Merge branch 'raw-add-drop-reasons-and-use-another-hash-function'

Eric Dumazet says:

====================
raw: add drop reasons and use another hash function

Two first patches add drop reasons to raw input processing.

Last patch spreads RAW sockets in the shared hash tables
to avoid long hash buckets in some cases.
====================

Link: https://lore.kernel.org/r/20230202094100.3083177-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 21 insertions, 16 deletions

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 006c1f0ed8b4..94df935ee0c5 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -93,7 +93,7 @@ int raw_hash_sk(struct sock *sk)
 	struct raw_hashinfo *h = sk->sk_prot->h.raw_hash;
 	struct hlist_nulls_head *hlist;
 
-	hlist = &h->ht[inet_sk(sk)->inet_num & (RAW_HTABLE_SIZE - 1)];
+	hlist = &h->ht[raw_hashfunc(sock_net(sk), inet_sk(sk)->inet_num)];
 
 	spin_lock(&h->lock);
 	__sk_nulls_add_node_rcu(sk, hlist);
@@ -160,9 +160,9 @@ static int icmp_filter(const struct sock *sk, const struct sk_buff *skb)
  * RFC 1122: SHOULD pass TOS value up to the transport layer.
  * -> It does. And not only TOS, but all IP header.
  */
-static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
+static int raw_v4_input(struct net *net, struct sk_buff *skb,
+			const struct iphdr *iph, int hash)
 {
-	struct net *net = dev_net(skb->dev);
 	struct hlist_nulls_head *hlist;
 	struct hlist_nulls_node *hnode;
 	int sdif = inet_sdif(skb);
@@ -193,9 +193,10 @@ static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
 
 int raw_local_deliver(struct sk_buff *skb, int protocol)
 {
-	int hash = protocol & (RAW_HTABLE_SIZE - 1);
+	struct net *net = dev_net(skb->dev);
 
-	return raw_v4_input(skb, ip_hdr(skb), hash);
+	return raw_v4_input(net, skb, ip_hdr(skb),
+			    raw_hashfunc(net, protocol));
 }
 
 static void raw_err(struct sock *sk, struct sk_buff *skb, u32 info)
@@ -271,7 +272,7 @@ void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
 	struct sock *sk;
 	int hash;
 
-	hash = protocol & (RAW_HTABLE_SIZE - 1);
+	hash = raw_hashfunc(net, protocol);
 	hlist = &raw_v4_hashinfo.ht[hash];
 
 	rcu_read_lock();
@@ -287,11 +288,13 @@ void raw_icmp_error(struct sk_buff *skb, int protocol, u32 info)
 
 static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason;
+
 	/* Charge it to the socket. */
 
 	ipv4_pktinfo_prepare(sk, skb);
-	if (sock_queue_rcv_skb(sk, skb) < 0) {
-		kfree_skb(skb);
+	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
+		kfree_skb_reason(skb, reason);
 		return NET_RX_DROP;
 	}
 
@@ -302,7 +305,7 @@ int raw_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) {
 		atomic_inc(&sk->sk_drops);
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_XFRM_POLICY);
 		return NET_RX_DROP;
 	}
 	nf_reset_ct(skb);
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index ada087b50541..bac9ba747bde 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -152,7 +152,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr)
 	saddr = &ipv6_hdr(skb)->saddr;
 	daddr = saddr + 1;
 
-	hash = nexthdr & (RAW_HTABLE_SIZE - 1);
+	hash = raw_hashfunc(net, nexthdr);
 	hlist = &raw_v6_hashinfo.ht[hash];
 	rcu_read_lock();
 	sk_nulls_for_each(sk, hnode, hlist) {
@@ -338,7 +338,7 @@ void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
 	struct sock *sk;
 	int hash;
 
-	hash = nexthdr & (RAW_HTABLE_SIZE - 1);
+	hash = raw_hashfunc(net, nexthdr);
 	hlist = &raw_v6_hashinfo.ht[hash];
 	rcu_read_lock();
 	sk_nulls_for_each(sk, hnode, hlist) {
@@ -355,17 +355,19 @@ void raw6_icmp_error(struct sk_buff *skb, int nexthdr,
 
 static inline int rawv6_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
+	enum skb_drop_reason reason;
+
 	if ((raw6_sk(sk)->checksum || rcu_access_pointer(sk->sk_filter)) &&
 	    skb_checksum_complete(skb)) {
 		atomic_inc(&sk->sk_drops);
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
 		return NET_RX_DROP;
 	}
 
 	/* Charge it to the socket. */
 	skb_dst_drop(skb);
-	if (sock_queue_rcv_skb(sk, skb) < 0) {
-		kfree_skb(skb);
+	if (sock_queue_rcv_skb_reason(sk, skb, &reason) < 0) {
+		kfree_skb_reason(skb, reason);
 		return NET_RX_DROP;
 	}
 
@@ -386,7 +388,7 @@ int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
 
 	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
 		atomic_inc(&sk->sk_drops);
-		kfree_skb(skb);
+		kfree_skb_reason(skb, SKB_DROP_REASON_XFRM_POLICY);
 		return NET_RX_DROP;
 	}
 
@@ -410,7 +412,7 @@ int rawv6_rcv(struct sock *sk, struct sk_buff *skb)
 	if (inet->hdrincl) {
 		if (skb_checksum_complete(skb)) {
 			atomic_inc(&sk->sk_drops);
-			kfree_skb(skb);
+			kfree_skb_reason(skb, SKB_DROP_REASON_SKB_CSUM);
 			return NET_RX_DROP;
 		}
 	}