lib/zebra.h

   1 /* Zebra common header.
   2    Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Kunihiro Ishiguro
   3
   4 This file is part of GNU Zebra.
   5
   6 GNU Zebra is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 2, or (at your option) any
   9 later version.
  10
  11 GNU Zebra is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18 Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19 02111-1307, USA.  */
  20
  21 #ifndef _ZEBRA_H
  22 #define _ZEBRA_H
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include "config.h"
  26 #endif /* HAVE_CONFIG_H */
  27
  28 #ifdef SUNOS_5
  29 #define _XPG4_2
  30 #define __EXTENSIONS__
  31 typedef unsigned int    u_int32_t;
  32 typedef unsigned short  u_int16_t;
  33 typedef unsigned char   u_int8_t;
  34 #endif /* SUNOS_5 */
  35
  36 #ifndef HAVE_SOCKLEN_T
  37 typedef int socklen_t;
  38 #endif /* HAVE_SOCKLEN_T */
  39
  40 #include <unistd.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <stddef.h>
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <signal.h>
  48 #include <string.h>
  49 #include <pwd.h>
  50 #include <grp.h>
  51 #ifdef HAVE_STROPTS_H
  52 #include <stropts.h>
  53 #endif /* HAVE_STROPTS_H */
  54 #ifdef HAVE_SYS_SELECT_H
  55 #include <sys/select.h>
  56 #endif /* HAVE_SYS_SELECT_H */
  57 #include <sys/stat.h>
  58 #include <sys/types.h>
  59 #include <sys/param.h>
  60 #ifdef HAVE_SYS_SYSCTL_H
  61 #ifdef GNU_LINUX
  62 #include <linux/types.h>
  63 #endif
  64 #include <sys/sysctl.h>
  65 #endif /* HAVE_SYS_SYSCTL_H */
  66 #include <sys/ioctl.h>
  67 #ifdef HAVE_SYS_CONF_H
  68 #include <sys/conf.h>
  69 #endif /* HAVE_SYS_CONF_H */
  70 #ifdef HAVE_SYS_KSYM_H
  71 #include <sys/ksym.h>
  72 #endif /* HAVE_SYS_KSYM_H */
  73 #include <syslog.h>
  74 #ifdef TIME_WITH_SYS_TIME
  75 # include <sys/time.h>
  76 # include <time.h>
  77 #else
  78 # ifdef HAVE_SYS_TIME_H
  79 #  include <sys/time.h>
  80 # else
  81 #  include <time.h>
  82 # endif
  83 #endif /* TIME_WITH_SYS_TIME */
  84 #include <sys/uio.h>
  85 #include <sys/utsname.h>
  86 #ifdef HAVE_RUSAGE
  87 #include <sys/resource.h>
  88 #endif /* HAVE_RUSAGE */
  89 #ifdef HAVE_LIMITS_H
  90 #include <limits.h>
  91 #endif /* HAVE_LIMITS_H */
  92 #ifdef HAVE_INTTYPES_H
  93 #include <inttypes.h>
  94 #endif /* HAVE_INTTYPES_H */
  95
  96 /* machine dependent includes */
  97 #ifdef SUNOS_5
  98 #include <strings.h>
  99 #endif /* SUNOS_5 */
 100
 101 /* machine dependent includes */
 102 #ifdef HAVE_LINUX_VERSION_H
 103 #include <linux/version.h>
 104 #endif /* HAVE_LINUX_VERSION_H */
 105
 106 #ifdef HAVE_ASM_TYPES_H
 107 #include <asm/types.h>
 108 #endif /* HAVE_ASM_TYPES_H */
 109
 110 /* misc include group */
 111 #include <stdarg.h>
 112 #if !(defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L)
 113 /* Not C99; do we need to define va_copy? */
 114 #ifndef va_copy
 115 #ifdef __va_copy
 116 #define va_copy(DST,SRC) __va_copy(DST,SRC)
 117 #else
 118 /* Now we are desperate; this should work on many typical platforms.
 119    But this is slightly dangerous, because the standard does not require
 120    va_copy to be a macro. */
 121 #define va_copy(DST,SRC) memcpy(&(DST), &(SRC), sizeof(va_list))
 122 #warning "Not C99 and no va_copy macro available, falling back to memcpy"
 123 #endif /* __va_copy */
 124 #endif /* !va_copy */
 125 #endif /* !C99 */
 126
 127
 128 #ifdef HAVE_LCAPS
 129 #include <sys/capability.h>
 130 #include <sys/prctl.h>
 131 #endif /* HAVE_LCAPS */
 132
 133 #ifdef HAVE_SOLARIS_CAPABILITIES
 134 #include <priv.h>
 135 #endif /* HAVE_SOLARIS_CAPABILITIES */
 136
 137 /* network include group */
 138
 139 #include <sys/socket.h>
 140
 141 #ifdef HAVE_SYS_SOCKIO_H
 142 #include <sys/sockio.h>
 143 #endif /* HAVE_SYS_SOCKIO_H */
 144
 145 #ifdef __APPLE__
 146 #define __APPLE_USE_RFC_3542
 147 #endif
 148
 149 #ifdef HAVE_NETINET_IN_H
 150 #include <netinet/in.h>
 151 #endif /* HAVE_NETINET_IN_H */
 152 #include <netinet/in_systm.h>
 153 #include <netinet/ip.h>
 154 #include <netinet/tcp.h>
 155
 156 #ifdef HAVE_NET_NETOPT_H
 157 #include <net/netopt.h>
 158 #endif /* HAVE_NET_NETOPT_H */
 159
 160 #include <net/if.h>
 161
 162 #ifdef HAVE_NET_IF_DL_H
 163 #include <net/if_dl.h>
 164 #endif /* HAVE_NET_IF_DL_H */
 165
 166 #ifdef HAVE_NET_IF_VAR_H
 167 #include <net/if_var.h>
 168 #endif /* HAVE_NET_IF_VAR_H */
 169
 170 #ifdef HAVE_NET_ROUTE_H
 171 #include <net/route.h>
 172 #endif /* HAVE_NET_ROUTE_H */
 173
 174 #ifdef HAVE_NETLINK
 175 #include <linux/netlink.h>
 176 #include <linux/rtnetlink.h>
 177 #include <linux/filter.h>
 178 #else
 179 #define RT_TABLE_MAIN           0
 180 #endif /* HAVE_NETLINK */
 181
 182 #ifdef HAVE_NETDB_H
 183 #include <netdb.h>
 184 #endif /* HAVE_NETDB_H */
 185
 186 #include <arpa/inet.h>
 187
 188 #ifdef HAVE_INET_ND_H
 189 #include <inet/nd.h>
 190 #endif /* HAVE_INET_ND_H */
 191
 192 #ifdef HAVE_NETINET_IN_VAR_H
 193 #include <netinet/in_var.h>
 194 #endif /* HAVE_NETINET_IN_VAR_H */
 195
 196 #ifdef HAVE_NETINET6_IN6_VAR_H
 197 #include <netinet6/in6_var.h>
 198 #endif /* HAVE_NETINET6_IN6_VAR_H */
 199
 200 #ifdef HAVE_NETINET_IN6_VAR_H
 201 #include <netinet/in6_var.h>
 202 #endif /* HAVE_NETINET_IN6_VAR_H */
 203
 204 #ifdef HAVE_NETINET6_IN_H
 205 #include <netinet6/in.h>
 206 #endif /* HAVE_NETINET6_IN_H */
 207
 208
 209 #ifdef HAVE_NETINET6_IP6_H
 210 #include <netinet6/ip6.h>
 211 #endif /* HAVE_NETINET6_IP6_H */
 212
 213 #ifdef HAVE_NETINET_ICMP6_H
 214 #include <netinet/icmp6.h>
 215 #endif /* HAVE_NETINET_ICMP6_H */
 216
 217 #ifdef HAVE_NETINET6_ND6_H
 218 #include <netinet6/nd6.h>
 219 #endif /* HAVE_NETINET6_ND6_H */
 220
 221 /* Some systems do not define UINT32_MAX, etc.. from inttypes.h
 222  * e.g. this makes life easier for FBSD 4.11 users.
 223  */
 224 #ifndef INT8_MAX
 225 #define INT8_MAX        (127)
 226 #endif
 227 #ifndef INT16_MAX
 228 #define INT16_MAX       (32767)
 229 #endif
 230 #ifndef INT32_MAX
 231 #define INT32_MAX       (2147483647)
 232 #endif
 233 #ifndef UINT8_MAX
 234 #define UINT8_MAX       (255U)
 235 #endif
 236 #ifndef UINT16_MAX
 237 #define UINT16_MAX      (65535U)
 238 #endif
 239 #ifndef UINT32_MAX
 240 #define UINT32_MAX      (4294967295U)
 241 #endif
 242
 243 #ifdef HAVE_GLIBC_BACKTRACE
 244 #include <execinfo.h>
 245 #endif /* HAVE_GLIBC_BACKTRACE */
 246
 247 #ifdef BSDI_NRL
 248
 249 #ifdef HAVE_NETINET6_IN6_H
 250 #include <netinet6/in6.h>
 251 #endif /* HAVE_NETINET6_IN6_H */
 252
 253 #ifdef NRL
 254 #include <netinet6/in6.h>
 255 #endif /* NRL */
 256
 257 #define IN6_ARE_ADDR_EQUAL IN6_IS_ADDR_EQUAL
 258
 259 #endif /* BSDI_NRL */
 260
 261 /* Local includes: */
 262 #if !(defined(__GNUC__) || defined(VTYSH_EXTRACT_PL))
 263 #define __attribute__(x)
 264 #endif  /* !__GNUC__ || VTYSH_EXTRACT_PL */
 265
 266 #include "zassert.h"
 267 #include "str.h"
 268
 269
 270 #ifdef HAVE_BROKEN_CMSG_FIRSTHDR
 271 /* This bug is present in Solaris 8 and pre-patch Solaris 9 <sys/socket.h>;
 272    please refer to http://bugzilla.quagga.net/show_bug.cgi?id=142 */
 273
 274 /* Check that msg_controllen is large enough. */
 275 #define ZCMSG_FIRSTHDR(mhdr) \
 276   (((size_t)((mhdr)->msg_controllen) >= sizeof(struct cmsghdr)) ? \
 277    CMSG_FIRSTHDR(mhdr) : (struct cmsghdr *)NULL)
 278
 279 #warning "CMSG_FIRSTHDR is broken on this platform, using a workaround"
 280
 281 #else /* HAVE_BROKEN_CMSG_FIRSTHDR */
 282 #define ZCMSG_FIRSTHDR(M) CMSG_FIRSTHDR(M)
 283 #endif /* HAVE_BROKEN_CMSG_FIRSTHDR */
 284
 285
 286
 287 /*
 288  * RFC 3542 defines several macros for using struct cmsghdr.
 289  * Here, we define those that are not present
 290  */
 291
 292 /*
 293  * Internal defines, for use only in this file.
 294  * These are likely wrong on other than ILP32 machines, so warn.
 295  */
 296 #ifndef _CMSG_DATA_ALIGN
 297 #define _CMSG_DATA_ALIGN(n)           (((n) + 3) & ~3)
 298 #endif /* _CMSG_DATA_ALIGN */
 299
 300 #ifndef _CMSG_HDR_ALIGN
 301 #define _CMSG_HDR_ALIGN(n)            (((n) + 3) & ~3)
 302 #endif /* _CMSG_HDR_ALIGN */
 303
 304 /*
 305  * CMSG_SPACE and CMSG_LEN are required in RFC3542, but were new in that
 306  * version.
 307  */
 308 #ifndef CMSG_SPACE
 309 #define CMSG_SPACE(l)       (_CMSG_DATA_ALIGN(sizeof(struct cmsghdr)) + \
 310                               _CMSG_HDR_ALIGN(l))
 311 #warning "assuming 4-byte alignment for CMSG_SPACE"
 312 #endif  /* CMSG_SPACE */
 313
 314
 315 #ifndef CMSG_LEN
 316 #define CMSG_LEN(l)         (_CMSG_DATA_ALIGN(sizeof(struct cmsghdr)) + (l))
 317 #warning "assuming 4-byte alignment for CMSG_LEN"
 318 #endif /* CMSG_LEN */
 319
 320
 321 /*  The definition of struct in_pktinfo is missing in old version of
 322     GLIBC 2.1 (Redhat 6.1).  */
 323 #if defined (GNU_LINUX) && ! defined (HAVE_STRUCT_IN_PKTINFO)
 324 struct in_pktinfo
 325 {
 326   int ipi_ifindex;
 327   struct in_addr ipi_spec_dst;
 328   struct in_addr ipi_addr;
 329 };
 330 #endif
 331
 332 /*
 333  * OSPF Fragmentation / fragmented writes
 334  *
 335  * ospfd can support writing fragmented packets, for cases where
 336  * kernel will not fragment IP_HDRINCL and/or multicast destined
 337  * packets (ie TTBOMK all kernels, BSD, SunOS, Linux). However,
 338  * SunOS, probably BSD too, clobber the user supplied IP ID and IP
 339  * flags fields, hence user-space fragmentation will not work.
 340  * Only Linux is known to leave IP header unmolested.
 341  * Further, fragmentation really should be done the kernel, which already
 342  * supports it, and which avoids nasty IP ID state problems.
 343  *
 344  * Fragmentation of OSPF packets can be required on networks with router
 345  * with many many interfaces active in one area, or on networks with links
 346  * with low MTUs.
 347  */
 348 #ifdef GNU_LINUX
 349 #define WANT_OSPF_WRITE_FRAGMENT
 350 #endif
 351
 352 /*
 353  * IP_HDRINCL / struct ip byte order
 354  *
 355  * Linux: network byte order
 356  * *BSD: network, except for length and offset. (cf Stevens)
 357  * SunOS: nominally as per BSD. but bug: network order on LE.
 358  * OpenBSD: network byte order, apart from older versions which are as per
 359  *          *BSD
 360  */
 361 #if defined(__NetBSD__) || defined(__FreeBSD__) \
 362    || (defined(__OpenBSD__) && (OpenBSD < 200311)) \
 363    || (defined(__APPLE__)) \
 364    || (defined(SUNOS_5) && defined(WORDS_BIGENDIAN))
 365 #define HAVE_IP_HDRINCL_BSD_ORDER
 366 #endif
 367
 368 /* Define BYTE_ORDER, if not defined. Useful for compiler conditional
 369  * code, rather than preprocessor conditional.
 370  * Not all the world has this BSD define.
 371  */
 372 #ifndef BYTE_ORDER
 373 #define BIG_ENDIAN      4321    /* least-significant byte first (vax, pc) */
 374 #define LITTLE_ENDIAN   1234    /* most-significant byte first (IBM, net) */
 375 #define PDP_ENDIAN      3412    /* LSB first in word, MSW first in long (pdp) */
 376
 377 #if defined(WORDS_BIGENDIAN)
 378 #define BYTE_ORDER      BIG_ENDIAN
 379 #else /* !WORDS_BIGENDIAN */
 380 #define BYTE_ORDER      LITTLE_ENDIAN
 381 #endif /* WORDS_BIGENDIAN */
 382
 383 #endif /* ndef BYTE_ORDER */
 384
 385 /* MAX / MIN are not commonly defined, but useful */
 386 #ifndef MAX
 387 #define MAX(a, b) ((a) > (b) ? (a) : (b))
 388 #endif
 389 #ifndef MIN
 390 #define MIN(a, b) ((a) < (b) ? (a) : (b))
 391 #endif
 392
 393 #define ZEBRA_NUM_OF(x) (sizeof (x) / sizeof (x[0]))
 394
 395 /* For old definition. */
 396 #ifndef IN6_ARE_ADDR_EQUAL
 397 #define IN6_ARE_ADDR_EQUAL IN6_IS_ADDR_EQUAL
 398 #endif /* IN6_ARE_ADDR_EQUAL */
 399
 400 /* default zebra TCP port for zclient */
 401 #define ZEBRA_PORT                      2600
 402
 403 /* Zebra message types. */
 404 #define ZEBRA_INTERFACE_ADD                1
 405 #define ZEBRA_INTERFACE_DELETE             2
 406 #define ZEBRA_INTERFACE_ADDRESS_ADD        3
 407 #define ZEBRA_INTERFACE_ADDRESS_DELETE     4
 408 #define ZEBRA_INTERFACE_UP                 5
 409 #define ZEBRA_INTERFACE_DOWN               6
 410 #define ZEBRA_IPV4_ROUTE_ADD               7
 411 #define ZEBRA_IPV4_ROUTE_DELETE            8
 412 #define ZEBRA_IPV6_ROUTE_ADD               9
 413 #define ZEBRA_IPV6_ROUTE_DELETE           10
 414 #define ZEBRA_REDISTRIBUTE_ADD            11
 415 #define ZEBRA_REDISTRIBUTE_DELETE         12
 416 #define ZEBRA_REDISTRIBUTE_DEFAULT_ADD    13
 417 #define ZEBRA_REDISTRIBUTE_DEFAULT_DELETE 14
 418 #define ZEBRA_IPV4_NEXTHOP_LOOKUP         15
 419 #define ZEBRA_IPV6_NEXTHOP_LOOKUP         16
 420 #define ZEBRA_IPV4_IMPORT_LOOKUP          17
 421 #define ZEBRA_IPV6_IMPORT_LOOKUP          18
 422 #define ZEBRA_INTERFACE_RENAME            19
 423 #define ZEBRA_ROUTER_ID_ADD               20
 424 #define ZEBRA_ROUTER_ID_DELETE            21
 425 #define ZEBRA_ROUTER_ID_UPDATE            22
 426 #define ZEBRA_HELLO                       23
 427 #define ZEBRA_NEXTHOP_REGISTER            24
 428 #define ZEBRA_NEXTHOP_UNREGISTER          25
 429 #define ZEBRA_NEXTHOP_UPDATE              26
 430 #define ZEBRA_MESSAGE_MAX                 27
 431
 432 /* Marker value used in new Zserv, in the byte location corresponding
 433  * the command value in the old zserv header. To allow old and new
 434  * Zserv headers to be distinguished from each other.
 435  */
 436 #define ZEBRA_HEADER_MARKER              255
 437
 438 /* Zebra route's types are defined in route_types.h */
 439 #include "route_types.h"
 440
 441 /* Note: whenever a new route-type or zserv-command is added the
 442  * corresponding {command,route}_types[] table in lib/log.c MUST be
 443  * updated! */
 444
 445 /* Map a route type to a string.  For example, ZEBRA_ROUTE_RIPNG -> "ripng". */
 446 extern const char *zebra_route_string(unsigned int route_type);
 447 /* Map a route type to a char.  For example, ZEBRA_ROUTE_RIPNG -> 'R'. */
 448 extern char zebra_route_char(unsigned int route_type);
 449 /* Map a zserv command type to the same string,
 450  * e.g. ZEBRA_INTERFACE_ADD -> "ZEBRA_INTERFACE_ADD" */
 451 /* Map a protocol name to its number. e.g. ZEBRA_ROUTE_BGP->9*/
 452 extern int proto_name2num(const char *s);
 453 /* Map redistribute X argument to protocol number.
 454  * unlike proto_name2num, this accepts shorthands and takes
 455  * an AFI value to restrict input */
 456 extern int proto_redistnum(int afi, const char *s);
 457
 458 extern const char *zserv_command_string (unsigned int command);
 459
 460 /* Zebra's family types. */
 461 #define ZEBRA_FAMILY_IPV4                1
 462 #define ZEBRA_FAMILY_IPV6                2
 463 #define ZEBRA_FAMILY_MAX                 3
 464
 465 /* Error codes of zebra. */
 466 #define ZEBRA_ERR_NOERROR                0
 467 #define ZEBRA_ERR_RTEXIST               -1
 468 #define ZEBRA_ERR_RTUNREACH             -2
 469 #define ZEBRA_ERR_EPERM                 -3
 470 #define ZEBRA_ERR_RTNOEXIST             -4
 471 #define ZEBRA_ERR_KERNEL                -5
 472
 473 /* Zebra message flags */
 474 #define ZEBRA_FLAG_INTERNAL           0x01
 475 #define ZEBRA_FLAG_SELFROUTE          0x02
 476 #define ZEBRA_FLAG_BLACKHOLE          0x04
 477 #define ZEBRA_FLAG_IBGP               0x08
 478 #define ZEBRA_FLAG_SELECTED           0x10
 479 #define ZEBRA_FLAG_CHANGED            0x20
 480 #define ZEBRA_FLAG_STATIC             0x40
 481 #define ZEBRA_FLAG_REJECT             0x80
 482
 483 /* Zebra nexthop flags. */
 484 #define ZEBRA_NEXTHOP_IFINDEX            1
 485 #define ZEBRA_NEXTHOP_IFNAME             2
 486 #define ZEBRA_NEXTHOP_IPV4               3
 487 #define ZEBRA_NEXTHOP_IPV4_IFINDEX       4
 488 #define ZEBRA_NEXTHOP_IPV4_IFNAME        5
 489 #define ZEBRA_NEXTHOP_IPV6               6
 490 #define ZEBRA_NEXTHOP_IPV6_IFINDEX       7
 491 #define ZEBRA_NEXTHOP_IPV6_IFNAME        8
 492 #define ZEBRA_NEXTHOP_BLACKHOLE          9
 493
 494 #ifndef INADDR_LOOPBACK
 495 #define INADDR_LOOPBACK 0x7f000001      /* Internet address 127.0.0.1.  */
 496 #endif
 497
 498 /* Address family numbers from RFC1700. */
 499 #define AFI_IP                    1
 500 #define AFI_IP6                   2
 501 #define AFI_MAX                   3
 502
 503 /* Subsequent Address Family Identifier. */
 504 #define SAFI_UNICAST              1
 505 #define SAFI_MULTICAST            2
 506 #define SAFI_RESERVED_3           3
 507 #define SAFI_MPLS_VPN             4
 508 #define SAFI_MAX                  5
 509
 510 /* Filter direction.  */
 511 #define FILTER_IN                 0
 512 #define FILTER_OUT                1
 513 #define FILTER_MAX                2
 514
 515 /* Default Administrative Distance of each protocol. */
 516 #define ZEBRA_KERNEL_DISTANCE_DEFAULT      0
 517 #define ZEBRA_CONNECT_DISTANCE_DEFAULT     0
 518 #define ZEBRA_STATIC_DISTANCE_DEFAULT      1
 519 #define ZEBRA_RIP_DISTANCE_DEFAULT       120
 520 #define ZEBRA_RIPNG_DISTANCE_DEFAULT     120
 521 #define ZEBRA_OSPF_DISTANCE_DEFAULT      110
 522 #define ZEBRA_OSPF6_DISTANCE_DEFAULT     110
 523 #define ZEBRA_ISIS_DISTANCE_DEFAULT      115
 524 #define ZEBRA_IBGP_DISTANCE_DEFAULT      200
 525 #define ZEBRA_EBGP_DISTANCE_DEFAULT       20
 526
 527 /* Flag manipulation macros. */
 528 #define CHECK_FLAG(V,F)      ((V) & (F))
 529 #define SET_FLAG(V,F)        (V) |= (F)
 530 #define UNSET_FLAG(V,F)      (V) &= ~(F)
 531 #define RESET_FLAG(V)        (V) = 0
 532
 533 /* AFI and SAFI type. */
 534 typedef u_int16_t afi_t;
 535 typedef u_int8_t safi_t;
 536
 537 /* Zebra types. Used in Zserv message header. */
 538 typedef u_int16_t zebra_size_t;
 539 typedef u_int16_t zebra_command_t;
 540
 541 /* FIFO -- first in first out structure and macros.  */
 542 struct fifo
 543 {
 544   struct fifo *next;
 545   struct fifo *prev;
 546 };
 547
 548 #define FIFO_INIT(F)                                  \
 549   do {                                                \
 550     struct fifo *Xfifo = (struct fifo *)(F);          \
 551     Xfifo->next = Xfifo->prev = Xfifo;                \
 552   } while (0)
 553
 554 #define FIFO_ADD(F,N)                                 \
 555   do {                                                \
 556     struct fifo *Xfifo = (struct fifo *)(F);          \
 557     struct fifo *Xnode = (struct fifo *)(N);          \
 558     Xnode->next = Xfifo;                              \
 559     Xnode->prev = Xfifo->prev;                        \
 560     Xfifo->prev = Xfifo->prev->next = Xnode;          \
 561   } while (0)
 562
 563 #define FIFO_DEL(N)                                   \
 564   do {                                                \
 565     struct fifo *Xnode = (struct fifo *)(N);          \
 566     Xnode->prev->next = Xnode->next;                  \
 567     Xnode->next->prev = Xnode->prev;                  \
 568   } while (0)
 569
 570 #define FIFO_HEAD(F)                                  \
 571   ((((struct fifo *)(F))->next == (struct fifo *)(F)) \
 572   ? NULL : (F)->next)
 573
 574 #define FIFO_EMPTY(F)                                 \
 575   (((struct fifo *)(F))->next == (struct fifo *)(F))
 576
 577 #define FIFO_TOP(F)                                   \
 578   (FIFO_EMPTY(F) ? NULL : ((struct fifo *)(F))->next)
 579
 580 #endif /* _ZEBRA_H */