blob: 546d2d439dda65a195f7e635b7dc564def1da077 [file] [log] [blame]
Daniel Borkmannda5bab02013-06-08 12:56:03 +02001/*
2 * IPV4 GSO/GRO offload support
3 * Linux INET implementation
4 *
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.
9 *
10 * UDPv4 GSO support
11 */
12
13#include <linux/skbuff.h>
14#include <net/udp.h>
15#include <net/protocol.h>
16
Or Gerlitzb582ef02014-01-20 13:59:19 +020017static DEFINE_SPINLOCK(udp_offload_lock);
Shlomo Pongratza1d0cd82014-01-22 15:23:29 +020018static struct udp_offload_priv __rcu *udp_offload_base __read_mostly;
Or Gerlitzb582ef02014-01-20 13:59:19 +020019
Shlomo Pongratza664a4f2014-02-02 15:42:10 +020020#define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock))
21
Or Gerlitzb582ef02014-01-20 13:59:19 +020022struct udp_offload_priv {
23 struct udp_offload *offload;
24 struct rcu_head rcu;
25 struct udp_offload_priv __rcu *next;
26};
27
Daniel Borkmannda5bab02013-06-08 12:56:03 +020028static int udp4_ufo_send_check(struct sk_buff *skb)
29{
30 if (!pskb_may_pull(skb, sizeof(struct udphdr)))
31 return -EINVAL;
32
33 if (likely(!skb->encapsulation)) {
34 const struct iphdr *iph;
35 struct udphdr *uh;
36
37 iph = ip_hdr(skb);
38 uh = udp_hdr(skb);
39
40 uh->check = ~csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
41 IPPROTO_UDP, 0);
42 skb->csum_start = skb_transport_header(skb) - skb->head;
43 skb->csum_offset = offsetof(struct udphdr, check);
44 skb->ip_summed = CHECKSUM_PARTIAL;
45 }
46
47 return 0;
48}
49
50static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
51 netdev_features_t features)
52{
53 struct sk_buff *segs = ERR_PTR(-EINVAL);
54 unsigned int mss;
Wei-Chun Chao7a7ffba2013-12-26 13:10:22 -080055 int offset;
56 __wsum csum;
57
58 if (skb->encapsulation &&
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070059 (skb_shinfo(skb)->gso_type &
60 (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) {
Wei-Chun Chao7a7ffba2013-12-26 13:10:22 -080061 segs = skb_udp_tunnel_segment(skb, features);
62 goto out;
63 }
Daniel Borkmannda5bab02013-06-08 12:56:03 +020064
65 mss = skb_shinfo(skb)->gso_size;
66 if (unlikely(skb->len <= mss))
67 goto out;
68
69 if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
70 /* Packet is from an untrusted source, reset gso_segs. */
71 int type = skb_shinfo(skb)->gso_type;
72
73 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
74 SKB_GSO_UDP_TUNNEL |
Tom Herbert0f4f4ff2014-06-04 17:20:16 -070075 SKB_GSO_UDP_TUNNEL_CSUM |
Eric Dumazetcb32f512013-10-19 11:42:57 -070076 SKB_GSO_IPIP |
Tom Herbert4749c092014-06-04 17:20:23 -070077 SKB_GSO_GRE | SKB_GSO_GRE_CSUM |
78 SKB_GSO_MPLS) ||
Daniel Borkmannda5bab02013-06-08 12:56:03 +020079 !(type & (SKB_GSO_UDP))))
80 goto out;
81
82 skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss);
83
84 segs = NULL;
85 goto out;
86 }
87
Wei-Chun Chao7a7ffba2013-12-26 13:10:22 -080088 /* Do software UFO. Complete and fill in the UDP checksum as
89 * HW cannot do checksum of UDP packets sent as multiple
90 * IP fragments.
91 */
92 offset = skb_checksum_start_offset(skb);
93 csum = skb_checksum(skb, offset, skb->len - offset, 0);
94 offset += skb->csum_offset;
95 *(__sum16 *)(skb->data + offset) = csum_fold(csum);
96 skb->ip_summed = CHECKSUM_NONE;
97
Daniel Borkmannda5bab02013-06-08 12:56:03 +020098 /* Fragment the skb. IP headers of the fragments are updated in
99 * inet_gso_segment()
100 */
Wei-Chun Chao7a7ffba2013-12-26 13:10:22 -0800101 segs = skb_segment(skb, features);
Daniel Borkmannda5bab02013-06-08 12:56:03 +0200102out:
103 return segs;
104}
105
Or Gerlitzb582ef02014-01-20 13:59:19 +0200106int udp_add_offload(struct udp_offload *uo)
107{
Or Gerlitzb5aaab12014-01-29 18:08:59 +0200108 struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC);
Or Gerlitzb582ef02014-01-20 13:59:19 +0200109
110 if (!new_offload)
111 return -ENOMEM;
112
113 new_offload->offload = uo;
114
115 spin_lock(&udp_offload_lock);
Shlomo Pongratza664a4f2014-02-02 15:42:10 +0200116 new_offload->next = udp_offload_base;
117 rcu_assign_pointer(udp_offload_base, new_offload);
Or Gerlitzb582ef02014-01-20 13:59:19 +0200118 spin_unlock(&udp_offload_lock);
119
120 return 0;
121}
122EXPORT_SYMBOL(udp_add_offload);
123
124static void udp_offload_free_routine(struct rcu_head *head)
125{
126 struct udp_offload_priv *ou_priv = container_of(head, struct udp_offload_priv, rcu);
127 kfree(ou_priv);
128}
129
130void udp_del_offload(struct udp_offload *uo)
131{
132 struct udp_offload_priv __rcu **head = &udp_offload_base;
133 struct udp_offload_priv *uo_priv;
134
135 spin_lock(&udp_offload_lock);
136
Shlomo Pongratza664a4f2014-02-02 15:42:10 +0200137 uo_priv = udp_deref_protected(*head);
Or Gerlitzb582ef02014-01-20 13:59:19 +0200138 for (; uo_priv != NULL;
Shlomo Pongratza664a4f2014-02-02 15:42:10 +0200139 uo_priv = udp_deref_protected(*head)) {
Or Gerlitzb582ef02014-01-20 13:59:19 +0200140 if (uo_priv->offload == uo) {
Shlomo Pongratza664a4f2014-02-02 15:42:10 +0200141 rcu_assign_pointer(*head,
142 udp_deref_protected(uo_priv->next));
Or Gerlitzb582ef02014-01-20 13:59:19 +0200143 goto unlock;
144 }
145 head = &uo_priv->next;
146 }
Shlomo Pongratza1d0cd82014-01-22 15:23:29 +0200147 pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo->port));
Or Gerlitzb582ef02014-01-20 13:59:19 +0200148unlock:
149 spin_unlock(&udp_offload_lock);
150 if (uo_priv != NULL)
151 call_rcu(&uo_priv->rcu, udp_offload_free_routine);
152}
153EXPORT_SYMBOL(udp_del_offload);
154
155static struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
156{
157 struct udp_offload_priv *uo_priv;
158 struct sk_buff *p, **pp = NULL;
159 struct udphdr *uh, *uh2;
160 unsigned int hlen, off;
161 int flush = 1;
162
163 if (NAPI_GRO_CB(skb)->udp_mark ||
164 (!skb->encapsulation && skb->ip_summed != CHECKSUM_COMPLETE))
165 goto out;
166
167 /* mark that this skb passed once through the udp gro layer */
168 NAPI_GRO_CB(skb)->udp_mark = 1;
169
170 off = skb_gro_offset(skb);
171 hlen = off + sizeof(*uh);
172 uh = skb_gro_header_fast(skb, off);
173 if (skb_gro_header_hard(skb, hlen)) {
174 uh = skb_gro_header_slow(skb, hlen, off);
175 if (unlikely(!uh))
176 goto out;
177 }
178
179 rcu_read_lock();
180 uo_priv = rcu_dereference(udp_offload_base);
181 for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
182 if (uo_priv->offload->port == uh->dest &&
183 uo_priv->offload->callbacks.gro_receive)
184 goto unflush;
185 }
186 goto out_unlock;
187
188unflush:
189 flush = 0;
190
191 for (p = *head; p; p = p->next) {
192 if (!NAPI_GRO_CB(p)->same_flow)
193 continue;
194
195 uh2 = (struct udphdr *)(p->data + off);
196 if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
197 NAPI_GRO_CB(p)->same_flow = 0;
198 continue;
199 }
200 }
201
202 skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */
Tom Herbert6bae1d42014-06-10 18:54:26 -0700203 skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
Or Gerlitzb582ef02014-01-20 13:59:19 +0200204 pp = uo_priv->offload->callbacks.gro_receive(head, skb);
205
206out_unlock:
207 rcu_read_unlock();
208out:
209 NAPI_GRO_CB(skb)->flush |= flush;
210 return pp;
211}
212
213static int udp_gro_complete(struct sk_buff *skb, int nhoff)
214{
215 struct udp_offload_priv *uo_priv;
216 __be16 newlen = htons(skb->len - nhoff);
217 struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
218 int err = -ENOSYS;
219
220 uh->len = newlen;
221
222 rcu_read_lock();
223
224 uo_priv = rcu_dereference(udp_offload_base);
225 for (; uo_priv != NULL; uo_priv = rcu_dereference(uo_priv->next)) {
226 if (uo_priv->offload->port == uh->dest &&
227 uo_priv->offload->callbacks.gro_complete)
228 break;
229 }
230
231 if (uo_priv != NULL)
232 err = uo_priv->offload->callbacks.gro_complete(skb, nhoff + sizeof(struct udphdr));
233
234 rcu_read_unlock();
235 return err;
236}
237
Daniel Borkmannda5bab02013-06-08 12:56:03 +0200238static const struct net_offload udpv4_offload = {
239 .callbacks = {
240 .gso_send_check = udp4_ufo_send_check,
241 .gso_segment = udp4_ufo_fragment,
Or Gerlitzb582ef02014-01-20 13:59:19 +0200242 .gro_receive = udp_gro_receive,
243 .gro_complete = udp_gro_complete,
Daniel Borkmannda5bab02013-06-08 12:56:03 +0200244 },
245};
246
247int __init udpv4_offload_init(void)
248{
249 return inet_add_offload(&udpv4_offload, IPPROTO_UDP);
250}