xref: /linux/io_uring/net.c (revision 32b4d29280ed2a991dc196d5845b892acedc63b8)
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 "filetable.h"
14 #include "io_uring.h"
15 #include "kbuf.h"
16 #include "alloc_cache.h"
17 #include "net.h"
18 #include "notif.h"
19 #include "rsrc.h"
20 #include "zcrx.h"
21 
22 struct io_shutdown {
23 	struct file			*file;
24 	int				how;
25 };
26 
27 struct io_accept {
28 	struct file			*file;
29 	struct sockaddr __user		*addr;
30 	int __user			*addr_len;
31 	int				flags;
32 	int				iou_flags;
33 	u32				file_slot;
34 	unsigned long			nofile;
35 };
36 
37 struct io_socket {
38 	struct file			*file;
39 	int				domain;
40 	int				type;
41 	int				protocol;
42 	int				flags;
43 	u32				file_slot;
44 	unsigned long			nofile;
45 };
46 
47 struct io_connect {
48 	struct file			*file;
49 	struct sockaddr __user		*addr;
50 	int				addr_len;
51 	bool				in_progress;
52 	bool				seen_econnaborted;
53 };
54 
55 struct io_bind {
56 	struct file			*file;
57 	int				addr_len;
58 };
59 
60 struct io_listen {
61 	struct file			*file;
62 	int				backlog;
63 };
64 
65 struct io_sr_msg {
66 	struct file			*file;
67 	union {
68 		struct compat_msghdr __user	*umsg_compat;
69 		struct user_msghdr __user	*umsg;
70 		void __user			*buf;
71 	};
72 	int				len;
73 	unsigned			done_io;
74 	unsigned			msg_flags;
75 	unsigned			nr_multishot_loops;
76 	u16				flags;
77 	/* initialised and used only by !msg send variants */
78 	u16				buf_group;
79 	/* per-invocation mshot limit */
80 	unsigned			mshot_len;
81 	/* overall mshot byte limit */
82 	unsigned			mshot_total_len;
83 	void __user			*msg_control;
84 	/* used only for send zerocopy */
85 	struct io_kiocb 		*notif;
86 };
87 
88 /*
89  * The UAPI flags are the lower 8 bits, as that's all sqe->ioprio will hold
90  * anyway. Use the upper 8 bits for internal uses.
91  */
92 enum sr_retry_flags {
93 	IORING_RECV_RETRY	= (1U << 15),
94 	IORING_RECV_PARTIAL_MAP	= (1U << 14),
95 	IORING_RECV_MSHOT_CAP	= (1U << 13),
96 	IORING_RECV_MSHOT_LIM	= (1U << 12),
97 	IORING_RECV_MSHOT_DONE	= (1U << 11),
98 
99 	IORING_RECV_RETRY_CLEAR	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
100 	IORING_RECV_NO_RETRY	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP |
101 				  IORING_RECV_MSHOT_CAP | IORING_RECV_MSHOT_DONE,
102 };
103 
104 /*
105  * Number of times we'll try and do receives if there's more data. If we
106  * exceed this limit, then add us to the back of the queue and retry from
107  * there. This helps fairness between flooding clients.
108  */
109 #define MULTISHOT_MAX_RETRY	32
110 
111 struct io_recvzc {
112 	struct file			*file;
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 		io_req_async_data_clear(req, REQ_F_NEED_CLEANUP);
183 }
184 
185 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
186 {
187 	struct io_ring_ctx *ctx = req->ctx;
188 	struct io_async_msghdr *hdr;
189 
190 	hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req);
191 	if (!hdr)
192 		return NULL;
193 
194 	/* If the async data was cached, we might have an iov cached inside. */
195 	if (hdr->vec.iovec)
196 		req->flags |= REQ_F_NEED_CLEANUP;
197 	return hdr;
198 }
199 
200 static inline void io_mshot_prep_retry(struct io_kiocb *req,
201 				       struct io_async_msghdr *kmsg)
202 {
203 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
204 
205 	req->flags &= ~REQ_F_BL_EMPTY;
206 	sr->done_io = 0;
207 	sr->flags &= ~IORING_RECV_RETRY_CLEAR;
208 	sr->len = sr->mshot_len;
209 }
210 
211 static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg,
212 			     const struct iovec __user *uiov, unsigned uvec_seg,
213 			     int ddir)
214 {
215 	struct iovec *iov;
216 	int ret, nr_segs;
217 
218 	if (iomsg->vec.iovec) {
219 		nr_segs = iomsg->vec.nr;
220 		iov = iomsg->vec.iovec;
221 	} else {
222 		nr_segs = 1;
223 		iov = &iomsg->fast_iov;
224 	}
225 
226 	ret = __import_iovec(ddir, uiov, uvec_seg, nr_segs, &iov,
227 			     &iomsg->msg.msg_iter, io_is_compat(req->ctx));
228 	if (unlikely(ret < 0))
229 		return ret;
230 
231 	if (iov) {
232 		req->flags |= REQ_F_NEED_CLEANUP;
233 		io_vec_reset_iovec(&iomsg->vec, iov, iomsg->msg.msg_iter.nr_segs);
234 	}
235 	return 0;
236 }
237 
238 static int io_compat_msg_copy_hdr(struct io_kiocb *req,
239 				  struct io_async_msghdr *iomsg,
240 				  struct compat_msghdr *msg, int ddir,
241 				  struct sockaddr __user **save_addr)
242 {
243 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
244 	struct compat_iovec __user *uiov;
245 	int ret;
246 
247 	if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
248 		return -EFAULT;
249 
250 	ret = __get_compat_msghdr(&iomsg->msg, msg, save_addr);
251 	if (ret)
252 		return ret;
253 
254 	uiov = compat_ptr(msg->msg_iov);
255 	if (req->flags & REQ_F_BUFFER_SELECT) {
256 		if (msg->msg_iovlen == 0) {
257 			sr->len = 0;
258 		} else if (msg->msg_iovlen > 1) {
259 			return -EINVAL;
260 		} else {
261 			struct compat_iovec tmp_iov;
262 
263 			if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov)))
264 				return -EFAULT;
265 			sr->len = tmp_iov.iov_len;
266 		}
267 	}
268 	return 0;
269 }
270 
271 static int io_copy_msghdr_from_user(struct user_msghdr *msg,
272 				    struct user_msghdr __user *umsg)
273 {
274 	if (!user_access_begin(umsg, sizeof(*umsg)))
275 		return -EFAULT;
276 	unsafe_get_user(msg->msg_name, &umsg->msg_name, ua_end);
277 	unsafe_get_user(msg->msg_namelen, &umsg->msg_namelen, ua_end);
278 	unsafe_get_user(msg->msg_iov, &umsg->msg_iov, ua_end);
279 	unsafe_get_user(msg->msg_iovlen, &umsg->msg_iovlen, ua_end);
280 	unsafe_get_user(msg->msg_control, &umsg->msg_control, ua_end);
281 	unsafe_get_user(msg->msg_controllen, &umsg->msg_controllen, ua_end);
282 	user_access_end();
283 	return 0;
284 ua_end:
285 	user_access_end();
286 	return -EFAULT;
287 }
288 
289 static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
290 			   struct user_msghdr *msg, int ddir,
291 			   struct sockaddr __user **save_addr)
292 {
293 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
294 	struct user_msghdr __user *umsg = sr->umsg;
295 	int ret;
296 
297 	iomsg->msg.msg_name = &iomsg->addr;
298 	iomsg->msg.msg_iter.nr_segs = 0;
299 
300 	if (io_is_compat(req->ctx)) {
301 		struct compat_msghdr cmsg;
302 
303 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ddir, save_addr);
304 		if (ret)
305 			return ret;
306 
307 		memset(msg, 0, sizeof(*msg));
308 		msg->msg_namelen = cmsg.msg_namelen;
309 		msg->msg_controllen = cmsg.msg_controllen;
310 		msg->msg_iov = compat_ptr(cmsg.msg_iov);
311 		msg->msg_iovlen = cmsg.msg_iovlen;
312 		return 0;
313 	}
314 
315 	ret = io_copy_msghdr_from_user(msg, umsg);
316 	if (unlikely(ret))
317 		return ret;
318 
319 	msg->msg_flags = 0;
320 
321 	ret = __copy_msghdr(&iomsg->msg, msg, save_addr);
322 	if (ret)
323 		return ret;
324 
325 	if (req->flags & REQ_F_BUFFER_SELECT) {
326 		if (msg->msg_iovlen == 0) {
327 			sr->len = 0;
328 		} else if (msg->msg_iovlen > 1) {
329 			return -EINVAL;
330 		} else {
331 			struct iovec __user *uiov = msg->msg_iov;
332 			struct iovec tmp_iov;
333 
334 			if (copy_from_user(&tmp_iov, uiov, sizeof(tmp_iov)))
335 				return -EFAULT;
336 			sr->len = tmp_iov.iov_len;
337 		}
338 	}
339 	return 0;
340 }
341 
342 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
343 {
344 	struct io_async_msghdr *io = req->async_data;
345 
346 	io_netmsg_iovec_free(io);
347 }
348 
349 static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
350 {
351 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
352 	struct io_async_msghdr *kmsg = req->async_data;
353 	void __user *addr;
354 	u16 addr_len;
355 	int ret;
356 
357 	sr->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
358 
359 	if (READ_ONCE(sqe->__pad3[0]))
360 		return -EINVAL;
361 
362 	kmsg->msg.msg_name = NULL;
363 	kmsg->msg.msg_namelen = 0;
364 	kmsg->msg.msg_control = NULL;
365 	kmsg->msg.msg_controllen = 0;
366 	kmsg->msg.msg_ubuf = NULL;
367 
368 	addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
369 	addr_len = READ_ONCE(sqe->addr_len);
370 	if (addr) {
371 		ret = move_addr_to_kernel(addr, addr_len, &kmsg->addr);
372 		if (unlikely(ret < 0))
373 			return ret;
374 		kmsg->msg.msg_name = &kmsg->addr;
375 		kmsg->msg.msg_namelen = addr_len;
376 	}
377 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
378 		if (!(sr->flags & IORING_SEND_VECTORIZED)) {
379 			req->flags |= REQ_F_IMPORT_BUFFER;
380 			return 0;
381 		}
382 
383 		kmsg->msg.msg_iter.nr_segs = sr->len;
384 		return io_prep_reg_iovec(req, &kmsg->vec, sr->buf, sr->len);
385 	}
386 	if (req->flags & REQ_F_BUFFER_SELECT)
387 		return 0;
388 
389 	if (sr->flags & IORING_SEND_VECTORIZED)
390 		return io_net_import_vec(req, kmsg, sr->buf, sr->len, ITER_SOURCE);
391 
392 	return import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
393 }
394 
395 static int io_sendmsg_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
396 {
397 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
398 	struct io_async_msghdr *kmsg = req->async_data;
399 	struct user_msghdr msg;
400 	int ret;
401 
402 	sr->flags |= IORING_SEND_VECTORIZED;
403 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
404 	ret = io_msg_copy_hdr(req, kmsg, &msg, ITER_SOURCE, NULL);
405 	if (unlikely(ret))
406 		return ret;
407 	/* save msg_control as sys_sendmsg() overwrites it */
408 	sr->msg_control = kmsg->msg.msg_control_user;
409 
410 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
411 		kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen;
412 		return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov,
413 					 msg.msg_iovlen);
414 	}
415 	if (req->flags & REQ_F_BUFFER_SELECT)
416 		return 0;
417 	return io_net_import_vec(req, kmsg, msg.msg_iov, msg.msg_iovlen, ITER_SOURCE);
418 }
419 
420 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE | IORING_SEND_VECTORIZED)
421 
422 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
423 {
424 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
425 
426 	sr->done_io = 0;
427 	sr->len = READ_ONCE(sqe->len);
428 	if (unlikely(sr->len < 0))
429 		return -EINVAL;
430 	sr->flags = READ_ONCE(sqe->ioprio);
431 	if (sr->flags & ~SENDMSG_FLAGS)
432 		return -EINVAL;
433 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
434 	if (sr->msg_flags & MSG_DONTWAIT)
435 		req->flags |= REQ_F_NOWAIT;
436 	if (req->flags & REQ_F_BUFFER_SELECT)
437 		sr->buf_group = req->buf_index;
438 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
439 		if (req->opcode == IORING_OP_SENDMSG)
440 			return -EINVAL;
441 		sr->msg_flags |= MSG_WAITALL;
442 		req->flags |= REQ_F_MULTISHOT;
443 	}
444 
445 	if (io_is_compat(req->ctx))
446 		sr->msg_flags |= MSG_CMSG_COMPAT;
447 
448 	if (unlikely(!io_msg_alloc_async(req)))
449 		return -ENOMEM;
450 	if (req->opcode != IORING_OP_SENDMSG)
451 		return io_send_setup(req, sqe);
452 	if (unlikely(sqe->addr2 || sqe->file_index))
453 		return -EINVAL;
454 	return io_sendmsg_setup(req, sqe);
455 }
456 
457 static void io_req_msg_cleanup(struct io_kiocb *req,
458 			       unsigned int issue_flags)
459 {
460 	io_netmsg_recycle(req, issue_flags);
461 }
462 
463 /*
464  * For bundle completions, we need to figure out how many segments we consumed.
465  * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
466  * could be using an ITER_IOVEC. If the latter, then if we consumed all of
467  * the segments, then it's a trivial questiont o answer. If we have residual
468  * data in the iter, then loop the segments to figure out how much we
469  * transferred.
470  */
471 static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
472 {
473 	struct iovec *iov;
474 	int nbufs;
475 
476 	/* no data is always zero segments, and a ubuf is always 1 segment */
477 	if (ret <= 0)
478 		return 0;
479 	if (iter_is_ubuf(&kmsg->msg.msg_iter))
480 		return 1;
481 
482 	iov = kmsg->vec.iovec;
483 	if (!iov)
484 		iov = &kmsg->fast_iov;
485 
486 	/* if all data was transferred, it's basic pointer math */
487 	if (!iov_iter_count(&kmsg->msg.msg_iter))
488 		return iter_iov(&kmsg->msg.msg_iter) - iov;
489 
490 	/* short transfer, count segments */
491 	nbufs = 0;
492 	do {
493 		int this_len = min_t(int, iov[nbufs].iov_len, ret);
494 
495 		nbufs++;
496 		ret -= this_len;
497 	} while (ret);
498 
499 	return nbufs;
500 }
501 
502 static int io_net_kbuf_recyle(struct io_kiocb *req, struct io_buffer_list *bl,
503 			      struct io_async_msghdr *kmsg, int len)
504 {
505 	req->flags |= REQ_F_BL_NO_RECYCLE;
506 	if (req->flags & REQ_F_BUFFERS_COMMIT)
507 		io_kbuf_commit(req, bl, len, io_bundle_nbufs(kmsg, len));
508 	return IOU_RETRY;
509 }
510 
511 static inline bool io_send_finish(struct io_kiocb *req,
512 				  struct io_async_msghdr *kmsg,
513 				  struct io_br_sel *sel)
514 {
515 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
516 	bool bundle_finished = sel->val <= 0;
517 	unsigned int cflags;
518 
519 	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
520 		cflags = io_put_kbuf(req, sel->val, sel->buf_list);
521 		goto finish;
522 	}
523 
524 	cflags = io_put_kbufs(req, sel->val, sel->buf_list, io_bundle_nbufs(kmsg, sel->val));
525 
526 	/*
527 	 * Don't start new bundles if the buffer list is empty, or if the
528 	 * current operation needed to go through polling to complete.
529 	 */
530 	if (bundle_finished || req->flags & (REQ_F_BL_EMPTY | REQ_F_POLLED))
531 		goto finish;
532 
533 	/*
534 	 * Fill CQE for this receive and see if we should keep trying to
535 	 * receive from this socket.
536 	 */
537 	if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
538 		io_mshot_prep_retry(req, kmsg);
539 		return false;
540 	}
541 
542 	/* Otherwise stop bundle and use the current result. */
543 finish:
544 	io_req_set_res(req, sel->val, cflags);
545 	sel->val = IOU_COMPLETE;
546 	return true;
547 }
548 
549 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
550 {
551 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
552 	struct io_async_msghdr *kmsg = req->async_data;
553 	struct socket *sock;
554 	unsigned flags;
555 	int min_ret = 0;
556 	int ret;
557 
558 	sock = sock_from_file(req->file);
559 	if (unlikely(!sock))
560 		return -ENOTSOCK;
561 
562 	if (!(req->flags & REQ_F_POLLED) &&
563 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
564 		return -EAGAIN;
565 
566 	flags = sr->msg_flags;
567 	if (issue_flags & IO_URING_F_NONBLOCK)
568 		flags |= MSG_DONTWAIT;
569 	if (flags & MSG_WAITALL)
570 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
571 
572 	kmsg->msg.msg_control_user = sr->msg_control;
573 
574 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
575 
576 	if (ret < min_ret) {
577 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
578 			return -EAGAIN;
579 		if (ret > 0 && io_net_retry(sock, flags)) {
580 			kmsg->msg.msg_controllen = 0;
581 			kmsg->msg.msg_control = NULL;
582 			sr->done_io += ret;
583 			return -EAGAIN;
584 		}
585 		if (ret == -ERESTARTSYS)
586 			ret = -EINTR;
587 		req_set_fail(req);
588 	}
589 	io_req_msg_cleanup(req, issue_flags);
590 	if (ret >= 0)
591 		ret += sr->done_io;
592 	else if (sr->done_io)
593 		ret = sr->done_io;
594 	io_req_set_res(req, ret, 0);
595 	return IOU_COMPLETE;
596 }
597 
598 static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags,
599 				 struct io_br_sel *sel, struct io_async_msghdr *kmsg)
600 {
601 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
602 	struct buf_sel_arg arg = {
603 		.iovs = &kmsg->fast_iov,
604 		.max_len = min_not_zero(sr->len, INT_MAX),
605 		.nr_iovs = 1,
606 		.buf_group = sr->buf_group,
607 	};
608 	int ret;
609 
610 	if (kmsg->vec.iovec) {
611 		arg.nr_iovs = kmsg->vec.nr;
612 		arg.iovs = kmsg->vec.iovec;
613 		arg.mode = KBUF_MODE_FREE;
614 	}
615 
616 	if (!(sr->flags & IORING_RECVSEND_BUNDLE))
617 		arg.nr_iovs = 1;
618 	else
619 		arg.mode |= KBUF_MODE_EXPAND;
620 
621 	ret = io_buffers_select(req, &arg, sel, issue_flags);
622 	if (unlikely(ret < 0))
623 		return ret;
624 
625 	if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
626 		kmsg->vec.nr = ret;
627 		kmsg->vec.iovec = arg.iovs;
628 		req->flags |= REQ_F_NEED_CLEANUP;
629 	}
630 	sr->len = arg.out_len;
631 
632 	if (ret == 1) {
633 		sr->buf = arg.iovs[0].iov_base;
634 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
635 					&kmsg->msg.msg_iter);
636 		if (unlikely(ret))
637 			return ret;
638 	} else {
639 		iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE,
640 				arg.iovs, ret, arg.out_len);
641 	}
642 
643 	return 0;
644 }
645 
646 int io_send(struct io_kiocb *req, unsigned int issue_flags)
647 {
648 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
649 	struct io_async_msghdr *kmsg = req->async_data;
650 	struct io_br_sel sel = { };
651 	struct socket *sock;
652 	unsigned flags;
653 	int min_ret = 0;
654 	int ret;
655 
656 	sock = sock_from_file(req->file);
657 	if (unlikely(!sock))
658 		return -ENOTSOCK;
659 
660 	if (!(req->flags & REQ_F_POLLED) &&
661 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
662 		return -EAGAIN;
663 
664 	flags = sr->msg_flags;
665 	if (issue_flags & IO_URING_F_NONBLOCK)
666 		flags |= MSG_DONTWAIT;
667 
668 retry_bundle:
669 	sel.buf_list = NULL;
670 	if (io_do_buffer_select(req)) {
671 		ret = io_send_select_buffer(req, issue_flags, &sel, kmsg);
672 		if (ret)
673 			return ret;
674 	}
675 
676 	/*
677 	 * If MSG_WAITALL is set, or this is a bundle send, then we need
678 	 * the full amount. If just bundle is set, if we do a short send
679 	 * then we complete the bundle sequence rather than continue on.
680 	 */
681 	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
682 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
683 
684 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
685 	kmsg->msg.msg_flags = flags;
686 	ret = sock_sendmsg(sock, &kmsg->msg);
687 	if (ret < min_ret) {
688 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
689 			return -EAGAIN;
690 
691 		if (ret > 0 && io_net_retry(sock, flags)) {
692 			sr->len -= ret;
693 			sr->buf += ret;
694 			sr->done_io += ret;
695 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
696 		}
697 		if (ret == -ERESTARTSYS)
698 			ret = -EINTR;
699 		req_set_fail(req);
700 	}
701 	if (ret >= 0)
702 		ret += sr->done_io;
703 	else if (sr->done_io)
704 		ret = sr->done_io;
705 
706 	sel.val = ret;
707 	if (!io_send_finish(req, kmsg, &sel))
708 		goto retry_bundle;
709 
710 	io_req_msg_cleanup(req, issue_flags);
711 	return sel.val;
712 }
713 
714 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
715 				 struct io_async_msghdr *iomsg,
716 				 int namelen, size_t controllen)
717 {
718 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
719 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
720 		int hdr;
721 
722 		if (unlikely(namelen < 0))
723 			return -EOVERFLOW;
724 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
725 					namelen, &hdr))
726 			return -EOVERFLOW;
727 		if (check_add_overflow(hdr, controllen, &hdr))
728 			return -EOVERFLOW;
729 
730 		iomsg->namelen = namelen;
731 		iomsg->controllen = controllen;
732 		return 0;
733 	}
734 
735 	return 0;
736 }
737 
738 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
739 			       struct io_async_msghdr *iomsg)
740 {
741 	struct user_msghdr msg;
742 	int ret;
743 
744 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST, &iomsg->uaddr);
745 	if (unlikely(ret))
746 		return ret;
747 
748 	if (!(req->flags & REQ_F_BUFFER_SELECT)) {
749 		ret = io_net_import_vec(req, iomsg, msg.msg_iov, msg.msg_iovlen,
750 					ITER_DEST);
751 		if (unlikely(ret))
752 			return ret;
753 	}
754 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
755 					msg.msg_controllen);
756 }
757 
758 static int io_recvmsg_prep_setup(struct io_kiocb *req)
759 {
760 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
761 	struct io_async_msghdr *kmsg;
762 
763 	kmsg = io_msg_alloc_async(req);
764 	if (unlikely(!kmsg))
765 		return -ENOMEM;
766 
767 	if (req->opcode == IORING_OP_RECV) {
768 		kmsg->msg.msg_name = NULL;
769 		kmsg->msg.msg_namelen = 0;
770 		kmsg->msg.msg_inq = 0;
771 		kmsg->msg.msg_control = NULL;
772 		kmsg->msg.msg_get_inq = 1;
773 		kmsg->msg.msg_controllen = 0;
774 		kmsg->msg.msg_ubuf = NULL;
775 
776 		if (req->flags & REQ_F_BUFFER_SELECT)
777 			return 0;
778 		return import_ubuf(ITER_DEST, sr->buf, sr->len,
779 				   &kmsg->msg.msg_iter);
780 	}
781 
782 	return io_recvmsg_copy_hdr(req, kmsg);
783 }
784 
785 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
786 			IORING_RECVSEND_BUNDLE)
787 
788 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
789 {
790 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
791 
792 	sr->done_io = 0;
793 
794 	if (unlikely(sqe->addr2))
795 		return -EINVAL;
796 
797 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
798 	sr->len = READ_ONCE(sqe->len);
799 	if (unlikely(sr->len < 0))
800 		return -EINVAL;
801 	sr->flags = READ_ONCE(sqe->ioprio);
802 	if (sr->flags & ~RECVMSG_FLAGS)
803 		return -EINVAL;
804 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
805 	if (sr->msg_flags & MSG_DONTWAIT)
806 		req->flags |= REQ_F_NOWAIT;
807 	if (sr->msg_flags & MSG_ERRQUEUE)
808 		req->flags |= REQ_F_CLEAR_POLLIN;
809 	if (req->flags & REQ_F_BUFFER_SELECT)
810 		sr->buf_group = req->buf_index;
811 	sr->mshot_total_len = sr->mshot_len = 0;
812 	if (sr->flags & IORING_RECV_MULTISHOT) {
813 		if (!(req->flags & REQ_F_BUFFER_SELECT))
814 			return -EINVAL;
815 		if (sr->msg_flags & MSG_WAITALL)
816 			return -EINVAL;
817 		if (req->opcode == IORING_OP_RECV) {
818 			sr->mshot_len = sr->len;
819 			sr->mshot_total_len = READ_ONCE(sqe->optlen);
820 			if (sr->mshot_total_len)
821 				sr->flags |= IORING_RECV_MSHOT_LIM;
822 		} else if (sqe->optlen) {
823 			return -EINVAL;
824 		}
825 		req->flags |= REQ_F_APOLL_MULTISHOT;
826 	} else if (sqe->optlen) {
827 		return -EINVAL;
828 	}
829 
830 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
831 		if (req->opcode == IORING_OP_RECVMSG)
832 			return -EINVAL;
833 	}
834 
835 	if (io_is_compat(req->ctx))
836 		sr->msg_flags |= MSG_CMSG_COMPAT;
837 
838 	sr->nr_multishot_loops = 0;
839 	return io_recvmsg_prep_setup(req);
840 }
841 
842 /* bits to clear in old and inherit in new cflags on bundle retry */
843 #define CQE_F_MASK	(IORING_CQE_F_SOCK_NONEMPTY|IORING_CQE_F_MORE)
844 
845 /*
846  * Finishes io_recv and io_recvmsg.
847  *
848  * Returns true if it is actually finished, or false if it should run
849  * again (for multishot).
850  */
851 static inline bool io_recv_finish(struct io_kiocb *req,
852 				  struct io_async_msghdr *kmsg,
853 				  struct io_br_sel *sel, bool mshot_finished,
854 				  unsigned issue_flags)
855 {
856 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
857 	unsigned int cflags = 0;
858 
859 	if (kmsg->msg.msg_inq > 0)
860 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
861 
862 	if (sel->val > 0 && sr->flags & IORING_RECV_MSHOT_LIM) {
863 		/*
864 		 * If sr->len hits zero, the limit has been reached. Mark
865 		 * mshot as finished, and flag MSHOT_DONE as well to prevent
866 		 * a potential bundle from being retried.
867 		 */
868 		sr->mshot_total_len -= min_t(int, sel->val, sr->mshot_total_len);
869 		if (!sr->mshot_total_len) {
870 			sr->flags |= IORING_RECV_MSHOT_DONE;
871 			mshot_finished = true;
872 		}
873 	}
874 
875 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
876 		size_t this_ret = sel->val - sr->done_io;
877 
878 		cflags |= io_put_kbufs(req, this_ret, sel->buf_list, io_bundle_nbufs(kmsg, this_ret));
879 		if (sr->flags & IORING_RECV_RETRY)
880 			cflags = req->cqe.flags | (cflags & CQE_F_MASK);
881 		if (sr->mshot_len && sel->val >= sr->mshot_len)
882 			sr->flags |= IORING_RECV_MSHOT_CAP;
883 		/* bundle with no more immediate buffers, we're done */
884 		if (req->flags & REQ_F_BL_EMPTY)
885 			goto finish;
886 		/*
887 		 * If more is available AND it was a full transfer, retry and
888 		 * append to this one
889 		 */
890 		if (!(sr->flags & IORING_RECV_NO_RETRY) &&
891 		    kmsg->msg.msg_inq > 1 && this_ret > 0 &&
892 		    !iov_iter_count(&kmsg->msg.msg_iter)) {
893 			req->cqe.flags = cflags & ~CQE_F_MASK;
894 			sr->len = kmsg->msg.msg_inq;
895 			sr->done_io += this_ret;
896 			sr->flags |= IORING_RECV_RETRY;
897 			return false;
898 		}
899 	} else {
900 		cflags |= io_put_kbuf(req, sel->val, sel->buf_list);
901 	}
902 
903 	/*
904 	 * Fill CQE for this receive and see if we should keep trying to
905 	 * receive from this socket.
906 	 */
907 	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
908 	    io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
909 		sel->val = IOU_RETRY;
910 		io_mshot_prep_retry(req, kmsg);
911 		/* Known not-empty or unknown state, retry */
912 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
913 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY &&
914 			    !(sr->flags & IORING_RECV_MSHOT_CAP)) {
915 				return false;
916 			}
917 			/* mshot retries exceeded, force a requeue */
918 			sr->nr_multishot_loops = 0;
919 			sr->flags &= ~IORING_RECV_MSHOT_CAP;
920 			if (issue_flags & IO_URING_F_MULTISHOT)
921 				sel->val = IOU_REQUEUE;
922 		}
923 		return true;
924 	}
925 
926 	/* Finish the request / stop multishot. */
927 finish:
928 	io_req_set_res(req, sel->val, cflags);
929 	sel->val = IOU_COMPLETE;
930 	io_req_msg_cleanup(req, issue_flags);
931 	return true;
932 }
933 
934 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
935 				     struct io_sr_msg *sr, void __user **buf,
936 				     size_t *len)
937 {
938 	unsigned long ubuf = (unsigned long) *buf;
939 	unsigned long hdr;
940 
941 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
942 		kmsg->controllen;
943 	if (*len < hdr)
944 		return -EFAULT;
945 
946 	if (kmsg->controllen) {
947 		unsigned long control = ubuf + hdr - kmsg->controllen;
948 
949 		kmsg->msg.msg_control_user = (void __user *) control;
950 		kmsg->msg.msg_controllen = kmsg->controllen;
951 	}
952 
953 	sr->buf = *buf; /* stash for later copy */
954 	*buf = (void __user *) (ubuf + hdr);
955 	kmsg->payloadlen = *len = *len - hdr;
956 	return 0;
957 }
958 
959 struct io_recvmsg_multishot_hdr {
960 	struct io_uring_recvmsg_out msg;
961 	struct sockaddr_storage addr;
962 };
963 
964 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
965 				struct io_async_msghdr *kmsg,
966 				unsigned int flags, bool *finished)
967 {
968 	int err;
969 	int copy_len;
970 	struct io_recvmsg_multishot_hdr hdr;
971 
972 	if (kmsg->namelen)
973 		kmsg->msg.msg_name = &hdr.addr;
974 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
975 	kmsg->msg.msg_namelen = 0;
976 
977 	if (sock->file->f_flags & O_NONBLOCK)
978 		flags |= MSG_DONTWAIT;
979 
980 	err = sock_recvmsg(sock, &kmsg->msg, flags);
981 	*finished = err <= 0;
982 	if (err < 0)
983 		return err;
984 
985 	hdr.msg = (struct io_uring_recvmsg_out) {
986 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
987 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
988 	};
989 
990 	hdr.msg.payloadlen = err;
991 	if (err > kmsg->payloadlen)
992 		err = kmsg->payloadlen;
993 
994 	copy_len = sizeof(struct io_uring_recvmsg_out);
995 	if (kmsg->msg.msg_namelen > kmsg->namelen)
996 		copy_len += kmsg->namelen;
997 	else
998 		copy_len += kmsg->msg.msg_namelen;
999 
1000 	/*
1001 	 *      "fromlen shall refer to the value before truncation.."
1002 	 *                      1003.1g
1003 	 */
1004 	hdr.msg.namelen = kmsg->msg.msg_namelen;
1005 
1006 	/* ensure that there is no gap between hdr and sockaddr_storage */
1007 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
1008 		     sizeof(struct io_uring_recvmsg_out));
1009 	if (copy_to_user(io->buf, &hdr, copy_len)) {
1010 		*finished = true;
1011 		return -EFAULT;
1012 	}
1013 
1014 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
1015 			kmsg->controllen + err;
1016 }
1017 
1018 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
1019 {
1020 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1021 	struct io_async_msghdr *kmsg = req->async_data;
1022 	struct io_br_sel sel = { };
1023 	struct socket *sock;
1024 	unsigned flags;
1025 	int ret, min_ret = 0;
1026 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1027 	bool mshot_finished = true;
1028 
1029 	sock = sock_from_file(req->file);
1030 	if (unlikely(!sock))
1031 		return -ENOTSOCK;
1032 
1033 	if (!(req->flags & REQ_F_POLLED) &&
1034 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1035 		return -EAGAIN;
1036 
1037 	flags = sr->msg_flags;
1038 	if (force_nonblock)
1039 		flags |= MSG_DONTWAIT;
1040 
1041 retry_multishot:
1042 	sel.buf_list = NULL;
1043 	if (io_do_buffer_select(req)) {
1044 		size_t len = sr->len;
1045 
1046 		sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
1047 		if (!sel.addr)
1048 			return -ENOBUFS;
1049 
1050 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
1051 			ret = io_recvmsg_prep_multishot(kmsg, sr, &sel.addr, &len);
1052 			if (ret) {
1053 				io_kbuf_recycle(req, sel.buf_list, issue_flags);
1054 				return ret;
1055 			}
1056 		}
1057 
1058 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, sel.addr, len);
1059 	}
1060 
1061 	kmsg->msg.msg_get_inq = 1;
1062 	kmsg->msg.msg_inq = -1;
1063 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
1064 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
1065 					   &mshot_finished);
1066 	} else {
1067 		/* disable partial retry for recvmsg with cmsg attached */
1068 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
1069 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1070 
1071 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
1072 					 kmsg->uaddr, flags);
1073 	}
1074 
1075 	if (ret < min_ret) {
1076 		if (ret == -EAGAIN && force_nonblock) {
1077 			io_kbuf_recycle(req, sel.buf_list, issue_flags);
1078 			return IOU_RETRY;
1079 		}
1080 		if (ret > 0 && io_net_retry(sock, flags)) {
1081 			sr->done_io += ret;
1082 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
1083 		}
1084 		if (ret == -ERESTARTSYS)
1085 			ret = -EINTR;
1086 		req_set_fail(req);
1087 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1088 		req_set_fail(req);
1089 	}
1090 
1091 	if (ret > 0)
1092 		ret += sr->done_io;
1093 	else if (sr->done_io)
1094 		ret = sr->done_io;
1095 	else
1096 		io_kbuf_recycle(req, sel.buf_list, issue_flags);
1097 
1098 	sel.val = ret;
1099 	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags))
1100 		goto retry_multishot;
1101 
1102 	return sel.val;
1103 }
1104 
1105 static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
1106 			      struct io_br_sel *sel, unsigned int issue_flags)
1107 {
1108 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1109 	int ret;
1110 
1111 	/*
1112 	 * If the ring isn't locked, then don't use the peek interface
1113 	 * to grab multiple buffers as we will lock/unlock between
1114 	 * this selection and posting the buffers.
1115 	 */
1116 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
1117 	    sr->flags & IORING_RECVSEND_BUNDLE) {
1118 		struct buf_sel_arg arg = {
1119 			.iovs = &kmsg->fast_iov,
1120 			.nr_iovs = 1,
1121 			.mode = KBUF_MODE_EXPAND,
1122 			.buf_group = sr->buf_group,
1123 		};
1124 
1125 		if (kmsg->vec.iovec) {
1126 			arg.nr_iovs = kmsg->vec.nr;
1127 			arg.iovs = kmsg->vec.iovec;
1128 			arg.mode |= KBUF_MODE_FREE;
1129 		}
1130 
1131 		if (sel->val)
1132 			arg.max_len = sel->val;
1133 		else if (kmsg->msg.msg_inq > 1)
1134 			arg.max_len = min_not_zero(sel->val, (ssize_t) kmsg->msg.msg_inq);
1135 
1136 		/* if mshot limited, ensure we don't go over */
1137 		if (sr->flags & IORING_RECV_MSHOT_LIM)
1138 			arg.max_len = min_not_zero(arg.max_len, sr->mshot_total_len);
1139 		ret = io_buffers_peek(req, &arg, sel);
1140 		if (unlikely(ret < 0))
1141 			return ret;
1142 
1143 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
1144 			kmsg->vec.nr = ret;
1145 			kmsg->vec.iovec = arg.iovs;
1146 			req->flags |= REQ_F_NEED_CLEANUP;
1147 		}
1148 		if (arg.partial_map)
1149 			sr->flags |= IORING_RECV_PARTIAL_MAP;
1150 
1151 		/* special case 1 vec, can be a fast path */
1152 		if (ret == 1) {
1153 			sr->buf = arg.iovs[0].iov_base;
1154 			sr->len = arg.iovs[0].iov_len;
1155 			goto map_ubuf;
1156 		}
1157 		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
1158 				arg.out_len);
1159 	} else {
1160 		size_t len = sel->val;
1161 
1162 		*sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
1163 		if (!sel->addr)
1164 			return -ENOBUFS;
1165 		sr->buf = sel->addr;
1166 		sr->len = len;
1167 map_ubuf:
1168 		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
1169 				  &kmsg->msg.msg_iter);
1170 		if (unlikely(ret))
1171 			return ret;
1172 	}
1173 
1174 	return 0;
1175 }
1176 
1177 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
1178 {
1179 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1180 	struct io_async_msghdr *kmsg = req->async_data;
1181 	struct io_br_sel sel;
1182 	struct socket *sock;
1183 	unsigned flags;
1184 	int ret, min_ret = 0;
1185 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1186 	bool mshot_finished;
1187 
1188 	if (!(req->flags & REQ_F_POLLED) &&
1189 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1190 		return -EAGAIN;
1191 
1192 	sock = sock_from_file(req->file);
1193 	if (unlikely(!sock))
1194 		return -ENOTSOCK;
1195 
1196 	flags = sr->msg_flags;
1197 	if (force_nonblock)
1198 		flags |= MSG_DONTWAIT;
1199 
1200 retry_multishot:
1201 	sel.buf_list = NULL;
1202 	if (io_do_buffer_select(req)) {
1203 		sel.val = sr->len;
1204 		ret = io_recv_buf_select(req, kmsg, &sel, issue_flags);
1205 		if (unlikely(ret < 0)) {
1206 			kmsg->msg.msg_inq = -1;
1207 			goto out_free;
1208 		}
1209 		sr->buf = NULL;
1210 	}
1211 
1212 	kmsg->msg.msg_flags = 0;
1213 	kmsg->msg.msg_inq = -1;
1214 
1215 	if (flags & MSG_WAITALL)
1216 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1217 
1218 	ret = sock_recvmsg(sock, &kmsg->msg, flags);
1219 	if (ret < min_ret) {
1220 		if (ret == -EAGAIN && force_nonblock) {
1221 			io_kbuf_recycle(req, sel.buf_list, issue_flags);
1222 			return IOU_RETRY;
1223 		}
1224 		if (ret > 0 && io_net_retry(sock, flags)) {
1225 			sr->len -= ret;
1226 			sr->buf += ret;
1227 			sr->done_io += ret;
1228 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
1229 		}
1230 		if (ret == -ERESTARTSYS)
1231 			ret = -EINTR;
1232 		req_set_fail(req);
1233 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1234 out_free:
1235 		req_set_fail(req);
1236 	}
1237 
1238 	mshot_finished = ret <= 0;
1239 	if (ret > 0)
1240 		ret += sr->done_io;
1241 	else if (sr->done_io)
1242 		ret = sr->done_io;
1243 	else
1244 		io_kbuf_recycle(req, sel.buf_list, issue_flags);
1245 
1246 	sel.val = ret;
1247 	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags))
1248 		goto retry_multishot;
1249 
1250 	return sel.val;
1251 }
1252 
1253 int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1254 {
1255 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1256 	unsigned ifq_idx;
1257 
1258 	if (unlikely(sqe->addr2 || sqe->addr || sqe->addr3))
1259 		return -EINVAL;
1260 
1261 	ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx);
1262 	zc->ifq = xa_load(&req->ctx->zcrx_ctxs, ifq_idx);
1263 	if (!zc->ifq)
1264 		return -EINVAL;
1265 
1266 	zc->len = READ_ONCE(sqe->len);
1267 	zc->flags = READ_ONCE(sqe->ioprio);
1268 	if (READ_ONCE(sqe->msg_flags))
1269 		return -EINVAL;
1270 	if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT))
1271 		return -EINVAL;
1272 	/* multishot required */
1273 	if (!(zc->flags & IORING_RECV_MULTISHOT))
1274 		return -EINVAL;
1275 	/* All data completions are posted as aux CQEs. */
1276 	req->flags |= REQ_F_APOLL_MULTISHOT;
1277 
1278 	return 0;
1279 }
1280 
1281 int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
1282 {
1283 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1284 	struct socket *sock;
1285 	unsigned int len;
1286 	int ret;
1287 
1288 	if (!(req->flags & REQ_F_POLLED) &&
1289 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1290 		return -EAGAIN;
1291 
1292 	sock = sock_from_file(req->file);
1293 	if (unlikely(!sock))
1294 		return -ENOTSOCK;
1295 
1296 	len = zc->len;
1297 	ret = io_zcrx_recv(req, zc->ifq, sock, 0, issue_flags, &zc->len);
1298 	if (len && zc->len == 0) {
1299 		io_req_set_res(req, 0, 0);
1300 
1301 		return IOU_COMPLETE;
1302 	}
1303 	if (unlikely(ret <= 0) && ret != -EAGAIN) {
1304 		if (ret == -ERESTARTSYS)
1305 			ret = -EINTR;
1306 		if (ret == IOU_REQUEUE)
1307 			return IOU_REQUEUE;
1308 
1309 		req_set_fail(req);
1310 		io_req_set_res(req, ret, 0);
1311 		return IOU_COMPLETE;
1312 	}
1313 	return IOU_RETRY;
1314 }
1315 
1316 void io_send_zc_cleanup(struct io_kiocb *req)
1317 {
1318 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1319 	struct io_async_msghdr *io = req->async_data;
1320 
1321 	if (req_has_async_data(req))
1322 		io_netmsg_iovec_free(io);
1323 	if (zc->notif) {
1324 		io_notif_flush(zc->notif);
1325 		zc->notif = NULL;
1326 	}
1327 }
1328 
1329 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1330 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE | \
1331 				IORING_SEND_VECTORIZED)
1332 
1333 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1334 {
1335 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1336 	struct io_ring_ctx *ctx = req->ctx;
1337 	struct io_async_msghdr *iomsg;
1338 	struct io_kiocb *notif;
1339 	u64 user_data;
1340 	int ret;
1341 
1342 	zc->done_io = 0;
1343 
1344 	if (unlikely(READ_ONCE(sqe->__pad2[0])))
1345 		return -EINVAL;
1346 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1347 	if (req->flags & REQ_F_CQE_SKIP)
1348 		return -EINVAL;
1349 
1350 	notif = zc->notif = io_alloc_notif(ctx);
1351 	if (!notif)
1352 		return -ENOMEM;
1353 	user_data = READ_ONCE(sqe->addr3);
1354 	if (!user_data)
1355 		user_data = req->cqe.user_data;
1356 
1357 	notif->cqe.user_data = user_data;
1358 	notif->cqe.res = 0;
1359 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1360 	req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY;
1361 
1362 	zc->flags = READ_ONCE(sqe->ioprio);
1363 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1364 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1365 			return -EINVAL;
1366 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1367 			struct io_notif_data *nd = io_notif_to_data(notif);
1368 
1369 			nd->zc_report = true;
1370 			nd->zc_used = false;
1371 			nd->zc_copied = false;
1372 		}
1373 	}
1374 
1375 	zc->len = READ_ONCE(sqe->len);
1376 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
1377 	req->buf_index = READ_ONCE(sqe->buf_index);
1378 	if (zc->msg_flags & MSG_DONTWAIT)
1379 		req->flags |= REQ_F_NOWAIT;
1380 
1381 	if (io_is_compat(ctx))
1382 		zc->msg_flags |= MSG_CMSG_COMPAT;
1383 
1384 	iomsg = io_msg_alloc_async(req);
1385 	if (unlikely(!iomsg))
1386 		return -ENOMEM;
1387 
1388 	if (req->opcode == IORING_OP_SEND_ZC) {
1389 		ret = io_send_setup(req, sqe);
1390 	} else {
1391 		if (unlikely(sqe->addr2 || sqe->file_index))
1392 			return -EINVAL;
1393 		ret = io_sendmsg_setup(req, sqe);
1394 	}
1395 	if (unlikely(ret))
1396 		return ret;
1397 
1398 	if (!(zc->flags & IORING_RECVSEND_FIXED_BUF)) {
1399 		iomsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1400 		return io_notif_account_mem(zc->notif, iomsg->msg.msg_iter.count);
1401 	}
1402 	iomsg->msg.sg_from_iter = io_sg_from_iter;
1403 	return 0;
1404 }
1405 
1406 static int io_sg_from_iter_iovec(struct sk_buff *skb,
1407 				 struct iov_iter *from, size_t length)
1408 {
1409 	skb_zcopy_downgrade_managed(skb);
1410 	return zerocopy_fill_skb_from_iter(skb, from, length);
1411 }
1412 
1413 static int io_sg_from_iter(struct sk_buff *skb,
1414 			   struct iov_iter *from, size_t length)
1415 {
1416 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1417 	int frag = shinfo->nr_frags;
1418 	int ret = 0;
1419 	struct bvec_iter bi;
1420 	ssize_t copied = 0;
1421 	unsigned long truesize = 0;
1422 
1423 	if (!frag)
1424 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1425 	else if (unlikely(!skb_zcopy_managed(skb)))
1426 		return zerocopy_fill_skb_from_iter(skb, from, length);
1427 
1428 	bi.bi_size = min(from->count, length);
1429 	bi.bi_bvec_done = from->iov_offset;
1430 	bi.bi_idx = 0;
1431 
1432 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1433 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1434 
1435 		copied += v.bv_len;
1436 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1437 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1438 					   v.bv_offset, v.bv_len);
1439 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1440 	}
1441 	if (bi.bi_size)
1442 		ret = -EMSGSIZE;
1443 
1444 	shinfo->nr_frags = frag;
1445 	from->bvec += bi.bi_idx;
1446 	from->nr_segs -= bi.bi_idx;
1447 	from->count -= copied;
1448 	from->iov_offset = bi.bi_bvec_done;
1449 
1450 	skb->data_len += copied;
1451 	skb->len += copied;
1452 	skb->truesize += truesize;
1453 	return ret;
1454 }
1455 
1456 static int io_send_zc_import(struct io_kiocb *req,
1457 			     struct io_async_msghdr *kmsg,
1458 			     unsigned int issue_flags)
1459 {
1460 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1461 	struct io_kiocb *notif = sr->notif;
1462 	int ret;
1463 
1464 	WARN_ON_ONCE(!(sr->flags & IORING_RECVSEND_FIXED_BUF));
1465 
1466 	notif->buf_index = req->buf_index;
1467 
1468 	if (!(sr->flags & IORING_SEND_VECTORIZED)) {
1469 		ret = io_import_reg_buf(notif, &kmsg->msg.msg_iter,
1470 					(u64)(uintptr_t)sr->buf, sr->len,
1471 					ITER_SOURCE, issue_flags);
1472 	} else {
1473 		unsigned uvec_segs = kmsg->msg.msg_iter.nr_segs;
1474 
1475 		ret = io_import_reg_vec(ITER_SOURCE, &kmsg->msg.msg_iter,
1476 					notif, &kmsg->vec, uvec_segs,
1477 					issue_flags);
1478 	}
1479 
1480 	if (unlikely(ret))
1481 		return ret;
1482 	req->flags &= ~REQ_F_IMPORT_BUFFER;
1483 	return 0;
1484 }
1485 
1486 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1487 {
1488 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1489 	struct io_async_msghdr *kmsg = req->async_data;
1490 	struct socket *sock;
1491 	unsigned msg_flags;
1492 	int ret, min_ret = 0;
1493 
1494 	sock = sock_from_file(req->file);
1495 	if (unlikely(!sock))
1496 		return -ENOTSOCK;
1497 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1498 		return -EOPNOTSUPP;
1499 	if (!(req->flags & REQ_F_POLLED) &&
1500 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1501 		return -EAGAIN;
1502 
1503 	if (req->flags & REQ_F_IMPORT_BUFFER) {
1504 		ret = io_send_zc_import(req, kmsg, issue_flags);
1505 		if (unlikely(ret))
1506 			return ret;
1507 	}
1508 
1509 	msg_flags = sr->msg_flags;
1510 	if (issue_flags & IO_URING_F_NONBLOCK)
1511 		msg_flags |= MSG_DONTWAIT;
1512 	if (msg_flags & MSG_WAITALL)
1513 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1514 
1515 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1516 
1517 	if (req->opcode == IORING_OP_SEND_ZC) {
1518 		msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1519 		kmsg->msg.msg_flags = msg_flags;
1520 		ret = sock_sendmsg(sock, &kmsg->msg);
1521 	} else {
1522 		kmsg->msg.msg_control_user = sr->msg_control;
1523 		ret = __sys_sendmsg_sock(sock, &kmsg->msg, msg_flags);
1524 	}
1525 
1526 	if (unlikely(ret < min_ret)) {
1527 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1528 			return -EAGAIN;
1529 
1530 		if (ret > 0 && io_net_retry(sock, sr->msg_flags)) {
1531 			sr->done_io += ret;
1532 			return -EAGAIN;
1533 		}
1534 		if (ret == -ERESTARTSYS)
1535 			ret = -EINTR;
1536 		req_set_fail(req);
1537 	}
1538 
1539 	if (ret >= 0)
1540 		ret += sr->done_io;
1541 	else if (sr->done_io)
1542 		ret = sr->done_io;
1543 
1544 	/*
1545 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1546 	 * flushing notif to io_send_zc_cleanup()
1547 	 */
1548 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1549 		io_notif_flush(sr->notif);
1550 		sr->notif = NULL;
1551 		io_req_msg_cleanup(req, 0);
1552 	}
1553 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1554 	return IOU_COMPLETE;
1555 }
1556 
1557 void io_sendrecv_fail(struct io_kiocb *req)
1558 {
1559 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1560 
1561 	if (sr->done_io)
1562 		req->cqe.res = sr->done_io;
1563 
1564 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1565 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1566 		req->cqe.flags |= IORING_CQE_F_MORE;
1567 }
1568 
1569 #define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
1570 			 IORING_ACCEPT_POLL_FIRST)
1571 
1572 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1573 {
1574 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1575 
1576 	if (sqe->len || sqe->buf_index)
1577 		return -EINVAL;
1578 
1579 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1580 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1581 	accept->flags = READ_ONCE(sqe->accept_flags);
1582 	accept->nofile = rlimit(RLIMIT_NOFILE);
1583 	accept->iou_flags = READ_ONCE(sqe->ioprio);
1584 	if (accept->iou_flags & ~ACCEPT_FLAGS)
1585 		return -EINVAL;
1586 
1587 	accept->file_slot = READ_ONCE(sqe->file_index);
1588 	if (accept->file_slot) {
1589 		if (accept->flags & SOCK_CLOEXEC)
1590 			return -EINVAL;
1591 		if (accept->iou_flags & IORING_ACCEPT_MULTISHOT &&
1592 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1593 			return -EINVAL;
1594 	}
1595 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1596 		return -EINVAL;
1597 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1598 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1599 	if (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
1600 		req->flags |= REQ_F_APOLL_MULTISHOT;
1601 	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
1602 		req->flags |= REQ_F_NOWAIT;
1603 	return 0;
1604 }
1605 
1606 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1607 {
1608 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1609 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1610 	bool fixed = !!accept->file_slot;
1611 	struct proto_accept_arg arg = {
1612 		.flags = force_nonblock ? O_NONBLOCK : 0,
1613 	};
1614 	struct file *file;
1615 	unsigned cflags;
1616 	int ret, fd;
1617 
1618 	if (!(req->flags & REQ_F_POLLED) &&
1619 	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
1620 		return -EAGAIN;
1621 
1622 retry:
1623 	if (!fixed) {
1624 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1625 		if (unlikely(fd < 0))
1626 			return fd;
1627 	}
1628 	arg.err = 0;
1629 	arg.is_empty = -1;
1630 	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
1631 			 accept->flags);
1632 	if (IS_ERR(file)) {
1633 		if (!fixed)
1634 			put_unused_fd(fd);
1635 		ret = PTR_ERR(file);
1636 		if (ret == -EAGAIN && force_nonblock &&
1637 		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT))
1638 			return IOU_RETRY;
1639 
1640 		if (ret == -ERESTARTSYS)
1641 			ret = -EINTR;
1642 	} else if (!fixed) {
1643 		fd_install(fd, file);
1644 		ret = fd;
1645 	} else {
1646 		ret = io_fixed_fd_install(req, issue_flags, file,
1647 						accept->file_slot);
1648 	}
1649 
1650 	cflags = 0;
1651 	if (!arg.is_empty)
1652 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
1653 
1654 	if (ret >= 0 && (req->flags & REQ_F_APOLL_MULTISHOT) &&
1655 	    io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
1656 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
1657 			goto retry;
1658 		return IOU_RETRY;
1659 	}
1660 
1661 	io_req_set_res(req, ret, cflags);
1662 	if (ret < 0)
1663 		req_set_fail(req);
1664 	return IOU_COMPLETE;
1665 }
1666 
1667 void io_socket_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
1668 {
1669 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1670 
1671 	bctx->socket.family = sock->domain;
1672 	bctx->socket.type = sock->type;
1673 	bctx->socket.protocol = sock->protocol;
1674 }
1675 
1676 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1677 {
1678 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1679 
1680 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1681 		return -EINVAL;
1682 
1683 	sock->domain = READ_ONCE(sqe->fd);
1684 	sock->type = READ_ONCE(sqe->off);
1685 	sock->protocol = READ_ONCE(sqe->len);
1686 	sock->file_slot = READ_ONCE(sqe->file_index);
1687 	sock->nofile = rlimit(RLIMIT_NOFILE);
1688 
1689 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1690 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1691 		return -EINVAL;
1692 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1693 		return -EINVAL;
1694 	return 0;
1695 }
1696 
1697 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1698 {
1699 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1700 	bool fixed = !!sock->file_slot;
1701 	struct file *file;
1702 	int ret, fd;
1703 
1704 	if (!fixed) {
1705 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1706 		if (unlikely(fd < 0))
1707 			return fd;
1708 	}
1709 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1710 	if (IS_ERR(file)) {
1711 		if (!fixed)
1712 			put_unused_fd(fd);
1713 		ret = PTR_ERR(file);
1714 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1715 			return -EAGAIN;
1716 		if (ret == -ERESTARTSYS)
1717 			ret = -EINTR;
1718 		req_set_fail(req);
1719 	} else if (!fixed) {
1720 		fd_install(fd, file);
1721 		ret = fd;
1722 	} else {
1723 		ret = io_fixed_fd_install(req, issue_flags, file,
1724 					    sock->file_slot);
1725 	}
1726 	io_req_set_res(req, ret, 0);
1727 	return IOU_COMPLETE;
1728 }
1729 
1730 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1731 {
1732 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1733 	struct io_async_msghdr *io;
1734 
1735 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1736 		return -EINVAL;
1737 
1738 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1739 	conn->addr_len =  READ_ONCE(sqe->addr2);
1740 	conn->in_progress = conn->seen_econnaborted = false;
1741 
1742 	io = io_msg_alloc_async(req);
1743 	if (unlikely(!io))
1744 		return -ENOMEM;
1745 
1746 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr);
1747 }
1748 
1749 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1750 {
1751 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1752 	struct io_async_msghdr *io = req->async_data;
1753 	unsigned file_flags;
1754 	int ret;
1755 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1756 
1757 	if (connect->in_progress) {
1758 		struct poll_table_struct pt = { ._key = EPOLLERR };
1759 
1760 		if (vfs_poll(req->file, &pt) & EPOLLERR)
1761 			goto get_sock_err;
1762 	}
1763 
1764 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1765 
1766 	ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,
1767 				 file_flags);
1768 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1769 	    && force_nonblock) {
1770 		if (ret == -EINPROGRESS) {
1771 			connect->in_progress = true;
1772 		} else if (ret == -ECONNABORTED) {
1773 			if (connect->seen_econnaborted)
1774 				goto out;
1775 			connect->seen_econnaborted = true;
1776 		}
1777 		return -EAGAIN;
1778 	}
1779 	if (connect->in_progress) {
1780 		/*
1781 		 * At least bluetooth will return -EBADFD on a re-connect
1782 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1783 		 * which means the previous result is good. For both of these,
1784 		 * grab the sock_error() and use that for the completion.
1785 		 */
1786 		if (ret == -EBADFD || ret == -EISCONN) {
1787 get_sock_err:
1788 			ret = sock_error(sock_from_file(req->file)->sk);
1789 		}
1790 	}
1791 	if (ret == -ERESTARTSYS)
1792 		ret = -EINTR;
1793 out:
1794 	if (ret < 0)
1795 		req_set_fail(req);
1796 	io_req_msg_cleanup(req, issue_flags);
1797 	io_req_set_res(req, ret, 0);
1798 	return IOU_COMPLETE;
1799 }
1800 
1801 int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1802 {
1803 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1804 	struct sockaddr __user *uaddr;
1805 	struct io_async_msghdr *io;
1806 
1807 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1808 		return -EINVAL;
1809 
1810 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1811 	bind->addr_len =  READ_ONCE(sqe->addr2);
1812 
1813 	io = io_msg_alloc_async(req);
1814 	if (unlikely(!io))
1815 		return -ENOMEM;
1816 	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
1817 }
1818 
1819 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
1820 {
1821 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1822 	struct io_async_msghdr *io = req->async_data;
1823 	struct socket *sock;
1824 	int ret;
1825 
1826 	sock = sock_from_file(req->file);
1827 	if (unlikely(!sock))
1828 		return -ENOTSOCK;
1829 
1830 	ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
1831 	if (ret < 0)
1832 		req_set_fail(req);
1833 	io_req_set_res(req, ret, 0);
1834 	return 0;
1835 }
1836 
1837 int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1838 {
1839 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1840 
1841 	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
1842 		return -EINVAL;
1843 
1844 	listen->backlog = READ_ONCE(sqe->len);
1845 	return 0;
1846 }
1847 
1848 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
1849 {
1850 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1851 	struct socket *sock;
1852 	int ret;
1853 
1854 	sock = sock_from_file(req->file);
1855 	if (unlikely(!sock))
1856 		return -ENOTSOCK;
1857 
1858 	ret = __sys_listen_socket(sock, listen->backlog);
1859 	if (ret < 0)
1860 		req_set_fail(req);
1861 	io_req_set_res(req, ret, 0);
1862 	return 0;
1863 }
1864 
1865 void io_netmsg_cache_free(const void *entry)
1866 {
1867 	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
1868 
1869 	io_vec_free(&kmsg->vec);
1870 	kfree(kmsg);
1871 }
1872