harden ipc and frontend recovery

srv.c

@@ -2,30 +2,53 @@
 #include "fn.h"
 
 static char adir[40];
+static Channel *clientc;
 
-static void
-sendkey(int fd, u32int ks, u32int mod, int want)
+int
+srvreadkey(int fd, Keyreq *kr)
 {
-	Keyreq kr;
+	uchar req[Ipcreqsz];
+	u32int ks, mod;
+	int want;
 
-	kr.fd = fd;
-	kr.ks = ks;
-	kr.mod = mod;
-	kr.want = want;
-	chansend(keyc, &kr);
+	if(ipcreadn(fd, req, sizeof req) < 0)
+		return -1;
+	ipcunpackreq(req, &want, &mod, &ks);
+	kr->ks = ks;
+	kr->mod = mod;
+	kr->want = want;
+	return 0;
 }
 
 static void
 clientthread(void *arg)
 {
+	Channel *reply;
 	int fd;
-	uchar req[4];
+	Keyreq kr;
+	Keyres res;
+	uchar out[Ipcmaxresp];
+	char commit[Maxutf], preedit[Maxutf];
+	int n, ncommit, npreedit;
+	uchar token;
 
 	fd = (int)(uintptr)arg;
 	threadsetname("client %d", fd);
-	while(read(fd, req, 4) == 4)
-		sendkey(fd, req[2] | (req[3] << 8), req[1], req[0]);
+	reply = chancreate(sizeof(Keyres), 0);
+	kr.reply = reply;
+	while(srvreadkey(fd, &kr) == 0){
+		chansend(keyc, &kr);
+		chanrecv(reply, &res);
+		ncommit = stoutf(&res.commit, commit, sizeof commit);
+		npreedit = stoutf(&res.preedit, preedit, sizeof preedit);
+		n = ipcpackresp(out, sizeof out, res.eaten,
+			commit, ncommit, preedit, npreedit, kr.want);
+		if(n < 0 || ipcsend(fd, out, n) < 0)
+			break;
+	}
+	chanfree(reply);
 	close(fd);
+	chanrecv(clientc, &token);
 }
 
 static void
@@ -33,7 +56,7 @@ srvinit(void)
 {
 	char addr[64];
 
-	snprint(addr, sizeof(addr), "unix!/tmp/strans.%d", getuid());
+	snprint(addr, sizeof(addr), "unix!" IPCPATH, getuid());
 	remove(addr + 5);
 	if(announce(addr, adir) < 0)
 		die("announce: %r");
@@ -44,13 +67,23 @@ srvthread(void*)
 {
 	char ldir[40];
 	int fd;
+	uchar token;
 
 	threadsetname("srv");
 	srvinit();
+	token = 0;
+	clientc = chancreate(sizeof token, Maxclients);
 	for(;;){
 		fd = listen(adir, ldir);
 		if(fd < 0)
 			continue;
-		proccreate(clientthread, (void*)(uintptr)fd, 8192);
+		if(channbsend(clientc, &token) <= 0){
+			close(fd);
+			continue;
+		}
+		if(proccreate(clientthread, (void*)(uintptr)fd, 8192) < 0){
+			chanrecv(clientc, &token);
+			close(fd);
+		}
 	}
 }