mips: Set the CP0.Config3.DSP and CP0.Config3.DSP2P bits
[qemu.git] / net / tap-linux.c
1 /*
2 * QEMU System Emulator
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26 #include "tap_int.h"
27 #include "tap-linux.h"
28 #include "net/tap.h"
29
30 #include <net/if.h>
31 #include <sys/ioctl.h>
32
33 #include "sysemu/sysemu.h"
34 #include "qemu-common.h"
35 #include "qemu/error-report.h"
36
37 #define PATH_NET_TUN "/dev/net/tun"
38
39 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
40 int vnet_hdr_required, int mq_required)
41 {
42 struct ifreq ifr;
43 int fd, ret;
44 int len = sizeof(struct virtio_net_hdr);
45 unsigned int features;
46
47 TFR(fd = open(PATH_NET_TUN, O_RDWR));
48 if (fd < 0) {
49 error_report("could not open %s: %m", PATH_NET_TUN);
50 return -1;
51 }
52 memset(&ifr, 0, sizeof(ifr));
53 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
54
55 if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
56 error_report("warning: TUNGETFEATURES failed: %s", strerror(errno));
57 features = 0;
58 }
59
60 if (features & IFF_ONE_QUEUE) {
61 ifr.ifr_flags |= IFF_ONE_QUEUE;
62 }
63
64 if (*vnet_hdr) {
65 if (features & IFF_VNET_HDR) {
66 *vnet_hdr = 1;
67 ifr.ifr_flags |= IFF_VNET_HDR;
68 } else {
69 *vnet_hdr = 0;
70 }
71
72 if (vnet_hdr_required && !*vnet_hdr) {
73 error_report("vnet_hdr=1 requested, but no kernel "
74 "support for IFF_VNET_HDR available");
75 close(fd);
76 return -1;
77 }
78 /*
79 * Make sure vnet header size has the default value: for a persistent
80 * tap it might have been modified e.g. by another instance of qemu.
81 * Ignore errors since old kernels do not support this ioctl: in this
82 * case the header size implicitly has the correct value.
83 */
84 ioctl(fd, TUNSETVNETHDRSZ, &len);
85 }
86
87 if (mq_required) {
88 if (!(features & IFF_MULTI_QUEUE)) {
89 error_report("multiqueue required, but no kernel "
90 "support for IFF_MULTI_QUEUE available");
91 close(fd);
92 return -1;
93 } else {
94 ifr.ifr_flags |= IFF_MULTI_QUEUE;
95 }
96 }
97
98 if (ifname[0] != '\0')
99 pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
100 else
101 pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
102 ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
103 if (ret != 0) {
104 if (ifname[0] != '\0') {
105 error_report("could not configure %s (%s): %m", PATH_NET_TUN, ifr.ifr_name);
106 } else {
107 error_report("could not configure %s: %m", PATH_NET_TUN);
108 }
109 close(fd);
110 return -1;
111 }
112 pstrcpy(ifname, ifname_size, ifr.ifr_name);
113 fcntl(fd, F_SETFL, O_NONBLOCK);
114 return fd;
115 }
116
117 /* sndbuf implements a kind of flow control for tap.
118 * Unfortunately when it's enabled, and packets are sent
119 * to other guests on the same host, the receiver
120 * can lock up the transmitter indefinitely.
121 *
122 * To avoid packet loss, sndbuf should be set to a value lower than the tx
123 * queue capacity of any destination network interface.
124 * Ethernet NICs generally have txqueuelen=1000, so 1Mb is
125 * a good value, given a 1500 byte MTU.
126 */
127 #define TAP_DEFAULT_SNDBUF 0
128
129 int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
130 {
131 int sndbuf;
132
133 sndbuf = !tap->has_sndbuf ? TAP_DEFAULT_SNDBUF :
134 tap->sndbuf > INT_MAX ? INT_MAX :
135 tap->sndbuf;
136
137 if (!sndbuf) {
138 sndbuf = INT_MAX;
139 }
140
141 if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && tap->has_sndbuf) {
142 error_report("TUNSETSNDBUF ioctl failed: %s", strerror(errno));
143 return -1;
144 }
145 return 0;
146 }
147
148 int tap_probe_vnet_hdr(int fd)
149 {
150 struct ifreq ifr;
151
152 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
153 error_report("TUNGETIFF ioctl() failed: %s", strerror(errno));
154 return 0;
155 }
156
157 return ifr.ifr_flags & IFF_VNET_HDR;
158 }
159
160 int tap_probe_has_ufo(int fd)
161 {
162 unsigned offload;
163
164 offload = TUN_F_CSUM | TUN_F_UFO;
165
166 if (ioctl(fd, TUNSETOFFLOAD, offload) < 0)
167 return 0;
168
169 return 1;
170 }
171
172 /* Verify that we can assign given length */
173 int tap_probe_vnet_hdr_len(int fd, int len)
174 {
175 int orig;
176 if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) {
177 return 0;
178 }
179 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
180 return 0;
181 }
182 /* Restore original length: we can't handle failure. */
183 if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) {
184 fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
185 strerror(errno));
186 abort();
187 return -errno;
188 }
189 return 1;
190 }
191
192 void tap_fd_set_vnet_hdr_len(int fd, int len)
193 {
194 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
195 fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
196 strerror(errno));
197 abort();
198 }
199 }
200
201 void tap_fd_set_offload(int fd, int csum, int tso4,
202 int tso6, int ecn, int ufo)
203 {
204 unsigned int offload = 0;
205
206 /* Check if our kernel supports TUNSETOFFLOAD */
207 if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
208 return;
209 }
210
211 if (csum) {
212 offload |= TUN_F_CSUM;
213 if (tso4)
214 offload |= TUN_F_TSO4;
215 if (tso6)
216 offload |= TUN_F_TSO6;
217 if ((tso4 || tso6) && ecn)
218 offload |= TUN_F_TSO_ECN;
219 if (ufo)
220 offload |= TUN_F_UFO;
221 }
222
223 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
224 offload &= ~TUN_F_UFO;
225 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
226 fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
227 strerror(errno));
228 }
229 }
230 }
231
232 /* Enable a specific queue of tap. */
233 int tap_fd_enable(int fd)
234 {
235 struct ifreq ifr;
236 int ret;
237
238 memset(&ifr, 0, sizeof(ifr));
239
240 ifr.ifr_flags = IFF_ATTACH_QUEUE;
241 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
242
243 if (ret != 0) {
244 error_report("could not enable queue");
245 }
246
247 return ret;
248 }
249
250 /* Disable a specific queue of tap/ */
251 int tap_fd_disable(int fd)
252 {
253 struct ifreq ifr;
254 int ret;
255
256 memset(&ifr, 0, sizeof(ifr));
257
258 ifr.ifr_flags = IFF_DETACH_QUEUE;
259 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
260
261 if (ret != 0) {
262 error_report("could not disable queue");
263 }
264
265 return ret;
266 }
267
268 int tap_fd_get_ifname(int fd, char *ifname)
269 {
270 struct ifreq ifr;
271
272 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
273 error_report("TUNGETIFF ioctl() failed: %s",
274 strerror(errno));
275 return -1;
276 }
277
278 pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
279 return 0;
280 }