nvdimm acpi: initialize the resource used by NVDIMM ACPI
[qemu/ar7.git] / net / tap-linux.c
blob0929cf76f5b680ec07d59a6c4b35f20dbdadbe71
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2009 Red Hat, Inc.
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:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
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.
26 #include "qemu/osdep.h"
27 #include "tap_int.h"
28 #include "tap-linux.h"
29 #include "net/tap.h"
31 #include <net/if.h>
32 #include <sys/ioctl.h>
34 #include "sysemu/sysemu.h"
35 #include "qemu-common.h"
36 #include "qemu/error-report.h"
38 #define PATH_NET_TUN "/dev/net/tun"
40 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
41 int vnet_hdr_required, int mq_required, Error **errp)
43 struct ifreq ifr;
44 int fd, ret;
45 int len = sizeof(struct virtio_net_hdr);
46 unsigned int features;
48 TFR(fd = open(PATH_NET_TUN, O_RDWR));
49 if (fd < 0) {
50 error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN);
51 return -1;
53 memset(&ifr, 0, sizeof(ifr));
54 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
56 if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
57 error_report("warning: TUNGETFEATURES failed: %s", strerror(errno));
58 features = 0;
61 if (features & IFF_ONE_QUEUE) {
62 ifr.ifr_flags |= IFF_ONE_QUEUE;
65 if (*vnet_hdr) {
66 if (features & IFF_VNET_HDR) {
67 *vnet_hdr = 1;
68 ifr.ifr_flags |= IFF_VNET_HDR;
69 } else {
70 *vnet_hdr = 0;
73 if (vnet_hdr_required && !*vnet_hdr) {
74 error_setg(errp, "vnet_hdr=1 requested, but no kernel "
75 "support for IFF_VNET_HDR available");
76 close(fd);
77 return -1;
80 * Make sure vnet header size has the default value: for a persistent
81 * tap it might have been modified e.g. by another instance of qemu.
82 * Ignore errors since old kernels do not support this ioctl: in this
83 * case the header size implicitly has the correct value.
85 ioctl(fd, TUNSETVNETHDRSZ, &len);
88 if (mq_required) {
89 if (!(features & IFF_MULTI_QUEUE)) {
90 error_setg(errp, "multiqueue required, but no kernel "
91 "support for IFF_MULTI_QUEUE available");
92 close(fd);
93 return -1;
94 } else {
95 ifr.ifr_flags |= IFF_MULTI_QUEUE;
99 if (ifname[0] != '\0')
100 pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
101 else
102 pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
103 ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
104 if (ret != 0) {
105 if (ifname[0] != '\0') {
106 error_setg_errno(errp, errno, "could not configure %s (%s)",
107 PATH_NET_TUN, ifr.ifr_name);
108 } else {
109 error_setg_errno(errp, errno, "could not configure %s",
110 PATH_NET_TUN);
112 close(fd);
113 return -1;
115 pstrcpy(ifname, ifname_size, ifr.ifr_name);
116 fcntl(fd, F_SETFL, O_NONBLOCK);
117 return fd;
120 /* sndbuf implements a kind of flow control for tap.
121 * Unfortunately when it's enabled, and packets are sent
122 * to other guests on the same host, the receiver
123 * can lock up the transmitter indefinitely.
125 * To avoid packet loss, sndbuf should be set to a value lower than the tx
126 * queue capacity of any destination network interface.
127 * Ethernet NICs generally have txqueuelen=1000, so 1Mb is
128 * a good value, given a 1500 byte MTU.
130 #define TAP_DEFAULT_SNDBUF 0
132 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
134 int sndbuf;
136 sndbuf = !tap->has_sndbuf ? TAP_DEFAULT_SNDBUF :
137 tap->sndbuf > INT_MAX ? INT_MAX :
138 tap->sndbuf;
140 if (!sndbuf) {
141 sndbuf = INT_MAX;
144 if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && tap->has_sndbuf) {
145 error_setg_errno(errp, errno, "TUNSETSNDBUF ioctl failed");
149 int tap_probe_vnet_hdr(int fd)
151 struct ifreq ifr;
153 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
154 error_report("TUNGETIFF ioctl() failed: %s", strerror(errno));
155 return 0;
158 return ifr.ifr_flags & IFF_VNET_HDR;
161 int tap_probe_has_ufo(int fd)
163 unsigned offload;
165 offload = TUN_F_CSUM | TUN_F_UFO;
167 if (ioctl(fd, TUNSETOFFLOAD, offload) < 0)
168 return 0;
170 return 1;
173 /* Verify that we can assign given length */
174 int tap_probe_vnet_hdr_len(int fd, int len)
176 int orig;
177 if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) {
178 return 0;
180 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
181 return 0;
183 /* Restore original length: we can't handle failure. */
184 if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) {
185 fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
186 strerror(errno));
187 abort();
188 return -errno;
190 return 1;
193 void tap_fd_set_vnet_hdr_len(int fd, int len)
195 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
196 fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
197 strerror(errno));
198 abort();
202 int tap_fd_set_vnet_le(int fd, int is_le)
204 int arg = is_le ? 1 : 0;
206 if (!ioctl(fd, TUNSETVNETLE, &arg)) {
207 return 0;
210 /* Check if our kernel supports TUNSETVNETLE */
211 if (errno == EINVAL) {
212 return -errno;
215 error_report("TUNSETVNETLE ioctl() failed: %s.", strerror(errno));
216 abort();
219 int tap_fd_set_vnet_be(int fd, int is_be)
221 int arg = is_be ? 1 : 0;
223 if (!ioctl(fd, TUNSETVNETBE, &arg)) {
224 return 0;
227 /* Check if our kernel supports TUNSETVNETBE */
228 if (errno == EINVAL) {
229 return -errno;
232 error_report("TUNSETVNETBE ioctl() failed: %s.", strerror(errno));
233 abort();
236 void tap_fd_set_offload(int fd, int csum, int tso4,
237 int tso6, int ecn, int ufo)
239 unsigned int offload = 0;
241 /* Check if our kernel supports TUNSETOFFLOAD */
242 if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
243 return;
246 if (csum) {
247 offload |= TUN_F_CSUM;
248 if (tso4)
249 offload |= TUN_F_TSO4;
250 if (tso6)
251 offload |= TUN_F_TSO6;
252 if ((tso4 || tso6) && ecn)
253 offload |= TUN_F_TSO_ECN;
254 if (ufo)
255 offload |= TUN_F_UFO;
258 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
259 offload &= ~TUN_F_UFO;
260 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
261 fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
262 strerror(errno));
267 /* Enable a specific queue of tap. */
268 int tap_fd_enable(int fd)
270 struct ifreq ifr;
271 int ret;
273 memset(&ifr, 0, sizeof(ifr));
275 ifr.ifr_flags = IFF_ATTACH_QUEUE;
276 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
278 if (ret != 0) {
279 error_report("could not enable queue");
282 return ret;
285 /* Disable a specific queue of tap/ */
286 int tap_fd_disable(int fd)
288 struct ifreq ifr;
289 int ret;
291 memset(&ifr, 0, sizeof(ifr));
293 ifr.ifr_flags = IFF_DETACH_QUEUE;
294 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
296 if (ret != 0) {
297 error_report("could not disable queue");
300 return ret;
303 int tap_fd_get_ifname(int fd, char *ifname)
305 struct ifreq ifr;
307 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
308 error_report("TUNGETIFF ioctl() failed: %s",
309 strerror(errno));
310 return -1;
313 pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
314 return 0;