xref: /netbsd-src/sys/stand/efiboot/efifile.c (revision f3cfa6f6ce31685c6c4a758bc430e69eb99f50a4)
1 /* $NetBSD: efifile.c,v 1.3 2018/08/26 21:28:18 jmcneill Exp $ */
2 
3 /*-
4  * Copyright (c) 2018 Jared McNeill <jmcneill@invisible.ca>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 
31 #include "efiboot.h"
32 #include "efifile.h"
33 
34 static EFI_HANDLE *efi_vol;
35 static UINTN efi_nvol;
36 
37 static int
38 efi_file_parse(const char *fname, UINTN *pvol, const char **pfile)
39 {
40 	intmax_t vol;
41 	char *ep = NULL;
42 
43 	if (strchr(fname, ':') != NULL) {
44 		if (strncasecmp(fname, "fs", 2) != 0)
45 			return EINVAL;
46 		vol = strtoimax(fname + 2, &ep, 10);
47 		if (vol < 0 || vol >= efi_nvol || *ep != ':')
48 			return ENXIO;
49 		*pvol = vol;
50 		*pfile = ep + 1;
51 		return 0;
52 	}
53 
54 	return EINVAL;
55 }
56 
57 void
58 efi_file_system_probe(void)
59 {
60 	EFI_STATUS status;
61 
62 	status = LibLocateHandle(ByProtocol, &FileSystemProtocol, NULL, &efi_nvol, &efi_vol);
63 	if (EFI_ERROR(status))
64 		return;
65 }
66 
67 int
68 efi_file_open(struct open_file *f, ...)
69 {
70 	EFI_DEVICE_PATH *dp;
71 	SIMPLE_READ_FILE srf;
72 	EFI_HANDLE device, file;
73 	EFI_STATUS status;
74 	UINTN vol;
75 	const char *fname, *path;
76 	CHAR16 *upath;
77 	va_list ap;
78 	size_t len;
79 	int rv, n;
80 
81 	va_start(ap, f);
82 	fname = va_arg(ap, const char *);
83 	va_end(ap);
84 
85 	rv = efi_file_parse(fname, &vol, &path);
86 	if (rv != 0)
87 		return rv;
88 
89 	device = efi_vol[vol];
90 
91 	upath = NULL;
92 	rv = utf8_to_ucs2(path, &upath, &len);
93 	if (rv != 0)
94 		return rv;
95 
96 	dp = FileDevicePath(device, upath);
97 	FreePool(upath);
98 	if (dp == NULL)
99 		return EINVAL;
100 
101 	status = OpenSimpleReadFile(TRUE, NULL, 0, &dp, &file, &srf);
102 	FreePool(dp);
103 	if (EFI_ERROR(status))
104 		return status == EFI_NOT_FOUND ? ENOENT : EIO;
105 
106 	for (n = 0; n < ndevs; n++)
107 		if (strcmp(DEV_NAME(&devsw[n]), "efifile") == 0) {
108 			f->f_dev = &devsw[n];
109 			break;
110 		}
111 	if (n == ndevs)
112 		return ENXIO;
113 	f->f_devdata = f;
114 	f->f_fsdata = srf;
115 	f->f_flags = F_NODEV | F_READ;
116 
117 	return 0;
118 }
119 
120 int
121 efi_file_close(struct open_file *f)
122 {
123 	SIMPLE_READ_FILE srf = f->f_fsdata;
124 
125 	CloseSimpleReadFile(srf);
126 
127 	return 0;
128 }
129 
130 int
131 efi_file_strategy(void *devdata, int rw, daddr_t dblk, size_t size, void *buf, size_t *rsize)
132 {
133 	struct open_file *f = devdata;
134 	SIMPLE_READ_FILE srf = f->f_fsdata;
135 	EFI_STATUS status;
136 	UINTN len;
137 
138 	if (rw != F_READ)
139 		return EROFS;
140 
141 	len = size;
142 	status = ReadSimpleReadFile(srf, f->f_offset, &len, buf);
143 	if (EFI_ERROR(status))
144 		return EIO;
145 	*rsize = len;
146 
147 	return 0;
148 }
149