Commit | Line | Data |
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da5bab07 DB |
1 | /* |
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 | ||
b582ef09 | 17 | static DEFINE_SPINLOCK(udp_offload_lock); |
a1d0cd8e | 18 | static struct udp_offload_priv __rcu *udp_offload_base __read_mostly; |
b582ef09 | 19 | |
a664a4f7 SP |
20 | #define udp_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&udp_offload_lock)) |
21 | ||
b582ef09 OG |
22 | struct udp_offload_priv { |
23 | struct udp_offload *offload; | |
24 | struct rcu_head rcu; | |
25 | struct udp_offload_priv __rcu *next; | |
26 | }; | |
27 | ||
da5bab07 DB |
28 | static 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 | ||
155e010e TH |
50 | struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, |
51 | netdev_features_t features) | |
52 | { | |
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; | |
60 | unsigned int oldlen; | |
61 | bool need_csum; | |
62 | ||
63 | oldlen = (u16)~skb->len; | |
64 | ||
65 | if (unlikely(!pskb_may_pull(skb, tnl_hlen))) | |
66 | goto out; | |
67 | ||
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); | |
74 | ||
75 | need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); | |
76 | if (need_csum) | |
77 | skb->encap_hdr_csum = 1; | |
78 | ||
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); | |
27446442 | 82 | if (IS_ERR_OR_NULL(segs)) { |
155e010e TH |
83 | skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, |
84 | mac_len); | |
85 | goto out; | |
86 | } | |
87 | ||
88 | outer_hlen = skb_tnl_header_len(skb); | |
89 | udp_offset = outer_hlen - tnl_hlen; | |
90 | skb = segs; | |
91 | do { | |
92 | struct udphdr *uh; | |
93 | int len; | |
94 | ||
95 | skb_reset_inner_headers(skb); | |
96 | skb->encapsulation = 1; | |
97 | ||
98 | skb->mac_len = mac_len; | |
99 | ||
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; | |
105 | uh = udp_hdr(skb); | |
106 | uh->len = htons(len); | |
107 | ||
108 | if (need_csum) { | |
109 | __be32 delta = htonl(oldlen + len); | |
110 | ||
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); | |
115 | ||
116 | if (uh->check == 0) | |
117 | uh->check = CSUM_MANGLED_0; | |
118 | } | |
119 | ||
120 | skb->protocol = protocol; | |
121 | } while ((skb = skb->next)); | |
122 | out: | |
123 | return segs; | |
124 | } | |
125 | ||
da5bab07 DB |
126 | static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, |
127 | netdev_features_t features) | |
128 | { | |
129 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
130 | unsigned int mss; | |
7a7ffbab WCC |
131 | int offset; |
132 | __wsum csum; | |
133 | ||
134 | if (skb->encapsulation && | |
0f4f4ffa TH |
135 | (skb_shinfo(skb)->gso_type & |
136 | (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { | |
7a7ffbab WCC |
137 | segs = skb_udp_tunnel_segment(skb, features); |
138 | goto out; | |
139 | } | |
da5bab07 DB |
140 | |
141 | mss = skb_shinfo(skb)->gso_size; | |
142 | if (unlikely(skb->len <= mss)) | |
143 | goto out; | |
144 | ||
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; | |
148 | ||
149 | if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY | | |
150 | SKB_GSO_UDP_TUNNEL | | |
0f4f4ffa | 151 | SKB_GSO_UDP_TUNNEL_CSUM | |
cb32f511 | 152 | SKB_GSO_IPIP | |
4749c09c TH |
153 | SKB_GSO_GRE | SKB_GSO_GRE_CSUM | |
154 | SKB_GSO_MPLS) || | |
da5bab07 DB |
155 | !(type & (SKB_GSO_UDP)))) |
156 | goto out; | |
157 | ||
158 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
159 | ||
160 | segs = NULL; | |
161 | goto out; | |
162 | } | |
163 | ||
7a7ffbab WCC |
164 | /* Do software UFO. Complete and fill in the UDP checksum as |
165 | * HW cannot do checksum of UDP packets sent as multiple | |
166 | * IP fragments. | |
167 | */ | |
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; | |
173 | ||
da5bab07 DB |
174 | /* Fragment the skb. IP headers of the fragments are updated in |
175 | * inet_gso_segment() | |
176 | */ | |
7a7ffbab | 177 | segs = skb_segment(skb, features); |
da5bab07 DB |
178 | out: |
179 | return segs; | |
180 | } | |
181 | ||
b582ef09 OG |
182 | int udp_add_offload(struct udp_offload *uo) |
183 | { | |
b5aaab12 | 184 | struct udp_offload_priv *new_offload = kzalloc(sizeof(*new_offload), GFP_ATOMIC); |
b582ef09 OG |
185 | |
186 | if (!new_offload) | |
187 | return -ENOMEM; | |
188 | ||
189 | new_offload->offload = uo; | |
190 | ||
191 | spin_lock(&udp_offload_lock); | |
a664a4f7 SP |
192 | new_offload->next = udp_offload_base; |
193 | rcu_assign_pointer(udp_offload_base, new_offload); | |
b582ef09 OG |
194 | spin_unlock(&udp_offload_lock); |
195 | ||
196 | return 0; | |
197 | } | |
198 | EXPORT_SYMBOL(udp_add_offload); | |
199 | ||
200 | static void udp_offload_free_routine(struct rcu_head *head) | |
201 | { | |
202 | struct udp_offload_priv *ou_priv = container_of(head, struct udp_offload_priv, rcu); | |
203 | kfree(ou_priv); | |
204 | } | |
205 | ||
206 | void udp_del_offload(struct udp_offload *uo) | |
207 | { | |
208 | struct udp_offload_priv __rcu **head = &udp_offload_base; | |
209 | struct udp_offload_priv *uo_priv; | |
210 | ||
211 | spin_lock(&udp_offload_lock); | |
212 | ||
a664a4f7 | 213 | uo_priv = udp_deref_protected(*head); |
b582ef09 | 214 | for (; uo_priv != NULL; |
a664a4f7 | 215 | uo_priv = udp_deref_protected(*head)) { |
b582ef09 | 216 | if (uo_priv->offload == uo) { |
a664a4f7 SP |
217 | rcu_assign_pointer(*head, |
218 | udp_deref_protected(uo_priv->next)); | |
b582ef09 OG |
219 | goto unlock; |
220 | } | |
221 | head = &uo_priv->next; | |
222 | } | |
a1d0cd8e | 223 | pr_warn("udp_del_offload: didn't find offload for port %d\n", ntohs(uo->port)); |
b582ef09 OG |
224 | unlock: |
225 | spin_unlock(&udp_offload_lock); | |
226 | if (uo_priv != NULL) | |
227 | call_rcu(&uo_priv->rcu, udp_offload_free_routine); | |
228 | } | |
229 | EXPORT_SYMBOL(udp_del_offload); | |
230 | ||
231 | static struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb) | |
232 | { | |
233 | struct udp_offload_priv *uo_priv; | |
234 | struct sk_buff *p, **pp = NULL; | |
235 | struct udphdr *uh, *uh2; | |
236 | unsigned int hlen, off; | |
237 | int flush = 1; | |
238 | ||
239 | if (NAPI_GRO_CB(skb)->udp_mark || | |
240 | (!skb->encapsulation && skb->ip_summed != CHECKSUM_COMPLETE)) | |
241 | goto out; | |
242 | ||
243 | /* mark that this skb passed once through the udp gro layer */ | |
244 | NAPI_GRO_CB(skb)->udp_mark = 1; | |
245 | ||
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); | |
251 | if (unlikely(!uh)) | |
252 | goto out; | |
253 | } | |
254 | ||
255 | rcu_read_lock(); | |
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) | |
260 | goto unflush; | |
261 | } | |
262 | goto out_unlock; | |
263 | ||
264 | unflush: | |
265 | flush = 0; | |
266 | ||
267 | for (p = *head; p; p = p->next) { | |
268 | if (!NAPI_GRO_CB(p)->same_flow) | |
269 | continue; | |
270 | ||
271 | uh2 = (struct udphdr *)(p->data + off); | |
272 | if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) { | |
273 | NAPI_GRO_CB(p)->same_flow = 0; | |
274 | continue; | |
275 | } | |
276 | } | |
277 | ||
278 | skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ | |
6bae1d4c | 279 | skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); |
b582ef09 OG |
280 | pp = uo_priv->offload->callbacks.gro_receive(head, skb); |
281 | ||
282 | out_unlock: | |
283 | rcu_read_unlock(); | |
284 | out: | |
285 | NAPI_GRO_CB(skb)->flush |= flush; | |
286 | return pp; | |
287 | } | |
288 | ||
289 | static int udp_gro_complete(struct sk_buff *skb, int nhoff) | |
290 | { | |
291 | struct udp_offload_priv *uo_priv; | |
292 | __be16 newlen = htons(skb->len - nhoff); | |
293 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
294 | int err = -ENOSYS; | |
295 | ||
296 | uh->len = newlen; | |
297 | ||
298 | rcu_read_lock(); | |
299 | ||
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) | |
304 | break; | |
305 | } | |
306 | ||
307 | if (uo_priv != NULL) | |
308 | err = uo_priv->offload->callbacks.gro_complete(skb, nhoff + sizeof(struct udphdr)); | |
309 | ||
310 | rcu_read_unlock(); | |
311 | return err; | |
312 | } | |
313 | ||
da5bab07 DB |
314 | static const struct net_offload udpv4_offload = { |
315 | .callbacks = { | |
316 | .gso_send_check = udp4_ufo_send_check, | |
317 | .gso_segment = udp4_ufo_fragment, | |
b582ef09 OG |
318 | .gro_receive = udp_gro_receive, |
319 | .gro_complete = udp_gro_complete, | |
da5bab07 DB |
320 | }, |
321 | }; | |
322 | ||
323 | int __init udpv4_offload_init(void) | |
324 | { | |
325 | return inet_add_offload(&udpv4_offload, IPPROTO_UDP); | |
326 | } |