xref: /linux/io_uring/net.c (revision 6028b543884f8735e057ec9eea4908cd61cab230)
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/un.h>
8 #include <linux/compat.h>
9 #include <net/compat.h>
10 #include <linux/io_uring.h>
11 
12 #include <uapi/linux/io_uring.h>
13 
14 #include "filetable.h"
15 #include "io_uring.h"
16 #include "kbuf.h"
17 #include "alloc_cache.h"
18 #include "net.h"
19 #include "notif.h"
20 #include "rsrc.h"
21 #include "zcrx.h"
22 
23 struct io_shutdown {
24 	struct file			*file;
25 	int				how;
26 };
27 
28 struct io_accept {
29 	struct file			*file;
30 	struct sockaddr __user		*addr;
31 	int __user			*addr_len;
32 	int				flags;
33 	int				iou_flags;
34 	u32				file_slot;
35 	unsigned long			nofile;
36 };
37 
38 struct io_socket {
39 	struct file			*file;
40 	int				domain;
41 	int				type;
42 	int				protocol;
43 	int				flags;
44 	u32				file_slot;
45 	unsigned long			nofile;
46 };
47 
48 struct io_connect {
49 	struct file			*file;
50 	struct sockaddr __user		*addr;
51 	int				addr_len;
52 	bool				in_progress;
53 	bool				seen_econnaborted;
54 };
55 
56 struct io_bind {
57 	struct file			*file;
58 	int				addr_len;
59 };
60 
61 struct io_listen {
62 	struct file			*file;
63 	int				backlog;
64 };
65 
66 struct io_sr_msg {
67 	struct file			*file;
68 	union {
69 		struct compat_msghdr __user	*umsg_compat;
70 		struct user_msghdr __user	*umsg;
71 		void __user			*buf;
72 	};
73 	int				len;
74 	unsigned			done_io;
75 	unsigned			msg_flags;
76 	unsigned			nr_multishot_loops;
77 	u16				flags;
78 	/* initialised and used only by !msg send variants */
79 	u16				buf_group;
80 	/* per-invocation mshot limit */
81 	unsigned			mshot_len;
82 	/* overall mshot byte limit */
83 	unsigned			mshot_total_len;
84 	void __user			*msg_control;
85 	/* used only for send zerocopy */
86 	struct io_kiocb 		*notif;
87 };
88 
89 /*
90  * The UAPI flags are the lower 8 bits, as that's all sqe->ioprio will hold
91  * anyway. Use the upper 8 bits for internal uses.
92  */
93 enum sr_retry_flags {
94 	IORING_RECV_RETRY	= (1U << 15),
95 	IORING_RECV_PARTIAL_MAP	= (1U << 14),
96 	IORING_RECV_MSHOT_CAP	= (1U << 13),
97 	IORING_RECV_MSHOT_LIM	= (1U << 12),
98 	IORING_RECV_MSHOT_DONE	= (1U << 11),
99 
100 	IORING_RECV_RETRY_CLEAR	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
101 	IORING_RECV_NO_RETRY	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP |
102 				  IORING_RECV_MSHOT_CAP | IORING_RECV_MSHOT_DONE,
103 };
104 
105 /*
106  * Number of times we'll try and do receives if there's more data. If we
107  * exceed this limit, then add us to the back of the queue and retry from
108  * there. This helps fairness between flooding clients.
109  */
110 #define MULTISHOT_MAX_RETRY	32
111 
112 struct io_recvzc {
113 	struct file			*file;
114 	u16				flags;
115 	u32				len;
116 	struct io_zcrx_ifq		*ifq;
117 };
118 
119 static int io_sg_from_iter_iovec(struct sk_buff *skb,
120 				 struct iov_iter *from, size_t length);
121 static int io_sg_from_iter(struct sk_buff *skb,
122 			   struct iov_iter *from, size_t length);
123 
124 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
125 {
126 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
127 
128 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
129 		     sqe->buf_index || sqe->splice_fd_in))
130 		return -EINVAL;
131 
132 	shutdown->how = READ_ONCE(sqe->len);
133 	req->flags |= REQ_F_FORCE_ASYNC;
134 	return 0;
135 }
136 
137 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
138 {
139 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
140 	struct socket *sock;
141 	int ret;
142 
143 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
144 
145 	sock = sock_from_file(req->file);
146 	if (unlikely(!sock))
147 		return -ENOTSOCK;
148 
149 	ret = __sys_shutdown_sock(sock, shutdown->how);
150 	io_req_set_res(req, ret, 0);
151 	return IOU_COMPLETE;
152 }
153 
154 static bool io_net_retry(struct socket *sock, int flags)
155 {
156 	if (!(flags & MSG_WAITALL))
157 		return false;
158 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
159 }
160 
161 static void io_netmsg_iovec_free(struct io_async_msghdr *kmsg)
162 {
163 	if (kmsg->vec.iovec)
164 		io_vec_free(&kmsg->vec);
165 }
166 
167 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
168 {
169 	struct io_async_msghdr *hdr = req->async_data;
170 
171 	/* can't recycle, ensure we free the iovec if we have one */
172 	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
173 		io_netmsg_iovec_free(hdr);
174 		return;
175 	}
176 
177 	/* Let normal cleanup path reap it if we fail adding to the cache */
178 	io_alloc_cache_vec_kasan(&hdr->vec);
179 	if (hdr->vec.nr > IO_VEC_CACHE_SOFT_CAP)
180 		io_vec_free(&hdr->vec);
181 
182 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr))
183 		io_req_async_data_clear(req, REQ_F_NEED_CLEANUP);
184 }
185 
186 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
187 {
188 	struct io_ring_ctx *ctx = req->ctx;
189 	struct io_async_msghdr *hdr;
190 
191 	hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req);
192 	if (!hdr)
193 		return NULL;
194 
195 	/* If the async data was cached, we might have an iov cached inside. */
196 	if (hdr->vec.iovec)
197 		req->flags |= REQ_F_NEED_CLEANUP;
198 	return hdr;
199 }
200 
201 static inline void io_mshot_prep_retry(struct io_kiocb *req,
202 				       struct io_async_msghdr *kmsg)
203 {
204 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
205 
206 	req->flags &= ~REQ_F_BL_EMPTY;
207 	sr->done_io = 0;
208 	sr->flags &= ~IORING_RECV_RETRY_CLEAR;
209 	sr->len = sr->mshot_len;
210 }
211 
212 static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg,
213 			     const struct iovec __user *uiov, unsigned uvec_seg,
214 			     int ddir)
215 {
216 	struct iovec *iov;
217 	int ret, nr_segs;
218 
219 	if (iomsg->vec.iovec) {
220 		nr_segs = iomsg->vec.nr;
221 		iov = iomsg->vec.iovec;
222 	} else {
223 		nr_segs = 1;
224 		iov = &iomsg->fast_iov;
225 	}
226 
227 	ret = __import_iovec(ddir, uiov, uvec_seg, nr_segs, &iov,
228 			     &iomsg->msg.msg_iter, io_is_compat(req->ctx));
229 	if (unlikely(ret < 0))
230 		return ret;
231 
232 	if (iov) {
233 		req->flags |= REQ_F_NEED_CLEANUP;
234 		io_vec_reset_iovec(&iomsg->vec, iov, iomsg->msg.msg_iter.nr_segs);
235 	}
236 	return 0;
237 }
238 
239 static int io_copy_msghdr_from_user(struct user_msghdr *msg,
240 				    struct user_msghdr __user *umsg)
241 {
242 	if (!user_access_begin(umsg, sizeof(*umsg)))
243 		return -EFAULT;
244 	unsafe_get_user(msg->msg_name, &umsg->msg_name, ua_end);
245 	unsafe_get_user(msg->msg_namelen, &umsg->msg_namelen, ua_end);
246 	unsafe_get_user(msg->msg_iov, &umsg->msg_iov, ua_end);
247 	unsafe_get_user(msg->msg_iovlen, &umsg->msg_iovlen, ua_end);
248 	unsafe_get_user(msg->msg_control, &umsg->msg_control, ua_end);
249 	unsafe_get_user(msg->msg_controllen, &umsg->msg_controllen, ua_end);
250 	user_access_end();
251 	return 0;
252 ua_end:
253 	user_access_end();
254 	return -EFAULT;
255 }
256 
257 static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
258 			   struct user_msghdr *msg,
259 			   struct sockaddr __user **save_addr)
260 {
261 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
262 	int ret;
263 
264 	iomsg->msg.msg_name = &iomsg->addr;
265 	iomsg->msg.msg_iter.nr_segs = 0;
266 
267 	if (io_is_compat(req->ctx)) {
268 		struct compat_msghdr cmsg;
269 
270 		if (copy_from_user(&cmsg, sr->umsg_compat, sizeof(cmsg)))
271 			return -EFAULT;
272 
273 		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, save_addr);
274 		if (ret)
275 			return ret;
276 
277 		memset(msg, 0, sizeof(*msg));
278 		msg->msg_namelen = cmsg.msg_namelen;
279 		msg->msg_controllen = cmsg.msg_controllen;
280 		msg->msg_iov = compat_ptr(cmsg.msg_iov);
281 		msg->msg_iovlen = cmsg.msg_iovlen;
282 	} else {
283 		ret = io_copy_msghdr_from_user(msg, sr->umsg);
284 		if (unlikely(ret))
285 			return ret;
286 
287 		msg->msg_flags = 0;
288 
289 		ret = __copy_msghdr(&iomsg->msg, msg, save_addr);
290 		if (ret)
291 			return ret;
292 	}
293 
294 	if (req->flags & REQ_F_BUFFER_SELECT) {
295 		if (msg->msg_iovlen == 0) {
296 			sr->len = 0;
297 		} else if (msg->msg_iovlen > 1) {
298 			return -EINVAL;
299 		} else {
300 			struct iovec fast_iov, *iov;
301 
302 			iov = iovec_from_user(msg->msg_iov, 1, 1, &fast_iov,
303 					      io_is_compat(req->ctx));
304 			if (IS_ERR(iov))
305 				return PTR_ERR(iov);
306 			sr->len = iov->iov_len;
307 		}
308 	}
309 	return 0;
310 }
311 
312 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
313 {
314 	struct io_async_msghdr *io = req->async_data;
315 
316 	io_netmsg_iovec_free(io);
317 }
318 
319 static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
320 {
321 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
322 	struct io_async_msghdr *kmsg = req->async_data;
323 	void __user *addr;
324 	u16 addr_len;
325 	int ret;
326 
327 	sr->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
328 
329 	if (READ_ONCE(sqe->__pad3[0]))
330 		return -EINVAL;
331 
332 	kmsg->msg.msg_name = NULL;
333 	kmsg->msg.msg_namelen = 0;
334 	kmsg->msg.msg_control = NULL;
335 	kmsg->msg.msg_controllen = 0;
336 	kmsg->msg.msg_ubuf = NULL;
337 
338 	addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
339 	addr_len = READ_ONCE(sqe->addr_len);
340 	if (addr) {
341 		ret = move_addr_to_kernel(addr, addr_len, &kmsg->addr);
342 		if (unlikely(ret < 0))
343 			return ret;
344 		kmsg->msg.msg_name = &kmsg->addr;
345 		kmsg->msg.msg_namelen = addr_len;
346 	}
347 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
348 		if (!(sr->flags & IORING_SEND_VECTORIZED)) {
349 			req->flags |= REQ_F_IMPORT_BUFFER;
350 			return 0;
351 		}
352 
353 		kmsg->msg.msg_iter.nr_segs = sr->len;
354 		return io_prep_reg_iovec(req, &kmsg->vec, sr->buf, sr->len);
355 	}
356 	if (req->flags & REQ_F_BUFFER_SELECT)
357 		return 0;
358 
359 	if (sr->flags & IORING_SEND_VECTORIZED)
360 		return io_net_import_vec(req, kmsg, sr->buf, sr->len, ITER_SOURCE);
361 
362 	return import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
363 }
364 
365 static int io_sendmsg_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
366 {
367 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
368 	struct io_async_msghdr *kmsg = req->async_data;
369 	struct user_msghdr msg;
370 	int ret;
371 
372 	sr->flags |= IORING_SEND_VECTORIZED;
373 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
374 	ret = io_msg_copy_hdr(req, kmsg, &msg, NULL);
375 	if (unlikely(ret))
376 		return ret;
377 	/* save msg_control as sys_sendmsg() overwrites it */
378 	sr->msg_control = kmsg->msg.msg_control_user;
379 
380 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
381 		kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen;
382 		return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov,
383 					 msg.msg_iovlen);
384 	}
385 	if (req->flags & REQ_F_BUFFER_SELECT)
386 		return 0;
387 	return io_net_import_vec(req, kmsg, msg.msg_iov, msg.msg_iovlen, ITER_SOURCE);
388 }
389 
390 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE | \
391 			IORING_SEND_VECTORIZED | IORING_RECVSEND_FIXED_BUF)
392 
393 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
394 {
395 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
396 
397 	sr->done_io = 0;
398 	sr->len = READ_ONCE(sqe->len);
399 	if (unlikely(sr->len < 0))
400 		return -EINVAL;
401 	sr->flags = READ_ONCE(sqe->ioprio);
402 	if (sr->flags & ~SENDMSG_FLAGS)
403 		return -EINVAL;
404 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
405 		/* registered buffer send only supported for plain IORING_OP_SEND */
406 		if (req->opcode != IORING_OP_SEND ||
407 		    (req->flags & REQ_F_BUFFER_SELECT) ||
408 		    (sr->flags & (IORING_RECVSEND_BUNDLE|IORING_SEND_VECTORIZED)))
409 			return -EINVAL;
410 		req->buf_index = READ_ONCE(sqe->buf_index);
411 	}
412 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
413 	if (sr->msg_flags & MSG_DONTWAIT)
414 		req->flags |= REQ_F_NOWAIT;
415 	if (req->flags & REQ_F_BUFFER_SELECT)
416 		sr->buf_group = req->buf_index;
417 	sr->mshot_total_len = sr->mshot_len = 0;
418 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
419 		if (req->opcode == IORING_OP_SENDMSG)
420 			return -EINVAL;
421 		sr->msg_flags |= MSG_WAITALL;
422 		req->flags |= REQ_F_MULTISHOT;
423 	}
424 
425 	if (io_is_compat(req->ctx))
426 		sr->msg_flags |= MSG_CMSG_COMPAT;
427 
428 	if (unlikely(!io_msg_alloc_async(req)))
429 		return -ENOMEM;
430 	if (req->opcode != IORING_OP_SENDMSG)
431 		return io_send_setup(req, sqe);
432 	if (unlikely(sqe->addr2 || sqe->file_index))
433 		return -EINVAL;
434 	return io_sendmsg_setup(req, sqe);
435 }
436 
437 static void io_req_msg_cleanup(struct io_kiocb *req,
438 			       unsigned int issue_flags)
439 {
440 	io_netmsg_recycle(req, issue_flags);
441 }
442 
443 /*
444  * For bundle completions, we need to figure out how many segments we consumed.
445  * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
446  * could be using an ITER_IOVEC. If the latter, then if we consumed all of
447  * the segments, then it's a trivial questiont o answer. If we have residual
448  * data in the iter, then loop the segments to figure out how much we
449  * transferred.
450  */
451 static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
452 {
453 	struct iovec *iov;
454 	int nbufs;
455 
456 	/* no data is always zero segments, and a ubuf is always 1 segment */
457 	if (ret <= 0)
458 		return 0;
459 	if (iter_is_ubuf(&kmsg->msg.msg_iter))
460 		return 1;
461 
462 	iov = kmsg->vec.iovec;
463 	if (!iov)
464 		iov = &kmsg->fast_iov;
465 
466 	/* if all data was transferred, it's basic pointer math */
467 	if (!iov_iter_count(&kmsg->msg.msg_iter))
468 		return iter_iov(&kmsg->msg.msg_iter) - iov;
469 
470 	/* short transfer, count segments */
471 	nbufs = 0;
472 	do {
473 		int this_len = min_t(int, iov[nbufs].iov_len, ret);
474 
475 		nbufs++;
476 		ret -= this_len;
477 	} while (ret);
478 
479 	return nbufs;
480 }
481 
482 static int io_net_kbuf_recyle(struct io_kiocb *req, struct io_buffer_list *bl,
483 			      struct io_async_msghdr *kmsg, int len)
484 {
485 	req->flags |= REQ_F_BL_NO_RECYCLE;
486 	if (req->flags & REQ_F_BUFFERS_COMMIT)
487 		io_kbuf_commit(req, bl, len, io_bundle_nbufs(kmsg, len));
488 	return IOU_RETRY;
489 }
490 
491 static inline bool io_send_finish(struct io_kiocb *req,
492 				  struct io_async_msghdr *kmsg,
493 				  struct io_br_sel *sel)
494 {
495 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
496 	bool bundle_finished = sel->val <= 0;
497 	unsigned int cflags;
498 
499 	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
500 		cflags = io_put_kbuf(req, sel->val, sel->buf_list);
501 		goto finish;
502 	}
503 
504 	cflags = io_put_kbufs(req, sel->val, sel->buf_list, io_bundle_nbufs(kmsg, sel->val));
505 
506 	/*
507 	 * Don't start new bundles if the buffer list is empty, or if the
508 	 * current operation needed to go through polling to complete.
509 	 */
510 	if (bundle_finished || req->flags & (REQ_F_BL_EMPTY | REQ_F_POLLED))
511 		goto finish;
512 
513 	/*
514 	 * Fill CQE for this receive and see if we should keep trying to
515 	 * receive from this socket.
516 	 */
517 	if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
518 		io_mshot_prep_retry(req, kmsg);
519 		return false;
520 	}
521 
522 	/* Otherwise stop bundle and use the current result. */
523 finish:
524 	io_req_set_res(req, sel->val, cflags);
525 	sel->val = IOU_COMPLETE;
526 	return true;
527 }
528 
529 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
530 {
531 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
532 	struct io_async_msghdr *kmsg = req->async_data;
533 	struct socket *sock;
534 	unsigned flags;
535 	int min_ret = 0;
536 	int ret;
537 
538 	sock = sock_from_file(req->file);
539 	if (unlikely(!sock))
540 		return -ENOTSOCK;
541 
542 	if (!(req->flags & REQ_F_POLLED) &&
543 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
544 		return -EAGAIN;
545 
546 	flags = sr->msg_flags;
547 	if (issue_flags & IO_URING_F_NONBLOCK)
548 		flags |= MSG_DONTWAIT;
549 	if (flags & MSG_WAITALL)
550 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
551 
552 	kmsg->msg.msg_control_user = sr->msg_control;
553 
554 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
555 
556 	if (ret < min_ret) {
557 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
558 			return -EAGAIN;
559 		if (ret > 0 && io_net_retry(sock, flags)) {
560 			kmsg->msg.msg_controllen = 0;
561 			kmsg->msg.msg_control = NULL;
562 			sr->done_io += ret;
563 			return -EAGAIN;
564 		}
565 		if (ret == -ERESTARTSYS)
566 			ret = -EINTR;
567 		req_set_fail(req);
568 	}
569 	io_req_msg_cleanup(req, issue_flags);
570 	if (ret >= 0)
571 		ret += sr->done_io;
572 	else if (sr->done_io)
573 		ret = sr->done_io;
574 	io_req_set_res(req, ret, 0);
575 	return IOU_COMPLETE;
576 }
577 
578 static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags,
579 				 struct io_br_sel *sel, struct io_async_msghdr *kmsg)
580 {
581 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
582 	struct buf_sel_arg arg = {
583 		.iovs = &kmsg->fast_iov,
584 		.max_len = min_not_zero(sr->len, INT_MAX),
585 		.nr_iovs = 1,
586 		.buf_group = sr->buf_group,
587 	};
588 	int ret;
589 
590 	if (kmsg->vec.iovec) {
591 		arg.nr_iovs = kmsg->vec.nr;
592 		arg.iovs = kmsg->vec.iovec;
593 		arg.mode = KBUF_MODE_FREE;
594 	}
595 
596 	if (!(sr->flags & IORING_RECVSEND_BUNDLE))
597 		arg.nr_iovs = 1;
598 	else
599 		arg.mode |= KBUF_MODE_EXPAND;
600 
601 	ret = io_buffers_select(req, &arg, sel, issue_flags);
602 	if (unlikely(ret < 0))
603 		return ret;
604 
605 	if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
606 		kmsg->vec.nr = ret;
607 		kmsg->vec.iovec = arg.iovs;
608 		req->flags |= REQ_F_NEED_CLEANUP;
609 	}
610 	sr->len = arg.out_len;
611 
612 	if (ret == 1) {
613 		sr->buf = arg.iovs[0].iov_base;
614 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
615 					&kmsg->msg.msg_iter);
616 		if (unlikely(ret))
617 			return ret;
618 	} else {
619 		iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE,
620 				arg.iovs, ret, arg.out_len);
621 	}
622 
623 	return 0;
624 }
625 
626 int io_send(struct io_kiocb *req, unsigned int issue_flags)
627 {
628 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
629 	struct io_async_msghdr *kmsg = req->async_data;
630 	struct io_br_sel sel = { };
631 	struct socket *sock;
632 	unsigned flags;
633 	int min_ret = 0;
634 	int ret;
635 
636 	sock = sock_from_file(req->file);
637 	if (unlikely(!sock))
638 		return -ENOTSOCK;
639 
640 	if (!(req->flags & REQ_F_POLLED) &&
641 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
642 		return -EAGAIN;
643 
644 	if (req->flags & REQ_F_IMPORT_BUFFER) {
645 		ret = io_import_reg_buf(req, &kmsg->msg.msg_iter,
646 					(u64)(uintptr_t)sr->buf, sr->len,
647 					ITER_SOURCE, issue_flags);
648 		if (unlikely(ret))
649 			return ret;
650 		req->flags &= ~REQ_F_IMPORT_BUFFER;
651 	}
652 
653 	flags = sr->msg_flags;
654 	if (issue_flags & IO_URING_F_NONBLOCK)
655 		flags |= MSG_DONTWAIT;
656 
657 retry_bundle:
658 	sel.buf_list = NULL;
659 	if (io_do_buffer_select(req)) {
660 		ret = io_send_select_buffer(req, issue_flags, &sel, kmsg);
661 		if (ret)
662 			return ret;
663 	}
664 
665 	/*
666 	 * If MSG_WAITALL is set, or this is a bundle send, then we need
667 	 * the full amount. If just bundle is set, if we do a short send
668 	 * then we complete the bundle sequence rather than continue on.
669 	 */
670 	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
671 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
672 
673 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
674 	kmsg->msg.msg_flags = flags;
675 	ret = sock_sendmsg(sock, &kmsg->msg);
676 	if (ret < min_ret) {
677 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
678 			return -EAGAIN;
679 
680 		if (ret > 0 && io_net_retry(sock, flags)) {
681 			sr->len -= ret;
682 			sr->buf += ret;
683 			sr->done_io += ret;
684 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
685 		}
686 		if (ret == -ERESTARTSYS)
687 			ret = -EINTR;
688 		req_set_fail(req);
689 	}
690 	if (ret >= 0)
691 		ret += sr->done_io;
692 	else if (sr->done_io)
693 		ret = sr->done_io;
694 
695 	sel.val = ret;
696 	if (!io_send_finish(req, kmsg, &sel))
697 		goto retry_bundle;
698 
699 	io_req_msg_cleanup(req, issue_flags);
700 	return sel.val;
701 }
702 
703 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
704 				 struct io_async_msghdr *iomsg,
705 				 int namelen, size_t controllen)
706 {
707 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
708 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
709 		int hdr;
710 
711 		if (unlikely(namelen < 0))
712 			return -EOVERFLOW;
713 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
714 					namelen, &hdr))
715 			return -EOVERFLOW;
716 		if (check_add_overflow(hdr, controllen, &hdr))
717 			return -EOVERFLOW;
718 
719 		iomsg->namelen = namelen;
720 		iomsg->controllen = controllen;
721 		return 0;
722 	}
723 
724 	return 0;
725 }
726 
727 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
728 			       struct io_async_msghdr *iomsg)
729 {
730 	struct user_msghdr msg;
731 	int ret;
732 
733 	ret = io_msg_copy_hdr(req, iomsg, &msg, &iomsg->uaddr);
734 	if (unlikely(ret))
735 		return ret;
736 
737 	if (!(req->flags & REQ_F_BUFFER_SELECT)) {
738 		ret = io_net_import_vec(req, iomsg, msg.msg_iov, msg.msg_iovlen,
739 					ITER_DEST);
740 		if (unlikely(ret))
741 			return ret;
742 	}
743 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
744 					msg.msg_controllen);
745 }
746 
747 static int io_recvmsg_prep_setup(struct io_kiocb *req)
748 {
749 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
750 	struct io_async_msghdr *kmsg;
751 
752 	kmsg = io_msg_alloc_async(req);
753 	if (unlikely(!kmsg))
754 		return -ENOMEM;
755 
756 	if (req->opcode == IORING_OP_RECV) {
757 		kmsg->msg.msg_name = NULL;
758 		kmsg->msg.msg_namelen = 0;
759 		kmsg->msg.msg_inq = 0;
760 		kmsg->msg.msg_control = NULL;
761 		kmsg->msg.msg_get_inq = 1;
762 		kmsg->msg.msg_controllen = 0;
763 		kmsg->msg.msg_ubuf = NULL;
764 
765 		if (req->flags & REQ_F_BUFFER_SELECT)
766 			return 0;
767 		if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
768 			req->flags |= REQ_F_IMPORT_BUFFER;
769 			return 0;
770 		}
771 		return import_ubuf(ITER_DEST, sr->buf, sr->len,
772 				   &kmsg->msg.msg_iter);
773 	}
774 
775 	return io_recvmsg_copy_hdr(req, kmsg);
776 }
777 
778 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
779 			IORING_RECVSEND_BUNDLE | IORING_RECVSEND_FIXED_BUF)
780 
781 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
782 {
783 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
784 
785 	sr->done_io = 0;
786 
787 	if (unlikely(sqe->addr2))
788 		return -EINVAL;
789 
790 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
791 	sr->len = READ_ONCE(sqe->len);
792 	if (unlikely(sr->len < 0))
793 		return -EINVAL;
794 	sr->flags = READ_ONCE(sqe->ioprio);
795 	if (sr->flags & ~RECVMSG_FLAGS)
796 		return -EINVAL;
797 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
798 		/* registered buffer recv only for plain IORING_OP_RECV */
799 		if (req->opcode != IORING_OP_RECV ||
800 		    (req->flags & REQ_F_BUFFER_SELECT) ||
801 		    (sr->flags & (IORING_RECV_MULTISHOT | IORING_RECVSEND_BUNDLE)))
802 			return -EINVAL;
803 		req->buf_index = READ_ONCE(sqe->buf_index);
804 	}
805 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
806 	if (sr->msg_flags & MSG_DONTWAIT)
807 		req->flags |= REQ_F_NOWAIT;
808 	if (sr->msg_flags & MSG_ERRQUEUE)
809 		req->flags |= REQ_F_CLEAR_POLLIN;
810 	if (req->flags & REQ_F_BUFFER_SELECT)
811 		sr->buf_group = req->buf_index;
812 	sr->mshot_total_len = sr->mshot_len = 0;
813 	if (sr->flags & IORING_RECV_MULTISHOT) {
814 		if (!(req->flags & REQ_F_BUFFER_SELECT))
815 			return -EINVAL;
816 		if (sr->msg_flags & MSG_WAITALL)
817 			return -EINVAL;
818 		if (req->opcode == IORING_OP_RECV) {
819 			sr->mshot_len = sr->len;
820 			sr->mshot_total_len = READ_ONCE(sqe->optlen);
821 			if (sr->mshot_total_len)
822 				sr->flags |= IORING_RECV_MSHOT_LIM;
823 		} else if (sqe->optlen) {
824 			return -EINVAL;
825 		}
826 		req->flags |= REQ_F_APOLL_MULTISHOT;
827 	} else if (sqe->optlen) {
828 		return -EINVAL;
829 	}
830 
831 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
832 		if (req->opcode == IORING_OP_RECVMSG)
833 			return -EINVAL;
834 	}
835 
836 	if (io_is_compat(req->ctx))
837 		sr->msg_flags |= MSG_CMSG_COMPAT;
838 
839 	sr->nr_multishot_loops = 0;
840 	return io_recvmsg_prep_setup(req);
841 }
842 
843 /* bits to clear in old and inherit in new cflags on bundle retry */
844 #define CQE_F_MASK	(IORING_CQE_F_SOCK_NONEMPTY|IORING_CQE_F_MORE|\
845 			 IORING_CQE_F_BUF_MORE)
846 
847 /*
848  * Finishes io_recv and io_recvmsg.
849  *
850  * Returns true if it is actually finished, or false if it should run
851  * again (for multishot).
852  */
853 static inline bool io_recv_finish(struct io_kiocb *req,
854 				  struct io_async_msghdr *kmsg,
855 				  struct io_br_sel *sel, bool mshot_finished,
856 				  unsigned issue_flags, int consumed)
857 {
858 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
859 	unsigned int cflags = 0;
860 
861 	if (kmsg->msg.msg_inq > 0)
862 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
863 
864 	if (sel->val > 0 && sr->flags & IORING_RECV_MSHOT_LIM) {
865 		/*
866 		 * If sr->len hits zero, the limit has been reached. Mark
867 		 * mshot as finished, and flag MSHOT_DONE as well to prevent
868 		 * a potential bundle from being retried.
869 		 */
870 		sr->mshot_total_len -= min_t(int, sel->val, sr->mshot_total_len);
871 		if (!sr->mshot_total_len) {
872 			sr->flags |= IORING_RECV_MSHOT_DONE;
873 			mshot_finished = true;
874 		}
875 	}
876 
877 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
878 		size_t this_ret = sel->val - sr->done_io;
879 
880 		cflags |= io_put_kbufs(req, consumed, sel->buf_list, io_bundle_nbufs(kmsg, consumed));
881 		if (sr->flags & IORING_RECV_RETRY)
882 			cflags = req->cqe.flags | (cflags & CQE_F_MASK);
883 		if (sr->mshot_len && sel->val >= sr->mshot_len)
884 			sr->flags |= IORING_RECV_MSHOT_CAP;
885 		/* bundle with no more immediate buffers, we're done */
886 		if (req->flags & REQ_F_BL_EMPTY)
887 			goto finish;
888 		/*
889 		 * If more is available AND it was a full transfer, retry and
890 		 * append to this one
891 		 */
892 		if (!(sr->flags & IORING_RECV_NO_RETRY) &&
893 		    kmsg->msg.msg_inq > 1 && this_ret > 0 &&
894 		    !iov_iter_count(&kmsg->msg.msg_iter)) {
895 			req->cqe.flags = cflags & ~CQE_F_MASK;
896 			sr->len = kmsg->msg.msg_inq;
897 			sr->done_io += this_ret;
898 			sr->flags |= IORING_RECV_RETRY;
899 			return false;
900 		}
901 	} else {
902 		cflags |= io_put_kbuf(req, consumed, sel->buf_list);
903 	}
904 
905 	/*
906 	 * Fill CQE for this receive and see if we should keep trying to
907 	 * receive from this socket.
908 	 */
909 	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
910 	    io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
911 		sel->val = IOU_RETRY;
912 		io_mshot_prep_retry(req, kmsg);
913 		/* Known not-empty or unknown state, retry */
914 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
915 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY &&
916 			    !(sr->flags & IORING_RECV_MSHOT_CAP)) {
917 				return false;
918 			}
919 			/* mshot retries exceeded, force a requeue */
920 			sr->nr_multishot_loops = 0;
921 			sr->flags &= ~IORING_RECV_MSHOT_CAP;
922 			if (issue_flags & IO_URING_F_MULTISHOT)
923 				sel->val = IOU_REQUEUE;
924 		}
925 		return true;
926 	}
927 
928 	/* Finish the request / stop multishot. */
929 finish:
930 	io_req_set_res(req, sel->val, cflags);
931 	sel->val = IOU_COMPLETE;
932 	io_req_msg_cleanup(req, issue_flags);
933 	return true;
934 }
935 
936 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
937 				     struct io_sr_msg *sr, void __user **buf,
938 				     size_t *len)
939 {
940 	unsigned long ubuf = (unsigned long) *buf;
941 	unsigned long hdr;
942 
943 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
944 		kmsg->controllen;
945 	if (*len < hdr)
946 		return -EFAULT;
947 
948 	if (kmsg->controllen) {
949 		unsigned long control = ubuf + hdr - kmsg->controllen;
950 
951 		kmsg->msg.msg_control_user = (void __user *) control;
952 		kmsg->msg.msg_controllen = kmsg->controllen;
953 	}
954 
955 	sr->buf = *buf; /* stash for later copy */
956 	*buf = (void __user *) (ubuf + hdr);
957 	kmsg->payloadlen = *len = *len - hdr;
958 	return 0;
959 }
960 
961 struct io_recvmsg_multishot_hdr {
962 	struct io_uring_recvmsg_out msg;
963 	struct sockaddr_storage addr;
964 };
965 
966 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
967 				struct io_async_msghdr *kmsg,
968 				unsigned int flags, bool *finished)
969 {
970 	int err;
971 	int copy_len;
972 	struct io_recvmsg_multishot_hdr hdr;
973 
974 	if (kmsg->namelen)
975 		kmsg->msg.msg_name = &hdr.addr;
976 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
977 	kmsg->msg.msg_namelen = 0;
978 
979 	if (sock->file->f_flags & O_NONBLOCK)
980 		flags |= MSG_DONTWAIT;
981 
982 	err = sock_recvmsg(sock, &kmsg->msg, flags);
983 	*finished = err <= 0;
984 	if (err < 0)
985 		return err;
986 
987 	hdr.msg = (struct io_uring_recvmsg_out) {
988 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
989 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
990 	};
991 
992 	hdr.msg.payloadlen = err;
993 	if (err > kmsg->payloadlen)
994 		err = kmsg->payloadlen;
995 
996 	copy_len = sizeof(struct io_uring_recvmsg_out);
997 	if (kmsg->msg.msg_namelen > kmsg->namelen)
998 		copy_len += kmsg->namelen;
999 	else
1000 		copy_len += kmsg->msg.msg_namelen;
1001 
1002 	/*
1003 	 *      "fromlen shall refer to the value before truncation.."
1004 	 *                      1003.1g
1005 	 */
1006 	hdr.msg.namelen = kmsg->msg.msg_namelen;
1007 
1008 	/* ensure that there is no gap between hdr and sockaddr_storage */
1009 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
1010 		     sizeof(struct io_uring_recvmsg_out));
1011 	if (copy_to_user(io->buf, &hdr, copy_len)) {
1012 		*finished = true;
1013 		return -EFAULT;
1014 	}
1015 
1016 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
1017 			kmsg->controllen + err;
1018 }
1019 
1020 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
1021 {
1022 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1023 	struct io_async_msghdr *kmsg = req->async_data;
1024 	struct io_br_sel sel = { };
1025 	struct socket *sock;
1026 	unsigned flags;
1027 	int ret, min_ret = 0;
1028 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1029 	bool mshot_finished = true;
1030 	int consumed = 0;
1031 	size_t len;
1032 
1033 	sock = sock_from_file(req->file);
1034 	if (unlikely(!sock))
1035 		return -ENOTSOCK;
1036 
1037 	if (!(req->flags & REQ_F_POLLED) &&
1038 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1039 		return -EAGAIN;
1040 
1041 	flags = sr->msg_flags;
1042 	if (force_nonblock)
1043 		flags |= MSG_DONTWAIT;
1044 
1045 retry_multishot:
1046 	sel.buf_list = NULL;
1047 	len = sr->len;
1048 	if (io_do_buffer_select(req)) {
1049 		sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
1050 		if (!sel.addr)
1051 			return -ENOBUFS;
1052 
1053 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
1054 			ret = io_recvmsg_prep_multishot(kmsg, sr, &sel.addr, &len);
1055 			if (ret) {
1056 				io_kbuf_recycle(req, sel.buf_list, issue_flags);
1057 				return ret;
1058 			}
1059 		}
1060 
1061 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, sel.addr, len);
1062 	}
1063 
1064 	kmsg->msg.msg_get_inq = 1;
1065 	kmsg->msg.msg_inq = -1;
1066 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
1067 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
1068 					   &mshot_finished);
1069 		consumed = ret;
1070 	} else {
1071 		/* disable partial retry for recvmsg with cmsg attached */
1072 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
1073 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1074 
1075 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
1076 					 kmsg->uaddr, flags);
1077 		/*
1078 		 * With MSG_TRUNC, the net layer will return the full size of
1079 		 * the packet, even if we only filled part of it in the buffers.
1080 		 * Adjust the returned size to consume only the real part of the
1081 		 * buffer.
1082 		 */
1083 		consumed = ret;
1084 		if (ret > 0)
1085 			consumed = min_t(size_t, ret, len);
1086 	}
1087 
1088 	if (ret < min_ret) {
1089 		if (ret == -EAGAIN && force_nonblock) {
1090 			io_kbuf_recycle(req, sel.buf_list, issue_flags);
1091 			return IOU_RETRY;
1092 		}
1093 		if (ret > 0 && io_net_retry(sock, flags)) {
1094 			sr->done_io += ret;
1095 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
1096 		}
1097 		if (ret == -ERESTARTSYS)
1098 			ret = -EINTR;
1099 		req_set_fail(req);
1100 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1101 		req_set_fail(req);
1102 	}
1103 
1104 	if (ret > 0)
1105 		ret += sr->done_io;
1106 	else if (sr->done_io)
1107 		ret = sr->done_io;
1108 	else
1109 		io_kbuf_recycle(req, sel.buf_list, issue_flags);
1110 
1111 	sel.val = ret;
1112 	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags, consumed))
1113 		goto retry_multishot;
1114 
1115 	return sel.val;
1116 }
1117 
1118 static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
1119 			      struct io_br_sel *sel, unsigned int issue_flags)
1120 {
1121 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1122 	size_t len;
1123 	int ret;
1124 
1125 	/*
1126 	 * If the ring isn't locked, then don't use the peek interface
1127 	 * to grab multiple buffers as we will lock/unlock between
1128 	 * this selection and posting the buffers.
1129 	 */
1130 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
1131 	    sr->flags & IORING_RECVSEND_BUNDLE) {
1132 		struct buf_sel_arg arg = {
1133 			.iovs = &kmsg->fast_iov,
1134 			.nr_iovs = 1,
1135 			.mode = KBUF_MODE_EXPAND,
1136 			.buf_group = sr->buf_group,
1137 		};
1138 
1139 		if (kmsg->vec.iovec) {
1140 			arg.nr_iovs = kmsg->vec.nr;
1141 			arg.iovs = kmsg->vec.iovec;
1142 			arg.mode |= KBUF_MODE_FREE;
1143 		}
1144 
1145 		if (sel->val)
1146 			arg.max_len = sel->val;
1147 		else if (kmsg->msg.msg_inq > 1)
1148 			arg.max_len = min_not_zero(sel->val, (ssize_t) kmsg->msg.msg_inq);
1149 
1150 		/* if mshot limited, ensure we don't go over */
1151 		if (sr->flags & IORING_RECV_MSHOT_LIM)
1152 			arg.max_len = min_not_zero(arg.max_len, sr->mshot_total_len);
1153 		ret = io_buffers_peek(req, &arg, sel);
1154 		if (unlikely(ret < 0))
1155 			return ret;
1156 
1157 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
1158 			kmsg->vec.nr = ret;
1159 			kmsg->vec.iovec = arg.iovs;
1160 			req->flags |= REQ_F_NEED_CLEANUP;
1161 		}
1162 		if (arg.partial_map)
1163 			sr->flags |= IORING_RECV_PARTIAL_MAP;
1164 
1165 		/* special case 1 vec, can be a fast path */
1166 		if (ret == 1) {
1167 			sr->buf = arg.iovs[0].iov_base;
1168 			len = sr->len = arg.iovs[0].iov_len;
1169 			goto map_ubuf;
1170 		}
1171 		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
1172 			      arg.out_len);
1173 		len = arg.out_len;
1174 	} else {
1175 		len = sel->val;
1176 
1177 		*sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
1178 		if (!sel->addr)
1179 			return -ENOBUFS;
1180 		sr->buf = sel->addr;
1181 		sr->len = len;
1182 map_ubuf:
1183 		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
1184 				  &kmsg->msg.msg_iter);
1185 		if (unlikely(ret))
1186 			return ret;
1187 	}
1188 
1189 	return len;
1190 }
1191 
1192 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
1193 {
1194 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1195 	struct io_async_msghdr *kmsg = req->async_data;
1196 	struct io_br_sel sel;
1197 	struct socket *sock;
1198 	unsigned flags;
1199 	int ret, min_ret = 0, consumed = 0;
1200 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1201 	bool mshot_finished;
1202 	size_t len = 0;
1203 
1204 	sock = sock_from_file(req->file);
1205 	if (unlikely(!sock))
1206 		return -ENOTSOCK;
1207 
1208 	if (!(req->flags & REQ_F_POLLED) &&
1209 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1210 		return -EAGAIN;
1211 
1212 	flags = sr->msg_flags;
1213 	if (force_nonblock)
1214 		flags |= MSG_DONTWAIT;
1215 
1216 	if (req->flags & REQ_F_IMPORT_BUFFER) {
1217 		ret = io_import_reg_buf(req, &kmsg->msg.msg_iter,
1218 					(u64)(uintptr_t)sr->buf, sr->len,
1219 					ITER_DEST, issue_flags);
1220 		if (unlikely(ret)) {
1221 			kmsg->msg.msg_inq = -1;
1222 			sel.buf_list = NULL;
1223 			goto out_free;
1224 		}
1225 		req->flags &= ~REQ_F_IMPORT_BUFFER;
1226 	}
1227 
1228 retry_multishot:
1229 	sel.buf_list = NULL;
1230 	len = sr->len;
1231 	if (io_do_buffer_select(req)) {
1232 		sel.val = sr->len;
1233 		ret = io_recv_buf_select(req, kmsg, &sel, issue_flags);
1234 		if (unlikely(ret < 0)) {
1235 			kmsg->msg.msg_inq = -1;
1236 			goto out_free;
1237 		}
1238 		len = ret;
1239 		sr->buf = NULL;
1240 	}
1241 
1242 	kmsg->msg.msg_flags = 0;
1243 	kmsg->msg.msg_inq = -1;
1244 
1245 	if (flags & MSG_WAITALL)
1246 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1247 
1248 	ret = sock_recvmsg(sock, &kmsg->msg, flags);
1249 	if (ret < min_ret) {
1250 		if (ret == -EAGAIN && force_nonblock) {
1251 			io_kbuf_recycle(req, sel.buf_list, issue_flags);
1252 			return IOU_RETRY;
1253 		}
1254 		if (ret > 0 && io_net_retry(sock, flags)) {
1255 			sr->len -= ret;
1256 			sr->buf += ret;
1257 			sr->done_io += ret;
1258 			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
1259 		}
1260 		if (ret == -ERESTARTSYS)
1261 			ret = -EINTR;
1262 		req_set_fail(req);
1263 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1264 out_free:
1265 		req_set_fail(req);
1266 	}
1267 
1268 	mshot_finished = ret <= 0;
1269 
1270 	/*
1271 	 * With MSG_TRUNC, the net layer will return the full size of
1272 	 * the packet, even if we only filled part of it in the buffers.
1273 	 * Adjust the returned size to consume only the real part of the
1274 	 * buffer.
1275 	 */
1276 	consumed = ret;
1277 	if (ret > 0)
1278 		consumed = min_t(size_t, ret, len);
1279 
1280 	if (ret > 0)
1281 		ret += sr->done_io;
1282 	else if (sr->done_io)
1283 		ret = sr->done_io;
1284 	else
1285 		io_kbuf_recycle(req, sel.buf_list, issue_flags);
1286 
1287 	sel.val = ret;
1288 	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags, consumed))
1289 		goto retry_multishot;
1290 
1291 	return sel.val;
1292 }
1293 
1294 int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1295 {
1296 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1297 	unsigned ifq_idx;
1298 
1299 	if (unlikely(sqe->addr2 || sqe->addr || sqe->addr3))
1300 		return -EINVAL;
1301 
1302 	ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx);
1303 	zc->ifq = xa_load(&req->ctx->zcrx_ctxs, ifq_idx);
1304 	if (!zc->ifq)
1305 		return -EINVAL;
1306 
1307 	zc->len = READ_ONCE(sqe->len);
1308 	zc->flags = READ_ONCE(sqe->ioprio);
1309 	if (READ_ONCE(sqe->msg_flags))
1310 		return -EINVAL;
1311 	if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT))
1312 		return -EINVAL;
1313 	/* multishot required */
1314 	if (!(zc->flags & IORING_RECV_MULTISHOT))
1315 		return -EINVAL;
1316 	/* All data completions are posted as aux CQEs. */
1317 	req->flags |= REQ_F_APOLL_MULTISHOT;
1318 
1319 	return 0;
1320 }
1321 
1322 int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
1323 {
1324 	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
1325 	struct socket *sock;
1326 	unsigned int len;
1327 	int ret;
1328 
1329 	sock = sock_from_file(req->file);
1330 	if (unlikely(!sock))
1331 		return -ENOTSOCK;
1332 
1333 	if (!(req->flags & REQ_F_POLLED) &&
1334 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1335 		return -EAGAIN;
1336 
1337 	len = zc->len;
1338 	ret = io_zcrx_recv(req, zc->ifq, sock, 0, issue_flags, &zc->len);
1339 	if (len && zc->len == 0) {
1340 		io_req_set_res(req, 0, 0);
1341 
1342 		return IOU_COMPLETE;
1343 	}
1344 	if (unlikely(ret <= 0) && ret != -EAGAIN) {
1345 		if (ret == -ERESTARTSYS)
1346 			ret = -EINTR;
1347 		if (ret == IOU_REQUEUE)
1348 			return IOU_REQUEUE;
1349 
1350 		req_set_fail(req);
1351 		io_req_set_res(req, ret, 0);
1352 		return IOU_COMPLETE;
1353 	}
1354 	return IOU_RETRY;
1355 }
1356 
1357 void io_send_zc_cleanup(struct io_kiocb *req)
1358 {
1359 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1360 	struct io_async_msghdr *io = req->async_data;
1361 
1362 	if (req_has_async_data(req))
1363 		io_netmsg_iovec_free(io);
1364 	if (zc->notif) {
1365 		io_notif_flush(zc->notif);
1366 		zc->notif = NULL;
1367 	}
1368 }
1369 
1370 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1371 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE | \
1372 				IORING_SEND_VECTORIZED)
1373 
1374 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1375 {
1376 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1377 	struct io_ring_ctx *ctx = req->ctx;
1378 	struct io_async_msghdr *iomsg;
1379 	struct io_kiocb *notif;
1380 	u64 user_data;
1381 	int ret;
1382 
1383 	zc->done_io = 0;
1384 
1385 	if (unlikely(READ_ONCE(sqe->__pad2[0])))
1386 		return -EINVAL;
1387 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1388 	if (req->flags & REQ_F_CQE_SKIP)
1389 		return -EINVAL;
1390 
1391 	notif = zc->notif = io_alloc_notif(ctx);
1392 	if (!notif)
1393 		return -ENOMEM;
1394 	user_data = READ_ONCE(sqe->addr3);
1395 	if (!user_data)
1396 		user_data = req->cqe.user_data;
1397 
1398 	notif->cqe.user_data = user_data;
1399 	notif->cqe.res = 0;
1400 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1401 	req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY;
1402 
1403 	zc->flags = READ_ONCE(sqe->ioprio);
1404 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1405 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1406 			return -EINVAL;
1407 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1408 			struct io_notif_data *nd = io_notif_to_data(notif);
1409 
1410 			nd->zc_report = true;
1411 			nd->zc_used = false;
1412 			nd->zc_copied = false;
1413 		}
1414 	}
1415 
1416 	zc->len = READ_ONCE(sqe->len);
1417 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
1418 	req->buf_index = READ_ONCE(sqe->buf_index);
1419 	if (zc->msg_flags & MSG_DONTWAIT)
1420 		req->flags |= REQ_F_NOWAIT;
1421 
1422 	if (io_is_compat(ctx))
1423 		zc->msg_flags |= MSG_CMSG_COMPAT;
1424 
1425 	iomsg = io_msg_alloc_async(req);
1426 	if (unlikely(!iomsg))
1427 		return -ENOMEM;
1428 
1429 	if (req->opcode == IORING_OP_SEND_ZC) {
1430 		ret = io_send_setup(req, sqe);
1431 	} else {
1432 		if (unlikely(sqe->addr2 || sqe->file_index))
1433 			return -EINVAL;
1434 		ret = io_sendmsg_setup(req, sqe);
1435 	}
1436 	if (unlikely(ret))
1437 		return ret;
1438 
1439 	if (!(zc->flags & IORING_RECVSEND_FIXED_BUF)) {
1440 		iomsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1441 		return io_notif_account_mem(zc->notif, iomsg->msg.msg_iter.count);
1442 	}
1443 	iomsg->msg.sg_from_iter = io_sg_from_iter;
1444 	return 0;
1445 }
1446 
1447 static int io_sg_from_iter_iovec(struct sk_buff *skb,
1448 				 struct iov_iter *from, size_t length)
1449 {
1450 	skb_zcopy_downgrade_managed(skb);
1451 	return zerocopy_fill_skb_from_iter(skb, from, length);
1452 }
1453 
1454 static int io_sg_from_iter(struct sk_buff *skb,
1455 			   struct iov_iter *from, size_t length)
1456 {
1457 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1458 	int frag = shinfo->nr_frags;
1459 	int ret = 0;
1460 	struct bvec_iter bi;
1461 	ssize_t copied = 0;
1462 	unsigned long truesize = 0;
1463 
1464 	if (!frag)
1465 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1466 	else if (unlikely(!skb_zcopy_managed(skb)))
1467 		return zerocopy_fill_skb_from_iter(skb, from, length);
1468 
1469 	bi.bi_size = min(from->count, length);
1470 	bi.bi_offset = from->iov_offset;
1471 	bi.bi_idx = 0;
1472 
1473 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1474 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1475 
1476 		copied += v.bv_len;
1477 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1478 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1479 					   v.bv_offset, v.bv_len);
1480 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1481 	}
1482 	if (bi.bi_size)
1483 		ret = -EMSGSIZE;
1484 
1485 	shinfo->nr_frags = frag;
1486 	from->bvec += bi.bi_idx;
1487 	from->nr_segs -= bi.bi_idx;
1488 	from->count -= copied;
1489 	from->iov_offset = bi.bi_offset;
1490 
1491 	skb->data_len += copied;
1492 	skb->len += copied;
1493 	skb->truesize += truesize;
1494 	return ret;
1495 }
1496 
1497 static int io_send_zc_import(struct io_kiocb *req,
1498 			     struct io_async_msghdr *kmsg,
1499 			     unsigned int issue_flags)
1500 {
1501 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1502 	struct io_kiocb *notif = sr->notif;
1503 	int ret;
1504 
1505 	WARN_ON_ONCE(!(sr->flags & IORING_RECVSEND_FIXED_BUF));
1506 
1507 	notif->buf_index = req->buf_index;
1508 
1509 	if (!(sr->flags & IORING_SEND_VECTORIZED)) {
1510 		ret = io_import_reg_buf(notif, &kmsg->msg.msg_iter,
1511 					(u64)(uintptr_t)sr->buf, sr->len,
1512 					ITER_SOURCE, issue_flags);
1513 	} else {
1514 		unsigned uvec_segs = kmsg->msg.msg_iter.nr_segs;
1515 
1516 		ret = io_import_reg_vec(ITER_SOURCE, &kmsg->msg.msg_iter,
1517 					notif, &kmsg->vec, uvec_segs,
1518 					issue_flags);
1519 	}
1520 
1521 	if (unlikely(ret))
1522 		return ret;
1523 	req->flags &= ~REQ_F_IMPORT_BUFFER;
1524 	return 0;
1525 }
1526 
1527 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1528 {
1529 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1530 	struct io_async_msghdr *kmsg = req->async_data;
1531 	struct socket *sock;
1532 	unsigned msg_flags;
1533 	int ret, min_ret = 0;
1534 
1535 	sock = sock_from_file(req->file);
1536 	if (unlikely(!sock))
1537 		return -ENOTSOCK;
1538 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1539 		return -EOPNOTSUPP;
1540 	if (!(req->flags & REQ_F_POLLED) &&
1541 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1542 		return -EAGAIN;
1543 
1544 	if (req->flags & REQ_F_IMPORT_BUFFER) {
1545 		ret = io_send_zc_import(req, kmsg, issue_flags);
1546 		if (unlikely(ret))
1547 			return ret;
1548 	}
1549 
1550 	msg_flags = sr->msg_flags;
1551 	if (issue_flags & IO_URING_F_NONBLOCK)
1552 		msg_flags |= MSG_DONTWAIT;
1553 	if (msg_flags & MSG_WAITALL)
1554 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1555 
1556 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1557 
1558 	if (req->opcode == IORING_OP_SEND_ZC) {
1559 		msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1560 		kmsg->msg.msg_flags = msg_flags;
1561 		ret = sock_sendmsg(sock, &kmsg->msg);
1562 	} else {
1563 		kmsg->msg.msg_control_user = sr->msg_control;
1564 		ret = __sys_sendmsg_sock(sock, &kmsg->msg, msg_flags);
1565 	}
1566 
1567 	if (unlikely(ret < min_ret)) {
1568 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1569 			return -EAGAIN;
1570 
1571 		if (ret > 0 && io_net_retry(sock, sr->msg_flags)) {
1572 			sr->done_io += ret;
1573 			return -EAGAIN;
1574 		}
1575 		if (ret == -ERESTARTSYS)
1576 			ret = -EINTR;
1577 		req_set_fail(req);
1578 	}
1579 
1580 	if (ret >= 0)
1581 		ret += sr->done_io;
1582 	else if (sr->done_io)
1583 		ret = sr->done_io;
1584 
1585 	/*
1586 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1587 	 * flushing notif to io_send_zc_cleanup()
1588 	 */
1589 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1590 		io_notif_flush(sr->notif);
1591 		sr->notif = NULL;
1592 		io_req_msg_cleanup(req, 0);
1593 	}
1594 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1595 	return IOU_COMPLETE;
1596 }
1597 
1598 void io_sendrecv_fail(struct io_kiocb *req)
1599 {
1600 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1601 
1602 	if (sr->done_io)
1603 		req->cqe.res = sr->done_io;
1604 
1605 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1606 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1607 		req->cqe.flags |= IORING_CQE_F_MORE;
1608 }
1609 
1610 #define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
1611 			 IORING_ACCEPT_POLL_FIRST)
1612 
1613 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1614 {
1615 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1616 
1617 	if (sqe->len || sqe->buf_index)
1618 		return -EINVAL;
1619 
1620 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1621 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1622 	accept->flags = READ_ONCE(sqe->accept_flags);
1623 	accept->nofile = rlimit(RLIMIT_NOFILE);
1624 	accept->iou_flags = READ_ONCE(sqe->ioprio);
1625 	if (accept->iou_flags & ~ACCEPT_FLAGS)
1626 		return -EINVAL;
1627 
1628 	accept->file_slot = READ_ONCE(sqe->file_index);
1629 	if (accept->file_slot) {
1630 		if (accept->flags & SOCK_CLOEXEC)
1631 			return -EINVAL;
1632 		if (accept->iou_flags & IORING_ACCEPT_MULTISHOT &&
1633 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1634 			return -EINVAL;
1635 	}
1636 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1637 		return -EINVAL;
1638 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1639 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1640 	if (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
1641 		req->flags |= REQ_F_APOLL_MULTISHOT;
1642 	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
1643 		req->flags |= REQ_F_NOWAIT;
1644 	return 0;
1645 }
1646 
1647 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1648 {
1649 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1650 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1651 	bool fixed = !!accept->file_slot;
1652 	struct proto_accept_arg arg = {
1653 		.flags = force_nonblock ? O_NONBLOCK : 0,
1654 	};
1655 	struct file *file;
1656 	unsigned cflags;
1657 	int ret, fd;
1658 
1659 	if (!(req->flags & REQ_F_POLLED) &&
1660 	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
1661 		return -EAGAIN;
1662 
1663 retry:
1664 	if (!fixed) {
1665 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1666 		if (unlikely(fd < 0))
1667 			return fd;
1668 	}
1669 	arg.err = 0;
1670 	arg.is_empty = -1;
1671 	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
1672 			 accept->flags);
1673 	if (IS_ERR(file)) {
1674 		if (!fixed)
1675 			put_unused_fd(fd);
1676 		ret = PTR_ERR(file);
1677 		if (ret == -EAGAIN && force_nonblock &&
1678 		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT))
1679 			return IOU_RETRY;
1680 
1681 		if (ret == -ERESTARTSYS)
1682 			ret = -EINTR;
1683 	} else if (!fixed) {
1684 		fd_install(fd, file);
1685 		ret = fd;
1686 	} else {
1687 		ret = io_fixed_fd_install(req, issue_flags, file,
1688 						accept->file_slot);
1689 	}
1690 
1691 	cflags = 0;
1692 	if (!arg.is_empty)
1693 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
1694 
1695 	if (ret >= 0 && (req->flags & REQ_F_APOLL_MULTISHOT) &&
1696 	    io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
1697 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
1698 			goto retry;
1699 		return IOU_RETRY;
1700 	}
1701 
1702 	io_req_set_res(req, ret, cflags);
1703 	if (ret < 0)
1704 		req_set_fail(req);
1705 	return IOU_COMPLETE;
1706 }
1707 
1708 void io_socket_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
1709 {
1710 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1711 
1712 	bctx->socket.family = sock->domain;
1713 	bctx->socket.type = sock->type;
1714 	bctx->socket.protocol = sock->protocol;
1715 }
1716 
1717 void io_connect_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
1718 {
1719 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1720 	struct sockaddr_storage *ss = req->async_data;
1721 
1722 	/*
1723 	 * move_addr_to_kernel() skips the copy for addr_len == 0, so
1724 	 * iomsg->addr may hold stale data from a prior CONNECT. Bail
1725 	 * unless addr_len covers the family discriminator.
1726 	 */
1727 	if (conn->addr_len < (int)sizeof(sa_family_t))
1728 		return;
1729 
1730 	bctx->connect.family = ss->ss_family;
1731 	switch (ss->ss_family) {
1732 	case AF_INET: {
1733 		struct sockaddr_in *sin = (struct sockaddr_in *)ss;
1734 
1735 		if (conn->addr_len < (int)sizeof(*sin))
1736 			break;
1737 		bctx->connect.port = sin->sin_port;
1738 		bctx->connect.v4_addr = sin->sin_addr.s_addr;
1739 		break;
1740 	}
1741 	case AF_INET6: {
1742 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ss;
1743 
1744 		if (conn->addr_len < (int)sizeof(*sin6))
1745 			break;
1746 		bctx->connect.port = sin6->sin6_port;
1747 		memcpy(bctx->connect.v6_addr, &sin6->sin6_addr,
1748 		       sizeof(bctx->connect.v6_addr));
1749 		break;
1750 	}
1751 	default:
1752 		/* family is set; per-family fields stay zero - family-only filtering */
1753 		break;
1754 	}
1755 }
1756 
1757 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1758 {
1759 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1760 
1761 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1762 		return -EINVAL;
1763 
1764 	sock->domain = READ_ONCE(sqe->fd);
1765 	sock->type = READ_ONCE(sqe->off);
1766 	sock->protocol = READ_ONCE(sqe->len);
1767 	sock->file_slot = READ_ONCE(sqe->file_index);
1768 	sock->nofile = rlimit(RLIMIT_NOFILE);
1769 
1770 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1771 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1772 		return -EINVAL;
1773 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1774 		return -EINVAL;
1775 	return 0;
1776 }
1777 
1778 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1779 {
1780 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1781 	bool fixed = !!sock->file_slot;
1782 	struct file *file;
1783 	int ret, fd;
1784 
1785 	if (!fixed) {
1786 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1787 		if (unlikely(fd < 0))
1788 			return fd;
1789 	}
1790 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1791 	if (IS_ERR(file)) {
1792 		if (!fixed)
1793 			put_unused_fd(fd);
1794 		ret = PTR_ERR(file);
1795 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1796 			return -EAGAIN;
1797 		if (ret == -ERESTARTSYS)
1798 			ret = -EINTR;
1799 		req_set_fail(req);
1800 	} else if (!fixed) {
1801 		fd_install(fd, file);
1802 		ret = fd;
1803 	} else {
1804 		ret = io_fixed_fd_install(req, issue_flags, file,
1805 					    sock->file_slot);
1806 	}
1807 	io_req_set_res(req, ret, 0);
1808 	return IOU_COMPLETE;
1809 }
1810 
1811 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1812 {
1813 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1814 	struct sockaddr_storage *addr;
1815 
1816 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1817 		return -EINVAL;
1818 
1819 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1820 	conn->addr_len =  READ_ONCE(sqe->addr2);
1821 	conn->in_progress = conn->seen_econnaborted = false;
1822 
1823 	addr = io_uring_alloc_async_data(NULL, req);
1824 	if (unlikely(!addr))
1825 		return -ENOMEM;
1826 
1827 	return move_addr_to_kernel(conn->addr, conn->addr_len, addr);
1828 }
1829 
1830 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1831 {
1832 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1833 	struct sockaddr_storage *addr = req->async_data;
1834 	unsigned file_flags;
1835 	int ret;
1836 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1837 
1838 	if (connect->in_progress) {
1839 		struct poll_table_struct pt = { ._key = EPOLLERR };
1840 
1841 		if (vfs_poll(req->file, &pt) & EPOLLERR)
1842 			goto get_sock_err;
1843 	}
1844 
1845 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1846 
1847 	ret = __sys_connect_file(req->file, addr, connect->addr_len, file_flags);
1848 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1849 	    && force_nonblock) {
1850 		if (ret == -EINPROGRESS) {
1851 			connect->in_progress = true;
1852 		} else if (ret == -ECONNABORTED) {
1853 			if (connect->seen_econnaborted)
1854 				goto out;
1855 			connect->seen_econnaborted = true;
1856 		}
1857 		return -EAGAIN;
1858 	}
1859 	if (connect->in_progress) {
1860 		/*
1861 		 * At least bluetooth will return -EBADFD on a re-connect
1862 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1863 		 * which means the previous result is good. For both of these,
1864 		 * grab the sock_error() and use that for the completion.
1865 		 */
1866 		if (ret == -EBADFD || ret == -EISCONN) {
1867 get_sock_err:
1868 			ret = sock_error(sock_from_file(req->file)->sk);
1869 		}
1870 	}
1871 	if (ret == -ERESTARTSYS)
1872 		ret = -EINTR;
1873 out:
1874 	if (ret < 0)
1875 		req_set_fail(req);
1876 	io_req_set_res(req, ret, 0);
1877 	return IOU_COMPLETE;
1878 }
1879 
1880 /*
1881  * Check if bind request would potentially end up with filename_create(),
1882  * which in turn end up in mnt_want_write() which will grab the fs
1883  * percpu start write sem. This can trigger a lockdep warning.
1884  */
1885 static int io_bind_file_create(const struct sockaddr_storage *addr, int addr_len)
1886 {
1887 	const struct sockaddr_un *sun;
1888 
1889 	if (addr->ss_family != AF_UNIX)
1890 		return 0;
1891 	if (addr_len <= offsetof(struct sockaddr_un, sun_path))
1892 		return 0;
1893 	sun = (const struct sockaddr_un *) addr;
1894 	return sun->sun_path[0] != '\0';
1895 }
1896 
1897 int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1898 {
1899 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1900 	struct sockaddr __user *uaddr;
1901 	struct sockaddr_storage *addr;
1902 	int ret;
1903 
1904 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1905 		return -EINVAL;
1906 
1907 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1908 	bind->addr_len =  READ_ONCE(sqe->addr2);
1909 
1910 	addr = io_uring_alloc_async_data(NULL, req);
1911 	if (unlikely(!addr))
1912 		return -ENOMEM;
1913 	ret = move_addr_to_kernel(uaddr, bind->addr_len, addr);
1914 	if (unlikely(ret))
1915 		return ret;
1916 	if (io_bind_file_create(addr, bind->addr_len))
1917 		req->flags |= REQ_F_FORCE_ASYNC;
1918 	return 0;
1919 }
1920 
1921 
1922 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
1923 {
1924 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1925 	struct sockaddr_storage *addr = req->async_data;
1926 	struct socket *sock;
1927 	int ret;
1928 
1929 	sock = sock_from_file(req->file);
1930 	if (unlikely(!sock))
1931 		return -ENOTSOCK;
1932 
1933 	ret = __sys_bind_socket(sock, addr, bind->addr_len);
1934 	if (ret < 0)
1935 		req_set_fail(req);
1936 	io_req_set_res(req, ret, 0);
1937 	return 0;
1938 }
1939 
1940 int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1941 {
1942 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1943 
1944 	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
1945 		return -EINVAL;
1946 
1947 	listen->backlog = READ_ONCE(sqe->len);
1948 	return 0;
1949 }
1950 
1951 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
1952 {
1953 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1954 	struct socket *sock;
1955 	int ret;
1956 
1957 	sock = sock_from_file(req->file);
1958 	if (unlikely(!sock))
1959 		return -ENOTSOCK;
1960 
1961 	ret = __sys_listen_socket(sock, listen->backlog);
1962 	if (ret < 0)
1963 		req_set_fail(req);
1964 	io_req_set_res(req, ret, 0);
1965 	return 0;
1966 }
1967 
1968 void io_netmsg_cache_free(const void *entry)
1969 {
1970 	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
1971 
1972 	io_vec_free(&kmsg->vec);
1973 	kfree(kmsg);
1974 }
1975