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 27 #include <assert.h> 28 #include <errno.h> 29 #include <libelf.h> 30 #include <stdlib.h> 31 32 #include "_libelf.h" 33 34 ELFTC_VCSID("$Id: elf_data.c 2921 2013-03-04 16:19:22Z jkoshy $"); 35 36 Elf_Data * 37 elf_getdata(Elf_Scn *s, Elf_Data *ed) 38 { 39 Elf *e; 40 unsigned int sh_type; 41 int elfclass, elftype; 42 size_t fsz, msz, count; 43 struct _Libelf_Data *d; 44 uint64_t sh_align, sh_offset, sh_size; 45 int (*xlate)(char *_d, size_t _dsz, char *_s, size_t _c, int _swap); 46 47 d = (struct _Libelf_Data *) ed; 48 49 if (s == NULL || (e = s->s_elf) == NULL || 50 (d != NULL && s != d->d_scn)) { 51 LIBELF_SET_ERROR(ARGUMENT, 0); 52 return (NULL); 53 } 54 55 assert(e->e_kind == ELF_K_ELF); 56 57 if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL) 58 return (&d->d_data); 59 60 if (d != NULL) 61 return (&STAILQ_NEXT(d, d_next)->d_data); 62 63 if (e->e_rawfile == NULL) { 64 /* 65 * In the ELF_C_WRITE case, there is no source that 66 * can provide data for the section. 67 */ 68 LIBELF_SET_ERROR(ARGUMENT, 0); 69 return (NULL); 70 } 71 72 elfclass = e->e_class; 73 74 assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); 75 76 if (elfclass == ELFCLASS32) { 77 sh_type = s->s_shdr.s_shdr32.sh_type; 78 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 79 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 80 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 81 } else { 82 sh_type = s->s_shdr.s_shdr64.sh_type; 83 sh_offset = s->s_shdr.s_shdr64.sh_offset; 84 sh_size = s->s_shdr.s_shdr64.sh_size; 85 sh_align = s->s_shdr.s_shdr64.sh_addralign; 86 } 87 88 if (sh_type == SHT_NULL) { 89 LIBELF_SET_ERROR(SECTION, 0); 90 return (NULL); 91 } 92 93 if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST || 94 elftype > ELF_T_LAST || (sh_type != SHT_NOBITS && 95 sh_offset + sh_size > (uint64_t) e->e_rawsize)) { 96 LIBELF_SET_ERROR(SECTION, 0); 97 return (NULL); 98 } 99 100 if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize) 101 (elftype, (size_t) 1, e->e_version)) == 0) { 102 LIBELF_SET_ERROR(UNIMPL, 0); 103 return (NULL); 104 } 105 106 if (sh_size % fsz) { 107 LIBELF_SET_ERROR(SECTION, 0); 108 return (NULL); 109 } 110 111 count = sh_size / fsz; 112 113 msz = _libelf_msize(elftype, elfclass, e->e_version); 114 115 assert(msz > 0); 116 117 if ((d = _libelf_allocate_data(s)) == NULL) 118 return (NULL); 119 120 d->d_data.d_buf = NULL; 121 d->d_data.d_off = 0; 122 d->d_data.d_align = sh_align; 123 d->d_data.d_size = msz * count; 124 d->d_data.d_type = elftype; 125 d->d_data.d_version = e->e_version; 126 127 if (sh_type == SHT_NOBITS || sh_size == 0) { 128 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 129 return (&d->d_data); 130 } 131 132 if ((d->d_data.d_buf = malloc(msz*count)) == NULL) { 133 (void) _libelf_release_data(d); 134 LIBELF_SET_ERROR(RESOURCE, 0); 135 return (NULL); 136 } 137 138 d->d_flags |= LIBELF_F_DATA_MALLOCED; 139 140 xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass); 141 if (!(*xlate)(d->d_data.d_buf, d->d_data.d_size, 142 e->e_rawfile + sh_offset, count, 143 e->e_byteorder != LIBELF_PRIVATE(byteorder))) { 144 _libelf_release_data(d); 145 LIBELF_SET_ERROR(DATA, 0); 146 return (NULL); 147 } 148 149 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 150 151 return (&d->d_data); 152 } 153 154 Elf_Data * 155 elf_newdata(Elf_Scn *s) 156 { 157 Elf *e; 158 struct _Libelf_Data *d; 159 160 if (s == NULL || (e = s->s_elf) == NULL) { 161 LIBELF_SET_ERROR(ARGUMENT, 0); 162 return (NULL); 163 } 164 165 assert(e->e_kind == ELF_K_ELF); 166 167 /* 168 * elf_newdata() has to append a data descriptor, so 169 * bring in existing section data if not already present. 170 */ 171 if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data)) 172 if (elf_getdata(s, NULL) == NULL) 173 return (NULL); 174 175 if ((d = _libelf_allocate_data(s)) == NULL) 176 return (NULL); 177 178 STAILQ_INSERT_TAIL(&s->s_data, d, d_next); 179 180 d->d_data.d_align = 1; 181 d->d_data.d_buf = NULL; 182 d->d_data.d_off = (uint64_t) ~0; 183 d->d_data.d_size = 0; 184 d->d_data.d_type = ELF_T_BYTE; 185 d->d_data.d_version = LIBELF_PRIVATE(version); 186 187 (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY); 188 189 return (&d->d_data); 190 } 191 192 /* 193 * Retrieve a data descriptor for raw (untranslated) data for section 194 * `s'. 195 */ 196 197 Elf_Data * 198 elf_rawdata(Elf_Scn *s, Elf_Data *ed) 199 { 200 Elf *e; 201 int elf_class; 202 uint32_t sh_type; 203 struct _Libelf_Data *d; 204 uint64_t sh_align, sh_offset, sh_size; 205 206 if (s == NULL || (e = s->s_elf) == NULL || e->e_rawfile == NULL) { 207 LIBELF_SET_ERROR(ARGUMENT, 0); 208 return (NULL); 209 } 210 211 assert(e->e_kind == ELF_K_ELF); 212 213 d = (struct _Libelf_Data *) ed; 214 215 if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL) 216 return (&d->d_data); 217 218 if (d != NULL) 219 return (&STAILQ_NEXT(d, d_next)->d_data); 220 221 elf_class = e->e_class; 222 223 assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64); 224 225 if (elf_class == ELFCLASS32) { 226 sh_type = s->s_shdr.s_shdr32.sh_type; 227 sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; 228 sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; 229 sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; 230 } else { 231 sh_type = s->s_shdr.s_shdr64.sh_type; 232 sh_offset = s->s_shdr.s_shdr64.sh_offset; 233 sh_size = s->s_shdr.s_shdr64.sh_size; 234 sh_align = s->s_shdr.s_shdr64.sh_addralign; 235 } 236 237 if (sh_type == SHT_NULL) { 238 LIBELF_SET_ERROR(SECTION, 0); 239 return (NULL); 240 } 241 242 if ((d = _libelf_allocate_data(s)) == NULL) 243 return (NULL); 244 245 d->d_data.d_buf = (sh_type == SHT_NOBITS || sh_size == 0) ? NULL : 246 e->e_rawfile + sh_offset; 247 d->d_data.d_off = 0; 248 d->d_data.d_align = sh_align; 249 d->d_data.d_size = sh_size; 250 d->d_data.d_type = ELF_T_BYTE; 251 d->d_data.d_version = e->e_version; 252 253 STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next); 254 255 return (&d->d_data); 256 } 257