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/io_uring/cmd.h>
6#include <linux/io_uring/net.h>
7#include <linux/security.h>
8#include <linux/nospec.h>
9#include <net/sock.h>
10
11#include <uapi/linux/io_uring.h>
12#include <asm/ioctls.h>
13
14#include "io_uring.h"
15#include "alloc_cache.h"
16#include "rsrc.h"
17#include "uring_cmd.h"
18
19static struct uring_cache *io_uring_async_get(struct io_kiocb *req)
20{
21	struct io_ring_ctx *ctx = req->ctx;
22	struct uring_cache *cache;
23
24	cache = io_alloc_cache_get(&ctx->uring_cache);
25	if (cache) {
26		req->flags |= REQ_F_ASYNC_DATA;
27		req->async_data = cache;
28		return cache;
29	}
30	if (!io_alloc_async_data(req))
31		return req->async_data;
32	return NULL;
33}
34
35static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
36{
37	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
38	struct uring_cache *cache = req->async_data;
39
40	if (issue_flags & IO_URING_F_UNLOCKED)
41		return;
42	if (io_alloc_cache_put(&req->ctx->uring_cache, cache)) {
43		ioucmd->sqe = NULL;
44		req->async_data = NULL;
45		req->flags &= ~REQ_F_ASYNC_DATA;
46	}
47}
48
49bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
50				   struct task_struct *task, bool cancel_all)
51{
52	struct hlist_node *tmp;
53	struct io_kiocb *req;
54	bool ret = false;
55
56	lockdep_assert_held(&ctx->uring_lock);
57
58	hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd,
59			hash_node) {
60		struct io_uring_cmd *cmd = io_kiocb_to_cmd(req,
61				struct io_uring_cmd);
62		struct file *file = req->file;
63
64		if (!cancel_all && req->task != task)
65			continue;
66
67		if (cmd->flags & IORING_URING_CMD_CANCELABLE) {
68			/* ->sqe isn't available if no async data */
69			if (!req_has_async_data(req))
70				cmd->sqe = NULL;
71			file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL |
72						   IO_URING_F_COMPLETE_DEFER);
73			ret = true;
74		}
75	}
76	io_submit_flush_completions(ctx);
77	return ret;
78}
79
80static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd,
81		unsigned int issue_flags)
82{
83	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
84	struct io_ring_ctx *ctx = req->ctx;
85
86	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE))
87		return;
88
89	cmd->flags &= ~IORING_URING_CMD_CANCELABLE;
90	io_ring_submit_lock(ctx, issue_flags);
91	hlist_del(&req->hash_node);
92	io_ring_submit_unlock(ctx, issue_flags);
93}
94
95/*
96 * Mark this command as concelable, then io_uring_try_cancel_uring_cmd()
97 * will try to cancel this issued command by sending ->uring_cmd() with
98 * issue_flags of IO_URING_F_CANCEL.
99 *
100 * The command is guaranteed to not be done when calling ->uring_cmd()
101 * with IO_URING_F_CANCEL, but it is driver's responsibility to deal
102 * with race between io_uring canceling and normal completion.
103 */
104void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
105		unsigned int issue_flags)
106{
107	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
108	struct io_ring_ctx *ctx = req->ctx;
109
110	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) {
111		cmd->flags |= IORING_URING_CMD_CANCELABLE;
112		io_ring_submit_lock(ctx, issue_flags);
113		hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd);
114		io_ring_submit_unlock(ctx, issue_flags);
115	}
116}
117EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
118
119static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
120{
121	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
122
123	/* task_work executor checks the deffered list completion */
124	ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER);
125}
126
127void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
128			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
129			unsigned flags)
130{
131	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
132
133	ioucmd->task_work_cb = task_work_cb;
134	req->io_task_work.func = io_uring_cmd_work;
135	__io_req_task_work_add(req, flags);
136}
137EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
138
139static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
140					  u64 extra1, u64 extra2)
141{
142	req->big_cqe.extra1 = extra1;
143	req->big_cqe.extra2 = extra2;
144}
145
146/*
147 * Called by consumers of io_uring_cmd, if they originally returned
148 * -EIOCBQUEUED upon receiving the command.
149 */
150void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
151		       unsigned issue_flags)
152{
153	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
154
155	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
156
157	if (ret < 0)
158		req_set_fail(req);
159
160	io_req_set_res(req, ret, 0);
161	if (req->ctx->flags & IORING_SETUP_CQE32)
162		io_req_set_cqe32_extra(req, res2, 0);
163	io_req_uring_cleanup(req, issue_flags);
164	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
165		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
166		smp_store_release(&req->iopoll_completed, 1);
167	} else if (issue_flags & IO_URING_F_COMPLETE_DEFER) {
168		if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED))
169			return;
170		io_req_complete_defer(req);
171	} else {
172		req->io_task_work.func = io_req_task_complete;
173		io_req_task_work_add(req);
174	}
175}
176EXPORT_SYMBOL_GPL(io_uring_cmd_done);
177
178static int io_uring_cmd_prep_setup(struct io_kiocb *req,
179				   const struct io_uring_sqe *sqe)
180{
181	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
182	struct uring_cache *cache;
183
184	cache = io_uring_async_get(req);
185	if (unlikely(!cache))
186		return -ENOMEM;
187
188	if (!(req->flags & REQ_F_FORCE_ASYNC)) {
189		/* defer memcpy until we need it */
190		ioucmd->sqe = sqe;
191		return 0;
192	}
193
194	memcpy(req->async_data, sqe, uring_sqe_size(req->ctx));
195	ioucmd->sqe = req->async_data;
196	return 0;
197}
198
199int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
200{
201	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
202
203	if (sqe->__pad1)
204		return -EINVAL;
205
206	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
207	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
208		return -EINVAL;
209
210	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
211		struct io_ring_ctx *ctx = req->ctx;
212		u16 index;
213
214		req->buf_index = READ_ONCE(sqe->buf_index);
215		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
216			return -EFAULT;
217		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
218		req->imu = ctx->user_bufs[index];
219		io_req_set_rsrc_node(req, ctx, 0);
220	}
221	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
222
223	return io_uring_cmd_prep_setup(req, sqe);
224}
225
226int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
227{
228	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
229	struct io_ring_ctx *ctx = req->ctx;
230	struct file *file = req->file;
231	int ret;
232
233	if (!file->f_op->uring_cmd)
234		return -EOPNOTSUPP;
235
236	ret = security_uring_cmd(ioucmd);
237	if (ret)
238		return ret;
239
240	if (ctx->flags & IORING_SETUP_SQE128)
241		issue_flags |= IO_URING_F_SQE128;
242	if (ctx->flags & IORING_SETUP_CQE32)
243		issue_flags |= IO_URING_F_CQE32;
244	if (ctx->compat)
245		issue_flags |= IO_URING_F_COMPAT;
246	if (ctx->flags & IORING_SETUP_IOPOLL) {
247		if (!file->f_op->uring_cmd_iopoll)
248			return -EOPNOTSUPP;
249		issue_flags |= IO_URING_F_IOPOLL;
250		req->iopoll_completed = 0;
251	}
252
253	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
254	if (ret == -EAGAIN) {
255		struct uring_cache *cache = req->async_data;
256
257		if (ioucmd->sqe != (void *) cache)
258			memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx));
259		return -EAGAIN;
260	} else if (ret == -EIOCBQUEUED) {
261		return -EIOCBQUEUED;
262	}
263
264	if (ret < 0)
265		req_set_fail(req);
266	io_req_uring_cleanup(req, issue_flags);
267	io_req_set_res(req, ret, 0);
268	return ret;
269}
270
271int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
272			      struct iov_iter *iter, void *ioucmd)
273{
274	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
275
276	return io_import_fixed(rw, iter, req->imu, ubuf, len);
277}
278EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
279
280static inline int io_uring_cmd_getsockopt(struct socket *sock,
281					  struct io_uring_cmd *cmd,
282					  unsigned int issue_flags)
283{
284	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
285	int optlen, optname, level, err;
286	void __user *optval;
287
288	level = READ_ONCE(cmd->sqe->level);
289	if (level != SOL_SOCKET)
290		return -EOPNOTSUPP;
291
292	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
293	optname = READ_ONCE(cmd->sqe->optname);
294	optlen = READ_ONCE(cmd->sqe->optlen);
295
296	err = do_sock_getsockopt(sock, compat, level, optname,
297				 USER_SOCKPTR(optval),
298				 KERNEL_SOCKPTR(&optlen));
299	if (err)
300		return err;
301
302	/* On success, return optlen */
303	return optlen;
304}
305
306static inline int io_uring_cmd_setsockopt(struct socket *sock,
307					  struct io_uring_cmd *cmd,
308					  unsigned int issue_flags)
309{
310	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
311	int optname, optlen, level;
312	void __user *optval;
313	sockptr_t optval_s;
314
315	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
316	optname = READ_ONCE(cmd->sqe->optname);
317	optlen = READ_ONCE(cmd->sqe->optlen);
318	level = READ_ONCE(cmd->sqe->level);
319	optval_s = USER_SOCKPTR(optval);
320
321	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
322				  optlen);
323}
324
325#if defined(CONFIG_NET)
326int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
327{
328	struct socket *sock = cmd->file->private_data;
329	struct sock *sk = sock->sk;
330	struct proto *prot = READ_ONCE(sk->sk_prot);
331	int ret, arg = 0;
332
333	if (!prot || !prot->ioctl)
334		return -EOPNOTSUPP;
335
336	switch (cmd->sqe->cmd_op) {
337	case SOCKET_URING_OP_SIOCINQ:
338		ret = prot->ioctl(sk, SIOCINQ, &arg);
339		if (ret)
340			return ret;
341		return arg;
342	case SOCKET_URING_OP_SIOCOUTQ:
343		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
344		if (ret)
345			return ret;
346		return arg;
347	case SOCKET_URING_OP_GETSOCKOPT:
348		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
349	case SOCKET_URING_OP_SETSOCKOPT:
350		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
351	default:
352		return -EOPNOTSUPP;
353	}
354}
355EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
356#endif
357