1/*- 2 * Copyright (c) 2006 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 <sys/cdefs.h> 28__FBSDID("$FreeBSD$"); 29 30#include <assert.h> 31#include <errno.h> 32#include <libelf.h> 33#include <stdlib.h> 34 35#include "_libelf.h" 36 37 38Elf_Data * 39elf_getdata(Elf_Scn *s, Elf_Data *d) 40{ 41 Elf *e; 42 size_t fsz, msz, count; 43 int elfclass, elftype; 44 unsigned int sh_type; 45 uint64_t sh_align, sh_offset, sh_size; 46 int (*xlate)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); 47 48 if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF || 49 (d != NULL && s != d->d_scn)) { 50 LIBELF_SET_ERROR(ARGUMENT, 0); 51 return (NULL); 52 } 53 54 if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL) 55 return (d); 56 57 if (d != NULL) 58 return (STAILQ_NEXT(d, d_next)); 59 60 if (e->e_rawfile == NULL) { 61 LIBELF_SET_ERROR(SEQUENCE, 0); 62 return (NULL); 63 } 64 65 elfclass = e->e_class; 66 67 assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); 68 69 if (elfclass == ELFCLASS32) { 70 sh_type = s->s_shdr.s_shdr32.sh_type; 71 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 72 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 73 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 74 } else { 75 sh_type = s->s_shdr.s_shdr64.sh_type; 76 sh_offset = s->s_shdr.s_shdr64.sh_offset; 77 sh_size = s->s_shdr.s_shdr64.sh_size; 78 sh_align = s->s_shdr.s_shdr64.sh_addralign; 79 } 80 81 if (sh_type == SHT_NULL) { 82 LIBELF_SET_ERROR(SECTION, 0); 83 return (NULL); 84 } 85 86 if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST || 87 elftype > ELF_T_LAST || (sh_type != SHT_NOBITS && 88 sh_offset + sh_size > (uint64_t) e->e_rawsize)) { 89 LIBELF_SET_ERROR(SECTION, 0); 90 return (NULL); 91 } 92 93 if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize) 94 (elftype, (size_t) 1, e->e_version)) == 0) { 95 LIBELF_SET_ERROR(UNIMPL, 0); 96 return (NULL); 97 } 98 99 if (sh_size % fsz) { 100 LIBELF_SET_ERROR(SECTION, 0); 101 return (NULL); 102 } 103 104 count = sh_size / fsz; 105 106 msz = _libelf_msize(elftype, elfclass, e->e_version); 107 108 assert(msz > 0); 109 110 if ((d = _libelf_allocate_data(s)) == NULL) 111 return (NULL); 112 113 d->d_buf = NULL; 114 d->d_off = 0; 115 d->d_align = sh_align; 116 d->d_size = msz * count; 117 d->d_type = elftype; 118 d->d_version = e->e_version; 119 120 if (sh_type == SHT_NOBITS || sh_size == 0) { 121 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 122 return (d); 123 } 124 125 if ((d->d_buf = malloc(msz*count)) == NULL) { 126 (void) _libelf_release_data(d); 127 LIBELF_SET_ERROR(RESOURCE, 0); 128 return (NULL); 129 } 130 131 d->d_flags |= LIBELF_F_MALLOCED; 132 133 xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass); 134 if (!(*xlate)(d->d_buf, d->d_size, e->e_rawfile + sh_offset, count, 135 e->e_byteorder != LIBELF_PRIVATE(byteorder))) { 136 _libelf_release_data(d); 137 LIBELF_SET_ERROR(DATA, 0); 138 return (NULL); 139 } 140 141 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 142 143 return (d); 144} 145 146Elf_Data * 147elf_newdata(Elf_Scn *s) 148{ 149 Elf *e; 150 Elf_Data *d; 151 152 if (s == NULL || (e = s->s_elf) == NULL || 153 e->e_kind != ELF_K_ELF) { 154 LIBELF_SET_ERROR(ARGUMENT, 0); 155 return (NULL); 156 } 157 158 /* 159 * elf_newdata() has to append a data descriptor, so 160 * bring in existing section data if not already present. 161 */ 162 if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data)) 163 if (elf_getdata(s, NULL) == NULL) 164 return (NULL); 165 166 if ((d = _libelf_allocate_data(s)) == NULL) 167 return (NULL); 168 169 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 170 171 d->d_align = 1; 172 d->d_buf = NULL; 173 d->d_off = (uint64_t) ~0; 174 d->d_size = 0; 175 d->d_type = ELF_T_BYTE; 176 d->d_version = LIBELF_PRIVATE(version); 177 178 (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY); 179 180 return (d); 181} 182 183/* 184 * Retrieve a data descriptor for raw (untranslated) data for section 185 * `s'. 186 */ 187 188Elf_Data * 189elf_rawdata(Elf_Scn *s, Elf_Data *d) 190{ 191 Elf *e; 192 int elf_class; 193 uint32_t sh_type; 194 uint64_t sh_align, sh_offset, sh_size; 195 196 if (s == NULL || (e = s->s_elf) == NULL || 197 e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) { 198 LIBELF_SET_ERROR(ARGUMENT, 0); 199 return (NULL); 200 } 201 202 if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL) 203 return (d); 204 205 if (d != NULL) 206 return (STAILQ_NEXT(d, d_next)); 207 208 elf_class = e->e_class; 209 210 assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64); 211 212 if (elf_class == ELFCLASS32) { 213 sh_type = s->s_shdr.s_shdr32.sh_type; 214 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 215 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 216 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 217 } else { 218 sh_type = s->s_shdr.s_shdr64.sh_type; 219 sh_offset = s->s_shdr.s_shdr64.sh_offset; 220 sh_size = s->s_shdr.s_shdr64.sh_size; 221 sh_align = s->s_shdr.s_shdr64.sh_addralign; 222 } 223 224 if (sh_type == SHT_NULL) { 225 LIBELF_SET_ERROR(SECTION, 0); 226 return (NULL); 227 } 228 229 if ((d = _libelf_allocate_data(s)) == NULL) 230 return (NULL); 231 232 d->d_buf = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL : 233 e->e_rawfile + sh_offset; 234 d->d_off = 0; 235 d->d_align = sh_align; 236 d->d_size = sh_size; 237 d->d_type = ELF_T_BYTE; 238 d->d_version = e->e_version; 239 240 STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next); 241 242 return (d); 243} 244