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 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 78 #ifdef TAPGIFNAME 79 if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) { 80 fprintf(stderr, "warning: could not get tap name: %s\n", 81 strerror(errno)); 82 return -1; 83 } 84 pstrcpy(ifname, ifname_size, ifr.ifr_name); 85 #else 86 if (fstat(fd, &s) < 0) { 87 fprintf(stderr, 88 "warning: could not stat /dev/tap: no virtual network emulation: %s\n", 89 strerror(errno)); 90 return -1; 91 } 92 dev = devname(s.st_rdev, S_IFCHR); 93 pstrcpy(ifname, ifname_size, dev); 94 #endif 95 96 if (*vnet_hdr) { 97 /* BSD doesn't have IFF_VNET_HDR */ 98 *vnet_hdr = 0; 99 100 if (vnet_hdr_required && !*vnet_hdr) { 101 error_report("vnet_hdr=1 requested, but no kernel " 102 "support for IFF_VNET_HDR available"); 103 close(fd); 104 return -1; 105 } 106 } 107 fcntl(fd, F_SETFL, O_NONBLOCK); 108 return fd; 109 } 110 111 int tap_set_sndbuf(int fd, const NetdevTapOptions *tap) 112 { 113 return 0; 114 } 115 116 int tap_probe_vnet_hdr(int fd) 117 { 118 return 0; 119 } 120 121 int tap_probe_has_ufo(int fd) 122 { 123 return 0; 124 } 125 126 int tap_probe_vnet_hdr_len(int fd, int len) 127 { 128 return 0; 129 } 130 131 void tap_fd_set_vnet_hdr_len(int fd, int len) 132 { 133 } 134 135 void tap_fd_set_offload(int fd, int csum, int tso4, 136 int tso6, int ecn, int ufo) 137 { 138 } 139 140 int tap_fd_enable(int fd) 141 { 142 return -1; 143 } 144 145 int tap_fd_disable(int fd) 146 { 147 return -1; 148 } 149 150 int tap_fd_get_ifname(int fd, char *ifname) 151 { 152 return -1; 153 } 154