Commit | Line | Data |
---|---|---|
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 | ||
8bce6d7d TH |
17 | static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, |
18 | netdev_features_t features, | |
19 | struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, | |
20 | netdev_features_t features), | |
4bcb877d | 21 | __be16 new_protocol, bool is_ipv6) |
155e010e | 22 | { |
dbef491e | 23 | int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb); |
22463876 | 24 | bool remcsum, need_csum, offload_csum, ufo; |
155e010e | 25 | struct sk_buff *segs = ERR_PTR(-EINVAL); |
dbef491e | 26 | struct udphdr *uh = udp_hdr(skb); |
155e010e | 27 | u16 mac_offset = skb->mac_header; |
155e010e | 28 | __be16 protocol = skb->protocol; |
dbef491e | 29 | u16 mac_len = skb->mac_len; |
155e010e | 30 | int udp_offset, outer_hlen; |
08334824 | 31 | __wsum partial; |
155e010e TH |
32 | |
33 | if (unlikely(!pskb_may_pull(skb, tnl_hlen))) | |
34 | goto out; | |
35 | ||
08334824 AD |
36 | /* Adjust partial header checksum to negate old length. |
37 | * We cannot rely on the value contained in uh->len as it is | |
38 | * possible that the actual value exceeds the boundaries of the | |
39 | * 16 bit length field due to the header being added outside of an | |
40 | * IP or IPv6 frame that was already limited to 64K - 1. | |
41 | */ | |
802ab55a AD |
42 | if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) |
43 | partial = (__force __wsum)uh->len; | |
44 | else | |
45 | partial = (__force __wsum)htonl(skb->len); | |
46 | partial = csum_sub(csum_unfold(uh->check), partial); | |
dbef491e AD |
47 | |
48 | /* setup inner skb. */ | |
155e010e | 49 | skb->encapsulation = 0; |
5197f349 | 50 | SKB_GSO_CB(skb)->encap_level = 0; |
155e010e TH |
51 | __skb_pull(skb, tnl_hlen); |
52 | skb_reset_mac_header(skb); | |
53 | skb_set_network_header(skb, skb_inner_network_offset(skb)); | |
54 | skb->mac_len = skb_inner_network_offset(skb); | |
8bce6d7d | 55 | skb->protocol = new_protocol; |
fdaefd62 AD |
56 | |
57 | need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM); | |
4bcb877d | 58 | skb->encap_hdr_csum = need_csum; |
fdaefd62 AD |
59 | |
60 | remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); | |
e585f236 | 61 | skb->remcsum_offload = remcsum; |
155e010e | 62 | |
22463876 AD |
63 | ufo = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP); |
64 | ||
4bcb877d TH |
65 | /* Try to offload checksum if possible */ |
66 | offload_csum = !!(need_csum && | |
fdaefd62 AD |
67 | (skb->dev->features & |
68 | (is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) : | |
69 | (NETIF_F_HW_CSUM | NETIF_F_IP_CSUM)))); | |
155e010e | 70 | |
bef3c6c9 AD |
71 | features &= skb->dev->hw_enc_features; |
72 | ||
7fbeffed AD |
73 | /* The only checksum offload we care about from here on out is the |
74 | * outer one so strip the existing checksum feature flags and | |
75 | * instead set the flag based on our outer checksum offload value. | |
76 | */ | |
22463876 | 77 | if (remcsum || ufo) { |
7fbeffed | 78 | features &= ~NETIF_F_CSUM_MASK; |
22463876 | 79 | if (!need_csum || offload_csum) |
7fbeffed AD |
80 | features |= NETIF_F_HW_CSUM; |
81 | } | |
82 | ||
155e010e | 83 | /* segment inner packet. */ |
bef3c6c9 | 84 | segs = gso_inner_segment(skb, features); |
27446442 | 85 | if (IS_ERR_OR_NULL(segs)) { |
155e010e TH |
86 | skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset, |
87 | mac_len); | |
88 | goto out; | |
89 | } | |
90 | ||
91 | outer_hlen = skb_tnl_header_len(skb); | |
92 | udp_offset = outer_hlen - tnl_hlen; | |
93 | skb = segs; | |
94 | do { | |
802ab55a | 95 | unsigned int len; |
4bcb877d | 96 | |
fdaefd62 | 97 | if (remcsum) |
4bcb877d | 98 | skb->ip_summed = CHECKSUM_NONE; |
fdaefd62 AD |
99 | |
100 | /* Set up inner headers if we are offloading inner checksum */ | |
101 | if (skb->ip_summed == CHECKSUM_PARTIAL) { | |
4bcb877d TH |
102 | skb_reset_inner_headers(skb); |
103 | skb->encapsulation = 1; | |
104 | } | |
155e010e TH |
105 | |
106 | skb->mac_len = mac_len; | |
4bcb877d | 107 | skb->protocol = protocol; |
155e010e | 108 | |
dbef491e | 109 | __skb_push(skb, outer_hlen); |
155e010e TH |
110 | skb_reset_mac_header(skb); |
111 | skb_set_network_header(skb, mac_len); | |
112 | skb_set_transport_header(skb, udp_offset); | |
802ab55a | 113 | len = skb->len - udp_offset; |
155e010e | 114 | uh = udp_hdr(skb); |
802ab55a AD |
115 | |
116 | /* If we are only performing partial GSO the inner header | |
117 | * will be using a length value equal to only one MSS sized | |
118 | * segment instead of the entire frame. | |
119 | */ | |
120 | if (skb_is_gso(skb)) { | |
121 | uh->len = htons(skb_shinfo(skb)->gso_size + | |
122 | SKB_GSO_CB(skb)->data_offset + | |
123 | skb->head - (unsigned char *)uh); | |
124 | } else { | |
125 | uh->len = htons(len); | |
126 | } | |
155e010e | 127 | |
4bcb877d TH |
128 | if (!need_csum) |
129 | continue; | |
130 | ||
802ab55a AD |
131 | uh->check = ~csum_fold(csum_add(partial, |
132 | (__force __wsum)htonl(len))); | |
155e010e | 133 | |
fdaefd62 AD |
134 | if (skb->encapsulation || !offload_csum) { |
135 | uh->check = gso_make_checksum(skb, ~uh->check); | |
155e010e TH |
136 | if (uh->check == 0) |
137 | uh->check = CSUM_MANGLED_0; | |
fdaefd62 AD |
138 | } else { |
139 | skb->ip_summed = CHECKSUM_PARTIAL; | |
140 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
141 | skb->csum_offset = offsetof(struct udphdr, check); | |
155e010e | 142 | } |
155e010e TH |
143 | } while ((skb = skb->next)); |
144 | out: | |
145 | return segs; | |
146 | } | |
147 | ||
8bce6d7d TH |
148 | struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb, |
149 | netdev_features_t features, | |
150 | bool is_ipv6) | |
151 | { | |
152 | __be16 protocol = skb->protocol; | |
153 | const struct net_offload **offloads; | |
154 | const struct net_offload *ops; | |
155 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
156 | struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb, | |
157 | netdev_features_t features); | |
158 | ||
159 | rcu_read_lock(); | |
160 | ||
161 | switch (skb->inner_protocol_type) { | |
162 | case ENCAP_TYPE_ETHER: | |
163 | protocol = skb->inner_protocol; | |
164 | gso_inner_segment = skb_mac_gso_segment; | |
165 | break; | |
166 | case ENCAP_TYPE_IPPROTO: | |
167 | offloads = is_ipv6 ? inet6_offloads : inet_offloads; | |
168 | ops = rcu_dereference(offloads[skb->inner_ipproto]); | |
169 | if (!ops || !ops->callbacks.gso_segment) | |
170 | goto out_unlock; | |
171 | gso_inner_segment = ops->callbacks.gso_segment; | |
172 | break; | |
173 | default: | |
174 | goto out_unlock; | |
175 | } | |
176 | ||
177 | segs = __skb_udp_tunnel_segment(skb, features, gso_inner_segment, | |
4bcb877d | 178 | protocol, is_ipv6); |
8bce6d7d TH |
179 | |
180 | out_unlock: | |
181 | rcu_read_unlock(); | |
182 | ||
183 | return segs; | |
184 | } | |
a6024562 | 185 | EXPORT_SYMBOL(skb_udp_tunnel_segment); |
8bce6d7d | 186 | |
da5bab07 DB |
187 | static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, |
188 | netdev_features_t features) | |
189 | { | |
190 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
191 | unsigned int mss; | |
7a7ffbab | 192 | __wsum csum; |
f71470b3 TH |
193 | struct udphdr *uh; |
194 | struct iphdr *iph; | |
7a7ffbab WCC |
195 | |
196 | if (skb->encapsulation && | |
0f4f4ffa TH |
197 | (skb_shinfo(skb)->gso_type & |
198 | (SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))) { | |
8bce6d7d | 199 | segs = skb_udp_tunnel_segment(skb, features, false); |
7a7ffbab WCC |
200 | goto out; |
201 | } | |
da5bab07 | 202 | |
f71470b3 TH |
203 | if (!pskb_may_pull(skb, sizeof(struct udphdr))) |
204 | goto out; | |
205 | ||
da5bab07 DB |
206 | mss = skb_shinfo(skb)->gso_size; |
207 | if (unlikely(skb->len <= mss)) | |
208 | goto out; | |
209 | ||
210 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
211 | /* Packet is from an untrusted source, reset gso_segs. */ | |
da5bab07 DB |
212 | |
213 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
214 | ||
215 | segs = NULL; | |
216 | goto out; | |
217 | } | |
218 | ||
7a7ffbab WCC |
219 | /* Do software UFO. Complete and fill in the UDP checksum as |
220 | * HW cannot do checksum of UDP packets sent as multiple | |
221 | * IP fragments. | |
222 | */ | |
f71470b3 TH |
223 | |
224 | uh = udp_hdr(skb); | |
225 | iph = ip_hdr(skb); | |
226 | ||
227 | uh->check = 0; | |
228 | csum = skb_checksum(skb, 0, skb->len, 0); | |
229 | uh->check = udp_v4_check(skb->len, iph->saddr, iph->daddr, csum); | |
230 | if (uh->check == 0) | |
231 | uh->check = CSUM_MANGLED_0; | |
232 | ||
7a7ffbab WCC |
233 | skb->ip_summed = CHECKSUM_NONE; |
234 | ||
22463876 AD |
235 | /* If there is no outer header we can fake a checksum offload |
236 | * due to the fact that we have already done the checksum in | |
237 | * software prior to segmenting the frame. | |
238 | */ | |
239 | if (!skb->encap_hdr_csum) | |
240 | features |= NETIF_F_HW_CSUM; | |
241 | ||
da5bab07 DB |
242 | /* Fragment the skb. IP headers of the fragments are updated in |
243 | * inet_gso_segment() | |
244 | */ | |
7a7ffbab | 245 | segs = skb_segment(skb, features); |
da5bab07 DB |
246 | out: |
247 | return segs; | |
248 | } | |
249 | ||
57c67ff4 | 250 | struct sk_buff **udp_gro_receive(struct sk_buff **head, struct sk_buff *skb, |
a6024562 | 251 | struct udphdr *uh, udp_lookup_t lookup) |
b582ef09 | 252 | { |
b582ef09 | 253 | struct sk_buff *p, **pp = NULL; |
57c67ff4 TH |
254 | struct udphdr *uh2; |
255 | unsigned int off = skb_gro_offset(skb); | |
b582ef09 | 256 | int flush = 1; |
a6024562 | 257 | struct sock *sk; |
b582ef09 | 258 | |
fac8e0f5 | 259 | if (NAPI_GRO_CB(skb)->encap_mark || |
662880f4 TH |
260 | (skb->ip_summed != CHECKSUM_PARTIAL && |
261 | NAPI_GRO_CB(skb)->csum_cnt == 0 && | |
262 | !NAPI_GRO_CB(skb)->csum_valid)) | |
b582ef09 OG |
263 | goto out; |
264 | ||
fac8e0f5 JG |
265 | /* mark that this skb passed once through the tunnel gro layer */ |
266 | NAPI_GRO_CB(skb)->encap_mark = 1; | |
b582ef09 OG |
267 | |
268 | rcu_read_lock(); | |
a6024562 TH |
269 | sk = (*lookup)(skb, uh->source, uh->dest); |
270 | ||
271 | if (sk && udp_sk(sk)->gro_receive) | |
272 | goto unflush; | |
b582ef09 OG |
273 | goto out_unlock; |
274 | ||
275 | unflush: | |
276 | flush = 0; | |
277 | ||
278 | for (p = *head; p; p = p->next) { | |
279 | if (!NAPI_GRO_CB(p)->same_flow) | |
280 | continue; | |
281 | ||
282 | uh2 = (struct udphdr *)(p->data + off); | |
57c67ff4 TH |
283 | |
284 | /* Match ports and either checksums are either both zero | |
285 | * or nonzero. | |
286 | */ | |
287 | if ((*(u32 *)&uh->source != *(u32 *)&uh2->source) || | |
288 | (!uh->check ^ !uh2->check)) { | |
b582ef09 OG |
289 | NAPI_GRO_CB(p)->same_flow = 0; |
290 | continue; | |
291 | } | |
292 | } | |
293 | ||
294 | skb_gro_pull(skb, sizeof(struct udphdr)); /* pull encapsulating udp header */ | |
6bae1d4c | 295 | skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr)); |
a6024562 | 296 | pp = udp_sk(sk)->gro_receive(sk, head, skb); |
b582ef09 OG |
297 | |
298 | out_unlock: | |
299 | rcu_read_unlock(); | |
300 | out: | |
301 | NAPI_GRO_CB(skb)->flush |= flush; | |
302 | return pp; | |
303 | } | |
a6024562 | 304 | EXPORT_SYMBOL(udp_gro_receive); |
b582ef09 | 305 | |
57c67ff4 TH |
306 | static struct sk_buff **udp4_gro_receive(struct sk_buff **head, |
307 | struct sk_buff *skb) | |
308 | { | |
309 | struct udphdr *uh = udp_gro_udphdr(skb); | |
310 | ||
2abb7cdc TH |
311 | if (unlikely(!uh)) |
312 | goto flush; | |
57c67ff4 | 313 | |
2abb7cdc | 314 | /* Don't bother verifying checksum if we're going to flush anyway. */ |
2d8f7e2c | 315 | if (NAPI_GRO_CB(skb)->flush) |
2abb7cdc TH |
316 | goto skip; |
317 | ||
318 | if (skb_gro_checksum_validate_zero_check(skb, IPPROTO_UDP, uh->check, | |
319 | inet_gro_compute_pseudo)) | |
320 | goto flush; | |
321 | else if (uh->check) | |
322 | skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check, | |
323 | inet_gro_compute_pseudo); | |
324 | skip: | |
efc98d08 | 325 | NAPI_GRO_CB(skb)->is_ipv6 = 0; |
a6024562 | 326 | return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb); |
2abb7cdc TH |
327 | |
328 | flush: | |
329 | NAPI_GRO_CB(skb)->flush = 1; | |
330 | return NULL; | |
57c67ff4 TH |
331 | } |
332 | ||
a6024562 TH |
333 | int udp_gro_complete(struct sk_buff *skb, int nhoff, |
334 | udp_lookup_t lookup) | |
b582ef09 | 335 | { |
b582ef09 OG |
336 | __be16 newlen = htons(skb->len - nhoff); |
337 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
338 | int err = -ENOSYS; | |
a6024562 | 339 | struct sock *sk; |
b582ef09 OG |
340 | |
341 | uh->len = newlen; | |
342 | ||
229740c6 JR |
343 | /* Set encapsulation before calling into inner gro_complete() functions |
344 | * to make them set up the inner offsets. | |
345 | */ | |
346 | skb->encapsulation = 1; | |
347 | ||
b582ef09 | 348 | rcu_read_lock(); |
a6024562 TH |
349 | sk = (*lookup)(skb, uh->source, uh->dest); |
350 | if (sk && udp_sk(sk)->gro_complete) | |
351 | err = udp_sk(sk)->gro_complete(sk, skb, | |
352 | nhoff + sizeof(struct udphdr)); | |
b582ef09 | 353 | rcu_read_unlock(); |
6db93ea1 TH |
354 | |
355 | if (skb->remcsum_offload) | |
356 | skb_shinfo(skb)->gso_type |= SKB_GSO_TUNNEL_REMCSUM; | |
357 | ||
b582ef09 OG |
358 | return err; |
359 | } | |
a6024562 | 360 | EXPORT_SYMBOL(udp_gro_complete); |
b582ef09 | 361 | |
72bb17b3 | 362 | static int udp4_gro_complete(struct sk_buff *skb, int nhoff) |
57c67ff4 TH |
363 | { |
364 | const struct iphdr *iph = ip_hdr(skb); | |
365 | struct udphdr *uh = (struct udphdr *)(skb->data + nhoff); | |
366 | ||
6db93ea1 TH |
367 | if (uh->check) { |
368 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; | |
57c67ff4 TH |
369 | uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr, |
370 | iph->daddr, 0); | |
6db93ea1 TH |
371 | } else { |
372 | skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; | |
373 | } | |
57c67ff4 | 374 | |
a6024562 | 375 | return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb); |
57c67ff4 TH |
376 | } |
377 | ||
da5bab07 DB |
378 | static const struct net_offload udpv4_offload = { |
379 | .callbacks = { | |
da5bab07 | 380 | .gso_segment = udp4_ufo_fragment, |
57c67ff4 TH |
381 | .gro_receive = udp4_gro_receive, |
382 | .gro_complete = udp4_gro_complete, | |
da5bab07 DB |
383 | }, |
384 | }; | |
385 | ||
386 | int __init udpv4_offload_init(void) | |
387 | { | |
388 | return inet_add_offload(&udpv4_offload, IPPROTO_UDP); | |
389 | } |