1*4882a593Smuzhiyun /* Copyright 2002 Jeff Dike
2*4882a593Smuzhiyun * Licensed under the GPL
3*4882a593Smuzhiyun */
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <stdio.h>
6*4882a593Smuzhiyun #include <stdlib.h>
7*4882a593Smuzhiyun #include <string.h>
8*4882a593Smuzhiyun #include <errno.h>
9*4882a593Smuzhiyun #include <fcntl.h>
10*4882a593Smuzhiyun #include <unistd.h>
11*4882a593Smuzhiyun #include <pwd.h>
12*4882a593Smuzhiyun #include <grp.h>
13*4882a593Smuzhiyun #include <net/if.h>
14*4882a593Smuzhiyun #include <sys/ioctl.h>
15*4882a593Smuzhiyun #include <linux/if_tun.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun /* TUNSETGROUP appeared in 2.6.23 */
18*4882a593Smuzhiyun #ifndef TUNSETGROUP
19*4882a593Smuzhiyun #define TUNSETGROUP _IOW('T', 206, int)
20*4882a593Smuzhiyun #endif
21*4882a593Smuzhiyun
Usage(char * name,int status)22*4882a593Smuzhiyun static void Usage(char *name, int status)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun fprintf(stderr, "Create: %s [-b] [-u owner] [-g group] [-t device-name] "
25*4882a593Smuzhiyun "[-f tun-clone-device]\n", name);
26*4882a593Smuzhiyun fprintf(stderr, "Delete: %s -d device-name [-f tun-clone-device]\n\n",
27*4882a593Smuzhiyun name);
28*4882a593Smuzhiyun fprintf(stderr, "The default tun clone device is /dev/net/tun - some systems"
29*4882a593Smuzhiyun " use\n/dev/misc/net/tun instead\n\n");
30*4882a593Smuzhiyun fprintf(stderr, "-b will result in brief output (just the device name)\n");
31*4882a593Smuzhiyun exit(status);
32*4882a593Smuzhiyun }
33*4882a593Smuzhiyun
main(int argc,char ** argv)34*4882a593Smuzhiyun int main(int argc, char **argv)
35*4882a593Smuzhiyun {
36*4882a593Smuzhiyun struct ifreq ifr;
37*4882a593Smuzhiyun struct passwd *pw;
38*4882a593Smuzhiyun struct group *gr;
39*4882a593Smuzhiyun uid_t owner = -1;
40*4882a593Smuzhiyun gid_t group = -1;
41*4882a593Smuzhiyun int tap_fd, opt, delete = 0, brief = 0;
42*4882a593Smuzhiyun char *tun = "", *file = "/dev/net/tun", *name = argv[0], *end;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun while((opt = getopt(argc, argv, "bd:f:t:u:g:h")) > 0){
45*4882a593Smuzhiyun switch(opt) {
46*4882a593Smuzhiyun case 'b':
47*4882a593Smuzhiyun brief = 1;
48*4882a593Smuzhiyun break;
49*4882a593Smuzhiyun case 'd':
50*4882a593Smuzhiyun delete = 1;
51*4882a593Smuzhiyun tun = optarg;
52*4882a593Smuzhiyun break;
53*4882a593Smuzhiyun case 'f':
54*4882a593Smuzhiyun file = optarg;
55*4882a593Smuzhiyun break;
56*4882a593Smuzhiyun case 'u':
57*4882a593Smuzhiyun pw = getpwnam(optarg);
58*4882a593Smuzhiyun if(pw != NULL){
59*4882a593Smuzhiyun owner = pw->pw_uid;
60*4882a593Smuzhiyun break;
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun owner = strtol(optarg, &end, 0);
63*4882a593Smuzhiyun if(*end != '\0'){
64*4882a593Smuzhiyun fprintf(stderr, "'%s' is neither a username nor a numeric uid.\n",
65*4882a593Smuzhiyun optarg);
66*4882a593Smuzhiyun Usage(name, 1);
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun break;
69*4882a593Smuzhiyun case 'g':
70*4882a593Smuzhiyun gr = getgrnam(optarg);
71*4882a593Smuzhiyun if(gr != NULL){
72*4882a593Smuzhiyun group = gr->gr_gid;
73*4882a593Smuzhiyun break;
74*4882a593Smuzhiyun }
75*4882a593Smuzhiyun group = strtol(optarg, &end, 0);
76*4882a593Smuzhiyun if(*end != '\0'){
77*4882a593Smuzhiyun fprintf(stderr, "'%s' is neither a groupname nor a numeric group.\n",
78*4882a593Smuzhiyun optarg);
79*4882a593Smuzhiyun Usage(name, 1);
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun break;
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun case 't':
84*4882a593Smuzhiyun tun = optarg;
85*4882a593Smuzhiyun break;
86*4882a593Smuzhiyun case 'h':
87*4882a593Smuzhiyun Usage(name, 0);
88*4882a593Smuzhiyun break;
89*4882a593Smuzhiyun default:
90*4882a593Smuzhiyun Usage(name, 1);
91*4882a593Smuzhiyun }
92*4882a593Smuzhiyun }
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun argv += optind;
95*4882a593Smuzhiyun argc -= optind;
96*4882a593Smuzhiyun
97*4882a593Smuzhiyun if(argc > 0)
98*4882a593Smuzhiyun Usage(name, 1);
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun if((tap_fd = open(file, O_RDWR)) < 0){
101*4882a593Smuzhiyun fprintf(stderr, "Failed to open '%s' : ", file);
102*4882a593Smuzhiyun perror("");
103*4882a593Smuzhiyun exit(1);
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
106*4882a593Smuzhiyun memset(&ifr, 0, sizeof(ifr));
107*4882a593Smuzhiyun
108*4882a593Smuzhiyun ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
109*4882a593Smuzhiyun strncpy(ifr.ifr_name, tun, sizeof(ifr.ifr_name) - 1);
110*4882a593Smuzhiyun if(ioctl(tap_fd, TUNSETIFF, (void *) &ifr) < 0){
111*4882a593Smuzhiyun perror("TUNSETIFF");
112*4882a593Smuzhiyun exit(1);
113*4882a593Smuzhiyun }
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun if(delete){
116*4882a593Smuzhiyun if(ioctl(tap_fd, TUNSETPERSIST, 0) < 0){
117*4882a593Smuzhiyun perror("disabling TUNSETPERSIST");
118*4882a593Smuzhiyun exit(1);
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun printf("Set '%s' nonpersistent\n", ifr.ifr_name);
121*4882a593Smuzhiyun }
122*4882a593Smuzhiyun else {
123*4882a593Smuzhiyun /* emulate behaviour prior to TUNSETGROUP */
124*4882a593Smuzhiyun if(owner == -1 && group == -1) {
125*4882a593Smuzhiyun owner = geteuid();
126*4882a593Smuzhiyun }
127*4882a593Smuzhiyun
128*4882a593Smuzhiyun if(owner != -1) {
129*4882a593Smuzhiyun if(ioctl(tap_fd, TUNSETOWNER, owner) < 0){
130*4882a593Smuzhiyun perror("TUNSETOWNER");
131*4882a593Smuzhiyun exit(1);
132*4882a593Smuzhiyun }
133*4882a593Smuzhiyun }
134*4882a593Smuzhiyun if(group != -1) {
135*4882a593Smuzhiyun if(ioctl(tap_fd, TUNSETGROUP, group) < 0){
136*4882a593Smuzhiyun perror("TUNSETGROUP");
137*4882a593Smuzhiyun exit(1);
138*4882a593Smuzhiyun }
139*4882a593Smuzhiyun }
140*4882a593Smuzhiyun
141*4882a593Smuzhiyun if(ioctl(tap_fd, TUNSETPERSIST, 1) < 0){
142*4882a593Smuzhiyun perror("enabling TUNSETPERSIST");
143*4882a593Smuzhiyun exit(1);
144*4882a593Smuzhiyun }
145*4882a593Smuzhiyun
146*4882a593Smuzhiyun if(brief)
147*4882a593Smuzhiyun printf("%s\n", ifr.ifr_name);
148*4882a593Smuzhiyun else {
149*4882a593Smuzhiyun printf("Set '%s' persistent and owned by", ifr.ifr_name);
150*4882a593Smuzhiyun if(owner != -1)
151*4882a593Smuzhiyun printf(" uid %d", owner);
152*4882a593Smuzhiyun if(group != -1)
153*4882a593Smuzhiyun printf(" gid %d", group);
154*4882a593Smuzhiyun printf("\n");
155*4882a593Smuzhiyun }
156*4882a593Smuzhiyun }
157*4882a593Smuzhiyun return(0);
158*4882a593Smuzhiyun }
159