harden ipc and frontend recovery

xim/Makefile

@@ -1,5 +1,7 @@
 CC = cc
-CFLAGS = -Wall -Wextra -O2 -I.. -Ixcb-imdkit/src
+XKB_CFLAGS := $(shell pkg-config --cflags xkbcommon)
+XKB_LIBS := $(shell pkg-config --libs xkbcommon)
+CFLAGS = -Wall -Wextra -O2 -I.. -Ixcb-imdkit/src $(XKB_CFLAGS)
 PROG = strans-xim
 
 SRCS = $(wildcard *.c)
@@ -9,8 +11,8 @@ LIBS = xcb-imdkit/libxcb-imdkit.a xcb-util/libxcb-util.a
 
 all: $(PROG)
 
-$(PROG): $(OBJS) $(LIBS)
-	$(CC) -o $@ $(OBJS) $(LIBS) -lxcb
+$(PROG): $(OBJS) $(LIBS) ../ipc.c ../ipc.h
+	$(CC) $(CFLAGS) -o $@ $(OBJS) ../ipc.c $(LIBS) -lxcb $(XKB_LIBS)
 
 $(OBJS): ../ipc.h
 

xim/main.c

@@ -5,13 +5,14 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <xcb/xcb.h>
+#include <xkbcommon/xkbcommon.h>
 #include "imdkit.h"
 #include "encoding.h"
 #include "ipc.h"
 
 static xcb_connection_t *conn;
 static xcb_im_t *xim;
-static int srvfd;
+static int srvfd = -1;
 static xcb_keysym_t *kmap;
 static uint8_t minkc, maxkc;
 static uint8_t symsper;
@@ -105,50 +106,74 @@ commit(xcb_im_input_context_t *ic, char *s, int len)
 }
 
 static void
+srvclose(void)
+{
+	if(srvfd < 0)
+		return;
+	close(srvfd);
+	srvfd = -1;
+}
+
+static int
 srvconnect(void)
 {
 	struct sockaddr_un addr;
+	int fd;
 
-	srvfd = socket(AF_UNIX, SOCK_STREAM, 0);
-	if(srvfd < 0)
-		die("socket failed");
+	if(srvfd >= 0)
+		return 0;
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if(fd < 0)
+		return -1;
 	memset(&addr, 0, sizeof(addr));
 	addr.sun_family = AF_UNIX;
-	snprintf(addr.sun_path, sizeof(addr.sun_path), "/tmp/strans.%d", getuid());
-	if(connect(srvfd, (struct sockaddr*)&addr, sizeof(addr)) < 0)
-		die("can't connect to strans");
+	snprintf(addr.sun_path, sizeof(addr.sun_path), IPCPATH, getuid());
+	if(connect(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0){
+		close(fd);
+		return -1;
+	}
+	srvfd = fd;
+	return 0;
 }
 
 static int
 readresp(xcb_im_input_context_t *ic)
 {
-	unsigned char buf[64];
-	int n;
+	char buf[Ipcfieldmax+1];
+	Ipcresp resp;
 
-	if(read(srvfd, buf, 2) != 2)
+	if(ipcreadresp(srvfd, 0, buf, sizeof buf, NULL, 0, &resp) < 0)
 		return -1;
-	n = buf[1];
-	if(n > 0 && (size_t)n < sizeof(buf) && read(srvfd, buf+2, n) == n)
-		commit(ic, (char*)(buf+2), n);
-	return buf[0];
+	if(buf[0] != '\0')
+		commit(ic, buf, strlen(buf));
+	return resp.eaten;
 }
 
 static void
 kpress(xcb_im_input_context_t *ic, xcb_key_press_event_t *ev)
 {
-	unsigned char buf[4];
-	uint32_t key;
+	unsigned char buf[Ipcreqsz];
+	uint32_t key, rune;
+	int eaten;
 
 	key = kget(ev->detail, ev->state);
-	if(key >= 0xff00)
+	rune = xkb_keysym_to_utf32(key);
+	if(rune >= ' ' && rune != 0x7f)
+		key = rune;
+	else if(key >= 0xff00 && key <= 0xffff)
 		key = Kspec + (key - 0xff00);
-	buf[0] = 0;
-	buf[1] = ev->state;
-	buf[2] = key;
-	buf[3] = key >> 8;
-	if(write(srvfd, buf, 4) != 4)
-		die("write failed");
-	if(readresp(ic) == 0)
+	else
+		key = rune;
+	ipcpackreq(buf, 0, ev->state, key);
+	eaten = 0;
+	if(srvconnect() == 0){
+		if(ipcsend(srvfd, buf, sizeof buf) < 0 ||
+		   (eaten = readresp(ic)) < 0){
+			srvclose();
+			eaten = 0;
+		}
+	}
+	if(eaten == 0)
 		xcb_im_forward_event(xim, ic, ev);
 	xcb_flush(conn);
 }
@@ -156,15 +181,13 @@ kpress(xcb_im_input_context_t *ic, xcb_key_press_event_t *ev)
 static void
 reset(xcb_im_input_context_t *ic)
 {
-	unsigned char buf[4];
-	
-	buf[0] = 0;
-	buf[1] = 0;
-	buf[2] = Kesc & 0xff;
-	buf[3] = Kesc >> 8;
-	if(write(srvfd, buf, 4) != 4)
-		die("write failed");
-	readresp(ic);
+	unsigned char buf[Ipcreqsz];
+
+	ipcpackreq(buf, 0, 0, Kesc);
+	if(srvconnect() < 0)
+		return;
+	if(ipcsend(srvfd, buf, sizeof buf) < 0 || readresp(ic) < 0)
+		srvclose();
 }
 
 static void
@@ -173,6 +196,11 @@ callback(xcb_im_t *im, xcb_im_client_t *client, xcb_im_input_context_t *ic,
 {
 	xcb_key_press_event_t *ev;
 
+	(void)im;
+	(void)client;
+	(void)frame;
+	(void)user;
+
 	switch(hdr->major_opcode){
 	case XCB_XIM_FORWARD_EVENT:
 		ev = arg;
@@ -220,7 +248,6 @@ main(void)
 {
 	xcb_generic_event_t *ev;
 
-	srvconnect();
 	ximinit();
 	for(;;){
 		ev = xcb_wait_for_event(conn);
@@ -229,5 +256,6 @@ main(void)
 		xcb_im_filter_event(xim, ev);
 		free(ev);
 	}
+	srvclose();
 	return 0;
 }