From d3b58c47d330de8c29898fe9746f7530408f8a59 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Fri, 26 Jun 2015 11:58:19 +0200 Subject: can: replace timestamp as unique skb attribute Commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for overlapping CAN filters" requires the skb->tstamp to be set to check for identical CAN skbs. Without timestamping to be required by user space applications this timestamp was not generated which lead to commit 36c01245eb8 "can: fix loss of CAN frames in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs by introducing several __net_timestamp() calls. This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb() to add __net_timestamp() after skbuff creation to prevent the frame loss fixed in mainline Linux. This patch removes the timestamp dependency and uses an atomic counter to create an unique identifier together with the skbuff pointer. Btw: the new skbcnt element introduced in struct can_skb_priv has to be initialized with zero in out-of-tree drivers which are not using alloc_can{,fd}_skb() too. Signed-off-by: Oliver Hartkopp Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- net/can/af_can.c | 12 +++++++----- net/can/bcm.c | 2 ++ net/can/raw.c | 7 ++++--- 3 files changed, 13 insertions(+), 8 deletions(-) (limited to 'net') diff --git a/net/can/af_can.c b/net/can/af_can.c index 7933e62..166d436 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -89,6 +89,8 @@ struct timer_list can_stattimer; /* timer for statistics update */ struct s_stats can_stats; /* packet statistics */ struct s_pstats can_pstats; /* receive list statistics */ +static atomic_t skbcounter = ATOMIC_INIT(0); + /* * af_can socket functions */ @@ -310,12 +312,8 @@ int can_send(struct sk_buff *skb, int loop) return err; } - if (newskb) { - if (!(newskb->tstamp.tv64)) - __net_timestamp(newskb); - + if (newskb) netif_rx_ni(newskb); - } /* update statistics */ can_stats.tx_frames++; @@ -683,6 +681,10 @@ static void can_receive(struct sk_buff *skb, struct net_device *dev) can_stats.rx_frames++; can_stats.rx_frames_delta++; + /* create non-zero unique skb identifier together with *skb */ + while (!(can_skb_prv(skb)->skbcnt)) + can_skb_prv(skb)->skbcnt = atomic_inc_return(&skbcounter); + rcu_read_lock(); /* deliver the packet to sockets listening on all devices */ diff --git a/net/can/bcm.c b/net/can/bcm.c index b523453..a1ba687 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -261,6 +261,7 @@ static void bcm_can_tx(struct bcm_op *op) can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; + can_skb_prv(skb)->skbcnt = 0; memcpy(skb_put(skb, CFSIZ), cf, CFSIZ); @@ -1217,6 +1218,7 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk) } can_skb_prv(skb)->ifindex = dev->ifindex; + can_skb_prv(skb)->skbcnt = 0; skb->dev = dev; can_skb_set_owner(skb, sk); err = can_send(skb, 1); /* send with loopback */ diff --git a/net/can/raw.c b/net/can/raw.c index 31b9748..2e67b14 100644 --- a/net/can/raw.c +++ b/net/can/raw.c @@ -75,7 +75,7 @@ MODULE_ALIAS("can-proto-1"); */ struct uniqframe { - ktime_t tstamp; + int skbcnt; const struct sk_buff *skb; unsigned int join_rx_count; }; @@ -133,7 +133,7 @@ static void raw_rcv(struct sk_buff *oskb, void *data) /* eliminate multiple filter matches for the same skb */ if (this_cpu_ptr(ro->uniq)->skb == oskb && - ktime_equal(this_cpu_ptr(ro->uniq)->tstamp, oskb->tstamp)) { + this_cpu_ptr(ro->uniq)->skbcnt == can_skb_prv(oskb)->skbcnt) { if (ro->join_filters) { this_cpu_inc(ro->uniq->join_rx_count); /* drop frame until all enabled filters matched */ @@ -144,7 +144,7 @@ static void raw_rcv(struct sk_buff *oskb, void *data) } } else { this_cpu_ptr(ro->uniq)->skb = oskb; - this_cpu_ptr(ro->uniq)->tstamp = oskb->tstamp; + this_cpu_ptr(ro->uniq)->skbcnt = can_skb_prv(oskb)->skbcnt; this_cpu_ptr(ro->uniq)->join_rx_count = 1; /* drop first frame to check all enabled filters? */ if (ro->join_filters && ro->count > 1) @@ -749,6 +749,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size) can_skb_reserve(skb); can_skb_prv(skb)->ifindex = dev->ifindex; + can_skb_prv(skb)->skbcnt = 0; err = memcpy_from_msg(skb_put(skb, size), msg, size); if (err < 0) -- cgit v1.1