1 /* 2 * getether.c : get the ethernet address of an interface 3 * 4 * All of this code is quite system-specific. As you may well 5 * guess, it took a good bit of detective work to figure out! 6 * 7 * If you figure out how to do this on another system, 8 * please let me know. <gwr@mc.com> 9 * 10 * $FreeBSD$ 11 */ 12 13 #include <sys/types.h> 14 #include <sys/socket.h> 15 16 #ifndef NO_UNISTD 17 #include <unistd.h> 18 #endif 19 20 #include <ctype.h> 21 #include <paths.h> 22 #include <string.h> 23 #include <syslog.h> 24 25 #include "getether.h" 26 #include "report.h" 27 #define EALEN 6 28 29 #if defined(ultrix) || (defined(__osf__) && defined(__alpha)) 30 /* 31 * This is really easy on Ultrix! Thanks to 32 * Harald Lundberg <hl@tekla.fi> for this code. 33 * 34 * The code here is not specific to the Alpha, but that was the 35 * only symbol we could find to identify DEC's version of OSF. 36 * (Perhaps we should just define DEC in the Makefile... -gwr) 37 */ 38 39 #include <sys/ioctl.h> 40 #include <net/if.h> /* struct ifdevea */ 41 42 getether(ifname, eap) 43 char *ifname, *eap; 44 { 45 int rc = -1; 46 int fd; 47 struct ifdevea phys; 48 bzero(&phys, sizeof(phys)); 49 strcpy(phys.ifr_name, ifname); 50 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 51 report(LOG_ERR, "getether: socket(INET,DGRAM) failed"); 52 return -1; 53 } 54 if (ioctl(fd, SIOCRPHYSADDR, &phys) < 0) { 55 report(LOG_ERR, "getether: ioctl SIOCRPHYSADDR failed"); 56 } else { 57 bcopy(&phys.current_pa[0], eap, EALEN); 58 rc = 0; 59 } 60 close(fd); 61 return rc; 62 } 63 64 #define GETETHER 65 #endif /* ultrix|osf1 */ 66 67 68 #ifdef SUNOS 69 70 #include <sys/sockio.h> 71 #include <sys/time.h> /* needed by net_if.h */ 72 #include <net/nit_if.h> /* for NIOCBIND */ 73 #include <net/if.h> /* for struct ifreq */ 74 75 getether(ifname, eap) 76 char *ifname; /* interface name from ifconfig structure */ 77 char *eap; /* Ether address (output) */ 78 { 79 int rc = -1; 80 81 struct ifreq ifrnit; 82 int nit; 83 84 bzero((char *) &ifrnit, sizeof(ifrnit)); 85 strlcpy(&ifrnit.ifr_name[0], ifname, IFNAMSIZ); 86 87 nit = open("/dev/nit", 0); 88 if (nit < 0) { 89 report(LOG_ERR, "getether: open /dev/nit: %s", 90 get_errmsg()); 91 return rc; 92 } 93 do { 94 if (ioctl(nit, NIOCBIND, &ifrnit) < 0) { 95 report(LOG_ERR, "getether: NIOCBIND on nit"); 96 break; 97 } 98 if (ioctl(nit, SIOCGIFADDR, &ifrnit) < 0) { 99 report(LOG_ERR, "getether: SIOCGIFADDR on nit"); 100 break; 101 } 102 bcopy(&ifrnit.ifr_addr.sa_data[0], eap, EALEN); 103 rc = 0; 104 } while (0); 105 close(nit); 106 return rc; 107 } 108 109 #define GETETHER 110 #endif /* SUNOS */ 111 112 113 #if defined(__FreeBSD__) || defined(__NetBSD__) 114 /* Thanks to John Brezak <brezak@ch.hp.com> for this code. */ 115 #include <sys/ioctl.h> 116 #include <sys/time.h> 117 #include <net/if.h> 118 #include <net/if_dl.h> 119 #include <net/if_types.h> 120 121 int 122 getether(ifname, eap) 123 char *ifname; /* interface name from ifconfig structure */ 124 char *eap; /* Ether address (output) */ 125 { 126 int fd, rc = -1; 127 int n; 128 struct ifreq ibuf[16]; 129 struct ifconf ifc; 130 struct ifreq *ifrp, *ifend; 131 132 /* Fetch the interface configuration */ 133 fd = socket(AF_INET, SOCK_DGRAM, 0); 134 if (fd < 0) { 135 report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg()); 136 return (fd); 137 } 138 ifc.ifc_len = sizeof(ibuf); 139 ifc.ifc_buf = (caddr_t) ibuf; 140 if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 || 141 ifc.ifc_len < sizeof(struct ifreq)) { 142 report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg()); 143 goto out; 144 } 145 /* Search interface configuration list for link layer address. */ 146 ifrp = ibuf; 147 ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len); 148 while (ifrp < ifend) { 149 /* Look for interface */ 150 if (strcmp(ifname, ifrp->ifr_name) == 0 && 151 ifrp->ifr_addr.sa_family == AF_LINK && 152 ((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) { 153 bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN); 154 rc = 0; 155 break; 156 } 157 /* Bump interface config pointer */ 158 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); 159 if (n < sizeof(*ifrp)) 160 n = sizeof(*ifrp); 161 ifrp = (struct ifreq *) ((char *) ifrp + n); 162 } 163 164 out: 165 close(fd); 166 return (rc); 167 } 168 169 #define GETETHER 170 #endif /* __NetBSD__ */ 171 172 173 #ifdef SVR4 174 /* 175 * This is for "Streams TCP/IP" by Lachman Associates. 176 * They sure made this cumbersome! -gwr 177 */ 178 179 #include <sys/sockio.h> 180 #include <sys/dlpi.h> 181 #include <stropts.h> 182 #include <string.h> 183 #ifndef NULL 184 #define NULL 0 185 #endif 186 187 int 188 getether(ifname, eap) 189 char *ifname; /* interface name from ifconfig structure */ 190 char *eap; /* Ether address (output) */ 191 { 192 int rc = -1; 193 char devname[32]; 194 char tmpbuf[sizeof(union DL_primitives) + 16]; 195 struct strbuf cbuf; 196 int fd, flags; 197 union DL_primitives *dlp; 198 char *enaddr; 199 int unit = -1; /* which unit to attach */ 200 201 snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname); 202 fd = open(devname, 2); 203 if (fd < 0) { 204 /* Try without the trailing digit. */ 205 char *p = devname + 5; 206 while (isalpha(*p)) 207 p++; 208 if (isdigit(*p)) { 209 unit = *p - '0'; 210 *p = '\0'; 211 } 212 fd = open(devname, 2); 213 if (fd < 0) { 214 report(LOG_ERR, "getether: open %s: %s", 215 devname, get_errmsg()); 216 return rc; 217 } 218 } 219 #ifdef DL_ATTACH_REQ 220 /* 221 * If this is a "Style 2" DLPI, then we must "attach" first 222 * to tell the driver which unit (board, port) we want. 223 * For now, decide this based on the device name. 224 * (Should do "info_req" and check dl_provider_style ...) 225 */ 226 if (unit >= 0) { 227 memset(tmpbuf, 0, sizeof(tmpbuf)); 228 dlp = (union DL_primitives *) tmpbuf; 229 dlp->dl_primitive = DL_ATTACH_REQ; 230 dlp->attach_req.dl_ppa = unit; 231 cbuf.buf = tmpbuf; 232 cbuf.len = DL_ATTACH_REQ_SIZE; 233 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 234 report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg()); 235 goto out; 236 } 237 /* Recv the ack. */ 238 cbuf.buf = tmpbuf; 239 cbuf.maxlen = sizeof(tmpbuf); 240 flags = 0; 241 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 242 report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg()); 243 goto out; 244 } 245 /* 246 * Check the type, etc. 247 */ 248 if (dlp->dl_primitive == DL_ERROR_ACK) { 249 report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d", 250 dlp->error_ack.dl_errno, 251 dlp->error_ack.dl_unix_errno); 252 goto out; 253 } 254 if (dlp->dl_primitive != DL_OK_ACK) { 255 report(LOG_ERR, "getether: attach: not OK or ERROR"); 256 goto out; 257 } 258 } /* unit >= 0 */ 259 #endif /* DL_ATTACH_REQ */ 260 261 /* 262 * Get the Ethernet address the same way the ARP module 263 * does when it is pushed onto a new stream (bind). 264 * One should instead be able just do a dl_info_req 265 * but many drivers do not supply the hardware address 266 * in the response to dl_info_req (they MUST supply it 267 * for dl_bind_ack because the ARP module requires it). 268 */ 269 memset(tmpbuf, 0, sizeof(tmpbuf)); 270 dlp = (union DL_primitives *) tmpbuf; 271 dlp->dl_primitive = DL_BIND_REQ; 272 dlp->bind_req.dl_sap = 0x8FF; /* XXX - Unused SAP */ 273 cbuf.buf = tmpbuf; 274 cbuf.len = DL_BIND_REQ_SIZE; 275 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 276 report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg()); 277 goto out; 278 } 279 /* Recv the ack. */ 280 cbuf.buf = tmpbuf; 281 cbuf.maxlen = sizeof(tmpbuf); 282 flags = 0; 283 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 284 report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg()); 285 goto out; 286 } 287 /* 288 * Check the type, etc. 289 */ 290 if (dlp->dl_primitive == DL_ERROR_ACK) { 291 report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d", 292 dlp->error_ack.dl_errno, 293 dlp->error_ack.dl_unix_errno); 294 goto out; 295 } 296 if (dlp->dl_primitive != DL_BIND_ACK) { 297 report(LOG_ERR, "getether: bind: not OK or ERROR"); 298 goto out; 299 } 300 if (dlp->bind_ack.dl_addr_offset == 0) { 301 report(LOG_ERR, "getether: bind: ack has no address"); 302 goto out; 303 } 304 if (dlp->bind_ack.dl_addr_length < EALEN) { 305 report(LOG_ERR, "getether: bind: ack address truncated"); 306 goto out; 307 } 308 /* 309 * Copy the Ethernet address out of the message. 310 */ 311 enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset; 312 memcpy(eap, enaddr, EALEN); 313 rc = 0; 314 315 out: 316 close(fd); 317 return rc; 318 } 319 320 #define GETETHER 321 #endif /* SVR4 */ 322 323 324 #ifdef __linux__ 325 /* 326 * This is really easy on Linux! This version (for linux) 327 * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and 328 * updated by Pauline Middelink <middelin@polyware.iaf.nl> 329 * 330 * The code is almost identical to the Ultrix code - however 331 * the names are different to confuse the innocent :-) 332 * Most of this code was stolen from the Ultrix bit above. 333 */ 334 335 #include <memory.h> 336 #include <sys/ioctl.h> 337 #include <net/if.h> /* struct ifreq */ 338 #include <sys/socketio.h> /* Needed for IOCTL defs */ 339 340 int 341 getether(ifname, eap) 342 char *ifname, *eap; 343 { 344 int rc = -1; 345 int fd; 346 struct ifreq phys; 347 348 memset(&phys, 0, sizeof(phys)); 349 strcpy(phys.ifr_name, ifname); 350 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 351 report(LOG_ERR, "getether: socket(INET,DGRAM) failed"); 352 return -1; 353 } 354 if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) { 355 report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed"); 356 } else { 357 memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN); 358 rc = 0; 359 } 360 close(fd); 361 return rc; 362 } 363 364 #define GETETHER 365 #endif /* __linux__ */ 366 367 368 /* If we don't know how on this system, just return an error. */ 369 #ifndef GETETHER 370 int 371 getether(ifname, eap) 372 char *ifname, *eap; 373 { 374 return -1; 375 } 376 377 #endif /* !GETETHER */ 378 379 /* 380 * Local Variables: 381 * tab-width: 4 382 * c-indent-level: 4 383 * c-argdecl-indent: 4 384 * c-continued-statement-offset: 4 385 * c-continued-brace-offset: -4 386 * c-label-offset: -4 387 * c-brace-offset: 0 388 * End: 389 */ 390