From d5709f7ab77679d407a7687fc5ad7cc7442cc651 Mon Sep 17 00:00:00 2001 From: Hadar Hen Zion Date: Wed, 17 Aug 2016 13:36:10 +0300 Subject: [PATCH] flow_dissector: For stripped vlan, get vlan info from skb->vlan_tci Early in the datapath skb_vlan_untag function is called, stripped the vlan from the skb and set skb->vlan_tci and skb->vlan_proto fields. The current dissection doesn't handle stripped vlan packets correctly. In some flows, vlan doesn't exist in skb->data anymore when applying flow dissection on the skb, fix that. In case vlan info wasn't stripped before applying flow_dissector (RPS flow for example), or in case of skb with multiple vlans (e.g. 802.1ad), get the vlan info from skb->data. The flow_dissector correctly skips any number of vlans and stores only the first level vlan. Fixes: 0744dd00c1b1 ('net: introduce skb_flow_dissect()') Signed-off-by: Hadar Hen Zion Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- net/core/flow_dissector.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 91028ae2fb01..362d693c003f 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -119,12 +119,14 @@ bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_dissector_key_ports *key_ports; struct flow_dissector_key_tags *key_tags; struct flow_dissector_key_keyid *key_keyid; + bool skip_vlan = false; u8 ip_proto = 0; bool ret = false; if (!data) { data = skb->data; - proto = skb->protocol; + proto = skb_vlan_tag_present(skb) ? + skb->vlan_proto : skb->protocol; nhoff = skb_network_offset(skb); hlen = skb_headlen(skb); } @@ -243,23 +245,39 @@ ipv6: case htons(ETH_P_8021AD): case htons(ETH_P_8021Q): { const struct vlan_hdr *vlan; - struct vlan_hdr _vlan; - vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan); - if (!vlan) - goto out_bad; + if (skb_vlan_tag_present(skb)) + proto = skb->protocol; + + if (!skb_vlan_tag_present(skb) || + proto == cpu_to_be16(ETH_P_8021Q) || + proto == cpu_to_be16(ETH_P_8021AD)) { + struct vlan_hdr _vlan; + + vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), + data, hlen, &_vlan); + if (!vlan) + goto out_bad; + proto = vlan->h_vlan_encapsulated_proto; + nhoff += sizeof(*vlan); + if (skip_vlan) + goto again; + } + skip_vlan = true; if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_VLANID)) { key_tags = skb_flow_dissector_target(flow_dissector, FLOW_DISSECTOR_KEY_VLANID, target_container); - key_tags->vlan_id = skb_vlan_tag_get_id(skb); + if (skb_vlan_tag_present(skb)) + key_tags->vlan_id = skb_vlan_tag_get_id(skb); + else + key_tags->vlan_id = ntohs(vlan->h_vlan_TCI) & + VLAN_VID_MASK; } - proto = vlan->h_vlan_encapsulated_proto; - nhoff += sizeof(*vlan); goto again; } case htons(ETH_P_PPP_SES): { -- 2.20.1