xref: /linux/io_uring/uring_cmd.c (revision 19cebbab995b2c99e927d6c5f3f24ded0740efd5)
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 #include <net/sock.h>
9 
10 #include <uapi/linux/io_uring.h>
11 #include <asm/ioctls.h>
12 
13 #include "io_uring.h"
14 #include "rsrc.h"
15 #include "uring_cmd.h"
16 
17 static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd,
18 		unsigned int issue_flags)
19 {
20 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
21 	struct io_ring_ctx *ctx = req->ctx;
22 
23 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE))
24 		return;
25 
26 	cmd->flags &= ~IORING_URING_CMD_CANCELABLE;
27 	io_ring_submit_lock(ctx, issue_flags);
28 	hlist_del(&req->hash_node);
29 	io_ring_submit_unlock(ctx, issue_flags);
30 }
31 
32 /*
33  * Mark this command as concelable, then io_uring_try_cancel_uring_cmd()
34  * will try to cancel this issued command by sending ->uring_cmd() with
35  * issue_flags of IO_URING_F_CANCEL.
36  *
37  * The command is guaranteed to not be done when calling ->uring_cmd()
38  * with IO_URING_F_CANCEL, but it is driver's responsibility to deal
39  * with race between io_uring canceling and normal completion.
40  */
41 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
42 		unsigned int issue_flags)
43 {
44 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
45 	struct io_ring_ctx *ctx = req->ctx;
46 
47 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) {
48 		cmd->flags |= IORING_URING_CMD_CANCELABLE;
49 		io_ring_submit_lock(ctx, issue_flags);
50 		hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd);
51 		io_ring_submit_unlock(ctx, issue_flags);
52 	}
53 }
54 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
55 
56 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
57 {
58 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
59 	unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
60 
61 	ioucmd->task_work_cb(ioucmd, issue_flags);
62 }
63 
64 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
65 			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
66 			unsigned flags)
67 {
68 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
69 
70 	ioucmd->task_work_cb = task_work_cb;
71 	req->io_task_work.func = io_uring_cmd_work;
72 	__io_req_task_work_add(req, flags);
73 }
74 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
75 
76 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
77 					  u64 extra1, u64 extra2)
78 {
79 	req->big_cqe.extra1 = extra1;
80 	req->big_cqe.extra2 = extra2;
81 }
82 
83 /*
84  * Called by consumers of io_uring_cmd, if they originally returned
85  * -EIOCBQUEUED upon receiving the command.
86  */
87 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
88 		       unsigned issue_flags)
89 {
90 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
91 
92 	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
93 
94 	if (ret < 0)
95 		req_set_fail(req);
96 
97 	io_req_set_res(req, ret, 0);
98 	if (req->ctx->flags & IORING_SETUP_CQE32)
99 		io_req_set_cqe32_extra(req, res2, 0);
100 	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
101 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
102 		smp_store_release(&req->iopoll_completed, 1);
103 	} else {
104 		struct io_tw_state ts = {
105 			.locked = !(issue_flags & IO_URING_F_UNLOCKED),
106 		};
107 		io_req_task_complete(req, &ts);
108 	}
109 }
110 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
111 
112 int io_uring_cmd_prep_async(struct io_kiocb *req)
113 {
114 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
115 
116 	memcpy(req->async_data, ioucmd->sqe, uring_sqe_size(req->ctx));
117 	ioucmd->sqe = req->async_data;
118 	return 0;
119 }
120 
121 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
122 {
123 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
124 
125 	if (sqe->__pad1)
126 		return -EINVAL;
127 
128 	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
129 	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
130 		return -EINVAL;
131 
132 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
133 		struct io_ring_ctx *ctx = req->ctx;
134 		u16 index;
135 
136 		req->buf_index = READ_ONCE(sqe->buf_index);
137 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
138 			return -EFAULT;
139 		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
140 		req->imu = ctx->user_bufs[index];
141 		io_req_set_rsrc_node(req, ctx, 0);
142 	}
143 	ioucmd->sqe = sqe;
144 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
145 	return 0;
146 }
147 
148 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
149 {
150 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
151 	struct io_ring_ctx *ctx = req->ctx;
152 	struct file *file = req->file;
153 	int ret;
154 
155 	if (!file->f_op->uring_cmd)
156 		return -EOPNOTSUPP;
157 
158 	ret = security_uring_cmd(ioucmd);
159 	if (ret)
160 		return ret;
161 
162 	if (ctx->flags & IORING_SETUP_SQE128)
163 		issue_flags |= IO_URING_F_SQE128;
164 	if (ctx->flags & IORING_SETUP_CQE32)
165 		issue_flags |= IO_URING_F_CQE32;
166 	if (ctx->compat)
167 		issue_flags |= IO_URING_F_COMPAT;
168 	if (ctx->flags & IORING_SETUP_IOPOLL) {
169 		if (!file->f_op->uring_cmd_iopoll)
170 			return -EOPNOTSUPP;
171 		issue_flags |= IO_URING_F_IOPOLL;
172 		req->iopoll_completed = 0;
173 	}
174 
175 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
176 	if (ret == -EAGAIN) {
177 		if (!req_has_async_data(req)) {
178 			if (io_alloc_async_data(req))
179 				return -ENOMEM;
180 			io_uring_cmd_prep_async(req);
181 		}
182 		return -EAGAIN;
183 	}
184 
185 	if (ret != -EIOCBQUEUED) {
186 		if (ret < 0)
187 			req_set_fail(req);
188 		io_req_set_res(req, ret, 0);
189 		return ret;
190 	}
191 
192 	return IOU_ISSUE_SKIP_COMPLETE;
193 }
194 
195 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
196 			      struct iov_iter *iter, void *ioucmd)
197 {
198 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
199 
200 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
201 }
202 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
203 
204 static inline int io_uring_cmd_getsockopt(struct socket *sock,
205 					  struct io_uring_cmd *cmd,
206 					  unsigned int issue_flags)
207 {
208 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
209 	int optlen, optname, level, err;
210 	void __user *optval;
211 
212 	level = READ_ONCE(cmd->sqe->level);
213 	if (level != SOL_SOCKET)
214 		return -EOPNOTSUPP;
215 
216 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
217 	optname = READ_ONCE(cmd->sqe->optname);
218 	optlen = READ_ONCE(cmd->sqe->optlen);
219 
220 	err = do_sock_getsockopt(sock, compat, level, optname,
221 				 USER_SOCKPTR(optval),
222 				 KERNEL_SOCKPTR(&optlen));
223 	if (err)
224 		return err;
225 
226 	/* On success, return optlen */
227 	return optlen;
228 }
229 
230 static inline int io_uring_cmd_setsockopt(struct socket *sock,
231 					  struct io_uring_cmd *cmd,
232 					  unsigned int issue_flags)
233 {
234 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
235 	int optname, optlen, level;
236 	void __user *optval;
237 	sockptr_t optval_s;
238 
239 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
240 	optname = READ_ONCE(cmd->sqe->optname);
241 	optlen = READ_ONCE(cmd->sqe->optlen);
242 	level = READ_ONCE(cmd->sqe->level);
243 	optval_s = USER_SOCKPTR(optval);
244 
245 	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
246 				  optlen);
247 }
248 
249 #if defined(CONFIG_NET)
250 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
251 {
252 	struct socket *sock = cmd->file->private_data;
253 	struct sock *sk = sock->sk;
254 	struct proto *prot = READ_ONCE(sk->sk_prot);
255 	int ret, arg = 0;
256 
257 	if (!prot || !prot->ioctl)
258 		return -EOPNOTSUPP;
259 
260 	switch (cmd->sqe->cmd_op) {
261 	case SOCKET_URING_OP_SIOCINQ:
262 		ret = prot->ioctl(sk, SIOCINQ, &arg);
263 		if (ret)
264 			return ret;
265 		return arg;
266 	case SOCKET_URING_OP_SIOCOUTQ:
267 		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
268 		if (ret)
269 			return ret;
270 		return arg;
271 	case SOCKET_URING_OP_GETSOCKOPT:
272 		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
273 	case SOCKET_URING_OP_SETSOCKOPT:
274 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
275 	default:
276 		return -EOPNOTSUPP;
277 	}
278 }
279 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
280 #endif
281