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 static int 359 vend_rfc1048(u_char *cp, u_int len) 360 { 361 u_char *ep; 362 int size; 363 u_char tag; 364 const char *val; 365 366 #ifdef BOOTP_DEBUG 367 if (debug) 368 printf("vend_rfc1048 bootp info. len=%d\n", len); 369 #endif 370 ep = cp + len; 371 372 /* Step over magic cookie */ 373 cp += sizeof(int); 374 375 setenv_(cp, ep, NULL); 376 377 while (cp < ep) { 378 tag = *cp++; 379 size = *cp++; 380 if (tag == TAG_END) 381 break; 382 383 if (tag == TAG_SUBNET_MASK) { 384 bcopy(cp, &netmask, sizeof(netmask)); 385 } 386 if (tag == TAG_GATEWAY) { 387 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 388 } 389 if (tag == TAG_SWAPSERVER) { 390 /* let it override bp_siaddr */ 391 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr)); 392 } 393 if (tag == TAG_ROOTPATH) { 394 if ((val = getenv("dhcp.root-path")) == NULL) 395 val = (const char *)cp; 396 strlcpy(rootpath, val, sizeof(rootpath)); 397 } 398 if (tag == TAG_HOSTNAME) { 399 if ((val = getenv("dhcp.host-name")) == NULL) 400 val = (const char *)cp; 401 strlcpy(hostname, val, sizeof(hostname)); 402 } 403 if (tag == TAG_INTF_MTU) { 404 intf_mtu = 0; 405 if ((val = getenv("dhcp.interface-mtu")) != NULL) { 406 unsigned long tmp; 407 char *end; 408 409 errno = 0; 410 /* 411 * Do not allow MTU to exceed max IPv4 packet 412 * size, max value of 16-bit word. 413 */ 414 tmp = strtoul(val, &end, 0); 415 if (errno != 0 || 416 *val == '\0' || *end != '\0' || 417 tmp > USHRT_MAX) { 418 printf("%s: bad value: \"%s\", " 419 "ignoring\n", 420 "dhcp.interface-mtu", val); 421 } else { 422 intf_mtu = (u_int)tmp; 423 } 424 } 425 if (intf_mtu <= 0) 426 intf_mtu = be16dec(cp); 427 } 428 #ifdef SUPPORT_DHCP 429 if (tag == TAG_DHCP_MSGTYPE) { 430 if(*cp != expected_dhcpmsgtype) 431 return(-1); 432 dhcp_ok = 1; 433 } 434 if (tag == TAG_SERVERID) { 435 bcopy(cp, &dhcp_serverip.s_addr, 436 sizeof(dhcp_serverip.s_addr)); 437 } 438 #endif 439 cp += size; 440 } 441 return(0); 442 } 443 444 #ifdef BOOTP_VEND_CMU 445 static void 446 vend_cmu(u_char *cp) 447 { 448 struct cmu_vend *vp; 449 450 #ifdef BOOTP_DEBUG 451 if (debug) 452 printf("vend_cmu bootp info.\n"); 453 #endif 454 vp = (struct cmu_vend *)cp; 455 456 if (vp->v_smask.s_addr != 0) { 457 netmask = vp->v_smask.s_addr; 458 } 459 if (vp->v_dgate.s_addr != 0) { 460 gateip = vp->v_dgate; 461 } 462 } 463 #endif 464 465 #ifdef DHCP_ENV 466 /* 467 * Parse DHCP options and store them into kenv variables. 468 * Original code from Danny Braniss, modifications by Luigi Rizzo. 469 * 470 * The parser is driven by tables which specify the type and name of 471 * each dhcp option and how it appears in kenv. 472 * The first entry in the list contains the prefix used to set the kenv 473 * name (including the . if needed), the last entry must have a 0 tag. 474 * Entries do not need to be sorted though it helps for readability. 475 * 476 * Certain vendor-specific tables can be enabled according to DHCP_ENV. 477 * Set it to 0 if you don't want any. 478 */ 479 enum opt_fmt { __NONE = 0, 480 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */ 481 __IP, /* IPv4 address */ 482 __TXT, /* C string */ 483 __BYTES, /* byte sequence, printed %02x */ 484 __INDIR, /* name=value */ 485 __ILIST, /* name=value;name=value ... */ 486 __VE, /* vendor specific, recurse */ 487 }; 488 489 struct dhcp_opt { 490 uint8_t tag; 491 uint8_t fmt; 492 const char *desc; 493 }; 494 495 static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */ 496 #if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */ 497 {0, 0, "FreeBSD"}, /* prefix */ 498 {1, __TXT, "kernel"}, 499 {2, __TXT, "kernelname"}, 500 {3, __TXT, "kernel_options"}, 501 {4, __IP, "usr-ip"}, 502 {5, __TXT, "conf-path"}, 503 {6, __TXT, "rc.conf0"}, 504 {7, __TXT, "rc.conf1"}, 505 {8, __TXT, "rc.conf2"}, 506 {9, __TXT, "rc.conf3"}, 507 {10, __TXT, "rc.conf4"}, 508 {11, __TXT, "rc.conf5"}, 509 {12, __TXT, "rc.conf6"}, 510 {13, __TXT, "rc.conf7"}, 511 {14, __TXT, "rc.conf8"}, 512 {15, __TXT, "rc.conf9"}, 513 514 {20, __TXT, "boot.nfsroot.options"}, 515 516 {245, __INDIR, ""}, 517 {246, __INDIR, ""}, 518 {247, __INDIR, ""}, 519 {248, __INDIR, ""}, 520 {249, __INDIR, ""}, 521 {250, __INDIR, ""}, 522 {251, __INDIR, ""}, 523 {252, __INDIR, ""}, 524 {253, __INDIR, ""}, 525 {254, __INDIR, ""}, 526 527 #elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */ 528 {0, 0, "pxe"}, /* prefix */ 529 {93, __16, "system-architecture"}, 530 {94, __BYTES, "network-interface"}, 531 {97, __BYTES, "machine-identifier"}, 532 #else /* default (empty) table */ 533 {0, 0, "dhcp.vendor."}, /* prefix */ 534 #endif 535 {0, __TXT, "%soption-%d"} 536 }; 537 538 static struct dhcp_opt dhcp_opt[] = { 539 /* DHCP Option names, formats and codes, from RFC2132. */ 540 {0, 0, "dhcp."}, // prefix 541 {1, __IP, "subnet-mask"}, 542 {2, __32, "time-offset"}, /* this is signed */ 543 {3, __IP, "routers"}, 544 {4, __IP, "time-servers"}, 545 {5, __IP, "ien116-name-servers"}, 546 {6, __IP, "domain-name-servers"}, 547 {7, __IP, "log-servers"}, 548 {8, __IP, "cookie-servers"}, 549 {9, __IP, "lpr-servers"}, 550 {10, __IP, "impress-servers"}, 551 {11, __IP, "resource-location-servers"}, 552 {12, __TXT, "host-name"}, 553 {13, __16, "boot-size"}, 554 {14, __TXT, "merit-dump"}, 555 {15, __TXT, "domain-name"}, 556 {16, __IP, "swap-server"}, 557 {17, __TXT, "root-path"}, 558 {18, __TXT, "extensions-path"}, 559 {19, __8, "ip-forwarding"}, 560 {20, __8, "non-local-source-routing"}, 561 {21, __IP, "policy-filter"}, 562 {22, __16, "max-dgram-reassembly"}, 563 {23, __8, "default-ip-ttl"}, 564 {24, __32, "path-mtu-aging-timeout"}, 565 {25, __16, "path-mtu-plateau-table"}, 566 {26, __16, "interface-mtu"}, 567 {27, __8, "all-subnets-local"}, 568 {28, __IP, "broadcast-address"}, 569 {29, __8, "perform-mask-discovery"}, 570 {30, __8, "mask-supplier"}, 571 {31, __8, "perform-router-discovery"}, 572 {32, __IP, "router-solicitation-address"}, 573 {33, __IP, "static-routes"}, 574 {34, __8, "trailer-encapsulation"}, 575 {35, __32, "arp-cache-timeout"}, 576 {36, __8, "ieee802-3-encapsulation"}, 577 {37, __8, "default-tcp-ttl"}, 578 {38, __32, "tcp-keepalive-interval"}, 579 {39, __8, "tcp-keepalive-garbage"}, 580 {40, __TXT, "nis-domain"}, 581 {41, __IP, "nis-servers"}, 582 {42, __IP, "ntp-servers"}, 583 {43, __VE, "vendor-encapsulated-options"}, 584 {44, __IP, "netbios-name-servers"}, 585 {45, __IP, "netbios-dd-server"}, 586 {46, __8, "netbios-node-type"}, 587 {47, __TXT, "netbios-scope"}, 588 {48, __IP, "x-font-servers"}, 589 {49, __IP, "x-display-managers"}, 590 {50, __IP, "dhcp-requested-address"}, 591 {51, __32, "dhcp-lease-time"}, 592 {52, __8, "dhcp-option-overload"}, 593 {53, __8, "dhcp-message-type"}, 594 {54, __IP, "dhcp-server-identifier"}, 595 {55, __8, "dhcp-parameter-request-list"}, 596 {56, __TXT, "dhcp-message"}, 597 {57, __16, "dhcp-max-message-size"}, 598 {58, __32, "dhcp-renewal-time"}, 599 {59, __32, "dhcp-rebinding-time"}, 600 {60, __TXT, "vendor-class-identifier"}, 601 {61, __TXT, "dhcp-client-identifier"}, 602 {64, __TXT, "nisplus-domain"}, 603 {65, __IP, "nisplus-servers"}, 604 {66, __TXT, "tftp-server-name"}, 605 {67, __TXT, "bootfile-name"}, 606 {68, __IP, "mobile-ip-home-agent"}, 607 {69, __IP, "smtp-server"}, 608 {70, __IP, "pop-server"}, 609 {71, __IP, "nntp-server"}, 610 {72, __IP, "www-server"}, 611 {73, __IP, "finger-server"}, 612 {74, __IP, "irc-server"}, 613 {75, __IP, "streettalk-server"}, 614 {76, __IP, "streettalk-directory-assistance-server"}, 615 {77, __TXT, "user-class"}, 616 {85, __IP, "nds-servers"}, 617 {86, __TXT, "nds-tree-name"}, 618 {87, __TXT, "nds-context"}, 619 {210, __TXT, "authenticate"}, 620 621 /* use the following entries for arbitrary variables */ 622 {246, __ILIST, ""}, 623 {247, __ILIST, ""}, 624 {248, __ILIST, ""}, 625 {249, __ILIST, ""}, 626 {250, __INDIR, ""}, 627 {251, __INDIR, ""}, 628 {252, __INDIR, ""}, 629 {253, __INDIR, ""}, 630 {254, __INDIR, ""}, 631 {0, __TXT, "%soption-%d"} 632 }; 633 634 /* 635 * parse a dhcp response, set environment variables translating options 636 * names and values according to the tables above. Also set dhcp.tags 637 * to the list of selected tags. 638 */ 639 static void 640 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts) 641 { 642 u_char *ncp; 643 u_char tag; 644 char tags[512], *tp; /* the list of tags */ 645 646 #define FLD_SEP ',' /* separator in list of elements */ 647 ncp = cp; 648 tp = tags; 649 if (opts == NULL) 650 opts = dhcp_opt; 651 652 while (ncp < ep) { 653 unsigned int size; /* option size */ 654 char *vp, *endv, buf[256]; /* the value buffer */ 655 struct dhcp_opt *op; 656 657 tag = *ncp++; /* extract tag and size */ 658 size = *ncp++; 659 cp = ncp; /* current payload */ 660 ncp += size; /* point to the next option */ 661 662 if (tag == TAG_END) 663 break; 664 if (tag == 0) 665 continue; 666 667 for (op = opts+1; op->tag && op->tag != tag; op++) 668 ; 669 /* if not found we end up on the default entry */ 670 671 /* 672 * Copy data into the buffer. libstand does not have snprintf so we 673 * need to be careful with sprintf(). With strings, the source is 674 * always <256 char so shorter than the buffer so we are safe; with 675 * other arguments, the longest string is inet_ntoa which is 16 bytes 676 * so we make sure to have always enough room in the string before 677 * trying an sprint. 678 */ 679 vp = buf; 680 *vp = '\0'; 681 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */ 682 683 switch(op->fmt) { 684 case __NONE: 685 break; /* should not happen */ 686 687 case __VE: /* recurse, vendor specific */ 688 setenv_(cp, cp+size, vndr_opt); 689 break; 690 691 case __IP: /* ip address */ 692 for (; size > 0 && vp < endv; size -= 4, cp += 4) { 693 struct in_addr in_ip; /* ip addresses */ 694 if (vp != buf) 695 *vp++ = FLD_SEP; 696 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr)); 697 sprintf(vp, "%s", inet_ntoa(in_ip)); 698 vp += strlen(vp); 699 } 700 break; 701 702 case __BYTES: /* opaque byte string */ 703 for (; size > 0 && vp < endv; size -= 1, cp += 1) { 704 sprintf(vp, "%02x", *cp); 705 vp += strlen(vp); 706 } 707 break; 708 709 case __TXT: 710 bcopy(cp, buf, size); /* cannot overflow */ 711 buf[size] = 0; 712 break; 713 714 case __32: 715 case __16: 716 case __8: /* op->fmt is also the length of each field */ 717 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) { 718 uint32_t v; 719 if (op->fmt == __32) 720 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3]; 721 else if (op->fmt == __16) 722 v = (cp[0]<<8) + cp[1]; 723 else 724 v = cp[0]; 725 if (vp != buf) 726 *vp++ = FLD_SEP; 727 sprintf(vp, "%u", v); 728 vp += strlen(vp); 729 } 730 break; 731 732 case __INDIR: /* name=value */ 733 case __ILIST: /* name=value;name=value... */ 734 bcopy(cp, buf, size); /* cannot overflow */ 735 buf[size] = '\0'; 736 for (endv = buf; endv; endv = vp) { 737 u_char *s = NULL; /* semicolon ? */ 738 739 /* skip leading whitespace */ 740 while (*endv && strchr(" \t\n\r", *endv)) 741 endv++; 742 vp = strchr(endv, '='); /* find name=value separator */ 743 if (!vp) 744 break; 745 *vp++ = 0; 746 if (op->fmt == __ILIST && (s = strchr(vp, ';'))) 747 *s++ = '\0'; 748 setenv(endv, vp, 1); 749 vp = s; /* prepare for next round */ 750 } 751 buf[0] = '\0'; /* option already done */ 752 } 753 754 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */ 755 if (tp != tags) 756 *tp++ = FLD_SEP; 757 sprintf(tp, "%d", tag); 758 tp += strlen(tp); 759 } 760 if (buf[0]) { 761 char env[128]; /* the string name */ 762 763 if (op->tag == 0) 764 sprintf(env, op->desc, opts[0].desc, tag); 765 else 766 sprintf(env, "%s%s", opts[0].desc, op->desc); 767 /* 768 * Do not replace existing values in the environment, so that 769 * locally-obtained values can override server-provided values. 770 */ 771 setenv(env, buf, 0); 772 } 773 } 774 if (tp != tags) { 775 char env[128]; /* the string name */ 776 sprintf(env, "%stags", opts[0].desc); 777 setenv(env, tags, 1); 778 } 779 } 780 #endif /* additional dhcp */ 781