new program to forward x connections

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@393 ec53bebd-3082-4978-b11e-865c3cabbd6b

appl/kx/kx.c

@@ -0,0 +1,254 @@
+#include "kx.h"
+
+RCSID("$Id$");
+
+static char *prog;
+
+static void
+usage()
+{
+  fprintf (stderr, "Usage: %s local-display-number host|display\n",
+	   prog);
+  exit (1);
+}
+
+static int
+doit_host (char *host, unsigned dnr, int fd)
+{
+  CREDENTIALS cred;
+  KTEXT_ST text;
+  MSG_DAT msg;
+  int status;
+  des_key_schedule schedule;
+  struct sockaddr_in thisaddr, thataddr;
+  int addrlen;
+  void *ret;
+  struct hostent *hostent;
+  int s;
+  struct sockaddr_un unixaddr;
+  des_cblock iv1, iv2;
+  int num1 = 0, num2 = 0;
+
+  /*
+   * Establish authenticated connection
+   */
+
+  hostent = gethostbyname (host);
+  if (hostent == NULL) {
+    fprintf (stderr, "%s: gethostbyname '%s' failed: ", prog, host);
+    return 1;
+  }
+
+  memset (&thataddr, 0, sizeof(thataddr));
+  thataddr.sin_family = AF_INET;
+  thataddr.sin_port   = k_getportbyname ("kx", "tcp", htons(2111));
+  memcpy (&thataddr.sin_addr, hostent->h_addr, sizeof(thataddr.sin_addr));
+
+  s = socket (AF_INET, SOCK_STREAM, 0);
+  if (s < 0) {
+    fprintf (stderr, "%s: socket failed: %s\n", prog, k_strerror(errno));
+    return 1;
+  }
+  if (connect (s, (struct sockaddr *)&thataddr, sizeof(thataddr)) < 0) {
+    fprintf (stderr, "%s: connect(%s) failed: %s\n", prog, host,
+	     k_strerror(errno));
+    return 1;
+  }
+  addrlen = sizeof(thisaddr);
+  if (getsockname (s, (struct sockaddr *)&thisaddr, &addrlen) < 0 ||
+      addrlen != sizeof(thisaddr)) {
+    fprintf (stderr, "%s: getsockname(%s) failed: %s\n",
+	     prog, host, k_strerror(errno));
+    return 1;
+  }
+  status = krb_sendauth (KOPT_DO_MUTUAL, s, &text, "rcmd",
+			 host, krb_realmofhost (host),
+			 getpid(), &msg, &cred, schedule,
+			 &thisaddr, &thataddr, "KXSERV.0");
+  if (status != KSUCCESS) {
+    fprintf (stderr, "%s: %s: %s\n", prog, host,
+	     krb_get_err_text(status));
+    return 1;
+  }
+  /*
+   * Send parameters.
+   */
+
+  {
+    u_char b = dnr;
+    char buf[128];
+    int ret;
+    
+    if (write (s, &b, sizeof(b)) != sizeof(b)) {
+      fprintf (stderr, "%s: write: %s\n", prog, k_strerror (errno));
+      return 1;
+    }
+    if (read (s, &b, sizeof(b)) != sizeof(b)) {
+      fprintf (stderr, "%s: read: %s\n", prog, k_strerror (errno));
+      return 1;
+    }
+    if (b) {
+      fprintf (stderr, "%s: Error from '%s': ", prog, host);
+      ret = read (s, buf, sizeof(buf));
+      if(ret < 0) {
+	fprintf (stderr, "%s: read: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+      fprintf (stderr, "%s\n", buf);
+      return 1;
+    }
+  }
+
+  memcpy (&iv1, &cred.session, sizeof(iv1));
+  memcpy (&iv2, &cred.session, sizeof(iv2));
+  for (;;) {
+    fd_set fdset;
+    int ret;
+    char buf[BUFSIZ];
+
+    FD_ZERO(&fdset);
+    FD_SET(s, &fdset);
+    FD_SET(fd, &fdset);
+
+    ret = select (256, &fdset, NULL, NULL, NULL); /* XXX */
+    if (ret < 0 && errno != EINTR) {
+      fprintf (stderr, "%s: select: %s\n", prog, k_strerror (errno));
+      return 1;
+    }
+    if (FD_ISSET(s, &fdset)) {
+      ret = read (s, buf, sizeof(buf));
+      if (ret == 0)
+	return 0;
+      if (ret < 0) {
+	fprintf (stderr, "%s: read: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+#ifndef NOENCRYPTION
+      des_cfb64_encrypt (buf, buf, ret, schedule, &iv1,
+			 &num1, DES_DECRYPT);
+#endif
+      ret = krb_net_write (fd, buf, ret);
+      if (ret < 0) {
+	fprintf (stderr, "%s: write: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+    }
+    if (FD_ISSET(fd, &fdset)) {
+      ret = read (fd, buf, sizeof(buf));
+      if (ret == 0)
+	return 0;
+      if (ret < 0) {
+	fprintf (stderr, "%s: read: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+#ifndef NOENCRYPTION
+      des_cfb64_encrypt (buf, buf, ret, schedule, &iv2,
+			 &num2, DES_ENCRYPT);
+#endif
+      ret = krb_net_write (s, buf, ret);
+      if (ret < 0) {
+	fprintf (stderr, "%s: write: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+    }
+  }
+}
+
+/*
+ * Listen for calls to the remote X-server.
+ */
+
+static int
+doit (unsigned localnr, char *host, unsigned remotenr)
+{
+  int fd;
+  struct sockaddr_un addr;
+  int dnr;
+
+  fd = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (fd < 0) {
+    fprintf (stderr, "%s: socket failed: %s\n", prog, k_strerror(errno));
+    return 1;
+  }    
+  addr.sun_family = AF_UNIX;
+  sprintf (addr.sun_path, "/tmp/.X11-unix/X%u", localnr);
+  unlink (addr.sun_path);
+  if(bind (fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
+    fprintf (stderr, "%s: bind failed: %s\n", prog,
+	     k_strerror(errno));
+    return 1;
+  }
+  if (listen (fd, 5) < 0) {
+    fprintf (stderr, "%s: listen failed: %s\n", prog,
+	     k_strerror(errno));
+    return 1;
+  }
+  for (;;) {
+    int newfd;
+    struct sockaddr_un that;
+    int len;
+    pid_t pid;
+
+    len = sizeof (that);
+    newfd = accept (fd, (struct sockaddr *)&that, &len);
+    if (newfd < 0)
+      if (errno == EINTR)
+	continue;
+      else {
+	fprintf (stderr, "%s: accept: %s\n", prog, k_strerror (errno));
+	return 1;
+      }
+    fprintf (stderr, "%s: New connection\n", prog);
+    pid = fork ();
+    if (pid < 0) {
+      fprintf (stderr, "%s: fork: %s\n", prog, k_strerror (errno));
+      return 1;
+    } else if (pid == 0) {
+      close (fd);
+      return doit_host (host, remotenr, newfd);
+    } else {
+      close (newfd);
+    }
+  }
+}
+
+static
+RETSIGTYPE
+childhandler ()
+{
+  pid_t pid;
+  int status;
+
+  do { 
+    pid = waitpid (-1, &status, WNOHANG|WUNTRACED);
+  } while(pid);
+  signal (SIGCHLD, childhandler);
+}
+
+/*
+ * fx - forward x connection.
+ */
+
+int
+main(argc, argv)
+     int argc;
+     char **argv;
+{
+  int dnr;
+  char *p;
+
+  prog = argv[0];
+  if (argc != 3)
+    usage ();
+
+  p = strchr (argv[2], ':');
+  if (p) {
+    *p = '\0';
+    dnr = atoi (p+1);
+  } else
+    dnr = 0;
+
+  signal (SIGCHLD, childhandler);
+
+  return doit (atoi(argv[1]), argv[2], dnr);
+}