1 files changed, 66 insertions, 167 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index cc695c9f09ec..123b35ddfd71 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -758,8 +758,6 @@ static int unix_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned lon
 static int unix_shutdown(struct socket *, int);
 static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t);
 static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int);
-static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset,
-				    size_t size, int flags);
 static ssize_t unix_stream_splice_read(struct socket *,  loff_t *ppos,
 				       struct pipe_inode_info *, size_t size,
 				       unsigned int flags);
@@ -852,7 +850,6 @@ static const struct proto_ops unix_stream_ops = {
 	.recvmsg =	unix_stream_recvmsg,
 	.read_skb =	unix_stream_read_skb,
 	.mmap =		sock_no_mmap,
-	.sendpage =	unix_stream_sendpage,
 	.splice_read =	unix_stream_splice_read,
 	.set_peek_off =	unix_set_peek_off,
 	.show_fdinfo =	unix_show_fdinfo,
@@ -878,7 +875,6 @@ static const struct proto_ops unix_dgram_ops = {
 	.read_skb =	unix_read_skb,
 	.recvmsg =	unix_dgram_recvmsg,
 	.mmap =		sock_no_mmap,
-	.sendpage =	sock_no_sendpage,
 	.set_peek_off =	unix_set_peek_off,
 	.show_fdinfo =	unix_show_fdinfo,
 };
@@ -902,7 +898,6 @@ static const struct proto_ops unix_seqpacket_ops = {
 	.sendmsg =	unix_seqpacket_sendmsg,
 	.recvmsg =	unix_seqpacket_recvmsg,
 	.mmap =		sock_no_mmap,
-	.sendpage =	sock_no_sendpage,
 	.set_peek_off =	unix_set_peek_off,
 	.show_fdinfo =	unix_show_fdinfo,
 };
@@ -921,11 +916,26 @@ static void unix_unhash(struct sock *sk)
 	 */
 }
 
+static bool unix_bpf_bypass_getsockopt(int level, int optname)
+{
+	if (level == SOL_SOCKET) {
+		switch (optname) {
+		case SO_PEERPIDFD:
+			return true;
+		default:
+			return false;
+		}
+	}
+
+	return false;
+}
+
 struct proto unix_dgram_proto = {
 	.name			= "UNIX",
 	.owner			= THIS_MODULE,
 	.obj_size		= sizeof(struct unix_sock),
 	.close			= unix_close,
+	.bpf_bypass_getsockopt	= unix_bpf_bypass_getsockopt,
 #ifdef CONFIG_BPF_SYSCALL
 	.psock_update_sk_prot	= unix_dgram_bpf_update_proto,
 #endif
@@ -937,6 +947,7 @@ struct proto unix_stream_proto = {
 	.obj_size		= sizeof(struct unix_sock),
 	.close			= unix_close,
 	.unhash			= unix_unhash,
+	.bpf_bypass_getsockopt	= unix_bpf_bypass_getsockopt,
 #ifdef CONFIG_BPF_SYSCALL
 	.psock_update_sk_prot	= unix_stream_bpf_update_proto,
 #endif
@@ -1361,7 +1372,8 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 		if (err)
 			goto out;
 
-		if (test_bit(SOCK_PASSCRED, &sock->flags) &&
+		if ((test_bit(SOCK_PASSCRED, &sock->flags) ||
+		     test_bit(SOCK_PASSPIDFD, &sock->flags)) &&
 		    !unix_sk(sk)->addr) {
 			err = unix_autobind(sk);
 			if (err)
@@ -1469,7 +1481,8 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	if (err)
 		goto out;
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+	if ((test_bit(SOCK_PASSCRED, &sock->flags) ||
+	     test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) {
 		err = unix_autobind(sk);
 		if (err)
 			goto out;
@@ -1670,6 +1683,8 @@ static void unix_sock_inherit_flags(const struct socket *old,
 {
 	if (test_bit(SOCK_PASSCRED, &old->flags))
 		set_bit(SOCK_PASSCRED, &new->flags);
+	if (test_bit(SOCK_PASSPIDFD, &old->flags))
+		set_bit(SOCK_PASSPIDFD, &new->flags);
 	if (test_bit(SOCK_PASSSEC, &old->flags))
 		set_bit(SOCK_PASSSEC, &new->flags);
 }
@@ -1819,8 +1834,10 @@ static bool unix_passcred_enabled(const struct socket *sock,
 				  const struct sock *other)
 {
 	return test_bit(SOCK_PASSCRED, &sock->flags) ||
+	       test_bit(SOCK_PASSPIDFD, &sock->flags) ||
 	       !other->sk_socket ||
-	       test_bit(SOCK_PASSCRED, &other->sk_socket->flags);
+	       test_bit(SOCK_PASSCRED, &other->sk_socket->flags) ||
+	       test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags);
 }
 
 /*
@@ -1839,24 +1856,6 @@ static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
 	}
 }
 
-static int maybe_init_creds(struct scm_cookie *scm,
-			    struct socket *socket,
-			    const struct sock *other)
-{
-	int err;
-	struct msghdr msg = { .msg_controllen = 0 };
-
-	err = scm_send(socket, &msg, scm, false);
-	if (err)
-		return err;
-
-	if (unix_passcred_enabled(socket, other)) {
-		scm->pid = get_pid(task_tgid(current));
-		current_uid_gid(&scm->creds.uid, &scm->creds.gid);
-	}
-	return err;
-}
-
 static bool unix_skb_scm_eq(struct sk_buff *skb,
 			    struct scm_cookie *scm)
 {
@@ -1922,7 +1921,8 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 			goto out;
 	}
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+	if ((test_bit(SOCK_PASSCRED, &sock->flags) ||
+	     test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) {
 		err = unix_autobind(sk);
 		if (err)
 			goto out;
@@ -2200,19 +2200,25 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 	while (sent < len) {
 		size = len - sent;
 
-		/* Keep two messages in the pipe so it schedules better */
-		size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
+		if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) {
+			skb = sock_alloc_send_pskb(sk, 0, 0,
+						   msg->msg_flags & MSG_DONTWAIT,
+						   &err, 0);
+		} else {
+			/* Keep two messages in the pipe so it schedules better */
+			size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64);
 
-		/* allow fallback to order-0 allocations */
-		size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
+			/* allow fallback to order-0 allocations */
+			size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ);
 
-		data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
+			data_len = max_t(int, 0, size - SKB_MAX_HEAD(0));
 
-		data_len = min_t(size_t, size, PAGE_ALIGN(data_len));
+			data_len = min_t(size_t, size, PAGE_ALIGN(data_len));
 
-		skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
-					   msg->msg_flags & MSG_DONTWAIT, &err,
-					   get_order(UNIX_SKB_FRAGS_SZ));
+			skb = sock_alloc_send_pskb(sk, size - data_len, data_len,
+						   msg->msg_flags & MSG_DONTWAIT, &err,
+						   get_order(UNIX_SKB_FRAGS_SZ));
+		}
 		if (!skb)
 			goto out_err;
 
@@ -2224,13 +2230,24 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg,
 		}
 		fds_sent = true;
 
-		skb_put(skb, size - data_len);
-		skb->data_len = data_len;
-		skb->len = size;
-		err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size);
-		if (err) {
-			kfree_skb(skb);
-			goto out_err;
+		if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) {
+			err = skb_splice_from_iter(skb, &msg->msg_iter, size,
+						   sk->sk_allocation);
+			if (err < 0) {
+				kfree_skb(skb);
+				goto out_err;
+			}
+			size = err;
+			refcount_add(size, &sk->sk_wmem_alloc);
+		} else {
+			skb_put(skb, size - data_len);
+			skb->data_len = data_len;
+			skb->len = size;
+			err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size);
+			if (err) {
+				kfree_skb(skb);
+				goto out_err;
+			}
 		}
 
 		unix_state_lock(other);
@@ -2272,122 +2289,6 @@ out_err:
 	return sent ? : err;
 }
 
-static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
-				    int offset, size_t size, int flags)
-{
-	int err;
-	bool send_sigpipe = false;
-	bool init_scm = true;
-	struct scm_cookie scm;
-	struct sock *other, *sk = socket->sk;
-	struct sk_buff *skb, *newskb = NULL, *tail = NULL;
-
-	if (flags & MSG_OOB)
-		return -EOPNOTSUPP;
-
-	other = unix_peer(sk);
-	if (!other || sk->sk_state != TCP_ESTABLISHED)
-		return -ENOTCONN;
-
-	if (false) {
-alloc_skb:
-		unix_state_unlock(other);
-		mutex_unlock(&unix_sk(other)->iolock);
-		newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
-					      &err, 0);
-		if (!newskb)
-			goto err;
-	}
-
-	/* we must acquire iolock as we modify already present
-	 * skbs in the sk_receive_queue and mess with skb->len
-	 */
-	err = mutex_lock_interruptible(&unix_sk(other)->iolock);
-	if (err) {
-		err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
-		goto err;
-	}
-
-	if (sk->sk_shutdown & SEND_SHUTDOWN) {
-		err = -EPIPE;
-		send_sigpipe = true;
-		goto err_unlock;
-	}
-
-	unix_state_lock(other);
-
-	if (sock_flag(other, SOCK_DEAD) ||
-	    other->sk_shutdown & RCV_SHUTDOWN) {
-		err = -EPIPE;
-		send_sigpipe = true;
-		goto err_state_unlock;
-	}
-
-	if (init_scm) {
-		err = maybe_init_creds(&scm, socket, other);
-		if (err)
-			goto err_state_unlock;
-		init_scm = false;
-	}
-
-	skb = skb_peek_tail(&other->sk_receive_queue);
-	if (tail && tail == skb) {
-		skb = newskb;
-	} else if (!skb || !unix_skb_scm_eq(skb, &scm)) {
-		if (newskb) {
-			skb = newskb;
-		} else {
-			tail = skb;
-			goto alloc_skb;
-		}
-	} else if (newskb) {
-		/* this is fast path, we don't necessarily need to
-		 * call to kfree_skb even though with newskb == NULL
-		 * this - does no harm
-		 */
-		consume_skb(newskb);
-		newskb = NULL;
-	}
-
-	if (skb_append_pagefrags(skb, page, offset, size)) {
-		tail = skb;
-		goto alloc_skb;
-	}
-
-	skb->len += size;
-	skb->data_len += size;
-	skb->truesize += size;
-	refcount_add(size, &sk->sk_wmem_alloc);
-
-	if (newskb) {
-		err = unix_scm_to_skb(&scm, skb, false);
-		if (err)
-			goto err_state_unlock;
-		spin_lock(&other->sk_receive_queue.lock);
-		__skb_queue_tail(&other->sk_receive_queue, newskb);
-		spin_unlock(&other->sk_receive_queue.lock);
-	}
-
-	unix_state_unlock(other);
-	mutex_unlock(&unix_sk(other)->iolock);
-
-	other->sk_data_ready(other);
-	scm_destroy(&scm);
-	return size;
-
-err_state_unlock:
-	unix_state_unlock(other);
-err_unlock:
-	mutex_unlock(&unix_sk(other)->iolock);
-err:
-	kfree_skb(newskb);
-	if (send_sigpipe && !(flags & MSG_NOSIGNAL))
-		send_sig(SIGPIPE, current, 0);
-	if (!init_scm)
-		scm_destroy(&scm);
-	return err;
-}
-
 static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg,
 				  size_t len)
 {
@@ -2526,7 +2427,7 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
 	}
 	err = (flags & MSG_TRUNC) ? skb->len - skip : size;
 
-	scm_recv(sock, msg, &scm, flags);
+	scm_recv_unix(sock, msg, &scm, flags);
 
 out_free:
 	skb_free_datagram(sk, skb);
@@ -2553,7 +2454,7 @@ static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 {
 	struct unix_sock *u = unix_sk(sk);
 	struct sk_buff *skb;
-	int err, copied;
+	int err;
 
 	mutex_lock(&u->iolock);
 	skb = skb_recv_datagram(sk, MSG_DONTWAIT, &err);
@@ -2561,10 +2462,7 @@ static int unix_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 	if (!skb)
 		return err;
 
-	copied = recv_actor(sk, skb);
-	kfree_skb(skb);
-
-	return copied;
+	return recv_actor(sk, skb);
 }
 
 /*
@@ -2824,7 +2722,8 @@ unlock:
 			/* Never glue messages from different writers */
 			if (!unix_skb_scm_eq(skb, &scm))
 				break;
-		} else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
+		} else if (test_bit(SOCK_PASSCRED, &sock->flags) ||
+			   test_bit(SOCK_PASSPIDFD, &sock->flags)) {
 			/* Copy credentials */
 			scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
 			unix_set_secdata(&scm, skb);
@@ -2909,7 +2808,7 @@ unlock:
 
 	mutex_unlock(&u->iolock);
 	if (state->msg)
-		scm_recv(sock, state->msg, &scm, flags);
+		scm_recv_unix(sock, state->msg, &scm, flags);
 	else
 		scm_destroy(&scm);
 out: