projects/linux·blob v6.7 · refs

560 lines · 13.3 KiB

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 int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock,
104 bool restore);
105 struct proto *sk_proto;
106 struct mutex work_mutex;
107 struct sk_psock_work_state work_state;
108 struct delayed_work work;
109 struct sock *sk_pair;
110 struct rcu_work rwork;
111};
112
113int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
114 int elem_first_coalesce);
115int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
116 u32 off, u32 len);
117void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len);
118int sk_msg_free(struct sock *sk, struct sk_msg *msg);
119int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg);
120void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes);
121void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
122 u32 bytes);
123
124void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes);
125void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes);
126
127int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
128 struct sk_msg *msg, u32 bytes);
129int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
130 struct sk_msg *msg, u32 bytes);
131int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
132 int len, int flags);
133bool sk_msg_is_readable(struct sock *sk);
134
135static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
136{
137 WARN_ON(i == msg->sg.end && bytes);
138}
139
140static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes)
141{
142 if (psock->apply_bytes) {
143 if (psock->apply_bytes < bytes)
144 psock->apply_bytes = 0;
145 else
146 psock->apply_bytes -= bytes;
147 }
148}
149
150static inline u32 sk_msg_iter_dist(u32 start, u32 end)
151{
152 return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start);
153}
154
155#define sk_msg_iter_var_prev(var) \
156 do { \
157 if (var == 0) \
158 var = NR_MSG_FRAG_IDS - 1; \
159 else \
160 var--; \
161 } while (0)
162
163#define sk_msg_iter_var_next(var) \
164 do { \
165 var++; \
166 if (var == NR_MSG_FRAG_IDS) \
167 var = 0; \
168 } while (0)
169
170#define sk_msg_iter_prev(msg, which) \
171 sk_msg_iter_var_prev(msg->sg.which)
172
173#define sk_msg_iter_next(msg, which) \
174 sk_msg_iter_var_next(msg->sg.which)
175
176static inline void sk_msg_init(struct sk_msg *msg)
177{
178 BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS);
179 memset(msg, 0, sizeof(*msg));
180 sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
181}
182
183static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
184 int which, u32 size)
185{
186 dst->sg.data[which] = src->sg.data[which];
187 dst->sg.data[which].length = size;
188 dst->sg.size += size;
189 src->sg.size -= size;
190 src->sg.data[which].length -= size;
191 src->sg.data[which].offset += size;
192}
193
194static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
195{
196 memcpy(dst, src, sizeof(*src));
197 sk_msg_init(src);
198}
199
200static inline bool sk_msg_full(const struct sk_msg *msg)
201{
202 return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS;
203}
204
205static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
206{
207 return sk_msg_iter_dist(msg->sg.start, msg->sg.end);
208}
209
210static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which)
211{
212 return &msg->sg.data[which];
213}
214
215static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which)
216{
217 return msg->sg.data[which];
218}
219
220static inline struct page *sk_msg_page(struct sk_msg *msg, int which)
221{
222 return sg_page(sk_msg_elem(msg, which));
223}
224
225static inline bool sk_msg_to_ingress(const struct sk_msg *msg)
226{
227 return msg->flags & BPF_F_INGRESS;
228}
229
230static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
231{
232 struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
233
234 if (test_bit(msg->sg.start, msg->sg.copy)) {
235 msg->data = NULL;
236 msg->data_end = NULL;
237 } else {
238 msg->data = sg_virt(sge);
239 msg->data_end = msg->data + sge->length;
240 }
241}
242
243static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
244 u32 len, u32 offset)
245{
246 struct scatterlist *sge;
247
248 get_page(page);
249 sge = sk_msg_elem(msg, msg->sg.end);
250 sg_set_page(sge, page, len, offset);
251 sg_unmark_end(sge);
252
253 __set_bit(msg->sg.end, msg->sg.copy);
254 msg->sg.size += len;
255 sk_msg_iter_next(msg, end);
256}
257
258static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state)
259{
260 do {
261 if (copy_state)
262 __set_bit(i, msg->sg.copy);
263 else
264 __clear_bit(i, msg->sg.copy);
265 sk_msg_iter_var_next(i);
266 if (i == msg->sg.end)
267 break;
268 } while (1);
269}
270
271static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
272{
273 sk_msg_sg_copy(msg, start, true);
274}
275
276static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start)
277{
278 sk_msg_sg_copy(msg, start, false);
279}
280
281static inline struct sk_psock *sk_psock(const struct sock *sk)
282{
283 return __rcu_dereference_sk_user_data_with_flags(sk,
284 SK_USER_DATA_PSOCK);
285}
286
287static inline void sk_psock_set_state(struct sk_psock *psock,
288 enum sk_psock_state_bits bit)
289{
290 set_bit(bit, &psock->state);
291}
292
293static inline void sk_psock_clear_state(struct sk_psock *psock,
294 enum sk_psock_state_bits bit)
295{
296 clear_bit(bit, &psock->state);
297}
298
299static inline bool sk_psock_test_state(const struct sk_psock *psock,
300 enum sk_psock_state_bits bit)
301{
302 return test_bit(bit, &psock->state);
303}
304
305static inline void sock_drop(struct sock *sk, struct sk_buff *skb)
306{
307 sk_drops_add(sk, skb);
308 kfree_skb(skb);
309}
310
311static inline void sk_psock_queue_msg(struct sk_psock *psock,
312 struct sk_msg *msg)
313{
314 spin_lock_bh(&psock->ingress_lock);
315 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED))
316 list_add_tail(&msg->list, &psock->ingress_msg);
317 else {
318 sk_msg_free(psock->sk, msg);
319 kfree(msg);
320 }
321 spin_unlock_bh(&psock->ingress_lock);
322}
323
324static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
325{
326 struct sk_msg *msg;
327
328 spin_lock_bh(&psock->ingress_lock);
329 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
330 if (msg)
331 list_del(&msg->list);
332 spin_unlock_bh(&psock->ingress_lock);
333 return msg;
334}
335
336static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
337{
338 struct sk_msg *msg;
339
340 spin_lock_bh(&psock->ingress_lock);
341 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
342 spin_unlock_bh(&psock->ingress_lock);
343 return msg;
344}
345
346static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
347 struct sk_msg *msg)
348{
349 struct sk_msg *ret;
350
351 spin_lock_bh(&psock->ingress_lock);
352 if (list_is_last(&msg->list, &psock->ingress_msg))
353 ret = NULL;
354 else
355 ret = list_next_entry(msg, list);
356 spin_unlock_bh(&psock->ingress_lock);
357 return ret;
358}
359
360static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
361{
362 return psock ? list_empty(&psock->ingress_msg) : true;
363}
364
365static inline void kfree_sk_msg(struct sk_msg *msg)
366{
367 if (msg->skb)
368 consume_skb(msg->skb);
369 kfree(msg);
370}
371
372static inline void sk_psock_report_error(struct sk_psock *psock, int err)
373{
374 struct sock *sk = psock->sk;
375
376 sk->sk_err = err;
377 sk_error_report(sk);
378}
379
380struct sk_psock *sk_psock_init(struct sock *sk, int node);
381void sk_psock_stop(struct sk_psock *psock);
382
383#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
384int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
385void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
386void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
387#else
388static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
389{
390 return -EOPNOTSUPP;
391}
392
393static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
394{
395}
396
397static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
398{
399}
400#endif
401
402void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
403void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
404
405int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
406 struct sk_msg *msg);
407
408static inline struct sk_psock_link *sk_psock_init_link(void)
409{
410 return kzalloc(sizeof(struct sk_psock_link),
411 GFP_ATOMIC | __GFP_NOWARN);
412}
413
414static inline void sk_psock_free_link(struct sk_psock_link *link)
415{
416 kfree(link);
417}
418
419struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock);
420
421static inline void sk_psock_cork_free(struct sk_psock *psock)
422{
423 if (psock->cork) {
424 sk_msg_free(psock->sk, psock->cork);
425 kfree(psock->cork);
426 psock->cork = NULL;
427 }
428}
429
430static inline void sk_psock_restore_proto(struct sock *sk,
431 struct sk_psock *psock)
432{
433 if (psock->psock_update_sk_prot)
434 psock->psock_update_sk_prot(sk, psock, true);
435}
436
437static inline struct sk_psock *sk_psock_get(struct sock *sk)
438{
439 struct sk_psock *psock;
440
441 rcu_read_lock();
442 psock = sk_psock(sk);
443 if (psock && !refcount_inc_not_zero(&psock->refcnt))
444 psock = NULL;
445 rcu_read_unlock();
446 return psock;
447}
448
449void sk_psock_drop(struct sock *sk, struct sk_psock *psock);
450
451static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock)
452{
453 if (refcount_dec_and_test(&psock->refcnt))
454 sk_psock_drop(sk, psock);
455}
456
457static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock)
458{
459 if (psock->saved_data_ready)
460 psock->saved_data_ready(sk);
461 else
462 sk->sk_data_ready(sk);
463}
464
465static inline void psock_set_prog(struct bpf_prog **pprog,
466 struct bpf_prog *prog)
467{
468 prog = xchg(pprog, prog);
469 if (prog)
470 bpf_prog_put(prog);
471}
472
473static inline int psock_replace_prog(struct bpf_prog **pprog,
474 struct bpf_prog *prog,
475 struct bpf_prog *old)
476{
477 if (cmpxchg(pprog, old, prog) != old)
478 return -ENOENT;
479
480 if (old)
481 bpf_prog_put(old);
482
483 return 0;
484}
485
486static inline void psock_progs_drop(struct sk_psock_progs *progs)
487{
488 psock_set_prog(&progs->msg_parser, NULL);
489 psock_set_prog(&progs->stream_parser, NULL);
490 psock_set_prog(&progs->stream_verdict, NULL);
491 psock_set_prog(&progs->skb_verdict, NULL);
492}
493
494int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb);
495
496static inline bool sk_psock_strp_enabled(struct sk_psock *psock)
497{
498 if (!psock)
499 return false;
500 return !!psock->saved_data_ready;
501}
502
503static inline bool sk_is_udp(const struct sock *sk)
504{
505 return sk->sk_type == SOCK_DGRAM &&
506 sk->sk_protocol == IPPROTO_UDP;
507}
508
509#if IS_ENABLED(CONFIG_NET_SOCK_MSG)
510
511#define BPF_F_STRPARSER (1UL << 1)
512
513/* We only have two bits so far. */
514#define BPF_F_PTR_MASK ~(BPF_F_INGRESS | BPF_F_STRPARSER)
515
516static inline bool skb_bpf_strparser(const struct sk_buff *skb)
517{
518 unsigned long sk_redir = skb->_sk_redir;
519
520 return sk_redir & BPF_F_STRPARSER;
521}
522
523static inline void skb_bpf_set_strparser(struct sk_buff *skb)
524{
525 skb->_sk_redir |= BPF_F_STRPARSER;
526}
527
528static inline bool skb_bpf_ingress(const struct sk_buff *skb)
529{
530 unsigned long sk_redir = skb->_sk_redir;
531
532 return sk_redir & BPF_F_INGRESS;
533}
534
535static inline void skb_bpf_set_ingress(struct sk_buff *skb)
536{
537 skb->_sk_redir |= BPF_F_INGRESS;
538}
539
540static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir,
541 bool ingress)
542{
543 skb->_sk_redir = (unsigned long)sk_redir;
544 if (ingress)
545 skb->_sk_redir |= BPF_F_INGRESS;
546}
547
548static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb)
549{
550 unsigned long sk_redir = skb->_sk_redir;
551
552 return (struct sock *)(sk_redir & BPF_F_PTR_MASK);
553}
554
555static inline void skb_bpf_redirect_clear(struct sk_buff *skb)
556{
557 skb->_sk_redir = 0;
558}
559#endif /* CONFIG_NET_SOCK_MSG */
560#endif /* _LINUX_SKMSG_H */