in_var.h

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1985, 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.
 * 3. 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.
 */

#ifndef _NETINET_IN_VAR_H_
#define _NETINET_IN_VAR_H_

/*
 * Argument structure for SIOCAIFADDR.
 */
struct	in_aliasreq {
	char	ifra_name[IFNAMSIZ];		/* if name, e.g. "en0" */
	struct	sockaddr_in ifra_addr;
	struct	sockaddr_in ifra_broadaddr;
#define ifra_dstaddr ifra_broadaddr
	struct	sockaddr_in ifra_mask;
	int	ifra_vhid;
};

#ifdef _KERNEL
#include <sys/queue.h>
#include <sys/fnv_hash.h>
#include <sys/tree.h>

struct igmp_ifsoftc;
struct in_multi;
struct lltable;
SLIST_HEAD(in_multi_head, in_multi);

/*
 * IPv4 per-interface state.
 */
struct in_ifinfo {
	struct lltable		*ii_llt;	/* ARP state */
	struct igmp_ifsoftc	*ii_igmp;	/* IGMP state */
	struct in_multi		*ii_allhosts;	/* 224.0.0.1 membership */
};

/*
 * Interface address, Internet version.  One of these structures
 * is allocated for each Internet address on an interface.
 * The ifaddr structure contains the protocol-independent part
 * of the structure and is assumed to be first.
 */
struct in_ifaddr {
	struct	ifaddr ia_ifa;		/* protocol-independent info */
#define	ia_ifp		ia_ifa.ifa_ifp
#define ia_flags	ia_ifa.ifa_flags
					/* ia_subnet{,mask} in host order */
	u_long	ia_subnet;		/* subnet address */
	u_long	ia_subnetmask;		/* mask of subnet */
	CK_LIST_ENTRY(in_ifaddr) ia_hash;	/* hash of internet addresses */
	CK_STAILQ_ENTRY(in_ifaddr) ia_link;	/* list of internet addresses */
	struct	sockaddr_in ia_addr;	/* reserve space for interface name */
	struct	sockaddr_in ia_dstaddr; /* reserve space for broadcast addr */
#define	ia_broadaddr	ia_dstaddr
	struct	sockaddr_in ia_sockmask; /* reserve space for general netmask */
	struct	callout ia_garp_timer;	/* timer for retransmitting GARPs */
	int	ia_garp_count;		/* count of retransmitted GARPs */
};

/*
 * Given a pointer to an in_ifaddr (ifaddr),
 * return a pointer to the addr as a sockaddr_in.
 */
#define IA_SIN(ia)    (&(((struct in_ifaddr *)(ia))->ia_addr))
#define IA_DSTSIN(ia) (&(((struct in_ifaddr *)(ia))->ia_dstaddr))
#define IA_MASKSIN(ia) (&(((struct in_ifaddr *)(ia))->ia_sockmask))

#define IN_LNAOF(in, ifa) \
	((ntohl((in).s_addr) & ~((struct in_ifaddr *)(ifa)->ia_subnetmask))

#ifdef _KERNEL
#define IN_ARE_MASKED_ADDR_EQUAL(d, a, m)	(		\
	((((d).s_addr ^ (a).s_addr) & (m).s_addr)) == 0 )
#endif

#define LLTABLE(ifp)	((struct in_ifinfo *)(ifp)->if_inet)->ii_llt
/*
 * Hash table for IP addresses.
 */
CK_STAILQ_HEAD(in_ifaddrhead, in_ifaddr);
CK_LIST_HEAD(in_ifaddrhashhead, in_ifaddr);

VNET_DECLARE(struct in_ifaddrhashhead *, in_ifaddrhashtbl);
VNET_DECLARE(struct in_ifaddrhead, in_ifaddrhead);
VNET_DECLARE(u_long, in_ifaddrhmask);		/* mask for hash table */

#define	V_in_ifaddrhashtbl	VNET(in_ifaddrhashtbl)
#define	V_in_ifaddrhead		VNET(in_ifaddrhead)
#define	V_in_ifaddrhmask	VNET(in_ifaddrhmask)

#define INADDR_NHASH_LOG2       9
#define INADDR_NHASH		(1 << INADDR_NHASH_LOG2)
#define INADDR_HASHVAL(x)	fnv_32_buf((&(x)), sizeof(x), FNV1_32_INIT)
#define INADDR_HASH(x) \
	(&V_in_ifaddrhashtbl[INADDR_HASHVAL(x) & V_in_ifaddrhmask])

/*
 * Macro for finding the internet address structure (in_ifaddr)
 * corresponding to one of our IP addresses (in_addr).
 */
#define INADDR_TO_IFADDR(addr, ia) \
	/* struct in_addr addr; */ \
	/* struct in_ifaddr *ia; */ \
do {									\
	NET_EPOCH_ASSERT();						\
	CK_LIST_FOREACH(ia, INADDR_HASH((addr).s_addr), ia_hash)	\
		if (IA_SIN(ia)->sin_addr.s_addr == (addr).s_addr)	\
			break;						\
} while (0)

/*
 * Macro for finding the interface (ifnet structure) corresponding to one
 * of our IP addresses.
 */
#define INADDR_TO_IFP(addr, ifp) \
	/* struct in_addr addr; */ \
	/* struct ifnet *ifp; */ \
{ \
	struct in_ifaddr *ia; \
\
	INADDR_TO_IFADDR(addr, ia); \
	(ifp) = (ia == NULL) ? NULL : ia->ia_ifp; \
}

/*
 * Macro for finding the internet address structure (in_ifaddr) corresponding
 * to a given interface (ifnet structure).
 */
#define IFP_TO_IA(ifp, ia)						\
	/* struct ifnet *ifp; */					\
	/* struct in_ifaddr *ia; */					\
do {									\
	NET_EPOCH_ASSERT();						\
	for ((ia) = CK_STAILQ_FIRST(&V_in_ifaddrhead);			\
	    (ia) != NULL && (ia)->ia_ifp != (ifp);			\
	    (ia) = CK_STAILQ_NEXT((ia), ia_link))			\
		continue;						\
} while (0)

/*
 * Legacy IPv4 IGMP per-link structure.
 */
struct router_info {
	struct ifnet *rti_ifp;
	int    rti_type; /* type of router which is querier on this interface */
	int    rti_time; /* # of slow timeouts since last old query */
	SLIST_ENTRY(router_info) rti_list;
};

/*
 * IPv4 multicast IGMP-layer source entry.
 */
struct ip_msource {
	RB_ENTRY(ip_msource)	ims_link;	/* RB tree links */
	in_addr_t		ims_haddr;	/* host byte order */
	struct ims_st {
		uint16_t	ex;		/* # of exclusive members */
		uint16_t	in;		/* # of inclusive members */
	}			ims_st[2];	/* state at t0, t1 */
	uint8_t			ims_stp;	/* pending query */
};

/*
 * IPv4 multicast PCB-layer source entry.
 */
struct in_msource {
	RB_ENTRY(ip_msource)	ims_link;	/* RB tree links */
	in_addr_t		ims_haddr;	/* host byte order */
	uint8_t			imsl_st[2];	/* state before/at commit */
};

RB_HEAD(ip_msource_tree, ip_msource);	/* define struct ip_msource_tree */

static __inline int
ip_msource_cmp(const struct ip_msource *a, const struct ip_msource *b)
{

	if (a->ims_haddr < b->ims_haddr)
		return (-1);
	if (a->ims_haddr == b->ims_haddr)
		return (0);
	return (1);
}
RB_PROTOTYPE(ip_msource_tree, ip_msource, ims_link, ip_msource_cmp);

/*
 * IPv4 multicast PCB-layer group filter descriptor.
 */
struct in_mfilter {
	struct ip_msource_tree	imf_sources; /* source list for (S,G) */
	u_long			imf_nsrc;    /* # of source entries */
	uint8_t			imf_st[2];   /* state before/at commit */
	struct in_multi	       *imf_inm;     /* associated multicast address */
	STAILQ_ENTRY(in_mfilter) imf_entry;  /* list entry */
};

/*
 * Helper types and functions for IPv4 multicast filters.
 */
STAILQ_HEAD(ip_mfilter_head, in_mfilter);

struct in_mfilter *ip_mfilter_alloc(int mflags, int st0, int st1);
void ip_mfilter_free(struct in_mfilter *);

static inline void
ip_mfilter_init(struct ip_mfilter_head *head)
{

	STAILQ_INIT(head);
}

static inline struct in_mfilter *
ip_mfilter_first(const struct ip_mfilter_head *head)
{

	return (STAILQ_FIRST(head));
}

static inline void
ip_mfilter_insert(struct ip_mfilter_head *head, struct in_mfilter *imf)
{

	STAILQ_INSERT_TAIL(head, imf, imf_entry);
}

static inline void
ip_mfilter_remove(struct ip_mfilter_head *head, struct in_mfilter *imf)
{

	STAILQ_REMOVE(head, imf, in_mfilter, imf_entry);
}

#define	IP_MFILTER_FOREACH(imf, head) \
	STAILQ_FOREACH(imf, head, imf_entry)

static inline size_t
ip_mfilter_count(struct ip_mfilter_head *head)
{
	struct in_mfilter *imf;
	size_t num = 0;

	STAILQ_FOREACH(imf, head, imf_entry)
		num++;
	return (num);
}

/*
 * IPv4 group descriptor.
 *
 * For every entry on an ifnet's if_multiaddrs list which represents
 * an IP multicast group, there is one of these structures.
 *
 * If any source filters are present, then a node will exist in the RB-tree
 * to permit fast lookup by source whenever an operation takes place.
 * This permits pre-order traversal when we issue reports.
 * Source filter trees are kept separately from the socket layer to
 * greatly simplify locking.
 *
 * When IGMPv3 is active, inm_timer is the response to group query timer.
 * The state-change timer inm_sctimer is separate; whenever state changes
 * for the group the state change record is generated and transmitted,
 * and kept if retransmissions are necessary.
 *
 * FUTURE: inm_link is now only used when groups are being purged
 * on a detaching ifnet. It could be demoted to a SLIST_ENTRY, but
 * because it is at the very start of the struct, we can't do this
 * w/o breaking the ABI for ifmcstat.
 */
struct in_multi {
	LIST_ENTRY(in_multi) inm_link;	/* to-be-released by in_ifdetach */
	struct	in_addr inm_addr;	/* IP multicast address, convenience */
	struct	ifnet *inm_ifp;		/* back pointer to ifnet */
	struct	ifmultiaddr *inm_ifma;	/* back pointer to ifmultiaddr */
	u_int	inm_timer;		/* IGMPv1/v2 group / v3 query timer */
	u_int	inm_state;		/* state of the membership */
	void	*inm_rti;		/* unused, legacy field */
	u_int	inm_refcount;		/* reference count */

	/* New fields for IGMPv3 follow. */
	struct igmp_ifsoftc	*inm_igi;	/* IGMP info */
	SLIST_ENTRY(in_multi)	 inm_nrele;	/* to-be-released by IGMP */
	struct ip_msource_tree	 inm_srcs;	/* tree of sources */
	u_long			 inm_nsrc;	/* # of tree entries */

	struct mbufq		 inm_scq;	/* queue of pending
						 * state-change packets */
	struct timeval		 inm_lastgsrtv;	/* Time of last G-S-R query */
	uint16_t		 inm_sctimer;	/* state-change timer */
	uint16_t		 inm_scrv;	/* state-change rexmit count */

	/*
	 * SSM state counters which track state at T0 (the time the last
	 * state-change report's RV timer went to zero) and T1
	 * (time of pending report, i.e. now).
	 * Used for computing IGMPv3 state-change reports. Several refcounts
	 * are maintained here to optimize for common use-cases.
	 */
	struct inm_st {
		uint16_t	iss_fmode;	/* IGMP filter mode */
		uint16_t	iss_asm;	/* # of ASM listeners */
		uint16_t	iss_ex;		/* # of exclusive members */
		uint16_t	iss_in;		/* # of inclusive members */
		uint16_t	iss_rec;	/* # of recorded sources */
	}			inm_st[2];	/* state at t0, t1 */
};

/*
 * Helper function to derive the filter mode on a source entry
 * from its internal counters. Predicates are:
 *  A source is only excluded if all listeners exclude it.
 *  A source is only included if no listeners exclude it,
 *  and at least one listener includes it.
 * May be used by ifmcstat(8).
 */
static __inline uint8_t
ims_get_mode(const struct in_multi *inm, const struct ip_msource *ims,
    uint8_t t)
{

	t = !!t;
	if (inm->inm_st[t].iss_ex > 0 &&
	    inm->inm_st[t].iss_ex == ims->ims_st[t].ex)
		return (MCAST_EXCLUDE);
	else if (ims->ims_st[t].in > 0 && ims->ims_st[t].ex == 0)
		return (MCAST_INCLUDE);
	return (MCAST_UNDEFINED);
}

#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet);
SYSCTL_DECL(_net_inet_ip);
SYSCTL_DECL(_net_inet_raw);
#endif

/*
 * Lock macros for IPv4 layer multicast address lists.  IPv4 lock goes
 * before link layer multicast locks in the lock order.  In most cases,
 * consumers of IN_*_MULTI() macros should acquire the locks before
 * calling them; users of the in_{add,del}multi() functions should not.
 */
extern struct mtx in_multi_list_mtx;
extern struct sx in_multi_sx;

#define	IN_MULTI_LIST_LOCK()		mtx_lock(&in_multi_list_mtx)
#define	IN_MULTI_LIST_UNLOCK()	mtx_unlock(&in_multi_list_mtx)
#define	IN_MULTI_LIST_LOCK_ASSERT()	mtx_assert(&in_multi_list_mtx, MA_OWNED)
#define	IN_MULTI_LIST_UNLOCK_ASSERT() mtx_assert(&in_multi_list_mtx, MA_NOTOWNED)

#define	IN_MULTI_LOCK()		sx_xlock(&in_multi_sx)
#define	IN_MULTI_UNLOCK()	sx_xunlock(&in_multi_sx)
#define	IN_MULTI_LOCK_ASSERT()	sx_assert(&in_multi_sx, SA_XLOCKED)
#define	IN_MULTI_UNLOCK_ASSERT() sx_assert(&in_multi_sx, SA_XUNLOCKED)

void inm_disconnect(struct in_multi *inm);

/*
 * Get the in_multi pointer from a ifmultiaddr.
 * Returns NULL if ifmultiaddr is no longer valid.
 */
static __inline struct in_multi *
inm_ifmultiaddr_get_inm(struct ifmultiaddr *ifma)
{

	NET_EPOCH_ASSERT();

	return ((ifma->ifma_addr->sa_family != AF_INET ||
	    (ifma->ifma_flags & IFMA_F_ENQUEUED) == 0) ? NULL :
	    ifma->ifma_protospec);
}

/* Acquire an in_multi record. */
static __inline void
inm_acquire_locked(struct in_multi *inm)
{

	IN_MULTI_LIST_LOCK_ASSERT();
	++inm->inm_refcount;
}

static __inline void
inm_acquire(struct in_multi *inm)
{
	IN_MULTI_LIST_LOCK();
	inm_acquire_locked(inm);
	IN_MULTI_LIST_UNLOCK();
}

static __inline void
inm_rele_locked(struct in_multi_head *inmh, struct in_multi *inm)
{
	MPASS(inm->inm_refcount > 0);
	IN_MULTI_LIST_LOCK_ASSERT();

	if (--inm->inm_refcount == 0) {
		MPASS(inmh != NULL);
		inm_disconnect(inm);
		inm->inm_ifma->ifma_protospec = NULL;
		SLIST_INSERT_HEAD(inmh, inm, inm_nrele);
	}
}

/*
 * Return values for imo_multi_filter().
 */
#define MCAST_PASS		0	/* Pass */
#define MCAST_NOTGMEMBER	1	/* This host not a member of group */
#define MCAST_NOTSMEMBER	2	/* This host excluded source */
#define MCAST_MUTED		3	/* [deprecated] */

struct rib_head;
struct	ip_moptions;
struct ucred;

struct in_multi *inm_lookup_locked(struct ifnet *, const struct in_addr);
struct in_multi *inm_lookup(struct ifnet *, const struct in_addr);
int	imo_multi_filter(const struct ip_moptions *, const struct ifnet *,
	    const struct sockaddr *, const struct sockaddr *);
void	inm_commit(struct in_multi *);
void	inm_clear_recorded(struct in_multi *);
void	inm_print(const struct in_multi *);
int	inm_record_source(struct in_multi *inm, const in_addr_t);
void	inm_release_deferred(struct in_multi *);
void	inm_release_list_deferred(struct in_multi_head *);
void	inm_release_wait(void *);
int	in_joingroup(struct ifnet *, const struct in_addr *,
	    /*const*/ struct in_mfilter *, struct in_multi **);
int	in_joingroup_locked(struct ifnet *, const struct in_addr *,
	    /*const*/ struct in_mfilter *, struct in_multi **);
int	in_leavegroup(struct in_multi *, /*const*/ struct in_mfilter *);
int	in_leavegroup_locked(struct in_multi *,
	    /*const*/ struct in_mfilter *);
int	in_mask2len(struct in_addr *);
int	in_control(struct socket *, u_long, void *, struct ifnet *,
	    struct thread *);
int	in_control_ioctl(u_long, void *, struct ifnet *,
	    struct ucred *);
int	in_addprefix(struct in_ifaddr *);
int	in_scrubprefix(struct in_ifaddr *, u_int);
void	in_ifscrub_all(void);
void	ip_input(struct mbuf *);
void	ip_direct_input(struct mbuf *);
void	in_ifadown(struct ifaddr *ifa, int);
struct	mbuf	*ip_tryforward(struct mbuf *);
struct rib_head *in_inithead(uint32_t fibnum);
void	in_ifattach(void *, struct ifnet *);

#ifdef VIMAGE
void	in_detachhead(struct rib_head *rh);
#endif

#endif /* _KERNEL */

/* INET6 stuff */
#include <netinet6/in6_var.h>

#endif /* _NETINET_IN_VAR_H_ */