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/*
* RRS section definitions.
* Nomenclature and, more importantly, the layout of the various
* data structures defined in this header file are borrowed from
* Sun Microsystems' original <link.h>, so we can provide compatibility
* with the SunOS 4.x shared library scheme.
*
* $Id: link.h,v 1.2 1993/10/22 21:04:19 pk Exp $
* (derived from: @(#)link.h 1.6 88/08/19 SMI
* Copyright (c) 1987 by Sun Microsystems, Inc.)
*/
#ifndef _LINK_H_
#define _LINK_H_
/*
* A `link_object' structure descibes a shared object that is needed
* to complete the link edit process of the object containing it.
* A list of such objects (chained through `lo_next') is pointed at
* by `ld_need' in the link_dynamic_2 structure.
*/
struct link_object {
long lo_name; /* name (relative to load address) */
u_int lo_library : 1, /* searched for by library rules */
lo_unused : 31;
short lo_major; /* major version number */
short lo_minor; /* minor version number */
long lo_next; /* next one (often relative) */
};
/*
* `link_maps' 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 link_map {
caddr_t lm_addr; /* address at which object mapped */
char *lm_name; /* full name of loaded object */
struct link_map *lm_next; /* next object in map */
struct link_object *lm_lop; /* link object that got us here */
caddr_t lm_lob; /* base address for said link object */
u_int lm_rwt : 1; /* text is read/write */
struct link_dynamic *lm_ld; /* dynamic structure */
caddr_t lm_lpd; /* loader 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 address by the `ld_symbols' 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
};
/*
* The `link_dynamic_2' structure contains offsets to various data
* structures needed to do run-time relocation.
*/
struct link_dynamic_2 {
struct link_map *ld_loaded; /* list of loaded objects */
long ld_need; /* list of needed objects */
long ld_rules; /* search rules for library objects */
long ld_got; /* global offset table */
long ld_plt; /* procedure linkage table */
long ld_rel; /* relocation table */
long ld_hash; /* symbol hash table */
long ld_symbols; /* symbol table itself */
long (*ld_stab_hash)(); /* "pointer" to symbol hash function */
long ld_buckets; /* number of hash buckets */
long ld_strings; /* symbol strings */
long ld_str_sz; /* size of symbol strings */
long ld_text_sz; /* size of text area */
long ld_plt_sz; /* size of procedure linkage table */
};
/*
* RRS symbol hash table, addressed by `ld_hash' in link_dynamic_2
* 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 (`ld_symbols'), `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 */
};
/*
* Debugger interface structure.
*/
struct ld_debug {
int ldd_version; /* version # of interface */
int ldd_in_debugger; /* a debugger is running us */
int ldd_sym_loaded; /* we loaded some symbols */
char *ldd_bp_addr; /* place for ld-generated bpt */
int ldd_bp_inst; /* instruction which was there */
struct rt_symbol *ldd_cp; /* commons we built */
};
/*
* Entry points into ld.so - user interface to the run-time linker.
* (see also libdl.a)
*/
struct ld_entry {
int (*dlopen)();
int (*dlclose)();
int (*dlsym)();
};
/*
* 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 `ld_un' provides for different versions of the dynamic
* linking mechanism (switched on by `ld_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 link_dynamic {
int ld_version; /* version # of this structure */
struct ld_debug *ldd;
union {
struct link_dynamic_2 *ld_2;
} ld_un;
struct ld_entry *ld_entry;
};
#define LD_VERSION_SUN (3)
#define LD_VERSION_BSD (8)
#define LD_VERSION_NZLIST_P(v) ((v) >= 8)
#define LD_GOT(x) ((x)->ld_un.ld_2->ld_got)
#define LD_PLT(x) ((x)->ld_un.ld_2->ld_plt)
#define LD_REL(x) ((x)->ld_un.ld_2->ld_rel)
#define LD_SYMBOL(x) ((x)->ld_un.ld_2->ld_symbols)
#define LD_HASH(x) ((x)->ld_un.ld_2->ld_hash)
#define LD_STRINGS(x) ((x)->ld_un.ld_2->ld_strings)
#define LD_NEED(x) ((x)->ld_un.ld_2->ld_need)
#define LD_BUCKETS(x) ((x)->ld_un.ld_2->ld_buckets)
#define LD_GOTSZ(x) ((x)->ld_un.ld_2->ld_plt - (x)->ld_un.ld_2->ld_got)
#define LD_RELSZ(x) ((x)->ld_un.ld_2->ld_hash - (x)->ld_un.ld_2->ld_rel)
#define LD_HASHSZ(x) ((x)->ld_un.ld_2->ld_symbols - (x)->ld_un.ld_2->ld_hash)
#define LD_STABSZ(x) ((x)->ld_un.ld_2->ld_strings - (x)->ld_un.ld_2->ld_symbols)
#define LD_PLTSZ(x) ((x)->ld_un.ld_2->ld_plt_sz)
#define LD_STRSZ(x) ((x)->ld_un.ld_2->ld_str_sz)
#define LD_TEXTSZ(x) ((x)->ld_un.ld_2->ld_text_sz)
/*
* Interface to ld.so (see link(5))
*/
struct crt_ldso {
int crt_ba; /* Base address of ld.so */
int crt_dzfd; /* "/dev/zero" file decriptor (SunOS) */
int crt_ldfd; /* ld.so file descriptor */
struct link_dynamic *crt_dp;/* Main's __DYNAMIC */
char **crt_ep; /* environment strings */
caddr_t crt_bp; /* Breakpoint if run from debugger */
};
/*
* Version passed from crt0 to ld.so (1st argument to _rtld()).
*/
#define CRT_VERSION_SUN 1
#define CRT_VERSION_BSD 2
/*
* 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
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) */
};
#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_ */
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