xref: /linux/io_uring/net.c (revision 83439a0f1ce6a592f95e41338320b5f01b98a356)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/slab.h>
6 #include <linux/net.h>
7 #include <linux/compat.h>
8 #include <net/compat.h>
9 #include <linux/io_uring.h>
10 
11 #include <uapi/linux/io_uring.h>
12 
13 #include "io_uring.h"
14 #include "kbuf.h"
15 #include "alloc_cache.h"
16 #include "net.h"
17 #include "notif.h"
18 #include "rsrc.h"
19 
20 #if defined(CONFIG_NET)
21 struct io_shutdown {
22 	struct file			*file;
23 	int				how;
24 };
25 
26 struct io_accept {
27 	struct file			*file;
28 	struct sockaddr __user		*addr;
29 	int __user			*addr_len;
30 	int				flags;
31 	u32				file_slot;
32 	unsigned long			nofile;
33 };
34 
35 struct io_socket {
36 	struct file			*file;
37 	int				domain;
38 	int				type;
39 	int				protocol;
40 	int				flags;
41 	u32				file_slot;
42 	unsigned long			nofile;
43 };
44 
45 struct io_connect {
46 	struct file			*file;
47 	struct sockaddr __user		*addr;
48 	int				addr_len;
49 };
50 
51 struct io_sr_msg {
52 	struct file			*file;
53 	union {
54 		struct compat_msghdr __user	*umsg_compat;
55 		struct user_msghdr __user	*umsg;
56 		void __user			*buf;
57 	};
58 	unsigned			len;
59 	unsigned			done_io;
60 	unsigned			msg_flags;
61 	u16				flags;
62 	/* initialised and used only by !msg send variants */
63 	u16				addr_len;
64 	void __user			*addr;
65 	/* used only for send zerocopy */
66 	struct io_kiocb 		*notif;
67 };
68 
69 #define IO_APOLL_MULTI_POLLED (REQ_F_APOLL_MULTISHOT | REQ_F_POLLED)
70 
71 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
72 {
73 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
74 
75 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
76 		     sqe->buf_index || sqe->splice_fd_in))
77 		return -EINVAL;
78 
79 	shutdown->how = READ_ONCE(sqe->len);
80 	return 0;
81 }
82 
83 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
84 {
85 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
86 	struct socket *sock;
87 	int ret;
88 
89 	if (issue_flags & IO_URING_F_NONBLOCK)
90 		return -EAGAIN;
91 
92 	sock = sock_from_file(req->file);
93 	if (unlikely(!sock))
94 		return -ENOTSOCK;
95 
96 	ret = __sys_shutdown_sock(sock, shutdown->how);
97 	io_req_set_res(req, ret, 0);
98 	return IOU_OK;
99 }
100 
101 static bool io_net_retry(struct socket *sock, int flags)
102 {
103 	if (!(flags & MSG_WAITALL))
104 		return false;
105 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
106 }
107 
108 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
109 {
110 	struct io_async_msghdr *hdr = req->async_data;
111 
112 	if (!req_has_async_data(req) || issue_flags & IO_URING_F_UNLOCKED)
113 		return;
114 
115 	/* Let normal cleanup path reap it if we fail adding to the cache */
116 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
117 		req->async_data = NULL;
118 		req->flags &= ~REQ_F_ASYNC_DATA;
119 	}
120 }
121 
122 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
123 						  unsigned int issue_flags)
124 {
125 	struct io_ring_ctx *ctx = req->ctx;
126 	struct io_cache_entry *entry;
127 	struct io_async_msghdr *hdr;
128 
129 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
130 	    (entry = io_alloc_cache_get(&ctx->netmsg_cache)) != NULL) {
131 		hdr = container_of(entry, struct io_async_msghdr, cache);
132 		hdr->free_iov = NULL;
133 		req->flags |= REQ_F_ASYNC_DATA;
134 		req->async_data = hdr;
135 		return hdr;
136 	}
137 
138 	if (!io_alloc_async_data(req)) {
139 		hdr = req->async_data;
140 		hdr->free_iov = NULL;
141 		return hdr;
142 	}
143 	return NULL;
144 }
145 
146 static inline struct io_async_msghdr *io_msg_alloc_async_prep(struct io_kiocb *req)
147 {
148 	/* ->prep_async is always called from the submission context */
149 	return io_msg_alloc_async(req, 0);
150 }
151 
152 static int io_setup_async_msg(struct io_kiocb *req,
153 			      struct io_async_msghdr *kmsg,
154 			      unsigned int issue_flags)
155 {
156 	struct io_async_msghdr *async_msg;
157 
158 	if (req_has_async_data(req))
159 		return -EAGAIN;
160 	async_msg = io_msg_alloc_async(req, issue_flags);
161 	if (!async_msg) {
162 		kfree(kmsg->free_iov);
163 		return -ENOMEM;
164 	}
165 	req->flags |= REQ_F_NEED_CLEANUP;
166 	memcpy(async_msg, kmsg, sizeof(*kmsg));
167 	if (async_msg->msg.msg_name)
168 		async_msg->msg.msg_name = &async_msg->addr;
169 	/* if were using fast_iov, set it to the new one */
170 	if (!kmsg->free_iov) {
171 		size_t fast_idx = kmsg->msg.msg_iter.iov - kmsg->fast_iov;
172 		async_msg->msg.msg_iter.iov = &async_msg->fast_iov[fast_idx];
173 	}
174 
175 	return -EAGAIN;
176 }
177 
178 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
179 			       struct io_async_msghdr *iomsg)
180 {
181 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
182 
183 	iomsg->msg.msg_name = &iomsg->addr;
184 	iomsg->free_iov = iomsg->fast_iov;
185 	return sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags,
186 					&iomsg->free_iov);
187 }
188 
189 int io_send_prep_async(struct io_kiocb *req)
190 {
191 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
192 	struct io_async_msghdr *io;
193 	int ret;
194 
195 	if (!zc->addr || req_has_async_data(req))
196 		return 0;
197 	io = io_msg_alloc_async_prep(req);
198 	if (!io)
199 		return -ENOMEM;
200 	ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr);
201 	return ret;
202 }
203 
204 static int io_setup_async_addr(struct io_kiocb *req,
205 			      struct sockaddr_storage *addr_storage,
206 			      unsigned int issue_flags)
207 {
208 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
209 	struct io_async_msghdr *io;
210 
211 	if (!sr->addr || req_has_async_data(req))
212 		return -EAGAIN;
213 	io = io_msg_alloc_async(req, issue_flags);
214 	if (!io)
215 		return -ENOMEM;
216 	memcpy(&io->addr, addr_storage, sizeof(io->addr));
217 	return -EAGAIN;
218 }
219 
220 int io_sendmsg_prep_async(struct io_kiocb *req)
221 {
222 	int ret;
223 
224 	if (!io_msg_alloc_async_prep(req))
225 		return -ENOMEM;
226 	ret = io_sendmsg_copy_hdr(req, req->async_data);
227 	if (!ret)
228 		req->flags |= REQ_F_NEED_CLEANUP;
229 	return ret;
230 }
231 
232 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
233 {
234 	struct io_async_msghdr *io = req->async_data;
235 
236 	kfree(io->free_iov);
237 }
238 
239 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
240 {
241 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
242 
243 	if (req->opcode == IORING_OP_SEND) {
244 		if (READ_ONCE(sqe->__pad3[0]))
245 			return -EINVAL;
246 		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
247 		sr->addr_len = READ_ONCE(sqe->addr_len);
248 	} else if (sqe->addr2 || sqe->file_index) {
249 		return -EINVAL;
250 	}
251 
252 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
253 	sr->len = READ_ONCE(sqe->len);
254 	sr->flags = READ_ONCE(sqe->ioprio);
255 	if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
256 		return -EINVAL;
257 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
258 	if (sr->msg_flags & MSG_DONTWAIT)
259 		req->flags |= REQ_F_NOWAIT;
260 
261 #ifdef CONFIG_COMPAT
262 	if (req->ctx->compat)
263 		sr->msg_flags |= MSG_CMSG_COMPAT;
264 #endif
265 	sr->done_io = 0;
266 	return 0;
267 }
268 
269 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
270 {
271 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
272 	struct io_async_msghdr iomsg, *kmsg;
273 	struct socket *sock;
274 	unsigned flags;
275 	int min_ret = 0;
276 	int ret;
277 
278 	sock = sock_from_file(req->file);
279 	if (unlikely(!sock))
280 		return -ENOTSOCK;
281 
282 	if (req_has_async_data(req)) {
283 		kmsg = req->async_data;
284 	} else {
285 		ret = io_sendmsg_copy_hdr(req, &iomsg);
286 		if (ret)
287 			return ret;
288 		kmsg = &iomsg;
289 	}
290 
291 	if (!(req->flags & REQ_F_POLLED) &&
292 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
293 		return io_setup_async_msg(req, kmsg, issue_flags);
294 
295 	flags = sr->msg_flags;
296 	if (issue_flags & IO_URING_F_NONBLOCK)
297 		flags |= MSG_DONTWAIT;
298 	if (flags & MSG_WAITALL)
299 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
300 
301 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
302 
303 	if (ret < min_ret) {
304 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
305 			return io_setup_async_msg(req, kmsg, issue_flags);
306 		if (ret > 0 && io_net_retry(sock, flags)) {
307 			sr->done_io += ret;
308 			req->flags |= REQ_F_PARTIAL_IO;
309 			return io_setup_async_msg(req, kmsg, issue_flags);
310 		}
311 		if (ret == -ERESTARTSYS)
312 			ret = -EINTR;
313 		req_set_fail(req);
314 	}
315 	/* fast path, check for non-NULL to avoid function call */
316 	if (kmsg->free_iov)
317 		kfree(kmsg->free_iov);
318 	req->flags &= ~REQ_F_NEED_CLEANUP;
319 	io_netmsg_recycle(req, issue_flags);
320 	if (ret >= 0)
321 		ret += sr->done_io;
322 	else if (sr->done_io)
323 		ret = sr->done_io;
324 	io_req_set_res(req, ret, 0);
325 	return IOU_OK;
326 }
327 
328 int io_send(struct io_kiocb *req, unsigned int issue_flags)
329 {
330 	struct sockaddr_storage __address;
331 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
332 	struct msghdr msg;
333 	struct iovec iov;
334 	struct socket *sock;
335 	unsigned flags;
336 	int min_ret = 0;
337 	int ret;
338 
339 	msg.msg_name = NULL;
340 	msg.msg_control = NULL;
341 	msg.msg_controllen = 0;
342 	msg.msg_namelen = 0;
343 	msg.msg_ubuf = NULL;
344 
345 	if (sr->addr) {
346 		if (req_has_async_data(req)) {
347 			struct io_async_msghdr *io = req->async_data;
348 
349 			msg.msg_name = &io->addr;
350 		} else {
351 			ret = move_addr_to_kernel(sr->addr, sr->addr_len, &__address);
352 			if (unlikely(ret < 0))
353 				return ret;
354 			msg.msg_name = (struct sockaddr *)&__address;
355 		}
356 		msg.msg_namelen = sr->addr_len;
357 	}
358 
359 	if (!(req->flags & REQ_F_POLLED) &&
360 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
361 		return io_setup_async_addr(req, &__address, issue_flags);
362 
363 	sock = sock_from_file(req->file);
364 	if (unlikely(!sock))
365 		return -ENOTSOCK;
366 
367 	ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
368 	if (unlikely(ret))
369 		return ret;
370 
371 	flags = sr->msg_flags;
372 	if (issue_flags & IO_URING_F_NONBLOCK)
373 		flags |= MSG_DONTWAIT;
374 	if (flags & MSG_WAITALL)
375 		min_ret = iov_iter_count(&msg.msg_iter);
376 
377 	msg.msg_flags = flags;
378 	ret = sock_sendmsg(sock, &msg);
379 	if (ret < min_ret) {
380 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
381 			return io_setup_async_addr(req, &__address, issue_flags);
382 
383 		if (ret > 0 && io_net_retry(sock, flags)) {
384 			sr->len -= ret;
385 			sr->buf += ret;
386 			sr->done_io += ret;
387 			req->flags |= REQ_F_PARTIAL_IO;
388 			return io_setup_async_addr(req, &__address, issue_flags);
389 		}
390 		if (ret == -ERESTARTSYS)
391 			ret = -EINTR;
392 		req_set_fail(req);
393 	}
394 	if (ret >= 0)
395 		ret += sr->done_io;
396 	else if (sr->done_io)
397 		ret = sr->done_io;
398 	io_req_set_res(req, ret, 0);
399 	return IOU_OK;
400 }
401 
402 static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
403 {
404 	int hdr;
405 
406 	if (iomsg->namelen < 0)
407 		return true;
408 	if (check_add_overflow((int)sizeof(struct io_uring_recvmsg_out),
409 			       iomsg->namelen, &hdr))
410 		return true;
411 	if (check_add_overflow(hdr, (int)iomsg->controllen, &hdr))
412 		return true;
413 
414 	return false;
415 }
416 
417 static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
418 				 struct io_async_msghdr *iomsg)
419 {
420 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
421 	struct user_msghdr msg;
422 	int ret;
423 
424 	if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
425 		return -EFAULT;
426 
427 	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
428 	if (ret)
429 		return ret;
430 
431 	if (req->flags & REQ_F_BUFFER_SELECT) {
432 		if (msg.msg_iovlen == 0) {
433 			sr->len = iomsg->fast_iov[0].iov_len = 0;
434 			iomsg->fast_iov[0].iov_base = NULL;
435 			iomsg->free_iov = NULL;
436 		} else if (msg.msg_iovlen > 1) {
437 			return -EINVAL;
438 		} else {
439 			if (copy_from_user(iomsg->fast_iov, msg.msg_iov, sizeof(*msg.msg_iov)))
440 				return -EFAULT;
441 			sr->len = iomsg->fast_iov[0].iov_len;
442 			iomsg->free_iov = NULL;
443 		}
444 
445 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
446 			iomsg->namelen = msg.msg_namelen;
447 			iomsg->controllen = msg.msg_controllen;
448 			if (io_recvmsg_multishot_overflow(iomsg))
449 				return -EOVERFLOW;
450 		}
451 	} else {
452 		iomsg->free_iov = iomsg->fast_iov;
453 		ret = __import_iovec(READ, msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV,
454 				     &iomsg->free_iov, &iomsg->msg.msg_iter,
455 				     false);
456 		if (ret > 0)
457 			ret = 0;
458 	}
459 
460 	return ret;
461 }
462 
463 #ifdef CONFIG_COMPAT
464 static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
465 					struct io_async_msghdr *iomsg)
466 {
467 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
468 	struct compat_msghdr msg;
469 	struct compat_iovec __user *uiov;
470 	int ret;
471 
472 	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
473 		return -EFAULT;
474 
475 	ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
476 	if (ret)
477 		return ret;
478 
479 	uiov = compat_ptr(msg.msg_iov);
480 	if (req->flags & REQ_F_BUFFER_SELECT) {
481 		compat_ssize_t clen;
482 
483 		if (msg.msg_iovlen == 0) {
484 			sr->len = 0;
485 		} else if (msg.msg_iovlen > 1) {
486 			return -EINVAL;
487 		} else {
488 			if (!access_ok(uiov, sizeof(*uiov)))
489 				return -EFAULT;
490 			if (__get_user(clen, &uiov->iov_len))
491 				return -EFAULT;
492 			if (clen < 0)
493 				return -EINVAL;
494 			sr->len = clen;
495 		}
496 
497 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
498 			iomsg->namelen = msg.msg_namelen;
499 			iomsg->controllen = msg.msg_controllen;
500 			if (io_recvmsg_multishot_overflow(iomsg))
501 				return -EOVERFLOW;
502 		}
503 	} else {
504 		iomsg->free_iov = iomsg->fast_iov;
505 		ret = __import_iovec(READ, (struct iovec __user *)uiov, msg.msg_iovlen,
506 				   UIO_FASTIOV, &iomsg->free_iov,
507 				   &iomsg->msg.msg_iter, true);
508 		if (ret < 0)
509 			return ret;
510 	}
511 
512 	return 0;
513 }
514 #endif
515 
516 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
517 			       struct io_async_msghdr *iomsg)
518 {
519 	iomsg->msg.msg_name = &iomsg->addr;
520 
521 #ifdef CONFIG_COMPAT
522 	if (req->ctx->compat)
523 		return __io_compat_recvmsg_copy_hdr(req, iomsg);
524 #endif
525 
526 	return __io_recvmsg_copy_hdr(req, iomsg);
527 }
528 
529 int io_recvmsg_prep_async(struct io_kiocb *req)
530 {
531 	int ret;
532 
533 	if (!io_msg_alloc_async_prep(req))
534 		return -ENOMEM;
535 	ret = io_recvmsg_copy_hdr(req, req->async_data);
536 	if (!ret)
537 		req->flags |= REQ_F_NEED_CLEANUP;
538 	return ret;
539 }
540 
541 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)
542 
543 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
544 {
545 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
546 
547 	if (unlikely(sqe->file_index || sqe->addr2))
548 		return -EINVAL;
549 
550 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
551 	sr->len = READ_ONCE(sqe->len);
552 	sr->flags = READ_ONCE(sqe->ioprio);
553 	if (sr->flags & ~(RECVMSG_FLAGS))
554 		return -EINVAL;
555 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
556 	if (sr->msg_flags & MSG_DONTWAIT)
557 		req->flags |= REQ_F_NOWAIT;
558 	if (sr->msg_flags & MSG_ERRQUEUE)
559 		req->flags |= REQ_F_CLEAR_POLLIN;
560 	if (sr->flags & IORING_RECV_MULTISHOT) {
561 		if (!(req->flags & REQ_F_BUFFER_SELECT))
562 			return -EINVAL;
563 		if (sr->msg_flags & MSG_WAITALL)
564 			return -EINVAL;
565 		if (req->opcode == IORING_OP_RECV && sr->len)
566 			return -EINVAL;
567 		req->flags |= REQ_F_APOLL_MULTISHOT;
568 	}
569 
570 #ifdef CONFIG_COMPAT
571 	if (req->ctx->compat)
572 		sr->msg_flags |= MSG_CMSG_COMPAT;
573 #endif
574 	sr->done_io = 0;
575 	return 0;
576 }
577 
578 static inline void io_recv_prep_retry(struct io_kiocb *req)
579 {
580 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
581 
582 	sr->done_io = 0;
583 	sr->len = 0; /* get from the provided buffer */
584 }
585 
586 /*
587  * Finishes io_recv and io_recvmsg.
588  *
589  * Returns true if it is actually finished, or false if it should run
590  * again (for multishot).
591  */
592 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
593 				  unsigned int cflags, bool mshot_finished)
594 {
595 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
596 		io_req_set_res(req, *ret, cflags);
597 		*ret = IOU_OK;
598 		return true;
599 	}
600 
601 	if (!mshot_finished) {
602 		if (io_post_aux_cqe(req->ctx, req->cqe.user_data, *ret,
603 				    cflags | IORING_CQE_F_MORE, false)) {
604 			io_recv_prep_retry(req);
605 			return false;
606 		}
607 		/*
608 		 * Otherwise stop multishot but use the current result.
609 		 * Probably will end up going into overflow, but this means
610 		 * we cannot trust the ordering anymore
611 		 */
612 	}
613 
614 	io_req_set_res(req, *ret, cflags);
615 
616 	if (req->flags & REQ_F_POLLED)
617 		*ret = IOU_STOP_MULTISHOT;
618 	else
619 		*ret = IOU_OK;
620 	return true;
621 }
622 
623 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
624 				     struct io_sr_msg *sr, void __user **buf,
625 				     size_t *len)
626 {
627 	unsigned long ubuf = (unsigned long) *buf;
628 	unsigned long hdr;
629 
630 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
631 		kmsg->controllen;
632 	if (*len < hdr)
633 		return -EFAULT;
634 
635 	if (kmsg->controllen) {
636 		unsigned long control = ubuf + hdr - kmsg->controllen;
637 
638 		kmsg->msg.msg_control_user = (void __user *) control;
639 		kmsg->msg.msg_controllen = kmsg->controllen;
640 	}
641 
642 	sr->buf = *buf; /* stash for later copy */
643 	*buf = (void __user *) (ubuf + hdr);
644 	kmsg->payloadlen = *len = *len - hdr;
645 	return 0;
646 }
647 
648 struct io_recvmsg_multishot_hdr {
649 	struct io_uring_recvmsg_out msg;
650 	struct sockaddr_storage addr;
651 };
652 
653 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
654 				struct io_async_msghdr *kmsg,
655 				unsigned int flags, bool *finished)
656 {
657 	int err;
658 	int copy_len;
659 	struct io_recvmsg_multishot_hdr hdr;
660 
661 	if (kmsg->namelen)
662 		kmsg->msg.msg_name = &hdr.addr;
663 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
664 	kmsg->msg.msg_namelen = 0;
665 
666 	if (sock->file->f_flags & O_NONBLOCK)
667 		flags |= MSG_DONTWAIT;
668 
669 	err = sock_recvmsg(sock, &kmsg->msg, flags);
670 	*finished = err <= 0;
671 	if (err < 0)
672 		return err;
673 
674 	hdr.msg = (struct io_uring_recvmsg_out) {
675 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
676 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
677 	};
678 
679 	hdr.msg.payloadlen = err;
680 	if (err > kmsg->payloadlen)
681 		err = kmsg->payloadlen;
682 
683 	copy_len = sizeof(struct io_uring_recvmsg_out);
684 	if (kmsg->msg.msg_namelen > kmsg->namelen)
685 		copy_len += kmsg->namelen;
686 	else
687 		copy_len += kmsg->msg.msg_namelen;
688 
689 	/*
690 	 *      "fromlen shall refer to the value before truncation.."
691 	 *                      1003.1g
692 	 */
693 	hdr.msg.namelen = kmsg->msg.msg_namelen;
694 
695 	/* ensure that there is no gap between hdr and sockaddr_storage */
696 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
697 		     sizeof(struct io_uring_recvmsg_out));
698 	if (copy_to_user(io->buf, &hdr, copy_len)) {
699 		*finished = true;
700 		return -EFAULT;
701 	}
702 
703 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
704 			kmsg->controllen + err;
705 }
706 
707 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
708 {
709 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
710 	struct io_async_msghdr iomsg, *kmsg;
711 	struct socket *sock;
712 	unsigned int cflags;
713 	unsigned flags;
714 	int ret, min_ret = 0;
715 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
716 	bool mshot_finished = true;
717 
718 	sock = sock_from_file(req->file);
719 	if (unlikely(!sock))
720 		return -ENOTSOCK;
721 
722 	if (req_has_async_data(req)) {
723 		kmsg = req->async_data;
724 	} else {
725 		ret = io_recvmsg_copy_hdr(req, &iomsg);
726 		if (ret)
727 			return ret;
728 		kmsg = &iomsg;
729 	}
730 
731 	if (!(req->flags & REQ_F_POLLED) &&
732 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
733 		return io_setup_async_msg(req, kmsg, issue_flags);
734 
735 retry_multishot:
736 	if (io_do_buffer_select(req)) {
737 		void __user *buf;
738 		size_t len = sr->len;
739 
740 		buf = io_buffer_select(req, &len, issue_flags);
741 		if (!buf)
742 			return -ENOBUFS;
743 
744 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
745 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
746 			if (ret) {
747 				io_kbuf_recycle(req, issue_flags);
748 				return ret;
749 			}
750 		}
751 
752 		kmsg->fast_iov[0].iov_base = buf;
753 		kmsg->fast_iov[0].iov_len = len;
754 		iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov, 1,
755 				len);
756 	}
757 
758 	flags = sr->msg_flags;
759 	if (force_nonblock)
760 		flags |= MSG_DONTWAIT;
761 	if (flags & MSG_WAITALL)
762 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
763 
764 	kmsg->msg.msg_get_inq = 1;
765 	if (req->flags & REQ_F_APOLL_MULTISHOT)
766 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
767 					   &mshot_finished);
768 	else
769 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
770 					 kmsg->uaddr, flags);
771 
772 	if (ret < min_ret) {
773 		if (ret == -EAGAIN && force_nonblock) {
774 			ret = io_setup_async_msg(req, kmsg, issue_flags);
775 			if (ret == -EAGAIN && (req->flags & IO_APOLL_MULTI_POLLED) ==
776 					       IO_APOLL_MULTI_POLLED) {
777 				io_kbuf_recycle(req, issue_flags);
778 				return IOU_ISSUE_SKIP_COMPLETE;
779 			}
780 			return ret;
781 		}
782 		if (ret > 0 && io_net_retry(sock, flags)) {
783 			sr->done_io += ret;
784 			req->flags |= REQ_F_PARTIAL_IO;
785 			return io_setup_async_msg(req, kmsg, issue_flags);
786 		}
787 		if (ret == -ERESTARTSYS)
788 			ret = -EINTR;
789 		req_set_fail(req);
790 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
791 		req_set_fail(req);
792 	}
793 
794 	if (ret > 0)
795 		ret += sr->done_io;
796 	else if (sr->done_io)
797 		ret = sr->done_io;
798 	else
799 		io_kbuf_recycle(req, issue_flags);
800 
801 	cflags = io_put_kbuf(req, issue_flags);
802 	if (kmsg->msg.msg_inq)
803 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
804 
805 	if (!io_recv_finish(req, &ret, cflags, mshot_finished))
806 		goto retry_multishot;
807 
808 	if (mshot_finished) {
809 		io_netmsg_recycle(req, issue_flags);
810 		/* fast path, check for non-NULL to avoid function call */
811 		if (kmsg->free_iov)
812 			kfree(kmsg->free_iov);
813 		req->flags &= ~REQ_F_NEED_CLEANUP;
814 	}
815 
816 	return ret;
817 }
818 
819 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
820 {
821 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
822 	struct msghdr msg;
823 	struct socket *sock;
824 	struct iovec iov;
825 	unsigned int cflags;
826 	unsigned flags;
827 	int ret, min_ret = 0;
828 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
829 	size_t len = sr->len;
830 
831 	if (!(req->flags & REQ_F_POLLED) &&
832 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
833 		return -EAGAIN;
834 
835 	sock = sock_from_file(req->file);
836 	if (unlikely(!sock))
837 		return -ENOTSOCK;
838 
839 retry_multishot:
840 	if (io_do_buffer_select(req)) {
841 		void __user *buf;
842 
843 		buf = io_buffer_select(req, &len, issue_flags);
844 		if (!buf)
845 			return -ENOBUFS;
846 		sr->buf = buf;
847 	}
848 
849 	ret = import_single_range(READ, sr->buf, len, &iov, &msg.msg_iter);
850 	if (unlikely(ret))
851 		goto out_free;
852 
853 	msg.msg_name = NULL;
854 	msg.msg_namelen = 0;
855 	msg.msg_control = NULL;
856 	msg.msg_get_inq = 1;
857 	msg.msg_flags = 0;
858 	msg.msg_controllen = 0;
859 	msg.msg_iocb = NULL;
860 	msg.msg_ubuf = NULL;
861 
862 	flags = sr->msg_flags;
863 	if (force_nonblock)
864 		flags |= MSG_DONTWAIT;
865 	if (flags & MSG_WAITALL)
866 		min_ret = iov_iter_count(&msg.msg_iter);
867 
868 	ret = sock_recvmsg(sock, &msg, flags);
869 	if (ret < min_ret) {
870 		if (ret == -EAGAIN && force_nonblock) {
871 			if ((req->flags & IO_APOLL_MULTI_POLLED) == IO_APOLL_MULTI_POLLED) {
872 				io_kbuf_recycle(req, issue_flags);
873 				return IOU_ISSUE_SKIP_COMPLETE;
874 			}
875 
876 			return -EAGAIN;
877 		}
878 		if (ret > 0 && io_net_retry(sock, flags)) {
879 			sr->len -= ret;
880 			sr->buf += ret;
881 			sr->done_io += ret;
882 			req->flags |= REQ_F_PARTIAL_IO;
883 			return -EAGAIN;
884 		}
885 		if (ret == -ERESTARTSYS)
886 			ret = -EINTR;
887 		req_set_fail(req);
888 	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
889 out_free:
890 		req_set_fail(req);
891 	}
892 
893 	if (ret > 0)
894 		ret += sr->done_io;
895 	else if (sr->done_io)
896 		ret = sr->done_io;
897 	else
898 		io_kbuf_recycle(req, issue_flags);
899 
900 	cflags = io_put_kbuf(req, issue_flags);
901 	if (msg.msg_inq)
902 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
903 
904 	if (!io_recv_finish(req, &ret, cflags, ret <= 0))
905 		goto retry_multishot;
906 
907 	return ret;
908 }
909 
910 void io_send_zc_cleanup(struct io_kiocb *req)
911 {
912 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
913 	struct io_async_msghdr *io;
914 
915 	if (req_has_async_data(req)) {
916 		io = req->async_data;
917 		/* might be ->fast_iov if *msg_copy_hdr failed */
918 		if (io->free_iov != io->fast_iov)
919 			kfree(io->free_iov);
920 	}
921 	if (zc->notif) {
922 		io_notif_flush(zc->notif);
923 		zc->notif = NULL;
924 	}
925 }
926 
927 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
928 {
929 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
930 	struct io_ring_ctx *ctx = req->ctx;
931 	struct io_kiocb *notif;
932 
933 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
934 		return -EINVAL;
935 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
936 	if (req->flags & REQ_F_CQE_SKIP)
937 		return -EINVAL;
938 
939 	zc->flags = READ_ONCE(sqe->ioprio);
940 	if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST |
941 			  IORING_RECVSEND_FIXED_BUF))
942 		return -EINVAL;
943 	notif = zc->notif = io_alloc_notif(ctx);
944 	if (!notif)
945 		return -ENOMEM;
946 	notif->cqe.user_data = req->cqe.user_data;
947 	notif->cqe.res = 0;
948 	notif->cqe.flags = IORING_CQE_F_NOTIF;
949 	req->flags |= REQ_F_NEED_CLEANUP;
950 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
951 		unsigned idx = READ_ONCE(sqe->buf_index);
952 
953 		if (unlikely(idx >= ctx->nr_user_bufs))
954 			return -EFAULT;
955 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
956 		req->imu = READ_ONCE(ctx->user_bufs[idx]);
957 		io_req_set_rsrc_node(notif, ctx, 0);
958 	}
959 
960 	if (req->opcode == IORING_OP_SEND_ZC) {
961 		if (READ_ONCE(sqe->__pad3[0]))
962 			return -EINVAL;
963 		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
964 		zc->addr_len = READ_ONCE(sqe->addr_len);
965 	} else {
966 		if (unlikely(sqe->addr2 || sqe->file_index))
967 			return -EINVAL;
968 		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
969 			return -EINVAL;
970 	}
971 
972 	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
973 	zc->len = READ_ONCE(sqe->len);
974 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
975 	if (zc->msg_flags & MSG_DONTWAIT)
976 		req->flags |= REQ_F_NOWAIT;
977 
978 	zc->done_io = 0;
979 
980 #ifdef CONFIG_COMPAT
981 	if (req->ctx->compat)
982 		zc->msg_flags |= MSG_CMSG_COMPAT;
983 #endif
984 	return 0;
985 }
986 
987 static int io_sg_from_iter_iovec(struct sock *sk, struct sk_buff *skb,
988 				 struct iov_iter *from, size_t length)
989 {
990 	skb_zcopy_downgrade_managed(skb);
991 	return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
992 }
993 
994 static int io_sg_from_iter(struct sock *sk, struct sk_buff *skb,
995 			   struct iov_iter *from, size_t length)
996 {
997 	struct skb_shared_info *shinfo = skb_shinfo(skb);
998 	int frag = shinfo->nr_frags;
999 	int ret = 0;
1000 	struct bvec_iter bi;
1001 	ssize_t copied = 0;
1002 	unsigned long truesize = 0;
1003 
1004 	if (!frag)
1005 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1006 	else if (unlikely(!skb_zcopy_managed(skb)))
1007 		return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
1008 
1009 	bi.bi_size = min(from->count, length);
1010 	bi.bi_bvec_done = from->iov_offset;
1011 	bi.bi_idx = 0;
1012 
1013 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1014 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1015 
1016 		copied += v.bv_len;
1017 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1018 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1019 					   v.bv_offset, v.bv_len);
1020 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1021 	}
1022 	if (bi.bi_size)
1023 		ret = -EMSGSIZE;
1024 
1025 	shinfo->nr_frags = frag;
1026 	from->bvec += bi.bi_idx;
1027 	from->nr_segs -= bi.bi_idx;
1028 	from->count -= copied;
1029 	from->iov_offset = bi.bi_bvec_done;
1030 
1031 	skb->data_len += copied;
1032 	skb->len += copied;
1033 	skb->truesize += truesize;
1034 
1035 	if (sk && sk->sk_type == SOCK_STREAM) {
1036 		sk_wmem_queued_add(sk, truesize);
1037 		if (!skb_zcopy_pure(skb))
1038 			sk_mem_charge(sk, truesize);
1039 	} else {
1040 		refcount_add(truesize, &skb->sk->sk_wmem_alloc);
1041 	}
1042 	return ret;
1043 }
1044 
1045 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1046 {
1047 	struct sockaddr_storage __address;
1048 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1049 	struct msghdr msg;
1050 	struct iovec iov;
1051 	struct socket *sock;
1052 	unsigned msg_flags;
1053 	int ret, min_ret = 0;
1054 
1055 	sock = sock_from_file(req->file);
1056 	if (unlikely(!sock))
1057 		return -ENOTSOCK;
1058 
1059 	msg.msg_name = NULL;
1060 	msg.msg_control = NULL;
1061 	msg.msg_controllen = 0;
1062 	msg.msg_namelen = 0;
1063 
1064 	if (zc->addr) {
1065 		if (req_has_async_data(req)) {
1066 			struct io_async_msghdr *io = req->async_data;
1067 
1068 			msg.msg_name = &io->addr;
1069 		} else {
1070 			ret = move_addr_to_kernel(zc->addr, zc->addr_len, &__address);
1071 			if (unlikely(ret < 0))
1072 				return ret;
1073 			msg.msg_name = (struct sockaddr *)&__address;
1074 		}
1075 		msg.msg_namelen = zc->addr_len;
1076 	}
1077 
1078 	if (!(req->flags & REQ_F_POLLED) &&
1079 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1080 		return io_setup_async_addr(req, &__address, issue_flags);
1081 
1082 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1083 		ret = io_import_fixed(WRITE, &msg.msg_iter, req->imu,
1084 					(u64)(uintptr_t)zc->buf, zc->len);
1085 		if (unlikely(ret))
1086 			return ret;
1087 		msg.sg_from_iter = io_sg_from_iter;
1088 	} else {
1089 		ret = import_single_range(WRITE, zc->buf, zc->len, &iov,
1090 					  &msg.msg_iter);
1091 		if (unlikely(ret))
1092 			return ret;
1093 		ret = io_notif_account_mem(zc->notif, zc->len);
1094 		if (unlikely(ret))
1095 			return ret;
1096 		msg.sg_from_iter = io_sg_from_iter_iovec;
1097 	}
1098 
1099 	msg_flags = zc->msg_flags | MSG_ZEROCOPY;
1100 	if (issue_flags & IO_URING_F_NONBLOCK)
1101 		msg_flags |= MSG_DONTWAIT;
1102 	if (msg_flags & MSG_WAITALL)
1103 		min_ret = iov_iter_count(&msg.msg_iter);
1104 
1105 	msg.msg_flags = msg_flags;
1106 	msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1107 	ret = sock_sendmsg(sock, &msg);
1108 
1109 	if (unlikely(ret < min_ret)) {
1110 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1111 			return io_setup_async_addr(req, &__address, issue_flags);
1112 
1113 		if (ret > 0 && io_net_retry(sock, msg.msg_flags)) {
1114 			zc->len -= ret;
1115 			zc->buf += ret;
1116 			zc->done_io += ret;
1117 			req->flags |= REQ_F_PARTIAL_IO;
1118 			return io_setup_async_addr(req, &__address, issue_flags);
1119 		}
1120 		if (ret == -ERESTARTSYS)
1121 			ret = -EINTR;
1122 		req_set_fail(req);
1123 	}
1124 
1125 	if (ret >= 0)
1126 		ret += zc->done_io;
1127 	else if (zc->done_io)
1128 		ret = zc->done_io;
1129 
1130 	/*
1131 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1132 	 * flushing notif to io_send_zc_cleanup()
1133 	 */
1134 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1135 		io_notif_flush(zc->notif);
1136 		req->flags &= ~REQ_F_NEED_CLEANUP;
1137 	}
1138 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1139 	return IOU_OK;
1140 }
1141 
1142 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1143 {
1144 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1145 	struct io_async_msghdr iomsg, *kmsg;
1146 	struct socket *sock;
1147 	unsigned flags;
1148 	int ret, min_ret = 0;
1149 
1150 	sock = sock_from_file(req->file);
1151 	if (unlikely(!sock))
1152 		return -ENOTSOCK;
1153 
1154 	if (req_has_async_data(req)) {
1155 		kmsg = req->async_data;
1156 	} else {
1157 		ret = io_sendmsg_copy_hdr(req, &iomsg);
1158 		if (ret)
1159 			return ret;
1160 		kmsg = &iomsg;
1161 	}
1162 
1163 	if (!(req->flags & REQ_F_POLLED) &&
1164 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1165 		return io_setup_async_msg(req, kmsg, issue_flags);
1166 
1167 	flags = sr->msg_flags | MSG_ZEROCOPY;
1168 	if (issue_flags & IO_URING_F_NONBLOCK)
1169 		flags |= MSG_DONTWAIT;
1170 	if (flags & MSG_WAITALL)
1171 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1172 
1173 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1174 	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1175 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1176 
1177 	if (unlikely(ret < min_ret)) {
1178 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1179 			return io_setup_async_msg(req, kmsg, issue_flags);
1180 
1181 		if (ret > 0 && io_net_retry(sock, flags)) {
1182 			sr->done_io += ret;
1183 			req->flags |= REQ_F_PARTIAL_IO;
1184 			return io_setup_async_msg(req, kmsg, issue_flags);
1185 		}
1186 		if (ret == -ERESTARTSYS)
1187 			ret = -EINTR;
1188 		req_set_fail(req);
1189 	}
1190 	/* fast path, check for non-NULL to avoid function call */
1191 	if (kmsg->free_iov) {
1192 		kfree(kmsg->free_iov);
1193 		kmsg->free_iov = NULL;
1194 	}
1195 
1196 	io_netmsg_recycle(req, issue_flags);
1197 	if (ret >= 0)
1198 		ret += sr->done_io;
1199 	else if (sr->done_io)
1200 		ret = sr->done_io;
1201 
1202 	/*
1203 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1204 	 * flushing notif to io_send_zc_cleanup()
1205 	 */
1206 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1207 		io_notif_flush(sr->notif);
1208 		req->flags &= ~REQ_F_NEED_CLEANUP;
1209 	}
1210 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1211 	return IOU_OK;
1212 }
1213 
1214 void io_sendrecv_fail(struct io_kiocb *req)
1215 {
1216 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1217 
1218 	if (req->flags & REQ_F_PARTIAL_IO)
1219 		req->cqe.res = sr->done_io;
1220 
1221 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1222 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1223 		req->cqe.flags |= IORING_CQE_F_MORE;
1224 }
1225 
1226 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1227 {
1228 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1229 	unsigned flags;
1230 
1231 	if (sqe->len || sqe->buf_index)
1232 		return -EINVAL;
1233 
1234 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1235 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1236 	accept->flags = READ_ONCE(sqe->accept_flags);
1237 	accept->nofile = rlimit(RLIMIT_NOFILE);
1238 	flags = READ_ONCE(sqe->ioprio);
1239 	if (flags & ~IORING_ACCEPT_MULTISHOT)
1240 		return -EINVAL;
1241 
1242 	accept->file_slot = READ_ONCE(sqe->file_index);
1243 	if (accept->file_slot) {
1244 		if (accept->flags & SOCK_CLOEXEC)
1245 			return -EINVAL;
1246 		if (flags & IORING_ACCEPT_MULTISHOT &&
1247 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1248 			return -EINVAL;
1249 	}
1250 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1251 		return -EINVAL;
1252 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1253 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1254 	if (flags & IORING_ACCEPT_MULTISHOT)
1255 		req->flags |= REQ_F_APOLL_MULTISHOT;
1256 	return 0;
1257 }
1258 
1259 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1260 {
1261 	struct io_ring_ctx *ctx = req->ctx;
1262 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1263 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1264 	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
1265 	bool fixed = !!accept->file_slot;
1266 	struct file *file;
1267 	int ret, fd;
1268 
1269 retry:
1270 	if (!fixed) {
1271 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1272 		if (unlikely(fd < 0))
1273 			return fd;
1274 	}
1275 	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
1276 			 accept->flags);
1277 	if (IS_ERR(file)) {
1278 		if (!fixed)
1279 			put_unused_fd(fd);
1280 		ret = PTR_ERR(file);
1281 		if (ret == -EAGAIN && force_nonblock) {
1282 			/*
1283 			 * if it's multishot and polled, we don't need to
1284 			 * return EAGAIN to arm the poll infra since it
1285 			 * has already been done
1286 			 */
1287 			if ((req->flags & IO_APOLL_MULTI_POLLED) ==
1288 			    IO_APOLL_MULTI_POLLED)
1289 				ret = IOU_ISSUE_SKIP_COMPLETE;
1290 			return ret;
1291 		}
1292 		if (ret == -ERESTARTSYS)
1293 			ret = -EINTR;
1294 		req_set_fail(req);
1295 	} else if (!fixed) {
1296 		fd_install(fd, file);
1297 		ret = fd;
1298 	} else {
1299 		ret = io_fixed_fd_install(req, issue_flags, file,
1300 						accept->file_slot);
1301 	}
1302 
1303 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
1304 		io_req_set_res(req, ret, 0);
1305 		return IOU_OK;
1306 	}
1307 
1308 	if (ret >= 0 &&
1309 	    io_post_aux_cqe(ctx, req->cqe.user_data, ret, IORING_CQE_F_MORE, false))
1310 		goto retry;
1311 
1312 	io_req_set_res(req, ret, 0);
1313 	if (req->flags & REQ_F_POLLED)
1314 		return IOU_STOP_MULTISHOT;
1315 	return IOU_OK;
1316 }
1317 
1318 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1319 {
1320 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1321 
1322 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1323 		return -EINVAL;
1324 
1325 	sock->domain = READ_ONCE(sqe->fd);
1326 	sock->type = READ_ONCE(sqe->off);
1327 	sock->protocol = READ_ONCE(sqe->len);
1328 	sock->file_slot = READ_ONCE(sqe->file_index);
1329 	sock->nofile = rlimit(RLIMIT_NOFILE);
1330 
1331 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1332 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1333 		return -EINVAL;
1334 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1335 		return -EINVAL;
1336 	return 0;
1337 }
1338 
1339 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1340 {
1341 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1342 	bool fixed = !!sock->file_slot;
1343 	struct file *file;
1344 	int ret, fd;
1345 
1346 	if (!fixed) {
1347 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1348 		if (unlikely(fd < 0))
1349 			return fd;
1350 	}
1351 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1352 	if (IS_ERR(file)) {
1353 		if (!fixed)
1354 			put_unused_fd(fd);
1355 		ret = PTR_ERR(file);
1356 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1357 			return -EAGAIN;
1358 		if (ret == -ERESTARTSYS)
1359 			ret = -EINTR;
1360 		req_set_fail(req);
1361 	} else if (!fixed) {
1362 		fd_install(fd, file);
1363 		ret = fd;
1364 	} else {
1365 		ret = io_fixed_fd_install(req, issue_flags, file,
1366 					    sock->file_slot);
1367 	}
1368 	io_req_set_res(req, ret, 0);
1369 	return IOU_OK;
1370 }
1371 
1372 int io_connect_prep_async(struct io_kiocb *req)
1373 {
1374 	struct io_async_connect *io = req->async_data;
1375 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1376 
1377 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
1378 }
1379 
1380 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1381 {
1382 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1383 
1384 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1385 		return -EINVAL;
1386 
1387 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1388 	conn->addr_len =  READ_ONCE(sqe->addr2);
1389 	return 0;
1390 }
1391 
1392 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1393 {
1394 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1395 	struct io_async_connect __io, *io;
1396 	unsigned file_flags;
1397 	int ret;
1398 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1399 
1400 	if (req_has_async_data(req)) {
1401 		io = req->async_data;
1402 	} else {
1403 		ret = move_addr_to_kernel(connect->addr,
1404 						connect->addr_len,
1405 						&__io.address);
1406 		if (ret)
1407 			goto out;
1408 		io = &__io;
1409 	}
1410 
1411 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1412 
1413 	ret = __sys_connect_file(req->file, &io->address,
1414 					connect->addr_len, file_flags);
1415 	if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
1416 		if (req_has_async_data(req))
1417 			return -EAGAIN;
1418 		if (io_alloc_async_data(req)) {
1419 			ret = -ENOMEM;
1420 			goto out;
1421 		}
1422 		memcpy(req->async_data, &__io, sizeof(__io));
1423 		return -EAGAIN;
1424 	}
1425 	if (ret == -ERESTARTSYS)
1426 		ret = -EINTR;
1427 out:
1428 	if (ret < 0)
1429 		req_set_fail(req);
1430 	io_req_set_res(req, ret, 0);
1431 	return IOU_OK;
1432 }
1433 
1434 void io_netmsg_cache_free(struct io_cache_entry *entry)
1435 {
1436 	kfree(container_of(entry, struct io_async_msghdr, cache));
1437 }
1438 #endif
1439