linux/include/net/ip6_route.h
Eric Dumazet e8dfd42c17 ipv6: introduce dst_rt6_info() helper
Instead of (struct rt6_info *)dst casts, we can use :

 #define dst_rt6_info(_ptr) \
         container_of_const(_ptr, struct rt6_info, dst)

Some places needed missing const qualifiers :

ip6_confirm_neigh(), ipv6_anycast_destination(),
ipv6_unicast_destination(), has_gateway()

v2: added missing parts (David Ahern)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-29 13:32:01 +01:00

349 lines
9.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_IP6_ROUTE_H
#define _NET_IP6_ROUTE_H
#include <net/addrconf.h>
#include <net/flow.h>
#include <net/ip6_fib.h>
#include <net/sock.h>
#include <net/lwtunnel.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/route.h>
#include <net/nexthop.h>
struct route_info {
__u8 type;
__u8 length;
__u8 prefix_len;
#if defined(__BIG_ENDIAN_BITFIELD)
__u8 reserved_h:3,
route_pref:2,
reserved_l:3;
#elif defined(__LITTLE_ENDIAN_BITFIELD)
__u8 reserved_l:3,
route_pref:2,
reserved_h:3;
#endif
__be32 lifetime;
__u8 prefix[]; /* 0,8 or 16 */
};
#define RT6_LOOKUP_F_IFACE 0x00000001
#define RT6_LOOKUP_F_REACHABLE 0x00000002
#define RT6_LOOKUP_F_HAS_SADDR 0x00000004
#define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008
#define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010
#define RT6_LOOKUP_F_SRCPREF_COA 0x00000020
#define RT6_LOOKUP_F_IGNORE_LINKSTATE 0x00000040
#define RT6_LOOKUP_F_DST_NOREF 0x00000080
/* We do not (yet ?) support IPv6 jumbograms (RFC 2675)
* Unlike IPv4, hdr->seg_len doesn't include the IPv6 header
*/
#define IP6_MAX_MTU (0xFFFF + sizeof(struct ipv6hdr))
/*
* rt6_srcprefs2flags() and rt6_flags2srcprefs() translate
* between IPV6_ADDR_PREFERENCES socket option values
* IPV6_PREFER_SRC_TMP = 0x1
* IPV6_PREFER_SRC_PUBLIC = 0x2
* IPV6_PREFER_SRC_COA = 0x4
* and above RT6_LOOKUP_F_SRCPREF_xxx flags.
*/
static inline int rt6_srcprefs2flags(unsigned int srcprefs)
{
return (srcprefs & IPV6_PREFER_SRC_MASK) << 3;
}
static inline unsigned int rt6_flags2srcprefs(int flags)
{
return (flags >> 3) & IPV6_PREFER_SRC_MASK;
}
static inline bool rt6_need_strict(const struct in6_addr *daddr)
{
return ipv6_addr_type(daddr) &
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL | IPV6_ADDR_LOOPBACK);
}
/* fib entries using a nexthop object can not be coalesced into
* a multipath route
*/
static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
{
/* the RTF_ADDRCONF flag filters out RA's */
return !(f6i->fib6_flags & RTF_ADDRCONF) && !f6i->nh &&
f6i->fib6_nh->fib_nh_gw_family;
}
void ip6_route_input(struct sk_buff *skb);
struct dst_entry *ip6_route_input_lookup(struct net *net,
struct net_device *dev,
struct flowi6 *fl6,
const struct sk_buff *skb, int flags);
struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
struct flowi6 *fl6, int flags);
static inline struct dst_entry *ip6_route_output(struct net *net,
const struct sock *sk,
struct flowi6 *fl6)
{
return ip6_route_output_flags(net, sk, fl6, 0);
}
/* Only conditionally release dst if flags indicates
* !RT6_LOOKUP_F_DST_NOREF or dst is in uncached_list.
*/
static inline void ip6_rt_put_flags(struct rt6_info *rt, int flags)
{
if (!(flags & RT6_LOOKUP_F_DST_NOREF) ||
!list_empty(&rt->dst.rt_uncached))
ip6_rt_put(rt);
}
struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
const struct sk_buff *skb, int flags);
struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
int ifindex, struct flowi6 *fl6,
const struct sk_buff *skb, int flags);
void ip6_route_init_special_entries(void);
int ip6_route_init(void);
void ip6_route_cleanup(void);
int ipv6_route_ioctl(struct net *net, unsigned int cmd,
struct in6_rtmsg *rtmsg);
int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
struct netlink_ext_ack *extack);
int ip6_ins_rt(struct net *net, struct fib6_info *f6i);
int ip6_del_rt(struct net *net, struct fib6_info *f6i, bool skip_notify);
void rt6_flush_exceptions(struct fib6_info *f6i);
void rt6_age_exceptions(struct fib6_info *f6i, struct fib6_gc_args *gc_args,
unsigned long now);
static inline int ip6_route_get_saddr(struct net *net, struct fib6_info *f6i,
const struct in6_addr *daddr,
unsigned int prefs,
struct in6_addr *saddr)
{
int err = 0;
if (f6i && f6i->fib6_prefsrc.plen) {
*saddr = f6i->fib6_prefsrc.addr;
} else {
struct net_device *dev = f6i ? fib6_info_nh_dev(f6i) : NULL;
err = ipv6_dev_get_saddr(net, dev, daddr, prefs, saddr);
}
return err;
}
struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
const struct in6_addr *saddr, int oif,
const struct sk_buff *skb, int flags);
u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
const struct sk_buff *skb, struct flow_keys *hkeys);
struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
void fib6_force_start_gc(struct net *net);
struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
const struct in6_addr *addr, bool anycast,
gfp_t gfp_flags, struct netlink_ext_ack *extack);
struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
int flags);
/*
* support functions for ND
*
*/
struct fib6_info *rt6_get_dflt_router(struct net *net,
const struct in6_addr *addr,
struct net_device *dev);
struct fib6_info *rt6_add_dflt_router(struct net *net,
const struct in6_addr *gwaddr,
struct net_device *dev, unsigned int pref,
u32 defrtr_usr_metric,
int lifetime);
void rt6_purge_dflt_routers(struct net *net);
int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
const struct in6_addr *gwaddr);
void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, int oif,
u32 mark, kuid_t uid);
void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu);
void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
kuid_t uid);
void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif);
void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk);
struct netlink_callback;
struct rt6_rtnl_dump_arg {
struct sk_buff *skb;
struct netlink_callback *cb;
struct net *net;
struct fib_dump_filter filter;
};
int rt6_dump_route(struct fib6_info *f6i, void *p_arg, unsigned int skip);
void rt6_mtu_change(struct net_device *dev, unsigned int mtu);
void rt6_remove_prefsrc(struct inet6_ifaddr *ifp);
void rt6_clean_tohost(struct net *net, struct in6_addr *gateway);
void rt6_sync_up(struct net_device *dev, unsigned char nh_flags);
void rt6_disable_ip(struct net_device *dev, unsigned long event);
void rt6_sync_down_dev(struct net_device *dev, unsigned long event);
void rt6_multipath_rebalance(struct fib6_info *f6i);
void rt6_uncached_list_add(struct rt6_info *rt);
void rt6_uncached_list_del(struct rt6_info *rt);
static inline const struct rt6_info *skb_rt6_info(const struct sk_buff *skb)
{
const struct dst_entry *dst = skb_dst(skb);
if (dst)
return dst_rt6_info(dst);
return NULL;
}
/*
* Store a destination cache entry in a socket
*/
static inline void ip6_dst_store(struct sock *sk, struct dst_entry *dst,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
{
struct ipv6_pinfo *np = inet6_sk(sk);
np->dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
sk_setup_caps(sk, dst);
np->daddr_cache = daddr;
#ifdef CONFIG_IPV6_SUBTREES
np->saddr_cache = saddr;
#endif
}
void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
const struct flowi6 *fl6);
static inline bool ipv6_unicast_destination(const struct sk_buff *skb)
{
const struct rt6_info *rt = dst_rt6_info(skb_dst(skb));
return rt->rt6i_flags & RTF_LOCAL;
}
static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
const struct in6_addr *daddr)
{
const struct rt6_info *rt = dst_rt6_info(dst);
return rt->rt6i_flags & RTF_ANYCAST ||
(rt->rt6i_dst.plen < 127 &&
!(rt->rt6i_flags & (RTF_GATEWAY | RTF_NONEXTHOP)) &&
ipv6_addr_equal(&rt->rt6i_dst.addr, daddr));
}
int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
int (*output)(struct net *, struct sock *, struct sk_buff *));
static inline unsigned int ip6_skb_dst_mtu(const struct sk_buff *skb)
{
const struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
inet6_sk(skb->sk) : NULL;
const struct dst_entry *dst = skb_dst(skb);
unsigned int mtu;
if (np && READ_ONCE(np->pmtudisc) >= IPV6_PMTUDISC_PROBE) {
mtu = READ_ONCE(dst->dev->mtu);
mtu -= lwtunnel_headroom(dst->lwtstate, mtu);
} else {
mtu = dst_mtu(dst);
}
return mtu;
}
static inline bool ip6_sk_accept_pmtu(const struct sock *sk)
{
u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc);
return pmtudisc != IPV6_PMTUDISC_INTERFACE &&
pmtudisc != IPV6_PMTUDISC_OMIT;
}
static inline bool ip6_sk_ignore_df(const struct sock *sk)
{
u8 pmtudisc = READ_ONCE(inet6_sk(sk)->pmtudisc);
return pmtudisc < IPV6_PMTUDISC_DO ||
pmtudisc == IPV6_PMTUDISC_OMIT;
}
static inline const struct in6_addr *rt6_nexthop(const struct rt6_info *rt,
const struct in6_addr *daddr)
{
if (rt->rt6i_flags & RTF_GATEWAY)
return &rt->rt6i_gateway;
else if (unlikely(rt->rt6i_flags & RTF_CACHE))
return &rt->rt6i_dst.addr;
else
return daddr;
}
static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
{
struct fib6_nh *nha, *nhb;
if (a->nh || b->nh)
return nexthop_cmp(a->nh, b->nh);
nha = a->fib6_nh;
nhb = b->fib6_nh;
return nha->fib_nh_dev == nhb->fib_nh_dev &&
ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&
!lwtunnel_cmp_encap(nha->fib_nh_lws, nhb->fib_nh_lws);
}
static inline unsigned int ip6_dst_mtu_maybe_forward(const struct dst_entry *dst,
bool forwarding)
{
struct inet6_dev *idev;
unsigned int mtu;
if (!forwarding || dst_metric_locked(dst, RTAX_MTU)) {
mtu = dst_metric_raw(dst, RTAX_MTU);
if (mtu)
goto out;
}
mtu = IPV6_MIN_MTU;
rcu_read_lock();
idev = __in6_dev_get(dst->dev);
if (idev)
mtu = READ_ONCE(idev->cnf.mtu6);
rcu_read_unlock();
out:
return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
}
u32 ip6_mtu_from_fib6(const struct fib6_result *res,
const struct in6_addr *daddr,
const struct in6_addr *saddr);
struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
struct net_device *dev, struct sk_buff *skb,
const void *daddr);
#endif