From df30f7408b187929dbde72661c7f7c615268f1d0 Mon Sep 17 00:00:00 2001 From: pravin shelar Date: Mon, 26 Dec 2016 08:31:27 -0800 Subject: [PATCH] openvswitch: upcall: Fix vlan handling. Networking stack accelerate vlan tag handling by keeping topmost vlan header in skb. This works as long as packet remains in OVS datapath. But during OVS upcall vlan header is pushed on to the packet. When such packet is sent back to OVS datapath, core networking stack might not handle it correctly. Following patch avoids this issue by accelerating the vlan tag during flow key extract. This simplifies datapath by bringing uniform packet processing for packets from all code paths. Fixes: 5108bbaddc ("openvswitch: add processing of L3 packets"). CC: Jarno Rajahalme CC: Jiri Benc Signed-off-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/datapath.c | 1 - net/openvswitch/flow.c | 54 +++++++++++++++++++------------------- 2 files changed, 27 insertions(+), 28 deletions(-) diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 2d4c4d3911c0..9c62b6325f7a 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -606,7 +606,6 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info) rcu_assign_pointer(flow->sf_acts, acts); packet->priority = flow->key.phy.priority; packet->mark = flow->key.phy.skb_mark; - packet->protocol = flow->key.eth.type; rcu_read_lock(); dp = get_dp_rcu(net, ovs_header->dp_ifindex); diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 08aa926cd5cf..2c0a00f7f1b7 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -312,7 +312,8 @@ static bool icmp6hdr_ok(struct sk_buff *skb) * Returns 0 if it encounters a non-vlan or incomplete packet. * Returns 1 after successfully parsing vlan tag. */ -static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh) +static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh, + bool untag_vlan) { struct vlan_head *vh = (struct vlan_head *)skb->data; @@ -330,7 +331,20 @@ static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh) key_vh->tci = vh->tci | htons(VLAN_TAG_PRESENT); key_vh->tpid = vh->tpid; - __skb_pull(skb, sizeof(struct vlan_head)); + if (unlikely(untag_vlan)) { + int offset = skb->data - skb_mac_header(skb); + u16 tci; + int err; + + __skb_push(skb, offset); + err = __skb_vlan_pop(skb, &tci); + __skb_pull(skb, offset); + if (err) + return err; + __vlan_hwaccel_put_tag(skb, key_vh->tpid, tci); + } else { + __skb_pull(skb, sizeof(struct vlan_head)); + } return 1; } @@ -351,13 +365,13 @@ static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key) key->eth.vlan.tpid = skb->vlan_proto; } else { /* Parse outer vlan tag in the non-accelerated case. */ - res = parse_vlan_tag(skb, &key->eth.vlan); + res = parse_vlan_tag(skb, &key->eth.vlan, true); if (res <= 0) return res; } /* Parse inner vlan tag. */ - res = parse_vlan_tag(skb, &key->eth.cvlan); + res = parse_vlan_tag(skb, &key->eth.cvlan, false); if (res <= 0) return res; @@ -800,29 +814,15 @@ int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr, if (err) return err; - if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) { - /* key_extract assumes that skb->protocol is set-up for - * layer 3 packets which is the case for other callers, - * in particular packets recieved from the network stack. - * Here the correct value can be set from the metadata - * extracted above. - */ - skb->protocol = key->eth.type; - } else { - struct ethhdr *eth; - - skb_reset_mac_header(skb); - eth = eth_hdr(skb); - - /* Normally, setting the skb 'protocol' field would be - * handled by a call to eth_type_trans(), but it assumes - * there's a sending device, which we may not have. - */ - if (eth_proto_is_802_3(eth->h_proto)) - skb->protocol = eth->h_proto; - else - skb->protocol = htons(ETH_P_802_2); - } + /* key_extract assumes that skb->protocol is set-up for + * layer 3 packets which is the case for other callers, + * in particular packets received from the network stack. + * Here the correct value can be set from the metadata + * extracted above. + * For L2 packet key eth type would be zero. skb protocol + * would be set to correct value later during key-extact. + */ + skb->protocol = key->eth.type; return key_extract(skb, key); } -- 2.39.5