xref: /openbsd/lib/libelf/gelf_phdr.c (revision a1b5ec25)
1 /*-
2  * Copyright (c) 2006,2008 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 
27 #include <gelf.h>
28 #include <libelf.h>
29 #include <limits.h>
30 #include <stdint.h>
31 
32 #include "_libelf.h"
33 
34 ELFTC_VCSID("$Id: gelf_phdr.c,v 1.1 2019/02/01 05:27:38 jsg Exp $");
35 
36 Elf32_Phdr *
elf32_getphdr(Elf * e)37 elf32_getphdr(Elf *e)
38 {
39 	return (_libelf_getphdr(e, ELFCLASS32));
40 }
41 
42 Elf64_Phdr *
elf64_getphdr(Elf * e)43 elf64_getphdr(Elf *e)
44 {
45 	return (_libelf_getphdr(e, ELFCLASS64));
46 }
47 
48 GElf_Phdr *
gelf_getphdr(Elf * e,int index,GElf_Phdr * d)49 gelf_getphdr(Elf *e, int index, GElf_Phdr *d)
50 {
51 	int ec;
52 	Elf32_Ehdr *eh32;
53 	Elf64_Ehdr *eh64;
54 	Elf32_Phdr *ep32;
55 	Elf64_Phdr *ep64;
56 	size_t phnum;
57 
58 	if (d == NULL || e == NULL ||
59 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) ||
60 	    (e->e_kind != ELF_K_ELF) || index < 0 ||
61 	    elf_getphdrnum(e, &phnum) < 0) {
62 		LIBELF_SET_ERROR(ARGUMENT, 0);
63 		return (NULL);
64 	}
65 
66 	if ((size_t)index >= phnum) {
67 		LIBELF_SET_ERROR(ARGUMENT, 0);
68 		return (NULL);
69 	}
70 
71 	if (ec == ELFCLASS32) {
72 		if ((eh32 = _libelf_ehdr(e, ELFCLASS32, 0)) == NULL ||
73 		    ((ep32 = _libelf_getphdr(e, ELFCLASS32)) == NULL))
74 			return (NULL);
75 
76 		ep32 += index;
77 
78 		d->p_type   = ep32->p_type;
79 		d->p_offset = ep32->p_offset;
80 		d->p_vaddr  = (Elf64_Addr) ep32->p_vaddr;
81 		d->p_paddr  = (Elf64_Addr) ep32->p_paddr;
82 		d->p_filesz = (Elf64_Xword) ep32->p_filesz;
83 		d->p_memsz  = (Elf64_Xword) ep32->p_memsz;
84 		d->p_flags  = ep32->p_flags;
85 		d->p_align  = (Elf64_Xword) ep32->p_align;
86 
87 	} else {
88 		if ((eh64 = _libelf_ehdr(e, ELFCLASS64, 0)) == NULL ||
89 		    (ep64 = _libelf_getphdr(e, ELFCLASS64)) == NULL)
90 			return (NULL);
91 
92 		ep64 += index;
93 
94 		*d = *ep64;
95 	}
96 
97 	return (d);
98 }
99 
100 Elf32_Phdr *
elf32_newphdr(Elf * e,size_t count)101 elf32_newphdr(Elf *e, size_t count)
102 {
103 	return (_libelf_newphdr(e, ELFCLASS32, count));
104 }
105 
106 Elf64_Phdr *
elf64_newphdr(Elf * e,size_t count)107 elf64_newphdr(Elf *e, size_t count)
108 {
109 	return (_libelf_newphdr(e, ELFCLASS64, count));
110 }
111 
112 void *
gelf_newphdr(Elf * e,size_t count)113 gelf_newphdr(Elf *e, size_t count)
114 {
115 	if (e == NULL) {
116 		LIBELF_SET_ERROR(ARGUMENT, 0);
117 		return (NULL);
118 	}
119 	return (_libelf_newphdr(e, e->e_class, count));
120 }
121 
122 int
gelf_update_phdr(Elf * e,int ndx,GElf_Phdr * s)123 gelf_update_phdr(Elf *e, int ndx, GElf_Phdr *s)
124 {
125 	int ec;
126 	size_t phnum;
127 	void *ehdr;
128 	Elf32_Phdr *ph32;
129 	Elf64_Phdr *ph64;
130 
131 	if (s == NULL || e == NULL || e->e_kind != ELF_K_ELF ||
132 	    ((ec = e->e_class) != ELFCLASS32 && ec != ELFCLASS64) ||
133 	    elf_getphdrnum(e, &phnum) < 0) {
134 		LIBELF_SET_ERROR(ARGUMENT, 0);
135 		return (0);
136 	}
137 
138 	if (e->e_cmd == ELF_C_READ) {
139 		LIBELF_SET_ERROR(MODE, 0);
140 		return (0);
141 	}
142 
143 	if ((ehdr = _libelf_ehdr(e, ec, 0)) == NULL)
144 		return (0);
145 
146 	if (ndx < 0 || (size_t)ndx > phnum) {
147 		LIBELF_SET_ERROR(ARGUMENT, 0);
148 		return (0);
149 	}
150 
151 	(void) elf_flagphdr(e, ELF_C_SET, ELF_F_DIRTY);
152 
153 	if (ec == ELFCLASS64) {
154 		ph64 = e->e_u.e_elf.e_phdr.e_phdr64 + ndx;
155 		*ph64 = *s;
156 		return (1);
157 	}
158 
159 	ph32 = e->e_u.e_elf.e_phdr.e_phdr32 + ndx;
160 
161 	ph32->p_type     =  s->p_type;
162 	ph32->p_flags    =  s->p_flags;
163 	LIBELF_COPY_U32(ph32, s, p_offset);
164 	LIBELF_COPY_U32(ph32, s, p_vaddr);
165 	LIBELF_COPY_U32(ph32, s, p_paddr);
166 	LIBELF_COPY_U32(ph32, s, p_filesz);
167 	LIBELF_COPY_U32(ph32, s, p_memsz);
168 	LIBELF_COPY_U32(ph32, s, p_align);
169 
170 	return (1);
171 }
172