xferbuf.c File Reference

Data transfer buffer. More...

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ipxe/xfer.h>
#include <ipxe/iobuf.h>
#include <ipxe/umalloc.h>
#include <ipxe/profile.h>
#include <ipxe/xferbuf.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
void	xferbuf_free (struct xfer_buffer *xferbuf)
	Free data transfer buffer. More...
static int	xferbuf_ensure_size (struct xfer_buffer *xferbuf, size_t len)
	Ensure that data transfer buffer is large enough for the specified size. More...
int	xferbuf_write (struct xfer_buffer *xferbuf, size_t offset, const void *data, size_t len)
	Write to data transfer buffer. More...
int	xferbuf_read (struct xfer_buffer *xferbuf, size_t offset, void *data, size_t len)
	Read from data transfer buffer. More...
int	xferbuf_deliver (struct xfer_buffer *xferbuf, struct io_buffer *iobuf, struct xfer_metadata *meta)
	Add received data to data transfer buffer. More...
static int	xferbuf_malloc_realloc (struct xfer_buffer *xferbuf, size_t len)
	Reallocate malloc()-based data buffer. More...
static void	xferbuf_malloc_write (struct xfer_buffer *xferbuf, size_t offset, const void *data, size_t len)
	Write data to malloc()-based data buffer. More...
static void	xferbuf_malloc_read (struct xfer_buffer *xferbuf, size_t offset, void *data, size_t len)
	Read data from malloc()-based data buffer. More...
static int	xferbuf_umalloc_realloc (struct xfer_buffer *xferbuf, size_t len)
	Reallocate umalloc()-based data buffer. More...
static void	xferbuf_umalloc_write (struct xfer_buffer *xferbuf, size_t offset, const void *data, size_t len)
	Write data to umalloc()-based data buffer. More...
static void	xferbuf_umalloc_read (struct xfer_buffer *xferbuf, size_t offset, void *data, size_t len)
	Read data from umalloc()-based data buffer. More...
struct xfer_buffer *	xfer_buffer (struct interface *intf)
	Get underlying data transfer buffer. More...

Variables
static struct profiler xferbuf_deliver_profiler	__profiler
	Data delivery profiler. More...
struct xfer_buffer_operations	xferbuf_malloc_operations
	malloc()-based data buffer operations More...
struct xfer_buffer_operations	xferbuf_umalloc_operations
	umalloc()-based data buffer operations More...

Detailed Description

Data transfer buffer.

Definition in file xferbuf.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

xferbuf_free()

void xferbuf_free

(

struct xfer_buffer *

xferbuf

)

Free data transfer buffer.

Parameters

xferbuf

Data transfer buffer

Definition at line 58 of file xferbuf.c.

                                                  {

        xferbuf->op->realloc ( xferbuf, 0 );
        xferbuf->len = 0;
        xferbuf->pos = 0;
}

References xfer_buffer::len, xfer_buffer::op, xfer_buffer::pos, and xfer_buffer_operations::realloc.

Referenced by peerblk_reset(), peermux_free(), validator_free(), and validator_xfer_close().

xferbuf_ensure_size()

static int xferbuf_ensure_size ( struct xfer_buffer *  xferbuf, size_t  len  )

static

Ensure that data transfer buffer is large enough for the specified size.

Parameters

xferbuf	Data transfer buffer
len	Required minimum size

Return values

rc	Return status code

Definition at line 72 of file xferbuf.c.

                                                                           {
        int rc;

        /* If buffer is already large enough, do nothing */
        if ( len <= xferbuf->len )
                return 0;

        /* Extend buffer */
        if ( ( rc = xferbuf->op->realloc ( xferbuf, len ) ) != 0 ) {
                DBGC ( xferbuf, "XFERBUF %p could not extend buffer to "
                       "%zd bytes: %s\n", xferbuf, len, strerror ( rc ) );
                return rc;
        }
        xferbuf->len = len;

        return 0;
}

References DBGC, len, xfer_buffer::len, xfer_buffer::op, rc, xfer_buffer_operations::realloc, and strerror().

Referenced by xferbuf_write().

xferbuf_write()

int xferbuf_write	(	struct xfer_buffer *	xferbuf,
		size_t	offset,
		const void *	data,
		size_t	len
	)

Write to data transfer buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to write
len	Length of data

Definition at line 98 of file xferbuf.c.

                                                   {
        size_t max_len;
        int rc;

        /* Check for overflow */
        max_len = ( offset + len );
        if ( max_len < offset )
                return -EOVERFLOW;

        /* Ensure buffer is large enough to contain this write */
        if ( ( rc = xferbuf_ensure_size ( xferbuf, max_len ) ) != 0 )
                return rc;

        /* Copy data to buffer */
        profile_start ( &xferbuf_write_profiler );
        xferbuf->op->write ( xferbuf, offset, data, len );
        profile_stop ( &xferbuf_write_profiler );

        return 0;
}

References data, EOVERFLOW, len, max_len, offset, xfer_buffer::op, profile_start(), profile_stop(), rc, xfer_buffer_operations::write, and xferbuf_ensure_size().

Referenced by peerblk_decrypt_write(), peerblk_retrieval_rx(), and xferbuf_deliver().

xferbuf_read()

int xferbuf_read	(	struct xfer_buffer *	xferbuf,
		size_t	offset,
		void *	data,
		size_t	len
	)

Read from data transfer buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to write
len	Length of data

Definition at line 128 of file xferbuf.c.

                                            {

        /* Check that read is within buffer range */
        if ( ( offset > xferbuf->len ) ||
             ( len > ( xferbuf->len - offset ) ) )
                return -ENOENT;

        /* Copy data from buffer */
        profile_start ( &xferbuf_read_profiler );
        xferbuf->op->read ( xferbuf, offset, data, len );
        profile_stop ( &xferbuf_read_profiler );

        return 0;
}

References data, ENOENT, len, xfer_buffer::len, offset, xfer_buffer::op, profile_start(), profile_stop(), and xfer_buffer_operations::read.

Referenced by peerblk_decrypt_read().

xferbuf_deliver()

int xferbuf_deliver	(	struct xfer_buffer *	xferbuf,
		struct io_buffer *	iobuf,
		struct xfer_metadata *	meta
	)

Add received data to data transfer buffer.

Parameters

xferbuf	Data transfer buffer
iobuf	I/O buffer
meta	Data transfer metadata

Return values

rc	Return status code

Definition at line 152 of file xferbuf.c.

                                                   {
        size_t len = iob_len ( iobuf );
        size_t pos;
        int rc;

        /* Start profiling */
        profile_start ( &xferbuf_deliver_profiler );

        /* Calculate new buffer position */
        pos = xferbuf->pos;
        if ( meta->flags & XFER_FL_ABS_OFFSET )
                pos = 0;
        pos += meta->offset;

        /* Write data to buffer */
        if ( ( rc = xferbuf_write ( xferbuf, pos, iobuf->data, len ) ) != 0 )
                goto done;

        /* Update current buffer position */
        xferbuf->pos = ( pos + len );

 done:
        free_iob ( iobuf );
        profile_stop ( &xferbuf_deliver_profiler );
        return rc;
}

References io_buffer::data, done, free_iob(), iob_len(), len, meta(), xfer_buffer::pos, profile_start(), profile_stop(), rc, XFER_FL_ABS_OFFSET, and xferbuf_write().

Referenced by blktrans_deliver(), downloader_deliver(), efi_pxe_tftp_deliver(), peermux_info_deliver(), and validator_xfer_deliver().

xferbuf_malloc_realloc()

static int xferbuf_malloc_realloc ( struct xfer_buffer *  xferbuf, size_t  len  )

static

Reallocate malloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
len	New length (or zero to free buffer)

Return values

rc	Return status code

Definition at line 187 of file xferbuf.c.

                                                                              {
        void *new_data;

        new_data = realloc ( xferbuf->data, len );
        if ( ! new_data )
                return -ENOSPC;
        xferbuf->data = new_data;
        return 0;
}

References xfer_buffer::data, ENOSPC, len, and realloc().

xferbuf_malloc_write()

static void xferbuf_malloc_write ( struct xfer_buffer *  xferbuf, size_t  offset, const void *  data, size_t  len  )

static

Write data to malloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to copy
len	Length of data

Definition at line 205 of file xferbuf.c.

                                                                  {

        memcpy ( ( xferbuf->data + offset ), data, len );
}

References xfer_buffer::data, data, len, memcpy(), and offset.

xferbuf_malloc_read()

static void xferbuf_malloc_read ( struct xfer_buffer *  xferbuf, size_t  offset, void *  data, size_t  len  )

static

Read data from malloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to read
len	Length of data

Definition at line 219 of file xferbuf.c.

                                                           {

        memcpy ( data, ( xferbuf->data + offset ), len );
}

References xfer_buffer::data, data, len, memcpy(), and offset.

xferbuf_umalloc_realloc()

static int xferbuf_umalloc_realloc ( struct xfer_buffer *  xferbuf, size_t  len  )

static

Reallocate umalloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
len	New length (or zero to free buffer)

Return values

rc	Return status code

Definition at line 239 of file xferbuf.c.

                                                                               {
        userptr_t *udata = xferbuf->data;
        userptr_t new_udata;

        new_udata = urealloc ( *udata, len );
        if ( ! new_udata )
                return -ENOSPC;
        *udata = new_udata;
        return 0;
}

References xfer_buffer::data, ENOSPC, len, and urealloc().

xferbuf_umalloc_write()

static void xferbuf_umalloc_write ( struct xfer_buffer *  xferbuf, size_t  offset, const void *  data, size_t  len  )

static

Write data to umalloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to copy
len	Length of data

Definition at line 258 of file xferbuf.c.

                                                                   {
        userptr_t *udata = xferbuf->data;

        copy_to_user ( *udata, offset, data, len );
}

References copy_to_user(), xfer_buffer::data, data, len, and offset.

xferbuf_umalloc_read()

static void xferbuf_umalloc_read ( struct xfer_buffer *  xferbuf, size_t  offset, void *  data, size_t  len  )

static

Read data from umalloc()-based data buffer.

Parameters

xferbuf	Data transfer buffer
offset	Starting offset
data	Data to read
len	Length of data

Definition at line 273 of file xferbuf.c.

                                                            {
        userptr_t *udata = xferbuf->data;

        copy_from_user ( data, *udata, offset, len );
}

References copy_from_user(), xfer_buffer::data, data, len, and offset.

xfer_buffer()

struct xfer_buffer* xfer_buffer

(

struct interface *

intf

)

Get underlying data transfer buffer.

Parameters

interface

Data transfer interface

Return values

xferbuf

Data transfer buffer, or NULL on error

This call will check that the xfer_buffer() handler belongs to the destination interface which also provides xfer_deliver() for this interface.

This is done to prevent accidental accesses to a data transfer buffer which may be located behind a non-transparent datapath via a series of pass-through interfaces.

Definition at line 301 of file xferbuf.c.

                                                            {
        struct interface *dest;
        xfer_buffer_TYPE ( void * ) *op =
                intf_get_dest_op ( intf, xfer_buffer, &dest );
        void *object = intf_object ( dest );
        struct interface *xfer_deliver_dest;
        struct xfer_buffer *xferbuf;

        /* Check that this operation is provided by the same interface
         * which handles xfer_deliver().
         */
        ( void ) intf_get_dest_op ( intf, xfer_deliver, &xfer_deliver_dest );

        if ( op && ( dest == xfer_deliver_dest ) ) {
                xferbuf = op ( object );
        } else {
                /* Default is to not have a data transfer buffer */
                xferbuf = NULL;
        }

        intf_put ( xfer_deliver_dest );
        intf_put ( dest );
        return xferbuf;
}

References dest, interface::intf, intf_get_dest_op, intf_object(), intf_put(), NULL, op, xfer_buffer_TYPE, and xfer_deliver().

Referenced by http_content_buffer(), peerblk_decrypt(), and peermux_block_buffer().

Variable Documentation

__profiler

struct profiler xferbuf_read_profiler __profiler

static

Initial value:

=
        { .name = "xferbuf.deliver" }

Data delivery profiler.

Data read profiler.

Data write profiler.

Definition at line 42 of file xferbuf.c.

xferbuf_malloc_operations

struct xfer_buffer_operations xferbuf_malloc_operations

Initial value:

= {
        .realloc = xferbuf_malloc_realloc,
        .write = xferbuf_malloc_write,
        .read = xferbuf_malloc_read,
}

malloc()-based data buffer operations

Definition at line 226 of file xferbuf.c.

Referenced by xferbuf_malloc_init().

xferbuf_umalloc_operations

struct xfer_buffer_operations xferbuf_umalloc_operations

Initial value:

= {
        .realloc = xferbuf_umalloc_realloc,
        .write = xferbuf_umalloc_write,
        .read = xferbuf_umalloc_read,
}

umalloc()-based data buffer operations

Definition at line 281 of file xferbuf.c.

Referenced by xferbuf_umalloc_init().