| /* Return size of GNU compressed section. |
| Copyright (C) 2015 Red Hat, Inc. |
| This file is part of elfutils. |
| |
| This file is free software; you can redistribute it and/or modify |
| it under the terms of either |
| |
| * the GNU Lesser General Public License as published by the Free |
| Software Foundation; either version 3 of the License, or (at |
| your option) any later version |
| |
| or |
| |
| * the GNU General Public License as published by the Free |
| Software Foundation; either version 2 of the License, or (at |
| your option) any later version |
| |
| or both in parallel, as here. |
| |
| elfutils is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received copies of the GNU General Public License and |
| the GNU Lesser General Public License along with this program. If |
| not, see <http://www.gnu.org/licenses/>. */ |
| |
| #ifdef HAVE_CONFIG_H |
| # include <config.h> |
| #endif |
| |
| #include "libdwelfP.h" |
| #include "libelfP.h" |
| |
| ssize_t |
| dwelf_scn_gnu_compressed_size (Elf_Scn *scn) |
| { |
| if (scn == NULL) |
| return -1; |
| |
| GElf_Shdr shdr; |
| if (gelf_getshdr (scn, &shdr) == NULL) |
| return -1; |
| |
| /* Allocated or no bits sections can never be compressed. */ |
| if ((shdr.sh_flags & SHF_ALLOC) != 0 |
| || shdr.sh_type == SHT_NULL |
| || shdr.sh_type == SHT_NOBITS) |
| return -1; |
| |
| Elf_Data *d = elf_rawdata (scn, NULL); |
| if (d == NULL) |
| return -1; |
| |
| if (d->d_size >= 4 + 8 |
| && memcmp (d->d_buf, "ZLIB", 4) == 0) |
| { |
| /* There is a 12-byte header of "ZLIB" followed by |
| an 8-byte big-endian size. There is only one type and |
| alignment isn't preserved separately. */ |
| uint64_t size; |
| memcpy (&size, d->d_buf + 4, sizeof size); |
| size = be64toh (size); |
| |
| /* One more sanity check, size should be bigger than original |
| data size plus some overhead (4 chars ZLIB + 8 bytes size + 6 |
| bytes zlib stream overhead + 5 bytes overhead max for one 16K |
| block) and should fit into a size_t. */ |
| if (size + 4 + 8 + 6 + 5 < d->d_size || size > SIZE_MAX) |
| return -1; |
| |
| return size; |
| } |
| |
| return -1; |
| } |