1 /* $NetBSD: in.h,v 1.110 2020/08/20 21:21:32 riastradh Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1990, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)in.h 8.3 (Berkeley) 1/3/94 32 */ 33 34 /* 35 * Constants and structures defined by the internet system, 36 * Per RFC 790, September 1981, and numerous additions. 37 */ 38 39 #ifndef _NETINET_IN_H_ 40 #define _NETINET_IN_H_ 41 42 #include <sys/featuretest.h> 43 #include <machine/int_types.h> 44 45 #ifndef _BSD_UINT8_T_ 46 typedef __uint8_t uint8_t; 47 #define _BSD_UINT8_T_ 48 #endif 49 50 #ifndef _BSD_UINT32_T_ 51 typedef __uint32_t uint32_t; 52 #define _BSD_UINT32_T_ 53 #endif 54 55 #include <sys/ansi.h> 56 57 #ifndef in_addr_t 58 typedef __in_addr_t in_addr_t; 59 #define in_addr_t __in_addr_t 60 #endif 61 62 #ifndef in_port_t 63 typedef __in_port_t in_port_t; 64 #define in_port_t __in_port_t 65 #endif 66 67 #ifndef sa_family_t 68 typedef __sa_family_t sa_family_t; 69 #define sa_family_t __sa_family_t 70 #endif 71 72 /* 73 * Protocols 74 */ 75 #define IPPROTO_IP 0 /* dummy for IP */ 76 #define IPPROTO_HOPOPTS 0 /* IP6 hop-by-hop options */ 77 #define IPPROTO_ICMP 1 /* control message protocol */ 78 #define IPPROTO_IGMP 2 /* group mgmt protocol */ 79 #define IPPROTO_GGP 3 /* gateway^2 (deprecated) */ 80 #define IPPROTO_IPV4 4 /* IP header */ 81 #define IPPROTO_IPIP 4 /* IP inside IP */ 82 #define IPPROTO_TCP 6 /* tcp */ 83 #define IPPROTO_EGP 8 /* exterior gateway protocol */ 84 #define IPPROTO_PUP 12 /* pup */ 85 #define IPPROTO_UDP 17 /* user datagram protocol */ 86 #define IPPROTO_IDP 22 /* xns idp */ 87 #define IPPROTO_TP 29 /* tp-4 w/ class negotiation */ 88 #define IPPROTO_DCCP 33 /* DCCP */ 89 #define IPPROTO_IPV6 41 /* IP6 header */ 90 #define IPPROTO_ROUTING 43 /* IP6 routing header */ 91 #define IPPROTO_FRAGMENT 44 /* IP6 fragmentation header */ 92 #define IPPROTO_RSVP 46 /* resource reservation */ 93 #define IPPROTO_GRE 47 /* GRE encaps RFC 1701 */ 94 #define IPPROTO_ESP 50 /* encap. security payload */ 95 #define IPPROTO_AH 51 /* authentication header */ 96 #define IPPROTO_MOBILE 55 /* IP Mobility RFC 2004 */ 97 #define IPPROTO_IPV6_ICMP 58 /* IPv6 ICMP */ 98 #define IPPROTO_ICMPV6 58 /* ICMP6 */ 99 #define IPPROTO_NONE 59 /* IP6 no next header */ 100 #define IPPROTO_DSTOPTS 60 /* IP6 destination option */ 101 #define IPPROTO_EON 80 /* ISO cnlp */ 102 #define IPPROTO_ETHERIP 97 /* Ethernet-in-IP */ 103 #define IPPROTO_ENCAP 98 /* encapsulation header */ 104 #define IPPROTO_PIM 103 /* Protocol indep. multicast */ 105 #define IPPROTO_IPCOMP 108 /* IP Payload Comp. Protocol */ 106 #define IPPROTO_VRRP 112 /* VRRP RFC 2338 */ 107 #define IPPROTO_CARP 112 /* Common Address Resolution Protocol */ 108 #define IPPROTO_L2TP 115 /* L2TPv3 */ 109 #define IPPROTO_SCTP 132 /* SCTP */ 110 #define IPPROTO_PFSYNC 240 /* PFSYNC */ 111 #define IPPROTO_RAW 255 /* raw IP packet */ 112 #define IPPROTO_MAX 256 113 114 /* last return value of *_input(), meaning "all job for this pkt is done". */ 115 #define IPPROTO_DONE 257 116 117 /* sysctl placeholder for (FAST_)IPSEC */ 118 #define CTL_IPPROTO_IPSEC 258 119 120 121 /* 122 * Local port number conventions: 123 * 124 * Ports < IPPORT_RESERVED are reserved for privileged processes (e.g. root), 125 * unless a kernel is compiled with IPNOPRIVPORTS defined. 126 * 127 * When a user does a bind(2) or connect(2) with a port number of zero, 128 * a non-conflicting local port address is chosen. 129 * 130 * The default range is IPPORT_ANONMIN to IPPORT_ANONMAX, although 131 * that is settable by sysctl(3); net.inet.ip.anonportmin and 132 * net.inet.ip.anonportmax respectively. 133 * 134 * A user may set the IPPROTO_IP option IP_PORTRANGE to change this 135 * default assignment range. 136 * 137 * The value IP_PORTRANGE_DEFAULT causes the default behavior. 138 * 139 * The value IP_PORTRANGE_HIGH is the same as IP_PORTRANGE_DEFAULT, 140 * and exists only for FreeBSD compatibility purposes. 141 * 142 * The value IP_PORTRANGE_LOW changes the range to the "low" are 143 * that is (by convention) restricted to privileged processes. 144 * This convention is based on "vouchsafe" principles only. 145 * It is only secure if you trust the remote host to restrict these ports. 146 * The range is IPPORT_RESERVEDMIN to IPPORT_RESERVEDMAX. 147 */ 148 149 #define IPPORT_RESERVED 1024 150 #define IPPORT_ANONMIN 49152 151 #define IPPORT_ANONMAX 65535 152 #define IPPORT_RESERVEDMIN 600 153 #define IPPORT_RESERVEDMAX (IPPORT_RESERVED-1) 154 155 /* 156 * Internet address (a structure for historical reasons) 157 */ 158 struct in_addr { 159 in_addr_t s_addr; 160 } __packed; 161 162 /* 163 * Definitions of bits in internet address integers. 164 * On subnets, the decomposition of addresses to host and net parts 165 * is done according to subnet mask, not the masks here. 166 * 167 * By byte-swapping the constants, we avoid ever having to byte-swap IP 168 * addresses inside the kernel. Unfortunately, user-level programs rely 169 * on these macros not doing byte-swapping. 170 */ 171 #ifdef _KERNEL 172 #define __IPADDR(x) ((uint32_t) htonl((uint32_t)(x))) 173 #else 174 #define __IPADDR(x) ((uint32_t)(x)) 175 #endif 176 177 #define IN_CLASSA(i) (((uint32_t)(i) & __IPADDR(0x80000000)) == \ 178 __IPADDR(0x00000000)) 179 #define IN_CLASSA_NET __IPADDR(0xff000000) 180 #define IN_CLASSA_NSHIFT 24 181 #define IN_CLASSA_HOST __IPADDR(0x00ffffff) 182 #define IN_CLASSA_MAX 128 183 184 #define IN_CLASSB(i) (((uint32_t)(i) & __IPADDR(0xc0000000)) == \ 185 __IPADDR(0x80000000)) 186 #define IN_CLASSB_NET __IPADDR(0xffff0000) 187 #define IN_CLASSB_NSHIFT 16 188 #define IN_CLASSB_HOST __IPADDR(0x0000ffff) 189 #define IN_CLASSB_MAX 65536 190 191 #define IN_CLASSC(i) (((uint32_t)(i) & __IPADDR(0xe0000000)) == \ 192 __IPADDR(0xc0000000)) 193 #define IN_CLASSC_NET __IPADDR(0xffffff00) 194 #define IN_CLASSC_NSHIFT 8 195 #define IN_CLASSC_HOST __IPADDR(0x000000ff) 196 197 #define IN_CLASSD(i) (((uint32_t)(i) & __IPADDR(0xf0000000)) == \ 198 __IPADDR(0xe0000000)) 199 /* These ones aren't really net and host fields, but routing needn't know. */ 200 #define IN_CLASSD_NET __IPADDR(0xf0000000) 201 #define IN_CLASSD_NSHIFT 28 202 #define IN_CLASSD_HOST __IPADDR(0x0fffffff) 203 #define IN_MULTICAST(i) IN_CLASSD(i) 204 205 #define IN_EXPERIMENTAL(i) (((uint32_t)(i) & __IPADDR(0xf0000000)) == \ 206 __IPADDR(0xf0000000)) 207 #define IN_BADCLASS(i) (((uint32_t)(i) & __IPADDR(0xf0000000)) == \ 208 __IPADDR(0xf0000000)) 209 210 #define IN_LINKLOCAL(i) (((uint32_t)(i) & __IPADDR(0xffff0000)) == \ 211 __IPADDR(0xa9fe0000)) 212 213 #define IN_PRIVATE(i) ((((uint32_t)(i) & __IPADDR(0xff000000)) == \ 214 __IPADDR(0x0a000000)) || \ 215 (((uint32_t)(i) & __IPADDR(0xfff00000)) == \ 216 __IPADDR(0xac100000)) || \ 217 (((uint32_t)(i) & __IPADDR(0xffff0000)) == \ 218 __IPADDR(0xc0a80000))) 219 220 #define IN_LOCAL_GROUP(i) (((uint32_t)(i) & __IPADDR(0xffffff00)) == \ 221 __IPADDR(0xe0000000)) 222 223 #define IN_ANY_LOCAL(i) (IN_LINKLOCAL(i) || IN_LOCAL_GROUP(i)) 224 225 #define INADDR_ANY __IPADDR(0x00000000) 226 #define INADDR_LOOPBACK __IPADDR(0x7f000001) 227 #define INADDR_BROADCAST __IPADDR(0xffffffff) /* must be masked */ 228 #define INADDR_NONE __IPADDR(0xffffffff) /* -1 return */ 229 230 #define INADDR_UNSPEC_GROUP __IPADDR(0xe0000000) /* 224.0.0.0 */ 231 #define INADDR_ALLHOSTS_GROUP __IPADDR(0xe0000001) /* 224.0.0.1 */ 232 #define INADDR_ALLRTRS_GROUP __IPADDR(0xe0000002) /* 224.0.0.2 */ 233 #define INADDR_CARP_GROUP __IPADDR(0xe0000012) /* 224.0.0.18 */ 234 #define INADDR_MAX_LOCAL_GROUP __IPADDR(0xe00000ff) /* 224.0.0.255 */ 235 236 #define IN_LOOPBACKNET 127 /* official! */ 237 238 #define IN_RFC3021_MASK __IPADDR(0xfffffffe) 239 240 /* 241 * Socket address, internet style. 242 */ 243 struct sockaddr_in { 244 uint8_t sin_len; 245 sa_family_t sin_family; 246 in_port_t sin_port; 247 struct in_addr sin_addr; 248 __int8_t sin_zero[8]; 249 }; 250 251 #define INET_ADDRSTRLEN 16 252 253 /* 254 * Structure used to describe IP options. 255 * Used to store options internally, to pass them to a process, 256 * or to restore options retrieved earlier. 257 * The ip_dst is used for the first-hop gateway when using a source route 258 * (this gets put into the header proper). 259 */ 260 struct ip_opts { 261 struct in_addr ip_dst; /* first hop, 0 w/o src rt */ 262 #if defined(__cplusplus) 263 __int8_t Ip_opts[40]; /* actually variable in size */ 264 #else 265 __int8_t ip_opts[40]; /* actually variable in size */ 266 #endif 267 }; 268 269 /* 270 * Options for use with [gs]etsockopt at the IP level. 271 * First word of comment is data type; bool is stored in int. 272 */ 273 #define IP_OPTIONS 1 /* buf/ip_opts; set/get IP options */ 274 #define IP_HDRINCL 2 /* int; header is included with data */ 275 #define IP_TOS 3 /* int; IP type of service and preced. */ 276 #define IP_TTL 4 /* int; IP time to live */ 277 #define IP_RECVOPTS 5 /* bool; receive all IP opts w/dgram */ 278 #define IP_RECVRETOPTS 6 /* bool; receive IP opts for response */ 279 #define IP_RECVDSTADDR 7 /* bool; receive IP dst addr w/dgram */ 280 #define IP_RETOPTS 8 /* ip_opts; set/get IP options */ 281 #define IP_MULTICAST_IF 9 /* in_addr; set/get IP multicast i/f */ 282 #define IP_MULTICAST_TTL 10 /* u_char; set/get IP multicast ttl */ 283 #define IP_MULTICAST_LOOP 11 /* u_char; set/get IP multicast loopback */ 284 /* The add and drop membership option numbers need to match with the v6 ones */ 285 #define IP_ADD_MEMBERSHIP 12 /* ip_mreq; add an IP group membership */ 286 #define IP_DROP_MEMBERSHIP 13 /* ip_mreq; drop an IP group membership */ 287 #define IP_PORTALGO 18 /* int; port selection algo (rfc6056) */ 288 #define IP_PORTRANGE 19 /* int; range to use for ephemeral port */ 289 #define IP_RECVIF 20 /* bool; receive reception if w/dgram */ 290 #define IP_ERRORMTU 21 /* int; get MTU of last xmit = EMSGSIZE */ 291 #define IP_IPSEC_POLICY 22 /* struct; get/set security policy */ 292 #define IP_RECVTTL 23 /* bool; receive IP TTL w/dgram */ 293 #define IP_MINTTL 24 /* minimum TTL for packet or drop */ 294 #define IP_PKTINFO 25 /* struct; set default src if/addr */ 295 #define IP_RECVPKTINFO 26 /* int; receive dst if/addr w/dgram */ 296 297 #define IP_SENDSRCADDR IP_RECVDSTADDR /* FreeBSD compatibility */ 298 299 /* 300 * Information sent in the control message of a datagram socket for 301 * IP_PKTINFO and IP_RECVPKTINFO. 302 */ 303 struct in_pktinfo { 304 struct in_addr ipi_addr; /* src/dst address */ 305 unsigned int ipi_ifindex; /* interface index */ 306 }; 307 308 #define ipi_spec_dst ipi_addr /* Solaris/Linux compatibility */ 309 310 /* 311 * Defaults and limits for options 312 */ 313 #define IP_DEFAULT_MULTICAST_TTL 1 /* normally limit m'casts to 1 hop */ 314 #define IP_DEFAULT_MULTICAST_LOOP 1 /* normally hear sends if a member */ 315 #define IP_MAX_MEMBERSHIPS 20 /* per socket; must fit in one mbuf */ 316 317 /* 318 * Argument structure for IP_ADD_MEMBERSHIP and IP_DROP_MEMBERSHIP. 319 */ 320 struct ip_mreq { 321 struct in_addr imr_multiaddr; /* IP multicast address of group */ 322 struct in_addr imr_interface; /* local IP address of interface */ 323 }; 324 325 /* 326 * Argument for IP_PORTRANGE: 327 * - which range to search when port is unspecified at bind() or connect() 328 */ 329 #define IP_PORTRANGE_DEFAULT 0 /* default range */ 330 #define IP_PORTRANGE_HIGH 1 /* same as DEFAULT (FreeBSD compat) */ 331 #define IP_PORTRANGE_LOW 2 /* use privileged range */ 332 333 #if defined(_NETBSD_SOURCE) 334 /* 335 * Definitions for inet sysctl operations. 336 * 337 * Third level is protocol number. 338 * Fourth level is desired variable within that protocol. 339 */ 340 341 /* 342 * Names for IP sysctl objects 343 */ 344 #define IPCTL_FORWARDING 1 /* act as router */ 345 #define IPCTL_SENDREDIRECTS 2 /* may send redirects when forwarding */ 346 #define IPCTL_DEFTTL 3 /* default TTL */ 347 /* IPCTL_DEFMTU=4, never implemented */ 348 #define IPCTL_FORWSRCRT 5 /* forward source-routed packets */ 349 #define IPCTL_DIRECTEDBCAST 6 /* default broadcast behavior */ 350 #define IPCTL_ALLOWSRCRT 7 /* allow/drop all source-routed pkts */ 351 #define IPCTL_SUBNETSARELOCAL 8 /* treat subnets as local addresses */ 352 #define IPCTL_MTUDISC 9 /* allow path MTU discovery */ 353 #define IPCTL_ANONPORTMIN 10 /* minimum ephemeral port */ 354 #define IPCTL_ANONPORTMAX 11 /* maximum ephemeral port */ 355 #define IPCTL_MTUDISCTIMEOUT 12 /* allow path MTU discovery */ 356 #define IPCTL_MAXFLOWS 13 /* maximum ip flows allowed */ 357 #define IPCTL_HOSTZEROBROADCAST 14 /* is host zero a broadcast addr? */ 358 #define IPCTL_GIF_TTL 15 /* default TTL for gif encap packet */ 359 #define IPCTL_LOWPORTMIN 16 /* minimum reserved port */ 360 #define IPCTL_LOWPORTMAX 17 /* maximum reserved port */ 361 #define IPCTL_MAXFRAGPACKETS 18 /* max packets reassembly queue */ 362 #define IPCTL_GRE_TTL 19 /* default TTL for gre encap packet */ 363 #define IPCTL_CHECKINTERFACE 20 /* drop pkts in from 'wrong' iface */ 364 #define IPCTL_IFQ 21 /* IP packet input queue */ 365 #define IPCTL_RANDOMID 22 /* use random IP ids (if configured) */ 366 #define IPCTL_LOOPBACKCKSUM 23 /* do IP checksum on loopback */ 367 #define IPCTL_STATS 24 /* IP statistics */ 368 #define IPCTL_DAD_COUNT 25 /* DAD packets to send */ 369 370 #endif /* _NETBSD_SOURCE */ 371 372 /* INET6 stuff */ 373 #define __KAME_NETINET_IN_H_INCLUDED_ 374 #include <netinet6/in6.h> 375 #undef __KAME_NETINET_IN_H_INCLUDED_ 376 377 #ifdef _KERNEL 378 #include <sys/psref.h> 379 380 /* 381 * in_cksum_phdr: 382 * 383 * Compute significant parts of the IPv4 checksum pseudo-header 384 * for use in a delayed TCP/UDP checksum calculation. 385 * 386 * Args: 387 * 388 * src Source IP address 389 * dst Destination IP address 390 * lenproto htons(proto-hdr-len + proto-number) 391 */ 392 static __inline u_int16_t __unused 393 in_cksum_phdr(u_int32_t src, u_int32_t dst, u_int32_t lenproto) 394 { 395 u_int32_t sum; 396 397 sum = lenproto + 398 (u_int16_t)(src >> 16) + 399 (u_int16_t)(src /*& 0xffff*/) + 400 (u_int16_t)(dst >> 16) + 401 (u_int16_t)(dst /*& 0xffff*/); 402 403 sum = (u_int16_t)(sum >> 16) + (u_int16_t)(sum /*& 0xffff*/); 404 405 if (sum > 0xffff) 406 sum -= 0xffff; 407 408 return (sum); 409 } 410 411 /* 412 * in_cksum_addword: 413 * 414 * Add the two 16-bit network-order values, carry, and return. 415 */ 416 static __inline u_int16_t __unused 417 in_cksum_addword(u_int16_t a, u_int16_t b) 418 { 419 u_int32_t sum = a + b; 420 421 if (sum > 0xffff) 422 sum -= 0xffff; 423 424 return (sum); 425 } 426 427 extern struct in_addr zeroin_addr; 428 extern u_char ip_protox[]; 429 extern const struct sockaddr_in in_any; 430 431 int in_broadcast(struct in_addr, struct ifnet *); 432 int in_direct(struct in_addr, struct ifnet *); 433 int in_canforward(struct in_addr); 434 int cpu_in_cksum(struct mbuf *, int, int, uint32_t); 435 int in_cksum(struct mbuf *, int); 436 int in4_cksum(struct mbuf *, u_int8_t, int, int); 437 int in_localaddr(struct in_addr); 438 void in_socktrim(struct sockaddr_in *); 439 440 void in_len2mask(struct in_addr *, u_int); 441 442 void in_if_link_up(struct ifnet *); 443 void in_if_link_down(struct ifnet *); 444 void in_if_up(struct ifnet *); 445 void in_if_down(struct ifnet *); 446 void in_if_link_state_change(struct ifnet *, int); 447 448 struct route; 449 struct ip_moptions; 450 451 struct in_ifaddr *in_selectsrc(struct sockaddr_in *, 452 struct route *, int, struct ip_moptions *, int *, struct psref *); 453 454 struct ip; 455 int in_tunnel_validate(const struct ip *, struct in_addr, struct in_addr); 456 457 #define in_hosteq(s,t) ((s).s_addr == (t).s_addr) 458 #define in_nullhost(x) ((x).s_addr == INADDR_ANY) 459 460 #define satosin(sa) ((struct sockaddr_in *)(sa)) 461 #define satocsin(sa) ((const struct sockaddr_in *)(sa)) 462 #define sintosa(sin) ((struct sockaddr *)(sin)) 463 #define sintocsa(sin) ((const struct sockaddr *)(sin)) 464 #define ifatoia(ifa) ((struct in_ifaddr *)(ifa)) 465 466 int sockaddr_in_cmp(const struct sockaddr *, const struct sockaddr *); 467 const void *sockaddr_in_const_addr(const struct sockaddr *, socklen_t *); 468 void *sockaddr_in_addr(struct sockaddr *, socklen_t *); 469 470 static __inline void 471 sockaddr_in_init1(struct sockaddr_in *sin, const struct in_addr *addr, 472 in_port_t port) 473 { 474 sin->sin_port = port; 475 sin->sin_addr = *addr; 476 memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); 477 } 478 479 static __inline void 480 sockaddr_in_init(struct sockaddr_in *sin, const struct in_addr *addr, 481 in_port_t port) 482 { 483 sin->sin_family = AF_INET; 484 sin->sin_len = sizeof(*sin); 485 sockaddr_in_init1(sin, addr, port); 486 } 487 488 static __inline struct sockaddr * 489 sockaddr_in_alloc(const struct in_addr *addr, in_port_t port, int flags) 490 { 491 struct sockaddr *sa; 492 493 sa = sockaddr_alloc(AF_INET, sizeof(struct sockaddr_in), flags); 494 495 if (sa == NULL) 496 return NULL; 497 498 sockaddr_in_init1(satosin(sa), addr, port); 499 500 return sa; 501 } 502 #endif /* _KERNEL */ 503 504 #if defined(_KERNEL) || defined(_TEST) 505 int in_print(char *, size_t, const struct in_addr *); 506 #define IN_PRINT(b, a) (in_print((b), sizeof(b), a), (b)) 507 int sin_print(char *, size_t, const void *); 508 #endif 509 510 #endif /* !_NETINET_IN_H_ */ 511