1 /* Copyright (C) 1991-2001, 2003, 2004, 2006, 2007 2 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 02111-1307 USA. */ 19 20 #ifndef _NETINET_IN_H 21 #define _NETINET_IN_H 1 22 23 #include <features.h> 24 #include <stdint.h> 25 #include <sys/socket.h> 26 #include <bits/types.h> 27 28 29 __BEGIN_DECLS 30 31 /* Standard well-defined IP protocols. */ 32 enum 33 { 34 IPPROTO_IP = 0, /* Dummy protocol for TCP. */ 35 #define IPPROTO_IP IPPROTO_IP 36 IPPROTO_HOPOPTS = 0, /* IPv6 Hop-by-Hop options. */ 37 #define IPPROTO_HOPOPTS IPPROTO_HOPOPTS 38 IPPROTO_ICMP = 1, /* Internet Control Message Protocol. */ 39 #define IPPROTO_ICMP IPPROTO_ICMP 40 IPPROTO_IGMP = 2, /* Internet Group Management Protocol. */ 41 #define IPPROTO_IGMP IPPROTO_IGMP 42 IPPROTO_IPIP = 4, /* IPIP tunnels (older KA9Q tunnels use 94). */ 43 #define IPPROTO_IPIP IPPROTO_IPIP 44 IPPROTO_TCP = 6, /* Transmission Control Protocol. */ 45 #define IPPROTO_TCP IPPROTO_TCP 46 IPPROTO_EGP = 8, /* Exterior Gateway Protocol. */ 47 #define IPPROTO_EGP IPPROTO_EGP 48 IPPROTO_PUP = 12, /* PUP protocol. */ 49 #define IPPROTO_PUP IPPROTO_PUP 50 IPPROTO_UDP = 17, /* User Datagram Protocol. */ 51 #define IPPROTO_UDP IPPROTO_UDP 52 IPPROTO_IDP = 22, /* XNS IDP protocol. */ 53 #define IPPROTO_IDP IPPROTO_IDP 54 IPPROTO_TP = 29, /* SO Transport Protocol Class 4. */ 55 #define IPPROTO_TP IPPROTO_TP 56 IPPROTO_IPV6 = 41, /* IPv6 header. */ 57 #define IPPROTO_IPV6 IPPROTO_IPV6 58 IPPROTO_ROUTING = 43, /* IPv6 routing header. */ 59 #define IPPROTO_ROUTING IPPROTO_ROUTING 60 IPPROTO_FRAGMENT = 44, /* IPv6 fragmentation header. */ 61 #define IPPROTO_FRAGMENT IPPROTO_FRAGMENT 62 IPPROTO_RSVP = 46, /* Reservation Protocol. */ 63 #define IPPROTO_RSVP IPPROTO_RSVP 64 IPPROTO_GRE = 47, /* General Routing Encapsulation. */ 65 #define IPPROTO_GRE IPPROTO_GRE 66 IPPROTO_ESP = 50, /* encapsulating security payload. */ 67 #define IPPROTO_ESP IPPROTO_ESP 68 IPPROTO_AH = 51, /* authentication header. */ 69 #define IPPROTO_AH IPPROTO_AH 70 IPPROTO_ICMPV6 = 58, /* ICMPv6. */ 71 #define IPPROTO_ICMPV6 IPPROTO_ICMPV6 72 IPPROTO_NONE = 59, /* IPv6 no next header. */ 73 #define IPPROTO_NONE IPPROTO_NONE 74 IPPROTO_DSTOPTS = 60, /* IPv6 destination options. */ 75 #define IPPROTO_DSTOPTS IPPROTO_DSTOPTS 76 IPPROTO_MTP = 92, /* Multicast Transport Protocol. */ 77 #define IPPROTO_MTP IPPROTO_MTP 78 IPPROTO_ENCAP = 98, /* Encapsulation Header. */ 79 #define IPPROTO_ENCAP IPPROTO_ENCAP 80 IPPROTO_PIM = 103, /* Protocol Independent Multicast. */ 81 #define IPPROTO_PIM IPPROTO_PIM 82 IPPROTO_COMP = 108, /* Compression Header Protocol. */ 83 #define IPPROTO_COMP IPPROTO_COMP 84 IPPROTO_SCTP = 132, /* Stream Control Transmission Protocol. */ 85 #define IPPROTO_SCTP IPPROTO_SCTP 86 IPPROTO_RAW = 255, /* Raw IP packets. */ 87 #define IPPROTO_RAW IPPROTO_RAW 88 IPPROTO_MAX 89 }; 90 91 92 /* Type to represent a port. */ 93 typedef uint16_t in_port_t; 94 95 /* Standard well-known ports. */ 96 enum 97 { 98 IPPORT_ECHO = 7, /* Echo service. */ 99 IPPORT_DISCARD = 9, /* Discard transmissions service. */ 100 IPPORT_SYSTAT = 11, /* System status service. */ 101 IPPORT_DAYTIME = 13, /* Time of day service. */ 102 IPPORT_NETSTAT = 15, /* Network status service. */ 103 IPPORT_FTP = 21, /* File Transfer Protocol. */ 104 IPPORT_TELNET = 23, /* Telnet protocol. */ 105 IPPORT_SMTP = 25, /* Simple Mail Transfer Protocol. */ 106 IPPORT_TIMESERVER = 37, /* Timeserver service. */ 107 IPPORT_NAMESERVER = 42, /* Domain Name Service. */ 108 IPPORT_WHOIS = 43, /* Internet Whois service. */ 109 IPPORT_MTP = 57, 110 111 IPPORT_TFTP = 69, /* Trivial File Transfer Protocol. */ 112 IPPORT_RJE = 77, 113 IPPORT_FINGER = 79, /* Finger service. */ 114 IPPORT_TTYLINK = 87, 115 IPPORT_SUPDUP = 95, /* SUPDUP protocol. */ 116 117 118 IPPORT_EXECSERVER = 512, /* execd service. */ 119 IPPORT_LOGINSERVER = 513, /* rlogind service. */ 120 IPPORT_CMDSERVER = 514, 121 IPPORT_EFSSERVER = 520, 122 123 /* UDP ports. */ 124 IPPORT_BIFFUDP = 512, 125 IPPORT_WHOSERVER = 513, 126 IPPORT_ROUTESERVER = 520, 127 128 /* Ports less than this value are reserved for privileged processes. */ 129 IPPORT_RESERVED = 1024, 130 131 /* Ports greater this value are reserved for (non-privileged) servers. */ 132 IPPORT_USERRESERVED = 5000 133 }; 134 135 136 /* Internet address. */ 137 typedef uint32_t in_addr_t; 138 struct in_addr 139 { 140 in_addr_t s_addr; 141 }; 142 143 144 /* Definitions of the bits in an Internet address integer. 145 146 On subnets, host and network parts are found according to 147 the subnet mask, not these masks. */ 148 149 #define IN_CLASSA(a) ((((in_addr_t)(a)) & 0x80000000) == 0) 150 #define IN_CLASSA_NET 0xff000000 151 #define IN_CLASSA_NSHIFT 24 152 #define IN_CLASSA_HOST (0xffffffff & ~IN_CLASSA_NET) 153 #define IN_CLASSA_MAX 128 154 155 #define IN_CLASSB(a) ((((in_addr_t)(a)) & 0xc0000000) == 0x80000000) 156 #define IN_CLASSB_NET 0xffff0000 157 #define IN_CLASSB_NSHIFT 16 158 #define IN_CLASSB_HOST (0xffffffff & ~IN_CLASSB_NET) 159 #define IN_CLASSB_MAX 65536 160 161 #define IN_CLASSC(a) ((((in_addr_t)(a)) & 0xe0000000) == 0xc0000000) 162 #define IN_CLASSC_NET 0xffffff00 163 #define IN_CLASSC_NSHIFT 8 164 #define IN_CLASSC_HOST (0xffffffff & ~IN_CLASSC_NET) 165 166 #define IN_CLASSD(a) ((((in_addr_t)(a)) & 0xf0000000) == 0xe0000000) 167 #define IN_MULTICAST(a) IN_CLASSD(a) 168 169 #define IN_EXPERIMENTAL(a) ((((in_addr_t)(a)) & 0xe0000000) == 0xe0000000) 170 #define IN_BADCLASS(a) ((((in_addr_t)(a)) & 0xf0000000) == 0xf0000000) 171 172 /* Address to accept any incoming messages. */ 173 #define INADDR_ANY ((in_addr_t) 0x00000000) 174 /* Address to send to all hosts. */ 175 #define INADDR_BROADCAST ((in_addr_t) 0xffffffff) 176 /* Address indicating an error return. */ 177 #define INADDR_NONE ((in_addr_t) 0xffffffff) 178 179 /* Network number for local host loopback. */ 180 #define IN_LOOPBACKNET 127 181 /* Address to loopback in software to local host. */ 182 #ifndef INADDR_LOOPBACK 183 # define INADDR_LOOPBACK ((in_addr_t) 0x7f000001) /* Inet 127.0.0.1. */ 184 #endif 185 186 /* Defines for Multicast INADDR. */ 187 #define INADDR_UNSPEC_GROUP ((in_addr_t) 0xe0000000) /* 224.0.0.0 */ 188 #define INADDR_ALLHOSTS_GROUP ((in_addr_t) 0xe0000001) /* 224.0.0.1 */ 189 #define INADDR_ALLRTRS_GROUP ((in_addr_t) 0xe0000002) /* 224.0.0.2 */ 190 #define INADDR_MAX_LOCAL_GROUP ((in_addr_t) 0xe00000ff) /* 224.0.0.255 */ 191 192 193 /* IPv6 address */ 194 struct in6_addr 195 { 196 union 197 { 198 uint8_t u6_addr8[16]; 199 uint16_t u6_addr16[8]; 200 uint32_t u6_addr32[4]; 201 } in6_u; 202 #define s6_addr in6_u.u6_addr8 203 #define s6_addr16 in6_u.u6_addr16 204 #define s6_addr32 in6_u.u6_addr32 205 }; 206 207 extern const struct in6_addr in6addr_any; /* :: */ 208 extern const struct in6_addr in6addr_loopback; /* ::1 */ 209 #define IN6ADDR_ANY_INIT { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } } } 210 #define IN6ADDR_LOOPBACK_INIT { { { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 } } } 211 212 #define INET_ADDRSTRLEN 16 213 #define INET6_ADDRSTRLEN 46 214 215 216 /* Structure describing an Internet socket address. */ 217 struct sockaddr_in 218 { 219 __SOCKADDR_COMMON (sin_); 220 in_port_t sin_port; /* Port number. */ 221 struct in_addr sin_addr; /* Internet address. */ 222 223 /* Pad to size of `struct sockaddr'. */ 224 unsigned char sin_zero[sizeof (struct sockaddr) - 225 __SOCKADDR_COMMON_SIZE - 226 sizeof (in_port_t) - 227 sizeof (struct in_addr)]; 228 }; 229 230 /* Ditto, for IPv6. */ 231 struct sockaddr_in6 232 { 233 __SOCKADDR_COMMON (sin6_); 234 in_port_t sin6_port; /* Transport layer port # */ 235 uint32_t sin6_flowinfo; /* IPv6 flow information */ 236 struct in6_addr sin6_addr; /* IPv6 address */ 237 uint32_t sin6_scope_id; /* IPv6 scope-id */ 238 }; 239 240 241 /* IPv4 multicast request. */ 242 struct ip_mreq 243 { 244 /* IP multicast address of group. */ 245 struct in_addr imr_multiaddr; 246 247 /* Local IP address of interface. */ 248 struct in_addr imr_interface; 249 }; 250 251 struct ip_mreq_source 252 { 253 /* IP multicast address of group. */ 254 struct in_addr imr_multiaddr; 255 256 /* IP address of source. */ 257 struct in_addr imr_interface; 258 259 /* IP address of interface. */ 260 struct in_addr imr_sourceaddr; 261 }; 262 263 /* Likewise, for IPv6. */ 264 struct ipv6_mreq 265 { 266 /* IPv6 multicast address of group */ 267 struct in6_addr ipv6mr_multiaddr; 268 269 /* local interface */ 270 unsigned int ipv6mr_interface; 271 }; 272 273 274 /* Multicast group request. */ 275 struct group_req 276 { 277 /* Interface index. */ 278 uint32_t gr_interface; 279 280 /* Group address. */ 281 struct sockaddr_storage gr_group; 282 }; 283 284 struct group_source_req 285 { 286 /* Interface index. */ 287 uint32_t gsr_interface; 288 289 /* Group address. */ 290 struct sockaddr_storage gsr_group; 291 292 /* Source address. */ 293 struct sockaddr_storage gsr_source; 294 }; 295 296 297 /* Full-state filter operations. */ 298 struct ip_msfilter 299 { 300 /* IP multicast address of group. */ 301 struct in_addr imsf_multiaddr; 302 303 /* Local IP address of interface. */ 304 struct in_addr imsf_interface; 305 306 /* Filter mode. */ 307 uint32_t imsf_fmode; 308 309 /* Number of source addresses. */ 310 uint32_t imsf_numsrc; 311 /* Source addresses. */ 312 struct in_addr imsf_slist[1]; 313 }; 314 315 #define IP_MSFILTER_SIZE(numsrc) (sizeof (struct ip_msfilter) \ 316 - sizeof (struct in_addr) \ 317 + (numsrc) * sizeof (struct in_addr)) 318 319 struct group_filter 320 { 321 /* Interface index. */ 322 uint32_t gf_interface; 323 324 /* Group address. */ 325 struct sockaddr_storage gf_group; 326 327 /* Filter mode. */ 328 uint32_t gf_fmode; 329 330 /* Number of source addresses. */ 331 uint32_t gf_numsrc; 332 /* Source addresses. */ 333 struct sockaddr_storage gf_slist[1]; 334 }; 335 336 #define GROUP_FILTER_SIZE(numsrc) (sizeof (struct group_filter) \ 337 - sizeof (struct sockaddr_storage) \ 338 + ((numsrc) \ 339 * sizeof (struct sockaddr_storage))) 340 341 342 /* Get system-specific definitions. */ 343 #include <bits/in.h> 344 345 /* Functions to convert between host and network byte order. 346 347 Please note that these functions normally take `unsigned long int' or 348 `unsigned short int' values as arguments and also return them. But 349 this was a short-sighted decision since on different systems the types 350 may have different representations but the values are always the same. */ 351 352 extern uint32_t ntohl (uint32_t __netlong) __THROW __attribute__ ((__const__)); 353 extern uint16_t ntohs (uint16_t __netshort) 354 __THROW __attribute__ ((__const__)); 355 extern uint32_t htonl (uint32_t __hostlong) 356 __THROW __attribute__ ((__const__)); 357 extern uint16_t htons (uint16_t __hostshort) 358 __THROW __attribute__ ((__const__)); 359 360 #include <endian.h> 361 362 /* Get machine dependent optimized versions of byte swapping functions. */ 363 #include <bits/byteswap.h> 364 365 #ifdef __OPTIMIZE__ 366 /* We can optimize calls to the conversion functions. Either nothing has 367 to be done or we are using directly the byte-swapping functions which 368 often can be inlined. */ 369 # if __BYTE_ORDER == __BIG_ENDIAN 370 /* The host byte order is the same as network byte order, 371 so these functions are all just identity. */ 372 # define ntohl(x) (x) 373 # define ntohs(x) (x) 374 # define htonl(x) (x) 375 # define htons(x) (x) 376 # else 377 # if __BYTE_ORDER == __LITTLE_ENDIAN 378 # define ntohl(x) __bswap_32 (x) 379 # define ntohs(x) __bswap_16 (x) 380 # define htonl(x) __bswap_32 (x) 381 # define htons(x) __bswap_16 (x) 382 # endif 383 # endif 384 #endif 385 386 #define IN6_IS_ADDR_UNSPECIFIED(a) \ 387 (((__const uint32_t *) (a))[0] == 0 \ 388 && ((__const uint32_t *) (a))[1] == 0 \ 389 && ((__const uint32_t *) (a))[2] == 0 \ 390 && ((__const uint32_t *) (a))[3] == 0) 391 392 #define IN6_IS_ADDR_LOOPBACK(a) \ 393 (((__const uint32_t *) (a))[0] == 0 \ 394 && ((__const uint32_t *) (a))[1] == 0 \ 395 && ((__const uint32_t *) (a))[2] == 0 \ 396 && ((__const uint32_t *) (a))[3] == htonl (1)) 397 398 #define IN6_IS_ADDR_MULTICAST(a) (((__const uint8_t *) (a))[0] == 0xff) 399 400 #define IN6_IS_ADDR_LINKLOCAL(a) \ 401 ((((__const uint32_t *) (a))[0] & htonl (0xffc00000)) \ 402 == htonl (0xfe800000)) 403 404 #define IN6_IS_ADDR_SITELOCAL(a) \ 405 ((((__const uint32_t *) (a))[0] & htonl (0xffc00000)) \ 406 == htonl (0xfec00000)) 407 408 #define IN6_IS_ADDR_V4MAPPED(a) \ 409 ((((__const uint32_t *) (a))[0] == 0) \ 410 && (((__const uint32_t *) (a))[1] == 0) \ 411 && (((__const uint32_t *) (a))[2] == htonl (0xffff))) 412 413 #define IN6_IS_ADDR_V4COMPAT(a) \ 414 ((((__const uint32_t *) (a))[0] == 0) \ 415 && (((__const uint32_t *) (a))[1] == 0) \ 416 && (((__const uint32_t *) (a))[2] == 0) \ 417 && (ntohl (((__const uint32_t *) (a))[3]) > 1)) 418 419 #define IN6_ARE_ADDR_EQUAL(a,b) \ 420 ((((__const uint32_t *) (a))[0] == ((__const uint32_t *) (b))[0]) \ 421 && (((__const uint32_t *) (a))[1] == ((__const uint32_t *) (b))[1]) \ 422 && (((__const uint32_t *) (a))[2] == ((__const uint32_t *) (b))[2]) \ 423 && (((__const uint32_t *) (a))[3] == ((__const uint32_t *) (b))[3])) 424 425 /* Bind socket to a privileged IP port. */ 426 extern int bindresvport (int __sockfd, struct sockaddr_in *__sock_in) __THROW; 427 428 /* The IPv6 version of this function. */ 429 extern int bindresvport6 (int __sockfd, struct sockaddr_in6 *__sock_in) 430 __THROW; 431 432 433 #define IN6_IS_ADDR_MC_NODELOCAL(a) \ 434 (IN6_IS_ADDR_MULTICAST(a) \ 435 && ((((__const uint8_t *) (a))[1] & 0xf) == 0x1)) 436 437 #define IN6_IS_ADDR_MC_LINKLOCAL(a) \ 438 (IN6_IS_ADDR_MULTICAST(a) \ 439 && ((((__const uint8_t *) (a))[1] & 0xf) == 0x2)) 440 441 #define IN6_IS_ADDR_MC_SITELOCAL(a) \ 442 (IN6_IS_ADDR_MULTICAST(a) \ 443 && ((((__const uint8_t *) (a))[1] & 0xf) == 0x5)) 444 445 #define IN6_IS_ADDR_MC_ORGLOCAL(a) \ 446 (IN6_IS_ADDR_MULTICAST(a) \ 447 && ((((__const uint8_t *) (a))[1] & 0xf) == 0x8)) 448 449 #define IN6_IS_ADDR_MC_GLOBAL(a) \ 450 (IN6_IS_ADDR_MULTICAST(a) \ 451 && ((((__const uint8_t *) (a))[1] & 0xf) == 0xe)) 452 453 /* IPv6 packet information. */ 454 struct in6_pktinfo 455 { 456 struct in6_addr ipi6_addr; /* src/dst IPv6 address */ 457 unsigned int ipi6_ifindex; /* send/recv interface index */ 458 }; 459 460 /* IPv6 MTU information. */ 461 struct ip6_mtuinfo 462 { 463 struct sockaddr_in6 ip6m_addr; /* dst address including zone ID */ 464 uint32_t ip6m_mtu; /* path MTU in host byte order */ 465 }; 466 467 468 #ifdef __USE_GNU 469 /* Obsolete hop-by-hop and Destination Options Processing (RFC 2292). */ 470 extern int inet6_option_space (int __nbytes) 471 __THROW __attribute_deprecated__; 472 extern int inet6_option_init (void *__bp, struct cmsghdr **__cmsgp, 473 int __type) __THROW __attribute_deprecated__; 474 extern int inet6_option_append (struct cmsghdr *__cmsg, 475 __const uint8_t *__typep, int __multx, 476 int __plusy) __THROW __attribute_deprecated__; 477 extern uint8_t *inet6_option_alloc (struct cmsghdr *__cmsg, int __datalen, 478 int __multx, int __plusy) 479 __THROW __attribute_deprecated__; 480 extern int inet6_option_next (__const struct cmsghdr *__cmsg, 481 uint8_t **__tptrp) 482 __THROW __attribute_deprecated__; 483 extern int inet6_option_find (__const struct cmsghdr *__cmsg, 484 uint8_t **__tptrp, int __type) 485 __THROW __attribute_deprecated__; 486 487 488 /* Hop-by-Hop and Destination Options Processing (RFC 3542). */ 489 extern int inet6_opt_init (void *__extbuf, socklen_t __extlen) __THROW; 490 extern int inet6_opt_append (void *__extbuf, socklen_t __extlen, int __offset, 491 uint8_t __type, socklen_t __len, uint8_t __align, 492 void **__databufp) __THROW; 493 extern int inet6_opt_finish (void *__extbuf, socklen_t __extlen, int __offset) 494 __THROW; 495 extern int inet6_opt_set_val (void *__databuf, int __offset, void *__val, 496 socklen_t __vallen) __THROW; 497 extern int inet6_opt_next (void *__extbuf, socklen_t __extlen, int __offset, 498 uint8_t *__typep, socklen_t *__lenp, 499 void **__databufp) __THROW; 500 extern int inet6_opt_find (void *__extbuf, socklen_t __extlen, int __offset, 501 uint8_t __type, socklen_t *__lenp, 502 void **__databufp) __THROW; 503 extern int inet6_opt_get_val (void *__databuf, int __offset, void *__val, 504 socklen_t __vallen) __THROW; 505 506 507 /* Routing Header Option (RFC 3542). */ 508 extern socklen_t inet6_rth_space (int __type, int __segments) __THROW; 509 extern void *inet6_rth_init (void *__bp, socklen_t __bp_len, int __type, 510 int __segments) __THROW; 511 extern int inet6_rth_add (void *__bp, __const struct in6_addr *__addr) __THROW; 512 extern int inet6_rth_reverse (__const void *__in, void *__out) __THROW; 513 extern int inet6_rth_segments (__const void *__bp) __THROW; 514 extern struct in6_addr *inet6_rth_getaddr (__const void *__bp, int __index) 515 __THROW; 516 517 518 /* Multicast source filter support. */ 519 520 /* Get IPv4 source filter. */ 521 extern int getipv4sourcefilter (int __s, struct in_addr __interface_addr, 522 struct in_addr __group, uint32_t *__fmode, 523 uint32_t *__numsrc, struct in_addr *__slist) 524 __THROW; 525 526 /* Set IPv4 source filter. */ 527 extern int setipv4sourcefilter (int __s, struct in_addr __interface_addr, 528 struct in_addr __group, uint32_t __fmode, 529 uint32_t __numsrc, 530 __const struct in_addr *__slist) 531 __THROW; 532 533 534 /* Get source filter. */ 535 extern int getsourcefilter (int __s, uint32_t __interface_addr, 536 __const struct sockaddr *__group, 537 socklen_t __grouplen, uint32_t *__fmode, 538 uint32_t *__numsrc, 539 struct sockaddr_storage *__slist) __THROW; 540 541 /* Set source filter. */ 542 extern int setsourcefilter (int __s, uint32_t __interface_addr, 543 __const struct sockaddr *__group, 544 socklen_t __grouplen, uint32_t __fmode, 545 uint32_t __numsrc, 546 __const struct sockaddr_storage *__slist) __THROW; 547 #endif /* use GNU */ 548 549 __END_DECLS 550 551 #endif /* netinet/in.h */ 552