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 <netinet/in.h>
43 #include <netinet/in_systm.h>
44
45 #include <string.h>
46
47 #define BOOTP_DEBUGxx
48 #define SUPPORT_DHCP
49
50 #define DHCP_ENV_NOVENDOR 1 /* do not parse vendor options */
51 #define DHCP_ENV_PXE 10 /* assume pxe vendor options */
52 #define DHCP_ENV_FREEBSD 11 /* assume freebsd vendor options */
53 /* set DHCP_ENV to one of the values above to export dhcp options to kenv */
54 #define DHCP_ENV DHCP_ENV_NO_VENDOR
55
56 #include "stand.h"
57 #include "net.h"
58 #include "netif.h"
59 #include "bootp.h"
60
61
62 struct in_addr servip;
63
64 static n_long nmask, smask;
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
bootp(sock,flag)95 bootp(sock, flag)
96 int sock;
97 int flag;
98 {
99 struct iodesc *d;
100 struct bootp *bp;
101 struct {
102 u_char header[HEADER_SIZE];
103 struct bootp wbootp;
104 } wbuf;
105 struct {
106 u_char header[HEADER_SIZE];
107 struct bootp rbootp;
108 } rbuf;
109
110 #ifdef BOOTP_DEBUG
111 if (debug)
112 printf("bootp: socket=%d\n", sock);
113 #endif
114 if (!bot)
115 bot = getsecs();
116
117 if (!(d = socktodesc(sock))) {
118 printf("bootp: bad socket. %d\n", sock);
119 return;
120 }
121 #ifdef BOOTP_DEBUG
122 if (debug)
123 printf("bootp: d=%lx\n", (long)d);
124 #endif
125
126 bp = &wbuf.wbootp;
127 bzero(bp, sizeof(*bp));
128
129 bp->bp_op = BOOTREQUEST;
130 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */
131 bp->bp_hlen = 6;
132 bp->bp_xid = htonl(d->xid);
133 MACPY(d->myea, bp->bp_chaddr);
134 strncpy(bp->bp_file, bootfile, sizeof(bp->bp_file));
135 bcopy(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048));
136 #ifdef SUPPORT_DHCP
137 bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
138 bp->bp_vend[5] = 1;
139 bp->bp_vend[6] = DHCPDISCOVER;
140
141 /*
142 * If we are booting from PXE, we want to send the string
143 * 'PXEClient' to the DHCP server so you have the option of
144 * only responding to PXE aware dhcp requests.
145 */
146 if (flag & BOOTP_PXE) {
147 bp->bp_vend[7] = TAG_CLASSID;
148 bp->bp_vend[8] = 9;
149 bcopy("PXEClient", &bp->bp_vend[9], 9);
150 bp->bp_vend[18] = TAG_END;
151 } else
152 bp->bp_vend[7] = TAG_END;
153 #else
154 bp->bp_vend[4] = TAG_END;
155 #endif
156
157 d->myip.s_addr = INADDR_ANY;
158 d->myport = htons(IPPORT_BOOTPC);
159 d->destip.s_addr = INADDR_BROADCAST;
160 d->destport = htons(IPPORT_BOOTPS);
161
162 #ifdef SUPPORT_DHCP
163 expected_dhcpmsgtype = DHCPOFFER;
164 dhcp_ok = 0;
165 #endif
166
167 if(sendrecv(d,
168 bootpsend, bp, sizeof(*bp),
169 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
170 == -1) {
171 printf("bootp: no reply\n");
172 return;
173 }
174
175 #ifdef SUPPORT_DHCP
176 if(dhcp_ok) {
177 u_int32_t leasetime;
178 bp->bp_vend[6] = DHCPREQUEST;
179 bp->bp_vend[7] = TAG_REQ_ADDR;
180 bp->bp_vend[8] = 4;
181 bcopy(&rbuf.rbootp.bp_yiaddr, &bp->bp_vend[9], 4);
182 bp->bp_vend[13] = TAG_SERVERID;
183 bp->bp_vend[14] = 4;
184 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
185 bp->bp_vend[19] = TAG_LEASETIME;
186 bp->bp_vend[20] = 4;
187 leasetime = htonl(300);
188 bcopy(&leasetime, &bp->bp_vend[21], 4);
189 if (flag & BOOTP_PXE) {
190 bp->bp_vend[25] = TAG_CLASSID;
191 bp->bp_vend[26] = 9;
192 bcopy("PXEClient", &bp->bp_vend[27], 9);
193 bp->bp_vend[36] = TAG_END;
194 } else
195 bp->bp_vend[25] = TAG_END;
196
197 expected_dhcpmsgtype = DHCPACK;
198
199 if(sendrecv(d,
200 bootpsend, bp, sizeof(*bp),
201 bootprecv, &rbuf.rbootp, sizeof(rbuf.rbootp))
202 == -1) {
203 printf("DHCPREQUEST failed\n");
204 return;
205 }
206 }
207 #endif
208
209 myip = d->myip = rbuf.rbootp.bp_yiaddr;
210 servip = rbuf.rbootp.bp_siaddr;
211 if(rootip.s_addr == INADDR_ANY) rootip = servip;
212 bcopy(rbuf.rbootp.bp_file, bootfile, sizeof(bootfile));
213 bootfile[sizeof(bootfile) - 1] = '\0';
214
215 if (IN_CLASSA(ntohl(myip.s_addr)))
216 nmask = htonl(IN_CLASSA_NET);
217 else if (IN_CLASSB(ntohl(myip.s_addr)))
218 nmask = htonl(IN_CLASSB_NET);
219 else
220 nmask = htonl(IN_CLASSC_NET);
221 #ifdef BOOTP_DEBUG
222 if (debug)
223 printf("'native netmask' is %s\n", intoa(nmask));
224 #endif
225
226 /* Check subnet mask against net mask; toss if bogus */
227 if ((nmask & smask) != nmask) {
228 #ifdef BOOTP_DEBUG
229 if (debug)
230 printf("subnet mask (%s) bad\n", intoa(smask));
231 #endif
232 smask = 0;
233 }
234
235 /* Get subnet (or natural net) mask */
236 netmask = nmask;
237 if (smask)
238 netmask = smask;
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 }
264
265 /* Transmit a bootp request */
266 static ssize_t
bootpsend(d,pkt,len)267 bootpsend(d, pkt, len)
268 struct iodesc *d;
269 void *pkt;
270 size_t len;
271 {
272 struct bootp *bp;
273
274 #ifdef BOOTP_DEBUG
275 if (debug)
276 printf("bootpsend: d=%lx called.\n", (long)d);
277 #endif
278
279 bp = pkt;
280 bp->bp_secs = htons((u_short)(getsecs() - bot));
281
282 #ifdef BOOTP_DEBUG
283 if (debug)
284 printf("bootpsend: calling sendudp\n");
285 #endif
286
287 return (sendudp(d, pkt, len));
288 }
289
290 static ssize_t
bootprecv(d,pkt,len,tleft)291 bootprecv(d, pkt, len, tleft)
292 struct iodesc *d;
293 void *pkt;
294 size_t len;
295 time_t tleft;
296 {
297 ssize_t n;
298 struct bootp *bp;
299
300 #ifdef BOOTP_DEBUGx
301 if (debug)
302 printf("bootp_recvoffer: called\n");
303 #endif
304
305 n = readudp(d, pkt, len, tleft);
306 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
307 goto bad;
308
309 bp = (struct bootp *)pkt;
310
311 #ifdef BOOTP_DEBUG
312 if (debug)
313 printf("bootprecv: checked. bp = 0x%lx, n = %d\n",
314 (long)bp, (int)n);
315 #endif
316 if (bp->bp_xid != htonl(d->xid)) {
317 #ifdef BOOTP_DEBUG
318 if (debug) {
319 printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
320 d->xid, ntohl(bp->bp_xid));
321 }
322 #endif
323 goto bad;
324 }
325
326 #ifdef BOOTP_DEBUG
327 if (debug)
328 printf("bootprecv: got one!\n");
329 #endif
330
331 /* Suck out vendor info */
332 if (bcmp(vm_rfc1048, bp->bp_vend, sizeof(vm_rfc1048)) == 0) {
333 if(vend_rfc1048(bp->bp_vend, sizeof(bp->bp_vend)) != 0)
334 goto bad;
335 }
336 #ifdef BOOTP_VEND_CMU
337 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
338 vend_cmu(bp->bp_vend);
339 #endif
340 else
341 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
342
343 return(n);
344 bad:
345 errno = 0;
346 return (-1);
347 }
348
349 static int
vend_rfc1048(cp,len)350 vend_rfc1048(cp, len)
351 u_char *cp;
352 u_int len;
353 {
354 u_char *ep;
355 int size;
356 u_char tag;
357 const char *val;
358
359 #ifdef BOOTP_DEBUG
360 if (debug)
361 printf("vend_rfc1048 bootp info. len=%d\n", len);
362 #endif
363 ep = cp + len;
364
365 /* Step over magic cookie */
366 cp += sizeof(int);
367
368 setenv_(cp, ep, NULL);
369
370 while (cp < ep) {
371 tag = *cp++;
372 size = *cp++;
373 if (tag == TAG_END)
374 break;
375
376 if (tag == TAG_SUBNET_MASK) {
377 bcopy(cp, &smask, sizeof(smask));
378 }
379 if (tag == TAG_GATEWAY) {
380 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
381 }
382 if (tag == TAG_SWAPSERVER) {
383 /* let it override bp_siaddr */
384 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr));
385 }
386 if (tag == TAG_ROOTPATH) {
387 if ((val = getenv("dhcp.root-path")) == NULL)
388 val = (const char *)cp;
389 strlcpy(rootpath, val, sizeof(rootpath));
390 }
391 if (tag == TAG_HOSTNAME) {
392 if ((val = getenv("dhcp.host-name")) == NULL)
393 val = (const char *)cp;
394 strlcpy(hostname, val, sizeof(hostname));
395 }
396 #ifdef SUPPORT_DHCP
397 if (tag == TAG_DHCP_MSGTYPE) {
398 if(*cp != expected_dhcpmsgtype)
399 return(-1);
400 dhcp_ok = 1;
401 }
402 if (tag == TAG_SERVERID) {
403 bcopy(cp, &dhcp_serverip.s_addr,
404 sizeof(dhcp_serverip.s_addr));
405 }
406 #endif
407 cp += size;
408 }
409 return(0);
410 }
411
412 #ifdef BOOTP_VEND_CMU
413 static void
vend_cmu(cp)414 vend_cmu(cp)
415 u_char *cp;
416 {
417 struct cmu_vend *vp;
418
419 #ifdef BOOTP_DEBUG
420 if (debug)
421 printf("vend_cmu bootp info.\n");
422 #endif
423 vp = (struct cmu_vend *)cp;
424
425 if (vp->v_smask.s_addr != 0) {
426 smask = vp->v_smask.s_addr;
427 }
428 if (vp->v_dgate.s_addr != 0) {
429 gateip = vp->v_dgate;
430 }
431 }
432 #endif
433
434 #ifdef DHCP_ENV
435 /*
436 * Parse DHCP options and store them into kenv variables.
437 * Original code from Danny Braniss, modifications by Luigi Rizzo.
438 *
439 * The parser is driven by tables which specify the type and name of
440 * each dhcp option and how it appears in kenv.
441 * The first entry in the list contains the prefix used to set the kenv
442 * name (including the . if needed), the last entry must have a 0 tag.
443 * Entries do not need to be sorted though it helps for readability.
444 *
445 * Certain vendor-specific tables can be enabled according to DHCP_ENV.
446 * Set it to 0 if you don't want any.
447 */
448 enum opt_fmt { __NONE = 0,
449 __8 = 1, __16 = 2, __32 = 4, /* Unsigned fields, value=size */
450 __IP, /* IPv4 address */
451 __TXT, /* C string */
452 __BYTES, /* byte sequence, printed %02x */
453 __INDIR, /* name=value */
454 __ILIST, /* name=value;name=value ... */
455 __VE, /* vendor specific, recurse */
456 };
457
458 struct dhcp_opt {
459 uint8_t tag;
460 uint8_t fmt;
461 const char *desc;
462 };
463
464 static struct dhcp_opt vndr_opt[] = { /* Vendor Specific Options */
465 #if DHCP_ENV == DHCP_ENV_FREEBSD /* FreeBSD table in the original code */
466 {0, 0, "FreeBSD"}, /* prefix */
467 {1, __TXT, "kernel"},
468 {2, __TXT, "kernelname"},
469 {3, __TXT, "kernel_options"},
470 {4, __IP, "usr-ip"},
471 {5, __TXT, "conf-path"},
472 {6, __TXT, "rc.conf0"},
473 {7, __TXT, "rc.conf1"},
474 {8, __TXT, "rc.conf2"},
475 {9, __TXT, "rc.conf3"},
476 {10, __TXT, "rc.conf4"},
477 {11, __TXT, "rc.conf5"},
478 {12, __TXT, "rc.conf6"},
479 {13, __TXT, "rc.conf7"},
480 {14, __TXT, "rc.conf8"},
481 {15, __TXT, "rc.conf9"},
482
483 {20, __TXT, "boot.nfsroot.options"},
484
485 {245, __INDIR, ""},
486 {246, __INDIR, ""},
487 {247, __INDIR, ""},
488 {248, __INDIR, ""},
489 {249, __INDIR, ""},
490 {250, __INDIR, ""},
491 {251, __INDIR, ""},
492 {252, __INDIR, ""},
493 {253, __INDIR, ""},
494 {254, __INDIR, ""},
495
496 #elif DHCP_ENV == DHCP_ENV_PXE /* some pxe options, RFC4578 */
497 {0, 0, "pxe"}, /* prefix */
498 {93, __16, "system-architecture"},
499 {94, __BYTES, "network-interface"},
500 {97, __BYTES, "machine-identifier"},
501 #else /* default (empty) table */
502 {0, 0, "dhcp.vendor."}, /* prefix */
503 #endif
504 {0, __TXT, "%soption-%d"}
505 };
506
507 static struct dhcp_opt dhcp_opt[] = {
508 /* DHCP Option names, formats and codes, from RFC2132. */
509 {0, 0, "dhcp."}, // prefix
510 {1, __IP, "subnet-mask"},
511 {2, __32, "time-offset"}, /* this is signed */
512 {3, __IP, "routers"},
513 {4, __IP, "time-servers"},
514 {5, __IP, "ien116-name-servers"},
515 {6, __IP, "domain-name-servers"},
516 {7, __IP, "log-servers"},
517 {8, __IP, "cookie-servers"},
518 {9, __IP, "lpr-servers"},
519 {10, __IP, "impress-servers"},
520 {11, __IP, "resource-location-servers"},
521 {12, __TXT, "host-name"},
522 {13, __16, "boot-size"},
523 {14, __TXT, "merit-dump"},
524 {15, __TXT, "domain-name"},
525 {16, __IP, "swap-server"},
526 {17, __TXT, "root-path"},
527 {18, __TXT, "extensions-path"},
528 {19, __8, "ip-forwarding"},
529 {20, __8, "non-local-source-routing"},
530 {21, __IP, "policy-filter"},
531 {22, __16, "max-dgram-reassembly"},
532 {23, __8, "default-ip-ttl"},
533 {24, __32, "path-mtu-aging-timeout"},
534 {25, __16, "path-mtu-plateau-table"},
535 {26, __16, "interface-mtu"},
536 {27, __8, "all-subnets-local"},
537 {28, __IP, "broadcast-address"},
538 {29, __8, "perform-mask-discovery"},
539 {30, __8, "mask-supplier"},
540 {31, __8, "perform-router-discovery"},
541 {32, __IP, "router-solicitation-address"},
542 {33, __IP, "static-routes"},
543 {34, __8, "trailer-encapsulation"},
544 {35, __32, "arp-cache-timeout"},
545 {36, __8, "ieee802-3-encapsulation"},
546 {37, __8, "default-tcp-ttl"},
547 {38, __32, "tcp-keepalive-interval"},
548 {39, __8, "tcp-keepalive-garbage"},
549 {40, __TXT, "nis-domain"},
550 {41, __IP, "nis-servers"},
551 {42, __IP, "ntp-servers"},
552 {43, __VE, "vendor-encapsulated-options"},
553 {44, __IP, "netbios-name-servers"},
554 {45, __IP, "netbios-dd-server"},
555 {46, __8, "netbios-node-type"},
556 {47, __TXT, "netbios-scope"},
557 {48, __IP, "x-font-servers"},
558 {49, __IP, "x-display-managers"},
559 {50, __IP, "dhcp-requested-address"},
560 {51, __32, "dhcp-lease-time"},
561 {52, __8, "dhcp-option-overload"},
562 {53, __8, "dhcp-message-type"},
563 {54, __IP, "dhcp-server-identifier"},
564 {55, __8, "dhcp-parameter-request-list"},
565 {56, __TXT, "dhcp-message"},
566 {57, __16, "dhcp-max-message-size"},
567 {58, __32, "dhcp-renewal-time"},
568 {59, __32, "dhcp-rebinding-time"},
569 {60, __TXT, "vendor-class-identifier"},
570 {61, __TXT, "dhcp-client-identifier"},
571 {64, __TXT, "nisplus-domain"},
572 {65, __IP, "nisplus-servers"},
573 {66, __TXT, "tftp-server-name"},
574 {67, __TXT, "bootfile-name"},
575 {68, __IP, "mobile-ip-home-agent"},
576 {69, __IP, "smtp-server"},
577 {70, __IP, "pop-server"},
578 {71, __IP, "nntp-server"},
579 {72, __IP, "www-server"},
580 {73, __IP, "finger-server"},
581 {74, __IP, "irc-server"},
582 {75, __IP, "streettalk-server"},
583 {76, __IP, "streettalk-directory-assistance-server"},
584 {77, __TXT, "user-class"},
585 {85, __IP, "nds-servers"},
586 {86, __TXT, "nds-tree-name"},
587 {87, __TXT, "nds-context"},
588 {210, __TXT, "authenticate"},
589
590 /* use the following entries for arbitrary variables */
591 {246, __ILIST, ""},
592 {247, __ILIST, ""},
593 {248, __ILIST, ""},
594 {249, __ILIST, ""},
595 {250, __INDIR, ""},
596 {251, __INDIR, ""},
597 {252, __INDIR, ""},
598 {253, __INDIR, ""},
599 {254, __INDIR, ""},
600 {0, __TXT, "%soption-%d"}
601 };
602
603 /*
604 * parse a dhcp response, set environment variables translating options
605 * names and values according to the tables above. Also set dhcp.tags
606 * to the list of selected tags.
607 */
608 static void
setenv_(u_char * cp,u_char * ep,struct dhcp_opt * opts)609 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts)
610 {
611 u_char *ncp;
612 u_char tag;
613 char tags[512], *tp; /* the list of tags */
614
615 #define FLD_SEP ',' /* separator in list of elements */
616 ncp = cp;
617 tp = tags;
618 if (opts == NULL)
619 opts = dhcp_opt;
620
621 while (ncp < ep) {
622 unsigned int size; /* option size */
623 char *vp, *endv, buf[256]; /* the value buffer */
624 struct dhcp_opt *op;
625
626 tag = *ncp++; /* extract tag and size */
627 size = *ncp++;
628 cp = ncp; /* current payload */
629 ncp += size; /* point to the next option */
630
631 if (tag == TAG_END)
632 break;
633 if (tag == 0)
634 continue;
635
636 for (op = opts+1; op->tag && op->tag != tag; op++)
637 ;
638 /* if not found we end up on the default entry */
639
640 /*
641 * Copy data into the buffer. libstand does not have snprintf so we
642 * need to be careful with sprintf(). With strings, the source is
643 * always <256 char so shorter than the buffer so we are safe; with
644 * other arguments, the longest string is inet_ntoa which is 16 bytes
645 * so we make sure to have always enough room in the string before
646 * trying an sprint.
647 */
648 vp = buf;
649 *vp = '\0';
650 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */
651
652 switch(op->fmt) {
653 case __NONE:
654 break; /* should not happen */
655
656 case __VE: /* recurse, vendor specific */
657 setenv_(cp, cp+size, vndr_opt);
658 break;
659
660 case __IP: /* ip address */
661 for (; size > 0 && vp < endv; size -= 4, cp += 4) {
662 struct in_addr in_ip; /* ip addresses */
663 if (vp != buf)
664 *vp++ = FLD_SEP;
665 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr));
666 sprintf(vp, "%s", inet_ntoa(in_ip));
667 vp += strlen(vp);
668 }
669 break;
670
671 case __BYTES: /* opaque byte string */
672 for (; size > 0 && vp < endv; size -= 1, cp += 1) {
673 sprintf(vp, "%02x", *cp);
674 vp += strlen(vp);
675 }
676 break;
677
678 case __TXT:
679 bcopy(cp, buf, size); /* cannot overflow */
680 buf[size] = 0;
681 break;
682
683 case __32:
684 case __16:
685 case __8: /* op->fmt is also the length of each field */
686 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) {
687 uint32_t v;
688 if (op->fmt == __32)
689 v = (cp[0]<<24) + (cp[1]<<16) + (cp[2]<<8) + cp[3];
690 else if (op->fmt == __16)
691 v = (cp[0]<<8) + cp[1];
692 else
693 v = cp[0];
694 if (vp != buf)
695 *vp++ = FLD_SEP;
696 sprintf(vp, "%u", v);
697 vp += strlen(vp);
698 }
699 break;
700
701 case __INDIR: /* name=value */
702 case __ILIST: /* name=value;name=value... */
703 bcopy(cp, buf, size); /* cannot overflow */
704 buf[size] = '\0';
705 for (endv = buf; endv; endv = vp) {
706 u_char *s = NULL; /* semicolon ? */
707
708 /* skip leading whitespace */
709 while (*endv && strchr(" \t\n\r", *endv))
710 endv++;
711 vp = strchr(endv, '='); /* find name=value separator */
712 if (!vp)
713 break;
714 *vp++ = 0;
715 if (op->fmt == __ILIST && (s = strchr(vp, ';')))
716 *s++ = '\0';
717 setenv(endv, vp, 1);
718 vp = s; /* prepare for next round */
719 }
720 buf[0] = '\0'; /* option already done */
721 }
722
723 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */
724 if (tp != tags)
725 *tp++ = FLD_SEP;
726 sprintf(tp, "%d", tag);
727 tp += strlen(tp);
728 }
729 if (buf[0]) {
730 char env[128]; /* the string name */
731
732 if (op->tag == 0)
733 sprintf(env, op->desc, opts[0].desc, tag);
734 else
735 sprintf(env, "%s%s", opts[0].desc, op->desc);
736 /*
737 * Do not replace existing values in the environment, so that
738 * locally-obtained values can override server-provided values.
739 */
740 setenv(env, buf, 0);
741 }
742 }
743 if (tp != tags) {
744 char env[128]; /* the string name */
745 sprintf(env, "%stags", opts[0].desc);
746 setenv(env, tags, 1);
747 }
748 }
749 #endif /* additional dhcp */
750