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 } 154