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26#include "qemu/osdep.h"
27#include "qemu-common.h"
28#include "tap_int.h"
29#include "tap-linux.h"
30#include "net/tap.h"
31
32#include <net/if.h>
33#include <sys/ioctl.h>
34
35#include "qapi/error.h"
36#include "qemu/error-report.h"
37#include "qemu/cutils.h"
38
39#define PATH_NET_TUN "/dev/net/tun"
40
41int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
42 int vnet_hdr_required, int mq_required, Error **errp)
43{
44 struct ifreq ifr;
45 int fd, ret;
46 int len = sizeof(struct virtio_net_hdr);
47 unsigned int features;
48
49 TFR(fd = open(PATH_NET_TUN, O_RDWR));
50 if (fd < 0) {
51 error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN);
52 return -1;
53 }
54 memset(&ifr, 0, sizeof(ifr));
55 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
56
57 if (ioctl(fd, TUNGETFEATURES, &features) == -1) {
58 warn_report("TUNGETFEATURES failed: %s", strerror(errno));
59 features = 0;
60 }
61
62 if (features & IFF_ONE_QUEUE) {
63 ifr.ifr_flags |= IFF_ONE_QUEUE;
64 }
65
66 if (*vnet_hdr) {
67 if (features & IFF_VNET_HDR) {
68 *vnet_hdr = 1;
69 ifr.ifr_flags |= IFF_VNET_HDR;
70 } else {
71 *vnet_hdr = 0;
72 }
73
74 if (vnet_hdr_required && !*vnet_hdr) {
75 error_setg(errp, "vnet_hdr=1 requested, but no kernel "
76 "support for IFF_VNET_HDR available");
77 close(fd);
78 return -1;
79 }
80
81
82
83
84
85
86 ioctl(fd, TUNSETVNETHDRSZ, &len);
87 }
88
89 if (mq_required) {
90 if (!(features & IFF_MULTI_QUEUE)) {
91 error_setg(errp, "multiqueue required, but no kernel "
92 "support for IFF_MULTI_QUEUE available");
93 close(fd);
94 return -1;
95 } else {
96 ifr.ifr_flags |= IFF_MULTI_QUEUE;
97 }
98 }
99
100 if (ifname[0] != '\0')
101 pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname);
102 else
103 pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d");
104 ret = ioctl(fd, TUNSETIFF, (void *) &ifr);
105 if (ret != 0) {
106 if (ifname[0] != '\0') {
107 error_setg_errno(errp, errno, "could not configure %s (%s)",
108 PATH_NET_TUN, ifr.ifr_name);
109 } else {
110 error_setg_errno(errp, errno, "could not configure %s",
111 PATH_NET_TUN);
112 }
113 close(fd);
114 return -1;
115 }
116 pstrcpy(ifname, ifname_size, ifr.ifr_name);
117 fcntl(fd, F_SETFL, O_NONBLOCK);
118 return fd;
119}
120
121
122
123
124
125
126
127
128
129
130
131#define TAP_DEFAULT_SNDBUF 0
132
133void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
134{
135 int sndbuf;
136
137 sndbuf = !tap->has_sndbuf ? TAP_DEFAULT_SNDBUF :
138 tap->sndbuf > INT_MAX ? INT_MAX :
139 tap->sndbuf;
140
141 if (!sndbuf) {
142 sndbuf = INT_MAX;
143 }
144
145 if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && tap->has_sndbuf) {
146 error_setg_errno(errp, errno, "TUNSETSNDBUF ioctl failed");
147 }
148}
149
150int tap_probe_vnet_hdr(int fd, Error **errp)
151{
152 struct ifreq ifr;
153
154 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
155
156 error_setg_errno(errp, errno,
157 "Unable to query TUNGETIFF on FD %d", fd);
158 return -1;
159 }
160
161 return ifr.ifr_flags & IFF_VNET_HDR;
162}
163
164int tap_probe_has_ufo(int fd)
165{
166 unsigned offload;
167
168 offload = TUN_F_CSUM | TUN_F_UFO;
169
170 if (ioctl(fd, TUNSETOFFLOAD, offload) < 0)
171 return 0;
172
173 return 1;
174}
175
176
177int tap_probe_vnet_hdr_len(int fd, int len)
178{
179 int orig;
180 if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) {
181 return 0;
182 }
183 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
184 return 0;
185 }
186
187 if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) {
188 fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
189 strerror(errno));
190 abort();
191 return -errno;
192 }
193 return 1;
194}
195
196void tap_fd_set_vnet_hdr_len(int fd, int len)
197{
198 if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) {
199 fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n",
200 strerror(errno));
201 abort();
202 }
203}
204
205int tap_fd_set_vnet_le(int fd, int is_le)
206{
207 int arg = is_le ? 1 : 0;
208
209 if (!ioctl(fd, TUNSETVNETLE, &arg)) {
210 return 0;
211 }
212
213
214 if (errno == EINVAL) {
215 return -errno;
216 }
217
218 error_report("TUNSETVNETLE ioctl() failed: %s.", strerror(errno));
219 abort();
220}
221
222int tap_fd_set_vnet_be(int fd, int is_be)
223{
224 int arg = is_be ? 1 : 0;
225
226 if (!ioctl(fd, TUNSETVNETBE, &arg)) {
227 return 0;
228 }
229
230
231 if (errno == EINVAL) {
232 return -errno;
233 }
234
235 error_report("TUNSETVNETBE ioctl() failed: %s.", strerror(errno));
236 abort();
237}
238
239void tap_fd_set_offload(int fd, int csum, int tso4,
240 int tso6, int ecn, int ufo)
241{
242 unsigned int offload = 0;
243
244
245 if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
246 return;
247 }
248
249 if (csum) {
250 offload |= TUN_F_CSUM;
251 if (tso4)
252 offload |= TUN_F_TSO4;
253 if (tso6)
254 offload |= TUN_F_TSO6;
255 if ((tso4 || tso6) && ecn)
256 offload |= TUN_F_TSO_ECN;
257 if (ufo)
258 offload |= TUN_F_UFO;
259 }
260
261 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
262 offload &= ~TUN_F_UFO;
263 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
264 fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
265 strerror(errno));
266 }
267 }
268}
269
270
271int tap_fd_enable(int fd)
272{
273 struct ifreq ifr;
274 int ret;
275
276 memset(&ifr, 0, sizeof(ifr));
277
278 ifr.ifr_flags = IFF_ATTACH_QUEUE;
279 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
280
281 if (ret != 0) {
282 error_report("could not enable queue");
283 }
284
285 return ret;
286}
287
288
289int tap_fd_disable(int fd)
290{
291 struct ifreq ifr;
292 int ret;
293
294 memset(&ifr, 0, sizeof(ifr));
295
296 ifr.ifr_flags = IFF_DETACH_QUEUE;
297 ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr);
298
299 if (ret != 0) {
300 error_report("could not disable queue");
301 }
302
303 return ret;
304}
305
306int tap_fd_get_ifname(int fd, char *ifname)
307{
308 struct ifreq ifr;
309
310 if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
311 error_report("TUNGETIFF ioctl() failed: %s",
312 strerror(errno));
313 return -1;
314 }
315
316 pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);
317 return 0;
318}
319
320int tap_fd_set_steering_ebpf(int fd, int prog_fd)
321{
322 if (ioctl(fd, TUNSETSTEERINGEBPF, (void *) &prog_fd) != 0) {
323 error_report("Issue while setting TUNSETSTEERINGEBPF:"
324 " %s with fd: %d, prog_fd: %d",
325 strerror(errno), fd, prog_fd);
326
327 return -1;
328 }
329
330 return 0;
331}
332