aboutsummaryrefslogtreecommitdiff
path: root/arch/um/os-Linux/drivers/ethertap_user.c
blob: db3d6481375a7c55cf5885771093f9a784d1db43 (plain)
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
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
/*
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
 * James Leu (jleu@mindspring.net).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 * Licensed under the GPL.
 */

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include "etap.h"
#include "os.h"
#include "net_user.h"
#include "um_malloc.h"

#define MAX_PACKET ETH_MAX_PACKET

static int etap_user_init(void *data, void *dev)
{
	struct ethertap_data *pri = data;

	pri->dev = dev;
	return 0;
}

struct addr_change {
	enum { ADD_ADDR, DEL_ADDR } what;
	unsigned char addr[4];
	unsigned char netmask[4];
};

static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
			int fd)
{
	struct addr_change change;
	char *output;
	int n;

	change.what = op;
	memcpy(change.addr, addr, sizeof(change.addr));
	memcpy(change.netmask, netmask, sizeof(change.netmask));
	CATCH_EINTR(n = write(fd, &change, sizeof(change)));
	if (n != sizeof(change)) {
		printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
		       errno);
		return;
	}

	output = uml_kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
	if (output == NULL)
		printk(UM_KERN_ERR "etap_change : Failed to allocate output "
		       "buffer\n");
	read_output(fd, output, UM_KERN_PAGE_SIZE);
	if (output != NULL) {
		printk("%s", output);
		kfree(output);
	}
}

static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
			   void *arg)
{
	etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
}

static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
			    void *arg)
{
	etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
}

struct etap_pre_exec_data {
	int control_remote;
	int control_me;
	int data_me;
};

static void etap_pre_exec(void *arg)
{
	struct etap_pre_exec_data *data = arg;

	dup2(data->control_remote, 1);
	close(data->data_me);
	close(data->control_me);
}

static int etap_tramp(char *dev, char *gate, int control_me,
		      int control_remote, int data_me, int data_remote)
{
	struct etap_pre_exec_data pe_data;
	int pid, err, n;
	char version_buf[sizeof("nnnnn\0")];
	char data_fd_buf[sizeof("nnnnnn\0")];
	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
	char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
			       data_fd_buf, gate_buf, NULL };
	char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
				 dev, data_fd_buf, NULL };
	char **args, c;

	sprintf(data_fd_buf, "%d", data_remote);
	sprintf(version_buf, "%d", UML_NET_VERSION);
	if (gate != NULL) {
		strcpy(gate_buf, gate);
		args = setup_args;
	}
	else args = nosetup_args;

	err = 0;
	pe_data.control_remote = control_remote;
	pe_data.control_me = control_me;
	pe_data.data_me = data_me;
	pid = run_helper(etap_pre_exec, &pe_data, args);

	if (pid < 0)
		err = pid;
	close(data_remote);
	close(control_remote);
	CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
	if (n != sizeof(c)) {
		err = -errno;
		printk(UM_KERN_ERR "etap_tramp : read of status failed, "
		       "err = %d\n", -err);
		return err;
	}
	if (c != 1) {
		printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
		err = helper_wait(pid);
	}
	return err;
}

static int etap_open(void *data)
{
	struct ethertap_data *pri = data;
	char *output;
	int data_fds[2], control_fds[2], err, output_len;

	err = tap_open_common(pri->dev, pri->gate_addr);
	if (err)
		return err;

	err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
	if (err) {
		err = -errno;
		printk(UM_KERN_ERR "etap_open - data socketpair failed - "
		       "err = %d\n", errno);
		return err;
	}

	err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
	if (err) {
		err = -errno;
		printk(UM_KERN_ERR "etap_open - control socketpair failed - "
		       "err = %d\n", errno);
		goto out_close_data;
	}

	err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
			 control_fds[1], data_fds[0], data_fds[1]);
	output_len = UM_KERN_PAGE_SIZE;
	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
	read_output(control_fds[0], output, output_len);

	if (output == NULL)
		printk(UM_KERN_ERR "etap_open : failed to allocate output "
		       "buffer\n");
	else {
		printk("%s", output);
		kfree(output);
	}

	if (err < 0) {
		printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
		goto out_close_control;
	}

	pri->data_fd = data_fds[0];
	pri->control_fd = control_fds[0];
	iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
	return data_fds[0];

out_close_control:
	close(control_fds[0]);
	close(control_fds[1]);
out_close_data:
	close(data_fds[0]);
	close(data_fds[1]);
	return err;
}

static void etap_close(int fd, void *data)
{
	struct ethertap_data *pri = data;

	iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
	close(fd);

	if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
		printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
		       "errno = %d\n", errno);

	if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
		printk(UM_KERN_ERR "etap_close - shutdown control socket "
		       "failed, errno = %d\n", errno);

	close(pri->data_fd);
	pri->data_fd = -1;
	close(pri->control_fd);
	pri->control_fd = -1;
}

static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
			  void *data)
{
	struct ethertap_data *pri = data;

	tap_check_ips(pri->gate_addr, addr);
	if (pri->control_fd == -1)
		return;
	etap_open_addr(addr, netmask, &pri->control_fd);
}

static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
			  void *data)
{
	struct ethertap_data *pri = data;

	if (pri->control_fd == -1)
		return;

	etap_close_addr(addr, netmask, &pri->control_fd);
}

const struct net_user_info ethertap_user_info = {
	.init		= etap_user_init,
	.open		= etap_open,
	.close	 	= etap_close,
	.remove	 	= NULL,
	.add_address	= etap_add_addr,
	.delete_address = etap_del_addr,
	.mtu		= ETH_MAX_PACKET,
	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
};