xref: /openbmc/qemu/net/tap-bsd.c (revision d901eff3)
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 "net/tap.h"
26 #include "qemu-common.h"
27 #include "sysemu.h"
28 #include "qemu-error.h"
29 
30 #ifdef __NetBSD__
31 #include <sys/ioctl.h>
32 #include <net/if.h>
33 #include <net/if_tap.h>
34 #endif
35 
36 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
37 {
38     int fd;
39 #ifdef TAPGIFNAME
40     struct ifreq ifr;
41 #else
42     char *dev;
43     struct stat s;
44 #endif
45 
46 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
47     /* if no ifname is given, always start the search from tap0/tun0. */
48     int i;
49     char dname[100];
50 
51     for (i = 0; i < 10; i++) {
52         if (*ifname) {
53             snprintf(dname, sizeof dname, "/dev/%s", ifname);
54         } else {
55 #if defined(__OpenBSD__)
56             snprintf(dname, sizeof dname, "/dev/tun%d", i);
57 #else
58             snprintf(dname, sizeof dname, "/dev/tap%d", i);
59 #endif
60         }
61         TFR(fd = open(dname, O_RDWR));
62         if (fd >= 0) {
63             break;
64         }
65         else if (errno == ENXIO || errno == ENOENT) {
66             break;
67         }
68         if (*ifname) {
69             break;
70         }
71     }
72     if (fd < 0) {
73         error_report("warning: could not open %s (%s): no virtual network emulation",
74                    dname, strerror(errno));
75         return -1;
76     }
77 #else
78     TFR(fd = open("/dev/tap", O_RDWR));
79     if (fd < 0) {
80         fprintf(stderr,
81             "warning: could not open /dev/tap: no virtual network emulation: %s\n",
82             strerror(errno));
83         return -1;
84     }
85 #endif
86 
87 #ifdef TAPGIFNAME
88     if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
89         fprintf(stderr, "warning: could not get tap name: %s\n",
90             strerror(errno));
91         return -1;
92     }
93     pstrcpy(ifname, ifname_size, ifr.ifr_name);
94 #else
95     if (fstat(fd, &s) < 0) {
96         fprintf(stderr,
97             "warning: could not stat /dev/tap: no virtual network emulation: %s\n",
98             strerror(errno));
99         return -1;
100     }
101     dev = devname(s.st_rdev, S_IFCHR);
102     pstrcpy(ifname, ifname_size, dev);
103 #endif
104 
105     if (*vnet_hdr) {
106         /* BSD doesn't have IFF_VNET_HDR */
107         *vnet_hdr = 0;
108 
109         if (vnet_hdr_required && !*vnet_hdr) {
110             error_report("vnet_hdr=1 requested, but no kernel "
111                          "support for IFF_VNET_HDR available");
112             close(fd);
113             return -1;
114         }
115     }
116     fcntl(fd, F_SETFL, O_NONBLOCK);
117     return fd;
118 }
119 
120 int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
121 {
122     return 0;
123 }
124 
125 int tap_probe_vnet_hdr(int fd)
126 {
127     return 0;
128 }
129 
130 int tap_probe_has_ufo(int fd)
131 {
132     return 0;
133 }
134 
135 int tap_probe_vnet_hdr_len(int fd, int len)
136 {
137     return 0;
138 }
139 
140 void tap_fd_set_vnet_hdr_len(int fd, int len)
141 {
142 }
143 
144 void tap_fd_set_offload(int fd, int csum, int tso4,
145                         int tso6, int ecn, int ufo)
146 {
147 }
148