Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
28850dc7 DB |
2 | /* |
3 | * IPV4 GSO/GRO offload support | |
4 | * Linux INET implementation | |
5 | * | |
28850dc7 DB |
6 | * TCPv4 GSO/GRO support |
7 | */ | |
8 | ||
028e0a47 | 9 | #include <linux/indirect_call_wrapper.h> |
28850dc7 DB |
10 | #include <linux/skbuff.h> |
11 | #include <net/tcp.h> | |
12 | #include <net/protocol.h> | |
13 | ||
f066e2b0 WB |
14 | static void tcp_gso_tstamp(struct sk_buff *skb, unsigned int ts_seq, |
15 | unsigned int seq, unsigned int mss) | |
4ed2d765 WB |
16 | { |
17 | while (skb) { | |
f066e2b0 WB |
18 | if (before(ts_seq, seq + mss)) { |
19 | skb_shinfo(skb)->tx_flags |= SKBTX_SW_TSTAMP; | |
4ed2d765 WB |
20 | skb_shinfo(skb)->tskey = ts_seq; |
21 | return; | |
22 | } | |
23 | ||
24 | skb = skb->next; | |
25 | seq += mss; | |
26 | } | |
27 | } | |
28 | ||
74abc20c ED |
29 | static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb, |
30 | netdev_features_t features) | |
d020f8f7 | 31 | { |
121d57af WB |
32 | if (!(skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4)) |
33 | return ERR_PTR(-EINVAL); | |
34 | ||
d020f8f7 TH |
35 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) |
36 | return ERR_PTR(-EINVAL); | |
37 | ||
38 | if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) { | |
39 | const struct iphdr *iph = ip_hdr(skb); | |
40 | struct tcphdr *th = tcp_hdr(skb); | |
41 | ||
42 | /* Set up checksum pseudo header, usually expect stack to | |
43 | * have done this already. | |
44 | */ | |
45 | ||
46 | th->check = 0; | |
47 | skb->ip_summed = CHECKSUM_PARTIAL; | |
48 | __tcp_v4_send_check(skb, iph->saddr, iph->daddr); | |
49 | } | |
50 | ||
51 | return tcp_gso_segment(skb, features); | |
52 | } | |
53 | ||
28be6e07 | 54 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
28850dc7 DB |
55 | netdev_features_t features) |
56 | { | |
57 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
0d08c42c | 58 | unsigned int sum_truesize = 0; |
28850dc7 DB |
59 | struct tcphdr *th; |
60 | unsigned int thlen; | |
61 | unsigned int seq; | |
62 | __be32 delta; | |
63 | unsigned int oldlen; | |
64 | unsigned int mss; | |
65 | struct sk_buff *gso_skb = skb; | |
66 | __sum16 newcheck; | |
67 | bool ooo_okay, copy_destructor; | |
68 | ||
28850dc7 DB |
69 | th = tcp_hdr(skb); |
70 | thlen = th->doff * 4; | |
71 | if (thlen < sizeof(*th)) | |
72 | goto out; | |
73 | ||
74 | if (!pskb_may_pull(skb, thlen)) | |
75 | goto out; | |
76 | ||
77 | oldlen = (u16)~skb->len; | |
78 | __skb_pull(skb, thlen); | |
79 | ||
a7eea416 | 80 | mss = skb_shinfo(skb)->gso_size; |
28850dc7 DB |
81 | if (unlikely(skb->len <= mss)) |
82 | goto out; | |
83 | ||
84 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
85 | /* Packet is from an untrusted source, reset gso_segs. */ | |
28850dc7 DB |
86 | |
87 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
88 | ||
89 | segs = NULL; | |
90 | goto out; | |
91 | } | |
92 | ||
93 | copy_destructor = gso_skb->destructor == tcp_wfree; | |
94 | ooo_okay = gso_skb->ooo_okay; | |
95 | /* All segments but the first should have ooo_okay cleared */ | |
96 | skb->ooo_okay = 0; | |
97 | ||
98 | segs = skb_segment(skb, features); | |
99 | if (IS_ERR(segs)) | |
100 | goto out; | |
101 | ||
102 | /* Only first segment might have ooo_okay set */ | |
103 | segs->ooo_okay = ooo_okay; | |
104 | ||
07b26c94 SK |
105 | /* GSO partial and frag_list segmentation only requires splitting |
106 | * the frame into an MSS multiple and possibly a remainder, both | |
107 | * cases return a GSO skb. So update the mss now. | |
108 | */ | |
109 | if (skb_is_gso(segs)) | |
110 | mss *= skb_shinfo(segs)->gso_segs; | |
111 | ||
28850dc7 DB |
112 | delta = htonl(oldlen + (thlen + mss)); |
113 | ||
114 | skb = segs; | |
115 | th = tcp_hdr(skb); | |
116 | seq = ntohl(th->seq); | |
117 | ||
4ed2d765 WB |
118 | if (unlikely(skb_shinfo(gso_skb)->tx_flags & SKBTX_SW_TSTAMP)) |
119 | tcp_gso_tstamp(segs, skb_shinfo(gso_skb)->tskey, seq, mss); | |
120 | ||
28850dc7 DB |
121 | newcheck = ~csum_fold((__force __wsum)((__force u32)th->check + |
122 | (__force u32)delta)); | |
123 | ||
802ab55a | 124 | while (skb->next) { |
28850dc7 DB |
125 | th->fin = th->psh = 0; |
126 | th->check = newcheck; | |
127 | ||
08b64fcc AD |
128 | if (skb->ip_summed == CHECKSUM_PARTIAL) |
129 | gso_reset_checksum(skb, ~th->check); | |
130 | else | |
e9c3a24b | 131 | th->check = gso_make_checksum(skb, ~th->check); |
28850dc7 DB |
132 | |
133 | seq += mss; | |
134 | if (copy_destructor) { | |
135 | skb->destructor = gso_skb->destructor; | |
136 | skb->sk = gso_skb->sk; | |
0d08c42c | 137 | sum_truesize += skb->truesize; |
28850dc7 DB |
138 | } |
139 | skb = skb->next; | |
140 | th = tcp_hdr(skb); | |
141 | ||
142 | th->seq = htonl(seq); | |
143 | th->cwr = 0; | |
802ab55a | 144 | } |
28850dc7 DB |
145 | |
146 | /* Following permits TCP Small Queues to work well with GSO : | |
147 | * The callback to TCP stack will be called at the time last frag | |
148 | * is freed at TX completion, and not right now when gso_skb | |
149 | * is freed by GSO engine | |
150 | */ | |
151 | if (copy_destructor) { | |
7ec318fe ED |
152 | int delta; |
153 | ||
28850dc7 DB |
154 | swap(gso_skb->sk, skb->sk); |
155 | swap(gso_skb->destructor, skb->destructor); | |
0d08c42c | 156 | sum_truesize += skb->truesize; |
7ec318fe ED |
157 | delta = sum_truesize - gso_skb->truesize; |
158 | /* In some pathological cases, delta can be negative. | |
159 | * We need to either use refcount_add() or refcount_sub_and_test() | |
160 | */ | |
161 | if (likely(delta >= 0)) | |
162 | refcount_add(delta, &skb->sk->sk_wmem_alloc); | |
163 | else | |
164 | WARN_ON_ONCE(refcount_sub_and_test(-delta, &skb->sk->sk_wmem_alloc)); | |
28850dc7 DB |
165 | } |
166 | ||
167 | delta = htonl(oldlen + (skb_tail_pointer(skb) - | |
168 | skb_transport_header(skb)) + | |
169 | skb->data_len); | |
170 | th->check = ~csum_fold((__force __wsum)((__force u32)th->check + | |
171 | (__force u32)delta)); | |
08b64fcc AD |
172 | if (skb->ip_summed == CHECKSUM_PARTIAL) |
173 | gso_reset_checksum(skb, ~th->check); | |
174 | else | |
e9c3a24b | 175 | th->check = gso_make_checksum(skb, ~th->check); |
28850dc7 DB |
176 | out: |
177 | return segs; | |
178 | } | |
28850dc7 | 179 | |
d4546c25 | 180 | struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb) |
28850dc7 | 181 | { |
d4546c25 | 182 | struct sk_buff *pp = NULL; |
28850dc7 DB |
183 | struct sk_buff *p; |
184 | struct tcphdr *th; | |
185 | struct tcphdr *th2; | |
186 | unsigned int len; | |
187 | unsigned int thlen; | |
188 | __be32 flags; | |
189 | unsigned int mss = 1; | |
190 | unsigned int hlen; | |
191 | unsigned int off; | |
192 | int flush = 1; | |
193 | int i; | |
194 | ||
195 | off = skb_gro_offset(skb); | |
196 | hlen = off + sizeof(*th); | |
197 | th = skb_gro_header_fast(skb, off); | |
198 | if (skb_gro_header_hard(skb, hlen)) { | |
199 | th = skb_gro_header_slow(skb, hlen, off); | |
200 | if (unlikely(!th)) | |
201 | goto out; | |
202 | } | |
203 | ||
204 | thlen = th->doff * 4; | |
205 | if (thlen < sizeof(*th)) | |
206 | goto out; | |
207 | ||
208 | hlen = off + thlen; | |
209 | if (skb_gro_header_hard(skb, hlen)) { | |
210 | th = skb_gro_header_slow(skb, hlen, off); | |
211 | if (unlikely(!th)) | |
212 | goto out; | |
213 | } | |
214 | ||
215 | skb_gro_pull(skb, thlen); | |
216 | ||
217 | len = skb_gro_len(skb); | |
218 | flags = tcp_flag_word(th); | |
219 | ||
d4546c25 | 220 | list_for_each_entry(p, head, list) { |
28850dc7 DB |
221 | if (!NAPI_GRO_CB(p)->same_flow) |
222 | continue; | |
223 | ||
224 | th2 = tcp_hdr(p); | |
225 | ||
226 | if (*(u32 *)&th->source ^ *(u32 *)&th2->source) { | |
227 | NAPI_GRO_CB(p)->same_flow = 0; | |
228 | continue; | |
229 | } | |
230 | ||
231 | goto found; | |
232 | } | |
d4546c25 | 233 | p = NULL; |
28850dc7 DB |
234 | goto out_check_final; |
235 | ||
236 | found: | |
bf5a755f | 237 | /* Include the IP ID check below from the inner most IP hdr */ |
1530545e | 238 | flush = NAPI_GRO_CB(p)->flush; |
28850dc7 DB |
239 | flush |= (__force int)(flags & TCP_FLAG_CWR); |
240 | flush |= (__force int)((flags ^ tcp_flag_word(th2)) & | |
241 | ~(TCP_FLAG_CWR | TCP_FLAG_FIN | TCP_FLAG_PSH)); | |
242 | flush |= (__force int)(th->ack_seq ^ th2->ack_seq); | |
243 | for (i = sizeof(*th); i < thlen; i += 4) | |
244 | flush |= *(u32 *)((u8 *)th + i) ^ | |
245 | *(u32 *)((u8 *)th2 + i); | |
246 | ||
1530545e AD |
247 | /* When we receive our second frame we can made a decision on if we |
248 | * continue this flow as an atomic flow with a fixed ID or if we use | |
249 | * an incrementing ID. | |
250 | */ | |
251 | if (NAPI_GRO_CB(p)->flush_id != 1 || | |
252 | NAPI_GRO_CB(p)->count != 1 || | |
253 | !NAPI_GRO_CB(p)->is_atomic) | |
254 | flush |= NAPI_GRO_CB(p)->flush_id; | |
255 | else | |
256 | NAPI_GRO_CB(p)->is_atomic = false; | |
257 | ||
a7eea416 | 258 | mss = skb_shinfo(p)->gso_size; |
28850dc7 DB |
259 | |
260 | flush |= (len - 1) >= mss; | |
261 | flush |= (ntohl(th2->seq) + skb_gro_len(p)) ^ ntohl(th->seq); | |
41ed9c04 BP |
262 | #ifdef CONFIG_TLS_DEVICE |
263 | flush |= p->decrypted ^ skb->decrypted; | |
264 | #endif | |
28850dc7 | 265 | |
d4546c25 | 266 | if (flush || skb_gro_receive(p, skb)) { |
28850dc7 DB |
267 | mss = 1; |
268 | goto out_check_final; | |
269 | } | |
270 | ||
28850dc7 DB |
271 | tcp_flag_word(th2) |= flags & (TCP_FLAG_FIN | TCP_FLAG_PSH); |
272 | ||
273 | out_check_final: | |
274 | flush = len < mss; | |
275 | flush |= (__force int)(flags & (TCP_FLAG_URG | TCP_FLAG_PSH | | |
276 | TCP_FLAG_RST | TCP_FLAG_SYN | | |
277 | TCP_FLAG_FIN)); | |
278 | ||
279 | if (p && (!NAPI_GRO_CB(skb)->same_flow || flush)) | |
d4546c25 | 280 | pp = p; |
28850dc7 DB |
281 | |
282 | out: | |
bf5a755f | 283 | NAPI_GRO_CB(skb)->flush |= (flush != 0); |
28850dc7 DB |
284 | |
285 | return pp; | |
286 | } | |
28850dc7 DB |
287 | |
288 | int tcp_gro_complete(struct sk_buff *skb) | |
289 | { | |
290 | struct tcphdr *th = tcp_hdr(skb); | |
291 | ||
299603e8 | 292 | skb->csum_start = (unsigned char *)th - skb->head; |
28850dc7 DB |
293 | skb->csum_offset = offsetof(struct tcphdr, check); |
294 | skb->ip_summed = CHECKSUM_PARTIAL; | |
295 | ||
296 | skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count; | |
297 | ||
298 | if (th->cwr) | |
299 | skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; | |
300 | ||
301 | return 0; | |
302 | } | |
303 | EXPORT_SYMBOL(tcp_gro_complete); | |
304 | ||
028e0a47 PA |
305 | INDIRECT_CALLABLE_SCOPE |
306 | struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb) | |
28850dc7 | 307 | { |
cc5c00bb | 308 | /* Don't bother verifying checksum if we're going to flush anyway. */ |
149d0774 TH |
309 | if (!NAPI_GRO_CB(skb)->flush && |
310 | skb_gro_checksum_validate(skb, IPPROTO_TCP, | |
311 | inet_gro_compute_pseudo)) { | |
28850dc7 DB |
312 | NAPI_GRO_CB(skb)->flush = 1; |
313 | return NULL; | |
28850dc7 DB |
314 | } |
315 | ||
316 | return tcp_gro_receive(head, skb); | |
317 | } | |
318 | ||
028e0a47 | 319 | INDIRECT_CALLABLE_SCOPE int tcp4_gro_complete(struct sk_buff *skb, int thoff) |
28850dc7 DB |
320 | { |
321 | const struct iphdr *iph = ip_hdr(skb); | |
322 | struct tcphdr *th = tcp_hdr(skb); | |
323 | ||
299603e8 JC |
324 | th->check = ~tcp_v4_check(skb->len - thoff, iph->saddr, |
325 | iph->daddr, 0); | |
c3caf119 | 326 | skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; |
28850dc7 | 327 | |
1530545e AD |
328 | if (NAPI_GRO_CB(skb)->is_atomic) |
329 | skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_FIXEDID; | |
330 | ||
28850dc7 DB |
331 | return tcp_gro_complete(skb); |
332 | } | |
333 | ||
334 | static const struct net_offload tcpv4_offload = { | |
335 | .callbacks = { | |
d020f8f7 | 336 | .gso_segment = tcp4_gso_segment, |
28850dc7 DB |
337 | .gro_receive = tcp4_gro_receive, |
338 | .gro_complete = tcp4_gro_complete, | |
339 | }, | |
340 | }; | |
341 | ||
342 | int __init tcpv4_offload_init(void) | |
343 | { | |
344 | return inet_add_offload(&tcpv4_offload, IPPROTO_TCP); | |
345 | } |