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