[PATCH 5.14 073/151] netfilter: nf_tables: honor NLM_F_CREATE and NLM_F_EXCL in event notification

Greg Kroah-Hartman
2021-10-11T14:08:26Z

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ Upstream commit 6fb721cf781808ee2ca5e737fb0592cc68de3381 ]

Include the NLM_F_CREATE and NLM_F_EXCL flags in netlink event
notifications, otherwise userspace cannot distiguish between create and
add commands.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/netfilter/nf_tables.h | 2 +-
net/netfilter/nf_tables_api.c | 47 +++++++++++++++++++++++--------
net/netfilter/nft_quota.c | 2 +-
3 files changed, 37 insertions(+), 14 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 148f5d8ee5ab..a16171c5fd9e 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1202,7 +1202,7 @@ struct nft_object *nft_obj_lookup(const struct net *net,

void nft_obj_notify(struct net *net, const struct nft_table *table,
struct nft_object *obj, u32 portid, u32 seq,
- int event, int family, int report, gfp_t gfp);
+ int event, u16 flags, int family, int report, gfp_t gfp);

/**
* struct nft_object_type - stateful object type
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c8acd26c7201..c0851fec11d4 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -780,6 +780,7 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event)
{
struct nftables_pernet *nft_net;
struct sk_buff *skb;
+ u16 flags = 0;
int err;

if (!ctx->report &&
@@ -790,8 +791,11 @@ static void nf_tables_table_notify(const struct nft_ctx *ctx, int event)
if (skb == NULL)
goto err;

+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);
+
err = nf_tables_fill_table_info(skb, ctx->net, ctx->portid, ctx->seq,
- event, 0, ctx->family, ctx->table);
+ event, flags, ctx->family, ctx->table);
if (err < 0) {
kfree_skb(skb);
goto err;
@@ -1563,6 +1567,7 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
{
struct nftables_pernet *nft_net;
struct sk_buff *skb;
+ u16 flags = 0;
int err;

if (!ctx->report &&
@@ -1573,8 +1578,11 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event)
if (skb == NULL)
goto err;

+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);
+
err = nf_tables_fill_chain_info(skb, ctx->net, ctx->portid, ctx->seq,
- event, 0, ctx->family, ctx->table,
+ event, flags, ctx->family, ctx->table,
ctx->chain);
if (err < 0) {
kfree_skb(skb);
@@ -2945,6 +2953,8 @@ static void nf_tables_rule_notify(const struct nft_ctx *ctx,
}
if (ctx->flags & (NLM_F_APPEND | NLM_F_REPLACE))
flags |= NLM_F_APPEND;
+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);

err = nf_tables_fill_rule_info(skb, ctx->net, ctx->portid, ctx->seq,
event, flags, ctx->family, ctx->table,
@@ -3957,8 +3967,9 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx,
gfp_t gfp_flags)
{
struct nftables_pernet *nft_net = nft_pernet(ctx->net);
- struct sk_buff *skb;
u32 portid = ctx->portid;
+ struct sk_buff *skb;
+ u16 flags = 0;
int err;

if (!ctx->report &&
@@ -3969,7 +3980,10 @@ static void nf_tables_set_notify(const struct nft_ctx *ctx,
if (skb == NULL)
goto err;

- err = nf_tables_fill_set(skb, ctx, set, event, 0);
+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);
+
+ err = nf_tables_fill_set(skb, ctx, set, event, flags);
if (err < 0) {
kfree_skb(skb);
goto err;
@@ -5245,12 +5259,13 @@ static int nf_tables_getsetelem(struct sk_buff *skb,
static void nf_tables_setelem_notify(const struct nft_ctx *ctx,
const struct nft_set *set,
const struct nft_set_elem *elem,
- int event, u16 flags)
+ int event)
{
struct nftables_pernet *nft_net;
struct net *net = ctx->net;
u32 portid = ctx->portid;
struct sk_buff *skb;
+ u16 flags = 0;
int err;

if (!ctx->report && !nfnetlink_has_listeners(net, NFNLGRP_NFTABLES))
@@ -5260,6 +5275,9 @@ static void nf_tables_setelem_notify(const struct nft_ctx *ctx,
if (skb == NULL)
goto err;

+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);
+
err = nf_tables_fill_setelem_info(skb, ctx, 0, portid, event, flags,
set, elem);
if (err < 0) {
@@ -6935,7 +6953,7 @@ static int nf_tables_delobj(struct sk_buff *skb, const struct nfnl_info *info,

void nft_obj_notify(struct net *net, const struct nft_table *table,
struct nft_object *obj, u32 portid, u32 seq, int event,
- int family, int report, gfp_t gfp)
+ u16 flags, int family, int report, gfp_t gfp)
{
struct nftables_pernet *nft_net = nft_pernet(net);
struct sk_buff *skb;
@@ -6960,8 +6978,9 @@ void nft_obj_notify(struct net *net, const struct nft_table *table,
if (skb == NULL)
goto err;

- err = nf_tables_fill_obj_info(skb, net, portid, seq, event, 0, family,
- table, obj, false);
+ err = nf_tables_fill_obj_info(skb, net, portid, seq, event,
+ flags & (NLM_F_CREATE | NLM_F_EXCL),
+ family, table, obj, false);
if (err < 0) {
kfree_skb(skb);
goto err;
@@ -6978,7 +6997,7 @@ static void nf_tables_obj_notify(const struct nft_ctx *ctx,
struct nft_object *obj, int event)
{
nft_obj_notify(ctx->net, ctx->table, obj, ctx->portid, ctx->seq, event,
- ctx->family, ctx->report, GFP_KERNEL);
+ ctx->flags, ctx->family, ctx->report, GFP_KERNEL);
}

/*
@@ -7759,6 +7778,7 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx,
{
struct nftables_pernet *nft_net = nft_pernet(ctx->net);
struct sk_buff *skb;
+ u16 flags = 0;
int err;

if (!ctx->report &&
@@ -7769,8 +7789,11 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx,
if (skb == NULL)
goto err;

+ if (ctx->flags & (NLM_F_CREATE | NLM_F_EXCL))
+ flags |= ctx->flags & (NLM_F_CREATE | NLM_F_EXCL);
+
err = nf_tables_fill_flowtable_info(skb, ctx->net, ctx->portid,
- ctx->seq, event, 0,
+ ctx->seq, event, flags,
ctx->family, flowtable, hook_list);
if (err < 0) {
kfree_skb(skb);
@@ -8648,7 +8671,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
nft_setelem_activate(net, te->set, &te->elem);
nf_tables_setelem_notify(&trans->ctx, te->set,
&te->elem,
- NFT_MSG_NEWSETELEM, 0);
+ NFT_MSG_NEWSETELEM);
nft_trans_destroy(trans);
break;
case NFT_MSG_DELSETELEM:
@@ -8656,7 +8679,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)

nf_tables_setelem_notify(&trans->ctx, te->set,
&te->elem,
- NFT_MSG_DELSETELEM, 0);
+ NFT_MSG_DELSETELEM);
nft_setelem_remove(net, te->set, &te->elem);
if (!nft_setelem_is_catchall(te->set, &te->elem)) {
atomic_dec(&te->set->nelems);
diff --git a/net/netfilter/nft_quota.c b/net/netfilter/nft_quota.c
index 0363f533a42b..c4d1389f7185 100644
--- a/net/netfilter/nft_quota.c
+++ b/net/netfilter/nft_quota.c
@@ -60,7 +60,7 @@ static void nft_quota_obj_eval(struct nft_object *obj,
if (overquota &&
!test_and_set_bit(NFT_QUOTA_DEPLETED_BIT, &priv->flags))
nft_obj_notify(nft_net(pkt), obj->key.table, obj, 0, 0,
- NFT_MSG_NEWOBJ, nft_pf(pkt), 0, GFP_ATOMIC);
+ NFT_MSG_NEWOBJ, 0, nft_pf(pkt), 0, GFP_ATOMIC);
}

static int nft_quota_do_init(const struct nlattr * const tb[],
--
2.33.0