xref: /freebsd/sys/dev/efidev/efidev.c (revision 580744621f33383027108364dcadad718df46ffe)
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 
61 		error = efi_get_table(&egtioc->uuid, &egtioc->ptr);
62 		break;
63 	}
64 	case EFIIOC_GET_TIME:
65 	{
66 		struct efi_tm *tm = (struct efi_tm *)addr;
67 
68 		error = efi_get_time(tm);
69 		break;
70 	}
71 	case EFIIOC_SET_TIME:
72 	{
73 		struct efi_tm *tm = (struct efi_tm *)addr;
74 
75 		error = efi_set_time(tm);
76 		break;
77 	}
78 	case EFIIOC_VAR_GET:
79 	{
80 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
81 		void *data;
82 		efi_char *name;
83 
84 		data = malloc(ev->datasize, M_TEMP, M_WAITOK);
85 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
86 		error = copyin(ev->name, name, ev->namesize);
87 		if (error)
88 			goto vg_out;
89 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
90 			error = EINVAL;
91 			goto vg_out;
92 		}
93 
94 		error = efi_var_get(name, &ev->vendor, &ev->attrib,
95 		    &ev->datasize, data);
96 
97 		if (error == 0) {
98 			error = copyout(data, ev->data, ev->datasize);
99 		} else if (error == EOVERFLOW) {
100 			/*
101 			 * Pass back the size we really need, but
102 			 * convert the error to 0 so the copyout
103 			 * happens. datasize was updated in the
104 			 * efi_var_get call.
105 			 */
106 			ev->data = NULL;
107 			error = 0;
108 		}
109 vg_out:
110 		free(data, M_TEMP);
111 		free(name, M_TEMP);
112 		break;
113 	}
114 	case EFIIOC_VAR_NEXT:
115 	{
116 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
117 		efi_char *name;
118 
119 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
120 		error = copyin(ev->name, name, ev->namesize);
121 		if (error)
122 			goto vn_out;
123 		/* Note: namesize is the buffer size, not the string lenght */
124 
125 		error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
126 		if (error == 0) {
127 			error = copyout(name, ev->name, ev->namesize);
128 		} else if (error == EOVERFLOW) {
129 			ev->name = NULL;
130 			error = 0;
131 		}
132 	vn_out:
133 		free(name, M_TEMP);
134 		break;
135 	}
136 	case EFIIOC_VAR_SET:
137 	{
138 		struct efi_var_ioc *ev = (struct efi_var_ioc *)addr;
139 		void *data = NULL;
140 		efi_char *name;
141 
142 		/* datasize == 0 -> delete (more or less) */
143 		if (ev->datasize > 0)
144 			data = malloc(ev->datasize, M_TEMP, M_WAITOK);
145 		name = malloc(ev->namesize, M_TEMP, M_WAITOK);
146 		if (ev->datasize) {
147 			error = copyin(ev->data, data, ev->datasize);
148 			if (error)
149 				goto vs_out;
150 		}
151 		error = copyin(ev->name, name, ev->namesize);
152 		if (error)
153 			goto vs_out;
154 		if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
155 			error = EINVAL;
156 			goto vs_out;
157 		}
158 
159 		error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
160 		    data);
161 vs_out:
162 		free(data, M_TEMP);
163 		free(name, M_TEMP);
164 		break;
165 	}
166 	default:
167 		error = ENOTTY;
168 		break;
169 	}
170 
171 	return (error);
172 }
173 
174 static struct cdev *efidev;
175 
176 static int
177 efidev_modevents(module_t m, int event, void *arg __unused)
178 {
179 	struct make_dev_args mda;
180 	int error;
181 
182 	switch (event) {
183 	case MOD_LOAD:
184 		/*
185 		 * If we have no efi environment, then don't create the device.
186 		 */
187 		if (efi_rt_ok() != 0)
188 			return (0);
189 		make_dev_args_init(&mda);
190 		mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
191 		mda.mda_devsw = &efi_cdevsw;
192 		mda.mda_uid = UID_ROOT;
193 		mda.mda_gid = GID_WHEEL;
194 		mda.mda_mode = 0700;
195 		error = make_dev_s(&mda, &efidev, "efi");
196 		return (error);
197 
198 	case MOD_UNLOAD:
199 		if (efidev != NULL)
200 			destroy_dev(efidev);
201 		efidev = NULL;
202 		return (0);
203 
204 	case MOD_SHUTDOWN:
205 		return (0);
206 
207 	default:
208 		return (EOPNOTSUPP);
209 	}
210 }
211 
212 static moduledata_t efidev_moddata = {
213 	.name = "efidev",
214 	.evhand = efidev_modevents,
215 	.priv = NULL,
216 };
217 
218 DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
219 MODULE_VERSION(efidev, 1);
220 MODULE_DEPEND(efidev, efirt, 1, 1, 1);
221