xref: /openbsd/lib/libelf/_libelf.h (revision 63b93652)
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: _libelf.h,v 1.3 2020/05/18 06:46:23 jsg Exp $
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 	off_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 typedef int _libelf_translator_function(unsigned char *_dst, size_t dsz,
198     unsigned char *_src, size_t _cnt, int _byteswap);
199 
200 #ifdef __cplusplus
201 extern "C" {
202 #endif
203 struct _Libelf_Data *_libelf_allocate_data(Elf_Scn *_s);
204 Elf	*_libelf_allocate_elf(void);
205 Elf_Scn	*_libelf_allocate_scn(Elf *_e, size_t _ndx);
206 Elf_Arhdr *_libelf_ar_gethdr(Elf *_e);
207 Elf	*_libelf_ar_open(Elf *_e, int _reporterror);
208 Elf	*_libelf_ar_open_member(int _fd, Elf_Cmd _c, Elf *_ar);
209 Elf_Arsym *_libelf_ar_process_bsd_symtab(Elf *_ar, size_t *_dst);
210 Elf_Arsym *_libelf_ar_process_svr4_symtab(Elf *_ar, size_t *_dst);
211 long	 _libelf_checksum(Elf *_e, int _elfclass);
212 void	*_libelf_ehdr(Elf *_e, int _elfclass, int _allocate);
213 int	_libelf_elfmachine(Elf *_e);
214 unsigned int _libelf_falign(Elf_Type _t, int _elfclass);
215 size_t	_libelf_fsize(Elf_Type _t, int _elfclass, unsigned int _version,
216     size_t count);
217 _libelf_translator_function *_libelf_get_translator(Elf_Type _t,
218     int _direction, int _elfclass, int _elfmachine);
219 void	*_libelf_getphdr(Elf *_e, int _elfclass);
220 void	*_libelf_getshdr(Elf_Scn *_scn, int _elfclass);
221 void	_libelf_init_elf(Elf *_e, Elf_Kind _kind);
222 int	_libelf_load_section_headers(Elf *e, void *ehdr);
223 unsigned int _libelf_malign(Elf_Type _t, int _elfclass);
224 Elf	*_libelf_memory(unsigned char *_image, size_t _sz, int _reporterror);
225 size_t	_libelf_msize(Elf_Type _t, int _elfclass, unsigned int _version);
226 void	*_libelf_newphdr(Elf *_e, int _elfclass, size_t _count);
227 Elf	*_libelf_open_object(int _fd, Elf_Cmd _c, int _reporterror);
228 struct _Libelf_Data *_libelf_release_data(struct _Libelf_Data *_d);
229 void	_libelf_release_elf(Elf *_e);
230 Elf_Scn	*_libelf_release_scn(Elf_Scn *_s);
231 int	_libelf_setphnum(Elf *_e, void *_eh, int _elfclass, size_t _phnum);
232 int	_libelf_setshnum(Elf *_e, void *_eh, int _elfclass, size_t _shnum);
233 int	_libelf_setshstrndx(Elf *_e, void *_eh, int _elfclass,
234     size_t _shstrndx);
235 Elf_Data *_libelf_xlate(Elf_Data *_d, const Elf_Data *_s,
236     unsigned int _encoding, int _elfclass, int _elfmachine, int _direction);
237 int	_libelf_xlate_shtype(uint32_t _sht);
238 #ifdef __cplusplus
239 }
240 #endif
241 
242 #endif	/* __LIBELF_H_ */
243