1 /* Decompression support for libdwfl: zlib (gzip) and/or bzlib (bzip2). 2 Copyright (C) 2009 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 5 Red Hat elfutils is free software; you can redistribute it and/or modify 6 it under the terms of the GNU General Public License as published by the 7 Free Software Foundation; version 2 of the License. 8 9 Red Hat elfutils is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License along 15 with Red Hat elfutils; if not, write to the Free Software Foundation, 16 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 17 18 In addition, as a special exception, Red Hat, Inc. gives You the 19 additional right to link the code of Red Hat elfutils with code licensed 20 under any Open Source Initiative certified open source license 21 (http://www.opensource.org/licenses/index.php) which requires the 22 distribution of source code with any binary distribution and to 23 distribute linked combinations of the two. Non-GPL Code permitted under 24 this exception must only link to the code of Red Hat elfutils through 25 those well defined interfaces identified in the file named EXCEPTION 26 found in the source code files (the "Approved Interfaces"). The files 27 of Non-GPL Code may instantiate templates or use macros or inline 28 functions from the Approved Interfaces without causing the resulting 29 work to be covered by the GNU General Public License. Only Red Hat, 30 Inc. may make changes or additions to the list of Approved Interfaces. 31 Red Hat's grant of this exception is conditioned upon your not adding 32 any new exceptions. If you wish to add a new Approved Interface or 33 exception, please contact Red Hat. You must obey the GNU General Public 34 License in all respects for all of the Red Hat elfutils code and other 35 code used in conjunction with Red Hat elfutils except the Non-GPL Code 36 covered by this exception. If you modify this file, you may extend this 37 exception to your version of the file, but you are not obligated to do 38 so. If you do not wish to provide this exception without modification, 39 you must delete this exception statement from your version and license 40 this file solely under the GPL without exception. 41 42 Red Hat elfutils is an included package of the Open Invention Network. 43 An included package of the Open Invention Network is a package for which 44 Open Invention Network licensees cross-license their patents. No patent 45 license is granted, either expressly or impliedly, by designation as an 46 included package. Should you wish to participate in the Open Invention 47 Network licensing program, please visit www.openinventionnetwork.com 48 <http://www.openinventionnetwork.com>. */ 49 50 #include "../libelf/libelfP.h" 51 #undef _ 52 #include "libdwflP.h" 53 54 #include <unistd.h> 55 56 #if !USE_ZLIB 57 # define __libdw_gunzip(...) false 58 #endif 59 60 #if !USE_BZLIB 61 # define __libdw_bunzip2(...) false 62 #endif 63 64 #if !USE_LZMA 65 # define __libdw_unlzma(...) false 66 #endif 67 68 /* Consumes and replaces *ELF only on success. */ 69 static Dwfl_Error 70 decompress (int fd __attribute__ ((unused)), Elf **elf) 71 { 72 Dwfl_Error error = DWFL_E_BADELF; 73 void *buffer = NULL; 74 size_t size = 0; 75 76 #if USE_ZLIB || USE_BZLIB || USE_LZMA 77 const off64_t offset = (*elf)->start_offset; 78 void *const mapped = ((*elf)->map_address == NULL ? NULL 79 : (*elf)->map_address + offset); 80 const size_t mapped_size = (*elf)->maximum_size; 81 if (mapped_size == 0) 82 return error; 83 84 error = __libdw_gunzip (fd, offset, mapped, mapped_size, &buffer, &size); 85 if (error == DWFL_E_BADELF) 86 error = __libdw_bunzip2 (fd, offset, mapped, mapped_size, &buffer, &size); 87 if (error == DWFL_E_BADELF) 88 error = __libdw_unlzma (fd, offset, mapped, mapped_size, &buffer, &size); 89 #endif 90 91 if (error == DWFL_E_NOERROR) 92 { 93 if (unlikely (size == 0)) 94 { 95 error = DWFL_E_BADELF; 96 free (buffer); 97 } 98 else 99 { 100 Elf *memelf = elf_memory (buffer, size); 101 if (memelf == NULL) 102 { 103 error = DWFL_E_LIBELF; 104 free (buffer); 105 } 106 else 107 { 108 memelf->flags |= ELF_F_MALLOCED; 109 elf_end (*elf); 110 *elf = memelf; 111 } 112 } 113 } 114 else 115 free (buffer); 116 117 return error; 118 } 119 120 static Dwfl_Error 121 what_kind (int fd, Elf **elfp, Elf_Kind *kind, bool *close_fd) 122 { 123 Dwfl_Error error = DWFL_E_NOERROR; 124 *kind = elf_kind (*elfp); 125 if (unlikely (*kind == ELF_K_NONE)) 126 { 127 if (unlikely (*elfp == NULL)) 128 error = DWFL_E_LIBELF; 129 else 130 { 131 error = decompress (fd, elfp); 132 if (error == DWFL_E_NOERROR) 133 { 134 *close_fd = true; 135 *kind = elf_kind (*elfp); 136 } 137 } 138 } 139 return error; 140 } 141 142 Dwfl_Error internal_function 143 __libdw_open_file (int *fdp, Elf **elfp, bool close_on_fail, bool archive_ok) 144 { 145 bool close_fd = false; 146 147 Elf *elf = elf_begin (*fdp, ELF_C_READ_MMAP_PRIVATE, NULL); 148 149 Elf_Kind kind; 150 Dwfl_Error error = what_kind (*fdp, &elf, &kind, &close_fd); 151 if (error == DWFL_E_BADELF) 152 { 153 /* It's not an ELF file or a compressed file. 154 See if it's an image with a header preceding the real file. */ 155 156 off64_t offset = elf->start_offset; 157 error = __libdw_image_header (*fdp, &offset, 158 (elf->map_address == NULL ? NULL 159 : elf->map_address + offset), 160 elf->maximum_size); 161 if (error == DWFL_E_NOERROR) 162 { 163 /* Pure evil. libelf needs some better interfaces. */ 164 elf->kind = ELF_K_AR; 165 elf->state.ar.elf_ar_hdr.ar_name = "libdwfl is faking you out"; 166 elf->state.ar.elf_ar_hdr.ar_size = elf->maximum_size - offset; 167 elf->state.ar.offset = offset - sizeof (struct ar_hdr); 168 Elf *subelf = elf_begin (-1, ELF_C_READ_MMAP_PRIVATE, elf); 169 elf->kind = ELF_K_NONE; 170 if (unlikely (subelf == NULL)) 171 error = DWFL_E_LIBELF; 172 else 173 { 174 subelf->parent = NULL; 175 subelf->flags |= elf->flags & (ELF_F_MMAPPED | ELF_F_MALLOCED); 176 elf->flags &= ~(ELF_F_MMAPPED | ELF_F_MALLOCED); 177 elf_end (elf); 178 elf = subelf; 179 error = what_kind (*fdp, &elf, &kind, &close_fd); 180 } 181 } 182 } 183 184 if (error == DWFL_E_NOERROR 185 && kind != ELF_K_ELF 186 && !(archive_ok && kind == ELF_K_AR)) 187 error = DWFL_E_BADELF; 188 189 if (error != DWFL_E_NOERROR) 190 { 191 elf_end (elf); 192 elf = NULL; 193 } 194 195 if (error == DWFL_E_NOERROR ? close_fd : close_on_fail) 196 { 197 close (*fdp); 198 *fdp = -1; 199 } 200 201 *elfp = elf; 202 return error; 203 } 204
