xref: /freebsd/sys/dev/efidev/efidev.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/kernel.h>
30 #include <sys/bus.h>
31 #include <sys/conf.h>
32 #include <sys/lock.h>
33 #include <sys/malloc.h>
34 #include <sys/module.h>
35 
36 #include <machine/efi.h>
37 #include <sys/efiio.h>
38 
39 static d_ioctl_t efidev_ioctl;
40 
41 static struct cdevsw efi_cdevsw = {
42 	.d_name = "efi",
43 	.d_version = D_VERSION,
44 	.d_ioctl = efidev_ioctl,
45 };
46 
47 static int
48 efidev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
49     int flags __unused, struct thread *td __unused)
50 {
51 	int error;
52 
53 	switch (cmd) {
54 	case EFIIOC_GET_TABLE:
55 	{
56 		struct efi_get_table_ioc *egtioc =
57 		    (struct efi_get_table_ioc *)addr;
58 		void *buf = NULL;
59 
60 		error = efi_copy_table(&egtioc->uuid, egtioc->buf ? &buf : NULL,
61 		    egtioc->buf_len, &egtioc->table_len);
62 
63 		if (error != 0 || egtioc->buf == NULL)
64 			break;
65 
66 		if (egtioc->buf_len < egtioc->table_len) {
67 			error = EINVAL;
68 			free(buf, M_TEMP);
69 			break;
70 		}
71 
72 		error = copyout(buf, egtioc->buf, egtioc->buf_len);
73 		free(buf, M_TEMP);
74 
75 		break;
76 	}
77 	case EFIIOC_GET_TIME:
78 	{
79 		struct efi_tm *tm = (struct efi_tm *)addr;
80 
81 		error = efi_get_time(tm);
82 		break;
83 	}
84 	case EFIIOC_SET_TIME:
85 	{
86 		struct efi_tm *tm = (struct efi_tm *)addr;
87 
88 		error = efi_set_time(tm);
89 		break;
90 	}
91 	case EFIIOC_GET_WAKETIME:
92 	{
93 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
94 
95 		error = efi_get_waketime(&wt->enabled, &wt->pending,
96 		    &wt->waketime);
97 		break;
98 	}
99 	case EFIIOC_SET_WAKETIME:
100 	{
101 		struct efi_waketime_ioc *wt = (struct efi_waketime_ioc *)addr;
102 
103 		error = efi_set_waketime(wt->enabled, &wt->waketime);
104 		break;
105 	}
106 	case EFIIOC_VAR_GET:
107 	{
108 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
109 		void *data;
110 		efi_char *name;
111 
112 		data = malloc(ev->datasize, M_TEMP, M_WAITOK);
113 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
114 		error = copyin(ev->name, name, ev->namesize);
115 		if (error)
116 			goto vg_out;
117 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
118 			error = EINVAL;
119 			goto vg_out;
120 		}
121 
122 		error = efi_var_get(name, &ev->vendor, &ev->attrib,
123 		    &ev->datasize, data);
124 
125 		if (error == 0) {
126 			error = copyout(data, ev->data, ev->datasize);
127 		} else if (error == EOVERFLOW) {
128 			/*
129 			 * Pass back the size we really need, but
130 			 * convert the error to 0 so the copyout
131 			 * happens. datasize was updated in the
132 			 * efi_var_get call.
133 			 */
134 			ev->data = NULL;
135 			error = 0;
136 		}
137 vg_out:
138 		free(data, M_TEMP);
139 		free(name, M_TEMP);
140 		break;
141 	}
142 	case EFIIOC_VAR_NEXT:
143 	{
144 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
145 		efi_char *name;
146 
147 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
148 		error = copyin(ev->name, name, ev->namesize);
149 		if (error)
150 			goto vn_out;
151 		/* Note: namesize is the buffer size, not the string lenght */
152 
153 		error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
154 		if (error == 0) {
155 			error = copyout(name, ev->name, ev->namesize);
156 		} else if (error == EOVERFLOW) {
157 			ev->name = NULL;
158 			error = 0;
159 		}
160 	vn_out:
161 		free(name, M_TEMP);
162 		break;
163 	}
164 	case EFIIOC_VAR_SET:
165 	{
166 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
167 		void *data = NULL;
168 		efi_char *name;
169 
170 		/* datasize == 0 -> delete (more or less) */
171 		if (ev->datasize > 0)
172 			data = malloc(ev->datasize, M_TEMP, M_WAITOK);
173 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
174 		if (ev->datasize) {
175 			error = copyin(ev->data, data, ev->datasize);
176 			if (error)
177 				goto vs_out;
178 		}
179 		error = copyin(ev->name, name, ev->namesize);
180 		if (error)
181 			goto vs_out;
182 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
183 			error = EINVAL;
184 			goto vs_out;
185 		}
186 
187 		error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
188 		    data);
189 vs_out:
190 		free(data, M_TEMP);
191 		free(name, M_TEMP);
192 		break;
193 	}
194 	default:
195 		error = ENOTTY;
196 		break;
197 	}
198 
199 	return (error);
200 }
201 
202 static struct cdev *efidev;
203 
204 static int
205 efidev_modevents(module_t m, int event, void *arg __unused)
206 {
207 	struct make_dev_args mda;
208 	int error;
209 
210 	switch (event) {
211 	case MOD_LOAD:
212 		/*
213 		 * If we have no efi environment, then don't create the device.
214 		 */
215 		if (efi_rt_ok() != 0)
216 			return (0);
217 		make_dev_args_init(&mda);
218 		mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
219 		mda.mda_devsw = &efi_cdevsw;
220 		mda.mda_uid = UID_ROOT;
221 		mda.mda_gid = GID_WHEEL;
222 		mda.mda_mode = 0700;
223 		error = make_dev_s(&mda, &efidev, "efi");
224 		return (error);
225 
226 	case MOD_UNLOAD:
227 		if (efidev != NULL)
228 			destroy_dev(efidev);
229 		efidev = NULL;
230 		return (0);
231 
232 	case MOD_SHUTDOWN:
233 		return (0);
234 
235 	default:
236 		return (EOPNOTSUPP);
237 	}
238 }
239 
240 static moduledata_t efidev_moddata = {
241 	.name = "efidev",
242 	.evhand = efidev_modevents,
243 	.priv = NULL,
244 };
245 
246 DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
247 MODULE_VERSION(efidev, 1);
248 MODULE_DEPEND(efidev, efirt, 1, 1, 1);
249