1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
/* Copyright 2001 Jeff Dike and others
* Licensed under the GPL
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <net/if.h>
#include <sys/un.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <linux/if_tun.h>
#include "host.h"
#include "output.h"
static int do_tuntap_up(char *gate_addr, struct output *output,
struct ifreq *ifr)
{
int tap_fd;
char *ifconfig_argv[] = { "ifconfig", ifr->ifr_name, gate_addr, "netmask",
"255.255.255.255", "up", NULL };
char *insmod_argv[] = { "modprobe", "tun", NULL };
if(setreuid(0, 0) < 0){
output_errno(output, "setreuid to root failed : ");
return(-1);
}
/* XXX hardcoded dir name and perms */
umask(0);
mkdir("/dev/net", 0755);
/* #includes for MISC_MAJOR and TUN_MINOR bomb in userspace */
mk_node("/dev/net/tun", 10, 200);
do_exec(insmod_argv, 0, output);
if((tap_fd = open("/dev/net/tun", O_RDWR)) < 0){
output_errno(output, "Opening /dev/net/tun failed : ");
return(-1);
}
memset(ifr, 0, sizeof(*ifr));
ifr->ifr_flags = IFF_TAP | IFF_NO_PI;
ifr->ifr_name[0] = '\0';
if(ioctl(tap_fd, TUNSETIFF, (void *) ifr) < 0){
output_errno(output, "TUNSETIFF : ");
return(-1);
}
if((*gate_addr != '\0') && do_exec(ifconfig_argv, 1, output))
return(-1);
forward_ip(output);
return(tap_fd);
}
static void tuntap_up(int fd, int argc, char **argv)
{
struct ifreq ifr;
struct msghdr msg;
struct cmsghdr *cmsg;
struct output output = INIT_OUTPUT;
struct iovec iov[2];
int tap_fd, *fd_ptr;
char anc[CMSG_SPACE(sizeof(tap_fd))];
char *gate_addr;
msg.msg_control = NULL;
msg.msg_controllen = 0;
iov[0].iov_base = NULL;
iov[0].iov_len = 0;
if(argc < 1){
add_output(&output, "Too few arguments to tuntap_up\n", -1);
goto out;
}
gate_addr = argv[0];
if((tap_fd = do_tuntap_up(gate_addr, &output, &ifr)) > 0){
iov[0].iov_base = ifr.ifr_name;
iov[0].iov_len = IFNAMSIZ;
msg.msg_control = anc;
msg.msg_controllen = sizeof(anc);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(tap_fd));
msg.msg_controllen = cmsg->cmsg_len;
fd_ptr = (int *) CMSG_DATA(cmsg);
*fd_ptr = tap_fd;
}
out:
iov[1].iov_base = output.buffer;
iov[1].iov_len = output.used;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = iov;
msg.msg_iovlen = sizeof(iov)/sizeof(iov[0]);
msg.msg_flags = 0;
if(sendmsg(fd, &msg, 0) < 0){
perror("sendmsg");
exit(1);
}
}
void tuntap_v2(int argc, char **argv)
{
char *op = argv[0];
if(!strcmp(op, "up")) tuntap_up(atoi(argv[2]), argc - 3, argv + 3);
else if(!strcmp(op, "add") || !strcmp(op, "del"))
change_addr(argv[1], argv[2], argv[3], NULL, NULL);
else {
fprintf(stderr, "Bad tuntap op : '%s'\n", op);
exit(1);
}
}
void tuntap_v3(int argc, char **argv)
{
char *op = argv[0];
struct output output = INIT_OUTPUT;
if(!strcmp(op, "up")) tuntap_up(1, argc - 2, argv + 2);
else if(!strcmp(op, "add") || !strcmp(op, "del"))
change_addr(op, argv[1], argv[2], NULL, &output);
else {
fprintf(stderr, "Bad tuntap op : '%s'\n", op);
exit(1);
}
write_output(1, &output);
}
void tuntap_v4(int argc, char **argv)
{
char *op;
struct output output = INIT_OUTPUT;
if(argc < 1){
add_output(&output, "uml_net : too few arguments to tuntap_v4\n", -1);
write_output(1, &output);
exit(1);
}
op = argv[0];
if(!strcmp(op, "up")) tuntap_up(1, argc - 1, argv + 1);
else if(!strcmp(op, "add") || !strcmp(op, "del")){
if(argc < 4)
add_output(&output, "uml_net : too few arguments to tuntap "
"change_addr\n", -1);
else change_addr(op, argv[1], argv[2], argv[3], &output);
write_output(1, &output);
}
else {
fprintf(stderr, "Bad tuntap op : '%s'\n", op);
exit(1);
}
}
|
