xref: /openbmc/linux/io_uring/net.c (revision 0f9b4c3ca5fdf3e177266ef994071b1a03f07318)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/slab.h>
6 #include <linux/net.h>
7 #include <linux/compat.h>
8 #include <net/compat.h>
9 #include <linux/io_uring.h>
10 
11 #include <uapi/linux/io_uring.h>
12 
13 #include "io_uring.h"
14 #include "kbuf.h"
15 #include "alloc_cache.h"
16 #include "net.h"
17 #include "notif.h"
18 #include "rsrc.h"
19 
20 #if defined(CONFIG_NET)
21 struct io_shutdown {
22 	struct file			*file;
23 	int				how;
24 };
25 
26 struct io_accept {
27 	struct file			*file;
28 	struct sockaddr __user		*addr;
29 	int __user			*addr_len;
30 	int				flags;
31 	u32				file_slot;
32 	unsigned long			nofile;
33 };
34 
35 struct io_socket {
36 	struct file			*file;
37 	int				domain;
38 	int				type;
39 	int				protocol;
40 	int				flags;
41 	u32				file_slot;
42 	unsigned long			nofile;
43 };
44 
45 struct io_connect {
46 	struct file			*file;
47 	struct sockaddr __user		*addr;
48 	int				addr_len;
49 	bool				in_progress;
50 	bool				seen_econnaborted;
51 };
52 
53 struct io_sr_msg {
54 	struct file			*file;
55 	union {
56 		struct compat_msghdr __user	*umsg_compat;
57 		struct user_msghdr __user	*umsg;
58 		void __user			*buf;
59 	};
60 	unsigned			len;
61 	unsigned			done_io;
62 	unsigned			msg_flags;
63 	unsigned			nr_multishot_loops;
64 	u16				flags;
65 	/* initialised and used only by !msg send variants */
66 	u16				addr_len;
67 	u16				buf_group;
68 	void __user			*addr;
69 	void __user			*msg_control;
70 	/* used only for send zerocopy */
71 	struct io_kiocb 		*notif;
72 };
73 
74 /*
75  * Number of times we'll try and do receives if there's more data. If we
76  * exceed this limit, then add us to the back of the queue and retry from
77  * there. This helps fairness between flooding clients.
78  */
79 #define MULTISHOT_MAX_RETRY	32
80 
io_check_multishot(struct io_kiocb * req,unsigned int issue_flags)81 static inline bool io_check_multishot(struct io_kiocb *req,
82 				      unsigned int issue_flags)
83 {
84 	/*
85 	 * When ->locked_cq is set we only allow to post CQEs from the original
86 	 * task context. Usual request completions will be handled in other
87 	 * generic paths but multipoll may decide to post extra cqes.
88 	 */
89 	return !(issue_flags & IO_URING_F_IOWQ) ||
90 		!(req->flags & REQ_F_APOLL_MULTISHOT) ||
91 		!req->ctx->task_complete;
92 }
93 
io_shutdown_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)94 int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
95 {
96 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
97 
98 	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
99 		     sqe->buf_index || sqe->splice_fd_in))
100 		return -EINVAL;
101 
102 	shutdown->how = READ_ONCE(sqe->len);
103 	req->flags |= REQ_F_FORCE_ASYNC;
104 	return 0;
105 }
106 
io_shutdown(struct io_kiocb * req,unsigned int issue_flags)107 int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
108 {
109 	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
110 	struct socket *sock;
111 	int ret;
112 
113 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
114 
115 	sock = sock_from_file(req->file);
116 	if (unlikely(!sock))
117 		return -ENOTSOCK;
118 
119 	ret = __sys_shutdown_sock(sock, shutdown->how);
120 	io_req_set_res(req, ret, 0);
121 	return IOU_OK;
122 }
123 
io_net_retry(struct socket * sock,int flags)124 static bool io_net_retry(struct socket *sock, int flags)
125 {
126 	if (!(flags & MSG_WAITALL))
127 		return false;
128 	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
129 }
130 
io_netmsg_recycle(struct io_kiocb * req,unsigned int issue_flags)131 static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
132 {
133 	struct io_async_msghdr *hdr = req->async_data;
134 
135 	if (!req_has_async_data(req) || issue_flags & IO_URING_F_UNLOCKED)
136 		return;
137 
138 	/* Let normal cleanup path reap it if we fail adding to the cache */
139 	if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
140 		req->async_data = NULL;
141 		req->flags &= ~REQ_F_ASYNC_DATA;
142 	}
143 }
144 
io_msg_alloc_async(struct io_kiocb * req,unsigned int issue_flags)145 static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
146 						  unsigned int issue_flags)
147 {
148 	struct io_ring_ctx *ctx = req->ctx;
149 	struct io_cache_entry *entry;
150 	struct io_async_msghdr *hdr;
151 
152 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
153 		entry = io_alloc_cache_get(&ctx->netmsg_cache);
154 		if (entry) {
155 			hdr = container_of(entry, struct io_async_msghdr, cache);
156 			hdr->free_iov = NULL;
157 			req->flags |= REQ_F_ASYNC_DATA;
158 			req->async_data = hdr;
159 			return hdr;
160 		}
161 	}
162 
163 	if (!io_alloc_async_data(req)) {
164 		hdr = req->async_data;
165 		hdr->free_iov = NULL;
166 		return hdr;
167 	}
168 	return NULL;
169 }
170 
io_msg_alloc_async_prep(struct io_kiocb * req)171 static inline struct io_async_msghdr *io_msg_alloc_async_prep(struct io_kiocb *req)
172 {
173 	/* ->prep_async is always called from the submission context */
174 	return io_msg_alloc_async(req, 0);
175 }
176 
io_setup_async_msg(struct io_kiocb * req,struct io_async_msghdr * kmsg,unsigned int issue_flags)177 static int io_setup_async_msg(struct io_kiocb *req,
178 			      struct io_async_msghdr *kmsg,
179 			      unsigned int issue_flags)
180 {
181 	struct io_async_msghdr *async_msg;
182 
183 	if (req_has_async_data(req))
184 		return -EAGAIN;
185 	async_msg = io_msg_alloc_async(req, issue_flags);
186 	if (!async_msg) {
187 		kfree(kmsg->free_iov);
188 		return -ENOMEM;
189 	}
190 	req->flags |= REQ_F_NEED_CLEANUP;
191 	memcpy(async_msg, kmsg, sizeof(*kmsg));
192 	if (async_msg->msg.msg_name)
193 		async_msg->msg.msg_name = &async_msg->addr;
194 
195 	if ((req->flags & REQ_F_BUFFER_SELECT) && !async_msg->msg.msg_iter.nr_segs)
196 		return -EAGAIN;
197 
198 	/* if were using fast_iov, set it to the new one */
199 	if (iter_is_iovec(&kmsg->msg.msg_iter) && !kmsg->free_iov) {
200 		size_t fast_idx = iter_iov(&kmsg->msg.msg_iter) - kmsg->fast_iov;
201 		async_msg->msg.msg_iter.__iov = &async_msg->fast_iov[fast_idx];
202 	}
203 
204 	return -EAGAIN;
205 }
206 
207 #ifdef CONFIG_COMPAT
io_compat_msg_copy_hdr(struct io_kiocb * req,struct io_async_msghdr * iomsg,struct compat_msghdr * msg,int ddir)208 static int io_compat_msg_copy_hdr(struct io_kiocb *req,
209 				  struct io_async_msghdr *iomsg,
210 				  struct compat_msghdr *msg, int ddir)
211 {
212 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
213 	struct compat_iovec __user *uiov;
214 	int ret;
215 
216 	if (copy_from_user(msg, sr->umsg_compat, sizeof(*msg)))
217 		return -EFAULT;
218 
219 	uiov = compat_ptr(msg->msg_iov);
220 	if (req->flags & REQ_F_BUFFER_SELECT) {
221 		compat_ssize_t clen;
222 
223 		iomsg->free_iov = NULL;
224 		if (msg->msg_iovlen == 0) {
225 			sr->len = 0;
226 		} else if (msg->msg_iovlen > 1) {
227 			return -EINVAL;
228 		} else {
229 			if (!access_ok(uiov, sizeof(*uiov)))
230 				return -EFAULT;
231 			if (__get_user(clen, &uiov->iov_len))
232 				return -EFAULT;
233 			if (clen < 0)
234 				return -EINVAL;
235 			sr->len = clen;
236 		}
237 
238 		return 0;
239 	}
240 
241 	iomsg->free_iov = iomsg->fast_iov;
242 	ret = __import_iovec(ddir, (struct iovec __user *)uiov, msg->msg_iovlen,
243 				UIO_FASTIOV, &iomsg->free_iov,
244 				&iomsg->msg.msg_iter, true);
245 	if (unlikely(ret < 0))
246 		return ret;
247 
248 	return 0;
249 }
250 #endif
251 
io_msg_copy_hdr(struct io_kiocb * req,struct io_async_msghdr * iomsg,struct user_msghdr * msg,int ddir)252 static 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 	int ret;
257 
258 	if (copy_from_user(msg, sr->umsg, sizeof(*sr->umsg)))
259 		return -EFAULT;
260 
261 	if (req->flags & REQ_F_BUFFER_SELECT) {
262 		if (msg->msg_iovlen == 0) {
263 			sr->len = iomsg->fast_iov[0].iov_len = 0;
264 			iomsg->fast_iov[0].iov_base = NULL;
265 			iomsg->free_iov = NULL;
266 		} else if (msg->msg_iovlen > 1) {
267 			return -EINVAL;
268 		} else {
269 			if (copy_from_user(iomsg->fast_iov, msg->msg_iov,
270 					   sizeof(*msg->msg_iov)))
271 				return -EFAULT;
272 			sr->len = iomsg->fast_iov[0].iov_len;
273 			iomsg->free_iov = NULL;
274 		}
275 
276 		return 0;
277 	}
278 
279 	iomsg->free_iov = iomsg->fast_iov;
280 	ret = __import_iovec(ddir, msg->msg_iov, msg->msg_iovlen, UIO_FASTIOV,
281 				&iomsg->free_iov, &iomsg->msg.msg_iter, false);
282 	if (unlikely(ret < 0))
283 		return ret;
284 
285 	return 0;
286 }
287 
io_sendmsg_copy_hdr(struct io_kiocb * req,struct io_async_msghdr * iomsg)288 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
289 			       struct io_async_msghdr *iomsg)
290 {
291 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
292 	struct user_msghdr msg;
293 	int ret;
294 
295 	iomsg->msg.msg_name = &iomsg->addr;
296 	iomsg->msg.msg_iter.nr_segs = 0;
297 
298 #ifdef CONFIG_COMPAT
299 	if (unlikely(req->ctx->compat)) {
300 		struct compat_msghdr cmsg;
301 
302 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_SOURCE);
303 		if (unlikely(ret))
304 			return ret;
305 
306 		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, NULL);
307 		sr->msg_control = iomsg->msg.msg_control_user;
308 		return ret;
309 	}
310 #endif
311 
312 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_SOURCE);
313 	if (unlikely(ret))
314 		return ret;
315 
316 	ret = __copy_msghdr(&iomsg->msg, &msg, NULL);
317 
318 	/* save msg_control as sys_sendmsg() overwrites it */
319 	sr->msg_control = iomsg->msg.msg_control_user;
320 	return ret;
321 }
322 
io_send_prep_async(struct io_kiocb * req)323 int io_send_prep_async(struct io_kiocb *req)
324 {
325 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
326 	struct io_async_msghdr *io;
327 	int ret;
328 
329 	if (!zc->addr || req_has_async_data(req))
330 		return 0;
331 	io = io_msg_alloc_async_prep(req);
332 	if (!io)
333 		return -ENOMEM;
334 	ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr);
335 	return ret;
336 }
337 
io_setup_async_addr(struct io_kiocb * req,struct sockaddr_storage * addr_storage,unsigned int issue_flags)338 static int io_setup_async_addr(struct io_kiocb *req,
339 			      struct sockaddr_storage *addr_storage,
340 			      unsigned int issue_flags)
341 {
342 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
343 	struct io_async_msghdr *io;
344 
345 	if (!sr->addr || req_has_async_data(req))
346 		return -EAGAIN;
347 	io = io_msg_alloc_async(req, issue_flags);
348 	if (!io)
349 		return -ENOMEM;
350 	memcpy(&io->addr, addr_storage, sizeof(io->addr));
351 	return -EAGAIN;
352 }
353 
io_sendmsg_prep_async(struct io_kiocb * req)354 int io_sendmsg_prep_async(struct io_kiocb *req)
355 {
356 	int ret;
357 
358 	if (!io_msg_alloc_async_prep(req))
359 		return -ENOMEM;
360 	ret = io_sendmsg_copy_hdr(req, req->async_data);
361 	if (!ret)
362 		req->flags |= REQ_F_NEED_CLEANUP;
363 	return ret;
364 }
365 
io_sendmsg_recvmsg_cleanup(struct io_kiocb * req)366 void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
367 {
368 	struct io_async_msghdr *io = req->async_data;
369 
370 	kfree(io->free_iov);
371 }
372 
io_sendmsg_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)373 int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
374 {
375 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
376 
377 	if (req->opcode == IORING_OP_SEND) {
378 		if (READ_ONCE(sqe->__pad3[0]))
379 			return -EINVAL;
380 		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
381 		sr->addr_len = READ_ONCE(sqe->addr_len);
382 	} else if (sqe->addr2 || sqe->file_index) {
383 		return -EINVAL;
384 	}
385 
386 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
387 	sr->len = READ_ONCE(sqe->len);
388 	sr->flags = READ_ONCE(sqe->ioprio);
389 	if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
390 		return -EINVAL;
391 	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
392 	if (sr->msg_flags & MSG_DONTWAIT)
393 		req->flags |= REQ_F_NOWAIT;
394 
395 #ifdef CONFIG_COMPAT
396 	if (req->ctx->compat)
397 		sr->msg_flags |= MSG_CMSG_COMPAT;
398 #endif
399 	sr->done_io = 0;
400 	return 0;
401 }
402 
io_sendmsg(struct io_kiocb * req,unsigned int issue_flags)403 int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
404 {
405 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
406 	struct io_async_msghdr iomsg, *kmsg;
407 	struct socket *sock;
408 	unsigned flags;
409 	int min_ret = 0;
410 	int ret;
411 
412 	sock = sock_from_file(req->file);
413 	if (unlikely(!sock))
414 		return -ENOTSOCK;
415 
416 	if (req_has_async_data(req)) {
417 		kmsg = req->async_data;
418 		kmsg->msg.msg_control_user = sr->msg_control;
419 	} else {
420 		ret = io_sendmsg_copy_hdr(req, &iomsg);
421 		if (ret)
422 			return ret;
423 		kmsg = &iomsg;
424 	}
425 
426 	if (!(req->flags & REQ_F_POLLED) &&
427 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
428 		return io_setup_async_msg(req, kmsg, issue_flags);
429 
430 	flags = sr->msg_flags;
431 	if (issue_flags & IO_URING_F_NONBLOCK)
432 		flags |= MSG_DONTWAIT;
433 	if (flags & MSG_WAITALL)
434 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
435 
436 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
437 
438 	if (ret < min_ret) {
439 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
440 			return io_setup_async_msg(req, kmsg, issue_flags);
441 		if (ret > 0 && io_net_retry(sock, flags)) {
442 			kmsg->msg.msg_controllen = 0;
443 			kmsg->msg.msg_control = NULL;
444 			sr->done_io += ret;
445 			req->flags |= REQ_F_PARTIAL_IO;
446 			return io_setup_async_msg(req, kmsg, issue_flags);
447 		}
448 		if (ret == -ERESTARTSYS)
449 			ret = -EINTR;
450 		req_set_fail(req);
451 	}
452 	/* fast path, check for non-NULL to avoid function call */
453 	if (kmsg->free_iov)
454 		kfree(kmsg->free_iov);
455 	req->flags &= ~REQ_F_NEED_CLEANUP;
456 	io_netmsg_recycle(req, issue_flags);
457 	if (ret >= 0)
458 		ret += sr->done_io;
459 	else if (sr->done_io)
460 		ret = sr->done_io;
461 	io_req_set_res(req, ret, 0);
462 	return IOU_OK;
463 }
464 
io_send(struct io_kiocb * req,unsigned int issue_flags)465 int io_send(struct io_kiocb *req, unsigned int issue_flags)
466 {
467 	struct sockaddr_storage __address;
468 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
469 	struct msghdr msg;
470 	struct socket *sock;
471 	unsigned flags;
472 	int min_ret = 0;
473 	int ret;
474 
475 	msg.msg_name = NULL;
476 	msg.msg_control = NULL;
477 	msg.msg_controllen = 0;
478 	msg.msg_namelen = 0;
479 	msg.msg_ubuf = NULL;
480 
481 	if (sr->addr) {
482 		if (req_has_async_data(req)) {
483 			struct io_async_msghdr *io = req->async_data;
484 
485 			msg.msg_name = &io->addr;
486 		} else {
487 			ret = move_addr_to_kernel(sr->addr, sr->addr_len, &__address);
488 			if (unlikely(ret < 0))
489 				return ret;
490 			msg.msg_name = (struct sockaddr *)&__address;
491 		}
492 		msg.msg_namelen = sr->addr_len;
493 	}
494 
495 	if (!(req->flags & REQ_F_POLLED) &&
496 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
497 		return io_setup_async_addr(req, &__address, issue_flags);
498 
499 	sock = sock_from_file(req->file);
500 	if (unlikely(!sock))
501 		return -ENOTSOCK;
502 
503 	ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
504 	if (unlikely(ret))
505 		return ret;
506 
507 	flags = sr->msg_flags;
508 	if (issue_flags & IO_URING_F_NONBLOCK)
509 		flags |= MSG_DONTWAIT;
510 	if (flags & MSG_WAITALL)
511 		min_ret = iov_iter_count(&msg.msg_iter);
512 
513 	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
514 	msg.msg_flags = flags;
515 	ret = sock_sendmsg(sock, &msg);
516 	if (ret < min_ret) {
517 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
518 			return io_setup_async_addr(req, &__address, issue_flags);
519 
520 		if (ret > 0 && io_net_retry(sock, flags)) {
521 			sr->len -= ret;
522 			sr->buf += ret;
523 			sr->done_io += ret;
524 			req->flags |= REQ_F_PARTIAL_IO;
525 			return io_setup_async_addr(req, &__address, issue_flags);
526 		}
527 		if (ret == -ERESTARTSYS)
528 			ret = -EINTR;
529 		req_set_fail(req);
530 	}
531 	if (ret >= 0)
532 		ret += sr->done_io;
533 	else if (sr->done_io)
534 		ret = sr->done_io;
535 	io_req_set_res(req, ret, 0);
536 	return IOU_OK;
537 }
538 
io_recvmsg_mshot_prep(struct io_kiocb * req,struct io_async_msghdr * iomsg,int namelen,size_t controllen)539 static int io_recvmsg_mshot_prep(struct io_kiocb *req,
540 				 struct io_async_msghdr *iomsg,
541 				 int namelen, size_t controllen)
542 {
543 	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
544 			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
545 		int hdr;
546 
547 		if (unlikely(namelen < 0))
548 			return -EOVERFLOW;
549 		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
550 					namelen, &hdr))
551 			return -EOVERFLOW;
552 		if (check_add_overflow(hdr, controllen, &hdr))
553 			return -EOVERFLOW;
554 
555 		iomsg->namelen = namelen;
556 		iomsg->controllen = controllen;
557 		return 0;
558 	}
559 
560 	return 0;
561 }
562 
io_recvmsg_copy_hdr(struct io_kiocb * req,struct io_async_msghdr * iomsg)563 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
564 			       struct io_async_msghdr *iomsg)
565 {
566 	struct user_msghdr msg;
567 	int ret;
568 
569 	iomsg->msg.msg_name = &iomsg->addr;
570 	iomsg->msg.msg_iter.nr_segs = 0;
571 
572 #ifdef CONFIG_COMPAT
573 	if (unlikely(req->ctx->compat)) {
574 		struct compat_msghdr cmsg;
575 
576 		ret = io_compat_msg_copy_hdr(req, iomsg, &cmsg, ITER_DEST);
577 		if (unlikely(ret))
578 			return ret;
579 
580 		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, &iomsg->uaddr);
581 		if (unlikely(ret))
582 			return ret;
583 
584 		return io_recvmsg_mshot_prep(req, iomsg, cmsg.msg_namelen,
585 						cmsg.msg_controllen);
586 	}
587 #endif
588 
589 	ret = io_msg_copy_hdr(req, iomsg, &msg, ITER_DEST);
590 	if (unlikely(ret))
591 		return ret;
592 
593 	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
594 	if (unlikely(ret))
595 		return ret;
596 
597 	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
598 					msg.msg_controllen);
599 }
600 
io_recvmsg_prep_async(struct io_kiocb * req)601 int io_recvmsg_prep_async(struct io_kiocb *req)
602 {
603 	struct io_async_msghdr *iomsg;
604 	int ret;
605 
606 	if (!io_msg_alloc_async_prep(req))
607 		return -ENOMEM;
608 	iomsg = req->async_data;
609 	ret = io_recvmsg_copy_hdr(req, iomsg);
610 	if (!ret)
611 		req->flags |= REQ_F_NEED_CLEANUP;
612 	return ret;
613 }
614 
615 #define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)
616 
io_recvmsg_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)617 int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
618 {
619 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
620 
621 	if (unlikely(sqe->file_index || sqe->addr2))
622 		return -EINVAL;
623 
624 	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
625 	sr->len = READ_ONCE(sqe->len);
626 	sr->flags = READ_ONCE(sqe->ioprio);
627 	if (sr->flags & ~(RECVMSG_FLAGS))
628 		return -EINVAL;
629 	sr->msg_flags = READ_ONCE(sqe->msg_flags);
630 	if (sr->msg_flags & MSG_DONTWAIT)
631 		req->flags |= REQ_F_NOWAIT;
632 	if (sr->msg_flags & MSG_ERRQUEUE)
633 		req->flags |= REQ_F_CLEAR_POLLIN;
634 	if (sr->flags & IORING_RECV_MULTISHOT) {
635 		if (!(req->flags & REQ_F_BUFFER_SELECT))
636 			return -EINVAL;
637 		if (sr->msg_flags & MSG_WAITALL)
638 			return -EINVAL;
639 		if (req->opcode == IORING_OP_RECV && sr->len)
640 			return -EINVAL;
641 		req->flags |= REQ_F_APOLL_MULTISHOT;
642 		/*
643 		 * Store the buffer group for this multishot receive separately,
644 		 * as if we end up doing an io-wq based issue that selects a
645 		 * buffer, it has to be committed immediately and that will
646 		 * clear ->buf_list. This means we lose the link to the buffer
647 		 * list, and the eventual buffer put on completion then cannot
648 		 * restore it.
649 		 */
650 		sr->buf_group = req->buf_index;
651 	}
652 
653 #ifdef CONFIG_COMPAT
654 	if (req->ctx->compat)
655 		sr->msg_flags |= MSG_CMSG_COMPAT;
656 #endif
657 	sr->done_io = 0;
658 	sr->nr_multishot_loops = 0;
659 	return 0;
660 }
661 
io_recv_prep_retry(struct io_kiocb * req)662 static inline void io_recv_prep_retry(struct io_kiocb *req)
663 {
664 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
665 
666 	sr->done_io = 0;
667 	sr->len = 0; /* get from the provided buffer */
668 	req->buf_index = sr->buf_group;
669 }
670 
671 /*
672  * Finishes io_recv and io_recvmsg.
673  *
674  * Returns true if it is actually finished, or false if it should run
675  * again (for multishot).
676  */
io_recv_finish(struct io_kiocb * req,int * ret,struct msghdr * msg,bool mshot_finished,unsigned issue_flags)677 static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
678 				  struct msghdr *msg, bool mshot_finished,
679 				  unsigned issue_flags)
680 {
681 	unsigned int cflags;
682 
683 	cflags = io_put_kbuf(req, issue_flags);
684 	if (msg->msg_inq && msg->msg_inq != -1)
685 		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
686 
687 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
688 		io_req_set_res(req, *ret, cflags);
689 		*ret = IOU_OK;
690 		return true;
691 	}
692 
693 	if (mshot_finished)
694 		goto finish;
695 
696 	/*
697 	 * Fill CQE for this receive and see if we should keep trying to
698 	 * receive from this socket.
699 	 */
700 	if (io_fill_cqe_req_aux(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
701 				*ret, cflags | IORING_CQE_F_MORE)) {
702 		struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
703 		int mshot_retry_ret = IOU_ISSUE_SKIP_COMPLETE;
704 
705 		io_recv_prep_retry(req);
706 		/* Known not-empty or unknown state, retry */
707 		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || msg->msg_inq == -1) {
708 			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY)
709 				return false;
710 			/* mshot retries exceeded, force a requeue */
711 			sr->nr_multishot_loops = 0;
712 			mshot_retry_ret = IOU_REQUEUE;
713 		}
714 		if (issue_flags & IO_URING_F_MULTISHOT)
715 			*ret = mshot_retry_ret;
716 		else
717 			*ret = -EAGAIN;
718 		return true;
719 	}
720 	/* Otherwise stop multishot but use the current result. */
721 finish:
722 	io_req_set_res(req, *ret, cflags);
723 
724 	if (issue_flags & IO_URING_F_MULTISHOT)
725 		*ret = IOU_STOP_MULTISHOT;
726 	else
727 		*ret = IOU_OK;
728 	return true;
729 }
730 
io_recvmsg_prep_multishot(struct io_async_msghdr * kmsg,struct io_sr_msg * sr,void __user ** buf,size_t * len)731 static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
732 				     struct io_sr_msg *sr, void __user **buf,
733 				     size_t *len)
734 {
735 	unsigned long ubuf = (unsigned long) *buf;
736 	unsigned long hdr;
737 
738 	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
739 		kmsg->controllen;
740 	if (*len < hdr)
741 		return -EFAULT;
742 
743 	if (kmsg->controllen) {
744 		unsigned long control = ubuf + hdr - kmsg->controllen;
745 
746 		kmsg->msg.msg_control_user = (void __user *) control;
747 		kmsg->msg.msg_controllen = kmsg->controllen;
748 	}
749 
750 	sr->buf = *buf; /* stash for later copy */
751 	*buf = (void __user *) (ubuf + hdr);
752 	kmsg->payloadlen = *len = *len - hdr;
753 	return 0;
754 }
755 
756 struct io_recvmsg_multishot_hdr {
757 	struct io_uring_recvmsg_out msg;
758 	struct sockaddr_storage addr;
759 };
760 
io_recvmsg_multishot(struct socket * sock,struct io_sr_msg * io,struct io_async_msghdr * kmsg,unsigned int flags,bool * finished)761 static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
762 				struct io_async_msghdr *kmsg,
763 				unsigned int flags, bool *finished)
764 {
765 	int err;
766 	int copy_len;
767 	struct io_recvmsg_multishot_hdr hdr;
768 
769 	if (kmsg->namelen)
770 		kmsg->msg.msg_name = &hdr.addr;
771 	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
772 	kmsg->msg.msg_namelen = 0;
773 
774 	if (sock->file->f_flags & O_NONBLOCK)
775 		flags |= MSG_DONTWAIT;
776 
777 	err = sock_recvmsg(sock, &kmsg->msg, flags);
778 	*finished = err <= 0;
779 	if (err < 0)
780 		return err;
781 
782 	hdr.msg = (struct io_uring_recvmsg_out) {
783 		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
784 		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
785 	};
786 
787 	hdr.msg.payloadlen = err;
788 	if (err > kmsg->payloadlen)
789 		err = kmsg->payloadlen;
790 
791 	copy_len = sizeof(struct io_uring_recvmsg_out);
792 	if (kmsg->msg.msg_namelen > kmsg->namelen)
793 		copy_len += kmsg->namelen;
794 	else
795 		copy_len += kmsg->msg.msg_namelen;
796 
797 	/*
798 	 *      "fromlen shall refer to the value before truncation.."
799 	 *                      1003.1g
800 	 */
801 	hdr.msg.namelen = kmsg->msg.msg_namelen;
802 
803 	/* ensure that there is no gap between hdr and sockaddr_storage */
804 	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
805 		     sizeof(struct io_uring_recvmsg_out));
806 	if (copy_to_user(io->buf, &hdr, copy_len)) {
807 		*finished = true;
808 		return -EFAULT;
809 	}
810 
811 	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
812 			kmsg->controllen + err;
813 }
814 
io_recvmsg(struct io_kiocb * req,unsigned int issue_flags)815 int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
816 {
817 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
818 	struct io_async_msghdr iomsg, *kmsg;
819 	struct socket *sock;
820 	unsigned flags;
821 	int ret, min_ret = 0;
822 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
823 	bool mshot_finished = true;
824 
825 	sock = sock_from_file(req->file);
826 	if (unlikely(!sock))
827 		return -ENOTSOCK;
828 
829 	if (req_has_async_data(req)) {
830 		kmsg = req->async_data;
831 	} else {
832 		ret = io_recvmsg_copy_hdr(req, &iomsg);
833 		if (ret)
834 			return ret;
835 		kmsg = &iomsg;
836 	}
837 
838 	if (!(req->flags & REQ_F_POLLED) &&
839 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
840 		return io_setup_async_msg(req, kmsg, issue_flags);
841 
842 	if (!io_check_multishot(req, issue_flags))
843 		return io_setup_async_msg(req, kmsg, issue_flags);
844 
845 retry_multishot:
846 	if (io_do_buffer_select(req)) {
847 		void __user *buf;
848 		size_t len = sr->len;
849 
850 		buf = io_buffer_select(req, &len, issue_flags);
851 		if (!buf)
852 			return -ENOBUFS;
853 
854 		if (req->flags & REQ_F_APOLL_MULTISHOT) {
855 			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
856 			if (ret) {
857 				io_kbuf_recycle(req, issue_flags);
858 				return ret;
859 			}
860 		}
861 
862 		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, buf, len);
863 	}
864 
865 	flags = sr->msg_flags;
866 	if (force_nonblock)
867 		flags |= MSG_DONTWAIT;
868 
869 	kmsg->msg.msg_get_inq = 1;
870 	kmsg->msg.msg_inq = -1;
871 	if (req->flags & REQ_F_APOLL_MULTISHOT) {
872 		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
873 					   &mshot_finished);
874 	} else {
875 		/* disable partial retry for recvmsg with cmsg attached */
876 		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
877 			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
878 
879 		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
880 					 kmsg->uaddr, flags);
881 	}
882 
883 	if (ret < min_ret) {
884 		if (ret == -EAGAIN && force_nonblock) {
885 			ret = io_setup_async_msg(req, kmsg, issue_flags);
886 			if (ret == -EAGAIN && (issue_flags & IO_URING_F_MULTISHOT)) {
887 				io_kbuf_recycle(req, issue_flags);
888 				return IOU_ISSUE_SKIP_COMPLETE;
889 			}
890 			return ret;
891 		}
892 		if (ret > 0 && io_net_retry(sock, flags)) {
893 			sr->done_io += ret;
894 			req->flags |= REQ_F_PARTIAL_IO;
895 			return io_setup_async_msg(req, kmsg, issue_flags);
896 		}
897 		if (ret == -ERESTARTSYS)
898 			ret = -EINTR;
899 		req_set_fail(req);
900 	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
901 		req_set_fail(req);
902 	}
903 
904 	if (ret > 0)
905 		ret += sr->done_io;
906 	else if (sr->done_io)
907 		ret = sr->done_io;
908 	else
909 		io_kbuf_recycle(req, issue_flags);
910 
911 	if (!io_recv_finish(req, &ret, &kmsg->msg, mshot_finished, issue_flags))
912 		goto retry_multishot;
913 
914 	if (mshot_finished) {
915 		/* fast path, check for non-NULL to avoid function call */
916 		if (kmsg->free_iov)
917 			kfree(kmsg->free_iov);
918 		io_netmsg_recycle(req, issue_flags);
919 		req->flags &= ~REQ_F_NEED_CLEANUP;
920 	} else if (ret == -EAGAIN)
921 		return io_setup_async_msg(req, kmsg, issue_flags);
922 
923 	return ret;
924 }
925 
io_recv(struct io_kiocb * req,unsigned int issue_flags)926 int io_recv(struct io_kiocb *req, unsigned int issue_flags)
927 {
928 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
929 	struct msghdr msg;
930 	struct socket *sock;
931 	unsigned flags;
932 	int ret, min_ret = 0;
933 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
934 	size_t len = sr->len;
935 	bool mshot_finished;
936 
937 	if (!(req->flags & REQ_F_POLLED) &&
938 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
939 		return -EAGAIN;
940 
941 	if (!io_check_multishot(req, issue_flags))
942 		return -EAGAIN;
943 
944 	sock = sock_from_file(req->file);
945 	if (unlikely(!sock))
946 		return -ENOTSOCK;
947 
948 	msg.msg_name = NULL;
949 	msg.msg_namelen = 0;
950 	msg.msg_control = NULL;
951 	msg.msg_get_inq = 1;
952 	msg.msg_controllen = 0;
953 	msg.msg_iocb = NULL;
954 	msg.msg_ubuf = NULL;
955 
956 retry_multishot:
957 	if (io_do_buffer_select(req)) {
958 		void __user *buf;
959 
960 		buf = io_buffer_select(req, &len, issue_flags);
961 		if (!buf)
962 			return -ENOBUFS;
963 		sr->buf = buf;
964 		sr->len = len;
965 	}
966 
967 	ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
968 	if (unlikely(ret))
969 		goto out_free;
970 
971 	msg.msg_inq = -1;
972 	msg.msg_flags = 0;
973 
974 	flags = sr->msg_flags;
975 	if (force_nonblock)
976 		flags |= MSG_DONTWAIT;
977 	if (flags & MSG_WAITALL)
978 		min_ret = iov_iter_count(&msg.msg_iter);
979 
980 	ret = sock_recvmsg(sock, &msg, flags);
981 	if (ret < min_ret) {
982 		if (ret == -EAGAIN && force_nonblock) {
983 			if (issue_flags & IO_URING_F_MULTISHOT) {
984 				io_kbuf_recycle(req, issue_flags);
985 				return IOU_ISSUE_SKIP_COMPLETE;
986 			}
987 
988 			return -EAGAIN;
989 		}
990 		if (ret > 0 && io_net_retry(sock, flags)) {
991 			sr->len -= ret;
992 			sr->buf += ret;
993 			sr->done_io += ret;
994 			req->flags |= REQ_F_PARTIAL_IO;
995 			return -EAGAIN;
996 		}
997 		if (ret == -ERESTARTSYS)
998 			ret = -EINTR;
999 		req_set_fail(req);
1000 	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
1001 out_free:
1002 		req_set_fail(req);
1003 	}
1004 
1005 	mshot_finished = ret <= 0;
1006 	if (ret > 0)
1007 		ret += sr->done_io;
1008 	else if (sr->done_io)
1009 		ret = sr->done_io;
1010 	else
1011 		io_kbuf_recycle(req, issue_flags);
1012 
1013 	if (!io_recv_finish(req, &ret, &msg, mshot_finished, issue_flags))
1014 		goto retry_multishot;
1015 
1016 	return ret;
1017 }
1018 
io_send_zc_cleanup(struct io_kiocb * req)1019 void io_send_zc_cleanup(struct io_kiocb *req)
1020 {
1021 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1022 	struct io_async_msghdr *io;
1023 
1024 	if (req_has_async_data(req)) {
1025 		io = req->async_data;
1026 		/* might be ->fast_iov if *msg_copy_hdr failed */
1027 		if (io->free_iov != io->fast_iov)
1028 			kfree(io->free_iov);
1029 	}
1030 	if (zc->notif) {
1031 		io_notif_flush(zc->notif);
1032 		zc->notif = NULL;
1033 	}
1034 }
1035 
1036 #define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
1037 #define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE)
1038 
io_send_zc_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)1039 int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1040 {
1041 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1042 	struct io_ring_ctx *ctx = req->ctx;
1043 	struct io_kiocb *notif;
1044 
1045 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
1046 		return -EINVAL;
1047 	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
1048 	if (req->flags & REQ_F_CQE_SKIP)
1049 		return -EINVAL;
1050 
1051 	notif = zc->notif = io_alloc_notif(ctx);
1052 	if (!notif)
1053 		return -ENOMEM;
1054 	notif->cqe.user_data = req->cqe.user_data;
1055 	notif->cqe.res = 0;
1056 	notif->cqe.flags = IORING_CQE_F_NOTIF;
1057 	req->flags |= REQ_F_NEED_CLEANUP;
1058 
1059 	zc->flags = READ_ONCE(sqe->ioprio);
1060 	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
1061 		if (zc->flags & ~IO_ZC_FLAGS_VALID)
1062 			return -EINVAL;
1063 		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
1064 			io_notif_set_extended(notif);
1065 			io_notif_to_data(notif)->zc_report = true;
1066 		}
1067 	}
1068 
1069 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1070 		unsigned idx = READ_ONCE(sqe->buf_index);
1071 
1072 		if (unlikely(idx >= ctx->nr_user_bufs))
1073 			return -EFAULT;
1074 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
1075 		req->imu = READ_ONCE(ctx->user_bufs[idx]);
1076 		io_req_set_rsrc_node(notif, ctx, 0);
1077 	}
1078 
1079 	if (req->opcode == IORING_OP_SEND_ZC) {
1080 		if (READ_ONCE(sqe->__pad3[0]))
1081 			return -EINVAL;
1082 		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1083 		zc->addr_len = READ_ONCE(sqe->addr_len);
1084 	} else {
1085 		if (unlikely(sqe->addr2 || sqe->file_index))
1086 			return -EINVAL;
1087 		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
1088 			return -EINVAL;
1089 	}
1090 
1091 	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
1092 	zc->len = READ_ONCE(sqe->len);
1093 	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
1094 	if (zc->msg_flags & MSG_DONTWAIT)
1095 		req->flags |= REQ_F_NOWAIT;
1096 
1097 	zc->done_io = 0;
1098 
1099 #ifdef CONFIG_COMPAT
1100 	if (req->ctx->compat)
1101 		zc->msg_flags |= MSG_CMSG_COMPAT;
1102 #endif
1103 	return 0;
1104 }
1105 
io_sg_from_iter_iovec(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,size_t length)1106 static int io_sg_from_iter_iovec(struct sock *sk, struct sk_buff *skb,
1107 				 struct iov_iter *from, size_t length)
1108 {
1109 	skb_zcopy_downgrade_managed(skb);
1110 	return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
1111 }
1112 
io_sg_from_iter(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,size_t length)1113 static int io_sg_from_iter(struct sock *sk, struct sk_buff *skb,
1114 			   struct iov_iter *from, size_t length)
1115 {
1116 	struct skb_shared_info *shinfo = skb_shinfo(skb);
1117 	int frag = shinfo->nr_frags;
1118 	int ret = 0;
1119 	struct bvec_iter bi;
1120 	ssize_t copied = 0;
1121 	unsigned long truesize = 0;
1122 
1123 	if (!frag)
1124 		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
1125 	else if (unlikely(!skb_zcopy_managed(skb)))
1126 		return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
1127 
1128 	bi.bi_size = min(from->count, length);
1129 	bi.bi_bvec_done = from->iov_offset;
1130 	bi.bi_idx = 0;
1131 
1132 	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
1133 		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);
1134 
1135 		copied += v.bv_len;
1136 		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
1137 		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
1138 					   v.bv_offset, v.bv_len);
1139 		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
1140 	}
1141 	if (bi.bi_size)
1142 		ret = -EMSGSIZE;
1143 
1144 	shinfo->nr_frags = frag;
1145 	from->bvec += bi.bi_idx;
1146 	from->nr_segs -= bi.bi_idx;
1147 	from->count -= copied;
1148 	from->iov_offset = bi.bi_bvec_done;
1149 
1150 	skb->data_len += copied;
1151 	skb->len += copied;
1152 	skb->truesize += truesize;
1153 
1154 	if (sk && sk->sk_type == SOCK_STREAM) {
1155 		sk_wmem_queued_add(sk, truesize);
1156 		if (!skb_zcopy_pure(skb))
1157 			sk_mem_charge(sk, truesize);
1158 	} else {
1159 		refcount_add(truesize, &skb->sk->sk_wmem_alloc);
1160 	}
1161 	return ret;
1162 }
1163 
io_send_zc(struct io_kiocb * req,unsigned int issue_flags)1164 int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
1165 {
1166 	struct sockaddr_storage __address;
1167 	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
1168 	struct msghdr msg;
1169 	struct socket *sock;
1170 	unsigned msg_flags;
1171 	int ret, min_ret = 0;
1172 
1173 	sock = sock_from_file(req->file);
1174 	if (unlikely(!sock))
1175 		return -ENOTSOCK;
1176 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1177 		return -EOPNOTSUPP;
1178 
1179 	msg.msg_name = NULL;
1180 	msg.msg_control = NULL;
1181 	msg.msg_controllen = 0;
1182 	msg.msg_namelen = 0;
1183 
1184 	if (zc->addr) {
1185 		if (req_has_async_data(req)) {
1186 			struct io_async_msghdr *io = req->async_data;
1187 
1188 			msg.msg_name = &io->addr;
1189 		} else {
1190 			ret = move_addr_to_kernel(zc->addr, zc->addr_len, &__address);
1191 			if (unlikely(ret < 0))
1192 				return ret;
1193 			msg.msg_name = (struct sockaddr *)&__address;
1194 		}
1195 		msg.msg_namelen = zc->addr_len;
1196 	}
1197 
1198 	if (!(req->flags & REQ_F_POLLED) &&
1199 	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
1200 		return io_setup_async_addr(req, &__address, issue_flags);
1201 
1202 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
1203 		ret = io_import_fixed(ITER_SOURCE, &msg.msg_iter, req->imu,
1204 					(u64)(uintptr_t)zc->buf, zc->len);
1205 		if (unlikely(ret))
1206 			return ret;
1207 		msg.sg_from_iter = io_sg_from_iter;
1208 	} else {
1209 		io_notif_set_extended(zc->notif);
1210 		ret = import_ubuf(ITER_SOURCE, zc->buf, zc->len, &msg.msg_iter);
1211 		if (unlikely(ret))
1212 			return ret;
1213 		ret = io_notif_account_mem(zc->notif, zc->len);
1214 		if (unlikely(ret))
1215 			return ret;
1216 		msg.sg_from_iter = io_sg_from_iter_iovec;
1217 	}
1218 
1219 	msg_flags = zc->msg_flags | MSG_ZEROCOPY;
1220 	if (issue_flags & IO_URING_F_NONBLOCK)
1221 		msg_flags |= MSG_DONTWAIT;
1222 	if (msg_flags & MSG_WAITALL)
1223 		min_ret = iov_iter_count(&msg.msg_iter);
1224 	msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
1225 
1226 	msg.msg_flags = msg_flags;
1227 	msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
1228 	ret = sock_sendmsg(sock, &msg);
1229 
1230 	if (unlikely(ret < min_ret)) {
1231 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1232 			return io_setup_async_addr(req, &__address, issue_flags);
1233 
1234 		if (ret > 0 && io_net_retry(sock, msg.msg_flags)) {
1235 			zc->len -= ret;
1236 			zc->buf += ret;
1237 			zc->done_io += ret;
1238 			req->flags |= REQ_F_PARTIAL_IO;
1239 			return io_setup_async_addr(req, &__address, issue_flags);
1240 		}
1241 		if (ret == -ERESTARTSYS)
1242 			ret = -EINTR;
1243 		req_set_fail(req);
1244 	}
1245 
1246 	if (ret >= 0)
1247 		ret += zc->done_io;
1248 	else if (zc->done_io)
1249 		ret = zc->done_io;
1250 
1251 	/*
1252 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1253 	 * flushing notif to io_send_zc_cleanup()
1254 	 */
1255 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1256 		io_notif_flush(zc->notif);
1257 		req->flags &= ~REQ_F_NEED_CLEANUP;
1258 	}
1259 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1260 	return IOU_OK;
1261 }
1262 
io_sendmsg_zc(struct io_kiocb * req,unsigned int issue_flags)1263 int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
1264 {
1265 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1266 	struct io_async_msghdr iomsg, *kmsg;
1267 	struct socket *sock;
1268 	unsigned flags;
1269 	int ret, min_ret = 0;
1270 
1271 	io_notif_set_extended(sr->notif);
1272 
1273 	sock = sock_from_file(req->file);
1274 	if (unlikely(!sock))
1275 		return -ENOTSOCK;
1276 	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
1277 		return -EOPNOTSUPP;
1278 
1279 	if (req_has_async_data(req)) {
1280 		kmsg = req->async_data;
1281 		kmsg->msg.msg_control_user = sr->msg_control;
1282 	} else {
1283 		ret = io_sendmsg_copy_hdr(req, &iomsg);
1284 		if (ret)
1285 			return ret;
1286 		kmsg = &iomsg;
1287 	}
1288 
1289 	if (!(req->flags & REQ_F_POLLED) &&
1290 	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
1291 		return io_setup_async_msg(req, kmsg, issue_flags);
1292 
1293 	flags = sr->msg_flags | MSG_ZEROCOPY;
1294 	if (issue_flags & IO_URING_F_NONBLOCK)
1295 		flags |= MSG_DONTWAIT;
1296 	if (flags & MSG_WAITALL)
1297 		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
1298 
1299 	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
1300 	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
1301 	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
1302 
1303 	if (unlikely(ret < min_ret)) {
1304 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1305 			return io_setup_async_msg(req, kmsg, issue_flags);
1306 
1307 		if (ret > 0 && io_net_retry(sock, flags)) {
1308 			sr->done_io += ret;
1309 			req->flags |= REQ_F_PARTIAL_IO;
1310 			return io_setup_async_msg(req, kmsg, issue_flags);
1311 		}
1312 		if (ret == -ERESTARTSYS)
1313 			ret = -EINTR;
1314 		req_set_fail(req);
1315 	}
1316 	/* fast path, check for non-NULL to avoid function call */
1317 	if (kmsg->free_iov) {
1318 		kfree(kmsg->free_iov);
1319 		kmsg->free_iov = NULL;
1320 	}
1321 
1322 	io_netmsg_recycle(req, issue_flags);
1323 	if (ret >= 0)
1324 		ret += sr->done_io;
1325 	else if (sr->done_io)
1326 		ret = sr->done_io;
1327 
1328 	/*
1329 	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
1330 	 * flushing notif to io_send_zc_cleanup()
1331 	 */
1332 	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
1333 		io_notif_flush(sr->notif);
1334 		req->flags &= ~REQ_F_NEED_CLEANUP;
1335 	}
1336 	io_req_set_res(req, ret, IORING_CQE_F_MORE);
1337 	return IOU_OK;
1338 }
1339 
io_sendrecv_fail(struct io_kiocb * req)1340 void io_sendrecv_fail(struct io_kiocb *req)
1341 {
1342 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
1343 
1344 	if (req->flags & REQ_F_PARTIAL_IO)
1345 		req->cqe.res = sr->done_io;
1346 
1347 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
1348 	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
1349 		req->cqe.flags |= IORING_CQE_F_MORE;
1350 }
1351 
io_accept_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)1352 int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1353 {
1354 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1355 	unsigned flags;
1356 
1357 	if (sqe->len || sqe->buf_index)
1358 		return -EINVAL;
1359 
1360 	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1361 	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
1362 	accept->flags = READ_ONCE(sqe->accept_flags);
1363 	accept->nofile = rlimit(RLIMIT_NOFILE);
1364 	flags = READ_ONCE(sqe->ioprio);
1365 	if (flags & ~IORING_ACCEPT_MULTISHOT)
1366 		return -EINVAL;
1367 
1368 	accept->file_slot = READ_ONCE(sqe->file_index);
1369 	if (accept->file_slot) {
1370 		if (accept->flags & SOCK_CLOEXEC)
1371 			return -EINVAL;
1372 		if (flags & IORING_ACCEPT_MULTISHOT &&
1373 		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
1374 			return -EINVAL;
1375 	}
1376 	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1377 		return -EINVAL;
1378 	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
1379 		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
1380 	if (flags & IORING_ACCEPT_MULTISHOT)
1381 		req->flags |= REQ_F_APOLL_MULTISHOT;
1382 	return 0;
1383 }
1384 
io_accept(struct io_kiocb * req,unsigned int issue_flags)1385 int io_accept(struct io_kiocb *req, unsigned int issue_flags)
1386 {
1387 	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
1388 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1389 	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
1390 	bool fixed = !!accept->file_slot;
1391 	struct file *file;
1392 	int ret, fd;
1393 
1394 	if (!io_check_multishot(req, issue_flags))
1395 		return -EAGAIN;
1396 retry:
1397 	if (!fixed) {
1398 		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
1399 		if (unlikely(fd < 0))
1400 			return fd;
1401 	}
1402 	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
1403 			 accept->flags);
1404 	if (IS_ERR(file)) {
1405 		if (!fixed)
1406 			put_unused_fd(fd);
1407 		ret = PTR_ERR(file);
1408 		if (ret == -EAGAIN && force_nonblock) {
1409 			/*
1410 			 * if it's multishot and polled, we don't need to
1411 			 * return EAGAIN to arm the poll infra since it
1412 			 * has already been done
1413 			 */
1414 			if (issue_flags & IO_URING_F_MULTISHOT)
1415 				return IOU_ISSUE_SKIP_COMPLETE;
1416 			return ret;
1417 		}
1418 		if (ret == -ERESTARTSYS)
1419 			ret = -EINTR;
1420 		req_set_fail(req);
1421 	} else if (!fixed) {
1422 		fd_install(fd, file);
1423 		ret = fd;
1424 	} else {
1425 		ret = io_fixed_fd_install(req, issue_flags, file,
1426 						accept->file_slot);
1427 	}
1428 
1429 	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
1430 		io_req_set_res(req, ret, 0);
1431 		return IOU_OK;
1432 	}
1433 
1434 	if (ret < 0)
1435 		return ret;
1436 	if (io_fill_cqe_req_aux(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
1437 				ret, IORING_CQE_F_MORE))
1438 		goto retry;
1439 
1440 	io_req_set_res(req, ret, 0);
1441 	return IOU_STOP_MULTISHOT;
1442 }
1443 
io_socket_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)1444 int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1445 {
1446 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1447 
1448 	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
1449 		return -EINVAL;
1450 
1451 	sock->domain = READ_ONCE(sqe->fd);
1452 	sock->type = READ_ONCE(sqe->off);
1453 	sock->protocol = READ_ONCE(sqe->len);
1454 	sock->file_slot = READ_ONCE(sqe->file_index);
1455 	sock->nofile = rlimit(RLIMIT_NOFILE);
1456 
1457 	sock->flags = sock->type & ~SOCK_TYPE_MASK;
1458 	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
1459 		return -EINVAL;
1460 	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
1461 		return -EINVAL;
1462 	return 0;
1463 }
1464 
io_socket(struct io_kiocb * req,unsigned int issue_flags)1465 int io_socket(struct io_kiocb *req, unsigned int issue_flags)
1466 {
1467 	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
1468 	bool fixed = !!sock->file_slot;
1469 	struct file *file;
1470 	int ret, fd;
1471 
1472 	if (!fixed) {
1473 		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
1474 		if (unlikely(fd < 0))
1475 			return fd;
1476 	}
1477 	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
1478 	if (IS_ERR(file)) {
1479 		if (!fixed)
1480 			put_unused_fd(fd);
1481 		ret = PTR_ERR(file);
1482 		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
1483 			return -EAGAIN;
1484 		if (ret == -ERESTARTSYS)
1485 			ret = -EINTR;
1486 		req_set_fail(req);
1487 	} else if (!fixed) {
1488 		fd_install(fd, file);
1489 		ret = fd;
1490 	} else {
1491 		ret = io_fixed_fd_install(req, issue_flags, file,
1492 					    sock->file_slot);
1493 	}
1494 	io_req_set_res(req, ret, 0);
1495 	return IOU_OK;
1496 }
1497 
io_connect_prep_async(struct io_kiocb * req)1498 int io_connect_prep_async(struct io_kiocb *req)
1499 {
1500 	struct io_async_connect *io = req->async_data;
1501 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1502 
1503 	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
1504 }
1505 
io_connect_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)1506 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
1507 {
1508 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
1509 
1510 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
1511 		return -EINVAL;
1512 
1513 	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
1514 	conn->addr_len =  READ_ONCE(sqe->addr2);
1515 	conn->in_progress = conn->seen_econnaborted = false;
1516 	return 0;
1517 }
1518 
io_connect(struct io_kiocb * req,unsigned int issue_flags)1519 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
1520 {
1521 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
1522 	struct io_async_connect __io, *io;
1523 	unsigned file_flags;
1524 	int ret;
1525 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
1526 
1527 	if (req_has_async_data(req)) {
1528 		io = req->async_data;
1529 	} else {
1530 		ret = move_addr_to_kernel(connect->addr,
1531 						connect->addr_len,
1532 						&__io.address);
1533 		if (ret)
1534 			goto out;
1535 		io = &__io;
1536 	}
1537 
1538 	if (unlikely(req->flags & REQ_F_FAIL)) {
1539 		ret = -ECONNRESET;
1540 		goto out;
1541 	}
1542 
1543 	file_flags = force_nonblock ? O_NONBLOCK : 0;
1544 
1545 	ret = __sys_connect_file(req->file, &io->address,
1546 					connect->addr_len, file_flags);
1547 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
1548 	    && force_nonblock) {
1549 		if (ret == -EINPROGRESS) {
1550 			connect->in_progress = true;
1551 		} else if (ret == -ECONNABORTED) {
1552 			if (connect->seen_econnaborted)
1553 				goto out;
1554 			connect->seen_econnaborted = true;
1555 		}
1556 		if (req_has_async_data(req))
1557 			return -EAGAIN;
1558 		if (io_alloc_async_data(req)) {
1559 			ret = -ENOMEM;
1560 			goto out;
1561 		}
1562 		memcpy(req->async_data, &__io, sizeof(__io));
1563 		return -EAGAIN;
1564 	}
1565 	if (connect->in_progress) {
1566 		/*
1567 		 * At least bluetooth will return -EBADFD on a re-connect
1568 		 * attempt, and it's (supposedly) also valid to get -EISCONN
1569 		 * which means the previous result is good. For both of these,
1570 		 * grab the sock_error() and use that for the completion.
1571 		 */
1572 		if (ret == -EBADFD || ret == -EISCONN)
1573 			ret = sock_error(sock_from_file(req->file)->sk);
1574 	}
1575 	if (ret == -ERESTARTSYS)
1576 		ret = -EINTR;
1577 out:
1578 	if (ret < 0)
1579 		req_set_fail(req);
1580 	io_req_set_res(req, ret, 0);
1581 	return IOU_OK;
1582 }
1583 
io_netmsg_cache_free(struct io_cache_entry * entry)1584 void io_netmsg_cache_free(struct io_cache_entry *entry)
1585 {
1586 	kfree(container_of(entry, struct io_async_msghdr, cache));
1587 }
1588 #endif
1589