fix: repair IBus context lifecycle

ibus.c

@@ -14,7 +14,9 @@ enum
 {
 	Maxwatches	= 32,
 	Maxconns	= 16,
+	Maxcontexts	= 64,
 	Relmask		= 1<<30,
+	Ibussupermask	= 1<<26,
 };
 
 typedef struct Watch Watch;
@@ -23,24 +25,41 @@ struct Watch
 	DBusWatch	*w;
 };
 
+typedef struct Ictx Ictx;
+struct Ictx
+{
+	DBusConnection	*conn;
+	char	path[64];
+	uvlong	owner;
+	int	focused;
+	Caret	caret;
+};
+
 static Watch watches[Maxwatches];
 static int nwatches;
 static DBusConnection *conns[Maxconns];
 static int nconns;
 static DBusServer *srv;
-static char addrfile[256];
+static Ictx contexts[Maxcontexts];
+static char addrfile[512];
+static dev_t addrdev;
+static ino_t addrino;
+static int addrowned;
 static int icctr;
 static int busctr;
 static Channel *replyc;
-static uvlong owner;
 
 static DBusHandlerResult onmsg(DBusConnection*, DBusMessage*, void*);
 
 static void
 unlinkaddr(void)
 {
-	if(addrfile[0] != '\0')
+	struct stat st;
+
+	if(addrowned && lstat(addrfile, &st) == 0 &&
+	   st.st_dev == addrdev && st.st_ino == addrino)
 		unlink(addrfile);
+	addrowned = 0;
 }
 
 static void
@@ -98,7 +117,8 @@ buildaddrpath(char *buf, int sz)
 {
 	char mid[64], host[64], num[8], *cfg, *home;
 	struct stat st;
-	char dir[256];
+	char dir[512];
+	int n;
 
 	machineid(mid, sizeof(mid));
 	if(mid[0] == '\0')
@@ -106,15 +126,17 @@ buildaddrpath(char *buf, int sz)
 	xdisplay(host, sizeof(host), num, sizeof(num));
 	cfg = getenv("XDG_CONFIG_HOME");
 	if(cfg != nil && cfg[0] != '\0')
-		snprintf(dir, sizeof(dir), "%s/ibus/bus", cfg);
+		n = snprintf(dir, sizeof(dir), "%s/ibus/bus", cfg);
 	else{
 		home = getenv("HOME");
 		if(home == nil)
 			return -1;
-		snprintf(dir, sizeof(dir), "%s/.config/ibus/bus", home);
+		n = snprintf(dir, sizeof(dir), "%s/.config/ibus/bus", home);
 	}
+	if(n < 0 || n >= (int)sizeof dir)
+		return -1;
 	if(stat(dir, &st) < 0){
-		char tmp[256];
+		char tmp[512];
 		char *p;
 		strncpy(tmp, dir, sizeof(tmp));
 		tmp[sizeof(tmp)-1] = '\0';
@@ -126,23 +148,55 @@ buildaddrpath(char *buf, int sz)
 			}
 		mkdir(tmp, 0700);
 	}
-	snprintf(buf, sz, "%s/%s-%s-%s", dir, mid, host, num);
-	return 0;
+	n = snprintf(buf, sz, "%s/%s-%s-%s", dir, mid, host, num);
+	return n < 0 || n >= sz ? -1 : 0;
 }
 
 static int
 writeaddr(char *path, char *addr)
 {
+	char tmp[576];
 	FILE *fp;
+	struct stat st;
+	int fd, n, ok;
 
-	fp = fopen(path, "w");
-	if(fp == nil)
+	n = snprintf(tmp, sizeof tmp, "%s.tmp.XXXXXX", path);
+	if(n < 0 || n >= (int)sizeof tmp)
 		return -1;
-	fprintf(fp, "IBUS_ADDRESS=%s\n", addr);
-	fprintf(fp, "IBUS_DAEMON_PID=%d\n", (int)getpid());
+	fd = mkstemp(tmp);
+	if(fd < 0)
+		return -1;
+	ok = 0;
+	fp = nil;
+	if(fchmod(fd, 0600) < 0)
+		goto out;
+	fp = fdopen(fd, "w");
+	if(fp == nil)
+		goto out;
+	fd = -1;
+	if(fprintf(fp, "IBUS_ADDRESS=%s\n", addr) < 0 ||
+	   fprintf(fp, "IBUS_DAEMON_PID=%d\n", (int)getpid()) < 0 ||
+	   fflush(fp) < 0 || fsync(fileno(fp)) < 0)
+		goto out;
+	if(fclose(fp) < 0){
+		fp = nil;
+		goto out;
+	}
+	fp = nil;
+	if(rename(tmp, path) < 0 || lstat(path, &st) < 0)
+		goto out;
+	addrdev = st.st_dev;
+	addrino = st.st_ino;
+	addrowned = 1;
+	ok = 1;
+out:
+	if(fp != nil)
 		fclose(fp);
-	chmod(path, 0600);
-	return 0;
+	if(fd >= 0)
+		close(fd);
+	if(!ok)
+		unlink(tmp);
+	return ok ? 0 : -1;
 }
 
 static dbus_bool_t
@@ -204,38 +258,72 @@ mget(u32int state)
 	if(state & (1<<0)) m |= Mshift;
 	if(state & (1<<2)) m |= Mctrl;
 	if(state & (1<<3)) m |= Malt;
-	if(state & (1<<6)) m |= Msuper;
+	if(state & ((1<<6)|Ibussupermask)) m |= Msuper;
 	return m;
 }
 
+static Ictx*
+findcontext(DBusConnection *conn, const char *path)
+{
+	int i;
+
+	for(i = 0; i < nelem(contexts); i++)
+		if(contexts[i].conn == conn && strcmp(contexts[i].path, path) == 0)
+			return &contexts[i];
+	return nil;
+}
+
+static Ictx*
+newcontext(DBusConnection *conn, const char *path)
+{
+	int i;
+
+	for(i = 0; i < nelem(contexts); i++)
+		if(contexts[i].conn == nil){
+			memset(&contexts[i], 0, sizeof contexts[i]);
+			contexts[i].conn = conn;
+			contexts[i].owner = ownernew();
+			strncpy(contexts[i].path, path, sizeof contexts[i].path);
+			contexts[i].path[sizeof contexts[i].path-1] = '\0';
+			return &contexts[i];
+		}
+	return nil;
+}
+
 static void
-sendkey(u32int ks, u32int mod, Keyres *res)
+sendrequest(Ictx *ctx, int op, u32int ks, u32int mod, Keyres *res)
 {
 	Keyreq kr;
 
 	memset(&kr, 0, sizeof kr);
-	kr.owner = owner;
-	kr.op = Keypress;
+	kr.owner = ctx->owner;
+	kr.op = op;
 	kr.ks = ks;
 	kr.mod = mod;
-	kr.want = 1;
+	kr.caret = ctx->caret;
+	kr.want = op == Keypress;
 	kr.reply = replyc;
 	chansend(keyc, &kr);
 	chanrecv(replyc, res);
 }
 
 static void
-sendreset(void)
+releasecontext(Ictx *ctx)
 {
-	Keyreq kr;
 	Keyres res;
 
-	memset(&kr, 0, sizeof kr);
-	kr.owner = owner;
-	kr.op = Keyreset;
-	kr.reply = replyc;
-	chansend(keyc, &kr);
-	chanrecv(replyc, &res);
+	if(replyc != nil)
+		sendrequest(ctx, Keyrelease, 0, 0, &res);
+	ctx->focused = 0;
+	memset(&ctx->caret, 0, sizeof ctx->caret);
+
+}
+
+static void
+dropcontext(Ictx *ctx)
+{
+	releasecontext(ctx);
+	memset(ctx, 0, sizeof *ctx);
 }
 
 static void
@@ -318,15 +406,53 @@ handlehello(DBusConnection *c, DBusMessage *m)
 	return DBUS_HANDLER_RESULT_HANDLED;
 }
 
+static DBusHandlerResult
+handleerror(DBusConnection *c, DBusMessage *m, const char *name,
+	const char *text)
+{
+	DBusMessage *r;
+
+	r = dbus_message_new_error(m, name, text);
+	if(r != nil){
+		dbus_connection_send(c, r, nil);
+		dbus_message_unref(r);
+	}
+	return DBUS_HANDLER_RESULT_HANDLED;
+}
+
+static DBusHandlerResult
+handlebool(DBusConnection *c, DBusMessage *m, int value)
+{
+	DBusMessage *r;
+	dbus_bool_t b;
+
+	r = dbus_message_new_method_return(m);
+	b = value ? TRUE : FALSE;
+	dbus_message_append_args(r, DBUS_TYPE_BOOLEAN, &b, DBUS_TYPE_INVALID);
+	dbus_connection_send(c, r, nil);
+	dbus_message_unref(r);
+	return DBUS_HANDLER_RESULT_HANDLED;
+}
+
 static DBusHandlerResult
 handlecreate(DBusConnection *c, DBusMessage *m)
 {
 	DBusMessage *r;
 	char path[64];
 	const char *pp;
+	Ictx *ctx;
+	int n;
 
 	icctr++;
-	snprintf(path, sizeof(path), "/org/freedesktop/IBus/InputContext_%d", icctr);
+	n = snprintf(path, sizeof(path),
+		"/org/freedesktop/IBus/InputContext_%d", icctr);
+	if(n < 0 || n >= (int)sizeof path)
+		return handleerror(c, m, DBUS_ERROR_LIMITS_EXCEEDED,
+			"input context path exhausted");
+	ctx = newcontext(c, path);
+	if(ctx == nil)
+		return handleerror(c, m, DBUS_ERROR_LIMITS_EXCEEDED,
+			"too many input contexts");
 	pp = path;
 	r = dbus_message_new_method_return(m);
 	dbus_message_append_args(r, DBUS_TYPE_OBJECT_PATH, &pp, DBUS_TYPE_INVALID);
@@ -336,14 +462,12 @@ handlecreate(DBusConnection *c, DBusMessage *m)
 }
 
 static DBusHandlerResult
-handlekey(DBusConnection *c, DBusMessage *m)
+handlekey(DBusConnection *c, DBusMessage *m, Ictx *ctx)
 {
-	DBusMessage *r;
 	DBusError err;
 	dbus_uint32_t sym, code, state;
 	Keyres res;
 	char commit[Maxutf], preedit[Maxutf];
-	dbus_bool_t b;
 	u32int ks, mod;
 
 	dbus_error_init(&err);
@@ -356,28 +480,17 @@ handlekey(DBusConnection *c, DBusMessage *m)
 		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 	}
 	USED(code);
-	if(state & Relmask){
-		r = dbus_message_new_method_return(m);
-		b = FALSE;
-		dbus_message_append_args(r, DBUS_TYPE_BOOLEAN, &b, DBUS_TYPE_INVALID);
-		dbus_connection_send(c, r, nil);
-		dbus_message_unref(r);
-		return DBUS_HANDLER_RESULT_HANDLED;
-	}
+	if(state & Relmask || !ctx->focused)
+		return handlebool(c, m, 0);
 	ks = kget(sym);
 	mod = mget(state);
-	sendkey(ks, mod, &res);
+	sendrequest(ctx, Keypress, ks, mod, &res);
 	stoutf(&res.commit, commit, sizeof commit);
 	stoutf(&res.preedit, preedit, sizeof preedit);
 	if(commit[0] != '\0')
 		emitcommit(c, dbus_message_get_path(m), commit);
 	emitpreedit(c, dbus_message_get_path(m), preedit);
-	r = dbus_message_new_method_return(m);
-	b = res.eaten ? TRUE : FALSE;
-	dbus_message_append_args(r, DBUS_TYPE_BOOLEAN, &b, DBUS_TYPE_INVALID);
-	dbus_connection_send(c, r, nil);
-	dbus_message_unref(r);
-	return DBUS_HANDLER_RESULT_HANDLED;
+	return handlebool(c, m, res.eaten);
 }
 
 static DBusHandlerResult
@@ -392,13 +505,66 @@ handlenoop(DBusConnection *c, DBusMessage *m)
 }
 
 static DBusHandlerResult
-handlereset(DBusConnection *c, DBusMessage *m)
+handlereset(DBusConnection *c, DBusMessage *m, Ictx *ctx)
 {
-	sendreset();
+	Keyres res;
+
+	sendrequest(ctx, Keyreset, 0, 0, &res);
 	emitpreedit(c, dbus_message_get_path(m), "");
 	return handlenoop(c, m);
 }
 
+static DBusHandlerResult
+handlefocusin(DBusConnection *c, DBusMessage *m, Ictx *ctx)
+{
+	ctx->focused = 1;
+	return handlenoop(c, m);
+}
+
+static DBusHandlerResult
+handlefocusout(DBusConnection *c, DBusMessage *m, Ictx *ctx)
+{
+	releasecontext(ctx);
+	emitpreedit(c, dbus_message_get_path(m), "");
+	return handlenoop(c, m);
+}
+
+static DBusHandlerResult
+handledestroy(DBusConnection *c, DBusMessage *m, Ictx *ctx)
+{
+	dropcontext(ctx);
+	return handlenoop(c, m);
+}
+
+static DBusHandlerResult
+handlecursor(DBusConnection *c, DBusMessage *m, Ictx *ctx)
+{
+	DBusError err;
+	dbus_int32_t x, y, w, h;
+	Keyres res;
+
+	dbus_error_init(&err);
+	if(!dbus_message_get_args(m, &err,
+		DBUS_TYPE_INT32, &x, DBUS_TYPE_INT32, &y,
+		DBUS_TYPE_INT32, &w, DBUS_TYPE_INT32, &h,
+		DBUS_TYPE_INVALID)){
+		dbus_error_free(&err);
+		return handleerror(c, m, DBUS_ERROR_INVALID_ARGS,
+			"SetCursorLocation expects four integers");
+	}
+	if(w < 0 || h < 0)
+		return handleerror(c, m, DBUS_ERROR_INVALID_ARGS,
+			"cursor dimensions must not be negative");
+	ctx->caret.valid = 1;
+	ctx->caret.x = x;
+	ctx->caret.y = y;
+	ctx->caret.w = w;
+	ctx->caret.h = h;
+	if(ctx->focused)
+		sendrequest(ctx, Keycaret, 0, 0, &res);
+	return handlenoop(c, m);
+}
+
 static const char introspectxml[] =
 "<!DOCTYPE node PUBLIC \"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN\"\n"
 " \"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd\">\n"
@@ -448,6 +614,7 @@ static DBusHandlerResult
 onmsg(DBusConnection *c, DBusMessage *m, void *_)
 {
 	const char *iface, *member, *path;
+	Ictx *ctx;
 
 	USED(_);
 	if(dbus_message_get_type(m) != DBUS_MESSAGE_TYPE_METHOD_CALL)
@@ -472,15 +639,23 @@ onmsg(DBusConnection *c, DBusMessage *m, void *_)
 			return handlecreate(c, m);
 	}
 	if(strcmp(iface, "org.freedesktop.IBus.InputContext") == 0){
+		ctx = findcontext(c, path);
+		if(ctx == nil)
+			return handleerror(c, m, DBUS_ERROR_UNKNOWN_OBJECT,
+				"unknown input context");
 		if(strcmp(member, "ProcessKeyEvent") == 0)
-			return handlekey(c, m);
-		if(strcmp(member, "FocusOut") == 0
-		|| strcmp(member, "Reset") == 0)
-			return handlereset(c, m);
-		if(strcmp(member, "FocusIn") == 0
-		|| strcmp(member, "Destroy") == 0
-		|| strcmp(member, "SetCapabilities") == 0
-		|| strcmp(member, "SetCursorLocation") == 0
+			return handlekey(c, m, ctx);
+		if(strcmp(member, "FocusIn") == 0)
+			return handlefocusin(c, m, ctx);
+		if(strcmp(member, "FocusOut") == 0)
+			return handlefocusout(c, m, ctx);
+		if(strcmp(member, "Reset") == 0)
+			return handlereset(c, m, ctx);
+		if(strcmp(member, "Destroy") == 0)
+			return handledestroy(c, m, ctx);
+		if(strcmp(member, "SetCursorLocation") == 0)
+			return handlecursor(c, m, ctx);
+		if(strcmp(member, "SetCapabilities") == 0
 		|| strcmp(member, "SetEngine") == 0)
 			return handlenoop(c, m);
 	}
@@ -507,7 +682,7 @@ newconn(DBusServer *s, DBusConnection *c, void *_)
 static void
 pruneconns(void)
 {
-	int i, j;
+	int i, j, k;
 
 	j = 0;
 	for(i = 0; i < nconns; i++){
@@ -515,6 +690,9 @@ pruneconns(void)
 			conns[j++] = conns[i];
 			continue;
 		}
+		for(k = 0; k < nelem(contexts); k++)
+			if(contexts[k].conn == conns[i])
+				dropcontext(&contexts[k]);
 		dbus_connection_unref(conns[i]);
 	}
 	nconns = j;
@@ -531,8 +709,11 @@ ibusinit(void)
 		fprintf(stderr, "strans: ibus: cannot build address path\n");
 		return -1;
 	}
-	unlink(addrfile);
-	snprintf(addr, sizeof(addr), "unix:abstract=strans-%d", (int)getpid());
+	if(snprintf(addr, sizeof(addr), "unix:abstract=strans-%d",
+	   (int)getpid()) >= (int)sizeof addr){
+		fprintf(stderr, "strans: ibus: address is too long\n");
+		return -1;
+	}
 	dbus_error_init(&err);
 	srv = dbus_server_listen(addr, &err);
 	if(srv == nil){
@@ -571,7 +752,6 @@ ibusthread(void *_)
 	if(ibusinit() < 0)
 		return;
 	replyc = chancreate(sizeof(Keyres), 0);
-	owner = ownernew();
 	for(;;){
 		n = 0;
 		for(i = 0; i < nwatches && n < Maxwatches; i++){