xref: /openbmc/qemu/net/tap-bsd.c (revision ed75658a)
1 /*
2  * QEMU System Emulator
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qapi/error.h"
27 #include "tap_int.h"
28 #include "qemu/cutils.h"
29 #include "qemu/error-report.h"
30 
31 #if defined(__NetBSD__) || defined(__FreeBSD__)
32 #include <sys/ioctl.h>
33 #include <net/if.h>
34 #include <net/if_tap.h>
35 #endif
36 
37 #ifndef __FreeBSD__
38 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
39              int vnet_hdr_required, int mq_required, Error **errp)
40 {
41     int fd;
42 #ifdef TAPGIFNAME
43     struct ifreq ifr;
44 #else
45     char *dev;
46     struct stat s;
47 #endif
48 
49     /* if no ifname is given, always start the search from tap0/tun0. */
50     int i;
51     char dname[100];
52 
53     for (i = 0; i < 10; i++) {
54         if (*ifname) {
55             snprintf(dname, sizeof dname, "/dev/%s", ifname);
56         } else {
57             snprintf(dname, sizeof dname, "/dev/tap%d", i);
58         }
59         fd = RETRY_ON_EINTR(open(dname, O_RDWR));
60         if (fd >= 0) {
61             break;
62         }
63         else if (errno == ENXIO || errno == ENOENT) {
64             break;
65         }
66         if (*ifname) {
67             break;
68         }
69     }
70     if (fd < 0) {
71         error_setg_errno(errp, errno, "could not open %s", dname);
72         return -1;
73     }
74 
75 #ifdef TAPGIFNAME
76     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
77         error_setg_errno(errp, errno, "could not get tap name");
78         return -1;
79     }
80     pstrcpy(ifname, ifname_size, ifr.ifr_name);
81 #else
82     if (fstat(fd, &s) < 0) {
83         error_setg_errno(errp, errno, "could not stat %s", dname);
84         return -1;
85     }
86     dev = devname(s.st_rdev, S_IFCHR);
87     pstrcpy(ifname, ifname_size, dev);
88 #endif
89 
90     if (*vnet_hdr) {
91         /* BSD doesn't have IFF_VNET_HDR */
92         *vnet_hdr = 0;
93 
94         if (vnet_hdr_required && !*vnet_hdr) {
95             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
96                        "support for IFF_VNET_HDR available");
97             close(fd);
98             return -1;
99         }
100     }
101     g_unix_set_fd_nonblocking(fd, true, NULL);
102     return fd;
103 }
104 
105 #else /* __FreeBSD__ */
106 
107 #define PATH_NET_TAP "/dev/tap"
108 
109 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
110 {
111     int fd, s, ret;
112     struct ifreq ifr;
113 
114     fd = RETRY_ON_EINTR(open(PATH_NET_TAP, O_RDWR));
115     if (fd < 0) {
116         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
117         return -1;
118     }
119 
120     memset(&ifr, 0, sizeof(ifr));
121 
122     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
123     if (ret < 0) {
124         error_setg_errno(errp, errno, "could not get tap interface name");
125         close(fd);
126         return -1;
127     }
128 
129     if (ifname[0] != '\0') {
130         /* User requested the interface to have a specific name */
131         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
132         if (s < 0) {
133             error_setg_errno(errp, errno,
134                              "could not open socket to set interface name");
135             close(fd);
136             return -1;
137         }
138         ifr.ifr_data = ifname;
139         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
140         close(s);
141         if (ret < 0) {
142             error_setg(errp, "could not set tap interface name");
143             close(fd);
144             return -1;
145         }
146     } else {
147         pstrcpy(ifname, ifname_size, ifr.ifr_name);
148     }
149 
150     return fd;
151 }
152 
153 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
154              int vnet_hdr_required, int mq_required, Error **errp)
155 {
156     int fd = -1;
157 
158     /* If the specified tap device already exists just use it. */
159     if (ifname[0] != '\0') {
160         char dname[100];
161         snprintf(dname, sizeof dname, "/dev/%s", ifname);
162         fd = RETRY_ON_EINTR(open(dname, O_RDWR));
163         if (fd < 0 && errno != ENOENT) {
164             error_setg_errno(errp, errno, "could not open %s", dname);
165             return -1;
166         }
167     }
168 
169     if (fd < 0) {
170         /* Tap device not specified or does not exist. */
171         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
172             return -1;
173         }
174     }
175 
176     if (*vnet_hdr) {
177         /* BSD doesn't have IFF_VNET_HDR */
178         *vnet_hdr = 0;
179 
180         if (vnet_hdr_required && !*vnet_hdr) {
181             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
182                        "support for IFF_VNET_HDR available");
183             goto error;
184         }
185     }
186     if (mq_required) {
187         error_setg(errp, "mq_required requested, but no kernel support"
188                    " for IFF_MULTI_QUEUE available");
189         goto error;
190     }
191 
192     g_unix_set_fd_nonblocking(fd, true, NULL);
193     return fd;
194 
195 error:
196     close(fd);
197     return -1;
198 }
199 #endif /* __FreeBSD__ */
200 
201 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
202 {
203 }
204 
205 int tap_probe_vnet_hdr(int fd, Error **errp)
206 {
207     return 0;
208 }
209 
210 int tap_probe_has_ufo(int fd)
211 {
212     return 0;
213 }
214 
215 int tap_probe_has_uso(int fd)
216 {
217     return 0;
218 }
219 
220 int tap_probe_vnet_hdr_len(int fd, int len)
221 {
222     return 0;
223 }
224 
225 void tap_fd_set_vnet_hdr_len(int fd, int len)
226 {
227 }
228 
229 int tap_fd_set_vnet_le(int fd, int is_le)
230 {
231     return -EINVAL;
232 }
233 
234 int tap_fd_set_vnet_be(int fd, int is_be)
235 {
236     return -EINVAL;
237 }
238 
239 void tap_fd_set_offload(int fd, int csum, int tso4,
240                         int tso6, int ecn, int ufo, int uso4, int uso6)
241 {
242 }
243 
244 int tap_fd_enable(int fd)
245 {
246     return -1;
247 }
248 
249 int tap_fd_disable(int fd)
250 {
251     return -1;
252 }
253 
254 int tap_fd_get_ifname(int fd, char *ifname)
255 {
256     return -1;
257 }
258 
259 int tap_fd_set_steering_ebpf(int fd, int prog_fd)
260 {
261     return -1;
262 }
263