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