diff options
Diffstat (limited to 'ext/libelf/elf_begin.c')
| -rw-r--r-- | ext/libelf/elf_begin.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/ext/libelf/elf_begin.c b/ext/libelf/elf_begin.c new file mode 100644 index 000000000..1ffd26651 --- /dev/null +++ b/ext/libelf/elf_begin.c @@ -0,0 +1,154 @@ +/*- + * 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 <sys/types.h> +#include <sys/errno.h> +#include <sys/mman.h> +#include <sys/stat.h> + +#include <ar.h> +#include <ctype.h> +#include "libelf.h" + +#include "_libelf.h" + +static Elf * +_libelf_open_object(int fd, Elf_Cmd c) +{ + Elf *e; + void *m; + struct stat sb; + + /* + * 'Raw' files are always mapped with 'PROT_READ'. At + * elf_update(3) time for files opened with ELF_C_RDWR the + * mapping is unmapped, file data is written to using write(2) + * and then the raw data is immediately mapped back in. + */ + if (fstat(fd, &sb) < 0) { + LIBELF_SET_ERROR(IO, errno); + return (NULL); + } + + m = NULL; + if ((m = mmap(NULL, (size_t) sb.st_size, PROT_READ, MAP_PRIVATE, fd, + (off_t) 0)) == MAP_FAILED) { + LIBELF_SET_ERROR(IO, errno); + return (NULL); + } + + if ((e = elf_memory(m, (size_t) sb.st_size)) == NULL) { + (void) munmap(m, (size_t) sb.st_size); + return (NULL); + } + + e->e_flags |= LIBELF_F_MMAP; + e->e_fd = fd; + e->e_cmd = c; + + if (c == ELF_C_RDWR && e->e_kind == ELF_K_AR) { + (void) elf_end(e); + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + return (e); +} + +Elf * +elf_begin(int fd, Elf_Cmd c, Elf *a) +{ + Elf *e; + + e = NULL; + + if (LIBELF_PRIVATE(version) == EV_NONE) { + LIBELF_SET_ERROR(SEQUENCE, 0); + return (NULL); + } + + switch (c) { + case ELF_C_NULL: + return (NULL); + + case ELF_C_WRITE: + + if (a != NULL) { /* not allowed for ar(1) archives. */ + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + /* + * Check writeability of `fd' immediately and fail if + * not writeable. + */ + if (ftruncate(fd, (off_t) 0) < 0) { + LIBELF_SET_ERROR(IO, errno); + return (NULL); + } + + if ((e = _libelf_allocate_elf()) != NULL) { + _libelf_init_elf(e, ELF_K_ELF); + e->e_byteorder = LIBELF_PRIVATE(byteorder); + e->e_fd = fd; + e->e_cmd = c; + } + return (e); + + case ELF_C_RDWR: + if (a != NULL) { /* not allowed for ar(1) archives. */ + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + /*FALLTHROUGH*/ + case ELF_C_READ: + /* + * Descriptor `a' could be for a regular ELF file, or + * for an ar(1) archive. + */ + if (a && (a->e_fd != fd || c != a->e_cmd)) { + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + } + + break; + + default: + LIBELF_SET_ERROR(ARGUMENT, 0); + return (NULL); + + } + + if (a == NULL) + e = _libelf_open_object(fd, c); + else if (a->e_kind == ELF_K_AR) + e = _libelf_ar_open_member(fd, c, a); + else + (e = a)->e_activations++; + + return (e); +} |