LCOM1920-T02G10

/*        $NetBSD: link_aout.h,v 1.21 2008/04/28 20:22:54 martin Exp $        */

/*-

 * Copyright (c) 1998 The NetBSD Foundation, Inc.

 * All rights reserved.

 *

 * This code is derived from software contributed to The NetBSD Foundation

 * by Paul Kranenburg.

 *

 * 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS

 * ``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 FOUNDATION OR CONTRIBUTORS

 * 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.

 */

/*

 * RRS section definitions.

 *

 * The layout of some data structures defined in this header file is

 * such that we can provide compatibility with the SunOS 4.x shared

 * library scheme.

 */

#ifndef _LINK_AOUT_H_

#define _LINK_AOUT_H_

#include <dlfcn.h>                        /* for Dl_info */

#include <a.out.h>                        /* for struct nlist */

/*

 * 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) */

        u_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 */

        u_int                som_write : 1;        /* Text is currently writable */

        struct _dynamic        *som_dynamic;        /* _dynamic structure */

        caddr_t                som_spd;        /* Private data */

};

/*

 * Symbol description with size. This is simply an `nlist' with

 * one field (nz_size) added.

 * Used to convey size information on items in the data segment

 * of shared objects. An array of these live in the shared object's

 * text segment and is addressed by the `sdt_nzlist' field.

 */

struct nzlist {

        struct nlist        nlist;

        u_long                nz_size;

#define nz_un                nlist.n_un

#define nz_strx                nlist.n_un.n_strx

#define nz_name                nlist.n_un.n_name

#define nz_type                nlist.n_type

#define nz_value        nlist.n_value

#define nz_desc                nlist.n_desc

#define nz_other        nlist.n_other

};

#define N_AUX(p)        ((p)->n_other & 0xf)

#define N_BIND(p)        (((unsigned int)(p)->n_other >> 4) & 0xf)

#define N_OTHER(r, v)        (((unsigned int)(r) << 4) | ((v) & 0xf))

#define AUX_OBJECT        1

#define AUX_FUNC        2

#define AUX_LABEL        3

/*#define BIND_LOCAL        0        not used */

/*#define BIND_GLOBAL        1        not used */

#define BIND_WEAK        2

/*

 * The `section_dispatch_table' structure contains offsets to various data

 * structures needed to do run-time relocation.

 */

struct section_dispatch_table {

        struct so_map *sdt_loaded;        /* List of loaded objects */

        long        sdt_sods;                /* List of shared objects descriptors */

        long        sdt_paths;                /* Library search paths */

        long        sdt_got;                /* Global offset table */

        long        sdt_plt;                /* Procedure linkage table */

        long        sdt_rel;                /* Relocation table */

        long        sdt_hash;                /* Symbol hash table */

        long        sdt_nzlist;                /* Symbol table itself */

        long        sdt_filler2;                /* Unused (was: stab_hash) */

        long        sdt_buckets;                /* Number of hash buckets */

        long        sdt_strings;                /* Symbol strings */

        long        sdt_str_sz;                /* Size of symbol strings */

        long        sdt_text_sz;                /* Size of text area */

        long        sdt_plt_sz;                /* Size of procedure linkage table */

};

/*

 * RRS symbol hash table, addressed by `sdt_hash' in section_dispatch_table.

 * Used to quickly lookup symbols of the shared object by hashing

 * on the symbol's name. `rh_symbolnum' is the index of the symbol

 * in the shared object's symbol list (`sdt_nzlist'), `rh_next' is

 * the next symbol in the hash bucket (in case of collisions).

 */

struct rrs_hash {

        int        rh_symbolnum;                /* Symbol number */

        int        rh_next;                /* Next hash entry */

};

/*

 * `rt_symbols' is used to keep track of run-time allocated commons

 * and data items copied from shared objects.

 */

struct rt_symbol {

        struct nzlist                *rt_sp;                /* The symbol */

        struct rt_symbol        *rt_next;        /* Next in linear list */

        struct rt_symbol        *rt_link;        /* Next in bucket */

        caddr_t                        rt_srcaddr;        /* Address of "master" copy */

        struct so_map                *rt_smp;        /* Originating map */

};

/*

 * Debugger interface structure.

 */

struct so_debug {

        int        dd_version;                /* Version # of interface */

        int        dd_in_debugger;                /* Set when run by debugger */

        int        dd_sym_loaded;                /* Run-time linking brought more

                                           symbols into scope */

        char            *dd_bpt_addr;                /* Address of rtld-generated bpt */

        int        dd_bpt_shadow;                /* Original contents of bpt */

        struct rt_symbol *dd_cc;        /* Allocated commons/copied data */

};

/*

 * Entry points into ld.so - user interface to the run-time linker.

 */

struct ld_entry {

        void        *(*dlopen)(const char *, int);

        int        (*dlclose)(void *);

        void        *(*dlsym)(void *, const char *);

        int        (*dlctl)(void *, int, void *);

        void        (*dlexit)(void);

        int        (*dladdr)(const void *, Dl_info *);

        void        (*dlrsrvd[2])(void);

};

/*

 * This is the structure pointed at by the __DYNAMIC symbol if an

 * executable requires the attention of the run-time link editor.

 * __DYNAMIC is given the value zero if no run-time linking needs to

 * be done (it is always present in shared objects).

 * The union `d_un' provides for different versions of the dynamic

 * linking mechanism (switched on by `d_version'). The last version

 * used by Sun is 3. We leave some room here and go to version number

 * 8 for NetBSD, the main difference lying in the support for the

 * `nz_list' type of symbols.

 */

struct        _dynamic {

        int                d_version;        /* version # of this interface */

        struct so_debug        *d_debug;

        union {

                struct section_dispatch_table *d_sdt;

        } d_un;

        struct ld_entry *d_entry;        /* compat - now in crt_ldso */

};

#define LD_VERSION_SUN                (3)

#define LD_VERSION_BSD                (8)

#define LD_VERSION_NZLIST_P(v)        ((v) >= 8)

#define LD_GOT(x)        ((x)->d_un.d_sdt->sdt_got)

#define LD_PLT(x)        ((x)->d_un.d_sdt->sdt_plt)

#define LD_REL(x)        ((x)->d_un.d_sdt->sdt_rel)

#define LD_SYMBOL(x)        ((x)->d_un.d_sdt->sdt_nzlist)

#define LD_HASH(x)        ((x)->d_un.d_sdt->sdt_hash)

#define LD_STRINGS(x)        ((x)->d_un.d_sdt->sdt_strings)

#define LD_NEED(x)        ((x)->d_un.d_sdt->sdt_sods)

#define LD_BUCKETS(x)        ((x)->d_un.d_sdt->sdt_buckets)

#define LD_PATHS(x)        ((x)->d_un.d_sdt->sdt_paths)

#define LD_GOTSZ(x)        ((x)->d_un.d_sdt->sdt_plt - (x)->d_un.d_sdt->sdt_got)

#define LD_RELSZ(x)        ((x)->d_un.d_sdt->sdt_hash - (x)->d_un.d_sdt->sdt_rel)

#define LD_HASHSZ(x)        ((x)->d_un.d_sdt->sdt_nzlist - (x)->d_un.d_sdt->sdt_hash)

#define LD_STABSZ(x)        ((x)->d_un.d_sdt->sdt_strings - (x)->d_un.d_sdt->sdt_nzlist)

#define LD_PLTSZ(x)        ((x)->d_un.d_sdt->sdt_plt_sz)

#define LD_STRSZ(x)        ((x)->d_un.d_sdt->sdt_str_sz)

#define LD_TEXTSZ(x)        ((x)->d_un.d_sdt->sdt_text_sz)

/*

 * Interface to ld.so

 */

struct crt_ldso {

        int                crt_ba;                /* Base address of ld.so */

        int                crt_dzfd;        /* "/dev/zero" file descriptor (SunOS) */

        int                crt_ldfd;        /* ld.so file descriptor */

        struct _dynamic        *crt_dp;        /* Main's __DYNAMIC */

        char                **crt_ep;        /* environment strings */

        caddr_t                crt_bp;                /* Breakpoint if run from debugger */

        char                *crt_prog;        /* Program name (v3) */

        char                *crt_ldso;        /* Link editor name (v4) */

        struct ld_entry        *crt_ldentry;        /* dl*() access (v4) */

};

/*

 * Version passed from crt0 to ld.so (1st argument to _rtld()).

 */

#define CRT_VERSION_SUN                1

#define CRT_VERSION_BSD_2        2

#define CRT_VERSION_BSD_3        3

#define CRT_VERSION_BSD_4        4

/*

 * 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_AOUT_H_ */