harden ipc and frontend recovery

gtk/Makefile

@@ -2,8 +2,8 @@ CFLAGS = -Wall -O2 -I.. `pkg-config --cflags gtk+-3.0`
 LDFLAGS = `pkg-config --libs gtk+-3.0`
 DSTDIR ?= $(shell find /usr/lib* -type d -path "*/gtk-3.0/*/immodules" 2>/dev/null | head -1)
 
-im-strans.so: main.c
-	$(CC) -shared -fPIC $(CFLAGS) -o $@ $< $(LDFLAGS)
+im-strans.so: main.c ../ipc.c ../ipc.h
+	$(CC) -shared -fPIC $(CFLAGS) -o $@ main.c ../ipc.c $(LDFLAGS)
 
 docker: main.c Dockerfile
 	docker build -t strans-gtk .

gtk/main.c

@@ -12,7 +12,7 @@ struct Im
 {
 	GtkIMContext parent;
 	int fd;
-	char pre[256];
+	char pre[Ipcfieldmax+1];
 	int prelen;
 };
 
@@ -36,52 +36,61 @@ srvconnect(Im *im)
 		return;
 	memset(&addr, 0, sizeof(addr));
 	addr.sun_family = AF_UNIX;
-	snprintf(addr.sun_path, sizeof(addr.sun_path), "/tmp/strans.%d", getuid());
+	snprintf(addr.sun_path, sizeof(addr.sun_path), IPCPATH, getuid());
 	if(connect(im->fd, (struct sockaddr*)&addr, sizeof(addr)) < 0){
 		close(im->fd);
 		im->fd = -1;
 	}
 }
 
+static void
+srvclose(Im *im)
+{
+	int was;
+
+	if(im->fd >= 0)
+		close(im->fd);
+	im->fd = -1;
+	was = im->prelen;
+	im->pre[0] = '\0';
+	im->prelen = 0;
+	if(was > 0){
+		g_signal_emit_by_name(im, "preedit-changed");
+		g_signal_emit_by_name(im, "preedit-end");
+	}
+}
+
 static int
 readresp(Im *im, char *buf, int bufsz)
 {
-	unsigned char hdr[2], pl;
-	int n, was;
+	Ipcresp resp;
+	int was;
 
-	if(read(im->fd, hdr, 2) != 2)
-		return -1;
-	n = hdr[1];
-	buf[0] = '\0';
-	if(n > 0 && n < bufsz){
-		if(read(im->fd, buf, n) != n)
-			return -1;
-		buf[n] = '\0';
-	}
-	if(read(im->fd, &pl, 1) != 1)
-		return -1;
-	if(pl >= sizeof(im->pre))
-		return -1;
 	was = im->prelen;
-	if(pl > 0 && read(im->fd, im->pre, pl) != pl)
+	if(ipcreadresp(im->fd, 1, buf, bufsz, im->pre,
+		sizeof(im->pre), &resp) < 0)
 		return -1;
-	im->pre[pl] = '\0';
-	im->prelen = pl;
-	if(was == 0 && pl > 0)
+	im->prelen = resp.npreedit;
+	if(was == 0 && im->prelen > 0)
 		g_signal_emit_by_name(im, "preedit-start");
-	if(was != 0 || pl != 0)
+	if(was != 0 || im->prelen != 0)
 		g_signal_emit_by_name(im, "preedit-changed");
-	if(was > 0 && pl == 0)
+	if(was > 0 && im->prelen == 0)
 		g_signal_emit_by_name(im, "preedit-end");
-	return hdr[0];
+	return resp.eaten;
 }
 
 static uint32_t
 kget(uint32_t gdk)
 {
-	if(gdk >= 0xff00)
+	uint32_t u;
+
+	u = gdk_keyval_to_unicode(gdk);
+	if((gdk & 0xff000000) == 0x01000000 && u != 0)
+		return u;
+	if(gdk >= 0xff00 && gdk <= 0xffff)
 		return Kspec + (gdk - 0xff00);
-	return gdk_keyval_to_unicode(gdk);
+	return u;
 }
 
 static uint32_t
@@ -104,17 +113,17 @@ mget(uint32_t state)
 static void
 sendreset(Im *im)
 {
-	unsigned char buf[4];
-	char resp[64];
+	unsigned char buf[Ipcreqsz];
+	char resp[Ipcfieldmax+1];
 
-	if(im->fd < 0)
+	if(im->fd < 0){
+		srvclose(im);
 		return;
-	buf[0] = 1;
-	buf[1] = 0;
-	buf[2] = Kesc & 0xff;
-	buf[3] = Kesc >> 8;
-	if(send(im->fd, buf, 4, MSG_NOSIGNAL) == 4)
-		readresp(im, resp, sizeof(resp));
+	}
+	ipcpackreq(buf, 1, 0, Kesc);
+	if(ipcsend(im->fd, buf, sizeof buf) < 0 ||
+	   readresp(im, resp, sizeof(resp)) < 0)
+		srvclose(im);
 }
 
 static gboolean
@@ -137,8 +146,8 @@ static gboolean
 kpress(GtkIMContext *ctx, GdkEventKey *ev)
 {
 	Im *im;
-	unsigned char buf[4];
-	char resp[64];
+	unsigned char buf[Ipcreqsz];
+	char resp[Ipcfieldmax+1];
 	uint32_t key, mod;
 	int r;
 	GtkInputPurpose purpose;
@@ -154,21 +163,18 @@ kpress(GtkIMContext *ctx, GdkEventKey *ev)
 	if(purpose == GTK_INPUT_PURPOSE_PASSWORD || purpose == GTK_INPUT_PURPOSE_PIN)
 		return plaincommit(ctx, key, mod);
 	srvconnect(im);
-	if(im->fd < 0)
+	if(im->fd < 0){
+		srvclose(im);
 		return plaincommit(ctx, key, mod);
-	buf[0] = 1;
-	buf[1] = mod;
-	buf[2] = key & 0xff;
-	buf[3] = key >> 8;
-	if(send(im->fd, buf, 4, MSG_NOSIGNAL) != 4){
-		close(im->fd);
-		im->fd = -1;
+	}
+	ipcpackreq(buf, 1, mod, key);
+	if(ipcsend(im->fd, buf, sizeof buf) < 0){
+		srvclose(im);
 		return plaincommit(ctx, key, mod);
 	}
 	r = readresp(im, resp, sizeof(resp));
 	if(r < 0){
-		close(im->fd);
-		im->fd = -1;
+		srvclose(im);
 		return plaincommit(ctx, key, mod);
 	}
 	if(resp[0] != '\0')
@@ -228,6 +234,8 @@ static void
 init(Im *im)
 {
 	im->fd = -1;
+	im->pre[0] = '\0';
+	im->prelen = 0;
 }
 
 static void