text: /*-
   * Copyright (c) 1980, 1986, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)route.h	8.4 (Berkeley) 1/9/95
   * $FreeBSD: release/9.1.0/sys/net/route.h 235103 2012-05-06 20:26:22Z bz $
   */
  
  #ifndef _NET_ROUTE_H_
  #define _NET_ROUTE_H_
  
  /*
   * Kernel resident routing tables.
   *
   * The routing tables are initialized when interface addresses
   * are set by making entries for all directly connected interfaces.
   */
  
  /*
   * A route consists of a destination address, a reference
   * to a routing entry, and a reference to an llentry.  
   * These are often held by protocols in their control
   * blocks, e.g. inpcb.
   */
  struct route {
  	struct	rtentry *ro_rt;
  	struct	llentry *ro_lle;
  	struct	in_ifaddr *ro_ia;
  	int		ro_flags;
  	struct	sockaddr ro_dst;
  };
  
  #define RT_CACHING_CONTEXT	0x1
  
  /*
   * These numbers are used by reliable protocols for determining
   * retransmission behavior and are included in the routing structure.
   */
  struct rt_metrics_lite {
  	u_long	rmx_mtu;	/* MTU for this path */
  	u_long	rmx_expire;	/* lifetime for route, e.g. redirect */
  	u_long	rmx_pksent;	/* packets sent using this route */
  	u_long	rmx_weight;	/* absolute weight */ 
  };
  
  struct rt_metrics {
  	u_long	rmx_locks;	/* Kernel must leave these values alone */
  	u_long	rmx_mtu;	/* MTU for this path */
  	u_long	rmx_hopcount;	/* max hops expected */
  	u_long	rmx_expire;	/* lifetime for route, e.g. redirect */
  	u_long	rmx_recvpipe;	/* inbound delay-bandwidth product */
  	u_long	rmx_sendpipe;	/* outbound delay-bandwidth product */
  	u_long	rmx_ssthresh;	/* outbound gateway buffer limit */
  	u_long	rmx_rtt;	/* estimated round trip time */
  	u_long	rmx_rttvar;	/* estimated rtt variance */
  	u_long	rmx_pksent;	/* packets sent using this route */
  	u_long	rmx_weight;	/* route weight */
  	u_long	rmx_filler[3];	/* will be used for T/TCP later */
  };
  
  /*
   * rmx_rtt and rmx_rttvar are stored as microseconds;
   * RTTTOPRHZ(rtt) converts to a value suitable for use
   * by a protocol slowtimo counter.
   */
  #define	RTM_RTTUNIT	1000000	/* units for rtt, rttvar, as units per sec */
  #define	RTTTOPRHZ(r)	((r) / (RTM_RTTUNIT / PR_SLOWHZ))
  
  #define	RT_DEFAULT_FIB	0	/* Explicitly mark fib=0 restricted cases */
  extern u_int rt_numfibs;	/* number fo usable routing tables */
  /*
   * XXX kernel function pointer `rt_output' is visible to applications.
   */
  struct mbuf;
  
  /*
   * We distinguish between routes to hosts and routes to networks,
   * preferring the former if available.  For each route we infer
   * the interface to use from the gateway address supplied when
   * the route was entered.  Routes that forward packets through
   * gateways are marked so that the output routines know to address the
   * gateway rather than the ultimate destination.
   */
  #ifndef RNF_NORMAL
  #include <net/radix.h>
  #ifdef RADIX_MPATH
  #include <net/radix_mpath.h>
  #endif
  #endif
  struct rtentry {
  	struct	radix_node rt_nodes[2];	/* tree glue, and other values */
  	/*
  	 * XXX struct rtentry must begin with a struct radix_node (or two!)
  	 * because the code does some casts of a 'struct radix_node *'
  	 * to a 'struct rtentry *'
  	 */
  #define	rt_key(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_key)))
  #define	rt_mask(r)	(*((struct sockaddr **)(&(r)->rt_nodes->rn_mask)))
  	struct	sockaddr *rt_gateway;	/* value */
  	int	rt_flags;		/* up/down?, host/net */
  	int	rt_refcnt;		/* # held references */
  	struct	ifnet *rt_ifp;		/* the answer: interface to use */
  	struct	ifaddr *rt_ifa;		/* the answer: interface address to use */
  	struct	rt_metrics_lite rt_rmx;	/* metrics used by rx'ing protocols */
  	u_int	rt_fibnum;		/* which FIB */
  #ifdef _KERNEL
  	/* XXX ugly, user apps use this definition but don't have a mtx def */
  	struct	mtx rt_mtx;		/* mutex for routing entry */
  #endif
  };
  
  /*
   * Following structure necessary for 4.3 compatibility;
   * We should eventually move it to a compat file.
   */
  struct ortentry {
  	u_long	rt_hash;		/* to speed lookups */
  	struct	sockaddr rt_dst;	/* key */
  	struct	sockaddr rt_gateway;	/* value */
  	short	rt_flags;		/* up/down?, host/net */
  	short	rt_refcnt;		/* # held references */
  	u_long	rt_use;			/* raw # packets forwarded */
  	struct	ifnet *rt_ifp;		/* the answer: interface to use */
  };
  
  #define rt_use rt_rmx.rmx_pksent
  
  #define	RTF_UP		0x1		/* route usable */
  #define	RTF_GATEWAY	0x2		/* destination is a gateway */
  #define	RTF_HOST	0x4		/* host entry (net otherwise) */
  #define	RTF_REJECT	0x8		/* host or net unreachable */
  #define	RTF_DYNAMIC	0x10		/* created dynamically (by redirect) */
  #define	RTF_MODIFIED	0x20		/* modified dynamically (by redirect) */
  #define RTF_DONE	0x40		/* message confirmed */
  /*			0x80		   unused, was RTF_DELCLONE */
  /*			0x100		   unused, was RTF_CLONING */
  #define RTF_XRESOLVE	0x200		/* external daemon resolves name */
  #define RTF_LLINFO	0x400		/* DEPRECATED - exists ONLY for backward 
  					   compatibility */
  #define RTF_LLDATA	0x400		/* used by apps to add/del L2 entries */
  #define RTF_STATIC	0x800		/* manually added */
  #define RTF_BLACKHOLE	0x1000		/* just discard pkts (during updates) */
  #define RTF_PROTO2	0x4000		/* protocol specific routing flag */
  #define RTF_PROTO1	0x8000		/* protocol specific routing flag */
  
  /* XXX: temporary to stay API/ABI compatible with userland */
  #ifndef _KERNEL
  #define RTF_PRCLONING	0x10000		/* unused, for compatibility */
  #endif
  
  /*			0x20000		   unused, was RTF_WASCLONED */
  #define RTF_PROTO3	0x40000		/* protocol specific routing flag */
  /*			0x80000		   unused */
  #define RTF_PINNED	0x100000	/* future use */
  #define	RTF_LOCAL	0x200000 	/* route represents a local address */
  #define	RTF_BROADCAST	0x400000	/* route represents a bcast address */
  #define	RTF_MULTICAST	0x800000	/* route represents a mcast address */
  					/* 0x8000000 and up unassigned */
  #define	RTF_STICKY	 0x10000000	/* always route dst->src */
  
  #define	RTF_RNH_LOCKED	 0x40000000	/* radix node head is locked */
  
  /* Mask of RTF flags that are allowed to be modified by RTM_CHANGE. */
  #define RTF_FMASK	\
  	(RTF_PROTO1 | RTF_PROTO2 | RTF_PROTO3 | RTF_BLACKHOLE | \
  	 RTF_REJECT | RTF_STATIC | RTF_STICKY)
  
  /*
   * Routing statistics.
   */
  struct	rtstat {
  	short	rts_badredirect;	/* bogus redirect calls */
  	short	rts_dynamic;		/* routes created by redirects */
  	short	rts_newgateway;		/* routes modified by redirects */
  	short	rts_unreach;		/* lookups which failed */
  	short	rts_wildcard;		/* lookups satisfied by a wildcard */
  };
  /*
   * Structures for routing messages.
   */
  struct rt_msghdr {
  	u_short	rtm_msglen;	/* to skip over non-understood messages */
  	u_char	rtm_version;	/* future binary compatibility */
  	u_char	rtm_type;	/* message type */
  	u_short	rtm_index;	/* index for associated ifp */
  	int	rtm_flags;	/* flags, incl. kern & message, e.g. DONE */
  	int	rtm_addrs;	/* bitmask identifying sockaddrs in msg */
  	pid_t	rtm_pid;	/* identify sender */
  	int	rtm_seq;	/* for sender to identify action */
  	int	rtm_errno;	/* why failed */
  	int	rtm_fmask;	/* bitmask used in RTM_CHANGE message */
  	u_long	rtm_inits;	/* which metrics we are initializing */
  	struct	rt_metrics rtm_rmx; /* metrics themselves */
  };
  
  #define RTM_VERSION	5	/* Up the ante and ignore older versions */
  
  /*
   * Message types.
   */
  #define RTM_ADD		0x1	/* Add Route */
  #define RTM_DELETE	0x2	/* Delete Route */
  #define RTM_CHANGE	0x3	/* Change Metrics or flags */
  #define RTM_GET		0x4	/* Report Metrics */
  #define RTM_LOSING	0x5	/* Kernel Suspects Partitioning */
  #define RTM_REDIRECT	0x6	/* Told to use different route */
  #define RTM_MISS	0x7	/* Lookup failed on this address */
  #define RTM_LOCK	0x8	/* fix specified metrics */
  #define RTM_OLDADD	0x9	/* caused by SIOCADDRT */
  #define RTM_OLDDEL	0xa	/* caused by SIOCDELRT */
  #define RTM_RESOLVE	0xb	/* req to resolve dst to LL addr */
  #define RTM_NEWADDR	0xc	/* address being added to iface */
  #define RTM_DELADDR	0xd	/* address being removed from iface */
  #define RTM_IFINFO	0xe	/* iface going up/down etc. */
  #define	RTM_NEWMADDR	0xf	/* mcast group membership being added to if */
  #define	RTM_DELMADDR	0x10	/* mcast group membership being deleted */
  #define	RTM_IFANNOUNCE	0x11	/* iface arrival/departure */
  #define	RTM_IEEE80211	0x12	/* IEEE80211 wireless event */
  
  /*
   * Bitmask values for rtm_inits and rmx_locks.
   */
  #define RTV_MTU		0x1	/* init or lock _mtu */
  #define RTV_HOPCOUNT	0x2	/* init or lock _hopcount */
  #define RTV_EXPIRE	0x4	/* init or lock _expire */
  #define RTV_RPIPE	0x8	/* init or lock _recvpipe */
  #define RTV_SPIPE	0x10	/* init or lock _sendpipe */
  #define RTV_SSTHRESH	0x20	/* init or lock _ssthresh */
  #define RTV_RTT		0x40	/* init or lock _rtt */
  #define RTV_RTTVAR	0x80	/* init or lock _rttvar */
  #define RTV_WEIGHT	0x100	/* init or lock _weight */
  
  /*
   * Bitmask values for rtm_addrs.
   */
  #define RTA_DST		0x1	/* destination sockaddr present */
  #define RTA_GATEWAY	0x2	/* gateway sockaddr present */
  #define RTA_NETMASK	0x4	/* netmask sockaddr present */
  #define RTA_GENMASK	0x8	/* cloning mask sockaddr present */
  #define RTA_IFP		0x10	/* interface name sockaddr present */
  #define RTA_IFA		0x20	/* interface addr sockaddr present */
  #define RTA_AUTHOR	0x40	/* sockaddr for author of redirect */
  #define RTA_BRD		0x80	/* for NEWADDR, broadcast or p-p dest addr */
  
  /*
   * Index offsets for sockaddr array for alternate internal encoding.
   */
  #define RTAX_DST	0	/* destination sockaddr present */
  #define RTAX_GATEWAY	1	/* gateway sockaddr present */
  #define RTAX_NETMASK	2	/* netmask sockaddr present */
  #define RTAX_GENMASK	3	/* cloning mask sockaddr present */
  #define RTAX_IFP	4	/* interface name sockaddr present */
  #define RTAX_IFA	5	/* interface addr sockaddr present */
  #define RTAX_AUTHOR	6	/* sockaddr for author of redirect */
  #define RTAX_BRD	7	/* for NEWADDR, broadcast or p-p dest addr */
  #define RTAX_MAX	8	/* size of array to allocate */
  
  struct rt_addrinfo {
  	int	rti_addrs;
  	struct	sockaddr *rti_info[RTAX_MAX];
  	int	rti_flags;
  	struct	ifaddr *rti_ifa;
  	struct	ifnet *rti_ifp;
  };
  
  /*
   * This macro returns the size of a struct sockaddr when passed
   * through a routing socket. Basically we round up sa_len to
   * a multiple of sizeof(long), with a minimum of sizeof(long).
   * The check for a NULL pointer is just a convenience, probably never used.
   * The case sa_len == 0 should only apply to empty structures.
   */
  #define SA_SIZE(sa)						\
      (  (!(sa) || ((struct sockaddr *)(sa))->sa_len == 0) ?	\
  	sizeof(long)		:				\
  	1 + ( (((struct sockaddr *)(sa))->sa_len - 1) | (sizeof(long) - 1) ) )
  
  #ifdef _KERNEL
  
  #define RT_LINK_IS_UP(ifp)	(!((ifp)->if_capabilities & IFCAP_LINKSTATE) \
  				 || (ifp)->if_link_state == LINK_STATE_UP)
  
  #define	RT_LOCK_INIT(_rt) \
  	mtx_init(&(_rt)->rt_mtx, "rtentry", NULL, MTX_DEF | MTX_DUPOK)
  #define	RT_LOCK(_rt)		mtx_lock(&(_rt)->rt_mtx)
  #define	RT_UNLOCK(_rt)		mtx_unlock(&(_rt)->rt_mtx)
  #define	RT_LOCK_DESTROY(_rt)	mtx_destroy(&(_rt)->rt_mtx)
  #define	RT_LOCK_ASSERT(_rt)	mtx_assert(&(_rt)->rt_mtx, MA_OWNED)
  
  #define	RT_ADDREF(_rt)	do {					\
  	RT_LOCK_ASSERT(_rt);					\
  	KASSERT((_rt)->rt_refcnt >= 0,				\
  		("negative refcnt %d", (_rt)->rt_refcnt));	\
  	(_rt)->rt_refcnt++;					\
  } while (0)
  
  #define	RT_REMREF(_rt)	do {					\
  	RT_LOCK_ASSERT(_rt);					\
  	KASSERT((_rt)->rt_refcnt > 0,				\
  		("bogus refcnt %d", (_rt)->rt_refcnt));	\
  	(_rt)->rt_refcnt--;					\
  } while (0)
  
  #define	RTFREE_LOCKED(_rt) do {					\
  	if ((_rt)->rt_refcnt <= 1)				\
  		rtfree(_rt);					\
  	else {							\
  		RT_REMREF(_rt);					\
  		RT_UNLOCK(_rt);					\
  	}							\
  	/* guard against invalid refs */			\
  	_rt = 0;						\
  } while (0)
  
  #define	RTFREE(_rt) do {					\
  	RT_LOCK(_rt);						\
  	RTFREE_LOCKED(_rt);					\
  } while (0)
  
  struct radix_node_head *rt_tables_get_rnh(int, int);
  
  struct ifmultiaddr;
  
  void	 rt_ieee80211msg(struct ifnet *, int, void *, size_t);
  void	 rt_ifannouncemsg(struct ifnet *, int);
  void	 rt_ifmsg(struct ifnet *);
  void	 rt_missmsg(int, struct rt_addrinfo *, int, int);
  void	 rt_missmsg_fib(int, struct rt_addrinfo *, int, int, int);
  void	 rt_newaddrmsg(int, struct ifaddr *, int, struct rtentry *);
  void	 rt_newaddrmsg_fib(int, struct ifaddr *, int, struct rtentry *, int);
  void	 rt_newmaddrmsg(int, struct ifmultiaddr *);
  int	 rt_setgate(struct rtentry *, struct sockaddr *, struct sockaddr *);
  void 	 rt_maskedcopy(struct sockaddr *, struct sockaddr *, struct sockaddr *);
  
  /*
   * Note the following locking behavior:
   *
   *    rtalloc_ign() and rtalloc() return ro->ro_rt unlocked
   *
   *    rtalloc1() returns a locked rtentry
   *
   *    rtfree() and RTFREE_LOCKED() require a locked rtentry
   *
   *    RTFREE() uses an unlocked entry.
   */
  
  int	 rtexpunge(struct rtentry *);
  void	 rtfree(struct rtentry *);
  int	 rt_check(struct rtentry **, struct rtentry **, struct sockaddr *);
  
  /* XXX MRT COMPAT VERSIONS THAT SET UNIVERSE to 0 */
  /* Thes are used by old code not yet converted to use multiple FIBS */
  int	 rt_getifa(struct rt_addrinfo *);
  void	 rtalloc_ign(struct route *ro, u_long ignflags);
  void	 rtalloc(struct route *ro); /* XXX deprecated, use rtalloc_ign(ro, 0) */
  struct rtentry *rtalloc1(struct sockaddr *, int, u_long);
  int	 rtinit(struct ifaddr *, int, int);
  int	 rtioctl(u_long, caddr_t);
  void	 rtredirect(struct sockaddr *, struct sockaddr *,
  	    struct sockaddr *, int, struct sockaddr *);
  int	 rtrequest(int, struct sockaddr *,
  	    struct sockaddr *, struct sockaddr *, int, struct rtentry **);
  
  #ifndef BURN_BRIDGES
  /* defaults to "all" FIBs */
  int	 rtinit_fib(struct ifaddr *, int, int);
  #endif
  
  /* XXX MRT NEW VERSIONS THAT USE FIBs
   * For now the protocol indepedent versions are the same as the AF_INET ones
   * but this will change.. 
   */
  int	 rt_getifa_fib(struct rt_addrinfo *, u_int fibnum);
  void	 rtalloc_ign_fib(struct route *ro, u_long ignflags, u_int fibnum);
  void	 rtalloc_fib(struct route *ro, u_int fibnum);
  struct rtentry *rtalloc1_fib(struct sockaddr *, int, u_long, u_int);
  int	 rtioctl_fib(u_long, caddr_t, u_int);
  void	 rtredirect_fib(struct sockaddr *, struct sockaddr *,
  	    struct sockaddr *, int, struct sockaddr *, u_int);
  int	 rtrequest_fib(int, struct sockaddr *,
  	    struct sockaddr *, struct sockaddr *, int, struct rtentry **, u_int);
  int	 rtrequest1_fib(int, struct rt_addrinfo *, struct rtentry **, u_int);
  
  #include <sys/eventhandler.h>
  typedef void (*rtevent_arp_update_fn)(void *, struct rtentry *, uint8_t *, struct sockaddr *);
  typedef void (*rtevent_redirect_fn)(void *, struct rtentry *, struct rtentry *, struct sockaddr *);
  /* route_arp_update_event is no longer generated; see arp_update_event */
  EVENTHANDLER_DECLARE(route_arp_update_event, rtevent_arp_update_fn);
  EVENTHANDLER_DECLARE(route_redirect_event, rtevent_redirect_fn);
  #endif
  
  #endif
  