freebsd-skq/sys/netinet/in_var.h
vangyzen e993e06c3b Add GARP retransmit capability
A single gratuitous ARP (GARP) is always transmitted when an IPv4
address is added to an interface, and that is usually sufficient.
However, in some circumstances, such as when a shared address is
passed between cluster nodes, this single GARP may occasionally be
dropped or lost.  This can lead to neighbors on the network link
working with a stale ARP cache and sending packets destined for
that address to the node that previously owned the address, which
may not respond.

To avoid this situation, GARP retransmissions can be enabled by setting
the net.link.ether.inet.garp_rexmit_count sysctl to a value greater
than zero.  The setting represents the maximum number of retransmissions.
The interval between retransmissions is calculated using an exponential
backoff algorithm, doubling each time, so the retransmission intervals
are: {1, 2, 4, 8, 16, ...} (seconds).

Due to the exponential backoff algorithm used for the interval
between GARP retransmissions, the maximum number of retransmissions
is limited to 16 for sanity.  This limit corresponds to a maximum
interval between retransmissions of 2^16 seconds ~= 18 hours.
Increasing this limit is possible, but sending out GARPs spaced
days apart would be of little use.

Submitted by:	David A. Bright <david.a.bright@dell.com>
MFC after:	1 month
Relnotes:	yes
Sponsored by:	Dell EMC
Differential Revision:	https://reviews.freebsd.org/D7695
2016-10-02 01:42:45 +00:00

400 lines
14 KiB
C

/*-
* 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.
* 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.
*
* @(#)in_var.h 8.2 (Berkeley) 1/9/95
* $FreeBSD$
*/
#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;
/*
* 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 */
LIST_ENTRY(in_ifaddr) ia_hash; /* entry in bucket of inet addresses */
TAILQ_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))
extern u_char inetctlerrmap[];
#define LLTABLE(ifp) \
((struct in_ifinfo *)(ifp)->if_afdata[AF_INET])->ii_llt
/*
* Hash table for IP addresses.
*/
TAILQ_HEAD(in_ifaddrhead, in_ifaddr);
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])
extern struct rmlock in_ifaddr_lock;
#define IN_IFADDR_LOCK_ASSERT() rm_assert(&in_ifaddr_lock, RA_LOCKED)
#define IN_IFADDR_RLOCK(t) rm_rlock(&in_ifaddr_lock, (t))
#define IN_IFADDR_RLOCK_ASSERT() rm_assert(&in_ifaddr_lock, RA_RLOCKED)
#define IN_IFADDR_RUNLOCK(t) rm_runlock(&in_ifaddr_lock, (t))
#define IN_IFADDR_WLOCK() rm_wlock(&in_ifaddr_lock)
#define IN_IFADDR_WLOCK_ASSERT() rm_assert(&in_ifaddr_lock, RA_WLOCKED)
#define IN_IFADDR_WUNLOCK() rm_wunlock(&in_ifaddr_lock)
/*
* 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 { \
\
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, t) \
/* struct ifnet *ifp; */ \
/* struct in_ifaddr *ia; */ \
/* struct rm_priotracker *t; */ \
do { \
IN_IFADDR_RLOCK((t)); \
for ((ia) = TAILQ_FIRST(&V_in_ifaddrhead); \
(ia) != NULL && (ia)->ia_ifp != (ifp); \
(ia) = TAILQ_NEXT((ia), ia_link)) \
continue; \
if ((ia) != NULL) \
ifa_ref(&(ia)->ia_ifa); \
IN_IFADDR_RUNLOCK((t)); \
} 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 */
};
/*
* 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_mtx;
#define IN_MULTI_LOCK() mtx_lock(&in_multi_mtx)
#define IN_MULTI_UNLOCK() mtx_unlock(&in_multi_mtx)
#define IN_MULTI_LOCK_ASSERT() mtx_assert(&in_multi_mtx, MA_OWNED)
#define IN_MULTI_UNLOCK_ASSERT() mtx_assert(&in_multi_mtx, MA_NOTOWNED)
/* Acquire an in_multi record. */
static __inline void
inm_acquire_locked(struct in_multi *inm)
{
IN_MULTI_LOCK_ASSERT();
++inm->inm_refcount;
}
/*
* 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 rtentry;
struct route;
struct ip_moptions;
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(struct in_multi *);
void inm_release_locked(struct in_multi *);
struct in_multi *
in_addmulti(struct in_addr *, struct ifnet *);
void in_delmulti(struct in_multi *);
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_control(struct socket *, u_long, caddr_t, struct ifnet *,
struct thread *);
int in_addprefix(struct in_ifaddr *, int);
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 *);
void *in_domifattach(struct ifnet *);
void in_domifdetach(struct ifnet *, void *);
/* XXX */
void in_rtalloc_ign(struct route *ro, u_long ignflags, u_int fibnum);
void in_rtredirect(struct sockaddr *, struct sockaddr *,
struct sockaddr *, int, struct sockaddr *, u_int);
#endif /* _KERNEL */
/* INET6 stuff */
#include <netinet6/in6_var.h>
#endif /* _NETINET_IN_VAR_H_ */