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
19 enum __sk_action {
20 __SK_DROP = 0,
21 __SK_PASS,
22 __SK_REDIRECT,
23 __SK_NONE,
24 };
25
26 struct 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. */
43 struct 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
56 struct 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 struct bpf_link *msg_parser_link;
62 struct bpf_link *stream_parser_link;
63 struct bpf_link *stream_verdict_link;
64 struct bpf_link *skb_verdict_link;
65 };
66
67 enum sk_psock_state_bits {
68 SK_PSOCK_TX_ENABLED,
69 SK_PSOCK_RX_STRP_ENABLED,
70 };
71
72 struct sk_psock_link {
73 struct list_head list;
74 struct bpf_map *map;
75 void *link_raw;
76 };
77
78 struct sk_psock_work_state {
79 u32 len;
80 u32 off;
81 };
82
83 struct sk_psock {
84 struct sock *sk;
85 struct sock *sk_redir;
86 u32 apply_bytes;
87 u32 cork_bytes;
88 u32 eval;
89 bool redir_ingress; /* undefined if sk_redir is null */
90 struct sk_msg *cork;
91 struct sk_psock_progs progs;
92 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
93 struct strparser strp;
94 u32 copied_seq;
95 u32 ingress_bytes;
96 #endif
97 struct sk_buff_head ingress_skb;
98 struct list_head ingress_msg;
99 spinlock_t ingress_lock;
100 unsigned long state;
101 struct list_head link;
102 spinlock_t link_lock;
103 refcount_t refcnt;
104 void (*saved_unhash)(struct sock *sk);
105 void (*saved_destroy)(struct sock *sk);
106 void (*saved_close)(struct sock *sk, long timeout);
107 void (*saved_write_space)(struct sock *sk);
108 void (*saved_data_ready)(struct sock *sk);
109 /* psock_update_sk_prot may be called with restore=false many times
110 * so the handler must be safe for this case. It will be called
111 * exactly once with restore=true when the psock is being destroyed
112 * and psock refcnt is zero, but before an RCU grace period.
113 */
114 int (*psock_update_sk_prot)(struct sock *sk, struct sk_psock *psock,
115 bool restore);
116 struct proto *sk_proto;
117 struct mutex work_mutex;
118 struct sk_psock_work_state work_state;
119 struct delayed_work work;
120 struct sock *sk_pair;
121 struct rcu_work rwork;
122 };
123
124 int sk_msg_alloc(struct sock *sk, struct sk_msg *msg, int len,
125 int elem_first_coalesce);
126 int sk_msg_clone(struct sock *sk, struct sk_msg *dst, struct sk_msg *src,
127 u32 off, u32 len);
128 void sk_msg_trim(struct sock *sk, struct sk_msg *msg, int len);
129 int sk_msg_free(struct sock *sk, struct sk_msg *msg);
130 int sk_msg_free_nocharge(struct sock *sk, struct sk_msg *msg);
131 void sk_msg_free_partial(struct sock *sk, struct sk_msg *msg, u32 bytes);
132 void sk_msg_free_partial_nocharge(struct sock *sk, struct sk_msg *msg,
133 u32 bytes);
134
135 void sk_msg_return(struct sock *sk, struct sk_msg *msg, int bytes);
136 void sk_msg_return_zero(struct sock *sk, struct sk_msg *msg, int bytes);
137
138 int sk_msg_zerocopy_from_iter(struct sock *sk, struct iov_iter *from,
139 struct sk_msg *msg, u32 bytes);
140 int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
141 struct sk_msg *msg, u32 bytes);
142 int sk_msg_recvmsg(struct sock *sk, struct sk_psock *psock, struct msghdr *msg,
143 int len, int flags);
144 bool sk_msg_is_readable(struct sock *sk);
145
sk_msg_check_to_free(struct sk_msg * msg,u32 i,u32 bytes)146 static inline void sk_msg_check_to_free(struct sk_msg *msg, u32 i, u32 bytes)
147 {
148 WARN_ON(i == msg->sg.end && bytes);
149 }
150
sk_msg_apply_bytes(struct sk_psock * psock,u32 bytes)151 static inline void sk_msg_apply_bytes(struct sk_psock *psock, u32 bytes)
152 {
153 if (psock->apply_bytes) {
154 if (psock->apply_bytes < bytes)
155 psock->apply_bytes = 0;
156 else
157 psock->apply_bytes -= bytes;
158 }
159 }
160
sk_msg_iter_dist(u32 start,u32 end)161 static inline u32 sk_msg_iter_dist(u32 start, u32 end)
162 {
163 return end >= start ? end - start : end + (NR_MSG_FRAG_IDS - start);
164 }
165
166 #define sk_msg_iter_var_prev(var) \
167 do { \
168 if (var == 0) \
169 var = NR_MSG_FRAG_IDS - 1; \
170 else \
171 var--; \
172 } while (0)
173
174 #define sk_msg_iter_var_next(var) \
175 do { \
176 var++; \
177 if (var == NR_MSG_FRAG_IDS) \
178 var = 0; \
179 } while (0)
180
181 #define sk_msg_iter_prev(msg, which) \
182 sk_msg_iter_var_prev(msg->sg.which)
183
184 #define sk_msg_iter_next(msg, which) \
185 sk_msg_iter_var_next(msg->sg.which)
186
sk_msg_init(struct sk_msg * msg)187 static inline void sk_msg_init(struct sk_msg *msg)
188 {
189 BUILD_BUG_ON(ARRAY_SIZE(msg->sg.data) - 1 != NR_MSG_FRAG_IDS);
190 memset(msg, 0, sizeof(*msg));
191 sg_init_marker(msg->sg.data, NR_MSG_FRAG_IDS);
192 }
193
sk_msg_xfer(struct sk_msg * dst,struct sk_msg * src,int which,u32 size)194 static inline void sk_msg_xfer(struct sk_msg *dst, struct sk_msg *src,
195 int which, u32 size)
196 {
197 dst->sg.data[which] = src->sg.data[which];
198 dst->sg.data[which].length = size;
199 dst->sg.size += size;
200 src->sg.size -= size;
201 src->sg.data[which].length -= size;
202 src->sg.data[which].offset += size;
203 }
204
sk_msg_xfer_full(struct sk_msg * dst,struct sk_msg * src)205 static inline void sk_msg_xfer_full(struct sk_msg *dst, struct sk_msg *src)
206 {
207 memcpy(dst, src, sizeof(*src));
208 sk_msg_init(src);
209 }
210
sk_msg_full(const struct sk_msg * msg)211 static inline bool sk_msg_full(const struct sk_msg *msg)
212 {
213 return sk_msg_iter_dist(msg->sg.start, msg->sg.end) == MAX_MSG_FRAGS;
214 }
215
sk_msg_elem_used(const struct sk_msg * msg)216 static inline u32 sk_msg_elem_used(const struct sk_msg *msg)
217 {
218 return sk_msg_iter_dist(msg->sg.start, msg->sg.end);
219 }
220
sk_msg_elem(struct sk_msg * msg,int which)221 static inline struct scatterlist *sk_msg_elem(struct sk_msg *msg, int which)
222 {
223 return &msg->sg.data[which];
224 }
225
sk_msg_elem_cpy(struct sk_msg * msg,int which)226 static inline struct scatterlist sk_msg_elem_cpy(struct sk_msg *msg, int which)
227 {
228 return msg->sg.data[which];
229 }
230
sk_msg_page(struct sk_msg * msg,int which)231 static inline struct page *sk_msg_page(struct sk_msg *msg, int which)
232 {
233 return sg_page(sk_msg_elem(msg, which));
234 }
235
sk_msg_to_ingress(const struct sk_msg * msg)236 static inline bool sk_msg_to_ingress(const struct sk_msg *msg)
237 {
238 return msg->flags & BPF_F_INGRESS;
239 }
240
sk_msg_compute_data_pointers(struct sk_msg * msg)241 static inline void sk_msg_compute_data_pointers(struct sk_msg *msg)
242 {
243 struct scatterlist *sge = sk_msg_elem(msg, msg->sg.start);
244
245 if (test_bit(msg->sg.start, msg->sg.copy)) {
246 msg->data = NULL;
247 msg->data_end = NULL;
248 } else {
249 msg->data = sg_virt(sge);
250 msg->data_end = msg->data + sge->length;
251 }
252 }
253
sk_msg_page_add(struct sk_msg * msg,struct page * page,u32 len,u32 offset)254 static inline void sk_msg_page_add(struct sk_msg *msg, struct page *page,
255 u32 len, u32 offset)
256 {
257 struct scatterlist *sge;
258
259 get_page(page);
260 sge = sk_msg_elem(msg, msg->sg.end);
261 sg_set_page(sge, page, len, offset);
262 sg_unmark_end(sge);
263
264 __set_bit(msg->sg.end, msg->sg.copy);
265 msg->sg.size += len;
266 sk_msg_iter_next(msg, end);
267 }
268
sk_msg_sg_copy(struct sk_msg * msg,u32 i,bool copy_state)269 static inline void sk_msg_sg_copy(struct sk_msg *msg, u32 i, bool copy_state)
270 {
271 do {
272 if (copy_state)
273 __set_bit(i, msg->sg.copy);
274 else
275 __clear_bit(i, msg->sg.copy);
276 sk_msg_iter_var_next(i);
277 if (i == msg->sg.end)
278 break;
279 } while (1);
280 }
281
sk_msg_sg_copy_set(struct sk_msg * msg,u32 start)282 static inline void sk_msg_sg_copy_set(struct sk_msg *msg, u32 start)
283 {
284 sk_msg_sg_copy(msg, start, true);
285 }
286
sk_msg_sg_copy_clear(struct sk_msg * msg,u32 start)287 static inline void sk_msg_sg_copy_clear(struct sk_msg *msg, u32 start)
288 {
289 sk_msg_sg_copy(msg, start, false);
290 }
291
sk_psock(const struct sock * sk)292 static inline struct sk_psock *sk_psock(const struct sock *sk)
293 {
294 return __rcu_dereference_sk_user_data_with_flags(sk,
295 SK_USER_DATA_PSOCK);
296 }
297
sk_psock_set_state(struct sk_psock * psock,enum sk_psock_state_bits bit)298 static inline void sk_psock_set_state(struct sk_psock *psock,
299 enum sk_psock_state_bits bit)
300 {
301 set_bit(bit, &psock->state);
302 }
303
sk_psock_clear_state(struct sk_psock * psock,enum sk_psock_state_bits bit)304 static inline void sk_psock_clear_state(struct sk_psock *psock,
305 enum sk_psock_state_bits bit)
306 {
307 clear_bit(bit, &psock->state);
308 }
309
sk_psock_test_state(const struct sk_psock * psock,enum sk_psock_state_bits bit)310 static inline bool sk_psock_test_state(const struct sk_psock *psock,
311 enum sk_psock_state_bits bit)
312 {
313 return test_bit(bit, &psock->state);
314 }
315
sock_drop(struct sock * sk,struct sk_buff * skb)316 static inline void sock_drop(struct sock *sk, struct sk_buff *skb)
317 {
318 sk_drops_add(sk, skb);
319 kfree_skb(skb);
320 }
321
sk_psock_queue_msg(struct sk_psock * psock,struct sk_msg * msg)322 static inline bool sk_psock_queue_msg(struct sk_psock *psock,
323 struct sk_msg *msg)
324 {
325 bool ret;
326
327 spin_lock_bh(&psock->ingress_lock);
328 if (sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
329 list_add_tail(&msg->list, &psock->ingress_msg);
330 ret = true;
331 } else {
332 sk_msg_free(psock->sk, msg);
333 kfree(msg);
334 ret = false;
335 }
336 spin_unlock_bh(&psock->ingress_lock);
337 return ret;
338 }
339
sk_psock_dequeue_msg(struct sk_psock * psock)340 static inline struct sk_msg *sk_psock_dequeue_msg(struct sk_psock *psock)
341 {
342 struct sk_msg *msg;
343
344 spin_lock_bh(&psock->ingress_lock);
345 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
346 if (msg)
347 list_del(&msg->list);
348 spin_unlock_bh(&psock->ingress_lock);
349 return msg;
350 }
351
sk_psock_peek_msg(struct sk_psock * psock)352 static inline struct sk_msg *sk_psock_peek_msg(struct sk_psock *psock)
353 {
354 struct sk_msg *msg;
355
356 spin_lock_bh(&psock->ingress_lock);
357 msg = list_first_entry_or_null(&psock->ingress_msg, struct sk_msg, list);
358 spin_unlock_bh(&psock->ingress_lock);
359 return msg;
360 }
361
sk_psock_next_msg(struct sk_psock * psock,struct sk_msg * msg)362 static inline struct sk_msg *sk_psock_next_msg(struct sk_psock *psock,
363 struct sk_msg *msg)
364 {
365 struct sk_msg *ret;
366
367 spin_lock_bh(&psock->ingress_lock);
368 if (list_is_last(&msg->list, &psock->ingress_msg))
369 ret = NULL;
370 else
371 ret = list_next_entry(msg, list);
372 spin_unlock_bh(&psock->ingress_lock);
373 return ret;
374 }
375
sk_psock_queue_empty(const struct sk_psock * psock)376 static inline bool sk_psock_queue_empty(const struct sk_psock *psock)
377 {
378 return psock ? list_empty(&psock->ingress_msg) : true;
379 }
380
kfree_sk_msg(struct sk_msg * msg)381 static inline void kfree_sk_msg(struct sk_msg *msg)
382 {
383 if (msg->skb)
384 consume_skb(msg->skb);
385 kfree(msg);
386 }
387
sk_psock_report_error(struct sk_psock * psock,int err)388 static inline void sk_psock_report_error(struct sk_psock *psock, int err)
389 {
390 struct sock *sk = psock->sk;
391
392 sk->sk_err = err;
393 sk_error_report(sk);
394 }
395
396 struct sk_psock *sk_psock_init(struct sock *sk, int node);
397 void sk_psock_stop(struct sk_psock *psock);
398
399 #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER)
400 int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock);
401 void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock);
402 void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock);
403 #else
sk_psock_init_strp(struct sock * sk,struct sk_psock * psock)404 static inline int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock)
405 {
406 return -EOPNOTSUPP;
407 }
408
sk_psock_start_strp(struct sock * sk,struct sk_psock * psock)409 static inline void sk_psock_start_strp(struct sock *sk, struct sk_psock *psock)
410 {
411 }
412
sk_psock_stop_strp(struct sock * sk,struct sk_psock * psock)413 static inline void sk_psock_stop_strp(struct sock *sk, struct sk_psock *psock)
414 {
415 }
416 #endif
417
418 void sk_psock_start_verdict(struct sock *sk, struct sk_psock *psock);
419 void sk_psock_stop_verdict(struct sock *sk, struct sk_psock *psock);
420
421 int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
422 struct sk_msg *msg);
423
424 /*
425 * This specialized allocator has to be a macro for its allocations to be
426 * accounted separately (to have a separate alloc_tag). The typecast is
427 * intentional to enforce typesafety.
428 */
429 #define sk_psock_init_link() \
430 ((struct sk_psock_link *)kzalloc(sizeof(struct sk_psock_link), \
431 GFP_ATOMIC | __GFP_NOWARN))
432
sk_psock_free_link(struct sk_psock_link * link)433 static inline void sk_psock_free_link(struct sk_psock_link *link)
434 {
435 kfree(link);
436 }
437
438 struct sk_psock_link *sk_psock_link_pop(struct sk_psock *psock);
439
sk_psock_cork_free(struct sk_psock * psock)440 static inline void sk_psock_cork_free(struct sk_psock *psock)
441 {
442 if (psock->cork) {
443 sk_msg_free(psock->sk, psock->cork);
444 kfree(psock->cork);
445 psock->cork = NULL;
446 }
447 }
448
sk_psock_restore_proto(struct sock * sk,struct sk_psock * psock)449 static inline void sk_psock_restore_proto(struct sock *sk,
450 struct sk_psock *psock)
451 {
452 if (psock->psock_update_sk_prot)
453 psock->psock_update_sk_prot(sk, psock, true);
454 }
455
sk_psock_get(struct sock * sk)456 static inline struct sk_psock *sk_psock_get(struct sock *sk)
457 {
458 struct sk_psock *psock;
459
460 rcu_read_lock();
461 psock = sk_psock(sk);
462 if (psock && !refcount_inc_not_zero(&psock->refcnt))
463 psock = NULL;
464 rcu_read_unlock();
465 return psock;
466 }
467
468 void sk_psock_drop(struct sock *sk, struct sk_psock *psock);
469
sk_psock_put(struct sock * sk,struct sk_psock * psock)470 static inline void sk_psock_put(struct sock *sk, struct sk_psock *psock)
471 {
472 if (refcount_dec_and_test(&psock->refcnt))
473 sk_psock_drop(sk, psock);
474 }
475
sk_psock_data_ready(struct sock * sk,struct sk_psock * psock)476 static inline void sk_psock_data_ready(struct sock *sk, struct sk_psock *psock)
477 {
478 read_lock_bh(&sk->sk_callback_lock);
479 if (psock->saved_data_ready)
480 psock->saved_data_ready(sk);
481 else
482 sk->sk_data_ready(sk);
483 read_unlock_bh(&sk->sk_callback_lock);
484 }
485
psock_set_prog(struct bpf_prog ** pprog,struct bpf_prog * prog)486 static inline void psock_set_prog(struct bpf_prog **pprog,
487 struct bpf_prog *prog)
488 {
489 prog = xchg(pprog, prog);
490 if (prog)
491 bpf_prog_put(prog);
492 }
493
psock_replace_prog(struct bpf_prog ** pprog,struct bpf_prog * prog,struct bpf_prog * old)494 static inline int psock_replace_prog(struct bpf_prog **pprog,
495 struct bpf_prog *prog,
496 struct bpf_prog *old)
497 {
498 if (cmpxchg(pprog, old, prog) != old)
499 return -ENOENT;
500
501 if (old)
502 bpf_prog_put(old);
503
504 return 0;
505 }
506
psock_progs_drop(struct sk_psock_progs * progs)507 static inline void psock_progs_drop(struct sk_psock_progs *progs)
508 {
509 psock_set_prog(&progs->msg_parser, NULL);
510 psock_set_prog(&progs->stream_parser, NULL);
511 psock_set_prog(&progs->stream_verdict, NULL);
512 psock_set_prog(&progs->skb_verdict, NULL);
513 }
514
515 int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb);
516
sk_psock_strp_enabled(struct sk_psock * psock)517 static inline bool sk_psock_strp_enabled(struct sk_psock *psock)
518 {
519 if (!psock)
520 return false;
521 return !!psock->saved_data_ready;
522 }
523
524 #if IS_ENABLED(CONFIG_NET_SOCK_MSG)
525
526 #define BPF_F_STRPARSER (1UL << 1)
527
528 /* We only have two bits so far. */
529 #define BPF_F_PTR_MASK ~(BPF_F_INGRESS | BPF_F_STRPARSER)
530
skb_bpf_strparser(const struct sk_buff * skb)531 static inline bool skb_bpf_strparser(const struct sk_buff *skb)
532 {
533 unsigned long sk_redir = skb->_sk_redir;
534
535 return sk_redir & BPF_F_STRPARSER;
536 }
537
skb_bpf_set_strparser(struct sk_buff * skb)538 static inline void skb_bpf_set_strparser(struct sk_buff *skb)
539 {
540 skb->_sk_redir |= BPF_F_STRPARSER;
541 }
542
skb_bpf_ingress(const struct sk_buff * skb)543 static inline bool skb_bpf_ingress(const struct sk_buff *skb)
544 {
545 unsigned long sk_redir = skb->_sk_redir;
546
547 return sk_redir & BPF_F_INGRESS;
548 }
549
skb_bpf_set_ingress(struct sk_buff * skb)550 static inline void skb_bpf_set_ingress(struct sk_buff *skb)
551 {
552 skb->_sk_redir |= BPF_F_INGRESS;
553 }
554
skb_bpf_set_redir(struct sk_buff * skb,struct sock * sk_redir,bool ingress)555 static inline void skb_bpf_set_redir(struct sk_buff *skb, struct sock *sk_redir,
556 bool ingress)
557 {
558 skb->_sk_redir = (unsigned long)sk_redir;
559 if (ingress)
560 skb->_sk_redir |= BPF_F_INGRESS;
561 }
562
skb_bpf_redirect_fetch(const struct sk_buff * skb)563 static inline struct sock *skb_bpf_redirect_fetch(const struct sk_buff *skb)
564 {
565 unsigned long sk_redir = skb->_sk_redir;
566
567 return (struct sock *)(sk_redir & BPF_F_PTR_MASK);
568 }
569
skb_bpf_redirect_clear(struct sk_buff * skb)570 static inline void skb_bpf_redirect_clear(struct sk_buff *skb)
571 {
572 skb->_sk_redir = 0;
573 }
574 #endif /* CONFIG_NET_SOCK_MSG */
575 #endif /* _LINUX_SKMSG_H */
576