1 /* 2 * dovend.c : Inserts all but the first few vendor options. 3 * 4 * $FreeBSD: src/libexec/bootpd/dovend.c,v 1.5.2.1 2003/02/15 05:36:01 kris Exp $ 5 */ 6 7 #include <sys/types.h> 8 9 #include <netinet/in.h> 10 #include <arpa/inet.h> /* inet_ntoa */ 11 12 #include <stdlib.h> 13 #include <stdio.h> 14 #include <string.h> 15 #include <errno.h> 16 #include <syslog.h> 17 18 #ifndef USE_BFUNCS 19 # include <memory.h> 20 /* Yes, memcpy is OK here (no overlapped copies). */ 21 # define bcopy(a,b,c) memcpy(b,a,c) 22 # define bzero(p,l) memset(p,0,l) 23 # define bcmp(a,b,c) memcmp(a,b,c) 24 # define index strchr 25 #endif 26 27 #include "bootp.h" 28 #include "bootpd.h" 29 #include "report.h" 30 #include "dovend.h" 31 32 PRIVATE int insert_generic(struct shared_bindata *, byte **, int *); 33 34 /* 35 * Insert the 2nd part of the options into an option buffer. 36 * Return amount of space used. 37 * 38 * This inserts everything EXCEPT: 39 * magic cookie, subnet mask, gateway, bootsize, extension file 40 * Those are handled separately (in bootpd.c) to allow this function 41 * to be shared between bootpd and bootpef. 42 * 43 * When an "extension file" is in use, the options inserted by 44 * this function go into the exten_file, not the bootp response. 45 */ 46 47 int 48 dovend_rfc1497(struct host *hp, byte *buf, int len) 49 { 50 int bytesleft = len; 51 byte *vp = buf; 52 53 static const char noroom[] = "%s: No room for \"%s\" option"; 54 #define NEED(LEN, MSG) do \ 55 if (bytesleft < (LEN)) { \ 56 report(LOG_NOTICE, noroom, \ 57 hp->hostname->string, MSG); \ 58 return (vp - buf); \ 59 } while (0) 60 61 /* 62 * Note that the following have already been inserted: 63 * magic_cookie, subnet_mask, gateway, bootsize 64 * 65 * The remaining options are inserted in order of importance. 66 * (Of course the importance of each is a matter of opinion.) 67 * The option insertion order should probably be configurable. 68 * 69 * This is the order used in the NetBSD version. Can anyone 70 * explain why the time_offset and swap_server are first? 71 * Also, why is the hostname so far down the list? -gwr 72 */ 73 74 if (hp->flags.time_offset) { 75 NEED(6, "to"); 76 *vp++ = TAG_TIME_OFFSET;/* -1 byte */ 77 *vp++ = 4; /* -1 byte */ 78 insert_u_long(htonl(hp->time_offset), &vp); /* -4 bytes */ 79 bytesleft -= 6; 80 } 81 /* 82 * swap server, root path, dump path 83 */ 84 if (hp->flags.swap_server) { 85 NEED(6, "sw"); 86 /* There is just one SWAP_SERVER, so it is not an iplist. */ 87 *vp++ = TAG_SWAP_SERVER;/* -1 byte */ 88 *vp++ = 4; /* -1 byte */ 89 insert_u_long(hp->swap_server.s_addr, &vp); /* -4 bytes */ 90 bytesleft -= 6; /* Fix real count */ 91 } 92 if (hp->flags.root_path) { 93 /* 94 * Check for room for root_path. Add 2 to account for 95 * TAG_ROOT_PATH and length. 96 */ 97 len = strlen(hp->root_path->string); 98 NEED((len + 2), "rp"); 99 *vp++ = TAG_ROOT_PATH; 100 *vp++ = (byte) (len & 0xFF); 101 bcopy(hp->root_path->string, vp, len); 102 vp += len; 103 bytesleft -= len + 2; 104 } 105 if (hp->flags.dump_file) { 106 /* 107 * Check for room for dump_file. Add 2 to account for 108 * TAG_DUMP_FILE and length. 109 */ 110 len = strlen(hp->dump_file->string); 111 NEED((len + 2), "df"); 112 *vp++ = TAG_DUMP_FILE; 113 *vp++ = (byte) (len & 0xFF); 114 bcopy(hp->dump_file->string, vp, len); 115 vp += len; 116 bytesleft -= len + 2; 117 } 118 /* 119 * DNS server and domain 120 */ 121 if (hp->flags.domain_server) { 122 if (insert_ip(TAG_DOMAIN_SERVER, 123 hp->domain_server, 124 &vp, &bytesleft)) 125 NEED(8, "ds"); 126 } 127 if (hp->flags.domain_name) { 128 /* 129 * Check for room for domain_name. Add 2 to account for 130 * TAG_DOMAIN_NAME and length. 131 */ 132 len = strlen(hp->domain_name->string); 133 NEED((len + 2), "dn"); 134 *vp++ = TAG_DOMAIN_NAME; 135 *vp++ = (byte) (len & 0xFF); 136 bcopy(hp->domain_name->string, vp, len); 137 vp += len; 138 bytesleft -= len + 2; 139 } 140 /* 141 * NIS (YP) server and domain 142 */ 143 if (hp->flags.nis_server) { 144 if (insert_ip(TAG_NIS_SERVER, 145 hp->nis_server, 146 &vp, &bytesleft)) 147 NEED(8, "ds"); 148 } 149 if (hp->flags.nis_domain) { 150 /* 151 * Check for room for nis_domain. Add 2 to account for 152 * TAG_NIS_DOMAIN and length. 153 */ 154 len = strlen(hp->nis_domain->string); 155 NEED((len + 2), "dn"); 156 *vp++ = TAG_NIS_DOMAIN; 157 *vp++ = (byte) (len & 0xFF); 158 bcopy(hp->nis_domain->string, vp, len); 159 vp += len; 160 bytesleft -= len + 2; 161 } 162 /* IEN 116 name server */ 163 if (hp->flags.name_server) { 164 if (insert_ip(TAG_NAME_SERVER, 165 hp->name_server, 166 &vp, &bytesleft)) 167 NEED(8, "ns"); 168 } 169 if (hp->flags.rlp_server) { 170 if (insert_ip(TAG_RLP_SERVER, 171 hp->rlp_server, 172 &vp, &bytesleft)) 173 NEED(8, "rl"); 174 } 175 /* Time server (RFC 868) */ 176 if (hp->flags.time_server) { 177 if (insert_ip(TAG_TIME_SERVER, 178 hp->time_server, 179 &vp, &bytesleft)) 180 NEED(8, "ts"); 181 } 182 /* NTP (time) Server (RFC 1129) */ 183 if (hp->flags.ntp_server) { 184 if (insert_ip(TAG_NTP_SERVER, 185 hp->ntp_server, 186 &vp, &bytesleft)) 187 NEED(8, "ts"); 188 } 189 /* 190 * I wonder: If the hostname were "promoted" into the BOOTP 191 * response part, might these "extension" files possibly be 192 * shared between several clients? 193 * 194 * Also, why not just use longer BOOTP packets with all the 195 * additional length used as option data. This bootpd version 196 * already supports that feature by replying with the same 197 * packet length as the client request packet. -gwr 198 */ 199 if (hp->flags.name_switch && hp->flags.send_name) { 200 /* 201 * Check for room for hostname. Add 2 to account for 202 * TAG_HOST_NAME and length. 203 */ 204 len = strlen(hp->hostname->string); 205 #if 0 206 /* 207 * XXX - Too much magic. The user can always set the hostname 208 * to the short version in the bootptab file. -gwr 209 */ 210 if ((len + 2) > bytesleft) { 211 /* 212 * Not enough room for full (domain-qualified) hostname, try 213 * stripping it down to just the first field (host). 214 */ 215 char *tmpstr = hp->hostname->string; 216 len = 0; 217 while (*tmpstr && (*tmpstr != '.')) { 218 tmpstr++; 219 len++; 220 } 221 } 222 #endif 223 NEED((len + 2), "hn"); 224 *vp++ = TAG_HOST_NAME; 225 *vp++ = (byte) (len & 0xFF); 226 bcopy(hp->hostname->string, vp, len); 227 vp += len; 228 bytesleft -= len + 2; 229 } 230 /* 231 * The rest of these are less important, so they go last. 232 */ 233 if (hp->flags.lpr_server) { 234 if (insert_ip(TAG_LPR_SERVER, 235 hp->lpr_server, 236 &vp, &bytesleft)) 237 NEED(8, "lp"); 238 } 239 if (hp->flags.cookie_server) { 240 if (insert_ip(TAG_COOKIE_SERVER, 241 hp->cookie_server, 242 &vp, &bytesleft)) 243 NEED(8, "cs"); 244 } 245 if (hp->flags.log_server) { 246 if (insert_ip(TAG_LOG_SERVER, 247 hp->log_server, 248 &vp, &bytesleft)) 249 NEED(8, "lg"); 250 } 251 /* 252 * XXX - Add new tags here (to insert options) 253 */ 254 if (hp->flags.generic) { 255 if (insert_generic(hp->generic, &vp, &bytesleft)) 256 NEED(64, "(generic)"); 257 } 258 /* 259 * The end marker is inserted by the caller. 260 */ 261 return (vp - buf); 262 #undef NEED 263 } /* dovend_rfc1497 */ 264 265 266 267 /* 268 * Insert a tag value, a length value, and a list of IP addresses into the 269 * memory buffer indirectly pointed to by "dest". "tag" is the RFC1048 tag 270 * number to use, "iplist" is a pointer to a list of IP addresses 271 * (struct in_addr_list), and "bytesleft" points to an integer which 272 * indicates the size of the "dest" buffer. 273 * 274 * Return zero if everything fits. 275 * 276 * This is used to fill the vendor-specific area of a bootp packet in 277 * conformance to RFC1048. 278 */ 279 280 int 281 insert_ip(byte tag, struct in_addr_list *iplist, byte **dest, int *bytesleft) 282 { 283 struct in_addr *addrptr; 284 unsigned addrcount = 1; 285 byte *d; 286 287 if (iplist == NULL) 288 return (0); 289 290 if (*bytesleft >= 6) { 291 d = *dest; /* Save pointer for later */ 292 **dest = tag; 293 (*dest) += 2; 294 (*bytesleft) -= 2; /* Account for tag and length */ 295 addrptr = iplist->addr; 296 addrcount = iplist->addrcount; 297 while ((*bytesleft >= 4) && (addrcount > 0)) { 298 insert_u_long(addrptr->s_addr, dest); 299 addrptr++; 300 addrcount--; 301 (*bytesleft) -= 4; /* Four bytes per address */ 302 } 303 d[1] = (byte) ((*dest - d - 2) & 0xFF); 304 } 305 return (addrcount); 306 } 307 308 309 310 /* 311 * Insert generic data into a bootp packet. The data is assumed to already 312 * be in RFC1048 format. It is inserted using a first-fit algorithm which 313 * attempts to insert as many tags as possible. Tags and data which are 314 * too large to fit are skipped; any remaining tags are tried until they 315 * have all been exhausted. 316 * Return zero if everything fits. 317 */ 318 319 static int 320 insert_generic(struct shared_bindata *gendata, byte **buff, int *bytesleft) 321 { 322 byte *srcptr; 323 int length, numbytes; 324 int skipped = 0; 325 326 if (gendata == NULL) 327 return (0); 328 329 srcptr = gendata->data; 330 length = gendata->length; 331 while ((length > 0) && (*bytesleft > 0)) { 332 switch (*srcptr) { 333 case TAG_END: 334 length = 0; /* Force an exit on next iteration */ 335 break; 336 case TAG_PAD: 337 *(*buff)++ = *srcptr++; 338 (*bytesleft)--; 339 length--; 340 break; 341 default: 342 numbytes = srcptr[1] + 2; 343 if (*bytesleft < numbytes) 344 skipped += numbytes; 345 else { 346 bcopy(srcptr, *buff, numbytes); 347 (*buff) += numbytes; 348 (*bytesleft) -= numbytes; 349 } 350 srcptr += numbytes; 351 length -= numbytes; 352 break; 353 } 354 } /* while */ 355 return (skipped); 356 } 357 358 /* 359 * Insert the unsigned long "value" into memory starting at the byte 360 * pointed to by the byte pointer (*dest). (*dest) is updated to 361 * point to the next available byte. 362 * 363 * Since it is desirable to internally store network addresses in network 364 * byte order (in struct in_addr's), this routine expects longs to be 365 * passed in network byte order. 366 * 367 * However, due to the nature of the main algorithm, the long must be in 368 * host byte order, thus necessitating the use of ntohl() first. 369 */ 370 371 void 372 insert_u_long(u_int32 value, byte **dest) 373 { 374 byte *temp; 375 int n; 376 377 value = ntohl(value); /* Must use host byte order here */ 378 temp = (*dest += 4); 379 for (n = 4; n > 0; n--) { 380 *--temp = (byte) (value & 0xFF); 381 value >>= 8; 382 } 383 /* Final result is network byte order */ 384 } 385