/*      $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:
*/

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