Merge branch 'for-davem' of git://gitorious.org/linux-can/linux-can-next

Marc Kleine-Budde says:

====================
this is a pull-request for net-next/master. There is are 9 patches by
Fabio Baltieri and Kurt Van Dijck which add LED infrastructure and
support for CAN devices. Bernd Krumboeck adds a driver for the USB CAN
adapter from 8 devices. Oliver Hartkopp improves the CAN gateway
functionality. There are 4 patches by me, which clean up the CAN's
Kconfig.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 80 insertions, 27 deletions

diff --git a/net/can/Kconfig b/net/can/Kconfig
index 03200699d274..a15c0e0d1fc7 100644
--- a/net/can/Kconfig
+++ b/net/can/Kconfig
@@ -16,10 +16,11 @@ menuconfig CAN
 	  If you want CAN support you should say Y here and also to the
 	  specific driver for your controller(s) below.
 
+if CAN
+
 config CAN_RAW
 	tristate "Raw CAN Protocol (raw access with CAN-ID filtering)"
-	depends on CAN
-	default N
+	default y
 	---help---
 	  The raw CAN protocol option offers access to the CAN bus via
 	  the BSD socket API. You probably want to use the raw socket in
@@ -29,8 +30,7 @@ config CAN_RAW
 
 config CAN_BCM
 	tristate "Broadcast Manager CAN Protocol (with content filtering)"
-	depends on CAN
-	default N
+	default y
 	---help---
 	  The Broadcast Manager offers content filtering, timeout monitoring,
 	  sending of RTR frames, and cyclic CAN messages without permanent user
@@ -42,8 +42,7 @@ config CAN_BCM
 
 config CAN_GW
 	tristate "CAN Gateway/Router (with netlink configuration)"
-	depends on CAN
-	default N
+	default y
 	---help---
 	  The CAN Gateway/Router is used to route (and modify) CAN frames.
 	  It is based on the PF_CAN core infrastructure for msg filtering and
@@ -53,3 +52,5 @@ config CAN_GW
 	  by the netlink configuration interface known e.g. from iptables.
 
 source "drivers/net/can/Kconfig"
+
+endif
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 969b7cdff59d..ccc27b9e8384 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -54,6 +54,7 @@
 #include <linux/skbuff.h>
 #include <linux/can.h>
 #include <linux/can/core.h>
+#include <linux/can/skb.h>
 #include <linux/can/bcm.h>
 #include <linux/slab.h>
 #include <net/sock.h>
@@ -256,10 +257,13 @@ static void bcm_can_tx(struct bcm_op *op)
 		return;
 	}
 
-	skb = alloc_skb(CFSIZ, gfp_any());
+	skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), gfp_any());
 	if (!skb)
 		goto out;
 
+	skb_reserve(skb, sizeof(struct can_skb_priv));
+	((struct can_skb_priv *)(skb->head))->ifindex = dev->ifindex;
+
 	memcpy(skb_put(skb, CFSIZ), cf, CFSIZ);
 
 	/* send with loopback */
@@ -1199,11 +1203,12 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
 	if (!ifindex)
 		return -ENODEV;
 
-	skb = alloc_skb(CFSIZ, GFP_KERNEL);
-
+	skb = alloc_skb(CFSIZ + sizeof(struct can_skb_priv), GFP_KERNEL);
 	if (!skb)
 		return -ENOMEM;
 
+	skb_reserve(skb, sizeof(struct can_skb_priv));
+
 	err = memcpy_fromiovec(skb_put(skb, CFSIZ), msg->msg_iov, CFSIZ);
 	if (err < 0) {
 		kfree_skb(skb);
@@ -1216,6 +1221,7 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk)
 		return -ENODEV;
 	}
 
+	((struct can_skb_priv *)(skb->head))->ifindex = dev->ifindex;
 	skb->dev = dev;
 	skb->sk  = sk;
 	err = can_send(skb, 1); /* send with loopback */
diff --git a/net/can/gw.c b/net/can/gw.c
index 574dda78eb0f..acdd4656cc3b 100644
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -42,6 +42,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
+#include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/rcupdate.h>
@@ -52,19 +53,31 @@
 #include <linux/skbuff.h>
 #include <linux/can.h>
 #include <linux/can/core.h>
+#include <linux/can/skb.h>
 #include <linux/can/gw.h>
 #include <net/rtnetlink.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
 
-#define CAN_GW_VERSION "20101209"
-static __initconst const char banner[] =
-	KERN_INFO "can: netlink gateway (rev " CAN_GW_VERSION ")\n";
+#define CAN_GW_VERSION "20130117"
+#define CAN_GW_NAME "can-gw"
 
 MODULE_DESCRIPTION("PF_CAN netlink gateway");
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
-MODULE_ALIAS("can-gw");
+MODULE_ALIAS(CAN_GW_NAME);
+
+#define CGW_MIN_HOPS 1
+#define CGW_MAX_HOPS 6
+#define CGW_DEFAULT_HOPS 1
+
+static unsigned int max_hops __read_mostly = CGW_DEFAULT_HOPS;
+module_param(max_hops, uint, S_IRUGO);
+MODULE_PARM_DESC(max_hops,
+		 "maximum " CAN_GW_NAME " routing hops for CAN frames "
+		 "(valid values: " __stringify(CGW_MIN_HOPS) "-"
+		 __stringify(CGW_MAX_HOPS) " hops, "
+		 "default: " __stringify(CGW_DEFAULT_HOPS) ")");
 
 static HLIST_HEAD(cgw_list);
 static struct notifier_block notifier;
@@ -118,6 +131,7 @@ struct cgw_job {
 	struct rcu_head rcu;
 	u32 handled_frames;
 	u32 dropped_frames;
+	u32 deleted_frames;
 	struct cf_mod mod;
 	union {
 		/* CAN frame data source */
@@ -338,15 +352,40 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
 	struct sk_buff *nskb;
 	int modidx = 0;
 
-	/* do not handle already routed frames - see comment below */
-	if (skb_mac_header_was_set(skb))
+	/*
+	 * Do not handle CAN frames routed more than 'max_hops' times.
+	 * In general we should never catch this delimiter which is intended
+	 * to cover a misconfiguration protection (e.g. circular CAN routes).
+	 *
+	 * The Controller Area Network controllers only accept CAN frames with
+	 * correct CRCs - which are not visible in the controller registers.
+	 * According to skbuff.h documentation the csum_start element for IP
+	 * checksums is undefined/unsued when ip_summed == CHECKSUM_UNNECESSARY.
+	 * Only CAN skbs can be processed here which already have this property.
+	 */
+
+#define cgw_hops(skb) ((skb)->csum_start)
+
+	BUG_ON(skb->ip_summed != CHECKSUM_UNNECESSARY);
+
+	if (cgw_hops(skb) >= max_hops) {
+		/* indicate deleted frames due to misconfiguration */
+		gwj->deleted_frames++;
 		return;
+	}
 
 	if (!(gwj->dst.dev->flags & IFF_UP)) {
 		gwj->dropped_frames++;
 		return;
 	}
 
+	/* is sending the skb back to the incoming interface not allowed? */
+	if (!(gwj->flags & CGW_FLAGS_CAN_IIF_TX_OK) &&
+	    skb_headroom(skb) == sizeof(struct can_skb_priv) &&
+	    (((struct can_skb_priv *)(skb->head))->ifindex ==
+	     gwj->dst.dev->ifindex))
+		return;
+
 	/*
 	 * clone the given skb, which has not been done in can_rcv()
 	 *
@@ -363,15 +402,8 @@ static void can_can_gw_rcv(struct sk_buff *skb, void *data)
 		return;
 	}
 
-	/*
-	 * Mark routed frames by setting some mac header length which is
-	 * not relevant for the CAN frames located in the skb->data section.
-	 *
-	 * As dev->header_ops is not set in CAN netdevices no one is ever
-	 * accessing the various header offsets in the CAN skbuffs anyway.
-	 * E.g. using the packet socket to read CAN frames is still working.
-	 */
-	skb_set_mac_header(nskb, 8);
+	/* put the incremented hop counter in the cloned skb */
+	cgw_hops(nskb) = cgw_hops(skb) + 1;
 	nskb->dev = gwj->dst.dev;
 
 	/* pointer to modifiable CAN frame */
@@ -472,6 +504,11 @@ static int cgw_put_job(struct sk_buff *skb, struct cgw_job *gwj, int type,
 			goto cancel;
 	}
 
+	if (gwj->deleted_frames) {
+		if (nla_put_u32(skb, CGW_DELETED, gwj->deleted_frames) < 0)
+			goto cancel;
+	}
+
 	/* check non default settings of attributes */
 
 	if (gwj->mod.modtype.and) {
@@ -771,6 +808,7 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh,
 
 	gwj->handled_frames = 0;
 	gwj->dropped_frames = 0;
+	gwj->deleted_frames = 0;
 	gwj->flags = r->flags;
 	gwj->gwtype = r->gwtype;
 
@@ -895,7 +933,11 @@ static int cgw_remove_job(struct sk_buff *skb,  struct nlmsghdr *nlh, void *arg)
 
 static __init int cgw_module_init(void)
 {
-	printk(banner);
+	/* sanitize given module parameter */
+	max_hops = clamp_t(unsigned int, max_hops, CGW_MIN_HOPS, CGW_MAX_HOPS);
+
+	pr_info("can: netlink gateway (rev " CAN_GW_VERSION ") max_hops=%d\n",
+		max_hops);
 
 	cgw_cache = kmem_cache_create("can_gw", sizeof(struct cgw_job),
 				      0, 0, NULL);
diff --git a/net/can/raw.c b/net/can/raw.c
index 5b0e3e330d97..5d860e8dcc52 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -50,6 +50,7 @@
 #include <linux/skbuff.h>
 #include <linux/can.h>
 #include <linux/can/core.h>
+#include <linux/can/skb.h>
 #include <linux/can/raw.h>
 #include <net/sock.h>
 #include <net/net_namespace.h>
@@ -699,11 +700,14 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 	if (!dev)
 		return -ENXIO;
 
-	skb = sock_alloc_send_skb(sk, size, msg->msg_flags & MSG_DONTWAIT,
-				  &err);
+	skb = sock_alloc_send_skb(sk, size + sizeof(struct can_skb_priv),
+				  msg->msg_flags & MSG_DONTWAIT, &err);
 	if (!skb)
 		goto put_dev;
 
+	skb_reserve(skb, sizeof(struct can_skb_priv));
+	((struct can_skb_priv *)(skb->head))->ifindex = dev->ifindex;
+
 	err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 	if (err < 0)
 		goto free_skb;