diff options
Diffstat (limited to 'ext/libelf/elf_data.c')
| -rw-r--r-- | ext/libelf/elf_data.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/ext/libelf/elf_data.c b/ext/libelf/elf_data.c new file mode 100644 index 000000000..71e957502 --- /dev/null +++ b/ext/libelf/elf_data.c @@ -0,0 +1,222 @@ +/*- + * 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 <errno.h> +#include "libelf.h" +#include <stdlib.h> + +#include "_libelf.h" + + +Elf_Data * +elf_getdata(Elf_Scn *s, Elf_Data *d) +{ + Elf *e; + char *dst; + size_t fsz, msz, count; + int elfclass, elftype; + unsigned int sh_type; + uint64_t sh_align, sh_offset, sh_size; + void (*xlate)(char *_d, char *_s, size_t _c, int _swap); + + if (s == NULL || (e = s->s_elf) == NULL || e->e_kind != ELF_K_ELF || + (d != NULL && s != d->d_scn)) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + if (d == NULL && (d = STAILQ_FIRST(&s->s_data)) != NULL) + return (d); + + if (d != NULL) + return (STAILQ_NEXT(d, d_next)); + + if (e->e_rawfile == NULL) { + LIBELF_SET_ERROR(SEQUENCE, 0); + return (NULL); + } + + elfclass = e->e_class; + + assert(elfclass == ELFCLASS32 || elfclass == ELFCLASS64); + + if (elfclass == ELFCLASS32) { + sh_type = s->s_shdr.s_shdr32.sh_type; + sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; + sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; + sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; + } else { + sh_type = s->s_shdr.s_shdr64.sh_type; + sh_offset = s->s_shdr.s_shdr64.sh_offset; + sh_size = s->s_shdr.s_shdr64.sh_size; + sh_align = s->s_shdr.s_shdr64.sh_addralign; + } + + if ((elftype = _libelf_xlate_shtype(sh_type)) < ELF_T_FIRST || + elftype > ELF_T_LAST || + sh_offset + sh_size > (uint64_t) e->e_rawsize) { + LIBELF_SET_ERROR(SECTION, 0); + return (NULL); + } + + if ((fsz = (elfclass == ELFCLASS32 ? elf32_fsize : elf64_fsize)(elftype, + (size_t) 1, e->e_version)) == 0) { + LIBELF_SET_ERROR(UNIMPL, 0); + return (NULL); + } + + + if (sh_size % fsz) { + LIBELF_SET_ERROR(SECTION, 0); + return (NULL); + } + + count = sh_size / fsz; + + msz = _libelf_msize(elftype, elfclass, e->e_version); + + assert(msz > 0); + + if ((dst = malloc(msz*count)) == NULL) { + LIBELF_SET_ERROR(RESOURCE, 0); + return (NULL); + } + + if ((d = _libelf_allocate_data(s)) == NULL) + return (NULL); + + d->d_buf = dst; + d->d_off = 0; + d->d_align = sh_align; + d->d_size = msz * count; + d->d_type = elftype; + d->d_version = e->e_version; + + d->d_flags |= LIBELF_F_MALLOCED; + STAILQ_INSERT_TAIL(&s->s_data, d, d_next); + + xlate = _libelf_get_translator(elftype, ELF_TOMEMORY, elfclass); + (*xlate)(d->d_buf, e->e_rawfile + sh_offset, count, e->e_byteorder != + LIBELF_PRIVATE(byteorder)); + + return (d); +} + +Elf_Data * +elf_newdata(Elf_Scn *s) +{ + Elf *e; + Elf_Data *d; + + if (s == NULL || (e = s->s_elf) == NULL || + e->e_kind != ELF_K_ELF) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + /* + * elf_newdata() has to append a data descriptor, so + * bring in existing section data if not already present. + */ + if (e->e_rawfile && s->s_size > 0 && STAILQ_EMPTY(&s->s_data)) + if (elf_getdata(s, NULL) == NULL) + return (NULL); + + if ((d = malloc(sizeof(Elf_Data))) == NULL) { + LIBELF_SET_ERROR(RESOURCE, errno); + return (NULL); + } + + STAILQ_INSERT_TAIL(&s->s_data, d, d_next); + d->d_flags = 0; + d->d_scn = s; + + d->d_align = 1; + d->d_buf = NULL; + d->d_off = (uint64_t) ~0; + d->d_size = 0; + d->d_type = ELF_T_BYTE; + d->d_version = LIBELF_PRIVATE(version); + + (void) elf_flagscn(s, ELF_C_SET, ELF_F_DIRTY); + + return (d); +} + +/* + * Retrieve a data descriptor for raw (untranslated) data for section + * `s'. + */ + +Elf_Data * +elf_rawdata(Elf_Scn *s, Elf_Data *d) +{ + Elf *e; + int elf_class; + uint64_t sh_align, sh_offset, sh_size; + + if (s == NULL || (e = s->s_elf) == NULL || + e->e_kind != ELF_K_ELF || e->e_rawfile == NULL) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + if (d == NULL && (d = STAILQ_FIRST(&s->s_rawdata)) != NULL) + return (d); + + if (d != NULL) + return (STAILQ_NEXT(d, d_next)); + + elf_class = e->e_class; + + assert(elf_class == ELFCLASS32 || elf_class == ELFCLASS64); + + if (elf_class == ELFCLASS32) { + sh_offset = (uint64_t) s->s_shdr.s_shdr32.sh_offset; + sh_size = (uint64_t) s->s_shdr.s_shdr32.sh_size; + sh_align = (uint64_t) s->s_shdr.s_shdr32.sh_addralign; + } else { + sh_offset = s->s_shdr.s_shdr64.sh_offset; + sh_size = s->s_shdr.s_shdr64.sh_size; + sh_align = s->s_shdr.s_shdr64.sh_addralign; + } + + if ((d = _libelf_allocate_data(s)) == NULL) + return (NULL); + + d->d_buf = e->e_rawfile + sh_offset; + d->d_off = 0; + d->d_align = sh_align; + d->d_size = sh_size; + d->d_type = ELF_T_BYTE; + d->d_version = e->e_version; + + STAILQ_INSERT_TAIL(&s->s_rawdata, d, d_next); + + return (d); +} |