fragment.h

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#ifndef _IPXE_FRAGMENT_H
#define _IPXE_FRAGMENT_H

/** @file
 *
 * Fragment reassembly
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );

#include <stdint.h>
#include <ipxe/list.h>
#include <ipxe/iobuf.h>
#include <ipxe/retry.h>

/** Fragment reassembly timeout */
#define FRAGMENT_TIMEOUT ( TICKS_PER_SEC / 2 )

/** A fragment reassembly buffer */
struct fragment {
        /* List of fragment reassembly buffers */
        struct list_head list;
        /** Reassembled packet */
        struct io_buffer *iobuf;
        /** Length of non-fragmentable portion of reassembled packet */
        size_t hdrlen;
        /** Reassembly timer */
        struct retry_timer timer;
        /** Fragment reassembler */
        struct fragment_reassembler *fragments;
};

/** A fragment reassembler */
struct fragment_reassembler {
        /** List of fragment reassembly buffers */
        struct list_head list;
        /**
         * Check if fragment matches fragment reassembly buffer
         *
         * @v fragment          Fragment reassembly buffer
         * @v iobuf             I/O buffer
         * @v hdrlen            Length of non-fragmentable potion of I/O buffer
         * @ret is_fragment     Fragment matches this reassembly buffer
         */
        int ( * is_fragment ) ( struct fragment *fragment,
                                struct io_buffer *iobuf, size_t hdrlen );
        /**
         * Get fragment offset
         *
         * @v iobuf             I/O buffer
         * @v hdrlen            Length of non-fragmentable potion of I/O buffer
         * @ret offset          Offset
         */
        size_t ( * fragment_offset ) ( struct io_buffer *iobuf, size_t hdrlen );
        /**
         * Check if more fragments exist
         *
         * @v iobuf             I/O buffer
         * @v hdrlen            Length of non-fragmentable potion of I/O buffer
         * @ret more_frags      More fragments exist
         */
        int ( * more_fragments ) ( struct io_buffer *iobuf, size_t hdrlen );
        /** Associated IP statistics */
        struct ip_statistics *stats;
};

extern struct io_buffer *
fragment_reassemble ( struct fragment_reassembler *fragments,
                      struct io_buffer *iobuf, size_t *hdrlen );

#endif /* _IPXE_FRAGMENT_H */