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