1/* $NetBSD: efifile.c,v 1.5 2020/07/15 00:51:40 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
34static EFI_HANDLE *efi_vol;
35static UINTN efi_nvol;
36
37static int
38efi_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
57void
58efi_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
67int
68efi_file_open(struct open_file *f, ...)
69{
70	EFI_DEVICE_PATH *file_dp, *dp;
71	SIMPLE_READ_FILE *srf;
72	EFI_HANDLE device;
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	upath = NULL;
90	rv = utf8_to_ucs2(path, &upath, &len);
91	if (rv != 0)
92		return rv;
93
94	file_dp = FileDevicePath(efi_vol[vol], upath);
95	FreePool(upath);
96	if (file_dp == NULL)
97		return EINVAL;
98
99	srf = AllocatePool(sizeof(*srf));
100	if (srf == NULL)
101		return ENOMEM;
102
103	dp = file_dp;
104	status = OpenSimpleReadFile(FALSE, NULL, 0, &dp, &device, srf);
105	FreePool(file_dp);
106	if (EFI_ERROR(status)) {
107		FreePool(srf);
108		return status == EFI_NOT_FOUND ? ENOENT : EIO;
109	}
110
111	for (n = 0; n < ndevs; n++)
112		if (strcmp(DEV_NAME(&devsw[n]), "efifile") == 0) {
113			f->f_dev = &devsw[n];
114			break;
115		}
116	if (n == ndevs) {
117		FreePool(srf);
118		return ENXIO;
119	}
120	f->f_devdata = f;
121	f->f_fsdata = srf;
122	f->f_flags = F_NODEV | F_READ;
123
124	return 0;
125}
126
127int
128efi_file_close(struct open_file *f)
129{
130	SIMPLE_READ_FILE *srf = f->f_fsdata;
131
132	CloseSimpleReadFile(*srf);
133	FreePool(srf);
134
135	return 0;
136}
137
138int
139efi_file_strategy(void *devdata, int rw, daddr_t dblk, size_t size, void *buf, size_t *rsize)
140{
141	struct open_file *f = devdata;
142	SIMPLE_READ_FILE *srf = f->f_fsdata;
143	EFI_STATUS status;
144	UINTN len;
145
146	if (rw != F_READ)
147		return EROFS;
148
149	len = size;
150	status = ReadSimpleReadFile(*srf, f->f_offset, &len, buf);
151	if (EFI_ERROR(status))
152		return EIO;
153	*rsize = len;
154
155	return 0;
156}
157
158int
159efi_file_path(EFI_DEVICE_PATH *dp, const char *fname, char *buf, size_t buflen)
160{
161	UINTN vol;
162	int depth;
163
164	depth = efi_device_path_count(dp);
165	if (depth == 0)
166		return ENODEV;
167
168	for (vol = 0; vol < efi_nvol; vol++) {
169		if (efi_device_path_ncmp(dp, DevicePathFromHandle(efi_vol[vol]), depth) == 0)
170			break;
171	}
172	if (vol == efi_nvol)
173		return ENOENT;
174
175	snprintf(buf, buflen, "fs%u:%s", (u_int)vol, fname);
176	return 0;
177}
178