[patch] patch to correct nstx's usage of Linux tuntap

nstx-1.1_beta6_00-linux-tuntap.patch (text/plain), 12.81 KB, created by Steve Brudenell on 2009-03-17 04:33:50 UTC

diff -ru nstx-1.1-beta6.orig/nstx_tuntap.c nstx-1.1-beta6/nstx_tuntap.c
--- nstx-1.1-beta6.orig/nstx_tuntap.c	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstx_tuntap.c	2009-03-16 22:45:28.000000000 +0000
@@ -19,13 +19,15 @@
 
 #ifdef linux
 #include <linux/if_tun.h>
-#define TUNDEV "/dev/net/tun"
+#define TUNINT "tun0"
+#define TUNDEVNODE "/dev/net/tun"
 #else
 #	include <net/if_tun.h>
+#	define TUNINT "NULL?"
 #	if __FreeBSD_version < 500000
-#		define TUNDEV "/dev/tun2"
+#		define TUNDEVNODE "/dev/tun2"
 #	else
-#		define TUNDEV "/dev/tun"
+#		define TUNDEVNODE "/dev/tun"
 #	endif
 #endif
 
@@ -33,127 +35,135 @@
 
 #define MAXPKT 2000
 
-#define TAPDEV "/dev/tap0"
+#define TAPINT "tap0"
+#define TAPDEVNODE "/dev/net/tun"
 
 int tfd = -1, nfd = -1;
 static char dev[IFNAMSIZ+1];
 
-static int tun_alloc (const char *path);
+static int tun_alloc (const char * interface, const char * device_node);
+static int tap_alloc (const char * interface, const char * device_node);
+
 #ifdef linux
-static int tap_alloc (const char *path);
+static int tuntap_alloc_linux(const char * interface, const char * device_node,
+        int mode);
+#else
+static int tun_alloc_bsd(const char * interface, const char * device_node);
 #endif
 
 void
-open_tuntap(const char *device)
+open_tuntap(const char * interface, const char * device_node, int tun)
 {
-   int	tunerr;
-#ifdef linux
-   int	taperr;
-#endif
+   int err;
+
+   if (!interface)
+       interface = (tun ? TUNINT : TAPINT);
+
+   if (!device_node)
+       device_node = (tun ? TUNDEVNODE : TAPDEVNODE);
+
+   fprintf(stderr, "Opening %s interface %s at %s... ", tun ? "tun" : "tap",
+           interface, device_node);
+
+   err = (tun ? tun_alloc(interface, device_node) : tap_alloc(interface,
+               device_node));
+
+   if (!err) {
+       fprintf(stderr, "using interface %s\n", dev);
+
+       if (tun)
+           fprintf(stderr, "you will now need to assign an ip and routing to "
+                   "this interface\n");
+       else
+           fprintf(stderr, "you will now need to add bridging or other rules "
+                   "to this interface\n");
+       return;
+   }
    
-   fprintf(stderr, "Opening tun/tap-device... ");
-   if ((tunerr = tun_alloc(device ? device : TUNDEV))
+   fprintf(stderr, "failed! (%s)\n", strerror(err));
+
+   fprintf(stderr, "Diagnostics: ");
+
+   if (err == EPERM)
+       fprintf(stderr, "you usually have to be root to use nstx.\n");
+   else if (err == ENOENT)
+       fprintf(stderr, "maybe you need kernel support -- did you modprobe "
+               "tap?\n");
+   else if (err == ENODEV)
+       fprintf(stderr, "maybe you need kernel support -- did you modprobe "
+               "tap?\n");
 #ifdef linux
-	&& (taperr = tap_alloc(device ? device : TAPDEV))
+#else
+   else if ((err == EINVAL) && !tun)
+       fprintf(stderr, "tap support is only available under linux\n");
 #endif
-   ) {
-      fprintf(stderr, "failed!\n"
-	              "Diagnostics:\nTun ("TUNDEV"): ");
-      switch (tunerr) {
-       case EPERM:
-	 fprintf(stderr, "Permission denied. You usually have to "
-		         "be root to use nstx.\n");
-	 break;
-       case ENOENT:
-	 fprintf(stderr, TUNDEV " not found. Please create /dev/net/ and\n"
-		 "     mknod /dev/net/tun c 10 200 to use the tun-device\n");
-	 break;
-       case ENODEV:
-	 fprintf(stderr, "Device not available. Make sure you have "
-		 "kernel-support\n     for the tun-device. Under linux, you "
-		 "need tun.o (Universal tun/tap-device)\n");
-	 break;
-       default:
-	 perror("Unexpected error");
-	 break;
-      }
-      fprintf(stderr, "Tap ("TAPDEV"):\n(only available under linux)\n");
+   else
+       fprintf(stderr, "none, sorry\n");
+
+   exit(EXIT_FAILURE);
+}
+
+int tun_alloc(const char * interface, const char * device_node) 
+{
 #ifdef linux
-      switch (taperr) {
-       case EPERM:
-	 fprintf(stderr, "Permission denied. You generally have to "
-		 "be root to use nstx.\n");
-	 break;
-       case ENOENT:
-	 fprintf(stderr, TAPDEV " not found. Please\n"
-		 "     mknod /dev/tap0 c 36 16 to use the tap-device\n");
-	 break;
-       case ENODEV:
-	 fprintf(stderr, "Device not available. Make sure you have kernel-support\n"
-		 "     for the tap-device. Under linux, you need netlink_dev.o and ethertap.o\n");
-	 break;
-       default:
-	 fprintf(stderr, "Unexpected error: %s\n", strerror(taperr));
-	 break;
-      }
+    return tuntap_alloc_linux(interface, device_node, IFF_TUN);
+#else
+    return tun_alloc_bsd(interface, device_node);
 #endif
-      exit(EXIT_FAILURE);
-   }
-   
-   fprintf(stderr, "using device %s\n"
-	  "Please configure this device appropriately (IP, routes, etc.)\n", dev);
 }
 
-int
-tun_alloc (const char *path) 
+int tap_alloc(const char * interface, const char * device_node) 
 {
 #ifdef linux
-   struct ifreq ifr;
+    return tuntap_alloc_linux(interface, device_node, IFF_TAP);
 #else
-   struct stat st;
+    return EINVAL;
 #endif
- 
-   if ((tfd = open(path, O_RDWR)) < 0)
-     return errno;
+}
 
 #ifdef linux
-   memset(&ifr, 0, sizeof(ifr));
+
+int tuntap_alloc_linux(const char * interface, const char * device_node,
+        int mode)
+{
+    struct ifreq ifr;
+
+    if ((tfd = open(device_node, O_RDWR)) < 0)
+        return errno;
+
+    memset(&ifr, 0, sizeof(ifr));
    
-   ifr.ifr_flags = IFF_TUN|IFF_NO_PI;
+    ifr.ifr_flags = mode | IFF_NO_PI;
+    strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
+    ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = 0;
    
-   if (ioctl(tfd, TUNSETIFF, (void *) &ifr) < 0)
-     {
-	close(tfd);
-	tfd = -1;
-	return errno;
-     }
-   strncpy(dev, ifr.ifr_name, IFNAMSIZ+1);
-#else
-   fstat(tfd, &st);
-   strncpy(dev, devname(st.st_rdev, S_IFCHR), IFNAMSIZ+1);
-#endif
+    if (ioctl(tfd, TUNSETIFF, (void *) &ifr) < 0) {
+        close(tfd);
+        tfd = -1;
+        return errno;
+    }
+
+    strncpy(dev, ifr.ifr_name, IFNAMSIZ+1);
    
-   return 0;
+    return 0;
 }
 
+#else /* bsd */
 
-#ifdef linux
-int
-tap_alloc(const char *path)
+int tun_alloc_bsd(const char * interface, const char * device_node)
 {
-   char *ptr;
-   
-   if ((tfd = open(path, O_RDWR)) < 0)
+   struct stat st;
+
+   if ((tfd = open(device_node, O_RDWR)) < 0)
      return errno;
-   
-   if ((ptr = strrchr(path, '/')))
-     strncpy(dev, ptr+1, IFNAMSIZ+1);
-   else
-     strncpy(dev, path, IFNAMSIZ+1);
+
+   fstat(tfd, &st);
+   strncpy(dev, devname(st.st_rdev, S_IFCHR), IFNAMSIZ+1);
    
    return 0;
 }
-#endif
+
+#endif /* linux/bsd */
 
 void
 open_ns(const char *ip)
diff -ru nstx-1.1-beta6.orig/nstxcd.8 nstx-1.1-beta6/nstxcd.8
--- nstx-1.1-beta6.orig/nstxcd.8	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstxcd.8	2009-03-16 23:16:21.000000000 +0000
@@ -3,7 +3,7 @@
 nstxcd \- IP over DNS tunneling client
 
 .SH SYNOPSIS
-.B "nstxcd \fIDOMAIN\fR \fIIPADDRESS\fR"
+.B "nstxcd \fIOPTIONS\fR \fIDOMAIN\fR \fIIPADDRESS\fR"
 
 .SH DESCRIPTION
 .B nstxcd
@@ -13,6 +13,14 @@
 .SH OPTIONS
 .B nstxcd
 takes the following options:
+.IP \-I tun/tap interface
+Use this tun/tap interface instead of the default (tun0/tap0)
+.IP \-d tun/tap device node
+Use this tun/tap device node instead of the default (/dev/net/tun on Linux)
+.IP \-t
+Tun mode (default)
+.IP \-T
+Tap mode
 .IP "domain"
 The domain that nstxcd will send requests to. This domain must be delegated
 to a machine that is running nstxd.
@@ -22,9 +30,9 @@
 .SH USAGE
 .Bnstxcd
 should be run against a domain that has been delegated to a machine running
-nstxd. It will then take any packets that are sent to the tun0 interface and
-send them over DNS to the other tunnel endpoint. Responses will appear on 
-the tun0 interface.
+nstxd. It will then take any packets that are sent to the tun/tap interface and
+send them over DNS to the other tunnel endpoint. Responses will appear on the
+tun/tap interface.
 
 .SH AUTHORS
 
diff -ru nstx-1.1-beta6.orig/nstxcd.c nstx-1.1-beta6/nstxcd.c
--- nstx-1.1-beta6.orig/nstxcd.c	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstxcd.c	2009-03-16 23:16:07.000000000 +0000
@@ -55,25 +55,44 @@
 static void
 usage(const char *prog, int code)
 {
-	fprintf(stderr, "Usage: %s [-d tun-device] <domainname> <dns-server>\n"
-	    "Example: %s tun.yomama.com 125.23.53.12\n", prog, prog);
+	fprintf(stderr, "Usage: %s [options] <domainname> <dns-server>\n"
+	    "Where options are:\n"
+	    "\t-d path (use this tun/tap device node instead of default)\n"
+	    "\t-I interface (use this tun/tap interface instead of default)\n"
+#ifdef linux
+	    "\t-t (tun mode, default)\n"
+	    "\t-T (tap mode)\n"
+#endif
+	    "example:\n"
+	    "%s tun.yomama.com 125.23.53.12\n", prog, prog);
 	exit(code);
 }
 
 int main (int argc, char * argv[]) {
   struct nstxmsg *msg;
-  const char	*device = NULL;
+  const char	*interface = NULL;
+  const char	*device_node = NULL;
   int 		 ch;
+  int tun = 1;
 
   nsid = time(NULL);
  
   if (argc < 3)
 	usage(argv[0], EX_USAGE);
 
-  while ((ch = getopt(argc, argv, "hd:")) != -1) {
+  while ((ch = getopt(argc, argv, "hd:I:tT")) != -1) {
 	switch (ch) {
+	case 'I':
+		interface = optarg;
+		break;
 	case 'd':
-		device = optarg;
+		device_node = optarg;
+		break;
+	case 't':
+        tun = 1;
+		break;
+	case 'T':
+        tun = 0;
 		break;
 	case 'h':
 		usage(argv[0], 0);
@@ -85,7 +104,7 @@
   dns_setsuffix(argv[optind]);
 
   qsettimeout(10);
-  open_tuntap(device);
+  open_tuntap(interface, device_node, tun);
   open_ns(argv[optind + 1]);
 
   for (;;) {
diff -ru nstx-1.1-beta6.orig/nstxd.8 nstx-1.1-beta6/nstxd.8
--- nstx-1.1-beta6.orig/nstxd.8	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstxd.8	2009-03-16 23:16:32.000000000 +0000
@@ -3,7 +3,7 @@
 nstxd \- IP over DNS tunneling daemon
 
 .SH SYNOPSIS
-.B "nstxd \fIOPTION\fR \fIDOMAIN\fR"
+.B "nstxd \fIOPTIONS\fR \fIDOMAIN\fR"
 
 .SH DESCRIPTION
 .B nstxd
@@ -14,8 +14,14 @@
 .SH OPTIONS
 .B nstxd
 takes the following option:
-.IP \-d tun-device
-Use this tun device instead of tun0
+.IP \-I tun/tap interface
+Use this tun/tap interface instead of the default (tun0/tap0)
+.IP \-d tun/tap device node
+Use this tun/tap device node instead of the default (/dev/net/tun on linux)
+.IP \-t
+Tun mode (default)
+.IP \-T
+Tap mode
 .IP \-i ipaddr
 Bind to this IP address rather than every available address
 .IP \-C dir
@@ -33,9 +39,9 @@
 .SH USAGE
 A domain should be delegated to the machine that will run nstxd. nstxd should
 then be run giving that domain as the only argument. nstxd will then listen
-for requests and translate them into IP packets that will appear on the tun0
-interface. Packets sent to the tun0 interface will be transferred back to
-the client as DNS answers.
+for requests and translate them into IP packets that will appear on the given
+tun/tap interface. Packets sent to the tun/tap interface will be transferred
+back to the client as DNS answers.
 
 .SH AUTHORS
 
diff -ru nstx-1.1-beta6.orig/nstxd.c nstx-1.1-beta6/nstxd.c
--- nstx-1.1-beta6.orig/nstxd.c	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstxd.c	2009-03-16 23:15:30.000000000 +0000
@@ -55,7 +55,12 @@
 {
 	fprintf (stderr, "usage: %s [options] <domainname>\n"
 	    "Where options are:\n"
-	    "\t-d tun-device (use this tun/tap device instead of default\n"
+	    "\t-d path (use this tun/tap device node instead of default)\n"
+	    "\t-I interface (use this tun/tap interface instead of default)\n"
+#ifdef linux
+	    "\t-t (tun mode, default)\n"
+	    "\t-T (tap mode)\n"
+#endif
 	    "\t-i ip.to.bi.nd (bind to port 53 on this IP only)\n"
 	    "\t-C dir (chroot() to this directory after initialization)\n"
 	    "\t-D (call daemon(3) to detach from terminal)\n"
@@ -68,13 +73,15 @@
 
 int main (int argc, char *argv[]) {
    signed char	 ch;
-   const char	*device = NULL, *dir = NULL;
+   const char	*interface = NULL, *dir = NULL;
+   const char	*device_node = NULL;
    in_addr_t	 bindto = INADDR_ANY;
    uid_t	 uid = 0;
    int		 daemonize = 0;
    int		 logmask = LOG_UPTO(LOG_INFO);
+   int tun = 1;
    
-   while ((ch = getopt(argc, argv, "gDC:u:hd:i:")) != -1) {
+   while ((ch = getopt(argc, argv, "gDC:u:hd:I:i:tT")) != -1) {
 	switch(ch) {
 	case 'i':
 		bindto = inet_addr(optarg);
@@ -84,8 +91,17 @@
 			exit(EX_USAGE);
 		}
 		break;
+	case 'I':
+		interface = optarg;
+		break;
 	case 'd':
-		device = optarg;
+		device_node = optarg;
+		break;
+	case 't':
+        tun = 1;
+		break;
+	case 'T':
+        tun = 0;
 		break;
 	case 'D':
 		daemonize = 1;
@@ -121,7 +137,7 @@
 
    dns_setsuffix(argv[optind]);
    
-   open_tuntap(device);
+   open_tuntap(interface, device_node, tun);
    open_ns_bind(bindto);
    
    if (dir) {
diff -ru nstx-1.1-beta6.orig/nstxfun.h nstx-1.1-beta6/nstxfun.h
--- nstx-1.1-beta6.orig/nstxfun.h	2009-03-16 05:31:24.000000000 +0000
+++ nstx-1.1-beta6/nstxfun.h	2009-03-16 22:40:44.000000000 +0000
@@ -52,7 +52,7 @@
 
 /* DNS */
 
-void open_tuntap (const char *device);
+void open_tuntap (const char * interface, const char * device_node, int tun);
 void open_ns (const char *ip);
 void open_ns_bind(in_addr_t ip);