| /* |
| * Copyright (C) 2014 Google, Inc. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; version 2 of the License. |
| * |
| * This program 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 a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc. |
| */ |
| |
| #ifndef ELFPARSING_H |
| #define ELFPARSING_H |
| |
| #include "elf.h" |
| #include "common.h" |
| |
| struct parsed_elf { |
| Elf64_Ehdr ehdr; |
| Elf64_Phdr *phdr; |
| Elf64_Shdr *shdr; |
| /* |
| * The relocs array contains pointers to arrays of relocation |
| * structures. Each index into the relocs array corresponds to its |
| * corresponding section index. i.e. if a section i is of type SHT_REL |
| * or SHT_RELA then the corresponding index into the relocs array will |
| * contain the associated relocations. Otherwise thee entry will be |
| * NULL. |
| */ |
| Elf64_Rela **relocs; |
| /* |
| * Similarly to the relocs array the strtabs array consists of an |
| * array of pointers where each entry represents a potential struct |
| * buffer pointer. Only setions of type SHT_STRTAB will have a non-NULL |
| * entry. |
| */ |
| struct buffer **strtabs; |
| /* Parsed symbols. */ |
| Elf64_Sym *syms; |
| }; |
| |
| #define ELF_PARSE_PHDR (1 << 0) |
| #define ELF_PARSE_SHDR (1 << 1) |
| #define ELF_PARSE_RELOC (1 << 2) |
| #define ELF_PARSE_STRTAB (1 << 3) |
| #define ELF_PARSE_SYMTAB (1 << 4) |
| |
| #define ELF_PARSE_ALL (-1) |
| |
| /* |
| * Parse an ELF file contained within provide struct buffer. The ELF header |
| * is always parsed while the flags value containing the ELF_PARSE_* values |
| * determine if other parts of the ELF file will be parsed as well. |
| * Returns 0 on success, < 0 error. |
| */ |
| int parse_elf(const struct buffer *pinput, struct parsed_elf *pelf, int flags); |
| |
| /* |
| * Clean up memory associated with parsed_elf. |
| */ |
| void parsed_elf_destroy(struct parsed_elf *pelf); |
| |
| |
| int |
| elf_headers(const struct buffer *pinput, |
| Elf64_Ehdr *ehdr, |
| Elf64_Phdr **pphdr, |
| Elf64_Shdr **pshdr); |
| |
| /* ELF writing support. */ |
| struct elf_writer; |
| |
| /* |
| * Initialize a 64-bit ELF header provided the inputs. While the structure |
| * is a 64-bit header one can specify a 32-bit machine. The 64-bit version |
| * is just used as a common structure. If one wants to specify the entry |
| * point, for example, the caller can set it after filling in the common |
| * bits. The machine, nbits, and endian values should be from the ELF |
| * definitions (e.g. EM_386, ELFCLASS32, and ELFDATA2LSB) found in elf.h |
| * with no endian conversion required. |
| */ |
| void elf_init_eheader(Elf64_Ehdr *ehdr, int machine, int nbits, int endian); |
| |
| /* |
| * Initialize a new ELF writer. Deafult machine type, endianness, etc is |
| * copied from the passed in Elf64_Ehdr. Returns NULL on failure, valid |
| * pointer on success. |
| */ |
| struct elf_writer *elf_writer_init(const Elf64_Ehdr *ehdr); |
| |
| /* |
| * Clean up any internal state represented by ew. Aftewards the elf_writer |
| * is invalid. |
| */ |
| void elf_writer_destroy(struct elf_writer *ew); |
| |
| /* |
| * Add a section to the ELF file. Section type, flags, and memsize are |
| * maintained from the passed in Elf64_Shdr. The buffer represents the |
| * content of the section while the name is the name of section itself. |
| * Returns < 0 on error, 0 on success. |
| */ |
| int elf_writer_add_section(struct elf_writer *ew, const Elf64_Shdr *shdr, |
| struct buffer *contents, const char *name); |
| |
| /* Add an absolute symbol to the ELF file returning < 0 on error, index of |
| * symbol otherwise. */ |
| int elf_writer_add_symbol(struct elf_writer *ew, const char *name, |
| const char *section_name, |
| Elf64_Addr value, Elf64_Word size, |
| int binding, int type); |
| |
| /* Add an absolute relocation referencing the provided symbol name. Returns < 0 |
| * on error, 0 on success. */ |
| int elf_writer_add_rel(struct elf_writer *ew, const char *sym, Elf64_Addr addr); |
| |
| /* |
| * Serialize the ELF file to the output buffer. Return < 0 on error, |
| * 0 on success. |
| */ |
| int elf_writer_serialize(struct elf_writer *ew, struct buffer *out); |
| |
| #endif /* ELFPARSING_H */ |