diff options
author | Scott McMillan <scott.a.mcmillan@intel.com> | 2010-06-02 12:53:56 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2010-06-02 12:53:56 (GMT) |
commit | 614f60fa9d73a9e8fdff3df83381907fea7c5649 (patch) | |
tree | a1b7704393b7042242470db09d59944bca67ec51 | |
parent | 7dad171c39dc83bd267c4f98d8b02d38e0d65596 (diff) | |
download | linux-614f60fa9d73a9e8fdff3df83381907fea7c5649.tar.xz |
packet_mmap: expose hw packet timestamps to network packet capture utilities
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>
-rw-r--r-- | Documentation/networking/packet_mmap.txt | 26 | ||||
-rw-r--r-- | include/linux/if_packet.h | 1 | ||||
-rw-r--r-- | net/packet/af_packet.c | 37 |
3 files changed, 62 insertions, 2 deletions
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index 98f71a5..2546aa4 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt @@ -493,6 +493,32 @@ The user can also use poll() to check if a buffer is available: pfd.events = POLLOUT; retval = poll(&pfd, 1, timeout); +------------------------------------------------------------------------------- ++ PACKET_TIMESTAMP +------------------------------------------------------------------------------- + +The PACKET_TIMESTAMP setting determines the source of the timestamp in +the packet meta information. If your NIC is capable of timestamping +packets in hardware, you can request those hardware timestamps to used. +Note: you may need to enable the generation of hardware timestamps with +SIOCSHWTSTAMP. + +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 recognized by +PACKET_TIMESTAMP. SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over +SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set. + + int req = 0; + req |= SOF_TIMESTAMPING_SYS_HARDWARE; + setsockopt(fd, SOL_PACKET, PACKET_TIMESTAMP, (void *) &req, sizeof(req)) + +If PACKET_TIMESTAMP is not set, a software timestamp generated inside +the networking stack is used (the behavior before this setting was added). + +See include/linux/net_tstamp.h and Documentation/networking/timestamping +for more information on hardware timestamps. + -------------------------------------------------------------------------------- + THANKS -------------------------------------------------------------------------------- diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h index 6ac23ef..72bfa5a 100644 --- a/include/linux/if_packet.h +++ b/include/linux/if_packet.h @@ -48,6 +48,7 @@ struct sockaddr_ll { #define PACKET_LOSS 14 #define PACKET_VNET_HDR 15 #define PACKET_TX_TIMESTAMP 16 +#define PACKET_TIMESTAMP 17 struct tpacket_stats { unsigned int tp_packets; diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 2078a27..9a17f28 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -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; } |