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:
/*
* The ELF_C_WRITE command is required to ignore the
* descriptor passed in.
*/
a = NULL;
break;
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 descriptor `a' was opened
* using a valid file descriptor, we need to check if
* the passed in `fd' value matches the original one.
*/
if (a &&
((a->e_fd != -1 && 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(a->e_fd, c, a);
else
(e = a)->e_activations++;
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);
}