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 "tap_int.h" 26 #include "qemu-common.h" 27 #include "sysemu/sysemu.h" 28 #include "qemu/error-report.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, 37 int vnet_hdr_required, int mq_required) 38 { 39 int fd; 40 #ifdef TAPGIFNAME 41 struct ifreq ifr; 42 #else 43 char *dev; 44 struct stat s; 45 #endif 46 47 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || \ 48 defined(__OpenBSD__) || defined(__APPLE__) 49 /* if no ifname is given, always start the search from tap0/tun0. */ 50 int i; 51 char dname[100]; 52 53 for (i = 0; i < 10; i++) { 54 if (*ifname) { 55 snprintf(dname, sizeof dname, "/dev/%s", ifname); 56 } else { 57 #if defined(__OpenBSD__) 58 snprintf(dname, sizeof dname, "/dev/tun%d", i); 59 #else 60 snprintf(dname, sizeof dname, "/dev/tap%d", i); 61 #endif 62 } 63 TFR(fd = open(dname, O_RDWR)); 64 if (fd >= 0) { 65 break; 66 } 67 else if (errno == ENXIO || errno == ENOENT) { 68 break; 69 } 70 if (*ifname) { 71 break; 72 } 73 } 74 if (fd < 0) { 75 error_report("warning: could not open %s (%s): no virtual network emulation", 76 dname, strerror(errno)); 77 return -1; 78 } 79 #else 80 TFR(fd = open("/dev/tap", O_RDWR)); 81 if (fd < 0) { 82 fprintf(stderr, 83 "warning: could not open /dev/tap: no virtual network emulation: %s\n", 84 strerror(errno)); 85 return -1; 86 } 87 #endif 88 89 #ifdef TAPGIFNAME 90 if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) { 91 fprintf(stderr, "warning: could not get tap name: %s\n", 92 strerror(errno)); 93 return -1; 94 } 95 pstrcpy(ifname, ifname_size, ifr.ifr_name); 96 #else 97 if (fstat(fd, &s) < 0) { 98 fprintf(stderr, 99 "warning: could not stat /dev/tap: no virtual network emulation: %s\n", 100 strerror(errno)); 101 return -1; 102 } 103 dev = devname(s.st_rdev, S_IFCHR); 104 pstrcpy(ifname, ifname_size, dev); 105 #endif 106 107 if (*vnet_hdr) { 108 /* BSD doesn't have IFF_VNET_HDR */ 109 *vnet_hdr = 0; 110 111 if (vnet_hdr_required && !*vnet_hdr) { 112 error_report("vnet_hdr=1 requested, but no kernel " 113 "support for IFF_VNET_HDR available"); 114 close(fd); 115 return -1; 116 } 117 } 118 fcntl(fd, F_SETFL, O_NONBLOCK); 119 return fd; 120 } 121 122 int tap_set_sndbuf(int fd, const NetdevTapOptions *tap) 123 { 124 return 0; 125 } 126 127 int tap_probe_vnet_hdr(int fd) 128 { 129 return 0; 130 } 131 132 int tap_probe_has_ufo(int fd) 133 { 134 return 0; 135 } 136 137 int tap_probe_vnet_hdr_len(int fd, int len) 138 { 139 return 0; 140 } 141 142 void tap_fd_set_vnet_hdr_len(int fd, int len) 143 { 144 } 145 146 void tap_fd_set_offload(int fd, int csum, int tso4, 147 int tso6, int ecn, int ufo) 148 { 149 } 150 151 int tap_fd_enable(int fd) 152 { 153 return -1; 154 } 155 156 int tap_fd_disable(int fd) 157 { 158 return -1; 159 } 160 161 int tap_fd_get_ifname(int fd, char *ifname) 162 { 163 return -1; 164 } 165