xref: /openbmc/qemu/net/tap-bsd.c (revision fee5b753)
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 "tap_int.h"
27 #include "qemu-common.h"
28 #include "sysemu/sysemu.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 #if defined(__OpenBSD__)
58             snprintf(dname, sizeof dname, "/dev/tun%d", i);
59 #else
60             snprintf(dname, sizeof dname, "/dev/tap%d", i);
61 #endif
62         }
63         TFR(fd = open(dname, O_RDWR));
64         if (fd >= 0) {
65             break;
66         }
67         else if (errno == ENXIO || errno == ENOENT) {
68             break;
69         }
70         if (*ifname) {
71             break;
72         }
73     }
74     if (fd < 0) {
75         error_setg_errno(errp, errno, "could not open %s", dname);
76         return -1;
77     }
78 
79 #ifdef TAPGIFNAME
80     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
81         error_setg_errno(errp, errno, "could not get tap name");
82         return -1;
83     }
84     pstrcpy(ifname, ifname_size, ifr.ifr_name);
85 #else
86     if (fstat(fd, &s) < 0) {
87         error_setg_errno(errp, errno, "could not stat %s", dname);
88         return -1;
89     }
90     dev = devname(s.st_rdev, S_IFCHR);
91     pstrcpy(ifname, ifname_size, dev);
92 #endif
93 
94     if (*vnet_hdr) {
95         /* BSD doesn't have IFF_VNET_HDR */
96         *vnet_hdr = 0;
97 
98         if (vnet_hdr_required && !*vnet_hdr) {
99             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
100                        "support for IFF_VNET_HDR available");
101             close(fd);
102             return -1;
103         }
104     }
105     fcntl(fd, F_SETFL, O_NONBLOCK);
106     return fd;
107 }
108 
109 #else /* __FreeBSD__ */
110 
111 #define PATH_NET_TAP "/dev/tap"
112 
113 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
114 {
115     int fd, s, ret;
116     struct ifreq ifr;
117 
118     TFR(fd = open(PATH_NET_TAP, O_RDWR));
119     if (fd < 0) {
120         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
121         return -1;
122     }
123 
124     memset(&ifr, 0, sizeof(ifr));
125 
126     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
127     if (ret < 0) {
128         error_setg_errno(errp, errno, "could not get tap interface name");
129         close(fd);
130         return -1;
131     }
132 
133     if (ifname[0] != '\0') {
134         /* User requested the interface to have a specific name */
135         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
136         if (s < 0) {
137             error_setg_errno(errp, errno,
138                              "could not open socket to set interface name");
139             close(fd);
140             return -1;
141         }
142         ifr.ifr_data = ifname;
143         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
144         close(s);
145         if (ret < 0) {
146             error_setg(errp, "could not set tap interface name");
147             close(fd);
148             return -1;
149         }
150     } else {
151         pstrcpy(ifname, ifname_size, ifr.ifr_name);
152     }
153 
154     return fd;
155 }
156 
157 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
158              int vnet_hdr_required, int mq_required, Error **errp)
159 {
160     int fd = -1;
161 
162     /* If the specified tap device already exists just use it. */
163     if (ifname[0] != '\0') {
164         char dname[100];
165         snprintf(dname, sizeof dname, "/dev/%s", ifname);
166         TFR(fd = open(dname, O_RDWR));
167         if (fd < 0 && errno != ENOENT) {
168             error_setg_errno(errp, errno, "could not open %s", dname);
169             return -1;
170         }
171     }
172 
173     if (fd < 0) {
174         /* Tap device not specified or does not exist. */
175         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
176             return -1;
177         }
178     }
179 
180     if (*vnet_hdr) {
181         /* BSD doesn't have IFF_VNET_HDR */
182         *vnet_hdr = 0;
183 
184         if (vnet_hdr_required && !*vnet_hdr) {
185             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
186                        "support for IFF_VNET_HDR available");
187             goto error;
188         }
189     }
190     if (mq_required) {
191         error_setg(errp, "mq_required requested, but no kernel support"
192                    " for IFF_MULTI_QUEUE available");
193         goto error;
194     }
195 
196     fcntl(fd, F_SETFL, O_NONBLOCK);
197     return fd;
198 
199 error:
200     close(fd);
201     return -1;
202 }
203 #endif /* __FreeBSD__ */
204 
205 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
206 {
207 }
208 
209 int tap_probe_vnet_hdr(int fd)
210 {
211     return 0;
212 }
213 
214 int tap_probe_has_ufo(int fd)
215 {
216     return 0;
217 }
218 
219 int tap_probe_vnet_hdr_len(int fd, int len)
220 {
221     return 0;
222 }
223 
224 void tap_fd_set_vnet_hdr_len(int fd, int len)
225 {
226 }
227 
228 int tap_fd_set_vnet_le(int fd, int is_le)
229 {
230     return -EINVAL;
231 }
232 
233 int tap_fd_set_vnet_be(int fd, int is_be)
234 {
235     return -EINVAL;
236 }
237 
238 void tap_fd_set_offload(int fd, int csum, int tso4,
239                         int tso6, int ecn, int ufo)
240 {
241 }
242 
243 int tap_fd_enable(int fd)
244 {
245     return -1;
246 }
247 
248 int tap_fd_disable(int fd)
249 {
250     return -1;
251 }
252 
253 int tap_fd_get_ifname(int fd, char *ifname)
254 {
255     return -1;
256 }
257