1 files changed, 198 insertions, 101 deletions

diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 9b9b02052fd3..a268e1595b22 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -6,12 +6,31 @@
 #include <linux/bpf.h>
 #include <linux/init.h>
 #include <linux/wait.h>
+#include <linux/util_macros.h>
 
 #include <net/inet_common.h>
 #include <net/tls.h>
 
+void tcp_eat_skb(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_sock *tcp;
+	int copied;
+
+	if (!skb || !skb->len || !sk_is_tcp(sk))
+		return;
+
+	if (skb_bpf_strparser(skb))
+		return;
+
+	tcp = tcp_sk(sk);
+	copied = tcp->copied_seq + skb->len;
+	WRITE_ONCE(tcp->copied_seq, copied);
+	tcp_rcv_space_adjust(sk);
+	__tcp_cleanup_rbuf(sk, skb->len);
+}
+
 static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
-			   struct sk_msg *msg, u32 apply_bytes, int flags)
+			   struct sk_msg *msg, u32 apply_bytes)
 {
 	bool apply = apply_bytes;
 	struct scatterlist *sge;
@@ -30,13 +49,14 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
 		sge = sk_msg_elem(msg, i);
 		size = (apply && apply_bytes < sge->length) ?
 			apply_bytes : sge->length;
-		if (!sk_wmem_schedule(sk, size)) {
+		if (!__sk_rmem_schedule(sk, size, false)) {
 			if (!copied)
 				ret = -ENOMEM;
 			break;
 		}
 
 		sk_mem_charge(sk, size);
+		atomic_add(size, &sk->sk_rmem_alloc);
 		sk_msg_xfer(tmp, msg, i, size);
 		copied += size;
 		if (sge->length)
@@ -45,14 +65,18 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
 		tmp->sg.end = i;
 		if (apply) {
 			apply_bytes -= size;
-			if (!apply_bytes)
+			if (!apply_bytes) {
+				if (sge->length)
+					sk_msg_iter_var_prev(i);
 				break;
+			}
 		}
 	} while (i != msg->sg.end);
 
 	if (!ret) {
 		msg->sg.start = i;
-		sk_psock_queue_msg(psock, tmp);
+		if (!sk_psock_queue_msg(psock, tmp))
+			atomic_sub(copied, &sk->sk_rmem_alloc);
 		sk_psock_data_ready(sk, psock);
 	} else {
 		sk_msg_free(sk, tmp);
@@ -66,6 +90,7 @@ static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
 static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
 			int flags, bool uncharge)
 {
+	struct msghdr msghdr = {};
 	bool apply = apply_bytes;
 	struct scatterlist *sge;
 	struct page *page;
@@ -73,6 +98,7 @@ static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
 	u32 off;
 
 	while (1) {
+		struct bio_vec bvec;
 		bool has_tx_ulp;
 
 		sge = sk_msg_elem(msg, msg->sg.start);
@@ -83,17 +109,20 @@ static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
 
 		tcp_rate_check_app_limited(sk);
 retry:
+		msghdr.msg_flags = flags | MSG_SPLICE_PAGES;
 		has_tx_ulp = tls_sw_has_ctx_tx(sk);
-		if (has_tx_ulp) {
-			flags |= MSG_SENDPAGE_NOPOLICY;
-			ret = kernel_sendpage_locked(sk,
-						     page, off, size, flags);
-		} else {
-			ret = do_tcp_sendpages(sk, page, off, size, flags);
-		}
+		if (has_tx_ulp)
+			msghdr.msg_flags |= MSG_SENDPAGE_NOPOLICY;
 
+		if (size < sge->length && msg->sg.start != msg->sg.end)
+			msghdr.msg_flags |= MSG_MORE;
+
+		bvec_set_page(&bvec, page, size, off);
+		iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);
+		ret = tcp_sendmsg_locked(sk, &msghdr, size);
 		if (ret <= 0)
 			return ret;
+
 		if (apply)
 			apply_bytes -= ret;
 		msg->sg.size -= ret;
@@ -131,18 +160,16 @@ static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
 	return ret;
 }
 
-int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
-			  u32 bytes, int flags)
+int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,
+			  struct sk_msg *msg, u32 bytes, int flags)
 {
-	bool ingress = sk_msg_to_ingress(msg);
 	struct sk_psock *psock = sk_psock_get(sk);
 	int ret;
 
-	if (unlikely(!psock)) {
-		sk_msg_free(sk, msg);
-		return 0;
-	}
-	ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
+	if (unlikely(!psock))
+		return -EPIPE;
+
+	ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes) :
 			tcp_bpf_push_locked(sk, msg, bytes, flags, false);
 	sk_psock_put(sk, psock);
 	return ret;
@@ -166,32 +193,91 @@ static int tcp_msg_wait_data(struct sock *sk, struct sk_psock *psock,
 	sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 	ret = sk_wait_event(sk, &timeo,
 			    !list_empty(&psock->ingress_msg) ||
-			    !skb_queue_empty(&sk->sk_receive_queue), &wait);
+			    !skb_queue_empty_lockless(&sk->sk_receive_queue), &wait);
 	sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
 	remove_wait_queue(sk_sleep(sk), &wait);
 	return ret;
 }
 
+static bool is_next_msg_fin(struct sk_psock *psock)
+{
+	struct scatterlist *sge;
+	struct sk_msg *msg_rx;
+	int i;
+
+	msg_rx = sk_psock_peek_msg(psock);
+	i = msg_rx->sg.start;
+	sge = sk_msg_elem(msg_rx, i);
+	if (!sge->length) {
+		struct sk_buff *skb = msg_rx->skb;
+
+		if (skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
+			return true;
+	}
+	return false;
+}
+
 static int tcp_bpf_recvmsg_parser(struct sock *sk,
 				  struct msghdr *msg,
 				  size_t len,
-				  int nonblock,
 				  int flags,
 				  int *addr_len)
 {
+	int peek = flags & MSG_PEEK;
 	struct sk_psock *psock;
-	int copied;
+	struct tcp_sock *tcp;
+	int copied = 0;
+	u32 seq;
 
 	if (unlikely(flags & MSG_ERRQUEUE))
 		return inet_recv_error(sk, msg, len, addr_len);
 
+	if (!len)
+		return 0;
+
 	psock = sk_psock_get(sk);
 	if (unlikely(!psock))
-		return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+		return tcp_recvmsg(sk, msg, len, flags, addr_len);
 
 	lock_sock(sk);
+	tcp = tcp_sk(sk);
+	seq = tcp->copied_seq;
+	/* We may have received data on the sk_receive_queue pre-accept and
+	 * then we can not use read_skb in this context because we haven't
+	 * assigned a sk_socket yet so have no link to the ops. The work-around
+	 * is to check the sk_receive_queue and in these cases read skbs off
+	 * queue again. The read_skb hook is not running at this point because
+	 * of lock_sock so we avoid having multiple runners in read_skb.
+	 */
+	if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) {
+		tcp_data_ready(sk);
+		/* This handles the ENOMEM errors if we both receive data
+		 * pre accept and are already under memory pressure. At least
+		 * let user know to retry.
+		 */
+		if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) {
+			copied = -EAGAIN;
+			goto out;
+		}
+	}
+
 msg_bytes_ready:
 	copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
+	/* The typical case for EFAULT is the socket was gracefully
+	 * shutdown with a FIN pkt. So check here the other case is
+	 * some error on copy_page_to_iter which would be unexpected.
+	 * On fin return correct return code to zero.
+	 */
+	if (copied == -EFAULT) {
+		bool is_fin = is_next_msg_fin(psock);
+
+		if (is_fin) {
+			copied = 0;
+			seq++;
+			goto out;
+		}
+	}
+	seq += copied;
 	if (!copied) {
 		long timeo;
 		int data;
@@ -212,7 +298,7 @@ msg_bytes_ready:
 			goto out;
 		}
 
-		timeo = sock_rcvtimeo(sk, nonblock);
+		timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 		if (!timeo) {
 			copied = -EAGAIN;
 			goto out;
@@ -224,18 +310,29 @@ msg_bytes_ready:
 		}
 
 		data = tcp_msg_wait_data(sk, psock, timeo);
+		if (data < 0) {
+			copied = data;
+			goto unlock;
+		}
 		if (data && !sk_psock_queue_empty(psock))
 			goto msg_bytes_ready;
 		copied = -EAGAIN;
 	}
 out:
+	if (!peek)
+		WRITE_ONCE(tcp->copied_seq, seq);
+	tcp_rcv_space_adjust(sk);
+	if (copied > 0)
+		__tcp_cleanup_rbuf(sk, copied);
+
+unlock:
 	release_sock(sk);
 	sk_psock_put(sk, psock);
 	return copied;
 }
 
 static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
-		    int nonblock, int flags, int *addr_len)
+			   int flags, int *addr_len)
 {
 	struct sk_psock *psock;
 	int copied, ret;
@@ -243,13 +340,16 @@ static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 	if (unlikely(flags & MSG_ERRQUEUE))
 		return inet_recv_error(sk, msg, len, addr_len);
 
+	if (!len)
+		return 0;
+
 	psock = sk_psock_get(sk);
 	if (unlikely(!psock))
-		return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+		return tcp_recvmsg(sk, msg, len, flags, addr_len);
 	if (!skb_queue_empty(&sk->sk_receive_queue) &&
 	    sk_psock_queue_empty(psock)) {
 		sk_psock_put(sk, psock);
-		return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+		return tcp_recvmsg(sk, msg, len, flags, addr_len);
 	}
 	lock_sock(sk);
 msg_bytes_ready:
@@ -258,18 +358,24 @@ msg_bytes_ready:
 		long timeo;
 		int data;
 
-		timeo = sock_rcvtimeo(sk, nonblock);
+		timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 		data = tcp_msg_wait_data(sk, psock, timeo);
+		if (data < 0) {
+			ret = data;
+			goto unlock;
+		}
 		if (data) {
 			if (!sk_psock_queue_empty(psock))
 				goto msg_bytes_ready;
 			release_sock(sk);
 			sk_psock_put(sk, psock);
-			return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+			return tcp_recvmsg(sk, msg, len, flags, addr_len);
 		}
 		copied = -EAGAIN;
 	}
 	ret = copied;
+
+unlock:
 	release_sock(sk);
 	sk_psock_put(sk, psock);
 	return ret;
@@ -278,10 +384,10 @@ msg_bytes_ready:
 static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 				struct sk_msg *msg, int *copied, int flags)
 {
-	bool cork = false, enospc = sk_msg_full(msg);
+	bool cork = false, enospc = sk_msg_full(msg), redir_ingress;
 	struct sock *sk_redir;
-	u32 tosend, delta = 0;
-	u32 eval = __SK_NONE;
+	u32 tosend, origsize, sent, delta = 0;
+	u32 eval;
 	int ret;
 
 more_data:
@@ -302,8 +408,11 @@ more_data:
 		if (!psock->cork) {
 			psock->cork = kzalloc(sizeof(*psock->cork),
 					      GFP_ATOMIC | __GFP_NOWARN);
-			if (!psock->cork)
+			if (!psock->cork) {
+				sk_msg_free(sk, msg);
+				*copied = 0;
 				return -ENOMEM;
+			}
 		}
 		memcpy(psock->cork, msg, sizeof(*msg));
 		return 0;
@@ -312,6 +421,7 @@ more_data:
 	tosend = msg->sg.size;
 	if (psock->apply_bytes && psock->apply_bytes < tosend)
 		tosend = psock->apply_bytes;
+	eval = __SK_NONE;
 
 	switch (psock->eval) {
 	case __SK_PASS:
@@ -323,6 +433,7 @@ more_data:
 		sk_msg_apply_bytes(psock, tosend);
 		break;
 	case __SK_REDIRECT:
+		redir_ingress = psock->redir_ingress;
 		sk_redir = psock->sk_redir;
 		sk_msg_apply_bytes(psock, tosend);
 		if (!psock->apply_bytes) {
@@ -335,17 +446,20 @@ more_data:
 			cork = true;
 			psock->cork = NULL;
 		}
-		sk_msg_return(sk, msg, tosend);
 		release_sock(sk);
 
-		ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
+		origsize = msg->sg.size;
+		ret = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
+					    msg, tosend, flags);
+		sent = origsize - msg->sg.size;
 
 		if (eval == __SK_REDIRECT)
 			sock_put(sk_redir);
 
 		lock_sock(sk);
+		sk_mem_uncharge(sk, sent);
 		if (unlikely(ret < 0)) {
-			int free = sk_msg_free_nocharge(sk, msg);
+			int free = sk_msg_free(sk, msg);
 
 			if (!cork)
 				*copied -= free;
@@ -359,7 +473,7 @@ more_data:
 		break;
 	case __SK_DROP:
 	default:
-		sk_msg_free_partial(sk, msg, tosend);
+		sk_msg_free(sk, msg);
 		sk_msg_apply_bytes(psock, tosend);
 		*copied -= (tosend + delta);
 		return -EACCES;
@@ -384,12 +498,12 @@ more_data:
 static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 {
 	struct sk_msg tmp, *msg_tx = NULL;
-	int copied = 0, err = 0;
+	int copied = 0, err = 0, ret = 0;
 	struct sk_psock *psock;
 	long timeo;
 	int flags;
 
-	/* Don't let internal do_tcp_sendpages() flags through */
+	/* Don't let internal flags through */
 	flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
 	flags |= MSG_NO_SHARED_FRAGS;
 
@@ -427,14 +541,14 @@ static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
 			copy = msg_tx->sg.size - osize;
 		}
 
-		err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
+		ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
 					       copy);
-		if (err < 0) {
+		if (ret < 0) {
 			sk_msg_trim(sk, msg_tx, osize);
 			goto out_err;
 		}
 
-		copied += copy;
+		copied += ret;
 		if (psock->cork_bytes) {
 			if (size > psock->cork_bytes)
 				psock->cork_bytes = 0;
@@ -466,55 +580,7 @@ out_err:
 		err = sk_stream_error(sk, msg->msg_flags, err);
 	release_sock(sk);
 	sk_psock_put(sk, psock);
-	return copied ? copied : err;
-}
-
-static int tcp_bpf_sendpage(struct sock *sk, struct page *page, int offset,
-			    size_t size, int flags)
-{
-	struct sk_msg tmp, *msg = NULL;
-	int err = 0, copied = 0;
-	struct sk_psock *psock;
-	bool enospc = false;
-
-	psock = sk_psock_get(sk);
-	if (unlikely(!psock))
-		return tcp_sendpage(sk, page, offset, size, flags);
-
-	lock_sock(sk);
-	if (psock->cork) {
-		msg = psock->cork;
-	} else {
-		msg = &tmp;
-		sk_msg_init(msg);
-	}
-
-	/* Catch case where ring is full and sendpage is stalled. */
-	if (unlikely(sk_msg_full(msg)))
-		goto out_err;
-
-	sk_msg_page_add(msg, page, size, offset);
-	sk_mem_charge(sk, size);
-	copied = size;
-	if (sk_msg_full(msg))
-		enospc = true;
-	if (psock->cork_bytes) {
-		if (size > psock->cork_bytes)
-			psock->cork_bytes = 0;
-		else
-			psock->cork_bytes -= size;
-		if (psock->cork_bytes && !enospc)
-			goto out_err;
-		/* All cork bytes are accounted, rerun the prog. */
-		psock->eval = __SK_NONE;
-		psock->cork_bytes = 0;
-	}
-
-	err = tcp_bpf_send_verdict(sk, psock, msg, &copied, flags);
-out_err:
-	release_sock(sk);
-	sk_psock_put(sk, psock);
-	return copied ? copied : err;
+	return copied > 0 ? copied : err;
 }
 
 enum {
@@ -539,13 +605,13 @@ static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],
 				   struct proto *base)
 {
 	prot[TCP_BPF_BASE]			= *base;
+	prot[TCP_BPF_BASE].destroy		= sock_map_destroy;
 	prot[TCP_BPF_BASE].close		= sock_map_close;
 	prot[TCP_BPF_BASE].recvmsg		= tcp_bpf_recvmsg;
 	prot[TCP_BPF_BASE].sock_is_readable	= sk_msg_is_readable;
 
 	prot[TCP_BPF_TX]			= prot[TCP_BPF_BASE];
 	prot[TCP_BPF_TX].sendmsg		= tcp_bpf_sendmsg;
-	prot[TCP_BPF_TX].sendpage		= tcp_bpf_sendpage;
 
 	prot[TCP_BPF_RX]			= prot[TCP_BPF_BASE];
 	prot[TCP_BPF_RX].recvmsg		= tcp_bpf_recvmsg_parser;
@@ -580,10 +646,45 @@ static int tcp_bpf_assert_proto_ops(struct proto *ops)
 	 * indeed valid assumptions.
 	 */
 	return ops->recvmsg  == tcp_recvmsg &&
-	       ops->sendmsg  == tcp_sendmsg &&
-	       ops->sendpage == tcp_sendpage ? 0 : -ENOTSUPP;
+	       ops->sendmsg  == tcp_sendmsg ? 0 : -ENOTSUPP;
 }
 
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
+int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc,
+			   sk_read_actor_t recv_actor)
+{
+	struct sock *sk = strp->sk;
+	struct sk_psock *psock;
+	struct tcp_sock *tp;
+	int copied = 0;
+
+	tp = tcp_sk(sk);
+	rcu_read_lock();
+	psock = sk_psock(sk);
+	if (WARN_ON_ONCE(!psock)) {
+		desc->error = -EINVAL;
+		goto out;
+	}
+
+	psock->ingress_bytes = 0;
+	copied = tcp_read_sock_noack(sk, desc, recv_actor, true,
+				     &psock->copied_seq);
+	if (copied < 0)
+		goto out;
+	/* recv_actor may redirect skb to another socket (SK_REDIRECT) or
+	 * just put skb into ingress queue of current socket (SK_PASS).
+	 * For SK_REDIRECT, we need to ack the frame immediately but for
+	 * SK_PASS, we want to delay the ack until tcp_bpf_recvmsg_parser().
+	 */
+	tp->copied_seq = psock->copied_seq - psock->ingress_bytes;
+	tcp_rcv_space_adjust(sk);
+	__tcp_cleanup_rbuf(sk, copied - psock->ingress_bytes);
+out:
+	rcu_read_unlock();
+	return copied;
+}
+#endif /* CONFIG_BPF_STREAM_PARSER */
+
 int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
 {
 	int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
@@ -605,14 +706,11 @@ int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
 		} else {
 			sk->sk_write_space = psock->saved_write_space;
 			/* Pairs with lockless read in sk_clone_lock() */
-			WRITE_ONCE(sk->sk_prot, psock->sk_proto);
+			sock_replace_proto(sk, psock->sk_proto);
 		}
 		return 0;
 	}
 
-	if (inet_csk_has_ulp(sk))
-		return -EINVAL;
-
 	if (sk->sk_family == AF_INET6) {
 		if (tcp_bpf_assert_proto_ops(psock->sk_proto))
 			return -EINVAL;
@@ -621,7 +719,7 @@ int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
 	}
 
 	/* Pairs with lockless read in sk_clone_lock() */
-	WRITE_ONCE(sk->sk_prot, &tcp_bpf_prots[family][config]);
+	sock_replace_proto(sk, &tcp_bpf_prots[family][config]);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(tcp_bpf_update_proto);
@@ -633,10 +731,9 @@ EXPORT_SYMBOL_GPL(tcp_bpf_update_proto);
  */
 void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
 {
-	int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
 	struct proto *prot = newsk->sk_prot;
 
-	if (prot == &tcp_bpf_prots[family][TCP_BPF_BASE])
+	if (is_insidevar(prot, tcp_bpf_prots))
 		newsk->sk_prot = sk->sk_prot_creator;
 }
 #endif /* CONFIG_BPF_SYSCALL */