xref: /freebsd/sys/dev/efidev/efidev.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/param.h>
27 #include <sys/systm.h>
28 #include <sys/kernel.h>
29 #include <sys/bus.h>
30 #include <sys/conf.h>
31 #include <sys/lock.h>
32 #include <sys/malloc.h>
33 #include <sys/module.h>
34 
35 #include <machine/efi.h>
36 #include <sys/efiio.h>
37 
38 static d_ioctl_t efidev_ioctl;
39 
40 static struct cdevsw efi_cdevsw = {
41 	.d_name = "efi",
42 	.d_version = D_VERSION,
43 	.d_ioctl = efidev_ioctl,
44 };
45 
46 static int
47 efidev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
48     int flags __unused, struct thread *td __unused)
49 {
50 	int error;
51 
52 	switch (cmd) {
53 	case EFIIOC_GET_TABLE:
54 	{
55 		struct efi_get_table_ioc *egtioc =
56 		    (struct efi_get_table_ioc *)addr;
57 		void *buf = NULL;
58 
59 		error = efi_copy_table(&egtioc->uuid, egtioc->buf ? &buf : NULL,
60 		    egtioc->buf_len, &egtioc->table_len);
61 
62 		if (error != 0 || egtioc->buf == NULL)
63 			break;
64 
65 		if (egtioc->buf_len < egtioc->table_len) {
66 			error = EINVAL;
67 			free(buf, M_TEMP);
68 			break;
69 		}
70 
71 		error = copyout(buf, egtioc->buf, egtioc->buf_len);
72 		free(buf, M_TEMP);
73 
74 		break;
75 	}
76 	case EFIIOC_GET_TIME:
77 	{
78 		struct efi_tm *tm = (struct efi_tm *)addr;
79 
80 		error = efi_get_time(tm);
81 		break;
82 	}
83 	case EFIIOC_SET_TIME:
84 	{
85 		struct efi_tm *tm = (struct efi_tm *)addr;
86 
87 		error = efi_set_time(tm);
88 		break;
89 	}
90 	case EFIIOC_GET_WAKETIME:
91 	{
92 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
93 
94 		error = efi_get_waketime(&wt->enabled, &wt->pending,
95 		    &wt->waketime);
96 		break;
97 	}
98 	case EFIIOC_SET_WAKETIME:
99 	{
100 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
101 
102 		error = efi_set_waketime(wt->enabled, &wt->waketime);
103 		break;
104 	}
105 	case EFIIOC_VAR_GET:
106 	{
107 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
108 		void *data;
109 		efi_char *name;
110 
111 		data = malloc(ev->datasize, M_TEMP, M_WAITOK);
112 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
113 		error = copyin(ev->name, name, ev->namesize);
114 		if (error)
115 			goto vg_out;
116 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
117 			error = EINVAL;
118 			goto vg_out;
119 		}
120 
121 		error = efi_var_get(name, &ev->vendor, &ev->attrib,
122 		    &ev->datasize, data);
123 
124 		if (error == 0) {
125 			error = copyout(data, ev->data, ev->datasize);
126 		} else if (error == EOVERFLOW) {
127 			/*
128 			 * Pass back the size we really need, but
129 			 * convert the error to 0 so the copyout
130 			 * happens. datasize was updated in the
131 			 * efi_var_get call.
132 			 */
133 			ev->data = NULL;
134 			error = 0;
135 		}
136 vg_out:
137 		free(data, M_TEMP);
138 		free(name, M_TEMP);
139 		break;
140 	}
141 	case EFIIOC_VAR_NEXT:
142 	{
143 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
144 		efi_char *name;
145 
146 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
147 		error = copyin(ev->name, name, ev->namesize);
148 		if (error)
149 			goto vn_out;
150 		/* Note: namesize is the buffer size, not the string lenght */
151 
152 		error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
153 		if (error == 0) {
154 			error = copyout(name, ev->name, ev->namesize);
155 		} else if (error == EOVERFLOW) {
156 			ev->name = NULL;
157 			error = 0;
158 		}
159 	vn_out:
160 		free(name, M_TEMP);
161 		break;
162 	}
163 	case EFIIOC_VAR_SET:
164 	{
165 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
166 		void *data = NULL;
167 		efi_char *name;
168 
169 		/* datasize == 0 -> delete (more or less) */
170 		if (ev->datasize > 0)
171 			data = malloc(ev->datasize, M_TEMP, M_WAITOK);
172 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
173 		if (ev->datasize) {
174 			error = copyin(ev->data, data, ev->datasize);
175 			if (error)
176 				goto vs_out;
177 		}
178 		error = copyin(ev->name, name, ev->namesize);
179 		if (error)
180 			goto vs_out;
181 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
182 			error = EINVAL;
183 			goto vs_out;
184 		}
185 
186 		error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
187 		    data);
188 vs_out:
189 		free(data, M_TEMP);
190 		free(name, M_TEMP);
191 		break;
192 	}
193 	default:
194 		error = ENOTTY;
195 		break;
196 	}
197 
198 	return (error);
199 }
200 
201 static struct cdev *efidev;
202 
203 static int
204 efidev_modevents(module_t m, int event, void *arg __unused)
205 {
206 	struct make_dev_args mda;
207 	int error;
208 
209 	switch (event) {
210 	case MOD_LOAD:
211 		/*
212 		 * If we have no efi environment, then don't create the device.
213 		 */
214 		if (efi_rt_ok() != 0)
215 			return (0);
216 		make_dev_args_init(&mda);
217 		mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
218 		mda.mda_devsw = &efi_cdevsw;
219 		mda.mda_uid = UID_ROOT;
220 		mda.mda_gid = GID_WHEEL;
221 		mda.mda_mode = 0700;
222 		error = make_dev_s(&mda, &efidev, "efi");
223 		return (error);
224 
225 	case MOD_UNLOAD:
226 		if (efidev != NULL)
227 			destroy_dev(efidev);
228 		efidev = NULL;
229 		return (0);
230 
231 	case MOD_SHUTDOWN:
232 		return (0);
233 
234 	default:
235 		return (EOPNOTSUPP);
236 	}
237 }
238 
239 static moduledata_t efidev_moddata = {
240 	.name = "efidev",
241 	.evhand = efidev_modevents,
242 	.priv = NULL,
243 };
244 
245 DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
246 MODULE_VERSION(efidev, 1);
247 MODULE_DEPEND(efidev, efirt, 1, 1, 1);
248