xref: /openbmc/linux/io_uring/net.c (revision d5a05299306227d73b0febba9cecedf88931c507)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/slab.h>
6 #include <linux/net.h>
7 #include <linux/compat.h>
8 #include <net/compat.h>
9 #include <linux/io_uring.h>
10 
11 #include <uapi/linux/io_uring.h>
12 
13 #include "io_uring.h"
14 #include "kbuf.h"
15 #include "alloc_cache.h"
16 #include "net.h"
17 #include "notif.h"
18 #include "rsrc.h"
19 
20 #if defined(CONFIG_NET)
21 struct io_shutdown {
22 	struct file			*file;
23 	int				how;
24 };
25 
26 struct io_accept {
27 	struct file			*file;
28 	struct sockaddr __user		*addr;
29 	int __user			*addr_len;
30 	int				flags;
31 	u32				file_slot;
32 	unsigned long			nofile;
33 };
34 
35 struct io_socket {
36 	struct file			*file;
37 	int				domain;
38 	int				type;
39 	int				protocol;
40 	int				flags;
41 	u32				file_slot;
42 	unsigned long			nofile;
43 };
44 
45 struct io_connect {
46 	struct file			*file;
47 	struct sockaddr __user		*addr;
48 	int				addr_len;
49 	bool				in_progress;
50 	bool				seen_econnaborted;
51 };
52 
53 struct io_sr_msg {
54 	struct file			*file;
55 	union {
56 		struct compat_msghdr __user	*umsg_compat;
57 		struct user_msghdr __user	*umsg;
58 		void __user			*buf;
59 	};
60 	unsigned			len;
61 	unsigned			done_io;
62 	unsigned			msg_flags;
63 	u16				flags;
64 	/* initialised and used only by !msg send variants */
65 	u16				addr_len;
66 	u16				buf_group;
67 	void __user			*addr;
68 	void __user			*msg_control;
69 	/* used only for send zerocopy */
70 	struct io_kiocb 		*notif;
71 };
72 
73 static inline bool io_check_multishot(struct io_kiocb *req,
74 				      unsigned int issue_flags)
75 {
76 	/*
77 	 * When ->locked_cq is set we only allow to post CQEs from the original
78 	 * task context. Usual request completions will be handled in other
79 	 * generic paths but multipoll may decide to post extra cqes.
80 	 */
81 	return !(issue_flags & IO_URING_F_IOWQ) ||
82 		!(issue_flags & IO_URING_F_MULTISHOT) ||
83 		!req->ctx->task_complete;
84 }
85 
86 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
87 {
88 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
89 
90 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
91 		     sqe->buf_index || sqe->splice_fd_in))
92 		return -EINVAL;
93 
94 	shutdown->how = READ_ONCE(sqe->len);
95 	req->flags |= REQ_F_FORCE_ASYNC;
96 	return 0;
97 }
98 
99 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
100 {
101 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
102 	struct socket *sock;
103 	int ret;
104 
105 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
106 
107 	sock = sock_from_file(req->file);
108 	if (unlikely(!sock))
109 		return -ENOTSOCK;
110 
111 	ret = __sys_shutdown_sock(sock, shutdown->how);
112 	io_req_set_res(req, ret, 0);
113 	return IOU_OK;
114 }
115 
116 static bool io_net_retry(struct socket *sock, int flags)
117 {
118 	if (!(flags & MSG_WAITALL))
119 		return false;
120 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
121 }
122 
123 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
124 {
125 	struct io_async_msghdr *hdr = req->async_data;
126 
127 	if (!req_has_async_data(req) || issue_flags & IO_URING_F_UNLOCKED)
128 		return;
129 
130 	/* Let normal cleanup path reap it if we fail adding to the cache */
131 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
132 		req->async_data = NULL;
133 		req->flags &= ~REQ_F_ASYNC_DATA;
134 	}
135 }
136 
137 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
138 						  unsigned int issue_flags)
139 {
140 	struct io_ring_ctx *ctx = req->ctx;
141 	struct io_cache_entry *entry;
142 	struct io_async_msghdr *hdr;
143 
144 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
145 		entry = io_alloc_cache_get(&ctx->netmsg_cache);
146 		if (entry) {
147 			hdr = container_of(entry, struct io_async_msghdr, cache);
148 			hdr->free_iov = NULL;
149 			req->flags |= REQ_F_ASYNC_DATA;
150 			req->async_data = hdr;
151 			return hdr;
152 		}
153 	}
154 
155 	if (!io_alloc_async_data(req)) {
156 		hdr = req->async_data;
157 		hdr->free_iov = NULL;
158 		return hdr;
159 	}
160 	return NULL;
161 }
162 
163 static inline struct io_async_msghdr *io_msg_alloc_async_prep(struct io_kiocb *req)
164 {
165 	/* ->prep_async is always called from the submission context */
166 	return io_msg_alloc_async(req, 0);
167 }
168 
169 static int io_setup_async_msg(struct io_kiocb *req,
170 			      struct io_async_msghdr *kmsg,
171 			      unsigned int issue_flags)
172 {
173 	struct io_async_msghdr *async_msg;
174 
175 	if (req_has_async_data(req))
176 		return -EAGAIN;
177 	async_msg = io_msg_alloc_async(req, issue_flags);
178 	if (!async_msg) {
179 		kfree(kmsg->free_iov);
180 		return -ENOMEM;
181 	}
182 	req->flags |= REQ_F_NEED_CLEANUP;
183 	memcpy(async_msg, kmsg, sizeof(*kmsg));
184 	if (async_msg->msg.msg_name)
185 		async_msg->msg.msg_name = &async_msg->addr;
186 	/* if were using fast_iov, set it to the new one */
187 	if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) {
188 		size_t fast_idx = iter_iov(&kmsg->msg.msg_iter) - kmsg->fast_iov;
189 		async_msg->msg.msg_iter.__iov = &async_msg->fast_iov[fast_idx];
190 	}
191 
192 	return -EAGAIN;
193 }
194 
195 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
196 			       struct io_async_msghdr *iomsg)
197 {
198 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
199 	int ret;
200 
201 	iomsg->msg.msg_name = &iomsg->addr;
202 	iomsg->free_iov = iomsg->fast_iov;
203 	ret = sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags,
204 					&iomsg->free_iov);
205 	/* save msg_control as sys_sendmsg() overwrites it */
206 	sr->msg_control = iomsg->msg.msg_control_user;
207 	return ret;
208 }
209 
210 int io_send_prep_async(struct io_kiocb *req)
211 {
212 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
213 	struct io_async_msghdr *io;
214 	int ret;
215 
216 	if (!zc->addr || req_has_async_data(req))
217 		return 0;
218 	io = io_msg_alloc_async_prep(req);
219 	if (!io)
220 		return -ENOMEM;
221 	ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr);
222 	return ret;
223 }
224 
225 static int io_setup_async_addr(struct io_kiocb *req,
226 			      struct sockaddr_storage *addr_storage,
227 			      unsigned int issue_flags)
228 {
229 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
230 	struct io_async_msghdr *io;
231 
232 	if (!sr->addr || req_has_async_data(req))
233 		return -EAGAIN;
234 	io = io_msg_alloc_async(req, issue_flags);
235 	if (!io)
236 		return -ENOMEM;
237 	memcpy(&io->addr, addr_storage, sizeof(io->addr));
238 	return -EAGAIN;
239 }
240 
241 int io_sendmsg_prep_async(struct io_kiocb *req)
242 {
243 	int ret;
244 
245 	if (!io_msg_alloc_async_prep(req))
246 		return -ENOMEM;
247 	ret = io_sendmsg_copy_hdr(req, req->async_data);
248 	if (!ret)
249 		req->flags |= REQ_F_NEED_CLEANUP;
250 	return ret;
251 }
252 
253 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
254 {
255 	struct io_async_msghdr *io = req->async_data;
256 
257 	kfree(io->free_iov);
258 }
259 
260 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
261 {
262 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
263 
264 	if (req->opcode == IORING_OP_SEND) {
265 		if (READ_ONCE(sqe->__pad3[0]))
266 			return -EINVAL;
267 		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
268 		sr->addr_len = READ_ONCE(sqe->addr_len);
269 	} else if (sqe->addr2 || sqe->file_index) {
270 		return -EINVAL;
271 	}
272 
273 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
274 	sr->len = READ_ONCE(sqe->len);
275 	sr->flags = READ_ONCE(sqe->ioprio);
276 	if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
277 		return -EINVAL;
278 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
279 	if (sr->msg_flags & MSG_DONTWAIT)
280 		req->flags |= REQ_F_NOWAIT;
281 
282 #ifdef CONFIG_COMPAT
283 	if (req->ctx->compat)
284 		sr->msg_flags |= MSG_CMSG_COMPAT;
285 #endif
286 	sr->done_io = 0;
287 	return 0;
288 }
289 
290 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
291 {
292 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
293 	struct io_async_msghdr iomsg, *kmsg;
294 	struct socket *sock;
295 	unsigned flags;
296 	int min_ret = 0;
297 	int ret;
298 
299 	sock = sock_from_file(req->file);
300 	if (unlikely(!sock))
301 		return -ENOTSOCK;
302 
303 	if (req_has_async_data(req)) {
304 		kmsg = req->async_data;
305 		kmsg->msg.msg_control_user = sr->msg_control;
306 	} else {
307 		ret = io_sendmsg_copy_hdr(req, &iomsg);
308 		if (ret)
309 			return ret;
310 		kmsg = &iomsg;
311 	}
312 
313 	if (!(req->flags & REQ_F_POLLED) &&
314 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
315 		return io_setup_async_msg(req, kmsg, issue_flags);
316 
317 	flags = sr->msg_flags;
318 	if (issue_flags & IO_URING_F_NONBLOCK)
319 		flags |= MSG_DONTWAIT;
320 	if (flags & MSG_WAITALL)
321 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
322 
323 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
324 
325 	if (ret < min_ret) {
326 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
327 			return io_setup_async_msg(req, kmsg, issue_flags);
328 		if (ret > 0 && io_net_retry(sock, flags)) {
329 			kmsg->msg.msg_controllen = 0;
330 			kmsg->msg.msg_control = NULL;
331 			sr->done_io += ret;
332 			req->flags |= REQ_F_PARTIAL_IO;
333 			return io_setup_async_msg(req, kmsg, issue_flags);
334 		}
335 		if (ret == -ERESTARTSYS)
336 			ret = -EINTR;
337 		req_set_fail(req);
338 	}
339 	/* fast path, check for non-NULL to avoid function call */
340 	if (kmsg->free_iov)
341 		kfree(kmsg->free_iov);
342 	req->flags &= ~REQ_F_NEED_CLEANUP;
343 	io_netmsg_recycle(req, issue_flags);
344 	if (ret >= 0)
345 		ret += sr->done_io;
346 	else if (sr->done_io)
347 		ret = sr->done_io;
348 	io_req_set_res(req, ret, 0);
349 	return IOU_OK;
350 }
351 
352 int io_send(struct io_kiocb *req, unsigned int issue_flags)
353 {
354 	struct sockaddr_storage __address;
355 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
356 	struct msghdr msg;
357 	struct socket *sock;
358 	unsigned flags;
359 	int min_ret = 0;
360 	int ret;
361 
362 	msg.msg_name = NULL;
363 	msg.msg_control = NULL;
364 	msg.msg_controllen = 0;
365 	msg.msg_namelen = 0;
366 	msg.msg_ubuf = NULL;
367 
368 	if (sr->addr) {
369 		if (req_has_async_data(req)) {
370 			struct io_async_msghdr *io = req->async_data;
371 
372 			msg.msg_name = &io->addr;
373 		} else {
374 			ret = move_addr_to_kernel(sr->addr, sr->addr_len, &__address);
375 			if (unlikely(ret < 0))
376 				return ret;
377 			msg.msg_name = (struct sockaddr *)&__address;
378 		}
379 		msg.msg_namelen = sr->addr_len;
380 	}
381 
382 	if (!(req->flags & REQ_F_POLLED) &&
383 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
384 		return io_setup_async_addr(req, &__address, issue_flags);
385 
386 	sock = sock_from_file(req->file);
387 	if (unlikely(!sock))
388 		return -ENOTSOCK;
389 
390 	ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
391 	if (unlikely(ret))
392 		return ret;
393 
394 	flags = sr->msg_flags;
395 	if (issue_flags & IO_URING_F_NONBLOCK)
396 		flags |= MSG_DONTWAIT;
397 	if (flags & MSG_WAITALL)
398 		min_ret = iov_iter_count(&msg.msg_iter);
399 
400 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
401 	msg.msg_flags = flags;
402 	ret = sock_sendmsg(sock, &msg);
403 	if (ret < min_ret) {
404 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
405 			return io_setup_async_addr(req, &__address, issue_flags);
406 
407 		if (ret > 0 && io_net_retry(sock, flags)) {
408 			sr->len -= ret;
409 			sr->buf += ret;
410 			sr->done_io += ret;
411 			req->flags |= REQ_F_PARTIAL_IO;
412 			return io_setup_async_addr(req, &__address, issue_flags);
413 		}
414 		if (ret == -ERESTARTSYS)
415 			ret = -EINTR;
416 		req_set_fail(req);
417 	}
418 	if (ret >= 0)
419 		ret += sr->done_io;
420 	else if (sr->done_io)
421 		ret = sr->done_io;
422 	io_req_set_res(req, ret, 0);
423 	return IOU_OK;
424 }
425 
426 static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
427 {
428 	int hdr;
429 
430 	if (iomsg->namelen < 0)
431 		return true;
432 	if (check_add_overflow((int)sizeof(struct io_uring_recvmsg_out),
433 			       iomsg->namelen, &hdr))
434 		return true;
435 	if (check_add_overflow(hdr, (int)iomsg->controllen, &hdr))
436 		return true;
437 
438 	return false;
439 }
440 
441 static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
442 				 struct io_async_msghdr *iomsg)
443 {
444 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
445 	struct user_msghdr msg;
446 	int ret;
447 
448 	if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
449 		return -EFAULT;
450 
451 	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
452 	if (ret)
453 		return ret;
454 
455 	if (req->flags & REQ_F_BUFFER_SELECT) {
456 		if (msg.msg_iovlen == 0) {
457 			sr->len = iomsg->fast_iov[0].iov_len = 0;
458 			iomsg->fast_iov[0].iov_base = NULL;
459 			iomsg->free_iov = NULL;
460 		} else if (msg.msg_iovlen > 1) {
461 			return -EINVAL;
462 		} else {
463 			if (copy_from_user(iomsg->fast_iov, msg.msg_iov, sizeof(*msg.msg_iov)))
464 				return -EFAULT;
465 			sr->len = iomsg->fast_iov[0].iov_len;
466 			iomsg->free_iov = NULL;
467 		}
468 
469 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
470 			iomsg->namelen = msg.msg_namelen;
471 			iomsg->controllen = msg.msg_controllen;
472 			if (io_recvmsg_multishot_overflow(iomsg))
473 				return -EOVERFLOW;
474 		}
475 	} else {
476 		iomsg->free_iov = iomsg->fast_iov;
477 		ret = __import_iovec(ITER_DEST, msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV,
478 				     &iomsg->free_iov, &iomsg->msg.msg_iter,
479 				     false);
480 		if (ret > 0)
481 			ret = 0;
482 	}
483 
484 	return ret;
485 }
486 
487 #ifdef CONFIG_COMPAT
488 static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
489 					struct io_async_msghdr *iomsg)
490 {
491 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
492 	struct compat_msghdr msg;
493 	struct compat_iovec __user *uiov;
494 	int ret;
495 
496 	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
497 		return -EFAULT;
498 
499 	ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
500 	if (ret)
501 		return ret;
502 
503 	uiov = compat_ptr(msg.msg_iov);
504 	if (req->flags & REQ_F_BUFFER_SELECT) {
505 		compat_ssize_t clen;
506 
507 		iomsg->free_iov = NULL;
508 		if (msg.msg_iovlen == 0) {
509 			sr->len = 0;
510 		} else if (msg.msg_iovlen > 1) {
511 			return -EINVAL;
512 		} else {
513 			if (!access_ok(uiov, sizeof(*uiov)))
514 				return -EFAULT;
515 			if (__get_user(clen, &uiov->iov_len))
516 				return -EFAULT;
517 			if (clen < 0)
518 				return -EINVAL;
519 			sr->len = clen;
520 		}
521 
522 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
523 			iomsg->namelen = msg.msg_namelen;
524 			iomsg->controllen = msg.msg_controllen;
525 			if (io_recvmsg_multishot_overflow(iomsg))
526 				return -EOVERFLOW;
527 		}
528 	} else {
529 		iomsg->free_iov = iomsg->fast_iov;
530 		ret = __import_iovec(ITER_DEST, (struct iovec __user *)uiov, msg.msg_iovlen,
531 				   UIO_FASTIOV, &iomsg->free_iov,
532 				   &iomsg->msg.msg_iter, true);
533 		if (ret < 0)
534 			return ret;
535 	}
536 
537 	return 0;
538 }
539 #endif
540 
541 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
542 			       struct io_async_msghdr *iomsg)
543 {
544 	iomsg->msg.msg_name = &iomsg->addr;
545 
546 #ifdef CONFIG_COMPAT
547 	if (req->ctx->compat)
548 		return __io_compat_recvmsg_copy_hdr(req, iomsg);
549 #endif
550 
551 	return __io_recvmsg_copy_hdr(req, iomsg);
552 }
553 
554 int io_recvmsg_prep_async(struct io_kiocb *req)
555 {
556 	int ret;
557 
558 	if (!io_msg_alloc_async_prep(req))
559 		return -ENOMEM;
560 	ret = io_recvmsg_copy_hdr(req, req->async_data);
561 	if (!ret)
562 		req->flags |= REQ_F_NEED_CLEANUP;
563 	return ret;
564 }
565 
566 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)
567 
568 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
569 {
570 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
571 
572 	if (unlikely(sqe->file_index || sqe->addr2))
573 		return -EINVAL;
574 
575 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
576 	sr->len = READ_ONCE(sqe->len);
577 	sr->flags = READ_ONCE(sqe->ioprio);
578 	if (sr->flags & ~(RECVMSG_FLAGS))
579 		return -EINVAL;
580 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
581 	if (sr->msg_flags & MSG_DONTWAIT)
582 		req->flags |= REQ_F_NOWAIT;
583 	if (sr->msg_flags & MSG_ERRQUEUE)
584 		req->flags |= REQ_F_CLEAR_POLLIN;
585 	if (sr->flags & IORING_RECV_MULTISHOT) {
586 		if (!(req->flags & REQ_F_BUFFER_SELECT))
587 			return -EINVAL;
588 		if (sr->msg_flags & MSG_WAITALL)
589 			return -EINVAL;
590 		if (req->opcode == IORING_OP_RECV && sr->len)
591 			return -EINVAL;
592 		req->flags |= REQ_F_APOLL_MULTISHOT;
593 		/*
594 		 * Store the buffer group for this multishot receive separately,
595 		 * as if we end up doing an io-wq based issue that selects a
596 		 * buffer, it has to be committed immediately and that will
597 		 * clear ->buf_list. This means we lose the link to the buffer
598 		 * list, and the eventual buffer put on completion then cannot
599 		 * restore it.
600 		 */
601 		sr->buf_group = req->buf_index;
602 	}
603 
604 #ifdef CONFIG_COMPAT
605 	if (req->ctx->compat)
606 		sr->msg_flags |= MSG_CMSG_COMPAT;
607 #endif
608 	sr->done_io = 0;
609 	return 0;
610 }
611 
612 static inline void io_recv_prep_retry(struct io_kiocb *req)
613 {
614 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
615 
616 	sr->done_io = 0;
617 	sr->len = 0; /* get from the provided buffer */
618 	req->buf_index = sr->buf_group;
619 }
620 
621 /*
622  * Finishes io_recv and io_recvmsg.
623  *
624  * Returns true if it is actually finished, or false if it should run
625  * again (for multishot).
626  */
627 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
628 				  unsigned int cflags, bool mshot_finished,
629 				  unsigned issue_flags)
630 {
631 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
632 		io_req_set_res(req, *ret, cflags);
633 		*ret = IOU_OK;
634 		return true;
635 	}
636 
637 	if (!mshot_finished) {
638 		if (io_aux_cqe(req->ctx, issue_flags & IO_URING_F_COMPLETE_DEFER,
639 			       req->cqe.user_data, *ret, cflags | IORING_CQE_F_MORE, true)) {
640 			io_recv_prep_retry(req);
641 			return false;
642 		}
643 		/* Otherwise stop multishot but use the current result. */
644 	}
645 
646 	io_req_set_res(req, *ret, cflags);
647 
648 	if (issue_flags & IO_URING_F_MULTISHOT)
649 		*ret = IOU_STOP_MULTISHOT;
650 	else
651 		*ret = IOU_OK;
652 	return true;
653 }
654 
655 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
656 				     struct io_sr_msg *sr, void __user **buf,
657 				     size_t *len)
658 {
659 	unsigned long ubuf = (unsigned long) *buf;
660 	unsigned long hdr;
661 
662 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
663 		kmsg->controllen;
664 	if (*len < hdr)
665 		return -EFAULT;
666 
667 	if (kmsg->controllen) {
668 		unsigned long control = ubuf + hdr - kmsg->controllen;
669 
670 		kmsg->msg.msg_control_user = (void __user *) control;
671 		kmsg->msg.msg_controllen = kmsg->controllen;
672 	}
673 
674 	sr->buf = *buf; /* stash for later copy */
675 	*buf = (void __user *) (ubuf + hdr);
676 	kmsg->payloadlen = *len = *len - hdr;
677 	return 0;
678 }
679 
680 struct io_recvmsg_multishot_hdr {
681 	struct io_uring_recvmsg_out msg;
682 	struct sockaddr_storage addr;
683 };
684 
685 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
686 				struct io_async_msghdr *kmsg,
687 				unsigned int flags, bool *finished)
688 {
689 	int err;
690 	int copy_len;
691 	struct io_recvmsg_multishot_hdr hdr;
692 
693 	if (kmsg->namelen)
694 		kmsg->msg.msg_name = &hdr.addr;
695 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
696 	kmsg->msg.msg_namelen = 0;
697 
698 	if (sock->file->f_flags & O_NONBLOCK)
699 		flags |= MSG_DONTWAIT;
700 
701 	err = sock_recvmsg(sock, &kmsg->msg, flags);
702 	*finished = err <= 0;
703 	if (err < 0)
704 		return err;
705 
706 	hdr.msg = (struct io_uring_recvmsg_out) {
707 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
708 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
709 	};
710 
711 	hdr.msg.payloadlen = err;
712 	if (err > kmsg->payloadlen)
713 		err = kmsg->payloadlen;
714 
715 	copy_len = sizeof(struct io_uring_recvmsg_out);
716 	if (kmsg->msg.msg_namelen > kmsg->namelen)
717 		copy_len += kmsg->namelen;
718 	else
719 		copy_len += kmsg->msg.msg_namelen;
720 
721 	/*
722 	 *      "fromlen shall refer to the value before truncation.."
723 	 *                      1003.1g
724 	 */
725 	hdr.msg.namelen = kmsg->msg.msg_namelen;
726 
727 	/* ensure that there is no gap between hdr and sockaddr_storage */
728 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
729 		     sizeof(struct io_uring_recvmsg_out));
730 	if (copy_to_user(io->buf, &hdr, copy_len)) {
731 		*finished = true;
732 		return -EFAULT;
733 	}
734 
735 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
736 			kmsg->controllen + err;
737 }
738 
739 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
740 {
741 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
742 	struct io_async_msghdr iomsg, *kmsg;
743 	struct socket *sock;
744 	unsigned int cflags;
745 	unsigned flags;
746 	int ret, min_ret = 0;
747 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
748 	bool mshot_finished = true;
749 
750 	sock = sock_from_file(req->file);
751 	if (unlikely(!sock))
752 		return -ENOTSOCK;
753 
754 	if (req_has_async_data(req)) {
755 		kmsg = req->async_data;
756 	} else {
757 		ret = io_recvmsg_copy_hdr(req, &iomsg);
758 		if (ret)
759 			return ret;
760 		kmsg = &iomsg;
761 	}
762 
763 	if (!(req->flags & REQ_F_POLLED) &&
764 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
765 		return io_setup_async_msg(req, kmsg, issue_flags);
766 
767 	if (!io_check_multishot(req, issue_flags))
768 		return io_setup_async_msg(req, kmsg, issue_flags);
769 
770 retry_multishot:
771 	if (io_do_buffer_select(req)) {
772 		void __user *buf;
773 		size_t len = sr->len;
774 
775 		buf = io_buffer_select(req, &len, issue_flags);
776 		if (!buf)
777 			return -ENOBUFS;
778 
779 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
780 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
781 			if (ret) {
782 				io_kbuf_recycle(req, issue_flags);
783 				return ret;
784 			}
785 		}
786 
787 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
788 	}
789 
790 	flags = sr->msg_flags;
791 	if (force_nonblock)
792 		flags |= MSG_DONTWAIT;
793 
794 	kmsg->msg.msg_get_inq = 1;
795 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
796 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
797 					   &mshot_finished);
798 	} else {
799 		/* disable partial retry for recvmsg with cmsg attached */
800 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
801 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
802 
803 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
804 					 kmsg->uaddr, flags);
805 	}
806 
807 	if (ret < min_ret) {
808 		if (ret == -EAGAIN && force_nonblock) {
809 			ret = io_setup_async_msg(req, kmsg, issue_flags);
810 			if (ret == -EAGAIN && (issue_flags & IO_URING_F_MULTISHOT)) {
811 				io_kbuf_recycle(req, issue_flags);
812 				return IOU_ISSUE_SKIP_COMPLETE;
813 			}
814 			return ret;
815 		}
816 		if (ret > 0 && io_net_retry(sock, flags)) {
817 			sr->done_io += ret;
818 			req->flags |= REQ_F_PARTIAL_IO;
819 			return io_setup_async_msg(req, kmsg, issue_flags);
820 		}
821 		if (ret == -ERESTARTSYS)
822 			ret = -EINTR;
823 		req_set_fail(req);
824 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
825 		req_set_fail(req);
826 	}
827 
828 	if (ret > 0)
829 		ret += sr->done_io;
830 	else if (sr->done_io)
831 		ret = sr->done_io;
832 	else
833 		io_kbuf_recycle(req, issue_flags);
834 
835 	cflags = io_put_kbuf(req, issue_flags);
836 	if (kmsg->msg.msg_inq)
837 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
838 
839 	if (!io_recv_finish(req, &ret, cflags, mshot_finished, issue_flags))
840 		goto retry_multishot;
841 
842 	if (mshot_finished) {
843 		/* fast path, check for non-NULL to avoid function call */
844 		if (kmsg->free_iov)
845 			kfree(kmsg->free_iov);
846 		io_netmsg_recycle(req, issue_flags);
847 		req->flags &= ~REQ_F_NEED_CLEANUP;
848 	}
849 
850 	return ret;
851 }
852 
853 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
854 {
855 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
856 	struct msghdr msg;
857 	struct socket *sock;
858 	unsigned int cflags;
859 	unsigned flags;
860 	int ret, min_ret = 0;
861 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
862 	size_t len = sr->len;
863 
864 	if (!(req->flags & REQ_F_POLLED) &&
865 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
866 		return -EAGAIN;
867 
868 	if (!io_check_multishot(req, issue_flags))
869 		return -EAGAIN;
870 
871 	sock = sock_from_file(req->file);
872 	if (unlikely(!sock))
873 		return -ENOTSOCK;
874 
875 retry_multishot:
876 	if (io_do_buffer_select(req)) {
877 		void __user *buf;
878 
879 		buf = io_buffer_select(req, &len, issue_flags);
880 		if (!buf)
881 			return -ENOBUFS;
882 		sr->buf = buf;
883 	}
884 
885 	ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
886 	if (unlikely(ret))
887 		goto out_free;
888 
889 	msg.msg_name = NULL;
890 	msg.msg_namelen = 0;
891 	msg.msg_control = NULL;
892 	msg.msg_get_inq = 1;
893 	msg.msg_flags = 0;
894 	msg.msg_controllen = 0;
895 	msg.msg_iocb = NULL;
896 	msg.msg_ubuf = NULL;
897 
898 	flags = sr->msg_flags;
899 	if (force_nonblock)
900 		flags |= MSG_DONTWAIT;
901 	if (flags & MSG_WAITALL)
902 		min_ret = iov_iter_count(&msg.msg_iter);
903 
904 	ret = sock_recvmsg(sock, &msg, flags);
905 	if (ret < min_ret) {
906 		if (ret == -EAGAIN && force_nonblock) {
907 			if (issue_flags & IO_URING_F_MULTISHOT) {
908 				io_kbuf_recycle(req, issue_flags);
909 				return IOU_ISSUE_SKIP_COMPLETE;
910 			}
911 
912 			return -EAGAIN;
913 		}
914 		if (ret > 0 && io_net_retry(sock, flags)) {
915 			sr->len -= ret;
916 			sr->buf += ret;
917 			sr->done_io += ret;
918 			req->flags |= REQ_F_PARTIAL_IO;
919 			return -EAGAIN;
920 		}
921 		if (ret == -ERESTARTSYS)
922 			ret = -EINTR;
923 		req_set_fail(req);
924 	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
925 out_free:
926 		req_set_fail(req);
927 	}
928 
929 	if (ret > 0)
930 		ret += sr->done_io;
931 	else if (sr->done_io)
932 		ret = sr->done_io;
933 	else
934 		io_kbuf_recycle(req, issue_flags);
935 
936 	cflags = io_put_kbuf(req, issue_flags);
937 	if (msg.msg_inq)
938 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
939 
940 	if (!io_recv_finish(req, &ret, cflags, ret <= 0, issue_flags))
941 		goto retry_multishot;
942 
943 	return ret;
944 }
945 
946 void io_send_zc_cleanup(struct io_kiocb *req)
947 {
948 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
949 	struct io_async_msghdr *io;
950 
951 	if (req_has_async_data(req)) {
952 		io = req->async_data;
953 		/* might be ->fast_iov if *msg_copy_hdr failed */
954 		if (io->free_iov != io->fast_iov)
955 			kfree(io->free_iov);
956 	}
957 	if (zc->notif) {
958 		io_notif_flush(zc->notif);
959 		zc->notif = NULL;
960 	}
961 }
962 
963 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
964 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE)
965 
966 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
967 {
968 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
969 	struct io_ring_ctx *ctx = req->ctx;
970 	struct io_kiocb *notif;
971 
972 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
973 		return -EINVAL;
974 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
975 	if (req->flags & REQ_F_CQE_SKIP)
976 		return -EINVAL;
977 
978 	notif = zc->notif = io_alloc_notif(ctx);
979 	if (!notif)
980 		return -ENOMEM;
981 	notif->cqe.user_data = req->cqe.user_data;
982 	notif->cqe.res = 0;
983 	notif->cqe.flags = IORING_CQE_F_NOTIF;
984 	req->flags |= REQ_F_NEED_CLEANUP;
985 
986 	zc->flags = READ_ONCE(sqe->ioprio);
987 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
988 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
989 			return -EINVAL;
990 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
991 			io_notif_set_extended(notif);
992 			io_notif_to_data(notif)->zc_report = true;
993 		}
994 	}
995 
996 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
997 		unsigned idx = READ_ONCE(sqe->buf_index);
998 
999 		if (unlikely(idx >= ctx->nr_user_bufs))
1000 			return -EFAULT;
1001 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
1002 		req->imu = READ_ONCE(ctx->user_bufs[idx]);
1003 		io_req_set_rsrc_node(notif, ctx, 0);
1004 	}
1005 
1006 	if (req->opcode == IORING_OP_SEND_ZC) {
1007 		if (READ_ONCE(sqe->__pad3[0]))
1008 			return -EINVAL;
1009 		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1010 		zc->addr_len = READ_ONCE(sqe->addr_len);
1011 	} else {
1012 		if (unlikely(sqe->addr2 || sqe->file_index))
1013 			return -EINVAL;
1014 		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
1015 			return -EINVAL;
1016 	}
1017 
1018 	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
1019 	zc->len = READ_ONCE(sqe->len);
1020 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
1021 	if (zc->msg_flags & MSG_DONTWAIT)
1022 		req->flags |= REQ_F_NOWAIT;
1023 
1024 	zc->done_io = 0;
1025 
1026 #ifdef CONFIG_COMPAT
1027 	if (req->ctx->compat)
1028 		zc->msg_flags |= MSG_CMSG_COMPAT;
1029 #endif
1030 	return 0;
1031 }
1032 
1033 static int io_sg_from_iter_iovec(struct sock *sk, struct sk_buff *skb,
1034 				 struct iov_iter *from, size_t length)
1035 {
1036 	skb_zcopy_downgrade_managed(skb);
1037 	return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
1038 }
1039 
1040 static int io_sg_from_iter(struct sock *sk, struct sk_buff *skb,
1041 			   struct iov_iter *from, size_t length)
1042 {
1043 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1044 	int frag = shinfo->nr_frags;
1045 	int ret = 0;
1046 	struct bvec_iter bi;
1047 	ssize_t copied = 0;
1048 	unsigned long truesize = 0;
1049 
1050 	if (!frag)
1051 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1052 	else if (unlikely(!skb_zcopy_managed(skb)))
1053 		return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
1054 
1055 	bi.bi_size = min(from->count, length);
1056 	bi.bi_bvec_done = from->iov_offset;
1057 	bi.bi_idx = 0;
1058 
1059 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1060 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1061 
1062 		copied += v.bv_len;
1063 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1064 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1065 					   v.bv_offset, v.bv_len);
1066 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1067 	}
1068 	if (bi.bi_size)
1069 		ret = -EMSGSIZE;
1070 
1071 	shinfo->nr_frags = frag;
1072 	from->bvec += bi.bi_idx;
1073 	from->nr_segs -= bi.bi_idx;
1074 	from->count -= copied;
1075 	from->iov_offset = bi.bi_bvec_done;
1076 
1077 	skb->data_len += copied;
1078 	skb->len += copied;
1079 	skb->truesize += truesize;
1080 
1081 	if (sk && sk->sk_type == SOCK_STREAM) {
1082 		sk_wmem_queued_add(sk, truesize);
1083 		if (!skb_zcopy_pure(skb))
1084 			sk_mem_charge(sk, truesize);
1085 	} else {
1086 		refcount_add(truesize, &skb->sk->sk_wmem_alloc);
1087 	}
1088 	return ret;
1089 }
1090 
1091 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1092 {
1093 	struct sockaddr_storage __address;
1094 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1095 	struct msghdr msg;
1096 	struct socket *sock;
1097 	unsigned msg_flags;
1098 	int ret, min_ret = 0;
1099 
1100 	sock = sock_from_file(req->file);
1101 	if (unlikely(!sock))
1102 		return -ENOTSOCK;
1103 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1104 		return -EOPNOTSUPP;
1105 
1106 	msg.msg_name = NULL;
1107 	msg.msg_control = NULL;
1108 	msg.msg_controllen = 0;
1109 	msg.msg_namelen = 0;
1110 
1111 	if (zc->addr) {
1112 		if (req_has_async_data(req)) {
1113 			struct io_async_msghdr *io = req->async_data;
1114 
1115 			msg.msg_name = &io->addr;
1116 		} else {
1117 			ret = move_addr_to_kernel(zc->addr, zc->addr_len, &__address);
1118 			if (unlikely(ret < 0))
1119 				return ret;
1120 			msg.msg_name = (struct sockaddr *)&__address;
1121 		}
1122 		msg.msg_namelen = zc->addr_len;
1123 	}
1124 
1125 	if (!(req->flags & REQ_F_POLLED) &&
1126 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1127 		return io_setup_async_addr(req, &__address, issue_flags);
1128 
1129 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1130 		ret = io_import_fixed(ITER_SOURCE, &msg.msg_iter, req->imu,
1131 					(u64)(uintptr_t)zc->buf, zc->len);
1132 		if (unlikely(ret))
1133 			return ret;
1134 		msg.sg_from_iter = io_sg_from_iter;
1135 	} else {
1136 		io_notif_set_extended(zc->notif);
1137 		ret = import_ubuf(ITER_SOURCE, zc->buf, zc->len, &msg.msg_iter);
1138 		if (unlikely(ret))
1139 			return ret;
1140 		ret = io_notif_account_mem(zc->notif, zc->len);
1141 		if (unlikely(ret))
1142 			return ret;
1143 		msg.sg_from_iter = io_sg_from_iter_iovec;
1144 	}
1145 
1146 	msg_flags = zc->msg_flags | MSG_ZEROCOPY;
1147 	if (issue_flags & IO_URING_F_NONBLOCK)
1148 		msg_flags |= MSG_DONTWAIT;
1149 	if (msg_flags & MSG_WAITALL)
1150 		min_ret = iov_iter_count(&msg.msg_iter);
1151 	msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1152 
1153 	msg.msg_flags = msg_flags;
1154 	msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1155 	ret = sock_sendmsg(sock, &msg);
1156 
1157 	if (unlikely(ret < min_ret)) {
1158 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1159 			return io_setup_async_addr(req, &__address, issue_flags);
1160 
1161 		if (ret > 0 && io_net_retry(sock, msg.msg_flags)) {
1162 			zc->len -= ret;
1163 			zc->buf += ret;
1164 			zc->done_io += ret;
1165 			req->flags |= REQ_F_PARTIAL_IO;
1166 			return io_setup_async_addr(req, &__address, issue_flags);
1167 		}
1168 		if (ret == -ERESTARTSYS)
1169 			ret = -EINTR;
1170 		req_set_fail(req);
1171 	}
1172 
1173 	if (ret >= 0)
1174 		ret += zc->done_io;
1175 	else if (zc->done_io)
1176 		ret = zc->done_io;
1177 
1178 	/*
1179 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1180 	 * flushing notif to io_send_zc_cleanup()
1181 	 */
1182 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1183 		io_notif_flush(zc->notif);
1184 		req->flags &= ~REQ_F_NEED_CLEANUP;
1185 	}
1186 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1187 	return IOU_OK;
1188 }
1189 
1190 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1191 {
1192 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1193 	struct io_async_msghdr iomsg, *kmsg;
1194 	struct socket *sock;
1195 	unsigned flags;
1196 	int ret, min_ret = 0;
1197 
1198 	io_notif_set_extended(sr->notif);
1199 
1200 	sock = sock_from_file(req->file);
1201 	if (unlikely(!sock))
1202 		return -ENOTSOCK;
1203 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1204 		return -EOPNOTSUPP;
1205 
1206 	if (req_has_async_data(req)) {
1207 		kmsg = req->async_data;
1208 	} else {
1209 		ret = io_sendmsg_copy_hdr(req, &iomsg);
1210 		if (ret)
1211 			return ret;
1212 		kmsg = &iomsg;
1213 	}
1214 
1215 	if (!(req->flags & REQ_F_POLLED) &&
1216 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1217 		return io_setup_async_msg(req, kmsg, issue_flags);
1218 
1219 	flags = sr->msg_flags | MSG_ZEROCOPY;
1220 	if (issue_flags & IO_URING_F_NONBLOCK)
1221 		flags |= MSG_DONTWAIT;
1222 	if (flags & MSG_WAITALL)
1223 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1224 
1225 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1226 	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1227 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1228 
1229 	if (unlikely(ret < min_ret)) {
1230 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1231 			return io_setup_async_msg(req, kmsg, issue_flags);
1232 
1233 		if (ret > 0 && io_net_retry(sock, flags)) {
1234 			sr->done_io += ret;
1235 			req->flags |= REQ_F_PARTIAL_IO;
1236 			return io_setup_async_msg(req, kmsg, issue_flags);
1237 		}
1238 		if (ret == -ERESTARTSYS)
1239 			ret = -EINTR;
1240 		req_set_fail(req);
1241 	}
1242 	/* fast path, check for non-NULL to avoid function call */
1243 	if (kmsg->free_iov) {
1244 		kfree(kmsg->free_iov);
1245 		kmsg->free_iov = NULL;
1246 	}
1247 
1248 	io_netmsg_recycle(req, issue_flags);
1249 	if (ret >= 0)
1250 		ret += sr->done_io;
1251 	else if (sr->done_io)
1252 		ret = sr->done_io;
1253 
1254 	/*
1255 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1256 	 * flushing notif to io_send_zc_cleanup()
1257 	 */
1258 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1259 		io_notif_flush(sr->notif);
1260 		req->flags &= ~REQ_F_NEED_CLEANUP;
1261 	}
1262 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1263 	return IOU_OK;
1264 }
1265 
1266 void io_sendrecv_fail(struct io_kiocb *req)
1267 {
1268 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1269 
1270 	if (req->flags & REQ_F_PARTIAL_IO)
1271 		req->cqe.res = sr->done_io;
1272 
1273 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1274 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1275 		req->cqe.flags |= IORING_CQE_F_MORE;
1276 }
1277 
1278 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1279 {
1280 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1281 	unsigned flags;
1282 
1283 	if (sqe->len || sqe->buf_index)
1284 		return -EINVAL;
1285 
1286 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1287 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1288 	accept->flags = READ_ONCE(sqe->accept_flags);
1289 	accept->nofile = rlimit(RLIMIT_NOFILE);
1290 	flags = READ_ONCE(sqe->ioprio);
1291 	if (flags & ~IORING_ACCEPT_MULTISHOT)
1292 		return -EINVAL;
1293 
1294 	accept->file_slot = READ_ONCE(sqe->file_index);
1295 	if (accept->file_slot) {
1296 		if (accept->flags & SOCK_CLOEXEC)
1297 			return -EINVAL;
1298 		if (flags & IORING_ACCEPT_MULTISHOT &&
1299 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1300 			return -EINVAL;
1301 	}
1302 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1303 		return -EINVAL;
1304 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1305 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1306 	if (flags & IORING_ACCEPT_MULTISHOT)
1307 		req->flags |= REQ_F_APOLL_MULTISHOT;
1308 	return 0;
1309 }
1310 
1311 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1312 {
1313 	struct io_ring_ctx *ctx = req->ctx;
1314 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1315 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1316 	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
1317 	bool fixed = !!accept->file_slot;
1318 	struct file *file;
1319 	int ret, fd;
1320 
1321 	if (!io_check_multishot(req, issue_flags))
1322 		return -EAGAIN;
1323 retry:
1324 	if (!fixed) {
1325 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1326 		if (unlikely(fd < 0))
1327 			return fd;
1328 	}
1329 	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
1330 			 accept->flags);
1331 	if (IS_ERR(file)) {
1332 		if (!fixed)
1333 			put_unused_fd(fd);
1334 		ret = PTR_ERR(file);
1335 		if (ret == -EAGAIN && force_nonblock) {
1336 			/*
1337 			 * if it's multishot and polled, we don't need to
1338 			 * return EAGAIN to arm the poll infra since it
1339 			 * has already been done
1340 			 */
1341 			if (issue_flags & IO_URING_F_MULTISHOT)
1342 				ret = IOU_ISSUE_SKIP_COMPLETE;
1343 			return ret;
1344 		}
1345 		if (ret == -ERESTARTSYS)
1346 			ret = -EINTR;
1347 		req_set_fail(req);
1348 	} else if (!fixed) {
1349 		fd_install(fd, file);
1350 		ret = fd;
1351 	} else {
1352 		ret = io_fixed_fd_install(req, issue_flags, file,
1353 						accept->file_slot);
1354 	}
1355 
1356 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
1357 		io_req_set_res(req, ret, 0);
1358 		return IOU_OK;
1359 	}
1360 
1361 	if (ret < 0)
1362 		return ret;
1363 	if (io_aux_cqe(ctx, issue_flags & IO_URING_F_COMPLETE_DEFER,
1364 		       req->cqe.user_data, ret, IORING_CQE_F_MORE, true))
1365 		goto retry;
1366 
1367 	return -ECANCELED;
1368 }
1369 
1370 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1371 {
1372 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1373 
1374 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1375 		return -EINVAL;
1376 
1377 	sock->domain = READ_ONCE(sqe->fd);
1378 	sock->type = READ_ONCE(sqe->off);
1379 	sock->protocol = READ_ONCE(sqe->len);
1380 	sock->file_slot = READ_ONCE(sqe->file_index);
1381 	sock->nofile = rlimit(RLIMIT_NOFILE);
1382 
1383 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1384 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1385 		return -EINVAL;
1386 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1387 		return -EINVAL;
1388 	return 0;
1389 }
1390 
1391 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1392 {
1393 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1394 	bool fixed = !!sock->file_slot;
1395 	struct file *file;
1396 	int ret, fd;
1397 
1398 	if (!fixed) {
1399 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1400 		if (unlikely(fd < 0))
1401 			return fd;
1402 	}
1403 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1404 	if (IS_ERR(file)) {
1405 		if (!fixed)
1406 			put_unused_fd(fd);
1407 		ret = PTR_ERR(file);
1408 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1409 			return -EAGAIN;
1410 		if (ret == -ERESTARTSYS)
1411 			ret = -EINTR;
1412 		req_set_fail(req);
1413 	} else if (!fixed) {
1414 		fd_install(fd, file);
1415 		ret = fd;
1416 	} else {
1417 		ret = io_fixed_fd_install(req, issue_flags, file,
1418 					    sock->file_slot);
1419 	}
1420 	io_req_set_res(req, ret, 0);
1421 	return IOU_OK;
1422 }
1423 
1424 int io_connect_prep_async(struct io_kiocb *req)
1425 {
1426 	struct io_async_connect *io = req->async_data;
1427 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1428 
1429 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
1430 }
1431 
1432 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1433 {
1434 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1435 
1436 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1437 		return -EINVAL;
1438 
1439 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1440 	conn->addr_len =  READ_ONCE(sqe->addr2);
1441 	conn->in_progress = conn->seen_econnaborted = false;
1442 	return 0;
1443 }
1444 
1445 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1446 {
1447 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1448 	struct io_async_connect __io, *io;
1449 	unsigned file_flags;
1450 	int ret;
1451 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1452 
1453 	if (connect->in_progress) {
1454 		struct socket *socket;
1455 
1456 		ret = -ENOTSOCK;
1457 		socket = sock_from_file(req->file);
1458 		if (socket)
1459 			ret = sock_error(socket->sk);
1460 		goto out;
1461 	}
1462 
1463 	if (req_has_async_data(req)) {
1464 		io = req->async_data;
1465 	} else {
1466 		ret = move_addr_to_kernel(connect->addr,
1467 						connect->addr_len,
1468 						&__io.address);
1469 		if (ret)
1470 			goto out;
1471 		io = &__io;
1472 	}
1473 
1474 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1475 
1476 	ret = __sys_connect_file(req->file, &io->address,
1477 					connect->addr_len, file_flags);
1478 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1479 	    && force_nonblock) {
1480 		if (ret == -EINPROGRESS) {
1481 			connect->in_progress = true;
1482 			return -EAGAIN;
1483 		}
1484 		if (ret == -ECONNABORTED) {
1485 			if (connect->seen_econnaborted)
1486 				goto out;
1487 			connect->seen_econnaborted = true;
1488 		}
1489 		if (req_has_async_data(req))
1490 			return -EAGAIN;
1491 		if (io_alloc_async_data(req)) {
1492 			ret = -ENOMEM;
1493 			goto out;
1494 		}
1495 		memcpy(req->async_data, &__io, sizeof(__io));
1496 		return -EAGAIN;
1497 	}
1498 	if (ret == -ERESTARTSYS)
1499 		ret = -EINTR;
1500 out:
1501 	if (ret < 0)
1502 		req_set_fail(req);
1503 	io_req_set_res(req, ret, 0);
1504 	return IOU_OK;
1505 }
1506 
1507 void io_netmsg_cache_free(struct io_cache_entry *entry)
1508 {
1509 	kfree(container_of(entry, struct io_async_msghdr, cache));
1510 }
1511 #endif
1512