xref: /openbmc/qemu/net/tap-bsd.c (revision da34e65c) 
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-common.h"
29 #include "sysemu/sysemu.h"
30 #include "qemu/error-report.h"
31 
32 #if defined(__NetBSD__) || defined(__FreeBSD__)
33 #include <sys/ioctl.h>
34 #include <net/if.h>
35 #include <net/if_tap.h>
36 #endif
37 
38 #ifndef __FreeBSD__
39 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
40              int vnet_hdr_required, int mq_required, Error **errp)
41 {
42     int fd;
43 #ifdef TAPGIFNAME
44     struct ifreq ifr;
45 #else
46     char *dev;
47     struct stat s;
48 #endif
49 
50     /* if no ifname is given, always start the search from tap0/tun0. */
51     int i;
52     char dname[100];
53 
54     for (i = 0; i < 10; i++) {
55         if (*ifname) {
56             snprintf(dname, sizeof dname, "/dev/%s", ifname);
57         } else {
58 #if defined(__OpenBSD__)
59             snprintf(dname, sizeof dname, "/dev/tun%d", i);
60 #else
61             snprintf(dname, sizeof dname, "/dev/tap%d", i);
62 #endif
63         }
64         TFR(fd = open(dname, O_RDWR));
65         if (fd >= 0) {
66             break;
67         }
68         else if (errno == ENXIO || errno == ENOENT) {
69             break;
70         }
71         if (*ifname) {
72             break;
73         }
74     }
75     if (fd < 0) {
76         error_setg_errno(errp, errno, "could not open %s", dname);
77         return -1;
78     }
79 
80 #ifdef TAPGIFNAME
81     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
82         error_setg_errno(errp, errno, "could not get tap name");
83         return -1;
84     }
85     pstrcpy(ifname, ifname_size, ifr.ifr_name);
86 #else
87     if (fstat(fd, &s) < 0) {
88         error_setg_errno(errp, errno, "could not stat %s", dname);
89         return -1;
90     }
91     dev = devname(s.st_rdev, S_IFCHR);
92     pstrcpy(ifname, ifname_size, dev);
93 #endif
94 
95     if (*vnet_hdr) {
96         /* BSD doesn't have IFF_VNET_HDR */
97         *vnet_hdr = 0;
98 
99         if (vnet_hdr_required && !*vnet_hdr) {
100             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
101                        "support for IFF_VNET_HDR available");
102             close(fd);
103             return -1;
104         }
105     }
106     fcntl(fd, F_SETFL, O_NONBLOCK);
107     return fd;
108 }
109 
110 #else /* __FreeBSD__ */
111 
112 #define PATH_NET_TAP "/dev/tap"
113 
114 static int tap_open_clone(char *ifname, int ifname_size, Error **errp)
115 {
116     int fd, s, ret;
117     struct ifreq ifr;
118 
119     TFR(fd = open(PATH_NET_TAP, O_RDWR));
120     if (fd < 0) {
121         error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP);
122         return -1;
123     }
124 
125     memset(&ifr, 0, sizeof(ifr));
126 
127     ret = ioctl(fd, TAPGIFNAME, (void *)&ifr);
128     if (ret < 0) {
129         error_setg_errno(errp, errno, "could not get tap interface name");
130         close(fd);
131         return -1;
132     }
133 
134     if (ifname[0] != '\0') {
135         /* User requested the interface to have a specific name */
136         s = socket(AF_LOCAL, SOCK_DGRAM, 0);
137         if (s < 0) {
138             error_setg_errno(errp, errno,
139                              "could not open socket to set interface name");
140             close(fd);
141             return -1;
142         }
143         ifr.ifr_data = ifname;
144         ret = ioctl(s, SIOCSIFNAME, (void *)&ifr);
145         close(s);
146         if (ret < 0) {
147             error_setg(errp, "could not set tap interface name");
148             close(fd);
149             return -1;
150         }
151     } else {
152         pstrcpy(ifname, ifname_size, ifr.ifr_name);
153     }
154 
155     return fd;
156 }
157 
158 int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
159              int vnet_hdr_required, int mq_required, Error **errp)
160 {
161     int fd = -1;
162 
163     /* If the specified tap device already exists just use it. */
164     if (ifname[0] != '\0') {
165         char dname[100];
166         snprintf(dname, sizeof dname, "/dev/%s", ifname);
167         TFR(fd = open(dname, O_RDWR));
168         if (fd < 0 && errno != ENOENT) {
169             error_setg_errno(errp, errno, "could not open %s", dname);
170             return -1;
171         }
172     }
173 
174     if (fd < 0) {
175         /* Tap device not specified or does not exist. */
176         if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) {
177             return -1;
178         }
179     }
180 
181     if (*vnet_hdr) {
182         /* BSD doesn't have IFF_VNET_HDR */
183         *vnet_hdr = 0;
184 
185         if (vnet_hdr_required && !*vnet_hdr) {
186             error_setg(errp, "vnet_hdr=1 requested, but no kernel "
187                        "support for IFF_VNET_HDR available");
188             goto error;
189         }
190     }
191     if (mq_required) {
192         error_setg(errp, "mq_required requested, but no kernel support"
193                    " for IFF_MULTI_QUEUE available");
194         goto error;
195     }
196 
197     fcntl(fd, F_SETFL, O_NONBLOCK);
198     return fd;
199 
200 error:
201     close(fd);
202     return -1;
203 }
204 #endif /* __FreeBSD__ */
205 
206 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp)
207 {
208 }
209 
210 int tap_probe_vnet_hdr(int fd)
211 {
212     return 0;
213 }
214 
215 int tap_probe_has_ufo(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)
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