/*      $OpenBSD: link.h,v 1.15 2013/10/19 09:00:18 deraadt Exp $       */
/*      $NetBSD: link.h,v 1.10 1996/01/09 00:00:11 pk Exp $     */

/*
 * Copyright (c) 1993 Paul Kranenburg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


#ifndef _LINK_H_
#define _LINK_H_

#ifdef __ELF__
#include <link_elf.h>
#endif

/*
 * A `Shared Object Descriptor' describes a shared object that is needed
 * to complete the link edit process of the object containing it.
 * A list of such objects (chained through `sod_next') is pointed at
 * by `sdt_sods' in the section_dispatch_table structure.
 */

struct sod {    /* Shared Object Descriptor */
        long            sod_name;       /* name (relative to load address) */
        unsigned int    sod_library : 1,/* Searched for by library rules */
                        sod_reserved : 31;
        short           sod_major;      /* major version number */
        short           sod_minor;      /* minor version number */
        long            sod_next;       /* next sod */
};

/*
 * `Shared Object Map's are used by the run-time link editor (ld.so) to
 * keep track of all shared objects loaded into a process' address space.
 * These structures are only used at run-time and do not occur within
 * the text or data segment of an executable or shared library.
 */
struct so_map {         /* Shared Object Map */
        caddr_t         som_addr;       /* Address at which object mapped */
        char            *som_path;      /* Path to mmap'ed file */
        struct so_map   *som_next;      /* Next map in chain */
        struct sod      *som_sod;       /* Sod responsible for this map */
        caddr_t         som_sodbase;    /* Base address of this sod */
        unsigned int    som_write : 1;  /* Text is currently writable */
        struct _dynamic *som_dynamic;   /* _dynamic structure */
        caddr_t         som_spd;        /* Private data */
};


/*
 *      Debug rendezvous struct. Pointer to this is set up in the
 *      target code pointed by the DT_DEBUG tag. If it is
 *      defined.
 */
struct r_debug {
        int     r_version;              /* Protocol version. */
        struct link_map *r_map;         /* Head of list of loaded objects. */

        /*
         * This is the address of a function internal to the run-time linker,
         * that will always be called when the linker begins to map in a
         * library or unmap it, and again when the mapping change is complete.
         * The debugger can set a breakpoint at this address if it wants to
         * notice shared object mapping changes.
         */
        unsigned long r_brk;
        enum {
                /*
                 * This state value describes the mapping change taking place
                 * when the `r_brk' address is called.
                 */
                RT_CONSISTENT,          /* Mapping change is complete.  */
                RT_ADD,                 /* Adding a new object.  */
                RT_DELETE               /* Removing an object mapping.  */
        } r_state;

        unsigned long r_ldbase;         /* Base address the linker is loaded at.  */
};



/*
 * Maximum number of recognized shared object version numbers.
 */
#define MAXDEWEY        8

/*
 * Header of the hints file.
 */
struct hints_header {
        long            hh_magic;
#define HH_MAGIC        011421044151
        long            hh_version;     /* Interface version number */
#define LD_HINTS_VERSION_1      1
#define LD_HINTS_VERSION_2      2
        long            hh_hashtab;     /* Location of hash table */
        long            hh_nbucket;     /* Number of buckets in hashtab */
        long            hh_strtab;      /* Location of strings */
        long            hh_strtab_sz;   /* Size of strings */
        long            hh_ehints;      /* End of hints (max offset in file) */
        long            hh_dirlist;     /* Colon-separated list of srch dirs */
};

#define HH_BADMAG(hdr)  ((hdr).hh_magic != HH_MAGIC)

/*
 * Hash table element in hints file.
 */
struct hints_bucket {
        /* namex and pathx are indices into the string table */
        int             hi_namex;               /* Library name */
        int             hi_pathx;               /* Full path */
        int             hi_dewey[MAXDEWEY];     /* The versions */
        int             hi_ndewey;              /* Number of version numbers */
#define hi_major hi_dewey[0]
#define hi_minor hi_dewey[1]
        int             hi_next;                /* Next in this bucket */
};

#define _PATH_LD_HINTS          "/var/run/ld.so.hints"

#endif /* _LINK_H_ */