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