From ed246cee09b9865145a2e1e34f63ec0e31dd83a5 Mon Sep 17 00:00:00 2001 From: John Hurley Date: Sun, 7 Jul 2019 15:01:55 +0100 Subject: [PATCH] net: core: move pop MPLS functionality from OvS to core helper Open vSwitch provides code to pop an MPLS header to a packet. In preparation for supporting this in TC, move the pop code to an skb helper that can be reused. Remove the, now unused, update_ethertype static function from OvS. Signed-off-by: John Hurley Reviewed-by: Jakub Kicinski Reviewed-by: Simon Horman Reviewed-by: Willem de Bruijn Acked-by: Cong Wang Signed-off-by: David S. Miller --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 42 ++++++++++++++++++++++++++++++++++++++++++ net/openvswitch/actions.c | 37 ++----------------------------------- 3 files changed, 45 insertions(+), 35 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1dc55000710c..08d1c8e70540 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3448,6 +3448,7 @@ int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci); int skb_vlan_pop(struct sk_buff *skb); int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto); +int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto); struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy, gfp_t gfp); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 495fd743a935..8c00be4d8919 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5490,6 +5490,48 @@ int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto) EXPORT_SYMBOL_GPL(skb_mpls_push); /** + * skb_mpls_pop() - pop the outermost MPLS header + * + * @skb: buffer + * @next_proto: ethertype of header after popped MPLS header + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto) +{ + int err; + + if (unlikely(!eth_p_mpls(skb->protocol))) + return -EINVAL; + + err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); + if (unlikely(err)) + return err; + + skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN); + memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), + skb->mac_len); + + __skb_pull(skb, MPLS_HLEN); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb->mac_len); + + if (skb->dev && skb->dev->type == ARPHRD_ETHER) { + struct ethhdr *hdr; + + /* use mpls_hdr() to get ethertype to account for VLANs. */ + hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN); + skb_mod_eth_type(skb, hdr, next_proto); + } + skb->protocol = next_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_mpls_pop); + +/** * alloc_skb_with_frags - allocate skb with page frags * * @header_len: size of linear part diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index a9a6c9cbf946..62715bb8d611 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -160,18 +160,6 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, struct sw_flow_key *key, const struct nlattr *attr, int len); -static void update_ethertype(struct sk_buff *skb, struct ethhdr *hdr, - __be16 ethertype) -{ - if (skb->ip_summed == CHECKSUM_COMPLETE) { - __be16 diff[] = { ~(hdr->h_proto), ethertype }; - - skb->csum = csum_partial((char *)diff, sizeof(diff), skb->csum); - } - - hdr->h_proto = ethertype; -} - static int push_mpls(struct sk_buff *skb, struct sw_flow_key *key, const struct ovs_action_push_mpls *mpls) { @@ -190,31 +178,10 @@ static int pop_mpls(struct sk_buff *skb, struct sw_flow_key *key, { int err; - err = skb_ensure_writable(skb, skb->mac_len + MPLS_HLEN); - if (unlikely(err)) + err = skb_mpls_pop(skb, ethertype); + if (err) return err; - skb_postpull_rcsum(skb, mpls_hdr(skb), MPLS_HLEN); - - memmove(skb_mac_header(skb) + MPLS_HLEN, skb_mac_header(skb), - skb->mac_len); - - __skb_pull(skb, MPLS_HLEN); - skb_reset_mac_header(skb); - skb_set_network_header(skb, skb->mac_len); - - if (ovs_key_mac_proto(key) == MAC_PROTO_ETHERNET) { - struct ethhdr *hdr; - - /* mpls_hdr() is used to locate the ethertype field correctly in the - * presence of VLAN tags. - */ - hdr = (struct ethhdr *)((void *)mpls_hdr(skb) - ETH_HLEN); - update_ethertype(skb, hdr, ethertype); - } - if (eth_p_mpls(skb->protocol)) - skb->protocol = ethertype; - invalidate_flow_key(key); return 0; } -- 2.11.0