From f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1 Mon Sep 17 00:00:00 2001 From: William Tu Date: Fri, 10 Jun 2016 11:49:33 -0700 Subject: openvswitch: Add packet truncation support. The patch adds a new OVS action, OVS_ACTION_ATTR_TRUNC, in order to truncate packets. A 'max_len' is added for setting up the maximum packet size, and a 'cutlen' field is to record the number of bytes to trim the packet when the packet is outputting to a port, or when the packet is sent to userspace. Signed-off-by: William Tu Cc: Pravin Shelar Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/datapath.c | 29 +++++++++++++++++------------ 1 file changed, 17 insertions(+), 12 deletions(-) (limited to 'net/openvswitch/datapath.c') diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 856bd8dba676..673934295333 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -137,10 +137,12 @@ EXPORT_SYMBOL_GPL(lockdep_ovsl_is_held); static struct vport *new_vport(const struct vport_parms *); static int queue_gso_packets(struct datapath *dp, struct sk_buff *, const struct sw_flow_key *, - const struct dp_upcall_info *); + const struct dp_upcall_info *, + uint32_t cutlen); static int queue_userspace_packet(struct datapath *dp, struct sk_buff *, const struct sw_flow_key *, - const struct dp_upcall_info *); + const struct dp_upcall_info *, + uint32_t cutlen); /* Must be called with rcu_read_lock. */ static struct datapath *get_dp_rcu(struct net *net, int dp_ifindex) @@ -275,7 +277,7 @@ void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key) upcall.cmd = OVS_PACKET_CMD_MISS; upcall.portid = ovs_vport_find_upcall_portid(p, skb); upcall.mru = OVS_CB(skb)->mru; - error = ovs_dp_upcall(dp, skb, key, &upcall); + error = ovs_dp_upcall(dp, skb, key, &upcall, 0); if (unlikely(error)) kfree_skb(skb); else @@ -300,7 +302,8 @@ out: int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb, const struct sw_flow_key *key, - const struct dp_upcall_info *upcall_info) + const struct dp_upcall_info *upcall_info, + uint32_t cutlen) { struct dp_stats_percpu *stats; int err; @@ -311,9 +314,9 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb, } if (!skb_is_gso(skb)) - err = queue_userspace_packet(dp, skb, key, upcall_info); + err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen); else - err = queue_gso_packets(dp, skb, key, upcall_info); + err = queue_gso_packets(dp, skb, key, upcall_info, cutlen); if (err) goto err; @@ -331,7 +334,8 @@ err: static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb, const struct sw_flow_key *key, - const struct dp_upcall_info *upcall_info) + const struct dp_upcall_info *upcall_info, + uint32_t cutlen) { unsigned short gso_type = skb_shinfo(skb)->gso_type; struct sw_flow_key later_key; @@ -360,7 +364,7 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb, if (gso_type & SKB_GSO_UDP && skb != segs) key = &later_key; - err = queue_userspace_packet(dp, skb, key, upcall_info); + err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen); if (err) break; @@ -416,7 +420,8 @@ static void pad_packet(struct datapath *dp, struct sk_buff *skb) static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, const struct sw_flow_key *key, - const struct dp_upcall_info *upcall_info) + const struct dp_upcall_info *upcall_info, + uint32_t cutlen) { struct ovs_header *upcall; struct sk_buff *nskb = NULL; @@ -461,7 +466,7 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, else hlen = skb->len; - len = upcall_msg_size(upcall_info, hlen); + len = upcall_msg_size(upcall_info, hlen - cutlen); user_skb = genlmsg_new(len, GFP_ATOMIC); if (!user_skb) { err = -ENOMEM; @@ -515,9 +520,9 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, err = -ENOBUFS; goto out; } - nla->nla_len = nla_attr_size(skb->len); + nla->nla_len = nla_attr_size(skb->len - cutlen); - err = skb_zerocopy(user_skb, skb, skb->len, hlen); + err = skb_zerocopy(user_skb, skb, skb->len - cutlen, hlen); if (err) goto out; -- cgit v1.2.3-55-g7522 From b95e5928fcc76d156352570858abdea7b2628efd Mon Sep 17 00:00:00 2001 From: William Tu Date: Mon, 20 Jun 2016 07:26:17 -0700 Subject: openvswitch: Add packet len info to upcall. The commit f2a4d086ed4c ("openvswitch: Add packet truncation support.") introduces packet truncation before sending to userspace upcall receiver. This patch passes up the skb->len before truncation so that the upcall receiver knows the original packet size. Potentially this will be used by sFlow, where OVS translates sFlow config header=N to a sample action, truncating packet to N byte in kernel datapath. Thus, only N bytes instead of full-packet size is copied from kernel to userspace, saving the kernel-to-userspace bandwidth. Signed-off-by: William Tu Cc: Pravin Shelar Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- include/uapi/linux/openvswitch.h | 2 ++ net/openvswitch/datapath.c | 13 ++++++++++++- 2 files changed, 14 insertions(+), 1 deletion(-) (limited to 'net/openvswitch/datapath.c') diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h index 8274675ba9a3..d95a3018f6a1 100644 --- a/include/uapi/linux/openvswitch.h +++ b/include/uapi/linux/openvswitch.h @@ -166,6 +166,7 @@ enum ovs_packet_cmd { * output port is actually a tunnel port. Contains the output tunnel key * extracted from the packet as nested %OVS_TUNNEL_KEY_ATTR_* attributes. * @OVS_PACKET_ATTR_MRU: Present for an %OVS_PACKET_CMD_ACTION and + * @OVS_PACKET_ATTR_LEN: Packet size before truncation. * %OVS_PACKET_ATTR_USERSPACE action specify the Maximum received fragment * size. * @@ -185,6 +186,7 @@ enum ovs_packet_attr { OVS_PACKET_ATTR_PROBE, /* Packet operation is a feature probe, error logging should be suppressed. */ OVS_PACKET_ATTR_MRU, /* Maximum received IP fragment size. */ + OVS_PACKET_ATTR_LEN, /* Packet size before truncation. */ __OVS_PACKET_ATTR_MAX }; diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 673934295333..524c0fd3078e 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -387,7 +387,8 @@ static size_t upcall_msg_size(const struct dp_upcall_info *upcall_info, { size_t size = NLMSG_ALIGN(sizeof(struct ovs_header)) + nla_total_size(hdrlen) /* OVS_PACKET_ATTR_PACKET */ - + nla_total_size(ovs_key_attr_size()); /* OVS_PACKET_ATTR_KEY */ + + nla_total_size(ovs_key_attr_size()) /* OVS_PACKET_ATTR_KEY */ + + nla_total_size(sizeof(unsigned int)); /* OVS_PACKET_ATTR_LEN */ /* OVS_PACKET_ATTR_USERDATA */ if (upcall_info->userdata) @@ -514,6 +515,16 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb, pad_packet(dp, user_skb); } + /* Add OVS_PACKET_ATTR_LEN when packet is truncated */ + if (cutlen > 0) { + if (nla_put_u32(user_skb, OVS_PACKET_ATTR_LEN, + skb->len)) { + err = -ENOBUFS; + goto out; + } + pad_packet(dp, user_skb); + } + /* Only reserve room for attribute header, packet data is added * in skb_zerocopy() */ if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) { -- cgit v1.2.3-55-g7522