diff options
| author | John Hurley <john.hurley@netronome.com> | 2019-07-07 15:01:54 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-07-08 19:50:13 -0700 |
| commit | 8822e270d697010e6a4fd42a319dbefc33db91e1 (patch) | |
| tree | bb41f9cc2cc8071c04fc7f053404ca75b13e86c2 /net/core/skbuff.c | |
| parent | af144a983402f7fd324ce556d9f9011a8b3e01fe (diff) | |
net: core: move push MPLS functionality from OvS to core helper
Open vSwitch provides code to push an MPLS header to a packet. In
preparation for supporting this in TC, move the push code to an skb helper
that can be reused.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index cdb0ccdaac0b..495fd743a935 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -66,6 +66,7 @@ #include <net/checksum.h> #include <net/ip6_checksum.h> #include <net/xfrm.h> +#include <net/mpls.h> #include <linux/uaccess.h> #include <trace/events/skb.h> @@ -5425,6 +5426,69 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) } EXPORT_SYMBOL(skb_vlan_push); +/* Update the ethertype of hdr and the skb csum value if required. */ +static void skb_mod_eth_type(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; +} + +/** + * skb_mpls_push() - push a new MPLS header after the mac header + * + * @skb: buffer + * @mpls_lse: MPLS label stack entry to push + * @mpls_proto: ethertype of the new MPLS header (expects 0x8847 or 0x8848) + * + * Expects skb->data at mac header. + * + * Returns 0 on success, -errno otherwise. + */ +int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto) +{ + struct mpls_shim_hdr *lse; + int err; + + if (unlikely(!eth_p_mpls(mpls_proto))) + return -EINVAL; + + /* Networking stack does not allow simultaneous Tunnel and MPLS GSO. */ + if (skb->encapsulation) + return -EINVAL; + + err = skb_cow_head(skb, MPLS_HLEN); + if (unlikely(err)) + return err; + + if (!skb->inner_protocol) { + skb_set_inner_network_header(skb, skb->mac_len); + skb_set_inner_protocol(skb, skb->protocol); + } + + skb_push(skb, MPLS_HLEN); + memmove(skb_mac_header(skb) - MPLS_HLEN, skb_mac_header(skb), + skb->mac_len); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb->mac_len); + + lse = mpls_hdr(skb); + lse->label_stack_entry = mpls_lse; + skb_postpush_rcsum(skb, lse, MPLS_HLEN); + + if (skb->dev && skb->dev->type == ARPHRD_ETHER) + skb_mod_eth_type(skb, eth_hdr(skb), mpls_proto); + skb->protocol = mpls_proto; + + return 0; +} +EXPORT_SYMBOL_GPL(skb_mpls_push); + /** * alloc_skb_with_frags - allocate skb with page frags * |