feature: Add command()

docs/keyd-application-mapper.scdoc

@@ -76,8 +76,8 @@ to */var/run/keyd.socket* (i.e be a member of the *keyd* group).
 
 # A note on security
 
-Any user which can interact with a program that directly controls input devices
-should be assumed to have full access to the system.
+*Any user which can interact with a program that directly controls input devices
+should be assumed to have full access to the system.*
 
 While keyd offers slightly better isolation compared to other remappers by dint
 of mediating access through an IPC mechanism (rather than granting users

docs/keyd.scdoc

@@ -372,6 +372,15 @@ arguments.
 
 	macro2(400, 50, macro(Hello space World))
 
+*command(<shell command>)*
+	Execute the given shell command.
+
+	E.G
+
+	command(brightness down)
+
+*NOTE:* Commands are executed by root, which means any user which has access
+to the keyd socket should be assumed to have root access.
 
 *noop*
 	Do nothing.

src/descriptor.c

@@ -14,7 +14,9 @@
 
 #define MAX_ARGS 5
 
-/* modifies the input string */
+/* TODO: Make this a bit nicer. */
+
+/* Modifies the input string */
 static int parse_fn(char *s,
 		    char **name,
 		    char *args[MAX_ARGS],
@@ -314,13 +316,12 @@ static size_t escape(char *s)
 	return n;
 }
 
-
 static int parse_macro(const char *exp, struct macro *macro)
 {
-	char s[MAX_MACROEXP_LEN];
+	char s[MAX_MACROEXP_LEN+1];
 	int len = strlen(exp);
 
-	if (len >= MAX_MACROEXP_LEN) {
+	if (len > MAX_MACROEXP_LEN) {
 		err("macro exceeds maximum macro length (%d)", MAX_MACROEXP_LEN);
 		return -1;
 	}
@@ -394,7 +395,7 @@ int layer_table_lookup(const struct layer_table *lt, const char *name)
 int layer_table_add_entry(struct layer_table *lt, const char *exp)
 {
 	uint8_t code1, code2;
-	char *keystr, *descstr, *c, *s;
+	char *keystr, *descstr, *dot, *paren, *s;
 	char *layername = "main";
 	struct descriptor d;
 	struct layer *layer;
@@ -410,10 +411,13 @@ int layer_table_add_entry(struct layer_table *lt, const char *exp)
 	strcpy(buf, exp);
 	s = buf;
 
-	if ((c = strchr(s, '.'))) {
+	dot = strchr(s, '.');
+	paren = strchr(s, '(');
+
+	if (dot && (!paren || dot < paren)) {
 		layername = s;
-		*c = 0;
-		s = c+1;
+		*dot = 0;
+		s = dot+1;
 	}
 
 	if (parse_kvp(s, &keystr, &descstr) < 0) {
@@ -518,6 +522,36 @@ int create_layer(struct layer *layer, const char *desc, const struct layer_table
 	return 0;
 }
 
+int set_command_arg(struct descriptor *d, int idx,
+		    struct layer_table *lt, const char *exp)
+{
+	struct command *command = &lt->commands[lt->nr_commands];
+	int len = strlen(exp);
+
+	if (len == 0 || strstr(exp, "command(") != exp || exp[len-1] != ')')
+		return -1;
+
+	if (lt->nr_commands >= MAX_COMMANDS) {
+		err("maximum number of commands exceeded");
+		return 1;
+	}
+
+	if (len > MAX_COMMAND_LEN) {
+		err("maximum command length exceeded");
+		return 1;
+	}
+
+	strcpy(command->cmd, exp+8);
+	command->cmd[len-9] = 0;
+
+	command->cmd[len-1] = 0;
+	escape(command->cmd);
+
+	d->args[0].idx = lt->nr_commands;
+	lt->nr_commands++;
+	return 0;
+}
+
 /*
  * Returns:
  *
@@ -586,6 +620,11 @@ int parse_descriptor(const char *descstr,
 		if (keycode_to_mod(code))
 			fprintf(stderr,
 				"WARNING: mapping modifier keycodes directly may produce unintended results, you probably want layer(<modifier name>) instead\n");
+	} else if ((ret=set_command_arg(d, 0, lt, descstr)) >= 0) {
+		if (ret > 0)
+			return -1;
+		else
+			d->op = OP_COMMAND;
 	} else if ((ret=set_macro_arg(d, 0, lt, descstr, -1, -1)) >= 0) {
 		if (ret > 0)
 			return -1;

src/descriptor.h

@@ -29,6 +29,7 @@ enum op {
 	OP_TOGGLE,
 
 	OP_MACRO,
+	OP_COMMAND,
 	OP_TIMEOUT
 };
 

src/device.c

@@ -68,7 +68,7 @@ static int device_init(const char *path, struct device *dev)
 	int fd;
 	int type;
 
-	if ((fd = open(path, O_RDWR | O_NONBLOCK, 0600)) < 0) {
+	if ((fd = open(path, O_RDWR | O_NONBLOCK | O_CLOEXEC, 0600)) < 0) {
 		fprintf(stderr, "failed to open %s\n", path);
 		return -1;
 	}
@@ -167,7 +167,7 @@ int devmon_create()
 	assert(!init);
 	init = 1;
 
-	int fd = inotify_init1(IN_NONBLOCK);
+	int fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
 	if (fd < 0) {
 		perror("inotify");
 		exit(-1);

src/keyboard.c

@@ -324,6 +324,33 @@ static void activate_layer(struct keyboard *kbd, uint8_t code, struct layer *lay
 	kbd->last_layer_code = code;
 }
 
+static void execute_command(const char *cmd)
+{
+	int fd;
+
+	dbg("Executing command: %s", cmd);
+
+	if (fork())
+		return;
+
+	fd = open("/dev/null", O_RDWR);
+
+	if (fd < 0) {
+		perror("open");
+		exit(-1);
+	}
+
+	close(0);
+	close(1);
+	close(2);
+
+	dup2(fd, 0);
+	dup2(fd, 1);
+	dup2(fd, 2);
+
+	execl("/bin/sh", "/bin/sh", "-c", cmd);
+}
+
 static void clear_oneshot(struct keyboard *kbd)
 {
 	size_t i = 0;
@@ -348,6 +375,7 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code,
 	struct macro *macros = kbd->layer_table.macros;
 	struct timeout *timeouts = kbd->layer_table.timeouts;
 	struct layer *layers = kbd->layer_table.layers;
+	struct command *commands = kbd->layer_table.commands;
 
 	switch (d->op) {
 		struct macro *macro;
@@ -476,6 +504,10 @@ static long process_descriptor(struct keyboard *kbd, uint8_t code,
 			timeout = kbd->pending_timeout.t.timeout;
 		}
 		break;
+	case OP_COMMAND:
+		if (pressed)
+			execute_command(commands[d->args[0].idx].cmd);
+		break;
 	case OP_SWAP:
 		layer = &layers[d->args[0].idx];
 		macro = d->args[1].idx == -1 ? NULL : &macros[d->args[1].idx];

src/layer.h

@@ -16,6 +16,9 @@
 #define MAX_MACRO_SIZE	64
 #define MAX_MACROS	256
 
+#define MAX_COMMAND_LEN	256
+#define MAX_COMMANDS	64
+
 #define LT_NORMAL	0
 #define LT_LAYOUT	1
 #define LT_COMPOSITE	2
@@ -32,7 +35,7 @@
  */
 
 struct layer {
-	char name[MAX_LAYER_NAME_LEN];
+	char name[MAX_LAYER_NAME_LEN+1];
 
 	size_t nr_layers;
 	int layers[MAX_COMPOSITE_LAYERS];
@@ -48,6 +51,10 @@ struct layer {
 	long activation_time;
 };
 
+struct command {
+	char cmd[MAX_COMMAND_LEN+1];
+};
+
 struct timeout {
 	uint16_t timeout;
 	struct descriptor d1;
@@ -84,9 +91,11 @@ struct layer_table {
 
 	struct timeout timeouts[MAX_TIMEOUTS];
 	struct macro macros[MAX_MACROS];
+	struct command commands[MAX_COMMANDS];
 
 	size_t nr_macros;
 	size_t nr_timeouts;
+	size_t nr_commands;
 };
 
 #endif

src/vkbd/uinput.c

@@ -36,7 +36,7 @@ static int create_virtual_keyboard(const char *name)
 	size_t code;
 	struct uinput_user_dev udev = {0};
 
-	int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+	int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK | O_CLOEXEC);
 	if (fd < 0) {
 		perror("open uinput");
 		exit(-1);
@@ -93,7 +93,7 @@ static int create_virtual_pointer(const char *name)
 	uint16_t code;
 	struct uinput_user_dev udev = {0};
 
-	int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
+	int fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK | O_CLOEXEC);
 	if (fd < 0) {
 		perror("open");
 		exit(-1);