xref: /linux/io_uring/net.c (revision 0b0e9cdb3d1f8fda823b592b0667b4b0595e2ba7)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/slab.h>
6 #include <linux/net.h>
7 #include <linux/compat.h>
8 #include <net/compat.h>
9 #include <linux/io_uring.h>
10 
11 #include <uapi/linux/io_uring.h>
12 
13 #include "io_uring.h"
14 #include "kbuf.h"
15 #include "alloc_cache.h"
16 #include "net.h"
17 #include "notif.h"
18 #include "rsrc.h"
19 
20 #if defined(CONFIG_NET)
21 struct io_shutdown {
22 	struct file			*file;
23 	int				how;
24 };
25 
26 struct io_accept {
27 	struct file			*file;
28 	struct sockaddr __user		*addr;
29 	int __user			*addr_len;
30 	int				flags;
31 	int				iou_flags;
32 	u32				file_slot;
33 	unsigned long			nofile;
34 };
35 
36 struct io_socket {
37 	struct file			*file;
38 	int				domain;
39 	int				type;
40 	int				protocol;
41 	int				flags;
42 	u32				file_slot;
43 	unsigned long			nofile;
44 };
45 
46 struct io_connect {
47 	struct file			*file;
48 	struct sockaddr __user		*addr;
49 	int				addr_len;
50 	bool				in_progress;
51 	bool				seen_econnaborted;
52 };
53 
54 struct io_bind {
55 	struct file			*file;
56 	int				addr_len;
57 };
58 
59 struct io_listen {
60 	struct file			*file;
61 	int				backlog;
62 };
63 
64 struct io_sr_msg {
65 	struct file			*file;
66 	union {
67 		struct compat_msghdr __user	*umsg_compat;
68 		struct user_msghdr __user	*umsg;
69 		void __user			*buf;
70 	};
71 	int				len;
72 	unsigned			done_io;
73 	unsigned			msg_flags;
74 	unsigned			nr_multishot_loops;
75 	u16				flags;
76 	/* initialised and used only by !msg send variants */
77 	u16				addr_len;
78 	u16				buf_group;
79 	void __user			*addr;
80 	void __user			*msg_control;
81 	/* used only for send zerocopy */
82 	struct io_kiocb 		*notif;
83 };
84 
85 /*
86  * Number of times we'll try and do receives if there's more data. If we
87  * exceed this limit, then add us to the back of the queue and retry from
88  * there. This helps fairness between flooding clients.
89  */
90 #define MULTISHOT_MAX_RETRY	32
91 
92 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
93 {
94 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
95 
96 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
97 		     sqe->buf_index || sqe->splice_fd_in))
98 		return -EINVAL;
99 
100 	shutdown->how = READ_ONCE(sqe->len);
101 	req->flags |= REQ_F_FORCE_ASYNC;
102 	return 0;
103 }
104 
105 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
106 {
107 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
108 	struct socket *sock;
109 	int ret;
110 
111 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
112 
113 	sock = sock_from_file(req->file);
114 	if (unlikely(!sock))
115 		return -ENOTSOCK;
116 
117 	ret = __sys_shutdown_sock(sock, shutdown->how);
118 	io_req_set_res(req, ret, 0);
119 	return IOU_OK;
120 }
121 
122 static bool io_net_retry(struct socket *sock, int flags)
123 {
124 	if (!(flags & MSG_WAITALL))
125 		return false;
126 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
127 }
128 
129 static void io_netmsg_iovec_free(struct io_async_msghdr *kmsg)
130 {
131 	if (kmsg->free_iov) {
132 		kfree(kmsg->free_iov);
133 		kmsg->free_iov_nr = 0;
134 		kmsg->free_iov = NULL;
135 	}
136 }
137 
138 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
139 {
140 	struct io_async_msghdr *hdr = req->async_data;
141 	struct iovec *iov;
142 
143 	/* can't recycle, ensure we free the iovec if we have one */
144 	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
145 		io_netmsg_iovec_free(hdr);
146 		return;
147 	}
148 
149 	/* Let normal cleanup path reap it if we fail adding to the cache */
150 	iov = hdr->free_iov;
151 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr)) {
152 		if (iov)
153 			kasan_mempool_poison_object(iov);
154 		req->async_data = NULL;
155 		req->flags &= ~REQ_F_ASYNC_DATA;
156 	}
157 }
158 
159 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
160 {
161 	struct io_ring_ctx *ctx = req->ctx;
162 	struct io_async_msghdr *hdr;
163 
164 	hdr = io_alloc_cache_get(&ctx->netmsg_cache);
165 	if (hdr) {
166 		if (hdr->free_iov) {
167 			kasan_mempool_unpoison_object(hdr->free_iov,
168 				hdr->free_iov_nr * sizeof(struct iovec));
169 			req->flags |= REQ_F_NEED_CLEANUP;
170 		}
171 		req->flags |= REQ_F_ASYNC_DATA;
172 		req->async_data = hdr;
173 		return hdr;
174 	}
175 
176 	if (!io_alloc_async_data(req)) {
177 		hdr = req->async_data;
178 		hdr->free_iov_nr = 0;
179 		hdr->free_iov = NULL;
180 		return hdr;
181 	}
182 	return NULL;
183 }
184 
185 /* assign new iovec to kmsg, if we need to */
186 static int io_net_vec_assign(struct io_kiocb *req, struct io_async_msghdr *kmsg,
187 			     struct iovec *iov)
188 {
189 	if (iov) {
190 		req->flags |= REQ_F_NEED_CLEANUP;
191 		kmsg->free_iov_nr = kmsg->msg.msg_iter.nr_segs;
192 		if (kmsg->free_iov)
193 			kfree(kmsg->free_iov);
194 		kmsg->free_iov = iov;
195 	}
196 	return 0;
197 }
198 
199 static inline void io_mshot_prep_retry(struct io_kiocb *req,
200 				       struct io_async_msghdr *kmsg)
201 {
202 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
203 
204 	req->flags &= ~REQ_F_BL_EMPTY;
205 	sr->done_io = 0;
206 	sr->len = 0; /* get from the provided buffer */
207 	req->buf_index = sr->buf_group;
208 }
209 
210 #ifdef CONFIG_COMPAT
211 static int io_compat_msg_copy_hdr(struct io_kiocb *req,
212 				  struct io_async_msghdr *iomsg,
213 				  struct compat_msghdr *msg, int ddir)
214 {
215 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
216 	struct compat_iovec __user *uiov;
217 	struct iovec *iov;
218 	int ret, nr_segs;
219 
220 	if (iomsg->free_iov) {
221 		nr_segs = iomsg->free_iov_nr;
222 		iov = iomsg->free_iov;
223 	} else {
224 		iov = &iomsg->fast_iov;
225 		nr_segs = 1;
226 	}
227 
228 	if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
229 		return -EFAULT;
230 
231 	uiov = compat_ptr(msg->msg_iov);
232 	if (req->flags & REQ_F_BUFFER_SELECT) {
233 		compat_ssize_t clen;
234 
235 		if (msg->msg_iovlen == 0) {
236 			sr->len = iov->iov_len = 0;
237 			iov->iov_base = NULL;
238 		} else if (msg->msg_iovlen > 1) {
239 			return -EINVAL;
240 		} else {
241 			if (!access_ok(uiov, sizeof(*uiov)))
242 				return -EFAULT;
243 			if (__get_user(clen, &uiov->iov_len))
244 				return -EFAULT;
245 			if (clen < 0)
246 				return -EINVAL;
247 			sr->len = clen;
248 		}
249 
250 		return 0;
251 	}
252 
253 	ret = __import_iovec(ddir, (struct iovec __user *)uiov, msg->msg_iovlen,
254 				nr_segs, &iov, &iomsg->msg.msg_iter, true);
255 	if (unlikely(ret < 0))
256 		return ret;
257 
258 	return io_net_vec_assign(req, iomsg, iov);
259 }
260 #endif
261 
262 static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
263 			   struct user_msghdr *msg, int ddir)
264 {
265 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
266 	struct iovec *iov;
267 	int ret, nr_segs;
268 
269 	if (iomsg->free_iov) {
270 		nr_segs = iomsg->free_iov_nr;
271 		iov = iomsg->free_iov;
272 	} else {
273 		iov = &iomsg->fast_iov;
274 		nr_segs = 1;
275 	}
276 
277 	if (!user_access_begin(sr->umsg, sizeof(*sr->umsg)))
278 		return -EFAULT;
279 
280 	ret = -EFAULT;
281 	unsafe_get_user(msg->msg_name, &sr->umsg->msg_name, ua_end);
282 	unsafe_get_user(msg->msg_namelen, &sr->umsg->msg_namelen, ua_end);
283 	unsafe_get_user(msg->msg_iov, &sr->umsg->msg_iov, ua_end);
284 	unsafe_get_user(msg->msg_iovlen, &sr->umsg->msg_iovlen, ua_end);
285 	unsafe_get_user(msg->msg_control, &sr->umsg->msg_control, ua_end);
286 	unsafe_get_user(msg->msg_controllen, &sr->umsg->msg_controllen, ua_end);
287 	msg->msg_flags = 0;
288 
289 	if (req->flags & REQ_F_BUFFER_SELECT) {
290 		if (msg->msg_iovlen == 0) {
291 			sr->len = iov->iov_len = 0;
292 			iov->iov_base = NULL;
293 		} else if (msg->msg_iovlen > 1) {
294 			ret = -EINVAL;
295 			goto ua_end;
296 		} else {
297 			/* we only need the length for provided buffers */
298 			if (!access_ok(&msg->msg_iov[0].iov_len, sizeof(__kernel_size_t)))
299 				goto ua_end;
300 			unsafe_get_user(iov->iov_len, &msg->msg_iov[0].iov_len,
301 					ua_end);
302 			sr->len = iov->iov_len;
303 		}
304 		ret = 0;
305 ua_end:
306 		user_access_end();
307 		return ret;
308 	}
309 
310 	user_access_end();
311 	ret = __import_iovec(ddir, msg->msg_iov, msg->msg_iovlen, nr_segs,
312 				&iov, &iomsg->msg.msg_iter, false);
313 	if (unlikely(ret < 0))
314 		return ret;
315 
316 	return io_net_vec_assign(req, iomsg, iov);
317 }
318 
319 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
320 			       struct io_async_msghdr *iomsg)
321 {
322 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
323 	struct user_msghdr msg;
324 	int ret;
325 
326 	iomsg->msg.msg_name = &iomsg->addr;
327 	iomsg->msg.msg_iter.nr_segs = 0;
328 
329 #ifdef CONFIG_COMPAT
330 	if (unlikely(req->ctx->compat)) {
331 		struct compat_msghdr cmsg;
332 
333 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_SOURCE);
334 		if (unlikely(ret))
335 			return ret;
336 
337 		return __get_compat_msghdr(&iomsg->msg, &cmsg, NULL);
338 	}
339 #endif
340 
341 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_SOURCE);
342 	if (unlikely(ret))
343 		return ret;
344 
345 	ret = __copy_msghdr(&iomsg->msg, &msg, NULL);
346 
347 	/* save msg_control as sys_sendmsg() overwrites it */
348 	sr->msg_control = iomsg->msg.msg_control_user;
349 	return ret;
350 }
351 
352 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
353 {
354 	struct io_async_msghdr *io = req->async_data;
355 
356 	io_netmsg_iovec_free(io);
357 }
358 
359 static int io_send_setup(struct io_kiocb *req)
360 {
361 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
362 	struct io_async_msghdr *kmsg = req->async_data;
363 	int ret;
364 
365 	kmsg->msg.msg_name = NULL;
366 	kmsg->msg.msg_namelen = 0;
367 	kmsg->msg.msg_control = NULL;
368 	kmsg->msg.msg_controllen = 0;
369 	kmsg->msg.msg_ubuf = NULL;
370 
371 	if (sr->addr) {
372 		ret = move_addr_to_kernel(sr->addr, sr->addr_len, &kmsg->addr);
373 		if (unlikely(ret < 0))
374 			return ret;
375 		kmsg->msg.msg_name = &kmsg->addr;
376 		kmsg->msg.msg_namelen = sr->addr_len;
377 	}
378 	if (!io_do_buffer_select(req)) {
379 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
380 				  &kmsg->msg.msg_iter);
381 		if (unlikely(ret < 0))
382 			return ret;
383 	}
384 	return 0;
385 }
386 
387 static int io_sendmsg_prep_setup(struct io_kiocb *req, int is_msg)
388 {
389 	struct io_async_msghdr *kmsg;
390 	int ret;
391 
392 	kmsg = io_msg_alloc_async(req);
393 	if (unlikely(!kmsg))
394 		return -ENOMEM;
395 	if (!is_msg)
396 		return io_send_setup(req);
397 	ret = io_sendmsg_copy_hdr(req, kmsg);
398 	if (!ret)
399 		req->flags |= REQ_F_NEED_CLEANUP;
400 	return ret;
401 }
402 
403 #define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE)
404 
405 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
406 {
407 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
408 
409 	sr->done_io = 0;
410 
411 	if (req->opcode == IORING_OP_SEND) {
412 		if (READ_ONCE(sqe->__pad3[0]))
413 			return -EINVAL;
414 		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
415 		sr->addr_len = READ_ONCE(sqe->addr_len);
416 	} else if (sqe->addr2 || sqe->file_index) {
417 		return -EINVAL;
418 	}
419 
420 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
421 	sr->len = READ_ONCE(sqe->len);
422 	sr->flags = READ_ONCE(sqe->ioprio);
423 	if (sr->flags & ~SENDMSG_FLAGS)
424 		return -EINVAL;
425 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
426 	if (sr->msg_flags & MSG_DONTWAIT)
427 		req->flags |= REQ_F_NOWAIT;
428 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
429 		if (req->opcode == IORING_OP_SENDMSG)
430 			return -EINVAL;
431 		if (!(req->flags & REQ_F_BUFFER_SELECT))
432 			return -EINVAL;
433 		sr->msg_flags |= MSG_WAITALL;
434 		sr->buf_group = req->buf_index;
435 		req->buf_list = NULL;
436 	}
437 	if (req->flags & REQ_F_BUFFER_SELECT && sr->len)
438 		return -EINVAL;
439 
440 #ifdef CONFIG_COMPAT
441 	if (req->ctx->compat)
442 		sr->msg_flags |= MSG_CMSG_COMPAT;
443 #endif
444 	return io_sendmsg_prep_setup(req, req->opcode == IORING_OP_SENDMSG);
445 }
446 
447 static void io_req_msg_cleanup(struct io_kiocb *req,
448 			       unsigned int issue_flags)
449 {
450 	req->flags &= ~REQ_F_NEED_CLEANUP;
451 	io_netmsg_recycle(req, issue_flags);
452 }
453 
454 /*
455  * For bundle completions, we need to figure out how many segments we consumed.
456  * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
457  * could be using an ITER_IOVEC. If the latter, then if we consumed all of
458  * the segments, then it's a trivial questiont o answer. If we have residual
459  * data in the iter, then loop the segments to figure out how much we
460  * transferred.
461  */
462 static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
463 {
464 	struct iovec *iov;
465 	int nbufs;
466 
467 	/* no data is always zero segments, and a ubuf is always 1 segment */
468 	if (ret <= 0)
469 		return 0;
470 	if (iter_is_ubuf(&kmsg->msg.msg_iter))
471 		return 1;
472 
473 	iov = kmsg->free_iov;
474 	if (!iov)
475 		iov = &kmsg->fast_iov;
476 
477 	/* if all data was transferred, it's basic pointer math */
478 	if (!iov_iter_count(&kmsg->msg.msg_iter))
479 		return iter_iov(&kmsg->msg.msg_iter) - iov;
480 
481 	/* short transfer, count segments */
482 	nbufs = 0;
483 	do {
484 		int this_len = min_t(int, iov[nbufs].iov_len, ret);
485 
486 		nbufs++;
487 		ret -= this_len;
488 	} while (ret);
489 
490 	return nbufs;
491 }
492 
493 static inline bool io_send_finish(struct io_kiocb *req, int *ret,
494 				  struct io_async_msghdr *kmsg,
495 				  unsigned issue_flags)
496 {
497 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
498 	bool bundle_finished = *ret <= 0;
499 	unsigned int cflags;
500 
501 	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
502 		cflags = io_put_kbuf(req, issue_flags);
503 		goto finish;
504 	}
505 
506 	cflags = io_put_kbufs(req, io_bundle_nbufs(kmsg, *ret), issue_flags);
507 
508 	if (bundle_finished || req->flags & REQ_F_BL_EMPTY)
509 		goto finish;
510 
511 	/*
512 	 * Fill CQE for this receive and see if we should keep trying to
513 	 * receive from this socket.
514 	 */
515 	if (io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
516 		io_mshot_prep_retry(req, kmsg);
517 		return false;
518 	}
519 
520 	/* Otherwise stop bundle and use the current result. */
521 finish:
522 	io_req_set_res(req, *ret, cflags);
523 	*ret = IOU_OK;
524 	return true;
525 }
526 
527 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
528 {
529 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
530 	struct io_async_msghdr *kmsg = req->async_data;
531 	struct socket *sock;
532 	unsigned flags;
533 	int min_ret = 0;
534 	int ret;
535 
536 	sock = sock_from_file(req->file);
537 	if (unlikely(!sock))
538 		return -ENOTSOCK;
539 
540 	if (!(req->flags & REQ_F_POLLED) &&
541 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
542 		return -EAGAIN;
543 
544 	flags = sr->msg_flags;
545 	if (issue_flags & IO_URING_F_NONBLOCK)
546 		flags |= MSG_DONTWAIT;
547 	if (flags & MSG_WAITALL)
548 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
549 
550 	kmsg->msg.msg_control_user = sr->msg_control;
551 
552 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
553 
554 	if (ret < min_ret) {
555 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
556 			return -EAGAIN;
557 		if (ret > 0 && io_net_retry(sock, flags)) {
558 			kmsg->msg.msg_controllen = 0;
559 			kmsg->msg.msg_control = NULL;
560 			sr->done_io += ret;
561 			req->flags |= REQ_F_BL_NO_RECYCLE;
562 			return -EAGAIN;
563 		}
564 		if (ret == -ERESTARTSYS)
565 			ret = -EINTR;
566 		req_set_fail(req);
567 	}
568 	io_req_msg_cleanup(req, issue_flags);
569 	if (ret >= 0)
570 		ret += sr->done_io;
571 	else if (sr->done_io)
572 		ret = sr->done_io;
573 	io_req_set_res(req, ret, 0);
574 	return IOU_OK;
575 }
576 
577 int io_send(struct io_kiocb *req, unsigned int issue_flags)
578 {
579 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
580 	struct io_async_msghdr *kmsg = req->async_data;
581 	struct socket *sock;
582 	unsigned flags;
583 	int min_ret = 0;
584 	int ret;
585 
586 	sock = sock_from_file(req->file);
587 	if (unlikely(!sock))
588 		return -ENOTSOCK;
589 
590 	if (!(req->flags & REQ_F_POLLED) &&
591 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
592 		return -EAGAIN;
593 
594 	flags = sr->msg_flags;
595 	if (issue_flags & IO_URING_F_NONBLOCK)
596 		flags |= MSG_DONTWAIT;
597 
598 retry_bundle:
599 	if (io_do_buffer_select(req)) {
600 		struct buf_sel_arg arg = {
601 			.iovs = &kmsg->fast_iov,
602 			.max_len = INT_MAX,
603 			.nr_iovs = 1,
604 			.mode = KBUF_MODE_EXPAND,
605 		};
606 
607 		if (kmsg->free_iov) {
608 			arg.nr_iovs = kmsg->free_iov_nr;
609 			arg.iovs = kmsg->free_iov;
610 			arg.mode |= KBUF_MODE_FREE;
611 		}
612 
613 		if (!(sr->flags & IORING_RECVSEND_BUNDLE))
614 			arg.nr_iovs = 1;
615 
616 		ret = io_buffers_select(req, &arg, issue_flags);
617 		if (unlikely(ret < 0))
618 			return ret;
619 
620 		sr->len = arg.out_len;
621 		iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE, arg.iovs, ret,
622 				arg.out_len);
623 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->free_iov) {
624 			kmsg->free_iov_nr = ret;
625 			kmsg->free_iov = arg.iovs;
626 		}
627 	}
628 
629 	/*
630 	 * If MSG_WAITALL is set, or this is a bundle send, then we need
631 	 * the full amount. If just bundle is set, if we do a short send
632 	 * then we complete the bundle sequence rather than continue on.
633 	 */
634 	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
635 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
636 
637 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
638 	kmsg->msg.msg_flags = flags;
639 	ret = sock_sendmsg(sock, &kmsg->msg);
640 	if (ret < min_ret) {
641 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
642 			return -EAGAIN;
643 
644 		if (ret > 0 && io_net_retry(sock, flags)) {
645 			sr->len -= ret;
646 			sr->buf += ret;
647 			sr->done_io += ret;
648 			req->flags |= REQ_F_BL_NO_RECYCLE;
649 			return -EAGAIN;
650 		}
651 		if (ret == -ERESTARTSYS)
652 			ret = -EINTR;
653 		req_set_fail(req);
654 	}
655 	if (ret >= 0)
656 		ret += sr->done_io;
657 	else if (sr->done_io)
658 		ret = sr->done_io;
659 
660 	if (!io_send_finish(req, &ret, kmsg, issue_flags))
661 		goto retry_bundle;
662 
663 	io_req_msg_cleanup(req, issue_flags);
664 	return ret;
665 }
666 
667 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
668 				 struct io_async_msghdr *iomsg,
669 				 int namelen, size_t controllen)
670 {
671 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
672 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
673 		int hdr;
674 
675 		if (unlikely(namelen < 0))
676 			return -EOVERFLOW;
677 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
678 					namelen, &hdr))
679 			return -EOVERFLOW;
680 		if (check_add_overflow(hdr, controllen, &hdr))
681 			return -EOVERFLOW;
682 
683 		iomsg->namelen = namelen;
684 		iomsg->controllen = controllen;
685 		return 0;
686 	}
687 
688 	return 0;
689 }
690 
691 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
692 			       struct io_async_msghdr *iomsg)
693 {
694 	struct user_msghdr msg;
695 	int ret;
696 
697 	iomsg->msg.msg_name = &iomsg->addr;
698 	iomsg->msg.msg_iter.nr_segs = 0;
699 
700 #ifdef CONFIG_COMPAT
701 	if (unlikely(req->ctx->compat)) {
702 		struct compat_msghdr cmsg;
703 
704 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_DEST);
705 		if (unlikely(ret))
706 			return ret;
707 
708 		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, &iomsg->uaddr);
709 		if (unlikely(ret))
710 			return ret;
711 
712 		return io_recvmsg_mshot_prep(req, iomsg, cmsg.msg_namelen,
713 						cmsg.msg_controllen);
714 	}
715 #endif
716 
717 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST);
718 	if (unlikely(ret))
719 		return ret;
720 
721 	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
722 	if (unlikely(ret))
723 		return ret;
724 
725 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
726 					msg.msg_controllen);
727 }
728 
729 static int io_recvmsg_prep_setup(struct io_kiocb *req)
730 {
731 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
732 	struct io_async_msghdr *kmsg;
733 	int ret;
734 
735 	kmsg = io_msg_alloc_async(req);
736 	if (unlikely(!kmsg))
737 		return -ENOMEM;
738 
739 	if (req->opcode == IORING_OP_RECV) {
740 		kmsg->msg.msg_name = NULL;
741 		kmsg->msg.msg_namelen = 0;
742 		kmsg->msg.msg_control = NULL;
743 		kmsg->msg.msg_get_inq = 1;
744 		kmsg->msg.msg_controllen = 0;
745 		kmsg->msg.msg_iocb = NULL;
746 		kmsg->msg.msg_ubuf = NULL;
747 
748 		if (!io_do_buffer_select(req)) {
749 			ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
750 					  &kmsg->msg.msg_iter);
751 			if (unlikely(ret))
752 				return ret;
753 		}
754 		return 0;
755 	}
756 
757 	ret = io_recvmsg_copy_hdr(req, kmsg);
758 	if (!ret)
759 		req->flags |= REQ_F_NEED_CLEANUP;
760 	return ret;
761 }
762 
763 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
764 			IORING_RECVSEND_BUNDLE)
765 
766 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
767 {
768 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
769 
770 	sr->done_io = 0;
771 
772 	if (unlikely(sqe->file_index || sqe->addr2))
773 		return -EINVAL;
774 
775 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
776 	sr->len = READ_ONCE(sqe->len);
777 	sr->flags = READ_ONCE(sqe->ioprio);
778 	if (sr->flags & ~RECVMSG_FLAGS)
779 		return -EINVAL;
780 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
781 	if (sr->msg_flags & MSG_DONTWAIT)
782 		req->flags |= REQ_F_NOWAIT;
783 	if (sr->msg_flags & MSG_ERRQUEUE)
784 		req->flags |= REQ_F_CLEAR_POLLIN;
785 	if (req->flags & REQ_F_BUFFER_SELECT) {
786 		/*
787 		 * Store the buffer group for this multishot receive separately,
788 		 * as if we end up doing an io-wq based issue that selects a
789 		 * buffer, it has to be committed immediately and that will
790 		 * clear ->buf_list. This means we lose the link to the buffer
791 		 * list, and the eventual buffer put on completion then cannot
792 		 * restore it.
793 		 */
794 		sr->buf_group = req->buf_index;
795 		req->buf_list = NULL;
796 	}
797 	if (sr->flags & IORING_RECV_MULTISHOT) {
798 		if (!(req->flags & REQ_F_BUFFER_SELECT))
799 			return -EINVAL;
800 		if (sr->msg_flags & MSG_WAITALL)
801 			return -EINVAL;
802 		if (req->opcode == IORING_OP_RECV && sr->len)
803 			return -EINVAL;
804 		req->flags |= REQ_F_APOLL_MULTISHOT;
805 	}
806 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
807 		if (req->opcode == IORING_OP_RECVMSG)
808 			return -EINVAL;
809 	}
810 
811 #ifdef CONFIG_COMPAT
812 	if (req->ctx->compat)
813 		sr->msg_flags |= MSG_CMSG_COMPAT;
814 #endif
815 	sr->nr_multishot_loops = 0;
816 	return io_recvmsg_prep_setup(req);
817 }
818 
819 /*
820  * Finishes io_recv and io_recvmsg.
821  *
822  * Returns true if it is actually finished, or false if it should run
823  * again (for multishot).
824  */
825 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
826 				  struct io_async_msghdr *kmsg,
827 				  bool mshot_finished, unsigned issue_flags)
828 {
829 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
830 	unsigned int cflags = 0;
831 
832 	if (kmsg->msg.msg_inq > 0)
833 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
834 
835 	if (sr->flags & IORING_RECVSEND_BUNDLE) {
836 		cflags |= io_put_kbufs(req, io_bundle_nbufs(kmsg, *ret),
837 				      issue_flags);
838 		/* bundle with no more immediate buffers, we're done */
839 		if (req->flags & REQ_F_BL_EMPTY)
840 			goto finish;
841 	} else {
842 		cflags |= io_put_kbuf(req, issue_flags);
843 	}
844 
845 	/*
846 	 * Fill CQE for this receive and see if we should keep trying to
847 	 * receive from this socket.
848 	 */
849 	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
850 	    io_req_post_cqe(req, *ret, cflags | IORING_CQE_F_MORE)) {
851 		int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;
852 
853 		io_mshot_prep_retry(req, kmsg);
854 		/* Known not-empty or unknown state, retry */
855 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
856 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY)
857 				return false;
858 			/* mshot retries exceeded, force a requeue */
859 			sr->nr_multishot_loops = 0;
860 			mshot_retry_ret = IOU_REQUEUE;
861 		}
862 		if (issue_flags & IO_URING_F_MULTISHOT)
863 			*ret = mshot_retry_ret;
864 		else
865 			*ret = -EAGAIN;
866 		return true;
867 	}
868 
869 	/* Finish the request / stop multishot. */
870 finish:
871 	io_req_set_res(req, *ret, cflags);
872 
873 	if (issue_flags & IO_URING_F_MULTISHOT)
874 		*ret = IOU_STOP_MULTISHOT;
875 	else
876 		*ret = IOU_OK;
877 	io_req_msg_cleanup(req, issue_flags);
878 	return true;
879 }
880 
881 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
882 				     struct io_sr_msg *sr, void __user **buf,
883 				     size_t *len)
884 {
885 	unsigned long ubuf = (unsigned long) *buf;
886 	unsigned long hdr;
887 
888 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
889 		kmsg->controllen;
890 	if (*len < hdr)
891 		return -EFAULT;
892 
893 	if (kmsg->controllen) {
894 		unsigned long control = ubuf + hdr - kmsg->controllen;
895 
896 		kmsg->msg.msg_control_user = (void __user *) control;
897 		kmsg->msg.msg_controllen = kmsg->controllen;
898 	}
899 
900 	sr->buf = *buf; /* stash for later copy */
901 	*buf = (void __user *) (ubuf + hdr);
902 	kmsg->payloadlen = *len = *len - hdr;
903 	return 0;
904 }
905 
906 struct io_recvmsg_multishot_hdr {
907 	struct io_uring_recvmsg_out msg;
908 	struct sockaddr_storage addr;
909 };
910 
911 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
912 				struct io_async_msghdr *kmsg,
913 				unsigned int flags, bool *finished)
914 {
915 	int err;
916 	int copy_len;
917 	struct io_recvmsg_multishot_hdr hdr;
918 
919 	if (kmsg->namelen)
920 		kmsg->msg.msg_name = &hdr.addr;
921 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
922 	kmsg->msg.msg_namelen = 0;
923 
924 	if (sock->file->f_flags & O_NONBLOCK)
925 		flags |= MSG_DONTWAIT;
926 
927 	err = sock_recvmsg(sock, &kmsg->msg, flags);
928 	*finished = err <= 0;
929 	if (err < 0)
930 		return err;
931 
932 	hdr.msg = (struct io_uring_recvmsg_out) {
933 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
934 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
935 	};
936 
937 	hdr.msg.payloadlen = err;
938 	if (err > kmsg->payloadlen)
939 		err = kmsg->payloadlen;
940 
941 	copy_len = sizeof(struct io_uring_recvmsg_out);
942 	if (kmsg->msg.msg_namelen > kmsg->namelen)
943 		copy_len += kmsg->namelen;
944 	else
945 		copy_len += kmsg->msg.msg_namelen;
946 
947 	/*
948 	 *      "fromlen shall refer to the value before truncation.."
949 	 *                      1003.1g
950 	 */
951 	hdr.msg.namelen = kmsg->msg.msg_namelen;
952 
953 	/* ensure that there is no gap between hdr and sockaddr_storage */
954 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
955 		     sizeof(struct io_uring_recvmsg_out));
956 	if (copy_to_user(io->buf, &hdr, copy_len)) {
957 		*finished = true;
958 		return -EFAULT;
959 	}
960 
961 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
962 			kmsg->controllen + err;
963 }
964 
965 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
966 {
967 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
968 	struct io_async_msghdr *kmsg = req->async_data;
969 	struct socket *sock;
970 	unsigned flags;
971 	int ret, min_ret = 0;
972 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
973 	bool mshot_finished = true;
974 
975 	sock = sock_from_file(req->file);
976 	if (unlikely(!sock))
977 		return -ENOTSOCK;
978 
979 	if (!(req->flags & REQ_F_POLLED) &&
980 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
981 		return -EAGAIN;
982 
983 	flags = sr->msg_flags;
984 	if (force_nonblock)
985 		flags |= MSG_DONTWAIT;
986 
987 retry_multishot:
988 	if (io_do_buffer_select(req)) {
989 		void __user *buf;
990 		size_t len = sr->len;
991 
992 		buf = io_buffer_select(req, &len, issue_flags);
993 		if (!buf)
994 			return -ENOBUFS;
995 
996 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
997 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
998 			if (ret) {
999 				io_kbuf_recycle(req, issue_flags);
1000 				return ret;
1001 			}
1002 		}
1003 
1004 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
1005 	}
1006 
1007 	kmsg->msg.msg_get_inq = 1;
1008 	kmsg->msg.msg_inq = -1;
1009 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
1010 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
1011 					   &mshot_finished);
1012 	} else {
1013 		/* disable partial retry for recvmsg with cmsg attached */
1014 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
1015 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1016 
1017 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
1018 					 kmsg->uaddr, flags);
1019 	}
1020 
1021 	if (ret < min_ret) {
1022 		if (ret == -EAGAIN && force_nonblock) {
1023 			if (issue_flags & IO_URING_F_MULTISHOT) {
1024 				io_kbuf_recycle(req, issue_flags);
1025 				return IOU_ISSUE_SKIP_COMPLETE;
1026 			}
1027 			return -EAGAIN;
1028 		}
1029 		if (ret > 0 && io_net_retry(sock, flags)) {
1030 			sr->done_io += ret;
1031 			req->flags |= REQ_F_BL_NO_RECYCLE;
1032 			return -EAGAIN;
1033 		}
1034 		if (ret == -ERESTARTSYS)
1035 			ret = -EINTR;
1036 		req_set_fail(req);
1037 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1038 		req_set_fail(req);
1039 	}
1040 
1041 	if (ret > 0)
1042 		ret += sr->done_io;
1043 	else if (sr->done_io)
1044 		ret = sr->done_io;
1045 	else
1046 		io_kbuf_recycle(req, issue_flags);
1047 
1048 	if (!io_recv_finish(req, &ret, kmsg, mshot_finished, issue_flags))
1049 		goto retry_multishot;
1050 
1051 	return ret;
1052 }
1053 
1054 static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
1055 			      size_t *len, unsigned int issue_flags)
1056 {
1057 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1058 	int ret;
1059 
1060 	/*
1061 	 * If the ring isn't locked, then don't use the peek interface
1062 	 * to grab multiple buffers as we will lock/unlock between
1063 	 * this selection and posting the buffers.
1064 	 */
1065 	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
1066 	    sr->flags & IORING_RECVSEND_BUNDLE) {
1067 		struct buf_sel_arg arg = {
1068 			.iovs = &kmsg->fast_iov,
1069 			.nr_iovs = 1,
1070 			.mode = KBUF_MODE_EXPAND,
1071 		};
1072 
1073 		if (kmsg->free_iov) {
1074 			arg.nr_iovs = kmsg->free_iov_nr;
1075 			arg.iovs = kmsg->free_iov;
1076 			arg.mode |= KBUF_MODE_FREE;
1077 		}
1078 
1079 		if (kmsg->msg.msg_inq > 0)
1080 			arg.max_len = min_not_zero(sr->len, kmsg->msg.msg_inq);
1081 
1082 		ret = io_buffers_peek(req, &arg);
1083 		if (unlikely(ret < 0))
1084 			return ret;
1085 
1086 		/* special case 1 vec, can be a fast path */
1087 		if (ret == 1) {
1088 			sr->buf = arg.iovs[0].iov_base;
1089 			sr->len = arg.iovs[0].iov_len;
1090 			goto map_ubuf;
1091 		}
1092 		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
1093 				arg.out_len);
1094 		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->free_iov) {
1095 			kmsg->free_iov_nr = ret;
1096 			kmsg->free_iov = arg.iovs;
1097 		}
1098 	} else {
1099 		void __user *buf;
1100 
1101 		*len = sr->len;
1102 		buf = io_buffer_select(req, len, issue_flags);
1103 		if (!buf)
1104 			return -ENOBUFS;
1105 		sr->buf = buf;
1106 		sr->len = *len;
1107 map_ubuf:
1108 		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
1109 				  &kmsg->msg.msg_iter);
1110 		if (unlikely(ret))
1111 			return ret;
1112 	}
1113 
1114 	return 0;
1115 }
1116 
1117 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
1118 {
1119 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1120 	struct io_async_msghdr *kmsg = req->async_data;
1121 	struct socket *sock;
1122 	unsigned flags;
1123 	int ret, min_ret = 0;
1124 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1125 	size_t len = sr->len;
1126 
1127 	if (!(req->flags & REQ_F_POLLED) &&
1128 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1129 		return -EAGAIN;
1130 
1131 	sock = sock_from_file(req->file);
1132 	if (unlikely(!sock))
1133 		return -ENOTSOCK;
1134 
1135 	flags = sr->msg_flags;
1136 	if (force_nonblock)
1137 		flags |= MSG_DONTWAIT;
1138 
1139 retry_multishot:
1140 	if (io_do_buffer_select(req)) {
1141 		ret = io_recv_buf_select(req, kmsg, &len, issue_flags);
1142 		if (unlikely(ret)) {
1143 			kmsg->msg.msg_inq = -1;
1144 			goto out_free;
1145 		}
1146 		sr->buf = NULL;
1147 	}
1148 
1149 	kmsg->msg.msg_flags = 0;
1150 	kmsg->msg.msg_inq = -1;
1151 
1152 	if (flags & MSG_WAITALL)
1153 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1154 
1155 	ret = sock_recvmsg(sock, &kmsg->msg, flags);
1156 	if (ret < min_ret) {
1157 		if (ret == -EAGAIN && force_nonblock) {
1158 			if (issue_flags & IO_URING_F_MULTISHOT) {
1159 				io_kbuf_recycle(req, issue_flags);
1160 				return IOU_ISSUE_SKIP_COMPLETE;
1161 			}
1162 
1163 			return -EAGAIN;
1164 		}
1165 		if (ret > 0 && io_net_retry(sock, flags)) {
1166 			sr->len -= ret;
1167 			sr->buf += ret;
1168 			sr->done_io += ret;
1169 			req->flags |= REQ_F_BL_NO_RECYCLE;
1170 			return -EAGAIN;
1171 		}
1172 		if (ret == -ERESTARTSYS)
1173 			ret = -EINTR;
1174 		req_set_fail(req);
1175 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1176 out_free:
1177 		req_set_fail(req);
1178 	}
1179 
1180 	if (ret > 0)
1181 		ret += sr->done_io;
1182 	else if (sr->done_io)
1183 		ret = sr->done_io;
1184 	else
1185 		io_kbuf_recycle(req, issue_flags);
1186 
1187 	if (!io_recv_finish(req, &ret, kmsg, ret <= 0, issue_flags))
1188 		goto retry_multishot;
1189 
1190 	return ret;
1191 }
1192 
1193 void io_send_zc_cleanup(struct io_kiocb *req)
1194 {
1195 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1196 	struct io_async_msghdr *io = req->async_data;
1197 
1198 	if (req_has_async_data(req))
1199 		io_netmsg_iovec_free(io);
1200 	if (zc->notif) {
1201 		io_notif_flush(zc->notif);
1202 		zc->notif = NULL;
1203 	}
1204 }
1205 
1206 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1207 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE)
1208 
1209 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1210 {
1211 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1212 	struct io_ring_ctx *ctx = req->ctx;
1213 	struct io_kiocb *notif;
1214 
1215 	zc->done_io = 0;
1216 	req->flags |= REQ_F_POLL_NO_LAZY;
1217 
1218 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
1219 		return -EINVAL;
1220 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1221 	if (req->flags & REQ_F_CQE_SKIP)
1222 		return -EINVAL;
1223 
1224 	notif = zc->notif = io_alloc_notif(ctx);
1225 	if (!notif)
1226 		return -ENOMEM;
1227 	notif->cqe.user_data = req->cqe.user_data;
1228 	notif->cqe.res = 0;
1229 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1230 	req->flags |= REQ_F_NEED_CLEANUP;
1231 
1232 	zc->flags = READ_ONCE(sqe->ioprio);
1233 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1234 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1235 			return -EINVAL;
1236 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1237 			struct io_notif_data *nd = io_notif_to_data(notif);
1238 
1239 			nd->zc_report = true;
1240 			nd->zc_used = false;
1241 			nd->zc_copied = false;
1242 		}
1243 	}
1244 
1245 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1246 		unsigned idx = READ_ONCE(sqe->buf_index);
1247 
1248 		if (unlikely(idx >= ctx->nr_user_bufs))
1249 			return -EFAULT;
1250 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
1251 		req->imu = READ_ONCE(ctx->user_bufs[idx]);
1252 		io_req_set_rsrc_node(notif, ctx, 0);
1253 	}
1254 
1255 	if (req->opcode == IORING_OP_SEND_ZC) {
1256 		if (READ_ONCE(sqe->__pad3[0]))
1257 			return -EINVAL;
1258 		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1259 		zc->addr_len = READ_ONCE(sqe->addr_len);
1260 	} else {
1261 		if (unlikely(sqe->addr2 || sqe->file_index))
1262 			return -EINVAL;
1263 		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
1264 			return -EINVAL;
1265 	}
1266 
1267 	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
1268 	zc->len = READ_ONCE(sqe->len);
1269 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
1270 	if (zc->msg_flags & MSG_DONTWAIT)
1271 		req->flags |= REQ_F_NOWAIT;
1272 
1273 #ifdef CONFIG_COMPAT
1274 	if (req->ctx->compat)
1275 		zc->msg_flags |= MSG_CMSG_COMPAT;
1276 #endif
1277 	return io_sendmsg_prep_setup(req, req->opcode == IORING_OP_SENDMSG_ZC);
1278 }
1279 
1280 static int io_sg_from_iter_iovec(struct sk_buff *skb,
1281 				 struct iov_iter *from, size_t length)
1282 {
1283 	skb_zcopy_downgrade_managed(skb);
1284 	return zerocopy_fill_skb_from_iter(skb, from, length);
1285 }
1286 
1287 static int io_sg_from_iter(struct sk_buff *skb,
1288 			   struct iov_iter *from, size_t length)
1289 {
1290 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1291 	int frag = shinfo->nr_frags;
1292 	int ret = 0;
1293 	struct bvec_iter bi;
1294 	ssize_t copied = 0;
1295 	unsigned long truesize = 0;
1296 
1297 	if (!frag)
1298 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1299 	else if (unlikely(!skb_zcopy_managed(skb)))
1300 		return zerocopy_fill_skb_from_iter(skb, from, length);
1301 
1302 	bi.bi_size = min(from->count, length);
1303 	bi.bi_bvec_done = from->iov_offset;
1304 	bi.bi_idx = 0;
1305 
1306 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1307 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1308 
1309 		copied += v.bv_len;
1310 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1311 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1312 					   v.bv_offset, v.bv_len);
1313 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1314 	}
1315 	if (bi.bi_size)
1316 		ret = -EMSGSIZE;
1317 
1318 	shinfo->nr_frags = frag;
1319 	from->bvec += bi.bi_idx;
1320 	from->nr_segs -= bi.bi_idx;
1321 	from->count -= copied;
1322 	from->iov_offset = bi.bi_bvec_done;
1323 
1324 	skb->data_len += copied;
1325 	skb->len += copied;
1326 	skb->truesize += truesize;
1327 	return ret;
1328 }
1329 
1330 static int io_send_zc_import(struct io_kiocb *req, struct io_async_msghdr *kmsg)
1331 {
1332 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1333 	int ret;
1334 
1335 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
1336 		ret = io_import_fixed(ITER_SOURCE, &kmsg->msg.msg_iter, req->imu,
1337 					(u64)(uintptr_t)sr->buf, sr->len);
1338 		if (unlikely(ret))
1339 			return ret;
1340 		kmsg->msg.sg_from_iter = io_sg_from_iter;
1341 	} else {
1342 		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
1343 		if (unlikely(ret))
1344 			return ret;
1345 		ret = io_notif_account_mem(sr->notif, sr->len);
1346 		if (unlikely(ret))
1347 			return ret;
1348 		kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1349 	}
1350 
1351 	return ret;
1352 }
1353 
1354 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1355 {
1356 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1357 	struct io_async_msghdr *kmsg = req->async_data;
1358 	struct socket *sock;
1359 	unsigned msg_flags;
1360 	int ret, min_ret = 0;
1361 
1362 	sock = sock_from_file(req->file);
1363 	if (unlikely(!sock))
1364 		return -ENOTSOCK;
1365 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1366 		return -EOPNOTSUPP;
1367 
1368 	if (!(req->flags & REQ_F_POLLED) &&
1369 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1370 		return -EAGAIN;
1371 
1372 	if (!zc->done_io) {
1373 		ret = io_send_zc_import(req, kmsg);
1374 		if (unlikely(ret))
1375 			return ret;
1376 	}
1377 
1378 	msg_flags = zc->msg_flags;
1379 	if (issue_flags & IO_URING_F_NONBLOCK)
1380 		msg_flags |= MSG_DONTWAIT;
1381 	if (msg_flags & MSG_WAITALL)
1382 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1383 	msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1384 
1385 	kmsg->msg.msg_flags = msg_flags;
1386 	kmsg->msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1387 	ret = sock_sendmsg(sock, &kmsg->msg);
1388 
1389 	if (unlikely(ret < min_ret)) {
1390 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1391 			return -EAGAIN;
1392 
1393 		if (ret > 0 && io_net_retry(sock, kmsg->msg.msg_flags)) {
1394 			zc->len -= ret;
1395 			zc->buf += ret;
1396 			zc->done_io += ret;
1397 			req->flags |= REQ_F_BL_NO_RECYCLE;
1398 			return -EAGAIN;
1399 		}
1400 		if (ret == -ERESTARTSYS)
1401 			ret = -EINTR;
1402 		req_set_fail(req);
1403 	}
1404 
1405 	if (ret >= 0)
1406 		ret += zc->done_io;
1407 	else if (zc->done_io)
1408 		ret = zc->done_io;
1409 
1410 	/*
1411 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1412 	 * flushing notif to io_send_zc_cleanup()
1413 	 */
1414 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1415 		io_notif_flush(zc->notif);
1416 		io_req_msg_cleanup(req, 0);
1417 	}
1418 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1419 	return IOU_OK;
1420 }
1421 
1422 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1423 {
1424 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1425 	struct io_async_msghdr *kmsg = req->async_data;
1426 	struct socket *sock;
1427 	unsigned flags;
1428 	int ret, min_ret = 0;
1429 
1430 	sock = sock_from_file(req->file);
1431 	if (unlikely(!sock))
1432 		return -ENOTSOCK;
1433 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1434 		return -EOPNOTSUPP;
1435 
1436 	if (!(req->flags & REQ_F_POLLED) &&
1437 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1438 		return -EAGAIN;
1439 
1440 	flags = sr->msg_flags;
1441 	if (issue_flags & IO_URING_F_NONBLOCK)
1442 		flags |= MSG_DONTWAIT;
1443 	if (flags & MSG_WAITALL)
1444 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1445 
1446 	kmsg->msg.msg_control_user = sr->msg_control;
1447 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1448 	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1449 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1450 
1451 	if (unlikely(ret < min_ret)) {
1452 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1453 			return -EAGAIN;
1454 
1455 		if (ret > 0 && io_net_retry(sock, flags)) {
1456 			sr->done_io += ret;
1457 			req->flags |= REQ_F_BL_NO_RECYCLE;
1458 			return -EAGAIN;
1459 		}
1460 		if (ret == -ERESTARTSYS)
1461 			ret = -EINTR;
1462 		req_set_fail(req);
1463 	}
1464 
1465 	if (ret >= 0)
1466 		ret += sr->done_io;
1467 	else if (sr->done_io)
1468 		ret = sr->done_io;
1469 
1470 	/*
1471 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1472 	 * flushing notif to io_send_zc_cleanup()
1473 	 */
1474 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1475 		io_notif_flush(sr->notif);
1476 		io_req_msg_cleanup(req, 0);
1477 	}
1478 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1479 	return IOU_OK;
1480 }
1481 
1482 void io_sendrecv_fail(struct io_kiocb *req)
1483 {
1484 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1485 
1486 	if (sr->done_io)
1487 		req->cqe.res = sr->done_io;
1488 
1489 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1490 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1491 		req->cqe.flags |= IORING_CQE_F_MORE;
1492 }
1493 
1494 #define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
1495 			 IORING_ACCEPT_POLL_FIRST)
1496 
1497 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1498 {
1499 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1500 
1501 	if (sqe->len || sqe->buf_index)
1502 		return -EINVAL;
1503 
1504 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1505 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1506 	accept->flags = READ_ONCE(sqe->accept_flags);
1507 	accept->nofile = rlimit(RLIMIT_NOFILE);
1508 	accept->iou_flags = READ_ONCE(sqe->ioprio);
1509 	if (accept->iou_flags & ~ACCEPT_FLAGS)
1510 		return -EINVAL;
1511 
1512 	accept->file_slot = READ_ONCE(sqe->file_index);
1513 	if (accept->file_slot) {
1514 		if (accept->flags & SOCK_CLOEXEC)
1515 			return -EINVAL;
1516 		if (accept->iou_flags & IORING_ACCEPT_MULTISHOT &&
1517 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1518 			return -EINVAL;
1519 	}
1520 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1521 		return -EINVAL;
1522 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1523 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1524 	if (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
1525 		req->flags |= REQ_F_APOLL_MULTISHOT;
1526 	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
1527 		req->flags |= REQ_F_NOWAIT;
1528 	return 0;
1529 }
1530 
1531 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1532 {
1533 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1534 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1535 	bool fixed = !!accept->file_slot;
1536 	struct proto_accept_arg arg = {
1537 		.flags = force_nonblock ? O_NONBLOCK : 0,
1538 	};
1539 	struct file *file;
1540 	unsigned cflags;
1541 	int ret, fd;
1542 
1543 	if (!(req->flags & REQ_F_POLLED) &&
1544 	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
1545 		return -EAGAIN;
1546 
1547 retry:
1548 	if (!fixed) {
1549 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1550 		if (unlikely(fd < 0))
1551 			return fd;
1552 	}
1553 	arg.err = 0;
1554 	arg.is_empty = -1;
1555 	file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
1556 			 accept->flags);
1557 	if (IS_ERR(file)) {
1558 		if (!fixed)
1559 			put_unused_fd(fd);
1560 		ret = PTR_ERR(file);
1561 		if (ret == -EAGAIN && force_nonblock &&
1562 		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT)) {
1563 			/*
1564 			 * if it's multishot and polled, we don't need to
1565 			 * return EAGAIN to arm the poll infra since it
1566 			 * has already been done
1567 			 */
1568 			if (issue_flags & IO_URING_F_MULTISHOT)
1569 				return IOU_ISSUE_SKIP_COMPLETE;
1570 			return ret;
1571 		}
1572 		if (ret == -ERESTARTSYS)
1573 			ret = -EINTR;
1574 		req_set_fail(req);
1575 	} else if (!fixed) {
1576 		fd_install(fd, file);
1577 		ret = fd;
1578 	} else {
1579 		ret = io_fixed_fd_install(req, issue_flags, file,
1580 						accept->file_slot);
1581 	}
1582 
1583 	cflags = 0;
1584 	if (!arg.is_empty)
1585 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
1586 
1587 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
1588 		io_req_set_res(req, ret, cflags);
1589 		return IOU_OK;
1590 	}
1591 
1592 	if (ret < 0)
1593 		return ret;
1594 	if (io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
1595 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
1596 			goto retry;
1597 		if (issue_flags & IO_URING_F_MULTISHOT)
1598 			return IOU_ISSUE_SKIP_COMPLETE;
1599 		return -EAGAIN;
1600 	}
1601 
1602 	io_req_set_res(req, ret, cflags);
1603 	return IOU_STOP_MULTISHOT;
1604 }
1605 
1606 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1607 {
1608 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1609 
1610 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1611 		return -EINVAL;
1612 
1613 	sock->domain = READ_ONCE(sqe->fd);
1614 	sock->type = READ_ONCE(sqe->off);
1615 	sock->protocol = READ_ONCE(sqe->len);
1616 	sock->file_slot = READ_ONCE(sqe->file_index);
1617 	sock->nofile = rlimit(RLIMIT_NOFILE);
1618 
1619 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1620 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1621 		return -EINVAL;
1622 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1623 		return -EINVAL;
1624 	return 0;
1625 }
1626 
1627 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1628 {
1629 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1630 	bool fixed = !!sock->file_slot;
1631 	struct file *file;
1632 	int ret, fd;
1633 
1634 	if (!fixed) {
1635 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1636 		if (unlikely(fd < 0))
1637 			return fd;
1638 	}
1639 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1640 	if (IS_ERR(file)) {
1641 		if (!fixed)
1642 			put_unused_fd(fd);
1643 		ret = PTR_ERR(file);
1644 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1645 			return -EAGAIN;
1646 		if (ret == -ERESTARTSYS)
1647 			ret = -EINTR;
1648 		req_set_fail(req);
1649 	} else if (!fixed) {
1650 		fd_install(fd, file);
1651 		ret = fd;
1652 	} else {
1653 		ret = io_fixed_fd_install(req, issue_flags, file,
1654 					    sock->file_slot);
1655 	}
1656 	io_req_set_res(req, ret, 0);
1657 	return IOU_OK;
1658 }
1659 
1660 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1661 {
1662 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1663 	struct io_async_msghdr *io;
1664 
1665 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1666 		return -EINVAL;
1667 
1668 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1669 	conn->addr_len =  READ_ONCE(sqe->addr2);
1670 	conn->in_progress = conn->seen_econnaborted = false;
1671 
1672 	io = io_msg_alloc_async(req);
1673 	if (unlikely(!io))
1674 		return -ENOMEM;
1675 
1676 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr);
1677 }
1678 
1679 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1680 {
1681 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1682 	struct io_async_msghdr *io = req->async_data;
1683 	unsigned file_flags;
1684 	int ret;
1685 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1686 
1687 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1688 
1689 	ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,
1690 				 file_flags);
1691 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1692 	    && force_nonblock) {
1693 		if (ret == -EINPROGRESS) {
1694 			connect->in_progress = true;
1695 		} else if (ret == -ECONNABORTED) {
1696 			if (connect->seen_econnaborted)
1697 				goto out;
1698 			connect->seen_econnaborted = true;
1699 		}
1700 		return -EAGAIN;
1701 	}
1702 	if (connect->in_progress) {
1703 		/*
1704 		 * At least bluetooth will return -EBADFD on a re-connect
1705 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1706 		 * which means the previous result is good. For both of these,
1707 		 * grab the sock_error() and use that for the completion.
1708 		 */
1709 		if (ret == -EBADFD || ret == -EISCONN)
1710 			ret = sock_error(sock_from_file(req->file)->sk);
1711 	}
1712 	if (ret == -ERESTARTSYS)
1713 		ret = -EINTR;
1714 out:
1715 	if (ret < 0)
1716 		req_set_fail(req);
1717 	io_req_msg_cleanup(req, issue_flags);
1718 	io_req_set_res(req, ret, 0);
1719 	return IOU_OK;
1720 }
1721 
1722 int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1723 {
1724 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1725 	struct sockaddr __user *uaddr;
1726 	struct io_async_msghdr *io;
1727 
1728 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1729 		return -EINVAL;
1730 
1731 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1732 	bind->addr_len =  READ_ONCE(sqe->addr2);
1733 
1734 	io = io_msg_alloc_async(req);
1735 	if (unlikely(!io))
1736 		return -ENOMEM;
1737 	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
1738 }
1739 
1740 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
1741 {
1742 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
1743 	struct io_async_msghdr *io = req->async_data;
1744 	struct socket *sock;
1745 	int ret;
1746 
1747 	sock = sock_from_file(req->file);
1748 	if (unlikely(!sock))
1749 		return -ENOTSOCK;
1750 
1751 	ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
1752 	if (ret < 0)
1753 		req_set_fail(req);
1754 	io_req_set_res(req, ret, 0);
1755 	return 0;
1756 }
1757 
1758 int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1759 {
1760 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1761 
1762 	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
1763 		return -EINVAL;
1764 
1765 	listen->backlog = READ_ONCE(sqe->len);
1766 	return 0;
1767 }
1768 
1769 int io_listen(struct io_kiocb *req, unsigned int issue_flags)
1770 {
1771 	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
1772 	struct socket *sock;
1773 	int ret;
1774 
1775 	sock = sock_from_file(req->file);
1776 	if (unlikely(!sock))
1777 		return -ENOTSOCK;
1778 
1779 	ret = __sys_listen_socket(sock, listen->backlog);
1780 	if (ret < 0)
1781 		req_set_fail(req);
1782 	io_req_set_res(req, ret, 0);
1783 	return 0;
1784 }
1785 
1786 void io_netmsg_cache_free(const void *entry)
1787 {
1788 	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
1789 
1790 	if (kmsg->free_iov) {
1791 		kasan_mempool_unpoison_object(kmsg->free_iov,
1792 				kmsg->free_iov_nr * sizeof(struct iovec));
1793 		io_netmsg_iovec_free(kmsg);
1794 	}
1795 	kfree(kmsg);
1796 }
1797 #endif
1798