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authorMaciej W. Rozycki <macro@linux-mips.org>2018-10-09 23:57:49 +0100
committerDavid S. Miller <davem@davemloft.net>2018-10-15 21:46:06 -0700
commit9f9a742db40f95f4dc20fc7293de4ea6ddb24e47 (patch)
tree5cbd5bcf3514e362f9f42275961b4880deb92fac /net/core
parent61414f5ec9834df8aa4f55c90de16b71a3d6ca8d (diff)
FDDI: defza: Support capturing outgoing SMT traffic
DEC FDDIcontroller 700 (DEFZA) uses a Tx/Rx queue pair to communicate SMT frames with adapter's firmware. Any SMT frame received from the RMC via the Rx queue is queued back by the driver to the SMT Rx queue for the firmware to process. Similarly the firmware uses the SMT Tx queue to supply the driver with SMT frames which are queued back to the Tx queue for the RMC to send to the ring. When a network tap is attached to an FDDI interface handled by `defza' any incoming SMT frames captured are queued to our usual processing of network data received, which in turn delivers them to any listening taps. However the outgoing SMT frames produced by the firmware bypass our network protocol stack and are therefore not delivered to taps. This in turn means that taps are missing a part of network traffic sent by the adapter, which may make it more difficult to track down network problems or do general traffic analysis. Call `dev_queue_xmit_nit' then in the SMT Tx path, having checked that a network tap is attached, with a newly-created `dev_nit_active' helper wrapping the usual condition used in the transmit path. Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c13
1 files changed, 12 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index a4d39b87b4e5..8497feea8fb5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1976,6 +1976,17 @@ static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
return false;
}
+/**
+ * dev_nit_active - return true if any network interface taps are in use
+ *
+ * @dev: network device to check for the presence of taps
+ */
+bool dev_nit_active(struct net_device *dev)
+{
+ return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
+}
+EXPORT_SYMBOL_GPL(dev_nit_active);
+
/*
* Support routine. Sends outgoing frames to any network
* taps currently in use.
@@ -3233,7 +3244,7 @@ static int xmit_one(struct sk_buff *skb, struct net_device *dev,
unsigned int len;
int rc;
- if (!list_empty(&ptype_all) || !list_empty(&dev->ptype_all))
+ if (dev_nit_active(dev))
dev_queue_xmit_nit(skb, dev);
len = skb->len;