From d949d826c09fb65e230f55868ff70dc581ec06fa Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sat, 31 Aug 2013 13:44:37 +0800 Subject: [PATCH] ipv6: Add generic UDP Tunnel segmentation Similar to commit 731362674580cb0c696cd1b1a03d8461a10cf90a (tunneling: Add generic Tunnel segmentation) This patch adds generic tunneling offloading support for IPv6-UDP based tunnels. This can be used by tunneling protocols like VXLAN. Cc: Jesse Gross Cc: Pravin B Shelar Cc: Stephen Hemminger Cc: David S. Miller Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/ipv6/ip6_offload.c | 4 +- net/ipv6/udp_offload.c | 159 +++++++++++++++++++++++++++++++++---------------- 2 files changed, 111 insertions(+), 52 deletions(-) diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index a263b99..d82de72 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -91,6 +91,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, unsigned int unfrag_ip6hlen; u8 *prevhdr; int offset = 0; + bool tunnel; if (unlikely(skb_shinfo(skb)->gso_type & ~(SKB_GSO_UDP | @@ -106,6 +107,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h)))) goto out; + tunnel = skb->encapsulation; ipv6h = ipv6_hdr(skb); __skb_pull(skb, sizeof(*ipv6h)); segs = ERR_PTR(-EPROTONOSUPPORT); @@ -126,7 +128,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, ipv6h = ipv6_hdr(skb); ipv6h->payload_len = htons(skb->len - skb->mac_len - sizeof(*ipv6h)); - if (proto == IPPROTO_UDP) { + if (!tunnel && proto == IPPROTO_UDP) { unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index 5d1b8d7..7e5e5ac 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -21,26 +21,79 @@ static int udp6_ufo_send_check(struct sk_buff *skb) const struct ipv6hdr *ipv6h; struct udphdr *uh; - /* UDP Tunnel offload on ipv6 is not yet supported. */ - if (skb->encapsulation) - return -EINVAL; - if (!pskb_may_pull(skb, sizeof(*uh))) return -EINVAL; - ipv6h = ipv6_hdr(skb); - uh = udp_hdr(skb); + if (likely(!skb->encapsulation)) { + ipv6h = ipv6_hdr(skb); + uh = udp_hdr(skb); + + uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, + IPPROTO_UDP, 0); + skb->csum_start = skb_transport_header(skb) - skb->head; + skb->csum_offset = offsetof(struct udphdr, check); + skb->ip_summed = CHECKSUM_PARTIAL; + } - uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, - IPPROTO_UDP, 0); - skb->csum_start = skb_transport_header(skb) - skb->head; - skb->csum_offset = offsetof(struct udphdr, check); - skb->ip_summed = CHECKSUM_PARTIAL; return 0; } +static struct sk_buff *skb_udp6_tunnel_segment(struct sk_buff *skb, + netdev_features_t features) +{ + struct sk_buff *segs = ERR_PTR(-EINVAL); + int mac_len = skb->mac_len; + int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); + int outer_hlen; + netdev_features_t enc_features; + + if (unlikely(!pskb_may_pull(skb, tnl_hlen))) + goto out; + + skb->encapsulation = 0; + __skb_pull(skb, tnl_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, skb_inner_network_offset(skb)); + skb->mac_len = skb_inner_network_offset(skb); + + /* segment inner packet. */ + enc_features = skb->dev->hw_enc_features & netif_skb_features(skb); + segs = skb_mac_gso_segment(skb, enc_features); + if (!segs || IS_ERR(segs)) + goto out; + + outer_hlen = skb_tnl_header_len(skb); + skb = segs; + do { + struct udphdr *uh; + struct ipv6hdr *ipv6h; + int udp_offset = outer_hlen - tnl_hlen; + u32 len; + + skb->mac_len = mac_len; + + skb_push(skb, outer_hlen); + skb_reset_mac_header(skb); + skb_set_network_header(skb, mac_len); + skb_set_transport_header(skb, udp_offset); + uh = udp_hdr(skb); + uh->len = htons(skb->len - udp_offset); + ipv6h = ipv6_hdr(skb); + len = skb->len - udp_offset; + + uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, + len, IPPROTO_UDP, 0); + uh->check = csum_fold(skb_checksum(skb, udp_offset, len, 0)); + if (uh->check == 0) + uh->check = CSUM_MANGLED_0; + skb->ip_summed = CHECKSUM_NONE; + } while ((skb = skb->next)); +out: + return segs; +} + static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, - netdev_features_t features) + netdev_features_t features) { struct sk_buff *segs = ERR_PTR(-EINVAL); unsigned int mss; @@ -75,47 +128,51 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, goto out; } - /* Do software UFO. Complete and fill in the UDP checksum as HW cannot - * do checksum of UDP packets sent as multiple IP fragments. - */ - offset = skb_checksum_start_offset(skb); - csum = skb_checksum(skb, offset, skb->len - offset, 0); - offset += skb->csum_offset; - *(__sum16 *)(skb->data + offset) = csum_fold(csum); - skb->ip_summed = CHECKSUM_NONE; - - /* Check if there is enough headroom to insert fragment header. */ - tnl_hlen = skb_tnl_header_len(skb); - if (skb_headroom(skb) < (tnl_hlen + frag_hdr_sz)) { - if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz)) - goto out; + if (skb->encapsulation && skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL) + segs = skb_udp6_tunnel_segment(skb, features); + else { + /* Do software UFO. Complete and fill in the UDP checksum as HW cannot + * do checksum of UDP packets sent as multiple IP fragments. + */ + offset = skb_checksum_start_offset(skb); + csum = skb_checksum(skb, offset, skb->len - offset, 0); + offset += skb->csum_offset; + *(__sum16 *)(skb->data + offset) = csum_fold(csum); + skb->ip_summed = CHECKSUM_NONE; + + /* Check if there is enough headroom to insert fragment header. */ + tnl_hlen = skb_tnl_header_len(skb); + if (skb_headroom(skb) < (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. + */ + unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); + 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; + ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(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); } - /* Find the unfragmentable header and shift it left by frag_hdr_sz - * bytes to insert fragment header. - */ - unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); - 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; - ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(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; } -- 2.7.4