Added link.h for shared libs.

include/link.h

@@ -0,0 +1,234 @@
+/*
+ * 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_ */
+