2 * IPV4 GSO/GRO offload support
3 * Linux INET implementation
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License
7 * as published by the Free Software Foundation; either version
8 * 2 of the License, or (at your option) any later version.
13 #include <linux/skbuff.h>
15 #include <net/protocol.h>
17 static DEFINE_SPINLOCK(udp_offload_lock
);
18 static struct udp_offload_priv __rcu
*udp_offload_base __read_mostly
;
20 #define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock))
22 struct udp_offload_priv
{
23 struct udp_offload
*offload
;
25 struct udp_offload_priv __rcu
*next
;
28 static int udp4_ufo_send_check(struct sk_buff
*skb
)
30 if (!pskb_may_pull(skb
, sizeof(struct udphdr
)))
33 if (likely(!skb
->encapsulation
)) {
34 const struct iphdr
*iph
;
40 uh
->check
= ~csum_tcpudp_magic(iph
->saddr
, iph
->daddr
, skb
->len
,
42 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
43 skb
->csum_offset
= offsetof(struct udphdr
, check
);
44 skb
->ip_summed
= CHECKSUM_PARTIAL
;
50 struct sk_buff
*skb_udp_tunnel_segment(struct sk_buff
*skb
,
51 netdev_features_t features
)
53 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
54 u16 mac_offset
= skb
->mac_header
;
55 int mac_len
= skb
->mac_len
;
56 int tnl_hlen
= skb_inner_mac_header(skb
) - skb_transport_header(skb
);
57 __be16 protocol
= skb
->protocol
;
58 netdev_features_t enc_features
;
59 int udp_offset
, outer_hlen
;
63 oldlen
= (u16
)~skb
->len
;
65 if (unlikely(!pskb_may_pull(skb
, tnl_hlen
)))
68 skb
->encapsulation
= 0;
69 __skb_pull(skb
, tnl_hlen
);
70 skb_reset_mac_header(skb
);
71 skb_set_network_header(skb
, skb_inner_network_offset(skb
));
72 skb
->mac_len
= skb_inner_network_offset(skb
);
73 skb
->protocol
= htons(ETH_P_TEB
);
75 need_csum
= !!(skb_shinfo(skb
)->gso_type
& SKB_GSO_UDP_TUNNEL_CSUM
);
77 skb
->encap_hdr_csum
= 1;
79 /* segment inner packet. */
80 enc_features
= skb
->dev
->hw_enc_features
& netif_skb_features(skb
);
81 segs
= skb_mac_gso_segment(skb
, enc_features
);
82 if (IS_ERR_OR_NULL(segs
)) {
83 skb_gso_error_unwind(skb
, protocol
, tnl_hlen
, mac_offset
,
88 outer_hlen
= skb_tnl_header_len(skb
);
89 udp_offset
= outer_hlen
- tnl_hlen
;
95 skb_reset_inner_headers(skb
);
96 skb
->encapsulation
= 1;
98 skb
->mac_len
= mac_len
;
100 skb_push(skb
, outer_hlen
);
101 skb_reset_mac_header(skb
);
102 skb_set_network_header(skb
, mac_len
);
103 skb_set_transport_header(skb
, udp_offset
);
104 len
= skb
->len
- udp_offset
;
106 uh
->len
= htons(len
);
109 __be32 delta
= htonl(oldlen
+ len
);
111 uh
->check
= ~csum_fold((__force __wsum
)
112 ((__force u32
)uh
->check
+
113 (__force u32
)delta
));
114 uh
->check
= gso_make_checksum(skb
, ~uh
->check
);
117 uh
->check
= CSUM_MANGLED_0
;
120 skb
->protocol
= protocol
;
121 } while ((skb
= skb
->next
));
126 static struct sk_buff
*udp4_ufo_fragment(struct sk_buff
*skb
,
127 netdev_features_t features
)
129 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
134 if (skb
->encapsulation
&&
135 (skb_shinfo(skb
)->gso_type
&
136 (SKB_GSO_UDP_TUNNEL
|SKB_GSO_UDP_TUNNEL_CSUM
))) {
137 segs
= skb_udp_tunnel_segment(skb
, features
);
141 mss
= skb_shinfo(skb
)->gso_size
;
142 if (unlikely(skb
->len
<= mss
))
145 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
146 /* Packet is from an untrusted source, reset gso_segs. */
147 int type
= skb_shinfo(skb
)->gso_type
;
149 if (unlikely(type
& ~(SKB_GSO_UDP
| SKB_GSO_DODGY
|
151 SKB_GSO_UDP_TUNNEL_CSUM
|
153 SKB_GSO_GRE
| SKB_GSO_GRE_CSUM
|
155 !(type
& (SKB_GSO_UDP
))))
158 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
164 /* Do software UFO. Complete and fill in the UDP checksum as
165 * HW cannot do checksum of UDP packets sent as multiple
168 offset
= skb_checksum_start_offset(skb
);
169 csum
= skb_checksum(skb
, offset
, skb
->len
- offset
, 0);
170 offset
+= skb
->csum_offset
;
171 *(__sum16
*)(skb
->data
+ offset
) = csum_fold(csum
);
172 skb
->ip_summed
= CHECKSUM_NONE
;
174 /* Fragment the skb. IP headers of the fragments are updated in
177 segs
= skb_segment(skb
, features
);
182 int udp_add_offload(struct udp_offload
*uo
)
184 struct udp_offload_priv
*new_offload
= kzalloc(sizeof(*new_offload
), GFP_ATOMIC
);
189 new_offload
->offload
= uo
;
191 spin_lock(&udp_offload_lock
);
192 new_offload
->next
= udp_offload_base
;
193 rcu_assign_pointer(udp_offload_base
, new_offload
);
194 spin_unlock(&udp_offload_lock
);
198 EXPORT_SYMBOL(udp_add_offload
);
200 static void udp_offload_free_routine(struct rcu_head
*head
)
202 struct udp_offload_priv
*ou_priv
= container_of(head
, struct udp_offload_priv
, rcu
);
206 void udp_del_offload(struct udp_offload
*uo
)
208 struct udp_offload_priv __rcu
**head
= &udp_offload_base
;
209 struct udp_offload_priv
*uo_priv
;
211 spin_lock(&udp_offload_lock
);
213 uo_priv
= udp_deref_protected(*head
);
214 for (; uo_priv
!= NULL
;
215 uo_priv
= udp_deref_protected(*head
)) {
216 if (uo_priv
->offload
== uo
) {
217 rcu_assign_pointer(*head
,
218 udp_deref_protected(uo_priv
->next
));
221 head
= &uo_priv
->next
;
223 pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo
->port
));
225 spin_unlock(&udp_offload_lock
);
227 call_rcu(&uo_priv
->rcu
, udp_offload_free_routine
);
229 EXPORT_SYMBOL(udp_del_offload
);
231 static struct sk_buff
**udp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
)
233 struct udp_offload_priv
*uo_priv
;
234 struct sk_buff
*p
, **pp
= NULL
;
235 struct udphdr
*uh
, *uh2
;
236 unsigned int hlen
, off
;
239 if (NAPI_GRO_CB(skb
)->udp_mark
||
240 (!skb
->encapsulation
&& skb
->ip_summed
!= CHECKSUM_COMPLETE
))
243 /* mark that this skb passed once through the udp gro layer */
244 NAPI_GRO_CB(skb
)->udp_mark
= 1;
246 off
= skb_gro_offset(skb
);
247 hlen
= off
+ sizeof(*uh
);
248 uh
= skb_gro_header_fast(skb
, off
);
249 if (skb_gro_header_hard(skb
, hlen
)) {
250 uh
= skb_gro_header_slow(skb
, hlen
, off
);
256 uo_priv
= rcu_dereference(udp_offload_base
);
257 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
258 if (uo_priv
->offload
->port
== uh
->dest
&&
259 uo_priv
->offload
->callbacks
.gro_receive
)
267 for (p
= *head
; p
; p
= p
->next
) {
268 if (!NAPI_GRO_CB(p
)->same_flow
)
271 uh2
= (struct udphdr
*)(p
->data
+ off
);
272 if ((*(u32
*)&uh
->source
!= *(u32
*)&uh2
->source
)) {
273 NAPI_GRO_CB(p
)->same_flow
= 0;
278 skb_gro_pull(skb
, sizeof(struct udphdr
)); /* pull encapsulating udp header */
279 skb_gro_postpull_rcsum(skb
, uh
, sizeof(struct udphdr
));
280 pp
= uo_priv
->offload
->callbacks
.gro_receive(head
, skb
);
285 NAPI_GRO_CB(skb
)->flush
|= flush
;
289 static int udp_gro_complete(struct sk_buff
*skb
, int nhoff
)
291 struct udp_offload_priv
*uo_priv
;
292 __be16 newlen
= htons(skb
->len
- nhoff
);
293 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+ nhoff
);
300 uo_priv
= rcu_dereference(udp_offload_base
);
301 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
302 if (uo_priv
->offload
->port
== uh
->dest
&&
303 uo_priv
->offload
->callbacks
.gro_complete
)
308 err
= uo_priv
->offload
->callbacks
.gro_complete(skb
, nhoff
+ sizeof(struct udphdr
));
314 static const struct net_offload udpv4_offload
= {
316 .gso_send_check
= udp4_ufo_send_check
,
317 .gso_segment
= udp4_ufo_fragment
,
318 .gro_receive
= udp_gro_receive
,
319 .gro_complete
= udp_gro_complete
,
323 int __init
udpv4_offload_init(void)
325 return inet_add_offload(&udpv4_offload
, IPPROTO_UDP
);