grub-editenv: Add grub_util_readlink()

Currently grub-editenv and related tools are not able to follow symbolic
links when finding their config file. For example the grub-editenv create
command will wrongly overwrite a symlink in /boot/grub2/grubenv with a new
regular file, instead of creating a file in the path the symlink points to.

A following patch will change that and add support in grub-editenv to
follow symbolic links when finding the grub environment variables file.

Add a grub_util_readlink() helper function that is just a wrapper around
the platform specific function to read the value of a symbolic link. This
helper function will be used by the following patch for grub-editenv.

The helper function is not added for Windows, since this operating system
doesn't have a primitive to read the contents of a symbolic link.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Peter Jones 2020-01-17 17:10:42 +01:00 committed by Daniel Kiper
parent 9f03dc5d7b
commit 03e72830ab
2 changed files with 12 additions and 0 deletions

View file

@ -68,6 +68,12 @@ grub_util_rename (const char *from, const char *to)
return rename (from, to);
}
static inline ssize_t
grub_util_readlink (const char *name, char *buf, size_t bufsize)
{
return readlink(name, buf, bufsize);
}
#define grub_util_mkdir(a) mkdir ((a), 0755)
struct grub_util_fd

View file

@ -71,6 +71,12 @@ grub_util_rename (const char *from, const char *to)
return rename (from, to);
}
static inline ssize_t
grub_util_readlink (const char *name, char *buf, size_t bufsize)
{
return readlink(name, buf, bufsize);
}
#define grub_util_mkdir(a) mkdir ((a), 0755)
#if defined (__NetBSD__)