bpf, sockmap: Bundle psock->sk_redir and redir_ingress into a tagged …

…pointer Like skb->_sk_redir, we bundle the sock redirect pointer and the ingress bit to manage them together. Suggested-by: Jakub Sitnicki <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Pengcheng Yang <[email protected]>
danielocfb · Nov 10, 2023 · 596e9f5 · 596e9f5
1 parent 08949e6
commit 596e9f5
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Showing 4 changed files with 51 additions and 21 deletions.
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h
@@ -78,11 +78,10 @@ struct sk_psock_work_state {
 
 struct sk_psock {
 	struct sock			*sk;
-	struct sock			*sk_redir;
+	unsigned long			_sk_redir;
 	u32				apply_bytes;
 	u32				cork_bytes;
 	u32				eval;
-	bool				redir_ingress; /* undefined if sk_redir is null */
 	struct sk_msg			*cork;
 	struct sk_psock_progs		progs;
 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
@@ -283,6 +282,33 @@ static inline struct sk_psock *sk_psock(const struct sock *sk)
 							 SK_USER_DATA_PSOCK);
 }
 
+static inline bool sk_psock_ingress(const struct sk_psock *psock)
+{
+	unsigned long sk_redir = psock->_sk_redir;
+
+	return sk_redir & BPF_F_INGRESS;
+}
+
+static inline void sk_psock_set_redir(struct sk_psock *psock, struct sock *sk_redir,
+				      bool ingress)
+{
+	psock->_sk_redir = (unsigned long)sk_redir;
+	if (ingress)
+		psock->_sk_redir |= BPF_F_INGRESS;
+}
+
+static inline struct sock *sk_psock_get_redir(struct sk_psock *psock)
+{
+	unsigned long sk_redir = psock->_sk_redir;
+
+	return (struct sock *)(sk_redir & ~(BPF_F_INGRESS));
+}
+
+static inline void sk_psock_clear_redir(struct sk_psock *psock)
+{
+	psock->_sk_redir = 0;
+}
+
 static inline void sk_psock_set_state(struct sk_psock *psock,
 				      enum sk_psock_state_bits bit)
 {

diff --git a/net/core/skmsg.c b/net/core/skmsg.c
@@ -811,6 +811,7 @@ static void sk_psock_destroy(struct work_struct *work)
 {
 	struct sk_psock *psock = container_of(to_rcu_work(work),
 					      struct sk_psock, rwork);
+	struct sock *sk_redir = sk_psock_get_redir(psock);
 	/* No sk_callback_lock since already detached. */
 
 	sk_psock_done_strp(psock);
@@ -824,8 +825,8 @@ static void sk_psock_destroy(struct work_struct *work)
 	sk_psock_link_destroy(psock);
 	sk_psock_cork_free(psock);
 
-	if (psock->sk_redir)
-		sock_put(psock->sk_redir);
+	if (sk_redir)
+		sock_put(sk_redir);
 	sock_put(psock->sk);
 	kfree(psock);
 }
@@ -865,6 +866,7 @@ int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
 			 struct sk_msg *msg)
 {
 	struct bpf_prog *prog;
+	struct sock *sk_redir;
 	int ret;
 
 	rcu_read_lock();
@@ -880,17 +882,17 @@ int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
 	ret = sk_psock_map_verd(ret, msg->sk_redir);
 	psock->apply_bytes = msg->apply_bytes;
 	if (ret == __SK_REDIRECT) {
-		if (psock->sk_redir) {
-			sock_put(psock->sk_redir);
-			psock->sk_redir = NULL;
+		sk_redir = sk_psock_get_redir(psock);
+		if (sk_redir) {
+			sock_put(sk_redir);
+			sk_psock_clear_redir(psock);
 		}
 		if (!msg->sk_redir) {
 			ret = __SK_DROP;
 			goto out;
 		}
-		psock->redir_ingress = sk_msg_to_ingress(msg);
-		psock->sk_redir = msg->sk_redir;
-		sock_hold(psock->sk_redir);
+		sk_psock_set_redir(psock, msg->sk_redir, sk_msg_to_ingress(msg));
+		sock_hold(msg->sk_redir);
 	}
 out:
 	rcu_read_unlock();

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
@@ -427,14 +427,14 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 		sk_msg_apply_bytes(psock, tosend);
 		break;
 	case __SK_REDIRECT:
-		redir_ingress = psock->redir_ingress;
-		sk_redir = psock->sk_redir;
+		redir_ingress = sk_psock_ingress(psock);
+		sk_redir = sk_psock_get_redir(psock);
 		sk_msg_apply_bytes(psock, tosend);
 		if (!psock->apply_bytes) {
 			/* Clean up before releasing the sock lock. */
 			eval = psock->eval;
 			psock->eval = __SK_NONE;
-			psock->sk_redir = NULL;
+			sk_psock_clear_redir(psock);
 		}
 		if (psock->cork) {
 			cork = true;
@@ -476,9 +476,10 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 	if (likely(!ret)) {
 		if (!psock->apply_bytes) {
 			psock->eval =  __SK_NONE;
-			if (psock->sk_redir) {
-				sock_put(psock->sk_redir);
-				psock->sk_redir = NULL;
+			sk_redir = sk_psock_get_redir(psock);
+			if (sk_redir) {
+				sock_put(sk_redir);
+				sk_psock_clear_redir(psock);
 			}
 		}
 		if (msg &&

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
@@ -854,8 +854,8 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		}
 		break;
 	case __SK_REDIRECT:
-		redir_ingress = psock->redir_ingress;
-		sk_redir = psock->sk_redir;
+		redir_ingress = sk_psock_ingress(psock);
+		sk_redir = sk_psock_get_redir(psock);
 		memcpy(&msg_redir, msg, sizeof(*msg));
 		if (msg->apply_bytes < send)
 			msg->apply_bytes = 0;
@@ -898,9 +898,10 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		}
 		if (reset_eval) {
 			psock->eval = __SK_NONE;
-			if (psock->sk_redir) {
-				sock_put(psock->sk_redir);
-				psock->sk_redir = NULL;
+			sk_redir = sk_psock_get_redir(psock);
+			if (sk_redir) {
+				sock_put(sk_redir);
+				sk_psock_clear_redir(psock);
 			}
 		}
 		if (rec)