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