[efi] Implement the EFI_PXE_BASE_CODE_PROTOCOL
[ipxe.git] / src / drivers / linux / tap.c
1 /*
2 * Copyright (C) 2010 Piotr JaroszyƄski <p.jaroszynski@gmail.com>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #include <errno.h>
20 #include <string.h>
21 #include <stdio.h>
22 #include <linux_api.h>
23 #include <ipxe/list.h>
24 #include <ipxe/linux.h>
25 #include <ipxe/malloc.h>
26 #include <ipxe/device.h>
27 #include <ipxe/netdevice.h>
28 #include <ipxe/iobuf.h>
29 #include <ipxe/ethernet.h>
30 #include <ipxe/settings.h>
31 #include <ipxe/socket.h>
32
33 /* This hack prevents pre-2.6.32 headers from redefining struct sockaddr */
34 #define __GLIBC__ 2
35 #include <linux/socket.h>
36 #undef __GLIBC__
37 #include <linux/if.h>
38 #include <linux/if_ether.h>
39 #include <linux/if_tun.h>
40
41 #define RX_BUF_SIZE 1536
42
43 /** @file
44 *
45 * The TAP driver.
46 *
47 * The TAP is a Virtual Ethernet network device.
48 */
49
50 struct tap_nic {
51 /** Tap interface name */
52 char * interface;
53 /** File descriptor of the opened tap device */
54 int fd;
55 };
56
57 /** Open the TAP device */
58 static int tap_open(struct net_device * netdev)
59 {
60 struct tap_nic * nic = netdev->priv;
61 struct ifreq ifr;
62 int ret;
63
64 nic->fd = linux_open("/dev/net/tun", O_RDWR);
65 if (nic->fd < 0) {
66 DBGC(nic, "tap %p open('/dev/net/tun') = %d (%s)\n", nic, nic->fd, linux_strerror(linux_errno));
67 return nic->fd;
68 }
69
70 memset(&ifr, 0, sizeof(ifr));
71 /* IFF_NO_PI for no extra packet information */
72 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
73 strncpy(ifr.ifr_name, nic->interface, IFNAMSIZ);
74 DBGC(nic, "tap %p interface = '%s'\n", nic, nic->interface);
75
76 ret = linux_ioctl(nic->fd, TUNSETIFF, &ifr);
77
78 if (ret != 0) {
79 DBGC(nic, "tap %p ioctl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno));
80 linux_close(nic->fd);
81 return ret;
82 }
83
84 /* Set nonblocking mode to make tap_poll easier */
85 ret = linux_fcntl(nic->fd, F_SETFL, O_NONBLOCK);
86
87 if (ret != 0) {
88 DBGC(nic, "tap %p fcntl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno));
89 linux_close(nic->fd);
90 return ret;
91 }
92
93 return 0;
94 }
95
96 /** Close the TAP device */
97 static void tap_close(struct net_device *netdev)
98 {
99 struct tap_nic * nic = netdev->priv;
100 linux_close(nic->fd);
101 }
102
103 /**
104 * Transmit an ethernet packet.
105 *
106 * The packet can be written to the TAP device and marked as complete immediately.
107 */
108 static int tap_transmit(struct net_device *netdev, struct io_buffer *iobuf)
109 {
110 struct tap_nic * nic = netdev->priv;
111 int rc;
112
113 /* Pad and align packet */
114 iob_pad(iobuf, ETH_ZLEN);
115
116 rc = linux_write(nic->fd, iobuf->data, iobuf->tail - iobuf->data);
117 DBGC2(nic, "tap %p wrote %d bytes\n", nic, rc);
118 netdev_tx_complete(netdev, iobuf);
119
120 return 0;
121 }
122
123 /** Poll for new packets */
124 static void tap_poll(struct net_device *netdev)
125 {
126 struct tap_nic * nic = netdev->priv;
127 struct pollfd pfd;
128 struct io_buffer * iobuf;
129 int r;
130
131 pfd.fd = nic->fd;
132 pfd.events = POLLIN;
133 if (linux_poll(&pfd, 1, 0) == -1) {
134 DBGC(nic, "tap %p poll failed (%s)\n", nic, linux_strerror(linux_errno));
135 return;
136 }
137 if ((pfd.revents & POLLIN) == 0)
138 return;
139
140 /* At this point we know there is at least one new packet to be read */
141
142 iobuf = alloc_iob(RX_BUF_SIZE);
143 if (! iobuf)
144 goto allocfail;
145
146 while ((r = linux_read(nic->fd, iobuf->data, RX_BUF_SIZE)) > 0) {
147 DBGC2(nic, "tap %p read %d bytes\n", nic, r);
148
149 iob_put(iobuf, r);
150 netdev_rx(netdev, iobuf);
151
152 iobuf = alloc_iob(RX_BUF_SIZE);
153 if (! iobuf)
154 goto allocfail;
155 }
156
157 free_iob(iobuf);
158 return;
159
160 allocfail:
161 DBGC(nic, "tap %p alloc_iob failed\n", nic);
162 }
163
164 /**
165 * Set irq.
166 *
167 * Not used on linux, provide a dummy implementation.
168 */
169 static void tap_irq(struct net_device *netdev, int enable)
170 {
171 struct tap_nic *nic = netdev->priv;
172
173 DBGC(nic, "tap %p irq enable = %d\n", nic, enable);
174 }
175
176 /** Tap operations */
177 static struct net_device_operations tap_operations = {
178 .open = tap_open,
179 .close = tap_close,
180 .transmit = tap_transmit,
181 .poll = tap_poll,
182 .irq = tap_irq,
183 };
184
185 /** Handle a device request for the tap driver */
186 static int tap_probe(struct linux_device *device, struct linux_device_request *request)
187 {
188 struct linux_setting *if_setting;
189 struct net_device *netdev;
190 struct tap_nic *nic;
191 int rc;
192
193 netdev = alloc_etherdev(sizeof(*nic));
194 if (! netdev)
195 return -ENOMEM;
196
197 netdev_init(netdev, &tap_operations);
198 nic = netdev->priv;
199 linux_set_drvdata(device, netdev);
200 netdev->dev = &device->dev;
201 memset(nic, 0, sizeof(*nic));
202
203 /* Look for the mandatory if setting */
204 if_setting = linux_find_setting("if", &request->settings);
205
206 /* No if setting */
207 if (! if_setting) {
208 printf("tap missing a mandatory if setting\n");
209 rc = -EINVAL;
210 goto err_settings;
211 }
212
213 nic->interface = if_setting->value;
214 snprintf ( device->dev.name, sizeof ( device->dev.name ), "%s",
215 nic->interface );
216 device->dev.desc.bus_type = BUS_TYPE_TAP;
217 if_setting->applied = 1;
218
219 /* Apply rest of the settings */
220 linux_apply_settings(&request->settings, &netdev->settings.settings);
221
222 /* Register network device */
223 if ((rc = register_netdev(netdev)) != 0)
224 goto err_register;
225
226 netdev_link_up(netdev);
227
228 return 0;
229
230 err_settings:
231 unregister_netdev(netdev);
232 err_register:
233 netdev_nullify(netdev);
234 netdev_put(netdev);
235 return rc;
236 }
237
238 /** Remove the device */
239 static void tap_remove(struct linux_device *device)
240 {
241 struct net_device *netdev = linux_get_drvdata(device);
242 unregister_netdev(netdev);
243 netdev_nullify(netdev);
244 netdev_put(netdev);
245 }
246
247 /** Tap linux_driver */
248 struct linux_driver tap_driver __linux_driver = {
249 .name = "tap",
250 .probe = tap_probe,
251 .remove = tap_remove,
252 .can_probe = 1,
253 };