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: #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
37: #include <libutil.h>
38: #else
39: #include <util.h>
40: #endif
41:
42: int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)
43: {
44: int fd;
45: #ifdef TAPGIFNAME
46: struct ifreq ifr;
47: #else
48: char *dev;
49: struct stat s;
50: #endif
51:
52: #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
53: /* if no ifname is given, always start the search from tap0/tun0. */
54: int i;
55: char dname[100];
56:
57: for (i = 0; i < 10; i++) {
58: if (*ifname) {
59: snprintf(dname, sizeof dname, "/dev/%s", ifname);
60: } else {
61: #if defined(__OpenBSD__)
62: snprintf(dname, sizeof dname, "/dev/tun%d", i);
63: #else
64: snprintf(dname, sizeof dname, "/dev/tap%d", i);
65: #endif
66: }
67: TFR(fd = open(dname, O_RDWR));
68: if (fd >= 0) {
69: break;
70: }
71: else if (errno == ENXIO || errno == ENOENT) {
72: break;
73: }
74: if (*ifname) {
75: break;
76: }
77: }
78: if (fd < 0) {
79: error_report("warning: could not open %s (%s): no virtual network emulation",
80: dname, strerror(errno));
81: return -1;
82: }
83: #else
84: TFR(fd = open("/dev/tap", O_RDWR));
85: if (fd < 0) {
86: fprintf(stderr,
87: "warning: could not open /dev/tap: no virtual network emulation: %s\n",
88: strerror(errno));
89: return -1;
90: }
91: #endif
92:
93: #ifdef TAPGIFNAME
94: if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
95: fprintf(stderr, "warning: could not get tap name: %s\n",
96: strerror(errno));
97: return -1;
98: }
99: pstrcpy(ifname, ifname_size, ifr.ifr_name);
100: #else
101: if (fstat(fd, &s) < 0) {
102: fprintf(stderr,
103: "warning: could not stat /dev/tap: no virtual network emulation: %s\n",
104: strerror(errno));
105: return -1;
106: }
107: dev = devname(s.st_rdev, S_IFCHR);
108: pstrcpy(ifname, ifname_size, dev);
109: #endif
110:
111: if (*vnet_hdr) {
112: /* BSD doesn't have IFF_VNET_HDR */
113: *vnet_hdr = 0;
114:
115: if (vnet_hdr_required && !*vnet_hdr) {
116: error_report("vnet_hdr=1 requested, but no kernel "
117: "support for IFF_VNET_HDR available");
118: close(fd);
119: return -1;
120: }
121: }
122: fcntl(fd, F_SETFL, O_NONBLOCK);
123: return fd;
124: }
125:
126: int tap_set_sndbuf(int fd, QemuOpts *opts)
127: {
128: return 0;
129: }
130:
131: int tap_probe_vnet_hdr(int fd)
132: {
133: return 0;
134: }
135:
136: int tap_probe_has_ufo(int fd)
137: {
138: return 0;
139: }
140:
141: int tap_probe_vnet_hdr_len(int fd, int len)
142: {
143: return 0;
144: }
145:
146: void tap_fd_set_vnet_hdr_len(int fd, int len)
147: {
148: }
149:
150: void tap_fd_set_offload(int fd, int csum, int tso4,
151: int tso6, int ecn, int ufo)
152: {
153: }
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