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efiio.c revision 1.2 
      1 /* $NetBSD: efiio.c,v 1.2 2025/03/02 00:03:41 riastradh Exp $ */
      2 
      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  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     14  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     23  * SUCH DAMAGE.
     24  */
     25 
     26 #include <sys/cdefs.h>
     27 #ifndef lint
     28 __RCSID("$NetBSD: efiio.c,v 1.2 2025/03/02 00:03:41 riastradh Exp $");
     29 #endif /* not lint */
     30 
     31 #include <sys/efiio.h>
     32 #include <sys/ioctl.h>
     33 
     34 #include <assert.h>
     35 #include <err.h>
     36 #include <errno.h>
     37 #include <stdbool.h>
     38 #include <stdio.h>
     39 #include <stdlib.h>
     40 #include <util.h>
     41 
     42 #include "defs.h"
     43 #include "efiio.h"
     44 #include "utils.h"
     45 
     46 //******************************************************
     47 // Variable Attributes
     48 //******************************************************
     49 #if 0	/* see sys/efiio.h */
     50 struct efi_var_ioc {
     51 	uint16_t *	name;		/* vendor's variable name */
     52 	size_t		namesize;	/* size in bytes of the name buffer */
     53 	struct uuid	vendor;		/* unique identifier for vendor */
     54 	uint32_t	attrib;		/* variable attribute bitmask */
     55 	void *		data;		/* buffer containing variable data */
     56 	size_t		datasize;	/* size in bytes of the data buffer */
     57 };
     58 #endif
     59 
     60 static int
     61 xioctl(int fd, unsigned long request, void *buf)
     62 {
     63 	int rv;
     64 
     65 	rv = ioctl(fd, request, buf);
     66 	if (rv == -1 && errno != ENOENT)
     67 		err(EXIT_FAILURE, "%s: ioctl", __func__);
     68 	return rv;
     69 }
     70 
     71 PUBLIC int
     72 set_variable(int fd, struct efi_var_ioc *ev)
     73 {
     74 
     75 	return ioctl(fd, EFIIOC_VAR_SET, ev);
     76 }
     77 
     78 static inline int
     79 get_variable_core(int fd, struct efi_var_ioc *ev)
     80 {
     81 
     82 	if (xioctl(fd, EFIIOC_VAR_GET, ev) == -1)
     83 		return -1;
     84 
     85 	ev->data = emalloc(ev->datasize);
     86 	xioctl(fd, EFIIOC_VAR_GET, ev);
     87 	return 0;
     88 }
     89 
     90 PUBLIC struct efi_var_ioc
     91 get_variable(int fd, const char *name, struct uuid *vendor,
     92     uint32_t attrib)
     93 {
     94 	struct efi_var_ioc ev;
     95 
     96 	efi_var_init(&ev, name, vendor, attrib);
     97 	get_variable_core(fd, &ev);
     98 
     99 	return ev;
    100 }
    101 
    102 PUBLIC struct efi_var_ioc *
    103 get_next_variable(int fd, struct efi_var_ioc *ev)
    104 {
    105 	int rv;
    106 
    107 	rv = ioctl(fd, EFIIOC_VAR_NEXT, ev);
    108 	if (rv == -1 && errno != ENOENT)
    109 		err(EXIT_FAILURE, "%s: ioctl", __func__);
    110 	return ev;
    111 }
    112 
    113 PUBLIC void *
    114 get_table(int fd, struct uuid *uuid, size_t *buflen)
    115 {
    116 	struct efi_get_table_ioc egt;
    117 
    118 	memset(&egt, 0, sizeof(egt));
    119 	memcpy(&egt.uuid, uuid, sizeof(egt.uuid));
    120 
    121 	xioctl(fd, EFIIOC_GET_TABLE, &egt);
    122 	egt.buf = ecalloc(egt.table_len, 1);
    123 	egt.buf_len = egt.table_len;
    124 
    125 	xioctl(fd, EFIIOC_GET_TABLE, &egt);
    126 	*buflen = egt.table_len;
    127 	return egt.buf;
    128 }
    129 
    130 PUBLIC size_t
    131 get_variable_info(int fd, bool (*choose)(struct efi_var_ioc *, void *),
    132     int (*fn)(struct efi_var_ioc *ev, void *), void *arg)
    133 {
    134 	struct efi_var_ioc ev;
    135 	size_t cnt;
    136 	int rv;
    137 
    138 	assert(fn != NULL);
    139 	assert(arg != NULL);
    140 
    141 	memset(&ev, 0, sizeof(ev));
    142 
    143 	ev.name = ecalloc(EFI_VARNAME_MAXLENGTH, sizeof(*ev.name));
    144 	cnt = 0;
    145 	for (;;) {
    146 		ev.namesize = EFI_VARNAME_MAXLENGTH;
    147 		if (ioctl(fd, EFIIOC_VAR_NEXT, &ev) == -1) {
    148 			char *buf;
    149 
    150 			if (errno == ENOENT)
    151 				break;
    152 
    153 			/* XXX: ev is likely to be zero */
    154 			buf = ucs2_to_utf8(ev.name, ev.namesize, NULL, NULL);
    155 			err(EXIT_FAILURE, "%s: '%s'", __func__, buf);
    156 		}
    157 
    158 		if (choose != NULL && !choose(&ev, arg))
    159 			continue;
    160 
    161 		rv = get_variable_core(fd, &ev);
    162 		assert(rv == 0);
    163 		if (rv == -1)
    164 			err(EXIT_FAILURE, "get_variable_core");
    165 
    166 		cnt++;
    167 		fn(&ev, arg);
    168 
    169 		free(ev.data);
    170 	}
    171 	free(ev.name);
    172 	return cnt;
    173 }
    174