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efifile.c revision 1.3 
      1 /* $NetBSD: efifile.c,v 1.3 2018/08/26 21:28:18 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2018 Jared McNeill <jmcneill (at) 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