diff options
Diffstat (limited to 'ext/libelf/libelf_xlate.c')
| -rw-r--r-- | ext/libelf/libelf_xlate.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/ext/libelf/libelf_xlate.c b/ext/libelf/libelf_xlate.c new file mode 100644 index 000000000..c5fea208d --- /dev/null +++ b/ext/libelf/libelf_xlate.c @@ -0,0 +1,141 @@ +/*- + * Copyright (c) 2006 Joseph Koshy + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <assert.h> + +#include "libelf.h" +#include "_libelf.h" + +/* + * Translate to/from the file representation of ELF objects. + * + * Translation could potentially involve the following + * transformations: + * + * - an endianness conversion, + * - a change of layout, as the file representation of ELF objects + * can differ from their in-memory representation. + * - a change in representation due to a layout version change. + */ + +Elf_Data * +_libelf_xlate(Elf_Data *dst, const Elf_Data *src, unsigned int encoding, + int elfclass, int direction) +{ + size_t cnt, dsz, fsz, msz; + uintptr_t sb, se, db, de; + + if (encoding == ELFDATANONE) + encoding = LIBELF_PRIVATE(byteorder); + + if ((encoding != ELFDATA2LSB && encoding != ELFDATA2MSB) || + dst == NULL || src == NULL || dst == src) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); + assert(direction == ELF_TOFILE || direction == ELF_TOMEMORY); + + if (dst->d_version != src->d_version) { + LIBELF_SET_ERROR(UNIMPL, 0); + return (NULL); + } + + if (src->d_buf == NULL || dst->d_buf == NULL || + src->d_size == 0) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + if ((int) src->d_type < 0 || src->d_type >= ELF_T_NUM) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)(src->d_type, + (size_t) 1, src->d_version)) == 0) + return (NULL); + + msz = _libelf_msize(src->d_type, elfclass, src->d_version); + + assert(msz > 0); + + if (src->d_size % (direction == ELF_TOMEMORY ? fsz : msz)) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + /* + * Determine the number of objects that need to be converted, and + * the space required for the converted objects in the destination + * buffer. + */ + if (direction == ELF_TOMEMORY) { + cnt = src->d_size / fsz; + dsz = cnt * msz; + } else { + cnt = src->d_size / msz; + dsz = cnt * fsz; + } + + if (dst->d_size < dsz) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + sb = (uintptr_t) src->d_buf; + se = sb + src->d_size; + db = (uintptr_t) dst->d_buf; + de = db + dst->d_size; + + /* + * Check for overlapping buffers. Note that db == sb is + * allowed. + */ + if (db != sb && de > sb && se > db) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + if ((direction == ELF_TOMEMORY ? db : sb) % + _libelf_malign(src->d_type, elfclass)) { + LIBELF_SET_ERROR(DATA, 0); + return (NULL); + } + + dst->d_type = src->d_type; + dst->d_size = dsz; + + if (db == sb && encoding == LIBELF_PRIVATE(byteorder) && + fsz == msz) + return (dst); /* nothing more to do */ + + (_libelf_get_translator(src->d_type, direction, elfclass))(dst->d_buf, + src->d_buf, cnt, encoding != LIBELF_PRIVATE(byteorder)); + + return (dst); +} |