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