/* $NetBSD: rtld.h,v 1.73 2006/05/22 19:49:09 drochner Exp $ */ /* * Copyright 1996 John D. Polstra. * Copyright 1996 Matt Thomas * 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 John Polstra. * 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 RTLD_H #define RTLD_H #include #include #include #include #include #include #include "rtldenv.h" #include "link.h" #if defined(_RTLD_SOURCE) #ifndef RTLD_DEFAULT_LIBRARY_PATH #define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib" #endif #define _PATH_LD_HINTS "/etc/ld.so.conf" extern int _rtld_pagesz; #define round_down(x) ((x) & ~(_rtld_pagesz - 1)) #define round_up(x) round_down((x) + _rtld_pagesz - 1) #define NEW(type) ((type *) xmalloc(sizeof(type))) #define CNEW(type) ((type *) xcalloc(sizeof(type))) #endif /* _RTLD_SOURCE */ /* * C++ has mandated the use of the following keywords for its new boolean * type. We might as well follow their lead. */ typedef enum { false = 0, true = 1 } bool; struct Struct_Obj_Entry; typedef struct Struct_Objlist_Entry { SIMPLEQ_ENTRY(Struct_Objlist_Entry) link; struct Struct_Obj_Entry *obj; } Objlist_Entry; typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; typedef struct Struct_Needed_Entry { struct Struct_Needed_Entry *next; struct Struct_Obj_Entry *obj; unsigned long name; /* Offset of name in string table */ } Needed_Entry; typedef struct _rtld_search_path_t { struct _rtld_search_path_t *sp_next; const char *sp_path; size_t sp_pathlen; } Search_Path; #define RTLD_MAX_ENTRY 10 #define RTLD_MAX_LIBRARY 4 #define RTLD_MAX_CTL 2 typedef struct _rtld_library_xform_t { struct _rtld_library_xform_t *next; char *name; const char *ctlname; struct { char *value; char *library[RTLD_MAX_LIBRARY]; } entry[RTLD_MAX_ENTRY]; } Library_Xform; /* * Shared object descriptor. * * Items marked with "(%)" are dynamically allocated, and must be freed * when the structure is destroyed. */ #define RTLD_MAGIC 0xd550b87a #define RTLD_VERSION 1 #define RTLD_MAIN 0x800 typedef struct Struct_Obj_Entry { Elf32_Word magic; /* Magic number (sanity check) */ Elf32_Word version; /* Version number of struct format */ struct Struct_Obj_Entry *next; char *path; /* Pathname of underlying file (%) */ int refcount; int dl_refcount; /* Number of times loaded by dlopen */ /* These items are computed by map_object() or by digest_phdr(). */ caddr_t mapbase; /* Base address of mapped region */ size_t mapsize; /* Size of mapped region in bytes */ size_t textsize; /* Size of text segment in bytes */ Elf_Addr vaddrbase; /* Base address in shared object file */ caddr_t relocbase; /* Reloc const = mapbase - *vaddrbase */ Elf_Dyn *dynamic; /* Dynamic section */ caddr_t entry; /* Entry point */ const Elf_Phdr *__junk001; size_t pathlen; /* Pathname length */ /* Items from the dynamic section. */ Elf_Addr *pltgot; /* PLTGOT table */ const Elf_Rel *rel; /* Relocation entries */ const Elf_Rel *rellim; /* Limit of Relocation entries */ const Elf_Rela *rela; /* Relocation entries */ const Elf_Rela *relalim; /* Limit of Relocation entries */ const Elf_Rel *pltrel; /* PLT relocation entries */ const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */ const Elf_Rela *pltrela; /* PLT relocation entries */ const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */ const Elf_Sym *symtab; /* Symbol table */ const char *strtab; /* String table */ unsigned long strsize; /* Size in bytes of string table */ #ifdef __mips__ Elf_Word local_gotno; /* Number of local GOT entries */ Elf_Word symtabno; /* Number of dynamic symbols */ Elf_Word gotsym; /* First dynamic symbol in GOT */ #endif const Elf_Word *buckets; /* Hash table buckets array */ unsigned long nbuckets; /* Number of buckets */ const Elf_Word *chains; /* Hash table chain array */ unsigned long nchains; /* Number of chains */ Search_Path *rpaths; /* Search path specified in object */ Needed_Entry *needed; /* Shared objects needed by this (%) */ void (*init)(void); /* Initialization function to call */ void (*fini)(void); /* Termination function to call */ /* Entry points for dlopen() and friends. */ void *(*dlopen)(const char *, int); void *(*dlsym)(void *, const char *); char *(*dlerror)(void); int (*dlclose)(void *); int (*dladdr)(const void *, Dl_info *); u_int32_t mainprog:1, /* True if this is the main program */ rtld:1, /* True if this is the dynamic linker */ textrel:1, /* True if there are relocations to * text seg */ symbolic:1, /* True if generated with * "-Bsymbolic" */ printed:1, /* True if ldd has printed it */ isdynamic:1, /* True if this is a pure PIC object */ mainref:1, /* True if on _rtld_list_main */ globalref:1; /* True if on _rtld_list_global */ struct link_map linkmap; /* for GDB */ /* These items are computed by map_object() or by digest_phdr(). */ const char *interp; /* Pathname of the interpreter, if any */ Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ Objlist dagmembers; /* DAG has these members (%) */ dev_t dev; /* Object's filesystem's device */ ino_t ino; /* Object's inode number */ } Obj_Entry; #if defined(_RTLD_SOURCE) extern struct r_debug _rtld_debug; extern Search_Path *_rtld_default_paths; extern Obj_Entry *_rtld_objlist; extern Obj_Entry **_rtld_objtail; extern Obj_Entry *_rtld_objmain; extern Obj_Entry _rtld_objself; extern Search_Path *_rtld_paths; extern Library_Xform *_rtld_xforms; extern bool _rtld_trust; extern Objlist _rtld_list_global; extern Objlist _rtld_list_main; extern Elf_Sym _rtld_sym_zero; /* rtld.c */ /* * We export these symbols using _rtld_symbol_lookup and is_exported. */ char *dlerror(void); void *dlopen(const char *, int); void *dlsym(void *, const char *); int dlclose(void *); int dladdr(const void *, Dl_info *); void _rtld_error(const char *, ...) __attribute__((__format__(__printf__,1,2))); void _rtld_die(void) __attribute__((__noreturn__)); void *_rtld_objmain_sym(const char *); void _rtld_debug_state(void); void _rtld_linkmap_add(Obj_Entry *); void _rtld_linkmap_delete(Obj_Entry *); void _rtld_objlist_add(Objlist *, Obj_Entry *); Objlist_Entry *_rtld_objlist_find(Objlist *, const Obj_Entry *); /* headers.c */ void _rtld_digest_dynamic(Obj_Entry *); Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t); /* load.c */ Obj_Entry *_rtld_load_object(const char *, int); int _rtld_load_needed_objects(Obj_Entry *, int); int _rtld_preload(const char *); /* path.c */ void _rtld_add_paths(Search_Path **, const char *); void _rtld_process_hints(Search_Path **, Library_Xform **, const char *); int _rtld_sysctl(const char *, void *, size_t *); /* reloc.c */ int _rtld_do_copy_relocations(const Obj_Entry *); int _rtld_relocate_objects(Obj_Entry *, bool); int _rtld_relocate_nonplt_objects(const Obj_Entry *); int _rtld_relocate_plt_lazy(const Obj_Entry *); int _rtld_relocate_plt_objects(const Obj_Entry *); void _rtld_setup_pltgot(const Obj_Entry *); /* search.c */ Obj_Entry *_rtld_load_library(const char *, const Obj_Entry *, int); /* symbol.c */ unsigned long _rtld_elf_hash(const char *); const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long, const Obj_Entry *, bool); const Elf_Sym *_rtld_find_symdef(unsigned long, const Obj_Entry *, const Obj_Entry **, bool); const Elf_Sym *_rtld_symlook_list(const char *, unsigned long, const Objlist *, const Obj_Entry **, bool); const Elf_Sym *_rtld_symlook_default(const char *, unsigned long, const Obj_Entry *, const Obj_Entry **, bool); /* map_object.c */ Obj_Entry *_rtld_map_object(const char *, int, const struct stat *); void _rtld_obj_free(Obj_Entry *); Obj_Entry *_rtld_obj_new(void); /* function descriptors */ #ifdef __HAVE_FUNCTION_DESCRIPTORS Elf_Addr _rtld_function_descriptor_alloc(const Obj_Entry *, const Elf_Sym *, Elf_Addr); const void *_rtld_function_descriptor_function(const void *); #endif /* __HAVE_FUNCTION_DESCRIPTORS */ #endif /* _RTLD_SOURCE */ #endif /* RTLD_H */