/*      $NetBSD: link_aout.h,v 1.23 2016/01/23 01:26:14 dholland 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) */
       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 */
};

/*
* 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;
       unsigned 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_ */

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.