linux/include/net/nexthop.h
David Ahern 50cb8769f2 vxlan: Remove access to nexthop group struct
vxlan driver should be using helpers to access nexthop struct
internals. Remove open check if whether nexthop is multipath in
favor of the existing nexthop_is_multipath helper. Add a new
helper, nexthop_has_v4, to cover the need to check has_v4 in
a group.

Fixes: 1274e1cc42 ("vxlan: ecmp support for mac fdb entries")
Cc: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-10 13:20:20 -07:00

446 lines
9.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Generic nexthop implementation
*
* Copyright (c) 2017-19 Cumulus Networks
* Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
*/
#ifndef __LINUX_NEXTHOP_H
#define __LINUX_NEXTHOP_H
#include <linux/netdevice.h>
#include <linux/notifier.h>
#include <linux/route.h>
#include <linux/types.h>
#include <net/ip_fib.h>
#include <net/ip6_fib.h>
#include <net/netlink.h>
#define NEXTHOP_VALID_USER_FLAGS RTNH_F_ONLINK
struct nexthop;
struct nh_config {
u32 nh_id;
u8 nh_family;
u8 nh_protocol;
u8 nh_blackhole;
u8 nh_fdb;
u32 nh_flags;
int nh_ifindex;
struct net_device *dev;
union {
__be32 ipv4;
struct in6_addr ipv6;
} gw;
struct nlattr *nh_grp;
u16 nh_grp_type;
struct nlattr *nh_encap;
u16 nh_encap_type;
u32 nlflags;
struct nl_info nlinfo;
};
struct nh_info {
struct hlist_node dev_hash; /* entry on netns devhash */
struct nexthop *nh_parent;
u8 family;
bool reject_nh;
bool fdb_nh;
union {
struct fib_nh_common fib_nhc;
struct fib_nh fib_nh;
struct fib6_nh fib6_nh;
};
};
struct nh_grp_entry {
struct nexthop *nh;
u8 weight;
atomic_t upper_bound;
struct list_head nh_list;
struct nexthop *nh_parent; /* nexthop of group with this entry */
};
struct nh_group {
struct nh_group *spare; /* spare group for removals */
u16 num_nh;
bool mpath;
bool fdb_nh;
bool has_v4;
struct nh_grp_entry nh_entries[];
};
struct nexthop {
struct rb_node rb_node; /* entry on netns rbtree */
struct list_head fi_list; /* v4 entries using nh */
struct list_head f6i_list; /* v6 entries using nh */
struct list_head fdb_list; /* fdb entries using this nh */
struct list_head grp_list; /* nh group entries using this nh */
struct net *net;
u32 id;
u8 protocol; /* app managing this nh */
u8 nh_flags;
bool is_group;
refcount_t refcnt;
struct rcu_head rcu;
union {
struct nh_info __rcu *nh_info;
struct nh_group __rcu *nh_grp;
};
};
enum nexthop_event_type {
NEXTHOP_EVENT_ADD,
NEXTHOP_EVENT_DEL
};
int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
enum nexthop_event_type event_type,
struct nexthop *nh);
int register_nexthop_notifier(struct net *net, struct notifier_block *nb);
int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb);
/* caller is holding rcu or rtnl; no reference taken to nexthop */
struct nexthop *nexthop_find_by_id(struct net *net, u32 id);
void nexthop_free_rcu(struct rcu_head *head);
static inline bool nexthop_get(struct nexthop *nh)
{
return refcount_inc_not_zero(&nh->refcnt);
}
static inline void nexthop_put(struct nexthop *nh)
{
if (refcount_dec_and_test(&nh->refcnt))
call_rcu(&nh->rcu, nexthop_free_rcu);
}
static inline bool nexthop_cmp(const struct nexthop *nh1,
const struct nexthop *nh2)
{
return nh1 == nh2;
}
static inline bool nexthop_is_fdb(const struct nexthop *nh)
{
if (nh->is_group) {
const struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
return nh_grp->fdb_nh;
} else {
const struct nh_info *nhi;
nhi = rcu_dereference_rtnl(nh->nh_info);
return nhi->fdb_nh;
}
}
static inline bool nexthop_has_v4(const struct nexthop *nh)
{
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
return nh_grp->has_v4;
}
return false;
}
static inline bool nexthop_is_multipath(const struct nexthop *nh)
{
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
return nh_grp->mpath;
}
return false;
}
struct nexthop *nexthop_select_path(struct nexthop *nh, int hash);
static inline unsigned int nexthop_num_path(const struct nexthop *nh)
{
unsigned int rc = 1;
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
if (nh_grp->mpath)
rc = nh_grp->num_nh;
}
return rc;
}
static inline
struct nexthop *nexthop_mpath_select(const struct nh_group *nhg, int nhsel)
{
/* for_nexthops macros in fib_semantics.c grabs a pointer to
* the nexthop before checking nhsel
*/
if (nhsel >= nhg->num_nh)
return NULL;
return nhg->nh_entries[nhsel].nh;
}
static inline
int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh,
u8 rt_family)
{
struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
int i;
for (i = 0; i < nhg->num_nh; i++) {
struct nexthop *nhe = nhg->nh_entries[i].nh;
struct nh_info *nhi = rcu_dereference_rtnl(nhe->nh_info);
struct fib_nh_common *nhc = &nhi->fib_nhc;
int weight = nhg->nh_entries[i].weight;
if (fib_add_nexthop(skb, nhc, weight, rt_family) < 0)
return -EMSGSIZE;
}
return 0;
}
/* called with rcu lock */
static inline bool nexthop_is_blackhole(const struct nexthop *nh)
{
const struct nh_info *nhi;
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
if (nh_grp->num_nh > 1)
return false;
nh = nh_grp->nh_entries[0].nh;
}
nhi = rcu_dereference_rtnl(nh->nh_info);
return nhi->reject_nh;
}
static inline void nexthop_path_fib_result(struct fib_result *res, int hash)
{
struct nh_info *nhi;
struct nexthop *nh;
nh = nexthop_select_path(res->fi->nh, hash);
nhi = rcu_dereference(nh->nh_info);
res->nhc = &nhi->fib_nhc;
}
/* called with rcu read lock or rtnl held */
static inline
struct fib_nh_common *nexthop_fib_nhc(struct nexthop *nh, int nhsel)
{
struct nh_info *nhi;
BUILD_BUG_ON(offsetof(struct fib_nh, nh_common) != 0);
BUILD_BUG_ON(offsetof(struct fib6_nh, nh_common) != 0);
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
if (nh_grp->mpath) {
nh = nexthop_mpath_select(nh_grp, nhsel);
if (!nh)
return NULL;
}
}
nhi = rcu_dereference_rtnl(nh->nh_info);
return &nhi->fib_nhc;
}
/* called from fib_table_lookup with rcu_lock */
static inline
struct fib_nh_common *nexthop_get_nhc_lookup(const struct nexthop *nh,
int fib_flags,
const struct flowi4 *flp,
int *nhsel)
{
struct nh_info *nhi;
if (nh->is_group) {
struct nh_group *nhg = rcu_dereference(nh->nh_grp);
int i;
for (i = 0; i < nhg->num_nh; i++) {
struct nexthop *nhe = nhg->nh_entries[i].nh;
nhi = rcu_dereference(nhe->nh_info);
if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
*nhsel = i;
return &nhi->fib_nhc;
}
}
} else {
nhi = rcu_dereference(nh->nh_info);
if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
*nhsel = 0;
return &nhi->fib_nhc;
}
}
return NULL;
}
static inline bool nexthop_uses_dev(const struct nexthop *nh,
const struct net_device *dev)
{
struct nh_info *nhi;
if (nh->is_group) {
struct nh_group *nhg = rcu_dereference(nh->nh_grp);
int i;
for (i = 0; i < nhg->num_nh; i++) {
struct nexthop *nhe = nhg->nh_entries[i].nh;
nhi = rcu_dereference(nhe->nh_info);
if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
return true;
}
} else {
nhi = rcu_dereference(nh->nh_info);
if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
return true;
}
return false;
}
static inline unsigned int fib_info_num_path(const struct fib_info *fi)
{
if (unlikely(fi->nh))
return nexthop_num_path(fi->nh);
return fi->fib_nhs;
}
int fib_check_nexthop(struct nexthop *nh, u8 scope,
struct netlink_ext_ack *extack);
static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
{
if (unlikely(fi->nh))
return nexthop_fib_nhc(fi->nh, nhsel);
return &fi->fib_nh[nhsel].nh_common;
}
/* only used when fib_nh is built into fib_info */
static inline struct fib_nh *fib_info_nh(struct fib_info *fi, int nhsel)
{
WARN_ON(fi->nh);
return &fi->fib_nh[nhsel];
}
/*
* IPv6 variants
*/
int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
struct netlink_ext_ack *extack);
static inline struct fib6_nh *nexthop_fib6_nh(struct nexthop *nh)
{
struct nh_info *nhi;
if (nh->is_group) {
struct nh_group *nh_grp;
nh_grp = rcu_dereference_rtnl(nh->nh_grp);
nh = nexthop_mpath_select(nh_grp, 0);
if (!nh)
return NULL;
}
nhi = rcu_dereference_rtnl(nh->nh_info);
if (nhi->family == AF_INET6)
return &nhi->fib6_nh;
return NULL;
}
static inline struct net_device *fib6_info_nh_dev(struct fib6_info *f6i)
{
struct fib6_nh *fib6_nh;
fib6_nh = f6i->nh ? nexthop_fib6_nh(f6i->nh) : f6i->fib6_nh;
return fib6_nh->fib_nh_dev;
}
static inline void nexthop_path_fib6_result(struct fib6_result *res, int hash)
{
struct nexthop *nh = res->f6i->nh;
struct nh_info *nhi;
nh = nexthop_select_path(nh, hash);
nhi = rcu_dereference_rtnl(nh->nh_info);
if (nhi->reject_nh) {
res->fib6_type = RTN_BLACKHOLE;
res->fib6_flags |= RTF_REJECT;
res->nh = nexthop_fib6_nh(nh);
} else {
res->nh = &nhi->fib6_nh;
}
}
int nexthop_for_each_fib6_nh(struct nexthop *nh,
int (*cb)(struct fib6_nh *nh, void *arg),
void *arg);
static inline int nexthop_get_family(struct nexthop *nh)
{
struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
return nhi->family;
}
static inline
struct fib_nh_common *nexthop_fdb_nhc(struct nexthop *nh)
{
struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
return &nhi->fib_nhc;
}
static inline struct fib_nh_common *nexthop_path_fdb_result(struct nexthop *nh,
int hash)
{
struct nh_info *nhi;
struct nexthop *nhp;
nhp = nexthop_select_path(nh, hash);
if (unlikely(!nhp))
return NULL;
nhi = rcu_dereference(nhp->nh_info);
return &nhi->fib_nhc;
}
#endif