From 528a3a6f67d4fbe708b9f306be194e78b29e8d7a Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 17 Nov 2008 16:00:40 +0100 Subject: [PATCH] netfilter: ctnetlink: get rid of module refcounting in ctnetlink This patch replaces the unnecessary module refcounting with the read-side locks. With this patch, all the dump and fill_info function are called under the RCU read lock. Based on a patch from Fabian Hugelshofer. Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy --- net/netfilter/nf_conntrack_netlink.c | 38 +++++++++++++--------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index d87a9398a781..49a04fa0becc 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -105,16 +105,14 @@ ctnetlink_dump_tuples(struct sk_buff *skb, struct nf_conntrack_l3proto *l3proto; struct nf_conntrack_l4proto *l4proto; - l3proto = nf_ct_l3proto_find_get(tuple->src.l3num); + l3proto = __nf_ct_l3proto_find(tuple->src.l3num); ret = ctnetlink_dump_tuples_ip(skb, tuple, l3proto); - nf_ct_l3proto_put(l3proto); if (unlikely(ret < 0)) return ret; - l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum); + l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum); ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto); - nf_ct_l4proto_put(l4proto); return ret; } @@ -151,11 +149,9 @@ ctnetlink_dump_protoinfo(struct sk_buff *skb, const struct nf_conn *ct) struct nlattr *nest_proto; int ret; - l4proto = nf_ct_l4proto_find_get(nf_ct_l3num(ct), nf_ct_protonum(ct)); - if (!l4proto->to_nlattr) { - nf_ct_l4proto_put(l4proto); + l4proto = __nf_ct_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct)); + if (!l4proto->to_nlattr) return 0; - } nest_proto = nla_nest_start(skb, CTA_PROTOINFO | NLA_F_NESTED); if (!nest_proto) @@ -163,14 +159,11 @@ ctnetlink_dump_protoinfo(struct sk_buff *skb, const struct nf_conn *ct) ret = l4proto->to_nlattr(skb, nest_proto, ct); - nf_ct_l4proto_put(l4proto); - nla_nest_end(skb, nest_proto); return ret; nla_put_failure: - nf_ct_l4proto_put(l4proto); return -1; } @@ -184,7 +177,6 @@ ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct) if (!help) return 0; - rcu_read_lock(); helper = rcu_dereference(help->helper); if (!helper) goto out; @@ -199,11 +191,9 @@ ctnetlink_dump_helpinfo(struct sk_buff *skb, const struct nf_conn *ct) nla_nest_end(skb, nest_helper); out: - rcu_read_unlock(); return 0; nla_put_failure: - rcu_read_unlock(); return -1; } @@ -461,6 +451,7 @@ static int ctnetlink_conntrack_event(struct notifier_block *this, nfmsg->version = NFNETLINK_V0; nfmsg->res_id = 0; + rcu_read_lock(); nest_parms = nla_nest_start(skb, CTA_TUPLE_ORIG | NLA_F_NESTED); if (!nest_parms) goto nla_put_failure; @@ -517,13 +508,15 @@ static int ctnetlink_conntrack_event(struct notifier_block *this, && ctnetlink_dump_mark(skb, ct) < 0) goto nla_put_failure; #endif + rcu_read_unlock(); nlh->nlmsg_len = skb->tail - b; nfnetlink_send(skb, 0, group, 0); return NOTIFY_DONE; -nlmsg_failure: nla_put_failure: + rcu_read_unlock(); +nlmsg_failure: kfree_skb(skb); return NOTIFY_DONE; } @@ -795,8 +788,10 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb, return -ENOMEM; } + rcu_read_lock(); err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq, IPCTNL_MSG_CT_NEW, 1, ct); + rcu_read_unlock(); nf_ct_put(ct); if (err <= 0) goto free; @@ -1292,16 +1287,14 @@ ctnetlink_exp_dump_mask(struct sk_buff *skb, if (!nest_parms) goto nla_put_failure; - l3proto = nf_ct_l3proto_find_get(tuple->src.l3num); + l3proto = __nf_ct_l3proto_find(tuple->src.l3num); ret = ctnetlink_dump_tuples_ip(skb, &m, l3proto); - nf_ct_l3proto_put(l3proto); if (unlikely(ret < 0)) goto nla_put_failure; - l4proto = nf_ct_l4proto_find_get(tuple->src.l3num, tuple->dst.protonum); + l4proto = __nf_ct_l4proto_find(tuple->src.l3num, tuple->dst.protonum); ret = ctnetlink_dump_tuples_proto(skb, &m, l4proto); - nf_ct_l4proto_put(l4proto); if (unlikely(ret < 0)) goto nla_put_failure; @@ -1408,15 +1401,18 @@ static int ctnetlink_expect_event(struct notifier_block *this, nfmsg->version = NFNETLINK_V0; nfmsg->res_id = 0; + rcu_read_lock(); if (ctnetlink_exp_dump_expect(skb, exp) < 0) goto nla_put_failure; + rcu_read_unlock(); nlh->nlmsg_len = skb->tail - b; nfnetlink_send(skb, 0, NFNLGRP_CONNTRACK_EXP_NEW, 0); return NOTIFY_DONE; -nlmsg_failure: nla_put_failure: + rcu_read_unlock(); +nlmsg_failure: kfree_skb(skb); return NOTIFY_DONE; } @@ -1520,9 +1516,11 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb, if (!skb2) goto out; + rcu_read_lock(); err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).pid, nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW, 1, exp); + rcu_read_unlock(); if (err <= 0) goto free; -- 2.39.5