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