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(char *ifname, char *eap) 123 { 124 int fd, rc = -1; 125 int n; 126 struct ifreq ibuf[16]; 127 struct ifconf ifc; 128 struct ifreq *ifrp, *ifend; 129 130 /* Fetch the interface configuration */ 131 fd = socket(AF_INET, SOCK_DGRAM, 0); 132 if (fd < 0) { 133 report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg()); 134 return (fd); 135 } 136 ifc.ifc_len = sizeof(ibuf); 137 ifc.ifc_buf = (caddr_t) ibuf; 138 if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 || 139 ifc.ifc_len < sizeof(struct ifreq)) { 140 report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg()); 141 goto out; 142 } 143 /* Search interface configuration list for link layer address. */ 144 ifrp = ibuf; 145 ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len); 146 while (ifrp < ifend) { 147 /* Look for interface */ 148 if (strcmp(ifname, ifrp->ifr_name) == 0 && 149 ifrp->ifr_addr.sa_family == AF_LINK && 150 ((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) { 151 bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN); 152 rc = 0; 153 break; 154 } 155 /* Bump interface config pointer */ 156 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); 157 if (n < sizeof(*ifrp)) 158 n = sizeof(*ifrp); 159 ifrp = (struct ifreq *) ((char *) ifrp + n); 160 } 161 162 out: 163 close(fd); 164 return (rc); 165 } 166 167 #define GETETHER 168 #endif /* __NetBSD__ */ 169 170 171 #ifdef SVR4 172 /* 173 * This is for "Streams TCP/IP" by Lachman Associates. 174 * They sure made this cumbersome! -gwr 175 */ 176 177 #include <sys/sockio.h> 178 #include <sys/dlpi.h> 179 #include <stropts.h> 180 #include <string.h> 181 #ifndef NULL 182 #define NULL 0 183 #endif 184 185 int 186 getether(ifname, eap) 187 char *ifname; /* interface name from ifconfig structure */ 188 char *eap; /* Ether address (output) */ 189 { 190 int rc = -1; 191 char devname[32]; 192 char tmpbuf[sizeof(union DL_primitives) + 16]; 193 struct strbuf cbuf; 194 int fd, flags; 195 union DL_primitives *dlp; 196 char *enaddr; 197 int unit = -1; /* which unit to attach */ 198 199 snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname); 200 fd = open(devname, 2); 201 if (fd < 0) { 202 /* Try without the trailing digit. */ 203 char *p = devname + 5; 204 while (isalpha(*p)) 205 p++; 206 if (isdigit(*p)) { 207 unit = *p - '0'; 208 *p = '\0'; 209 } 210 fd = open(devname, 2); 211 if (fd < 0) { 212 report(LOG_ERR, "getether: open %s: %s", 213 devname, get_errmsg()); 214 return rc; 215 } 216 } 217 #ifdef DL_ATTACH_REQ 218 /* 219 * If this is a "Style 2" DLPI, then we must "attach" first 220 * to tell the driver which unit (board, port) we want. 221 * For now, decide this based on the device name. 222 * (Should do "info_req" and check dl_provider_style ...) 223 */ 224 if (unit >= 0) { 225 memset(tmpbuf, 0, sizeof(tmpbuf)); 226 dlp = (union DL_primitives *) tmpbuf; 227 dlp->dl_primitive = DL_ATTACH_REQ; 228 dlp->attach_req.dl_ppa = unit; 229 cbuf.buf = tmpbuf; 230 cbuf.len = DL_ATTACH_REQ_SIZE; 231 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 232 report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg()); 233 goto out; 234 } 235 /* Recv the ack. */ 236 cbuf.buf = tmpbuf; 237 cbuf.maxlen = sizeof(tmpbuf); 238 flags = 0; 239 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 240 report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg()); 241 goto out; 242 } 243 /* 244 * Check the type, etc. 245 */ 246 if (dlp->dl_primitive == DL_ERROR_ACK) { 247 report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d", 248 dlp->error_ack.dl_errno, 249 dlp->error_ack.dl_unix_errno); 250 goto out; 251 } 252 if (dlp->dl_primitive != DL_OK_ACK) { 253 report(LOG_ERR, "getether: attach: not OK or ERROR"); 254 goto out; 255 } 256 } /* unit >= 0 */ 257 #endif /* DL_ATTACH_REQ */ 258 259 /* 260 * Get the Ethernet address the same way the ARP module 261 * does when it is pushed onto a new stream (bind). 262 * One should instead be able just do a dl_info_req 263 * but many drivers do not supply the hardware address 264 * in the response to dl_info_req (they MUST supply it 265 * for dl_bind_ack because the ARP module requires it). 266 */ 267 memset(tmpbuf, 0, sizeof(tmpbuf)); 268 dlp = (union DL_primitives *) tmpbuf; 269 dlp->dl_primitive = DL_BIND_REQ; 270 dlp->bind_req.dl_sap = 0x8FF; /* XXX - Unused SAP */ 271 cbuf.buf = tmpbuf; 272 cbuf.len = DL_BIND_REQ_SIZE; 273 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 274 report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg()); 275 goto out; 276 } 277 /* Recv the ack. */ 278 cbuf.buf = tmpbuf; 279 cbuf.maxlen = sizeof(tmpbuf); 280 flags = 0; 281 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 282 report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg()); 283 goto out; 284 } 285 /* 286 * Check the type, etc. 287 */ 288 if (dlp->dl_primitive == DL_ERROR_ACK) { 289 report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d", 290 dlp->error_ack.dl_errno, 291 dlp->error_ack.dl_unix_errno); 292 goto out; 293 } 294 if (dlp->dl_primitive != DL_BIND_ACK) { 295 report(LOG_ERR, "getether: bind: not OK or ERROR"); 296 goto out; 297 } 298 if (dlp->bind_ack.dl_addr_offset == 0) { 299 report(LOG_ERR, "getether: bind: ack has no address"); 300 goto out; 301 } 302 if (dlp->bind_ack.dl_addr_length < EALEN) { 303 report(LOG_ERR, "getether: bind: ack address truncated"); 304 goto out; 305 } 306 /* 307 * Copy the Ethernet address out of the message. 308 */ 309 enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset; 310 memcpy(eap, enaddr, EALEN); 311 rc = 0; 312 313 out: 314 close(fd); 315 return rc; 316 } 317 318 #define GETETHER 319 #endif /* SVR4 */ 320 321 322 #ifdef __linux__ 323 /* 324 * This is really easy on Linux! This version (for linux) 325 * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and 326 * updated by Pauline Middelink <middelin@polyware.iaf.nl> 327 * 328 * The code is almost identical to the Ultrix code - however 329 * the names are different to confuse the innocent :-) 330 * Most of this code was stolen from the Ultrix bit above. 331 */ 332 333 #include <memory.h> 334 #include <sys/ioctl.h> 335 #include <net/if.h> /* struct ifreq */ 336 #include <sys/socketio.h> /* Needed for IOCTL defs */ 337 338 int 339 getether(ifname, eap) 340 char *ifname, *eap; 341 { 342 int rc = -1; 343 int fd; 344 struct ifreq phys; 345 346 memset(&phys, 0, sizeof(phys)); 347 strcpy(phys.ifr_name, ifname); 348 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 349 report(LOG_ERR, "getether: socket(INET,DGRAM) failed"); 350 return -1; 351 } 352 if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) { 353 report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed"); 354 } else { 355 memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN); 356 rc = 0; 357 } 358 close(fd); 359 return rc; 360 } 361 362 #define GETETHER 363 #endif /* __linux__ */ 364 365 366 /* If we don't know how on this system, just return an error. */ 367 #ifndef GETETHER 368 int 369 getether(ifname, eap) 370 char *ifname, *eap; 371 { 372 return -1; 373 } 374 375 #endif /* !GETETHER */ 376 377 /* 378 * Local Variables: 379 * tab-width: 4 380 * c-indent-level: 4 381 * c-argdecl-indent: 4 382 * c-continued-statement-offset: 4 383 * c-continued-brace-offset: -4 384 * c-label-offset: -4 385 * c-brace-offset: 0 386 * End: 387 */ 388