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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/*
* Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/uio.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/if_tun.h>
#include "net_user.h"
#include "tuntap.h"
#include "kern_util.h"
#include "user.h"
#include "os.h"
#define MAX_PACKET ETH_MAX_PACKET
static int tuntap_user_init(void *data, void *dev)
{
struct tuntap_data *pri = data;
pri->dev = dev;
return 0;
}
static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct tuntap_data *pri = data;
tap_check_ips(pri->gate_addr, addr);
if((pri->fd == -1) || pri->fixed_config)
return;
open_addr(addr, netmask, pri->dev_name);
}
static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
void *data)
{
struct tuntap_data *pri = data;
if((pri->fd == -1) || pri->fixed_config)
return;
close_addr(addr, netmask, pri->dev_name);
}
struct tuntap_pre_exec_data {
int stdout;
int close_me;
};
static void tuntap_pre_exec(void *arg)
{
struct tuntap_pre_exec_data *data = arg;
dup2(data->stdout, 1);
close(data->close_me);
}
static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
char *buffer, int buffer_len, int *used_out)
{
struct tuntap_pre_exec_data data;
char version_buf[sizeof("nnnnn\0")];
char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
NULL };
char buf[CMSG_SPACE(sizeof(*fd_out))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
int pid, n, err;
sprintf(version_buf, "%d", UML_NET_VERSION);
data.stdout = remote;
data.close_me = me;
pid = run_helper(tuntap_pre_exec, &data, argv);
if(pid < 0)
return -pid;
close(remote);
msg.msg_name = NULL;
msg.msg_namelen = 0;
if(buffer != NULL){
iov = ((struct iovec) { buffer, buffer_len });
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
}
else {
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
}
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
msg.msg_flags = 0;
n = recvmsg(me, &msg, 0);
*used_out = n;
if(n < 0){
err = -errno;
printk("tuntap_open_tramp : recvmsg failed - errno = %d\n",
errno);
return err;
}
CATCH_EINTR(waitpid(pid, NULL, 0));
cmsg = CMSG_FIRSTHDR(&msg);
if(cmsg == NULL){
printk("tuntap_open_tramp : didn't receive a message\n");
return -EINVAL;
}
if((cmsg->cmsg_level != SOL_SOCKET) ||
(cmsg->cmsg_type != SCM_RIGHTS)){
printk("tuntap_open_tramp : didn't receive a descriptor\n");
return -EINVAL;
}
*fd_out = ((int *) CMSG_DATA(cmsg))[0];
os_set_exec_close(*fd_out);
return 0;
}
static int tuntap_open(void *data)
{
struct ifreq ifr;
struct tuntap_data *pri = data;
char *output, *buffer;
int err, fds[2], len, used;
err = tap_open_common(pri->dev, pri->gate_addr);
if(err < 0)
return err;
if(pri->fixed_config){
pri->fd = os_open_file("/dev/net/tun",
of_cloexec(of_rdwr(OPENFLAGS())), 0);
if(pri->fd < 0){
printk("Failed to open /dev/net/tun, err = %d\n",
-pri->fd);
return pri->fd;
}
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
if(ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0){
err = -errno;
printk("TUNSETIFF failed, errno = %d\n", errno);
close(pri->fd);
return err;
}
}
else {
err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
if(err){
err = -errno;
printk("tuntap_open : socketpair failed - errno = %d\n",
errno);
return err;
}
buffer = get_output_buffer(&len);
if(buffer != NULL)
len--;
used = 0;
err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
fds[1], buffer, len, &used);
output = buffer;
if(err < 0) {
printk("%s", output);
free_output_buffer(buffer);
printk("tuntap_open_tramp failed - err = %d\n", -err);
return err;
}
pri->dev_name = uml_strdup(buffer);
output += IFNAMSIZ;
printk("%s", output);
free_output_buffer(buffer);
close(fds[0]);
iter_addresses(pri->dev, open_addr, pri->dev_name);
}
return pri->fd;
}
static void tuntap_close(int fd, void *data)
{
struct tuntap_data *pri = data;
if(!pri->fixed_config)
iter_addresses(pri->dev, close_addr, pri->dev_name);
close(fd);
pri->fd = -1;
}
static int tuntap_set_mtu(int mtu, void *data)
{
return mtu;
}
const struct net_user_info tuntap_user_info = {
.init = tuntap_user_init,
.open = tuntap_open,
.close = tuntap_close,
.remove = NULL,
.set_mtu = tuntap_set_mtu,
.add_address = tuntap_add_addr,
.delete_address = tuntap_del_addr,
.max_packet = MAX_PACKET
};
|
