xref: /openbmc/qemu/net/tap-bsd.c (revision 8e6fe6b8) 
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 "qemu-common.h"
27 #include "qapi/error.h"
28 #include "tap_int.h"
29 #include "qemu/cutils.h"
30 #include "sysemu/sysemu.h"
31 #include "qemu/error-report.h"
32 
33 #if defined(__NetBSD__) || defined(__FreeBSD__)
34 #include <sys/ioctl.h>
35 #include <net/if.h>
36 #include <net/if_tap.h>
37 #endif
38 
39 #if defined(__OpenBSD__)
40 #include <sys/param.h>
41 #endif
42 
43 #ifndef __FreeBSD__
44 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
45              int vnet_hdr_required, int mq_required, Error **errp)
46 {
47     int fd;
48 #ifdef TAPGIFNAME
49     struct ifreq ifr;
50 #else
51     char *dev;
52     struct stat s;
53 #endif
54 
55     /* if no ifname is given, always start the search from tap0/tun0. */
56     int i;
57     char dname[100];
58 
59     for (i = 0; i < 10; i++) {
60         if (*ifname) {
61             snprintf(dname, sizeof dname, "/dev/%s", ifname);
62         } else {
63 #if defined(__OpenBSD__) && OpenBSD < 201605
64             snprintf(dname, sizeof dname, "/dev/tun%d", i);
65 #else
66             snprintf(dname, sizeof dname, "/dev/tap%d", i);
67 #endif
68         }
69         TFR(fd = open(dname, O_RDWR));
70         if (fd >= 0) {
71             break;
72         }
73         else if (errno == ENXIO || errno == ENOENT) {
74             break;
75         }
76         if (*ifname) {
77             break;
78         }
79     }
80     if (fd < 0) {
81         error_setg_errno(errp, errno, "could not open %s", dname);
82         return -1;
83     }
84 
85 #ifdef TAPGIFNAME
86     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
87         error_setg_errno(errp, errno, "could not get tap name");
88         return -1;
89     }
90     pstrcpy(ifname, ifname_size, ifr.ifr_name);
91 #else
92     if (fstat(fd, &s) < 0) {
93         error_setg_errno(errp, errno, "could not stat %s", dname);
94         return -1;
95     }
96     dev = devname(s.st_rdev, S_IFCHR);
97     pstrcpy(ifname, ifname_size, dev);
98 #endif
99 
100     if (*vnet_hdr) {
101         /* BSD doesn't have IFF_VNET_HDR */
102         *vnet_hdr = 0;
103 
104         if (vnet_hdr_required && !*vnet_hdr) {
105             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
106                        "support for IFF_VNET_HDR available");
107             close(fd);
108             return -1;
109         }
110     }
111     fcntl(fd, F_SETFL, O_NONBLOCK);
112     return fd;
113 }
114 
115 #else /* __FreeBSD__ */
116 
117 #define PATH_NET_TAP "/dev/tap"
118 
119 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
120 {
121     int fd, s, ret;
122     struct ifreq ifr;
123 
124     TFR(fd = open(PATH_NET_TAP, O_RDWR));
125     if (fd < 0) {
126         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
127         return -1;
128     }
129 
130     memset(&ifr, 0, sizeof(ifr));
131 
132     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
133     if (ret < 0) {
134         error_setg_errno(errp, errno, "could not get tap interface name");
135         close(fd);
136         return -1;
137     }
138 
139     if (ifname[0] != '\0') {
140         /* User requested the interface to have a specific name */
141         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
142         if (s < 0) {
143             error_setg_errno(errp, errno,
144                              "could not open socket to set interface name");
145             close(fd);
146             return -1;
147         }
148         ifr.ifr_data = ifname;
149         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
150         close(s);
151         if (ret < 0) {
152             error_setg(errp, "could not set tap interface name");
153             close(fd);
154             return -1;
155         }
156     } else {
157         pstrcpy(ifname, ifname_size, ifr.ifr_name);
158     }
159 
160     return fd;
161 }
162 
163 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
164              int vnet_hdr_required, int mq_required, Error **errp)
165 {
166     int fd = -1;
167 
168     /* If the specified tap device already exists just use it. */
169     if (ifname[0] != '\0') {
170         char dname[100];
171         snprintf(dname, sizeof dname, "/dev/%s", ifname);
172         TFR(fd = open(dname, O_RDWR));
173         if (fd < 0 && errno != ENOENT) {
174             error_setg_errno(errp, errno, "could not open %s", dname);
175             return -1;
176         }
177     }
178 
179     if (fd < 0) {
180         /* Tap device not specified or does not exist. */
181         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
182             return -1;
183         }
184     }
185 
186     if (*vnet_hdr) {
187         /* BSD doesn't have IFF_VNET_HDR */
188         *vnet_hdr = 0;
189 
190         if (vnet_hdr_required && !*vnet_hdr) {
191             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
192                        "support for IFF_VNET_HDR available");
193             goto error;
194         }
195     }
196     if (mq_required) {
197         error_setg(errp, "mq_required requested, but no kernel support"
198                    " for IFF_MULTI_QUEUE available");
199         goto error;
200     }
201 
202     fcntl(fd, F_SETFL, O_NONBLOCK);
203     return fd;
204 
205 error:
206     close(fd);
207     return -1;
208 }
209 #endif /* __FreeBSD__ */
210 
211 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
212 {
213 }
214 
215 int tap_probe_vnet_hdr(int fd)
216 {
217     return 0;
218 }
219 
220 int tap_probe_has_ufo(int fd)
221 {
222     return 0;
223 }
224 
225 int tap_probe_vnet_hdr_len(int fd, int len)
226 {
227     return 0;
228 }
229 
230 void tap_fd_set_vnet_hdr_len(int fd, int len)
231 {
232 }
233 
234 int tap_fd_set_vnet_le(int fd, int is_le)
235 {
236     return -EINVAL;
237 }
238 
239 int tap_fd_set_vnet_be(int fd, int is_be)
240 {
241     return -EINVAL;
242 }
243 
244 void tap_fd_set_offload(int fd, int csum, int tso4,
245                         int tso6, int ecn, int ufo)
246 {
247 }
248 
249 int tap_fd_enable(int fd)
250 {
251     return -1;
252 }
253 
254 int tap_fd_disable(int fd)
255 {
256     return -1;
257 }
258 
259 int tap_fd_get_ifname(int fd, char *ifname)
260 {
261     return -1;
262 }
263