1 /* $NetBSD: bootp.c,v 1.14 1998/02/16 11:10:54 drochner Exp $ */
4 * Copyright (c) 1992 Regents of the University of California.
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.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
35 * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp (LBL)
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
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>
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
65 struct in_addr servip;
69 static char vm_rfc1048[4] = VM_RFC1048;
71 static char vm_cmu[4] = VM_CMU;
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);
79 static void vend_cmu(u_char *);
82 #ifdef DHCP_ENV /* export the dhcp response to kenv */
84 static void setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts);
86 #define setenv_(a, b, c)
90 static char expected_dhcpmsgtype = -1, dhcp_ok;
91 struct in_addr dhcp_serverip;
93 struct bootp *bootp_response;
94 size_t bootp_response_size;
97 bootp_fill_request(unsigned char *bp_vend)
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.
104 bp_vend[0] = TAG_CLASSID;
106 bcopy("PXEClient", &bp_vend[2], 9);
107 bp_vend[11] = TAG_USER_CLASS;
108 /* len of each user class + number of user class */
110 /* len of the first user class */
112 bcopy("FreeBSD", &bp_vend[14], 7);
113 bp_vend[21] = TAG_PARAM_REQ;
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;
125 /* Fetch required bootp infomation */
133 u_char header[HEADER_SIZE];
136 struct bootp *rbootp;
140 printf("bootp: socket=%d\n", sock);
145 if (!(d = socktodesc(sock))) {
146 printf("bootp: bad socket. %d\n", sock);
151 printf("bootp: d=%lx\n", (long)d);
155 bzero(bp, sizeof(*bp));
157 bp->bp_op = BOOTREQUEST;
158 bp->bp_htype = 1; /* 10Mb Ethernet (48 bits) */
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));
165 bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
167 bp->bp_vend[6] = DHCPDISCOVER;
168 bootp_fill_request(&bp->bp_vend[7]);
171 bp->bp_vend[4] = TAG_END;
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);
180 expected_dhcpmsgtype = DHCPOFFER;
185 bootpsend, bp, sizeof(*bp),
186 bootprecv, &pkt, (void **)&rbootp) == -1) {
187 printf("bootp: no reply\n");
194 bp->bp_vend[6] = DHCPREQUEST;
195 bp->bp_vend[7] = TAG_REQ_ADDR;
197 bcopy(&rbootp->bp_yiaddr, &bp->bp_vend[9], 4);
198 bp->bp_vend[13] = TAG_SERVERID;
200 bcopy(&dhcp_serverip.s_addr, &bp->bp_vend[15], 4);
201 bp->bp_vend[19] = TAG_LEASETIME;
203 leasetime = htonl(300);
204 bcopy(&leasetime, &bp->bp_vend[21], 4);
205 bootp_fill_request(&bp->bp_vend[25]);
207 expected_dhcpmsgtype = DHCPACK;
211 bootpsend, bp, sizeof(*bp),
212 bootprecv, &pkt, (void **)&rbootp) == -1) {
213 printf("DHCPREQUEST failed\n");
219 myip = d->myip = rbootp->bp_yiaddr;
220 servip = rbootp->bp_siaddr;
221 if (rootip.s_addr == INADDR_ANY)
223 bcopy(rbootp->bp_file, bootfile, sizeof(bootfile));
224 bootfile[sizeof(bootfile) - 1] = '\0';
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);
232 netmask = htonl(IN_CLASSC_NET);
235 printf("'native netmask' is %s\n", intoa(netmask));
241 printf("mask: %s\n", intoa(netmask));
244 /* We need a gateway if root is on a different net */
245 if (!SAMENET(myip, rootip, netmask)) {
248 printf("need gateway for root ip\n");
252 /* Toss gateway if on a different net */
253 if (!SAMENET(myip, gateip, netmask)) {
256 printf("gateway ip (%s) bad\n", inet_ntoa(gateip));
261 /* Bump xid so next request will be unique. */
266 /* Transmit a bootp request */
268 bootpsend(struct iodesc *d, void *pkt, size_t len)
274 printf("bootpsend: d=%lx called.\n", (long)d);
278 bp->bp_secs = htons((u_short)(getsecs() - bot));
282 printf("bootpsend: calling sendudp\n");
285 return (sendudp(d, pkt, len));
289 bootprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft)
297 printf("bootp_recvoffer: called\n");
301 n = readudp(d, &ptr, (void **)&bp, tleft);
302 if (n == -1 || n < sizeof(struct bootp) - BOOTP_VENDSIZE)
307 printf("bootprecv: checked. bp = %p, n = %zd\n", bp, n);
309 if (bp->bp_xid != htonl(d->xid)) {
312 printf("bootprecv: expected xid 0x%lx, got 0x%x\n",
313 d->xid, ntohl(bp->bp_xid));
321 printf("bootprecv: got one!\n");
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)
330 /* Save copy of bootp reply or DHCP ACK message */
331 if (bp->bp_op == BOOTREPLY &&
332 ((dhcp_ok == 1 && expected_dhcpmsgtype == DHCPACK) ||
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);
342 #ifdef BOOTP_VEND_CMU
343 else if (bcmp(vm_cmu, bp->bp_vend, sizeof(vm_cmu)) == 0)
344 vend_cmu(bp->bp_vend);
347 printf("bootprecv: unknown vendor 0x%lx\n", (long)bp->bp_vend);
359 vend_rfc1048(u_char *cp, u_int len)
368 printf("vend_rfc1048 bootp info. len=%d\n", len);
372 /* Step over magic cookie */
375 setenv_(cp, ep, NULL);
383 if (tag == TAG_SUBNET_MASK) {
384 bcopy(cp, &netmask, sizeof(netmask));
386 if (tag == TAG_GATEWAY) {
387 bcopy(cp, &gateip.s_addr, sizeof(gateip.s_addr));
389 if (tag == TAG_SWAPSERVER) {
390 /* let it override bp_siaddr */
391 bcopy(cp, &rootip.s_addr, sizeof(rootip.s_addr));
393 if (tag == TAG_ROOTPATH) {
394 if ((val = getenv("dhcp.root-path")) == NULL)
395 val = (const char *)cp;
396 strlcpy(rootpath, val, sizeof(rootpath));
398 if (tag == TAG_HOSTNAME) {
399 if ((val = getenv("dhcp.host-name")) == NULL)
400 val = (const char *)cp;
401 strlcpy(hostname, val, sizeof(hostname));
403 if (tag == TAG_INTF_MTU) {
405 if ((val = getenv("dhcp.interface-mtu")) != NULL) {
411 * Do not allow MTU to exceed max IPv4 packet
412 * size, max value of 16-bit word.
414 tmp = strtoul(val, &end, 0);
416 *val == '\0' || *end != '\0' ||
418 printf("%s: bad value: \"%s\", "
420 "dhcp.interface-mtu", val);
422 intf_mtu = (u_int)tmp;
426 intf_mtu = be16dec(cp);
429 if (tag == TAG_DHCP_MSGTYPE) {
430 if(*cp != expected_dhcpmsgtype)
434 if (tag == TAG_SERVERID) {
435 bcopy(cp, &dhcp_serverip.s_addr,
436 sizeof(dhcp_serverip.s_addr));
444 #ifdef BOOTP_VEND_CMU
452 printf("vend_cmu bootp info.\n");
454 vp = (struct cmu_vend *)cp;
456 if (vp->v_smask.s_addr != 0) {
457 netmask = vp->v_smask.s_addr;
459 if (vp->v_dgate.s_addr != 0) {
460 gateip = vp->v_dgate;
467 * Parse DHCP options and store them into kenv variables.
468 * Original code from Danny Braniss, modifications by Luigi Rizzo.
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.
476 * Certain vendor-specific tables can be enabled according to DHCP_ENV.
477 * Set it to 0 if you don't want any.
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 */
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"},
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"},
514 {20, __TXT, "boot.nfsroot.options"},
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 */
535 {0, __TXT, "%soption-%d"}
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"},
621 /* use the following entries for arbitrary variables */
631 {0, __TXT, "%soption-%d"}
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.
640 setenv_(u_char *cp, u_char *ep, struct dhcp_opt *opts)
644 char tags[512], *tp; /* the list of tags */
646 #define FLD_SEP ',' /* separator in list of elements */
653 unsigned int size; /* option size */
654 char *vp, *endv, buf[256]; /* the value buffer */
657 tag = *ncp++; /* extract tag and size */
659 cp = ncp; /* current payload */
660 ncp += size; /* point to the next option */
667 for (op = opts+1; op->tag && op->tag != tag; op++)
669 /* if not found we end up on the default entry */
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
681 endv = buf + sizeof(buf) - 1 - 16; /* last valid write position */
685 break; /* should not happen */
687 case __VE: /* recurse, vendor specific */
688 setenv_(cp, cp+size, vndr_opt);
691 case __IP: /* ip address */
692 for (; size > 0 && vp < endv; size -= 4, cp += 4) {
693 struct in_addr in_ip; /* ip addresses */
696 bcopy(cp, &in_ip.s_addr, sizeof(in_ip.s_addr));
697 sprintf(vp, "%s", inet_ntoa(in_ip));
702 case __BYTES: /* opaque byte string */
703 for (; size > 0 && vp < endv; size -= 1, cp += 1) {
704 sprintf(vp, "%02x", *cp);
710 bcopy(cp, buf, size); /* cannot overflow */
716 case __8: /* op->fmt is also the length of each field */
717 for (; size > 0 && vp < endv; size -= op->fmt, cp += op->fmt) {
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];
727 sprintf(vp, "%u", v);
732 case __INDIR: /* name=value */
733 case __ILIST: /* name=value;name=value... */
734 bcopy(cp, buf, size); /* cannot overflow */
736 for (endv = buf; endv; endv = vp) {
737 u_char *s = NULL; /* semicolon ? */
739 /* skip leading whitespace */
740 while (*endv && strchr(" \t\n\r", *endv))
742 vp = strchr(endv, '='); /* find name=value separator */
746 if (op->fmt == __ILIST && (s = strchr(vp, ';')))
749 vp = s; /* prepare for next round */
751 buf[0] = '\0'; /* option already done */
754 if (tp - tags < sizeof(tags) - 5) { /* add tag to the list */
757 sprintf(tp, "%d", tag);
761 char env[128]; /* the string name */
764 sprintf(env, op->desc, opts[0].desc, tag);
766 sprintf(env, "%s%s", opts[0].desc, op->desc);
768 * Do not replace existing values in the environment, so that
769 * locally-obtained values can override server-provided values.
775 char env[128]; /* the string name */
776 sprintf(env, "%stags", opts[0].desc);
777 setenv(env, tags, 1);
780 #endif /* additional dhcp */