xref: /freebsd/sys/dev/efidev/efidev.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3)
1 /*-
2  * Copyright (c) 2016 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer
9  *    in this position and unchanged.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/bus.h>
33 #include <sys/conf.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 
38 #include <machine/efi.h>
39 #include <sys/efiio.h>
40 
41 static d_ioctl_t efidev_ioctl;
42 
43 static struct cdevsw efi_cdevsw = {
44 	.d_name = "efi",
45 	.d_version = D_VERSION,
46 	.d_ioctl = efidev_ioctl,
47 };
48 
49 static int
50 efidev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
51     int flags __unused, struct thread *td __unused)
52 {
53 	int error;
54 
55 	switch (cmd) {
56 	case EFIIOC_GET_TABLE:
57 	{
58 		struct efi_get_table_ioc *egtioc =
59 		    (struct efi_get_table_ioc *)addr;
60 		void *buf = NULL;
61 
62 		error = efi_copy_table(&egtioc->uuid, egtioc->buf ? &buf : NULL,
63 		    egtioc->buf_len, &egtioc->table_len);
64 
65 		if (error != 0 || egtioc->buf == NULL)
66 			break;
67 
68 		if (egtioc->buf_len < egtioc->table_len) {
69 			error = EINVAL;
70 			free(buf, M_TEMP);
71 			break;
72 		}
73 
74 		error = copyout(buf, egtioc->buf, egtioc->buf_len);
75 		free(buf, M_TEMP);
76 
77 		break;
78 	}
79 	case EFIIOC_GET_TIME:
80 	{
81 		struct efi_tm *tm = (struct efi_tm *)addr;
82 
83 		error = efi_get_time(tm);
84 		break;
85 	}
86 	case EFIIOC_SET_TIME:
87 	{
88 		struct efi_tm *tm = (struct efi_tm *)addr;
89 
90 		error = efi_set_time(tm);
91 		break;
92 	}
93 	case EFIIOC_GET_WAKETIME:
94 	{
95 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
96 
97 		error = efi_get_waketime(&wt->enabled, &wt->pending,
98 		    &wt->waketime);
99 		break;
100 	}
101 	case EFIIOC_SET_WAKETIME:
102 	{
103 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
104 
105 		error = efi_set_waketime(wt->enabled, &wt->waketime);
106 		break;
107 	}
108 	case EFIIOC_VAR_GET:
109 	{
110 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
111 		void *data;
112 		efi_char *name;
113 
114 		data = malloc(ev->datasize, M_TEMP, M_WAITOK);
115 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
116 		error = copyin(ev->name, name, ev->namesize);
117 		if (error)
118 			goto vg_out;
119 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
120 			error = EINVAL;
121 			goto vg_out;
122 		}
123 
124 		error = efi_var_get(name, &ev->vendor, &ev->attrib,
125 		    &ev->datasize, data);
126 
127 		if (error == 0) {
128 			error = copyout(data, ev->data, ev->datasize);
129 		} else if (error == EOVERFLOW) {
130 			/*
131 			 * Pass back the size we really need, but
132 			 * convert the error to 0 so the copyout
133 			 * happens. datasize was updated in the
134 			 * efi_var_get call.
135 			 */
136 			ev->data = NULL;
137 			error = 0;
138 		}
139 vg_out:
140 		free(data, M_TEMP);
141 		free(name, M_TEMP);
142 		break;
143 	}
144 	case EFIIOC_VAR_NEXT:
145 	{
146 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
147 		efi_char *name;
148 
149 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
150 		error = copyin(ev->name, name, ev->namesize);
151 		if (error)
152 			goto vn_out;
153 		/* Note: namesize is the buffer size, not the string lenght */
154 
155 		error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
156 		if (error == 0) {
157 			error = copyout(name, ev->name, ev->namesize);
158 		} else if (error == EOVERFLOW) {
159 			ev->name = NULL;
160 			error = 0;
161 		}
162 	vn_out:
163 		free(name, M_TEMP);
164 		break;
165 	}
166 	case EFIIOC_VAR_SET:
167 	{
168 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
169 		void *data = NULL;
170 		efi_char *name;
171 
172 		/* datasize == 0 -> delete (more or less) */
173 		if (ev->datasize > 0)
174 			data = malloc(ev->datasize, M_TEMP, M_WAITOK);
175 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
176 		if (ev->datasize) {
177 			error = copyin(ev->data, data, ev->datasize);
178 			if (error)
179 				goto vs_out;
180 		}
181 		error = copyin(ev->name, name, ev->namesize);
182 		if (error)
183 			goto vs_out;
184 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
185 			error = EINVAL;
186 			goto vs_out;
187 		}
188 
189 		error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
190 		    data);
191 vs_out:
192 		free(data, M_TEMP);
193 		free(name, M_TEMP);
194 		break;
195 	}
196 	default:
197 		error = ENOTTY;
198 		break;
199 	}
200 
201 	return (error);
202 }
203 
204 static struct cdev *efidev;
205 
206 static int
207 efidev_modevents(module_t m, int event, void *arg __unused)
208 {
209 	struct make_dev_args mda;
210 	int error;
211 
212 	switch (event) {
213 	case MOD_LOAD:
214 		/*
215 		 * If we have no efi environment, then don't create the device.
216 		 */
217 		if (efi_rt_ok() != 0)
218 			return (0);
219 		make_dev_args_init(&mda);
220 		mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
221 		mda.mda_devsw = &efi_cdevsw;
222 		mda.mda_uid = UID_ROOT;
223 		mda.mda_gid = GID_WHEEL;
224 		mda.mda_mode = 0700;
225 		error = make_dev_s(&mda, &efidev, "efi");
226 		return (error);
227 
228 	case MOD_UNLOAD:
229 		if (efidev != NULL)
230 			destroy_dev(efidev);
231 		efidev = NULL;
232 		return (0);
233 
234 	case MOD_SHUTDOWN:
235 		return (0);
236 
237 	default:
238 		return (EOPNOTSUPP);
239 	}
240 }
241 
242 static moduledata_t efidev_moddata = {
243 	.name = "efidev",
244 	.evhand = efidev_modevents,
245 	.priv = NULL,
246 };
247 
248 DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
249 MODULE_VERSION(efidev, 1);
250 MODULE_DEPEND(efidev, efirt, 1, 1, 1);
251