xref: /linux/io_uring/net.c (revision 989fe6771266bdb82a815d78802c5aa7c918fdfd)
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 #include "zcrx.h"
20 
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				buf_group;
78 	/* per-invocation mshot limit */
79 	unsigned			mshot_len;
80 	/* overall mshot byte limit */
81 	unsigned			mshot_total_len;
82 	void __user			*msg_control;
83 	/* used only for send zerocopy */
84 	struct io_kiocb 		*notif;
85 };
86 
87 /*
88  * The UAPI flags are the lower 8 bits, as that's all sqe->ioprio will hold
89  * anyway. Use the upper 8 bits for internal uses.
90  */
91 enum sr_retry_flags {
92 	IORING_RECV_RETRY	= (1U << 15),
93 	IORING_RECV_PARTIAL_MAP	= (1U << 14),
94 	IORING_RECV_MSHOT_CAP	= (1U << 13),
95 	IORING_RECV_MSHOT_LIM	= (1U << 12),
96 	IORING_RECV_MSHOT_DONE	= (1U << 11),
97 
98 	IORING_RECV_RETRY_CLEAR	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
99 	IORING_RECV_NO_RETRY	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP |
100 				  IORING_RECV_MSHOT_CAP | IORING_RECV_MSHOT_DONE,
101 };
102 
103 /*
104  * Number of times we'll try and do receives if there's more data. If we
105  * exceed this limit, then add us to the back of the queue and retry from
106  * there. This helps fairness between flooding clients.
107  */
108 #define MULTISHOT_MAX_RETRY	32
109 
110 struct io_recvzc {
111 	struct file			*file;
112 	unsigned			msg_flags;
113 	u16				flags;
114 	u32				len;
115 	struct io_zcrx_ifq		*ifq;
116 };
117 
118 static int io_sg_from_iter_iovec(struct sk_buff *skb,
119 				 struct iov_iter *from, size_t length);
120 static int io_sg_from_iter(struct sk_buff *skb,
121 			   struct iov_iter *from, size_t length);
122 
123 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
124 {
125 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
126 
127 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
128 		     sqe->buf_index || sqe->splice_fd_in))
129 		return -EINVAL;
130 
131 	shutdown->how = READ_ONCE(sqe->len);
132 	req->flags |= REQ_F_FORCE_ASYNC;
133 	return 0;
134 }
135 
136 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
137 {
138 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
139 	struct socket *sock;
140 	int ret;
141 
142 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
143 
144 	sock = sock_from_file(req->file);
145 	if (unlikely(!sock))
146 		return -ENOTSOCK;
147 
148 	ret = __sys_shutdown_sock(sock, shutdown->how);
149 	io_req_set_res(req, ret, 0);
150 	return IOU_COMPLETE;
151 }
152 
153 static bool io_net_retry(struct socket *sock, int flags)
154 {
155 	if (!(flags & MSG_WAITALL))
156 		return false;
157 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
158 }
159 
160 static void io_netmsg_iovec_free(struct io_async_msghdr *kmsg)
161 {
162 	if (kmsg->vec.iovec)
163 		io_vec_free(&kmsg->vec);
164 }
165 
166 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
167 {
168 	struct io_async_msghdr *hdr = req->async_data;
169 
170 	/* can't recycle, ensure we free the iovec if we have one */
171 	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
172 		io_netmsg_iovec_free(hdr);
173 		return;
174 	}
175 
176 	/* Let normal cleanup path reap it if we fail adding to the cache */
177 	io_alloc_cache_vec_kasan(&hdr->vec);
178 	if (hdr->vec.nr > IO_VEC_CACHE_SOFT_CAP)
179 		io_vec_free(&hdr->vec);
180 
181 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr)) {
182 		req->async_data = NULL;
183 		req->flags &= ~(REQ_F_ASYNC_DATA|REQ_F_NEED_CLEANUP);
184 	}
185 }
186 
187 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
188 {
189 	struct io_ring_ctx *ctx = req->ctx;
190 	struct io_async_msghdr *hdr;
191 
192 	hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req);
193 	if (!hdr)
194 		return NULL;
195 
196 	/* If the async data was cached, we might have an iov cached inside. */
197 	if (hdr->vec.iovec)
198 		req->flags |= REQ_F_NEED_CLEANUP;
199 	return hdr;
200 }
201 
202 static inline void io_mshot_prep_retry(struct io_kiocb *req,
203 				       struct io_async_msghdr *kmsg)
204 {
205 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
206 
207 	req->flags &= ~REQ_F_BL_EMPTY;
208 	sr->done_io = 0;
209 	sr->flags &= ~IORING_RECV_RETRY_CLEAR;
210 	sr->len = sr->mshot_len;
211 }
212 
213 static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg,
214 			     const struct iovec __user *uiov, unsigned uvec_seg,
215 			     int ddir)
216 {
217 	struct iovec *iov;
218 	int ret, nr_segs;
219 
220 	if (iomsg->vec.iovec) {
221 		nr_segs = iomsg->vec.nr;
222 		iov = iomsg->vec.iovec;
223 	} else {
224 		nr_segs = 1;
225 		iov = &iomsg->fast_iov;
226 	}
227 
228 	ret = __import_iovec(ddir, uiov, uvec_seg, nr_segs, &iov,
229 			     &iomsg->msg.msg_iter, io_is_compat(req->ctx));
230 	if (unlikely(ret < 0))
231 		return ret;
232 
233 	if (iov) {
234 		req->flags |= REQ_F_NEED_CLEANUP;
235 		io_vec_reset_iovec(&iomsg->vec, iov, iomsg->msg.msg_iter.nr_segs);
236 	}
237 	return 0;
238 }
239 
240 static int io_compat_msg_copy_hdr(struct io_kiocb *req,
241 				  struct io_async_msghdr *iomsg,
242 				  struct compat_msghdr *msg, int ddir,
243 				  struct sockaddr __user **save_addr)
244 {
245 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
246 	struct compat_iovec __user *uiov;
247 	int ret;
248 
249 	if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
250 		return -EFAULT;
251 
252 	ret = __get_compat_msghdr(&iomsg->msg, msg, save_addr);
253 	if (ret)
254 		return ret;
255 
256 	uiov = compat_ptr(msg->msg_iov);
257 	if (req->flags & REQ_F_BUFFER_SELECT) {
258 		if (msg->msg_iovlen == 0) {
259 			sr->len = 0;
260 		} else if (msg->msg_iovlen > 1) {
261 			return -EINVAL;
262 		} else {
263 			struct compat_iovec tmp_iov;
264 
265 			if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov)))
266 				return -EFAULT;
267 			sr->len = tmp_iov.iov_len;
268 		}
269 	}
270 	return 0;
271 }
272 
273 static int io_copy_msghdr_from_user(struct user_msghdr *msg,
274 				    struct user_msghdr __user *umsg)
275 {
276 	if (!user_access_begin(umsg, sizeof(*umsg)))
277 		return -EFAULT;
278 	unsafe_get_user(msg->msg_name, &umsg->msg_name, ua_end);
279 	unsafe_get_user(msg->msg_namelen, &umsg->msg_namelen, ua_end);
280 	unsafe_get_user(msg->msg_iov, &umsg->msg_iov, ua_end);
281 	unsafe_get_user(msg->msg_iovlen, &umsg->msg_iovlen, ua_end);
282 	unsafe_get_user(msg->msg_control, &umsg->msg_control, ua_end);
283 	unsafe_get_user(msg->msg_controllen, &umsg->msg_controllen, ua_end);
284 	user_access_end();
285 	return 0;
286 ua_end:
287 	user_access_end();
288 	return -EFAULT;
289 }
290 
291 static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
292 			   struct user_msghdr *msg, int ddir,
293 			   struct sockaddr __user **save_addr)
294 {
295 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
296 	struct user_msghdr __user *umsg = sr->umsg;
297 	int ret;
298 
299 	iomsg->msg.msg_name = &iomsg->addr;
300 	iomsg->msg.msg_iter.nr_segs = 0;
301 
302 	if (io_is_compat(req->ctx)) {
303 		struct compat_msghdr cmsg;
304 
305 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ddir, save_addr);
306 		if (ret)
307 			return ret;
308 
309 		memset(msg, 0, sizeof(*msg));
310 		msg->msg_namelen = cmsg.msg_namelen;
311 		msg->msg_controllen = cmsg.msg_controllen;
312 		msg->msg_iov = compat_ptr(cmsg.msg_iov);
313 		msg->msg_iovlen = cmsg.msg_iovlen;
314 		return 0;
315 	}
316 
317 	ret = io_copy_msghdr_from_user(msg, umsg);
318 	if (unlikely(ret))
319 		return ret;
320 
321 	msg->msg_flags = 0;
322 
323 	ret = __copy_msghdr(&iomsg->msg, msg, save_addr);
324 	if (ret)
325 		return ret;
326 
327 	if (req->flags & REQ_F_BUFFER_SELECT) {
328 		if (msg->msg_iovlen == 0) {
329 			sr->len = 0;
330 		} else if (msg->msg_iovlen > 1) {
331 			return -EINVAL;
332 		} else {
333 			struct iovec __user *uiov = msg->msg_iov;
334 			struct iovec tmp_iov;
335 
336 			if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov)))
337 				return -EFAULT;
338 			sr->len = tmp_iov.iov_len;
339 		}
340 	}
341 	return 0;
342 }
343 
344 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
345 {
346 	struct io_async_msghdr *io = req->async_data;
347 
348 	io_netmsg_iovec_free(io);
349 }
350 
351 static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
352 {
353 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
354 	struct io_async_msghdr *kmsg = req->async_data;
355 	void __user *addr;
356 	u16 addr_len;
357 	int ret;
358 
359 	sr->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
360 
361 	if (READ_ONCE(sqe->__pad3[0]))
362 		return -EINVAL;
363 
364 	kmsg->msg.msg_name = NULL;
365 	kmsg->msg.msg_namelen = 0;
366 	kmsg->msg.msg_control = NULL;
367 	kmsg->msg.msg_controllen = 0;
368 	kmsg->msg.msg_ubuf = NULL;
369 
370 	addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
371 	addr_len = READ_ONCE(sqe->addr_len);
372 	if (addr) {
373 		ret = move_addr_to_kernel(addr, addr_len, &kmsg->addr);
374 		if (unlikely(ret < 0))
375 			return ret;
376 		kmsg->msg.msg_name = &kmsg->addr;
377 		kmsg->msg.msg_namelen = addr_len;
378 	}
379 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
380 		req->flags |= REQ_F_IMPORT_BUFFER;
381 		return 0;
382 	}
383 	if (req->flags & REQ_F_BUFFER_SELECT)
384 		return 0;
385 
386 	if (sr->flags & IORING_SEND_VECTORIZED)
387                return io_net_import_vec(req, kmsg, sr->buf, sr->len, ITER_SOURCE);
388 
389 	return import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
390 }
391 
392 static int io_sendmsg_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
393 {
394 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
395 	struct io_async_msghdr *kmsg = req->async_data;
396 	struct user_msghdr msg;
397 	int ret;
398 
399 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
400 	ret = io_msg_copy_hdr(req, kmsg, &msg, ITER_SOURCE, NULL);
401 	if (unlikely(ret))
402 		return ret;
403 	/* save msg_control as sys_sendmsg() overwrites it */
404 	sr->msg_control = kmsg->msg.msg_control_user;
405 
406 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
407 		kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen;
408 		return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov,
409 					 msg.msg_iovlen);
410 	}
411 	if (req->flags & REQ_F_BUFFER_SELECT)
412 		return 0;
413 	return io_net_import_vec(req, kmsg, msg.msg_iov, msg.msg_iovlen, ITER_SOURCE);
414 }
415 
416 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE | IORING_SEND_VECTORIZED)
417 
418 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
419 {
420 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
421 
422 	sr->done_io = 0;
423 	sr->len = READ_ONCE(sqe->len);
424 	sr->flags = READ_ONCE(sqe->ioprio);
425 	if (sr->flags & ~SENDMSG_FLAGS)
426 		return -EINVAL;
427 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
428 	if (sr->msg_flags & MSG_DONTWAIT)
429 		req->flags |= REQ_F_NOWAIT;
430 	if (req->flags & REQ_F_BUFFER_SELECT)
431 		sr->buf_group = req->buf_index;
432 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
433 		if (req->opcode == IORING_OP_SENDMSG)
434 			return -EINVAL;
435 		sr->msg_flags |= MSG_WAITALL;
436 		req->buf_list = NULL;
437 		req->flags |= REQ_F_MULTISHOT;
438 	}
439 
440 	if (io_is_compat(req->ctx))
441 		sr->msg_flags |= MSG_CMSG_COMPAT;
442 
443 	if (unlikely(!io_msg_alloc_async(req)))
444 		return -ENOMEM;
445 	if (req->opcode != IORING_OP_SENDMSG)
446 		return io_send_setup(req, sqe);
447 	if (unlikely(sqe->addr2 || sqe->file_index))
448 		return -EINVAL;
449 	return io_sendmsg_setup(req, sqe);
450 }
451 
452 static void io_req_msg_cleanup(struct io_kiocb *req,
453 			       unsigned int issue_flags)
454 {
455 	io_netmsg_recycle(req, issue_flags);
456 }
457 
458 /*
459  * For bundle completions, we need to figure out how many segments we consumed.
460  * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
461  * could be using an ITER_IOVEC. If the latter, then if we consumed all of
462  * the segments, then it's a trivial questiont o answer. If we have residual
463  * data in the iter, then loop the segments to figure out how much we
464  * transferred.
465  */
466 static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
467 {
468 	struct iovec *iov;
469 	int nbufs;
470 
471 	/* no data is always zero segments, and a ubuf is always 1 segment */
472 	if (ret <= 0)
473 		return 0;
474 	if (iter_is_ubuf(&kmsg->msg.msg_iter))
475 		return 1;
476 
477 	iov = kmsg->vec.iovec;
478 	if (!iov)
479 		iov = &kmsg->fast_iov;
480 
481 	/* if all data was transferred, it's basic pointer math */
482 	if (!iov_iter_count(&kmsg->msg.msg_iter))
483 		return iter_iov(&kmsg->msg.msg_iter) - iov;
484 
485 	/* short transfer, count segments */
486 	nbufs = 0;
487 	do {
488 		int this_len = min_t(int, iov[nbufs].iov_len, ret);
489 
490 		nbufs++;
491 		ret -= this_len;
492 	} while (ret);
493 
494 	return nbufs;
495 }
496 
497 static inline bool io_send_finish(struct io_kiocb *req, int *ret,
498 				  struct io_async_msghdr *kmsg,
499 				  unsigned issue_flags)
500 {
501 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
502 	bool bundle_finished = *ret <= 0;
503 	unsigned int cflags;
504 
505 	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
506 		cflags = io_put_kbuf(req, *ret, issue_flags);
507 		goto finish;
508 	}
509 
510 	cflags = io_put_kbufs(req, *ret, io_bundle_nbufs(kmsg, *ret), issue_flags);
511 
512 	if (bundle_finished || req->flags & REQ_F_BL_EMPTY)
513 		goto finish;
514 
515 	/*
516 	 * Fill CQE for this receive and see if we should keep trying to
517 	 * receive from this socket.
518 	 */
519 	if (io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
520 		io_mshot_prep_retry(req, kmsg);
521 		return false;
522 	}
523 
524 	/* Otherwise stop bundle and use the current result. */
525 finish:
526 	io_req_set_res(req, *ret, cflags);
527 	*ret = IOU_COMPLETE;
528 	return true;
529 }
530 
531 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
532 {
533 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
534 	struct io_async_msghdr *kmsg = req->async_data;
535 	struct socket *sock;
536 	unsigned flags;
537 	int min_ret = 0;
538 	int ret;
539 
540 	sock = sock_from_file(req->file);
541 	if (unlikely(!sock))
542 		return -ENOTSOCK;
543 
544 	if (!(req->flags & REQ_F_POLLED) &&
545 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
546 		return -EAGAIN;
547 
548 	flags = sr->msg_flags;
549 	if (issue_flags & IO_URING_F_NONBLOCK)
550 		flags |= MSG_DONTWAIT;
551 	if (flags & MSG_WAITALL)
552 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
553 
554 	kmsg->msg.msg_control_user = sr->msg_control;
555 
556 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
557 
558 	if (ret < min_ret) {
559 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
560 			return -EAGAIN;
561 		if (ret > 0 && io_net_retry(sock, flags)) {
562 			kmsg->msg.msg_controllen = 0;
563 			kmsg->msg.msg_control = NULL;
564 			sr->done_io += ret;
565 			req->flags |= REQ_F_BL_NO_RECYCLE;
566 			return -EAGAIN;
567 		}
568 		if (ret == -ERESTARTSYS)
569 			ret = -EINTR;
570 		req_set_fail(req);
571 	}
572 	io_req_msg_cleanup(req, issue_flags);
573 	if (ret >= 0)
574 		ret += sr->done_io;
575 	else if (sr->done_io)
576 		ret = sr->done_io;
577 	io_req_set_res(req, ret, 0);
578 	return IOU_COMPLETE;
579 }
580 
581 static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags,
582 				 struct io_async_msghdr *kmsg)
583 {
584 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
585 
586 	int ret;
587 	struct buf_sel_arg arg = {
588 		.iovs = &kmsg->fast_iov,
589 		.max_len = min_not_zero(sr->len, INT_MAX),
590 		.nr_iovs = 1,
591 		.buf_group = sr->buf_group,
592 	};
593 
594 	if (kmsg->vec.iovec) {
595 		arg.nr_iovs = kmsg->vec.nr;
596 		arg.iovs = kmsg->vec.iovec;
597 		arg.mode = KBUF_MODE_FREE;
598 	}
599 
600 	if (!(sr->flags & IORING_RECVSEND_BUNDLE))
601 		arg.nr_iovs = 1;
602 	else
603 		arg.mode |= KBUF_MODE_EXPAND;
604 
605 	ret = io_buffers_select(req, &arg, issue_flags);
606 	if (unlikely(ret < 0))
607 		return ret;
608 
609 	if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
610 		kmsg->vec.nr = ret;
611 		kmsg->vec.iovec = arg.iovs;
612 		req->flags |= REQ_F_NEED_CLEANUP;
613 	}
614 	sr->len = arg.out_len;
615 
616 	if (ret == 1) {
617 		sr->buf = arg.iovs[0].iov_base;
618 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
619 					&kmsg->msg.msg_iter);
620 		if (unlikely(ret))
621 			return ret;
622 	} else {
623 		iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE,
624 				arg.iovs, ret, arg.out_len);
625 	}
626 
627 	return 0;
628 }
629 
630 int io_send(struct io_kiocb *req, unsigned int issue_flags)
631 {
632 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
633 	struct io_async_msghdr *kmsg = req->async_data;
634 	struct socket *sock;
635 	unsigned flags;
636 	int min_ret = 0;
637 	int ret;
638 
639 	sock = sock_from_file(req->file);
640 	if (unlikely(!sock))
641 		return -ENOTSOCK;
642 
643 	if (!(req->flags & REQ_F_POLLED) &&
644 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
645 		return -EAGAIN;
646 
647 	flags = sr->msg_flags;
648 	if (issue_flags & IO_URING_F_NONBLOCK)
649 		flags |= MSG_DONTWAIT;
650 
651 retry_bundle:
652 	if (io_do_buffer_select(req)) {
653 		ret = io_send_select_buffer(req, issue_flags, kmsg);
654 		if (ret)
655 			return ret;
656 	}
657 
658 	/*
659 	 * If MSG_WAITALL is set, or this is a bundle send, then we need
660 	 * the full amount. If just bundle is set, if we do a short send
661 	 * then we complete the bundle sequence rather than continue on.
662 	 */
663 	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
664 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
665 
666 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
667 	kmsg->msg.msg_flags = flags;
668 	ret = sock_sendmsg(sock, &kmsg->msg);
669 	if (ret < min_ret) {
670 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
671 			return -EAGAIN;
672 
673 		if (ret > 0 && io_net_retry(sock, flags)) {
674 			sr->len -= ret;
675 			sr->buf += ret;
676 			sr->done_io += ret;
677 			req->flags |= REQ_F_BL_NO_RECYCLE;
678 			return -EAGAIN;
679 		}
680 		if (ret == -ERESTARTSYS)
681 			ret = -EINTR;
682 		req_set_fail(req);
683 	}
684 	if (ret >= 0)
685 		ret += sr->done_io;
686 	else if (sr->done_io)
687 		ret = sr->done_io;
688 
689 	if (!io_send_finish(req, &ret, kmsg, issue_flags))
690 		goto retry_bundle;
691 
692 	io_req_msg_cleanup(req, issue_flags);
693 	return ret;
694 }
695 
696 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
697 				 struct io_async_msghdr *iomsg,
698 				 int namelen, size_t controllen)
699 {
700 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
701 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
702 		int hdr;
703 
704 		if (unlikely(namelen < 0))
705 			return -EOVERFLOW;
706 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
707 					namelen, &hdr))
708 			return -EOVERFLOW;
709 		if (check_add_overflow(hdr, controllen, &hdr))
710 			return -EOVERFLOW;
711 
712 		iomsg->namelen = namelen;
713 		iomsg->controllen = controllen;
714 		return 0;
715 	}
716 
717 	return 0;
718 }
719 
720 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
721 			       struct io_async_msghdr *iomsg)
722 {
723 	struct user_msghdr msg;
724 	int ret;
725 
726 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST, &iomsg->uaddr);
727 	if (unlikely(ret))
728 		return ret;
729 
730 	if (!(req->flags & REQ_F_BUFFER_SELECT)) {
731 		ret = io_net_import_vec(req, iomsg, msg.msg_iov, msg.msg_iovlen,
732 					ITER_DEST);
733 		if (unlikely(ret))
734 			return ret;
735 	}
736 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
737 					msg.msg_controllen);
738 }
739 
740 static int io_recvmsg_prep_setup(struct io_kiocb *req)
741 {
742 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
743 	struct io_async_msghdr *kmsg;
744 
745 	kmsg = io_msg_alloc_async(req);
746 	if (unlikely(!kmsg))
747 		return -ENOMEM;
748 
749 	if (req->opcode == IORING_OP_RECV) {
750 		kmsg->msg.msg_name = NULL;
751 		kmsg->msg.msg_namelen = 0;
752 		kmsg->msg.msg_inq = 0;
753 		kmsg->msg.msg_control = NULL;
754 		kmsg->msg.msg_get_inq = 1;
755 		kmsg->msg.msg_controllen = 0;
756 		kmsg->msg.msg_iocb = NULL;
757 		kmsg->msg.msg_ubuf = NULL;
758 
759 		if (req->flags & REQ_F_BUFFER_SELECT)
760 			return 0;
761 		return import_ubuf(ITER_DEST, sr->buf, sr->len,
762 				   &kmsg->msg.msg_iter);
763 	}
764 
765 	return io_recvmsg_copy_hdr(req, kmsg);
766 }
767 
768 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
769 			IORING_RECVSEND_BUNDLE)
770 
771 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
772 {
773 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
774 
775 	sr->done_io = 0;
776 
777 	if (unlikely(sqe->addr2))
778 		return -EINVAL;
779 
780 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
781 	sr->len = READ_ONCE(sqe->len);
782 	sr->flags = READ_ONCE(sqe->ioprio);
783 	if (sr->flags & ~RECVMSG_FLAGS)
784 		return -EINVAL;
785 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
786 	if (sr->msg_flags & MSG_DONTWAIT)
787 		req->flags |= REQ_F_NOWAIT;
788 	if (sr->msg_flags & MSG_ERRQUEUE)
789 		req->flags |= REQ_F_CLEAR_POLLIN;
790 	if (req->flags & REQ_F_BUFFER_SELECT) {
791 		/*
792 		 * Store the buffer group for this multishot receive separately,
793 		 * as if we end up doing an io-wq based issue that selects a
794 		 * buffer, it has to be committed immediately and that will
795 		 * clear ->buf_list. This means we lose the link to the buffer
796 		 * list, and the eventual buffer put on completion then cannot
797 		 * restore it.
798 		 */
799 		sr->buf_group = req->buf_index;
800 		req->buf_list = NULL;
801 	}
802 	sr->mshot_total_len = sr->mshot_len = 0;
803 	if (sr->flags & IORING_RECV_MULTISHOT) {
804 		if (!(req->flags & REQ_F_BUFFER_SELECT))
805 			return -EINVAL;
806 		if (sr->msg_flags & MSG_WAITALL)
807 			return -EINVAL;
808 		if (req->opcode == IORING_OP_RECV) {
809 			sr->mshot_len = sr->len;
810 			sr->mshot_total_len = READ_ONCE(sqe->optlen);
811 			if (sr->mshot_total_len)
812 				sr->flags |= IORING_RECV_MSHOT_LIM;
813 		} else if (sqe->optlen) {
814 			return -EINVAL;
815 		}
816 		req->flags |= REQ_F_APOLL_MULTISHOT;
817 	} else if (sqe->optlen) {
818 		return -EINVAL;
819 	}
820 
821 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
822 		if (req->opcode == IORING_OP_RECVMSG)
823 			return -EINVAL;
824 	}
825 
826 	if (io_is_compat(req->ctx))
827 		sr->msg_flags |= MSG_CMSG_COMPAT;
828 
829 	sr->nr_multishot_loops = 0;
830 	return io_recvmsg_prep_setup(req);
831 }
832 
833 /* bits to clear in old and inherit in new cflags on bundle retry */
834 #define CQE_F_MASK	(IORING_CQE_F_SOCK_NONEMPTY|IORING_CQE_F_MORE)
835 
836 /*
837  * Finishes io_recv and io_recvmsg.
838  *
839  * Returns true if it is actually finished, or false if it should run
840  * again (for multishot).
841  */
842 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
843 				  struct io_async_msghdr *kmsg,
844 				  bool mshot_finished, unsigned issue_flags)
845 {
846 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
847 	unsigned int cflags = 0;
848 
849 	if (kmsg->msg.msg_inq > 0)
850 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
851 
852 	if (*ret > 0 && sr->flags & IORING_RECV_MSHOT_LIM) {
853 		/*
854 		 * If sr->len hits zero, the limit has been reached. Mark
855 		 * mshot as finished, and flag MSHOT_DONE as well to prevent
856 		 * a potential bundle from being retried.
857 		 */
858 		sr->mshot_total_len -= min_t(int, *ret, sr->mshot_total_len);
859 		if (!sr->mshot_total_len) {
860 			sr->flags |= IORING_RECV_MSHOT_DONE;
861 			mshot_finished = true;
862 		}
863 	}
864 
865 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
866 		size_t this_ret = *ret - sr->done_io;
867 
868 		cflags |= io_put_kbufs(req, this_ret, io_bundle_nbufs(kmsg, this_ret),
869 				      issue_flags);
870 		if (sr->flags & IORING_RECV_RETRY)
871 			cflags = req->cqe.flags | (cflags & CQE_F_MASK);
872 		if (sr->mshot_len && *ret >= sr->mshot_len)
873 			sr->flags |= IORING_RECV_MSHOT_CAP;
874 		/* bundle with no more immediate buffers, we're done */
875 		if (req->flags & REQ_F_BL_EMPTY)
876 			goto finish;
877 		/*
878 		 * If more is available AND it was a full transfer, retry and
879 		 * append to this one
880 		 */
881 		if (!(sr->flags & IORING_RECV_NO_RETRY) &&
882 		    kmsg->msg.msg_inq > 1 && this_ret > 0 &&
883 		    !iov_iter_count(&kmsg->msg.msg_iter)) {
884 			req->cqe.flags = cflags & ~CQE_F_MASK;
885 			sr->len = kmsg->msg.msg_inq;
886 			sr->done_io += this_ret;
887 			sr->flags |= IORING_RECV_RETRY;
888 			return false;
889 		}
890 	} else {
891 		cflags |= io_put_kbuf(req, *ret, issue_flags);
892 	}
893 
894 	/*
895 	 * Fill CQE for this receive and see if we should keep trying to
896 	 * receive from this socket.
897 	 */
898 	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
899 	    io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
900 		*ret = IOU_RETRY;
901 		io_mshot_prep_retry(req, kmsg);
902 		/* Known not-empty or unknown state, retry */
903 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
904 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY &&
905 			    !(sr->flags & IORING_RECV_MSHOT_CAP)) {
906 				return false;
907 			}
908 			/* mshot retries exceeded, force a requeue */
909 			sr->nr_multishot_loops = 0;
910 			sr->flags &= ~IORING_RECV_MSHOT_CAP;
911 			if (issue_flags & IO_URING_F_MULTISHOT)
912 				*ret = IOU_REQUEUE;
913 		}
914 		return true;
915 	}
916 
917 	/* Finish the request / stop multishot. */
918 finish:
919 	io_req_set_res(req, *ret, cflags);
920 	*ret = IOU_COMPLETE;
921 	io_req_msg_cleanup(req, issue_flags);
922 	return true;
923 }
924 
925 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
926 				     struct io_sr_msg *sr, void __user **buf,
927 				     size_t *len)
928 {
929 	unsigned long ubuf = (unsigned long) *buf;
930 	unsigned long hdr;
931 
932 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
933 		kmsg->controllen;
934 	if (*len < hdr)
935 		return -EFAULT;
936 
937 	if (kmsg->controllen) {
938 		unsigned long control = ubuf + hdr - kmsg->controllen;
939 
940 		kmsg->msg.msg_control_user = (void __user *) control;
941 		kmsg->msg.msg_controllen = kmsg->controllen;
942 	}
943 
944 	sr->buf = *buf; /* stash for later copy */
945 	*buf = (void __user *) (ubuf + hdr);
946 	kmsg->payloadlen = *len = *len - hdr;
947 	return 0;
948 }
949 
950 struct io_recvmsg_multishot_hdr {
951 	struct io_uring_recvmsg_out msg;
952 	struct sockaddr_storage addr;
953 };
954 
955 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
956 				struct io_async_msghdr *kmsg,
957 				unsigned int flags, bool *finished)
958 {
959 	int err;
960 	int copy_len;
961 	struct io_recvmsg_multishot_hdr hdr;
962 
963 	if (kmsg->namelen)
964 		kmsg->msg.msg_name = &hdr.addr;
965 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
966 	kmsg->msg.msg_namelen = 0;
967 
968 	if (sock->file->f_flags & O_NONBLOCK)
969 		flags |= MSG_DONTWAIT;
970 
971 	err = sock_recvmsg(sock, &kmsg->msg, flags);
972 	*finished = err <= 0;
973 	if (err < 0)
974 		return err;
975 
976 	hdr.msg = (struct io_uring_recvmsg_out) {
977 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
978 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
979 	};
980 
981 	hdr.msg.payloadlen = err;
982 	if (err > kmsg->payloadlen)
983 		err = kmsg->payloadlen;
984 
985 	copy_len = sizeof(struct io_uring_recvmsg_out);
986 	if (kmsg->msg.msg_namelen > kmsg->namelen)
987 		copy_len += kmsg->namelen;
988 	else
989 		copy_len += kmsg->msg.msg_namelen;
990 
991 	/*
992 	 *      "fromlen shall refer to the value before truncation.."
993 	 *                      1003.1g
994 	 */
995 	hdr.msg.namelen = kmsg->msg.msg_namelen;
996 
997 	/* ensure that there is no gap between hdr and sockaddr_storage */
998 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
999 		     sizeof(struct io_uring_recvmsg_out));
1000 	if (copy_to_user(io->buf, &hdr, copy_len)) {
1001 		*finished = true;
1002 		return -EFAULT;
1003 	}
1004 
1005 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
1006 			kmsg->controllen + err;
1007 }
1008 
1009 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
1010 {
1011 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1012 	struct io_async_msghdr *kmsg = req->async_data;
1013 	struct socket *sock;
1014 	unsigned flags;
1015 	int ret, min_ret = 0;
1016 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1017 	bool mshot_finished = true;
1018 
1019 	sock = sock_from_file(req->file);
1020 	if (unlikely(!sock))
1021 		return -ENOTSOCK;
1022 
1023 	if (!(req->flags & REQ_F_POLLED) &&
1024 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1025 		return -EAGAIN;
1026 
1027 	flags = sr->msg_flags;
1028 	if (force_nonblock)
1029 		flags |= MSG_DONTWAIT;
1030 
1031 retry_multishot:
1032 	if (io_do_buffer_select(req)) {
1033 		void __user *buf;
1034 		size_t len = sr->len;
1035 
1036 		buf = io_buffer_select(req, &len, sr->buf_group, issue_flags);
1037 		if (!buf)
1038 			return -ENOBUFS;
1039 
1040 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
1041 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
1042 			if (ret) {
1043 				io_kbuf_recycle(req, issue_flags);
1044 				return ret;
1045 			}
1046 		}
1047 
1048 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
1049 	}
1050 
1051 	kmsg->msg.msg_get_inq = 1;
1052 	kmsg->msg.msg_inq = -1;
1053 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
1054 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
1055 					   &mshot_finished);
1056 	} else {
1057 		/* disable partial retry for recvmsg with cmsg attached */
1058 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
1059 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1060 
1061 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
1062 					 kmsg->uaddr, flags);
1063 	}
1064 
1065 	if (ret < min_ret) {
1066 		if (ret == -EAGAIN && force_nonblock) {
1067 			if (issue_flags & IO_URING_F_MULTISHOT)
1068 				io_kbuf_recycle(req, issue_flags);
1069 
1070 			return IOU_RETRY;
1071 		}
1072 		if (ret > 0 && io_net_retry(sock, flags)) {
1073 			sr->done_io += ret;
1074 			req->flags |= REQ_F_BL_NO_RECYCLE;
1075 			return IOU_RETRY;
1076 		}
1077 		if (ret == -ERESTARTSYS)
1078 			ret = -EINTR;
1079 		req_set_fail(req);
1080 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1081 		req_set_fail(req);
1082 	}
1083 
1084 	if (ret > 0)
1085 		ret += sr->done_io;
1086 	else if (sr->done_io)
1087 		ret = sr->done_io;
1088 	else
1089 		io_kbuf_recycle(req, issue_flags);
1090 
1091 	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
1092 		goto retry_multishot;
1093 
1094 	return ret;
1095 }
1096 
1097 static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
1098 			      size_t *len, unsigned int issue_flags)
1099 {
1100 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1101 	int ret;
1102 
1103 	/*
1104 	 * If the ring isn't locked, then don't use the peek interface
1105 	 * to grab multiple buffers as we will lock/unlock between
1106 	 * this selection and posting the buffers.
1107 	 */
1108 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
1109 	    sr->flags & IORING_RECVSEND_BUNDLE) {
1110 		struct buf_sel_arg arg = {
1111 			.iovs = &kmsg->fast_iov,
1112 			.nr_iovs = 1,
1113 			.mode = KBUF_MODE_EXPAND,
1114 			.buf_group = sr->buf_group,
1115 		};
1116 
1117 		if (kmsg->vec.iovec) {
1118 			arg.nr_iovs = kmsg->vec.nr;
1119 			arg.iovs = kmsg->vec.iovec;
1120 			arg.mode |= KBUF_MODE_FREE;
1121 		}
1122 
1123 		if (*len)
1124 			arg.max_len = *len;
1125 		else if (kmsg->msg.msg_inq > 1)
1126 			arg.max_len = min_not_zero(*len, (size_t) kmsg->msg.msg_inq);
1127 
1128 		/* if mshot limited, ensure we don't go over */
1129 		if (sr->flags & IORING_RECV_MSHOT_LIM)
1130 			arg.max_len = min_not_zero(arg.max_len, sr->mshot_total_len);
1131 		ret = io_buffers_peek(req, &arg);
1132 		if (unlikely(ret < 0))
1133 			return ret;
1134 
1135 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
1136 			kmsg->vec.nr = ret;
1137 			kmsg->vec.iovec = arg.iovs;
1138 			req->flags |= REQ_F_NEED_CLEANUP;
1139 		}
1140 		if (arg.partial_map)
1141 			sr->flags |= IORING_RECV_PARTIAL_MAP;
1142 
1143 		/* special case 1 vec, can be a fast path */
1144 		if (ret == 1) {
1145 			sr->buf = arg.iovs[0].iov_base;
1146 			sr->len = arg.iovs[0].iov_len;
1147 			goto map_ubuf;
1148 		}
1149 		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
1150 				arg.out_len);
1151 	} else {
1152 		void __user *buf;
1153 
1154 		*len = sr->len;
1155 		buf = io_buffer_select(req, len, sr->buf_group, issue_flags);
1156 		if (!buf)
1157 			return -ENOBUFS;
1158 		sr->buf = buf;
1159 		sr->len = *len;
1160 map_ubuf:
1161 		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
1162 				  &kmsg->msg.msg_iter);
1163 		if (unlikely(ret))
1164 			return ret;
1165 	}
1166 
1167 	return 0;
1168 }
1169 
1170 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
1171 {
1172 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1173 	struct io_async_msghdr *kmsg = req->async_data;
1174 	struct socket *sock;
1175 	unsigned flags;
1176 	int ret, min_ret = 0;
1177 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1178 	size_t len = sr->len;
1179 	bool mshot_finished;
1180 
1181 	if (!(req->flags & REQ_F_POLLED) &&
1182 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1183 		return -EAGAIN;
1184 
1185 	sock = sock_from_file(req->file);
1186 	if (unlikely(!sock))
1187 		return -ENOTSOCK;
1188 
1189 	flags = sr->msg_flags;
1190 	if (force_nonblock)
1191 		flags |= MSG_DONTWAIT;
1192 
1193 retry_multishot:
1194 	if (io_do_buffer_select(req)) {
1195 		ret = io_recv_buf_select(req, kmsg, &len, issue_flags);
1196 		if (unlikely(ret)) {
1197 			kmsg->msg.msg_inq = -1;
1198 			goto out_free;
1199 		}
1200 		sr->buf = NULL;
1201 	}
1202 
1203 	kmsg->msg.msg_flags = 0;
1204 	kmsg->msg.msg_inq = -1;
1205 
1206 	if (flags & MSG_WAITALL)
1207 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1208 
1209 	ret = sock_recvmsg(sock, &kmsg->msg, flags);
1210 	if (ret < min_ret) {
1211 		if (ret == -EAGAIN && force_nonblock) {
1212 			if (issue_flags & IO_URING_F_MULTISHOT)
1213 				io_kbuf_recycle(req, issue_flags);
1214 
1215 			return IOU_RETRY;
1216 		}
1217 		if (ret > 0 && io_net_retry(sock, flags)) {
1218 			sr->len -= ret;
1219 			sr->buf += ret;
1220 			sr->done_io += ret;
1221 			req->flags |= REQ_F_BL_NO_RECYCLE;
1222 			return -EAGAIN;
1223 		}
1224 		if (ret == -ERESTARTSYS)
1225 			ret = -EINTR;
1226 		req_set_fail(req);
1227 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1228 out_free:
1229 		req_set_fail(req);
1230 	}
1231 
1232 	mshot_finished = ret <= 0;
1233 	if (ret > 0)
1234 		ret += sr->done_io;
1235 	else if (sr->done_io)
1236 		ret = sr->done_io;
1237 	else
1238 		io_kbuf_recycle(req, issue_flags);
1239 
1240 	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
1241 		goto retry_multishot;
1242 
1243 	return ret;
1244 }
1245 
1246 int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1247 {
1248 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1249 	unsigned ifq_idx;
1250 
1251 	if (unlikely(sqe->addr2 || sqe->addr || sqe->addr3))
1252 		return -EINVAL;
1253 
1254 	ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx);
1255 	zc->ifq = xa_load(&req->ctx->zcrx_ctxs, ifq_idx);
1256 	if (!zc->ifq)
1257 		return -EINVAL;
1258 
1259 	zc->len = READ_ONCE(sqe->len);
1260 	zc->flags = READ_ONCE(sqe->ioprio);
1261 	zc->msg_flags = READ_ONCE(sqe->msg_flags);
1262 	if (zc->msg_flags)
1263 		return -EINVAL;
1264 	if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT))
1265 		return -EINVAL;
1266 	/* multishot required */
1267 	if (!(zc->flags & IORING_RECV_MULTISHOT))
1268 		return -EINVAL;
1269 	/* All data completions are posted as aux CQEs. */
1270 	req->flags |= REQ_F_APOLL_MULTISHOT;
1271 
1272 	return 0;
1273 }
1274 
1275 int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
1276 {
1277 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1278 	struct socket *sock;
1279 	unsigned int len;
1280 	int ret;
1281 
1282 	if (!(req->flags & REQ_F_POLLED) &&
1283 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1284 		return -EAGAIN;
1285 
1286 	sock = sock_from_file(req->file);
1287 	if (unlikely(!sock))
1288 		return -ENOTSOCK;
1289 
1290 	len = zc->len;
1291 	ret = io_zcrx_recv(req, zc->ifq, sock, zc->msg_flags | MSG_DONTWAIT,
1292 			   issue_flags, &zc->len);
1293 	if (len && zc->len == 0) {
1294 		io_req_set_res(req, 0, 0);
1295 
1296 		return IOU_COMPLETE;
1297 	}
1298 	if (unlikely(ret <= 0) && ret != -EAGAIN) {
1299 		if (ret == -ERESTARTSYS)
1300 			ret = -EINTR;
1301 		if (ret == IOU_REQUEUE)
1302 			return IOU_REQUEUE;
1303 
1304 		req_set_fail(req);
1305 		io_req_set_res(req, ret, 0);
1306 		return IOU_COMPLETE;
1307 	}
1308 	return IOU_RETRY;
1309 }
1310 
1311 void io_send_zc_cleanup(struct io_kiocb *req)
1312 {
1313 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1314 	struct io_async_msghdr *io = req->async_data;
1315 
1316 	if (req_has_async_data(req))
1317 		io_netmsg_iovec_free(io);
1318 	if (zc->notif) {
1319 		io_notif_flush(zc->notif);
1320 		zc->notif = NULL;
1321 	}
1322 }
1323 
1324 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1325 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE | \
1326 				IORING_SEND_VECTORIZED)
1327 
1328 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1329 {
1330 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1331 	struct io_ring_ctx *ctx = req->ctx;
1332 	struct io_async_msghdr *iomsg;
1333 	struct io_kiocb *notif;
1334 	int ret;
1335 
1336 	zc->done_io = 0;
1337 
1338 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
1339 		return -EINVAL;
1340 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1341 	if (req->flags & REQ_F_CQE_SKIP)
1342 		return -EINVAL;
1343 
1344 	notif = zc->notif = io_alloc_notif(ctx);
1345 	if (!notif)
1346 		return -ENOMEM;
1347 	notif->cqe.user_data = req->cqe.user_data;
1348 	notif->cqe.res = 0;
1349 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1350 	req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY;
1351 
1352 	zc->flags = READ_ONCE(sqe->ioprio);
1353 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1354 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1355 			return -EINVAL;
1356 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1357 			struct io_notif_data *nd = io_notif_to_data(notif);
1358 
1359 			nd->zc_report = true;
1360 			nd->zc_used = false;
1361 			nd->zc_copied = false;
1362 		}
1363 	}
1364 
1365 	zc->len = READ_ONCE(sqe->len);
1366 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
1367 	req->buf_index = READ_ONCE(sqe->buf_index);
1368 	if (zc->msg_flags & MSG_DONTWAIT)
1369 		req->flags |= REQ_F_NOWAIT;
1370 
1371 	if (io_is_compat(req->ctx))
1372 		zc->msg_flags |= MSG_CMSG_COMPAT;
1373 
1374 	iomsg = io_msg_alloc_async(req);
1375 	if (unlikely(!iomsg))
1376 		return -ENOMEM;
1377 
1378 	if (req->opcode == IORING_OP_SEND_ZC) {
1379 		ret = io_send_setup(req, sqe);
1380 	} else {
1381 		if (unlikely(sqe->addr2 || sqe->file_index))
1382 			return -EINVAL;
1383 		ret = io_sendmsg_setup(req, sqe);
1384 	}
1385 	if (unlikely(ret))
1386 		return ret;
1387 
1388 	if (!(zc->flags & IORING_RECVSEND_FIXED_BUF)) {
1389 		iomsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1390 		return io_notif_account_mem(zc->notif, iomsg->msg.msg_iter.count);
1391 	}
1392 	iomsg->msg.sg_from_iter = io_sg_from_iter;
1393 	return 0;
1394 }
1395 
1396 static int io_sg_from_iter_iovec(struct sk_buff *skb,
1397 				 struct iov_iter *from, size_t length)
1398 {
1399 	skb_zcopy_downgrade_managed(skb);
1400 	return zerocopy_fill_skb_from_iter(skb, from, length);
1401 }
1402 
1403 static int io_sg_from_iter(struct sk_buff *skb,
1404 			   struct iov_iter *from, size_t length)
1405 {
1406 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1407 	int frag = shinfo->nr_frags;
1408 	int ret = 0;
1409 	struct bvec_iter bi;
1410 	ssize_t copied = 0;
1411 	unsigned long truesize = 0;
1412 
1413 	if (!frag)
1414 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1415 	else if (unlikely(!skb_zcopy_managed(skb)))
1416 		return zerocopy_fill_skb_from_iter(skb, from, length);
1417 
1418 	bi.bi_size = min(from->count, length);
1419 	bi.bi_bvec_done = from->iov_offset;
1420 	bi.bi_idx = 0;
1421 
1422 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1423 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1424 
1425 		copied += v.bv_len;
1426 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1427 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1428 					   v.bv_offset, v.bv_len);
1429 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1430 	}
1431 	if (bi.bi_size)
1432 		ret = -EMSGSIZE;
1433 
1434 	shinfo->nr_frags = frag;
1435 	from->bvec += bi.bi_idx;
1436 	from->nr_segs -= bi.bi_idx;
1437 	from->count -= copied;
1438 	from->iov_offset = bi.bi_bvec_done;
1439 
1440 	skb->data_len += copied;
1441 	skb->len += copied;
1442 	skb->truesize += truesize;
1443 	return ret;
1444 }
1445 
1446 static int io_send_zc_import(struct io_kiocb *req, unsigned int issue_flags)
1447 {
1448 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1449 	struct io_async_msghdr *kmsg = req->async_data;
1450 
1451 	WARN_ON_ONCE(!(sr->flags & IORING_RECVSEND_FIXED_BUF));
1452 
1453 	sr->notif->buf_index = req->buf_index;
1454 	return io_import_reg_buf(sr->notif, &kmsg->msg.msg_iter,
1455 				(u64)(uintptr_t)sr->buf, sr->len,
1456 				ITER_SOURCE, issue_flags);
1457 }
1458 
1459 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1460 {
1461 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1462 	struct io_async_msghdr *kmsg = req->async_data;
1463 	struct socket *sock;
1464 	unsigned msg_flags;
1465 	int ret, min_ret = 0;
1466 
1467 	sock = sock_from_file(req->file);
1468 	if (unlikely(!sock))
1469 		return -ENOTSOCK;
1470 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1471 		return -EOPNOTSUPP;
1472 
1473 	if (!(req->flags & REQ_F_POLLED) &&
1474 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1475 		return -EAGAIN;
1476 
1477 	if (req->flags & REQ_F_IMPORT_BUFFER) {
1478 		req->flags &= ~REQ_F_IMPORT_BUFFER;
1479 		ret = io_send_zc_import(req, issue_flags);
1480 		if (unlikely(ret))
1481 			return ret;
1482 	}
1483 
1484 	msg_flags = zc->msg_flags;
1485 	if (issue_flags & IO_URING_F_NONBLOCK)
1486 		msg_flags |= MSG_DONTWAIT;
1487 	if (msg_flags & MSG_WAITALL)
1488 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1489 	msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1490 
1491 	kmsg->msg.msg_flags = msg_flags;
1492 	kmsg->msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1493 	ret = sock_sendmsg(sock, &kmsg->msg);
1494 
1495 	if (unlikely(ret < min_ret)) {
1496 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1497 			return -EAGAIN;
1498 
1499 		if (ret > 0 && io_net_retry(sock, kmsg->msg.msg_flags)) {
1500 			zc->len -= ret;
1501 			zc->buf += ret;
1502 			zc->done_io += ret;
1503 			req->flags |= REQ_F_BL_NO_RECYCLE;
1504 			return -EAGAIN;
1505 		}
1506 		if (ret == -ERESTARTSYS)
1507 			ret = -EINTR;
1508 		req_set_fail(req);
1509 	}
1510 
1511 	if (ret >= 0)
1512 		ret += zc->done_io;
1513 	else if (zc->done_io)
1514 		ret = zc->done_io;
1515 
1516 	/*
1517 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1518 	 * flushing notif to io_send_zc_cleanup()
1519 	 */
1520 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1521 		io_notif_flush(zc->notif);
1522 		zc->notif = NULL;
1523 		io_req_msg_cleanup(req, 0);
1524 	}
1525 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1526 	return IOU_COMPLETE;
1527 }
1528 
1529 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1530 {
1531 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1532 	struct io_async_msghdr *kmsg = req->async_data;
1533 	struct socket *sock;
1534 	unsigned flags;
1535 	int ret, min_ret = 0;
1536 
1537 	if (req->flags & REQ_F_IMPORT_BUFFER) {
1538 		unsigned uvec_segs = kmsg->msg.msg_iter.nr_segs;
1539 		int ret;
1540 
1541 		ret = io_import_reg_vec(ITER_SOURCE, &kmsg->msg.msg_iter, req,
1542 					&kmsg->vec, uvec_segs, issue_flags);
1543 		if (unlikely(ret))
1544 			return ret;
1545 		req->flags &= ~REQ_F_IMPORT_BUFFER;
1546 	}
1547 
1548 	sock = sock_from_file(req->file);
1549 	if (unlikely(!sock))
1550 		return -ENOTSOCK;
1551 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1552 		return -EOPNOTSUPP;
1553 
1554 	if (!(req->flags & REQ_F_POLLED) &&
1555 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1556 		return -EAGAIN;
1557 
1558 	flags = sr->msg_flags;
1559 	if (issue_flags & IO_URING_F_NONBLOCK)
1560 		flags |= MSG_DONTWAIT;
1561 	if (flags & MSG_WAITALL)
1562 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1563 
1564 	kmsg->msg.msg_control_user = sr->msg_control;
1565 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1566 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1567 
1568 	if (unlikely(ret < min_ret)) {
1569 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1570 			return -EAGAIN;
1571 
1572 		if (ret > 0 && io_net_retry(sock, flags)) {
1573 			sr->done_io += ret;
1574 			req->flags |= REQ_F_BL_NO_RECYCLE;
1575 			return -EAGAIN;
1576 		}
1577 		if (ret == -ERESTARTSYS)
1578 			ret = -EINTR;
1579 		req_set_fail(req);
1580 	}
1581 
1582 	if (ret >= 0)
1583 		ret += sr->done_io;
1584 	else if (sr->done_io)
1585 		ret = sr->done_io;
1586 
1587 	/*
1588 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1589 	 * flushing notif to io_send_zc_cleanup()
1590 	 */
1591 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1592 		io_notif_flush(sr->notif);
1593 		sr->notif = NULL;
1594 		io_req_msg_cleanup(req, 0);
1595 	}
1596 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1597 	return IOU_COMPLETE;
1598 }
1599 
1600 void io_sendrecv_fail(struct io_kiocb *req)
1601 {
1602 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1603 
1604 	if (sr->done_io)
1605 		req->cqe.res = sr->done_io;
1606 
1607 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1608 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1609 		req->cqe.flags |= IORING_CQE_F_MORE;
1610 }
1611 
1612 #define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
1613 			 IORING_ACCEPT_POLL_FIRST)
1614 
1615 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1616 {
1617 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1618 
1619 	if (sqe->len || sqe->buf_index)
1620 		return -EINVAL;
1621 
1622 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1623 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1624 	accept->flags = READ_ONCE(sqe->accept_flags);
1625 	accept->nofile = rlimit(RLIMIT_NOFILE);
1626 	accept->iou_flags = READ_ONCE(sqe->ioprio);
1627 	if (accept->iou_flags & ~ACCEPT_FLAGS)
1628 		return -EINVAL;
1629 
1630 	accept->file_slot = READ_ONCE(sqe->file_index);
1631 	if (accept->file_slot) {
1632 		if (accept->flags & SOCK_CLOEXEC)
1633 			return -EINVAL;
1634 		if (accept->iou_flags & IORING_ACCEPT_MULTISHOT &&
1635 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1636 			return -EINVAL;
1637 	}
1638 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1639 		return -EINVAL;
1640 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1641 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1642 	if (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
1643 		req->flags |= REQ_F_APOLL_MULTISHOT;
1644 	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
1645 		req->flags |= REQ_F_NOWAIT;
1646 	return 0;
1647 }
1648 
1649 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1650 {
1651 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1652 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1653 	bool fixed = !!accept->file_slot;
1654 	struct proto_accept_arg arg = {
1655 		.flags = force_nonblock ? O_NONBLOCK : 0,
1656 	};
1657 	struct file *file;
1658 	unsigned cflags;
1659 	int ret, fd;
1660 
1661 	if (!(req->flags & REQ_F_POLLED) &&
1662 	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
1663 		return -EAGAIN;
1664 
1665 retry:
1666 	if (!fixed) {
1667 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1668 		if (unlikely(fd < 0))
1669 			return fd;
1670 	}
1671 	arg.err = 0;
1672 	arg.is_empty = -1;
1673 	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
1674 			 accept->flags);
1675 	if (IS_ERR(file)) {
1676 		if (!fixed)
1677 			put_unused_fd(fd);
1678 		ret = PTR_ERR(file);
1679 		if (ret == -EAGAIN && force_nonblock &&
1680 		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT))
1681 			return IOU_RETRY;
1682 
1683 		if (ret == -ERESTARTSYS)
1684 			ret = -EINTR;
1685 	} else if (!fixed) {
1686 		fd_install(fd, file);
1687 		ret = fd;
1688 	} else {
1689 		ret = io_fixed_fd_install(req, issue_flags, file,
1690 						accept->file_slot);
1691 	}
1692 
1693 	cflags = 0;
1694 	if (!arg.is_empty)
1695 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
1696 
1697 	if (ret >= 0 && (req->flags & REQ_F_APOLL_MULTISHOT) &&
1698 	    io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
1699 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
1700 			goto retry;
1701 		return IOU_RETRY;
1702 	}
1703 
1704 	io_req_set_res(req, ret, cflags);
1705 	if (ret < 0)
1706 		req_set_fail(req);
1707 	return IOU_COMPLETE;
1708 }
1709 
1710 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1711 {
1712 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1713 
1714 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1715 		return -EINVAL;
1716 
1717 	sock->domain = READ_ONCE(sqe->fd);
1718 	sock->type = READ_ONCE(sqe->off);
1719 	sock->protocol = READ_ONCE(sqe->len);
1720 	sock->file_slot = READ_ONCE(sqe->file_index);
1721 	sock->nofile = rlimit(RLIMIT_NOFILE);
1722 
1723 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1724 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1725 		return -EINVAL;
1726 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1727 		return -EINVAL;
1728 	return 0;
1729 }
1730 
1731 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1732 {
1733 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1734 	bool fixed = !!sock->file_slot;
1735 	struct file *file;
1736 	int ret, fd;
1737 
1738 	if (!fixed) {
1739 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1740 		if (unlikely(fd < 0))
1741 			return fd;
1742 	}
1743 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1744 	if (IS_ERR(file)) {
1745 		if (!fixed)
1746 			put_unused_fd(fd);
1747 		ret = PTR_ERR(file);
1748 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1749 			return -EAGAIN;
1750 		if (ret == -ERESTARTSYS)
1751 			ret = -EINTR;
1752 		req_set_fail(req);
1753 	} else if (!fixed) {
1754 		fd_install(fd, file);
1755 		ret = fd;
1756 	} else {
1757 		ret = io_fixed_fd_install(req, issue_flags, file,
1758 					    sock->file_slot);
1759 	}
1760 	io_req_set_res(req, ret, 0);
1761 	return IOU_COMPLETE;
1762 }
1763 
1764 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1765 {
1766 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1767 	struct io_async_msghdr *io;
1768 
1769 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1770 		return -EINVAL;
1771 
1772 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1773 	conn->addr_len =  READ_ONCE(sqe->addr2);
1774 	conn->in_progress = conn->seen_econnaborted = false;
1775 
1776 	io = io_msg_alloc_async(req);
1777 	if (unlikely(!io))
1778 		return -ENOMEM;
1779 
1780 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr);
1781 }
1782 
1783 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1784 {
1785 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1786 	struct io_async_msghdr *io = req->async_data;
1787 	unsigned file_flags;
1788 	int ret;
1789 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1790 
1791 	if (connect->in_progress) {
1792 		struct poll_table_struct pt = { ._key = EPOLLERR };
1793 
1794 		if (vfs_poll(req->file, &pt) & EPOLLERR)
1795 			goto get_sock_err;
1796 	}
1797 
1798 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1799 
1800 	ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,
1801 				 file_flags);
1802 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1803 	    && force_nonblock) {
1804 		if (ret == -EINPROGRESS) {
1805 			connect->in_progress = true;
1806 		} else if (ret == -ECONNABORTED) {
1807 			if (connect->seen_econnaborted)
1808 				goto out;
1809 			connect->seen_econnaborted = true;
1810 		}
1811 		return -EAGAIN;
1812 	}
1813 	if (connect->in_progress) {
1814 		/*
1815 		 * At least bluetooth will return -EBADFD on a re-connect
1816 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1817 		 * which means the previous result is good. For both of these,
1818 		 * grab the sock_error() and use that for the completion.
1819 		 */
1820 		if (ret == -EBADFD || ret == -EISCONN) {
1821 get_sock_err:
1822 			ret = sock_error(sock_from_file(req->file)->sk);
1823 		}
1824 	}
1825 	if (ret == -ERESTARTSYS)
1826 		ret = -EINTR;
1827 out:
1828 	if (ret < 0)
1829 		req_set_fail(req);
1830 	io_req_msg_cleanup(req, issue_flags);
1831 	io_req_set_res(req, ret, 0);
1832 	return IOU_COMPLETE;
1833 }
1834 
1835 int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1836 {
1837 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1838 	struct sockaddr __user *uaddr;
1839 	struct io_async_msghdr *io;
1840 
1841 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1842 		return -EINVAL;
1843 
1844 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1845 	bind->addr_len =  READ_ONCE(sqe->addr2);
1846 
1847 	io = io_msg_alloc_async(req);
1848 	if (unlikely(!io))
1849 		return -ENOMEM;
1850 	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
1851 }
1852 
1853 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
1854 {
1855 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1856 	struct io_async_msghdr *io = req->async_data;
1857 	struct socket *sock;
1858 	int ret;
1859 
1860 	sock = sock_from_file(req->file);
1861 	if (unlikely(!sock))
1862 		return -ENOTSOCK;
1863 
1864 	ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
1865 	if (ret < 0)
1866 		req_set_fail(req);
1867 	io_req_set_res(req, ret, 0);
1868 	return 0;
1869 }
1870 
1871 int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1872 {
1873 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1874 
1875 	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
1876 		return -EINVAL;
1877 
1878 	listen->backlog = READ_ONCE(sqe->len);
1879 	return 0;
1880 }
1881 
1882 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
1883 {
1884 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1885 	struct socket *sock;
1886 	int ret;
1887 
1888 	sock = sock_from_file(req->file);
1889 	if (unlikely(!sock))
1890 		return -ENOTSOCK;
1891 
1892 	ret = __sys_listen_socket(sock, listen->backlog);
1893 	if (ret < 0)
1894 		req_set_fail(req);
1895 	io_req_set_res(req, ret, 0);
1896 	return 0;
1897 }
1898 
1899 void io_netmsg_cache_free(const void *entry)
1900 {
1901 	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
1902 
1903 	io_vec_free(&kmsg->vec);
1904 	kfree(kmsg);
1905 }
1906