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 "qemu/error-report.h" 30 31 #if defined(__NetBSD__) || defined(__FreeBSD__) 32 #include <sys/ioctl.h> 33 #include <net/if.h> 34 #include <net/if_tap.h> 35 #endif 36 37 #ifndef __FreeBSD__ 38 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, 39 int vnet_hdr_required, int mq_required, Error **errp) 40 { 41 int fd; 42 #ifdef TAPGIFNAME 43 struct ifreq ifr; 44 #else 45 char *dev; 46 struct stat s; 47 #endif 48 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 snprintf(dname, sizeof dname, "/dev/tap%d", i); 58 } 59 fd = RETRY_ON_EINTR(open(dname, O_RDWR)); 60 if (fd >= 0) { 61 break; 62 } 63 else if (errno == ENXIO || errno == ENOENT) { 64 break; 65 } 66 if (*ifname) { 67 break; 68 } 69 } 70 if (fd < 0) { 71 error_setg_errno(errp, errno, "could not open %s", dname); 72 return -1; 73 } 74 75 #ifdef TAPGIFNAME 76 if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) { 77 error_setg_errno(errp, errno, "could not get tap name"); 78 return -1; 79 } 80 pstrcpy(ifname, ifname_size, ifr.ifr_name); 81 #else 82 if (fstat(fd, &s) < 0) { 83 error_setg_errno(errp, errno, "could not stat %s", dname); 84 return -1; 85 } 86 dev = devname(s.st_rdev, S_IFCHR); 87 pstrcpy(ifname, ifname_size, dev); 88 #endif 89 90 if (*vnet_hdr) { 91 /* BSD doesn't have IFF_VNET_HDR */ 92 *vnet_hdr = 0; 93 94 if (vnet_hdr_required && !*vnet_hdr) { 95 error_setg(errp, "vnet_hdr=1 requested, but no kernel " 96 "support for IFF_VNET_HDR available"); 97 close(fd); 98 return -1; 99 } 100 } 101 g_unix_set_fd_nonblocking(fd, true, NULL); 102 return fd; 103 } 104 105 #else /* __FreeBSD__ */ 106 107 #define PATH_NET_TAP "/dev/tap" 108 109 static int tap_open_clone(char *ifname, int ifname_size, Error **errp) 110 { 111 int fd, s, ret; 112 struct ifreq ifr; 113 114 fd = RETRY_ON_EINTR(open(PATH_NET_TAP, O_RDWR)); 115 if (fd < 0) { 116 error_setg_errno(errp, errno, "could not open %s", PATH_NET_TAP); 117 return -1; 118 } 119 120 memset(&ifr, 0, sizeof(ifr)); 121 122 ret = ioctl(fd, TAPGIFNAME, (void *)&ifr); 123 if (ret < 0) { 124 error_setg_errno(errp, errno, "could not get tap interface name"); 125 close(fd); 126 return -1; 127 } 128 129 if (ifname[0] != '\0') { 130 /* User requested the interface to have a specific name */ 131 s = socket(AF_LOCAL, SOCK_DGRAM, 0); 132 if (s < 0) { 133 error_setg_errno(errp, errno, 134 "could not open socket to set interface name"); 135 close(fd); 136 return -1; 137 } 138 ifr.ifr_data = ifname; 139 ret = ioctl(s, SIOCSIFNAME, (void *)&ifr); 140 close(s); 141 if (ret < 0) { 142 error_setg(errp, "could not set tap interface name"); 143 close(fd); 144 return -1; 145 } 146 } else { 147 pstrcpy(ifname, ifname_size, ifr.ifr_name); 148 } 149 150 return fd; 151 } 152 153 int tap_open(char *ifname, int ifname_size, int *vnet_hdr, 154 int vnet_hdr_required, int mq_required, Error **errp) 155 { 156 int fd = -1; 157 158 /* If the specified tap device already exists just use it. */ 159 if (ifname[0] != '\0') { 160 char dname[100]; 161 snprintf(dname, sizeof dname, "/dev/%s", ifname); 162 fd = RETRY_ON_EINTR(open(dname, O_RDWR)); 163 if (fd < 0 && errno != ENOENT) { 164 error_setg_errno(errp, errno, "could not open %s", dname); 165 return -1; 166 } 167 } 168 169 if (fd < 0) { 170 /* Tap device not specified or does not exist. */ 171 if ((fd = tap_open_clone(ifname, ifname_size, errp)) < 0) { 172 return -1; 173 } 174 } 175 176 if (*vnet_hdr) { 177 /* BSD doesn't have IFF_VNET_HDR */ 178 *vnet_hdr = 0; 179 180 if (vnet_hdr_required && !*vnet_hdr) { 181 error_setg(errp, "vnet_hdr=1 requested, but no kernel " 182 "support for IFF_VNET_HDR available"); 183 goto error; 184 } 185 } 186 if (mq_required) { 187 error_setg(errp, "mq_required requested, but no kernel support" 188 " for IFF_MULTI_QUEUE available"); 189 goto error; 190 } 191 192 g_unix_set_fd_nonblocking(fd, true, NULL); 193 return fd; 194 195 error: 196 close(fd); 197 return -1; 198 } 199 #endif /* __FreeBSD__ */ 200 201 void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp) 202 { 203 } 204 205 int tap_probe_vnet_hdr(int fd, Error **errp) 206 { 207 return 0; 208 } 209 210 int tap_probe_has_ufo(int fd) 211 { 212 return 0; 213 } 214 215 int tap_probe_has_uso(int fd) 216 { 217 return 0; 218 } 219 220 void tap_fd_set_vnet_hdr_len(int fd, int len) 221 { 222 } 223 224 int tap_fd_set_vnet_le(int fd, int is_le) 225 { 226 return -EINVAL; 227 } 228 229 int tap_fd_set_vnet_be(int fd, int is_be) 230 { 231 return -EINVAL; 232 } 233 234 void tap_fd_set_offload(int fd, int csum, int tso4, 235 int tso6, int ecn, int ufo, int uso4, int uso6) 236 { 237 } 238 239 int tap_fd_enable(int fd) 240 { 241 return -1; 242 } 243 244 int tap_fd_disable(int fd) 245 { 246 return -1; 247 } 248 249 int tap_fd_get_ifname(int fd, char *ifname) 250 { 251 return -1; 252 } 253 254 int tap_fd_set_steering_ebpf(int fd, int prog_fd) 255 { 256 return -1; 257 } 258