1 /* 2 * Copyright (c) 1992 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This software was developed by the Computer Systems Engineering group 6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7 * contributed to Berkeley. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 36 #include <stddef.h> 37 #include <sys/types.h> 38 #include <sys/limits.h> 39 #include <sys/endian.h> 40 #include <netinet/in.h> 41 #include <netinet/in_systm.h> 42 43 #include <string.h> 44 45 #define BOOTP_DEBUGxx 46 #define SUPPORT_DHCP 47 48 #define DHCP_ENV_NOVENDOR 1 /* do not parse vendor options */ 49 #define DHCP_ENV_PXE 10 /* assume pxe vendor options */ 50 #define DHCP_ENV_FREEBSD 11 /* assume freebsd vendor options */ 51 /* set DHCP_ENV to one of the values above to export dhcp options to kenv */ 52 #define DHCP_ENV DHCP_ENV_NO_VENDOR 53 54 #include "stand.h" 55 #include "net.h" 56 #include "netif.h" 57 #include "bootp.h" 58 59 60 struct in_addr servip; 61 62 static time_t bot; 63 64 static char vm_rfc1048[4] = VM_RFC1048; 65 #ifdef BOOTP_VEND_CMU 66 static char vm_cmu[4] = VM_CMU; 67 #endif 68 69 /* Local forwards */ 70 static ssize_t bootpsend(struct iodesc *, void *, size_t); 71 static ssize_t bootprecv(struct iodesc *, void **, void **, time_t); 72 static int vend_rfc1048(u_char *, u_int); 73 #ifdef BOOTP_VEND_CMU 74 static void vend_cmu(u_char *); 75 #endif 76 77 #ifdef DHCP_ENV /* export the dhcp response to kenv */ 78 struct dhcp_opt; 79 static void setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts); 80 #else 81 #define setenv_(a, b, c) 82 #endif 83 84 #ifdef SUPPORT_DHCP 85 static char expected_dhcpmsgtype = -1, dhcp_ok; 86 struct in_addr dhcp_serverip; 87 #endif 88 struct bootp *bootp_response; 89 size_t bootp_response_size; 90 91 /* Fetch required bootp infomation */ 92 void 93 bootp(int sock) 94 { 95 void *pkt; 96 struct iodesc *d; 97 struct bootp *bp; 98 struct { 99 u_char header[HEADER_SIZE]; 100 struct bootp wbootp; 101 } wbuf; 102 struct bootp *rbootp; 103 104 #ifdef BOOTP_DEBUG 105 if (debug) 106 printf("bootp: socket=%d\n", sock); 107 #endif 108 if (!bot) 109 bot = getsecs(); 110 111 if (!(d = socktodesc(sock))) { 112 printf("bootp: bad socket. %d\n", sock); 113 return; 114 } 115 #ifdef BOOTP_DEBUG 116 if (debug) 117 printf("bootp: d=%lx\n", (long)d); 118 #endif 119 120 bp = &wbuf.wbootp; 121 bzero(bp, sizeof(*bp)); 122 123 bp->bp_op = BOOTREQUEST; 124 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */ 125 bp->bp_hlen = 6; 126 bp->bp_xid = htonl(d->xid); 127 MACPY(d->myea, bp->bp_chaddr); 128 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file)); 129 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)); 130 #ifdef SUPPORT_DHCP 131 bp->bp_vend[4] = TAG_DHCP_MSGTYPE; 132 bp->bp_vend[5] = 1; 133 bp->bp_vend[6] = DHCPDISCOVER; 134 135 /* 136 * We are booting from PXE, we want to send the string 137 * 'PXEClient' to the DHCP server so you have the option of 138 * only responding to PXE aware dhcp requests. 139 */ 140 bp->bp_vend[7] = TAG_CLASSID; 141 bp->bp_vend[8] = 9; 142 bcopy("PXEClient", &bp->bp_vend[9], 9); 143 bp->bp_vend[18] = TAG_USER_CLASS; 144 /* len of each user class + number of user class */ 145 bp->bp_vend[19] = 8; 146 /* len of the first user class */ 147 bp->bp_vend[20] = 7; 148 bcopy("illumos", &bp->bp_vend[21], 7); 149 bp->bp_vend[28] = TAG_PARAM_REQ; 150 bp->bp_vend[29] = 7; 151 bp->bp_vend[30] = TAG_ROOTPATH; 152 bp->bp_vend[31] = TAG_HOSTNAME; 153 bp->bp_vend[32] = TAG_SWAPSERVER; 154 bp->bp_vend[33] = TAG_GATEWAY; 155 bp->bp_vend[34] = TAG_SUBNET_MASK; 156 bp->bp_vend[35] = TAG_INTF_MTU; 157 bp->bp_vend[36] = TAG_SERVERID; 158 bp->bp_vend[37] = 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, &pkt, (void **)&rbootp) == -1) { 176 printf("bootp: no reply\n"); 177 return; 178 } 179 180 #ifdef SUPPORT_DHCP 181 if(dhcp_ok) { 182 u_int32_t leasetime; 183 bp->bp_vend[6] = DHCPREQUEST; 184 bp->bp_vend[7] = TAG_REQ_ADDR; 185 bp->bp_vend[8] = 4; 186 bcopy(&rbootp->bp_yiaddr, &bp->bp_vend[9], 4); 187 bp->bp_vend[13] = TAG_SERVERID; 188 bp->bp_vend[14] = 4; 189 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4); 190 bp->bp_vend[19] = TAG_LEASETIME; 191 bp->bp_vend[20] = 4; 192 leasetime = htonl(300); 193 bcopy(&leasetime, &bp->bp_vend[21], 4); 194 bp->bp_vend[25] = TAG_CLASSID; 195 bp->bp_vend[26] = 9; 196 bcopy("PXEClient", &bp->bp_vend[27], 9); 197 bp->bp_vend[36] = TAG_END; 198 199 expected_dhcpmsgtype = DHCPACK; 200 201 free(pkt); 202 if(sendrecv(d, 203 bootpsend, bp, sizeof(*bp), 204 bootprecv, &pkt, (void **)&rbootp) == -1) { 205 printf("DHCPREQUEST failed\n"); 206 return; 207 } 208 } 209 #endif 210 211 myip = d->myip = rbootp->bp_yiaddr; 212 servip = rbootp->bp_siaddr; 213 if (rootip.s_addr == INADDR_ANY) 214 rootip = servip; 215 bcopy(rbootp->bp_file, bootfile, sizeof(bootfile)); 216 bootfile[sizeof(bootfile) - 1] = '\0'; 217 218 if (!netmask) { 219 if (IN_CLASSA(ntohl(myip.s_addr))) 220 netmask = htonl(IN_CLASSA_NET); 221 else if (IN_CLASSB(ntohl(myip.s_addr))) 222 netmask = htonl(IN_CLASSB_NET); 223 else 224 netmask = htonl(IN_CLASSC_NET); 225 #ifdef BOOTP_DEBUG 226 if (debug) 227 printf("'native netmask' is %s\n", intoa(netmask)); 228 #endif 229 } 230 231 #ifdef BOOTP_DEBUG 232 if (debug) 233 printf("mask: %s\n", intoa(netmask)); 234 #endif 235 236 /* We need a gateway if root is on a different net */ 237 if (!SAMENET(myip, rootip, netmask)) { 238 #ifdef BOOTP_DEBUG 239 if (debug) 240 printf("need gateway for root ip\n"); 241 #endif 242 } 243 244 /* Toss gateway if on a different net */ 245 if (!SAMENET(myip, gateip, netmask)) { 246 #ifdef BOOTP_DEBUG 247 if (debug) 248 printf("gateway ip (%s) bad\n", inet_ntoa(gateip)); 249 #endif 250 gateip.s_addr = 0; 251 } 252 253 /* Bump xid so next request will be unique. */ 254 ++d->xid; 255 free(pkt); 256 } 257 258 /* Transmit a bootp request */ 259 static ssize_t 260 bootpsend(struct iodesc *d, void *pkt, size_t len) 261 { 262 struct bootp *bp; 263 264 #ifdef BOOTP_DEBUG 265 if (debug) 266 printf("bootpsend: d=%lx called.\n", (long)d); 267 #endif 268 269 bp = pkt; 270 bp->bp_secs = htons((u_short)(getsecs() - bot)); 271 272 #ifdef BOOTP_DEBUG 273 if (debug) 274 printf("bootpsend: calling sendudp\n"); 275 #endif 276 277 return (sendudp(d, pkt, len)); 278 } 279 280 static ssize_t 281 bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft) 282 { 283 ssize_t n; 284 struct bootp *bp; 285 void *ptr; 286 287 #ifdef BOOTP_DEBUG 288 if (debug) 289 printf("bootp_recvoffer: called\n"); 290 #endif 291 292 ptr = NULL; 293 n = readudp(d, &ptr, (void **)&bp, tleft); 294 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE) 295 goto bad; 296 297 #ifdef BOOTP_DEBUG 298 if (debug) 299 printf("bootprecv: checked. bp = %p, n = %zd\n", bp, n); 300 #endif 301 if (bp->bp_xid != htonl(d->xid)) { 302 #ifdef BOOTP_DEBUG 303 if (debug) { 304 printf("bootprecv: expected xid 0x%lx, got 0x%x\n", 305 d->xid, ntohl(bp->bp_xid)); 306 } 307 #endif 308 goto bad; 309 } 310 311 #ifdef BOOTP_DEBUG 312 if (debug) 313 printf("bootprecv: got one!\n"); 314 #endif 315 316 /* Suck out vendor info */ 317 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) { 318 int vsize = n - offsetof(struct bootp, bp_vend); 319 if(vend_rfc1048(bp->bp_vend, vsize) != 0) 320 goto bad; 321 322 /* Save copy of bootp reply or DHCP ACK message */ 323 if (bp->bp_op == BOOTREPLY && 324 ((dhcp_ok == 1 && expected_dhcpmsgtype == DHCPACK) || 325 dhcp_ok == 0)) { 326 free(bootp_response); 327 bootp_response = malloc(n); 328 if (bootp_response != NULL) { 329 bootp_response_size = n; 330 bcopy(bp, bootp_response, bootp_response_size); 331 } 332 } 333 } 334 #ifdef BOOTP_VEND_CMU 335 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0) 336 vend_cmu(bp->bp_vend); 337 #endif 338 else 339 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend); 340 341 *pkt = ptr; 342 *payload = bp; 343 return(n); 344 bad: 345 free(ptr); 346 errno = 0; 347 return (-1); 348 } 349 350 int 351 dhcp_try_rfc1048(uint8_t *cp, size_t len) 352 { 353 354 expected_dhcpmsgtype = DHCPACK; 355 if (bcmp(vm_rfc1048, cp, sizeof (vm_rfc1048)) == 0) { 356 return (vend_rfc1048(cp, len)); 357 } 358 return (-1); 359 } 360 361 static int 362 vend_rfc1048(u_char *cp, u_int len) 363 { 364 u_char *ep; 365 int size; 366 u_char tag; 367 const char *val; 368 369 #ifdef BOOTP_DEBUG 370 if (debug) 371 printf("vend_rfc1048 bootp info. len=%d\n", len); 372 #endif 373 ep = cp + len; 374 375 /* Step over magic cookie */ 376 cp += sizeof(int); 377 378 setenv_(cp, ep, NULL); 379 380 while (cp < ep) { 381 tag = *cp++; 382 size = *cp++; 383 if (tag == TAG_END) 384 break; 385 386 if (tag == TAG_SUBNET_MASK) { 387 bcopy(cp, &netmask, sizeof(netmask)); 388 } 389 if (tag == TAG_GATEWAY) { 390 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr)); 391 } 392 if (tag == TAG_SWAPSERVER) { 393 /* let it override bp_siaddr */ 394 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr)); 395 } 396 if (tag == TAG_ROOTPATH) { 397 if ((val = getenv("dhcp.root-path")) == NULL) 398 val = (const char *)cp; 399 strlcpy(rootpath, val, sizeof(rootpath)); 400 } 401 if (tag == TAG_HOSTNAME) { 402 if ((val = getenv("dhcp.host-name")) == NULL) 403 val = (const char *)cp; 404 strlcpy(hostname, val, sizeof(hostname)); 405 } 406 if (tag == TAG_INTF_MTU) { 407 intf_mtu = 0; 408 if ((val = getenv("dhcp.interface-mtu")) != NULL) { 409 unsigned long tmp; 410 char *end; 411 412 errno = 0; 413 /* 414 * Do not allow MTU to exceed max IPv4 packet 415 * size, max value of 16-bit word. 416 */ 417 tmp = strtoul(val, &end, 0); 418 if (errno != 0 || 419 *val == '\0' || *end != '\0' || 420 tmp > USHRT_MAX) { 421 printf("%s: bad value: \"%s\", " 422 "ignoring\n", 423 "dhcp.interface-mtu", val); 424 } else { 425 intf_mtu = (u_int)tmp; 426 } 427 } 428 if (intf_mtu == 0) 429 intf_mtu = be16dec(cp); 430 } 431 #ifdef SUPPORT_DHCP 432 if (tag == TAG_DHCP_MSGTYPE) { 433 if(*cp != expected_dhcpmsgtype) 434 return(-1); 435 dhcp_ok = 1; 436 } 437 if (tag == TAG_SERVERID) { 438 bcopy(cp, &dhcp_serverip.s_addr, 439 sizeof(dhcp_serverip.s_addr)); 440 } 441 #endif 442 cp += size; 443 } 444 return(0); 445 } 446 447 #ifdef BOOTP_VEND_CMU 448 static void 449 vend_cmu(u_char *cp) 450 { 451 struct cmu_vend *vp; 452 453 #ifdef BOOTP_DEBUG 454 if (debug) 455 printf("vend_cmu bootp info.\n"); 456 #endif 457 vp = (struct cmu_vend *)cp; 458 459 if (vp->v_smask.s_addr != 0) { 460 netmask = vp->v_smask.s_addr; 461 } 462 if (vp->v_dgate.s_addr != 0) { 463 gateip = vp->v_dgate; 464 } 465 } 466 #endif 467 468 #ifdef DHCP_ENV 469 /* 470 * Parse DHCP options and store them into kenv variables. 471 * Original code from Danny Braniss, modifications by Luigi Rizzo. 472 * 473 * The parser is driven by tables which specify the type and name of 474 * each dhcp option and how it appears in kenv. 475 * The first entry in the list contains the prefix used to set the kenv 476 * name (including the . if needed), the last entry must have a 0 tag. 477 * Entries do not need to be sorted though it helps for readability. 478 * 479 * Certain vendor-specific tables can be enabled according to DHCP_ENV. 480 * Set it to 0 if you don't want any. 481 */ 482 enum opt_fmt { __NONE = 0, 483 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */ 484 __IP, /* IPv4 address */ 485 __TXT, /* C string */ 486 __BYTES, /* byte sequence, printed %02x */ 487 __INDIR, /* name=value */ 488 __ILIST, /* name=value;name=value ... */ 489 __VE, /* vendor specific, recurse */ 490 }; 491 492 struct dhcp_opt { 493 uint8_t tag; 494 uint8_t fmt; 495 const char *desc; 496 }; 497 498 static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */ 499 #if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */ 500 {0, 0, "FreeBSD"}, /* prefix */ 501 {1, __TXT, "kernel"}, 502 {2, __TXT, "kernelname"}, 503 {3, __TXT, "kernel_options"}, 504 {4, __IP, "usr-ip"}, 505 {5, __TXT, "conf-path"}, 506 {6, __TXT, "rc.conf0"}, 507 {7, __TXT, "rc.conf1"}, 508 {8, __TXT, "rc.conf2"}, 509 {9, __TXT, "rc.conf3"}, 510 {10, __TXT, "rc.conf4"}, 511 {11, __TXT, "rc.conf5"}, 512 {12, __TXT, "rc.conf6"}, 513 {13, __TXT, "rc.conf7"}, 514 {14, __TXT, "rc.conf8"}, 515 {15, __TXT, "rc.conf9"}, 516 517 {20, __TXT, "boot.nfsroot.options"}, 518 519 {245, __INDIR, ""}, 520 {246, __INDIR, ""}, 521 {247, __INDIR, ""}, 522 {248, __INDIR, ""}, 523 {249, __INDIR, ""}, 524 {250, __INDIR, ""}, 525 {251, __INDIR, ""}, 526 {252, __INDIR, ""}, 527 {253, __INDIR, ""}, 528 {254, __INDIR, ""}, 529 530 #elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */ 531 {0, 0, "pxe"}, /* prefix */ 532 {93, __16, "system-architecture"}, 533 {94, __BYTES, "network-interface"}, 534 {97, __BYTES, "machine-identifier"}, 535 #else /* default (empty) table */ 536 {0, 0, "dhcp.vendor."}, /* prefix */ 537 #endif 538 {0, __TXT, "%soption-%d"} 539 }; 540 541 static struct dhcp_opt dhcp_opt[] = { 542 /* DHCP Option names, formats and codes, from RFC2132. */ 543 {0, 0, "dhcp."}, // prefix 544 {1, __IP, "subnet-mask"}, 545 {2, __32, "time-offset"}, /* this is signed */ 546 {3, __IP, "routers"}, 547 {4, __IP, "time-servers"}, 548 {5, __IP, "ien116-name-servers"}, 549 {6, __IP, "domain-name-servers"}, 550 {7, __IP, "log-servers"}, 551 {8, __IP, "cookie-servers"}, 552 {9, __IP, "lpr-servers"}, 553 {10, __IP, "impress-servers"}, 554 {11, __IP, "resource-location-servers"}, 555 {12, __TXT, "host-name"}, 556 {13, __16, "boot-size"}, 557 {14, __TXT, "merit-dump"}, 558 {15, __TXT, "domain-name"}, 559 {16, __IP, "swap-server"}, 560 {17, __TXT, "root-path"}, 561 {18, __TXT, "extensions-path"}, 562 {19, __8, "ip-forwarding"}, 563 {20, __8, "non-local-source-routing"}, 564 {21, __IP, "policy-filter"}, 565 {22, __16, "max-dgram-reassembly"}, 566 {23, __8, "default-ip-ttl"}, 567 {24, __32, "path-mtu-aging-timeout"}, 568 {25, __16, "path-mtu-plateau-table"}, 569 {26, __16, "interface-mtu"}, 570 {27, __8, "all-subnets-local"}, 571 {28, __IP, "broadcast-address"}, 572 {29, __8, "perform-mask-discovery"}, 573 {30, __8, "mask-supplier"}, 574 {31, __8, "perform-router-discovery"}, 575 {32, __IP, "router-solicitation-address"}, 576 {33, __IP, "static-routes"}, 577 {34, __8, "trailer-encapsulation"}, 578 {35, __32, "arp-cache-timeout"}, 579 {36, __8, "ieee802-3-encapsulation"}, 580 {37, __8, "default-tcp-ttl"}, 581 {38, __32, "tcp-keepalive-interval"}, 582 {39, __8, "tcp-keepalive-garbage"}, 583 {40, __TXT, "nis-domain"}, 584 {41, __IP, "nis-servers"}, 585 {42, __IP, "ntp-servers"}, 586 {43, __VE, "vendor-encapsulated-options"}, 587 {44, __IP, "netbios-name-servers"}, 588 {45, __IP, "netbios-dd-server"}, 589 {46, __8, "netbios-node-type"}, 590 {47, __TXT, "netbios-scope"}, 591 {48, __IP, "x-font-servers"}, 592 {49, __IP, "x-display-managers"}, 593 {50, __IP, "dhcp-requested-address"}, 594 {51, __32, "dhcp-lease-time"}, 595 {52, __8, "dhcp-option-overload"}, 596 {53, __8, "dhcp-message-type"}, 597 {54, __IP, "dhcp-server-identifier"}, 598 {55, __8, "dhcp-parameter-request-list"}, 599 {56, __TXT, "dhcp-message"}, 600 {57, __16, "dhcp-max-message-size"}, 601 {58, __32, "dhcp-renewal-time"}, 602 {59, __32, "dhcp-rebinding-time"}, 603 {60, __TXT, "vendor-class-identifier"}, 604 {61, __TXT, "dhcp-client-identifier"}, 605 {64, __TXT, "nisplus-domain"}, 606 {65, __IP, "nisplus-servers"}, 607 {66, __TXT, "tftp-server-name"}, 608 {67, __TXT, "bootfile-name"}, 609 {68, __IP, "mobile-ip-home-agent"}, 610 {69, __IP, "smtp-server"}, 611 {70, __IP, "pop-server"}, 612 {71, __IP, "nntp-server"}, 613 {72, __IP, "www-server"}, 614 {73, __IP, "finger-server"}, 615 {74, __IP, "irc-server"}, 616 {75, __IP, "streettalk-server"}, 617 {76, __IP, "streettalk-directory-assistance-server"}, 618 {77, __TXT, "user-class"}, 619 {85, __IP, "nds-servers"}, 620 {86, __TXT, "nds-tree-name"}, 621 {87, __TXT, "nds-context"}, 622 {210, __TXT, "authenticate"}, 623 624 /* use the following entries for arbitrary variables */ 625 {246, __ILIST, ""}, 626 {247, __ILIST, ""}, 627 {248, __ILIST, ""}, 628 {249, __ILIST, ""}, 629 {250, __INDIR, ""}, 630 {251, __INDIR, ""}, 631 {252, __INDIR, ""}, 632 {253, __INDIR, ""}, 633 {254, __INDIR, ""}, 634 {0, __TXT, "%soption-%d"} 635 }; 636 637 /* 638 * parse a dhcp response, set environment variables translating options 639 * names and values according to the tables above. Also set dhcp.tags 640 * to the list of selected tags. 641 */ 642 static void 643 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts) 644 { 645 u_char *ncp; 646 u_char tag; 647 char tags[512], *tp; /* the list of tags */ 648 649 #define FLD_SEP ',' /* separator in list of elements */ 650 ncp = cp; 651 tp = tags; 652 if (opts == NULL) 653 opts = dhcp_opt; 654 655 while (ncp < ep) { 656 unsigned int size; /* option size */ 657 char *vp, *endv, buf[256]; /* the value buffer */ 658 struct dhcp_opt *op; 659 660 tag = *ncp++; /* extract tag and size */ 661 size = *ncp++; 662 cp = ncp; /* current payload */ 663 ncp += size; /* point to the next option */ 664 665 if (tag == TAG_END) 666 break; 667 if (tag == 0) 668 continue; 669 670 for (op = opts+1; op->tag && op->tag != tag; op++) 671 ; 672 /* if not found we end up on the default entry */ 673 674 /* 675 * Copy data into the buffer. libstand does not have snprintf so we 676 * need to be careful with sprintf(). With strings, the source is 677 * always <256 char so shorter than the buffer so we are safe; with 678 * other arguments, the longest string is inet_ntoa which is 16 bytes 679 * so we make sure to have always enough room in the string before 680 * trying an sprint. 681 */ 682 vp = buf; 683 *vp = '\0'; 684 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */ 685 686 switch(op->fmt) { 687 case __NONE: 688 break; /* should not happen */ 689 690 case __VE: /* recurse, vendor specific */ 691 setenv_(cp, cp+size, vndr_opt); 692 break; 693 694 case __IP: /* ip address */ 695 for (; size > 0 && vp < endv; size -= 4, cp += 4) { 696 struct in_addr in_ip; /* ip addresses */ 697 if (vp != buf) 698 *vp++ = FLD_SEP; 699 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr)); 700 sprintf(vp, "%s", inet_ntoa(in_ip)); 701 vp += strlen(vp); 702 } 703 break; 704 705 case __BYTES: /* opaque byte string */ 706 for (; size > 0 && vp < endv; size -= 1, cp += 1) { 707 sprintf(vp, "%02x", *cp); 708 vp += strlen(vp); 709 } 710 break; 711 712 case __TXT: 713 bcopy(cp, buf, size); /* cannot overflow */ 714 buf[size] = 0; 715 break; 716 717 case __32: 718 case __16: 719 case __8: /* op->fmt is also the length of each field */ 720 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) { 721 uint32_t v; 722 if (op->fmt == __32) 723 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3]; 724 else if (op->fmt == __16) 725 v = (cp[0]<<8) + cp[1]; 726 else 727 v = cp[0]; 728 if (vp != buf) 729 *vp++ = FLD_SEP; 730 sprintf(vp, "%u", v); 731 vp += strlen(vp); 732 } 733 break; 734 735 case __INDIR: /* name=value */ 736 case __ILIST: /* name=value;name=value... */ 737 bcopy(cp, buf, size); /* cannot overflow */ 738 buf[size] = '\0'; 739 for (endv = buf; endv; endv = vp) { 740 u_char *s = NULL; /* semicolon ? */ 741 742 /* skip leading whitespace */ 743 while (*endv && strchr(" \t\n\r", *endv)) 744 endv++; 745 vp = strchr(endv, '='); /* find name=value separator */ 746 if (!vp) 747 break; 748 *vp++ = 0; 749 if (op->fmt == __ILIST && (s = strchr(vp, ';'))) 750 *s++ = '\0'; 751 setenv(endv, vp, 1); 752 vp = s; /* prepare for next round */ 753 } 754 buf[0] = '\0'; /* option already done */ 755 } 756 757 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */ 758 if (tp != tags) 759 *tp++ = FLD_SEP; 760 sprintf(tp, "%d", tag); 761 tp += strlen(tp); 762 } 763 if (buf[0]) { 764 char env[128]; /* the string name */ 765 766 if (op->tag == 0) 767 sprintf(env, op->desc, opts[0].desc, tag); 768 else 769 sprintf(env, "%s%s", opts[0].desc, op->desc); 770 /* 771 * Do not replace existing values in the environment, so that 772 * locally-obtained values can override server-provided values. 773 */ 774 setenv(env, buf, 0); 775 } 776 } 777 if (tp != tags) { 778 char env[128]; /* the string name */ 779 sprintf(env, "%stags", opts[0].desc); 780 setenv(env, tags, 1); 781 } 782 } 783 #endif /* additional dhcp */ 784