ipv4: Plumb support for nexthop object in a fib_info
Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the
fib_info side of the nexthop <-> fib_info relationship.
Add fi_list list_head to 'struct nexthop' to track fib_info entries
using a nexthop instance. Add __remove_nexthop_fib and add it to
__remove_nexthop to walk the new list_head and mark those fib entries
as dead when the nexthop is deleted.
Add a few nexthop helpers for use when a nexthop is added to fib_info:
- nexthop_cmp to determine if 2 nexthops are the same
- nexthop_path_fib_result to select a path for a multipath
'struct nexthop'
- nexthop_fib_nhc to select a specific fib_nh_common within a
multipath 'struct nexthop'
Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses
a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop
case.
Update the fib_info functions to check for fi->nh and take a different
path as needed:
- free_fib_info_rcu - put the nexthop object reference
- fib_release_info - remove the fib_info from the nexthop's fi_list
- nh_comp - use nexthop_cmp when either fib_info references a nexthop
object
- fib_info_hashfn - use the nexthop id for the hashing vs the oif of
each fib_nh in a fib_info
- fib_nlmsg_size - add space for the RTA_NH_ID attribute
- fib_create_info - verify nexthop reference can be taken, verify
nexthop spec is valid for fib entry, and add fib_info to fi_list for
a nexthop
- fib_select_multipath - use the new nexthop_path_fib_result to select a
path when nexthop objects are used
- fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat
it the same as a fib entry using 'blackhole'
The bulk of the changes are in fib_semantics.c and most of that is
moving the existing change_nexthops into an else branch.
Update the nexthop code to walk fi_list on a nexthop deleted to remove
fib entries referencing it.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 4a12c69..01e587a 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -236,9 +236,13 @@ static void free_fib_info_rcu(struct rcu_head *head)
{
struct fib_info *fi = container_of(head, struct fib_info, rcu);
- change_nexthops(fi) {
- fib_nh_release(fi->fib_net, nexthop_nh);
- } endfor_nexthops(fi);
+ if (fi->nh) {
+ nexthop_put(fi->nh);
+ } else {
+ change_nexthops(fi) {
+ fib_nh_release(fi->fib_net, nexthop_nh);
+ } endfor_nexthops(fi);
+ }
ip_fib_metrics_put(fi->fib_metrics);
@@ -264,11 +268,15 @@ void fib_release_info(struct fib_info *fi)
hlist_del(&fi->fib_hash);
if (fi->fib_prefsrc)
hlist_del(&fi->fib_lhash);
- change_nexthops(fi) {
- if (!nexthop_nh->fib_nh_dev)
- continue;
- hlist_del(&nexthop_nh->nh_hash);
- } endfor_nexthops(fi)
+ if (fi->nh) {
+ list_del(&fi->nh_list);
+ } else {
+ change_nexthops(fi) {
+ if (!nexthop_nh->fib_nh_dev)
+ continue;
+ hlist_del(&nexthop_nh->nh_hash);
+ } endfor_nexthops(fi)
+ }
fi->fib_dead = 1;
fib_info_put(fi);
}
@@ -279,6 +287,12 @@ static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi)
{
const struct fib_nh *onh;
+ if (fi->nh || ofi->nh)
+ return nexthop_cmp(fi->nh, ofi->nh) ? 0 : -1;
+
+ if (ofi->fib_nhs == 0)
+ return 0;
+
for_nexthops(fi) {
onh = fib_info_nh(ofi, nhsel);
@@ -323,9 +337,14 @@ static inline unsigned int fib_info_hashfn(const struct fib_info *fi)
val ^= (fi->fib_protocol << 8) | fi->fib_scope;
val ^= (__force u32)fi->fib_prefsrc;
val ^= fi->fib_priority;
- for_nexthops(fi) {
- val ^= fib_devindex_hashfn(nh->fib_nh_oif);
- } endfor_nexthops(fi)
+
+ if (fi->nh) {
+ val ^= fib_devindex_hashfn(fi->nh->id);
+ } else {
+ for_nexthops(fi) {
+ val ^= fib_devindex_hashfn(nh->fib_nh_oif);
+ } endfor_nexthops(fi)
+ }
return (val ^ (val >> 7) ^ (val >> 12)) & mask;
}
@@ -352,7 +371,7 @@ static struct fib_info *fib_find_info(struct fib_info *nfi)
memcmp(nfi->fib_metrics, fi->fib_metrics,
sizeof(u32) * RTAX_MAX) == 0 &&
!((nfi->fib_flags ^ fi->fib_flags) & ~RTNH_COMPARE_MASK) &&
- (nfi->fib_nhs == 0 || nh_comp(fi, nfi) == 0))
+ nh_comp(fi, nfi) == 0)
return fi;
}
@@ -399,6 +418,9 @@ static inline size_t fib_nlmsg_size(struct fib_info *fi)
/* space for nested metrics */
payload += nla_total_size((RTAX_MAX * nla_total_size(4)));
+ if (fi->nh)
+ payload += nla_total_size(4); /* RTA_NH_ID */
+
if (nhs) {
size_t nh_encapsize = 0;
/* Also handles the special case nhs == 1 */
@@ -585,6 +607,7 @@ static int fib_count_nexthops(struct rtnexthop *rtnh, int remaining,
return nhs;
}
+/* only called when fib_nh is integrated into fib_info */
static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
int remaining, struct fib_config *cfg,
struct netlink_ext_ack *extack)
@@ -683,6 +706,7 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh,
return ret;
}
+/* only called when fib_nh is integrated into fib_info */
static void fib_rebalance(struct fib_info *fi)
{
int total;
@@ -1262,6 +1286,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
{
int err;
struct fib_info *fi = NULL;
+ struct nexthop *nh = NULL;
struct fib_info *ofi;
int nhs = 1;
struct net *net = cfg->fc_nlinfo.nl_net;
@@ -1333,14 +1358,25 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
fi->fib_tb_id = cfg->fc_table;
fi->fib_nhs = nhs;
- change_nexthops(fi) {
- nexthop_nh->nh_parent = fi;
- } endfor_nexthops(fi)
+ if (nh) {
+ if (!nexthop_get(nh)) {
+ NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
+ err = -EINVAL;
+ } else {
+ err = 0;
+ fi->nh = nh;
+ }
+ } else {
+ change_nexthops(fi) {
+ nexthop_nh->nh_parent = fi;
+ } endfor_nexthops(fi)
- if (cfg->fc_mp)
- err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg, extack);
- else
- err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
+ if (cfg->fc_mp)
+ err = fib_get_nhs(fi, cfg->fc_mp, cfg->fc_mp_len, cfg,
+ extack);
+ else
+ err = fib_nh_init(net, fi->fib_nh, cfg, 1, extack);
+ }
if (err != 0)
goto failure;
@@ -1371,7 +1407,11 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
goto err_inval;
}
- if (cfg->fc_scope == RT_SCOPE_HOST) {
+ if (fi->nh) {
+ err = fib_check_nexthop(fi->nh, cfg->fc_scope, extack);
+ if (err)
+ goto failure;
+ } else if (cfg->fc_scope == RT_SCOPE_HOST) {
struct fib_nh *nh = fi->fib_nh;
/* Local address is added. */
@@ -1411,14 +1451,16 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
goto err_inval;
}
- change_nexthops(fi) {
- fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
- fi->fib_scope);
- if (nexthop_nh->fib_nh_gw_family == AF_INET6)
- fi->fib_nh_is_v6 = true;
- } endfor_nexthops(fi)
+ if (!fi->nh) {
+ change_nexthops(fi) {
+ fib_info_update_nhc_saddr(net, &nexthop_nh->nh_common,
+ fi->fib_scope);
+ if (nexthop_nh->fib_nh_gw_family == AF_INET6)
+ fi->fib_nh_is_v6 = true;
+ } endfor_nexthops(fi)
- fib_rebalance(fi);
+ fib_rebalance(fi);
+ }
link_it:
ofi = fib_find_info(fi);
@@ -1440,16 +1482,20 @@ struct fib_info *fib_create_info(struct fib_config *cfg,
head = &fib_info_laddrhash[fib_laddr_hashfn(fi->fib_prefsrc)];
hlist_add_head(&fi->fib_lhash, head);
}
- change_nexthops(fi) {
- struct hlist_head *head;
- unsigned int hash;
+ if (fi->nh) {
+ list_add(&fi->nh_list, &nh->fi_list);
+ } else {
+ change_nexthops(fi) {
+ struct hlist_head *head;
+ unsigned int hash;
- if (!nexthop_nh->fib_nh_dev)
- continue;
- hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
- head = &fib_info_devhash[hash];
- hlist_add_head(&nexthop_nh->nh_hash, head);
- } endfor_nexthops(fi)
+ if (!nexthop_nh->fib_nh_dev)
+ continue;
+ hash = fib_devindex_hashfn(nexthop_nh->fib_nh_dev->ifindex);
+ head = &fib_info_devhash[hash];
+ hlist_add_head(&nexthop_nh->nh_hash, head);
+ } endfor_nexthops(fi)
+ }
spin_unlock_bh(&fib_info_lock);
return fi;
@@ -1576,6 +1622,12 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
if (!mp)
goto nla_put_failure;
+ if (unlikely(fi->nh)) {
+ if (nexthop_mpath_fill_node(skb, fi->nh) < 0)
+ goto nla_put_failure;
+ goto mp_end;
+ }
+
for_nexthops(fi) {
if (fib_add_nexthop(skb, &nh->nh_common, nh->fib_nh_weight) < 0)
goto nla_put_failure;
@@ -1586,6 +1638,7 @@ static int fib_add_multipath(struct sk_buff *skb, struct fib_info *fi)
#endif
} endfor_nexthops(fi);
+mp_end:
nla_nest_end(skb, mp);
return 0;
@@ -1640,6 +1693,14 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
if (fi->fib_prefsrc &&
nla_put_in_addr(skb, RTA_PREFSRC, fi->fib_prefsrc))
goto nla_put_failure;
+
+ if (fi->nh) {
+ if (nla_put_u32(skb, RTA_NH_ID, fi->nh->id))
+ goto nla_put_failure;
+ if (nexthop_is_blackhole(fi->nh))
+ rtm->rtm_type = RTN_BLACKHOLE;
+ }
+
if (nhs == 1) {
const struct fib_nh_common *nhc = fib_info_nhc(fi, 0);
unsigned char flags = 0;
@@ -1784,6 +1845,8 @@ void fib_sync_mtu(struct net_device *dev, u32 orig_mtu)
* NETDEV_DOWN 0 LINKDOWN|DEAD Link down, not for scope host
* NETDEV_DOWN 1 LINKDOWN|DEAD Last address removed
* NETDEV_UNREGISTER 1 LINKDOWN|DEAD Device removed
+ *
+ * only used when fib_nh is built into fib_info
*/
int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force)
{
@@ -1931,6 +1994,8 @@ static void fib_select_default(const struct flowi4 *flp, struct fib_result *res)
/*
* Dead device goes up. We wake up dead nexthops.
* It takes sense only on multipath routes.
+ *
+ * only used when fib_nh is built into fib_info
*/
int fib_sync_up(struct net_device *dev, unsigned char nh_flags)
{
@@ -2025,6 +2090,11 @@ void fib_select_multipath(struct fib_result *res, int hash)
struct net *net = fi->fib_net;
bool first = false;
+ if (unlikely(res->fi->nh)) {
+ nexthop_path_fib_result(res, hash);
+ return;
+ }
+
change_nexthops(fi) {
if (net->ipv4.sysctl_fib_multipath_use_neigh) {
if (!fib_good_nh(nexthop_nh))