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authorFlorian Westphal <fw@strlen.de>2022-02-04 15:11:45 +0300
committerPablo Neira Ayuso <pablo@netfilter.org>2022-02-09 14:07:16 +0300
commit5948ed297eefe927628e43b5142ccde691a130fd (patch)
tree8146620fb4407aa8cc4c0dc4eca6628695e671d5
parent98eee88b8decb47ed9bacd0bbd698a36c1983a8a (diff)
downloadlinux-5948ed297eefe927628e43b5142ccde691a130fd.tar.xz
netfilter: ctnetlink: use dump structure instead of raw args
netlink_dump structure has a union of 'long args[6]' and a context buffer as scratch space. Convert ctnetlink to use a structure, its easier to read than the raw 'args' usage which comes with no type checks and no readable names. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--net/netfilter/nf_conntrack_netlink.c36
1 files changed, 24 insertions, 12 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index ac438370f94a..3d9f9ee50294 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -58,6 +58,12 @@
MODULE_LICENSE("GPL");
+struct ctnetlink_list_dump_ctx {
+ struct nf_conn *last;
+ unsigned int cpu;
+ bool done;
+};
+
static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_l4proto *l4proto)
@@ -1694,14 +1700,18 @@ static int ctnetlink_get_conntrack(struct sk_buff *skb,
static int ctnetlink_done_list(struct netlink_callback *cb)
{
- if (cb->args[1])
- nf_ct_put((struct nf_conn *)cb->args[1]);
+ struct ctnetlink_list_dump_ctx *ctx = (void *)cb->ctx;
+
+ if (ctx->last)
+ nf_ct_put(ctx->last);
+
return 0;
}
static int
ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying)
{
+ struct ctnetlink_list_dump_ctx *ctx = (void *)cb->ctx;
struct nf_conn *ct, *last;
struct nf_conntrack_tuple_hash *h;
struct hlist_nulls_node *n;
@@ -1712,12 +1722,12 @@ ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying
struct hlist_nulls_head *list;
struct net *net = sock_net(skb->sk);
- if (cb->args[2])
+ if (ctx->done)
return 0;
- last = (struct nf_conn *)cb->args[1];
+ last = ctx->last;
- for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {
+ for (cpu = ctx->cpu; cpu < nr_cpu_ids; cpu++) {
struct ct_pcpu *pcpu;
if (!cpu_possible(cpu))
@@ -1731,10 +1741,10 @@ restart:
ct = nf_ct_tuplehash_to_ctrack(h);
if (l3proto && nf_ct_l3num(ct) != l3proto)
continue;
- if (cb->args[1]) {
+ if (ctx->last) {
if (ct != last)
continue;
- cb->args[1] = 0;
+ ctx->last = NULL;
}
/* We can't dump extension info for the unconfirmed
@@ -1751,19 +1761,19 @@ restart:
if (res < 0) {
if (!refcount_inc_not_zero(&ct->ct_general.use))
continue;
- cb->args[0] = cpu;
- cb->args[1] = (unsigned long)ct;
+ ctx->cpu = cpu;
+ ctx->last = ct;
spin_unlock_bh(&pcpu->lock);
goto out;
}
}
- if (cb->args[1]) {
- cb->args[1] = 0;
+ if (ctx->last) {
+ ctx->last = NULL;
goto restart;
}
spin_unlock_bh(&pcpu->lock);
}
- cb->args[2] = 1;
+ ctx->done = true;
out:
if (last)
nf_ct_put(last);
@@ -3877,6 +3887,8 @@ static int __init ctnetlink_init(void)
{
int ret;
+ BUILD_BUG_ON(sizeof(struct ctnetlink_list_dump_ctx) > sizeof_field(struct netlink_callback, ctx));
+
ret = nfnetlink_subsys_register(&ctnl_subsys);
if (ret < 0) {
pr_err("ctnetlink_init: cannot register with nfnetlink.\n");