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
;
26 struct udp_offload_priv __rcu
*next
;
29 static struct sk_buff
*__skb_udp_tunnel_segment(struct sk_buff
*skb
,
30 netdev_features_t features
,
31 struct sk_buff
*(*gso_inner_segment
)(struct sk_buff
*skb
,
32 netdev_features_t features
),
33 __be16 new_protocol
, bool is_ipv6
)
35 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
36 u16 mac_offset
= skb
->mac_header
;
37 int mac_len
= skb
->mac_len
;
38 int tnl_hlen
= skb_inner_mac_header(skb
) - skb_transport_header(skb
);
39 __be16 protocol
= skb
->protocol
;
40 netdev_features_t enc_features
;
41 int udp_offset
, outer_hlen
;
43 bool need_csum
= !!(skb_shinfo(skb
)->gso_type
&
44 SKB_GSO_UDP_TUNNEL_CSUM
);
45 bool remcsum
= !!(skb_shinfo(skb
)->gso_type
& SKB_GSO_TUNNEL_REMCSUM
);
46 bool offload_csum
= false, dont_encap
= (need_csum
|| remcsum
);
48 oldlen
= (u16
)~skb
->len
;
50 if (unlikely(!pskb_may_pull(skb
, tnl_hlen
)))
53 skb
->encapsulation
= 0;
54 __skb_pull(skb
, tnl_hlen
);
55 skb_reset_mac_header(skb
);
56 skb_set_network_header(skb
, skb_inner_network_offset(skb
));
57 skb
->mac_len
= skb_inner_network_offset(skb
);
58 skb
->protocol
= new_protocol
;
59 skb
->encap_hdr_csum
= need_csum
;
60 skb
->remcsum_offload
= remcsum
;
62 /* Try to offload checksum if possible */
63 offload_csum
= !!(need_csum
&&
64 ((skb
->dev
->features
& NETIF_F_HW_CSUM
) ||
65 (skb
->dev
->features
& (is_ipv6
?
66 NETIF_F_IPV6_CSUM
: NETIF_F_IP_CSUM
))));
68 /* segment inner packet. */
69 enc_features
= skb
->dev
->hw_enc_features
& features
;
70 segs
= gso_inner_segment(skb
, enc_features
);
71 if (IS_ERR_OR_NULL(segs
)) {
72 skb_gso_error_unwind(skb
, protocol
, tnl_hlen
, mac_offset
,
77 outer_hlen
= skb_tnl_header_len(skb
);
78 udp_offset
= outer_hlen
- tnl_hlen
;
86 skb
->encapsulation
= 0;
87 skb
->ip_summed
= CHECKSUM_NONE
;
89 /* Only set up inner headers if we might be offloading
92 skb_reset_inner_headers(skb
);
93 skb
->encapsulation
= 1;
96 skb
->mac_len
= mac_len
;
97 skb
->protocol
= protocol
;
99 skb_push(skb
, outer_hlen
);
100 skb_reset_mac_header(skb
);
101 skb_set_network_header(skb
, mac_len
);
102 skb_set_transport_header(skb
, udp_offset
);
103 len
= skb
->len
- udp_offset
;
105 uh
->len
= htons(len
);
110 delta
= htonl(oldlen
+ len
);
112 uh
->check
= ~csum_fold((__force __wsum
)
113 ((__force u32
)uh
->check
+
114 (__force u32
)delta
));
116 skb
->ip_summed
= CHECKSUM_PARTIAL
;
117 skb
->csum_start
= skb_transport_header(skb
) - skb
->head
;
118 skb
->csum_offset
= offsetof(struct udphdr
, check
);
119 } else if (remcsum
) {
120 /* Need to calculate checksum from scratch,
121 * inner checksums are never when doing
122 * remote_checksum_offload.
125 skb
->csum
= skb_checksum(skb
, udp_offset
,
126 skb
->len
- udp_offset
,
128 uh
->check
= csum_fold(skb
->csum
);
130 uh
->check
= CSUM_MANGLED_0
;
132 uh
->check
= gso_make_checksum(skb
, ~uh
->check
);
135 uh
->check
= CSUM_MANGLED_0
;
137 } while ((skb
= skb
->next
));
142 struct sk_buff
*skb_udp_tunnel_segment(struct sk_buff
*skb
,
143 netdev_features_t features
,
146 __be16 protocol
= skb
->protocol
;
147 const struct net_offload
**offloads
;
148 const struct net_offload
*ops
;
149 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
150 struct sk_buff
*(*gso_inner_segment
)(struct sk_buff
*skb
,
151 netdev_features_t features
);
155 switch (skb
->inner_protocol_type
) {
156 case ENCAP_TYPE_ETHER
:
157 protocol
= skb
->inner_protocol
;
158 gso_inner_segment
= skb_mac_gso_segment
;
160 case ENCAP_TYPE_IPPROTO
:
161 offloads
= is_ipv6
? inet6_offloads
: inet_offloads
;
162 ops
= rcu_dereference(offloads
[skb
->inner_ipproto
]);
163 if (!ops
|| !ops
->callbacks
.gso_segment
)
165 gso_inner_segment
= ops
->callbacks
.gso_segment
;
171 segs
= __skb_udp_tunnel_segment(skb
, features
, gso_inner_segment
,
180 static struct sk_buff
*udp4_ufo_fragment(struct sk_buff
*skb
,
181 netdev_features_t features
)
183 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
189 if (skb
->encapsulation
&&
190 (skb_shinfo(skb
)->gso_type
&
191 (SKB_GSO_UDP_TUNNEL
|SKB_GSO_UDP_TUNNEL_CSUM
))) {
192 segs
= skb_udp_tunnel_segment(skb
, features
, false);
196 if (!pskb_may_pull(skb
, sizeof(struct udphdr
)))
199 mss
= skb_shinfo(skb
)->gso_size
;
200 if (unlikely(skb
->len
<= mss
))
203 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
204 /* Packet is from an untrusted source, reset gso_segs. */
205 int type
= skb_shinfo(skb
)->gso_type
;
207 if (unlikely(type
& ~(SKB_GSO_UDP
| SKB_GSO_DODGY
|
209 SKB_GSO_UDP_TUNNEL_CSUM
|
210 SKB_GSO_TUNNEL_REMCSUM
|
212 SKB_GSO_GRE
| SKB_GSO_GRE_CSUM
) ||
213 !(type
& (SKB_GSO_UDP
))))
216 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
222 /* Do software UFO. Complete and fill in the UDP checksum as
223 * HW cannot do checksum of UDP packets sent as multiple
231 csum
= skb_checksum(skb
, 0, skb
->len
, 0);
232 uh
->check
= udp_v4_check(skb
->len
, iph
->saddr
, iph
->daddr
, csum
);
234 uh
->check
= CSUM_MANGLED_0
;
236 skb
->ip_summed
= CHECKSUM_NONE
;
238 /* Fragment the skb. IP headers of the fragments are updated in
241 segs
= skb_segment(skb
, features
);
246 int udp_add_offload(struct net
*net
, struct udp_offload
*uo
)
248 struct udp_offload_priv
*new_offload
= kzalloc(sizeof(*new_offload
), GFP_ATOMIC
);
253 write_pnet(&new_offload
->net
, net
);
254 new_offload
->offload
= uo
;
256 spin_lock(&udp_offload_lock
);
257 new_offload
->next
= udp_offload_base
;
258 rcu_assign_pointer(udp_offload_base
, new_offload
);
259 spin_unlock(&udp_offload_lock
);
263 EXPORT_SYMBOL(udp_add_offload
);
265 static void udp_offload_free_routine(struct rcu_head
*head
)
267 struct udp_offload_priv
*ou_priv
= container_of(head
, struct udp_offload_priv
, rcu
);
271 void udp_del_offload(struct udp_offload
*uo
)
273 struct udp_offload_priv __rcu
**head
= &udp_offload_base
;
274 struct udp_offload_priv
*uo_priv
;
276 spin_lock(&udp_offload_lock
);
278 uo_priv
= udp_deref_protected(*head
);
279 for (; uo_priv
!= NULL
;
280 uo_priv
= udp_deref_protected(*head
)) {
281 if (uo_priv
->offload
== uo
) {
282 rcu_assign_pointer(*head
,
283 udp_deref_protected(uo_priv
->next
));
286 head
= &uo_priv
->next
;
288 pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo
->port
));
290 spin_unlock(&udp_offload_lock
);
292 call_rcu(&uo_priv
->rcu
, udp_offload_free_routine
);
294 EXPORT_SYMBOL(udp_del_offload
);
296 struct sk_buff
**udp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
,
299 struct udp_offload_priv
*uo_priv
;
300 struct sk_buff
*p
, **pp
= NULL
;
302 unsigned int off
= skb_gro_offset(skb
);
305 if (NAPI_GRO_CB(skb
)->udp_mark
||
306 (skb
->ip_summed
!= CHECKSUM_PARTIAL
&&
307 NAPI_GRO_CB(skb
)->csum_cnt
== 0 &&
308 !NAPI_GRO_CB(skb
)->csum_valid
))
311 /* mark that this skb passed once through the udp gro layer */
312 NAPI_GRO_CB(skb
)->udp_mark
= 1;
315 uo_priv
= rcu_dereference(udp_offload_base
);
316 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
317 if (net_eq(read_pnet(&uo_priv
->net
), dev_net(skb
->dev
)) &&
318 uo_priv
->offload
->port
== uh
->dest
&&
319 uo_priv
->offload
->callbacks
.gro_receive
)
327 for (p
= *head
; p
; p
= p
->next
) {
328 if (!NAPI_GRO_CB(p
)->same_flow
)
331 uh2
= (struct udphdr
*)(p
->data
+ off
);
333 /* Match ports and either checksums are either both zero
336 if ((*(u32
*)&uh
->source
!= *(u32
*)&uh2
->source
) ||
337 (!uh
->check
^ !uh2
->check
)) {
338 NAPI_GRO_CB(p
)->same_flow
= 0;
343 skb_gro_pull(skb
, sizeof(struct udphdr
)); /* pull encapsulating udp header */
344 skb_gro_postpull_rcsum(skb
, uh
, sizeof(struct udphdr
));
345 NAPI_GRO_CB(skb
)->proto
= uo_priv
->offload
->ipproto
;
346 pp
= uo_priv
->offload
->callbacks
.gro_receive(head
, skb
,
352 NAPI_GRO_CB(skb
)->flush
|= flush
;
356 static struct sk_buff
**udp4_gro_receive(struct sk_buff
**head
,
359 struct udphdr
*uh
= udp_gro_udphdr(skb
);
364 /* Don't bother verifying checksum if we're going to flush anyway. */
365 if (NAPI_GRO_CB(skb
)->flush
)
368 if (skb_gro_checksum_validate_zero_check(skb
, IPPROTO_UDP
, uh
->check
,
369 inet_gro_compute_pseudo
))
372 skb_gro_checksum_try_convert(skb
, IPPROTO_UDP
, uh
->check
,
373 inet_gro_compute_pseudo
);
375 NAPI_GRO_CB(skb
)->is_ipv6
= 0;
376 return udp_gro_receive(head
, skb
, uh
);
379 NAPI_GRO_CB(skb
)->flush
= 1;
383 int udp_gro_complete(struct sk_buff
*skb
, int nhoff
)
385 struct udp_offload_priv
*uo_priv
;
386 __be16 newlen
= htons(skb
->len
- nhoff
);
387 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+ nhoff
);
394 uo_priv
= rcu_dereference(udp_offload_base
);
395 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
396 if (net_eq(read_pnet(&uo_priv
->net
), dev_net(skb
->dev
)) &&
397 uo_priv
->offload
->port
== uh
->dest
&&
398 uo_priv
->offload
->callbacks
.gro_complete
)
403 NAPI_GRO_CB(skb
)->proto
= uo_priv
->offload
->ipproto
;
404 err
= uo_priv
->offload
->callbacks
.gro_complete(skb
,
405 nhoff
+ sizeof(struct udphdr
),
411 if (skb
->remcsum_offload
)
412 skb_shinfo(skb
)->gso_type
|= SKB_GSO_TUNNEL_REMCSUM
;
414 skb
->encapsulation
= 1;
415 skb_set_inner_mac_header(skb
, nhoff
+ sizeof(struct udphdr
));
420 static int udp4_gro_complete(struct sk_buff
*skb
, int nhoff
)
422 const struct iphdr
*iph
= ip_hdr(skb
);
423 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+ nhoff
);
426 skb_shinfo(skb
)->gso_type
|= SKB_GSO_UDP_TUNNEL_CSUM
;
427 uh
->check
= ~udp_v4_check(skb
->len
- nhoff
, iph
->saddr
,
430 skb_shinfo(skb
)->gso_type
|= SKB_GSO_UDP_TUNNEL
;
433 return udp_gro_complete(skb
, nhoff
);
436 static const struct net_offload udpv4_offload
= {
438 .gso_segment
= udp4_ufo_fragment
,
439 .gro_receive
= udp4_gro_receive
,
440 .gro_complete
= udp4_gro_complete
,
444 int __init
udpv4_offload_init(void)
446 return inet_add_offload(&udpv4_offload
, IPPROTO_UDP
);