xref: /linux/io_uring/net.c (revision be602cde657ee43d23adbf309be6d700d0106dc9)
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 	int				iou_flags;
32 	u32				file_slot;
33 	unsigned long			nofile;
34 };
35 
36 struct io_socket {
37 	struct file			*file;
38 	int				domain;
39 	int				type;
40 	int				protocol;
41 	int				flags;
42 	u32				file_slot;
43 	unsigned long			nofile;
44 };
45 
46 struct io_connect {
47 	struct file			*file;
48 	struct sockaddr __user		*addr;
49 	int				addr_len;
50 	bool				in_progress;
51 	bool				seen_econnaborted;
52 };
53 
54 struct io_bind {
55 	struct file			*file;
56 	int				addr_len;
57 };
58 
59 struct io_listen {
60 	struct file			*file;
61 	int				backlog;
62 };
63 
64 struct io_sr_msg {
65 	struct file			*file;
66 	union {
67 		struct compat_msghdr __user	*umsg_compat;
68 		struct user_msghdr __user	*umsg;
69 		void __user			*buf;
70 	};
71 	int				len;
72 	unsigned			done_io;
73 	unsigned			msg_flags;
74 	unsigned			nr_multishot_loops;
75 	u16				flags;
76 	/* initialised and used only by !msg send variants */
77 	u16				addr_len;
78 	u16				buf_group;
79 	void __user			*addr;
80 	void __user			*msg_control;
81 	/* used only for send zerocopy */
82 	struct io_kiocb 		*notif;
83 };
84 
85 /*
86  * Number of times we'll try and do receives if there's more data. If we
87  * exceed this limit, then add us to the back of the queue and retry from
88  * there. This helps fairness between flooding clients.
89  */
90 #define MULTISHOT_MAX_RETRY	32
91 
92 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
93 {
94 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
95 
96 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
97 		     sqe->buf_index || sqe->splice_fd_in))
98 		return -EINVAL;
99 
100 	shutdown->how = READ_ONCE(sqe->len);
101 	req->flags |= REQ_F_FORCE_ASYNC;
102 	return 0;
103 }
104 
105 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
106 {
107 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
108 	struct socket *sock;
109 	int ret;
110 
111 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
112 
113 	sock = sock_from_file(req->file);
114 	if (unlikely(!sock))
115 		return -ENOTSOCK;
116 
117 	ret = __sys_shutdown_sock(sock, shutdown->how);
118 	io_req_set_res(req, ret, 0);
119 	return IOU_OK;
120 }
121 
122 static bool io_net_retry(struct socket *sock, int flags)
123 {
124 	if (!(flags & MSG_WAITALL))
125 		return false;
126 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
127 }
128 
129 static void io_netmsg_iovec_free(struct io_async_msghdr *kmsg)
130 {
131 	if (kmsg->free_iov) {
132 		kfree(kmsg->free_iov);
133 		kmsg->free_iov_nr = 0;
134 		kmsg->free_iov = NULL;
135 	}
136 }
137 
138 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
139 {
140 	struct io_async_msghdr *hdr = req->async_data;
141 	struct iovec *iov;
142 
143 	/* can't recycle, ensure we free the iovec if we have one */
144 	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
145 		io_netmsg_iovec_free(hdr);
146 		return;
147 	}
148 
149 	/* Let normal cleanup path reap it if we fail adding to the cache */
150 	iov = hdr->free_iov;
151 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr)) {
152 		if (iov)
153 			kasan_mempool_poison_object(iov);
154 		req->async_data = NULL;
155 		req->flags &= ~REQ_F_ASYNC_DATA;
156 	}
157 }
158 
159 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
160 {
161 	struct io_ring_ctx *ctx = req->ctx;
162 	struct io_async_msghdr *hdr;
163 
164 	hdr = io_alloc_cache_get(&ctx->netmsg_cache);
165 	if (hdr) {
166 		if (hdr->free_iov) {
167 			kasan_mempool_unpoison_object(hdr->free_iov,
168 				hdr->free_iov_nr * sizeof(struct iovec));
169 			req->flags |= REQ_F_NEED_CLEANUP;
170 		}
171 		req->flags |= REQ_F_ASYNC_DATA;
172 		req->async_data = hdr;
173 		return hdr;
174 	}
175 
176 	if (!io_alloc_async_data(req)) {
177 		hdr = req->async_data;
178 		hdr->free_iov_nr = 0;
179 		hdr->free_iov = NULL;
180 		return hdr;
181 	}
182 	return NULL;
183 }
184 
185 /* assign new iovec to kmsg, if we need to */
186 static int io_net_vec_assign(struct io_kiocb *req, struct io_async_msghdr *kmsg,
187 			     struct iovec *iov)
188 {
189 	if (iov) {
190 		req->flags |= REQ_F_NEED_CLEANUP;
191 		kmsg->free_iov_nr = kmsg->msg.msg_iter.nr_segs;
192 		if (kmsg->free_iov)
193 			kfree(kmsg->free_iov);
194 		kmsg->free_iov = iov;
195 	}
196 	return 0;
197 }
198 
199 static inline void io_mshot_prep_retry(struct io_kiocb *req,
200 				       struct io_async_msghdr *kmsg)
201 {
202 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
203 
204 	req->flags &= ~REQ_F_BL_EMPTY;
205 	sr->done_io = 0;
206 	sr->len = 0; /* get from the provided buffer */
207 	req->buf_index = sr->buf_group;
208 }
209 
210 #ifdef CONFIG_COMPAT
211 static int io_compat_msg_copy_hdr(struct io_kiocb *req,
212 				  struct io_async_msghdr *iomsg,
213 				  struct compat_msghdr *msg, int ddir)
214 {
215 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
216 	struct compat_iovec __user *uiov;
217 	struct iovec *iov;
218 	int ret, nr_segs;
219 
220 	if (iomsg->free_iov) {
221 		nr_segs = iomsg->free_iov_nr;
222 		iov = iomsg->free_iov;
223 	} else {
224 		iov = &iomsg->fast_iov;
225 		nr_segs = 1;
226 	}
227 
228 	if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
229 		return -EFAULT;
230 
231 	uiov = compat_ptr(msg->msg_iov);
232 	if (req->flags & REQ_F_BUFFER_SELECT) {
233 		compat_ssize_t clen;
234 
235 		if (msg->msg_iovlen == 0) {
236 			sr->len = iov->iov_len = 0;
237 			iov->iov_base = NULL;
238 		} else if (msg->msg_iovlen > 1) {
239 			return -EINVAL;
240 		} else {
241 			if (!access_ok(uiov, sizeof(*uiov)))
242 				return -EFAULT;
243 			if (__get_user(clen, &uiov->iov_len))
244 				return -EFAULT;
245 			if (clen < 0)
246 				return -EINVAL;
247 			sr->len = clen;
248 		}
249 
250 		return 0;
251 	}
252 
253 	ret = __import_iovec(ddir, (struct iovec __user *)uiov, msg->msg_iovlen,
254 				nr_segs, &iov, &iomsg->msg.msg_iter, true);
255 	if (unlikely(ret < 0))
256 		return ret;
257 
258 	return io_net_vec_assign(req, iomsg, iov);
259 }
260 #endif
261 
262 static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
263 			   struct user_msghdr *msg, int ddir)
264 {
265 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
266 	struct iovec *iov;
267 	int ret, nr_segs;
268 
269 	if (iomsg->free_iov) {
270 		nr_segs = iomsg->free_iov_nr;
271 		iov = iomsg->free_iov;
272 	} else {
273 		iov = &iomsg->fast_iov;
274 		nr_segs = 1;
275 	}
276 
277 	if (!user_access_begin(sr->umsg, sizeof(*sr->umsg)))
278 		return -EFAULT;
279 
280 	ret = -EFAULT;
281 	unsafe_get_user(msg->msg_name, &sr->umsg->msg_name, ua_end);
282 	unsafe_get_user(msg->msg_namelen, &sr->umsg->msg_namelen, ua_end);
283 	unsafe_get_user(msg->msg_iov, &sr->umsg->msg_iov, ua_end);
284 	unsafe_get_user(msg->msg_iovlen, &sr->umsg->msg_iovlen, ua_end);
285 	unsafe_get_user(msg->msg_control, &sr->umsg->msg_control, ua_end);
286 	unsafe_get_user(msg->msg_controllen, &sr->umsg->msg_controllen, ua_end);
287 	msg->msg_flags = 0;
288 
289 	if (req->flags & REQ_F_BUFFER_SELECT) {
290 		if (msg->msg_iovlen == 0) {
291 			sr->len = iov->iov_len = 0;
292 			iov->iov_base = NULL;
293 		} else if (msg->msg_iovlen > 1) {
294 			ret = -EINVAL;
295 			goto ua_end;
296 		} else {
297 			/* we only need the length for provided buffers */
298 			if (!access_ok(&msg->msg_iov[0].iov_len, sizeof(__kernel_size_t)))
299 				goto ua_end;
300 			unsafe_get_user(iov->iov_len, &msg->msg_iov[0].iov_len,
301 					ua_end);
302 			sr->len = iov->iov_len;
303 		}
304 		ret = 0;
305 ua_end:
306 		user_access_end();
307 		return ret;
308 	}
309 
310 	user_access_end();
311 	ret = __import_iovec(ddir, msg->msg_iov, msg->msg_iovlen, nr_segs,
312 				&iov, &iomsg->msg.msg_iter, false);
313 	if (unlikely(ret < 0))
314 		return ret;
315 
316 	return io_net_vec_assign(req, iomsg, iov);
317 }
318 
319 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
320 			       struct io_async_msghdr *iomsg)
321 {
322 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
323 	struct user_msghdr msg;
324 	int ret;
325 
326 	iomsg->msg.msg_name = &iomsg->addr;
327 	iomsg->msg.msg_iter.nr_segs = 0;
328 
329 #ifdef CONFIG_COMPAT
330 	if (unlikely(req->ctx->compat)) {
331 		struct compat_msghdr cmsg;
332 
333 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_SOURCE);
334 		if (unlikely(ret))
335 			return ret;
336 
337 		return __get_compat_msghdr(&iomsg->msg, &cmsg, NULL);
338 	}
339 #endif
340 
341 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_SOURCE);
342 	if (unlikely(ret))
343 		return ret;
344 
345 	ret = __copy_msghdr(&iomsg->msg, &msg, NULL);
346 
347 	/* save msg_control as sys_sendmsg() overwrites it */
348 	sr->msg_control = iomsg->msg.msg_control_user;
349 	return ret;
350 }
351 
352 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
353 {
354 	struct io_async_msghdr *io = req->async_data;
355 
356 	io_netmsg_iovec_free(io);
357 }
358 
359 static int io_send_setup(struct io_kiocb *req)
360 {
361 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
362 	struct io_async_msghdr *kmsg = req->async_data;
363 	int ret;
364 
365 	kmsg->msg.msg_name = NULL;
366 	kmsg->msg.msg_namelen = 0;
367 	kmsg->msg.msg_control = NULL;
368 	kmsg->msg.msg_controllen = 0;
369 	kmsg->msg.msg_ubuf = NULL;
370 
371 	if (sr->addr) {
372 		ret = move_addr_to_kernel(sr->addr, sr->addr_len, &kmsg->addr);
373 		if (unlikely(ret < 0))
374 			return ret;
375 		kmsg->msg.msg_name = &kmsg->addr;
376 		kmsg->msg.msg_namelen = sr->addr_len;
377 	}
378 	if (!io_do_buffer_select(req)) {
379 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
380 				  &kmsg->msg.msg_iter);
381 		if (unlikely(ret < 0))
382 			return ret;
383 	}
384 	return 0;
385 }
386 
387 static int io_sendmsg_prep_setup(struct io_kiocb *req, int is_msg)
388 {
389 	struct io_async_msghdr *kmsg;
390 	int ret;
391 
392 	kmsg = io_msg_alloc_async(req);
393 	if (unlikely(!kmsg))
394 		return -ENOMEM;
395 	if (!is_msg)
396 		return io_send_setup(req);
397 	ret = io_sendmsg_copy_hdr(req, kmsg);
398 	if (!ret)
399 		req->flags |= REQ_F_NEED_CLEANUP;
400 	return ret;
401 }
402 
403 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE)
404 
405 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
406 {
407 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
408 
409 	sr->done_io = 0;
410 
411 	if (req->opcode == IORING_OP_SEND) {
412 		if (READ_ONCE(sqe->__pad3[0]))
413 			return -EINVAL;
414 		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
415 		sr->addr_len = READ_ONCE(sqe->addr_len);
416 	} else if (sqe->addr2 || sqe->file_index) {
417 		return -EINVAL;
418 	}
419 
420 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
421 	sr->len = READ_ONCE(sqe->len);
422 	sr->flags = READ_ONCE(sqe->ioprio);
423 	if (sr->flags & ~SENDMSG_FLAGS)
424 		return -EINVAL;
425 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
426 	if (sr->msg_flags & MSG_DONTWAIT)
427 		req->flags |= REQ_F_NOWAIT;
428 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
429 		if (req->opcode == IORING_OP_SENDMSG)
430 			return -EINVAL;
431 		if (!(req->flags & REQ_F_BUFFER_SELECT))
432 			return -EINVAL;
433 		sr->msg_flags |= MSG_WAITALL;
434 		sr->buf_group = req->buf_index;
435 		req->buf_list = NULL;
436 	}
437 
438 #ifdef CONFIG_COMPAT
439 	if (req->ctx->compat)
440 		sr->msg_flags |= MSG_CMSG_COMPAT;
441 #endif
442 	return io_sendmsg_prep_setup(req, req->opcode == IORING_OP_SENDMSG);
443 }
444 
445 static void io_req_msg_cleanup(struct io_kiocb *req,
446 			       unsigned int issue_flags)
447 {
448 	req->flags &= ~REQ_F_NEED_CLEANUP;
449 	io_netmsg_recycle(req, issue_flags);
450 }
451 
452 /*
453  * For bundle completions, we need to figure out how many segments we consumed.
454  * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
455  * could be using an ITER_IOVEC. If the latter, then if we consumed all of
456  * the segments, then it's a trivial questiont o answer. If we have residual
457  * data in the iter, then loop the segments to figure out how much we
458  * transferred.
459  */
460 static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
461 {
462 	struct iovec *iov;
463 	int nbufs;
464 
465 	/* no data is always zero segments, and a ubuf is always 1 segment */
466 	if (ret <= 0)
467 		return 0;
468 	if (iter_is_ubuf(&kmsg->msg.msg_iter))
469 		return 1;
470 
471 	iov = kmsg->free_iov;
472 	if (!iov)
473 		iov = &kmsg->fast_iov;
474 
475 	/* if all data was transferred, it's basic pointer math */
476 	if (!iov_iter_count(&kmsg->msg.msg_iter))
477 		return iter_iov(&kmsg->msg.msg_iter) - iov;
478 
479 	/* short transfer, count segments */
480 	nbufs = 0;
481 	do {
482 		int this_len = min_t(int, iov[nbufs].iov_len, ret);
483 
484 		nbufs++;
485 		ret -= this_len;
486 	} while (ret);
487 
488 	return nbufs;
489 }
490 
491 static inline bool io_send_finish(struct io_kiocb *req, int *ret,
492 				  struct io_async_msghdr *kmsg,
493 				  unsigned issue_flags)
494 {
495 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
496 	bool bundle_finished = *ret <= 0;
497 	unsigned int cflags;
498 
499 	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
500 		cflags = io_put_kbuf(req, *ret, issue_flags);
501 		goto finish;
502 	}
503 
504 	cflags = io_put_kbufs(req, *ret, io_bundle_nbufs(kmsg, *ret), issue_flags);
505 
506 	if (bundle_finished || req->flags & REQ_F_BL_EMPTY)
507 		goto finish;
508 
509 	/*
510 	 * Fill CQE for this receive and see if we should keep trying to
511 	 * receive from this socket.
512 	 */
513 	if (io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
514 		io_mshot_prep_retry(req, kmsg);
515 		return false;
516 	}
517 
518 	/* Otherwise stop bundle and use the current result. */
519 finish:
520 	io_req_set_res(req, *ret, cflags);
521 	*ret = IOU_OK;
522 	return true;
523 }
524 
525 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
526 {
527 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
528 	struct io_async_msghdr *kmsg = req->async_data;
529 	struct socket *sock;
530 	unsigned flags;
531 	int min_ret = 0;
532 	int ret;
533 
534 	sock = sock_from_file(req->file);
535 	if (unlikely(!sock))
536 		return -ENOTSOCK;
537 
538 	if (!(req->flags & REQ_F_POLLED) &&
539 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
540 		return -EAGAIN;
541 
542 	flags = sr->msg_flags;
543 	if (issue_flags & IO_URING_F_NONBLOCK)
544 		flags |= MSG_DONTWAIT;
545 	if (flags & MSG_WAITALL)
546 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
547 
548 	kmsg->msg.msg_control_user = sr->msg_control;
549 
550 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
551 
552 	if (ret < min_ret) {
553 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
554 			return -EAGAIN;
555 		if (ret > 0 && io_net_retry(sock, flags)) {
556 			kmsg->msg.msg_controllen = 0;
557 			kmsg->msg.msg_control = NULL;
558 			sr->done_io += ret;
559 			req->flags |= REQ_F_BL_NO_RECYCLE;
560 			return -EAGAIN;
561 		}
562 		if (ret == -ERESTARTSYS)
563 			ret = -EINTR;
564 		req_set_fail(req);
565 	}
566 	io_req_msg_cleanup(req, issue_flags);
567 	if (ret >= 0)
568 		ret += sr->done_io;
569 	else if (sr->done_io)
570 		ret = sr->done_io;
571 	io_req_set_res(req, ret, 0);
572 	return IOU_OK;
573 }
574 
575 int io_send(struct io_kiocb *req, unsigned int issue_flags)
576 {
577 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
578 	struct io_async_msghdr *kmsg = req->async_data;
579 	struct socket *sock;
580 	unsigned flags;
581 	int min_ret = 0;
582 	int ret;
583 
584 	sock = sock_from_file(req->file);
585 	if (unlikely(!sock))
586 		return -ENOTSOCK;
587 
588 	if (!(req->flags & REQ_F_POLLED) &&
589 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
590 		return -EAGAIN;
591 
592 	flags = sr->msg_flags;
593 	if (issue_flags & IO_URING_F_NONBLOCK)
594 		flags |= MSG_DONTWAIT;
595 
596 retry_bundle:
597 	if (io_do_buffer_select(req)) {
598 		struct buf_sel_arg arg = {
599 			.iovs = &kmsg->fast_iov,
600 			.max_len = min_not_zero(sr->len, INT_MAX),
601 			.nr_iovs = 1,
602 		};
603 
604 		if (kmsg->free_iov) {
605 			arg.nr_iovs = kmsg->free_iov_nr;
606 			arg.iovs = kmsg->free_iov;
607 			arg.mode = KBUF_MODE_FREE;
608 		}
609 
610 		if (!(sr->flags & IORING_RECVSEND_BUNDLE))
611 			arg.nr_iovs = 1;
612 		else
613 			arg.mode |= KBUF_MODE_EXPAND;
614 
615 		ret = io_buffers_select(req, &arg, issue_flags);
616 		if (unlikely(ret < 0))
617 			return ret;
618 
619 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->free_iov) {
620 			kmsg->free_iov_nr = ret;
621 			kmsg->free_iov = arg.iovs;
622 			req->flags |= REQ_F_NEED_CLEANUP;
623 		}
624 		sr->len = arg.out_len;
625 
626 		if (ret == 1) {
627 			sr->buf = arg.iovs[0].iov_base;
628 			ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
629 						&kmsg->msg.msg_iter);
630 			if (unlikely(ret))
631 				return ret;
632 		} else {
633 			iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE,
634 					arg.iovs, ret, arg.out_len);
635 		}
636 	}
637 
638 	/*
639 	 * If MSG_WAITALL is set, or this is a bundle send, then we need
640 	 * the full amount. If just bundle is set, if we do a short send
641 	 * then we complete the bundle sequence rather than continue on.
642 	 */
643 	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
644 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
645 
646 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
647 	kmsg->msg.msg_flags = flags;
648 	ret = sock_sendmsg(sock, &kmsg->msg);
649 	if (ret < min_ret) {
650 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
651 			return -EAGAIN;
652 
653 		if (ret > 0 && io_net_retry(sock, flags)) {
654 			sr->len -= ret;
655 			sr->buf += ret;
656 			sr->done_io += ret;
657 			req->flags |= REQ_F_BL_NO_RECYCLE;
658 			return -EAGAIN;
659 		}
660 		if (ret == -ERESTARTSYS)
661 			ret = -EINTR;
662 		req_set_fail(req);
663 	}
664 	if (ret >= 0)
665 		ret += sr->done_io;
666 	else if (sr->done_io)
667 		ret = sr->done_io;
668 
669 	if (!io_send_finish(req, &ret, kmsg, issue_flags))
670 		goto retry_bundle;
671 
672 	io_req_msg_cleanup(req, issue_flags);
673 	return ret;
674 }
675 
676 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
677 				 struct io_async_msghdr *iomsg,
678 				 int namelen, size_t controllen)
679 {
680 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
681 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
682 		int hdr;
683 
684 		if (unlikely(namelen < 0))
685 			return -EOVERFLOW;
686 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
687 					namelen, &hdr))
688 			return -EOVERFLOW;
689 		if (check_add_overflow(hdr, controllen, &hdr))
690 			return -EOVERFLOW;
691 
692 		iomsg->namelen = namelen;
693 		iomsg->controllen = controllen;
694 		return 0;
695 	}
696 
697 	return 0;
698 }
699 
700 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
701 			       struct io_async_msghdr *iomsg)
702 {
703 	struct user_msghdr msg;
704 	int ret;
705 
706 	iomsg->msg.msg_name = &iomsg->addr;
707 	iomsg->msg.msg_iter.nr_segs = 0;
708 
709 #ifdef CONFIG_COMPAT
710 	if (unlikely(req->ctx->compat)) {
711 		struct compat_msghdr cmsg;
712 
713 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_DEST);
714 		if (unlikely(ret))
715 			return ret;
716 
717 		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, &iomsg->uaddr);
718 		if (unlikely(ret))
719 			return ret;
720 
721 		return io_recvmsg_mshot_prep(req, iomsg, cmsg.msg_namelen,
722 						cmsg.msg_controllen);
723 	}
724 #endif
725 
726 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST);
727 	if (unlikely(ret))
728 		return ret;
729 
730 	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
731 	if (unlikely(ret))
732 		return ret;
733 
734 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
735 					msg.msg_controllen);
736 }
737 
738 static int io_recvmsg_prep_setup(struct io_kiocb *req)
739 {
740 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
741 	struct io_async_msghdr *kmsg;
742 	int ret;
743 
744 	kmsg = io_msg_alloc_async(req);
745 	if (unlikely(!kmsg))
746 		return -ENOMEM;
747 
748 	if (req->opcode == IORING_OP_RECV) {
749 		kmsg->msg.msg_name = NULL;
750 		kmsg->msg.msg_namelen = 0;
751 		kmsg->msg.msg_control = NULL;
752 		kmsg->msg.msg_get_inq = 1;
753 		kmsg->msg.msg_controllen = 0;
754 		kmsg->msg.msg_iocb = NULL;
755 		kmsg->msg.msg_ubuf = NULL;
756 
757 		if (!io_do_buffer_select(req)) {
758 			ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
759 					  &kmsg->msg.msg_iter);
760 			if (unlikely(ret))
761 				return ret;
762 		}
763 		return 0;
764 	}
765 
766 	ret = io_recvmsg_copy_hdr(req, kmsg);
767 	if (!ret)
768 		req->flags |= REQ_F_NEED_CLEANUP;
769 	return ret;
770 }
771 
772 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
773 			IORING_RECVSEND_BUNDLE)
774 
775 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
776 {
777 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
778 
779 	sr->done_io = 0;
780 
781 	if (unlikely(sqe->file_index || sqe->addr2))
782 		return -EINVAL;
783 
784 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
785 	sr->len = READ_ONCE(sqe->len);
786 	sr->flags = READ_ONCE(sqe->ioprio);
787 	if (sr->flags & ~RECVMSG_FLAGS)
788 		return -EINVAL;
789 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
790 	if (sr->msg_flags & MSG_DONTWAIT)
791 		req->flags |= REQ_F_NOWAIT;
792 	if (sr->msg_flags & MSG_ERRQUEUE)
793 		req->flags |= REQ_F_CLEAR_POLLIN;
794 	if (req->flags & REQ_F_BUFFER_SELECT) {
795 		/*
796 		 * Store the buffer group for this multishot receive separately,
797 		 * as if we end up doing an io-wq based issue that selects a
798 		 * buffer, it has to be committed immediately and that will
799 		 * clear ->buf_list. This means we lose the link to the buffer
800 		 * list, and the eventual buffer put on completion then cannot
801 		 * restore it.
802 		 */
803 		sr->buf_group = req->buf_index;
804 		req->buf_list = NULL;
805 	}
806 	if (sr->flags & IORING_RECV_MULTISHOT) {
807 		if (!(req->flags & REQ_F_BUFFER_SELECT))
808 			return -EINVAL;
809 		if (sr->msg_flags & MSG_WAITALL)
810 			return -EINVAL;
811 		if (req->opcode == IORING_OP_RECV && sr->len)
812 			return -EINVAL;
813 		req->flags |= REQ_F_APOLL_MULTISHOT;
814 	}
815 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
816 		if (req->opcode == IORING_OP_RECVMSG)
817 			return -EINVAL;
818 	}
819 
820 #ifdef CONFIG_COMPAT
821 	if (req->ctx->compat)
822 		sr->msg_flags |= MSG_CMSG_COMPAT;
823 #endif
824 	sr->nr_multishot_loops = 0;
825 	return io_recvmsg_prep_setup(req);
826 }
827 
828 /*
829  * Finishes io_recv and io_recvmsg.
830  *
831  * Returns true if it is actually finished, or false if it should run
832  * again (for multishot).
833  */
834 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
835 				  struct io_async_msghdr *kmsg,
836 				  bool mshot_finished, unsigned issue_flags)
837 {
838 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
839 	unsigned int cflags = 0;
840 
841 	if (kmsg->msg.msg_inq > 0)
842 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
843 
844 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
845 		cflags |= io_put_kbufs(req, *ret, io_bundle_nbufs(kmsg, *ret),
846 				      issue_flags);
847 		/* bundle with no more immediate buffers, we're done */
848 		if (req->flags & REQ_F_BL_EMPTY)
849 			goto finish;
850 	} else {
851 		cflags |= io_put_kbuf(req, *ret, issue_flags);
852 	}
853 
854 	/*
855 	 * Fill CQE for this receive and see if we should keep trying to
856 	 * receive from this socket.
857 	 */
858 	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
859 	    io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
860 		int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;
861 
862 		io_mshot_prep_retry(req, kmsg);
863 		/* Known not-empty or unknown state, retry */
864 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
865 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY)
866 				return false;
867 			/* mshot retries exceeded, force a requeue */
868 			sr->nr_multishot_loops = 0;
869 			mshot_retry_ret = IOU_REQUEUE;
870 		}
871 		if (issue_flags & IO_URING_F_MULTISHOT)
872 			*ret = mshot_retry_ret;
873 		else
874 			*ret = -EAGAIN;
875 		return true;
876 	}
877 
878 	/* Finish the request / stop multishot. */
879 finish:
880 	io_req_set_res(req, *ret, cflags);
881 
882 	if (issue_flags & IO_URING_F_MULTISHOT)
883 		*ret = IOU_STOP_MULTISHOT;
884 	else
885 		*ret = IOU_OK;
886 	io_req_msg_cleanup(req, issue_flags);
887 	return true;
888 }
889 
890 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
891 				     struct io_sr_msg *sr, void __user **buf,
892 				     size_t *len)
893 {
894 	unsigned long ubuf = (unsigned long) *buf;
895 	unsigned long hdr;
896 
897 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
898 		kmsg->controllen;
899 	if (*len < hdr)
900 		return -EFAULT;
901 
902 	if (kmsg->controllen) {
903 		unsigned long control = ubuf + hdr - kmsg->controllen;
904 
905 		kmsg->msg.msg_control_user = (void __user *) control;
906 		kmsg->msg.msg_controllen = kmsg->controllen;
907 	}
908 
909 	sr->buf = *buf; /* stash for later copy */
910 	*buf = (void __user *) (ubuf + hdr);
911 	kmsg->payloadlen = *len = *len - hdr;
912 	return 0;
913 }
914 
915 struct io_recvmsg_multishot_hdr {
916 	struct io_uring_recvmsg_out msg;
917 	struct sockaddr_storage addr;
918 };
919 
920 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
921 				struct io_async_msghdr *kmsg,
922 				unsigned int flags, bool *finished)
923 {
924 	int err;
925 	int copy_len;
926 	struct io_recvmsg_multishot_hdr hdr;
927 
928 	if (kmsg->namelen)
929 		kmsg->msg.msg_name = &hdr.addr;
930 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
931 	kmsg->msg.msg_namelen = 0;
932 
933 	if (sock->file->f_flags & O_NONBLOCK)
934 		flags |= MSG_DONTWAIT;
935 
936 	err = sock_recvmsg(sock, &kmsg->msg, flags);
937 	*finished = err <= 0;
938 	if (err < 0)
939 		return err;
940 
941 	hdr.msg = (struct io_uring_recvmsg_out) {
942 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
943 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
944 	};
945 
946 	hdr.msg.payloadlen = err;
947 	if (err > kmsg->payloadlen)
948 		err = kmsg->payloadlen;
949 
950 	copy_len = sizeof(struct io_uring_recvmsg_out);
951 	if (kmsg->msg.msg_namelen > kmsg->namelen)
952 		copy_len += kmsg->namelen;
953 	else
954 		copy_len += kmsg->msg.msg_namelen;
955 
956 	/*
957 	 *      "fromlen shall refer to the value before truncation.."
958 	 *                      1003.1g
959 	 */
960 	hdr.msg.namelen = kmsg->msg.msg_namelen;
961 
962 	/* ensure that there is no gap between hdr and sockaddr_storage */
963 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
964 		     sizeof(struct io_uring_recvmsg_out));
965 	if (copy_to_user(io->buf, &hdr, copy_len)) {
966 		*finished = true;
967 		return -EFAULT;
968 	}
969 
970 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
971 			kmsg->controllen + err;
972 }
973 
974 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
975 {
976 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
977 	struct io_async_msghdr *kmsg = req->async_data;
978 	struct socket *sock;
979 	unsigned flags;
980 	int ret, min_ret = 0;
981 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
982 	bool mshot_finished = true;
983 
984 	sock = sock_from_file(req->file);
985 	if (unlikely(!sock))
986 		return -ENOTSOCK;
987 
988 	if (!(req->flags & REQ_F_POLLED) &&
989 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
990 		return -EAGAIN;
991 
992 	flags = sr->msg_flags;
993 	if (force_nonblock)
994 		flags |= MSG_DONTWAIT;
995 
996 retry_multishot:
997 	if (io_do_buffer_select(req)) {
998 		void __user *buf;
999 		size_t len = sr->len;
1000 
1001 		buf = io_buffer_select(req, &len, issue_flags);
1002 		if (!buf)
1003 			return -ENOBUFS;
1004 
1005 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
1006 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
1007 			if (ret) {
1008 				io_kbuf_recycle(req, issue_flags);
1009 				return ret;
1010 			}
1011 		}
1012 
1013 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
1014 	}
1015 
1016 	kmsg->msg.msg_get_inq = 1;
1017 	kmsg->msg.msg_inq = -1;
1018 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
1019 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
1020 					   &mshot_finished);
1021 	} else {
1022 		/* disable partial retry for recvmsg with cmsg attached */
1023 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
1024 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1025 
1026 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
1027 					 kmsg->uaddr, flags);
1028 	}
1029 
1030 	if (ret < min_ret) {
1031 		if (ret == -EAGAIN && force_nonblock) {
1032 			if (issue_flags & IO_URING_F_MULTISHOT) {
1033 				io_kbuf_recycle(req, issue_flags);
1034 				return IOU_ISSUE_SKIP_COMPLETE;
1035 			}
1036 			return -EAGAIN;
1037 		}
1038 		if (ret > 0 && io_net_retry(sock, flags)) {
1039 			sr->done_io += ret;
1040 			req->flags |= REQ_F_BL_NO_RECYCLE;
1041 			return -EAGAIN;
1042 		}
1043 		if (ret == -ERESTARTSYS)
1044 			ret = -EINTR;
1045 		req_set_fail(req);
1046 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1047 		req_set_fail(req);
1048 	}
1049 
1050 	if (ret > 0)
1051 		ret += sr->done_io;
1052 	else if (sr->done_io)
1053 		ret = sr->done_io;
1054 	else
1055 		io_kbuf_recycle(req, issue_flags);
1056 
1057 	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
1058 		goto retry_multishot;
1059 
1060 	return ret;
1061 }
1062 
1063 static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
1064 			      size_t *len, unsigned int issue_flags)
1065 {
1066 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1067 	int ret;
1068 
1069 	/*
1070 	 * If the ring isn't locked, then don't use the peek interface
1071 	 * to grab multiple buffers as we will lock/unlock between
1072 	 * this selection and posting the buffers.
1073 	 */
1074 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
1075 	    sr->flags & IORING_RECVSEND_BUNDLE) {
1076 		struct buf_sel_arg arg = {
1077 			.iovs = &kmsg->fast_iov,
1078 			.nr_iovs = 1,
1079 			.mode = KBUF_MODE_EXPAND,
1080 		};
1081 
1082 		if (kmsg->free_iov) {
1083 			arg.nr_iovs = kmsg->free_iov_nr;
1084 			arg.iovs = kmsg->free_iov;
1085 			arg.mode |= KBUF_MODE_FREE;
1086 		}
1087 
1088 		if (kmsg->msg.msg_inq > 0)
1089 			arg.max_len = min_not_zero(sr->len, kmsg->msg.msg_inq);
1090 
1091 		ret = io_buffers_peek(req, &arg);
1092 		if (unlikely(ret < 0))
1093 			return ret;
1094 
1095 		/* special case 1 vec, can be a fast path */
1096 		if (ret == 1) {
1097 			sr->buf = arg.iovs[0].iov_base;
1098 			sr->len = arg.iovs[0].iov_len;
1099 			goto map_ubuf;
1100 		}
1101 		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
1102 				arg.out_len);
1103 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->free_iov) {
1104 			kmsg->free_iov_nr = ret;
1105 			kmsg->free_iov = arg.iovs;
1106 			req->flags |= REQ_F_NEED_CLEANUP;
1107 		}
1108 	} else {
1109 		void __user *buf;
1110 
1111 		*len = sr->len;
1112 		buf = io_buffer_select(req, len, issue_flags);
1113 		if (!buf)
1114 			return -ENOBUFS;
1115 		sr->buf = buf;
1116 		sr->len = *len;
1117 map_ubuf:
1118 		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
1119 				  &kmsg->msg.msg_iter);
1120 		if (unlikely(ret))
1121 			return ret;
1122 	}
1123 
1124 	return 0;
1125 }
1126 
1127 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
1128 {
1129 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1130 	struct io_async_msghdr *kmsg = req->async_data;
1131 	struct socket *sock;
1132 	unsigned flags;
1133 	int ret, min_ret = 0;
1134 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1135 	size_t len = sr->len;
1136 	bool mshot_finished;
1137 
1138 	if (!(req->flags & REQ_F_POLLED) &&
1139 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1140 		return -EAGAIN;
1141 
1142 	sock = sock_from_file(req->file);
1143 	if (unlikely(!sock))
1144 		return -ENOTSOCK;
1145 
1146 	flags = sr->msg_flags;
1147 	if (force_nonblock)
1148 		flags |= MSG_DONTWAIT;
1149 
1150 retry_multishot:
1151 	if (io_do_buffer_select(req)) {
1152 		ret = io_recv_buf_select(req, kmsg, &len, issue_flags);
1153 		if (unlikely(ret)) {
1154 			kmsg->msg.msg_inq = -1;
1155 			goto out_free;
1156 		}
1157 		sr->buf = NULL;
1158 	}
1159 
1160 	kmsg->msg.msg_flags = 0;
1161 	kmsg->msg.msg_inq = -1;
1162 
1163 	if (flags & MSG_WAITALL)
1164 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1165 
1166 	ret = sock_recvmsg(sock, &kmsg->msg, flags);
1167 	if (ret < min_ret) {
1168 		if (ret == -EAGAIN && force_nonblock) {
1169 			if (issue_flags & IO_URING_F_MULTISHOT) {
1170 				io_kbuf_recycle(req, issue_flags);
1171 				return IOU_ISSUE_SKIP_COMPLETE;
1172 			}
1173 
1174 			return -EAGAIN;
1175 		}
1176 		if (ret > 0 && io_net_retry(sock, flags)) {
1177 			sr->len -= ret;
1178 			sr->buf += ret;
1179 			sr->done_io += ret;
1180 			req->flags |= REQ_F_BL_NO_RECYCLE;
1181 			return -EAGAIN;
1182 		}
1183 		if (ret == -ERESTARTSYS)
1184 			ret = -EINTR;
1185 		req_set_fail(req);
1186 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1187 out_free:
1188 		req_set_fail(req);
1189 	}
1190 
1191 	mshot_finished = ret <= 0;
1192 	if (ret > 0)
1193 		ret += sr->done_io;
1194 	else if (sr->done_io)
1195 		ret = sr->done_io;
1196 	else
1197 		io_kbuf_recycle(req, issue_flags);
1198 
1199 	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
1200 		goto retry_multishot;
1201 
1202 	return ret;
1203 }
1204 
1205 void io_send_zc_cleanup(struct io_kiocb *req)
1206 {
1207 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1208 	struct io_async_msghdr *io = req->async_data;
1209 
1210 	if (req_has_async_data(req))
1211 		io_netmsg_iovec_free(io);
1212 	if (zc->notif) {
1213 		io_notif_flush(zc->notif);
1214 		zc->notif = NULL;
1215 	}
1216 }
1217 
1218 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1219 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE)
1220 
1221 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1222 {
1223 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1224 	struct io_ring_ctx *ctx = req->ctx;
1225 	struct io_kiocb *notif;
1226 
1227 	zc->done_io = 0;
1228 	req->flags |= REQ_F_POLL_NO_LAZY;
1229 
1230 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
1231 		return -EINVAL;
1232 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1233 	if (req->flags & REQ_F_CQE_SKIP)
1234 		return -EINVAL;
1235 
1236 	notif = zc->notif = io_alloc_notif(ctx);
1237 	if (!notif)
1238 		return -ENOMEM;
1239 	notif->cqe.user_data = req->cqe.user_data;
1240 	notif->cqe.res = 0;
1241 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1242 	req->flags |= REQ_F_NEED_CLEANUP;
1243 
1244 	zc->flags = READ_ONCE(sqe->ioprio);
1245 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1246 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1247 			return -EINVAL;
1248 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1249 			struct io_notif_data *nd = io_notif_to_data(notif);
1250 
1251 			nd->zc_report = true;
1252 			nd->zc_used = false;
1253 			nd->zc_copied = false;
1254 		}
1255 	}
1256 
1257 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1258 		unsigned idx = READ_ONCE(sqe->buf_index);
1259 
1260 		if (unlikely(idx >= ctx->nr_user_bufs))
1261 			return -EFAULT;
1262 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
1263 		req->imu = READ_ONCE(ctx->user_bufs[idx]);
1264 		io_req_set_rsrc_node(notif, ctx, 0);
1265 	}
1266 
1267 	if (req->opcode == IORING_OP_SEND_ZC) {
1268 		if (READ_ONCE(sqe->__pad3[0]))
1269 			return -EINVAL;
1270 		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1271 		zc->addr_len = READ_ONCE(sqe->addr_len);
1272 	} else {
1273 		if (unlikely(sqe->addr2 || sqe->file_index))
1274 			return -EINVAL;
1275 		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
1276 			return -EINVAL;
1277 	}
1278 
1279 	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
1280 	zc->len = READ_ONCE(sqe->len);
1281 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
1282 	if (zc->msg_flags & MSG_DONTWAIT)
1283 		req->flags |= REQ_F_NOWAIT;
1284 
1285 #ifdef CONFIG_COMPAT
1286 	if (req->ctx->compat)
1287 		zc->msg_flags |= MSG_CMSG_COMPAT;
1288 #endif
1289 	return io_sendmsg_prep_setup(req, req->opcode == IORING_OP_SENDMSG_ZC);
1290 }
1291 
1292 static int io_sg_from_iter_iovec(struct sk_buff *skb,
1293 				 struct iov_iter *from, size_t length)
1294 {
1295 	skb_zcopy_downgrade_managed(skb);
1296 	return zerocopy_fill_skb_from_iter(skb, from, length);
1297 }
1298 
1299 static int io_sg_from_iter(struct sk_buff *skb,
1300 			   struct iov_iter *from, size_t length)
1301 {
1302 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1303 	int frag = shinfo->nr_frags;
1304 	int ret = 0;
1305 	struct bvec_iter bi;
1306 	ssize_t copied = 0;
1307 	unsigned long truesize = 0;
1308 
1309 	if (!frag)
1310 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1311 	else if (unlikely(!skb_zcopy_managed(skb)))
1312 		return zerocopy_fill_skb_from_iter(skb, from, length);
1313 
1314 	bi.bi_size = min(from->count, length);
1315 	bi.bi_bvec_done = from->iov_offset;
1316 	bi.bi_idx = 0;
1317 
1318 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1319 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1320 
1321 		copied += v.bv_len;
1322 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1323 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1324 					   v.bv_offset, v.bv_len);
1325 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1326 	}
1327 	if (bi.bi_size)
1328 		ret = -EMSGSIZE;
1329 
1330 	shinfo->nr_frags = frag;
1331 	from->bvec += bi.bi_idx;
1332 	from->nr_segs -= bi.bi_idx;
1333 	from->count -= copied;
1334 	from->iov_offset = bi.bi_bvec_done;
1335 
1336 	skb->data_len += copied;
1337 	skb->len += copied;
1338 	skb->truesize += truesize;
1339 	return ret;
1340 }
1341 
1342 static int io_send_zc_import(struct io_kiocb *req, struct io_async_msghdr *kmsg)
1343 {
1344 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1345 	int ret;
1346 
1347 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
1348 		ret = io_import_fixed(ITER_SOURCE, &kmsg->msg.msg_iter, req->imu,
1349 					(u64)(uintptr_t)sr->buf, sr->len);
1350 		if (unlikely(ret))
1351 			return ret;
1352 		kmsg->msg.sg_from_iter = io_sg_from_iter;
1353 	} else {
1354 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
1355 		if (unlikely(ret))
1356 			return ret;
1357 		ret = io_notif_account_mem(sr->notif, sr->len);
1358 		if (unlikely(ret))
1359 			return ret;
1360 		kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1361 	}
1362 
1363 	return ret;
1364 }
1365 
1366 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1367 {
1368 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1369 	struct io_async_msghdr *kmsg = req->async_data;
1370 	struct socket *sock;
1371 	unsigned msg_flags;
1372 	int ret, min_ret = 0;
1373 
1374 	sock = sock_from_file(req->file);
1375 	if (unlikely(!sock))
1376 		return -ENOTSOCK;
1377 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1378 		return -EOPNOTSUPP;
1379 
1380 	if (!(req->flags & REQ_F_POLLED) &&
1381 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1382 		return -EAGAIN;
1383 
1384 	if (!zc->done_io) {
1385 		ret = io_send_zc_import(req, kmsg);
1386 		if (unlikely(ret))
1387 			return ret;
1388 	}
1389 
1390 	msg_flags = zc->msg_flags;
1391 	if (issue_flags & IO_URING_F_NONBLOCK)
1392 		msg_flags |= MSG_DONTWAIT;
1393 	if (msg_flags & MSG_WAITALL)
1394 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1395 	msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1396 
1397 	kmsg->msg.msg_flags = msg_flags;
1398 	kmsg->msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1399 	ret = sock_sendmsg(sock, &kmsg->msg);
1400 
1401 	if (unlikely(ret < min_ret)) {
1402 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1403 			return -EAGAIN;
1404 
1405 		if (ret > 0 && io_net_retry(sock, kmsg->msg.msg_flags)) {
1406 			zc->len -= ret;
1407 			zc->buf += ret;
1408 			zc->done_io += ret;
1409 			req->flags |= REQ_F_BL_NO_RECYCLE;
1410 			return -EAGAIN;
1411 		}
1412 		if (ret == -ERESTARTSYS)
1413 			ret = -EINTR;
1414 		req_set_fail(req);
1415 	}
1416 
1417 	if (ret >= 0)
1418 		ret += zc->done_io;
1419 	else if (zc->done_io)
1420 		ret = zc->done_io;
1421 
1422 	/*
1423 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1424 	 * flushing notif to io_send_zc_cleanup()
1425 	 */
1426 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1427 		io_notif_flush(zc->notif);
1428 		io_req_msg_cleanup(req, 0);
1429 	}
1430 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1431 	return IOU_OK;
1432 }
1433 
1434 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1435 {
1436 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1437 	struct io_async_msghdr *kmsg = req->async_data;
1438 	struct socket *sock;
1439 	unsigned flags;
1440 	int ret, min_ret = 0;
1441 
1442 	sock = sock_from_file(req->file);
1443 	if (unlikely(!sock))
1444 		return -ENOTSOCK;
1445 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1446 		return -EOPNOTSUPP;
1447 
1448 	if (!(req->flags & REQ_F_POLLED) &&
1449 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1450 		return -EAGAIN;
1451 
1452 	flags = sr->msg_flags;
1453 	if (issue_flags & IO_URING_F_NONBLOCK)
1454 		flags |= MSG_DONTWAIT;
1455 	if (flags & MSG_WAITALL)
1456 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1457 
1458 	kmsg->msg.msg_control_user = sr->msg_control;
1459 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1460 	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1461 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1462 
1463 	if (unlikely(ret < min_ret)) {
1464 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1465 			return -EAGAIN;
1466 
1467 		if (ret > 0 && io_net_retry(sock, flags)) {
1468 			sr->done_io += ret;
1469 			req->flags |= REQ_F_BL_NO_RECYCLE;
1470 			return -EAGAIN;
1471 		}
1472 		if (ret == -ERESTARTSYS)
1473 			ret = -EINTR;
1474 		req_set_fail(req);
1475 	}
1476 
1477 	if (ret >= 0)
1478 		ret += sr->done_io;
1479 	else if (sr->done_io)
1480 		ret = sr->done_io;
1481 
1482 	/*
1483 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1484 	 * flushing notif to io_send_zc_cleanup()
1485 	 */
1486 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1487 		io_notif_flush(sr->notif);
1488 		io_req_msg_cleanup(req, 0);
1489 	}
1490 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1491 	return IOU_OK;
1492 }
1493 
1494 void io_sendrecv_fail(struct io_kiocb *req)
1495 {
1496 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1497 
1498 	if (sr->done_io)
1499 		req->cqe.res = sr->done_io;
1500 
1501 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1502 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1503 		req->cqe.flags |= IORING_CQE_F_MORE;
1504 }
1505 
1506 #define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
1507 			 IORING_ACCEPT_POLL_FIRST)
1508 
1509 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1510 {
1511 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1512 
1513 	if (sqe->len || sqe->buf_index)
1514 		return -EINVAL;
1515 
1516 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1517 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1518 	accept->flags = READ_ONCE(sqe->accept_flags);
1519 	accept->nofile = rlimit(RLIMIT_NOFILE);
1520 	accept->iou_flags = READ_ONCE(sqe->ioprio);
1521 	if (accept->iou_flags & ~ACCEPT_FLAGS)
1522 		return -EINVAL;
1523 
1524 	accept->file_slot = READ_ONCE(sqe->file_index);
1525 	if (accept->file_slot) {
1526 		if (accept->flags & SOCK_CLOEXEC)
1527 			return -EINVAL;
1528 		if (accept->iou_flags & IORING_ACCEPT_MULTISHOT &&
1529 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1530 			return -EINVAL;
1531 	}
1532 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1533 		return -EINVAL;
1534 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1535 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1536 	if (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
1537 		req->flags |= REQ_F_APOLL_MULTISHOT;
1538 	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
1539 		req->flags |= REQ_F_NOWAIT;
1540 	return 0;
1541 }
1542 
1543 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1544 {
1545 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1546 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1547 	bool fixed = !!accept->file_slot;
1548 	struct proto_accept_arg arg = {
1549 		.flags = force_nonblock ? O_NONBLOCK : 0,
1550 	};
1551 	struct file *file;
1552 	unsigned cflags;
1553 	int ret, fd;
1554 
1555 	if (!(req->flags & REQ_F_POLLED) &&
1556 	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
1557 		return -EAGAIN;
1558 
1559 retry:
1560 	if (!fixed) {
1561 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1562 		if (unlikely(fd < 0))
1563 			return fd;
1564 	}
1565 	arg.err = 0;
1566 	arg.is_empty = -1;
1567 	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
1568 			 accept->flags);
1569 	if (IS_ERR(file)) {
1570 		if (!fixed)
1571 			put_unused_fd(fd);
1572 		ret = PTR_ERR(file);
1573 		if (ret == -EAGAIN && force_nonblock &&
1574 		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT)) {
1575 			/*
1576 			 * if it's multishot and polled, we don't need to
1577 			 * return EAGAIN to arm the poll infra since it
1578 			 * has already been done
1579 			 */
1580 			if (issue_flags & IO_URING_F_MULTISHOT)
1581 				return IOU_ISSUE_SKIP_COMPLETE;
1582 			return ret;
1583 		}
1584 		if (ret == -ERESTARTSYS)
1585 			ret = -EINTR;
1586 		req_set_fail(req);
1587 	} else if (!fixed) {
1588 		fd_install(fd, file);
1589 		ret = fd;
1590 	} else {
1591 		ret = io_fixed_fd_install(req, issue_flags, file,
1592 						accept->file_slot);
1593 	}
1594 
1595 	cflags = 0;
1596 	if (!arg.is_empty)
1597 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
1598 
1599 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
1600 		io_req_set_res(req, ret, cflags);
1601 		return IOU_OK;
1602 	}
1603 
1604 	if (ret < 0)
1605 		return ret;
1606 	if (io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
1607 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
1608 			goto retry;
1609 		if (issue_flags & IO_URING_F_MULTISHOT)
1610 			return IOU_ISSUE_SKIP_COMPLETE;
1611 		return -EAGAIN;
1612 	}
1613 
1614 	io_req_set_res(req, ret, cflags);
1615 	return IOU_STOP_MULTISHOT;
1616 }
1617 
1618 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1619 {
1620 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1621 
1622 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1623 		return -EINVAL;
1624 
1625 	sock->domain = READ_ONCE(sqe->fd);
1626 	sock->type = READ_ONCE(sqe->off);
1627 	sock->protocol = READ_ONCE(sqe->len);
1628 	sock->file_slot = READ_ONCE(sqe->file_index);
1629 	sock->nofile = rlimit(RLIMIT_NOFILE);
1630 
1631 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1632 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1633 		return -EINVAL;
1634 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1635 		return -EINVAL;
1636 	return 0;
1637 }
1638 
1639 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1640 {
1641 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1642 	bool fixed = !!sock->file_slot;
1643 	struct file *file;
1644 	int ret, fd;
1645 
1646 	if (!fixed) {
1647 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1648 		if (unlikely(fd < 0))
1649 			return fd;
1650 	}
1651 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1652 	if (IS_ERR(file)) {
1653 		if (!fixed)
1654 			put_unused_fd(fd);
1655 		ret = PTR_ERR(file);
1656 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1657 			return -EAGAIN;
1658 		if (ret == -ERESTARTSYS)
1659 			ret = -EINTR;
1660 		req_set_fail(req);
1661 	} else if (!fixed) {
1662 		fd_install(fd, file);
1663 		ret = fd;
1664 	} else {
1665 		ret = io_fixed_fd_install(req, issue_flags, file,
1666 					    sock->file_slot);
1667 	}
1668 	io_req_set_res(req, ret, 0);
1669 	return IOU_OK;
1670 }
1671 
1672 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1673 {
1674 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1675 	struct io_async_msghdr *io;
1676 
1677 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1678 		return -EINVAL;
1679 
1680 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1681 	conn->addr_len =  READ_ONCE(sqe->addr2);
1682 	conn->in_progress = conn->seen_econnaborted = false;
1683 
1684 	io = io_msg_alloc_async(req);
1685 	if (unlikely(!io))
1686 		return -ENOMEM;
1687 
1688 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr);
1689 }
1690 
1691 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1692 {
1693 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1694 	struct io_async_msghdr *io = req->async_data;
1695 	unsigned file_flags;
1696 	int ret;
1697 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1698 
1699 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1700 
1701 	ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,
1702 				 file_flags);
1703 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1704 	    && force_nonblock) {
1705 		if (ret == -EINPROGRESS) {
1706 			connect->in_progress = true;
1707 		} else if (ret == -ECONNABORTED) {
1708 			if (connect->seen_econnaborted)
1709 				goto out;
1710 			connect->seen_econnaborted = true;
1711 		}
1712 		return -EAGAIN;
1713 	}
1714 	if (connect->in_progress) {
1715 		/*
1716 		 * At least bluetooth will return -EBADFD on a re-connect
1717 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1718 		 * which means the previous result is good. For both of these,
1719 		 * grab the sock_error() and use that for the completion.
1720 		 */
1721 		if (ret == -EBADFD || ret == -EISCONN)
1722 			ret = sock_error(sock_from_file(req->file)->sk);
1723 	}
1724 	if (ret == -ERESTARTSYS)
1725 		ret = -EINTR;
1726 out:
1727 	if (ret < 0)
1728 		req_set_fail(req);
1729 	io_req_msg_cleanup(req, issue_flags);
1730 	io_req_set_res(req, ret, 0);
1731 	return IOU_OK;
1732 }
1733 
1734 int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1735 {
1736 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1737 	struct sockaddr __user *uaddr;
1738 	struct io_async_msghdr *io;
1739 
1740 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1741 		return -EINVAL;
1742 
1743 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1744 	bind->addr_len =  READ_ONCE(sqe->addr2);
1745 
1746 	io = io_msg_alloc_async(req);
1747 	if (unlikely(!io))
1748 		return -ENOMEM;
1749 	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
1750 }
1751 
1752 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
1753 {
1754 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1755 	struct io_async_msghdr *io = req->async_data;
1756 	struct socket *sock;
1757 	int ret;
1758 
1759 	sock = sock_from_file(req->file);
1760 	if (unlikely(!sock))
1761 		return -ENOTSOCK;
1762 
1763 	ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
1764 	if (ret < 0)
1765 		req_set_fail(req);
1766 	io_req_set_res(req, ret, 0);
1767 	return 0;
1768 }
1769 
1770 int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1771 {
1772 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1773 
1774 	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
1775 		return -EINVAL;
1776 
1777 	listen->backlog = READ_ONCE(sqe->len);
1778 	return 0;
1779 }
1780 
1781 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
1782 {
1783 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1784 	struct socket *sock;
1785 	int ret;
1786 
1787 	sock = sock_from_file(req->file);
1788 	if (unlikely(!sock))
1789 		return -ENOTSOCK;
1790 
1791 	ret = __sys_listen_socket(sock, listen->backlog);
1792 	if (ret < 0)
1793 		req_set_fail(req);
1794 	io_req_set_res(req, ret, 0);
1795 	return 0;
1796 }
1797 
1798 void io_netmsg_cache_free(const void *entry)
1799 {
1800 	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
1801 
1802 	if (kmsg->free_iov) {
1803 		kasan_mempool_unpoison_object(kmsg->free_iov,
1804 				kmsg->free_iov_nr * sizeof(struct iovec));
1805 		io_netmsg_iovec_free(kmsg);
1806 	}
1807 	kfree(kmsg);
1808 }
1809 #endif
1810