/* * dovend.c : Inserts all but the first few vendor options. * * $FreeBSD: src/libexec/bootpd/dovend.c,v 1.5.2.1 2003/02/15 05:36:01 kris Exp $ */ #include #include #include /* inet_ntoa */ #include #include #include #include #include #ifndef USE_BFUNCS # include /* Yes, memcpy is OK here (no overlapped copies). */ # define bcopy(a,b,c) memcpy(b,a,c) # define bzero(p,l) memset(p,0,l) # define bcmp(a,b,c) memcmp(a,b,c) # define index strchr #endif #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; 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). */ char *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 */ }