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 <net/if_tap.h> 32 #endif 33 34 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__DragonFly__) 35 #include <libutil.h> 36 #else 37 #include <util.h> 38 #endif 39 40 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required) 41 { 42 int fd; 43 char *dev; 44 struct stat s; 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, "warning: could not open /dev/tap: no virtual network emulation\n"); 81 return -1; 82 } 83 #endif 84 85 fstat(fd, &s); 86 dev = devname(s.st_rdev, S_IFCHR); 87 pstrcpy(ifname, ifname_size, dev); 88 89 if (*vnet_hdr) { 90 /* BSD doesn't have IFF_VNET_HDR */ 91 *vnet_hdr = 0; 92 93 if (vnet_hdr_required && !*vnet_hdr) { 94 error_report("vnet_hdr=1 requested, but no kernel " 95 "support for IFF_VNET_HDR available"); 96 close(fd); 97 return -1; 98 } 99 } 100 fcntl(fd, F_SETFL, O_NONBLOCK); 101 return fd; 102 } 103 104 int tap_set_sndbuf(int fd, QemuOpts *opts) 105 { 106 return 0; 107 } 108 109 int tap_probe_vnet_hdr(int fd) 110 { 111 return 0; 112 } 113 114 int tap_probe_has_ufo(int fd) 115 { 116 return 0; 117 } 118 119 int tap_probe_vnet_hdr_len(int fd, int len) 120 { 121 return 0; 122 } 123 124 void tap_fd_set_vnet_hdr_len(int fd, int len) 125 { 126 } 127 128 void tap_fd_set_offload(int fd, int csum, int tso4, 129 int tso6, int ecn, int ufo) 130 { 131 } 132