Commit 9f7f3ebe authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

ipv4: fib: Namespacify fib_info hash tables. 



We will convert RTM_NEWROUTE and RTM_DELROUTE to per-netns RTNL.
Then, we need to have per-netns hash tables for struct fib_info.

Let's allocate the hash tables per netns.

fib_info_hash, fib_info_hash_bits, and fib_info_cnt are now moved
to struct netns_ipv4 and accessed with net->ipv4.fib_XXX.

Also, the netns checks are removed from fib_find_info_nh() and
fib_find_info().

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250228042328.96624-9-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b79bcaf7

include/net/netns/ipv4.h

+3 −0
Original line number Diff line number Diff line
@@ -111,6 +111,9 @@ struct netns_ipv4 { 
#endif

	struct hlist_head	*fib_table_hash;

	struct sock		*fibnl;

	struct hlist_head	*fib_info_hash;

	unsigned int		fib_info_hash_bits;

	unsigned int		fib_info_cnt;



	struct sock		*mc_autojoin_sk;

net/ipv4/fib_semantics.c

+26 −35
Original line number Diff line number Diff line
@@ -50,10 +50,6 @@ 


#include "fib_lookup.h"



static struct hlist_head *fib_info_hash;

static unsigned int fib_info_hash_bits;

static unsigned int fib_info_cnt;



/* for_nexthops and change_nexthops only used when nexthop object

 * is not set in a fib_info. The logic within can reference fib_nh.

 */
@@ -256,8 +252,7 @@ void fib_release_info(struct fib_info *fi) 
	ASSERT_RTNL();

	if (fi && refcount_dec_and_test(&fi->fib_treeref)) {

		hlist_del(&fi->fib_hash);



		fib_info_cnt--;

		fi->fib_net->ipv4.fib_info_cnt--;



		if (fi->fib_prefsrc)

			hlist_del(&fi->fib_lhash);
@@ -333,11 +328,12 @@ static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope, 
static unsigned int fib_info_hashfn_result(const struct net *net,

					   unsigned int val)

{

	return hash_32(val ^ net_hash_mix(net), fib_info_hash_bits);

	return hash_32(val ^ net_hash_mix(net), net->ipv4.fib_info_hash_bits);

}



static struct hlist_head *fib_info_hash_bucket(struct fib_info *fi)

{

	struct net *net = fi->fib_net;

	unsigned int val;



	val = fib_info_hashfn_1(fi->fib_nhs, fi->fib_protocol,
@@ -352,16 +348,18 @@ static struct hlist_head *fib_info_hash_bucket(struct fib_info *fi) 
		} endfor_nexthops(fi)

	}



	return &fib_info_hash[fib_info_hashfn_result(fi->fib_net, val)];

	return &net->ipv4.fib_info_hash[fib_info_hashfn_result(net, val)];

}



static struct hlist_head *fib_info_laddrhash_bucket(const struct net *net,

						    __be32 val)

{

	u32 slot = hash_32(net_hash_mix(net) ^ (__force u32)val,

			   fib_info_hash_bits);

	unsigned int hash_bits = net->ipv4.fib_info_hash_bits;

	u32 slot;



	return &fib_info_hash[(1 << fib_info_hash_bits) + slot];

	slot = hash_32(net_hash_mix(net) ^ (__force u32)val, hash_bits);



	return &net->ipv4.fib_info_hash[(1 << hash_bits) + slot];

}



static struct hlist_head *fib_info_hash_alloc(unsigned int hash_bits)
@@ -376,22 +374,22 @@ static void fib_info_hash_free(struct hlist_head *head) 
	kvfree(head);

}



static void fib_info_hash_grow(void)

static void fib_info_hash_grow(struct net *net)

{

	unsigned int old_size = 1 << net->ipv4.fib_info_hash_bits;

	struct hlist_head *new_info_hash, *old_info_hash;

	unsigned int old_size = 1 << fib_info_hash_bits;

	unsigned int i;



	if (fib_info_cnt < old_size)

	if (net->ipv4.fib_info_cnt < old_size)

		return;



	new_info_hash = fib_info_hash_alloc(fib_info_hash_bits + 1);

	new_info_hash = fib_info_hash_alloc(net->ipv4.fib_info_hash_bits + 1);

	if (!new_info_hash)

		return;



	old_info_hash = fib_info_hash;

	fib_info_hash = new_info_hash;

	fib_info_hash_bits += 1;

	old_info_hash = net->ipv4.fib_info_hash;

	net->ipv4.fib_info_hash = new_info_hash;

	net->ipv4.fib_info_hash_bits += 1;



	for (i = 0; i < old_size; i++) {

		struct hlist_head *head = &old_info_hash[i];
@@ -429,13 +427,12 @@ static struct fib_info *fib_find_info_nh(struct net *net, 
				 (__force u32)cfg->fc_prefsrc,

				 cfg->fc_priority);

	hash = fib_info_hashfn_result(net, hash);

	head = &fib_info_hash[hash];

	head = &net->ipv4.fib_info_hash[hash];



	hlist_for_each_entry(fi, head, fib_hash) {

		if (!net_eq(fi->fib_net, net))

			continue;

		if (!fi->nh || fi->nh->id != cfg->fc_nh_id)

			continue;



		if (cfg->fc_protocol == fi->fib_protocol &&

		    cfg->fc_scope == fi->fib_scope &&

		    cfg->fc_prefsrc == fi->fib_prefsrc &&
@@ -455,10 +452,9 @@ static struct fib_info *fib_find_info(struct fib_info *nfi) 
	struct fib_info *fi;



	hlist_for_each_entry(fi, head, fib_hash) {

		if (!net_eq(fi->fib_net, nfi->fib_net))

			continue;

		if (fi->fib_nhs != nfi->fib_nhs)

			continue;



		if (nfi->fib_protocol == fi->fib_protocol &&

		    nfi->fib_scope == fi->fib_scope &&

		    nfi->fib_prefsrc == fi->fib_prefsrc &&
@@ -1406,7 +1402,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg, 
	}

#endif



	fib_info_hash_grow();

	fib_info_hash_grow(net);



	fi = kzalloc(struct_size(fi, fib_nh, nhs), GFP_KERNEL);

	if (!fi) {
@@ -1550,7 +1546,7 @@ struct fib_info *fib_create_info(struct fib_config *cfg, 
	refcount_set(&fi->fib_treeref, 1);

	refcount_set(&fi->fib_clntref, 1);



	fib_info_cnt++;

	net->ipv4.fib_info_cnt++;

	hlist_add_head(&fi->fib_hash, fib_info_hash_bucket(fi));



	if (fi->fib_prefsrc) {
@@ -2241,22 +2237,17 @@ int __net_init fib4_semantics_init(struct net *net) 
{

	unsigned int hash_bits = 4;



	if (!net_eq(net, &init_net))

		return 0;



	fib_info_hash = fib_info_hash_alloc(hash_bits);

	if (!fib_info_hash)

	net->ipv4.fib_info_hash = fib_info_hash_alloc(hash_bits);

	if (!net->ipv4.fib_info_hash)

		return -ENOMEM;



	fib_info_hash_bits = hash_bits;

	net->ipv4.fib_info_hash_bits = hash_bits;

	net->ipv4.fib_info_cnt = 0;



	return 0;

}



void __net_exit fib4_semantics_exit(struct net *net)

{

	if (!net_eq(net, &init_net))

		return;



	fib_info_hash_free(fib_info_hash);

	fib_info_hash_free(net->ipv4.fib_info_hash);

}