From 1bc91a5ddf3eaea0e0ea957cccf3abdcfcace00e Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Thu, 20 Jan 2022 13:07:01 +0100 Subject: [PATCH] netfilter: conntrack: handle ->destroy hook via nat_ops instead The nat module already exposes a few functions to the conntrack core. Move the nat extension destroy hook to it. After this, no conntrack extension needs a destroy hook. 'struct nf_ct_ext_type' and the register/unregister api can be removed in a followup patch. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter.h | 1 + include/net/netfilter/nf_conntrack_extend.h | 3 --- net/netfilter/nf_conntrack_core.c | 14 ++++++++++++-- net/netfilter/nf_conntrack_extend.c | 21 --------------------- net/netfilter/nf_nat_core.c | 13 +++---------- 5 files changed, 16 insertions(+), 36 deletions(-) diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h index 15e71bfff726..c2c6f332fb90 100644 --- a/include/linux/netfilter.h +++ b/include/linux/netfilter.h @@ -379,6 +379,7 @@ struct nf_nat_hook { unsigned int (*manip_pkt)(struct sk_buff *skb, struct nf_conn *ct, enum nf_nat_manip_type mtype, enum ip_conntrack_dir dir); + void (*remove_nat_bysrc)(struct nf_conn *ct); }; extern const struct nf_nat_hook __rcu *nf_nat_hook; diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h index 87d818414092..343f9194423a 100644 --- a/include/net/netfilter/nf_conntrack_extend.h +++ b/include/net/netfilter/nf_conntrack_extend.h @@ -79,9 +79,6 @@ void nf_ct_ext_destroy(struct nf_conn *ct); void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp); struct nf_ct_ext_type { - /* Destroys relationships (can be NULL). */ - void (*destroy)(struct nf_conn *ct); - enum nf_ct_ext_id id; }; diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 9edd3ae8d62e..8f0c0c0fd329 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -594,7 +594,7 @@ EXPORT_SYMBOL_GPL(nf_ct_tmpl_alloc); void nf_ct_tmpl_free(struct nf_conn *tmpl) { - nf_ct_ext_destroy(tmpl); + kfree(tmpl->ext); if (ARCH_KMALLOC_MINALIGN <= NFCT_INFOMASK) kfree((char *)tmpl - tmpl->proto.tmpl_padto); @@ -1597,7 +1597,17 @@ void nf_conntrack_free(struct nf_conn *ct) */ WARN_ON(refcount_read(&ct->ct_general.use) != 0); - nf_ct_ext_destroy(ct); + if (ct->status & IPS_SRC_NAT_DONE) { + const struct nf_nat_hook *nat_hook; + + rcu_read_lock(); + nat_hook = rcu_dereference(nf_nat_hook); + if (nat_hook) + nat_hook->remove_nat_bysrc(ct); + rcu_read_unlock(); + } + + kfree(ct->ext); kmem_cache_free(nf_conntrack_cachep, ct); cnet = nf_ct_pernet(net); diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c index 69a6cafcb045..6b772b804ee2 100644 --- a/net/netfilter/nf_conntrack_extend.c +++ b/net/netfilter/nf_conntrack_extend.c @@ -89,27 +89,6 @@ static __always_inline unsigned int total_extension_size(void) ; } -void nf_ct_ext_destroy(struct nf_conn *ct) -{ - unsigned int i; - struct nf_ct_ext_type *t; - - for (i = 0; i < NF_CT_EXT_NUM; i++) { - rcu_read_lock(); - t = rcu_dereference(nf_ct_ext_types[i]); - - /* Here the nf_ct_ext_type might have been unregisterd. - * I.e., it has responsible to cleanup private - * area in all conntracks when it is unregisterd. - */ - if (t && t->destroy) - t->destroy(ct); - rcu_read_unlock(); - } - - kfree(ct->ext); -} - void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp) { unsigned int newlen, newoff, oldlen, alloc; diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 2ff20d6a5afb..8cc31d695e36 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -838,7 +838,7 @@ static int nf_nat_proto_remove(struct nf_conn *i, void *data) return i->status & IPS_NAT_MASK ? 1 : 0; } -static void __nf_nat_cleanup_conntrack(struct nf_conn *ct) +static void nf_nat_cleanup_conntrack(struct nf_conn *ct) { unsigned int h; @@ -860,7 +860,7 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data) * will delete entry from already-freed table. */ if (test_and_clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status)) - __nf_nat_cleanup_conntrack(ct); + nf_nat_cleanup_conntrack(ct); /* don't delete conntrack. Although that would make things a lot * simpler, we'd end up flushing all conntracks on nat rmmod. @@ -868,15 +868,7 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data) return 0; } -/* No one using conntrack by the time this called. */ -static void nf_nat_cleanup_conntrack(struct nf_conn *ct) -{ - if (ct->status & IPS_SRC_NAT_DONE) - __nf_nat_cleanup_conntrack(ct); -} - static struct nf_ct_ext_type nat_extend __read_mostly = { - .destroy = nf_nat_cleanup_conntrack, .id = NF_CT_EXT_NAT, }; @@ -1171,6 +1163,7 @@ static const struct nf_nat_hook nat_hook = { .decode_session = __nf_nat_decode_session, #endif .manip_pkt = nf_nat_manip_pkt, + .remove_nat_bysrc = nf_nat_cleanup_conntrack, }; static int __init nf_nat_init(void)