1/*-
2 * Copyright (c) 2016 Netflix, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/sys/dev/efidev/efidev.c 332028 2018-04-04 13:58:18Z kevans $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/bus.h>
34#include <sys/conf.h>
35#include <sys/lock.h>
36#include <sys/malloc.h>
37#include <sys/module.h>
38
39#include <machine/efi.h>
40#include <sys/efiio.h>
41
42static d_ioctl_t efidev_ioctl;
43
44static struct cdevsw efi_cdevsw = {
45	.d_name = "efi",
46	.d_version = D_VERSION,
47	.d_ioctl = efidev_ioctl,
48};
49
50static int
51efidev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
52    int flags __unused, struct thread *td __unused)
53{
54	int error;
55
56	switch (cmd) {
57	case EFIIOC_GET_TABLE:
58	{
59		struct efi_get_table_ioc *egtioc =
60		    (struct efi_get_table_ioc *)addr;
61
62		error = efi_get_table(&egtioc->uuid, &egtioc->ptr);
63		break;
64	}
65	case EFIIOC_GET_TIME:
66	{
67		struct efi_tm *tm = (struct efi_tm *)addr;
68
69		error = efi_get_time(tm);
70		break;
71	}
72	case EFIIOC_SET_TIME:
73	{
74		struct efi_tm *tm = (struct efi_tm *)addr;
75
76		error = efi_set_time(tm);
77		break;
78	}
79	case EFIIOC_VAR_GET:
80	{
81		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
82		void *data;
83		efi_char *name;
84
85		data = malloc(ev->datasize, M_TEMP, M_WAITOK);
86		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
87		error = copyin(ev->name, name, ev->namesize);
88		if (error)
89			goto vg_out;
90		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
91			error = EINVAL;
92			goto vg_out;
93		}
94
95		error = efi_var_get(name, &ev->vendor, &ev->attrib,
96		    &ev->datasize, data);
97
98		if (error == 0) {
99			error = copyout(data, ev->data, ev->datasize);
100		} else if (error == EOVERFLOW) {
101			/*
102			 * Pass back the size we really need, but
103			 * convert the error to 0 so the copyout
104			 * happens. datasize was updated in the
105			 * efi_var_get call.
106			 */
107			ev->data = NULL;
108			error = 0;
109		}
110vg_out:
111		free(data, M_TEMP);
112		free(name, M_TEMP);
113		break;
114	}
115	case EFIIOC_VAR_NEXT:
116	{
117		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
118		efi_char *name;
119
120		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
121		error = copyin(ev->name, name, ev->namesize);
122		if (error)
123			goto vn_out;
124		/* Note: namesize is the buffer size, not the string lenght */
125
126		error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
127		if (error == 0) {
128			error = copyout(name, ev->name, ev->namesize);
129		} else if (error == EOVERFLOW) {
130			ev->name = NULL;
131			error = 0;
132		}
133	vn_out:
134		free(name, M_TEMP);
135		break;
136	}
137	case EFIIOC_VAR_SET:
138	{
139		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
140		void *data = NULL;
141		efi_char *name;
142
143		/* datasize == 0 -> delete (more or less) */
144		if (ev->datasize > 0)
145			data = malloc(ev->datasize, M_TEMP, M_WAITOK);
146		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
147		if (ev->datasize) {
148			error = copyin(ev->data, data, ev->datasize);
149			if (error)
150				goto vs_out;
151		}
152		error = copyin(ev->name, name, ev->namesize);
153		if (error)
154			goto vs_out;
155		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
156			error = EINVAL;
157			goto vs_out;
158		}
159
160		error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
161		    data);
162vs_out:
163		free(data, M_TEMP);
164		free(name, M_TEMP);
165		break;
166	}
167	default:
168		error = ENOTTY;
169		break;
170	}
171
172	return (error);
173}
174
175static struct cdev *efidev;
176
177static int
178efidev_modevents(module_t m, int event, void *arg __unused)
179{
180	struct make_dev_args mda;
181	int error;
182
183	switch (event) {
184	case MOD_LOAD:
185		/*
186		 * If we have no efi environment, then don't create the device.
187		 */
188		if (efi_rt_ok() != 0)
189			return (0);
190		make_dev_args_init(&mda);
191		mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
192		mda.mda_devsw = &efi_cdevsw;
193		mda.mda_uid = UID_ROOT;
194		mda.mda_gid = GID_WHEEL;
195		mda.mda_mode = 0700;
196		error = make_dev_s(&mda, &efidev, "efi");
197		return (error);
198
199	case MOD_UNLOAD:
200		if (efidev != NULL)
201			destroy_dev(efidev);
202		efidev = NULL;
203		return (0);
204
205	case MOD_SHUTDOWN:
206		return (0);
207
208	default:
209		return (EOPNOTSUPP);
210	}
211}
212
213static moduledata_t efidev_moddata = {
214	.name = "efidev",
215	.evhand = efidev_modevents,
216	.priv = NULL,
217};
218
219DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
220MODULE_VERSION(efidev, 1);
221MODULE_DEPEND(efidev, efirt, 1, 1, 1);
222