard = false;
+ }
+
+ // If a keyboard was added we need to restart...
+ if (is_new_keyboard == true) {
+ fprintf(stderr, "Hotplugged new keyboard: (%s)\n", name);
+ udev_unref(udev);
+ restart_tsak();
+ }
+ }
+ else {
+ fprintf(stderr, "No Device from receive_device(). An error occured.\n");
}
}
+
+ udev_unref(udev);
+
+ fprintf(stderr, "Hotplug monitoring process terminated\n");
}
}
}
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