From 5c8a9905ce3b04a4317d356d5481552fd17b63cb Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Tue, 2 Mar 2021 23:37:41 +0000 Subject: [linux] Add a generic function for reading files from sysfs Signed-off-by: Michael Brown --- src/include/ipxe/errfile.h | 1 + src/include/ipxe/linux_api.h | 3 ++ src/include/ipxe/linux_sysfs.h | 16 ++++++ src/interface/linux/linux_api.c | 16 ++++++ src/interface/linux/linux_sysfs.c | 107 ++++++++++++++++++++++++++++++++++++++ 5 files changed, 143 insertions(+) create mode 100644 src/include/ipxe/linux_sysfs.h create mode 100644 src/interface/linux/linux_sysfs.c diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index b5c5d18..3daf7bd 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -388,6 +388,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #define ERRFILE_efi_autoboot ( ERRFILE_OTHER | 0x00530000 ) #define ERRFILE_efi_autoexec ( ERRFILE_OTHER | 0x00540000 ) #define ERRFILE_efi_cachedhcp ( ERRFILE_OTHER | 0x00550000 ) +#define ERRFILE_linux_sysfs ( ERRFILE_OTHER | 0x00560000 ) /** @} */ diff --git a/src/include/ipxe/linux_api.h b/src/include/ipxe/linux_api.h index 040b52f..ab2e801 100644 --- a/src/include/ipxe/linux_api.h +++ b/src/include/ipxe/linux_api.h @@ -46,6 +46,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include #include #include +#include #define MAP_FAILED ( ( void * ) -1 ) #endif @@ -65,6 +66,8 @@ extern ssize_t __asmcall linux_read ( int fd, void *buf, size_t count ); extern ssize_t __asmcall linux_write ( int fd, const void *buf, size_t count ); extern int __asmcall linux_fcntl ( int fd, int cmd, ... ); extern int __asmcall linux_ioctl ( int fd, unsigned long request, ... ); +extern int __asmcall linux_statx ( int dirfd, const char *pathname, int flags, + unsigned int mask, struct statx *statxbuf ); extern int __asmcall linux_poll ( struct pollfd *fds, unsigned int nfds, int timeout ); extern int __asmcall linux_nanosleep ( const struct timespec *req, diff --git a/src/include/ipxe/linux_sysfs.h b/src/include/ipxe/linux_sysfs.h new file mode 100644 index 0000000..d97b649 --- /dev/null +++ b/src/include/ipxe/linux_sysfs.h @@ -0,0 +1,16 @@ +#ifndef _IPXE_LINUX_SYSFS_H +#define _IPXE_LINUX_SYSFS_H + +/** @file + * + * Linux sysfs files + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include + +extern int linux_sysfs_read ( const char *filename, userptr_t *data ); + +#endif /* _IPXE_LINUX_SYSFS_H */ diff --git a/src/interface/linux/linux_api.c b/src/interface/linux/linux_api.c index fa69433..6fa2b0e 100644 --- a/src/interface/linux/linux_api.c +++ b/src/interface/linux/linux_api.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include #include @@ -199,6 +200,20 @@ int __asmcall linux_ioctl ( int fd, unsigned long request, ... ) { } /** + * Wrap statx() + * + */ +int __asmcall linux_statx ( int dirfd, const char *pathname, int flags, + unsigned int mask, struct statx *statxbuf ) { + int ret; + + ret = statx ( dirfd, pathname, flags, mask, statxbuf ); + if ( ret == -1 ) + linux_errno = errno; + return ret; +} + +/** * Wrap poll() * */ @@ -516,6 +531,7 @@ PROVIDE_IPXE_SYM ( linux_read ); PROVIDE_IPXE_SYM ( linux_write ); PROVIDE_IPXE_SYM ( linux_fcntl ); PROVIDE_IPXE_SYM ( linux_ioctl ); +PROVIDE_IPXE_SYM ( linux_statx ); PROVIDE_IPXE_SYM ( linux_poll ); PROVIDE_IPXE_SYM ( linux_nanosleep ); PROVIDE_IPXE_SYM ( linux_usleep ); diff --git a/src/interface/linux/linux_sysfs.c b/src/interface/linux/linux_sysfs.c new file mode 100644 index 0000000..0b9f1f5 --- /dev/null +++ b/src/interface/linux/linux_sysfs.c @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2021 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include +#include +#include +#include +#include +#include + +/** @file + * + * Linux sysfs files + * + */ + +/** + * Read file from sysfs + * + * @v filename Filename + * @v data Data to fill in + * @ret len Length read, or negative error + */ +int linux_sysfs_read ( const char *filename, userptr_t *data ) { + struct statx statx; + size_t offset; + size_t len; + ssize_t read; + int fd; + int rc; + + /* Open file */ + fd = linux_open ( filename, O_RDONLY ); + if ( fd < 0 ) { + rc = -ELINUX ( linux_errno ); + DBGC ( filename, "LINUX could not open %s: %s\n", + filename, linux_strerror ( linux_errno ) ); + goto err_open; + } + + /* Get file length */ + if ( linux_statx ( fd, "", AT_EMPTY_PATH, STATX_SIZE, &statx ) == -1 ) { + rc = -ELINUX ( linux_errno ); + DBGC ( filename, "LINUX could not stat %s: %s\n", + filename, linux_strerror ( linux_errno ) ); + goto err_stat; + } + len = statx.stx_size; + + /* Allocate buffer */ + *data = umalloc ( len ); + if ( ! *data ) { + rc = -ENOMEM; + DBGC ( filename, "LINUX could not allocate %zd bytes for %s\n", + len, filename ); + goto err_alloc; + } + + /* Read file */ + for ( offset = 0 ; offset < len ; offset += read ) { + read = linux_read ( fd, user_to_virt ( *data, offset ), len ); + if ( read < 0 ) { + DBGC ( filename, "LINUX could not read %s: %s\n", + filename, linux_strerror ( linux_errno ) ); + goto err_read; + } + if ( read == 0 ) { + rc = -EIO; + DBGC ( filename, "LINUX read underlength %s\n", + filename ); + goto err_eof; + } + } + + /* Close file */ + linux_close ( fd ); + + DBGC ( filename, "LINUX read %s\n", filename ); + return len; + + err_eof: + err_read: + ufree ( *data ); + err_alloc: + err_stat: + linux_close ( fd ); + err_open: + return rc; +} -- cgit v1.1