NetBSD-5.0.2/usr.sbin/bootp/common/dovend.c
/* $NetBSD: dovend.c,v 1.6 2007/05/27 16:31:42 tls Exp $ */
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: dovend.c,v 1.6 2007/05/27 16:31:42 tls Exp $");
#endif
/*
* dovend.c : Inserts all but the first few vendor options.
*/
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h> /* inet_ntoa */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <errno.h>
#include <syslog.h>
#include "bootp.h"
#include "bootpd.h"
#include "report.h"
#include "dovend.h"
PRIVATE int insert_generic(struct shared_bindata *, byte **, int *);
/*
* Insert the 2nd part of the options into an option buffer.
* Return amount of space used.
*
* This inserts everything EXCEPT:
* magic cookie, subnet mask, gateway, bootsize, extension file
* Those are handled separately (in bootpd.c) to allow this function
* to be shared between bootpd and bootpef.
*
* When an "extension file" is in use, the options inserted by
* this function go into the exten_file, not the bootp response.
*/
int
dovend_rfc1497(struct host *hp, byte *buf, int len)
{
int bytesleft = len;
byte *vp = buf;
#if 0
char *tmpstr;
#endif
static const char noroom[] = "%s: No room for \"%s\" option";
#define NEED(LEN, MSG) do \
if (bytesleft < (LEN)) { \
report(LOG_NOTICE, noroom, \
hp->hostname->string, MSG); \
return (vp - buf); \
} while (0)
/*
* Note that the following have already been inserted:
* magic_cookie, subnet_mask, gateway, bootsize
*
* The remaining options are inserted in order of importance.
* (Of course the importance of each is a matter of opinion.)
* The option insertion order should probably be configurable.
*
* This is the order used in the NetBSD version. Can anyone
* explain why the time_offset and swap_server are first?
* Also, why is the hostname so far down the list? -gwr
*/
if (hp->flags.time_offset) {
NEED(6, "to");
*vp++ = TAG_TIME_OFFSET;/* -1 byte */
*vp++ = 4; /* -1 byte */
insert_u_long(htonl(hp->time_offset), &vp); /* -4 bytes */
bytesleft -= 6;
}
/*
* swap server, root path, dump path
*/
if (hp->flags.swap_server) {
NEED(6, "sw");
/* There is just one SWAP_SERVER, so it is not an iplist. */
*vp++ = TAG_SWAP_SERVER;/* -1 byte */
*vp++ = 4; /* -1 byte */
insert_u_long(hp->swap_server.s_addr, &vp); /* -4 bytes */
bytesleft -= 6; /* Fix real count */
}
if (hp->flags.root_path) {
/*
* Check for room for root_path. Add 2 to account for
* TAG_ROOT_PATH and length.
*/
len = strlen(hp->root_path->string);
NEED((len + 2), "rp");
*vp++ = TAG_ROOT_PATH;
*vp++ = (byte) (len & 0xFF);
bcopy(hp->root_path->string, vp, len);
vp += len;
bytesleft -= len + 2;
}
if (hp->flags.dump_file) {
/*
* Check for room for dump_file. Add 2 to account for
* TAG_DUMP_FILE and length.
*/
len = strlen(hp->dump_file->string);
NEED((len + 2), "df");
*vp++ = TAG_DUMP_FILE;
*vp++ = (byte) (len & 0xFF);
bcopy(hp->dump_file->string, vp, len);
vp += len;
bytesleft -= len + 2;
}
/*
* DNS server and domain
*/
if (hp->flags.domain_server) {
if (insert_ip(TAG_DOMAIN_SERVER,
hp->domain_server,
&vp, &bytesleft))
NEED(8, "ds");
}
if (hp->flags.domain_name) {
/*
* Check for room for domain_name. Add 2 to account for
* TAG_DOMAIN_NAME and length.
*/
len = strlen(hp->domain_name->string);
NEED((len + 2), "dn");
*vp++ = TAG_DOMAIN_NAME;
*vp++ = (byte) (len & 0xFF);
bcopy(hp->domain_name->string, vp, len);
vp += len;
bytesleft -= len + 2;
}
/*
* NIS (YP) server and domain
*/
if (hp->flags.nis_server) {
if (insert_ip(TAG_NIS_SERVER,
hp->nis_server,
&vp, &bytesleft))
NEED(8, "ds");
}
if (hp->flags.nis_domain) {
/*
* Check for room for nis_domain. Add 2 to account for
* TAG_NIS_DOMAIN and length.
*/
len = strlen(hp->nis_domain->string);
NEED((len + 2), "dn");
*vp++ = TAG_NIS_DOMAIN;
*vp++ = (byte) (len & 0xFF);
bcopy(hp->nis_domain->string, vp, len);
vp += len;
bytesleft -= len + 2;
}
/* IEN 116 name server */
if (hp->flags.name_server) {
if (insert_ip(TAG_NAME_SERVER,
hp->name_server,
&vp, &bytesleft))
NEED(8, "ns");
}
if (hp->flags.rlp_server) {
if (insert_ip(TAG_RLP_SERVER,
hp->rlp_server,
&vp, &bytesleft))
NEED(8, "rl");
}
/* Time server (RFC 868) */
if (hp->flags.time_server) {
if (insert_ip(TAG_TIME_SERVER,
hp->time_server,
&vp, &bytesleft))
NEED(8, "ts");
}
/* NTP (time) Server (RFC 1129) */
if (hp->flags.ntp_server) {
if (insert_ip(TAG_NTP_SERVER,
hp->ntp_server,
&vp, &bytesleft))
NEED(8, "ts");
}
/*
* I wonder: If the hostname were "promoted" into the BOOTP
* response part, might these "extension" files possibly be
* shared between several clients?
*
* Also, why not just use longer BOOTP packets with all the
* additional length used as option data. This bootpd version
* already supports that feature by replying with the same
* packet length as the client request packet. -gwr
*/
if (hp->flags.name_switch && hp->flags.send_name) {
/*
* Check for room for hostname. Add 2 to account for
* TAG_HOST_NAME and length.
*/
len = strlen(hp->hostname->string);
#if 0
/*
* XXX - Too much magic. The user can always set the hostname
* to the short version in the bootptab file. -gwr
*/
if ((len + 2) > bytesleft) {
/*
* Not enough room for full (domain-qualified) hostname, try
* stripping it down to just the first field (host).
*/
tmpstr = hp->hostname->string;
len = 0;
while (*tmpstr && (*tmpstr != '.')) {
tmpstr++;
len++;
}
}
#endif
NEED((len + 2), "hn");
*vp++ = TAG_HOST_NAME;
*vp++ = (byte) (len & 0xFF);
bcopy(hp->hostname->string, vp, len);
vp += len;
bytesleft -= len + 2;
}
/*
* The rest of these are less important, so they go last.
*/
if (hp->flags.lpr_server) {
if (insert_ip(TAG_LPR_SERVER,
hp->lpr_server,
&vp, &bytesleft))
NEED(8, "lp");
}
if (hp->flags.cookie_server) {
if (insert_ip(TAG_COOKIE_SERVER,
hp->cookie_server,
&vp, &bytesleft))
NEED(8, "cs");
}
if (hp->flags.log_server) {
if (insert_ip(TAG_LOG_SERVER,
hp->log_server,
&vp, &bytesleft))
NEED(8, "lg");
}
/*
* XXX - Add new tags here (to insert options)
*/
if (hp->flags.generic) {
if (insert_generic(hp->generic, &vp, &bytesleft))
NEED(64, "(generic)");
}
/*
* The end marker is inserted by the caller.
*/
return (vp - buf);
#undef NEED
} /* dovend_rfc1497 */
/*
* Insert a tag value, a length value, and a list of IP addresses into the
* memory buffer indirectly pointed to by "dest". "tag" is the RFC1048 tag
* number to use, "iplist" is a pointer to a list of IP addresses
* (struct in_addr_list), and "bytesleft" points to an integer which
* indicates the size of the "dest" buffer.
*
* Return zero if everything fits.
*
* This is used to fill the vendor-specific area of a bootp packet in
* conformance to RFC1048.
*/
int
insert_ip(byte tag, struct in_addr_list *iplist, byte **dest, int *bytesleft)
{
struct in_addr *addrptr;
unsigned addrcount = 1;
byte *d;
if (iplist == NULL)
return (0);
if (*bytesleft >= 6) {
d = *dest; /* Save pointer for later */
**dest = tag;
(*dest) += 2;
(*bytesleft) -= 2; /* Account for tag and length */
addrptr = iplist->addr;
addrcount = iplist->addrcount;
while ((*bytesleft >= 4) && (addrcount > 0)) {
insert_u_long(addrptr->s_addr, dest);
addrptr++;
addrcount--;
(*bytesleft) -= 4; /* Four bytes per address */
}
d[1] = (byte) ((*dest - d - 2) & 0xFF);
}
return (addrcount);
}
/*
* Insert generic data into a bootp packet. The data is assumed to already
* be in RFC1048 format. It is inserted using a first-fit algorithm which
* attempts to insert as many tags as possible. Tags and data which are
* too large to fit are skipped; any remaining tags are tried until they
* have all been exhausted.
* Return zero if everything fits.
*/
static int
insert_generic(struct shared_bindata *gendata, byte **buff, int *bytesleft)
{
byte *srcptr;
int length, numbytes;
int skipped = 0;
if (gendata == NULL)
return (0);
srcptr = gendata->data;
length = gendata->length;
while ((length > 0) && (*bytesleft > 0)) {
switch (*srcptr) {
case TAG_END:
length = 0; /* Force an exit on next iteration */
break;
case TAG_PAD:
*(*buff)++ = *srcptr++;
(*bytesleft)--;
length--;
break;
default:
numbytes = srcptr[1] + 2;
if (*bytesleft < numbytes)
skipped += numbytes;
else {
bcopy(srcptr, *buff, numbytes);
(*buff) += numbytes;
(*bytesleft) -= numbytes;
}
srcptr += numbytes;
length -= numbytes;
break;
}
} /* while */
return (skipped);
}
/*
* Insert the unsigned long "value" into memory starting at the byte
* pointed to by the byte pointer (*dest). (*dest) is updated to
* point to the next available byte.
*
* Since it is desirable to internally store network addresses in network
* byte order (in struct in_addr's), this routine expects longs to be
* passed in network byte order.
*
* However, due to the nature of the main algorithm, the long must be in
* host byte order, thus necessitating the use of ntohl() first.
*/
void
insert_u_long(u_int32 value, byte **dest)
{
byte *temp;
int n;
value = ntohl(value); /* Must use host byte order here */
temp = (*dest += 4);
for (n = 4; n > 0; n--) {
*--temp = (byte) (value & 0xFF);
value >>= 8;
}
/* Final result is network byte order */
}
/*
* Local Variables:
* tab-width: 4
* c-indent-level: 4
* c-argdecl-indent: 4
* c-continued-statement-offset: 4
* c-continued-brace-offset: -4
* c-label-offset: -4
* c-brace-offset: 0
* End:
*/