[uml-devel] Improvements to tunctl command line

[James R. L. <jl...@mi...>]

I made the command line to tunctl a little more usable.

-I added the ability to specify the tap interfaces to create.
-Setting the UID is optional.
-My tun device is /dev/misc/net/tun so I added an option to specify it.
-Usage() now is a bit more informational.

Jim
-- 
James R. Leu

----------------------------- snip --------------------------------------
--- tunctl.c	Thu Feb 14 11:38:02 2002
+++ tunctl.c.new	Thu Feb 14 11:48:38 2002
@@ -7,49 +7,70 @@
 #include <string.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <unistd.h>
 #include <net/if.h>
 #include <sys/ioctl.h>
 #include <linux/if_tun.h>
 
-static void Usage(void)
+static void Usage(char *name)
 {
-  fprintf(stderr, "persist uid\n");
-  fprintf(stderr, "persist -nopersist device-name\n");
+  fprintf(stderr, "Create: %s [-u owner] [-t device-name] [-f /dev/misc/net/tun]\n", name);
+  fprintf(stderr, "Delete: %s -d -t device-name [-f /dev/misc/net/tun]\n", name);
   exit(1);
 }
 
 int main(int argc, char **argv)
 {
   struct ifreq ifr;
-  char *end, *dev = "";
-  long owner;
+  long owner = -1;
   int tap_fd;
+  char *tun = "";
+  char *file = "/dev/net/tun";
+  int opt;
+  int delete = 0;
 
-  argc--;
-  argv++;
-  if(argc == 0) Usage();
-  if(!strcmp(*argv, "-nopersist")){
-    if(argc < 2) Usage();
-    dev = argv[1];
+  if(argc == 1) Usage(argv[0]);
+
+  while ((opt = getopt(argc,argv,"dt:u:f:h")) > 0) {
+    switch(opt) {
+      case 'f':
+	file = optarg;
+	break;
+      case 'd':
+        delete = 1;
+        break;
+      case 't':
+        tun = optarg;
+        break;
+      case 'p':
+        owner = strtol(optarg,NULL,0);
+        break;
+      case 'h':
+      default:
+        Usage(argv[0]);
+        return -1;
+    }
   }
-  else if(argc > 0){
-    owner = strtol(*argv, &end, 0);
-    if(*end != '\0') Usage();
+
+  if (delete && *tun == '\0') {
+    Usage(argv[0]);
+    return -1;
   }
-  else Usage();
 
-  if((tap_fd = open("/dev/net/tun", O_RDWR)) < 0){
-    perror("opening /dev/net/tun");
+  if((tap_fd = open(file, O_RDWR)) < 0){
+    perror("opening tun device");
     exit(1);
   }
+
   memset(&ifr, 0, sizeof(ifr));
   ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
-  strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
+  strncpy(ifr.ifr_name, tun, sizeof(ifr.ifr_name) - 1);
   if(ioctl(tap_fd, TUNSETIFF, (void *) &ifr) < 0){
     perror("TUNSETIFF");
     exit(1);
   }
-  if(*dev != '\0'){
+
+  if(delete) {
     if(ioctl(tap_fd, TUNSETPERSIST, 0) < 0){
       perror("TUNSETPERSIST");
       exit(1);
@@ -61,9 +82,13 @@
       perror("TUNSETPERSIST");
       exit(1);
     }
-    if(ioctl(tap_fd, TUNSETOWNER, owner) < 0){
-      perror("TUNSETPERSIST");
-      exit(1);
+    if (owner != -1) {
+      if(ioctl(tap_fd, TUNSETOWNER, owner) < 0){
+        perror("TUNSETPERSIST");
+        exit(1);
+      }
+    } else {
+      owner = getuid();
     }
     printf("Set '%s' persistent and owned by uid %ld\n", ifr.ifr_name, owner);
   }