1 /* $NetBSD: bootp.c,v 1.14 1998/02/16 11:10:54 drochner Exp $ */ 2 3 /* 4 * Copyright (c) 1992 Regents of the University of California. 5 * All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL) 36 */ 37 38 #include <sys/cdefs.h> 39 40 #include <stddef.h> 41 #include <sys/types.h> 42 #include <sys/limits.h> 43 #include <sys/endian.h> 44 #include <netinet/in.h> 45 #include <netinet/in_systm.h> 46 47 #include <string.h> 48 49 #define BOOTP_DEBUGxx 50 #define SUPPORT_DHCP 51 52 #define DHCP_ENV_NOVENDOR 1 /* do not parse vendor options */ 53 #define DHCP_ENV_PXE 10 /* assume pxe vendor options */ 54 #define DHCP_ENV_FREEBSD 11 /* assume freebsd vendor options */ 55 /* set DHCP_ENV to one of the values above to export dhcp options to kenv */ 56 #define DHCP_ENV DHCP_ENV_NO_VENDOR 57 58 #include "stand.h" 59 #include "net.h" 60 #include "netif.h" 61 #include "bootp.h" 62 63 64 struct in_addr servip; 65 66 static time_t bot; 67 68 static char vm_rfc1048[4] = VM_RFC1048; 69 #ifdef BOOTP_VEND_CMU 70 static char vm_cmu[4] = VM_CMU; 71 #endif 72 73 /* Local forwards */ 74 static ssize_t bootpsend(struct iodesc *, void *, size_t); 75 static ssize_t bootprecv(struct iodesc *, void **, void **, time_t); 76 static int vend_rfc1048(u_char *, u_int); 77 #ifdef BOOTP_VEND_CMU 78 static void vend_cmu(u_char *); 79 #endif 80 81 #ifdef DHCP_ENV /* export the dhcp response to kenv */ 82 struct dhcp_opt; 83 static void setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts); 84 #else 85 #define setenv_(a, b, c) 86 #endif 87 88 #ifdef SUPPORT_DHCP 89 static char expected_dhcpmsgtype = -1, dhcp_ok; 90 struct in_addr dhcp_serverip; 91 #endif 92 struct bootp *bootp_response; 93 size_t bootp_response_size; 94 95 /* Fetch required bootp infomation */ 96 void 97 bootp(int sock, int flag) 98 { 99 void *pkt; 100 struct iodesc *d; 101 struct bootp *bp; 102 struct { 103 u_char header[HEADER_SIZE]; 104 struct bootp wbootp; 105 } wbuf; 106 struct bootp *rbootp; 107 108 #ifdef BOOTP_DEBUG 109 if (debug) 110 printf("bootp: socket=%d\n", sock); 111 #endif 112 if (!bot) 113 bot = getsecs(); 114 115 if (!(d = socktodesc(sock))) { 116 printf("bootp: bad socket. %d\n", sock); 117 return; 118 } 119 #ifdef BOOTP_DEBUG 120 if (debug) 121 printf("bootp: d=%lx\n", (long)d); 122 #endif 123 124 bp = &wbuf.wbootp; 125 bzero(bp, sizeof(*bp)); 126 127 bp->bp_op = BOOTREQUEST; 128 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 129 bp->bp_hlen = 6; 130 bp->bp_xid = htonl(d->xid); 131 MACPY(d->myea, bp->bp_chaddr); 132 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file)); 133 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 134 #ifdef SUPPORT_DHCP 135 bp->bp_vend[4] = TAG_DHCP_MSGTYPE; 136 bp->bp_vend[5] = 1; 137 bp->bp_vend[6] = DHCPDISCOVER; 138 139 /* 140 * If we are booting from PXE, we want to send the string 141 * 'PXEClient' to the DHCP server so you have the option of 142 * only responding to PXE aware dhcp requests. 143 */ 144 if (flag & BOOTP_PXE) { 145 bp->bp_vend[7] = TAG_CLASSID; 146 bp->bp_vend[8] = 9; 147 bcopy("PXEClient", &bp->bp_vend[9], 9); 148 bp->bp_vend[18] = TAG_PARAM_REQ; 149 bp->bp_vend[19] = 7; 150 bp->bp_vend[20] = TAG_ROOTPATH; 151 bp->bp_vend[21] = TAG_HOSTNAME; 152 bp->bp_vend[22] = TAG_SWAPSERVER; 153 bp->bp_vend[23] = TAG_GATEWAY; 154 bp->bp_vend[24] = TAG_SUBNET_MASK; 155 bp->bp_vend[25] = TAG_INTF_MTU; 156 bp->bp_vend[26] = TAG_SERVERID; 157 bp->bp_vend[27] = TAG_END; 158 } else 159 bp->bp_vend[7] = TAG_END; 160 #else 161 bp->bp_vend[4] = TAG_END; 162 #endif 163 164 d->myip.s_addr = INADDR_ANY; 165 d->myport = htons(IPPORT_BOOTPC); 166 d->destip.s_addr = INADDR_BROADCAST; 167 d->destport = htons(IPPORT_BOOTPS); 168 169 #ifdef SUPPORT_DHCP 170 expected_dhcpmsgtype = DHCPOFFER; 171 dhcp_ok = 0; 172 #endif 173 174 if(sendrecv(d, 175 bootpsend, bp, sizeof(*bp), 176 bootprecv, &pkt, (void **)&rbootp) == -1) { 177 printf("bootp: no reply\n"); 178 return; 179 } 180 181 #ifdef SUPPORT_DHCP 182 if(dhcp_ok) { 183 u_int32_t leasetime; 184 bp->bp_vend[6] = DHCPREQUEST; 185 bp->bp_vend[7] = TAG_REQ_ADDR; 186 bp->bp_vend[8] = 4; 187 bcopy(&rbootp->bp_yiaddr, &bp->bp_vend[9], 4); 188 bp->bp_vend[13] = TAG_SERVERID; 189 bp->bp_vend[14] = 4; 190 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4); 191 bp->bp_vend[19] = TAG_LEASETIME; 192 bp->bp_vend[20] = 4; 193 leasetime = htonl(300); 194 bcopy(&leasetime, &bp->bp_vend[21], 4); 195 if (flag & BOOTP_PXE) { 196 bp->bp_vend[25] = TAG_CLASSID; 197 bp->bp_vend[26] = 9; 198 bcopy("PXEClient", &bp->bp_vend[27], 9); 199 bp->bp_vend[36] = TAG_END; 200 } else 201 bp->bp_vend[25] = TAG_END; 202 203 expected_dhcpmsgtype = DHCPACK; 204 205 free(pkt); 206 if(sendrecv(d, 207 bootpsend, bp, sizeof(*bp), 208 bootprecv, &pkt, (void **)&rbootp) == -1) { 209 printf("DHCPREQUEST failed\n"); 210 return; 211 } 212 } 213 #endif 214 215 myip = d->myip = rbootp->bp_yiaddr; 216 servip = rbootp->bp_siaddr; 217 if (rootip.s_addr == INADDR_ANY) 218 rootip = servip; 219 bcopy(rbootp->bp_file, bootfile, sizeof(bootfile)); 220 bootfile[sizeof(bootfile) - 1] = '\0'; 221 222 if (!netmask) { 223 if (IN_CLASSA(ntohl(myip.s_addr))) 224 netmask = htonl(IN_CLASSA_NET); 225 else if (IN_CLASSB(ntohl(myip.s_addr))) 226 netmask = htonl(IN_CLASSB_NET); 227 else 228 netmask = htonl(IN_CLASSC_NET); 229 #ifdef BOOTP_DEBUG 230 if (debug) 231 printf("'native netmask' is %s\n", intoa(netmask)); 232 #endif 233 } 234 235 #ifdef BOOTP_DEBUG 236 if (debug) 237 printf("mask: %s\n", intoa(netmask)); 238 #endif 239 240 /* We need a gateway if root is on a different net */ 241 if (!SAMENET(myip, rootip, netmask)) { 242 #ifdef BOOTP_DEBUG 243 if (debug) 244 printf("need gateway for root ip\n"); 245 #endif 246 } 247 248 /* Toss gateway if on a different net */ 249 if (!SAMENET(myip, gateip, netmask)) { 250 #ifdef BOOTP_DEBUG 251 if (debug) 252 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 253 #endif 254 gateip.s_addr = 0; 255 } 256 257 /* Bump xid so next request will be unique. */ 258 ++d->xid; 259 free(pkt); 260 } 261 262 /* Transmit a bootp request */ 263 static ssize_t 264 bootpsend(struct iodesc *d, void *pkt, size_t len) 265 { 266 struct bootp *bp; 267 268 #ifdef BOOTP_DEBUG 269 if (debug) 270 printf("bootpsend: d=%lx called.\n", (long)d); 271 #endif 272 273 bp = pkt; 274 bp->bp_secs = htons((u_short)(getsecs() - bot)); 275 276 #ifdef BOOTP_DEBUG 277 if (debug) 278 printf("bootpsend: calling sendudp\n"); 279 #endif 280 281 return (sendudp(d, pkt, len)); 282 } 283 284 static ssize_t 285 bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft) 286 { 287 ssize_t n; 288 struct bootp *bp; 289 void *ptr; 290 291 #ifdef BOOTP_DEBUG 292 if (debug) 293 printf("bootp_recvoffer: called\n"); 294 #endif 295 296 ptr = NULL; 297 n = readudp(d, &ptr, (void **)&bp, tleft); 298 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 299 goto bad; 300 301 #ifdef BOOTP_DEBUG 302 if (debug) 303 printf("bootprecv: checked. bp = %p, n = %zd\n", bp, n); 304 #endif 305 if (bp->bp_xid != htonl(d->xid)) { 306 #ifdef BOOTP_DEBUG 307 if (debug) { 308 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 309 d->xid, ntohl(bp->bp_xid)); 310 } 311 #endif 312 goto bad; 313 } 314 315 #ifdef BOOTP_DEBUG 316 if (debug) 317 printf("bootprecv: got one!\n"); 318 #endif 319 320 /* Suck out vendor info */ 321 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 322 int vsize = n - offsetof(struct bootp, bp_vend); 323 if(vend_rfc1048(bp->bp_vend, vsize) != 0) 324 goto bad; 325 326 /* Save copy of bootp reply or DHCP ACK message */ 327 if (bp->bp_op == BOOTREPLY && 328 ((dhcp_ok == 1 && expected_dhcpmsgtype == DHCPACK) || 329 dhcp_ok == 0)) { 330 free(bootp_response); 331 bootp_response = malloc(n); 332 if (bootp_response != NULL) { 333 bootp_response_size = n; 334 bcopy(bp, bootp_response, bootp_response_size); 335 } 336 } 337 } 338 #ifdef BOOTP_VEND_CMU 339 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 340 vend_cmu(bp->bp_vend); 341 #endif 342 else 343 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 344 345 *pkt = ptr; 346 *payload = bp; 347 return(n); 348 bad: 349 free(ptr); 350 errno = 0; 351 return (-1); 352 } 353 354 int 355 dhcp_try_rfc1048(uint8_t *cp, size_t len) 356 { 357 358 expected_dhcpmsgtype = DHCPACK; 359 if (bcmp(vm_rfc1048, cp, sizeof (vm_rfc1048)) == 0) { 360 return (vend_rfc1048(cp, len)); 361 } 362 return (-1); 363 } 364 365 static int 366 vend_rfc1048(u_char *cp, u_int len) 367 { 368 u_char *ep; 369 int size; 370 u_char tag; 371 const char *val; 372 373 #ifdef BOOTP_DEBUG 374 if (debug) 375 printf("vend_rfc1048 bootp info. len=%d\n", len); 376 #endif 377 ep = cp + len; 378 379 /* Step over magic cookie */ 380 cp += sizeof(int); 381 382 setenv_(cp, ep, NULL); 383 384 while (cp < ep) { 385 tag = *cp++; 386 size = *cp++; 387 if (tag == TAG_END) 388 break; 389 390 if (tag == TAG_SUBNET_MASK) { 391 bcopy(cp, &netmask, sizeof(netmask)); 392 } 393 if (tag == TAG_GATEWAY) { 394 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 395 } 396 if (tag == TAG_SWAPSERVER) { 397 /* let it override bp_siaddr */ 398 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr)); 399 } 400 if (tag == TAG_ROOTPATH) { 401 if ((val = getenv("dhcp.root-path")) == NULL) 402 val = (const char *)cp; 403 strlcpy(rootpath, val, sizeof(rootpath)); 404 } 405 if (tag == TAG_HOSTNAME) { 406 if ((val = getenv("dhcp.host-name")) == NULL) 407 val = (const char *)cp; 408 strlcpy(hostname, val, sizeof(hostname)); 409 } 410 if (tag == TAG_INTF_MTU) { 411 intf_mtu = 0; 412 if ((val = getenv("dhcp.interface-mtu")) != NULL) { 413 unsigned long tmp; 414 char *end; 415 416 errno = 0; 417 /* 418 * Do not allow MTU to exceed max IPv4 packet 419 * size, max value of 16-bit word. 420 */ 421 tmp = strtoul(val, &end, 0); 422 if (errno != 0 || 423 *val == '\0' || *end != '\0' || 424 tmp > USHRT_MAX) { 425 printf("%s: bad value: \"%s\", " 426 "ignoring\n", 427 "dhcp.interface-mtu", val); 428 } else { 429 intf_mtu = (u_int)tmp; 430 } 431 } 432 if (intf_mtu == 0) 433 intf_mtu = be16dec(cp); 434 } 435 #ifdef SUPPORT_DHCP 436 if (tag == TAG_DHCP_MSGTYPE) { 437 if(*cp != expected_dhcpmsgtype) 438 return(-1); 439 dhcp_ok = 1; 440 } 441 if (tag == TAG_SERVERID) { 442 bcopy(cp, &dhcp_serverip.s_addr, 443 sizeof(dhcp_serverip.s_addr)); 444 } 445 #endif 446 cp += size; 447 } 448 return(0); 449 } 450 451 #ifdef BOOTP_VEND_CMU 452 static void 453 vend_cmu(u_char *cp) 454 { 455 struct cmu_vend *vp; 456 457 #ifdef BOOTP_DEBUG 458 if (debug) 459 printf("vend_cmu bootp info.\n"); 460 #endif 461 vp = (struct cmu_vend *)cp; 462 463 if (vp->v_smask.s_addr != 0) { 464 netmask = vp->v_smask.s_addr; 465 } 466 if (vp->v_dgate.s_addr != 0) { 467 gateip = vp->v_dgate; 468 } 469 } 470 #endif 471 472 #ifdef DHCP_ENV 473 /* 474 * Parse DHCP options and store them into kenv variables. 475 * Original code from Danny Braniss, modifications by Luigi Rizzo. 476 * 477 * The parser is driven by tables which specify the type and name of 478 * each dhcp option and how it appears in kenv. 479 * The first entry in the list contains the prefix used to set the kenv 480 * name (including the . if needed), the last entry must have a 0 tag. 481 * Entries do not need to be sorted though it helps for readability. 482 * 483 * Certain vendor-specific tables can be enabled according to DHCP_ENV. 484 * Set it to 0 if you don't want any. 485 */ 486 enum opt_fmt { __NONE = 0, 487 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */ 488 __IP, /* IPv4 address */ 489 __TXT, /* C string */ 490 __BYTES, /* byte sequence, printed %02x */ 491 __INDIR, /* name=value */ 492 __ILIST, /* name=value;name=value ... */ 493 __VE, /* vendor specific, recurse */ 494 }; 495 496 struct dhcp_opt { 497 uint8_t tag; 498 uint8_t fmt; 499 const char *desc; 500 }; 501 502 static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */ 503 #if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */ 504 {0, 0, "FreeBSD"}, /* prefix */ 505 {1, __TXT, "kernel"}, 506 {2, __TXT, "kernelname"}, 507 {3, __TXT, "kernel_options"}, 508 {4, __IP, "usr-ip"}, 509 {5, __TXT, "conf-path"}, 510 {6, __TXT, "rc.conf0"}, 511 {7, __TXT, "rc.conf1"}, 512 {8, __TXT, "rc.conf2"}, 513 {9, __TXT, "rc.conf3"}, 514 {10, __TXT, "rc.conf4"}, 515 {11, __TXT, "rc.conf5"}, 516 {12, __TXT, "rc.conf6"}, 517 {13, __TXT, "rc.conf7"}, 518 {14, __TXT, "rc.conf8"}, 519 {15, __TXT, "rc.conf9"}, 520 521 {20, __TXT, "boot.nfsroot.options"}, 522 523 {245, __INDIR, ""}, 524 {246, __INDIR, ""}, 525 {247, __INDIR, ""}, 526 {248, __INDIR, ""}, 527 {249, __INDIR, ""}, 528 {250, __INDIR, ""}, 529 {251, __INDIR, ""}, 530 {252, __INDIR, ""}, 531 {253, __INDIR, ""}, 532 {254, __INDIR, ""}, 533 534 #elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */ 535 {0, 0, "pxe"}, /* prefix */ 536 {93, __16, "system-architecture"}, 537 {94, __BYTES, "network-interface"}, 538 {97, __BYTES, "machine-identifier"}, 539 #else /* default (empty) table */ 540 {0, 0, "dhcp.vendor."}, /* prefix */ 541 #endif 542 {0, __TXT, "%soption-%d"} 543 }; 544 545 static struct dhcp_opt dhcp_opt[] = { 546 /* DHCP Option names, formats and codes, from RFC2132. */ 547 {0, 0, "dhcp."}, // prefix 548 {1, __IP, "subnet-mask"}, 549 {2, __32, "time-offset"}, /* this is signed */ 550 {3, __IP, "routers"}, 551 {4, __IP, "time-servers"}, 552 {5, __IP, "ien116-name-servers"}, 553 {6, __IP, "domain-name-servers"}, 554 {7, __IP, "log-servers"}, 555 {8, __IP, "cookie-servers"}, 556 {9, __IP, "lpr-servers"}, 557 {10, __IP, "impress-servers"}, 558 {11, __IP, "resource-location-servers"}, 559 {12, __TXT, "host-name"}, 560 {13, __16, "boot-size"}, 561 {14, __TXT, "merit-dump"}, 562 {15, __TXT, "domain-name"}, 563 {16, __IP, "swap-server"}, 564 {17, __TXT, "root-path"}, 565 {18, __TXT, "extensions-path"}, 566 {19, __8, "ip-forwarding"}, 567 {20, __8, "non-local-source-routing"}, 568 {21, __IP, "policy-filter"}, 569 {22, __16, "max-dgram-reassembly"}, 570 {23, __8, "default-ip-ttl"}, 571 {24, __32, "path-mtu-aging-timeout"}, 572 {25, __16, "path-mtu-plateau-table"}, 573 {26, __16, "interface-mtu"}, 574 {27, __8, "all-subnets-local"}, 575 {28, __IP, "broadcast-address"}, 576 {29, __8, "perform-mask-discovery"}, 577 {30, __8, "mask-supplier"}, 578 {31, __8, "perform-router-discovery"}, 579 {32, __IP, "router-solicitation-address"}, 580 {33, __IP, "static-routes"}, 581 {34, __8, "trailer-encapsulation"}, 582 {35, __32, "arp-cache-timeout"}, 583 {36, __8, "ieee802-3-encapsulation"}, 584 {37, __8, "default-tcp-ttl"}, 585 {38, __32, "tcp-keepalive-interval"}, 586 {39, __8, "tcp-keepalive-garbage"}, 587 {40, __TXT, "nis-domain"}, 588 {41, __IP, "nis-servers"}, 589 {42, __IP, "ntp-servers"}, 590 {43, __VE, "vendor-encapsulated-options"}, 591 {44, __IP, "netbios-name-servers"}, 592 {45, __IP, "netbios-dd-server"}, 593 {46, __8, "netbios-node-type"}, 594 {47, __TXT, "netbios-scope"}, 595 {48, __IP, "x-font-servers"}, 596 {49, __IP, "x-display-managers"}, 597 {50, __IP, "dhcp-requested-address"}, 598 {51, __32, "dhcp-lease-time"}, 599 {52, __8, "dhcp-option-overload"}, 600 {53, __8, "dhcp-message-type"}, 601 {54, __IP, "dhcp-server-identifier"}, 602 {55, __8, "dhcp-parameter-request-list"}, 603 {56, __TXT, "dhcp-message"}, 604 {57, __16, "dhcp-max-message-size"}, 605 {58, __32, "dhcp-renewal-time"}, 606 {59, __32, "dhcp-rebinding-time"}, 607 {60, __TXT, "vendor-class-identifier"}, 608 {61, __TXT, "dhcp-client-identifier"}, 609 {64, __TXT, "nisplus-domain"}, 610 {65, __IP, "nisplus-servers"}, 611 {66, __TXT, "tftp-server-name"}, 612 {67, __TXT, "bootfile-name"}, 613 {68, __IP, "mobile-ip-home-agent"}, 614 {69, __IP, "smtp-server"}, 615 {70, __IP, "pop-server"}, 616 {71, __IP, "nntp-server"}, 617 {72, __IP, "www-server"}, 618 {73, __IP, "finger-server"}, 619 {74, __IP, "irc-server"}, 620 {75, __IP, "streettalk-server"}, 621 {76, __IP, "streettalk-directory-assistance-server"}, 622 {77, __TXT, "user-class"}, 623 {85, __IP, "nds-servers"}, 624 {86, __TXT, "nds-tree-name"}, 625 {87, __TXT, "nds-context"}, 626 {210, __TXT, "authenticate"}, 627 628 /* use the following entries for arbitrary variables */ 629 {246, __ILIST, ""}, 630 {247, __ILIST, ""}, 631 {248, __ILIST, ""}, 632 {249, __ILIST, ""}, 633 {250, __INDIR, ""}, 634 {251, __INDIR, ""}, 635 {252, __INDIR, ""}, 636 {253, __INDIR, ""}, 637 {254, __INDIR, ""}, 638 {0, __TXT, "%soption-%d"} 639 }; 640 641 /* 642 * parse a dhcp response, set environment variables translating options 643 * names and values according to the tables above. Also set dhcp.tags 644 * to the list of selected tags. 645 */ 646 static void 647 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts) 648 { 649 u_char *ncp; 650 u_char tag; 651 char tags[512], *tp; /* the list of tags */ 652 653 #define FLD_SEP ',' /* separator in list of elements */ 654 ncp = cp; 655 tp = tags; 656 if (opts == NULL) 657 opts = dhcp_opt; 658 659 while (ncp < ep) { 660 unsigned int size; /* option size */ 661 char *vp, *endv, buf[256]; /* the value buffer */ 662 struct dhcp_opt *op; 663 664 tag = *ncp++; /* extract tag and size */ 665 size = *ncp++; 666 cp = ncp; /* current payload */ 667 ncp += size; /* point to the next option */ 668 669 if (tag == TAG_END) 670 break; 671 if (tag == 0) 672 continue; 673 674 for (op = opts+1; op->tag && op->tag != tag; op++) 675 ; 676 /* if not found we end up on the default entry */ 677 678 /* 679 * Copy data into the buffer. libstand does not have snprintf so we 680 * need to be careful with sprintf(). With strings, the source is 681 * always <256 char so shorter than the buffer so we are safe; with 682 * other arguments, the longest string is inet_ntoa which is 16 bytes 683 * so we make sure to have always enough room in the string before 684 * trying an sprint. 685 */ 686 vp = buf; 687 *vp = '\0'; 688 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */ 689 690 switch(op->fmt) { 691 case __NONE: 692 break; /* should not happen */ 693 694 case __VE: /* recurse, vendor specific */ 695 setenv_(cp, cp+size, vndr_opt); 696 break; 697 698 case __IP: /* ip address */ 699 for (; size > 0 && vp < endv; size -= 4, cp += 4) { 700 struct in_addr in_ip; /* ip addresses */ 701 if (vp != buf) 702 *vp++ = FLD_SEP; 703 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr)); 704 sprintf(vp, "%s", inet_ntoa(in_ip)); 705 vp += strlen(vp); 706 } 707 break; 708 709 case __BYTES: /* opaque byte string */ 710 for (; size > 0 && vp < endv; size -= 1, cp += 1) { 711 sprintf(vp, "%02x", *cp); 712 vp += strlen(vp); 713 } 714 break; 715 716 case __TXT: 717 bcopy(cp, buf, size); /* cannot overflow */ 718 buf[size] = 0; 719 break; 720 721 case __32: 722 case __16: 723 case __8: /* op->fmt is also the length of each field */ 724 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) { 725 uint32_t v; 726 if (op->fmt == __32) 727 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3]; 728 else if (op->fmt == __16) 729 v = (cp[0]<<8) + cp[1]; 730 else 731 v = cp[0]; 732 if (vp != buf) 733 *vp++ = FLD_SEP; 734 sprintf(vp, "%u", v); 735 vp += strlen(vp); 736 } 737 break; 738 739 case __INDIR: /* name=value */ 740 case __ILIST: /* name=value;name=value... */ 741 bcopy(cp, buf, size); /* cannot overflow */ 742 buf[size] = '\0'; 743 for (endv = buf; endv; endv = vp) { 744 u_char *s = NULL; /* semicolon ? */ 745 746 /* skip leading whitespace */ 747 while (*endv && strchr(" \t\n\r", *endv)) 748 endv++; 749 vp = strchr(endv, '='); /* find name=value separator */ 750 if (!vp) 751 break; 752 *vp++ = 0; 753 if (op->fmt == __ILIST && (s = strchr(vp, ';'))) 754 *s++ = '\0'; 755 setenv(endv, vp, 1); 756 vp = s; /* prepare for next round */ 757 } 758 buf[0] = '\0'; /* option already done */ 759 } 760 761 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */ 762 if (tp != tags) 763 *tp++ = FLD_SEP; 764 sprintf(tp, "%d", tag); 765 tp += strlen(tp); 766 } 767 if (buf[0]) { 768 char env[128]; /* the string name */ 769 770 if (op->tag == 0) 771 sprintf(env, op->desc, opts[0].desc, tag); 772 else 773 sprintf(env, "%s%s", opts[0].desc, op->desc); 774 /* 775 * Do not replace existing values in the environment, so that 776 * locally-obtained values can override server-provided values. 777 */ 778 setenv(env, buf, 0); 779 } 780 } 781 if (tp != tags) { 782 char env[128]; /* the string name */ 783 sprintf(env, "%stags", opts[0].desc); 784 setenv(env, tags, 1); 785 } 786 } 787 #endif /* additional dhcp */ 788