xref: /linux/io_uring/uring_cmd.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
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.h>
6 #include <linux/security.h>
7 #include <linux/nospec.h>
8 
9 #include <uapi/linux/io_uring.h>
10 #include <uapi/asm-generic/ioctls.h>
11 
12 #include "io_uring.h"
13 #include "rsrc.h"
14 #include "uring_cmd.h"
15 
16 static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd,
17 		unsigned int issue_flags)
18 {
19 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
20 	struct io_ring_ctx *ctx = req->ctx;
21 
22 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE))
23 		return;
24 
25 	cmd->flags &= ~IORING_URING_CMD_CANCELABLE;
26 	io_ring_submit_lock(ctx, issue_flags);
27 	hlist_del(&req->hash_node);
28 	io_ring_submit_unlock(ctx, issue_flags);
29 }
30 
31 /*
32  * Mark this command as concelable, then io_uring_try_cancel_uring_cmd()
33  * will try to cancel this issued command by sending ->uring_cmd() with
34  * issue_flags of IO_URING_F_CANCEL.
35  *
36  * The command is guaranteed to not be done when calling ->uring_cmd()
37  * with IO_URING_F_CANCEL, but it is driver's responsibility to deal
38  * with race between io_uring canceling and normal completion.
39  */
40 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
41 		unsigned int issue_flags)
42 {
43 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
44 	struct io_ring_ctx *ctx = req->ctx;
45 
46 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) {
47 		cmd->flags |= IORING_URING_CMD_CANCELABLE;
48 		io_ring_submit_lock(ctx, issue_flags);
49 		hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd);
50 		io_ring_submit_unlock(ctx, issue_flags);
51 	}
52 }
53 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
54 
55 struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd)
56 {
57 	return cmd_to_io_kiocb(cmd)->task;
58 }
59 EXPORT_SYMBOL_GPL(io_uring_cmd_get_task);
60 
61 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
62 {
63 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
64 	unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
65 
66 	ioucmd->task_work_cb(ioucmd, issue_flags);
67 }
68 
69 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
70 			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
71 			unsigned flags)
72 {
73 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
74 
75 	ioucmd->task_work_cb = task_work_cb;
76 	req->io_task_work.func = io_uring_cmd_work;
77 	__io_req_task_work_add(req, flags);
78 }
79 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
80 
81 void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
82 			void (*task_work_cb)(struct io_uring_cmd *, unsigned))
83 {
84 	__io_uring_cmd_do_in_task(ioucmd, task_work_cb, IOU_F_TWQ_LAZY_WAKE);
85 }
86 EXPORT_SYMBOL_GPL(io_uring_cmd_do_in_task_lazy);
87 
88 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
89 					  u64 extra1, u64 extra2)
90 {
91 	req->big_cqe.extra1 = extra1;
92 	req->big_cqe.extra2 = extra2;
93 }
94 
95 /*
96  * Called by consumers of io_uring_cmd, if they originally returned
97  * -EIOCBQUEUED upon receiving the command.
98  */
99 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
100 		       unsigned issue_flags)
101 {
102 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
103 
104 	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
105 
106 	if (ret < 0)
107 		req_set_fail(req);
108 
109 	io_req_set_res(req, ret, 0);
110 	if (req->ctx->flags & IORING_SETUP_CQE32)
111 		io_req_set_cqe32_extra(req, res2, 0);
112 	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
113 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
114 		smp_store_release(&req->iopoll_completed, 1);
115 	} else {
116 		struct io_tw_state ts = {
117 			.locked = !(issue_flags & IO_URING_F_UNLOCKED),
118 		};
119 		io_req_task_complete(req, &ts);
120 	}
121 }
122 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
123 
124 int io_uring_cmd_prep_async(struct io_kiocb *req)
125 {
126 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
127 
128 	memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
129 	ioucmd->sqe = req->async_data;
130 	return 0;
131 }
132 
133 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
134 {
135 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
136 
137 	if (sqe->__pad1)
138 		return -EINVAL;
139 
140 	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
141 	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
142 		return -EINVAL;
143 
144 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
145 		struct io_ring_ctx *ctx = req->ctx;
146 		u16 index;
147 
148 		req->buf_index = READ_ONCE(sqe->buf_index);
149 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
150 			return -EFAULT;
151 		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
152 		req->imu = ctx->user_bufs[index];
153 		io_req_set_rsrc_node(req, ctx, 0);
154 	}
155 	ioucmd->sqe = sqe;
156 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
157 	return 0;
158 }
159 
160 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
161 {
162 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
163 	struct io_ring_ctx *ctx = req->ctx;
164 	struct file *file = req->file;
165 	int ret;
166 
167 	if (!file->f_op->uring_cmd)
168 		return -EOPNOTSUPP;
169 
170 	ret = security_uring_cmd(ioucmd);
171 	if (ret)
172 		return ret;
173 
174 	if (ctx->flags & IORING_SETUP_SQE128)
175 		issue_flags |= IO_URING_F_SQE128;
176 	if (ctx->flags & IORING_SETUP_CQE32)
177 		issue_flags |= IO_URING_F_CQE32;
178 	if (ctx->compat)
179 		issue_flags |= IO_URING_F_COMPAT;
180 	if (ctx->flags & IORING_SETUP_IOPOLL) {
181 		if (!file->f_op->uring_cmd_iopoll)
182 			return -EOPNOTSUPP;
183 		issue_flags |= IO_URING_F_IOPOLL;
184 		req->iopoll_completed = 0;
185 		WRITE_ONCE(ioucmd->cookie, NULL);
186 	}
187 
188 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
189 	if (ret == -EAGAIN) {
190 		if (!req_has_async_data(req)) {
191 			if (io_alloc_async_data(req))
192 				return -ENOMEM;
193 			io_uring_cmd_prep_async(req);
194 		}
195 		return -EAGAIN;
196 	}
197 
198 	if (ret != -EIOCBQUEUED) {
199 		if (ret < 0)
200 			req_set_fail(req);
201 		io_req_set_res(req, ret, 0);
202 		return ret;
203 	}
204 
205 	return IOU_ISSUE_SKIP_COMPLETE;
206 }
207 
208 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
209 			      struct iov_iter *iter, void *ioucmd)
210 {
211 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
212 
213 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
214 }
215 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
216 
217 static inline int io_uring_cmd_getsockopt(struct socket *sock,
218 					  struct io_uring_cmd *cmd,
219 					  unsigned int issue_flags)
220 {
221 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
222 	int optlen, optname, level, err;
223 	void __user *optval;
224 
225 	level = READ_ONCE(cmd->sqe->level);
226 	if (level != SOL_SOCKET)
227 		return -EOPNOTSUPP;
228 
229 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
230 	optname = READ_ONCE(cmd->sqe->optname);
231 	optlen = READ_ONCE(cmd->sqe->optlen);
232 
233 	err = do_sock_getsockopt(sock, compat, level, optname,
234 				 USER_SOCKPTR(optval),
235 				 KERNEL_SOCKPTR(&optlen));
236 	if (err)
237 		return err;
238 
239 	/* On success, return optlen */
240 	return optlen;
241 }
242 
243 static inline int io_uring_cmd_setsockopt(struct socket *sock,
244 					  struct io_uring_cmd *cmd,
245 					  unsigned int issue_flags)
246 {
247 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
248 	int optname, optlen, level;
249 	void __user *optval;
250 	sockptr_t optval_s;
251 
252 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
253 	optname = READ_ONCE(cmd->sqe->optname);
254 	optlen = READ_ONCE(cmd->sqe->optlen);
255 	level = READ_ONCE(cmd->sqe->level);
256 	optval_s = USER_SOCKPTR(optval);
257 
258 	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
259 				  optlen);
260 }
261 
262 #if defined(CONFIG_NET)
263 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
264 {
265 	struct socket *sock = cmd->file->private_data;
266 	struct sock *sk = sock->sk;
267 	struct proto *prot = READ_ONCE(sk->sk_prot);
268 	int ret, arg = 0;
269 
270 	if (!prot || !prot->ioctl)
271 		return -EOPNOTSUPP;
272 
273 	switch (cmd->sqe->cmd_op) {
274 	case SOCKET_URING_OP_SIOCINQ:
275 		ret = prot->ioctl(sk, SIOCINQ, &arg);
276 		if (ret)
277 			return ret;
278 		return arg;
279 	case SOCKET_URING_OP_SIOCOUTQ:
280 		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
281 		if (ret)
282 			return ret;
283 		return arg;
284 	case SOCKET_URING_OP_GETSOCKOPT:
285 		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
286 	case SOCKET_URING_OP_SETSOCKOPT:
287 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
288 	default:
289 		return -EOPNOTSUPP;
290 	}
291 }
292 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
293 #endif
294