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;