mirror of
https://github.com/ipxe/ipxe
synced 2026-02-02 07:52:48 +03:00
96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
/*
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* Copyright (C) 2021 Michael Brown <mbrown@fensystems.co.uk>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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FILE_LICENCE ( GPL2_OR_LATER );
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#include <string.h>
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#include <errno.h>
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#include <ipxe/umalloc.h>
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#include <ipxe/linux_api.h>
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#include <ipxe/linux.h>
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#include <ipxe/linux_sysfs.h>
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/** @file
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*
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* Linux sysfs files
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*
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*/
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/** Read blocksize */
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#define LINUX_SYSFS_BLKSIZE 4096
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/**
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* Read file from sysfs
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*
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* @v filename Filename
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* @v data Data to fill in
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* @ret len Length read, or negative error
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*/
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int linux_sysfs_read ( const char *filename, void **data ) {
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void *tmp;
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ssize_t read;
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size_t len;
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int fd;
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int rc;
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/* Open file */
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fd = linux_open ( filename, O_RDONLY );
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if ( fd < 0 ) {
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rc = -ELINUX ( linux_errno );
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DBGC ( filename, "LINUX could not open %s: %s\n",
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filename, linux_strerror ( linux_errno ) );
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goto err_open;
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}
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/* Read file */
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for ( *data = NULL, len = 0 ; ; len += read ) {
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/* (Re)allocate space */
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tmp = urealloc ( *data, ( len + LINUX_SYSFS_BLKSIZE ) );
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if ( ! tmp ) {
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rc = -ENOMEM;
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goto err_alloc;
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}
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*data = tmp;
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/* Read from file */
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read = linux_read ( fd, ( *data + len ), LINUX_SYSFS_BLKSIZE );
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if ( read == 0 )
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break;
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if ( read < 0 ) {
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DBGC ( filename, "LINUX could not read %s: %s\n",
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filename, linux_strerror ( linux_errno ) );
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goto err_read;
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}
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}
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/* Close file */
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linux_close ( fd );
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DBGC ( filename, "LINUX read %s\n", filename );
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return len;
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err_read:
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err_alloc:
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ufree ( *data );
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linux_close ( fd );
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err_open:
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return rc;
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}
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