1 files changed, 190 insertions, 113 deletions

diff --git a/net/can/isotp.c b/net/can/isotp.c
index d2a430b6a13b..f6f8ba1f816d 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -14,7 +14,6 @@
  * - use CAN_ISOTP_WAIT_TX_DONE flag to block the caller until the PDU is sent
  * - as we have static buffers the check whether the PDU fits into the buffer
  *   is done at FF reception time (no support for sending 'wait frames')
- * - take care of the tx-queue-len as traffic shaping is still on the TODO list
  *
  * Copyright (c) 2020 Volkswagen Group Electronic Research
  * All rights reserved.
@@ -87,9 +86,9 @@ MODULE_ALIAS("can-proto-6");
 /* ISO 15765-2:2016 supports more than 4095 byte per ISO PDU as the FF_DL can
  * take full 32 bit values (4 Gbyte). We would need some good concept to handle
  * this between user space and kernel space. For now increase the static buffer
- * to something about 8 kbyte to be able to test this new functionality.
+ * to something about 64 kbyte to be able to test this new functionality.
  */
-#define MAX_MSG_LENGTH 8200
+#define MAX_MSG_LENGTH 66000
 
 /* N_PCI type values in bits 7-4 of N_PCI bytes */
 #define N_PCI_SF 0x00	/* single frame */
@@ -141,8 +140,10 @@ struct isotp_sock {
 	struct can_isotp_options opt;
 	struct can_isotp_fc_options rxfc, txfc;
 	struct can_isotp_ll_options ll;
+	u32 frame_txtime;
 	u32 force_tx_stmin;
 	u32 force_rx_stmin;
+	u32 cfecho; /* consecutive frame echo tag */
 	struct tpcon rx, tx;
 	struct list_head notifier;
 	wait_queue_head_t wait;
@@ -360,7 +361,7 @@ static int isotp_rcv_fc(struct isotp_sock *so, struct canfd_frame *cf, int ae)
 
 		so->tx_gap = ktime_set(0, 0);
 		/* add transmission time for CAN frame N_As */
-		so->tx_gap = ktime_add_ns(so->tx_gap, so->opt.frame_txtime);
+		so->tx_gap = ktime_add_ns(so->tx_gap, so->frame_txtime);
 		/* add waiting time for consecutive frames N_Cs */
 		if (so->opt.flags & CAN_ISOTP_FORCE_TXSTMIN)
 			so->tx_gap = ktime_add_ns(so->tx_gap,
@@ -712,6 +713,63 @@ static void isotp_fill_dataframe(struct canfd_frame *cf, struct isotp_sock *so,
 		cf->data[0] = so->opt.ext_address;
 }
 
+static void isotp_send_cframe(struct isotp_sock *so)
+{
+	struct sock *sk = &so->sk;
+	struct sk_buff *skb;
+	struct net_device *dev;
+	struct canfd_frame *cf;
+	int can_send_ret;
+	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
+
+	dev = dev_get_by_index(sock_net(sk), so->ifindex);
+	if (!dev)
+		return;
+
+	skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv), GFP_ATOMIC);
+	if (!skb) {
+		dev_put(dev);
+		return;
+	}
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+
+	cf = (struct canfd_frame *)skb->data;
+	skb_put_zero(skb, so->ll.mtu);
+
+	/* create consecutive frame */
+	isotp_fill_dataframe(cf, so, ae, 0);
+
+	/* place consecutive frame N_PCI in appropriate index */
+	cf->data[ae] = N_PCI_CF | so->tx.sn++;
+	so->tx.sn %= 16;
+	so->tx.bs++;
+
+	cf->flags = so->ll.tx_flags;
+
+	skb->dev = dev;
+	can_skb_set_owner(skb, sk);
+
+	/* cfecho should have been zero'ed by init/isotp_rcv_echo() */
+	if (so->cfecho)
+		pr_notice_once("can-isotp: cfecho is %08X != 0\n", so->cfecho);
+
+	/* set consecutive frame echo tag */
+	so->cfecho = *(u32 *)cf->data;
+
+	/* send frame with local echo enabled */
+	can_send_ret = can_send(skb, 1);
+	if (can_send_ret) {
+		pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
+			       __func__, ERR_PTR(can_send_ret));
+		if (can_send_ret == -ENOBUFS)
+			pr_notice_once("can-isotp: tx queue is full\n");
+	}
+	dev_put(dev);
+}
+
 static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
 				int ae)
 {
@@ -748,19 +806,74 @@ static void isotp_create_fframe(struct canfd_frame *cf, struct isotp_sock *so,
 	so->tx.state = ISOTP_WAIT_FIRST_FC;
 }
 
+static void isotp_rcv_echo(struct sk_buff *skb, void *data)
+{
+	struct sock *sk = (struct sock *)data;
+	struct isotp_sock *so = isotp_sk(sk);
+	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+
+	/* only handle my own local echo skb's */
+	if (skb->sk != sk || so->cfecho != *(u32 *)cf->data)
+		return;
+
+	/* cancel local echo timeout */
+	hrtimer_cancel(&so->txtimer);
+
+	/* local echo skb with consecutive frame has been consumed */
+	so->cfecho = 0;
+
+	if (so->tx.idx >= so->tx.len) {
+		/* we are done */
+		so->tx.state = ISOTP_IDLE;
+		wake_up_interruptible(&so->wait);
+		return;
+	}
+
+	if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
+		/* stop and wait for FC with timeout */
+		so->tx.state = ISOTP_WAIT_FC;
+		hrtimer_start(&so->txtimer, ktime_set(1, 0),
+			      HRTIMER_MODE_REL_SOFT);
+		return;
+	}
+
+	/* no gap between data frames needed => use burst mode */
+	if (!so->tx_gap) {
+		isotp_send_cframe(so);
+		return;
+	}
+
+	/* start timer to send next consecutive frame with correct delay */
+	hrtimer_start(&so->txtimer, so->tx_gap, HRTIMER_MODE_REL_SOFT);
+}
+
 static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
 {
 	struct isotp_sock *so = container_of(hrtimer, struct isotp_sock,
 					     txtimer);
 	struct sock *sk = &so->sk;
-	struct sk_buff *skb;
-	struct net_device *dev;
-	struct canfd_frame *cf;
 	enum hrtimer_restart restart = HRTIMER_NORESTART;
-	int can_send_ret;
-	int ae = (so->opt.flags & CAN_ISOTP_EXTEND_ADDR) ? 1 : 0;
 
 	switch (so->tx.state) {
+	case ISOTP_SENDING:
+
+		/* cfecho should be consumed by isotp_rcv_echo() here */
+		if (!so->cfecho) {
+			/* start timeout for unlikely lost echo skb */
+			hrtimer_set_expires(&so->txtimer,
+					    ktime_add(ktime_get(),
+						      ktime_set(2, 0)));
+			restart = HRTIMER_RESTART;
+
+			/* push out the next consecutive frame */
+			isotp_send_cframe(so);
+			break;
+		}
+
+		/* cfecho has not been cleared in isotp_rcv_echo() */
+		pr_notice_once("can-isotp: cfecho %08X timeout\n", so->cfecho);
+		fallthrough;
+
 	case ISOTP_WAIT_FC:
 	case ISOTP_WAIT_FIRST_FC:
 
@@ -776,78 +889,6 @@ static enum hrtimer_restart isotp_tx_timer_handler(struct hrtimer *hrtimer)
 		wake_up_interruptible(&so->wait);
 		break;
 
-	case ISOTP_SENDING:
-
-		/* push out the next segmented pdu */
-		dev = dev_get_by_index(sock_net(sk), so->ifindex);
-		if (!dev)
-			break;
-
-isotp_tx_burst:
-		skb = alloc_skb(so->ll.mtu + sizeof(struct can_skb_priv),
-				GFP_ATOMIC);
-		if (!skb) {
-			dev_put(dev);
-			break;
-		}
-
-		can_skb_reserve(skb);
-		can_skb_prv(skb)->ifindex = dev->ifindex;
-		can_skb_prv(skb)->skbcnt = 0;
-
-		cf = (struct canfd_frame *)skb->data;
-		skb_put_zero(skb, so->ll.mtu);
-
-		/* create consecutive frame */
-		isotp_fill_dataframe(cf, so, ae, 0);
-
-		/* place consecutive frame N_PCI in appropriate index */
-		cf->data[ae] = N_PCI_CF | so->tx.sn++;
-		so->tx.sn %= 16;
-		so->tx.bs++;
-
-		cf->flags = so->ll.tx_flags;
-
-		skb->dev = dev;
-		can_skb_set_owner(skb, sk);
-
-		can_send_ret = can_send(skb, 1);
-		if (can_send_ret) {
-			pr_notice_once("can-isotp: %s: can_send_ret %pe\n",
-				       __func__, ERR_PTR(can_send_ret));
-			if (can_send_ret == -ENOBUFS)
-				pr_notice_once("can-isotp: tx queue is full, increasing txqueuelen may prevent this error\n");
-		}
-		if (so->tx.idx >= so->tx.len) {
-			/* we are done */
-			so->tx.state = ISOTP_IDLE;
-			dev_put(dev);
-			wake_up_interruptible(&so->wait);
-			break;
-		}
-
-		if (so->txfc.bs && so->tx.bs >= so->txfc.bs) {
-			/* stop and wait for FC */
-			so->tx.state = ISOTP_WAIT_FC;
-			dev_put(dev);
-			hrtimer_set_expires(&so->txtimer,
-					    ktime_add(ktime_get(),
-						      ktime_set(1, 0)));
-			restart = HRTIMER_RESTART;
-			break;
-		}
-
-		/* no gap between data frames needed => use burst mode */
-		if (!so->tx_gap)
-			goto isotp_tx_burst;
-
-		/* start timer to send next data frame with correct delay */
-		dev_put(dev);
-		hrtimer_set_expires(&so->txtimer,
-				    ktime_add(ktime_get(), so->tx_gap));
-		restart = HRTIMER_RESTART;
-		break;
-
 	default:
 		WARN_ON_ONCE(1);
 	}
@@ -1005,26 +1046,29 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 {
 	struct sock *sk = sock->sk;
 	struct sk_buff *skb;
-	int err = 0;
-	int noblock;
+	struct isotp_sock *so = isotp_sk(sk);
+	int noblock = flags & MSG_DONTWAIT;
+	int ret = 0;
 
-	noblock = flags & MSG_DONTWAIT;
-	flags &= ~MSG_DONTWAIT;
+	if (flags & ~(MSG_DONTWAIT | MSG_TRUNC))
+		return -EINVAL;
 
-	skb = skb_recv_datagram(sk, flags, noblock, &err);
+	if (!so->bound)
+		return -EADDRNOTAVAIL;
+
+	flags &= ~MSG_DONTWAIT;
+	skb = skb_recv_datagram(sk, flags, noblock, &ret);
 	if (!skb)
-		return err;
+		return ret;
 
 	if (size < skb->len)
 		msg->msg_flags |= MSG_TRUNC;
 	else
 		size = skb->len;
 
-	err = memcpy_to_msg(msg, skb->data, size);
-	if (err < 0) {
-		skb_free_datagram(sk, skb);
-		return err;
-	}
+	ret = memcpy_to_msg(msg, skb->data, size);
+	if (ret < 0)
+		goto out_err;
 
 	sock_recv_timestamp(msg, sk, skb);
 
@@ -1034,9 +1078,13 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		memcpy(msg->msg_name, skb->cb, msg->msg_namelen);
 	}
 
+	/* set length of return value */
+	ret = (flags & MSG_TRUNC) ? skb->len : size;
+
+out_err:
 	skb_free_datagram(sk, skb);
 
-	return size;
+	return ret;
 }
 
 static int isotp_release(struct socket *sock)
@@ -1075,6 +1123,9 @@ static int isotp_release(struct socket *sock)
 				can_rx_unregister(net, dev, so->rxid,
 						  SINGLE_MASK(so->rxid),
 						  isotp_rcv, sk);
+				can_rx_unregister(net, dev, so->txid,
+						  SINGLE_MASK(so->txid),
+						  isotp_rcv_echo, sk);
 				dev_put(dev);
 				synchronize_rcu();
 			}
@@ -1104,6 +1155,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	struct net *net = sock_net(sk);
 	int ifindex;
 	struct net_device *dev;
+	canid_t tx_id, rx_id;
 	int err = 0;
 	int notify_enetdown = 0;
 	int do_rx_reg = 1;
@@ -1111,8 +1163,18 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 	if (len < ISOTP_MIN_NAMELEN)
 		return -EINVAL;
 
-	if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
-		return -EADDRNOTAVAIL;
+	/* sanitize tx/rx CAN identifiers */
+	tx_id = addr->can_addr.tp.tx_id;
+	if (tx_id & CAN_EFF_FLAG)
+		tx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+	else
+		tx_id &= CAN_SFF_MASK;
+
+	rx_id = addr->can_addr.tp.rx_id;
+	if (rx_id & CAN_EFF_FLAG)
+		rx_id &= (CAN_EFF_FLAG | CAN_EFF_MASK);
+	else
+		rx_id &= CAN_SFF_MASK;
 
 	if (!addr->can_ifindex)
 		return -ENODEV;
@@ -1124,21 +1186,13 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 		do_rx_reg = 0;
 
 	/* do not validate rx address for functional addressing */
-	if (do_rx_reg) {
-		if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id) {
-			err = -EADDRNOTAVAIL;
-			goto out;
-		}
-
-		if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG)) {
-			err = -EADDRNOTAVAIL;
-			goto out;
-		}
+	if (do_rx_reg && rx_id == tx_id) {
+		err = -EADDRNOTAVAIL;
+		goto out;
 	}
 
 	if (so->bound && addr->can_ifindex == so->ifindex &&
-	    addr->can_addr.tp.rx_id == so->rxid &&
-	    addr->can_addr.tp.tx_id == so->txid)
+	    rx_id == so->rxid && tx_id == so->txid)
 		goto out;
 
 	dev = dev_get_by_index(net, addr->can_ifindex);
@@ -1161,11 +1215,18 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 
 	ifindex = dev->ifindex;
 
-	if (do_rx_reg)
-		can_rx_register(net, dev, addr->can_addr.tp.rx_id,
-				SINGLE_MASK(addr->can_addr.tp.rx_id),
+	if (do_rx_reg) {
+		can_rx_register(net, dev, rx_id, SINGLE_MASK(rx_id),
 				isotp_rcv, sk, "isotp", sk);
 
+		/* no consecutive frame echo skb in flight */
+		so->cfecho = 0;
+
+		/* register for echo skb's */
+		can_rx_register(net, dev, tx_id, SINGLE_MASK(tx_id),
+				isotp_rcv_echo, sk, "isotpe", sk);
+	}
+
 	dev_put(dev);
 
 	if (so->bound && do_rx_reg) {
@@ -1176,6 +1237,9 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 				can_rx_unregister(net, dev, so->rxid,
 						  SINGLE_MASK(so->rxid),
 						  isotp_rcv, sk);
+				can_rx_unregister(net, dev, so->txid,
+						  SINGLE_MASK(so->txid),
+						  isotp_rcv_echo, sk);
 				dev_put(dev);
 			}
 		}
@@ -1183,8 +1247,8 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 
 	/* switch to new settings */
 	so->ifindex = ifindex;
-	so->rxid = addr->can_addr.tp.rx_id;
-	so->txid = addr->can_addr.tp.tx_id;
+	so->rxid = rx_id;
+	so->txid = tx_id;
 	so->bound = 1;
 
 out:
@@ -1238,6 +1302,14 @@ static int isotp_setsockopt_locked(struct socket *sock, int level, int optname,
 		/* no separate rx_ext_address is given => use ext_address */
 		if (!(so->opt.flags & CAN_ISOTP_RX_EXT_ADDR))
 			so->opt.rx_ext_address = so->opt.ext_address;
+
+		/* check for frame_txtime changes (0 => no changes) */
+		if (so->opt.frame_txtime) {
+			if (so->opt.frame_txtime == CAN_ISOTP_FRAME_TXTIME_ZERO)
+				so->frame_txtime = 0;
+			else
+				so->frame_txtime = so->opt.frame_txtime;
+		}
 		break;
 
 	case CAN_ISOTP_RECV_FC:
@@ -1381,10 +1453,14 @@ static void isotp_notify(struct isotp_sock *so, unsigned long msg,
 	case NETDEV_UNREGISTER:
 		lock_sock(sk);
 		/* remove current filters & unregister */
-		if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST)))
+		if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) {
 			can_rx_unregister(dev_net(dev), dev, so->rxid,
 					  SINGLE_MASK(so->rxid),
 					  isotp_rcv, sk);
+			can_rx_unregister(dev_net(dev), dev, so->txid,
+					  SINGLE_MASK(so->txid),
+					  isotp_rcv_echo, sk);
+		}
 
 		so->ifindex = 0;
 		so->bound  = 0;
@@ -1439,6 +1515,7 @@ static int isotp_init(struct sock *sk)
 	so->opt.rxpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
 	so->opt.txpad_content = CAN_ISOTP_DEFAULT_PAD_CONTENT;
 	so->opt.frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
+	so->frame_txtime = CAN_ISOTP_DEFAULT_FRAME_TXTIME;
 	so->rxfc.bs = CAN_ISOTP_DEFAULT_RECV_BS;
 	so->rxfc.stmin = CAN_ISOTP_DEFAULT_RECV_STMIN;
 	so->rxfc.wftmax = CAN_ISOTP_DEFAULT_RECV_WFTMAX;