1  /*-
  2   * Copyright (c) 2006,2008-2011 Joseph Koshy
  3   * All rights reserved.
  4   *
  5   * Redistribution and use in source and binary forms, with or without
  6   * modification, are permitted provided that the following conditions
  7   * are met:
  8   * 1. Redistributions of source code must retain the above copyright
  9   *    notice, this list of conditions and the following disclaimer.
 10   * 2. Redistributions in binary form must reproduce the above copyright
 11   *    notice, this list of conditions and the following disclaimer in the
 12   *    documentation and/or other materials provided with the distribution.
 13   *
 14   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 15   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 16   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 17   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 18   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 19   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 20   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 21   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 22   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 23   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 24   * SUCH DAMAGE.
 25   *
 26   * $Id$
 27   */
 28  
 29  #ifndef	__LIBELF_H_
 30  #define	__LIBELF_H_
 31  
 32  #include <sys/queue.h>
 33  
 34  #include "_libelf_config.h"
 35  
 36  #include "_elftc.h"
 37  
 38  /*
 39   * Library-private data structures.
 40   */
 41  
 42  #define LIBELF_MSG_SIZE	256
 43  
 44  struct _libelf_globals {
 45  	int		libelf_arch;
 46  	unsigned int	libelf_byteorder;
 47  	int		libelf_class;
 48  	int		libelf_error;
 49  	int		libelf_fillchar;
 50  	unsigned int	libelf_version;
 51  	unsigned char	libelf_msg[LIBELF_MSG_SIZE];
 52  };
 53  
 54  extern struct _libelf_globals _libelf;
 55  
 56  #define	LIBELF_PRIVATE(N)	(_libelf.libelf_##N)
 57  
 58  #define	LIBELF_ELF_ERROR_MASK			0xFF
 59  #define	LIBELF_OS_ERROR_SHIFT			8
 60  
 61  #define	LIBELF_ERROR(E, O) (((E) & LIBELF_ELF_ERROR_MASK) |	\
 62  	((O) << LIBELF_OS_ERROR_SHIFT))
 63  
 64  #define	LIBELF_SET_ERROR(E, O) do {					\
 65  		LIBELF_PRIVATE(error) = LIBELF_ERROR(ELF_E_##E, (O));	\
 66  	} while (0)
 67  
 68  #define	LIBELF_ADJUST_AR_SIZE(S)	(((S) + 1U) & ~1U)
 69  
 70  /*
 71   * Flags for library internal use.  These use the upper 16 bits of the
 72   * `e_flags' field.
 73   */
 74  #define	LIBELF_F_API_MASK	0x00FFFFU  /* Flags defined by the API. */
 75  #define	LIBELF_F_AR_HEADER	0x010000U  /* translated header available */
 76  #define	LIBELF_F_AR_VARIANT_SVR4 0x020000U /* BSD style ar(1) archive */
 77  #define	LIBELF_F_DATA_MALLOCED	0x040000U /* whether data was malloc'ed */
 78  #define	LIBELF_F_RAWFILE_MALLOC	0x080000U /* whether e_rawfile was malloc'ed */
 79  #define	LIBELF_F_RAWFILE_MMAP	0x100000U /* whether e_rawfile was mmap'ed */
 80  #define	LIBELF_F_SHDRS_LOADED	0x200000U /* whether all shdrs were read in */
 81  #define	LIBELF_F_SPECIAL_FILE	0x400000U /* non-regular file */
 82  
 83  struct _Elf {
 84  	int		e_activations;	/* activation count */
 85  	unsigned int	e_byteorder;	/* ELFDATA* */
 86  	int		e_class;	/* ELFCLASS*  */
 87  	Elf_Cmd		e_cmd;		/* ELF_C_* used at creation time */
 88  	int		e_fd;		/* associated file descriptor */
 89  	unsigned int	e_flags;	/* ELF_F_* & LIBELF_F_* flags */
 90  	Elf_Kind	e_kind;		/* ELF_K_* */
 91  	Elf		*e_parent; 	/* non-NULL for archive members */
 92  	unsigned char	*e_rawfile;	/* uninterpreted bytes */
 93  	size_t		e_rawsize;	/* size of uninterpreted bytes */
 94  	unsigned int	e_version;	/* file version */
 95  
 96  	/*
 97  	 * Header information for archive members.  See the
 98  	 * LIBELF_F_AR_HEADER flag.
 99  	 */
100  	union {
101  		Elf_Arhdr	*e_arhdr;	/* translated header */
102  		unsigned char	*e_rawhdr;	/* untranslated header */
103  	} e_hdr;
104  
105  	union {
106  		struct {		/* ar(1) archives */
107  			off_t	e_next;	/* set by elf_rand()/elf_next() */
108  			int	e_nchildren;
109  			unsigned char *e_rawstrtab; /* file name strings */
110  			size_t	e_rawstrtabsz;
111  			unsigned char *e_rawsymtab;	/* symbol table */
112  			size_t	e_rawsymtabsz;
113  			Elf_Arsym *e_symtab;
114  			size_t	e_symtabsz;
115  		} e_ar;
116  		struct {		/* regular ELF files */
117  			union {
118  				Elf32_Ehdr *e_ehdr32;
119  				Elf64_Ehdr *e_ehdr64;
120  			} e_ehdr;
121  			union {
122  				Elf32_Phdr *e_phdr32;
123  				Elf64_Phdr *e_phdr64;
124  			} e_phdr;
125  			STAILQ_HEAD(, _Elf_Scn)	e_scn;	/* section list */
126  			size_t	e_nphdr;	/* number of Phdr entries */
127  			size_t	e_nscn;		/* number of sections */
128  			size_t	e_strndx;	/* string table section index */
129  		} e_elf;
130  	} e_u;
131  };
132  
133  /*
134   * The internal descriptor wrapping the "Elf_Data" type.
135   */
136  struct _Libelf_Data {
137  	Elf_Data	d_data;		/* The exported descriptor. */
138  	Elf_Scn		*d_scn;		/* The containing section */
139  	unsigned int	d_flags;
140  	STAILQ_ENTRY(_Libelf_Data) d_next;
141  };
142  
143  struct _Elf_Scn {
144  	union {
145  		Elf32_Shdr	s_shdr32;
146  		Elf64_Shdr	s_shdr64;
147  	} s_shdr;
148  	STAILQ_HEAD(, _Libelf_Data) s_data;	/* translated data */
149  	STAILQ_HEAD(, _Libelf_Data) s_rawdata;	/* raw data */
150  	STAILQ_ENTRY(_Elf_Scn) s_next;
151  	struct _Elf	*s_elf;		/* parent ELF descriptor */
152  	unsigned int	s_flags;	/* flags for the section as a whole */
153  	size_t		s_ndx;		/* index# for this section */
154  	uint64_t	s_offset;	/* managed by elf_update() */
155  	uint64_t	s_rawoff;	/* original offset in the file */
156  	uint64_t	s_size;		/* managed by elf_update() */
157  };
158  
159  
160  enum {
161  	ELF_TOFILE,
162  	ELF_TOMEMORY
163  };
164  
165  
166  /*
167   * The LIBELF_COPY macros are used to copy fields from a GElf_*
168   * structure to their 32-bit counterparts, while checking for out of
169   * range values.
170   *
171   * - LIBELF_COPY_U32 :: copy an unsigned 32 bit field.
172   * - LIBELF_COPY_S32 :: copy a signed 32 bit field.
173   */
174  
175  #define	LIBELF_COPY_U32(DST, SRC, NAME)	do {			\
176  		if ((SRC)->NAME > UINT32_MAX) {			\
177  			LIBELF_SET_ERROR(RANGE, 0);		\
178  			return (0);				\
179  		}						\
180  		(DST)->NAME = (SRC)->NAME & 0xFFFFFFFFU;	\
181  	} while (0)
182  
183  #define	LIBELF_COPY_S32(DST, SRC, NAME)	do {			\
184  		if ((SRC)->NAME > INT32_MAX ||			\
185  		    (SRC)->NAME < INT32_MIN) {			\
186  			LIBELF_SET_ERROR(RANGE, 0);		\
187  			return (0);				\
188  		}						\
189  		(DST)->NAME = (int32_t) (SRC)->NAME;		\
190  	} while (0)
191  
192  
193  /*
194   * Function Prototypes.
195   */
196  
197  __BEGIN_DECLS
198  struct _Libelf_Data *_libelf_allocate_data(Elf_Scn *_s);
199  Elf	*_libelf_allocate_elf(void);
200  Elf_Scn	*_libelf_allocate_scn(Elf *_e, size_t _ndx);
201  Elf_Arhdr *_libelf_ar_gethdr(Elf *_e);
202  Elf	*_libelf_ar_open(Elf *_e, int _reporterror);
203  Elf	*_libelf_ar_open_member(int _fd, Elf_Cmd _c, Elf *_ar);
204  Elf_Arsym *_libelf_ar_process_bsd_symtab(Elf *_ar, size_t *_dst);
205  Elf_Arsym *_libelf_ar_process_svr4_symtab(Elf *_ar, size_t *_dst);
206  long	 _libelf_checksum(Elf *_e, int _elfclass);
207  void	*_libelf_ehdr(Elf *_e, int _elfclass, int _allocate);
208  unsigned int _libelf_falign(Elf_Type _t, int _elfclass);
209  size_t	_libelf_fsize(Elf_Type _t, int _elfclass, unsigned int _version,
210      size_t count);
211  int	(*_libelf_get_translator(Elf_Type _t, int _direction, int _elfclass))
212  	    (unsigned char *_dst, size_t dsz, unsigned char *_src,
213  	     size_t _cnt, int _byteswap);
214  void	*_libelf_getphdr(Elf *_e, int _elfclass);
215  void	*_libelf_getshdr(Elf_Scn *_scn, int _elfclass);
216  void	_libelf_init_elf(Elf *_e, Elf_Kind _kind);
217  int	_libelf_load_section_headers(Elf *e, void *ehdr);
218  unsigned int _libelf_malign(Elf_Type _t, int _elfclass);
219  Elf	*_libelf_memory(unsigned char *_image, size_t _sz, int _reporterror);
220  size_t	_libelf_msize(Elf_Type _t, int _elfclass, unsigned int _version);
221  void	*_libelf_newphdr(Elf *_e, int _elfclass, size_t _count);
222  Elf	*_libelf_open_object(int _fd, Elf_Cmd _c, int _reporterror);
223  struct _Libelf_Data *_libelf_release_data(struct _Libelf_Data *_d);
224  Elf	*_libelf_release_elf(Elf *_e);
225  Elf_Scn	*_libelf_release_scn(Elf_Scn *_s);
226  int	_libelf_setphnum(Elf *_e, void *_eh, int _elfclass, size_t _phnum);
227  int	_libelf_setshnum(Elf *_e, void *_eh, int _elfclass, size_t _shnum);
228  int	_libelf_setshstrndx(Elf *_e, void *_eh, int _elfclass,
229      size_t _shstrndx);
230  Elf_Data *_libelf_xlate(Elf_Data *_d, const Elf_Data *_s,
231      unsigned int _encoding, int _elfclass, int _direction);
232  int	_libelf_xlate_shtype(uint32_t _sht);
233  __END_DECLS
234  
235  #endif	/* __LIBELF_H_ */