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1/* SPDX-License-Identifier: GPL-2.0 */
2/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
3
4#ifndef _LINUX_SKMSG_H
5#define _LINUX_SKMSG_H
6
7#include <linux/bpf.h>
8#include <linux/filter.h>
9#include <linux/scatterlist.h>
10#include <linux/skbuff.h>
11
12#include <net/sock.h>
13#include <net/tcp.h>
14#include <net/strparser.h>
15
16#define MAX_MSG_FRAGS MAX_SKB_FRAGS
17#define NR_MSG_FRAG_IDS (MAX_MSG_FRAGS + 1)
18
19enum __sk_action {
20 __SK_DROP = 0,
21 __SK_PASS,
22 __SK_REDIRECT,
23 __SK_NONE,
24};
25
26struct sk_msg_sg {
27 u32 start;
28 u32 curr;
29 u32 end;
30 u32 size;
31 u32 copybreak;
32 DECLARE_BITMAP(copy, MAX_MSG_FRAGS + 2);
33 /* The extra two elements:
34 * 1) used for chaining the front and sections when the list becomes
35 * partitioned (e.g. end < start). The crypto APIs require the
36 * chaining;
37 * 2) to chain tailer SG entries after the message.
38 */
39 struct scatterlist data[MAX_MSG_FRAGS + 2];
40};
41
42/* UAPI in filter.c depends on struct sk_msg_sg being first element. */
43struct sk_msg {
44 struct sk_msg_sg sg;
45 void *data;
46 void *data_end;
47 u32 apply_bytes;
48 u32 cork_bytes;
49 u32 flags;
50 struct sk_buff *skb;
51 struct sock *sk_redir;
52 struct sock *sk;
53 struct list_head list;
54};
55
56struct sk_psock_progs {
57 struct bpf_prog *msg_parser;
58 struct bpf_prog *stream_parser;
59 struct bpf_prog *stream_verdict;
60 struct bpf_prog *skb_verdict;
61};
62
63enum sk_psock_state_bits {
64 SK_PSOCK_TX_ENABLED,
65 SK_PSOCK_RX_STRP_ENABLED,
66};
67
68struct sk_psock_link {
69 struct list_head list;
70 struct bpf_map *map;
71 void *link_raw;
72};
73
74struct sk_psock_work_state {
75 u32 len;
76 u32 off;
77};
78
79struct sk_psock {
80 struct sock *sk;
81 struct sock *sk_redir;
82 u32 apply_bytes;
83 u32 cork_bytes;
84 u32 eval;
85 bool redir_ingress; /* undefined if sk_redir is null */
86 struct sk_msg *cork;
87 struct sk_psock_progs progs;
88#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
89 struct strparser strp;
90#endif
91 struct sk_buff_head ingress_skb;
92 struct list_head ingress_msg;
93 spinlock_t ingress_lock;
94 unsigned long state;
95 struct list_head link;
96 spinlock_t link_lock;
97 refcount_t refcnt;
98 void (*saved_unhash)(struct sock *sk);
99 void (*saved_destroy)(struct sock *sk);
100 void (*saved_close)(struct sock *sk, long timeout);
101 void (*saved_write_space)(struct sock *sk);
102 void (*saved_data_ready)(struct sock *sk);
103 /* psock_update_sk_prot may be called with restore=false many times
104 * so the handler must be safe for this case. It will be called
105 * exactly once with restore=true when the psock is being destroyed
106 * and psock refcnt is zero, but before an RCU grace period.
107 */
108 int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock,
109 bool restore);
110 struct proto *sk_proto;
111 struct mutex work_mutex;
112 struct sk_psock_work_state work_state;
113 struct delayed_work work;
114 struct sock *sk_pair;
115 struct rcu_work rwork;
116};
117
118int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
119 int elem_first_coalesce);
120int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
121 u32 off, u32 len);
122void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len);
123int sk_msg_free(struct sock *sk, struct sk_msg *msg);
124int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg);
125void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes);
126void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
127 u32 bytes);
128
129void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes);
130void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes);
131
132int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
133 struct sk_msg *msg, u32 bytes);
134int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
135 struct sk_msg *msg, u32 bytes);
136int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
137 int len, int flags);
138bool sk_msg_is_readable(struct sock *sk);
139
140static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
141{
142 WARN_ON(i == msg->sg.end && bytes);
143}
144
145static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes)
146{
147 if (psock->apply_bytes) {
148 if (psock->apply_bytes < bytes)
149 psock->apply_bytes = 0;
150 else
151 psock->apply_bytes -= bytes;
152 }
153}
154
155static inline u32 sk_msg_iter_dist(u32 start, u32 end)
156{
157 return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start);
158}
159
160#define sk_msg_iter_var_prev(var) \
161 do { \
162 if (var == 0) \
163 var = NR_MSG_FRAG_IDS - 1; \
164 else \
165 var--; \
166 } while (0)
167
168#define sk_msg_iter_var_next(var) \
169 do { \
170 var++; \
171 if (var == NR_MSG_FRAG_IDS) \
172 var = 0; \
173 } while (0)
174
175#define sk_msg_iter_prev(msg, which) \
176 sk_msg_iter_var_prev(msg->sg.which)
177
178#define sk_msg_iter_next(msg, which) \
179 sk_msg_iter_var_next(msg->sg.which)
180
181static inline void sk_msg_init(struct sk_msg *msg)
182{
183 BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS);
184 memset(msg, 0, sizeof(*msg));
185 sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
186}
187
188static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
189 int which, u32 size)
190{
191 dst->sg.data[which] = src->sg.data[which];
192 dst->sg.data[which].length = size;
193 dst->sg.size += size;
194 src->sg.size -= size;
195 src->sg.data[which].length -= size;
196 src->sg.data[which].offset += size;
197}
198
199static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
200{
201 memcpy(dst, src, sizeof(*src));
202 sk_msg_init(src);
203}
204
205static inline bool sk_msg_full(const struct sk_msg *msg)
206{
207 return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS;
208}
209
210static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
211{
212 return sk_msg_iter_dist(msg->sg.start, msg->sg.end);
213}
214
215static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which)
216{
217 return &msg->sg.data[which];
218}
219
220static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which)
221{
222 return msg->sg.data[which];
223}
224
225static inline struct page *sk_msg_page(struct sk_msg *msg, int which)
226{
227 return sg_page(sk_msg_elem(msg, which));
228}
229
230static inline bool sk_msg_to_ingress(const struct sk_msg *msg)
231{
232 return msg->flags & BPF_F_INGRESS;
233}
234
235static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
236{
237 struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
238
239 if (test_bit(msg->sg.start, msg->sg.copy)) {
240 msg->data = NULL;
241 msg->data_end = NULL;
242 } else {
243 msg->data = sg_virt(sge);
244 msg->data_end = msg->data + sge->length;
245 }
246}
247
248static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
249 u32 len, u32 offset)
250{
251 struct scatterlist *sge;
252
253 get_page(page);
254 sge = sk_msg_elem(msg, msg->sg.end);
255 sg_set_page(sge, page, len, offset);
256 sg_unmark_end(sge);
257
258 __set_bit(msg->sg.end, msg->sg.copy);
259 msg->sg.size += len;
260 sk_msg_iter_next(msg, end);
261}
262
263static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state)
264{
265 do {
266 if (copy_state)
267 __set_bit(i, msg->sg.copy);
268 else
269 __clear_bit(i, msg->sg.copy);
270 sk_msg_iter_var_next(i);
271 if (i == msg->sg.end)
272 break;
273 } while (1);
274}
275
276static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
277{
278 sk_msg_sg_copy(msg, start, true);
279}
280
281static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start)
282{
283 sk_msg_sg_copy(msg, start, false);
284}
285
286static inline struct sk_psock *sk_psock(const struct sock *sk)
287{
288 return __rcu_dereference_sk_user_data_with_flags(sk,
289 SK_USER_DATA_PSOCK);
290}
291
292static inline void sk_psock_set_state(struct sk_psock *psock,
293 enum sk_psock_state_bits bit)
294{
295 set_bit(bit, &psock->state);
296}
297
298static inline void sk_psock_clear_state(struct sk_psock *psock,
299 enum sk_psock_state_bits bit)
300{
301 clear_bit(bit, &psock->state);
302}
303
304static inline bool sk_psock_test_state(const struct sk_psock *psock,
305 enum sk_psock_state_bits bit)
306{
307 return test_bit(bit, &psock->state);
308}
309
310static inline void sock_drop(struct sock *sk, struct sk_buff *skb)
311{
312 sk_drops_add(sk, skb);
313 kfree_skb(skb);
314}
315
316static inline void sk_psock_queue_msg(struct sk_psock *psock,
317 struct sk_msg *msg)
318{
319 spin_lock_bh(&psock->ingress_lock);
320 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
321 list_add_tail(&msg->list, &psock->ingress_msg);
322 else {
323 sk_msg_free(psock->sk, msg);
324 kfree(msg);
325 }
326 spin_unlock_bh(&psock->ingress_lock);
327}
328
329static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
330{
331 struct sk_msg *msg;
332
333 spin_lock_bh(&psock->ingress_lock);
334 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
335 if (msg)
336 list_del(&msg->list);
337 spin_unlock_bh(&psock->ingress_lock);
338 return msg;
339}
340
341static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
342{
343 struct sk_msg *msg;
344
345 spin_lock_bh(&psock->ingress_lock);
346 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
347 spin_unlock_bh(&psock->ingress_lock);
348 return msg;
349}
350
351static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
352 struct sk_msg *msg)
353{
354 struct sk_msg *ret;
355
356 spin_lock_bh(&psock->ingress_lock);
357 if (list_is_last(&msg->list, &psock->ingress_msg))
358 ret = NULL;
359 else
360 ret = list_next_entry(msg, list);
361 spin_unlock_bh(&psock->ingress_lock);
362 return ret;
363}
364
365static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
366{
367 return psock ? list_empty(&psock->ingress_msg) : true;
368}
369
370static inline void kfree_sk_msg(struct sk_msg *msg)
371{
372 if (msg->skb)
373 consume_skb(msg->skb);
374 kfree(msg);
375}
376
377static inline void sk_psock_report_error(struct sk_psock *psock, int err)
378{
379 struct sock *sk = psock->sk;
380
381 sk->sk_err = err;
382 sk_error_report(sk);
383}
384
385struct sk_psock *sk_psock_init(struct sock *sk, int node);
386void sk_psock_stop(struct sk_psock *psock);
387
388#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
389int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
390void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
391void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
392#else
393static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
394{
395 return -EOPNOTSUPP;
396}
397
398static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
399{
400}
401
402static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
403{
404}
405#endif
406
407void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
408void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
409
410int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
411 struct sk_msg *msg);
412
413static inline struct sk_psock_link *sk_psock_init_link(void)
414{
415 return kzalloc(sizeof(struct sk_psock_link),
416 GFP_ATOMIC | __GFP_NOWARN);
417}
418
419static inline void sk_psock_free_link(struct sk_psock_link *link)
420{
421 kfree(link);
422}
423
424struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock);
425
426static inline void sk_psock_cork_free(struct sk_psock *psock)
427{
428 if (psock->cork) {
429 sk_msg_free(psock->sk, psock->cork);
430 kfree(psock->cork);
431 psock->cork = NULL;
432 }
433}
434
435static inline void sk_psock_restore_proto(struct sock *sk,
436 struct sk_psock *psock)
437{
438 if (psock->psock_update_sk_prot)
439 psock->psock_update_sk_prot(sk, psock, true);
440}
441
442static inline struct sk_psock *sk_psock_get(struct sock *sk)
443{
444 struct sk_psock *psock;
445
446 rcu_read_lock();
447 psock = sk_psock(sk);
448 if (psock && !refcount_inc_not_zero(&psock->refcnt))
449 psock = NULL;
450 rcu_read_unlock();
451 return psock;
452}
453
454void sk_psock_drop(struct sock *sk, struct sk_psock *psock);
455
456static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock)
457{
458 if (refcount_dec_and_test(&psock->refcnt))
459 sk_psock_drop(sk, psock);
460}
461
462static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock)
463{
464 if (psock->saved_data_ready)
465 psock->saved_data_ready(sk);
466 else
467 sk->sk_data_ready(sk);
468}
469
470static inline void psock_set_prog(struct bpf_prog **pprog,
471 struct bpf_prog *prog)
472{
473 prog = xchg(pprog, prog);
474 if (prog)
475 bpf_prog_put(prog);
476}
477
478static inline int psock_replace_prog(struct bpf_prog **pprog,
479 struct bpf_prog *prog,
480 struct bpf_prog *old)
481{
482 if (cmpxchg(pprog, old, prog) != old)
483 return -ENOENT;
484
485 if (old)
486 bpf_prog_put(old);
487
488 return 0;
489}
490
491static inline void psock_progs_drop(struct sk_psock_progs *progs)
492{
493 psock_set_prog(&progs->msg_parser, NULL);
494 psock_set_prog(&progs->stream_parser, NULL);
495 psock_set_prog(&progs->stream_verdict, NULL);
496 psock_set_prog(&progs->skb_verdict, NULL);
497}
498
499int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb);
500
501static inline bool sk_psock_strp_enabled(struct sk_psock *psock)
502{
503 if (!psock)
504 return false;
505 return !!psock->saved_data_ready;
506}
507
508#if IS_ENABLED(CONFIG_NET_SOCK_MSG)
509
510#define BPF_F_STRPARSER (1UL << 1)
511
512/* We only have two bits so far. */
513#define BPF_F_PTR_MASK ~(BPF_F_INGRESS | BPF_F_STRPARSER)
514
515static inline bool skb_bpf_strparser(const struct sk_buff *skb)
516{
517 unsigned long sk_redir = skb->_sk_redir;
518
519 return sk_redir & BPF_F_STRPARSER;
520}
521
522static inline void skb_bpf_set_strparser(struct sk_buff *skb)
523{
524 skb->_sk_redir |= BPF_F_STRPARSER;
525}
526
527static inline bool skb_bpf_ingress(const struct sk_buff *skb)
528{
529 unsigned long sk_redir = skb->_sk_redir;
530
531 return sk_redir & BPF_F_INGRESS;
532}
533
534static inline void skb_bpf_set_ingress(struct sk_buff *skb)
535{
536 skb->_sk_redir |= BPF_F_INGRESS;
537}
538
539static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir,
540 bool ingress)
541{
542 skb->_sk_redir = (unsigned long)sk_redir;
543 if (ingress)
544 skb->_sk_redir |= BPF_F_INGRESS;
545}
546
547static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb)
548{
549 unsigned long sk_redir = skb->_sk_redir;
550
551 return (struct sock *)(sk_redir & BPF_F_PTR_MASK);
552}
553
554static inline void skb_bpf_redirect_clear(struct sk_buff *skb)
555{
556 skb->_sk_redir = 0;
557}
558#endif /* CONFIG_NET_SOCK_MSG */
559#endif /* _LINUX_SKMSG_H */
560

Warning: This file is not a C or C++ file. It does not have highlighting.

source code of linux/include/linux/skmsg.h