dmi_save

Synopsis

#include <opendmi/context.h>

typedef enum dmi_save_flags {
    DMI_SAVE_FLAG_OVERWRITE = (1 << 0),
    DMI_SAVE_FLAG_ANONYMIZE = (1 << 1)
} dmi_save_flags_t;

bool dmi_save(dmi_context_t *context, const char *path, unsigned flags);

Description

The dmi_save function writes the SMBIOS data of an open context into a dump file, which dmi_load reads back.

The dump is interchangeable with the ones dmidecode --dump-bin writes: the entry point, padded with zeros to the largest size of an entry point, followed by the table. The table is written the way it has been read, and the address of the table the entry point holds is set to its offset within the file. A context read on a platform which gives no access to the entry point has none, and a 64-bit entry point is made up for it.

An existing file is replaced only with DMI_SAVE_FLAG_OVERWRITE. A dump into a regular file, existing or not, is written to a temporary file in the same directory, which is renamed over path only once it is complete: a failure neither leaves an incomplete dump behind nor destroys the file being replaced, and the replaced file keeps its permissions. Since path is replaced rather than written to, the directory must be writable, and other hard links to the file keep its former contents. Devices, pipes and symbolic links, e.g. /dev/stdout, are written directly instead. Devices and pipes, and the symbolic links to them, are written whether DMI_SAVE_FLAG_OVERWRITE is set or not, since there is no file to keep, while a symbolic link to a file, or to nothing, is taken as an existing file.

With DMI_SAVE_FLAG_ANONYMIZE, the table written is the copy dmi_anonymize makes of it, in which the values identifying the system, e.g. serial numbers, asset tags, UUIDs and MAC addresses, are replaced. The copy has the length and the layout of the table, so the entry point holds for it as it is, and the context itself is left as it is.

Parameters

context

Open context to save.

path

Path to the dump file.

flags

Flags of dmi_save_flags_t, zero for none:

DMI_SAVE_FLAG_OVERWRITE: Replace the file if it exists, rather than failing.
DMI_SAVE_FLAG_ANONYMIZE: Write the anonymized copy of the table, see dmi_anonymize.

Return value

Returns true if the dump has been written, and false otherwise.

Errors

DMI_ERROR_ARGUMENT_NULL: Path is nullptr.
DMI_ERROR_STATE_INVALID: Context is not open, or the table is to be anonymized and its structures carry additional information entries applied to them.
DMI_ERROR_ENTRY_LENGTH_INVALID: Entry point is longer than an entry point can be.
DMI_ERROR_FILE_OPEN_FAILED: File or its temporary file cannot be created, or the file exists and DMI_SAVE_FLAG_OVERWRITE is not set.
DMI_ERROR_FILE_WRITE_FAILED: File cannot be written, or the temporary file cannot be renamed over it.
DMI_ERROR_OUT_OF_MEMORY: Memory for the anonymized copy cannot be allocated.
DMI_ERROR_INTERNAL: Table cannot be anonymized, see dmi_anonymize.