diff options
Diffstat (limited to 'net/ipv6/udp_offload.c')
| -rw-r--r-- | net/ipv6/udp_offload.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c new file mode 100644 index 000000000..95dee9ca8 --- /dev/null +++ b/net/ipv6/udp_offload.c @@ -0,0 +1,177 @@ +/* + * IPV6 GSO/GRO offload support + * Linux INET6 implementation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * UDPv6 GSO support + */ +#include <linux/skbuff.h> +#include <linux/netdevice.h> +#include <net/protocol.h> +#include <net/ipv6.h> +#include <net/udp.h> +#include <net/ip6_checksum.h> +#include "ip6_offload.h" + +static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + unsigned int mss; + unsigned int unfrag_ip6hlen, unfrag_len; + struct frag_hdr *fptr; + u8 *packet_start, *prevhdr; + u8 nexthdr; + u8 frag_hdr_sz = sizeof(struct frag_hdr); + __wsum csum; + int tnl_hlen; + int err; + + mss = skb_shinfo(skb)->gso_size; + if (unlikely(skb->len <= mss)) + goto out; + + if (skb->encapsulation && skb_shinfo(skb)->gso_type & + (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM)) + segs = skb_udp_tunnel_segment(skb, features, true); + else { + const struct ipv6hdr *ipv6h; + struct udphdr *uh; + + if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4))) + goto out; + + if (!pskb_may_pull(skb, sizeof(struct udphdr))) + goto out; + + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) + return __udp_gso_segment(skb, features); + + /* Do software UFO. Complete and fill in the UDP checksum as HW cannot + * do checksum of UDP packets sent as multiple IP fragments. + */ + + uh = udp_hdr(skb); + ipv6h = ipv6_hdr(skb); + + uh->check = 0; + csum = skb_checksum(skb, 0, skb->len, 0); + uh->check = udp_v6_check(skb->len, &ipv6h->saddr, + &ipv6h->daddr, csum); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + + skb->ip_summed = CHECKSUM_UNNECESSARY; + + /* If there is no outer header we can fake a checksum offload + * due to the fact that we have already done the checksum in + * software prior to segmenting the frame. + */ + if (!skb->encap_hdr_csum) + features |= NETIF_F_HW_CSUM; + + /* Check if there is enough headroom to insert fragment header. */ + tnl_hlen = skb_tnl_header_len(skb); + if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) { + if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) + goto out; + } + + /* Find the unfragmentable header and shift it left by frag_hdr_sz + * bytes to insert fragment header. + */ + err = ip6_find_1stfragopt(skb, &prevhdr); + if (err < 0) + return ERR_PTR(err); + unfrag_ip6hlen = err; + nexthdr = *prevhdr; + *prevhdr = NEXTHDR_FRAGMENT; + unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) + + unfrag_ip6hlen + tnl_hlen; + packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset; + memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len); + + SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz; + skb->mac_header -= frag_hdr_sz; + skb->network_header -= frag_hdr_sz; + + fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); + fptr->nexthdr = nexthdr; + fptr->reserved = 0; + fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb); + + /* Fragment the skb. ipv6 header and the remaining fields of the + * fragment header are updated in ipv6_gso_segment() + */ + segs = skb_segment(skb, features); + } + +out: + return segs; +} + +static struct sk_buff *udp6_gro_receive(struct list_head *head, + struct sk_buff *skb) +{ + struct udphdr *uh = udp_gro_udphdr(skb); + + if (unlikely(!uh)) + goto flush; + + /* Don't bother verifying checksum if we're going to flush anyway. */ + if (NAPI_GRO_CB(skb)->flush) + goto skip; + + if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, + ip6_gro_compute_pseudo)) + goto flush; + else if (uh->check) + skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check, + ip6_gro_compute_pseudo); + +skip: + NAPI_GRO_CB(skb)->is_ipv6 = 1; + return udp_gro_receive(head, skb, uh, udp6_lib_lookup_skb); + +flush: + NAPI_GRO_CB(skb)->flush = 1; + return NULL; +} + +static int udp6_gro_complete(struct sk_buff *skb, int nhoff) +{ + const struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); + + if (uh->check) { + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; + uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr, + &ipv6h->daddr, 0); + } else { + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; + } + + return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb); +} + +static const struct net_offload udpv6_offload = { + .callbacks = { + .gso_segment = udp6_ufo_fragment, + .gro_receive = udp6_gro_receive, + .gro_complete = udp6_gro_complete, + }, +}; + +int udpv6_offload_init(void) +{ + return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); +} + +int udpv6_offload_exit(void) +{ + return inet6_del_offload(&udpv6_offload, IPPROTO_UDP); +} |