Use pipe instead of sigwait for krad tests

We've never used sigwait() before, and it has some problems on Solaris
10 (a nonconformant prototype by default, and experimentally it didn't
seem to work correctly with _POSIX_PTHREAD_SEMANTICS defined).  Use a
pipe instead.  Make t_daemon.py less chatty on stdout to avoid filling
the pipe buffer.

src/lib/krad/t_daemon.h

@@ -51,39 +51,32 @@ daemon_stop(void)
 static krb5_boolean
 daemon_start(int argc, const char **argv)
 {
-    sigset_t set;
-    int sig;
+    int fds[2];
+    char buf[1];
 
     if (argc != 3 || argv == NULL)
         return FALSE;
 
     if (daemon_pid != 0)
         return TRUE;
 
-    if (sigemptyset(&set) != 0)
-        return FALSE;
-
-    if (sigaddset(&set, SIGUSR1) != 0)
-        return FALSE;
-
-    if (sigaddset(&set, SIGCHLD) != 0)
-        return FALSE;
-
-    if (sigprocmask(SIG_BLOCK, &set, NULL) != 0)
+    if (pipe(fds) != 0)
         return FALSE;
 
+    /* Start the child process with the write end of the pipe as stdout. */
     daemon_pid = fork();
     if (daemon_pid == 0) {
-        close(STDOUT_FILENO);
-        open("/dev/null", O_WRONLY);
+        dup2(fds[1], STDOUT_FILENO);
+        close(fds[0]);
+        close(fds[1]);
         exit(execlp(argv[1], argv[1], argv[2], NULL));
     }
+    close(fds[1]);
 
-    if (sigwait(&set, &sig) != 0 || sig == SIGCHLD) {
-        daemon_stop();
-        daemon_pid = 0;
+    /* The child will write a sentinel character when it is listening. */
+    if (read(fds[0], buf, 1) != 1 || *buf != '~')
         return FALSE;
-    }
+    close(fds[0]);
 
     atexit(daemon_stop);
     return TRUE;

src/lib/krad/t_daemon.py

@@ -33,7 +33,7 @@
 try:
     from pyrad import dictionary, packet, server
 except ImportError:
-    sys.stdout.write("pyrad not found!\n")
+    sys.stderr.write("pyrad not found!\n")
     sys.exit(0)
 
 # We could use a dictionary file, but since we need
@@ -50,27 +50,24 @@ def _HandleAuthPacket(self, pkt):
 
         passwd = []
 
-        print "Request: "
         for key in pkt.keys():
             if key == "User-Password":
                 passwd = map(pkt.PwDecrypt, pkt[key])
-                print "\t%s\t%s" % (key, passwd)
-            else:
-                print "\t%s\t%s" % (key, pkt[key])
 
         reply = self.CreateReplyPacket(pkt)
         if passwd == ['accept']:
             reply.code = packet.AccessAccept
-            print "Response: %s" % "Access-Accept"
         else:
             reply.code = packet.AccessReject
-            print "Response: %s" % "Access-Reject"
-        print
         self.SendReplyPacket(pkt.fd, reply)
 
 srv = TestServer(addresses=["localhost"],
                  hosts={"127.0.0.1":
                         server.RemoteHost("127.0.0.1", "foo", "localhost")},
                  dict=dictionary.Dictionary(StringIO.StringIO(DICTIONARY)))
-os.kill(os.getppid(), signal.SIGUSR1)
+
+# Write a sentinel character to let the parent process know we're listening.
+sys.stdout.write("~")
+sys.stdout.flush()
+
 srv.Run()