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/* $OpenBSD: resolve.h,v 1.70 2013/11/13 05:41:42 deraadt Exp $ */
/*
* Copyright (c) 1998 Per Fogelstrom, Opsycon AB
*
* 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 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 _RESOLVE_H_
#define _RESOLVE_H_
#include <sys/queue.h>
#include <link.h>
#include <dlfcn.h>
#include <signal.h>
struct load_list {
struct load_list *next;
void *start;
size_t size;
int prot;
Elf_Addr moff;
long foff;
};
/*
* Structure describing a loaded object.
* The head of this struct must be compatible
* with struct link_map in sys/link.h
*/
typedef struct elf_object elf_object_t;
struct elf_object {
Elf_Addr obj_base; /* object's address '0' base */
char *load_name; /* Pointer to object name */
Elf_Dyn *load_dyn; /* Pointer to object dynamic data */
struct elf_object *next;
struct elf_object *prev;
/* End struct link_map compatible */
Elf_Addr load_base; /* Base address of loadable segments */
struct load_list *load_list;
u_int32_t load_size;
Elf_Addr got_addr;
Elf_Addr got_start;
size_t got_size;
Elf_Addr plt_start;
size_t plt_size;
union {
u_long info[DT_NUM + DT_PROCNUM];
struct {
Elf_Addr null; /* Not used */
Elf_Addr needed; /* Not used */
Elf_Addr pltrelsz;
Elf_Addr *pltgot;
Elf_Addr *hash;
const char *strtab;
const Elf_Sym *symtab;
Elf_RelA *rela;
Elf_Addr relasz;
Elf_Addr relaent;
Elf_Addr strsz;
Elf_Addr syment;
void (*init)(void);
void (*fini)(void);
const char *soname;
const char *rpath;
Elf_Addr symbolic;
Elf_Rel *rel;
Elf_Addr relsz;
Elf_Addr relent;
Elf_Addr pltrel;
Elf_Addr debug;
Elf_Addr textrel;
Elf_Addr jmprel;
} u;
} Dyn;
#define dyn Dyn.u
Elf_Addr relacount; /* DT_RELACOUNT */
Elf_Addr relcount; /* DT_RELCOUNT */
int status;
#define STAT_RELOC_DONE 0x01
#define STAT_GOT_DONE 0x02
#define STAT_INIT_DONE 0x04
#define STAT_FINI_DONE 0x08
#define STAT_FINI_READY 0x10
#define STAT_UNLOADED 0x20
#define STAT_NODELETE 0x40
#define STAT_VISITED 0x80
Elf_Phdr *phdrp;
int phdrc;
int obj_type;
#define OBJTYPE_LDR 1
#define OBJTYPE_EXE 2
#define OBJTYPE_LIB 3
#define OBJTYPE_DLO 4
int obj_flags; /* c.f. <sys/exec_elf.h> DF_1_* */
Elf_Word *buckets;
u_int32_t nbuckets;
Elf_Word *chains;
u_int32_t nchains;
Elf_Dyn *dynamic;
TAILQ_HEAD(,dep_node) child_list; /* direct dep libs of object */
TAILQ_HEAD(,dep_node) grpsym_list; /* ordered complete dep list */
TAILQ_HEAD(,dep_node) grpref_list; /* refs to other load groups */
int refcount; /* dep libs only */
int opencount; /* # dlopen() & exe */
int grprefcount; /* load group refs */
#define OBJECT_REF_CNT(object) \
((object->refcount + object->opencount + object->grprefcount))
#define OBJECT_DLREF_CNT(object) \
((object->opencount + object->grprefcount))
/* object that caused this module to be loaded, used in symbol lookup */
elf_object_t *load_object;
struct sod sod;
void *prebind_data;
/* for object confirmation */
dev_t dev;
ino_t inode;
/* last symbol lookup on this object, to avoid mutiple searches */
int lastlookup_head;
int lastlookup;
char **rpath;
/* nonzero if trace enabled for this object */
int traced;
};
struct dep_node {
TAILQ_ENTRY(dep_node) next_sib;
elf_object_t *data;
};
void _dl_add_object(elf_object_t *object);
elf_object_t *_dl_finalize_object(const char *objname, Elf_Dyn *dynp,
Elf_Phdr *phdrp, int phdrc, const int objtype, const long lbase,
const long obase);
void _dl_remove_object(elf_object_t *object);
void _dl_cleanup_objects(void);
elf_object_t *_dl_load_shlib(const char *, elf_object_t *, int, int);
elf_object_t *_dl_tryload_shlib(const char *libname, int type, int flags);
int _dl_md_reloc(elf_object_t *object, int rel, int relsz);
int _dl_md_reloc_got(elf_object_t *object, int lazy);
Elf_Addr _dl_find_symbol(const char *name, const Elf_Sym **this,
int flags, const Elf_Sym *ref_sym, elf_object_t *object,
const elf_object_t **pobj);
Elf_Addr _dl_find_symbol_bysym(elf_object_t *req_obj, unsigned int symidx,
const Elf_Sym **ref, int flags, const Elf_Sym *ref_sym,
const elf_object_t **pobj);
/*
* defines for _dl_find_symbol() flag field, three bits of meaning
* myself - clear: search all objects, set: search only this object
* warnnotfound - clear: no warning, set: warn if not found
* inplt - clear: possible plt ref set: real matching function.
*
* inplt - due to how ELF handles function addresses in shared libraries
* &func may actually refer to the plt entry in the main program
* rather than the actual function address in the .so file.
* This rather bizarre behavior is documented in the SVR4 ABI.
* when getting the function address to relocate a PLT entry
* the 'real' function address is necessary, not the possible PLT address.
*/
/* myself */
#define SYM_SEARCH_ALL 0x00
#define SYM_SEARCH_SELF 0x01
#define SYM_SEARCH_OTHER 0x02
#define SYM_SEARCH_NEXT 0x04
#define SYM_SEARCH_OBJ 0x08
/* warnnotfound */
#define SYM_NOWARNNOTFOUND 0x00
#define SYM_WARNNOTFOUND 0x10
/* inplt */
#define SYM_NOTPLT 0x00
#define SYM_PLT 0x20
#define SYM_DLSYM 0x40
int _dl_load_dep_libs(elf_object_t *object, int flags, int booting);
int _dl_rtld(elf_object_t *object);
void _dl_call_init(elf_object_t *object);
void _dl_link_child(elf_object_t *dep, elf_object_t *p);
void _dl_link_grpsym(elf_object_t *object, int checklist);
void _dl_cache_grpsym_list(elf_object_t *object);
void _dl_cache_grpsym_list_setup(elf_object_t *object);
void _dl_link_grpref(elf_object_t *load_group, elf_object_t *load_object);
void _dl_link_dlopen(elf_object_t *dep);
void _dl_unlink_dlopen(elf_object_t *dep);
void _dl_notify_unload_shlib(elf_object_t *object);
void _dl_unload_shlib(elf_object_t *object);
void _dl_unload_dlopen(void);
void _dl_run_all_dtors(void);
/* Please don't rename; gdb(1) knows about this. */
Elf_Addr _dl_bind(elf_object_t *object, int index);
int _dl_match_file(struct sod *sodp, const char *name, int namelen);
char *_dl_find_shlib(struct sod *sodp, char **searchpath, int nohints);
void _dl_load_list_free(struct load_list *load_list);
void _dl_debug_state(void);
void _dl_thread_kern_go(void);
void _dl_thread_kern_stop(void);
void _dl_thread_bind_lock(int, sigset_t *);
char *_dl_getenv(const char *, char **);
void _dl_unsetenv(const char *, char **);
void _dl_trace_setup(char **);
void _dl_trace_object_setup(elf_object_t *);
int _dl_trace_plt(const elf_object_t *, const char *);
extern elf_object_t *_dl_objects;
extern elf_object_t *_dl_last_object;
extern elf_object_t *_dl_loading_object;
extern const char *_dl_progname;
extern struct r_debug *_dl_debug_map;
extern int _dl_pagesz;
extern int _dl_errno;
extern char **_dl_libpath;
extern char *_dl_preload;
extern char *_dl_bindnow;
extern char *_dl_traceld;
extern char *_dl_tracefmt1;
extern char *_dl_tracefmt2;
extern char *_dl_traceprog;
extern char *_dl_debug;
extern int _dl_trust;
#define DL_DEB(P) do { if (_dl_debug) _dl_printf P ; } while (0)
#define DL_NOT_FOUND 1
#define DL_CANT_OPEN 2
#define DL_NOT_ELF 3
#define DL_CANT_OPEN_REF 4
#define DL_CANT_MMAP 5
#define DL_NO_SYMBOL 6
#define DL_INVALID_HANDLE 7
#define DL_INVALID_CTL 8
#define DL_NO_OBJECT 9
#define DL_CANT_FIND_OBJ 10
#define DL_CANT_LOAD_OBJ 11
#define DL_INVALID_MODE 12
#define ELF_ROUND(x,malign) (((x) + (malign)-1) & ~((malign)-1))
#define ELF_TRUNC(x,malign) ((x) & ~((malign)-1))
/* symbol lookup cache */
typedef struct sym_cache {
const elf_object_t *obj;
const Elf_Sym *sym;
int flags;
} sym_cache;
extern sym_cache *_dl_symcache;
extern int _dl_symcachestat_hits;
extern int _dl_symcachestat_lookups;
TAILQ_HEAD(dlochld, dep_node);
extern struct dlochld _dlopened_child_list;
/* variables used to avoid duplicate node checking */
int _dl_searchnum;
uint32_t _dl_skipnum;
void _dl_newsymsearch(void);
#endif /* _RESOLVE_H_ */
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