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 struct sk_buff
*__skb_udp_tunnel_segment(struct sk_buff
*skb
,
29 netdev_features_t features
,
30 struct sk_buff
*(*gso_inner_segment
)(struct sk_buff
*skb
,
31 netdev_features_t features
),
34 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
35 u16 mac_offset
= skb
->mac_header
;
36 int mac_len
= skb
->mac_len
;
37 int tnl_hlen
= skb_inner_mac_header(skb
) - skb_transport_header(skb
);
38 __be16 protocol
= skb
->protocol
;
39 netdev_features_t enc_features
;
40 int udp_offset
, outer_hlen
;
44 oldlen
= (u16
)~skb
->len
;
46 if (unlikely(!pskb_may_pull(skb
, tnl_hlen
)))
49 skb
->encapsulation
= 0;
50 __skb_pull(skb
, tnl_hlen
);
51 skb_reset_mac_header(skb
);
52 skb_set_network_header(skb
, skb_inner_network_offset(skb
));
53 skb
->mac_len
= skb_inner_network_offset(skb
);
54 skb
->protocol
= new_protocol
;
56 need_csum
= !!(skb_shinfo(skb
)->gso_type
& SKB_GSO_UDP_TUNNEL_CSUM
);
58 skb
->encap_hdr_csum
= 1;
60 /* segment inner packet. */
61 enc_features
= skb
->dev
->hw_enc_features
& features
;
62 segs
= gso_inner_segment(skb
, enc_features
);
63 if (IS_ERR_OR_NULL(segs
)) {
64 skb_gso_error_unwind(skb
, protocol
, tnl_hlen
, mac_offset
,
69 outer_hlen
= skb_tnl_header_len(skb
);
70 udp_offset
= outer_hlen
- tnl_hlen
;
76 skb_reset_inner_headers(skb
);
77 skb
->encapsulation
= 1;
79 skb
->mac_len
= mac_len
;
81 skb_push(skb
, outer_hlen
);
82 skb_reset_mac_header(skb
);
83 skb_set_network_header(skb
, mac_len
);
84 skb_set_transport_header(skb
, udp_offset
);
85 len
= skb
->len
- udp_offset
;
90 __be32 delta
= htonl(oldlen
+ len
);
92 uh
->check
= ~csum_fold((__force __wsum
)
93 ((__force u32
)uh
->check
+
95 uh
->check
= gso_make_checksum(skb
, ~uh
->check
);
98 uh
->check
= CSUM_MANGLED_0
;
101 skb
->protocol
= protocol
;
102 } while ((skb
= skb
->next
));
107 struct sk_buff
*skb_udp_tunnel_segment(struct sk_buff
*skb
,
108 netdev_features_t features
,
111 __be16 protocol
= skb
->protocol
;
112 const struct net_offload
**offloads
;
113 const struct net_offload
*ops
;
114 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
115 struct sk_buff
*(*gso_inner_segment
)(struct sk_buff
*skb
,
116 netdev_features_t features
);
120 switch (skb
->inner_protocol_type
) {
121 case ENCAP_TYPE_ETHER
:
122 protocol
= skb
->inner_protocol
;
123 gso_inner_segment
= skb_mac_gso_segment
;
125 case ENCAP_TYPE_IPPROTO
:
126 offloads
= is_ipv6
? inet6_offloads
: inet_offloads
;
127 ops
= rcu_dereference(offloads
[skb
->inner_ipproto
]);
128 if (!ops
|| !ops
->callbacks
.gso_segment
)
130 gso_inner_segment
= ops
->callbacks
.gso_segment
;
136 segs
= __skb_udp_tunnel_segment(skb
, features
, gso_inner_segment
,
145 static struct sk_buff
*udp4_ufo_fragment(struct sk_buff
*skb
,
146 netdev_features_t features
)
148 struct sk_buff
*segs
= ERR_PTR(-EINVAL
);
154 if (skb
->encapsulation
&&
155 (skb_shinfo(skb
)->gso_type
&
156 (SKB_GSO_UDP_TUNNEL
|SKB_GSO_UDP_TUNNEL_CSUM
))) {
157 segs
= skb_udp_tunnel_segment(skb
, features
, false);
161 if (!pskb_may_pull(skb
, sizeof(struct udphdr
)))
164 mss
= skb_shinfo(skb
)->gso_size
;
165 if (unlikely(skb
->len
<= mss
))
168 if (skb_gso_ok(skb
, features
| NETIF_F_GSO_ROBUST
)) {
169 /* Packet is from an untrusted source, reset gso_segs. */
170 int type
= skb_shinfo(skb
)->gso_type
;
172 if (unlikely(type
& ~(SKB_GSO_UDP
| SKB_GSO_DODGY
|
174 SKB_GSO_UDP_TUNNEL_CSUM
|
176 SKB_GSO_GRE
| SKB_GSO_GRE_CSUM
|
178 !(type
& (SKB_GSO_UDP
))))
181 skb_shinfo(skb
)->gso_segs
= DIV_ROUND_UP(skb
->len
, mss
);
187 /* Do software UFO. Complete and fill in the UDP checksum as
188 * HW cannot do checksum of UDP packets sent as multiple
196 csum
= skb_checksum(skb
, 0, skb
->len
, 0);
197 uh
->check
= udp_v4_check(skb
->len
, iph
->saddr
, iph
->daddr
, csum
);
199 uh
->check
= CSUM_MANGLED_0
;
201 skb
->ip_summed
= CHECKSUM_NONE
;
203 /* Fragment the skb. IP headers of the fragments are updated in
206 segs
= skb_segment(skb
, features
);
211 int udp_add_offload(struct udp_offload
*uo
)
213 struct udp_offload_priv
*new_offload
= kzalloc(sizeof(*new_offload
), GFP_ATOMIC
);
218 new_offload
->offload
= uo
;
220 spin_lock(&udp_offload_lock
);
221 new_offload
->next
= udp_offload_base
;
222 rcu_assign_pointer(udp_offload_base
, new_offload
);
223 spin_unlock(&udp_offload_lock
);
227 EXPORT_SYMBOL(udp_add_offload
);
229 static void udp_offload_free_routine(struct rcu_head
*head
)
231 struct udp_offload_priv
*ou_priv
= container_of(head
, struct udp_offload_priv
, rcu
);
235 void udp_del_offload(struct udp_offload
*uo
)
237 struct udp_offload_priv __rcu
**head
= &udp_offload_base
;
238 struct udp_offload_priv
*uo_priv
;
240 spin_lock(&udp_offload_lock
);
242 uo_priv
= udp_deref_protected(*head
);
243 for (; uo_priv
!= NULL
;
244 uo_priv
= udp_deref_protected(*head
)) {
245 if (uo_priv
->offload
== uo
) {
246 rcu_assign_pointer(*head
,
247 udp_deref_protected(uo_priv
->next
));
250 head
= &uo_priv
->next
;
252 pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo
->port
));
254 spin_unlock(&udp_offload_lock
);
256 call_rcu(&uo_priv
->rcu
, udp_offload_free_routine
);
258 EXPORT_SYMBOL(udp_del_offload
);
260 struct sk_buff
**udp_gro_receive(struct sk_buff
**head
, struct sk_buff
*skb
,
263 struct udp_offload_priv
*uo_priv
;
264 struct sk_buff
*p
, **pp
= NULL
;
266 unsigned int off
= skb_gro_offset(skb
);
269 if (NAPI_GRO_CB(skb
)->udp_mark
||
270 (skb
->ip_summed
!= CHECKSUM_PARTIAL
&&
271 NAPI_GRO_CB(skb
)->csum_cnt
== 0 &&
272 !NAPI_GRO_CB(skb
)->csum_valid
))
275 /* mark that this skb passed once through the udp gro layer */
276 NAPI_GRO_CB(skb
)->udp_mark
= 1;
279 uo_priv
= rcu_dereference(udp_offload_base
);
280 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
281 if (uo_priv
->offload
->port
== uh
->dest
&&
282 uo_priv
->offload
->callbacks
.gro_receive
)
290 for (p
= *head
; p
; p
= p
->next
) {
291 if (!NAPI_GRO_CB(p
)->same_flow
)
294 uh2
= (struct udphdr
*)(p
->data
+ off
);
296 /* Match ports and either checksums are either both zero
299 if ((*(u32
*)&uh
->source
!= *(u32
*)&uh2
->source
) ||
300 (!uh
->check
^ !uh2
->check
)) {
301 NAPI_GRO_CB(p
)->same_flow
= 0;
306 skb_gro_pull(skb
, sizeof(struct udphdr
)); /* pull encapsulating udp header */
307 skb_gro_postpull_rcsum(skb
, uh
, sizeof(struct udphdr
));
308 NAPI_GRO_CB(skb
)->proto
= uo_priv
->offload
->ipproto
;
309 pp
= uo_priv
->offload
->callbacks
.gro_receive(head
, skb
);
314 NAPI_GRO_CB(skb
)->flush
|= flush
;
318 static struct sk_buff
**udp4_gro_receive(struct sk_buff
**head
,
321 struct udphdr
*uh
= udp_gro_udphdr(skb
);
326 /* Don't bother verifying checksum if we're going to flush anyway. */
327 if (NAPI_GRO_CB(skb
)->flush
)
330 if (skb_gro_checksum_validate_zero_check(skb
, IPPROTO_UDP
, uh
->check
,
331 inet_gro_compute_pseudo
))
334 skb_gro_checksum_try_convert(skb
, IPPROTO_UDP
, uh
->check
,
335 inet_gro_compute_pseudo
);
337 NAPI_GRO_CB(skb
)->is_ipv6
= 0;
338 return udp_gro_receive(head
, skb
, uh
);
341 NAPI_GRO_CB(skb
)->flush
= 1;
345 int udp_gro_complete(struct sk_buff
*skb
, int nhoff
)
347 struct udp_offload_priv
*uo_priv
;
348 __be16 newlen
= htons(skb
->len
- nhoff
);
349 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+ nhoff
);
356 uo_priv
= rcu_dereference(udp_offload_base
);
357 for (; uo_priv
!= NULL
; uo_priv
= rcu_dereference(uo_priv
->next
)) {
358 if (uo_priv
->offload
->port
== uh
->dest
&&
359 uo_priv
->offload
->callbacks
.gro_complete
)
363 if (uo_priv
!= NULL
) {
364 NAPI_GRO_CB(skb
)->proto
= uo_priv
->offload
->ipproto
;
365 err
= uo_priv
->offload
->callbacks
.gro_complete(skb
, nhoff
+ sizeof(struct udphdr
));
372 static int udp4_gro_complete(struct sk_buff
*skb
, int nhoff
)
374 const struct iphdr
*iph
= ip_hdr(skb
);
375 struct udphdr
*uh
= (struct udphdr
*)(skb
->data
+ nhoff
);
378 uh
->check
= ~udp_v4_check(skb
->len
- nhoff
, iph
->saddr
,
381 return udp_gro_complete(skb
, nhoff
);
384 static const struct net_offload udpv4_offload
= {
386 .gso_segment
= udp4_ufo_fragment
,
387 .gro_receive
= udp4_gro_receive
,
388 .gro_complete
= udp4_gro_complete
,
392 int __init
udpv4_offload_init(void)
394 return inet_add_offload(&udpv4_offload
, IPPROTO_UDP
);