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packet_mmap: expose hw packet timestamps to network packet capture utilities

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This patch adds a setting, PACKET_TIMESTAMP, to specify the packet
timestamp source that is exported to capture utilities like tcpdump by
packet_mmap.

PACKET_TIMESTAMP accepts the same integer bit field as
SO_TIMESTAMPING.  However, only the SOF_TIMESTAMPING_SYS_HARDWARE and
SOF_TIMESTAMPING_RAW_HARDWARE values are currently recognized by
PACKET_TIMESTAMP.  SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over
SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set.

If PACKET_TIMESTAMP is not set, a software timestamp generated inside
the networking stack is used (the behavior before this setting was
added).

Signed-off-by: Scott McMillan <scott.a.mcmillan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Scott McMillan
2010-06-02 05:53:56 -07:00
committed by David S. Miller
parent 7dad171c39
commit 614f60fa9d
3 changed files with 62 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
net/packet/af_packet.c
View File

@@ -83,6 +83,7 @@
#include <linux/if_vlan.h>
#include <linux/virtio_net.h>
#include <linux/errqueue.h>
#include <linux/net_tstamp.h>
#ifdef CONFIG_INET
#include <net/inet_common.h>
@@ -202,6 +203,7 @@ struct packet_sock {
unsigned int tp_hdrlen;
unsigned int tp_reserve;
unsigned int tp_loss:1;
unsigned int tp_tstamp;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};
@@ -656,6 +658,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
struct sk_buff *copy_skb = NULL;
struct timeval tv;
struct timespec ts;
struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
if (skb->pkt_type == PACKET_LOOPBACK)
goto drop;
@@ -737,7 +740,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
h.h1->tp_snaplen = snaplen;
h.h1->tp_mac = macoff;
h.h1->tp_net = netoff;
if (skb->tstamp.tv64)
if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
&& shhwtstamps->syststamp.tv64)
tv = ktime_to_timeval(shhwtstamps->syststamp);
else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
&& shhwtstamps->hwtstamp.tv64)
tv = ktime_to_timeval(shhwtstamps->hwtstamp);
else if (skb->tstamp.tv64)
tv = ktime_to_timeval(skb->tstamp);
else
do_gettimeofday(&tv);
@@ -750,7 +759,13 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
h.h2->tp_snaplen = snaplen;
h.h2->tp_mac = macoff;
h.h2->tp_net = netoff;
if (skb->tstamp.tv64)
if ((po->tp_tstamp & SOF_TIMESTAMPING_SYS_HARDWARE)
&& shhwtstamps->syststamp.tv64)
ts = ktime_to_timespec(shhwtstamps->syststamp);
else if ((po->tp_tstamp & SOF_TIMESTAMPING_RAW_HARDWARE)
&& shhwtstamps->hwtstamp.tv64)
ts = ktime_to_timespec(shhwtstamps->hwtstamp);
else if (skb->tstamp.tv64)
ts = ktime_to_timespec(skb->tstamp);
else
getnstimeofday(&ts);
@@ -2027,6 +2042,18 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
po->has_vnet_hdr = !!val;
return 0;
}
case PACKET_TIMESTAMP:
{
int val;
if (optlen != sizeof(val))
return -EINVAL;
if (copy_from_user(&val, optval, sizeof(val)))
return -EFAULT;
po->tp_tstamp = val;
return 0;
}
default:
return -ENOPROTOOPT;
}
@@ -2119,6 +2146,12 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
val = po->tp_loss;
data = &val;
break;
case PACKET_TIMESTAMP:
if (len > sizeof(int))
len = sizeof(int);
val = po->tp_tstamp;
data = &val;
break;
default:
return -ENOPROTOOPT;
}