xref: /linux/io_uring/uring_cmd.c (revision eb2f932100288dbb881eadfed02e1459c6b9504c)
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/security.h>
7 #include <linux/nospec.h>
8 
9 #include <uapi/linux/io_uring.h>
10 #include <asm/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 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
56 {
57 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
58 	unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
59 
60 	ioucmd->task_work_cb(ioucmd, issue_flags);
61 }
62 
63 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
64 			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
65 			unsigned flags)
66 {
67 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
68 
69 	ioucmd->task_work_cb = task_work_cb;
70 	req->io_task_work.func = io_uring_cmd_work;
71 	__io_req_task_work_add(req, flags);
72 }
73 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
74 
75 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
76 					  u64 extra1, u64 extra2)
77 {
78 	req->big_cqe.extra1 = extra1;
79 	req->big_cqe.extra2 = extra2;
80 }
81 
82 /*
83  * Called by consumers of io_uring_cmd, if they originally returned
84  * -EIOCBQUEUED upon receiving the command.
85  */
86 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
87 		       unsigned issue_flags)
88 {
89 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
90 
91 	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
92 
93 	if (ret < 0)
94 		req_set_fail(req);
95 
96 	io_req_set_res(req, ret, 0);
97 	if (req->ctx->flags & IORING_SETUP_CQE32)
98 		io_req_set_cqe32_extra(req, res2, 0);
99 	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
100 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
101 		smp_store_release(&req->iopoll_completed, 1);
102 	} else {
103 		struct io_tw_state ts = {
104 			.locked = !(issue_flags & IO_URING_F_UNLOCKED),
105 		};
106 		io_req_task_complete(req, &ts);
107 	}
108 }
109 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
110 
111 int io_uring_cmd_prep_async(struct io_kiocb *req)
112 {
113 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
114 
115 	memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
116 	ioucmd->sqe = req->async_data;
117 	return 0;
118 }
119 
120 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
121 {
122 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
123 
124 	if (sqe->__pad1)
125 		return -EINVAL;
126 
127 	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
128 	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
129 		return -EINVAL;
130 
131 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
132 		struct io_ring_ctx *ctx = req->ctx;
133 		u16 index;
134 
135 		req->buf_index = READ_ONCE(sqe->buf_index);
136 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
137 			return -EFAULT;
138 		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
139 		req->imu = ctx->user_bufs[index];
140 		io_req_set_rsrc_node(req, ctx, 0);
141 	}
142 	ioucmd->sqe = sqe;
143 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
144 	return 0;
145 }
146 
147 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
148 {
149 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
150 	struct io_ring_ctx *ctx = req->ctx;
151 	struct file *file = req->file;
152 	int ret;
153 
154 	if (!file->f_op->uring_cmd)
155 		return -EOPNOTSUPP;
156 
157 	ret = security_uring_cmd(ioucmd);
158 	if (ret)
159 		return ret;
160 
161 	if (ctx->flags & IORING_SETUP_SQE128)
162 		issue_flags |= IO_URING_F_SQE128;
163 	if (ctx->flags & IORING_SETUP_CQE32)
164 		issue_flags |= IO_URING_F_CQE32;
165 	if (ctx->compat)
166 		issue_flags |= IO_URING_F_COMPAT;
167 	if (ctx->flags & IORING_SETUP_IOPOLL) {
168 		if (!file->f_op->uring_cmd_iopoll)
169 			return -EOPNOTSUPP;
170 		issue_flags |= IO_URING_F_IOPOLL;
171 		req->iopoll_completed = 0;
172 	}
173 
174 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
175 	if (ret == -EAGAIN) {
176 		if (!req_has_async_data(req)) {
177 			if (io_alloc_async_data(req))
178 				return -ENOMEM;
179 			io_uring_cmd_prep_async(req);
180 		}
181 		return -EAGAIN;
182 	}
183 
184 	if (ret != -EIOCBQUEUED) {
185 		if (ret < 0)
186 			req_set_fail(req);
187 		io_req_set_res(req, ret, 0);
188 		return ret;
189 	}
190 
191 	return IOU_ISSUE_SKIP_COMPLETE;
192 }
193 
194 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
195 			      struct iov_iter *iter, void *ioucmd)
196 {
197 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
198 
199 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
200 }
201 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
202 
203 static inline int io_uring_cmd_getsockopt(struct socket *sock,
204 					  struct io_uring_cmd *cmd,
205 					  unsigned int issue_flags)
206 {
207 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
208 	int optlen, optname, level, err;
209 	void __user *optval;
210 
211 	level = READ_ONCE(cmd->sqe->level);
212 	if (level != SOL_SOCKET)
213 		return -EOPNOTSUPP;
214 
215 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
216 	optname = READ_ONCE(cmd->sqe->optname);
217 	optlen = READ_ONCE(cmd->sqe->optlen);
218 
219 	err = do_sock_getsockopt(sock, compat, level, optname,
220 				 USER_SOCKPTR(optval),
221 				 KERNEL_SOCKPTR(&optlen));
222 	if (err)
223 		return err;
224 
225 	/* On success, return optlen */
226 	return optlen;
227 }
228 
229 static inline int io_uring_cmd_setsockopt(struct socket *sock,
230 					  struct io_uring_cmd *cmd,
231 					  unsigned int issue_flags)
232 {
233 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
234 	int optname, optlen, level;
235 	void __user *optval;
236 	sockptr_t optval_s;
237 
238 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
239 	optname = READ_ONCE(cmd->sqe->optname);
240 	optlen = READ_ONCE(cmd->sqe->optlen);
241 	level = READ_ONCE(cmd->sqe->level);
242 	optval_s = USER_SOCKPTR(optval);
243 
244 	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
245 				  optlen);
246 }
247 
248 #if defined(CONFIG_NET)
249 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
250 {
251 	struct socket *sock = cmd->file->private_data;
252 	struct sock *sk = sock->sk;
253 	struct proto *prot = READ_ONCE(sk->sk_prot);
254 	int ret, arg = 0;
255 
256 	if (!prot || !prot->ioctl)
257 		return -EOPNOTSUPP;
258 
259 	switch (cmd->sqe->cmd_op) {
260 	case SOCKET_URING_OP_SIOCINQ:
261 		ret = prot->ioctl(sk, SIOCINQ, &arg);
262 		if (ret)
263 			return ret;
264 		return arg;
265 	case SOCKET_URING_OP_SIOCOUTQ:
266 		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
267 		if (ret)
268 			return ret;
269 		return arg;
270 	case SOCKET_URING_OP_GETSOCKOPT:
271 		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
272 	case SOCKET_URING_OP_SETSOCKOPT:
273 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
274 	default:
275 		return -EOPNOTSUPP;
276 	}
277 }
278 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
279 #endif
280