diff options
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 * |