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