bootp.c revision 301056
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: stable/10/lib/libstand/bootp.c 301056 2016-05-31 17:01:54Z ian $"); 40 41#include <sys/types.h> 42#include <sys/endian.h> 43#include <netinet/in.h> 44#include <netinet/in_systm.h> 45 46#include <string.h> 47 48#define BOOTP_DEBUGxx 49#define SUPPORT_DHCP 50 51#define DHCP_ENV_NOVENDOR 1 /* do not parse vendor options */ 52#define DHCP_ENV_PXE 10 /* assume pxe vendor options */ 53#define DHCP_ENV_FREEBSD 11 /* assume freebsd vendor options */ 54/* set DHCP_ENV to one of the values above to export dhcp options to kenv */ 55#define DHCP_ENV DHCP_ENV_NO_VENDOR 56 57#include "stand.h" 58#include "net.h" 59#include "netif.h" 60#include "bootp.h" 61 62 63struct in_addr servip; 64 65static n_long nmask, smask; 66 67static time_t bot; 68 69static char vm_rfc1048[4] = VM_RFC1048; 70#ifdef BOOTP_VEND_CMU 71static char vm_cmu[4] = VM_CMU; 72#endif 73 74/* Local forwards */ 75static ssize_t bootpsend(struct iodesc *, void *, size_t); 76static ssize_t bootprecv(struct iodesc *, void *, size_t, time_t); 77static int vend_rfc1048(u_char *, u_int); 78#ifdef BOOTP_VEND_CMU 79static void vend_cmu(u_char *); 80#endif 81 82#ifdef DHCP_ENV /* export the dhcp response to kenv */ 83struct dhcp_opt; 84static 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 90static char expected_dhcpmsgtype = -1, dhcp_ok; 91struct in_addr dhcp_serverip; 92#endif 93 94/* Fetch required bootp infomation */ 95void 96bootp(sock, flag) 97 int sock; 98 int flag; 99{ 100 struct iodesc *d; 101 struct bootp *bp; 102 struct { 103 u_char header[HEADER_SIZE]; 104 struct bootp wbootp; 105 } wbuf; 106 struct { 107 u_char header[HEADER_SIZE]; 108 struct bootp rbootp; 109 } rbuf; 110 111#ifdef BOOTP_DEBUG 112 if (debug) 113 printf("bootp: socket=%d\n", sock); 114#endif 115 if (!bot) 116 bot = getsecs(); 117 118 if (!(d = socktodesc(sock))) { 119 printf("bootp: bad socket. %d\n", sock); 120 return; 121 } 122#ifdef BOOTP_DEBUG 123 if (debug) 124 printf("bootp: d=%lx\n", (long)d); 125#endif 126 127 bp = &wbuf.wbootp; 128 bzero(bp, sizeof(*bp)); 129 130 bp->bp_op = BOOTREQUEST; 131 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 132 bp->bp_hlen = 6; 133 bp->bp_xid = htonl(d->xid); 134 MACPY(d->myea, bp->bp_chaddr); 135 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file)); 136 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 137#ifdef SUPPORT_DHCP 138 bp->bp_vend[4] = TAG_DHCP_MSGTYPE; 139 bp->bp_vend[5] = 1; 140 bp->bp_vend[6] = DHCPDISCOVER; 141 142 /* 143 * If we are booting from PXE, we want to send the string 144 * 'PXEClient' to the DHCP server so you have the option of 145 * only responding to PXE aware dhcp requests. 146 */ 147 if (flag & BOOTP_PXE) { 148 bp->bp_vend[7] = TAG_CLASSID; 149 bp->bp_vend[8] = 9; 150 bcopy("PXEClient", &bp->bp_vend[9], 9); 151 bp->bp_vend[18] = TAG_END; 152 } else 153 bp->bp_vend[7] = TAG_END; 154#else 155 bp->bp_vend[4] = TAG_END; 156#endif 157 158 d->myip.s_addr = INADDR_ANY; 159 d->myport = htons(IPPORT_BOOTPC); 160 d->destip.s_addr = INADDR_BROADCAST; 161 d->destport = htons(IPPORT_BOOTPS); 162 163#ifdef SUPPORT_DHCP 164 expected_dhcpmsgtype = DHCPOFFER; 165 dhcp_ok = 0; 166#endif 167 168 if(sendrecv(d, 169 bootpsend, bp, sizeof(*bp), 170 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 171 == -1) { 172 printf("bootp: no reply\n"); 173 return; 174 } 175 176#ifdef SUPPORT_DHCP 177 if(dhcp_ok) { 178 u_int32_t leasetime; 179 bp->bp_vend[6] = DHCPREQUEST; 180 bp->bp_vend[7] = TAG_REQ_ADDR; 181 bp->bp_vend[8] = 4; 182 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4); 183 bp->bp_vend[13] = TAG_SERVERID; 184 bp->bp_vend[14] = 4; 185 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4); 186 bp->bp_vend[19] = TAG_LEASETIME; 187 bp->bp_vend[20] = 4; 188 leasetime = htonl(300); 189 bcopy(&leasetime, &bp->bp_vend[21], 4); 190 if (flag & BOOTP_PXE) { 191 bp->bp_vend[25] = TAG_CLASSID; 192 bp->bp_vend[26] = 9; 193 bcopy("PXEClient", &bp->bp_vend[27], 9); 194 bp->bp_vend[36] = TAG_END; 195 } else 196 bp->bp_vend[25] = TAG_END; 197 198 expected_dhcpmsgtype = DHCPACK; 199 200 if(sendrecv(d, 201 bootpsend, bp, sizeof(*bp), 202 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp)) 203 == -1) { 204 printf("DHCPREQUEST failed\n"); 205 return; 206 } 207 } 208#endif 209 210 myip = d->myip = rbuf.rbootp.bp_yiaddr; 211 servip = rbuf.rbootp.bp_siaddr; 212 if(rootip.s_addr == INADDR_ANY) rootip = servip; 213 bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile)); 214 bootfile[sizeof(bootfile) - 1] = '\0'; 215 216 if (IN_CLASSA(ntohl(myip.s_addr))) 217 nmask = htonl(IN_CLASSA_NET); 218 else if (IN_CLASSB(ntohl(myip.s_addr))) 219 nmask = htonl(IN_CLASSB_NET); 220 else 221 nmask = htonl(IN_CLASSC_NET); 222#ifdef BOOTP_DEBUG 223 if (debug) 224 printf("'native netmask' is %s\n", intoa(nmask)); 225#endif 226 227 /* Check subnet mask against net mask; toss if bogus */ 228 if ((nmask & smask) != nmask) { 229#ifdef BOOTP_DEBUG 230 if (debug) 231 printf("subnet mask (%s) bad\n", intoa(smask)); 232#endif 233 smask = 0; 234 } 235 236 /* Get subnet (or natural net) mask */ 237 netmask = nmask; 238 if (smask) 239 netmask = smask; 240#ifdef BOOTP_DEBUG 241 if (debug) 242 printf("mask: %s\n", intoa(netmask)); 243#endif 244 245 /* We need a gateway if root is on a different net */ 246 if (!SAMENET(myip, rootip, netmask)) { 247#ifdef BOOTP_DEBUG 248 if (debug) 249 printf("need gateway for root ip\n"); 250#endif 251 } 252 253 /* Toss gateway if on a different net */ 254 if (!SAMENET(myip, gateip, netmask)) { 255#ifdef BOOTP_DEBUG 256 if (debug) 257 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 258#endif 259 gateip.s_addr = 0; 260 } 261 262 /* Bump xid so next request will be unique. */ 263 ++d->xid; 264} 265 266/* Transmit a bootp request */ 267static ssize_t 268bootpsend(d, pkt, len) 269 struct iodesc *d; 270 void *pkt; 271 size_t len; 272{ 273 struct bootp *bp; 274 275#ifdef BOOTP_DEBUG 276 if (debug) 277 printf("bootpsend: d=%lx called.\n", (long)d); 278#endif 279 280 bp = pkt; 281 bp->bp_secs = htons((u_short)(getsecs() - bot)); 282 283#ifdef BOOTP_DEBUG 284 if (debug) 285 printf("bootpsend: calling sendudp\n"); 286#endif 287 288 return (sendudp(d, pkt, len)); 289} 290 291static ssize_t 292bootprecv(d, pkt, len, tleft) 293struct iodesc *d; 294void *pkt; 295size_t len; 296time_t tleft; 297{ 298 ssize_t n; 299 struct bootp *bp; 300 301#ifdef BOOTP_DEBUGx 302 if (debug) 303 printf("bootp_recvoffer: called\n"); 304#endif 305 306 n = readudp(d, pkt, len, tleft); 307 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 308 goto bad; 309 310 bp = (struct bootp *)pkt; 311 312#ifdef BOOTP_DEBUG 313 if (debug) 314 printf("bootprecv: checked. bp = 0x%lx, n = %d\n", 315 (long)bp, (int)n); 316#endif 317 if (bp->bp_xid != htonl(d->xid)) { 318#ifdef BOOTP_DEBUG 319 if (debug) { 320 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 321 d->xid, ntohl(bp->bp_xid)); 322 } 323#endif 324 goto bad; 325 } 326 327#ifdef BOOTP_DEBUG 328 if (debug) 329 printf("bootprecv: got one!\n"); 330#endif 331 332 /* Suck out vendor info */ 333 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 334 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0) 335 goto bad; 336 } 337#ifdef BOOTP_VEND_CMU 338 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 339 vend_cmu(bp->bp_vend); 340#endif 341 else 342 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 343 344 return(n); 345bad: 346 errno = 0; 347 return (-1); 348} 349 350static int 351vend_rfc1048(cp, len) 352 u_char *cp; 353 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 if ((val = getenv("dhcp.interface-mtu")) != NULL) { 399 intf_mtu = (u_int)strtoul(val, NULL, 0); 400 } else { 401 intf_mtu = be16dec(cp); 402 } 403 } 404#ifdef SUPPORT_DHCP 405 if (tag == TAG_DHCP_MSGTYPE) { 406 if(*cp != expected_dhcpmsgtype) 407 return(-1); 408 dhcp_ok = 1; 409 } 410 if (tag == TAG_SERVERID) { 411 bcopy(cp, &dhcp_serverip.s_addr, 412 sizeof(dhcp_serverip.s_addr)); 413 } 414#endif 415 cp += size; 416 } 417 return(0); 418} 419 420#ifdef BOOTP_VEND_CMU 421static void 422vend_cmu(cp) 423 u_char *cp; 424{ 425 struct cmu_vend *vp; 426 427#ifdef BOOTP_DEBUG 428 if (debug) 429 printf("vend_cmu bootp info.\n"); 430#endif 431 vp = (struct cmu_vend *)cp; 432 433 if (vp->v_smask.s_addr != 0) { 434 smask = vp->v_smask.s_addr; 435 } 436 if (vp->v_dgate.s_addr != 0) { 437 gateip = vp->v_dgate; 438 } 439} 440#endif 441 442#ifdef DHCP_ENV 443/* 444 * Parse DHCP options and store them into kenv variables. 445 * Original code from Danny Braniss, modifications by Luigi Rizzo. 446 * 447 * The parser is driven by tables which specify the type and name of 448 * each dhcp option and how it appears in kenv. 449 * The first entry in the list contains the prefix used to set the kenv 450 * name (including the . if needed), the last entry must have a 0 tag. 451 * Entries do not need to be sorted though it helps for readability. 452 * 453 * Certain vendor-specific tables can be enabled according to DHCP_ENV. 454 * Set it to 0 if you don't want any. 455 */ 456enum opt_fmt { __NONE = 0, 457 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */ 458 __IP, /* IPv4 address */ 459 __TXT, /* C string */ 460 __BYTES, /* byte sequence, printed %02x */ 461 __INDIR, /* name=value */ 462 __ILIST, /* name=value;name=value ... */ 463 __VE, /* vendor specific, recurse */ 464}; 465 466struct dhcp_opt { 467 uint8_t tag; 468 uint8_t fmt; 469 const char *desc; 470}; 471 472static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */ 473#if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */ 474 {0, 0, "FreeBSD"}, /* prefix */ 475 {1, __TXT, "kernel"}, 476 {2, __TXT, "kernelname"}, 477 {3, __TXT, "kernel_options"}, 478 {4, __IP, "usr-ip"}, 479 {5, __TXT, "conf-path"}, 480 {6, __TXT, "rc.conf0"}, 481 {7, __TXT, "rc.conf1"}, 482 {8, __TXT, "rc.conf2"}, 483 {9, __TXT, "rc.conf3"}, 484 {10, __TXT, "rc.conf4"}, 485 {11, __TXT, "rc.conf5"}, 486 {12, __TXT, "rc.conf6"}, 487 {13, __TXT, "rc.conf7"}, 488 {14, __TXT, "rc.conf8"}, 489 {15, __TXT, "rc.conf9"}, 490 491 {20, __TXT, "boot.nfsroot.options"}, 492 493 {245, __INDIR, ""}, 494 {246, __INDIR, ""}, 495 {247, __INDIR, ""}, 496 {248, __INDIR, ""}, 497 {249, __INDIR, ""}, 498 {250, __INDIR, ""}, 499 {251, __INDIR, ""}, 500 {252, __INDIR, ""}, 501 {253, __INDIR, ""}, 502 {254, __INDIR, ""}, 503 504#elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */ 505 {0, 0, "pxe"}, /* prefix */ 506 {93, __16, "system-architecture"}, 507 {94, __BYTES, "network-interface"}, 508 {97, __BYTES, "machine-identifier"}, 509#else /* default (empty) table */ 510 {0, 0, "dhcp.vendor."}, /* prefix */ 511#endif 512 {0, __TXT, "%soption-%d"} 513}; 514 515static struct dhcp_opt dhcp_opt[] = { 516 /* DHCP Option names, formats and codes, from RFC2132. */ 517 {0, 0, "dhcp."}, // prefix 518 {1, __IP, "subnet-mask"}, 519 {2, __32, "time-offset"}, /* this is signed */ 520 {3, __IP, "routers"}, 521 {4, __IP, "time-servers"}, 522 {5, __IP, "ien116-name-servers"}, 523 {6, __IP, "domain-name-servers"}, 524 {7, __IP, "log-servers"}, 525 {8, __IP, "cookie-servers"}, 526 {9, __IP, "lpr-servers"}, 527 {10, __IP, "impress-servers"}, 528 {11, __IP, "resource-location-servers"}, 529 {12, __TXT, "host-name"}, 530 {13, __16, "boot-size"}, 531 {14, __TXT, "merit-dump"}, 532 {15, __TXT, "domain-name"}, 533 {16, __IP, "swap-server"}, 534 {17, __TXT, "root-path"}, 535 {18, __TXT, "extensions-path"}, 536 {19, __8, "ip-forwarding"}, 537 {20, __8, "non-local-source-routing"}, 538 {21, __IP, "policy-filter"}, 539 {22, __16, "max-dgram-reassembly"}, 540 {23, __8, "default-ip-ttl"}, 541 {24, __32, "path-mtu-aging-timeout"}, 542 {25, __16, "path-mtu-plateau-table"}, 543 {26, __16, "interface-mtu"}, 544 {27, __8, "all-subnets-local"}, 545 {28, __IP, "broadcast-address"}, 546 {29, __8, "perform-mask-discovery"}, 547 {30, __8, "mask-supplier"}, 548 {31, __8, "perform-router-discovery"}, 549 {32, __IP, "router-solicitation-address"}, 550 {33, __IP, "static-routes"}, 551 {34, __8, "trailer-encapsulation"}, 552 {35, __32, "arp-cache-timeout"}, 553 {36, __8, "ieee802-3-encapsulation"}, 554 {37, __8, "default-tcp-ttl"}, 555 {38, __32, "tcp-keepalive-interval"}, 556 {39, __8, "tcp-keepalive-garbage"}, 557 {40, __TXT, "nis-domain"}, 558 {41, __IP, "nis-servers"}, 559 {42, __IP, "ntp-servers"}, 560 {43, __VE, "vendor-encapsulated-options"}, 561 {44, __IP, "netbios-name-servers"}, 562 {45, __IP, "netbios-dd-server"}, 563 {46, __8, "netbios-node-type"}, 564 {47, __TXT, "netbios-scope"}, 565 {48, __IP, "x-font-servers"}, 566 {49, __IP, "x-display-managers"}, 567 {50, __IP, "dhcp-requested-address"}, 568 {51, __32, "dhcp-lease-time"}, 569 {52, __8, "dhcp-option-overload"}, 570 {53, __8, "dhcp-message-type"}, 571 {54, __IP, "dhcp-server-identifier"}, 572 {55, __8, "dhcp-parameter-request-list"}, 573 {56, __TXT, "dhcp-message"}, 574 {57, __16, "dhcp-max-message-size"}, 575 {58, __32, "dhcp-renewal-time"}, 576 {59, __32, "dhcp-rebinding-time"}, 577 {60, __TXT, "vendor-class-identifier"}, 578 {61, __TXT, "dhcp-client-identifier"}, 579 {64, __TXT, "nisplus-domain"}, 580 {65, __IP, "nisplus-servers"}, 581 {66, __TXT, "tftp-server-name"}, 582 {67, __TXT, "bootfile-name"}, 583 {68, __IP, "mobile-ip-home-agent"}, 584 {69, __IP, "smtp-server"}, 585 {70, __IP, "pop-server"}, 586 {71, __IP, "nntp-server"}, 587 {72, __IP, "www-server"}, 588 {73, __IP, "finger-server"}, 589 {74, __IP, "irc-server"}, 590 {75, __IP, "streettalk-server"}, 591 {76, __IP, "streettalk-directory-assistance-server"}, 592 {77, __TXT, "user-class"}, 593 {85, __IP, "nds-servers"}, 594 {86, __TXT, "nds-tree-name"}, 595 {87, __TXT, "nds-context"}, 596 {210, __TXT, "authenticate"}, 597 598 /* use the following entries for arbitrary variables */ 599 {246, __ILIST, ""}, 600 {247, __ILIST, ""}, 601 {248, __ILIST, ""}, 602 {249, __ILIST, ""}, 603 {250, __INDIR, ""}, 604 {251, __INDIR, ""}, 605 {252, __INDIR, ""}, 606 {253, __INDIR, ""}, 607 {254, __INDIR, ""}, 608 {0, __TXT, "%soption-%d"} 609}; 610 611/* 612 * parse a dhcp response, set environment variables translating options 613 * names and values according to the tables above. Also set dhcp.tags 614 * to the list of selected tags. 615 */ 616static void 617setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts) 618{ 619 u_char *ncp; 620 u_char tag; 621 char tags[512], *tp; /* the list of tags */ 622 623#define FLD_SEP ',' /* separator in list of elements */ 624 ncp = cp; 625 tp = tags; 626 if (opts == NULL) 627 opts = dhcp_opt; 628 629 while (ncp < ep) { 630 unsigned int size; /* option size */ 631 char *vp, *endv, buf[256]; /* the value buffer */ 632 struct dhcp_opt *op; 633 634 tag = *ncp++; /* extract tag and size */ 635 size = *ncp++; 636 cp = ncp; /* current payload */ 637 ncp += size; /* point to the next option */ 638 639 if (tag == TAG_END) 640 break; 641 if (tag == 0) 642 continue; 643 644 for (op = opts+1; op->tag && op->tag != tag; op++) 645 ; 646 /* if not found we end up on the default entry */ 647 648 /* 649 * Copy data into the buffer. libstand does not have snprintf so we 650 * need to be careful with sprintf(). With strings, the source is 651 * always <256 char so shorter than the buffer so we are safe; with 652 * other arguments, the longest string is inet_ntoa which is 16 bytes 653 * so we make sure to have always enough room in the string before 654 * trying an sprint. 655 */ 656 vp = buf; 657 *vp = '\0'; 658 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */ 659 660 switch(op->fmt) { 661 case __NONE: 662 break; /* should not happen */ 663 664 case __VE: /* recurse, vendor specific */ 665 setenv_(cp, cp+size, vndr_opt); 666 break; 667 668 case __IP: /* ip address */ 669 for (; size > 0 && vp < endv; size -= 4, cp += 4) { 670 struct in_addr in_ip; /* ip addresses */ 671 if (vp != buf) 672 *vp++ = FLD_SEP; 673 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr)); 674 sprintf(vp, "%s", inet_ntoa(in_ip)); 675 vp += strlen(vp); 676 } 677 break; 678 679 case __BYTES: /* opaque byte string */ 680 for (; size > 0 && vp < endv; size -= 1, cp += 1) { 681 sprintf(vp, "%02x", *cp); 682 vp += strlen(vp); 683 } 684 break; 685 686 case __TXT: 687 bcopy(cp, buf, size); /* cannot overflow */ 688 buf[size] = 0; 689 break; 690 691 case __32: 692 case __16: 693 case __8: /* op->fmt is also the length of each field */ 694 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) { 695 uint32_t v; 696 if (op->fmt == __32) 697 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3]; 698 else if (op->fmt == __16) 699 v = (cp[0]<<8) + cp[1]; 700 else 701 v = cp[0]; 702 if (vp != buf) 703 *vp++ = FLD_SEP; 704 sprintf(vp, "%u", v); 705 vp += strlen(vp); 706 } 707 break; 708 709 case __INDIR: /* name=value */ 710 case __ILIST: /* name=value;name=value... */ 711 bcopy(cp, buf, size); /* cannot overflow */ 712 buf[size] = '\0'; 713 for (endv = buf; endv; endv = vp) { 714 u_char *s = NULL; /* semicolon ? */ 715 716 /* skip leading whitespace */ 717 while (*endv && strchr(" \t\n\r", *endv)) 718 endv++; 719 vp = strchr(endv, '='); /* find name=value separator */ 720 if (!vp) 721 break; 722 *vp++ = 0; 723 if (op->fmt == __ILIST && (s = strchr(vp, ';'))) 724 *s++ = '\0'; 725 setenv(endv, vp, 1); 726 vp = s; /* prepare for next round */ 727 } 728 buf[0] = '\0'; /* option already done */ 729 } 730 731 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */ 732 if (tp != tags) 733 *tp++ = FLD_SEP; 734 sprintf(tp, "%d", tag); 735 tp += strlen(tp); 736 } 737 if (buf[0]) { 738 char env[128]; /* the string name */ 739 740 if (op->tag == 0) 741 sprintf(env, op->desc, opts[0].desc, tag); 742 else 743 sprintf(env, "%s%s", opts[0].desc, op->desc); 744 /* 745 * Do not replace existing values in the environment, so that 746 * locally-obtained values can override server-provided values. 747 */ 748 setenv(env, buf, 0); 749 } 750 } 751 if (tp != tags) { 752 char env[128]; /* the string name */ 753 sprintf(env, "%stags", opts[0].desc); 754 setenv(env, tags, 1); 755 } 756} 757#endif /* additional dhcp */ 758