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 "qemu/osdep.h" 26 #include "qemu-common.h" 27 #include "qapi/error.h" 28 #include "tap_int.h" 29 #include "qemu/cutils.h" 30 #include "sysemu/sysemu.h" 31 #include "qemu/error-report.h" 32 33 #if defined(__NetBSD__) || defined(__FreeBSD__) 34 #include <sys/ioctl.h> 35 #include <net/if.h> 36 #include <net/if_tap.h> 37 #endif 38 39 #if defined(__OpenBSD__) 40 #include <sys/param.h> 41 #endif 42 43 #ifndef __FreeBSD__ 44 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, 45 int vnet_hdr_required, int mq_required, Error **errp) 46 { 47 int fd; 48 #ifdef TAPGIFNAME 49 struct ifreq ifr; 50 #else 51 char *dev; 52 struct stat s; 53 #endif 54 55 /* if no ifname is given, always start the search from tap0/tun0. */ 56 int i; 57 char dname[100]; 58 59 for (i = 0; i < 10; i++) { 60 if (*ifname) { 61 snprintf(dname, sizeof dname, "/dev/%s", ifname); 62 } else { 63 #if defined(__OpenBSD__) && OpenBSD < 201605 64 snprintf(dname, sizeof dname, "/dev/tun%d", i); 65 #else 66 snprintf(dname, sizeof dname, "/dev/tap%d", i); 67 #endif 68 } 69 TFR(fd = open(dname, O_RDWR)); 70 if (fd >= 0) { 71 break; 72 } 73 else if (errno == ENXIO || errno == ENOENT) { 74 break; 75 } 76 if (*ifname) { 77 break; 78 } 79 } 80 if (fd < 0) { 81 error_setg_errno(errp, errno, "could not open %s", dname); 82 return -1; 83 } 84 85 #ifdef TAPGIFNAME 86 if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) { 87 error_setg_errno(errp, errno, "could not get tap name"); 88 return -1; 89 } 90 pstrcpy(ifname, ifname_size, ifr.ifr_name); 91 #else 92 if (fstat(fd, &s) < 0) { 93 error_setg_errno(errp, errno, "could not stat %s", dname); 94 return -1; 95 } 96 dev = devname(s.st_rdev, S_IFCHR); 97 pstrcpy(ifname, ifname_size, dev); 98 #endif 99 100 if (*vnet_hdr) { 101 /* BSD doesn't have IFF_VNET_HDR */ 102 *vnet_hdr = 0; 103 104 if (vnet_hdr_required && !*vnet_hdr) { 105 error_setg(errp, "vnet_hdr=1 requested, but no kernel " 106 "support for IFF_VNET_HDR available"); 107 close(fd); 108 return -1; 109 } 110 } 111 fcntl(fd, F_SETFL, O_NONBLOCK); 112 return fd; 113 } 114 115 #else /* __FreeBSD__ */ 116 117 #define PATH_NET_TAP "/dev/tap" 118 119 static int tap_open_clone(char *ifname, int ifname_size, Error **errp) 120 { 121 int fd, s, ret; 122 struct ifreq ifr; 123 124 TFR(fd = open(PATH_NET_TAP, O_RDWR)); 125 if (fd < 0) { 126 error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP); 127 return -1; 128 } 129 130 memset(&ifr, 0, sizeof(ifr)); 131 132 ret = ioctl(fd, TAPGIFNAME, (void *)&ifr); 133 if (ret < 0) { 134 error_setg_errno(errp, errno, "could not get tap interface name"); 135 close(fd); 136 return -1; 137 } 138 139 if (ifname[0] != '\0') { 140 /* User requested the interface to have a specific name */ 141 s = socket(AF_LOCAL, SOCK_DGRAM, 0); 142 if (s < 0) { 143 error_setg_errno(errp, errno, 144 "could not open socket to set interface name"); 145 close(fd); 146 return -1; 147 } 148 ifr.ifr_data = ifname; 149 ret = ioctl(s, SIOCSIFNAME, (void *)&ifr); 150 close(s); 151 if (ret < 0) { 152 error_setg(errp, "could not set tap interface name"); 153 close(fd); 154 return -1; 155 } 156 } else { 157 pstrcpy(ifname, ifname_size, ifr.ifr_name); 158 } 159 160 return fd; 161 } 162 163 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, 164 int vnet_hdr_required, int mq_required, Error **errp) 165 { 166 int fd = -1; 167 168 /* If the specified tap device already exists just use it. */ 169 if (ifname[0] != '\0') { 170 char dname[100]; 171 snprintf(dname, sizeof dname, "/dev/%s", ifname); 172 TFR(fd = open(dname, O_RDWR)); 173 if (fd < 0 && errno != ENOENT) { 174 error_setg_errno(errp, errno, "could not open %s", dname); 175 return -1; 176 } 177 } 178 179 if (fd < 0) { 180 /* Tap device not specified or does not exist. */ 181 if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) { 182 return -1; 183 } 184 } 185 186 if (*vnet_hdr) { 187 /* BSD doesn't have IFF_VNET_HDR */ 188 *vnet_hdr = 0; 189 190 if (vnet_hdr_required && !*vnet_hdr) { 191 error_setg(errp, "vnet_hdr=1 requested, but no kernel " 192 "support for IFF_VNET_HDR available"); 193 goto error; 194 } 195 } 196 if (mq_required) { 197 error_setg(errp, "mq_required requested, but no kernel support" 198 " for IFF_MULTI_QUEUE available"); 199 goto error; 200 } 201 202 fcntl(fd, F_SETFL, O_NONBLOCK); 203 return fd; 204 205 error: 206 close(fd); 207 return -1; 208 } 209 #endif /* __FreeBSD__ */ 210 211 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp) 212 { 213 } 214 215 int tap_probe_vnet_hdr(int fd) 216 { 217 return 0; 218 } 219 220 int tap_probe_has_ufo(int fd) 221 { 222 return 0; 223 } 224 225 int tap_probe_vnet_hdr_len(int fd, int len) 226 { 227 return 0; 228 } 229 230 void tap_fd_set_vnet_hdr_len(int fd, int len) 231 { 232 } 233 234 int tap_fd_set_vnet_le(int fd, int is_le) 235 { 236 return -EINVAL; 237 } 238 239 int tap_fd_set_vnet_be(int fd, int is_be) 240 { 241 return -EINVAL; 242 } 243 244 void tap_fd_set_offload(int fd, int csum, int tso4, 245 int tso6, int ecn, int ufo) 246 { 247 } 248 249 int tap_fd_enable(int fd) 250 { 251 return -1; 252 } 253 254 int tap_fd_disable(int fd) 255 { 256 return -1; 257 } 258 259 int tap_fd_get_ifname(int fd, char *ifname) 260 { 261 return -1; 262 } 263