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: src/libexec/bootpd/getether.c,v 1.9.2.3 2003/02/15 05:36:01 kris Exp $ 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 strncpy(&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__) || defined(__DragonFly__) 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 /* 122 * ifname - interface name from ifconfig structure 123 * eap - Ether address (output) 124 */ 125 int 126 getether(char *ifname, char *eap) 127 { 128 int fd, rc = -1; 129 int n; 130 struct ifreq ibuf[16]; 131 struct ifconf ifc; 132 struct ifreq *ifrp, *ifend; 133 134 /* Fetch the interface configuration */ 135 fd = socket(AF_INET, SOCK_DGRAM, 0); 136 if (fd < 0) { 137 report(LOG_ERR, "getether: socket %s: %s", ifname, get_errmsg()); 138 return (fd); 139 } 140 ifc.ifc_len = sizeof(ibuf); 141 ifc.ifc_buf = (caddr_t) ibuf; 142 if (ioctl(fd, SIOCGIFCONF, (char *) &ifc) < 0 || 143 ifc.ifc_len < sizeof(struct ifreq)) { 144 report(LOG_ERR, "getether: SIOCGIFCONF: %s", get_errmsg()); 145 goto out; 146 } 147 /* Search interface configuration list for link layer address. */ 148 ifrp = ibuf; 149 ifend = (struct ifreq *) ((char *) ibuf + ifc.ifc_len); 150 while (ifrp < ifend) { 151 /* Look for interface */ 152 if (strcmp(ifname, ifrp->ifr_name) == 0 && 153 ifrp->ifr_addr.sa_family == AF_LINK && 154 ((struct sockaddr_dl *) &ifrp->ifr_addr)->sdl_type == IFT_ETHER) { 155 bcopy(LLADDR((struct sockaddr_dl *) &ifrp->ifr_addr), eap, EALEN); 156 rc = 0; 157 break; 158 } 159 /* Bump interface config pointer */ 160 n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); 161 if (n < sizeof(*ifrp)) 162 n = sizeof(*ifrp); 163 ifrp = (struct ifreq *) ((char *) ifrp + n); 164 } 165 166 out: 167 close(fd); 168 return (rc); 169 } 170 171 #define GETETHER 172 #endif /* __NetBSD__ */ 173 174 175 #ifdef SVR4 176 /* 177 * This is for "Streams TCP/IP" by Lachman Associates. 178 * They sure made this cumbersome! -gwr 179 */ 180 181 #include <sys/sockio.h> 182 #include <sys/dlpi.h> 183 #include <stropts.h> 184 #include <string.h> 185 186 int 187 getether(ifname, eap) 188 char *ifname; /* interface name from ifconfig structure */ 189 char *eap; /* Ether address (output) */ 190 { 191 int rc = -1; 192 char devname[32]; 193 char tmpbuf[sizeof(union DL_primitives) + 16]; 194 struct strbuf cbuf; 195 int fd, flags; 196 union DL_primitives *dlp; 197 char *enaddr; 198 int unit = -1; /* which unit to attach */ 199 200 snprintf(devname, sizeof(devname), "%s%s", _PATH_DEV, ifname); 201 fd = open(devname, 2); 202 if (fd < 0) { 203 /* Try without the trailing digit. */ 204 char *p = devname + 5; 205 while (isalpha(*p)) 206 p++; 207 if (isdigit(*p)) { 208 unit = *p - '0'; 209 *p = '\0'; 210 } 211 fd = open(devname, 2); 212 if (fd < 0) { 213 report(LOG_ERR, "getether: open %s: %s", 214 devname, get_errmsg()); 215 return rc; 216 } 217 } 218 #ifdef DL_ATTACH_REQ 219 /* 220 * If this is a "Style 2" DLPI, then we must "attach" first 221 * to tell the driver which unit (board, port) we want. 222 * For now, decide this based on the device name. 223 * (Should do "info_req" and check dl_provider_style ...) 224 */ 225 if (unit >= 0) { 226 memset(tmpbuf, 0, sizeof(tmpbuf)); 227 dlp = (union DL_primitives *) tmpbuf; 228 dlp->dl_primitive = DL_ATTACH_REQ; 229 dlp->attach_req.dl_ppa = unit; 230 cbuf.buf = tmpbuf; 231 cbuf.len = DL_ATTACH_REQ_SIZE; 232 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 233 report(LOG_ERR, "getether: attach: putmsg: %s", get_errmsg()); 234 goto out; 235 } 236 /* Recv the ack. */ 237 cbuf.buf = tmpbuf; 238 cbuf.maxlen = sizeof(tmpbuf); 239 flags = 0; 240 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 241 report(LOG_ERR, "getether: attach: getmsg: %s", get_errmsg()); 242 goto out; 243 } 244 /* 245 * Check the type, etc. 246 */ 247 if (dlp->dl_primitive == DL_ERROR_ACK) { 248 report(LOG_ERR, "getether: attach: dlpi_errno=%d, unix_errno=%d", 249 dlp->error_ack.dl_errno, 250 dlp->error_ack.dl_unix_errno); 251 goto out; 252 } 253 if (dlp->dl_primitive != DL_OK_ACK) { 254 report(LOG_ERR, "getether: attach: not OK or ERROR"); 255 goto out; 256 } 257 } /* unit >= 0 */ 258 #endif /* DL_ATTACH_REQ */ 259 260 /* 261 * Get the Ethernet address the same way the ARP module 262 * does when it is pushed onto a new stream (bind). 263 * One should instead be able just do an dl_info_req 264 * but many drivers do not supply the hardware address 265 * in the response to dl_info_req (they MUST supply it 266 * for dl_bind_ack because the ARP module requires it). 267 */ 268 memset(tmpbuf, 0, sizeof(tmpbuf)); 269 dlp = (union DL_primitives *) tmpbuf; 270 dlp->dl_primitive = DL_BIND_REQ; 271 dlp->bind_req.dl_sap = 0x8FF; /* XXX - Unused SAP */ 272 cbuf.buf = tmpbuf; 273 cbuf.len = DL_BIND_REQ_SIZE; 274 if (putmsg(fd, &cbuf, NULL, 0) < 0) { 275 report(LOG_ERR, "getether: bind: putmsg: %s", get_errmsg()); 276 goto out; 277 } 278 /* Recv the ack. */ 279 cbuf.buf = tmpbuf; 280 cbuf.maxlen = sizeof(tmpbuf); 281 flags = 0; 282 if (getmsg(fd, &cbuf, NULL, &flags) < 0) { 283 report(LOG_ERR, "getether: bind: getmsg: %s", get_errmsg()); 284 goto out; 285 } 286 /* 287 * Check the type, etc. 288 */ 289 if (dlp->dl_primitive == DL_ERROR_ACK) { 290 report(LOG_ERR, "getether: bind: dlpi_errno=%d, unix_errno=%d", 291 dlp->error_ack.dl_errno, 292 dlp->error_ack.dl_unix_errno); 293 goto out; 294 } 295 if (dlp->dl_primitive != DL_BIND_ACK) { 296 report(LOG_ERR, "getether: bind: not OK or ERROR"); 297 goto out; 298 } 299 if (dlp->bind_ack.dl_addr_offset == 0) { 300 report(LOG_ERR, "getether: bind: ack has no address"); 301 goto out; 302 } 303 if (dlp->bind_ack.dl_addr_length < EALEN) { 304 report(LOG_ERR, "getether: bind: ack address truncated"); 305 goto out; 306 } 307 /* 308 * Copy the Ethernet address out of the message. 309 */ 310 enaddr = tmpbuf + dlp->bind_ack.dl_addr_offset; 311 memcpy(eap, enaddr, EALEN); 312 rc = 0; 313 314 out: 315 close(fd); 316 return rc; 317 } 318 319 #define GETETHER 320 #endif /* SVR4 */ 321 322 323 #ifdef __linux__ 324 /* 325 * This is really easy on Linux! This version (for linux) 326 * written by Nigel Metheringham <nigelm@ohm.york.ac.uk> and 327 * updated by Pauline Middelink <middelin@polyware.iaf.nl> 328 * 329 * The code is almost identical to the Ultrix code - however 330 * the names are different to confuse the innocent :-) 331 * Most of this code was stolen from the Ultrix bit above. 332 */ 333 334 #include <memory.h> 335 #include <sys/ioctl.h> 336 #include <net/if.h> /* struct ifreq */ 337 #include <sys/socketio.h> /* Needed for IOCTL defs */ 338 339 int 340 getether(ifname, eap) 341 char *ifname, *eap; 342 { 343 int rc = -1; 344 int fd; 345 struct ifreq phys; 346 347 memset(&phys, 0, sizeof(phys)); 348 strcpy(phys.ifr_name, ifname); 349 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 350 report(LOG_ERR, "getether: socket(INET,DGRAM) failed"); 351 return -1; 352 } 353 if (ioctl(fd, SIOCGIFHWADDR, &phys) < 0) { 354 report(LOG_ERR, "getether: ioctl SIOCGIFHWADDR failed"); 355 } else { 356 memcpy(eap, &phys.ifr_hwaddr.sa_data, EALEN); 357 rc = 0; 358 } 359 close(fd); 360 return rc; 361 } 362 363 #define GETETHER 364 #endif /* __linux__ */ 365 366 367 /* If we don't know how on this system, just return an error. */ 368 #ifndef GETETHER 369 int 370 getether(ifname, eap) 371 char *ifname, *eap; 372 { 373 return -1; 374 } 375 376 #endif /* !GETETHER */ 377