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 * 3. 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 __FBSDID("$FreeBSD$"); 40 41 #include <stddef.h> 42 #include <sys/types.h> 43 #include <sys/limits.h> 44 #include <sys/endian.h> 45 #include <netinet/in.h> 46 #include <netinet/in_systm.h> 47 48 #include <string.h> 49 50 #define BOOTP_DEBUGxx 51 #define SUPPORT_DHCP 52 53 #define DHCP_ENV_NOVENDOR 1 /* do not parse vendor options */ 54 #define DHCP_ENV_PXE 10 /* assume pxe vendor options */ 55 #define DHCP_ENV_FREEBSD 11 /* assume freebsd vendor options */ 56 /* set DHCP_ENV to one of the values above to export dhcp options to kenv */ 57 #define DHCP_ENV DHCP_ENV_NO_VENDOR 58 59 #include "stand.h" 60 #include "net.h" 61 #include "netif.h" 62 #include "bootp.h" 63 64 65 struct in_addr servip; 66 67 static time_t bot; 68 69 static char vm_rfc1048[4] = VM_RFC1048; 70 #ifdef BOOTP_VEND_CMU 71 static char vm_cmu[4] = VM_CMU; 72 #endif 73 74 /* Local forwards */ 75 static ssize_t bootpsend(struct iodesc *, void *, size_t); 76 static ssize_t bootprecv(struct iodesc *, void **, void **, time_t); 77 static int vend_rfc1048(u_char *, u_int); 78 #ifdef BOOTP_VEND_CMU 79 static void vend_cmu(u_char *); 80 #endif 81 82 #ifdef DHCP_ENV /* export the dhcp response to kenv */ 83 struct dhcp_opt; 84 static void setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts); 85 #else 86 #define setenv_(a, b, c) 87 #endif 88 89 #ifdef SUPPORT_DHCP 90 static char expected_dhcpmsgtype = -1, dhcp_ok; 91 struct in_addr dhcp_serverip; 92 #endif 93 struct bootp *bootp_response; 94 size_t bootp_response_size; 95 96 static void 97 bootp_fill_request(unsigned char *bp_vend) 98 { 99 /* 100 * We are booting from PXE, we want to send the string 101 * 'PXEClient' to the DHCP server so you have the option of 102 * only responding to PXE aware dhcp requests. 103 */ 104 bp_vend[0] = TAG_CLASSID; 105 bp_vend[1] = 9; 106 bcopy("PXEClient", &bp_vend[2], 9); 107 bp_vend[11] = TAG_USER_CLASS; 108 /* len of each user class + number of user class */ 109 bp_vend[12] = 8; 110 /* len of the first user class */ 111 bp_vend[13] = 7; 112 bcopy("FreeBSD", &bp_vend[14], 7); 113 bp_vend[21] = TAG_PARAM_REQ; 114 bp_vend[22] = 7; 115 bp_vend[23] = TAG_ROOTPATH; 116 bp_vend[24] = TAG_HOSTNAME; 117 bp_vend[25] = TAG_SWAPSERVER; 118 bp_vend[26] = TAG_GATEWAY; 119 bp_vend[27] = TAG_SUBNET_MASK; 120 bp_vend[28] = TAG_INTF_MTU; 121 bp_vend[29] = TAG_SERVERID; 122 bp_vend[30] = TAG_END; 123 } 124 125 /* Fetch required bootp infomation */ 126 void 127 bootp(int sock) 128 { 129 void *pkt; 130 struct iodesc *d; 131 struct bootp *bp; 132 struct { 133 u_char header[HEADER_SIZE]; 134 struct bootp wbootp; 135 } wbuf; 136 struct bootp *rbootp; 137 138 #ifdef BOOTP_DEBUG 139 if (debug) 140 printf("bootp: socket=%d\n", sock); 141 #endif 142 if (!bot) 143 bot = getsecs(); 144 145 if (!(d = socktodesc(sock))) { 146 printf("bootp: bad socket. %d\n", sock); 147 return; 148 } 149 #ifdef BOOTP_DEBUG 150 if (debug) 151 printf("bootp: d=%lx\n", (long)d); 152 #endif 153 154 bp = &wbuf.wbootp; 155 bzero(bp, sizeof(*bp)); 156 157 bp->bp_op = BOOTREQUEST; 158 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 159 bp->bp_hlen = 6; 160 bp->bp_xid = htonl(d->xid); 161 MACPY(d->myea, bp->bp_chaddr); 162 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file)); 163 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 164 #ifdef SUPPORT_DHCP 165 bp->bp_vend[4] = TAG_DHCP_MSGTYPE; 166 bp->bp_vend[5] = 1; 167 bp->bp_vend[6] = DHCPDISCOVER; 168 bootp_fill_request(&bp->bp_vend[7]); 169 170 #else 171 bp->bp_vend[4] = TAG_END; 172 #endif 173 174 d->myip.s_addr = INADDR_ANY; 175 d->myport = htons(IPPORT_BOOTPC); 176 d->destip.s_addr = INADDR_BROADCAST; 177 d->destport = htons(IPPORT_BOOTPS); 178 179 #ifdef SUPPORT_DHCP 180 expected_dhcpmsgtype = DHCPOFFER; 181 dhcp_ok = 0; 182 #endif 183 184 if(sendrecv(d, 185 bootpsend, bp, sizeof(*bp), 186 bootprecv, &pkt, (void **)&rbootp) == -1) { 187 printf("bootp: no reply\n"); 188 return; 189 } 190 191 #ifdef SUPPORT_DHCP 192 if(dhcp_ok) { 193 u_int32_t leasetime; 194 bp->bp_vend[6] = DHCPREQUEST; 195 bp->bp_vend[7] = TAG_REQ_ADDR; 196 bp->bp_vend[8] = 4; 197 bcopy(&rbootp->bp_yiaddr, &bp->bp_vend[9], 4); 198 bp->bp_vend[13] = TAG_SERVERID; 199 bp->bp_vend[14] = 4; 200 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4); 201 bp->bp_vend[19] = TAG_LEASETIME; 202 bp->bp_vend[20] = 4; 203 leasetime = htonl(300); 204 bcopy(&leasetime, &bp->bp_vend[21], 4); 205 bootp_fill_request(&bp->bp_vend[25]); 206 207 expected_dhcpmsgtype = DHCPACK; 208 209 free(pkt); 210 if(sendrecv(d, 211 bootpsend, bp, sizeof(*bp), 212 bootprecv, &pkt, (void **)&rbootp) == -1) { 213 printf("DHCPREQUEST failed\n"); 214 return; 215 } 216 } 217 #endif 218 219 myip = d->myip = rbootp->bp_yiaddr; 220 servip = rbootp->bp_siaddr; 221 if (rootip.s_addr == INADDR_ANY) 222 rootip = servip; 223 bcopy(rbootp->bp_file, bootfile, sizeof(bootfile)); 224 bootfile[sizeof(bootfile) - 1] = '\0'; 225 226 if (!netmask) { 227 if (IN_CLASSA(ntohl(myip.s_addr))) 228 netmask = htonl(IN_CLASSA_NET); 229 else if (IN_CLASSB(ntohl(myip.s_addr))) 230 netmask = htonl(IN_CLASSB_NET); 231 else 232 netmask = htonl(IN_CLASSC_NET); 233 #ifdef BOOTP_DEBUG 234 if (debug) 235 printf("'native netmask' is %s\n", intoa(netmask)); 236 #endif 237 } 238 239 #ifdef BOOTP_DEBUG 240 if (debug) 241 printf("mask: %s\n", intoa(netmask)); 242 #endif 243 244 /* We need a gateway if root is on a different net */ 245 if (!SAMENET(myip, rootip, netmask)) { 246 #ifdef BOOTP_DEBUG 247 if (debug) 248 printf("need gateway for root ip\n"); 249 #endif 250 } 251 252 /* Toss gateway if on a different net */ 253 if (!SAMENET(myip, gateip, netmask)) { 254 #ifdef BOOTP_DEBUG 255 if (debug) 256 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 257 #endif 258 gateip.s_addr = 0; 259 } 260 261 /* Bump xid so next request will be unique. */ 262 ++d->xid; 263 free(pkt); 264 } 265 266 /* Transmit a bootp request */ 267 static ssize_t 268 bootpsend(struct iodesc *d, void *pkt, size_t len) 269 { 270 struct bootp *bp; 271 272 #ifdef BOOTP_DEBUG 273 if (debug) 274 printf("bootpsend: d=%lx called.\n", (long)d); 275 #endif 276 277 bp = pkt; 278 bp->bp_secs = htons((u_short)(getsecs() - bot)); 279 280 #ifdef BOOTP_DEBUG 281 if (debug) 282 printf("bootpsend: calling sendudp\n"); 283 #endif 284 285 return (sendudp(d, pkt, len)); 286 } 287 288 static ssize_t 289 bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft) 290 { 291 ssize_t n; 292 struct bootp *bp; 293 void *ptr; 294 295 #ifdef BOOTP_DEBUG 296 if (debug) 297 printf("bootp_recvoffer: called\n"); 298 #endif 299 300 ptr = NULL; 301 n = readudp(d, &ptr, (void **)&bp, tleft); 302 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 303 goto bad; 304 305 #ifdef BOOTP_DEBUG 306 if (debug) 307 printf("bootprecv: checked. bp = %p, n = %zd\n", bp, n); 308 #endif 309 if (bp->bp_xid != htonl(d->xid)) { 310 #ifdef BOOTP_DEBUG 311 if (debug) { 312 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 313 d->xid, ntohl(bp->bp_xid)); 314 } 315 #endif 316 goto bad; 317 } 318 319 #ifdef BOOTP_DEBUG 320 if (debug) 321 printf("bootprecv: got one!\n"); 322 #endif 323 324 /* Suck out vendor info */ 325 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 326 int vsize = n - offsetof(struct bootp, bp_vend); 327 if (vend_rfc1048(bp->bp_vend, vsize) != 0) 328 goto bad; 329 330 /* Save copy of bootp reply or DHCP ACK message */ 331 if (bp->bp_op == BOOTREPLY && 332 ((dhcp_ok == 1 && expected_dhcpmsgtype == DHCPACK) || 333 dhcp_ok == 0)) { 334 free(bootp_response); 335 bootp_response = malloc(n); 336 if (bootp_response != NULL) { 337 bootp_response_size = n; 338 bcopy(bp, bootp_response, bootp_response_size); 339 } 340 } 341 } 342 #ifdef BOOTP_VEND_CMU 343 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 344 vend_cmu(bp->bp_vend); 345 #endif 346 else 347 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 348 349 *pkt = ptr; 350 *payload = bp; 351 return (n); 352 bad: 353 free(ptr); 354 errno = 0; 355 return (-1); 356 } 357 358 int 359 dhcp_try_rfc1048(u_char *cp, u_int len) 360 { 361 362 expected_dhcpmsgtype = DHCPACK; 363 if (bcmp(vm_rfc1048, cp, sizeof(vm_rfc1048)) == 0) { 364 return (vend_rfc1048(cp, len)); 365 } 366 return (-1); 367 } 368 369 static int 370 vend_rfc1048(u_char *cp, u_int len) 371 { 372 u_char *ep; 373 int size; 374 u_char tag; 375 const char *val; 376 377 #ifdef BOOTP_DEBUG 378 if (debug) 379 printf("vend_rfc1048 bootp info. len=%d\n", len); 380 #endif 381 ep = cp + len; 382 383 /* Step over magic cookie */ 384 cp += sizeof(int); 385 386 setenv_(cp, ep, NULL); 387 388 while (cp < ep) { 389 tag = *cp++; 390 size = *cp++; 391 if (tag == TAG_END) 392 break; 393 394 if (tag == TAG_SUBNET_MASK) { 395 bcopy(cp, &netmask, sizeof(netmask)); 396 } 397 if (tag == TAG_GATEWAY) { 398 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 399 } 400 if (tag == TAG_SWAPSERVER) { 401 /* let it override bp_siaddr */ 402 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr)); 403 } 404 if (tag == TAG_ROOTPATH) { 405 if ((val = getenv("dhcp.root-path")) == NULL) 406 val = (const char *)cp; 407 strlcpy(rootpath, val, sizeof(rootpath)); 408 } 409 if (tag == TAG_HOSTNAME) { 410 if ((val = getenv("dhcp.host-name")) == NULL) 411 val = (const char *)cp; 412 strlcpy(hostname, val, sizeof(hostname)); 413 } 414 if (tag == TAG_INTF_MTU) { 415 intf_mtu = 0; 416 if ((val = getenv("dhcp.interface-mtu")) != NULL) { 417 unsigned long tmp; 418 char *end; 419 420 errno = 0; 421 /* 422 * Do not allow MTU to exceed max IPv4 packet 423 * size, max value of 16-bit word. 424 */ 425 tmp = strtoul(val, &end, 0); 426 if (errno != 0 || 427 *val == '\0' || *end != '\0' || 428 tmp > USHRT_MAX) { 429 printf("%s: bad value: \"%s\", " 430 "ignoring\n", 431 "dhcp.interface-mtu", val); 432 } else { 433 intf_mtu = (u_int)tmp; 434 } 435 } 436 if (intf_mtu <= 0) 437 intf_mtu = be16dec(cp); 438 } 439 #ifdef SUPPORT_DHCP 440 if (tag == TAG_DHCP_MSGTYPE) { 441 if(*cp != expected_dhcpmsgtype) 442 return(-1); 443 dhcp_ok = 1; 444 } 445 if (tag == TAG_SERVERID) { 446 bcopy(cp, &dhcp_serverip.s_addr, 447 sizeof(dhcp_serverip.s_addr)); 448 } 449 #endif 450 cp += size; 451 } 452 return(0); 453 } 454 455 #ifdef BOOTP_VEND_CMU 456 static void 457 vend_cmu(u_char *cp) 458 { 459 struct cmu_vend *vp; 460 461 #ifdef BOOTP_DEBUG 462 if (debug) 463 printf("vend_cmu bootp info.\n"); 464 #endif 465 vp = (struct cmu_vend *)cp; 466 467 if (vp->v_smask.s_addr != 0) { 468 netmask = vp->v_smask.s_addr; 469 } 470 if (vp->v_dgate.s_addr != 0) { 471 gateip = vp->v_dgate; 472 } 473 } 474 #endif 475 476 #ifdef DHCP_ENV 477 /* 478 * Parse DHCP options and store them into kenv variables. 479 * Original code from Danny Braniss, modifications by Luigi Rizzo. 480 * 481 * The parser is driven by tables which specify the type and name of 482 * each dhcp option and how it appears in kenv. 483 * The first entry in the list contains the prefix used to set the kenv 484 * name (including the . if needed), the last entry must have a 0 tag. 485 * Entries do not need to be sorted though it helps for readability. 486 * 487 * Certain vendor-specific tables can be enabled according to DHCP_ENV. 488 * Set it to 0 if you don't want any. 489 */ 490 enum opt_fmt { __NONE = 0, 491 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */ 492 __IP, /* IPv4 address */ 493 __TXT, /* C string */ 494 __BYTES, /* byte sequence, printed %02x */ 495 __INDIR, /* name=value */ 496 __ILIST, /* name=value;name=value ... */ 497 __VE, /* vendor specific, recurse */ 498 }; 499 500 struct dhcp_opt { 501 uint8_t tag; 502 uint8_t fmt; 503 const char *desc; 504 }; 505 506 static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */ 507 #if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */ 508 {0, 0, "FreeBSD"}, /* prefix */ 509 {1, __TXT, "kernel"}, 510 {2, __TXT, "kernelname"}, 511 {3, __TXT, "kernel_options"}, 512 {4, __IP, "usr-ip"}, 513 {5, __TXT, "conf-path"}, 514 {6, __TXT, "rc.conf0"}, 515 {7, __TXT, "rc.conf1"}, 516 {8, __TXT, "rc.conf2"}, 517 {9, __TXT, "rc.conf3"}, 518 {10, __TXT, "rc.conf4"}, 519 {11, __TXT, "rc.conf5"}, 520 {12, __TXT, "rc.conf6"}, 521 {13, __TXT, "rc.conf7"}, 522 {14, __TXT, "rc.conf8"}, 523 {15, __TXT, "rc.conf9"}, 524 525 {20, __TXT, "boot.nfsroot.options"}, 526 527 {245, __INDIR, ""}, 528 {246, __INDIR, ""}, 529 {247, __INDIR, ""}, 530 {248, __INDIR, ""}, 531 {249, __INDIR, ""}, 532 {250, __INDIR, ""}, 533 {251, __INDIR, ""}, 534 {252, __INDIR, ""}, 535 {253, __INDIR, ""}, 536 {254, __INDIR, ""}, 537 538 #elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */ 539 {0, 0, "pxe"}, /* prefix */ 540 {93, __16, "system-architecture"}, 541 {94, __BYTES, "network-interface"}, 542 {97, __BYTES, "machine-identifier"}, 543 #else /* default (empty) table */ 544 {0, 0, "dhcp.vendor."}, /* prefix */ 545 #endif 546 {0, __TXT, "%soption-%d"} 547 }; 548 549 static struct dhcp_opt dhcp_opt[] = { 550 /* DHCP Option names, formats and codes, from RFC2132. */ 551 {0, 0, "dhcp."}, // prefix 552 {1, __IP, "subnet-mask"}, 553 {2, __32, "time-offset"}, /* this is signed */ 554 {3, __IP, "routers"}, 555 {4, __IP, "time-servers"}, 556 {5, __IP, "ien116-name-servers"}, 557 {6, __IP, "domain-name-servers"}, 558 {7, __IP, "log-servers"}, 559 {8, __IP, "cookie-servers"}, 560 {9, __IP, "lpr-servers"}, 561 {10, __IP, "impress-servers"}, 562 {11, __IP, "resource-location-servers"}, 563 {12, __TXT, "host-name"}, 564 {13, __16, "boot-size"}, 565 {14, __TXT, "merit-dump"}, 566 {15, __TXT, "domain-name"}, 567 {16, __IP, "swap-server"}, 568 {17, __TXT, "root-path"}, 569 {18, __TXT, "extensions-path"}, 570 {19, __8, "ip-forwarding"}, 571 {20, __8, "non-local-source-routing"}, 572 {21, __IP, "policy-filter"}, 573 {22, __16, "max-dgram-reassembly"}, 574 {23, __8, "default-ip-ttl"}, 575 {24, __32, "path-mtu-aging-timeout"}, 576 {25, __16, "path-mtu-plateau-table"}, 577 {26, __16, "interface-mtu"}, 578 {27, __8, "all-subnets-local"}, 579 {28, __IP, "broadcast-address"}, 580 {29, __8, "perform-mask-discovery"}, 581 {30, __8, "mask-supplier"}, 582 {31, __8, "perform-router-discovery"}, 583 {32, __IP, "router-solicitation-address"}, 584 {33, __IP, "static-routes"}, 585 {34, __8, "trailer-encapsulation"}, 586 {35, __32, "arp-cache-timeout"}, 587 {36, __8, "ieee802-3-encapsulation"}, 588 {37, __8, "default-tcp-ttl"}, 589 {38, __32, "tcp-keepalive-interval"}, 590 {39, __8, "tcp-keepalive-garbage"}, 591 {40, __TXT, "nis-domain"}, 592 {41, __IP, "nis-servers"}, 593 {42, __IP, "ntp-servers"}, 594 {43, __VE, "vendor-encapsulated-options"}, 595 {44, __IP, "netbios-name-servers"}, 596 {45, __IP, "netbios-dd-server"}, 597 {46, __8, "netbios-node-type"}, 598 {47, __TXT, "netbios-scope"}, 599 {48, __IP, "x-font-servers"}, 600 {49, __IP, "x-display-managers"}, 601 {50, __IP, "dhcp-requested-address"}, 602 {51, __32, "dhcp-lease-time"}, 603 {52, __8, "dhcp-option-overload"}, 604 {53, __8, "dhcp-message-type"}, 605 {54, __IP, "dhcp-server-identifier"}, 606 {55, __8, "dhcp-parameter-request-list"}, 607 {56, __TXT, "dhcp-message"}, 608 {57, __16, "dhcp-max-message-size"}, 609 {58, __32, "dhcp-renewal-time"}, 610 {59, __32, "dhcp-rebinding-time"}, 611 {60, __TXT, "vendor-class-identifier"}, 612 {61, __TXT, "dhcp-client-identifier"}, 613 {64, __TXT, "nisplus-domain"}, 614 {65, __IP, "nisplus-servers"}, 615 {66, __TXT, "tftp-server-name"}, 616 {67, __TXT, "bootfile-name"}, 617 {68, __IP, "mobile-ip-home-agent"}, 618 {69, __IP, "smtp-server"}, 619 {70, __IP, "pop-server"}, 620 {71, __IP, "nntp-server"}, 621 {72, __IP, "www-server"}, 622 {73, __IP, "finger-server"}, 623 {74, __IP, "irc-server"}, 624 {75, __IP, "streettalk-server"}, 625 {76, __IP, "streettalk-directory-assistance-server"}, 626 {77, __TXT, "user-class"}, 627 {85, __IP, "nds-servers"}, 628 {86, __TXT, "nds-tree-name"}, 629 {87, __TXT, "nds-context"}, 630 {210, __TXT, "authenticate"}, 631 632 /* use the following entries for arbitrary variables */ 633 {246, __ILIST, ""}, 634 {247, __ILIST, ""}, 635 {248, __ILIST, ""}, 636 {249, __ILIST, ""}, 637 {250, __INDIR, ""}, 638 {251, __INDIR, ""}, 639 {252, __INDIR, ""}, 640 {253, __INDIR, ""}, 641 {254, __INDIR, ""}, 642 {0, __TXT, "%soption-%d"} 643 }; 644 645 /* 646 * parse a dhcp response, set environment variables translating options 647 * names and values according to the tables above. Also set dhcp.tags 648 * to the list of selected tags. 649 */ 650 static void 651 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts) 652 { 653 u_char *ncp; 654 u_char tag; 655 char tags[512], *tp; /* the list of tags */ 656 657 #define FLD_SEP ',' /* separator in list of elements */ 658 ncp = cp; 659 tp = tags; 660 if (opts == NULL) 661 opts = dhcp_opt; 662 663 while (ncp < ep) { 664 unsigned int size; /* option size */ 665 char *vp, *endv, buf[256]; /* the value buffer */ 666 struct dhcp_opt *op; 667 668 tag = *ncp++; /* extract tag and size */ 669 size = *ncp++; 670 cp = ncp; /* current payload */ 671 ncp += size; /* point to the next option */ 672 673 if (tag == TAG_END) 674 break; 675 if (tag == 0) 676 continue; 677 678 for (op = opts+1; op->tag && op->tag != tag; op++) 679 ; 680 /* if not found we end up on the default entry */ 681 682 /* 683 * Copy data into the buffer. libstand does not have snprintf so we 684 * need to be careful with sprintf(). With strings, the source is 685 * always <256 char so shorter than the buffer so we are safe; with 686 * other arguments, the longest string is inet_ntoa which is 16 bytes 687 * so we make sure to have always enough room in the string before 688 * trying an sprint. 689 */ 690 vp = buf; 691 *vp = '\0'; 692 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */ 693 694 switch(op->fmt) { 695 case __NONE: 696 break; /* should not happen */ 697 698 case __VE: /* recurse, vendor specific */ 699 setenv_(cp, cp+size, vndr_opt); 700 break; 701 702 case __IP: /* ip address */ 703 for (; size > 0 && vp < endv; size -= 4, cp += 4) { 704 struct in_addr in_ip; /* ip addresses */ 705 if (vp != buf) 706 *vp++ = FLD_SEP; 707 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr)); 708 sprintf(vp, "%s", inet_ntoa(in_ip)); 709 vp += strlen(vp); 710 } 711 break; 712 713 case __BYTES: /* opaque byte string */ 714 for (; size > 0 && vp < endv; size -= 1, cp += 1) { 715 sprintf(vp, "%02x", *cp); 716 vp += strlen(vp); 717 } 718 break; 719 720 case __TXT: 721 bcopy(cp, buf, size); /* cannot overflow */ 722 buf[size] = 0; 723 break; 724 725 case __32: 726 case __16: 727 case __8: /* op->fmt is also the length of each field */ 728 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) { 729 uint32_t v; 730 if (op->fmt == __32) 731 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3]; 732 else if (op->fmt == __16) 733 v = (cp[0]<<8) + cp[1]; 734 else 735 v = cp[0]; 736 if (vp != buf) 737 *vp++ = FLD_SEP; 738 sprintf(vp, "%u", v); 739 vp += strlen(vp); 740 } 741 break; 742 743 case __INDIR: /* name=value */ 744 case __ILIST: /* name=value;name=value... */ 745 bcopy(cp, buf, size); /* cannot overflow */ 746 buf[size] = '\0'; 747 for (endv = buf; endv; endv = vp) { 748 u_char *s = NULL; /* semicolon ? */ 749 750 /* skip leading whitespace */ 751 while (*endv && strchr(" \t\n\r", *endv)) 752 endv++; 753 vp = strchr(endv, '='); /* find name=value separator */ 754 if (!vp) 755 break; 756 *vp++ = 0; 757 if (op->fmt == __ILIST && (s = strchr(vp, ';'))) 758 *s++ = '\0'; 759 setenv(endv, vp, 1); 760 vp = s; /* prepare for next round */ 761 } 762 buf[0] = '\0'; /* option already done */ 763 } 764 765 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */ 766 if (tp != tags) 767 *tp++ = FLD_SEP; 768 sprintf(tp, "%d", tag); 769 tp += strlen(tp); 770 } 771 if (buf[0]) { 772 char env[128]; /* the string name */ 773 774 if (op->tag == 0) 775 sprintf(env, op->desc, opts[0].desc, tag); 776 else 777 sprintf(env, "%s%s", opts[0].desc, op->desc); 778 /* 779 * Do not replace existing values in the environment, so that 780 * locally-obtained values can override server-provided values. 781 */ 782 setenv(env, buf, 0); 783 } 784 } 785 if (tp != tags) { 786 char env[128]; /* the string name */ 787 sprintf(env, "%stags", opts[0].desc); 788 setenv(env, tags, 1); 789 } 790 } 791 #endif /* additional dhcp */ 792