1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * IPV6 GSO/GRO offload support
4 * Linux INET6 implementation
8 #include <linux/skbuff.h>
9 #include <linux/netdevice.h>
10 #include <linux/indirect_call_wrapper.h>
11 #include <net/protocol.h>
14 #include <net/ip6_checksum.h>
15 #include "ip6_offload.h"
19 static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
20 netdev_features_t features)
22 struct sk_buff *segs = ERR_PTR(-EINVAL);
24 unsigned int unfrag_ip6hlen, unfrag_len;
25 struct frag_hdr *fptr;
26 u8 *packet_start, *prevhdr;
28 u8 frag_hdr_sz = sizeof(struct frag_hdr);
33 if (skb->encapsulation && skb_shinfo(skb)->gso_type &
34 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
35 segs = skb_udp_tunnel_segment(skb, features, true);
37 const struct ipv6hdr *ipv6h;
40 if (!(skb_shinfo(skb)->gso_type & (SKB_GSO_UDP | SKB_GSO_UDP_L4)))
43 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
46 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
47 return __udp_gso_segment(skb, features, true);
49 mss = skb_shinfo(skb)->gso_size;
50 if (unlikely(skb->len <= mss))
53 /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
54 * do checksum of UDP packets sent as multiple IP fragments.
58 ipv6h = ipv6_hdr(skb);
61 csum = skb_checksum(skb, 0, skb->len, 0);
62 uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
65 uh->check = CSUM_MANGLED_0;
67 skb->ip_summed = CHECKSUM_UNNECESSARY;
69 /* If there is no outer header we can fake a checksum offload
70 * due to the fact that we have already done the checksum in
71 * software prior to segmenting the frame.
73 if (!skb->encap_hdr_csum)
74 features |= NETIF_F_HW_CSUM;
76 /* Check if there is enough headroom to insert fragment header. */
77 tnl_hlen = skb_tnl_header_len(skb);
78 if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
79 if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
83 /* Find the unfragmentable header and shift it left by frag_hdr_sz
84 * bytes to insert fragment header.
86 err = ip6_find_1stfragopt(skb, &prevhdr);
91 *prevhdr = NEXTHDR_FRAGMENT;
92 unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
93 unfrag_ip6hlen + tnl_hlen;
94 packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
95 memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
97 SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
98 skb->mac_header -= frag_hdr_sz;
99 skb->network_header -= frag_hdr_sz;
101 fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
102 fptr->nexthdr = nexthdr;
104 fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
106 /* Fragment the skb. ipv6 header and the remaining fields of the
107 * fragment header are updated in ipv6_gso_segment()
109 segs = skb_segment(skb, features);
116 static struct sock *udp6_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
119 const struct ipv6hdr *iph = skb_gro_network_header(skb);
120 struct net *net = dev_net(skb->dev);
123 inet6_get_iif_sdif(skb, &iif, &sdif);
125 return __udp6_lib_lookup(net, &iph->saddr, sport,
126 &iph->daddr, dport, iif,
127 sdif, net->ipv4.udp_table, NULL);
130 INDIRECT_CALLABLE_SCOPE
131 struct sk_buff *udp6_gro_receive(struct list_head *head, struct sk_buff *skb)
133 struct udphdr *uh = udp_gro_udphdr(skb);
134 struct sock *sk = NULL;
140 /* Don't bother verifying checksum if we're going to flush anyway. */
141 if (NAPI_GRO_CB(skb)->flush)
144 if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check,
145 ip6_gro_compute_pseudo))
148 skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
149 ip6_gro_compute_pseudo);
152 NAPI_GRO_CB(skb)->is_ipv6 = 1;
154 if (static_branch_unlikely(&udpv6_encap_needed_key))
155 sk = udp6_gro_lookup_skb(skb, uh->source, uh->dest);
157 pp = udp_gro_receive(head, skb, uh, sk);
161 NAPI_GRO_CB(skb)->flush = 1;
165 INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
167 const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
168 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
170 /* do fraglist only if there is no outer UDP encap (or we already processed it) */
171 if (NAPI_GRO_CB(skb)->is_flist && !NAPI_GRO_CB(skb)->encap_mark) {
172 uh->len = htons(skb->len - nhoff);
174 skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
175 skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
177 if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
178 if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
181 skb->ip_summed = CHECKSUM_UNNECESSARY;
189 uh->check = ~udp_v6_check(skb->len - nhoff, &ipv6h->saddr,
192 return udp_gro_complete(skb, nhoff, udp6_lib_lookup_skb);
195 static const struct net_offload udpv6_offload = {
197 .gso_segment = udp6_ufo_fragment,
198 .gro_receive = udp6_gro_receive,
199 .gro_complete = udp6_gro_complete,
203 int udpv6_offload_init(void)
205 return inet6_add_offload(&udpv6_offload, IPPROTO_UDP);
208 int udpv6_offload_exit(void)
210 return inet6_del_offload(&udpv6_offload, IPPROTO_UDP);